WorldWideScience

Sample records for apoptosis intersecting signaling

  1. Intersection of interferon and hypoxia signal transduction pathways in nitric oxide-induced tumor apoptosis.

    Science.gov (United States)

    Tendler, D S; Bao, C; Wang, T; Huang, E L; Ratovitski, E A; Pardoll, D A; Lowenstein, C J

    2001-05-01

    Activated macrophages play a central role in antitumor immunity. However, the stimuli that activate macrophages to kill tumor cells are not completely understood. Because the center of solid tumors can be hypoxic, we hypothesized that hypoxia may be an important signal in activating macrophages to kill tumor cells. Hypoxia stimulates IFN-primed macrophages to express the inducible nitric oxide synthase (NOS2) and to synthesize nitric oxide (NO). We show that this synergy between IFN and hypoxia is mediated by the direct interaction of the hypoxia inducible factor-1 (HIF-1) and IFN regulatory factor-1 (IRF-1), which are both required for the hypoxic transcription of NOS2. This interaction between HIF-1 and IRF-1 may explain the mechanism by which macrophages infiltrating into tumors are activated to express NOS2 and to produce NO, a mediator of tumor apoptosis.

  2. Intersection auxiliary signal system

    Science.gov (United States)

    Zhang, Jian

    1995-12-01

    Many intersection accidents are related to drivers' inappropriate responses to an amber signal light, due to their misjudgment on the traffic situation and/or their aggressive behavior. To reduce intersection accidents of this nature, this paper proposes the Intersection Auxiliary Signal System (IAS). IAS can be installed at selected intersections, where information regarding signal phasing, intersection geometry and speed limit is transmitted from an ultrasonic/infra-red transmitter. An on-vehicle device receivers and processes the information, the provides the driver with explicit suggestions on the correct action to take (continue to pass or decelerate to stop), or warnings against on-going incorrect actions. IAS is expected to be more effective in suburban intersections, which are usually characterized by greater dimension, longer amber phases, and higher vehicle speeds. Both the intersection transmitters and the on-vehicle processors are expected to have simple structures and low costs. Simulation results show that IAS has a significant effect on reducing red signal violation, especially when there is no significant dilemma zones.

  3. Ubiquitination in apoptosis signaling

    NARCIS (Netherlands)

    van de Kooij, L.W.

    2014-01-01

    The work described in this thesis focuses on ubiquitination and protein degradation, with an emphasis on how these processes regulate apoptosis signaling. More specifically, our aims were: 1. To increase the understanding of ubiquitin-mediated regulation of apoptosis signaling. 2. To identify the E3

  4. Opposed turns at signalized intersections

    Energy Technology Data Exchange (ETDEWEB)

    Akcelik, R.

    1989-06-01

    The 1985 Highway Capacity Manual (HCM) brought the U.S. and Australian methodologies for signalized intersections closer together. An important element in this methodology is the techniques used for the estimation of opposed (permissive) turn saturation flows. Although the basic modeling philosophies of the HCM and Australian methods are similar, there are significant differences in the procedures used and therefore in the results from the two methods. In particular, the latest methodology employed in the SIDRA software has eliminated the use of opposed turn adjustment factors for lane groups and adopted an explicit and direct method of modeling individual lanes. The purpose of this paper is to bring these new methods to the attention of the U.S. researchers since it is understood that efforts are being made to improve the 1985 HCM method.

  5. Evaluation of bike boxes at signalized intersections.

    Science.gov (United States)

    Dill, Jennifer; Monsere, Christopher M; McNeil, Nathan

    2012-01-01

    This paper presents a before-after study of bike boxes at 10 signalized intersections in Portland, Oregon. The bike boxes, also known as advanced stop lines or advanced stop boxes, were installed to increase visibility of cyclists and reduce conflicts between motor vehicles and cyclists, particularly in potential "right-hook" situations. Before and after video were analyzed for seven intersections with green bike boxes, three intersections with uncolored bike boxes, and two control intersections. User perceptions were measured through surveys of cyclists passing through five of the bike box intersections and of motorists working downtown, where the boxes were concentrated. Both the observations and survey of motorists found a high rate of compliance and understanding of the markings. Overall, 73% of the stopping motor vehicles did not encroach at all into the bike box. Both motor vehicle and bicycle encroachment in the pedestrian crosswalk fell significantly at the bike box locations compared to the control intersections. The bike boxes had mixed effects on the motorists' encroachment in the bicycle lane. The number of observed conflicts at the bike box locations decreased, while the total number of cyclists and motor vehicles turning right increased. Negative-binomial models based upon the data predict fewer conflicts with the boxes, particularly as right-turning motor vehicle volumes increase. Observations of yielding behavior at two bike box and one control intersection found an improvement in motorists yielding to cyclists at the bike box locations. Differences in the traffic volumes and location contexts make firm conclusions about the effects of green coloring of the boxes difficult. Higher shares of surveyed motorists felt that the bike boxes made driving safer rather than more dangerous, even when the sample was narrowed to respondents who were not also cyclists. Over three-quarters of the surveyed cyclists thought that the boxes made the intersection safer

  6. Eco-Approach and Departure at Signalized Intersections

    Science.gov (United States)

    2014-11-01

    The Eco-Approach and Departure at Signalized Intersections application uses wireless communications to give drivers recommendations that encourage "green" approaches to signalized intersections. The purpose of the application is to increase the fuel ...

  7. An analysis of intersection traffic signal warrants

    Directory of Open Access Journals (Sweden)

    Dražen Cvitanić

    2005-01-01

    Full Text Available This paper presents an analysis of the existing traffic signalwarrants and the cmresponding threshold values. The analysisof unsignalized intersections was conducted according to theanalytical procedures of Highway capacity manual. Traffic signaloptimization was conducted using Synchro software. Theresults showed that the cun-ent wan·ants are not sufficiently reliablein some situations and can be misleading in the process ofselecting the intersection control type. There are three majorreasons for insufficient reliability of the existing wan·ants. First,they are p1imarily based on total major and subject minor streetvolumes, so they do not take into account all the possible combinationsof volume distribution and composition of the turningmaneuvers. Second, they do not make difference betweenthree-leg T intersections and four-leg intersections, and finallythey are based only on an overall system operation without regm·ding the functionality of a specific approach.

  8. Evaluation of commercial video-based intersection signal actuation systems.

    Science.gov (United States)

    2008-12-01

    Video cameras and computer image processors have come into widespread use for the detection of : vehicles for signal actuation at controlled intersections. Video is considered both a cost-saving and : convenient alternative to conventional stop-line ...

  9. Apoptosis signaling and radiation protection

    International Nuclear Information System (INIS)

    Morita, Akinori; Suzuki, Norio; Hosoi, Yoshio

    2005-01-01

    Radiation protection by apoptosis control is the suppression of cell death in highly radiosensitive tissues. This paper describes the outline of radiation-induced apoptosis framework, apoptosis-concerned target molecules possibly related to apoptosis by radiation and their inhibitors. Although there are intrinsic (via mitochondria) and extrinsic (via death receptor) pathways in apoptosis, this review mainly mentions the former which is more important in radiation-induced apoptosis. Those molecules known at present in the apoptosis are caspase, Bcl-2 family and p53. Caspase, a group of cystein proteases, initiates apoptosis but its inhibition is known not always to result in apoptosis suppression, suggesting the existence of caspase-independent pathways. Bcl-2 family involves apoptosis-suppressing (possessing BH domains) and -promoting (lacking BH domains or possessing BH3 domain alone/BH3-only protein) groups. Two p53-transcription-dependent and one -independent pathways in p53-induced apoptosis are known and p53 can be a most possible target molecule since it positions at the start of apoptosis. Authors have found a vanadate inactivates p53. Inhibitors affecting upstream molecules of apoptosis will be the most useful candidate for apoptosis suppression/radiation protection. (S.I.) 106 refs

  10. Research on Driver Behavior in Yellow Interval at Signalized Intersections

    Directory of Open Access Journals (Sweden)

    Zhaosheng Yang

    2014-01-01

    Full Text Available Vehicles are often caught in dilemma zone when they approach signalized intersections in yellow interval. The existence of dilemma zone which is significantly influenced by driver behavior seriously affects the efficiency and safety of intersections. This paper proposes the driver behavior models in yellow interval by logistic regression and fuzzy decision tree modeling, respectively, based on camera image data. Vehicle’s speed and distance to stop line are considered in logistic regression model, which also brings in a dummy variable to describe installation of countdown timer display. Fuzzy decision tree model is generated by FID3 algorithm whose heuristic information is fuzzy information entropy based on membership functions. This paper concludes that fuzzy decision tree is more accurate to describe driver behavior at signalized intersection than logistic regression model.

  11. Impacts of fuel service stations located at signalized intersections on ...

    African Journals Online (AJOL)

    The impacts on traffic flows by Fuel Service Stations (FSS) located within 50 m vicinity of four (4) signalized intersections in Kumasi City were assessed. Changes in saturated flow rates, delays and lost times were the im-pact assessment indicators. Reduction in saturation flow rates ranged from low of 2 % to high of 56 % ...

  12. Low-cost safety measures at signalized intersections.

    Science.gov (United States)

    2008-05-01

    The objectives of this study were to: a) identify intersections with a high number of crashes involving a driver disregarding the traffic signal, b) identify types of low-cost safety measures which may be used as a countermeasure for red light runnin...

  13. MOTORCYCLE CRASH PREDICTION MODEL FOR NON-SIGNALIZED INTERSECTIONS

    Directory of Open Access Journals (Sweden)

    S. HARNEN

    2003-01-01

    Full Text Available This paper attempts to develop a prediction model for motorcycle crashes at non-signalized intersections on urban roads in Malaysia. The Generalized Linear Modeling approach was used to develop the model. The final model revealed that an increase in motorcycle and non-motorcycle flows entering an intersection is associated with an increase in motorcycle crashes. Non-motorcycle flow on major road had the greatest effect on the probability of motorcycle crashes. Approach speed, lane width, number of lanes, shoulder width and land use were also found to be significant in explaining motorcycle crashes. The model should assist traffic engineers to decide the need for appropriate intersection treatment that specifically designed for non-exclusive motorcycle lane facilities.

  14. Evaluation of Red Light Camera Enforcement at Signalized Intersections

    Directory of Open Access Journals (Sweden)

    Abdulrahman AlJanahi

    2007-12-01

    Full Text Available The study attempts to find the effectiveness of adopting red light cameras in reducing red light violators. An experimental approach was adopted to investigate the use of red light cameras at signalized intersections in the Kingdom of Bahrain. The study locations were divided into three groups. The first group was related to the approaches monitored with red light cameras. The second group was related to approaches without red light cameras, but located within an intersection that had one of its approaches monitored with red light cameras. The third group was related to intersection approaches located at intersection without red light cameras (controlled sites. A methodology was developed for data collection. The data were then tested statistically by Z-test using proportion methods to compare the proportion of red light violations occurring at different sites. The study found that the proportion of red light violators at approaches monitored with red light cameras was significantly less than those at the controlled sites for most of the time. Approaches without red light cameras located within intersections having red light cameras showed, in general, fewer violations than controlled sites, but the results were not significant for all times of the day. The study reveals that red light cameras have a positive effect on reducing red light violations. However, these conclusions need further evaluations to justify their safe and economic use.

  15. Mycobacterium tuberculosis effectors interfering host apoptosis signaling.

    Science.gov (United States)

    Liu, Minqiang; Li, Wu; Xiang, Xiaohong; Xie, Jianping

    2015-07-01

    Tuberculosis remains a serious human public health concern. The coevolution between its pathogen Mycobacterium tuberculosis and human host complicated the way to prevent and cure TB. Apoptosis plays subtle role in this interaction. The pathogen endeavors to manipulate the apoptosis via diverse effectors targeting key signaling nodes. In this paper, we summarized the effectors pathogen used to subvert the apoptosis, such as LpqH, ESAT-6/CFP-10, LAMs. The interplay between different forms of cell deaths, such as apoptosis, autophagy, necrosis, is also discussed with a focus on the modes of action of effectors, and implications for better TB control.

  16. Real-time prediction of queues at signalized intersections to support eco-driving applications.

    Science.gov (United States)

    2014-10-01

    The overall objective of this research is to develop models for predicting queue lengths at signalized intersections based on : the data from probe vehicles. The time and space coordinates of the probe vehicles going through signalized intersections ...

  17. Vehicular headways on signalized intersections: theory, models, and reality

    Science.gov (United States)

    Krbálek, Milan; Šleis, Jiří

    2015-01-01

    We discuss statistical properties of vehicular headways measured on signalized crossroads. On the basis of mathematical approaches, we formulate theoretical and empirically inspired criteria for the acceptability of theoretical headway distributions. Sequentially, the multifarious families of statistical distributions (commonly used to fit real-road headway statistics) are confronted with these criteria, and with original empirical time clearances gauged among neighboring vehicles leaving signal-controlled crossroads after a green signal appears. Using three different numerical schemes, we demonstrate that an arrangement of vehicles on an intersection is a consequence of the general stochastic nature of queueing systems, rather than a consequence of traffic rules, driver estimation processes, or decision-making procedures.

  18. Road Impedance Model Study under the Control of Intersection Signal

    Directory of Open Access Journals (Sweden)

    Yunlin Luo

    2015-01-01

    Full Text Available Road traffic impedance model is a difficult and critical point in urban traffic assignment and route guidance. The paper takes a signalized intersection as the research object. On the basis of traditional traffic wave theory including the implementation of traffic wave model and the analysis of vehicles’ gathering and dissipating, the road traffic impedance model is researched by determining the basic travel time and waiting delay time. Numerical example results have proved that the proposed model in this paper has received better calculation performance compared to existing model, especially in flat hours. The values of mean absolute percentage error (MAPE and mean absolute deviation (MAD are separately reduced by 3.78% and 2.62 s. It shows that the proposed model has feasibility and availability in road traffic impedance under intersection signal.

  19. Multinomial Logit Model of Pedestrian Crossing Behaviors at Signalized Intersections

    Directory of Open Access Journals (Sweden)

    Zhu-Ping Zhou

    2013-01-01

    Full Text Available Pedestrian crashes, making up a large proportion of road casualties, are more likely to occur at signalized intersections in China. This paper aims to study the different pedestrian behaviors of regular users, late starters, sneakers, and partial sneakers. Behavior information was observed manually in the field study. After that, the survey team distributed a questionnaire to the same participant who has been observed, to acquire detailed demographic and socioeconomic characteristics as well as attitude and preference indicators. Totally, 1878 pedestrians were surveyed at 16 signalized intersections in Nanjing. First, correlation analysis is performed to analyze each factor’s effect. Then, five latent variables including safety, conformity, comfort, flexibility, and fastness are obtained by structure equation modeling (SEM. Moreover, based on the results of SEM, a multinomial logit model with latent variables is developed to describe how the factors influence pedestrians’ behavior. Finally, some conclusions are drawn from the model: (1 for the choice of being late starters, arrival time, the presence of oncoming cars, and crosswalk length are the most important factors; (2 gender has the most significant effect on the pedestrians to be sneakers; and (3 age is the most important factor when pedestrians choose to be partial sneakers.

  20. Coordinated signal control for arterial intersections using fuzzy logic

    Science.gov (United States)

    Kermanian, Davood; Zare, Assef; Balochian, Saeed

    2013-09-01

    Every day growth of the vehicles has become one of the biggest problems of urbanism especially in major cities. This can waste people's time, increase the fuel consumption, air pollution, and increase the density of cars and vehicles. Fuzzy controllers have been widely used in many consumer products and industrial applications with success over the past two decades. This article proposes a comprehensive model of urban traffic network using state space equations and then using Fuzzy Logic Tool Box and SIMULINK Program MATLAB a fuzzy controller in order to optimize and coordinate signal control at two intersections at an arterial road. The fuzzy controller decides to extend, early cut or terminate a signal phase and phase sequence to ensure smooth flow of traffic with minimal waiting time and length of queue. Results show that the performance of the proposed traffic controller at novel fuzzy model is better that of conventional controllers under normal and abnormal traffic conditions.

  1. Signaling Pathways in Cardiac Myocyte Apoptosis

    Science.gov (United States)

    Xia, Peng; Liu, Yuening

    2016-01-01

    Cardiovascular diseases, the number 1 cause of death worldwide, are frequently associated with apoptotic death of cardiac myocytes. Since cardiomyocyte apoptosis is a highly regulated process, pharmacological intervention of apoptosis pathways may represent a promising therapeutic strategy for a number of cardiovascular diseases and disorders including myocardial infarction, ischemia/reperfusion injury, chemotherapy cardiotoxicity, and end-stage heart failure. Despite rapid growth of our knowledge in apoptosis signaling pathways, a clinically applicable treatment targeting this cellular process is currently unavailable. To help identify potential innovative directions for future research, it is necessary to have a full understanding of the apoptotic pathways currently known to be functional in cardiac myocytes. Here, we summarize recent progress in the regulation of cardiomyocyte apoptosis by multiple signaling molecules and pathways, with a focus on the involvement of these pathways in the pathogenesis of heart disease. In addition, we provide an update regarding bench to bedside translation of this knowledge and discuss unanswered questions that need further investigation. PMID:28101515

  2. A speed guidance strategy for multiple signalized intersections based on car-following model

    Science.gov (United States)

    Tang, Tie-Qiao; Yi, Zhi-Yan; Zhang, Jian; Wang, Tao; Leng, Jun-Qiang

    2018-04-01

    Signalized intersection has great roles in urban traffic system. The signal infrastructure and the driving behavior near the intersection are paramount factors that have significant impacts on traffic flow and energy consumption. In this paper, a speed guidance strategy is introduced into a car-following model to study the driving behavior and the fuel consumption in a single-lane road with multiple signalized intersections. The numerical results indicate that the proposed model can reduce the fuel consumption and the average stop times. The findings provide insightful guidance for the eco-driving strategies near the signalized intersections.

  3. Dimensioning of Signalized Intersections in Realistic Urban Environment

    Directory of Open Access Journals (Sweden)

    Matej Dobovšek

    2005-05-01

    Full Text Available It is very complex to assure the dynamics of traffic networkin urban environment because of the intensity of traffic flowsand the limited space in the urban area. Signalized intersectionsare undoubtedly very important and frequent element inroad traffic network in urban regions, which greatly influencesthe traffic flow dynamics on each section as in the whole trafficnetwork. The time (delay a vehicle needs to drive through anintersection directly influences the travel comfort, fuel consumption,traffic pollution and so on. There are many methodsfor dimensioning signalized intersections in the world literature.One of the most applied methods is the HIGHWAY CAPACI1YMANUAL (HCM 2000 which is based on competentinput traffic flows and other characteristics of traffic signalregulations. The intention of this paper is to establish whetherwe can use the HCM 2000 method directly in the Slovenian realenvironment. Based on the established methodology of researchand limited number of delay measurement in real environmentintersections, there have been some deviations. Thecompletion of the level of service criterion for signalized intersectionshas been proposed, with the intention for more suitabilityestimation in the realistic environment.

  4. Acceptability of Countdown Signals at an Urban Signalized Intersection and their Influence on Drivers Behaviour

    Directory of Open Access Journals (Sweden)

    Robert Rijavec

    2013-02-01

    Full Text Available There are different factors that affect driver’s behaviour at an urban signalized intersection. Complementary countdown signal heads can be used to inform the driver about the traffic light phase status. In the research presented in this paper, we explored how a countdown signal affects the driver’s reaction. We focused on the analysis of red/amber, red and amber running violations. We also observed and measured traffic flow start-up lost time and headway per cycle. Measurements took place in Ljubljana at a four-way intersection where two countdown signal heads are installed that face different directions. We used the “on-off-on” approach, using video surveillance and detection technology. According to the results of the investigative questionnaire, more than 84% of the surveyed drivers expressed positive opinion about the device. Analyses of field-test results have shown that the red and/or amber running violation rate is higher when the device is turned off. The results of the paper suggest that the countdown device had very little effect on the capacity of an urban signalized intersection.

  5. Green cooperative adaptive control systems in the vicinity of signalized intersections.

    Science.gov (United States)

    2014-10-01

    Vehicle stops and speed variations account for a large percentage of vehicle fuel losses especially at signalized intersections. : Recently, researchers have attempted to develop tools that reduce these losses by capitalizing on traffic signal inform...

  6. An extended car-following model at signalized intersections

    Science.gov (United States)

    Yu, Shaowei; Shi, Zhongke

    2014-08-01

    To simulate car-following behaviors better when the traffic light is red, three successive car-following data at a signalized intersection of Jinan in China were collected by using a new proposed data acquisition method and then analyzed to select input variables of the extended car-following model. An extended car-following model considering two leading cars' accelerations was proposed, calibrated and verified with field data obtained on the basis of the full velocity difference model and then a comparative model used for comparative research was also proposed and calibrated in the light of the GM model. The results indicate that the extended car-following model could fit measured data well, and that the fitting precision of the extended model is prior to the comparative model, whose mean absolute error is reduced by 22.83%. Finally a theoretical car-following model considering multiple leading cars' accelerations was put forward which has potential applicable to vehicle automation system and vehicle safety early warning system, and then the linear stability analysis and numerical simulations were conducted to analyze some observed physical features existing in the realistic traffic.

  7. Intersection signal control multi-objective optimization based on genetic algorithm

    OpenAIRE

    Zhanhong Zhou; Ming Cai

    2014-01-01

    A signal control intersection increases not only vehicle delay, but also vehicle emissions and fuel consumption in that area. Because more and more fuel and air pollution problems arise recently, an intersection signal control optimization method which aims at reducing vehicle emissions, fuel consumption and vehicle delay is required heavily. This paper proposed a signal control multi-object optimization method to reduce vehicle emissions, fuel consumption and vehicle delay simultaneously at ...

  8. Evaluating safety and operation of high-speed signalized intersections : final report, March 2010.

    Science.gov (United States)

    2010-03-01

    This Final Report reviews a research effort to evaluate the safety and operations of high-speed intersections in the State of : Oregon. In particular, this research effort focuses on four-leg, signalized intersections with speed limits of 45 mph or :...

  9. An MDP decomposition approach for traffic control at isolated signalized intersections

    NARCIS (Netherlands)

    Haijema, R.; van der Wal, J.

    2008-01-01

    This article presents a novel approach for the dynamic control of a signalized intersection. At the intersection, there is a number of arrival flows of cars, each having a single queue (lane). The set of all flows is partitioned into disjoint combinations of nonconflicting flows that will receive

  10. Mixed Vehicle Flow At Signalized Intersection: Markov Chain Analysis

    Directory of Open Access Journals (Sweden)

    Gertsbakh Ilya B.

    2015-09-01

    Full Text Available We assume that a Poisson flow of vehicles arrives at isolated signalized intersection, and each vehicle, independently of others, represents a random number X of passenger car units (PCU’s. We analyze numerically the stationary distribution of the queue process {Zn}, where Zn is the number of PCU’s in a queue at the beginning of the n-th red phase, n → ∞. We approximate the number Yn of PCU’s arriving during one red-green cycle by a two-parameter Negative Binomial Distribution (NBD. The well-known fact is that {Zn} follow an infinite-state Markov chain. We approximate its stationary distribution using a finite-state Markov chain. We show numerically that there is a strong dependence of the mean queue length E[Zn] in equilibrium on the input distribution of Yn and, in particular, on the ”over dispersion” parameter γ= Var[Yn]/E[Yn]. For Poisson input, γ = 1. γ > 1 indicates presence of heavy-tailed input. In reality it means that a relatively large ”portion” of PCU’s, considerably exceeding the average, may arrive with high probability during one red-green cycle. Empirical formulas are presented for an accurate estimation of mean queue length as a function of load and g of the input flow. Using the Markov chain technique, we analyze the mean ”virtual” delay time for a car which always arrives at the beginning of the red phase.

  11. Operation, analysis, and design of signalized intersections : a module for the introductory course in transportation engineering.

    Science.gov (United States)

    2014-02-01

    This report presents materials that can be used as the basis for a module on signalized intersections in the introductory : course in transportation engineering. The materials were developed based on studies of the work of students who took : this in...

  12. Relating the 2010 signalized intersection methodology to alternate approaches in the context of NYC conditions.

    Science.gov (United States)

    2013-11-01

    The Highway Capacity Manual (HCM) has had a delay-based level of service methodology for signalized intersections since 1985. : The 2010 HCM has revised the method for calculating delay. This happened concurrent with such jurisdictions as NYC reviewi...

  13. Speed limit recommendation in vicinity of signalized, high-speed intersection.

    Science.gov (United States)

    2012-04-01

    We evaluated the traffic operations and safety effects of 5 mph and 10 mph speed limit reductions in the vicinity of highspeed, : signalized intersections with advance warning flashers (AWF). Traffic operational effects of the reduced speed : limits ...

  14. AERIS : Eco-Vehicle Speed Control at Signalized Intersections Using I2V Communication

    Science.gov (United States)

    2012-06-01

    This report concentrates on a velocity advisory tool, or decision support system, for vehicles : approaching an intersection using communication capabilities between the infrastructure and : vehicles. The system uses available signal change informati...

  15. Using Cellular Automata to Investigate Pedestrian Conflicts with Vehicles in Crosswalk at Signalized Intersection

    Directory of Open Access Journals (Sweden)

    Xiaomeng Li

    2012-01-01

    Full Text Available The operational efficiency and safety of pedestrian flows at intersections is an important aspect of urban traffic. Particularly, conflicts between pedestrians and vehicles in crosswalk are one of the most influential factors for intersection safety. This paper presents a cellular automata model that simulates pedestrian and vehicle crossing behaviors at signalized intersections. Through the simulation, we investigate the effects of different pedestrian signal timing and crosswalk widths on the crosswalk capacity, the number of traffic conflicts between pedestrians and vehicles, and pedestrian delay due to the conflicts. The simulation results indicate that the cellular automata is an effective simulation platform for investigating complex pedestrian-related traffic phenomenon at signalized intersections.

  16. Intersection signal control multi-objective optimization based on genetic algorithm

    Directory of Open Access Journals (Sweden)

    Zhanhong Zhou

    2014-04-01

    Full Text Available A signal control intersection increases not only vehicle delay, but also vehicle emissions and fuel consumption in that area. Because more and more fuel and air pollution problems arise recently, an intersection signal control optimization method which aims at reducing vehicle emissions, fuel consumption and vehicle delay is required heavily. This paper proposed a signal control multi-object optimization method to reduce vehicle emissions, fuel consumption and vehicle delay simultaneously at an intersection. The optimization method combined the Paramics microscopic traffic simulation software, Comprehensive Modal Emissions Model (CMEM, and genetic algorithm. An intersection in Haizhu District, Guangzhou, was taken for a case study. The result of the case study shows the optimal timing scheme obtained from this method is better than the Webster timing scheme.

  17. Capacity Estimation Model for Signalized Intersections under the Impact of Access Point.

    Science.gov (United States)

    Zhao, Jing; Li, Peng; Zhou, Xizhao

    2016-01-01

    Highway Capacity Manual 2010 provides various factors to adjust the base saturation flow rate for the capacity analysis of signalized intersections. No factors, however, is considered for the potential change of signalized intersections capacity caused by the access point closeing to the signalized intersection. This paper presented a theoretical model to estimate the lane group capacity at signalized intersections with the consideration of the effects of access points. Two scenarios of access point locations, upstream or downstream of the signalized intersection, and impacts of six types of access traffic flow are taken into account. The proposed capacity model was validated based on VISSIM simulation. Results of extensive numerical analysis reveal the substantial impact of access point on the capacity, which has an inverse correlation with both the number of major street lanes and the distance between the intersection and access point. Moreover, among the six types of access traffic flows, the access traffic flow 1 (right-turning traffic from major street), flow 4 (left-turning traffic from access point), and flow 5 (left-turning traffic from major street) cause a more significant effect on lane group capacity than others. Some guidance on the mitigation of the negative effect is provided for practitioners.

  18. Capacity Estimation Model for Signalized Intersections under the Impact of Access Point.

    Directory of Open Access Journals (Sweden)

    Jing Zhao

    Full Text Available Highway Capacity Manual 2010 provides various factors to adjust the base saturation flow rate for the capacity analysis of signalized intersections. No factors, however, is considered for the potential change of signalized intersections capacity caused by the access point closeing to the signalized intersection. This paper presented a theoretical model to estimate the lane group capacity at signalized intersections with the consideration of the effects of access points. Two scenarios of access point locations, upstream or downstream of the signalized intersection, and impacts of six types of access traffic flow are taken into account. The proposed capacity model was validated based on VISSIM simulation. Results of extensive numerical analysis reveal the substantial impact of access point on the capacity, which has an inverse correlation with both the number of major street lanes and the distance between the intersection and access point. Moreover, among the six types of access traffic flows, the access traffic flow 1 (right-turning traffic from major street, flow 4 (left-turning traffic from access point, and flow 5 (left-turning traffic from major street cause a more significant effect on lane group capacity than others. Some guidance on the mitigation of the negative effect is provided for practitioners.

  19. Estimating rear-end accident probabilities at signalized intersections: a comparison study of intersections with and without green signal countdown devices.

    Science.gov (United States)

    Ni, Ying; Li, Keping

    2014-01-01

    Rear-end accidents are the most common accident type at signalized intersections, because the diversity of actions taken increases due to signal change. Green signal countdown devices (GSCDs), which have been widely installed in Asia, are thought to have the potential of improving capacity and reducing accidents, but some negative effects on intersection safety have been observed in practice; for example, an increase in rear-end accidents. A microscopic modeling approach was applied to estimate rear-end accident probability during the phase transition interval in the study. The rear-end accident probability is determined by the following probabilities: (1) a leading vehicle makes a "stop" decision, which was formulated by using a binary logistic model, and (2) the following vehicle fails to stop in the available stopping distance, which is closely related to the critical deceleration used by the leading vehicle. Based on the field observation carried out at 2 GSCD intersections and 2 NGSCD intersections (i.e., intersections without GSCD devices) along an arterial in Suzhou, the rear-end probabilities at GSCD and NGSCD intersections were calculated using Monte Carlo simulation. The results suggested that, on the one hand, GSCDs caused significantly negative safety effects during the flashing green interval, especially for vehicles in a zone ranging from 15 to 70 m; on the other hand, GSCD devices were helpful in reducing rear-end accidents during the yellow interval, especially in a zone from 0 to 50 m. GSCDs helped shorten indecision zones and reduce rear-end collisions near the stop line during the yellow interval, but they easily resulted in risky car following behavior and much higher rear-end collision probabilities at indecision zones during both flashing green and yellow intervals. GSCDs are recommended to be cautiously installed and education on safe driving behavior should be available.

  20. An Adaptive Model for Calculating the Correlation Degree of Multiple Adjacent Signalized Intersections

    Directory of Open Access Journals (Sweden)

    Linhong Wang

    2013-01-01

    Full Text Available As an important component of the urban adaptive traffic control system, subarea partition algorithm divides the road network into some small subareas and then determines the optimal signal control mode for each signalized intersection. Correlation model is the core of subarea partition algorithm because it can quantify the correlation degree of adjacent signalized intersections and decides whether these intersections can be grouped into one subarea. In most cases, there are more than two intersections in one subarea. However, current researches only focus on the correlation model for two adjacent intersections. The objective of this study is to develop a model which can calculate the correlation degree of multiple intersections adaptively. The cycle lengths, link lengths, number of intersections, and path flow between upstream and downstream coordinated phases were selected as the contributing factors of the correlation model. Their jointly impacts on the performance of the coordinated control mode relative to the isolated control mode were further studied using numerical experiments. The paper then proposed a correlation index (CI as an alternative to relative performance. The relationship between CI and the four contributing factors was established in order to predict the correlation, which determined whether adjacent intersections could be partitioned into one subarea. A value of 0 was set as the threshold of CI. If CI was larger than 0, multiple intersections could be partitioned into one subarea; otherwise, they should be separated. Finally, case studies were conducted in a real-life signalized network to evaluate the performance of the model. The results show that the CI simulates the relative performance well and could be a reliable index for subarea partition.

  1. Spatial modeling of bicycle activity at signalized intersections

    OpenAIRE

    Strauss, Jillian; Miranda-Moreno, Luis F.

    2013-01-01

    This paper presents a methodology to investigate the link between bicycle activity and built environment, road and transit network characteristics, and bicycle facilities while also accounting for spatial autocorrelation between intersections. The methodology includes the normalization of manual cyclist counts to average seasonal daily volumes (ASDV), taking into account temporal variations and using hourly, daily, and monthly expansion factors obtained from automatic bicycle count data. To c...

  2. Methodology for analysing capacity and level of service for signalized intersections (HCM 2000

    Directory of Open Access Journals (Sweden)

    Nedevska Ivana

    2016-01-01

    Highway Capacity Manual gives the opportunity to analyse the capacity and level of service of the roads in urban or rural areas, by defining the delay of the analysed facilities. To obtain these information, we must have data for geometric, traffic and signalization parameters, when the intersection is signalized.

  3. Determining u-turn adjustment factor for signalized intersections in Doha, Qatar

    Directory of Open Access Journals (Sweden)

    Hamad Khaled

    2017-01-01

    Full Text Available This paper summarizes the work conducted to estimating a U-turn adjustment factor at selected signalized intersections in Doha, Qatar. Unfortunately, the Highway Capacity Manual (HCM 2010 does not consider the effect of U-turn traffic on the capacity of signalized intersection; therefore, a few researchers attempted to develop U-turn adjustment factors to be added to the HCM analysis of signalized intersections when heavy U-turn traffic exists. To achieve this, the average headway was measured for U-tuning and left-turning vehicles at three different intersections in Doha. To estimate the U-turn adjustment factor, 198 queues with 2,327 U-turn vehicles and 1,564 left-turn vehicles were used to develop a regression model with the headway as the dependent variable and the U-turn percentage as the independent variable. The resulting quadratic model shows an increase in the average headway as the percentage of U-Turn traffic increases, with an R2 of 0.591. This indicates that the presence of U-turning vehicles has a significant effect on increasing the average headway thus reducing the capacity of signalized intersection. The result shows the U-Turn adjustment factor ranges from 0.76 for 100% of U-turn traffic to 0.95 for 10% of U-turn traffic.

  4. Estimation of fuel loss due to idling of vehicles at a signalized intersection in Chennai, India

    Science.gov (United States)

    Vasantha Kumar, S.; Gulati, Himanshu; Arora, Shivam

    2017-11-01

    The vehicles while waiting at signalized intersections are generally found to be in idling condition, i.e., not switching off their vehicles during red times. This phenomenon of idling of vehicles during red times at signalized intersections may lead to huge economic loss as lot of fuel is consumed by vehicles when they are in idling condition. The situation may even be worse in countries like India as different vehicle types consume varying amount of fuel. Only limited studies have been reported on estimation of fuel loss due to idling of vehicles in India. In the present study, one of the busy intersections in Chennai, namely, Tidel Park Junction in Rajiv Gandhi salai was considered. Data collection was carried out in one approach road of the intersection during morning and evening peak hours on a typical working day by manually noting down the red timings of each cycle and the corresponding number of two-wheelers, three-wheelers, passenger cars, light commercial vehicles (LCV) and heavy motorized vehicles (HMV) that were in idling mode. Using the fuel consumption values of various vehicles types suggested by Central Road Research Institute (CRRI), the total fuel loss during the study period was found to be Rs. 4,93,849/-. The installation of red timers, synchronization of signals, use of non-motorized transport for short trips and public awareness are some of the measures which government need to focus to save the fuel wasted at signalized intersections in major cities of India.

  5. An Eco-Driving Advisory System for Continuous Signalized Intersections by Vehicular Ad Hoc Network

    Directory of Open Access Journals (Sweden)

    Wei-Hsun Lee

    2018-01-01

    Full Text Available With the vehicular ad hoc network (VANET technology which support vehicle-to-vehicle (V2V and vehicle to road side unit (V2R/R2V communications, vehicles can preview the intersection signal plan such as signal countdown message. In this paper, an ecodriving advisory system (EDAS is proposed to reduce CO2 emissions and energy consumption by letting the vehicle continuously pass through multiple intersections with the minimum possibilities of stops. We extend the isolated intersection model to multiple continuous intersections scenario. A hybrid method combining three strategies including maximized throughput model (MTM, smooth speed model (SSM, and minimized acceleration and deceleration (MinADM is designed, and it is compared with related works maximized throughput model (MaxTM, open traffic light control model (OTLCM, and predictive cruise control (PCC models. Some issues for the practical application including safe car following, queue clearing, and gliding mode are discussed and conquered. Simulation results show that the proposed model outperforms OTLCM 25.1%~81.2% in the isolated intersection scenario for the CO2 emissions and 20.5%~84.3% in averaged travel time. It also performs better than the compared PCC model in CO2 emissions (19.9%~31.2% as well as travel time (24.5%~35.9% in the multiple intersections scenario.

  6. THE DIFFERENCES OF DRIVING BEHAVIOR AMONG DIFFERENT DRIVER AGE GROUPS AT SIGNALIZED INTERSECTIONS

    Directory of Open Access Journals (Sweden)

    Jian John LU, Ph.D., P.E.

    2000-01-01

    Full Text Available Over the past few years the population of older drivers has substantially increased across the United States. Older drivers are a group of special interest because of their potential age-related deficiencies. It is essential to understand their driving behavior and adjust the conditions of roadway systems according to their requirements. Likewise, driving behavior of older drivers needs to be considered in order to adequately estimate capacities at intersections. In the past few years, research projects were performed by the University of South Florida to analyze the differences of driving behavior among different driver age groups. Typically, the driving behavior of older drivers was evaluated by analyzing their start-up lost time and saturation headway at signalized intersections as compared to young and mid-age driver groups. Research results were based on data collected from signalized intersections with different land-use types. These intersections are located in west and central Florida where the elderly population has been increasing rapidly in recent years. From the results it was found that the presence of older drivers significantly reduced intersection capacity at all study sites because of their higher lost times and lower saturation flow rates. Therefore, driving behavior of older drivers should be considered in designing intersections located in places with a significant older driver population. In the research, models were developed to predict start-up lost time and saturation headway values generated by older drivers. Then, the variation in capacities with an increasing percentage of older drivers in the traffic stream was modeled. Finally, adjustment factors for different percentages of older drivers were developed to adjust intersection capacity. These factors are believed to account for the presence of older drivers in the traffic stream. The adjustment factors may be used in capacity analysis and design procedures for

  7. Safety propensity index for signalized and unsignalized intersections: exploration and assessment.

    Science.gov (United States)

    Schorr, Justin P; Hamdar, Samer H

    2014-10-01

    The objective of this study is to develop a safety propensity index (SPI) for both signalized and unsignalized intersections. Through the use of a structural equation modelling (SEM) approach safety is quantified in terms of multiple endogenous variables and related to various dimensions of exogenous variables. The singular valued SPI allows for identification of relationships between variables and lends itself well to a comparative analysis between models. The data provided by the Highway Safety Information System (HSIS) for the California transportation network was utilized for analysis. In total 22,422 collisions at unsignalized intersections and 20,215 collisions at signalized intersections (occurring between 2006 and 2010) were considered in the final models. The main benefits of the approach and the subsequent development of an SPI are (1) the identification of pertinent variables that effect safety at both intersection types, (2) the identification of similarities and differences at both types of intersections through model comparison, and (3) the quantification of safety in the form of an index such that a ranking system can be developed. If further developed, the adopted methodology may assist in safety related decision making and policy analysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Polycyclic’ Aromatic Hydrocarbon Induced Intracellular Signaling and Lymphocyte Apoptosis

    DEFF Research Database (Denmark)

    Schneider, Alexander M.

    lymphocytes. Our experiments on preB lymphocytes supported by stromal cells suggest that apoptosis is one of the mechanisms for PAH immunosuppression. It could be either due to direct effect of the PAH on the B cells, via stromal cell signaling. Ubiquitous PAH-like toxin, fluoranthene, was tested for it......’s ability to initiate apoptosis in T cell hybridomas. Our data demonstrate that PAH may induce apoptosis and innnunotoxicity in T cell branch of immune system. The mechanism of this process seems to be the AhR independent, and mediated by Ca...

  9. Cyclist activity and injury risk analysis at signalized intersections: a Bayesian modelling approach.

    Science.gov (United States)

    Strauss, Jillian; Miranda-Moreno, Luis F; Morency, Patrick

    2013-10-01

    This study proposes a two-equation Bayesian modelling approach to simultaneously study cyclist injury occurrence and bicycle activity at signalized intersections as joint outcomes. This approach deals with the potential presence of endogeneity and unobserved heterogeneities and is used to identify factors associated with both cyclist injuries and volumes. Its application to identify high-risk corridors is also illustrated. Montreal, Quebec, Canada is the application environment, using an extensive inventory of a large sample of signalized intersections containing disaggregate motor-vehicle traffic volumes and bicycle flows, geometric design, traffic control and built environment characteristics in the vicinity of the intersections. Cyclist injury data for the period of 2003-2008 is used in this study. Also, manual bicycle counts were standardized using temporal and weather adjustment factors to obtain average annual daily volumes. Results confirm and quantify the effects of both bicycle and motor-vehicle flows on cyclist injury occurrence. Accordingly, more cyclists at an intersection translate into more cyclist injuries but lower injury rates due to the non-linear association between bicycle volume and injury occurrence. Furthermore, the results emphasize the importance of turning motor-vehicle movements. The presence of bus stops and total crosswalk length increase cyclist injury occurrence whereas the presence of a raised median has the opposite effect. Bicycle activity through intersections was found to increase as employment, number of metro stations, land use mix, area of commercial land use type, length of bicycle facilities and the presence of schools within 50-800 m of the intersection increase. Intersections with three approaches are expected to have fewer cyclists than those with four. Using Bayesian analysis, expected injury frequency and injury rates were estimated for each intersection and used to rank corridors. Corridors with high bicycle volumes

  10. Role of the nucleus in apoptosis: signaling and execution.

    Science.gov (United States)

    Prokhorova, Evgeniia A; Zamaraev, Alexey V; Kopeina, Gelina S; Zhivotovsky, Boris; Lavrik, Inna N

    2015-12-01

    Since their establishment in the early 1970s, the nuclear changes upon apoptosis induction, such as the condensation of chromatin, disassembly of nuclear scaffold proteins and degradation of DNA, were, and still are, considered as the essential steps and hallmarks of apoptosis. These are the characteristics of the execution phase of apoptotic cell death. In addition, accumulating data clearly show that some nuclear events can lead to the induction of apoptosis. In particular, if DNA lesions resulting from deregulation during the cell cycle or DNA damage induced by chemotherapeutic drugs or viral infection cannot be efficiently eliminated, apoptotic mechanisms, which enable cellular transformation to be avoided, are activated in the nucleus. The functional heterogeneity of the nuclear organization allows the tight regulation of these signaling events that involve the movement of various nuclear proteins to other intracellular compartments (and vice versa) to initiate and govern apoptosis. Here, we discuss how these events are coordinated to execute apoptotic cell death.

  11. IMPACTS OF GROUP-BASED SIGNAL CONTROL POLICY ON DRIVER BEHAVIOR AND INTERSECTION SAFETY

    Directory of Open Access Journals (Sweden)

    Keshuang TANG

    2008-01-01

    Full Text Available Unlike the typical stage-based policy commonly applied in Japan, the group-based control (often called movement-based in the traffic control industry in Japan refers to such a control pattern that the controller is capable of separately allocating time to each signal group instead of stage based on traffic demand. In order to investigate its applicability at signalized intersections in Japan, an intersection located in Yokkaichi City of Mie Prefecture was selected as an experimental application site by the Japan Universal Traffic Management Society (UTMS. Based on the data collected at the intersection before and after implementing the group-based control policy respectively, this study evaluated the impacts of such a policy on driver behavior and intersection safety. To specify those impacts, a few models utilizing cycle-based data were first developed to interpret the occurrence probability and rate of red-light-running (RLR. Furthermore, analyses were performed on the yellow-entry time (Ye of the last cleared vehicle and post encroachment time (PET during the phase switching. Conclusions supported that the group-based control policy, along with certain other factors, directly or indirectly influenced the RLR behavior of through and right-turn traffics. Meanwhile, it has potential safety benefits as well, indicated by the declined Ye and increased PET values.

  12. Apoptosis and signalling in acid sphingomyelinase deficient cells

    Directory of Open Access Journals (Sweden)

    Sillence Dan J

    2001-11-01

    Full Text Available Abstract Background Recent evidence suggests that the activation of a non-specific lipid scramblase during apoptosis induces the flipping of sphingomyelin from the cell surface to the cytoplasmic leaftet of the plasma membrane. Inner leaflet sphingomyelin is then cleaved to ceramide by a neutral sphingomyelinase. The production of this non-membrane forming lipid induces blebbing of the plasma membrane to aid rapid engulfment by professional phagocytes. However contrary evidence suggests that cells which are deficient in acid sphingomyelinase are defective in apoptosis signalling. This data has been interpreted as support for the activation of acid sphingomyelinase as an early signal in apoptosis. Hypothesis An alternative explanation is put forward whereby the accumulation of intracellular sphingomyelin in sphingomyelinase deficient cells leads to the formation of intracellular rafts which lead to the sequestration of important signalling molecules that are normally present on the cell surface where they perform their function. Testing the hypothesis It is expected that the subcellular distribution of important signalling molecules is altered in acid sphingomyelinase deficient cells, leading to their sequestration in late endosomes / lysosomes. Other sphingolipid storage diseases such as Niemann-Pick type C which have normal acid sphingomyelinase activity would also be expected to show the same phenotype. Implications of the hypothesis If true the hypothesis would provide a mechanism for the pathology of the sphingolipid storage diseases at the cellular level and also have implications for the role of ceramide in apoptosis.

  13. Delay-based Passenger Car Equivalent at Signalized Intersections in Iran

    Directory of Open Access Journals (Sweden)

    Habibollah Nassiri

    2017-04-01

    Full Text Available Due to their different sizes and operational characteristics, vehicles other than passenger cars have a different influence on traffic operations especially at intersections. The passenger car equivalent (PCE is the parameter that shows how many passenger cars must be substituted for a specific heavy vehicle to represent its influence on traffic operation. PCE is commonly estimated using headway-based methods that consider the excess headway utilized by heavy vehicles. In this research, the PCE was estimated based on the delay parameter at three signalized intersections in Tehran, Iran. The data collected were traffic volume, travel time for each movement, signalization, and geometric design information. These data were analysed and three different models, one for each intersection, were constructed and calibrated using TRAF-NETSIM simulation software for unsaturated traffic conditions. PCE was estimated under different scenarios and the number of approach movements at each intersection. The results showed that for approaches with only one movement, PCE varies from 1.1 to 1.65. Similarly, for approaches with two and three movements, the PCE varies from 1.07 to 1.99 and from 0.76 to 3.6, respectively. In addition, a general model was developed for predicting PCE for intersections with all of the movements considered. The results obtained from this model showed that the average PCE of 1.5 is similar to the value recommended by the HCM (Highway Capacity Manual 1985. However, the predicted PCE value of 1.9 for saturated threshold is closer to the PCE value of 2 which was recommended by the HCM 2000 and HCM 2010.

  14. YIELDING BEHAVIOR OF TURNING VEHICLE DRIVER ON CROSSWALK AT SIGNALIZED INTERSECTION

    OpenAIRE

    HASINA, IASMIN

    2016-01-01

    Conflicts between Pedestrians/cyclists and tuning vehicles are very common at signalized intersection. Such conflicts increase the likelihood for a crash to occur. Since a crosswalk is the place designated for pedestrians to cross the road safely, the maneuvering of turning vehicles at crosswalks is characterized by their compliance with the priority rule: in interactions between turning vehicles and pedestrians on a crosswalk, the pedestrians should be allowed to pass first. Accident data re...

  15. Modeling Left-Turn Driving Behavior at Signalized Intersections with Mixed Traffic Conditions

    Directory of Open Access Journals (Sweden)

    Hong Li

    2016-01-01

    Full Text Available In many developing countries, mixed traffic is the most common type of urban transportation; traffic of this type faces many major problems in traffic engineering, such as conflicts, inefficiency, and security issues. This paper focuses on the traffic engineering concerns on the driving behavior of left-turning vehicles caused by different degrees of pedestrian violations. The traffic characteristics of left-turning vehicles and pedestrians in the affected region at a signalized intersection were analyzed and a cellular-automata-based “following-conflict” driving behavior model that mainly addresses four basic behavior modes was proposed to study the conflict and behavior mechanisms of left-turning vehicles by mathematic methodologies. Four basic driving behavior modes were reproduced in computer simulations, and a logit model of the behavior mode choice was also developed to analyze the relative share of each behavior mode. Finally, the microscopic characteristics of driving behaviors and the macroscopic parameters of traffic flow in the affected region were all determined. These data are important reference for geometry and capacity design for signalized intersections. The simulation results show that the proposed models are valid and can be used to represent the behavior of left-turning vehicles in the case of conflicts with illegally crossing pedestrians. These results will have potential applications on improving traffic safety and traffic capacity at signalized intersections with mixed traffic conditions.

  16. Targeting Apoptosis Signaling Pathways for Anticancer Therapy

    International Nuclear Information System (INIS)

    Fulda, Simone

    2011-01-01

    Treatment approaches for cancer, for example chemotherapy, radiotherapy, or immunotherapy, primarily act by inducing cell death in cancer cells. Consequently, the inability to trigger cell death pathways or alternatively, evasion of cancer cells to the induction of cell death pathways can result in resistance of cancers to current treatment protocols. Therefore, in order to overcome treatment resistance a better understanding of the underlying mechanisms that regulate cell death and survival pathways in cancers and in response to cancer therapy is necessary to develop molecular-targeted therapies. This strategy should lead to more effective and individualized treatment strategies that selectively target deregulated signaling pathways in a tumor type- and patient-specific manner.

  17. An Optimization Model of Multi-Intersection Signal Control for Trunk Road under Collaborative Information

    Directory of Open Access Journals (Sweden)

    Xun Li

    2017-01-01

    Full Text Available We proposed a signal control optimization model for urban main trunk line intersections. Four-phase intersection was analyzed and modeled based on the Cell Transmission Model (CTM. CTM and signal control model in our study had both been improved for multi-intersections by three-phase theory and information-exchanging. To achieve a real-time application, an improved genetic algorithm (GA was proposed finally, the DISCO traffic simulation software was used for numerical simulation experiment, and comparisons with the standard GA and CTM were reported in this paper. Experimental results indicate that our searching time is less than that of SGA by 38%, and our method needs only 1/3 iteration time of SGA. According to our DISCO traffic simulation processing, compared with SGA, if the input traffic flow is changed from free phase to synchronized phase, for example, less than 900 vel/h, the delay time can reduce to 87.99% by our method, and the minimum delay time is 77.76% of existing method. Furthermore, if input traffic volume is increased to 1200 vel/h or more at the synchronized phase, the summary and minimum values of average delay time are reduced to 81.16% and 75.83%, respectively, and the average delay time is reduced to 17.72 seconds.

  18. Evaluation of low-cost intersection countermeasures to reduce red-light-running violations : retro-reflective signal back plates.

    Science.gov (United States)

    2013-11-01

    Red light running has become a serious safety issue at signalized intersections throughout the : United States. One objective of this study was to identify the characteristics of red-light-running (RLR) : crashes and the drivers involved in those cra...

  19. Apoptosis signal-regulating kinase 1 mediates denbinobin-induced apoptosis in human lung adenocarcinoma cells

    Directory of Open Access Journals (Sweden)

    Pan Shiow-Lin

    2009-05-01

    Full Text Available Abstract In the present study, we explore the role of apoptosis signal-regulating kinase 1 (ASK1 in denbinobin-induced apoptosis in human lung adenocarcinoma (A549 cells. Denbinobin-induced cell apoptosis was attenuated by an ASK1 dominant-negative mutant (ASK1DN, two antioxidants (N-acetyl-L-cysteine (NAC and glutathione (GSH, a c-Jun N-terminal kinase (JNK inhibitor (SP600125, and an activator protein-1 (AP-1 inhibitor (curcumin. Treatment of A549 cells with denbinobin caused increases in ASK1 activity and reactive oxygen species (ROS production, and these effects were inhibited by NAC and GSH. Stimulation of A549 cells with denbinobin caused JNK activation; this effect was markedly inhibited by NAC, GSH, and ASK1DN. Denbinobin induced c-Jun phosphorylation, the formation of an AP-1-specific DNA-protein complex, and Bim expression. Bim knockdown using a bim short interfering RNA strategy also reduced denbinobin-induced A549 cell apoptosis. The denbinobin-mediated increases in c-Jun phosphorylation and Bim expression were inhibited by NAC, GSH, SP600125, ASK1DN, JNK1DN, and JNK2DN. These results suggest that denbinobin might activate ASK1 through ROS production to cause JNK/AP-1 activation, which in turn induces Bim expression, and ultimately results in A549 cell apoptosis.

  20. A Signal Coordination Control Based on Traversing Empty between Mid-Block Street Crossing and Intersection

    Directory of Open Access Journals (Sweden)

    Changjiang Zheng

    2012-01-01

    Full Text Available To solve the problem in pedestrian Mid-Block street crossing, the method of signal coordination control between mid-block street crossing and intersection is researched in this paper. The paper proposes to use “distance-flow rate-time” graph as the tool for building coordination control system model which is for different situations of traffic control. Through alternating the linear optimization model, the system outputs the distribution of signal timing and system operational factors (delays in vehicles and mid-block street crossing. Finally, taking one section on the Taiping North Road in Nanjing as an example, the signal coordination control is carried out. And the results which are delays in the vehicles and mid-block street crossing are compared to those in the current distribution of signal timing.

  1. Variability of Green Time to Discharge a Specified Number of Queued Vehicles at a Signalized Intersection

    Directory of Open Access Journals (Sweden)

    Yi Zhao

    2017-01-01

    Full Text Available The aim of this paper is to study the headway distribution of queued vehicles (less than 16 vehicles at signalized intersections. Existing studies usually take the average statistics of headway at any queuing place. When different percentile points of statistical data are assigned to headway, the passing rate (the rate of all queued vehicles passing the stop line under the ideal signal timing scheme varies. When selecting the mean value, the passing rate of a queue of fewer than 16 vehicles is no more than 65%. When selecting 75% as the percentile, the passing rate is up to 94%. The queue length also decides the assigned percentile of headway to ensure the passing rate reaches a certain level. The value assignation of headway directly affects lane capacity and start-up loss time. This paper provides a new perspective on parameter calibration and will make the signal timing algorithm method more effective.

  2. Best response game of traffic on road network of non-signalized intersections

    Science.gov (United States)

    Yao, Wang; Jia, Ning; Zhong, Shiquan; Li, Liying

    2018-01-01

    This paper studies the traffic flow in a grid road network with non-signalized intersections. The nature of the drivers in the network is simulated such that they play an iterative snowdrift game with other drivers. A cellular automata model is applied to study the characteristics of the traffic flow and the evolution of the behaviour of the drivers during the game. The drivers use best-response as their strategy to update rules. Three major findings are revealed. First, the cooperation rate in simulation experiences staircase-shaped drop as cost to benefit ratio r increases, and cooperation rate can be derived analytically as a function of cost to benefit ratio r. Second, we find that higher cooperation rate corresponds to higher average speed, lower density and higher flow. This reveals that defectors deteriorate the efficiency of traffic on non-signalized intersections. Third, the system experiences more randomness when the density is low because the drivers will not have much opportunity to update strategy when the density is low. These findings help to show how the strategy of drivers in a traffic network evolves and how their interactions influence the overall performance of the traffic system.

  3. Low Emissions and Delay Optimization for an Isolated Signalized Intersection Based on Vehicular Trajectories.

    Directory of Open Access Journals (Sweden)

    Ciyun Lin

    Full Text Available A traditional traffic signal control system is established based on vehicular delay, queue length, saturation and other indicators. However, due to the increasing severity of urban environmental pollution issues and the development of a resource-saving and environmentally friendly social philosophy, the development of low-carbon and energy-efficient urban transport is required. This paper first defines vehicular trajectories and the calculation of vehicular emissions based on VSP. Next, a regression analysis method is used to quantify the relationship between vehicular emissions and delay, and a traffic signal control model is established to reduce emissions and delay using the enumeration method combined with saturation constraints. Finally, one typical intersection of Changchun is selected to verify the model proposed in this paper; its performance efficiency is also compared using simulations in VISSIM. The results of this study show that the proposed model can significantly reduce vehicle delay and traffic emissions simultaneously.

  4. Human-like motion planning model for driving in signalized intersections

    Directory of Open Access Journals (Sweden)

    Yanlei Gu

    2017-10-01

    Full Text Available Highly automated and fully autonomous vehicles are much more likely to be accepted if they react in the same way as human drivers do, especially in a hybrid traffic situation, which allows autonomous vehicles and human-driven vehicles to share the same road. This paper proposes a human-like motion planning model to represent how human drivers assess environments and operate vehicles in signalized intersections. The developed model consists of a pedestrian intention detection model, gap detection model, and vehicle control model. These three submodels are individually responsible for situation assessment, decision making, and action, and also depend on each other in the process of motion planning. In addition, these submodels are constructed and learned on the basis of human drivers' data collected from real traffic environments. To verify the effectiveness of the proposed motion planning model, we compared the proposed model with actual human driver and pedestrian data. The experimental results showed that our proposed model and actual human driver behaviors are highly similar with respect to gap acceptance in intersections.

  5. Travel Time Model of Left-Turning Vehicles at Signalized Intersection

    Directory of Open Access Journals (Sweden)

    Leng Jun-qiang

    2012-01-01

    Full Text Available The travel time of left-turning vehicles at signalized intersection was discussed. Under the assumption that the opposing through vehicles headway follows M3 distribution, the travel time model was established on the basis of gap theory and queue theory. Comparison was done with the common model based on the assumption that the opposing through vehicles headway follows negative exponential distribution. The results show that the model in this paper has stronger applicability and its most relative error is less than 15%. In addition, the sensitivity analysis was done. The results show that the opposing through flow rate has significant impact on travel time. The impact of left-turning flow rate and following headway is light when the opposing through flow rate is small, the threshold is about 0.18 veh/s. The model established in this paper can well calculate travel time of left-turning vehicles at intersection, and the methodology may provide reference to other occasions.

  6. Safety surrogate histograms (SSH): A novel real-time safety assessment of dilemma zone related conflicts at signalized intersections.

    Science.gov (United States)

    Ghanipoor Machiani, Sahar; Abbas, Montasir

    2016-11-01

    Drivers' indecisiveness in dilemma zones (DZ) could result in crash-prone situations at signalized intersections. DZ is to the area ahead of an intersection in which drivers encounter a dilemma regarding whether to stop or proceed through the intersection when the signal turns yellow. An improper decision to stop by the leading driver, combined with the following driver deciding to go, can result in a rear-end collision, unless the following driver recognizes a collision is imminent and adjusts his or her behavior at or shortly after the onset of yellow. Considering the significance of DZ-related crashes, a comprehensive safety measure is needed to characterize the level of safety at signalized intersections. In this study, a novel safety surrogate measure was developed utilizing real-time radar field data. This new measure, called safety surrogate histogram (SSH), captures the degree and frequency of DZ-related conflicts at each intersection approach. SSH includes detailed information regarding the possibility of crashes, because it is calculated based on the vehicles conflicts. An example illustrating the application of the new methodology at two study sites in Virginia is presented and discussed, and a comparison is provided between SSH and other DZ-related safety surrogate measures mentioned in the literature. The results of the study reveal the efficacy of the SSH as complementary to existing surrogate measures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Differences in passenger car and large truck involved crash frequencies at urban signalized intersections: an exploratory analysis.

    Science.gov (United States)

    Dong, Chunjiao; Clarke, David B; Richards, Stephen H; Huang, Baoshan

    2014-01-01

    The influence of intersection features on safety has been examined extensively because intersections experience a relatively large proportion of motor vehicle conflicts and crashes. Although there are distinct differences between passenger cars and large trucks-size, operating characteristics, dimensions, and weight-modeling crash counts across vehicle types is rarely addressed. This paper develops and presents a multivariate regression model of crash frequencies by collision vehicle type using crash data for urban signalized intersections in Tennessee. In addition, the performance of univariate Poisson-lognormal (UVPLN), multivariate Poisson (MVP), and multivariate Poisson-lognormal (MVPLN) regression models in establishing the relationship between crashes, traffic factors, and geometric design of roadway intersections is investigated. Bayesian methods are used to estimate the unknown parameters of these models. The evaluation results suggest that the MVPLN model possesses most of the desirable statistical properties in developing the relationships. Compared to the UVPLN and MVP models, the MVPLN model better identifies significant factors and predicts crash frequencies. The findings suggest that traffic volume, truck percentage, lighting condition, and intersection angle significantly affect intersection safety. Important differences in car, car-truck, and truck crash frequencies with respect to various risk factors were found to exist between models. The paper provides some new or more comprehensive observations that have not been covered in previous studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Interaction networks of lithium and valproate molecular targets reveal a striking enrichment of apoptosis functional clusters and neurotrophin signaling.

    Science.gov (United States)

    Gupta, A; Schulze, T G; Nagarajan, V; Akula, N; Corona, W; Jiang, X-y; Hunter, N; McMahon, F J; Detera-Wadleigh, S D

    2012-08-01

    The overall neurobiological mechanisms by which lithium and valproate stabilize mood in bipolar disorder patients have yet to be fully defined. The therapeutic efficacy and dissimilar chemical structures of these medications suggest that they perturb both shared and disparate cellular processes. To investigate key pathways and functional clusters involved in the global action of lithium and valproate, we generated interaction networks formed by well-supported drug targets. Striking functional similarities emerged. Intersecting nodes in lithium and valproate networks highlighted a strong enrichment of apoptosis clusters and neurotrophin signaling. Other enriched pathways included MAPK, ErbB, insulin, VEGF, Wnt and long-term potentiation indicating a widespread effect of both drugs on diverse signaling systems. MAPK1/3 and AKT1/2 were the most preponderant nodes across pathways suggesting a central role in mediating pathway interactions. The convergence of biological responses unveils a functional signature for lithium and valproate that could be key modulators of their therapeutic efficacy.

  9. Implications of advanced warning messages on eliminating sun glare disturbances at signalized intersections

    Directory of Open Access Journals (Sweden)

    Qing Li

    2016-08-01

    Full Text Available Due to sun glare disturbances, drivers encounter fatal threats on roadways, particularly at signalized intersections. Many studies have attempted to develop applicable solutions, such as avoiding sun positions, applying road geometric re-directions, and wearing anti-glare glasses. None of these strategies have fully solved the problem. As one of the “Connected Vehicle” practices proposed by the U.S. Department of Transportation, advanced warning messages (AWMs are capable of providing wireless information about traffic controls. AWM acts as a supplement to conventional signs and signals, which can be blocked by obstacles or natural disturbances, such as sun glare. The drivers' smart advisory system (DSAS can provide drivers with AWM. Using a driving simulator this research explores the effects of DSAS messages on driving behaviors under sun glare disturbance. Statistical analyses were applied to assess (1 the negative impacts of sun glare, (2 the compensation of the DSAS AWM to sun glare effects, and (3 the improvement in driving performance due to DSAS AWM. Four performance indexes were measured, including (1 half kinetic energy speed, (2 mean approach speed, (3 brake response time, and (4 braking distance. The effects of the socio-demographic factors, such as gender, age, educational background, and driving experience were also studied. The analytical results illustrate that the DSAS can compensate for reduced visibility due to sun glare and improve driving performance to a normal visual situation, particularly for left turn and through movement.

  10. Role of CSL-dependent and independent Notch signaling pathways in cell apoptosis.

    Science.gov (United States)

    Zeng, Chong; Xing, Rui; Liu, Jing; Xing, Feiyue

    2016-01-01

    Apoptosis is a normally biological phenomenon in various organisms, involving complexly molecular mechanisms with a series of signaling processes. Notch signaling is found evolutionarily conserved in many species, playing a critical role in embryonic development, normal tissue homeostasis, angiogenesis and immunoregulation. The focus of this review is on currently novel advances about roles of CSL-dependent and independent Notch signaling pathways in cell apoptosis. The CSL can bind Notch intracellular domain (NIC) to act as a switch in mediating transcriptional activation or inactivation of the Notch signaling pathway downstream genes in the nucleus. It shows that CSL-dependent signaling regulates the cell apoptosis through Hes-1-PTEN-AKT-mTOR signaling, but rather the CSL-independent signaling mediates the cell apoptosis possibly via NIC-mTORC2-AKT-mTOR signaling, providing a new insight into apoptotic mechanisms.

  11. Stimulated Raman signals at conical intersections: Ab initio surface hopping simulation protocol with direct propagation of the nuclear wave function

    Energy Technology Data Exchange (ETDEWEB)

    Kowalewski, Markus, E-mail: mkowalew@uci.edu; Mukamel, Shaul, E-mail: smukamel@uci.edu [Department of Chemistry, University of California, Irvine, California 92697-2025 (United States)

    2015-07-28

    Femtosecond Stimulated Raman Spectroscopy (FSRS) signals that monitor the excited state conical intersections dynamics of acrolein are simulated. An effective time dependent Hamiltonian for two C—H vibrational marker bands is constructed on the fly using a local mode expansion combined with a semi-classical surface hopping simulation protocol. The signals are obtained by a direct forward and backward propagation of the vibrational wave function on a numerical grid. Earlier work is extended to fully incorporate the anharmonicities and intermode couplings.

  12. Stimulated Raman signals at conical intersections: Ab initio surface hopping simulation protocol with direct propagation of the nuclear wave function

    International Nuclear Information System (INIS)

    Kowalewski, Markus; Mukamel, Shaul

    2015-01-01

    Femtosecond Stimulated Raman Spectroscopy (FSRS) signals that monitor the excited state conical intersections dynamics of acrolein are simulated. An effective time dependent Hamiltonian for two C—H vibrational marker bands is constructed on the fly using a local mode expansion combined with a semi-classical surface hopping simulation protocol. The signals are obtained by a direct forward and backward propagation of the vibrational wave function on a numerical grid. Earlier work is extended to fully incorporate the anharmonicities and intermode couplings

  13. MicroRNAs regulate B-cell receptor signaling-induced apoptosis

    NARCIS (Netherlands)

    Kluiver, J. L.; Chen, C-Z

    Apoptosis induced by B-cell receptor (BCR) signaling is critical for antigen-driven selection, a process critical to tolerance and immunity. Here, we examined the roles of microRNAs (miRNAs) in BCR signaling-induced apoptosis using the widely applied WEHI-231 model. Comparison of miRNA levels in

  14. Influential factors of red-light running at signalized intersection and prediction using a rare events logistic regression model.

    Science.gov (United States)

    Ren, Yilong; Wang, Yunpeng; Wu, Xinkai; Yu, Guizhen; Ding, Chuan

    2016-10-01

    Red light running (RLR) has become a major safety concern at signalized intersection. To prevent RLR related crashes, it is critical to identify the factors that significantly impact the drivers' behaviors of RLR, and to predict potential RLR in real time. In this research, 9-month's RLR events extracted from high-resolution traffic data collected by loop detectors from three signalized intersections were applied to identify the factors that significantly affect RLR behaviors. The data analysis indicated that occupancy time, time gap, used yellow time, time left to yellow start, whether the preceding vehicle runs through the intersection during yellow, and whether there is a vehicle passing through the intersection on the adjacent lane were significantly factors for RLR behaviors. Furthermore, due to the rare events nature of RLR, a modified rare events logistic regression model was developed for RLR prediction. The rare events logistic regression method has been applied in many fields for rare events studies and shows impressive performance, but so far none of previous research has applied this method to study RLR. The results showed that the rare events logistic regression model performed significantly better than the standard logistic regression model. More importantly, the proposed RLR prediction method is purely based on loop detector data collected from a single advance loop detector located 400 feet away from stop-bar. This brings great potential for future field applications of the proposed method since loops have been widely implemented in many intersections and can collect data in real time. This research is expected to contribute to the improvement of intersection safety significantly. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. PASSENGER CAR EQUIVALENT (PCE OF THROUGH VEHICLES AT SIGNALIZED INTERSECTIONS IN DHAKA METROPOLITAN CITY, BANGLADESH

    Directory of Open Access Journals (Sweden)

    Partha SAHA

    2009-01-01

    PCE currently used in Bangladesh is based on the values given in Geometric Design of Highways (MoC, 2001, which is the modification of the values given by Webster (1958 on the study performed in the United Kingdom in the 50's and 60's. But now-a-days, the situation is far different both for traffic and road user as the characteristics have changed from that time. Hence, in this paper an empirical study was carried out to determine the PCE of different types of vehicle that reflect the actual traffic conditions of Dhaka Metropolitan City. Data were collected from ten signalized intersections and the headway ratio method was used to estimate the PCE of different types of vehicle. The main vehicle compositions observed during the study period consist of passenger cars, auto-rickshaws, mini-buses and buses. The PCE obtained in this study were compared to the values established earlier. It was found that the estimated PCE are smaller than those being used in Bangladesh.

  16. A simulator-based analysis of engineering treatments for right-hook bicycle crashes at signalized intersections.

    Science.gov (United States)

    Warner, Jennifer; Hurwitz, David S; Monsere, Christopher M; Fleskes, Kayla

    2017-07-01

    A right-hook crash is a crash between a right-turning motor vehicle and an adjacent through-moving bicycle. At signalized intersections, these crashes can occur during any portion of the green interval when conflicting bicycles and vehicles are moving concurrently. The objective of this research was to evaluate the effectiveness of four types of engineering countermeasures - regulatory signage, intersection pavement marking, smaller curb radius, and protected intersection design - at modifying driver behaviors that are known contributing factors in these crashes. This research focused on right-hook crashes that occur during the latter stage of the circular green indication at signalized intersections with a shared right-turn and through lane. Changes in driver performance in response to treatments were measured in a high-fidelity driving simulator. Twenty-eight participants each completed 22 right-turn maneuvers. A partially counterbalanced experimental design exposed drivers to critical scenarios, which had been determined in a previous experiment. For each turn, driver performance measures, including visual attention, crash avoidance, and potential crash severity, were collected. A total of 75 incidents (47 near-collisions and 28 collisions) were observed during the 616 right turns. All treatments had some positive effect on measured driver performance with respect to the right-turn vehicle conflicts. Further work is required to map the magnitude of these changes in driver performance to crash-based outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. EMPIRICAL STUDY ON USABILITY OF CROSSING SUPPORT SYSTEM FOR VISUALLY DISABLED AT SIGNALIZED INTERSECTION

    Science.gov (United States)

    Suzuki, Koji; Fujita, Motohiro; Matsuura, Kazuma; Fukuzono, Kazuyuki

    This paper evaluates the adjustment process for crossing support system for visually disabled at signalized intersections with the use of pedestrian traffic signals in concert with visible light communication (VLC) technology through outdoor experiments. As for the experiments, we put a blindfold on sighted people by eye mask in order to analyze the behavior of acquired visually disabled. And we used a full-scale crosswalk which is taking into consideration the crossing slope, the bumps at the edge of a crosswalk between the roadway and the sidewalkand crosswalk line. From the results of the survey, it is found that repetitive use of the VLC system decreased the number of lost their bearings completely and ended up standing immobile and reduced the crossing time for each person. On the other hand, it is shown that the performance of our VLC system is nearly equal to the existing support system from the view point of crossing time and the number of standing immobile and we clarified the effect factor for guidance accuracy by the regression analyses. Then we broke test subjects down into patterns by cluster analysis, and explained the walking characteristics for each group as they used the VLC system. In addition, we conducted the additional surveys for the quasi-blind subjects who had difficulty walking by using VLC system and visually impaired users. As a result, it is revealed that guidance accuracy was improved by providing the information about their receiving movement at several points on crosswalk and the habit of their walks for each user.

  18. Xanthohumol inhibits Notch signaling and induces apoptosis in hepatocellular carcinoma.

    Directory of Open Access Journals (Sweden)

    Selvi Kunnimalaiyaan

    Full Text Available Despite improvement in therapeutic strategies, median survival in advanced hepatocellular carcinoma (HCC remains less than one year. Therefore, molecularly targeted compounds with less toxic profiles are needed. Xanthohumol (XN, a prenylated chalcone has been shown to have anti-proliferative effects in various cancers types in vitro. XN treatment in healthy mice and humans yielded favorable pharmacokinetics and bioavailability. Therefore, we determined to study the effects of XN and understand the mechanism of its action in HCC. The effects of XN on a panel of HCC cell lines were assessed for cell viability, colony forming ability, and cellular proliferation. Cell lysates were analyzed for pro-apoptotic (c-PARP and cleaved caspase-3 and anti-apoptotic markers (survivin, cyclin D1, and Mcl-1. XN concentrations of 5 μM and above significantly reduced the cell viability, colony forming ability and also confluency of all four HCC cell lines studied. Furthermore, growth suppression due to apoptosis was evidenced by increased expression of pro-apoptotic and reduced expression of anti-apoptotic proteins. Importantly, XN treatment inhibited the Notch signaling pathway as evidenced by the decrease in the expression of Notch1 and HES-1 proteins. Ectopic expression of Notch1 in HCC cells reverses the anti-proliferative effect of XN as evidenced by reduced growth suppression compared to control. Taken together these results suggested that XN mediated growth suppression is appeared to be mediated by the inhibition of the Notch signaling pathway. Therefore, our findings warrants further studies on XN as a potential agent for the treatment for HCC.

  19. Analysis of Emission Effects Related to Drivers’ Compliance Rates for Cooperative Vehicle-Infrastructure System at Signalized Intersections

    Directory of Open Access Journals (Sweden)

    Ruohua Liao

    2018-01-01

    Full Text Available Unknown remaining time of signal phase at a signalized intersection generally results in extra accelerations and decelerations that increase variations of operating conditions and thus emissions. A cooperative vehicle-infrastructure system can reduce unnecessary speed changes by establishing communications between vehicles and the signal infrastructure. However, the environmental benefits largely depend on drivers’ compliance behaviors. To quantify the effects of drivers’ compliance rates on emissions, this study applied VISSIM 5.20 (Planung Transport Verkehr AG, Karlsruhe, Germany to develop a simulation model for a signalized intersection, in which light duty vehicles were equipped with a cooperative vehicle-infrastructure system. A vehicle-specific power (VSP-based model was used to estimate emissions. Based on simulation data, the effects of different compliance rates on VSP distributions, emission factors, and total emissions were analyzed. The results show the higher compliance rate decreases the proportion of VSP bin = 0, which means that the frequencies of braking and idling were lower and light duty vehicles ran more smoothly at the intersection if more light duty vehicles complied with the cooperative vehicle-infrastructure system, and emission factors for light duty vehicles decreased significantly as the compliance rate increased. The case study shows higher total emission reductions were observed with higher compliance rate for all of CO2, NOx, HC, and CO emissions. CO2 was reduced most significantly, decreased by 16% and 22% with compliance rates of 0.3 and 0.7, respectively.

  20. Analysis of Emission Effects Related to Drivers' Compliance Rates for Cooperative Vehicle-Infrastructure System at Signalized Intersections.

    Science.gov (United States)

    Liao, Ruohua; Chen, Xumei; Yu, Lei; Sun, Xiaofei

    2018-01-12

    Unknown remaining time of signal phase at a signalized intersection generally results in extra accelerations and decelerations that increase variations of operating conditions and thus emissions. A cooperative vehicle-infrastructure system can reduce unnecessary speed changes by establishing communications between vehicles and the signal infrastructure. However, the environmental benefits largely depend on drivers' compliance behaviors. To quantify the effects of drivers' compliance rates on emissions, this study applied VISSIM 5.20 (Planung Transport Verkehr AG, Karlsruhe, Germany) to develop a simulation model for a signalized intersection, in which light duty vehicles were equipped with a cooperative vehicle-infrastructure system. A vehicle-specific power (VSP)-based model was used to estimate emissions. Based on simulation data, the effects of different compliance rates on VSP distributions, emission factors, and total emissions were analyzed. The results show the higher compliance rate decreases the proportion of VSP bin = 0, which means that the frequencies of braking and idling were lower and light duty vehicles ran more smoothly at the intersection if more light duty vehicles complied with the cooperative vehicle-infrastructure system, and emission factors for light duty vehicles decreased significantly as the compliance rate increased. The case study shows higher total emission reductions were observed with higher compliance rate for all of CO₂, NO x , HC, and CO emissions. CO₂ was reduced most significantly, decreased by 16% and 22% with compliance rates of 0.3 and 0.7, respectively.

  1. Influence of dimension box differences and time differences during operations of red box for motorcycles at signalized intersection

    Science.gov (United States)

    Mulyadi, Agah Muhammad

    2017-11-01

    Performance of signalized intersection has declined due to a large number of motorcycles. The number of motorcycles reached 98.2 million units and the composition of motorcycles has reached around 81.7% of the total composition of vehicles in Indonesia (AISI, 2017). To solve that problem, the red box for motorcycles are provided at the signalized intersection. Red box for the motorcycle at signalized intersections was developed from the concept of Advance Stop Line (ASL) for bicycles. The Red Box was developed to split the queue between motorcycles and other vehicles when waiting at red light. This paper aims to evaluate the influence of the red box dimension and red time operation differences. The survey was conducted as many as 30 cycles of traffic signals per day. The data were analyzed using software IBM SPSS Statistics 20 by using Analysis of Variance (ANOVA) to obtain p-value (significant). The analysis shows that there are insignificant influences between the occupancy rates to the dimension of Red Box. Furthermore, that there is a significant difference that shows the dependency of only motorcycles in the Red Box Area towards red time operation.

  2. Optimization of Signal Timing of Intersections by Internal Metering of Queue Time Ratio of Vehicles in Network Scale

    Directory of Open Access Journals (Sweden)

    Mina Ghanbarikarekani

    2016-06-01

    Full Text Available Optimization of signal timing in urban network is usually done by minimizing the delay times or queue lengths. Sincethe effect of each intersection on the whole network is not considered in the mentioned methods, traffic congestion may occur in network links. Therefore, this paper has aimed to provide a timing optimization algorithm for traffic signals using internal timing policy based on balancing queue time ratio of vehicles in network links. In the proposed algorithm, the difference between the real queue time ratio and the optimum one for each link of intersection was minimized. To evaluate the efficiency of the proposed algorithm on traffic performance, the proposed algorithm was applied in a hypothetical network. By comparing the simulating software outputs, before and after implementing the algorithm, it was concluded that the queue time ratio algorithm has improved the traffic parameters by increasing the flow as well as reducing the delay time and density of the network.

  3. An extended car-following model at un-signalized intersections under V2V communication environment

    Science.gov (United States)

    Wang, Tao; Li, Peng

    2018-01-01

    An extended car-following model is proposed in this paper to analyze the impacts of V2V (vehicle to vehicle) communication on the micro driving behavior at the un-signalized intersection. A four-leg un-signalized intersection with twelve streams (left-turn, through movement, and right turn from each leg) is used. The effect of the guidance strategy on the reduction of the rate of stops and total delay is explored by comparing the proposed model and the traditional FVD car-following model. The numerical results illustrate that potential conflicts between vehicles can be predicted and some stops can be avoided by decelerating in advance. The driving comfort and traffic efficiency can be improved accordingly. More benefits could be obtained under the long communication range, low to medium traffic density, and simple traffic pattern conditions. PMID:29425243

  4. Kurarinol induces hepatocellular carcinoma cell apoptosis through suppressing cellular signal transducer and activator of transcription 3 signaling

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Guangwen; Yang, Jing; Zhao, Wenhao; Xu, Chan; Hong, Zongguo; Mei, Zhinan; Yang, Xinzhou, E-mail: xinzhou_yang@hotmail.com

    2014-12-01

    Kurarinol is a flavonoid isolated from roots of the medical plant Sophora flavescens. However, its cytotoxic activity against hepatocellular carcinoma (HCC) cells and toxic effects on mammalians remain largely unexplored. Here, the pro-apoptotic activities of kurarinol on HCC cells and its toxic impacts on tumor-bearing mice were evaluated. The molecular mechanisms underlying kurarinol-induced HCC cell apoptosis were also investigated. We found that kurarinol dose-dependently provoked HepG2, Huh-7 and H22 HCC cell apoptosis. In addition, kurarinol gave rise to a considerable decrease in the transcriptional activity of signal transducer and activator of transcription 3 (STAT3) in HCC cells. Suppression of STAT3 signaling is involved in kurarinol-induced HCC cell apoptosis. In vivo studies showed that kurarinol injection substantially induced transplanted H22 cell apoptosis with low toxic impacts on tumor-bearing mice. Similarly, the transcriptional activity of STAT3 in transplanted tumor tissues was significantly suppressed after kurarinol treatment. Collectively, our current research demonstrated that kurarinol has the capacity of inducing HCC cell apoptosis both in vitro and in vivo with undetectable toxic impacts on the host. Suppressing STAT3 signaling is implicated in kurarinol-mediated HCC cell apoptosis. - Highlights: • Kurarinol induces hepatocellular carcinoma (HCC) cell apoptosis. • Kurarinol induces HCC cell apoptosis via inhibiting STAT3. • Kurarinol exhibits low toxic effects on tumor-bearing animals.

  5. Kurarinol induces hepatocellular carcinoma cell apoptosis through suppressing cellular signal transducer and activator of transcription 3 signaling

    International Nuclear Information System (INIS)

    Shu, Guangwen; Yang, Jing; Zhao, Wenhao; Xu, Chan; Hong, Zongguo; Mei, Zhinan; Yang, Xinzhou

    2014-01-01

    Kurarinol is a flavonoid isolated from roots of the medical plant Sophora flavescens. However, its cytotoxic activity against hepatocellular carcinoma (HCC) cells and toxic effects on mammalians remain largely unexplored. Here, the pro-apoptotic activities of kurarinol on HCC cells and its toxic impacts on tumor-bearing mice were evaluated. The molecular mechanisms underlying kurarinol-induced HCC cell apoptosis were also investigated. We found that kurarinol dose-dependently provoked HepG2, Huh-7 and H22 HCC cell apoptosis. In addition, kurarinol gave rise to a considerable decrease in the transcriptional activity of signal transducer and activator of transcription 3 (STAT3) in HCC cells. Suppression of STAT3 signaling is involved in kurarinol-induced HCC cell apoptosis. In vivo studies showed that kurarinol injection substantially induced transplanted H22 cell apoptosis with low toxic impacts on tumor-bearing mice. Similarly, the transcriptional activity of STAT3 in transplanted tumor tissues was significantly suppressed after kurarinol treatment. Collectively, our current research demonstrated that kurarinol has the capacity of inducing HCC cell apoptosis both in vitro and in vivo with undetectable toxic impacts on the host. Suppressing STAT3 signaling is implicated in kurarinol-mediated HCC cell apoptosis. - Highlights: • Kurarinol induces hepatocellular carcinoma (HCC) cell apoptosis. • Kurarinol induces HCC cell apoptosis via inhibiting STAT3. • Kurarinol exhibits low toxic effects on tumor-bearing animals

  6. Modeling the frequency of opposing left-turn conflicts at signalized intersections using generalized linear regression models.

    Science.gov (United States)

    Zhang, Xin; Liu, Pan; Chen, Yuguang; Bai, Lu; Wang, Wei

    2014-01-01

    The primary objective of this study was to identify whether the frequency of traffic conflicts at signalized intersections can be modeled. The opposing left-turn conflicts were selected for the development of conflict predictive models. Using data collected at 30 approaches at 20 signalized intersections, the underlying distributions of the conflicts under different traffic conditions were examined. Different conflict-predictive models were developed to relate the frequency of opposing left-turn conflicts to various explanatory variables. The models considered include a linear regression model, a negative binomial model, and separate models developed for four traffic scenarios. The prediction performance of different models was compared. The frequency of traffic conflicts follows a negative binominal distribution. The linear regression model is not appropriate for the conflict frequency data. In addition, drivers behaved differently under different traffic conditions. Accordingly, the effects of conflicting traffic volumes on conflict frequency vary across different traffic conditions. The occurrences of traffic conflicts at signalized intersections can be modeled using generalized linear regression models. The use of conflict predictive models has potential to expand the uses of surrogate safety measures in safety estimation and evaluation.

  7. [Mechanisms of signaling associated with reactive nitrogen and oxygen in apoptosis].

    Science.gov (United States)

    Piłat, Justyna; Ługowski, Mateusz; Saczko, Jolanta; Choromańska, Anna; Chwiłkowska, Agnieszka; Banaś, Teresa; Kulbacka, Julita

    2016-05-01

    The knowledge of apoptotic mechanisms is essential in many biologic aspects related to both normal and neoplastic cells. Cell death by apoptosis is a very desirable way to eliminate unwanted cells: prevents release of the cellular content, which, in contrast to necrosis, provides no activation of inflammatory reactions. Apoptosis is a multistep process in where an extremely important role is played by caspases. Functions of caspases and their modifications are fundamental to understanding the signaling pathways responsible for regulation of apoptosis. These enzymes belong to a family of cysteine proteases that have the potential to destroy the enzymatic and structural proteins, and in the final stages of apoptosis, to lead to the disintegration of the cell. Apoptosis can be modulated by certain signaling pathway. © 2016 MEDPRESS.

  8. Proposition of delay model for signalized intersections with queueing theory analytical models usage

    Directory of Open Access Journals (Sweden)

    Grzegorz SIERPIŃSKI

    2007-01-01

    Full Text Available Time delay on intersections is a very important transport problem. Thearticle includes a proposition of time delay model. Variance of service times is considered by used average waiting time in queue for queuing system with compressed queuing processes usage as a part of proposed time delays model.

  9. Role of DNA mismatch repair and p53 in signaling induction of apoptosis by alkylating agents.

    Science.gov (United States)

    Hickman, M J; Samson, L D

    1999-09-14

    All cells are unavoidably exposed to chemicals that can alkylate DNA to form genotoxic damage. Among the various DNA lesions formed, O(6)-alkylguanine lesions can be highly cytotoxic, and we recently demonstrated that O(6)-methylguanine (O(6)MeG) and O(6)-chloroethylguanine (O(6)CEG) specifically initiate apoptosis in hamster cells. Here we show, in both hamster and human cells, that the MutSalpha branch of the DNA mismatch repair pathway (but not the MutSbeta branch) is absolutely required for signaling the initiation of apoptosis in response to O(6)MeGs and is partially required for signaling apoptosis in response to O(6)CEGs. Further, O(6)MeG lesions signal the stabilization of the p53 tumor suppressor, and such signaling is also MutSalpha-dependent. Despite this, MutSalpha-dependent apoptosis can be executed in a p53-independent manner. DNA mismatch repair status did not influence the response of cells to other inducers of p53 and apoptosis. Thus, it appears that mismatch repair status, rather than p53 status, is a strong indicator of the susceptibility of cells to alkylation-induced apoptosis. This experimental system will allow dissection of the signal transduction events that couple a specific type of DNA base lesion with the final outcome of apoptotic cell death.

  10. Low dose gamma irradiation enhances defined signaling components of intercellular reactive oxygen-mediated apoptosis induction

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, G, E-mail: georg.bauer@uniklinik-freiburg.de [Abteilung Virologie, Institut fuer Medizinische Mikrobiologie und Hygiene, Universitaet Freiburg, Freiburg (Germany)

    2011-01-01

    Transformed cells are selectively removed by intercellular ROS-mediated induction of apoptosis. Signaling is based on the HOCl and the NO/peroxynitrite pathway (major pathways) and the nitryl chloride and the metal-catalyzed Haber-Weiss pathway (minor pathways). During tumor progression, resistance against intercellular induction of apoptosis is acquired through expression of membrane-associated catalase. Low dose radiation of nontransformed cells has been shown to enhance intercellular induction of apoptosis. The present study was performed to define the signaling components which are modulated by low dose gamma irradiation. Low dose radiation induced the release of peroxidase from nontransformed, transformed and tumor cells. Extracellular superoxide anion generation was strongly enhanced in the case of transformed cells and tumor cells, but not in nontransformed cells. Enhancement of peroxidase release and superoxide anion generation either increased intercellular induction of apoptosis of transformed cells, or caused a partial protection under specific signaling conditions. In tumor cells, low dose radiation enhanced the production of major signaling components, but this had no effect on apoptosis induction, due to the strong resistance mechanism of tumor cells. Our data specify the nature of low dose radiation-induced effects on specific signaling components of intercellular induction of apoptosis at defined stages of multistep carcinogenesis.

  11. Endoplasmic Reticulum Is at the Crossroads of Autophagy, Inflammation, and Apoptosis Signaling Pathways and Participates in the Pathogenesis of Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Jing Su

    2013-01-01

    Full Text Available Diabetes mellitus (DM is a chronic metabolic disease, and its incidence is growing worldwide. The endoplasmic reticulum (ER is a central component of cellular functions and is involved in protein folding and trafficking, lipid synthesis, and maintenance of calcium homeostasis. The ER is also a sensor of both intra- and extracellular stress and thus participates in monitoring and maintaining cellular homeostasis. Therefore, the ER is one site of interaction between environmental signals and a cell’s biological function. The ER is tightly linked to autophagy, inflammation, and apoptosis, and recent evidence suggests that these processes are related to the pathogenesis of DM and its complications. Thus, the ER has been considered an intersection integrating multiple stress responses and playing an important role in metabolism-related diseases including DM. Here, we review the relationship between the ER and autophagy, inflammation, and apoptosis in DM to better understand the molecular mechanisms of this disease.

  12. A hazard-based duration model for analyzing crossing behavior of cyclists and electric bike riders at signalized intersections.

    Science.gov (United States)

    Yang, Xiaobao; Huan, Mei; Abdel-Aty, Mohamed; Peng, Yichuan; Gao, Ziyou

    2015-01-01

    This paper presents a hazard-based duration approach to investigate riders' waiting times, violation hazards, associated risk factors, and their differences between cyclists and electric bike riders at signalized intersections. A total of 2322 two-wheeled riders approaching the intersections during red light periods were observed in Beijing, China. The data were classified into censored and uncensored data to distinguish between safe crossing and red-light running behavior. The results indicated that the red-light crossing behavior of most riders was dependent on waiting time. They were inclined to terminate waiting behavior and run against the traffic light with the increase of waiting duration. Over half of the observed riders cannot endure 49s or longer. 25% of the riders can endure 97s or longer. Rider type, gender, waiting position, conformity tendency and crossing traffic volume were identified to have significant effects on riders' waiting times and violation hazards. Electric bike riders were found to be more sensitive to the external risk factors such as other riders' crossing behavior and crossing traffic volume than cyclists. Moreover, unobserved heterogeneity was examined in the proposed models. The finding of this paper can explain when and why cyclists and electric bike riders run against the red light at intersections. The results of this paper are useful for traffic design and management agencies to implement strategies to enhance the safety of riders. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Signal Control for Reducing Vehicle NOx and CO2 Emissions Based on Prediction of Arrival Traffic Flows at Intersections

    Science.gov (United States)

    Oda, Toshihiko

    Nitrogen oxide (NOx) and carbon dioxide (CO2) emissions from vehicles have been increasing every year because of the growing number of vehicles, and they cause serious environmental problems such as air pollution and global warming. To alleviate these problems, this paper proposes a new traffic signal control method for reducing vehicle NOx and CO2 emissions on arterial roads. To this end, we first model the amount of vehicle emissions as a function of the traffic delay and the number of stops at intersections. This step is necessary because it is difficult to obtain the amount of emissions directly using traffic control systems. Second, we introduce a signal control model in which the control parameters are continuously updated on the basis of predictions of arrival traffic flows at intersections. The signal timings are calculated in such a manner so as to minimize the weighted sum of the two emissions, which depend on the traffic flow. To evaluate the validity of this method, simulation experiments are carried out on an arterial road. The experiments show that the proposed method significantly outperforms existing methods in reducing both the emissions and travel time.

  14. SLP-2 inhibits cisplatin-induced apoptosis through MEK/ERK signaling and mitochondrial apoptosis pathway in cervical cancer cells.

    Science.gov (United States)

    Hu, Guolin; Zhang, Jialu; Xu, Feifei; Deng, Huan; Zhang, Weiwei; Kang, Shijun; Liang, Weijiang

    2018-03-08

    Stomatin-like protein 2 (STOML2 or SLP-2) is an oncogenic anti-apoptotic protein that is up-regulated in several types of cancer, including cervical cancer. However, the mechanisms responsible for the SLP-2 anti-apoptotic function remain poorly understood. Here, we show that siRNA-mediated SLP-2 suppression decreases growth of human cervical cancer HELA and SIHA cells, and increases cisplatin-induced apoptosis through activation of MEK/ERK signaling and suppression of the mitochondrial pathway. The inhibition of the mitochondrial pathway is mediated by increasing the mitochondrial Ca 2+ concentration and mitochondrial membrane potential, thereby downregulating p-MEK and p-ERK levels, upregulating the Bax/Bcl-2 ratio, increasing cytochrome C release from mitochondria into the cytosol, and upregulating levels of cleaved-caspase 9, cleaved-caspase 3 and cleaved-PARP. SLP-2 overexpression using adenovirus-STOML2 has the opposite effect: it upregulates p-MEK and p-ERK and downregulates the Bax/Bcl-2 ratio and levels of cleaved-caspase 9 to caspase 9, cleaved-caspase 3 to caspase 3, and cleaved-PARP to PARP in cisplatin-treated cells. These data show that SLP-2 inhibits the cisplatin-induced apoptosis by activating the MEK/ERK signaling and inhibiting the mitochondrial apoptosis pathway in cervical cancer cells. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  15. BAD enables ceramide to signal apoptosis via Ras and Raf-1.

    Science.gov (United States)

    Basu, S; Bayoumy, S; Zhang, Y; Lozano, J; Kolesnick, R

    1998-11-13

    Prior investigations document that proliferative signaling cascades, under some circumstances, initiate apoptosis, although mechanisms that dictate the final outcome are largely unknown. In COS-7 cells, ceramide signals Raf-1 activation through Ras (Zhang, Y., Yao, B., Delikat, S., Bayoumy, S., Lin, X. H., Basu, S., McGinley, M., Chan-Hui, P. Y., Lichenstein, H., and Kolesnick, R. (1997) Cell 89, 63-72), but not apoptosis. However, expression of small amounts of the pro-apoptotic Bcl-2 family member, BAD, conferred ceramide-induced apoptosis onto COS-7 cells. Ceramide signaled apoptosis in BAD-expressing cells by a pathway involving sequentially kinase suppressor of Ras (KSR)/ceramide-activated protein kinase, Ras, c-Raf-1, and MEK1. Downstream, this pathway linked to BAD dephosphorylation at serine 136 by prolonged inactivation of Akt/PKB. Further, mutation of BAD at serine 136 abrogated ceramide signaling of apoptosis. The present study indicates that when ceramide signals through the Ras/Raf cascade, the availability of a single target, BAD, may dictate an apoptotic outcome.

  16. Modelling and simulation of signal transductions in an apoptosis ...

    Indian Academy of Sciences (India)

    2006-12-12

    Dec 12, 2006 ... This paper first presents basic Petri net components representing molecular interactions and mechanisms of signalling pathways, and introduces a method to construct a Petri net model of a signalling pathway with these components. Then a simulation method of determining the delay time of transitions, ...

  17. Advances in cell proliferation and apoptosis signal pathway and therapies of polycystic kidney disease

    Directory of Open Access Journals (Sweden)

    Xiao-ying LIAN

    2016-12-01

    Full Text Available Polycystic kidney disease (PKD is one of the monogenic inherited diseases. In PKD, excessive cell proliferation and fluid secretion, and disruption of the mechanisms controlling tubular diameter may all lead to cyst formation. Current evidence has demonstrated that intracellular calcium ion and cAMP imbalance drive both abnormal cell proliferation and apoptosis signal pathway. The present paper summarized the evidence implicating calcium ion and cAMP as central players in the signaling pathway of cell proliferation and apoptosis in PKD, and considered the potential therapeutic approaches targeted to slow cyst growth in PKD. DOI: 10.11855/j.issn.0577-7402.2016.11.13

  18. Cell shrinkage as a signal to apoptosis in NIH 3T3 fibroblasts

    DEFF Research Database (Denmark)

    Friis, Martin B; Friborg, Christel R; Schneider, Linda

    2005-01-01

    Cell shrinkage is a hallmark of the apoptotic mode of programmed cell death, but it is as yet unclear whether a reduction in cell volume is a primary activation signal of apoptosis. Here we studied the effect of an acute elevation of osmolarity (NaCl or sucrose additions, final osmolarity 687...... mosmol l(-1)) on NIH 3T3 fibroblasts to identify components involved in the signal transduction from shrinkage to apoptosis. After 1.5 h the activity of caspase-3 started to increase followed after 3 h by the appearance of many apoptotic-like bodies. The caspase-3 activity increase was greatly enhanced...

  19. Eco-Approach and Departure System for Left-Turn Vehicles at a Fixed-Time Signalized Intersection

    Directory of Open Access Journals (Sweden)

    Huifu Jiang

    2018-01-01

    Full Text Available This research proposed an eco-approach and departure system for left-turn vehicles at a fixed-time signalized intersection. This system gives higher priority to enhancing traffic safety than improving mobility and fuel efficiency, and optimizes the entire traffic consisted of connected and automated vehicles (CAVs and conventional human-driven vehicles by providing ecological speed trajectories for left-turn CAVs. All the ecological speed trajectories are offline optimized before the implementation of system. The speed trajectory optimization is constructed in Pontryagin’s Minimum Principle structure. The before and after evaluation of the proposed system shows the percentage of vehicles that drive pass the intersection at safe speed increases by 2.14% to 45.65%, fuel consumption benefits range 0.53% to 18.44%, emission benefits range from 0.57% to 15.69%, no significant throughput benefits is observed. The proposed system significantly enhances the traffic safety and improves the fuel efficiency and emission reduction of left-turn vehicles with no adverse effect on mobility, and has a good robustness against the randomness of traffic. The investigation also indicates that the computation time of proposed system is greatly reduced compared to previous eco-driving system with online speed optimization. The computation time is up to 0.01 s. The proposed system is ready for real-time application.

  20. The necrotic signal induced by mycophenolic acid overcomes apoptosis-resistance in tumor cells.

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    Gwendaline Guidicelli

    Full Text Available BACKGROUND: The amount of inosine monophosphate dehydrogenase (IMPDH, a pivotal enzyme for the biosynthesis of the guanosine tri-phosphate (GTP, is frequently increased in tumor cells. The anti-viral agent ribavirin and the immunosuppressant mycophenolic acid (MPA are potent inhibitors of IMPDH. We recently showed that IMPDH inhibition led to a necrotic signal requiring the activation of Cdc42. METHODOLOGY/PRINCIPAL FINDINGS: Herein, we strengthened the essential role played by this small GTPase in the necrotic signal by silencing Cdc42 and by the ectopic expression of a constitutive active mutant of Cdc42. Since resistance to apoptosis is an essential step for the tumorigenesis process, we next examined the effect of the MPA-mediated necrotic signal on different tumor cells demonstrating various mechanisms of resistance to apoptosis (Bcl2-, HSP70-, Lyn-, BCR-ABL-overexpressing cells. All tested cells remained sensitive to MPA-mediated necrotic signal. Furthermore, inhibition of IMPDH activity in Chronic Lymphocytic Leukemia cells was significantly more efficient at eliminating malignant cells than apoptotic inducers. CONCLUSIONS/SIGNIFICANCE: These findings indicate that necrosis and apoptosis are split signals that share few if any common hub of signaling. In addition, the necrotic signaling pathway induced by depletion of the cellular amount of GTP/GDP would be of great interest to eliminate apoptotic-resistant tumor cells.

  1. Activation of Wnt/β-catenin signaling increases apoptosis in melanoma cells treated with trail.

    Directory of Open Access Journals (Sweden)

    Zachary F Zimmerman

    Full Text Available While the TRAIL pathway represents a promising therapeutic target in melanoma, resistance to TRAIL-mediated apoptosis remains a barrier to its successful adoption. Since the Wnt/β-catenin pathway has been implicated in facilitating melanoma cell apoptosis, we investigated the effect of Wnt/β-catenin signaling on regulating the responses of melanoma cells to TRAIL. Co-treatment of melanoma cell lines with WNT3A-conditioned media and recombinant TRAIL significantly enhanced apoptosis compared to treatment with TRAIL alone. This apoptosis correlates with increased abundance of the pro-apoptotic proteins BCL2L11 and BBC3, and with decreased abundance of the anti-apoptotic regulator Mcl1. We then confirmed the involvement of the Wnt/β-catenin signaling pathway by demonstrating that siRNA-mediated knockdown of an intracellular β-catenin antagonist, AXIN1, or treating cells with an inhibitor of GSK-3 also enhanced melanoma cell sensitivity to TRAIL. These studies describe a novel regulation of TRAIL sensitivity in melanoma by Wnt/β-catenin signaling, and suggest that strategies to enhance Wnt/β-catenin signaling in combination with TRAIL agonists warrant further investigation.

  2. Role of Notch-1 signaling in ethanol induced PC12 apoptosis | Li ...

    African Journals Online (AJOL)

    Chronic alcoholic dementia has crucial role in progress of neurodegenerative disease and affects a large portion of our aging population. Neuronal cell apoptosis may be a contributing factor of neurodegenerative disease (ND) and Alzheimer's disease (AD). Previous researches have indicated that Notch-1 signaling ...

  3. Microwave-induced Apoptosis and Cytotoxicity of NK Cells through ERK1/2 Signaling.

    Science.gov (United States)

    Zhao, Li; Li, Jing; Hao, Yan Hui; Gao, Ya Bing; Wang, Shui Ming; Zhang, Jing; Dong, Ji; Zhou, Hong Mei; Liu, Shu Chen; Peng, Rui Yun

    2017-05-01

    To investigate microwave-induced morphological and functional injury of natural killer (NK) cells and uncover their mechanisms. NK-92 cells were exposed to 10, 30, and 50 mW/cm2 microwaves for 5 min. Ultrastructural changes, cellular apoptosis and cell cycle regulation were detected at 1 h and 24 h after exposure. Cytotoxic activity was assayed at 1 h after exposure, while perforin and NKG2D expression were detected at 1 h, 6 h, and 12 h after exposure. To clarify the mechanisms, phosphorylated ERK (p-ERK) was detected at 1 h after exposure. Moreover, microwave-induced cellular apoptosis and cell cycle regulation were analyzed after blockade of ERK signaling by using U0126. Microwave-induced morphological and ultrastructural injury, dose-dependent apoptosis (P microwave exposure. Moreover, significant apoptosis was still detected at 24 h after 50 mW/cm2 microwave exposure (P microwave exposure model, microwaves impaired the cytotoxic activity of NK-92 cells at 1 h and down regulated perforin protein both at 1 h and 6 h after exposure (P microwave-induced apoptosis (P Microwave dose-dependently induced morphological and functional injury in NK-92 cells, possibly through ERK-mediated regulation of apoptosis and perforin expression. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  4. Toosendanin induces apoptosis through suppression of JNK signaling pathway in HL-60 cells.

    Science.gov (United States)

    Ju, Jianming; Qi, Zhichao; Cai, Xueting; Cao, Peng; Liu, Nan; Wang, Shuzhen; Chen, Yijun

    2013-02-01

    Toosendanin (TSN), a triterpenoid isolated from Melia toosendan Sieb. et Zucc., has been found to suppress proliferation and induce apoptosis in a variety of human cancer cells. However, the mechanism how TSN induces apoptosis remains poorly understood. In this study, we examined the effects of TSN on the growth, cell cycle arrest, induction of apoptosis and the involved signaling pathway in human promyelocytic leukemia HL-60 cells. Proliferation of HL-60 cells was inhibited in a dose-dependent manner with the IC(50 (48 h)) of 28 ng/mL. The growth inhibition was due primarily to the S phase arrest and cell apoptosis. Cell apoptosis induced by TSN was confirmed by Annexin V-FITC/propidium iodide staining. The increase of the pro-apoptotic protein Bax, cleaved PARP and caspase-3, and the decrease of anti-apoptotic protein Bcl-2 were observed. Western blot analysis indicated that TSN inhibits the CDC42/MEKK1/JNK pathway. Taken together, our study suggested, for the first time, that the pro-apoptotic effects of TSN on HL-60 cells were mediated through JNK signaling pathway. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Interferon-γ affects leukemia cell apoptosis through regulating Fas/FasL signaling pathway.

    Science.gov (United States)

    Xia, H-L; Li, C-J; Hou, X-F; Zhang, H; Wu, Z-H; Wang, J

    2017-05-01

    Imbalance of hematopoietic cell proliferation and apoptosis is one of the major causes of leukemia. Enhanced cell proliferation and reduced apoptosis lead to hemocytes accumulation. Fas/FasL signaling pathway promotes cell apoptosis. This study investigated the impact of interferon γ (IFN-γ) on chronic myelogenous leukemia cell proliferation and apoptosis to elucidate its interaction with Fas/FasL signaling pathway. Leukemia K562 cells were routinely cultivated and treated with 10 U/ml, 100 U/ml, and 1000 U/ml interferon for 12 h, 24 h, and 48 h, respectively. MTT assay was applied to test cell proliferation. TUNEL assay was adopted to determine cell apoptosis. Western blot was selected to detect Fas/FasL expression. Different concentrations of IFN-γ inhibited cell proliferation at various time points. IFN-γ at 1000 U/ml treatment for 48 h exhibited the strongest suppressive effect on cell proliferation (p facilitating Fas and FasL proteins expressions.

  6. Evaluation of Deployment Challenges of Wireless Sensor Networks at Signalized Intersections

    Directory of Open Access Journals (Sweden)

    Leyre Azpilicueta

    2016-07-01

    Full Text Available With the growing demand of Intelligent Transportation Systems (ITS for safer and more efficient transportation, research on and development of such vehicular communication systems have increased considerably in the last years. The use of wireless networks in vehicular environments has grown exponentially. However, it is highly important to analyze radio propagation prior to the deployment of a wireless sensor network in such complex scenarios. In this work, the radio wave characterization for ISM 2.4 GHz and 5 GHz Wireless Sensor Networks (WSNs deployed taking advantage of the existence of traffic light infrastructure has been assessed. By means of an in-house developed 3D ray launching algorithm, the impact of topology as well as urban morphology of the environment has been analyzed, emulating the realistic operation in the framework of the scenario. The complexity of the scenario, which is an intersection city area with traffic lights, vehicles, people, buildings, vegetation and urban environment, makes necessary the channel characterization with accurate models before the deployment of wireless networks. A measurement campaign has been conducted emulating the interaction of the system, in the vicinity of pedestrians as well as nearby vehicles. A real time interactive application has been developed and tested in order to visualize and monitor traffic as well as pedestrian user location and behavior. Results show that the use of deterministic tools in WSN deployment can aid in providing optimal layouts in terms of coverage, capacity and energy efficiency of the network.

  7. Game Theory Model of Traffic Participants within Amber Time at Signalized Intersection

    Directory of Open Access Journals (Sweden)

    Weiwei Qi

    2014-01-01

    Full Text Available The traffic light scheme is composed of red, green, and amber lights, and it has been defined clearly for the traffic access of red and green lights; however, the definition of that for the amber light is indistinct, which leads to the appearance of uncertainty factors and serious traffic conflicts during the amber light. At present, the traffic administrations are faced with the decision of whether to forbid passing or not during the amber light in the cities of China. On one hand, it will go against the purpose of setting amber lights if forbidding passing; on the other hand, it may lead to a mess of traffic flow running if not. And meanwhile the drivers are faced with the decision of passing the intersection or stopping during the amber light as well. So the decision-making behavior of traffic administrations and drivers can be converted into a double game model. And through quantification of their earnings in different choice conditions, the optimum decision-making plan under specific conditions could be solved via the Nash equilibrium solution concept. Thus the results will provide a basis for the formulation of the traffic management strategy.

  8. Traffic flow behavior at un-signalized intersection with crossings pedestrians

    Science.gov (United States)

    Khallouk, A.; Echab, H.; Ez-Zahraouy, H.; Lakouari, N.

    2018-02-01

    Mixed traffic flux composed of crossing pedestrians and vehicles extensively exists in cities. To study the characteristics of the interference traffic flux, we develop a pedestrian-vehicle cellular automata model to present the interaction behaviors on a simple cross road. By realizing the fundamental parameters (i.e. injecting rates α1, α2, the extracting rate β and the pedestrian arrival rate αP), simulations are carried out. The vehicular traffic flux is calculated in terms of rates. The effect of the crosswalk can be regarded as a dynamic impurity. The system phase diagrams in the (α1 ,αP) plane are built. It is found that the phase diagrams consist essentially of four phases namely Free Flow, Congested, Maximal Current and Gridlock. The value of the Maximal current phase depends on the extracting rate β, while the Gridlock phase is achieved only when the pedestrians generating rate is higher than a critical value. Furthermore, the effect of vehicles changing lane (Pch1 ,Pch2) and the location of the crosswalk XP on the dynamic characteristics of vehicles flow are investigated. It is found that traffic situation in the system is slightly enhanced if the location of the crosswalks XP is far from the intersection. However, when Pch1, Pch2 increase, the traffic becomes congested and the Gridlock phase enlarges.

  9. Influence of Stretching-Segment Storage Length on Urban Traffic Flow in Signalized Intersection

    Directory of Open Access Journals (Sweden)

    Weiwei Guo

    2011-12-01

    Full Text Available Intelligent traffic control is influenced by Stretching-segment design, parameters optimization of traffic control have to consider saturation flow rate in approach. Many intersections with different stretching-segment design forms are selected to study on saturation flow rate at peak rush hour and ordinary time hour, the characteristic of saturation flow rate in green time is analyzed. Based on the real traffic situation, the influence of the length of stretching-segment storage to straight-cross flow rate was explored in this study. The data showed that the duration and stability of saturation flow rate were highly influenced by the length of stretching-segment storage. A probabilistic computing model was proposed, which analyzed the effect of the length of stretching-segment to the flow rate and described the impact of vehicles in the upstream. Finally, the attenuate regulation of the straight-cross flow rate in green phase is developed by the analysis of vehicle's blocking.

  10. Evaluation of Deployment Challenges of Wireless Sensor Networks at Signalized Intersections

    Science.gov (United States)

    Azpilicueta, Leyre; López-Iturri, Peio; Aguirre, Erik; Martínez, Carlos; Astrain, José Javier; Villadangos, Jesús; Falcone, Francisco

    2016-01-01

    With the growing demand of Intelligent Transportation Systems (ITS) for safer and more efficient transportation, research on and development of such vehicular communication systems have increased considerably in the last years. The use of wireless networks in vehicular environments has grown exponentially. However, it is highly important to analyze radio propagation prior to the deployment of a wireless sensor network in such complex scenarios. In this work, the radio wave characterization for ISM 2.4 GHz and 5 GHz Wireless Sensor Networks (WSNs) deployed taking advantage of the existence of traffic light infrastructure has been assessed. By means of an in-house developed 3D ray launching algorithm, the impact of topology as well as urban morphology of the environment has been analyzed, emulating the realistic operation in the framework of the scenario. The complexity of the scenario, which is an intersection city area with traffic lights, vehicles, people, buildings, vegetation and urban environment, makes necessary the channel characterization with accurate models before the deployment of wireless networks. A measurement campaign has been conducted emulating the interaction of the system, in the vicinity of pedestrians as well as nearby vehicles. A real time interactive application has been developed and tested in order to visualize and monitor traffic as well as pedestrian user location and behavior. Results show that the use of deterministic tools in WSN deployment can aid in providing optimal layouts in terms of coverage, capacity and energy efficiency of the network. PMID:27455270

  11. Cyclic Compressive Stress Regulates Apoptosis in Rat Osteoblasts: Involvement of PI3K/Akt and JNK MAPK Signaling Pathways.

    Directory of Open Access Journals (Sweden)

    Fanglong Song

    Full Text Available It is widely accepted that physiological mechanical stimulation suppresses apoptosis and induces synthesis of extracellular matrix by osteoblasts; however, the effect of stress overloading on osteoblasts has not been fully illustrated. In the present study, we investigated the effect of cyclic compressive stress on rat osteoblasts apoptosis, using a novel liquid drop method to generate mechanical stress on osteoblast monolayers. After treatment with different levels of mechanical stress, apoptosis of osteoblasts and activations of mitogen-activated protein kinases (MAPKs and PI3-kinase (PI3K/Akt signaling pathways were investigated. Osteoblasts apoptosis was observed after treated with specific inhibitors prior to mechanical stimulation. Protein levels of Bax/Bcl-2/caspase-3 signaling were determined using western blot with or without inhibitors of PI3K/Akt and phosphorylation of c-jun N-terminal kinase (JNK MAPK. Results showed that mechanical stimulation led to osteoblasts apoptosis in a dose-dependent manner and a remarkable activation of MAPKs and PI3K/Akt signaling pathways. Activation of PI3K/Akt protected against apoptosis, whereas JNK MAPK increased apoptosis via regulation of Bax/Bcl-2/caspase-3 activation. In summary, the PI3K/Akt and JNK MAPK signaling pathways played opposing roles in osteoblasts apoptosis, resulting in inhibition of apoptosis upon small-magnitude stress and increased apoptosis upon large-magnitude stress.

  12. Brown seaweed fucoidan: biological activity and apoptosis, growth signaling mechanism in cancer.

    Science.gov (United States)

    Senthilkumar, Kalimuthu; Manivasagan, Panchanathan; Venkatesan, Jayachandran; Kim, Se-Kwon

    2013-09-01

    Seaweeds, being abundant sources of bioactive components have much interest in recent times. The complex polysaccharides from the brown, red and green seaweeds possess broad spectrum therapeutic properties. The sulfated polysaccharides are routinely used in biomedical research and have known biological activities. Fucoidan, a fucose-rich polysaccharide extracted from brown seaweed has various biological functions including anticancer effects. Cellular damage induces growth arrest and tumor suppression by inducing apoptosis, the mechanism of cell death depends on the magnitude of DNA damage following exposure to anticancer agents. Apoptosis is mainly regulated by cell growth signaling molecules. Number of research studies evidenced that fucoidan shown to induce cytotoxicity of various cancer cells, induces apoptosis, and inhibits invasion, metastasis and angiogenesis of cancer cells. There are few articles discussing on fucoidan biological activity but no specific review on cancer and its signaling mechanism. Hence, this review discusses the brown seaweed fucoidan structure and some biological function and role in apoptosis, invasion, metastasis, angiogenesis and growth signal mechanism on cancer. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Silver Nanoparticles Induce HePG-2 Cells Apoptosis Through ROS-Mediated Signaling Pathways

    Science.gov (United States)

    Zhu, Bing; Li, Yinghua; Lin, Zhengfang; Zhao, Mingqi; Xu, Tiantian; Wang, Changbing; Deng, Ning

    2016-04-01

    Recently, silver nanoparticles (AgNPs) have been shown to provide a novel approach to overcome tumors, especially those of hepatocarcinoma. However, the anticancer mechanism of silver nanoparticles is unclear. Thus, the purpose of this study was to estimate the effect of AgNPs on proliferation and activation of ROS-mediated signaling pathway on human hepatocellular carcinoma HePG-2 cells. A simple chemical method for preparing AgNPs with superior anticancer activity has been showed in this study. AgNPs were detected by transmission electronic microscopy (TEM) and energy dispersive X-ray (EDX). The size distribution and zeta potential of silver nanoparticles were detected by Zetasizer Nano. The average size of AgNPs (2 nm) observably increased the cellular uptake by endocytosis. AgNPs markedly inhibited the proliferation of HePG-2 cells through induction of apoptosis with caspase-3 activation and PARP cleavage. AgNPs with dose-dependent manner significantly increased the apoptotic cell population (sub-G1). Furthermore, AgNP-induced apoptosis was found dependent on the overproduction of reactive oxygen species (ROS) and affecting of MAPKs and AKT signaling and DNA damage-mediated p53 phosphorylation to advance HePG-2 cells apoptosis. Therefore, our results show that the mechanism of ROS-mediated signaling pathways may provide useful information in AgNP-induced HePG-2 cell apoptosis.

  14. SPAG6 regulates cell apoptosis through the TRAIL signal pathway in myelodysplastic syndromes.

    Science.gov (United States)

    Li, Xinxin; Yang, Bihui; Wang, Li; Chen, Liping; Luo, Xiaohua; Liu, Lin

    2017-05-01

    Myelodysplastic syndromes (MDSs) are a group of malignant clone hematopoietic stem-cell diseases, and the evolution and progression of MDS depend on the abnormal apoptosis of bone marrow cells. Our previous studies have indicated that sperm-associated antigen 6 (SPAG6), located in the uniparental disomy regions of myeloid cells, is overexpressed in patients with MDS as compared to controls, and SPAG6 can inhibit apoptosis of SKM-1. However, the concrete mechanism is still unclear. In the present study, it was found that the TNF-related apoptosis-inducing ligand (TRAIL)signal pathway was activated when the expression of SPAG6 was inhibited by SPAG6-shRNA lentivirus in SKM-1 cells. Additionally, the results of flow cytometry, Cell Counting Kit-8 assay and western blot analysis implied that the TRAIL signal pathway could be inhibited by a high expression of SPAG6. However, SPAG6 cannot influence the expression of TRAIL death receptors, except for FADD. Additionally the interaction between FADD and TRAIL death receptors also increased in SKM-1 cells infected with SPAG6-shRNA lentivirus. Thus, our study demonstrates that SPAG6 may regulate apoptosis in SKM-1 through the TRAIL signal pathway, indicating that SPAG6 could be a potential therapeutic target.

  15. Sangivamycin induces apoptosis by suppressing Erk signaling in primary effusion lymphoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Wakao, Kazufumi [Department of Biotechnology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu-shi 400-8511 (Japan); Watanabe, Tadashi [Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412 (Japan); Takadama, Tadatoshi; Ui, Sadaharu [Department of Biotechnology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu-shi 400-8511 (Japan); Shigemi, Zenpei; Kagawa, Hiroki [Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412 (Japan); Higashi, Chizuka; Ohga, Rie; Taira, Takahiro [Department of Molecular Cell Biology, Faculty of Medicine, University of Yamanashi, Chuoh-shi 409-3898 (Japan); Fujimuro, Masahiro, E-mail: fuji2@mb.kyoto-phu.ac.jp [Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412 (Japan)

    2014-02-07

    Highlights: • Sangivamycin induces the apoptosis of B cell lymphoma PEL cells. • Sangivamycin suppresses Erk signaling by inhibiting Erk phosphorylation in PEL cells. • The activation of Erk signaling is essential for PEL cell survival. • Sangivamycin induces the apoptosis of PEL cells without production of progeny virus. • Sangivamycin may serve as a novel drug for the treatment of PEL. - Abstract: Sangivamycin, a structural analog of adenosine and antibiotic exhibiting antitumor and antivirus activities, inhibits protein kinase C and the synthesis of both DNA and RNA. Primary effusion lymphoma (PEL) is an aggressive neoplasm caused by Kaposi’s sarcoma-associated herpesvirus (KSHV) in immunosuppressed patients and HIV-infected homosexual males. PEL cells are derived from post-germinal center B cells, and are infected with KSHV. Herein, we asked if sangivamycin might be useful to treat PEL. We found that sangivamycin killed PEL cells, and we explored the underlying mechanism. Sangivamycin treatment drastically decreased the viability of PEL cell lines compared to KSHV-uninfected B lymphoma cell lines. Sangivamycin induced the apoptosis of PEL cells by activating caspase-7 and -9. Further, sangivamycin suppressed the phosphorylation of Erk1/2 and Akt, thus inhibiting activation of the proteins. Inhibitors of Akt and MEK suppressed the proliferation of PEL cells compared to KSHV-uninfected cells. It is known that activation of Erk and Akt signaling inhibits apoptosis and promotes proliferation in PEL cells. Our data therefore suggest that sangivamycin induces apoptosis by inhibiting Erk and Akt signaling in such cells. We next investigated whether sangivamycin, in combination with an HSP90 inhibitor geldanamycin (GA) or valproate (valproic acid), potentiated the cytotoxic effects of the latter drugs on PEL cells. Compared to treatment with GA or valproate alone, the addition of sangivamycin enhanced cytotoxic activity. Our data thus indicate that

  16. Sangivamycin induces apoptosis by suppressing Erk signaling in primary effusion lymphoma cells

    International Nuclear Information System (INIS)

    Wakao, Kazufumi; Watanabe, Tadashi; Takadama, Tadatoshi; Ui, Sadaharu; Shigemi, Zenpei; Kagawa, Hiroki; Higashi, Chizuka; Ohga, Rie; Taira, Takahiro; Fujimuro, Masahiro

    2014-01-01

    Highlights: • Sangivamycin induces the apoptosis of B cell lymphoma PEL cells. • Sangivamycin suppresses Erk signaling by inhibiting Erk phosphorylation in PEL cells. • The activation of Erk signaling is essential for PEL cell survival. • Sangivamycin induces the apoptosis of PEL cells without production of progeny virus. • Sangivamycin may serve as a novel drug for the treatment of PEL. - Abstract: Sangivamycin, a structural analog of adenosine and antibiotic exhibiting antitumor and antivirus activities, inhibits protein kinase C and the synthesis of both DNA and RNA. Primary effusion lymphoma (PEL) is an aggressive neoplasm caused by Kaposi’s sarcoma-associated herpesvirus (KSHV) in immunosuppressed patients and HIV-infected homosexual males. PEL cells are derived from post-germinal center B cells, and are infected with KSHV. Herein, we asked if sangivamycin might be useful to treat PEL. We found that sangivamycin killed PEL cells, and we explored the underlying mechanism. Sangivamycin treatment drastically decreased the viability of PEL cell lines compared to KSHV-uninfected B lymphoma cell lines. Sangivamycin induced the apoptosis of PEL cells by activating caspase-7 and -9. Further, sangivamycin suppressed the phosphorylation of Erk1/2 and Akt, thus inhibiting activation of the proteins. Inhibitors of Akt and MEK suppressed the proliferation of PEL cells compared to KSHV-uninfected cells. It is known that activation of Erk and Akt signaling inhibits apoptosis and promotes proliferation in PEL cells. Our data therefore suggest that sangivamycin induces apoptosis by inhibiting Erk and Akt signaling in such cells. We next investigated whether sangivamycin, in combination with an HSP90 inhibitor geldanamycin (GA) or valproate (valproic acid), potentiated the cytotoxic effects of the latter drugs on PEL cells. Compared to treatment with GA or valproate alone, the addition of sangivamycin enhanced cytotoxic activity. Our data thus indicate that

  17. Interferon beta induces apoptosis in nasopharyngeal carcinoma cells via the TRAIL-signaling pathway.

    Science.gov (United States)

    Makowska, Anna; Wahab, Lora; Braunschweig, Till; Kapetanakis, Nikiforos-Ioannis; Vokuhl, Christian; Denecke, Bernd; Shen, Lian; Busson, Pierre; Kontny, Udo

    2018-03-06

    The combination of neoadjuvant chemotherapy, radiochemotherapy, and maintenance therapy with interferon beta (IFNβ) has led to superior results in the treatment of children and adolescents with nasopharyngeal carcinoma (NPC). However, nothing is known about the mechanism of the antitumor activity of IFNβ in NPC. Here, we investigate the role of IFNβ on apoptosis in NPC cells. Six NPC cell lines, one patient-derived NPC xenograft (PDX) and one SV40-transformed nasoepithelial cell line were used. Induction of apoptosis by IFNβ was measured by flow cytometric analysis of subG1-DNA-content, Hoechst 33258 staining and activation of caspase-3. Dissection of death ligand signaling pathways included measuring surface expression of its components by flow cytometry, activation by death ligands and neutralization with specific antibodies and siRNA. IFNβ induced apoptosis at concentrations achievable in humans in five of six NPC cell lines and in PDX cells but not in nasoepithelial cells. Inhibition of caspases-3 and -8 abrogated this effect suggesting IFNβ promoted apoptosis through the extrinsic pathway. IFNβ induced surface expression of TRAIL and TRAIL-R2 and the addition of an anti-TRAIL-antibody or transfection with TRAIL-siRNA blocked IFNβ-induced apoptosis. No induction of TRAIL-expression was noted in the IFNβ-resistant cell line. In conclusion, IFNβ leads to apoptosis in NPC cells in an autocrine way via the induction of TRAIL expression and subsequent activation of the TRAIL-signaling pathway. The mechanism described could at least partly explain the clinical benefit of IFNβ in the treatment of NPC. Further studies in a mouse-xenograft model are warranted to substantiate this effect in vivo .

  18. TGEV nucleocapsid protein induces cell cycle arrest and apoptosis through activation of p53 signaling.

    Science.gov (United States)

    Ding, Li; Huang, Yong; Du, Qian; Dong, Feng; Zhao, Xiaomin; Zhang, Wenlong; Xu, Xingang; Tong, Dewen

    2014-03-07

    Our previous studies showed that TGEV infection could induce cell cycle arrest and apoptosis via activation of p53 signaling in cultured host cells. However, it is unclear which viral gene causes these effects. In this study, we investigated the effects of TGEV nucleocapsid (N) protein on PK-15 cells. We found that TGEV N protein suppressed cell proliferation by causing cell cycle arrest at the S and G2/M phases and apoptosis. Characterization of various cellular proteins that are involved in regulating cell cycle progression demonstrated that the expression of N gene resulted in an accumulation of p53 and p21, which suppressed cyclin B1, cdc2 and cdk2 expression. Moreover, the expression of TGEV N gene promoted translocation of Bax to mitochondria, which in turn caused the release of cytochrome c, followed by activation of caspase-3, resulting in cell apoptosis in the transfected PK-15 cells following cell cycle arrest. Further studies showed that p53 inhibitor attenuated TGEV N protein induced cell cycle arrest at S and G2/M phases and apoptosis through reversing the expression changes of cdc2, cdk2 and cyclin B1 and the translocation changes of Bax and cytochrome c induced by TGEV N protein. Taken together, these results demonstrated that TGEV N protein might play an important role in TGEV infection-induced p53 activation and cell cycle arrest at the S and G2/M phases and apoptosis occurrence. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Apoptosis of bone marrow mesenchymal stem cells caused by homocysteine via activating JNK signal.

    Directory of Open Access Journals (Sweden)

    Benzhi Cai

    Full Text Available Bone marrow mesenchymal stem cells (BMSCs are capable of homing to and repair damaged myocardial tissues. Apoptosis of BMSCs in response to various pathological stimuli leads to the attenuation of healing ability of BMSCs. Plenty of evidence has shown that elevated homocysteine level is a novel independent risk factor of cardiovascular diseases. The present study was aimed to investigate whether homocysteine may induce apoptosis of BMSCs and its underlying mechanisms. Here we uncovered that homocysteine significantly inhibited the cellular viability of BMSCs. Furthermore, TUNEL, AO/EB, Hoechst 333342 and Live/Death staining demonstrated the apoptotic morphological appearance of BMSCs after homocysteine treatment. A distinct increase of ROS level was also observed in homocysteine-treated BMSCs. The blockage of ROS by DMTU and NAC prevented the apoptosis of BMSCs induced by homocysteine, indicating ROS was involved in the apoptosis of BMSCs. Moreover, homocysteine also caused the depolarization of mitochondrial membrane potential of BMSCs. Furthermore, apoptotic appearance and mitochondrial membrane potential depolarization in homocysteine-treated BMSCs was significantly reversed by JNK inhibitor but not p38 MAPK and ERK inhibitors. Western blot also confirmed that p-JNK was significantly activated after exposing BMSCs to homocysteine. Homocysteine treatment caused a significant reduction of BMSCs-secreted VEGF and IGF-1 in the culture medium. Collectively, elevated homocysteine induced the apoptosis of BMSCs via ROS-induced the activation of JNK signal, which provides more insight into the molecular mechanisms of hyperhomocysteinemia-related cardiovascular diseases.

  20. Apoptosis of Bone Marrow Mesenchymal Stem Cells Caused by Homocysteine via Activating JNK Signal

    Science.gov (United States)

    Liu, Yanju; Yang, Fan; Chen, Hongyang; Yin, Kun; Tan, Xueying; Zhu, Jiuxin; Pan, Zhenwei; Wang, Baoqiu; Lu, Yanjie

    2013-01-01

    Bone marrow mesenchymal stem cells (BMSCs) are capable of homing to and repair damaged myocardial tissues. Apoptosis of BMSCs in response to various pathological stimuli leads to the attenuation of healing ability of BMSCs. Plenty of evidence has shown that elevated homocysteine level is a novel independent risk factor of cardiovascular diseases. The present study was aimed to investigate whether homocysteine may induce apoptosis of BMSCs and its underlying mechanisms. Here we uncovered that homocysteine significantly inhibited the cellular viability of BMSCs. Furthermore, TUNEL, AO/EB, Hoechst 333342 and Live/Death staining demonstrated the apoptotic morphological appearance of BMSCs after homocysteine treatment. A distinct increase of ROS level was also observed in homocysteine-treated BMSCs. The blockage of ROS by DMTU and NAC prevented the apoptosis of BMSCs induced by homocysteine, indicating ROS was involved in the apoptosis of BMSCs. Moreover, homocysteine also caused the depolarization of mitochondrial membrane potential of BMSCs. Furthermore, apoptotic appearance and mitochondrial membrane potential depolarization in homocysteine-treated BMSCs was significantly reversed by JNK inhibitor but not p38 MAPK and ERK inhibitors. Western blot also confirmed that p-JNK was significantly activated after exposing BMSCs to homocysteine. Homocysteine treatment caused a significant reduction of BMSCs-secreted VEGF and IGF-1 in the culture medium. Collectively, elevated homocysteine induced the apoptosis of BMSCs via ROS-induced the activation of JNK signal, which provides more insight into the molecular mechanisms of hyperhomocysteinemia-related cardiovascular diseases. PMID:23667638

  1. Transmissible gastroenteritis virus infection induces cell apoptosis via activation of p53 signalling.

    Science.gov (United States)

    Huang, Yong; Ding, Li; Li, Zhaocai; Dai, Meiling; Zhao, Xiaomin; Li, Wei; Du, Qian; Xu, Xingang; Tong, Dewen

    2013-08-01

    Transmissible gastroenteritis virus (TGEV) infection induced apoptosis in several cell lines in vitro. Our previous studies demonstrated that TGEV could activate FasL- and mitochondria-mediated pathways to induce apoptosis in PK-15 cells. In this study, we investigated the regulation of p53 and p38 mitogen-activated protein kinases (MAPK) signalling pathways in the interaction of TGEV with host cells. We observed that TGEV infection decreased p300/CBP, downregulated MDM2 and promoted p53 phosphorylation at serines 15, 20 and 46, resulting in accumulation and activation of p53 in PK-15 cells. TGEV infection induced the transient activation of p38 MAPK in the early phase of inoculation and constant activation in the later phase of infection. However, UV-irradiated TGEV did not promote the activation of p53 and p38 MAPK in the later phase, whereas it only triggered the transient activation of p38 MAPK in the early phase. Blocking of p53 activation significantly inhibited the occurrence of apoptosis through suppressing the TGEV-induced FasL expression, Bcl-2 reduction, Bax and cytochrome c redistribution, while inhibition of p38 activity moderately blocked apoptosis induction and partly attenuated the accumulation and activation of p53. However, inhibition of p38 and p53 activity had no significant effects on viral gene transcription at 12 and 24 h post-infection. Taken together, these results demonstrated that TGEV infection promoted the activation of p38 MAPK and p53 signalling, and p53 signalling might play a dominant role in the regulation of cell apoptosis. These findings provide new insights into the function of p53 and p38 MAPK in the interaction of TGEV with host cells.

  2. Altered Expression of Signaling Genes in Jurkat Cells upon FTY720 Induced Apoptosis

    Directory of Open Access Journals (Sweden)

    Shaoheng He

    2010-09-01

    Full Text Available FTY720, a novel immunosuppressant, has a marked activity in decreasing peripheral blood T lymphocytes upon oral administration. Recent investigations suggest that the action of FTY720 on lymphocytes may result from its ability to induce cell apoptosis. However, the cell signaling mechanism involved in the FTY720-induced cell apoptosis remains unclear. Here we examined the apoptotic signal pathways mediated by FTY720 in Jurkat cells using microarray analysis. The results showed that FTY720 can induce Jurkat cell apoptosis in a dose and time dependent manner as assessed by cell viability, Hoechst 33258 staining, Annexin V binding and DNA fragmentation tests. cDNA microarray analysis showed that 10 µM of FTY720 up-regulated 54 and down-regulated 10 genes in Jurkat cells among the 458 apoptotic genes examined following the 6 h incubation period. At least five-fold increased expression of modulator of apoptosis-1 (MOAP-1, vascular endothelial growth factor (VEGF, tumor necrosis factor receptor-associated factors (TRAF 6, Caspase 2 (CASP 2, E2F transcription factor 1 (E2F 1 and Casapse 5 (CASP 5 genes was observed in microarray analyses; these results were confirmed with reverse transcription polymerase chain reaction (RT-PCR examination. Our findings suggest that the mitochondria related signaling pathways are the key pathways involved in the FTY720-induced apoptosis in Jurkat cells. And our results provide a new insight into the mechanism of FTY720, which allows us to draw the first simple diagram showing the potential pathways mediated by FTY720.

  3. Altered expression of signaling genes in Jurkat cells upon FTY720 induced apoptosis.

    Science.gov (United States)

    Wang, Fang; Tan, Wenfeng; Guo, Dunming; Zhu, Xiaomin; Qian, Keqing; He, Shaoheng

    2010-09-02

    FTY720, a novel immunosuppressant, has a marked activity in decreasing peripheral blood T lymphocytes upon oral administration. Recent investigations suggest that the action of FTY720 on lymphocytes may result from its ability to induce cell apoptosis. However, the cell signaling mechanism involved in the FTY720-induced cell apoptosis remains unclear. Here we examined the apoptotic signal pathways mediated by FTY720 in Jurkat cells using microarray analysis. The results showed that FTY720 can induce Jurkat cell apoptosis in a dose and time dependent manner as assessed by cell viability, Hoechst 33258 staining, Annexin V binding and DNA fragmentation tests. cDNA microarray analysis showed that 10 μM of FTY720 up-regulated 54 and down-regulated 10 genes in Jurkat cells among the 458 apoptotic genes examined following the 6 h incubation period. At least five-fold increased expression of modulator of apoptosis-1 (MOAP-1), vascular endothelial growth factor (VEGF), tumor necrosis factor receptor-associated factors (TRAF 6), Caspase 2 (CASP 2), E2F transcription factor 1 (E2F 1) and Casapse 5 (CASP 5) genes was observed in microarray analyses; these results were confirmed with reverse transcription polymerase chain reaction (RT-PCR) examination. Our findings suggest that the mitochondria related signaling pathways are the key pathways involved in the FTY720-induced apoptosis in Jurkat cells. And our results provide a new insight into the mechanism of FTY720, which allows us to draw the first simple diagram showing the potential pathways mediated by FTY720.

  4. Quinuclidinone derivative 6 induced apoptosis in human breast cancer cells via sphingomyelinase and JNK signaling.

    Science.gov (United States)

    Malki, Ahmed; El Ashry, El Sayed

    2012-10-01

    Novel quinuclidinone derivatives have been previously reported by our laboratory. In this study, we investigated the impact of two novel quinuclidinone derivatives 4 and 6 on apoptotic signaling in breast cancer cells (MCF-7) and their normal counterparts (MCF-12a). Our data revealed that derivatives 4 and 6 reduced proliferation and induced apoptosis in breast cancer cells. However, derivative 6 was less cytotoxic to normal breast epithelial cells than breast cancer cells; therefore, we focused on derivative 6 for further investigation. Flow cytometric analysis showed that quinuclidinone derivative 6 reduced the percentage of MCF-7 cells in G(2)/M which is confirmed by increased expression levels of cyclin B, while it arrests MCF12a in G1 phase judging from increased p21. Quinuclidinone derivative 6 increased expression levels of p53 and Bax at both protein and mRNA levels and reduced expression level of Mdm2, Bcl2, Akt and Bcl-XL It also increased mitochondrial apoptotic pathways by activating release of cytochrome c which is consistent with activation of caspase-9 as confirmed by caspase-9 inhibitor LEHD-CHO. Finally, it increased sphingomyelinase signaling and ceramide formation as well as its downstream targets ERK1/2, p38, and JNK. Inhibition of ERK1/2 with PD98059 exerted little effect on the derivative 6-induced apoptosis and p38 inhibition with SB203580 slightly lessened apoptosis, whereas inhibition of JNK with SP600125 markedly suppressed derivative 6-induced apoptosis. These results indicate that derivative-6 induced the activation of sphingomyelinase signaling and that JNK played a pivotal role in induction of apoptosis in human breast cancer cells. In vivo studies and molecular docking experiments are now in progress for further anticancer investigations.

  5. Taurine inhibits serum deprivation-induced osteoblast apoptosis via the taurine transporter/ERK signaling pathway

    Directory of Open Access Journals (Sweden)

    Lei-Yi Zhang

    2011-07-01

    Full Text Available Taurine has positive effects on bone metabolism. However, the effects of taurine on osteoblast apoptosis in vitro have not been reported. The aim of this study was to investigate the activity of taurine on apoptosis of mouse osteoblastic MC3T3-E1 cells. The data showed that 1, 5, 10, or 20 mM taurine resulted in 16.7, 34.2, 66.9, or 63.75% reduction of MC3T3-E1 cell apoptosis induced by the serum deprivation (serum-free α-MEM, respectively. Taurine (1, 5, or 10 mM also reduced cytochrome c release and inhibited activation of caspase-3 and -9, which were measured using fluorogenic substrates for caspase-3/caspase-9, in serum-deprived MC3T3-E1 cells. Furthermore, taurine (10 mM induced extracellular signal-regulated kinase (ERK phosphorylation in MC3T3-E1 cells. Knockdown of the taurine transporter (TAUT or treatment with the ERK-specific inhibitor PD98059 (10 μM blocked the activation of ERK induced by taurine (10 mM and abolished the anti-apoptotic effect of taurine (10 mM in MC3T3-E1 cells. The present results demonstrate for the first time that taurine inhibits serum deprivation-induced osteoblast apoptosis via the TAUT/ERK signaling pathway.

  6. Are signalized intersections with cycle tracks safer? A case-control study based on automated surrogate safety analysis using video data.

    Science.gov (United States)

    Zangenehpour, Sohail; Strauss, Jillian; Miranda-Moreno, Luis F; Saunier, Nicolas

    2016-01-01

    Cities in North America have been building bicycle infrastructure, in particular cycle tracks, with the intention of promoting urban cycling and improving cyclist safety. These facilities have been built and expanded but very little research has been done to investigate the safety impacts of cycle tracks, in particular at intersections, where cyclists interact with turning motor-vehicles. Some safety research has looked at injury data and most have reached the conclusion that cycle tracks have positive effects of cyclist safety. The objective of this work is to investigate the safety effects of cycle tracks at signalized intersections using a case-control study. For this purpose, a video-based method is proposed for analyzing the post-encroachment time as a surrogate measure of the severity of the interactions between cyclists and turning vehicles travelling in the same direction. Using the city of Montreal as the case study, a sample of intersections with and without cycle tracks on the right and left sides of the road were carefully selected accounting for intersection geometry and traffic volumes. More than 90h of video were collected from 23 intersections and processed to obtain cyclist and motor-vehicle trajectories and interactions. After cyclist and motor-vehicle interactions were defined, ordered logit models with random effects were developed to evaluate the safety effects of cycle tracks at intersections. Based on the extracted data from the recorded videos, it was found that intersection approaches with cycle tracks on the right are safer than intersection approaches with no cycle track. However, intersections with cycle tracks on the left compared to no cycle tracks seem to be significantly safer. Results also identify that the likelihood of a cyclist being involved in a dangerous interaction increases with increasing turning vehicle flow and decreases as the size of the cyclist group arriving at the intersection increases. The results highlight the

  7. Metabolic syndrome impairs notch signaling and promotes apoptosis in chronically ischemic myocardium.

    Science.gov (United States)

    Elmadhun, Nassrene Y; Sabe, Ashraf A; Lassaletta, Antonio D; Chu, Louis M; Kondra, Katelyn; Sturek, Michael; Sellke, Frank W

    2014-09-01

    Impaired angiogenesis is a known consequence of metabolic syndrome (MetS); however, the mechanism is not fully understood. Recent studies have shown that the notch signaling pathway is an integral component of cardiac angiogenesis. We tested, in a clinically relevant swine model, the effects of MetS on notch and apoptosis signaling in chronically ischemic myocardium. Ossabaw swine were fed either a regular diet (control [CTL], n = 8) or a high-cholesterol diet (MetS, n = 8) to induce MetS. An ameroid constrictor was placed to induce chronic myocardial ischemia. Eleven weeks later, the wine underwent cardiac harvest of the ischemic myocardium. Downregulation of pro-angiogenesis proteins notch2, notch4, jagged2, angiopoietin 1, and endothelial nitric oxide synthase were found in the MetS group compared with the CTL group. Also, upregulation of pro-apoptosis protein caspase 8 and downregulation of anti-angiogenesis protein phosphorylated forkhead box transcription factor 03 and pro-survival proteins phosphorylated P38 and heat shock protein 90 were present in the MetS group. Cell death was increased in the MetS group compared with the CTL group. Both CTL and MetS groups had a similar arteriolar count and capillary density, and notch3 and jagged1 were both similarly concentrated in the smooth muscle wall. MetS in chronic myocardial ischemia significantly impairs notch signaling by downregulating notch receptors, ligands, and pro-angiogenesis proteins. MetS also increases apoptosis signaling, decreases survival signaling, and increases cell death in chronically ischemic myocardium. Although short-term angiogenesis appears unaffected in this model of early MetS, the molecular signals for angiogenesis are impaired, suggesting that inhibition of notch signaling might underlie the decreased angiogenesis in later stages of MetS. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  8. The Signaling Cascades of Ginkgolide B-Induced Apoptosis in MCF-7 Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Wen-Hsiung Chan

    2007-11-01

    Full Text Available Ginkgolide B, the major active component of Ginkgo biloba extracts, can bothstimulate and inhibit apoptotic signaling. Here, we demonstrate that ginkgolide B caninduce the production of reactive oxygen species in MCF-7 breast cancer cells, leading toan increase in the intracellular concentrations of cytoplasmic free Ca2+ and nitric oxide(NO, loss of mitochondrial membrane potential (MMP, activation of caspase-9 and -3,and increase the mRNA expression levels of p53 and p21, which are known to be involvedin apoptotic signaling. In addition, prevention of ROS generation by pretreatment withN-acetyl cysteine (NAC could effectively block intracellular Ca2+ concentrationsincreases and apoptosis in ginkgolide B-treated MCF-7 cells. Moreover, pretreatment withnitric oxide (NO scavengers could inhibit ginkgolide B-induced MMP change andsequent apoptotic processes. Overall, our results signify that both ROS and NO playedimportant roles in ginkgolide B-induced apoptosis of MCF-7 cells. Based on these studyresults, we propose a model for ginkgolide B-induced cell apoptosis signaling cascades inMCF-7 cells.

  9. HCV upregulates Bim through the ROS/JNK signalling pathway, leading to Bax-mediated apoptosis.

    Science.gov (United States)

    Deng, Lin; Chen, Ming; Tanaka, Motofumi; Ku, Yonson; Itoh, Tomoo; Shoji, Ikuo; Hotta, Hak

    2015-09-01

    We previously reported that hepatitis C virus (HCV) infection induces Bax-triggered, mitochondrion-mediated apoptosis by using the HCV J6/JFH1 strain and Huh-7.5 cells. However, it was still unclear how HCV-induced Bax activation. In this study, we showed that the HCV-induced activation and mitochondrial accumulation of Bax were significantly attenuated by treatment with a general antioxidant, N-acetyl cysteine (NAC), or a specific c-Jun N-terminal kinase (JNK) inhibitor, SP600125, with the result suggesting that the reactive oxygen species (ROS)/JNK signalling pathway is upstream of Bax activation in HCV-induced apoptosis. We also demonstrated that HCV infection transcriptionally activated the gene for the pro-apoptotic protein Bim and the protein expression of three major splice variants of Bim (BimEL, BimL and BimS). The HCV-induced increase in the Bim mRNA and protein levels was significantly counteracted by treatment with NAC or SP600125, suggesting that the ROS/JNK signalling pathway is involved in Bim upregulation. Moreover, HCV infection led to a marked accumulation of Bim on the mitochondria to facilitate its interaction with Bax. On the other hand, downregulation of Bim by siRNA (small interfering RNA) significantly prevented HCV-mediated activation of Bax and caspase 3. Taken together, these observations suggest that HCV-induced ROS/JNK signalling transcriptionally activates Bim expression, which leads to Bax activation and apoptosis induction.

  10. Role of CD137 signaling in dengue virus-mediated apoptosis

    International Nuclear Information System (INIS)

    Nagila, Amar; Netsawang, Janjuree; Srisawat, Chatchawan; Noisakran, Sansanee; Morchang, Atthapan; Yasamut, Umpa; Puttikhunt, Chunya; Kasinrerk, Watchara

    2011-01-01

    Highlights: → For the first time the role of CD137 in dengue virus (DENV) infection. → Induction of DENV-mediated apoptosis by CD137 signaling. → Sensitization to CD137-mediated apoptosis by dengue virus capsid protein (DENV C). → Nuclear localization of DENV C is required for CD137-mediated apoptosis. -- Abstract: Hepatic dysfunction is a well recognized feature of dengue virus (DENV) infection. However, molecular mechanisms of hepatic injury are still poorly understood. A complex interaction between DENV and the host immune response contributes to DENV-mediated tissue injury. DENV capsid protein (DENV C) physically interacts with the human death domain-associated protein Daxx. A double substitution mutation in DENV C (R85A/K86A) abrogates Daxx interaction, nuclear localization and apoptosis. Therefore we compared the expression of cell death genes between HepG2 cells expressing DENV C and DENV C (R85A/K86A) using a real-time PCR array. Expression of CD137, which is a member of the tumor necrosis factor receptor family, increased significantly in HepG2 cells expressing DENV C compared to HepG2 cells expressing DENV C (R85A/K86A). In addition, CD137-mediated apoptotic activity in HepG2 cells expressing DENV C was significantly increased by anti-CD137 antibody compared to that of HepG2 cells expressing DENV C (R85A/K86A). In DENV-infected HepG2 cells, CD137 mRNA and CD137 positive cells significantly increased and CD137-mediated apoptotic activity was increased by anti-CD137 antibody. This work is the first to demonstrate the contribution of CD137 signaling to DENV-mediated apoptosis.

  11. Role of CD137 signaling in dengue virus-mediated apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Nagila, Amar [Medical Molecular Biology Unit, Office for Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok (Thailand); Department of Biochemistry, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok (Thailand); Netsawang, Janjuree [Faculty of Medical Technology, Rangsit University, Bangkok (Thailand); Srisawat, Chatchawan [Department of Biochemistry, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok (Thailand); Noisakran, Sansanee [Dengue Hemorrhagic Fever Research Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok (Thailand); Medical Biotechnology Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok (Thailand); Morchang, Atthapan; Yasamut, Umpa [Medical Molecular Biology Unit, Office for Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok (Thailand); Department of Immunology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok (Thailand); Puttikhunt, Chunya [Dengue Hemorrhagic Fever Research Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok (Thailand); Medical Biotechnology Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok (Thailand); Kasinrerk, Watchara [Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai (Thailand); Biomedical Technology Research Center, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency at Chiang Mai University, Chiang Mai (Thailand); and others

    2011-07-08

    Highlights: {yields} For the first time the role of CD137 in dengue virus (DENV) infection. {yields} Induction of DENV-mediated apoptosis by CD137 signaling. {yields} Sensitization to CD137-mediated apoptosis by dengue virus capsid protein (DENV C). {yields} Nuclear localization of DENV C is required for CD137-mediated apoptosis. -- Abstract: Hepatic dysfunction is a well recognized feature of dengue virus (DENV) infection. However, molecular mechanisms of hepatic injury are still poorly understood. A complex interaction between DENV and the host immune response contributes to DENV-mediated tissue injury. DENV capsid protein (DENV C) physically interacts with the human death domain-associated protein Daxx. A double substitution mutation in DENV C (R85A/K86A) abrogates Daxx interaction, nuclear localization and apoptosis. Therefore we compared the expression of cell death genes between HepG2 cells expressing DENV C and DENV C (R85A/K86A) using a real-time PCR array. Expression of CD137, which is a member of the tumor necrosis factor receptor family, increased significantly in HepG2 cells expressing DENV C compared to HepG2 cells expressing DENV C (R85A/K86A). In addition, CD137-mediated apoptotic activity in HepG2 cells expressing DENV C was significantly increased by anti-CD137 antibody compared to that of HepG2 cells expressing DENV C (R85A/K86A). In DENV-infected HepG2 cells, CD137 mRNA and CD137 positive cells significantly increased and CD137-mediated apoptotic activity was increased by anti-CD137 antibody. This work is the first to demonstrate the contribution of CD137 signaling to DENV-mediated apoptosis.

  12. Requirement for aspartate-cleaved bid in apoptosis signaling by DNA-damaging anti-cancer regimens

    NARCIS (Netherlands)

    Werner, Arlette B.; Tait, Stephen W. G.; de Vries, Evert; Eldering, Eric; Borst, Jannie

    2004-01-01

    Lymphoid malignancies can escape from DNA-damaging anti-cancer drugs and gamma-radiation by blocking apoptosis-signaling pathways. How these regimens induce apoptosis is incompletely defined, especially in cells with nonfunctional p53. We report here that the BH3-only Bcl-2 family member Bid is

  13. Regulating Axonal Responses to Injury: The Intersection between Signaling Pathways Involved in Axon Myelination and The Inhibition of Axon Regeneration

    Science.gov (United States)

    Rao, Sudheendra N. R.; Pearse, Damien D.

    2016-01-01

    Following spinal cord injury (SCI), a multitude of intrinsic and extrinsic factors adversely affect the gene programs that govern the expression of regeneration-associated genes (RAGs) and the production of a diversity of extracellular matrix molecules (ECM). Insufficient RAG expression in the injured neuron and the presence of inhibitory ECM at the lesion, leads to structural alterations in the axon that perturb the growth machinery, or form an extraneous barrier to axonal regeneration, respectively. Here, the role of myelin, both intact and debris, in antagonizing axon regeneration has been the focus of numerous investigations. These studies have employed antagonizing antibodies and knockout animals to examine how the growth cone of the re-growing axon responds to the presence of myelin and myelin-associated inhibitors (MAIs) within the lesion environment and caudal spinal cord. However, less attention has been placed on how the myelination of the axon after SCI, whether by endogenous glia or exogenously implanted glia, may alter axon regeneration. Here, we examine the intersection between intracellular signaling pathways in neurons and glia that are involved in axon myelination and axon growth, to provide greater insight into how interrogating this complex network of molecular interactions may lead to new therapeutics targeting SCI. PMID:27375427

  14. Ceramides And Stress Signalling Intersect With Autophagic Defects In Neurodegenerative Drosophila blue cheese (bchs) Mutants.

    Science.gov (United States)

    Hebbar, Sarita; Sahoo, Ishtapran; Matysik, Artur; Argudo Garcia, Irene; Osborne, Kathleen Amy; Papan, Cyrus; Torta, Federico; Narayanaswamy, Pradeep; Fun, Xiu Hui; Wenk, Markus R; Shevchenko, Andrej; Schwudke, Dominik; Kraut, Rachel

    2015-12-07

    Sphingolipid metabolites are involved in the regulation of autophagy, a degradative recycling process that is required to prevent neuronal degeneration. Drosophila blue cheese mutants neurodegenerate due to perturbations in autophagic flux, and consequent accumulation of ubiquitinated aggregates. Here, we demonstrate that blue cheese mutant brains exhibit an elevation in total ceramide levels; surprisingly, however, degeneration is ameliorated when the pool of available ceramides is further increased, and exacerbated when ceramide levels are decreased by altering sphingolipid catabolism or blocking de novo synthesis. Exogenous ceramide is seen to accumulate in autophagosomes, which are fewer in number and show less efficient clearance in blue cheese mutant neurons. Sphingolipid metabolism is also shifted away from salvage toward de novo pathways, while pro-growth Akt and MAP pathways are down-regulated, and ER stress is increased. All these defects are reversed under genetic rescue conditions that increase ceramide generation from salvage pathways. This constellation of effects suggests a possible mechanism whereby the observed deficit in a potentially ceramide-releasing autophagic pathway impedes survival signaling and exacerbates neuronal death.

  15. Antimony trioxide-induced apoptosis is dependent on SEK1/JNK signaling.

    Science.gov (United States)

    Mann, Koren K; Davison, Kelly; Colombo, Myrian; Colosimo, April L; Diaz, Zuanel; Padovani, Alessandra M S; Guo, Qi; Scrivens, P James; Gao, Wenli; Mader, Sylvie; Miller, Wilson H

    2006-01-05

    Very little is known concerning the toxicity of antimony, despite its commercial use as a flame retardant and medical use as a treatment for parasitic infections. Our previous studies show that antimony trioxide (Sb(2)O(3)) induces growth inhibition in patient-derived acute promyelocytic leukemia (APL) cell lines, a disease in which a related metal, arsenic trioxide (As(2)O(3)), is used clinically. However, signaling pathways initiated by Sb(2)O(3) treatment remain undefined. Here, we show that Sb(2)O(3) treatment of APL cells is associated with increased apoptosis as well as differentiation markers. Sb(2)O(3)-induced reactive oxygen species (ROS) correlated with increased apoptosis. In addition, when we decreased the buffering capacity of the cell by depleting glutathione, ROS production and apoptosis was enhanced. Arsenic-resistant APL cells with increased glutathione levels exhibited increased cross-resistance to Sb(2)O(3). Based on studies implicating c-jun kinase (JNK) in the mediation of the response to As(2)O(3), we investigated the role for JNK in Sb(2)O(3)-induced apoptosis. Sb(2)O(3) activates JNK and its downstream target, AP-1. In fibroblasts with a genetic deletion in SEK1, an upstream regulator of JNK, Sb(2)O(3)-induced growth inhibition as well as JNK activation was decreased. These data suggest roles for ROS and the SEK1/JNK pathway in the cytotoxicity associated with Sb(2)O(3) exposure.

  16. Cutis laxa: intersection of elastic fiber biogenesis, TGFβ signaling, the secretory pathway and metabolism.

    Science.gov (United States)

    Urban, Zsolt; Davis, Elaine C

    2014-01-01

    Cutis laxa (CL), a disease characterized by redundant and inelastic skin, displays extensive locus heterogeneity. Together with geroderma osteodysplasticum and arterial tortuosity syndrome, which show phenotypic overlap with CL, eleven CL-related genes have been identified to date, which encode proteins within 3 groups. Elastin, fibulin-4, fibulin-5 and latent transforming growth factor-β-binding protein 4 are secreted proteins which form elastic fibers and are involved in the sequestration and subsequent activation of transforming growth factor-β (TGFβ). Proteins within the second group, localized to the secretory pathway, perform transport and membrane trafficking functions necessary for the modification and secretion of elastic fiber components. Key proteins include a subunit of the vacuolar-type proton pump, which ensures the efficient secretion of tropoelastin, the precursor or elastin. A copper transporter is required for the activity of lysyl oxidases, which crosslink collagen and elastin. A Rab6-interacting goglin recruits kinesin motors to Golgi-vesicles facilitating the transport from the Golgi to the plasma membrane. The Rab and Ras interactor 2 regulates the activity of Rab5, a small guanosine triphosphatase essential for the endocytosis of various cell surface receptors, including integrins. Proteins of the third group related to CL perform metabolic functions within the mitochondria, inhibiting the accumulation of reactive oxygen species. Two of these proteins catalyze subsequent steps in the conversion of glutamate to proline. The third transports dehydroascorbate into mitochondria. Recent studies on CL-related proteins highlight the intricate connections among membrane trafficking, metabolism, extracellular matrix assembly, and TGFβ signaling. © 2013 Elsevier B.V. All rights reserved.

  17. Induction of apoptosis in breast cancer cells in vitro by Fas ligand reverse signaling.

    Science.gov (United States)

    Kolben, Thomas; Jeschke, Udo; Reimer, Toralf; Karsten, Nora; Schmoeckel, Elisa; Semmlinger, Anna; Mahner, Sven; Harbeck, Nadia; Kolben, Theresa M

    2018-02-01

    The Fas-antigen is a cell surface receptor that transduces apoptotic signals into cells. The purpose of this study was to evaluate FasL expression in breast cancer and to elucidate the role of its signaling in different breast cancer cell lines. T47D and MCF7 cells were used and cultured in Dulbecco's modified Eagle's medium. FasL translocation to the membrane was achieved by culturing the cells in the presence of human interferon-γ (IFNγ). Translocation was detected by immunofluorescence. The ability of a Fas:Fc fusion protein to trigger apoptosis in these cells was investigated by cell death detection ELISA. After incubation with IFNγ for 4 h and 18 h, apoptosis was assessed in response to treatment with Fas:Fc. Immunofluorescence revealed that the used cell lines were positive for FasL which was increased and changed to more membrane-bound FasL expression after IFNγ stimulation. After stimulation with 50 IU/ml IFNγ, Fas:Fc significantly increased MCF7 apoptosis (1.39 ± 0.06-fold, p = 0.0004) after 18 h. After stimulation with 100 IU/ml, Fas:Fc significantly increased apoptosis both after 4 h (1.49 ± 0.15-fold, p = 0.018) and 18 h (1.30 ± 0.06-fold, p = 0.013). In T47D cells this effect was seen after 4 h of stimulation with 50 IU/ml and addition of Fas:Fc (1.6 ± 0.08-fold, p = 0.03). Membrane-bound FasL expression could be induced by IFNγ in a breast cancer cell model. More importantly, in the presence of IFNγ the Fas:Fc fusion protein was able to transmit pro-apoptotic signals to T47D and MCF7 cells, significantly inducing apoptosis. The current findings support further in vivo studies regarding FasL activation as a potential target for therapeutic intervention in breast cancer.

  18. TRAIL receptor-selective mutants signal to apoptosis via TRAIL-R1 in primary lymphoid malignancies.

    Science.gov (United States)

    MacFarlane, Marion; Kohlhaas, Susan L; Sutcliffe, Michael J; Dyer, Martin J S; Cohen, Gerald M

    2005-12-15

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its agonistic antibodies, which are currently in early clinical trials for treating various malignancies, induce apoptosis through triggering of either TRAIL-R1 or TRAIL-R2. Based on studies using agonistic monoclonal antibodies, we recently proposed that primary chronic lymphocytic leukemic cells seem to signal apoptosis primarily through TRAIL-R1. We have now synthesized mutant forms of TRAIL specific for TRAIL-R1 or TRAIL-R2. The selectivity of these mutants to induce apoptosis in cell lines is due to selective binding to their cognate receptors resulting in apoptosis via formation of a death-inducing signaling complex. Using these mutants, we now unequivocally show that primary cells from patients with chronic lymphocytic leukemia and mantle cell lymphoma signal to apoptosis almost exclusively through TRAIL-R1. Thus, no significant therapeutic benefit can be anticipated from treating such patients with agents currently in clinical trials that signal predominantly through TRAIL-R2, such as HGS-ETR2 or Apo2L/TRAIL. Our study highlights the necessity to determine whether primary cells from a particular tumor signal via TRAIL-R1 or TRAIL-R2. Such information will provide a rational approach to optimize TRAIL therapy.

  19. EGF signalling pathway regulates colon cancer stem cell proliferation and apoptosis.

    Science.gov (United States)

    Feng, Y; Dai, X; Li, X; Wang, H; Liu, J; Zhang, J; Du, Y; Xia, L

    2012-10-01

    Cancer stem cells (CSCs) compose a subpopulation of cells within a tumour that can self-renew and proliferate. Growth factors such as epidermal growth factor (EGF) and basic fibroblast growth factor (b-FGF) promote cancer stem cell proliferation in many solid tumours. This study assesses whether EGF, bFGF and IGF signalling pathways are essential for colon CSC proliferation and self-renewal. Colon CSCs were cultured in serum-free medium (SFM) with one of the following growth factors: EGF, bFGF or IGF. Characteristics of CSC gene expression were evaluated by real time PCR. Tumourigenicity of CSCs was determined using a xenograft model in vivo. Effects of EGF receptor inhibitors, Gefitinib and PD153035, on CSC proliferation, apoptosis and signalling were evaluated using fluorescence-activated cell sorting and western blotting. Colon cancer cell HCT116 transformed to CSCs in SFM. Compared to other growth factors, EGF was essential to support proliferation of CSCs that expressed higher levels of progenitor genes (Musashi-1, LGR5) and lower levels of differential genes (CK20). CSCs promoted more rapid tumour growth than regular cancer cells in xenografts. EGFR inhibitors suppressed proliferation and induced apoptosis of CSCs by inhibiting autophosphorylation of EGFR and downstream signalling proteins, such as Akt kinase, extracellular signal-regulated kinase 1/2 (ERK 1/2). This study indicates that EGF signalling was essential for formation and maintenance of colon CSCs. Inhibition of the EGF signalling pathway may provide a useful strategy for treatment of colon cancer. © 2012 Blackwell Publishing Ltd.

  20. Role of DNA mismatch repair and p53 in signaling induction of apoptosis by alkylating agents

    OpenAIRE

    Hickman, Mark J.; Samson, Leona D.

    1999-01-01

    All cells are unavoidably exposed to chemicals that can alkylate DNA to form genotoxic damage. Among the various DNA lesions formed, O6-alkylguanine lesions can be highly cytotoxic, and we recently demonstrated that O6-methylguanine (O6MeG) and O6-chloroethylguanine (O6CEG) specifically initiate apoptosis in hamster cells. Here we show, in both hamster and human cells, that the MutSα branch of the DNA mismatch repair pathway (but not the MutSβ branch) is absolutely required for signaling the ...

  1. Tempol reduces podocyte apoptosis via PARP signaling pathway in experimental diabetes mellitus.

    Science.gov (United States)

    Peixoto, Elisa B M I; Papadimitriou, Alexandros; Lopes de Faria, Jacqueline M; Lopes de Faria, Jose B

    2012-01-01

    In diabetic hypertensive rats, tempol reduces albuminuria by restoring the redox imbalance. Increased formation of reactive oxygen species leading to activation of poly(ADP-ribose) polymerase (PARP)-1 and podocyte loss by apoptosis contribute to albuminuria in diabetes mellitus (DM). In the present study, we investigated the hypothesis that in DM tempol reduces albuminuria by inhibition of PARP-induced podocyte apoptosis. DM was induced in 4-week-old spontaneously hypertensive rats by streptozotocin. Mouse and human podocyte cell lines were cultured in normal or high-glucose conditions, with or without tempol and/or a PARP-1 inhibitor, PJ34. In diabetic rats, tempol treatment did not affect plasma glucose levels or systolic blood pressure. Albuminuria was higher in diabetic rats, and it was reduced by tempol. DM leads to an elevation of glomerular apoptotic cells and to podocyte loss; both were prevented by tempol treatment. DM increases the expression of poly(ADP-ribose)-modified proteins in isolated glomeruli, and it was reduced by tempol. In vitro, high glucose increased caspase-3 activity and led to a higher number of apoptotic cells that were prevented by tempol and the PARP-1 inhibitor. In DM, tempol reduces albuminuria associated with reduction of podocyte apoptosis and decreasing oxidative stress via PARP signaling. Copyright © 2012 S. Karger AG, Basel.

  2. Hyperoxia accelerates Fas-mediated signaling and apoptosis in the lungs of Legionella pneumophila pneumonia

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    Tanabe Yoshinari

    2011-04-01

    Full Text Available Abstract Background Oxygen supplementation is commonly given to the patients with severe pneumonia including Legionella disease. Recent data suggested that apoptosis may play an important role, not only in the pathogenesis of Legionella pneumonia, but also in oxygen-induced tissue damage. In the present study, the lethal sensitivity to Legionella pneumonia were compared in the setting of hyperoxia between wild-type and Fas-deficient mice. Findings C57BL/6 mice and B6.MRL-Faslpr mice characterized with Fas-deficiency were used in this study. After intratracheal administration of L. pneumophila, mice were kept in hyperoxic conditions (85-90% O2 conc. in an airtight chamber for 3 days. Bone-marrow derived macrophages infected with L. pneumophila were also kept in hyperoxic conditions. Caspase activity and cytokine production were determined by using commercially available kits. Smaller increases of several apoptosis markers, such as caspase-3 and -8, were demonstrated in Fas-deficient mice, even though the bacterial burdens in Fas-deficient and wild type mice were similar. Bone-marrow derived macrophages from Fas-deficient mice were shown to be more resistant to Legionella-induced cytotoxicity than those from wild-type mice under hyperoxia. Conclusions These results demonstrated that Fas-mediated signaling and apoptosis may be a crucial factor in the pathogenesis of Legionella pneumonia in the setting of hyperoxia.

  3. Inhibition of apoptosis signal-regulating kinase 1 enhances endochondral bone formation by increasing chondrocyte survival

    Science.gov (United States)

    Eaton, G J; Zhang, Q-S; Diallo, C; Matsuzawa, A; Ichijo, H; Steinbeck, M J; Freeman, T A

    2014-01-01

    Endochondral ossification is the result of chondrocyte differentiation, hypertrophy, death and replacement by bone. The careful timing and progression of this process is important for normal skeletal bone growth and development, as well as fracture repair. Apoptosis Signal-Regulating Kinase 1 (ASK1) is a mitogen-activated protein kinase (MAPK), which is activated by reactive oxygen species and other cellular stress events. Activation of ASK1 initiates a signaling cascade known to regulate diverse cellular events including cytokine and growth factor signaling, cell cycle regulation, cellular differentiation, hypertrophy, survival and apoptosis. ASK1 is highly expressed in hypertrophic chondrocytes, but the role of ASK1 in skeletal tissues has not been investigated. Herein, we report that ASK1 knockout (KO) mice display alterations in normal growth plate morphology, which include a shorter proliferative zone and a lengthened hypertrophic zone. These changes in growth plate dynamics result in accelerated long bone mineralization and an increased formation of trabecular bone, which can be attributed to an increased resistance of terminally differentiated chondrocytes to undergo cell death. Interestingly, under normal cell culture conditions, mouse embryonic fibroblasts (MEFs) derived from ASK1 KO mice show no differences in either MAPK signaling or osteogenic or chondrogenic differentiation when compared with wild-type (WT) MEFs. However, when cultured with stress activators, H2O2 or staurosporine, the KO cells show enhanced survival, an associated decrease in the activation of proteins involved in death signaling pathways and a reduction in markers of terminal differentiation. Furthermore, in both WT mice treated with the ASK1 inhibitor, NQDI-1, and ASK1 KO mice endochondral bone formation was increased in an ectopic ossification model. These findings highlight a previously unrealized role for ASK1 in regulating endochondral bone formation. Inhibition of ASK1 has

  4. Isocryptotanshinone Induced Apoptosis and Activated MAPK Signaling in Human Breast Cancer MCF-7 Cells.

    Science.gov (United States)

    Zhang, Xuenong; Luo, Weiwei; Zhao, Wenwen; Lu, Jinjian; Chen, Xiuping

    2015-06-01

    Isocryptotanshinone (ICTS) is a natural bioactive product that is isolated from the roots of the widely used medical herb Salvia miltiorrhiza. However, few reports exist on the mechanisms underlying the therapeutic effects of ICTS. Here, we report that ICTS has anticancer activity and describe the mechanism underlying this effect. The antiproliferative effect of ICTS was determined using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and clonogenic assays. The effect of ICTS on the cell cycle was measured using flow cytometry. Apoptosis was determined by Hoechst 33342 staining, DNA fragmentation assays, and Western blotting for apoptotic proteins. Finally, the effect of ICTS on mitogen-activated protein kinases (MAPKs) was determined by Western blotting. ICTS significantly inhibited proliferation of MCF-7 and MDA-MB-231 human breast cancer cells, HepG2 human liver cancer cells, and A549 human lung cancer cells in vitro. Among the tested cell lines, MCF-7 cells showed the highest sensitivity to ICTS. ICTS significantly inhibited colony formation by MCF-7 cells. Furthermore, exposure of MCF-7 cells to ICTS induced cell cycle arrest at the G1 phase and decreased mitochondrial membrane potential. Hoechst 33342 staining and Western blot analysis for apoptotic proteins suggested that ICTS induced apoptosis in MCF-7 cells. In addition, ICTS activated MAPK signaling in MCF-7 cells by inducing time- and concentration-dependent phosphorylation of JNK, ERK, and p38 MAPK. Our results suggest that ICTS inhibited MCF-7 cell proliferation by inducing apoptosis and activating MAPK signaling pathways.

  5. TNF-α- mediated-p38-dependent signaling pathway contributes to myocyte apoptosis in rats subjected to surgical trauma.

    Science.gov (United States)

    Wu, Huaxing; Wang, Guonian; Li, Shuai; Zhang, Mingyue; Li, Hulun; Wang, Kun

    2015-01-01

    The accumulation of cytokines in the plasma after trauma can induce myocyte apoptosis. We aimed to identify which cytokine(s) present in the plasma responsible for myocyte apoptosis, and delineated the signal transduction mechanism in rats subjected to surgical trauma. Rats were randomized into two groups: control and trauma groups, which was divided into five subgroups: posttraumatic 0, 3, 6, 12, and 24 h subgroups. Cardiomyocytes isolated from traumatized rats were incubated with one of the factors for 12 h (normal plasma; Cytomix; TNF-α; IL-1β; IFN-γ; trauma plasma; anti-TNF-α antibody; SB203580). Myocyte apoptosis, cytokine levels, and MAPKs activation, as the primary experimental outcomes, were measured by TUNEL, flow cytometry, ELISA and Western blot, respectively. Myocyte apoptosis was induced by surgical trauma during the early stage after trauma. Accompanying this change, plasma TNF-α, IL-1β, and IFN-γ levels were elevated in traumatized rats. Incubation of traumatized cardiomyocytes with cytomix or TNF-α alone induced myocyte apoptosis, and increased the activation of p38 and ERK1/2. Myocyte apoptosis and p38 activation were elevated in traumatized cardiomyocytes with trauma plasma, and these increases were partly abolished by anti-TNF-α antibody or SB203580. Our study demonstrated that there exists the TNF-α-mediated-p38-dependent signaling pathway that contributed to posttraumatic myocyte apoptosis of rats undergoing surgical trauma. © 2015 S. Karger AG, Basel.

  6. TNF-α- Mediated-p38-Dependent Signaling Pathway Contributes to Myocyte Apoptosis in Rats Subjected to Surgical Trauma

    Directory of Open Access Journals (Sweden)

    Huaxing Wu

    2015-03-01

    Full Text Available Background: The accumulation of cytokines in the plasma after trauma can induce myocyte apoptosis. We aimed to identify which cytokine(s present in the plasma responsible for myocyte apoptosis, and delineated the signal transduction mechanism in rats subjected to surgical trauma. Methods: Rats were randomized into two groups: control and trauma groups, which was divided into five subgroups: posttraumatic 0, 3, 6, 12, and 24 h subgroups. Cardiomyocytes isolated from traumatized rats were incubated with one of the factors for 12 h (normal plasma; Cytomix; TNF-α; IL-1β; IFN-γ; trauma plasma; anti-TNF-α antibody; SB203580. Myocyte apoptosis, cytokine levels, and MAPKs activation, as the primary experimental outcomes, were measured by TUNEL, flow cytometry, ELISA and Western blot, respectively. Results: Myocyte apoptosis was induced by surgical trauma during the early stage after trauma. Accompanying this change, plasma TNF-α, IL-1β, and IFN-γ levels were elevated in traumatized rats. Incubation of traumatized cardiomyocytes with cytomix or TNF-α alone induced myocyte apoptosis, and increased the activation of p38 and ERK1/2. Myocyte apoptosis and p38 activation were elevated in traumatized cardiomyocytes with trauma plasma, and these increases were partly abolished by anti-TNF-α antibody or SB203580. Conclusion: Our study demonstrated that there exists the TNF-α-mediated-p38-dependent signaling pathway that contributed to posttraumatic myocyte apoptosis of rats undergoing surgical trauma.

  7. The role of protein phosphatase 2A in regulating Wnt signaling and apoptosis

    Science.gov (United States)

    Li, Xinghai

    Protein phosphatase 2A (PP2A) is a major serine/threonine-specific phosphatase and regulates a significant array of cellular events. This dissertation primarily describes the novel role of PP2A in Wnt signaling and apoptosis. First, PP2A and its B56 regulatory subunit inhibit Wnt signaling in Xenopus. PP2A is required for β- catenin degradation in vitro. A PP2A heterotrimer containing A, C, and B56 subunits was co- immunoprecipitated with axin. A, C, and B56 subunits each have ventralizing ability in Xenopus embryos. B56 was epistatically positioned downstream of GSK3β and axin but upstream of β-catenin. Second, B56-targeted PP2A is required for survival and protects from apoptosis in Drosophila. Loss of A, C, or B56 subunits by RNA interference (RNAi) induced apoptosis in S2 cells, which requires the presence of specific caspases. Epistasis analysis placed B56-targeted PP2A functionally upstream of Apaf-1, Reaper and Hid, and p53. Loss of B56-targeted PP2A in Drosophila embryos by RNAi resulted in abortion of embryo development and this phenotype was rescued by co-RNAi of Drice. Third, two conserved domains in B subunits mediate binding to the A subunit of PP2A. B subunits have no detectable sequence homology among different families. In vitro expression of a series of B56α fragments identified two distinct domains that independently bound to the A subunit. Sequence alignment of these A subunit-binding domains recognized conserved residues in B/PR55 and B'/PR72 family members that serve a similar function. Fourth, to examine whether the B56β gene within 11q12 is a tumor suppressor mutated in neuroblastoma, the DNA and RNA samples from neuroblastoma patients and cell lines were analyzed and no mutations were identified in the coding regions of the B56β gene. Finally, to identify novel regulatory subunits of PP2A in S. cerevisiae , biochemical approaches for purifying PP2A-associated novel regulators were undertaken. Although the A and C subunit complex in the

  8. Insulin protects against Aβ-induced spatial memory impairment, hippocampal apoptosis and MAPKs signaling disruption.

    Science.gov (United States)

    Ghasemi, Rasoul; Zarifkar, Asadollah; Rastegar, Karim; maghsoudi, Nader; Moosavi, Maryam

    2014-10-01

    Alzheimer disease (AD) is a progressive neurodegenerative disease characterized by extracellular deposits of beta amyloid (Aβ) and neuronal loss particularly in the hippocampus. Accumulating evidences have implied that insulin signaling impairment plays a key role in the pathology of AD; as much as it is considered as type 3 Diabetes. MAPKs are a group of signaling molecules which are involved in pathobiology of AD. Therefore this study was designed to investigate if intrahippocampal insulin hinders Aβ-related memory deterioration, hippocampal apoptosis and MAPKs signaling alteration induced by Aβ. Adult male Sprague-Dawely rats weighing 250-300 g were used in this study. The canules were implanted bilaterally into CA1 region. Aβ25-35 was administered during first 4 days after surgery (5 μg/2.5 μL/daily). Insulin treatment (0.5 or 6 mU) was done during days 4-9. The animal's learning and memory capability was assessed on days 10-13 using Morris water maze. After finishing of behavioral studies the hippocampi was isolated and the amount of hippocampal cleaved caspase 3 (the landmark of apoptosis) and the phosphorylated (activated) forms of P38, JNK and ERK was analyzed by western blot. The results showed that insulin in 6 but not 0.5 mU reversed the memory loss induced by Aβ25-35. Western blot analysis revealed that Aβ25-35 induced elevation of caspase-3 and all 3 MAPks subfamily activity, while insulin in 6 mu restored ERK and P38 activation but has no effect on JNK. This study disclosed that intrahippocampal insulin treatment averts not only Aβ-induced memory deterioration but also hippocampal caspase-3, ERK and P38 activation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Brain apoptosis signaling pathways are regulated by methylphenidate treatment in young and adult rats.

    Science.gov (United States)

    Réus, Gislaine Z; Scaini, Giselli; Jeremias, Gabriela C; Furlanetto, Camila B; Morais, Meline O S; Mello-Santos, Lis Maira; Quevedo, João; Streck, Emilio L

    2014-10-02

    Methylphenidate (MPH) is commonly prescribed for children who have been diagnosed with attention deficit hyperactivity disorder (ADHD); however, the action mechanisms of methylphenidate have not been fully elucidated. Studies have shown a relationship between apoptosis signaling pathways and psychiatric disorders, as well as in therapeutic targets for such disorders. So, we investigated if chronic treatment with MPH at doses of 1, 2 and 10mg/kg could alter the levels of pro-apoptotic protein, Bax, anti-apoptotic protein, Bcl-2, caspase-3 and cytochrome c in the brain of young and adult Wistar rats. Our results showed that MPH at all doses increased Bax in the cortex; the Bcl-2 and caspase-3 were increased with MPH (1mg/kg) and were reduced with MPH (2 and 10mg/kg); the cytochrome c was reduced in the cortex after treatment with MPH at all doses; in the cerebellum there was an increase of Bax with MPH at all doses, however, there was a reduction of Bcl-2, caspase-3, and cytochrome c with MPH (2 and 10mg/kg); in the striatum the treatment with MPH (10mg/kg) decreased caspase-3 and cytochrome c; treatment with MPH (2 and 10mg/kg) increased Bax and decreased Bcl-2 in the hippocampus; and the caspase-3 and cytochrome c were reduced in the hippocampus with MPH (10mg/kg). In conclusion, our results suggest that MPH influences plasticity in the brain of young and adult rats; however, the effects were dependent of age and brain area, on the one hand activating the initial cascade of apoptosis, increasing Bax and reducing Bcl-2, but otherwise inhibiting apoptosis by reduction of caspase-3 and cytochrome c. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. A novel mechanism for p53 to regulate its target gene ECK in signaling apoptosis.

    Science.gov (United States)

    Jin, Y Jenny; Wang, Jianli; Qiao, Changhong; Hei, Tom K; Brandt-Rauf, Paul W; Yin, Yuxin

    2006-10-01

    Transcription factor p53 regulates its target genes through binding to DNA consensus sequence and activating the promoters of its downstream genes. The conventional p53 consensus binding sequence was defined as two copies of the 10-bp motif 5'-PuPuPuC(A/T)(T/A)GPyPyPy-3' with a spacer of 0 to 13 bp, which exists in the regulatory regions of some p53 target genes. However, there is no such p53 consensus sequence in the promoters of a number of p53-responsive genes, suggesting that there might be other mechanisms whereby p53 transactivates the promoters of its target genes. We report here that p53 uses a novel binding mechanism to regulate the transcription of epithelial cell kinase (ECK), a receptor protein-tyrosine kinase implicated in signal transduction. We show that p53 binds to a 10-bp perfect palindromic decanucleotide (GTGACGTCAC) in the ECK promoter, activates the ECK promoter, and increases the transcription of ECK. This palindrome is required for p53-mediated transactivation of the ECK promoter. ECK is highly responsive to oxidative damage that leads to cell death. Ectopic expression of ECK causes spontaneous apoptosis in breast cancer cells. We found that ectopic expression of a mutant ECK fails to induce apoptosis in cancer cells. Our findings show that p53 is a transcriptional regulator of ECK in mediating apoptosis. The discovery of the novel p53-binding motif in the promoter may lead to the identification of a new class of p53 target genes.

  11. Angiotensin-converting enzyme inhibitor captopril prevents activation-induced apoptosis by interfering with T cell activation signals

    Science.gov (United States)

    Odaka, C; Mizuochi, T

    2000-01-01

    Captopril is an orally active inhibitor of angiotensin-converting enzyme (ACE) which is widely used as an anti-hypertensive agent. In addition to its ability to reduce blood pressure, captopril has a number of other biological activities. Recently the drug was shown to inhibit Fas-induced apoptosis in human activated peripheral T cells and human lung epithelial cells. In this study, we investigated whether captopril blocks activation-induced apoptosis in murine T cell hybridomas, and found that captopril inhibited IL-2 synthesis and apoptotic cell death upon activation with anti-CD3 antibody. In addition, captopril inhibited an inducible caspase-3-like activity during activation-induced apoptosis. On the other hand, captopril did not interfere with Fas signalling, since anti-Fas antibody-induced apoptosis in Fas+ Jurkat cells was unaffected by the drug. Furthermore, we examined whether captopril blocks activation-induced apoptosis by interfering with expression of Fas, Fas ligand (FasL), or both on T cell hybridomas. FasL expression on activated T cells was significantly inhibited by captopril, whereas up-expression of Fas was partially inhibited, as assessed by cell surface staining. Taking all data together, we conclude that captopril prevents activation-induced apoptosis in T cell hybridomas by interfering with T cell activation signals. Captopril has been reported to induce systemic lupus erythematosus syndrome, and our findings may be useful for elucidating the mechanism of captopril-induced autoimmunity. PMID:10971519

  12. Itraconazole induces apoptosis and cell cycle arrest via inhibiting Hedgehog signaling in gastric cancer cells.

    Science.gov (United States)

    Hu, Qiang; Hou, Yi-Chao; Huang, Jiao; Fang, Jing-Yuan; Xiong, Hua

    2017-04-11

    Itraconazole has been proved therapeutically effective against a variety of human cancers. This study assessed the effect of itraconazole on the Hedgehog (Hh) pathway and proliferation of human gastric cancer cells. CCK-8 assay and colony formation assay were used to assess the effects of itraconazole on proliferation of gastric cancer cells. The expression of Hh signaling components in gastric cancer cells treated with itraconazole was evaluated by reverse-transcription polymerase chain reaction, immunoblotting and dual luciferase assay. Tumor xenograft models were used to assess the inhibitory effect of itraconazole on the proliferation of gastric cancer cells in vivo. Itraconazole could remarkably inhibit the proliferation of gastric cancer cells. When in combination with 5-FU, itraconazole significantly reduced the proliferation rate of cancer cells. Furthermore, itraconazole could regulate the G 1 -S transition and induce apoptosis of gastric cancer cells. Hh signaling was abnormally activated in human gastric cancer samples. In vitro, studies showed that the expression of glioma-associated zinc finger transcription factor 1 (Gli1) was decreased at both transcriptional and translational levels after treatment with itraconazole. Dual luciferase assay also indicated that itraconazole could inhibit the transcription of Gli1. In vivo studies demonstrated that monotherapy with itraconazole by oral administration could inhibit the growth of xenografts, and that itraconazole could significantly enhance the antitumor efficacy of the chemotherapeutic agent 5-FU. Hh signaling is activated in gastric tumor and itraconazole can inhibit the growth of gastric cancer cells by inhibiting Gli1 expression.

  13. Curcumin Inhibits Apoptosis of Chondrocytes through Activation ERK1/2 Signaling Pathways Induced Autophagy

    Directory of Open Access Journals (Sweden)

    Xiaodong Li

    2017-04-01

    Full Text Available Osteoarthritis (OA is an inflammatory disease of load-bearing synovial joints that is currently treated with drugs that exhibit numerous side effects and are only temporarily effective in treating pain, the main symptom of the disease. Consequently, there is an acute need for novel, safe, and more effective chemotherapeutic agents for the treatment of osteoarthritis and related arthritic diseases. Curcumin, the principal curcuminoid and the most active component in turmeric, is a biologically active phytochemical. Evidence from several recent in vitro studies suggests that curcumin may exert a chondroprotective effect through actions such as anti-inflammatory, anti-oxidative stress, and anti-catabolic activity that are critical for mitigating OA disease pathogenesis and symptoms. In the present study, we investigated the protective mechanisms of curcumin on interleukin 1β (IL-1β-stimulated primary chondrocytes in vitro. The treatment of interleukin (IL-1β significantly reduces the cell viability of chondrocytes in dose and time dependent manners. Co-treatment of curcumin with IL-1β significantly decreased the growth inhibition. We observed that curcumin inhibited IL-1β-induced apoptosis and caspase-3 activation in chondrocytes. Curcumin can increase the expression of phosphorylated extracellular signal-regulated kinases 1/2 (ERK1/2, autophagy marker light chain 3 (LC3-II, and Beclin-1 in chondrocytes. The expression of autophagy markers could be decreased when the chondrocytes were incubated with ERK1/2 inhibitor U0126. Our results suggest that curcumin suppresses apoptosis and inflammatory signaling through its actions on the ERK1/2-induced autophagy in chondrocytes. We propose that curcumin should be explored further for the prophylactic treatment of osteoarthritis in humans and companion animals.

  14. Cisplatin induced apoptosis of ovarian cancer A2780s cells by activation of ERK/p53/PUMA signals.

    Science.gov (United States)

    Song, Hao; Wei, Mei; Liu, Wenfen; Shen, Shulin; Li, Jiaqun; Wang, Liming

    2018-01-01

    Cisplatin (CDDP) is one of the most effective anticancer agents widely used in the treatment of solid tumors, including ovarian cancer. It is generally considered as a cytotoxic drug which kills cancer cells by causing DNA damage, and subsequently inducing apoptosis in cancer cells. However, the underlying mechanisms leading to cell apoptosis remain obscure. In this study, the signaling pathways involved in CDDP-induced apoptosis were examined using CDDP-sensitive ovarian cancer A2780s cells. A2780s cells were treated with CDDP (1.5-3 μg/ml) for 6h, 12h and 24h. Using siRNA targeting P53 and PUMA, and a selective MEK inhibitor, PD98059 to examine the relation between ERK1/2 activation, p53 and PUMA expression after exposure to CDDP, and the effect on CDDP-induced apoptosis. The results shown that treatment of A2780s cells with CDDP (3 μg/ml) for 6-24h induced apoptosis, resulting in the activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and accumulation of p53 and PUMA (p53 upregulated modulator of apoptosis) protein. Knockdown of P53 or PUMA by siRNA transfection blocked CDDP-induced apoptosis. Inhibition of ERK1/2 using PD98059, a selective MEK inhibitor, blocked the apoptotic cell death but prevented CDDP-induced accumulation of p53 and PUMA. Knockdown of P53 by siRNA transfection also blocked CDDP-induced accumulation of PUMA. We therefore concluded that CDDP activated ERK1/2 and induced-p53-dependent PUMA upregulation, resulting in triggering apoptosis in A2780s cells. Our study clearly demonstrates that the ERK1/2/p53/PUMA axis is related to CDDP-induced cell death in A2780s cells.

  15. Fas-Induced Apoptosis of Renal Cell Carcinoma is Mediated by Apoptosis Signal-Regulating Kinase 1 via Mitochondrial Damage-Dependent Caspase-8 Activation

    Directory of Open Access Journals (Sweden)

    Mohamed Hassan

    2009-01-01

    Full Text Available Renal cell carcinoma (RCC is a prototype of a chemo refractory tumour. It remains the most lethal of the common urologic cancers and is highly resistant to conventional therapy. Here, we confirmed the efficiency of anti-Fas monoclonal antibody (CH11 as alternative therapeutic approach for the treatment of RCC and investigated the molecular mechanism(s, whereby CH11 induces apoptosis of RCC cells. The present study shows an essential role for apoptosis signal-regulating kinase 1 (ASK1, together with both c-jun-N-terminal kinase (JNK and p38 pathways, and caspase-8 in this process. Furthermore, CH11-dependent induction of the ASK1–JNK/p38 pathways was found to activate the transcription factors AP-1 and ATF-2, and FADD-caspase-8-Bid signalling, resulting in the translocation of both Bax and Bak proteins, and subsequently mitochondrial dysregulation that is characterized by the loss of mitochondrial membrane potential (ΔΨm, cytochrome c release and cleavage of caspase-9, caspase-3 and PARP. Thus, the described molecular mechanisms of CH11-induced apoptosis suggest the reliability of Fas activation as an alternative therapeutic approach for the treatment of patients with advanced renal cell carcinoma.

  16. Lidocaine induces apoptosis via the mitochondrial pathway independently of death receptor signaling

    NARCIS (Netherlands)

    Werdehausen, Robert; Braun, Sebastian; Essmann, Frank; Schulze-Osthoff, Klaus; Walczak, Henning; Lipfert, Peter; Stevens, Markus F.

    2007-01-01

    BACKGROUND: Local anesthetics, especially lidocaine, can lead to persistent cauda equina syndrome after spinal anesthesia. Recently, lidocaine has been reported to trigger apoptosis, although the underlying mechanisms remain unknown. To elucidate the pathway of lidocaine-induced apoptosis, the

  17. Axin1 up-regulated 1 accelerates stress-induced cardiomyocytes apoptosis through activating Wnt/β-catenin signaling.

    Science.gov (United States)

    Ye, Xing; Lin, Junyi; Lin, Zebin; Xue, Aimin; Li, Liliang; Zhao, Ziqin; Liu, Li; Shen, Yiwen; Cong, Bin

    2017-10-15

    Stress-induced cardiomyocyte apoptosis contributes to the pathogenesis of a variety of cardiovascular diseases, but how stress induces cardiomyocyte apoptosis remains largely unclear. The present study aims to investigate the effects of Axin1 up-regulated 1 (Axud1), a novel pro-apoptotic protein, on the cardiomyocyte survival and the underlying mechanisms. To this end, a rat model under restraint stress (RS) was established and in vitro stress-induced cardiomyocytes culture was achieved. Our data showed that Axud1 was upregulated in the rat myocardia after exposure to RS. Anti-apoptotic Bcl-2 was decreased, whereas pro-apoptotic Bax and Cleaved caspase-3 (Cc3) were increased in a time-dependent manner. The Wnt/β-catenin signaling was observed to be interestingly activated in heart undergoing RS. In addition, the treatment of norepinephrine (NE) to in vitro cardiomyocytes increased Axud1 level and induced cell apoptosis. Wnt/β-catenin signaling was consistently activated. Knockdown of Axud1 using specific siRNA blunted NE-induced cardiomyocytes apoptosis and also inactivated the Wnt/β-catenin signaling. XAV-939, an inhibitor of Wnt/β-catenin signaling, partially reversed the pro-apoptotic effect of NE. In conclusion, Axud1 accelerated stress-induced cardiomyocytes apoptosis through activation of Wnt/β-catenin signaling pathway. Our data provided novel evidence that therapeutic strategies against Axud1 or Wnt/β-catenin signaling might be promising in relation to RS-induced myocardial injury. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Bid integrates intrinsic and extrinsic signaling in apoptosis induced by alpha-tocopheryl succinate in human gastric carcinoma cells

    Czech Academy of Sciences Publication Activity Database

    Zhao, Y.; Li, R.; Xia, W.; Neužil, Jiří; Lu, Y.; Zhang, H.; Zhao, X.; Zhang, X.; Sun, C.; Wu, K.

    2010-01-01

    Roč. 288, č. 1 (2010), s. 42-49 ISSN 0304-3835 R&D Projects: GA ČR(CZ) GA204/08/0811 Institutional research plan: CEZ:AV0Z50520701 Keywords : Alpha-tocopheryl succinate * signaling * apoptosis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.864, year: 2010

  19. Ginkgo biloba exocarp extracts induces apoptosis in Lewis lung cancer cells involving MAPK signaling pathways.

    Science.gov (United States)

    Cao, Chenjie; Su, Ya; Han, Dongdong; Gao, Yanqi; Zhang, Menghua; Chen, Huasheng; Xu, Aihua

    2017-02-23

    A fruit of Ginkgo biloba L. is known as Ginkgo nuts. It is an edible traditional Chinese medicine, and could be used for the treatment of cancer thousands of years ago in China. The extracts prepared from the exocarp of Ginkgo biloba (Ginkgo biloba exocarp extracts, GBEE) has the effects of anti-cancer, immune promotion, anti-aging and etc. To study the effects of GBEE inducing apoptosis in Lewis lung cancer (LLC) cells and the role of Mitogen-activated protein kinase(MAPK) signaling pathways in it. The LLC solid tumor model was established in C57BL/6J mice. The tumor-bearing mice were randomly divided into 5 groups. A normal control group without tumor cells was established additionally. There were 10 mice in each group, and they were dosed 24h after inoculation. The GBEE (50, 100, 200mg/kg b.w.) groups were dosed by intragastric gavage (i.g.). The mice in positive control group were intraperitoneal (i.p.) injected with cyclophosphamide (CPA) at a dose of 20mg/kg (b.w.). The model control group and the normal control group were both given normal saline (NS) by i.g.. All the groups were dosed at a volume of 0.1mL/10g (b.w.), once a day for 18d. The day after the last administration, the transplanted tumors was stripped and weighed, and the inhibition rate was calculated. In vitro experiments, MTT method was applied to detect the effects of GBEE on LLC cells and primary cultured mouse lung cells. Annexin V-FITC/PI method was used to detect the apoptosis rate of LLC cells. Rhodamine 123 method was used to detect the Mitochondrial transmembrane potential (MTP). Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to detect the levels of Fas mRNA. Western Blot was used to detect the expression of Bax, Bcl-2, Cyt C, cleaved Caspase-3 and MAPK proteins in the corresponding parts of LLC cells. GBEE (50-200mg/kg) inhibited the growth of LLC transplanted tumors with a dose-effect relationship. GBEE (5-160µg/mL) inhibited the proliferation of LLC

  20. Endoplasmic reticulum stress and IRE-1 signaling cause apoptosis in colon cancer cells in response to andrographolide treatment.

    Science.gov (United States)

    Banerjee, Aditi; Ahmed, Hafiz; Yang, Peixin; Czinn, Steven J; Blanchard, Thomas G

    2016-07-05

    The plant metabolite andrographolide induces cell cycle arrest and apoptosis in cancer cells. The mechanism(s) by which andrographolide induces apoptosis however, have not been elucidated. The present study was performed to determine the molecular events that promote apoptosis in andrographolide treated cells using T84, HCT116 and COLO 205 colon cancer cell lines. Andrographolide was determined to limit colony formation and Ki67 expression, alter nuclear morphology, increase cytoplasmic histone-associated-DNA-fragments, and increase cleaved caspase-3 levels. Andrographolide also induced significantly higher expression of endoplasmic reticulum (ER) stress proteins GRP-78 and IRE-1 by 48 h but not PERK or ATF6. Apoptosis signaling molecules BAX, spliced XBP-1 and CHOP were also significantly increased. Moreover, chemical inhibition of ER stress or IRE-1 depletion with siRNA in andrographolide treated cells significantly limited expression of IRE-1 and CHOP as determined by immunofluorescence staining, real time PCR, or immunobloting. This was accompanied by a decreased BAX/Bcl-2 ratio. Andrographolide significantly promotes cancer cell death compared to normal cells. These data demonstrate that andrographolide associated ER stress contributes to apoptosis through the activation of a pro-apoptotic GRP-78/IRE-1/XBP-1/CHOP signaling pathway.

  1. Myricitrin Attenuates High Glucose-Induced Apoptosis through Activating Akt-Nrf2 Signaling in H9c2 Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Bin Zhang

    2016-07-01

    Full Text Available Hyperglycemia, as well as diabetes mellitus, has been shown to trigger cardiac cell apoptosis. We have previously demonstrated that myricitrin prevents endothelial cell apoptosis. However, whether myricitrin can attenuate H9c2 cell apoptosis remains unknown. In this study, we established an experiment model in H9c2 cells exposed to high glucose. We tested the hypothesis that myricitrin may inhibit high glucose (HG-induced cardiac cell apoptosis as determined by TUNEL staining. Furthermore, myricitrin promoted antioxidative enzyme production, suppressed high glucose-induced reactive oxygen species (ROS production and decreased mitochondrial membrane potential (MMP in H9c2 cells. This agent significantly inhibited apoptotic protein expression, activated Akt and facilitated the transcription of NF-E2-related factor 2 (Nrf2-mediated protein (heme oxygenase-1 (HO-1 and quinone oxidoreductase 1 (NQO-1 expression as determined by Western blotting. Significantly, an Akt inhibitor (LY294002 or HO-1 inhibitor (ZnPP not only inhibited myricitrin-induced HO-1/NQO-1 upregulation but also alleviated its anti-apoptotic effects. In summary, these observations demonstrate that myricitrin activates Nrf2-mediated anti-oxidant signaling and attenuates H9c2 cell apoptosis induced by high glucose via activation of Akt signaling.

  2. Fas- and Mitochondria-Mediated Signaling Pathway Involved in Osteoblast Apoptosis Induced by AlCl3.

    Science.gov (United States)

    Xu, Feibo; Ren, Limin; Song, Miao; Shao, Bing; Han, Yanfei; Cao, Zheng; Li, Yanfei

    2017-10-12

    Aluminum (Al) is known to induce apoptosis of osteoblasts (OBs). However, the mechanism is not yet established. To investigate the apoptotic mechanism of OBs induced by aluminum trichloride (AlCl 3 ), the primary OBs from the craniums of fetal Wistar rats were exposed to 0 mg/mL (control group, CG), 0.06 mg/mL (low-dose group, LG), 0.12 mg/mL (mid-dose group, MG), and 0.24 mg/mL (high-dose group, HG) AlCl 3 for 24 h, respectively. We observed that AlCl 3 induced OB apoptosis with the appearance of apoptotic morphology and increase of apoptosis rate. Additionally, AlCl 3 treatment activated mitochondrial-mediated signaling pathway, accompanied by mitochondrial membrane potential (ΔΨm) depolarization, release of cytochrome c from the mitochondria to the cytoplasm, as well as survival signal-related factor caspase-9 and caspase-3 activation. AlCl 3 exposure also activated Fas/Fas ligand signaling pathway, presented as Fas, Fas ligand, and Fas-associated death domain expression enhancement and caspase-8 activation, as well as the hydrolysis of Bid to truncated Bid, suggesting that the Fas-mediated signaling pathway might aggravate mitochondria-mediated OB apoptosis through hydrolyzing Bid. Furthermore, AlCl 3 exposure inhibited Bcl-2 protein expression and increased the expressions of Bax, Bak, and Bim in varying degrees. These results indicated that AlCl 3 exposure induced OB apoptosis through activating Fas- and mitochondria-mediated signaling pathway and disrupted B-cell lymphoma-2 family proteins.

  3. The role of Six1 signaling in paclitaxel-dependent apoptosis in MCF-7 cell line

    Directory of Open Access Journals (Sweden)

    Marzieh Armat

    2016-01-01

    Full Text Available The resistance of cancer cells to chemotherapeutic agents represents the main problem in cancer treatment. Despite intensive research, mechanisms of resistance have not yet been fully elucidated. Six1 signaling has an important role in the expansion of progenitor cell populations during early embryogenesis. Six1 gene overexpression has been strongly associated with aggressiveness, invasiveness, and poor prognosis of different cancers. In this study, we investigated the role of Six1 signaling in resistance of MCF-7 breast cancer cells to taxanes. We first established in vitro paclitaxel-resistant MCF-7 breast cancer cells. Morphological modifications in paclitaxel-resistant cells were examined via light microscopic images and fluorescence-activated cell sorting analysis. Applying quantitative real-time polymerase chain reaction, we measured Six1, B-cell lymphoma/leukemia(BCL-2, BAX, and P53 mRNA expression levels in both non-resistant and resistant cells. Resistant cells were developed from the parent MCF-7 cells by applying increasing concentrations of paclitaxel up to 64 nM. The inhibitory concentration 50% value in resistant cells increased from 3.5 ± 0.03 to 511 ± 10.22 nM (p = 0.015. In paclitaxel-resistant cells, there was a significant increase in Six1 and BCL-2 mRNA levels (p = 0.0007 with a marked decrease in pro-apoptotic Bax mRNA expression level (p = 0.03; however, there was no significant change in P53 expression (p = 0.025. Our results suggest that identifying cancer patients with high Six1 expression and then inhibition of Six1 signaling can improve the efficiency of chemotherapeutic agents in the induction of apoptosis.

  4. Stathmin decreases cholangiocarcinoma cell line sensitivity to staurosporine-triggered apoptosis via the induction of ERK and Akt signaling

    Science.gov (United States)

    Bo, Xiaobo; Wang, Yaojie; Wang, Jiwen; Shen, Sheng; Liu, Han; Suo, Tao; Pan, Hongtao; Ai, Zhilong; Liu, Houbao

    2017-01-01

    Cholangiocarcinoma is a rare, but highly fatal malignancy. However, the intrinsic mechanism involved in its tumorigenesis remains obscure. An urgent need remains for a promising target for cholangiocarcinoma biological therapies. Based on comparative proteomical technologies, we found 253 and 231 different spots in gallbladder tumor cell lines and cholangiocarcinoma cell lines, respectively, relative to non-malignant cells. Using Mass Spectrometry (MS) and database searching, we chose seven differentially expressed proteins. High Stathmin expression was found in both cholangiocarcinoma and gallbladder carcinoma cells. Stathmin expression was validated using immunohistochemistry and western blot in cholangiocarcinoma tissue samples and peritumoral tissue. It was further revealed that high Stathmin expression was associated with the repression of staurosporine-induced apoptosis in the cholangiocarcinoma cell. Moreover, we found that Stathmin promoted cancer cell proliferation and inhibited its apoptosis through protein kinase B (Akt) and extracellular signal-regulated kinase (ERK) signaling. Integrin, β1 appears to serve as a partner of Stathmin induction of ERK and Akt signaling by inhibiting apoptosis in the cholangiocarcinoma cell. Understanding the regulation of anti-apoptosis effect by Stathmin might provide new insight into how to overcome therapeutic resistance in cholangiocarcinoma. PMID:28178656

  5. Ghrelin protected neonatal rat cardiomyocyte against hypoxia/reoxygenation injury by inhibiting apoptosis through Akt-mTOR signal.

    Science.gov (United States)

    Wang, Lifeng; Lu, Yingjie; Liu, Xian; Wang, Xiaoyun

    2017-04-01

    Reducing reperfusion period myocardial cell damage is efficient to reduce myocardial ischemia-reperfusion injury. Ghrelin can increase myocardial contractility, improve heart failure caused by myocardial infarction. This study aimed to investigate the protective effect of Ghrelin on myocardial hypoxia/reoxygenation (H/R) injury of neonatal rat cardiomyocytes (NRCMs) and to explore the mechanisms. We isolated the NRCMs, established myocardial H/R model, blocked growth hormone secretagogue receptor (GHSR) by siRNA technique, examined cell activity by MTT and LDH assay, detected apoptosis by Hoechst 33258 staining and flow cytometry and determined the expression levels of apoptosis related proteins and signaling pathway proteins by western blot. We found that Ghrelin can significantly improve cell activity and decrease apoptosis after H/R, however this effect was abolished by GHSR-siRNA. In addition, we found that Ghrelin can significantly increase the expression of Bcl-2 but inhibit the level of Bax and caspase-3. Further mechanism study found that the phosphorylation level of signaling pathway protein Akt and mTOR in Ghrelin treated group were significantly higher than that in other groups. In conclusion, Ghrelin can reduce the H/R damage on NRCMs and inhibit the apoptosis by activating Akt-mTOR signaling pathway.

  6. Development of minimum standards for event-based data collection loggers and performance measure definitions for signalized intersections.

    Science.gov (United States)

    2017-01-01

    The arterial traffic signal performance measures were not used to their fullest potential in the past. The development of traffic signal controllers with event-based, high-resolution data logging capabilities enabled the advances in derivation and vi...

  7. Development of minimum standards for event-based data collection loggers and performance measure definitions for signalized intersections [summary].

    Science.gov (United States)

    2017-01-01

    New traffic signal controllers, which have advanced data collection abilities, offer better information about the response of traffic signal timings to traffic flows. However, traffic engineers need more than raw data. The controllers must be set up ...

  8. Anti-apoptotic signaling and failure of apoptosis in the ischemic rat hippocampus

    DEFF Research Database (Denmark)

    Müller, Georg Johannes; Lassmann, Hans; Johansen, Flemming Fryd

    2007-01-01

    Several anti-apoptotic proteins are induced in CA1 neurons after transient forebrain ischemia (TFI), but fail to protect the majority of these cells from demise. Correlating cell death morphologies (apoptosis-like and necrosis-like death) with immunohistochemistry (IHC), we investigated whether...... anti-apoptosis contributes to survival, compromises apoptosis effector functions and/or delays death in CA1 neurons 1-7 days after TFI. As surrogate markers for bioenergetic failure, the IHC of respiratory chain complex (RCC) subunits was investigated. Dentate granule cell (DGC) apoptosis following...... colchicine injection severed as a reference for classical apoptosis. Heat shock protein 70 (Hsp70), neuronal apoptosis inhibitory protein (NAIP) and manganese superoxide dismutase (MnSOD) were upregulated in the majority of intact CA1 neurons paralleling the occurrence of CA1 neuronal death (days 3...

  9. Endogenous sulfur dioxide regulates hippocampal neuron apoptosis in developing epileptic rats and is associated with the PERK signaling pathway.

    Science.gov (United States)

    Niu, Manman; Han, Ying; Li, Qinrui; Zhang, Jing

    2018-02-05

    Epilepsy is among the most common neurological diseases in children. Recurrent seizures can result in hippocampal damage and seriously impair learning and memory functions in children. However, the mechanisms underlying epilepsy-related brain injury are unclear. Neuronal apoptosis is among the most common neuropathological manifestations of brain injury. Endogenous sulfur dioxide (SO 2 ) has been shown to be involved in seizures and related neuron apoptosis. However, the role of endogenous SO 2 in epilepsy remains unclear. This study assessed whether endogenous SO 2 is involved in epilepsy and its underlying mechanisms. Using a rat epilepsy model induced by an intraperitoneal injection of kainic acid (KA), we found that hippocampal neuron apoptosis was induced in epileptic rats, and the SO 2 content and aspartate aminotransferase (AAT) activity in the plasma were increased compared to those in the control group. However, the inhibition of SO 2 production by l-aspartate-β-hydroxamate (HDX) can subvert this response 72h after an epileptic seizure. No difference in apoptosis was observed 7 d after the epileptic seizure in the KA and KA+HDX groups. The protein expression levels of AAT2, glucose-regulated protein 78 (GRP78), pancreatic eIF2 kinase-like ER kinase (PERK) and phospho-PERK (p-PERK) were remarkably elevated in the hippocampi of the epileptic rats, while the HDX treatment was capable of reversing this process 7 d after the epileptic seizure. These results indicate that the inhibition of endogenous SO 2 production can alleviate neuronal apoptosis and is associated with the PERK signaling pathway during the initial stages after epileptic seizure, but inhibiting SO 2 production only delayed the occurrence of apoptosis and did not prevent neuronal apoptosis in the epileptic rats. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Dickkopf-1 induced apoptosis in human placental choriocarcinoma is independent of canonical Wnt signaling

    International Nuclear Information System (INIS)

    Peng Sha; Miao Chenglin; Li Jing; Fan Xiujun; Cao Yujing; Duan Enkui

    2006-01-01

    Placental choriocarcinoma, a reproductive system carcinoma in women, has about 0.81% occurrence frequency in China, which leads to over 90% lethality due to indistinct pathogenesis and the absence of efficient therapeutic treatment. In the present study, using immunostaining and reverse transcription PCR, we reported that Dickkopf-1 (Dkk-1) is prominently expressed in human cytotrophoblast (CTB) cell, but absent in the human placental choriocarcinoma cell line JAR and JEG3, implicating an unknown correlation between Dkk-1 and carcinogenesis of placental choriocarcinoma. Further, through exogenous introduction of Dkk-1, we found repressed proliferation in JAR and JEG3, induced apoptosis in JAR, and discovered significant tumor suppression effects of Dkk-1 in placental choriocarcinoma. Moreover we found that this function of Dkk-1 is achieved through c-Jun N-terminal kinase (JNK), whereas the canonical Wnt pathway may not have a great role. This discovery is not symphonic to previous functional understanding of Dkk-1, a canonical Wnt signaling antagonist. Together, our data indicate the possible correlation between Dkk-1 and human placental choriocarcinoma and suggest potential applications of Dkk-1 in treatment of human placental choriocarcinomas

  11. Pareto front–based multi-objective real-time traffic signal control model for intersections using particle swarm optimization algorithm

    Directory of Open Access Journals (Sweden)

    Pengpeng Jiao

    2016-08-01

    Full Text Available Real-time traffic control is very important for urban transportation systems. Due to conflicts among different optimization objectives, the existing multi-objective models often convert into single-objective problems through weighted sum method. To obtain real-time signal parameters and evaluation indices, this article puts forward a Pareto front–based multi-objective traffic signal control model using particle swarm optimization algorithm. The article first formulates a control model for intersections based on detected real-time link volumes, with minimum delay time, minimum number of stops, and maximum effective capacity as three objectives. Moreover, this article designs a step-by-step particle swarm optimization algorithm based on Pareto front for solution. Pareto dominance relation and density distance are employed for ranking, tournament selection is used to select and weed out particles, and Pareto front for the signal timing plan is then obtained, including time-varying cycle length and split. Finally, based on actual survey data, scenario analyses determine the optimal parameters of the particle swarm algorithm, comparisons with the current situation and existing models demonstrate the excellent performances, and the experiments incorporating outliers in the input data or total failure of detectors further prove the robustness. Generally, the proposed methodology is effective and robust enough for real-time traffic signal control.

  12. Annonacin Exerts Antitumor Activity through Induction of Apoptosis and Extracellular Signal-regulated Kinase Inhibition.

    Science.gov (United States)

    Yap, Chee Voon; Subramaniam, Kavita S; Khor, Sik Wey; Chung, Ivy

    2017-01-01

    Endometrial cancer (EC) is the most common gynecologic malignancy in developed countries. Annonacin, a natural pure compound extracted from the seeds of Annona muricata , is a potential alternative therapeutic agent to treat EC. To study the antitumor activity of annonacin and its mechanism of action in EC cells (ECCs). Viability of ECCs treated with annonacin for 72 h was determined using methyl thiazolyl tetrazolium assay. The induction of cell cycle arrest and apoptotic cell death was evaluated using propidium iodide and annexin V-PE/7-AAD assay, respectively. DNA strand breaks were visualized using transferase dUTP nick end labeling assay, and the effects of annonacin on survival signaling were determined using western blotting. Annonacin exhibited antiproliferative effects on EC cell lines (ECC-1 and HEC-1A) and primary cells (EC6-ept and EC14-ept) with EC 50 values ranging from 4.62 to 4.92 μg/ml. EC cells were shown arrested at G2/M phase after treated with 4 μg/ml of annonacin for 72 h. This led to a significant increase in apoptotic cell death (65.7%) in these cells when compared to vehicle-treated cells ( P cancer cells. Annonacin exerted antiproliferation effects on both endometrial cancer cell lines and primary cells via induction of apoptosis and inhibition of extracellular signal-regulated kinase. Our data represented that annonacin could be an alternative therapeutic treatment to combat endometrial cancer. Abbreviations Used: 7-AAD: 7-Amino-Actinomycin, ATP: Adenosine diphosphate, BSA: Bovine serum albumin, DNA: Deoxyribonucleic acid, EC: Endometrial cancer, ECC-1: Endometrial cancer cell-1, EC50: Half maximal effective concentration, Ept: Epithelial, FBS: Fetal bovine serum, HEC-1A: Human endometrial carcinoma-1A, MTT: Methyl thiazolyl tetrazolium, NaCl: Sodium chloride, NADH: Nicotinamide adenine dinucleotide, RPMI 1640: Roswell Park Memorial Institute Medium, SDS: Sodium dodecyl sulfate.

  13. Intersecting Attractors

    CERN Document Server

    Ferrara, S; Morales, J F; Samtleben, H

    2009-01-01

    We apply the entropy formalism to the study of the near-horizon geometry of extremal black p-brane intersections in D>5 dimensional supergravities. The scalar flow towards the horizon is described in terms an effective potential given by the superposition of the kinetic energies of all the forms under which the brane is charged. At the horizon active scalars get fixed to the minima of the effective potential and the entropy function is given in terms of U-duality invariants built entirely out of the black p-brane charges. The resulting entropy function reproduces the central charges of the dual boundary CFT and gives rise to a Bekenstein-Hawking like area law. The results are illustrated in the case of black holes and black string intersections in D=6, 7, 8 supergravities where the effective potentials, attractor equations, moduli spaces and entropy/central charges are worked out in full detail.

  14. Arctigenin promotes apoptosis in ovarian cancer cells via the iNOS/NO/STAT3/survivin signalling.

    Science.gov (United States)

    Huang, Ke; Li, Li-an; Meng, Yuan-guang; You, Yan-qin; Fu, Xiao-yu; Song, Lei

    2014-12-01

    Arctigenin is a biologically active lignan extracted from the seeds of Arctium lappa and shows anticancer activity against a variety of human cancers. The aim of this study was to determine the effects of arctigenin on ovarian cancer cell proliferation and survival and associated molecular mechanisms. Human ovarian cancer OVCAR3 and SKOV3 cells were treated with arctigenin, and cell proliferation and apoptosis were assessed. Western blot analysis was used to examine signal transducer and activator of transcription-3 (STAT3) phosphorylation and survivin and inducible nitric oxide synthase (iNOS) expression. The involvement of STAT3/survivin/iNOS/NO signalling in arctigenin action was checked. Arctigenin treatment resulted in a significant and dose-dependent inhibition of cell proliferation. Arctigenin-treated cells showed a 4-6 times increase in the percentage of apoptosis, compared with control cells. Pre-treatment with Ac-DEVD-CHO, a specific inhibitor of caspase-3, counteracted the induction of apoptosis by arctigenin. Arctigenin treatment significantly inhibited STAT3 phosphorylation and survivin and iNOS expression. Arctigenin-induced apoptosis was impaired by pre-transfection with survivin-expressing plasmid or addition of chemical nitric oxide (NO) donors. Additionally, exogenous NO prevented the suppression of STAT3 phosphorylation and survivin expression by arctigenin. Arctigenin treatment inhibits the proliferation and induces caspase-3-dependent apoptosis of ovarian cancer cells. Suppression of iNOS/NO/STAT3/survivin signalling is causally linked to the anticancer activity of arctigenin. Therefore, arctigenin may be applicable to anticancer therapy for ovarian cancer. © 2014 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  15. Cadmium-induced apoptosis in primary rat cerebral cortical neurons culture is mediated by a calcium signaling pathway.

    Directory of Open Access Journals (Sweden)

    Yan Yuan

    Full Text Available Cadmium (Cd is an extremely toxic metal, capable of severely damaging several organs, including the brain. Studies have shown that Cd disrupts intracellular free calcium ([Ca(2+]i homeostasis, leading to apoptosis in a variety of cells including primary murine neurons. Calcium is a ubiquitous intracellular ion which acts as a signaling mediator in numerous cellular processes including cell proliferation, differentiation, and survival/death. However, little is known about the role of calcium signaling in Cd-induced apoptosis in neuronal cells. Thus we investigated the role of calcium signaling in Cd-induced apoptosis in primary rat cerebral cortical neurons. Consistent with known toxic properties of Cd, exposure of cerebral cortical neurons to Cd caused morphological changes indicative of apoptosis and cell death. It also induced elevation of [Ca(2+]i and inhibition of Na(+/K(+-ATPase and Ca(2+/Mg(2+-ATPase activities. This Cd-induced elevation of [Ca(2+]i was suppressed by an IP3R inhibitor, 2-APB, suggesting that ER-regulated Ca(2+ is involved. In addition, we observed elevation of reactive oxygen species (ROS levels, dysfunction of cytochrome oxidase subunits (COX-I/II/III, depletion of mitochondrial membrane potential (ΔΨm, and cleavage of caspase-9, caspase-3 and poly (ADP-ribose polymerase (PARP during Cd exposure. Z-VAD-fmk, a pan caspase inhibitor, partially prevented Cd-induced apoptosis and cell death. Interestingly, apoptosis, cell death and these cellular events induced by Cd were blocked by BAPTA-AM, a specific intracellular Ca(2+ chelator. Furthermore, western blot analysis revealed an up-regulated expression of Bcl-2 and down-regulated expression of Bax. However, these were not blocked by BAPTA-AM. Thus Cd toxicity is in part due to its disruption of intracellular Ca(2+ homeostasis, by compromising ATPases activities and ER-regulated Ca(2+, and this elevation in Ca(2+ triggers the activation of the Ca(2+-mitochondria apoptotic

  16. Comparative analysis of driver's brake perception-reaction time at signalized intersections with and without countdown timer using parametric duration models.

    Science.gov (United States)

    Fu, Chuanyun; Zhang, Yaping; Bie, Yiming; Hu, Liwei

    2016-10-01

    Countdown timers display the time left on the current signal, which makes drivers be more ready to react to the phase change. However, previous related studies have rarely explored the effects of countdown timer on driver's brake perception-reaction time (BPRT) to yellow light. The goal of this study was therefore to characterize and model driver's BPRT to yellow signal at signalized intersections with and without countdown timer. BPRT data for "first-to-stop" vehicles after yellow onset within the transitional zone were collected through on-site observation at six signalized intersections in Harbin, China. Statistical analysis showed that the observed 15th, 50th, and 85th percentile BPRTs without countdown timer were 0.52, 0.84, and 1.26s, respectively. The observed 15th, 50th, and 85th percentile BPRTs with countdown timer were 0.32, 1.20, and 2.52s, respectively. Log-logistic distribution appeared to best fit the BPRT without countdown timer, while Weibull distribution seemed to best fit the BPRT with countdown timer. After that, a Log-logistic accelerated failure time (AFT) duration model was developed to model driver's BPRT without countdown timer, whereas a Weibull AFT duration model was established to model driver's BPRT with countdown timer. Three significant factors affecting the BPRT identified in both AFT models included yellow-onset distance from the stop line, yellow-onset approach speed, and deceleration rate. No matter whether the presence of countdown timer or not, BPRT increased as yellow-onset distance to the stop line or deceleration rate increased, but decreased as yellow-onset speed increased. The impairment of driver's BPRT due to countdown timer appeared to increase with yellow-onset distance to the stop line or deceleration rate, but decrease with yellow-onset speed. An increase in driver's BPRT because of countdown timer may induce risky driving behaviors (i.e., stop abruptly, or even violate traffic signal), revealing a weakness of

  17. Perturbation of Hoxb5 signaling in vagal and trunk neural crest cells causes apoptosis and neurocristopathies in mice.

    Science.gov (United States)

    Kam, M K M; Cheung, M C H; Zhu, J J; Cheng, W W C; Sat, E W Y; Tam, P K H; Lui, V C H

    2014-02-01

    Neural crest cells (NCCs) migrate from different regions along the anterior-posterior axis of the neural tube (NT) to form different structures. Defective NCC development causes congenital neurocristopathies affecting multiple NCC-derived tissues in human. Perturbed Hoxb5 signaling in vagal NCC causes enteric nervous system (ENS) defects. This study aims to further investigate if perturbed Hoxb5 signaling in trunk NCC contributes to defects of other NCC-derived tissues besides the ENS. We perturbed Hoxb5 signaling in NCC from the entire NT, and investigated its impact in the development of tissues derived from these cells in mice. Perturbation of Hoxb5 signaling in these NCC resulted in Sox9 downregulation, NCC apoptosis, hypoplastic sympathetic and dorsal root ganglia, hypopigmentation and ENS defects. Mutant mice with NCC-specific Sox9 deletion also displayed some of these phenotypes. In vitro and in vivo assays indicated that the Sox9 promoter was bound and trans-activated by Hoxb5. In ovo studies further revealed that Sox9 alleviated apoptosis induced by perturbed Hoxb5 signaling, and Hoxb5 induced ectopic Sox9 expression in chick NT. This study demonstrates that Hoxb5 regulates Sox9 expression in NCC and disruption of this signaling causes Sox9 downregulation, NCC apoptosis and multiple NCC-developmental defects. Phenotypes such as ENS deficiency, hypopigmentation and some of the neurological defects are reported in patients with Hirschsprung disease (HSCR). Whether dysregulation of Hoxb5 signaling and early depletion of NCC contribute to ENS defect and other neurocristopathies in HSCR patients deserves further investigation.

  18. Notch signaling is significantly suppressed in basal cell carcinomas and activation induces basal cell carcinoma cell apoptosis.

    Science.gov (United States)

    Shi, Feng-Tao; Yu, Mei; Zloty, David; Bell, Robert H; Wang, Eddy; Akhoundsadegh, Noushin; Leung, Gigi; Haegert, Anne; Carr, Nicholas; Shapiro, Jerry; McElwee, Kevin J

    2017-04-01

    A subset of basal cell carcinomas (BCCs) are directly derived from hair follicles (HFs). In some respects, HFs can be defined as 'ordered' skin appendage growths, while BCCs can be regarded as 'disordered' skin appendage growths. The aim of the present study was to examine HFs and BCCs to define the expression of common and unique signaling pathways in each skin appendage. Human nodular BCCs, along with HFs and non‑follicular skin epithelium from normal individuals, were examined using microarrays, qPCR, and immunohistochemistry. Subsequently, BCC cells and root sheath keratinocyte cells from HFs were cultured and treated with Notch signaling peptide Jagged1 (JAG1). Gene expression, protein levels, and cell apoptosis susceptibility were assessed using qPCR, immunoblotting, and flow cytometry, respectively. Specific molecular mechanisms were found to be involved in the process of cell self‑renewal in the HFs and BCCs, including Notch and Hedgehog signaling pathways. However, several key Notch signaling factors showed significant differential expression in BCCs compared with HFs. Stimulating Notch signaling with JAG1 induced apoptosis of BCC cells by increasing Fas ligand expression and downstream caspase-8 activation. The present study showed that Notch signaling pathway activity is suppressed in BCCs, and is highly expressed in HFs. Elements of the Notch pathway could, therefore, represent targets for the treatment of BCCs and potentially in hair follicle engineering.

  19. Star-PAP Control of BIK Expression and Apoptosis Is Regulated by Nuclear PIPKIα and PKCδ Signaling

    Science.gov (United States)

    Li, Weimin; Laishram, Rakesh S.; Ji, Zhe; Barlow, Christy A.; Tian, Bin; Anderson, Richard A.

    2012-01-01

    SUMMARY BIK protein is an initiator of mitochondrial apoptosis and BIK expression is induced by pro-apoptotic signals including DNA damage. Here we demonstrate that 3′-end processing and expression of BIK mRNA are controlled by the nuclear PI4,5P2-regulated poly(A) polymerase Star-PAP downstream of DNA damage. Nuclear PKCδ is a key mediator of apoptosis and DNA damage stimulates PKCδ association with the Star-PAP complex where PKCδ is required for Star-PAP-dependent BIK expression. PKCδ binds the PI4,5P2-generating enzyme PIPKIα, which is essential for PKCδ interaction with the Star-PAP complex and PKCδ activity is directly stimulated by PI4,5P2. Features in the BIK 3′-UTR uniquely define Star-PAP specificity and may block canonical PAP activity toward BIK mRNA. This reveals a nuclear phosphoinositide signaling nexus where PIPKIα, PI4,5P2 and PKCδ regulate Star-PAP control of BIK expression and induction of apoptosis. This pathway is distinct from the Star-PAP-mediated oxidative stress pathway indicating signal-specific regulation of mRNA 3′-end processing. PMID:22244330

  20. Micropterus salmoides rhabdovirus (MSRV) infection induced apoptosis and activated interferon signaling pathway in largemouth bass skin cells.

    Science.gov (United States)

    Gao, E-Bin; Chen, Guifang

    2018-03-03

    Largemouth bass (Micropterus salmoides) rhabdovirus (MSRV) was isolated from infected juveniles of largemouth bass, and the infected fish exhibited corkscrew, irregular swimming, and crooked body. To our knowledge, the potential molecular mechanisms underlying the pathogenesis of MSRV infection remain largely unknown. In the current study, we found that MSRV infection in largemouth bass skin (LBS) cells induced typical apoptosis, evidenced by the presence of apoptotic bodies and caspase-3 activation. To further analyze the host factors involved in MSRV infection in LBS cells, the transcriptomic profiles during MSRV infection were uncovered using deep RNA sequencing technique, and several differentially expressed genes (DEGs) were validated by quantitative PCR. Our results showed that a total of 124483 unigenes were assembled. Among them, 34465 and 27273 had significant hits to those in the NR and SwissProt databases. After MSRV infection, a total of 2432 and 2480 genes which involved in multiples pathways including TNF signaling, NF-κB signaling, Toll-like receptor signaling and RIG-I signaling pathway were differentially expressed in MSRV infected LBS cells compared to mock-infected cells at 12 h, respectively. Furthermore, quantitative PCR showed that the expression levels of 9 differentially expressed genes (DEGs) related to apoptosis and interferon signaling pathway was consistent with that from transcriptomic profiles. Together, our results not only demonstrated that interferon signaling pathway and apoptosis pathway might exerted crucial roles during MSRV infection, but also provided a useful resource for subsequent investigation of other immune-related genes related to virus infection. Copyright © 2018. Published by Elsevier Ltd.

  1. Syndecan-1-dependent suppression of PDK1/Akt/bad signaling by docosahexaenoic acid induces apoptosis in prostate cancer.

    Science.gov (United States)

    Hu, Yunping; Sun, Haiguo; Owens, Rick T; Gu, Zhennan; Wu, Jansheng; Chen, Yong Q; O'Flaherty, Joseph T; Edwards, Iris J

    2010-10-01

    Evidence indicates that diets enriched in n-3 polyunsaturated fatty acids (n-3 PUFAs) reduce the risk of prostate cancer, but biochemical mechanisms are unclear. Syndecan-1 (SDC-1), a transmembrane heparan sulfate proteoglycan, supports the integrity of the epithelial compartment. In tumor cells of epithelial lineage, SDC-1 is generally downregulated. This may result in perturbation of homeostasis and lead to progression of malignancy. Our studies have shown that the n-3 PUFA species, docosahexaenoic acid (DHA), increases SDC-1 expression in prostate tissues of Pten knockout (Pten(P-/-)) mice/cells and human prostate cancer cells. We have now determined that DHA-mediated up-regulation of SDC-1 induces apoptosis. Bovine serum albumin-bound DHA and exogenous human recombinant SDC-1 ecotodomain were delivered to PC3 and LNCaP cells in the presence or absence of SDC-1 small interfering (si)RNA. In the presence of control siRNA, both DHA and SDC-1 ectodomain induced apoptosis, whereas SDC-1 silencing blocked DHA-induced but not SDC-1 ectodomain-induced apoptosis. Downstream effectors of SDC-1 signaling linked to n-3 PUFA-induced apoptosis involved the 3'-phosphoinositide-dependent kinase 1 (PDK1)/Akt/Bad integrating network. A diet enriched in n-3 PUFA decreased phosphorylation of PDK1, Akt (T308), and Bad in prostates of Pten(P-/-) mice. Similar results were observed in human prostate cancer cells in response to DHA and SDC-1 ectodomain. The effect of DHA on PDK1/Akt/Bad signaling was abrogated by SDC-1 siRNA. These findings define a mechanism by which SDC-1-dependent suppression of phosphorylation of PDK1/Akt/Bad mediates n-3 PUFA-induced apoptosis in prostate cancer.

  2. Growth Factor Receptors and Apoptosis Regulators: Signaling Pathways, Prognosis, Chemosensitivity and Treatment Outcomes of Breast Cancer

    Directory of Open Access Journals (Sweden)

    Siddik Sarkar

    2009-01-01

    Full Text Available Biomarkers of breast cancer are necessary for prognosis and prediction to chemotherapy. Prognostic biomarkers provide information regarding outcome irrespective of therapy, while predictive biomarkers provide information regarding response to therapy. Candidate prognostic biomarkers for breast cancers are growth factor receptors, steroid receptors, Ki-67, cyclins, urokinase plasminogen activator, p53, p21, pro- and anti-apoptotic factors, BRCA1 and BRCA2. But currently, the predictive markers are Estrogen and Progesterone receptors responding to endocrine therapy, and HER-2 responding to herceptin. But there are numerous breast cancer cases, where tamoxifen is ineffective even after estrogen receptor positivity. This lead to search of new prognostic and predictive markers and the number of potential markers is constantly increasing due to proteomics and genomics studies. However, most biomarkers individually have poor sensitivity or specificity, or other clinical value. It can be resolved by studying various biomarkers simultaneously, which will help in better prognosis and increasing sensitivity for chemotherapeutic agents. This review is focusing on growth factor receptors, apoptosis markers, signaling cascades, and their correlation with other associated biomarkers in breast cancers. As our knowledge regarding molecular biomarkers for breast cancer increases, prognostic indices will be developed that combine the predictive power of individual molecular biomarkers with specific clinical and pathologic factors. Rigorous comparison of these existing as well as emerging markers with current treatment selection is likely to see an escalation in an era of personalized medicines to ensure the breast cancer patients receive optimal treatment. This will also solve the treatment modalities and complications related to chemotherapeutic regimens.

  3. Lymphotropic Virions Affect Chemokine Receptor-Mediated Neural Signaling and Apoptosis: Implications for Human Immunodeficiency Virus Type 1-Associated Dementia

    Science.gov (United States)

    Zheng, Jialin; Ghorpade, Anuja; Niemann, Douglas; Cotter, Robin L.; Thylin, Michael R.; Epstein, Leon; Swartz, Jennifer M.; Shepard, Robin B.; Liu, Xiaojuan; Nukuna, Adeline; Gendelman, Howard E.

    1999-01-01

    Chemokine receptors pivotal for human immunodeficiency virus type 1 (HIV-1) infection in lymphocytes and macrophages (CCR3, CCR5, and CXCR4) are expressed on neural cells (microglia, astrocytes, and/or neurons). It is these cells which are damaged during progressive HIV-1 infection of the central nervous system. We theorize that viral coreceptors could effect neural cell damage during HIV-1-associated dementia (HAD) without simultaneously affecting viral replication. To these ends, we studied the ability of diverse viral strains to affect intracellular signaling and apoptosis of neurons, astrocytes, and monocyte-derived macrophages. Inhibition of cyclic AMP, activation of inositol 1,4,5-trisphosphate, and apoptosis were induced by diverse HIV-1 strains, principally in neurons. Virions from T-cell-tropic (T-tropic) strains (MN, IIIB, and Lai) produced the most significant alterations in signaling of neurons and astrocytes. The HIV-1 envelope glycoprotein, gp120, induced markedly less neural damage than purified virions. Macrophage-tropic (M-tropic) strains (ADA, JR-FL, Bal, MS-CSF, and DJV) produced the least neural damage, while 89.6, a dual-tropic HIV-1 strain, elicited intermediate neural cell damage. All T-tropic strain-mediated neuronal impairments were blocked by the CXCR4 antibody, 12G5. In contrast, the M-tropic strains were only partially blocked by 12G5. CXCR4-mediated neuronal apoptosis was confirmed in pure populations of rat cerebellar granule neurons and was blocked by HA1004, an inhibitor of calcium/calmodulin-dependent protein kinase II, protein kinase A, and protein kinase C. Taken together, these results suggest that progeny HIV-1 virions can influence neuronal signal transduction and apoptosis. This process occurs, in part, through CXCR4 and is independent of CD4 binding. T-tropic viruses that traffic in and out of the brain during progressive HIV-1 disease may play an important role in HAD neuropathogenesis. PMID:10482576

  4. d,l-Sulforaphane Induces ROS-Dependent Apoptosis in Human Gliomablastoma Cells by Inactivating STAT3 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Ziwei Miao

    2017-01-01

    Full Text Available d,l-Sulforaphane (SFN, a synthetic analogue of broccoli-derived isomer l-SFN, exerts cytotoxic effects on multiple tumor cell types through different mechanisms and is more potent than the l-isomer at inhibiting cancer growth. However, the means by which SFN impairs glioblastoma (GBM cells remains poorly understood. In this study, we investigated the anti-cancer effect of SFN in GBM cells and determined the underlying molecular mechanisms. Cell viability assays, flow cytometry, immunofluorescence, and Western blot results revealed that SFN could induced apoptosis of GBM cells in a dose- and time-dependent manner, via up-regulation of caspase-3 and Bax, and down-regulation of Bcl-2. Mechanistically, SFN treatment led to increase the intracellular reactive oxygen species (ROS level in GBM cells. Meanwhile, SFN also suppressed both constitutive and IL-6-induced phosphorylation of STAT3, and the activation of upstream JAK2 and Src tyrosine kinases, dose- and time-dependently. Moreover, blockage of ROS production by using the ROS inhibitor N-acetyl-l-cysteine totally reversed SFN-mediated down-regulation of JAK2/Src-STAT3 signaling activation and the subsequent effects on apoptosis by blocking the induction of apoptosis-related genes in GBM cells. Taken together, our data suggests that SFN induces apoptosis in GBM cells via ROS-dependent inactivation of STAT3 phosphorylation. These findings motivate further evaluation of SFN as a cancer chemopreventive agent in GBM treatment.

  5. Nur77 inhibits oxLDL induced apoptosis of macrophages via the p38 MAPK signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Qin; Han, Fei; Peng, Shi; He, Ben, E-mail: heben@medmail.com.cn

    2016-03-18

    The interaction between macrophages and oxLDL plays a crucial role in the initiation and progression of atherosclerosis. As a key initiator in a number of plaque promoting processes, oxLDL induces variable effects such as cell apoptosis or proliferation. Orphan nuclear receptor Nur77 is potently induced in macrophages by diverse stimuli, suggesting that it is of importance in vascular inflammation resulting in atherosclerosis, but whether Nur77 induction is detrimental or protective is unclear. In our study, we explore the role of Nur77 in the regulation of oxLDL-induced macrophage apoptosis and the signaling pathways that are involved. We found that oxLDL induced Nur77 expression in a dose and time dependent fashion, and cell viability was decreased in parallel. To determine whether Nur77 induction contributes to the loss of cell viability or is a protective mechanism, the effect of Nur77 overexpression was examined. Importantly, Nur77 overexpression inhibited the oxLDL-induced decrease of cell viability, inhibited the production of apoptotic bodies and restored DNA synthesis following oxLDL exposure. Furthermore, we found that Nur77 induction is mediated through the p38 MAPK signaling pathway. After pretreatment with SB203580, cell viability was decreased, the expression of CyclinA2 and PCNA was attenuated and the percentage of cell apoptosis was enhanced. Likewise, Nur77 overexpression increased the expression of the cell cycle genes PCNA and p21, and attenuated the increase in caspase-3. On the other hand, knockdown of Nur77 expression by specific siRNA resulted in the increased expression of caspase 3. The results demonstrate that Nur77 is induced by oxLDL via the p38 MAPK signaling pathway, which is involved in the regulation of cell survival. Nur77 enhanced cell survival via suppressing apoptosis, without affecting cell proliferation of activated macrophages, which may be beneficial in patients with atherosclerosis. - Highlights: • oxLDL could induce Nur77

  6. Nur77 inhibits oxLDL induced apoptosis of macrophages via the p38 MAPK signaling pathway

    International Nuclear Information System (INIS)

    Shao, Qin; Han, Fei; Peng, Shi; He, Ben

    2016-01-01

    The interaction between macrophages and oxLDL plays a crucial role in the initiation and progression of atherosclerosis. As a key initiator in a number of plaque promoting processes, oxLDL induces variable effects such as cell apoptosis or proliferation. Orphan nuclear receptor Nur77 is potently induced in macrophages by diverse stimuli, suggesting that it is of importance in vascular inflammation resulting in atherosclerosis, but whether Nur77 induction is detrimental or protective is unclear. In our study, we explore the role of Nur77 in the regulation of oxLDL-induced macrophage apoptosis and the signaling pathways that are involved. We found that oxLDL induced Nur77 expression in a dose and time dependent fashion, and cell viability was decreased in parallel. To determine whether Nur77 induction contributes to the loss of cell viability or is a protective mechanism, the effect of Nur77 overexpression was examined. Importantly, Nur77 overexpression inhibited the oxLDL-induced decrease of cell viability, inhibited the production of apoptotic bodies and restored DNA synthesis following oxLDL exposure. Furthermore, we found that Nur77 induction is mediated through the p38 MAPK signaling pathway. After pretreatment with SB203580, cell viability was decreased, the expression of CyclinA2 and PCNA was attenuated and the percentage of cell apoptosis was enhanced. Likewise, Nur77 overexpression increased the expression of the cell cycle genes PCNA and p21, and attenuated the increase in caspase-3. On the other hand, knockdown of Nur77 expression by specific siRNA resulted in the increased expression of caspase 3. The results demonstrate that Nur77 is induced by oxLDL via the p38 MAPK signaling pathway, which is involved in the regulation of cell survival. Nur77 enhanced cell survival via suppressing apoptosis, without affecting cell proliferation of activated macrophages, which may be beneficial in patients with atherosclerosis. - Highlights: • oxLDL could induce Nur77

  7. Increasing the endogenous NO level causes catalase inactivation and reactivation of intercellular apoptosis signaling specifically in tumor cells.

    Science.gov (United States)

    Bauer, Georg

    2015-12-01

    Tumor cells generate extracellular superoxide anions and are protected against intercellular apoptosis-inducing HOCl- and NO/peroxynitrite signaling through the expression of membrane-associated catalase. This enzyme decomposes H2O2 and thus prevents HOCl synthesis. It efficiently interferes with NO/peroxynitrite signaling through oxidation of NO and decomposition of peroxynitrite. The regulatory potential of catalase at the crosspoint of ROS and RNS chemical biology, as well as its high local concentration on the outside of the cell membrane of tumor cells, establish tight control of intercellular signaling and thus prevent tumor cell apoptosis. Therefore, inhibition of catalase or its inactivation by singlet oxygen reactivate intercellular apoptosis-inducing signaling. Nitric oxide and peroxynitrite are connected with catalase in multiple and meaningful ways, as (i) NO can be oxidated by compound I of catalase, (ii) NO can reversibly inhibit catalase, (iii) peroxynitrite can be decomposed by catalase and (iv) the interaction between peroxynitrite and H2O2 leads to the generation of singlet oxygen that inactivates catalase. Therefore, modulation of the concentration of free NO through addition of arginine, inhibition of arginase, induction of NOS expression or inhibition of NO dioxygenase triggers an autoamplificatory biochemical cascade that is based on initial formation of singlet oxygen, amplification of superoxide anion/H2O2 and NO generation through singlet oxygen dependent stimulation of the FAS receptor and caspase-8. Finally, singlet oxygen is generated at sufficiently high concentration to inactivate protective catalase and to reactivate intercellular apoptosis-inducing ROS signaling. This regulatory network allows to establish several pathways for synergistic interactions, like the combination of modulators of NO metabolism with enhancers of superoxide anion generation, modulators of NO metabolism that act at different targets and between modulators of

  8. Increasing the endogenous NO level causes catalase inactivation and reactivation of intercellular apoptosis signaling specifically in tumor cells

    Science.gov (United States)

    Bauer, Georg

    2015-01-01

    Tumor cells generate extracellular superoxide anions and are protected against intercellular apoptosis-inducing HOCl- and NO/peroxynitrite signaling through the expression of membrane-associated catalase. This enzyme decomposes H2O2 and thus prevents HOCl synthesis. It efficiently interferes with NO/peroxynitrite signaling through oxidation of NO and decomposition of peroxynitrite. The regulatory potential of catalase at the crosspoint of ROS and RNS chemical biology, as well as its high local concentration on the outside of the cell membrane of tumor cells, establish tight control of intercellular signaling and thus prevent tumor cell apoptosis. Therefore, inhibition of catalase or its inactivation by singlet oxygen reactivate intercellular apoptosis-inducing signaling. Nitric oxide and peroxynitrite are connected with catalase in multiple and meaningful ways, as (i) NO can be oxidated by compound I of catalase, (ii) NO can reversibly inhibit catalase, (iii) peroxynitrite can be decomposed by catalase and (iv) the interaction between peroxynitrite and H2O2 leads to the generation of singlet oxygen that inactivates catalase. Therefore, modulation of the concentration of free NO through addition of arginine, inhibition of arginase, induction of NOS expression or inhibition of NO dioxygenase triggers an autoamplificatory biochemical cascade that is based on initial formation of singlet oxygen, amplification of superoxide anion/H2O2 and NO generation through singlet oxygen dependent stimulation of the FAS receptor and caspase-8. Finally, singlet oxygen is generated at sufficiently high concentration to inactivate protective catalase and to reactivate intercellular apoptosis-inducing ROS signaling. This regulatory network allows to establish several pathways for synergistic interactions, like the combination of modulators of NO metabolism with enhancers of superoxide anion generation, modulators of NO metabolism that act at different targets and between modulators of

  9. Belinostat-induced apoptosis and growth inhibition in pancreatic cancer cells involve activation of TAK1-AMPK signaling axis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bing, E-mail: wangbin69@yahoo.com; Wang, Xin-bao; Chen, Li-yu; Huang, Ling; Dong, Rui-zen

    2013-07-19

    Highlights: •Belinostat activates AMPK in cultured pancreatic cancer cells. •Activation of AMPK is important for belinostat-induced cytotoxic effects. •ROS and TAK1 are involved in belinostat-induced AMPK activation. •AMPK activation mediates mTOR inhibition by belinostat. -- Abstract: Pancreatic cancer accounts for more than 250,000 deaths worldwide each year. Recent studies have shown that belinostat, a novel pan histone deacetylases inhibitor (HDACi) induces apoptosis and growth inhibition in pancreatic cancer cells. However, the underlying mechanisms are not fully understood. In the current study, we found that AMP-activated protein kinase (AMPK) activation was required for belinostat-induced apoptosis and anti-proliferation in PANC-1 pancreatic cancer cells. A significant AMPK activation was induced by belinostat in PANC-1 cells. Inhibition of AMPK by RNAi knockdown or dominant negative (DN) mutation significantly inhibited belinostat-induced apoptosis in PANC-1 cells. Reversely, AMPK activator AICAR and A-769662 exerted strong cytotoxicity in PANC-1 cells. Belinostat promoted reactive oxygen species (ROS) production in PANC-1 cells, increased ROS induced transforming growth factor-β-activating kinase 1 (TAK1)/AMPK association to activate AMPK. Meanwhile, anti-oxidants N-Acetyl-Cysteine (NAC) and MnTBAP as well as TAK1 shRNA knockdown suppressed belinostat-induced AMPK activation and PANC-1 cell apoptosis. In conclusion, we propose that belinostat-induced apoptosis and growth inhibition require the activation of ROS-TAK1-AMPK signaling axis in cultured pancreatic cancer cells.

  10. Electromagnetic radiation at 900 MHz induces sperm apoptosis through bcl-2, bax and caspase-3 signaling pathways in rats.

    Science.gov (United States)

    Liu, Qi; Si, Tianlei; Xu, Xiaoyun; Liang, Fuqiang; Wang, Lufeng; Pan, Siyi

    2015-08-04

    The decreased reproductive capacity of men is an important factor contributing to infertility. Accumulating evidence has shown that Electromagnetic radiation potentially has negative effects on human health. However, whether radio frequency electromagnetic radiation (RF-EMR) affects the human reproductive system still requires further investigation. Therefore, The present study investigates whether RF-EMR at a frequency of 900 MHz can trigger sperm cell apoptosis and affect semen morphology, concentration, and microstructure. Twenty four rats were exposed to 900 MHz electromagnetic radiation with a special absorption rate of 0.66 ± 0.01 W/kg for 2 h/d. After 50d, the sperm count, morphology, apoptosis, reactive oxygen species (ROS), and total antioxidant capacity (TAC), representing the sum of enzymatic and nonenzymatic antioxidants, were investigated. Western blotting and reverse transcriptase PCR were used to determine the expression levels of apoptosis-related proteins and genes, including bcl-2, bax, cytochrome c, and capase-3. In the present study, the percentage of apoptotic sperm cells in the exposure group was significantly increased by 91.42% compared with the control group. Moreover, the ROS concentration in exposure group was increased by 46.21%, while the TAC was decreased by 28.01%. Radiation also dramatically decreased the protein and mRNA expression of bcl-2 and increased that of bax, cytochrome c, and capase-3. RF-EMR increases the ROS level and decreases TAC in rat sperm. Excessive oxidative stress alters the expression levels of apoptosis-related genes and triggers sperm apoptosis through bcl-2, bax, cytochrome c and caspase-3 signaling pathways.

  11. PI3K/Akt signaling mediated Hexokinase-2 expression inhibits cell apoptosis and promotes tumor growth in pediatric osteosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Zhuo, Baobiao; Li, Yuan; Li, Zhengwei; Qin, Haihui; Sun, Qingzeng; Zhang, Fengfei; Shen, Yang; Shi, Yingchun [Department of Surgery, The Children' s Hospital of Xuzhou, Xuzhou, Jiangsu Province 221006 (China); Wang, Rong, E-mail: wangrong2008163@163.com [Department of Ultrasonography, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu Province 221006 (China)

    2015-08-21

    Accumulating evidence has shown that PI3K/Akt pathway is frequently hyperactivated in osteosarcoma (OS) and contributes to tumor initiation and progression. Altered phenotype of glucose metabolism is a key hallmark of cancer cells including OS. However, the relationship between PI3K/Akt pathway and glucose metabolism in OS remains largely unexplored. In this study, we showed that elevated Hexokinase-2 (HK2) expression, which catalyzes the first essential step of glucose metabolism by conversion of glucose into glucose-6-phosphate, was induced by activated PI3K/Akt signaling. Immunohistochemical analysis showed that HK2 was overexpressed in 83.3% (25/30) specimens detected and was closely correlated with Ki67, a cell proliferation index. Silencing of endogenous HK2 resulted in decreased aerobic glycolysis as demonstrated by reduced glucose consumption and lactate production. Inhibition of PI3K/Akt signaling also suppressed aerobic glycolysis and this effect can be reversed by reintroduction of HK2. Furthermore, knockdown of HK2 led to increased cell apoptosis and reduced ability of colony formation; meanwhile, these effects were blocked by 2-Deoxy-D-glucose (2-DG), a glycolysis inhibitor through its actions on hexokinase, indicating that HK2 functions in cell apoptosis and growth were mediated by altered aerobic glycolysis. Taken together, our study reveals a novel relationship between PI3K/Akt signaling and aerobic glycolysis and indicates that PI3K/Akt/HK2 might be potential therapeutic approaches for OS. - Highlights: • PI3K/Akt signaling contributes to elevated expression of HK2 in osteosarcoma. • HK2 inhibits cell apoptosis and promotes tumor growth through enhanced Warburg effect. • Inhibition of glycolysis blocks the oncogenic activity of HK2.

  12. PI3K/Akt signaling mediated Hexokinase-2 expression inhibits cell apoptosis and promotes tumor growth in pediatric osteosarcoma

    International Nuclear Information System (INIS)

    Zhuo, Baobiao; Li, Yuan; Li, Zhengwei; Qin, Haihui; Sun, Qingzeng; Zhang, Fengfei; Shen, Yang; Shi, Yingchun; Wang, Rong

    2015-01-01

    Accumulating evidence has shown that PI3K/Akt pathway is frequently hyperactivated in osteosarcoma (OS) and contributes to tumor initiation and progression. Altered phenotype of glucose metabolism is a key hallmark of cancer cells including OS. However, the relationship between PI3K/Akt pathway and glucose metabolism in OS remains largely unexplored. In this study, we showed that elevated Hexokinase-2 (HK2) expression, which catalyzes the first essential step of glucose metabolism by conversion of glucose into glucose-6-phosphate, was induced by activated PI3K/Akt signaling. Immunohistochemical analysis showed that HK2 was overexpressed in 83.3% (25/30) specimens detected and was closely correlated with Ki67, a cell proliferation index. Silencing of endogenous HK2 resulted in decreased aerobic glycolysis as demonstrated by reduced glucose consumption and lactate production. Inhibition of PI3K/Akt signaling also suppressed aerobic glycolysis and this effect can be reversed by reintroduction of HK2. Furthermore, knockdown of HK2 led to increased cell apoptosis and reduced ability of colony formation; meanwhile, these effects were blocked by 2-Deoxy-D-glucose (2-DG), a glycolysis inhibitor through its actions on hexokinase, indicating that HK2 functions in cell apoptosis and growth were mediated by altered aerobic glycolysis. Taken together, our study reveals a novel relationship between PI3K/Akt signaling and aerobic glycolysis and indicates that PI3K/Akt/HK2 might be potential therapeutic approaches for OS. - Highlights: • PI3K/Akt signaling contributes to elevated expression of HK2 in osteosarcoma. • HK2 inhibits cell apoptosis and promotes tumor growth through enhanced Warburg effect. • Inhibition of glycolysis blocks the oncogenic activity of HK2

  13. Activating Nrf-2 signaling depresses unilateral ureteral obstruction-evoked mitochondrial stress-related autophagy, apoptosis and pyroptosis in kidney.

    Directory of Open Access Journals (Sweden)

    Shue Dong Chung

    Full Text Available Exacerbated oxidative stress and inflammation may induce three types of programmed cell death, autophagy, apoptosis and pyroptosis in unilateral ureteral obstruction (UUO kidney. Sulforaphane activating NF-E2-related nuclear factor erythroid-2 (Nrf-2 signaling may ameliorate UUO-induced renal damage. UUO was induced in the left kidney of female Wistar rats. The level of renal blood flow, cortical and medullary oxygen tension and reactive oxygen species (ROS was evaluated. Fibrosis, ED-1 (macrophage/monocyte infiltration, oxidative stress, autophagy, apoptosis and pyroptosis were evaluated by immunohistochemistry and Western blot in UUO kidneys. Effects of sulforaphane, an Nrf-2 activator, on Nrf-2- and mitochondrial stress-related proteins and renal injury were examined. UUO decreased renal blood flow and oxygen tension and increased renal ROS, 3-nitrotyrosine stain, ED-1 infiltration and fibrosis. Enhanced renal tubular Beclin-1 expression started at 4 h UUO and further enhanced at 3d UUO, whereas increased Atg-5-Atg12 and LC3-II expression were found at 3d UUO. Increased renal Bax/Bcl-2 ratio, caspase 3 and PARP fragments, apoptosis formation associated with increased caspase 1 and IL-1β expression for pyroptosis formation were started from 3d UUO. UUO reduced nuclear Nrf-2 translocation, increased cytosolic and inhibitory Nrf-2 expression, increased cytosolic Bax translocation to mitochondrial and enhanced mitochondrial Cytochrome c release into cytosol of the UUO kidneys. Sulforaphane significantly increased nuclear Nrf-2 translocation and decreased mitochondrial Bax translocation and Cytochrome c release into cytosol resulting in decreased renal injury. In conclusion, sulforaphane via activating Nrf-2 signaling preserved mitochondrial function and suppressed UUO-induced renal oxidative stress, inflammation, fibrosis, autophagy, apoptosis and pyroptosis.

  14. Distinct functional domains of PNMA5 mediate protein-protein interaction, nuclear localization, and apoptosis signaling in human cancer cells.

    Science.gov (United States)

    Lee, Yong Hoi; Pang, Siew Wai; Poh, Chit Laa; Tan, Kuan Onn

    2016-09-01

    Members of paraneoplastic Ma (PNMA) family have been identified as onconeuronal antigens, which aberrant expressions in cancer cells of patients with paraneoplastic disorder (PND) are closely linked to manifestation of auto-immunity, neuro-degeneration, and cancer. The purpose of present study was to determine the role of PNMA5 and its functional relationship to MOAP-1 (PNMA4) in human cancer cells. PNMA5 mutants were generated through deletion or site-directed mutagenesis and transiently expressed in human cancer cell lines to investigate their role in apoptosis, subcellular localization, and potential interaction with MOAP-1 through apoptosis assays, fluorescence microscopy, and co-immunoprecipitation studies, respectively. Over-expressed human PNMA5 exhibited nuclear localization pattern in both MCF-7 and HeLa cells. Deletion mapping and mutagenesis studies showed that C-terminus of PNMA5 is responsible for nuclear localization, while the amino acid residues (391KRRR) within the C-terminus of PNMA5 are required for nuclear targeting. Deletion mapping and co-immunoprecipitation studies showed that PNMA5 interacts with MOAP-1 and N-terminal domain of PNMA5 is required for interaction with MOAP-1. Furthermore, co-expression of PNMA5 and MOAP-1 in MCF-7 cells significantly enhanced chemo-sensitivity of MCF-7 to Etoposide treatment, indicating that PNMA5 and MOAP-1 interact synergistically to promote apoptotic signaling in MCF-7 cells. Our results show that PNMA5 promotes apoptosis signaling in HeLa and MCF-7 cells and interacts synergistically with MOAP-1 through its N-terminal domain to promote apoptosis and chemo-sensitivity in human cancer cells. The C-terminal domain of PNMA5 is required for nuclear localization; however, both N-and C-terminal domains of PNMA5 appear to be required for pro-apoptotic function.

  15. Ghrelin inhibits the apoptosis of MC3T3-E1 cells through ERK and AKT signaling pathway

    International Nuclear Information System (INIS)

    Liang, Qiu-Hua; Liu, Yuan; Wu, Shan-Shan; Cui, Rong-Rong; Yuan, Ling-Qing; Liao, Er-Yuan

    2013-01-01

    Ghrelin is a 28-amino-acid peptide that acts as a natural endogenous ligand of the growth hormone secretagogue receptor (GHSR) and strongly stimulates the release of growth hormone from the hypothalamus–pituitary axis. Previous studies have identified the important physiological effects of ghrelin on bone metabolism, such as regulating proliferation and differentiation of osteoblasts, independent of GH/IGF-1 axis. However, research on effects and mechanisms of ghrelin on osteoblast apoptosis is still rare. In this study, we identified expression of GHSR in MC3T3-E1 cells and determined the effects of ghrelin on the apoptosis of osteoblastic MC3T3-E1 cells and the mechanism involved. Our data demonstrated that ghrelin inhibited the apoptosis of osteoblastic MC3T3-E1 cells induced by serum deprivation, as determined by terminal deoxynucleotidyl transferase-mediated deoxyribonucleotide triphosphate nick end-labeling (TUNEL) and ELISA assays. Moreover, ghrelin upregulated Bcl-2 expression and downregulated Bax expression in a dose-dependent manner. Our study also showed decreased activated caspase-3 activity under the treatment of ghrelin. Further study suggested that ghrelin stimulated the phosphorylation of ERK and AKT. Pretreatment of cells with the ERK inhibitor PD98059, PI3K inhibitor LY294002, and GHSR-siRNA blocked the ghrelin-induced activation of ERK and AKT, respectively; however, ghrelin did not stimulate the phosphorylation of p38 or JNK. PD90859, LY294002 and GHSR-siRNA attenuated the anti-apoptosis effect of ghrelin in MC3T3-E1 cells. In conclusion, ghrelin inhibits the apoptosis of osteoblastic MC3T3-E1 cells induced by serum deprivation, which may be mediated by activating the GHSR/ERK and GHSR/PI3K/AKT signaling pathways. - Highlights: • We explored the effects of ghrelin on serum deprivation-induced MC3T3-E1 cells apoptosis. • Both ELISA and TUNEL were used to detect the apoptosis. • The receptor of ghrelin, GHSR, was expressed in MC3T3-E1

  16. Ghrelin inhibits the apoptosis of MC3T3-E1 cells through ERK and AKT signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Qiu-Hua; Liu, Yuan; Wu, Shan-Shan; Cui, Rong-Rong; Yuan, Ling-Qing, E-mail: allenylq@hotmail.com; Liao, Er-Yuan, E-mail: eyliao@21cn.com

    2013-11-01

    Ghrelin is a 28-amino-acid peptide that acts as a natural endogenous ligand of the growth hormone secretagogue receptor (GHSR) and strongly stimulates the release of growth hormone from the hypothalamus–pituitary axis. Previous studies have identified the important physiological effects of ghrelin on bone metabolism, such as regulating proliferation and differentiation of osteoblasts, independent of GH/IGF-1 axis. However, research on effects and mechanisms of ghrelin on osteoblast apoptosis is still rare. In this study, we identified expression of GHSR in MC3T3-E1 cells and determined the effects of ghrelin on the apoptosis of osteoblastic MC3T3-E1 cells and the mechanism involved. Our data demonstrated that ghrelin inhibited the apoptosis of osteoblastic MC3T3-E1 cells induced by serum deprivation, as determined by terminal deoxynucleotidyl transferase-mediated deoxyribonucleotide triphosphate nick end-labeling (TUNEL) and ELISA assays. Moreover, ghrelin upregulated Bcl-2 expression and downregulated Bax expression in a dose-dependent manner. Our study also showed decreased activated caspase-3 activity under the treatment of ghrelin. Further study suggested that ghrelin stimulated the phosphorylation of ERK and AKT. Pretreatment of cells with the ERK inhibitor PD98059, PI3K inhibitor LY294002, and GHSR-siRNA blocked the ghrelin-induced activation of ERK and AKT, respectively; however, ghrelin did not stimulate the phosphorylation of p38 or JNK. PD90859, LY294002 and GHSR-siRNA attenuated the anti-apoptosis effect of ghrelin in MC3T3-E1 cells. In conclusion, ghrelin inhibits the apoptosis of osteoblastic MC3T3-E1 cells induced by serum deprivation, which may be mediated by activating the GHSR/ERK and GHSR/PI3K/AKT signaling pathways. - Highlights: • We explored the effects of ghrelin on serum deprivation-induced MC3T3-E1 cells apoptosis. • Both ELISA and TUNEL were used to detect the apoptosis. • The receptor of ghrelin, GHSR, was expressed in MC3T3-E1

  17. Disruption of IGF-1R signaling increases TRAIL-induced apoptosis: A new potential therapy for the treatment of melanoma

    International Nuclear Information System (INIS)

    Karasic, Thomas B.; Hei, Tom K.; Ivanov, Vladimir N.

    2010-01-01

    Resistance of cancer cells to apoptosis is dependent on a balance of multiple genetic and epigenetic mechanisms, which up-regulate efficacy of the surviving growth factor-receptor signaling pathways and suppress death-receptor signaling pathways. The Insulin-like Growth Factor-1 Receptor (IGF-1R) signaling pathway is highly active in metastatic melanoma cells by mediating downstream activation of PI3K-AKT and MAPK pathways and controlling general cell survival and proliferation. In the present study, we used human melanoma lines with established genotypes that represented different phases of cancer development: radial-growth-phase WM35, vertical-growth-phase WM793, metastatic LU1205 and WM9 [1]. All these lines have normal NRAS. WM35, WM793, LU1205 and WM9 cells have mutated BRAF (V600E). WM35 and WM9 cells express normal PTEN, while in WM793 cells PTEN expression is down-regulated; finally, in LU1205 cells PTEN is inactivated by mutation. Cyclolignan picropodophyllin (PPP), a specific inhibitor of IGF-1R kinase activity, strongly down-regulated the basal levels of AKT activity in WM9 and in WM793 cells, modestly does so in LU1205, but has no effect on AKT activity in the early stage WM35 cells that are deficient in IGF-1R. In addition, PPP partially down-regulated the basal levels of active ERK1/2 in all lines used, highlighting the role of an alternative, non-BRAF pathway in MAPK activation. The final result of PPP treatment was an induction of apoptosis in WM793, WM9 and LU1205 melanoma cells. On the other hand, dose-dependent inhibition of IGF-1R kinase activity by PPP at a relatively narrow dose range (near 500 nM) has different effects on melanoma cells versus normal cells, inducing apoptosis in cancer cells and G2/M arrest of fibroblasts. To further enhance the pro-apoptotic effects of PPP on melanoma cells, we used a combined treatment of TNF-Related Apoptosis-Inducing Ligand (TRAIL) and PPP. This combination substantially increased death by apoptosis for

  18. Disruption of IGF-1R signaling increases TRAIL-induced apoptosis: A new potential therapy for the treatment of melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Karasic, Thomas B.; Hei, Tom K. [Center for Radiological Research, Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Ivanov, Vladimir N., E-mail: vni3@columbia.edu [Center for Radiological Research, Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States)

    2010-07-15

    Resistance of cancer cells to apoptosis is dependent on a balance of multiple genetic and epigenetic mechanisms, which up-regulate efficacy of the surviving growth factor-receptor signaling pathways and suppress death-receptor signaling pathways. The Insulin-like Growth Factor-1 Receptor (IGF-1R) signaling pathway is highly active in metastatic melanoma cells by mediating downstream activation of PI3K-AKT and MAPK pathways and controlling general cell survival and proliferation. In the present study, we used human melanoma lines with established genotypes that represented different phases of cancer development: radial-growth-phase WM35, vertical-growth-phase WM793, metastatic LU1205 and WM9 [1]. All these lines have normal NRAS. WM35, WM793, LU1205 and WM9 cells have mutated BRAF (V600E). WM35 and WM9 cells express normal PTEN, while in WM793 cells PTEN expression is down-regulated; finally, in LU1205 cells PTEN is inactivated by mutation. Cyclolignan picropodophyllin (PPP), a specific inhibitor of IGF-1R kinase activity, strongly down-regulated the basal levels of AKT activity in WM9 and in WM793 cells, modestly does so in LU1205, but has no effect on AKT activity in the early stage WM35 cells that are deficient in IGF-1R. In addition, PPP partially down-regulated the basal levels of active ERK1/2 in all lines used, highlighting the role of an alternative, non-BRAF pathway in MAPK activation. The final result of PPP treatment was an induction of apoptosis in WM793, WM9 and LU1205 melanoma cells. On the other hand, dose-dependent inhibition of IGF-1R kinase activity by PPP at a relatively narrow dose range (near 500 nM) has different effects on melanoma cells versus normal cells, inducing apoptosis in cancer cells and G2/M arrest of fibroblasts. To further enhance the pro-apoptotic effects of PPP on melanoma cells, we used a combined treatment of TNF-Related Apoptosis-Inducing Ligand (TRAIL) and PPP. This combination substantially increased death by apoptosis for

  19. Safety evaluation of driver cognitive failures and driving errors on right-turn filtering movement at signalized road intersections based on Fuzzy Cellular Automata (FCA) model.

    Science.gov (United States)

    Chai, Chen; Wong, Yiik Diew; Wang, Xuesong

    2017-07-01

    This paper proposes a simulation-based approach to estimate safety impact of driver cognitive failures and driving errors. Fuzzy Logic, which involves linguistic terms and uncertainty, is incorporated with Cellular Automata model to simulate decision-making process of right-turn filtering movement at signalized intersections. Simulation experiments are conducted to estimate the relationships between cognitive failures and driving errors with safety performance. Simulation results show Different types of cognitive failures are found to have varied relationship with driving errors and safety performance. For right-turn filtering movement, cognitive failures are more likely to result in driving errors with denser conflicting traffic stream. Moreover, different driving errors are found to have different safety impacts. The study serves to provide a novel approach to linguistically assess cognitions and replicate decision-making procedures of the individual driver. Compare to crash analysis, the proposed FCA model allows quantitative estimation of particular cognitive failures, and the impact of cognitions on driving errors and safety performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Loss of T-cadherin (CDH-13) regulates AKT signaling and desensitizes cells to apoptosis in melanoma.

    Science.gov (United States)

    Bosserhoff, Anja K; Ellmann, Lisa; Quast, Annika S; Eberle, Juergen; Boyle, Glen M; Kuphal, Silke

    2014-08-01

    An understanding of signaling pathways is a basic requirement for the treatment of melanoma. Currently, kinases are at the center of melanoma therapies. According to our research, additional alternative molecules are equally important for development of melanoma. In this regard, cancer progression is, among other factors, driven by an altered adhesion via cadherins. For instance, the de-regulated expression of the adhesion molecule T-cadherin is found in various cancer types, including melanoma, and influences migration and invasion. T-cadherin is thought to affect cellular function largely through its signaling and not its adhesion properties because the molecule is anchored into the cell membrane by a glycosylphosphatidylinositol (GPI) moiety. However, detailed knowledge about the consequences of the loss of T-cadherin in melanoma is currently lacking. For this reason, we were interested in assessing which signaling pathways are initiated by T-cadherin. The tumor growth of subcutaneously injected T-cadherin-positive melanoma cells was diminished compared with T-cadherin-negative cells in nude mice. The difference in tumor volume was not due to decreased proliferation but rather due to increased apoptosis. After the expression of T-cadherin was induced, we detected V-AKT murine thymoma viral oncogene homolog (AKT) and FoxO3a hypophosphorylation accompanied by the downregulation of the antiapoptotic molecules BCL-2, BCL-x and Clusterin. Furthermore, we detected a diminished transcriptional activity of CREB and AP-1. We demonstrated that T-cadherin functions as a pro-apoptotic tumor suppressor that antagonizes AKT/CREB/AP-1/FoxO3a signaling, whereas NFκB, TCF/LEF and mTOR are not part of the T-cadherin signaling pathway. Notably, we found that the restoration of T-cadherin in melanoma cells causes sensitization to apoptosis induced by CD95/Fas antibody CH-11. © 2013 Wiley Periodicals, Inc.

  1. [TRPM8 mediates PC-12 neuronal cell apoptosis induced by oxygen-glucose deprivation through cAMP-PKA/UCP4 signaling].

    Science.gov (United States)

    Li, Hong-Wei; Zhou, Bin; Zhang, Hai-Hong

    2016-08-20

    To explore the molecular mechanism responsible for apoptosis of PC-12 neuronal cells induced by oxygen-glucose deprivation (OGD). PC12 cells were exposed to OGD for 24 h to simulate ischemia-reperfusion injury. Flow cytometry was employed detect the cell apoptosis, and the expresions of TRPM8, UCP4, cAMP and PKA in the exposed cells were detected with RT-PCR and Western blotting. The changes in the expressions of Bax, Bcl-2, cAMP, PKA and UCP4 proteins were detected in the exposed cells in resposne to inhibition of TRPM8 and cAMP-PKA signal or over-expression of UCP4. OGD for 24 induced obvious apoptosis in PC-12 cells and caused TRPM8 over-expression and inhibition of UCP4 and cAMP-PKA signaling. Inhibiting TRPM8 expression reduced the cell apoptosis and up-regulated cAMP, p-PKA and UCP4 in the cells exposed to OGD. In cells exposed to OGD, inhibition of TRPM8 and cAMP-PKA signaling suppressed the expressio of UCP4 and increased the cell apoptosis. TRPM8 mediates OGD-induced PC12 cell apoptosis through cAMP-PKA/UCP4 signaling.

  2. Vitamin E succinate induces apoptosis via the PI3K/AKT signaling pathways in EC109 esophageal cancer cells

    Science.gov (United States)

    Yang, Peng; Zhao, Jiaying; Hou, Liying; Yang, Lei; Wu, Kun; Zhang, Linyou

    2016-01-01

    Esophageal cancer is the fourth most common gastrointestinal cancer, it generally has a poor prognosis and novel strategies are required for prevention and treatment. Vitamin E succinate (VES) is a potential chemical agent for cancer prevention and therapy as it exerts anti-tumor effects in a variety of cancers. However, the role of VES in tumorigenesis and progression of cancer remains to be elucidated. The present study aimed to determine the effects of VES in regulating the survival and apoptosis of human esophageal cancer cells. EC109 human esophageal cancer cells were used to investigate the anti-proliferative effects of VES. The MTT and Annexin V-fluorescein isothiocyanate/propidium iodide assays demonstrated that VES inhibited cell proliferation and induced apoptosis in esophageal cancer cells. Furthermore, VES downregulated constitutively active basal levels of phosphorylated (p)-serine-threonine kinase AKT (AKT) and p-mammalian target of rapamycin (mTOR), and decreased the phosphorylation of AKT substrates Bcl-2-associated death receptor and caspase-9, in addition to mTOR effectors, ribosomal protein S6 kinase β1 and eIF4E-binding protein 1. Phosphoinositide-3-kinase (PI3K) inhibitor, LY294002 suppressed p-AKT and p-mTOR, indicating PI3K is a common upstream mediator. The apoptosis induced by VES was increased by inhibition of AKT or mTOR with their respective inhibitor in esophageal cancer cells. The results of the present study suggested that VES targeted the PI3K/AKT signaling pathways and induced apoptosis in esophageal cancer cells. Furthermore, the current study suggests that VES may be useful in a combinational therapeutic strategy employing an mTOR inhibitor. PMID:27357907

  3. Targeting miR-155 suppresses proliferation and induces apoptosis of HL-60 cells by targeting Slug/PUMA signal.

    Science.gov (United States)

    Liang, Hui; Dong, Ziyan; Liu, Jiang-Feng; Chuang, Wei; Gao, Li-Zhen; Ren, Yu-Guo

    2017-09-01

    Recent studies have shown that high miR-155 expression was associated with poor prognosis in patients with acute myelogeneous leukemia (AML). Furthermore, targeting miR-155 results in monocytic differentiation and apoptosis. However, the exact role and mechanisms of miR-155 in human AML remains speculative. HL-60 cells were treated with anti-miR-155 for 72 h. Cell growth and apoptosis in vitro were detected by MTT, BrdU proliferation, colony formation and flow cytometry assay. The effect of anti-miR-155 on growth of HL-60 cells was also evaluated in a leukemia mouse model. Slug cDNA and PUMA siRNA trannsfection was used to assess the signal pathway. Different protein expression was detected by western blot assay and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) assay. The results shown that targeting miR-155 resulted in a 24-fold decrease of miR-155 expression compared to negative control in the HL-60 cells. Targeting miR-155 significantly downregulated Slug and upregulated PUMA expression, and decreased HL-60 cell growth by 70% , impaired colony formation by approximately 60%, and increased HL-60 cell apoptosis by 45%. Targeting PUMA reversed miR-155 sliencing-induced proliferation and apoptosis of HL-60 cells. Restoration of Slug decreased PUMA expression. In murine engraftment models of HL-60 cells, we showed that targeting miR-155 was able to reduce tumor growth. This was accompanied with decreased Slug expression and increased PUMA expression in these tumors. Collectively, our findings strongly suggest targeting miR-155 exhibited in vivo and in vitro antileukemic activities in AML through a novel mechanism resulting in inhibition of Slug expression and increase of PUMA expression.

  4. Combining BET and HDAC inhibitors synergistically induces apoptosis of melanoma and suppresses AKT and YAP signaling

    OpenAIRE

    Heinemann, Anja; Cullinane, Carleen; De Paoli-Iseppi, Ricardo; Wilmott, James S.; Gunatilake, Dilini; Madore, Jason; Strbenac, Dario; Yang, Jean Y.; Gowrishankar, Kavitha; Tiffen, Jessamy C.; Prinjha, Rab K.; Smithers, Nicholas; McArthur, Grant A.; Hersey, Peter; Gallagher, Stuart J.

    2015-01-01

    Histone acetylation marks have an important role in controlling gene expression and are removed by histone deacetylases (HDACs). These marks are read by bromodomain and extra-terminal (BET) proteins and novel inhibitiors of these proteins are currently in clinical development. Inhibitors of HDAC and BET proteins have individually been shown to cause apoptosis and reduce growth of melanoma cells. Here we show that combining the HDAC inhibitor LBH589 and BET inhibitor I-BET151 synergistically i...

  5. Apigenin induces caspase-dependent apoptosis by inhibiting signal transducer and activator of transcription 3 signaling in HER2-overexpressing SKBR3 breast cancer cells.

    Science.gov (United States)

    Seo, Hye-Sook; Ku, Jin Mo; Choi, Han-Seok; Woo, Jong-Kyu; Jang, Bo-Hyoung; Go, Hoyeon; Shin, Yong Cheol; Ko, Seong-Gyu

    2015-08-01

    Phytoestrogens have been demonstrated to inhibit tumor induction; however, their molecular mechanisms of action have remained elusive. The present study aimed to investigate the effects of a phytoestrogen, apigenin, on proliferation and apoptosis of the human epidermal growth factor receptor 2 (HER2)-expressing breast cancer cell line SKBR3. Proliferation assay, MTT assay, fluorescence-activated cell sorting analysis, western blot analysis, immunocytochemistry, reverse transcription-polymerase chain reaction and ELISA assay were used in the present study. The results of the present study indicated that apigenin inhibited the proliferation of SKBR3 cells in a dose-and time-dependent manner. This inhibition of growth was accompanied by an increase in the sub-G0/G1 apoptotic population. Furthermore, apigenin enhanced the expression levels of cleaved caspase-8 and -3, and induced the cleavage of poly(adenosine diphosphate ribose) polymerase in SKBR3 cells, confirming that apigenin promotes apoptosis via a caspase-dependent pathway. Apigenin additionally reduced the expression of phosphorylated (p)-janus kinase 2 and p-signal transducer and activator of transcription 3 (STAT3), inhibited CoCl2-induced vascular endothelial growth factor (VEGF) secretion and decreased the nuclear localization of STAT3. The STAT3 inhibitor S31-201 decreased the cellular proliferation rate and reduced the expression of p-STAT3 and VEGF. Therefore, these results suggested that apigenin induced apoptosis via the inhibition of STAT3 signaling in SKBR3 cells. In conclusion, the results of the present study indicated that apigenin may be a potentially useful compound for the prevention or treatment of HER2-overexpressing breast cancer.

  6. Down-Regulation of AKT Signalling by Ursolic Acid Induces Intrinsic Apoptosis and Sensitization to Doxorubicin in Soft Tissue Sarcoma.

    Directory of Open Access Journals (Sweden)

    Victor Hugo Villar

    Full Text Available Several important biological activities have been attributed to the pentacyclic triterpene ursolic acid (UA, being its antitumoral effect extensively studied in human adenocarcinomas. In this work, we focused on the efficacy and molecular mechanisms involved in the antitumoral effects of UA, as single agent or combined with doxorubicin (DXR, in human soft tissue sarcoma cells. UA (5-50 μM strongly inhibited (up to 80% the viability of STS cells at 24 h and its proliferation in soft agar, with higher concentrations increasing apoptotic death up to 30%. UA treatment (6-9 h strongly blocked the survival AKT/GSK3β/β-catenin signalling pathway, which led to a concomitant reduction of the anti-apoptotic proteins c-Myc and p21, altogether resulting in the activation of intrinsic apoptosis. Interestingly, UA at low concentrations (10-15 μM enhanced the antitumoral effects of DXR by up to 2-fold, while in parallel inhibiting DXR-induced AKT activation and p21 expression, two proteins implicated in antitumoral drug resistance and cell survival. In conclusion, UA is able to induce intrinsic apoptosis in human STS cells and also to sensitize these cells to DXR by blocking the AKT signalling pathway. Therefore, UA may have beneficial effects, if used as nutraceutical adjuvant during standard chemotherapy treatment of STS.

  7. Osthole promotes neuronal differentiation and inhibits apoptosis via Wnt/β-catenin signaling in an Alzheimer's disease model

    International Nuclear Information System (INIS)

    Yao, Yingjia; Gao, Zhong; Liang, Wenbo; Kong, Liang; Jiao, Yanan; Li, Shaoheng; Tao, Zhenyu; Yan, Yuhui; Yang, Jingxian

    2015-01-01

    Neurogenesis is the process by which neural stem cells (NSCs) proliferate and differentiate into neurons. This is diminished in several neurodegenerative disorders such as Alzheimer's disease (AD), which is characterized by the deposition of amyloid (A)β peptides and neuronal loss. Stimulating NSCs to replace lost neurons is therefore a promising approach for AD treatment. Our previous study demonstrated that osthole modulates NSC proliferation and differentiation, and may reduce Aβ protein expression in nerve cells. Here we investigated the mechanism underlying the effects of osthole on NSCs. We found that osthole enhances NSC proliferation and neuronal differentiation while suppressing apoptosis, effects that were exerted via activation of Wnt/β-catenin signaling. These results provide evidence that osthole can potentially be used as a therapeutic agent in the treatment of AD and other neurodegenerative disorders. - Highlights: • An Alzheimer's disease model was successfully established by transfecting APP gene into neural stem cells in vitro. • Roles of osthole in experimental AD cells were studied. • Osthole promotes proliferation and differentiation into neurons and inhibits accumulation of Aβ 1–42 peptide and apoptosis. • Osthole exerts protection via Wnt/β-catenin signaling pathway.

  8. Notch1 signaling inhibits growth of human hepatocellular carcinoma through induction of cell cycle arrest and apoptosis.

    Science.gov (United States)

    Qi, Runzi; An, Huazhang; Yu, Yizhi; Zhang, Minghui; Liu, Shuxun; Xu, Hongmei; Guo, Zhenghong; Cheng, Tao; Cao, Xuetao

    2003-12-01

    Notch signaling plays a critical role in maintaining the balance between cell proliferation, differentiation, and apoptosis; hence, perturbed Notch signaling may contribute to tumorigenesis. Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in Africa and Asia. The mechanisms that orchestrate the multiple oncogenic insults required for initiation and progression of HCC are not clear. We constitutively overexpressed active Notch1 in human HCC to explore the effects of Notch1 signaling on HCC cell growth and to investigate the underlying molecular mechanisms. We show here that overexpression of Notch1 was able to inhibit the growth of HCC cells in vitro and in vivo. Biochemical analysis revealed the involvement of cell cycle regulated proteins in Notch1-mediated G(0)/G(1) arrest of HCC cells. Compared with green fluorescent protein (GFP) control, transient transfection of Notch1 ICN decreased expression of cyclin A (3.5-fold), cyclin D1 (2-fold), cyclin E (4.5-fold), CDK2 (2.8-fold), and the phosphorylated form of retinoblastoma protein (3-fold). Up-regulation of p21(waf/cip1) protein expression was observed in SMMC7721-ICN cells stably expressing active Notch1 but not in SMMC7721-GFP cells, which only express GFP. Furthermore, a 12-fold increase in p53 expression and an increase (4.8-fold) in Jun-NH(2)-terminal kinase activation were induced in SMMC7721-ICN cells compared with SMMC7721-GFP cells. In contrast, expression of the antiapoptotic Bcl-2 protein could not be detected in SMMC7721-ICN cells. These findings suggest that Notch1 signaling may participate in the development of HCC cells, affecting multiple pathways that control both cell proliferation and apoptosis.

  9. Association of reactive oxygen species-mediated signal transduction with in vitro apoptosis sensitivity in chronic lymphocytic leukemia B cells.

    Directory of Open Access Journals (Sweden)

    Adam L Palazzo

    Full Text Available BACKGROUND: Chronic lymphocytic leukemia (CLL is a B cell malignancy with a variable clinical course and unpredictable response to therapeutic agents. Single cell network profiling (SCNP utilizing flow cytometry measures alterations in signaling biology in the context of molecular changes occurring in malignancies. In this study SCNP was used to identify proteomic profiles associated with in vitro apoptotic responsiveness of CLL B cells to fludarabine, as a basis for ultimately linking these with clinical outcome. METHODOLOGY/PRINCIPAL FINDING: SCNP was used to quantify modulated-signaling of B cell receptor (BCR network proteins and in vitro F-ara-A mediated apoptosis in 23 CLL samples. Of the modulators studied the reactive oxygen species, hydrogen peroxide (H₂O₂, a known intracellular second messenger and a general tyrosine phosphatase inhibitor stratified CLL samples into two sub-groups based on the percentage of B cells in a CLL sample with increased phosphorylation of BCR network proteins. Separately, in the same patient samples, in vitro exposure to F-ara-A also identified two sub-groups with B cells showing competence or refractoriness to apoptotic induction. Statistical analysis showed that in vitro F-ara-A apoptotic proficiency was highly associated with the proficiency of CLL B cells to undergo H₂O₂-augmented signaling. CONCLUSIONS/SIGNIFICANCE: This linkage in CLL B cells among the mechanisms governing chemotherapy-induced apoptosis increased signaling of BCR network proteins and a likely role of phosphatase activity suggests a means of stratifying patients for their response to F-ara-A based regimens. Future studies will examine the clinical applicability of these findings and also the utility of this approach in relating mechanism to function of therapeutic agents.

  10. Suppression of Grb2 expression improved hepatic steatosis, oxidative stress, and apoptosis induced by palmitic acid in vitro partly through insulin signaling alteration.

    Science.gov (United States)

    Shan, Xiangxiang; Miao, Yufeng; Fan, Rengen; Song, Changzhi; Wu, Guangzhou; Wan, Zhengqiang; Zhu, Jian; Sun, Guan; Zha, Wenzhang; Mu, Xiangming; Zhou, Guangjun; Chen, Yan

    2013-09-01

    In this study, we aimed to study the role of growth factor receptor-bound protein 2 (Grb2) in palmitic acid-induced steatosis and other "fatty liver" symptoms in vitro. HepG2 cells, with or without stably suppressed Grb2 expression, were incubated with palmitic acid for 24 h to induce typical clinical "fatty liver" features, including steatosis, impaired glucose metabolism, oxidative stress, and apoptosis. MTT and Oil Red O assays were applied to test cell viability and fat deposition, respectively. Glucose uptake assay was used to evaluate the glucose utilization of cells. Quantitative polymerase chain reaction and Western blot were used to measure expressional changes of key markers of insulin signaling, lipid/glucose metabolism, oxidative stress, and apoptosis. After 24-h palmitic acid induction, increased fat accumulation, reduced glucose uptake, impaired insulin signaling, enhanced oxidative stress, and increased apoptosis were observed in HepG2 cells. Suppression of Grb2 in HepG2 significantly reduced fat accumulation, improved glucose metabolism, ameliorated oxidative stress, and restored the activity of insulin receptor substrate-1/Akt and MEK/ERK pathways. In addition, Grb2 deficiency attenuated hepatic apoptosis shown by reduced activation of caspase-3 and fluorescent staining. Modulation of Bcl-2 and Bak1 also contributed to reduced apoptosis. In conclusion, suppression of Grb2 expression in HepG2 cells improved hepatic steatosis, glucose metabolism, oxidative stress, and apoptosis induced by palmitic acid incubation partly though modulating the insulin signaling pathway.

  11. Inositol Hexaphosphate Inhibits Proliferation and Induces Apoptosis of Colon Cancer Cells by Suppressing the AKT/mTOR Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Małgorzata Kapral

    2017-10-01

    Full Text Available Abstract: AKT, a serine/threonine protein kinase and mammalian target of rapamycin (mTOR plays a critical role in the proliferation and resistance to apoptosis that are essential to the development and progression of colon cancer. Therefore, AKT/mTOR signaling pathway has been recognized as an attractive target for anticancer therapy. Inositol hexaphosphate (InsP6, a natural occurring phytochemical, has been shown to have both preventive and therapeutic effects against various cancers, however, its exact molecular mechanisms of action are not fully understood. The aim of the in vitro study was to investigate the anticancer activity of InsP6 on colon cancer with the focus on inhibiting the AKT1 kinase and p70S6K1 as mTOR effector, in relation to proliferation and apoptosis of cells. The colon cancer Caco-2 cells were cultured using standard techniques and exposed to InsP6 at different concentrations (1 mM, 2.5 mM and 5 mM. Cellular proliferative activity was monitored by 5-bromo-2′-deoxyuridine (BrdU incorporation into cellular DNA. Flow cytometric analysis was performed for cell cycle progression and apoptosis studies. Real-time RT-qPCR was used to validate mRNA levels of CDNK1A, CDNK1B, CASP3, CASP9, AKT1 and S6K1 genes. The concentration of p21 protein as well as the activities of caspase 3, AKT1 and p70S6K1 were determined by the ELISA method. The results revealed that IP6 inhibited proliferation and stimulated apoptosis of colon cancer cells. This effect was mediated by an increase in the expression of genes encoding p21, p27, caspase 3, caspase 9 as well a decrease in transcription of AKT1 and S6K1. InsP6 suppressed phosphorylation of AKT1 and p70S6K1, downstream effector of mTOR. Based on these studies it may be concluded that InsP6 can reduce proliferation and induce apoptosis through inhibition of the AKT/mTOR pathway and mTOR effector followed by modulation of the expression and activity of several key components of these pathways in

  12. FoxP3 inhibits proliferation and induces apoptosis of gastric cancer cells by activating the apoptotic signaling pathway

    International Nuclear Information System (INIS)

    Ma, Gui-Fen; Chen, Shi-Yao; Sun, Zhi-Rong; Miao, Qing; Liu, Yi-Mei; Zeng, Xiao-Qing; Luo, Tian-Cheng; Ma, Li-Li; Lian, Jing-Jing; Song, Dong-Li

    2013-01-01

    Highlights: ► The article revealed FoxP3 gene function in gastric cancer firstly. ► Present the novel roles of FoxP3 in inhibiting proliferation and promoting apoptosis in gastric cancer cells. ► Overexpression of FoxP3 increased proapoptotic molecules and repressed antiapoptotic molecules. ► Silencing of FoxP3 reduced the expression of proapoptotic genes, such as PARP, caspase-3 and caspase-9. ► FoxP3 is sufficient for activating the apoptotic signaling pathway. -- Abstract: Forkhead Box Protein 3 (FoxP3) was identified as a key transcription factor to the occurring and function of the regulatory T cells (Tregs). However, limited evidence indicated its function in tumor cells. To elucidate the precise roles and underlying molecular mechanism of FoxP3 in gastric cancer (GC), we examined the expression of FoxP3 and the consequences of interfering with FoxP3 gene in human GC cell lines, AGS and MKN45, by multiple cellular and molecular approaches, such as immunofluorescence, gene transfection, CCK-8 assay, clone formation assay, TUNEL assay, Flow cytometry, immunoassay and quantities polymerase chain reaction (PCR). As a result, FoxP3 was expressed both in nucleus and cytoplasm of GC cells. Up-regulation of FoxP3 inhibited cell proliferation and promoted cell apoptosis. Overexpression of FoxP3 increased the protein and mRNA levels of proapoptotic molecules, such as poly ADP-ribose polymerase1 (PARP), caspase-3 and caspase-9, and repressed the expression of antiapoptotic molecules, such as cellular inhibitor of apoptosis-1 (c-IAP1) and the long isoform of B cell leukemia/lymphoma-2 (Bcl-2). Furthermore, silencing of FoxP3 by siRNA in GC cells reduced the expression of proapoptotic genes, such as PARP, caspase-3 and caspase-9. Collectively, our findings identify the novel roles of FoxP3 in inhibiting proliferation and inducing apoptosis in GC cells by regulating apoptotic signaling, which could be a promising therapeutic approach for gastric cancer.

  13. FoxP3 inhibits proliferation and induces apoptosis of gastric cancer cells by activating the apoptotic signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Gui-Fen [Department of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai (China); Chen, Shi-Yao, E-mail: shiyao_chen@163.com [Department of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai (China); Endoscopy Center, Zhongshan Hospital, Fudan University, Shanghai (China); Sun, Zhi-Rong [Department of Anesthesiology, Cancer Center, Fudan University, Shanghai (China); Miao, Qing; Liu, Yi-Mei; Zeng, Xiao-Qing; Luo, Tian-Cheng [Department of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai (China); Ma, Li-Li; Lian, Jing-Jing [Endoscopy Center, Zhongshan Hospital, Fudan University, Shanghai (China); Song, Dong-Li [Biomedical Research Center, Zhongshan Hospital, Fudan University, Shanghai (China)

    2013-01-11

    Highlights: Black-Right-Pointing-Pointer The article revealed FoxP3 gene function in gastric cancer firstly. Black-Right-Pointing-Pointer Present the novel roles of FoxP3 in inhibiting proliferation and promoting apoptosis in gastric cancer cells. Black-Right-Pointing-Pointer Overexpression of FoxP3 increased proapoptotic molecules and repressed antiapoptotic molecules. Black-Right-Pointing-Pointer Silencing of FoxP3 reduced the expression of proapoptotic genes, such as PARP, caspase-3 and caspase-9. Black-Right-Pointing-Pointer FoxP3 is sufficient for activating the apoptotic signaling pathway. -- Abstract: Forkhead Box Protein 3 (FoxP3) was identified as a key transcription factor to the occurring and function of the regulatory T cells (Tregs). However, limited evidence indicated its function in tumor cells. To elucidate the precise roles and underlying molecular mechanism of FoxP3 in gastric cancer (GC), we examined the expression of FoxP3 and the consequences of interfering with FoxP3 gene in human GC cell lines, AGS and MKN45, by multiple cellular and molecular approaches, such as immunofluorescence, gene transfection, CCK-8 assay, clone formation assay, TUNEL assay, Flow cytometry, immunoassay and quantities polymerase chain reaction (PCR). As a result, FoxP3 was expressed both in nucleus and cytoplasm of GC cells. Up-regulation of FoxP3 inhibited cell proliferation and promoted cell apoptosis. Overexpression of FoxP3 increased the protein and mRNA levels of proapoptotic molecules, such as poly ADP-ribose polymerase1 (PARP), caspase-3 and caspase-9, and repressed the expression of antiapoptotic molecules, such as cellular inhibitor of apoptosis-1 (c-IAP1) and the long isoform of B cell leukemia/lymphoma-2 (Bcl-2). Furthermore, silencing of FoxP3 by siRNA in GC cells reduced the expression of proapoptotic genes, such as PARP, caspase-3 and caspase-9. Collectively, our findings identify the novel roles of FoxP3 in inhibiting proliferation and inducing apoptosis

  14. DNA damage signaling and apoptosis in preinvasive tubal lesions of ovarian carcinoma.

    Science.gov (United States)

    Chene, Gautier; Ouellet, Veronique; Rahimi, Kurosh; Barres, Veronique; Caceres, Katia; Meunier, Liliane; Cyr, Louis; De Ladurantaye, Manon; Provencher, Diane; Mes Masson, Anne Marie

    2015-06-01

    High-grade serous ovarian cancer (HGSC) is the most life-threatening gynecological malignancy despite surgery and chemotherapy. A better understanding of the molecular basis of the preinvasive stages might be helpful in early detection and diagnosis. Genetic instability is 1 of the characteristics shared by most human cancers, and its level is variable through precancerous lesions to advanced cancer. Because DNA damage response (DDR) has been described as 1 of the first phases in genomic instability, we investigated the level of DDR activation and the apoptosis pathway in serous tubal intraepithelial carcinoma (STIC), the potential precursor of HGSC. A tissue microarray including 21 benign fallopian tubes, 21 STICs, 17 HGSCs from patients with STICs (associated ovarian cancer [AOC]) from the same individuals, and 30 HGSCs without STICs (non-AOC) was used in this study.Immunohistochemistry was performed to evaluate the level of DDR proteins (pATM, pChk2, γH2AX, 53BP1, and TRF2), apoptosis proteins (Bcl2, BAX, and BIM), and cyclin E. The expression of all DDR proteins increased from benign fallopian tubes to STICs. The level of expression of pATM, pChk2, γH2AX, and TRF2 was also increased in STICs in comparison with AOC. BAX, BIM, and cyclin E expressions were high in STICs, whereas Bcl2 expression was low. Immunohistochemical profiles of AOC and non-AOC were also different. These results suggest an activation of the DDR and apoptosis pathways in STICs, indicating that genomic instability may occur early in the precancerous lesions of HGSC.

  15. Metformin induces apoptosis through AMPK-dependent inhibition of UPR signaling in ALL lymphoblasts.

    Directory of Open Access Journals (Sweden)

    Gilles M Leclerc

    Full Text Available The outcome of patients with resistant phenotypes of acute lymphoblastic leukemia (ALL or those who relapse remains poor. We investigated the mechanism of cell death induced by metformin in Bp- and T-ALL cell models and primary cells, and show that metformin effectively induces apoptosis in ALL cells. Metformin activated AMPK, down-regulated the unfolded protein response (UPR demonstrated by significant decrease in the main UPR regulator GRP78, and led to UPR-mediated cell death via up-regulation of the ER stress/UPR cell death mediators IRE1α and CHOP. Using shRNA, we demonstrate that metformin-induced apoptosis is AMPK-dependent since AMPK knock-down rescued ALL cells, which correlated with down-regulation of IRE1α and CHOP and restoration of the UPR/GRP78 function. Additionally rapamycin, a known inhibitor of mTOR-dependent protein synthesis, rescued cells from metformin-induced apoptosis and down-regulated CHOP expression. Finally, metformin induced PIM-2 kinase activity and co-treatment of ALL cells with a PIM-1/2 kinase inhibitor plus metformin synergistically increased cell death, suggesting a buffering role for PIM-2 in metformin's cytotoxicity. Similar synergism was seen with agents targeting Akt in combination with metformin, supporting our original postulate that AMPK and Akt exert opposite regulatory roles on UPR activity in ALL. Taken together, our data indicate that metformin induces ALL cell death by triggering ER and proteotoxic stress and simultaneously down-regulating the physiologic UPR response responsible for effectively buffering proteotoxic stress. Our findings provide evidence for a role of metformin in ALL therapy and support strategies targeting synthetic lethal interactions with Akt and PIM kinases as suitable for future consideration for clinical translation in ALL.

  16. MEK/ERK signaling pathway in apoptosis of SW620 cell line and inhibition effect of resveratrol.

    Science.gov (United States)

    Chen, Hao; Jin, Zhi-Liang; Xu, Hai

    2016-01-01

    To study the involvement of MAPK MEK/ERK signaling transduction pathway in the apoptosis process of SW620 tumor cell line and the inhibition effect of resveratrol. SW620 cell lines were divided into 5 groups, namely, control group, PD98059 group, low-dose resveratrol group, mid-dose resveratrol group and high-dose resveratrol group. The inhibition rate of cell proliferation was detected by MTT method. The expression of apoptotic molecules and MEK/ERK signaling pathway related proteins were assayed by real-time PCR and Western blotting. Compared with control group, the proliferation of cells treated with resveratrol was significantly inhibited. In the case of apoptotic molecules, the expression of Bax, Caspase 3 and Caspase 9 was increased significantly while the expression of anti-apoptotic molecule Bcl2 was decreased significantly in resveratrol groups with a dose-dependent manner. In the case of molecules in MEK/ERK signaling pathway, the expression of Ras, Raf, MEK and ERK1/2 was decreased significantly in resveratrol groups with a dose-dependent manner. PD98059 and resveratrol can effectively inhibit the proliferation of SW620 through inhibiting the MEK/ERK signaling pathway. Copyright © 2016 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

  17. Colchicine induces apoptosis in HT‑29 human colon cancer cells via the AKT and c-Jun N-terminal kinase signaling pathways.

    Science.gov (United States)

    Huang, Zhen; Xu, Ye; Peng, Wei

    2015-10-01

    Colchicine is a natural compound, which belongs to the botanical family Colchicaceae and prevents growth of cancer cells via antimitotic activity by interacting with microtubules. Although numerous studies have demonstrated that the effect of colchicine on cell apoptosis is mediated by the activation of caspase‑3, the signaling pathways involved in the process remain unknown. In the current study, evidence is presented regarding the missing information using HT‑29 human colon cancer cells. The effect of colchicine on apoptosis in HT‑29 cells and the apoptosis‑associated signaling pathways were determined using various methods, including cell viability assay, Annexin V/propidium idodide (PI) binding, PI staining, Hoechst 33342 staining, mitochondrial membrane potential (Δψm) assay, reactive oxygen species (ROS) assay and western blot analysis. Colchicine was observed to induce a dose‑dependent reduction in cell viability in HT‑29 cells and early apoptosis occurred when the cells were treated with 1 µg/ml colchicine. Furthermore, colchicine treatment induced a loss of Δψm, increased ROS production, activated caspase‑3, upregulated BAX expression and downregulated Bcl‑2 expression, which evidenced the colchicine activity on apoptosis, potentially by acting via the intrinsic apoptotic signaling pathway. Colchicine increased phosphorylation of p38, although not phosphorylation of extracellular signal-regulated kinase and c-Jun N-terminal kinase, which indicates that colchicine activates the p38 signaling pathway in order to induce cell apoptosis. Therefore, colchicine exhibited significant growth inhibition of the HT‑29 colon cancer cell line and induced apoptosis in the cells via the mitochondrial pathway, which is regulated by p38 signaling pathways.

  18. Curcumin Analog DK1 Induces Apoptosis in Human Osteosarcoma Cells In Vitro through Mitochondria-Dependent Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Muhammad Nazirul Mubin Aziz

    2018-01-01

    Full Text Available Osteosarcoma is one of the primary malignant bone tumors that confer low survival rates for patients even with intensive regime treatments. Therefore, discovery of novel anti-osteosarcoma drugs derived from natural products that are not harmful to the normal cells remains crucial. Curcumin is one of the natural substances that have been extensively studied due to its anti-cancer properties and is pharmacologically safe considering its ubiquitous consumption for centuries. However, curcumin suffers from a poor circulating bioavailability, which has led to the development of a chemically synthesized curcuminoid analog, namely (Z-3-hydroxy-1-(2-hydroxyphenyl-3-phenylprop-2-en-1-one (DK1. In this study, the cytotoxic effects of the curcumin analog DK1 was investigated in both U-2OS and MG-63 osteosarcoma cell lines using 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay and cell death was microscopically examined via acridine orange/propidium iodide (AO/PI double staining. Flow cytometer analysis including Annexin V/Fluorescein isothiocyanate (FITC, cell cycle analysis and JC-1 were adapted to determine the mode of cell death. Subsequently in order to determine the mechanism of cell death, quantitative polymerase chain reaction (qPCR and proteome profiling was carried out to measure the expression of several apoptotic-related genes and proteins. Results indicated that DK1 induced U-2 OS and MG-63 morphological changes and substantially reduced cell numbers through induction of apoptosis. Several apoptotic genes and proteins were steadily expressed after treatment with DK1; including caspase 3, caspase 9, and BAX, which indicated that apoptosis occurred through a mitochondria-dependent signaling pathway. In conclusion, DK1 could be considered as a potential candidate for an anti-osteosarcoma drug in the near future, contingent upon its ability to induce apoptosis in osteosarcoma cell lines.

  19. Low proliferation and high apoptosis of osteoblastic cells on hydrophobic surface are associated with defective Ras signaling

    International Nuclear Information System (INIS)

    Chang, Eun-Ju; Kim, Hong-Hee; Huh, Jung-Eun; Kim, In-Ae; Seung Ko, Jea; Chung, Chong-Pyoung; Kim, Hyun-Man

    2005-01-01

    The hydrophobic (HPB) nature of most polymeric biomaterials has been a major obstacle in using those materials in vivo due to low compatibility with cells. However, there is little knowledge of the molecular detail to explain how surface hydrophobicity affects cell responses. In this study, we compared the proliferation and apoptosis of human osteoblastic MG63 cells adhered to hydrophilic (HPL) and hydrophobic surfaces. On the hydrophobic surface, less formation of focal contacts and actin stress fibers, a delay in cell cycle progression, and an increase in apoptosis were observed. By using fibroblast growth factor 1 (FGF1) as a model growth factor, we also investigated intracellular signaling pathways on hydrophilic and hydrophobic surfaces. The activation of Ras, Akt, and ERK by FGF1 was impaired in MG63 cells on the hydrophobic surface. The overexpression of constitutively active form of Ras and Akt rescued those cells from apoptosis and recovered cell cycle progression. Furthermore, their overexpression also restored the actin cytoskeletal organization on the hydrophobic surface. Finally, the proliferative, antiapoptotic, and cytoskeletal effects of constitutively active Ras in MG63 cells on the hydrophobic surface were blocked by wortmannin and PD98059 that inhibit Akt and ERK activation, respectively. Therefore, our results suggest that the activation of Ras and its downstream molecules Akt and ERK to an appropriate level is one of crucial elements in the determination of osteoblast cell responses. The Ras pathway may represent a cell biological target that should be considered for successful surface modification of biomaterials to induce adequate cell responses in the bone tissue

  20. Ursolic acid simultaneously targets multiple signaling pathways to suppress proliferation and induce apoptosis in colon cancer cells.

    Directory of Open Access Journals (Sweden)

    Jingshu Wang

    Full Text Available Ursolic acid (UA, a natural pentacyclic triterpenoid carboxylic acid distributed in medical herbs, exerts antitumor effects and is emerging as a promising compound for cancer prevention and therapy, but its excise mechanisms of action in colon cancer cells remains largely unknown. Here, we identified the molecular mechanisms by which UA inhibited cell proliferation and induced apoptosis in human colon cancer SW480 and LoVo cells. Treatment with UA led to significant inhibitions in cell viability and clone formation and changes in cell morphology and spreading. UA also suppressed colon cancer cell migration by inhibiting MMP9 and upregulating CDH1 expression. Further studies showed that UA inhibited the phosphorylation of Akt and ERK proteins. Pretreatment with an Akt or ERK-specific inhibitor considerably abrogated the proliferation inhibition by UA. UA also significantly inhibited colon cancer cell COX-2 expression and PGE2 production. Pretreatment with a COX-2 inhibitor (celecoxib abrogated the UA-induced cell proliferation. Moreover, we found that UA effectively promoted NF-κB and p300 translocation from cell nuclei to cytoplasm, and attenuated the p300-mediated acetylation of NF-κB and CREB2. Pretreatment with a p300 inhibitor (roscovitine abrogated the UA-induced cell proliferation, which is reversed by p300 overexpression. Furthermore, UA treatment induced colon cancer cell apoptosis, increased the cleavage of PARP, caspase-3 and 9, and trigged the release of cytochrome c from mitochondrial inter-membrane space into cytosol. These results indicate that UA inhibits cell proliferation and induces apoptosis in colon cancer cells through simultaneous modulation of the multiple signaling pathways such as MMP9/CDH1, Akt/ERK, COX-2/PGE2, p300/NF-κB/CREB2, and cytochrome c/caspase pathways.

  1. SENP1 inhibition induces apoptosis and growth arrest of multiple myeloma cells through modulation of NF-κB signaling

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jun [Graduate School of Anhui Medical University, Hefei (China); Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850 (China); Sun, Hui-Yan; Xiao, Feng-Jun; Wang, Hua [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850 (China); Yang, Yang [Department of Hematology, General Hospital of Air Force, Beijing (China); Wang, Lu; Gao, Chun-Ji [Department of Hematology, PLA General Hospital, Beijing (China); Guo, Zi-Kuan [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850 (China); Wu, Chu-Tse [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850 (China); Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu (China); Wang, Li-Sheng, E-mail: Wangls@bmi.ac.cn [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850 (China); Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu (China)

    2015-05-01

    SUMO/sentrin specific protease 1 (Senp1) is an important regulation protease in the protein sumoylation, which affects the cell cycle, proliferation and differentiation. The role of Senp1 mediated protein desumoylation in pathophysiological progression of multiple myeloma is unknown. In this study, we demonstrated that Senp1 is overexpressed and induced by IL-6 in multiple myeloma cells. Lentivirus-mediated Senp1 knockdown triggers apoptosis and reduces viability, proliferation and colony forming ability of MM cells. The NF-κB family members including P65 and inhibitor protein IkBα play important roles in regulation of MM cell survival and proliferation. We further demonstrated that Senp1 inhibition decreased IL-6-induced P65 and IkBα phosphorylation, leading to inactivation of NF-kB signaling in MM cells. These results delineate a key role for Senp1in IL-6 induced proliferation and survival of MM cells, suggesting it may be a potential new therapeutic target in MM. - Highlights: • Senp1 is overexpressed and induced by IL-6 in multiple myeloma cells. • Senp1 knockdown triggers apoptosis and reduces proliferation of MM cells. • Senp1 inhibition decreased IL-6-induced P65 and IkBα phosphorylation.

  2. SENP1 inhibition induces apoptosis and growth arrest of multiple myeloma cells through modulation of NF-κB signaling

    International Nuclear Information System (INIS)

    Xu, Jun; Sun, Hui-Yan; Xiao, Feng-Jun; Wang, Hua; Yang, Yang; Wang, Lu; Gao, Chun-Ji; Guo, Zi-Kuan; Wu, Chu-Tse; Wang, Li-Sheng

    2015-01-01

    SUMO/sentrin specific protease 1 (Senp1) is an important regulation protease in the protein sumoylation, which affects the cell cycle, proliferation and differentiation. The role of Senp1 mediated protein desumoylation in pathophysiological progression of multiple myeloma is unknown. In this study, we demonstrated that Senp1 is overexpressed and induced by IL-6 in multiple myeloma cells. Lentivirus-mediated Senp1 knockdown triggers apoptosis and reduces viability, proliferation and colony forming ability of MM cells. The NF-κB family members including P65 and inhibitor protein IkBα play important roles in regulation of MM cell survival and proliferation. We further demonstrated that Senp1 inhibition decreased IL-6-induced P65 and IkBα phosphorylation, leading to inactivation of NF-kB signaling in MM cells. These results delineate a key role for Senp1in IL-6 induced proliferation and survival of MM cells, suggesting it may be a potential new therapeutic target in MM. - Highlights: • Senp1 is overexpressed and induced by IL-6 in multiple myeloma cells. • Senp1 knockdown triggers apoptosis and reduces proliferation of MM cells. • Senp1 inhibition decreased IL-6-induced P65 and IkBα phosphorylation

  3. SKF95365 induces apoptosis and cell-cycle arrest by disturbing oncogenic Ca2+ signaling in nasopharyngeal carcinoma cells

    Directory of Open Access Journals (Sweden)

    Zhang J

    2015-10-01

    Full Text Available Jinyan Zhang,1 Jiazhang Wei,2 Qian He,3 Yan Lin,1 Rong Liang,1 Jiaxiang Ye,1 Zhe Zhang,4 Yongqiang Li1 1Department of Medical Oncology, Affiliated Cancer Hospital of Guangxi Medical University, 2Department of Otolaryngology-Head and Neck Oncology, The People’s Hospital of Guangxi Zhuang Autonomous Region, Nanning, People’s Republic of China; 3Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Japan; 4Department of Otolaryngology-Head & Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, People’s Republic of China Background: Aberrant modulation of store-operated calcium ions (Ca2+ entry promotes the progression of human malignancies. Previously, we reported that the blockage of store-operated Ca2+ entry inhibited epidermal growth factor (EGF-stimulated migration and distant metastasis in nasopharyngeal carcinoma (NPC cells. However, the effects of pharmacological blocker on other Ca2+ signaling-regulated malignant characteristics in NPC cells remained poorly understood. Methods: We examined the effects of SKF96365, an inhibitor of store-operated Ca2+ channel, on EGF-launched Ca2+ signaling in two NPC cell lines. We determined the effects of SKF96365 on cell proliferation, colony formation, apoptosis, and cell-cycle status in vitro. We further elucidated the antitumor activity of SKF96365 in xenograft-bearing mice. Results: It was found that SKF96365 disturbed the thapsigargin (TG-stimulated Ca2+ release from endoplasmic reticulum and the subsequent Ca2+ influx. SKF96365 alone stimulated Ca2+ responses merely due to endoplasmic reticulum-released Ca2+. SKF96365 promoted cell mortality, inhibited colony formation, and induced apoptosis and cell-cycle arrest, while blunting the EGF-evoked Ca2+ signaling. Furthermore, we confirmed that SKF96365 reduced NPC xenograft growth while activating caspase-7-related apoptotic pathway. Conclusion: SKF96365 exerts multiple antitumor

  4. Apoptosis is signalled early by low doses of ionising radiation in a radiation-induced bystander effect

    Energy Technology Data Exchange (ETDEWEB)

    Furlong, Hayley, E-mail: hayley.furlong@dit.ie [DIT Centre for Radiation and Environmental Science, Focas Research Institute, Dublin Institute of Technology, Kevin St, Dublin 8 (Ireland); School of Biological Sciences, College of Sciences and Health, Dublin Institute of Technology, Kevin St, Dublin 8 (Ireland); Mothersill, Carmel [Medical Physics and Applied Radiation Sciences, Nuclear Research Building, 1280 Hamilton, Ontario L8S 4K1 (Canada); Lyng, Fiona M. [DIT Centre for Radiation and Environmental Science, Focas Research Institute, Dublin Institute of Technology, Kevin St, Dublin 8 (Ireland); Howe, Orla [DIT Centre for Radiation and Environmental Science, Focas Research Institute, Dublin Institute of Technology, Kevin St, Dublin 8 (Ireland); School of Biological Sciences, College of Sciences and Health, Dublin Institute of Technology, Kevin St, Dublin 8 (Ireland)

    2013-01-15

    Highlights: ► Molecular mechanisms involved in the production of a radiation induced bystander effect are not well known. ► We investigate gene expression changes in apoptotic genes in both direct and bystander responses. ► We demonstrate initiation of the apoptotic cascade in a bystander response. ► Lower doses reveal a specific but differential response related to apoptosis compared to higher doses. - Abstract: It is known that ionising radiation (IR) induces a complex signalling apoptotic cascade post-exposure to low doses ultimately to remove damaged cells from a population, specifically via the intrinsic pathway. Therefore, it was hypothesised that bystander reporter cells may initiate a similar apoptotic response if exposed to low doses of IR (0.05 Gy and 0.5 Gy) and compared to directly irradiated cells. Key apoptotic genes were selected according to their role in the apoptotic cascade; tumour suppressor gene TP53, pro-apoptotic Bax and anti-apoptotic Bcl2, pro-apoptotic JNK and anti-apoptotic ERK, initiator caspase 2 and 9 and effector caspase 3, 6 and 7. The data generated consolidated the role of apoptosis following direct IR exposure for all doses and time points as pro-apoptotic genes such as Bax and JNK as well as initiator caspase 7 and effector caspase 3 and 9 were up-regulated. However, the gene expression profile for the bystander response was quite different and more complex in comparison to the direct response. The 0.05 Gy dose point had a more significant apoptosis gene expression profile compared to the 0.5 Gy dose point and genes were not always expressed within 1 h but were sometimes expressed 24 h later. The bystander data clearly demonstrates initiation of the apoptotic cascade by the up-regulation of TP53, Bax, Bcl-2, initiator caspase 2 and effector caspase 6. The effector caspases 3 and 7 of the bystander samples demonstrated down-regulation in their gene expression levels at 0.05 Gy and 0.5 Gy at both time points therefore not

  5. The signalling axis mediating neuronal apoptosis in response to [Pt(O,O'-acac)(γ-acac)(DMS)].

    Science.gov (United States)

    Muscella, Antonella; Calabriso, Nadia; Vetrugno, Carla; Fanizzi, Francesco Paolo; De Pascali, Sandra Angelica; Marsigliante, Santo

    2011-06-01

    It was previously shown that [Pt(O,O'-acac)(γ-acac)(DMS)] induces apoptosis in various cancer cells and exerts antimetastatic responses in vitro. In rats, [Pt(O,O'-acac)(γ-acac)(DMS)] reaches the central nervous system in quantities higher than cisplatin causing less excitotoxicity. The aim of the present paper was to investigate whether [Pt(O,O'-acac)(γ-acac)(DMS)] is able to exert cytotoxic effects on SH-SY5Y human neuroblastoma cell line, and to study the intracellular transduction mechanisms underlying these effects. Here we have demonstrated that [Pt(O,O'-acac)(γ-acac)(DMS)] was more effective than cisplatin in provoking apoptosis characterized by: (a) mitochondria depolarization, (b) decrease of Bcl-2 expression and increase of BAX expressions with cytosol-to-mitochondria translocation, (c) activation of caspase-7 and -9 and (d) generation of reactive oxygen species (ROS). [Pt(O,O'-acac)(γ-acac)(DMS)] provoked the activation of the following signalling kinases that were interacting with each other: PKC-δ and -ɛ, ERK1/2, p38MAPK, JNK1/2, NF-κB, c-src and FAK. We found that ROS generated by NADPH oxidase was responsible for the [Pt(O,O'-acac)(γ-acac)(DMS)]-mediated PKC-δ and -ɛ activation and consequential phosphorylation of all MAPKs. [Pt(O,O'-acac)(γ-acac)(DMS)]-induced mitochondrial apoptosis was blocked when p38MAPK and JNK1/2 were inhibited, whilst the effects on Bax/Bcl-2 mRNA and protein levels were blocked inhibiting NF-κB. NF-κB nuclear translocation was blocked inhibiting MEK1/2 activity. In addition to the induction of apoptosis [Pt(O,O'-acac)(γ-acac)(DMS)] downregulated pro-survival pathway. Survival inhibition started from mitochondrial ROS generation which induced c-src, FAK and Akt activation. In conclusion, our results suggest that [Pt(O,O'-acac)(γ-acac)(DMS)] may be considered a promising compound for the treatment of neuroblastoma. Further studies are warranted to explore in detail the therapeutic potential of this compound

  6. Apoptosis is signalled early by low doses of ionising radiation in a radiation-induced bystander effect

    International Nuclear Information System (INIS)

    Furlong, Hayley; Mothersill, Carmel; Lyng, Fiona M.; Howe, Orla

    2013-01-01

    Highlights: ► Molecular mechanisms involved in the production of a radiation induced bystander effect are not well known. ► We investigate gene expression changes in apoptotic genes in both direct and bystander responses. ► We demonstrate initiation of the apoptotic cascade in a bystander response. ► Lower doses reveal a specific but differential response related to apoptosis compared to higher doses. - Abstract: It is known that ionising radiation (IR) induces a complex signalling apoptotic cascade post-exposure to low doses ultimately to remove damaged cells from a population, specifically via the intrinsic pathway. Therefore, it was hypothesised that bystander reporter cells may initiate a similar apoptotic response if exposed to low doses of IR (0.05 Gy and 0.5 Gy) and compared to directly irradiated cells. Key apoptotic genes were selected according to their role in the apoptotic cascade; tumour suppressor gene TP53, pro-apoptotic Bax and anti-apoptotic Bcl2, pro-apoptotic JNK and anti-apoptotic ERK, initiator caspase 2 and 9 and effector caspase 3, 6 and 7. The data generated consolidated the role of apoptosis following direct IR exposure for all doses and time points as pro-apoptotic genes such as Bax and JNK as well as initiator caspase 7 and effector caspase 3 and 9 were up-regulated. However, the gene expression profile for the bystander response was quite different and more complex in comparison to the direct response. The 0.05 Gy dose point had a more significant apoptosis gene expression profile compared to the 0.5 Gy dose point and genes were not always expressed within 1 h but were sometimes expressed 24 h later. The bystander data clearly demonstrates initiation of the apoptotic cascade by the up-regulation of TP53, Bax, Bcl-2, initiator caspase 2 and effector caspase 6. The effector caspases 3 and 7 of the bystander samples demonstrated down-regulation in their gene expression levels at 0.05 Gy and 0.5 Gy at both time points therefore not

  7. Nrf2/p62 Signaling in Apoptosis Resistance and Its Role in Cadmium-induced Carcinogenesis*

    Science.gov (United States)

    Son, Young-Ok; Pratheeshkumar, Poyil; Roy, Ram Vinod; Hitron, John Andrew; Wang, Lei; Zhang, Zhuo; Shi, Xianglin

    2014-01-01

    The cadmium-transformed human lung bronchial epithelial BEAS-2B cells exhibit a property of apoptosis resistance as compared with normal non-transformed BEAS-2B cells. The level of basal reactive oxygen species (ROS) is extremely low in transformed cells in correlation with elevated expressions of both antioxidant enzymes (catalase, SOD1, and SOD2) and antiapoptotic proteins (Bcl-2/Bcl-xL). Moreover, Nrf2 and p62 are highly expressed in these transformed cells. The knockdown of Nrf2 or p62 by siRNA enhances ROS levels and cadmium-induced apoptosis. The binding activities of Nrf2 on the antioxidant response element promoter regions of p62/Bcl-2/Bcl-xL were dramatically increased in the cadmium-exposed transformed cells. Cadmium exposure increased the formation of LC3-II and the frequency of GFP-LC3 punctal cells in non-transformed BEAS-2B cells, whereas these increases are not shown in transformed cells, an indication of autophagy deficiency of transformed cells. Furthermore, the expression levels of Nrf2 and p62 are dramatically increased during chronic long term exposure to cadmium in the BEAS-2B cells as well as antiapoptotic proteins and antioxidant enzymes. These proteins are overexpressed in the tumor tissues derived from xenograft mouse models. Moreover, the colony growth is significantly attenuated in the transformed cells by siRNA transfection specific for Nrf2 or p62. Taken together, this study demonstrates that cadmium-transformed cells have acquired autophagy deficiency, leading to constitutive p62 and Nrf2 overexpression. These overexpressions up-regulate the antioxidant proteins catalase and SOD and the antiapoptotic proteins Bcl-2 and Bcl-xL. The final consequences are decrease in ROS generation, apoptotic resistance, and increased cell survival, proliferation, and tumorigenesis. PMID:25157103

  8. [Role of Rac1 signaling pathway of azathioprine and peptidoglycan in the regulation of monocyte-macrophage apoptosis in Crohn's disease].

    Science.gov (United States)

    Zhou, Z; Jing, Y; Ran, Y; Zhao, J; Zhou, L; Wang, B M

    2018-04-01

    Objective: To evaluate the changes of macrophages and expression of Rac1 in the inflammatory site of Crohn's disease, and to investigate the effects of 6-thioguanine (6-TG) and peptidoglycan on apoptosis of human peripheral blood monocyte-macrophage by regulating Rac1 signaling pathway. Methods: Ten patients with Crohn's disease and eight healthy controls diagnosed were enrolled at Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital from January 2013 to January 2014. The number of macrophages, apoptosis and expression of Rac1 in the inflammation sites and non-inflammation sites of intestinal mucosa were detected in both patients and controls. Peripheral blood mononuclear cells (PBMCs) were sorted by CD 14 immunomagnetic beads. The apoptosis of monocytes, expression of Rac1 and related apoptosis signaling molecules were detected in patients treated with peptidoglycan, 6-TG and Rac1 inhibitor NSC23766 and another 15 healthy donors. Results: The number of macrophages and apoptotic cells significantly increased in the inflammatory group of Crohn's disease patients compared with the non-inflammatory group. The expression of PAK1, downstream molecular of Rac1 signaling pathway of macrophages was also significantly higher in the inflammatory group of Crohn's disease patients than that in healthy controls and non-inflammatory group. Compared with control group, anti-apoptotic signals (NF-κB, Bcl-xL and STAT-3) in PBMCs increased in the peptidoglycan group, while slightly decreased in 6-TG group. 6-TG and NSC23766 significantly promoted peptidoglycan-related anti-apoptosis [peptidoglycan group (8.6±3.7)%, peptidoglycan+ 6-TG group (42.0±2.7)%, peptidoglycan+ NSC23766 group (58.5±6.9)%, PRac1 signaling pathway leading to macrophage apoptosis.

  9. RhoB protects human keratinocytes from UVB-induced apoptosis through epidermal growth factor receptor signaling.

    Science.gov (United States)

    Canguilhem, Bruno; Pradines, Anne; Baudouin, Caroline; Boby, Céline; Lajoie-Mazenc, Isabelle; Charveron, Marie; Favre, Gilles

    2005-12-30

    Exposure of the skin to UVB light results in the formation of DNA photolesions that can give rise to cell death, mutations, and the onset of carcinogenic events. Specific proteins are activated by UVB and then trigger signal transduction pathways that lead to cellular responses. An alteration of these signaling molecules is thought to be a fundamental event in tumor promotion by UVB irradiation. RhoB, encoding a small GTPase has been identified as a DNA damage-inducible gene. RhoB is involved in epidermal growth factor (EGF) receptor trafficking, cytoskeletal organization, cell transformation, and survival. We have analyzed the regulation of RhoB and elucidated its role in the cellular response of HaCaT keratinocytes to relevant environmental UVB irradiation. We report here that the activated GTP-bound form of RhoB is increased rapidly within 5 min of exposure to UVB, and then RhoB protein levels increased concomitantly with EGF receptor (EGFR) activation. Inhibition of UVB-induced EGFR activation prevents RhoB protein expression and AKT phosphorylation but not the early activation of RhoB. Blocking UVB-induced RhoB expression with specific small interfering RNAs inhibits AKT and glycogen synthase kinase-3beta phosphorylation through inhibition of EGFR expression. Moreover, down-regulation of RhoB potentiates UVB-induced cell apoptosis. In contrast, RhoB overexpression protects keratinocytes against UVB-induced apoptosis. These results indicated that RhoB is regulated upon UVB exposure by a two-step process consisting of an early EGFR-independent RhoB activation followed by an EGFR-dependent induction of RhoB expression. Moreover, we have demonstrated that RhoB is essential in regulating keratinocyte cell survival after UVB exposure, suggesting its potential role in photocarcinogenesis.

  10. Embelin-Induced Apoptosis of Human Prostate Cancer Cells Is Mediated through Modulation of Akt and β-Catenin Signaling.

    Directory of Open Access Journals (Sweden)

    Nahee Park

    Full Text Available There is increasing evidence that embelin, an active component of Embelia ribes, induces apoptosis in human cancer cells, but the detailed mechanisms are still unclear. Here, we have investigated the effect of embelin on the growth of human prostate cancer cells. Embelin strongly inhibited cell growth especially in human prostate cancer cell lines, including PC3, DU145, LNCaP-LN3 and normal prostate epithelial cell, RWPE-1 compared to breast cancer (MDA-MB-231, MCF-7, and T47D, hepatoma (HepG2, Hep3B, and HuH-7, or choriocarcinoma (JEG-3. We observed that embelin induced apoptosis of PC3 cells in a time-dependent manner correlated with decreased expression of Bcl-2, Bcl-xL, and Mcl-1, increased translocation of Bax into mitochondria, and a reduction in the mitochondrial membrane potential. Furthermore, embelin induced voltage-dependent anion channel (VDAC 1 expression and oligomerization, which may promote cytochrome c and AIF release. Because embelin was able to inhibit Akt activation and cyclooxygenase-2 expression, the effects on Wnt/ β-catenin signaling were determined. Embelin activated glycogen synthase kinase (GSK-3β by preventing phosphorylation and suppressed β-catenin expression. Attenuation of β-catenin-mediated TCF transcriptional activity and gene transcription, such as cyclin D1, c-myc, and matrix metalloproteinase (MMP-7, were shown in embelin-treated cells. The changes in β-catenin levels in response to embelin were blocked by lithium chloride, a GSK-3 inhibitor, indicating that embelin may decrease β-catenin expression via GSK-3β activation. Furthermore, exposure of PC3 cells to embelin resulted in a significant decrease in cell migration and invasion. In conclusion, these findings suggest that inhibition of Akt signaling and activation of GSK-3β partially contributes to the pro-apoptotic effect of embelin in prostate cancer cells.

  11. Humanin inhibits apoptosis in pituitary tumor cells through several signaling pathways including NF-κB activation.

    Science.gov (United States)

    Gottardo, María Florencia; Moreno Ayala, Mariela; Ferraris, Jimena; Zárate, Sandra; Pisera, Daniel; Candolfi, Marianela; Jaita, Gabriela; Seilicovich, Adriana

    2017-12-01

    Humanin (HN) and Rattin (HNr), its homologous in the rat, are peptides with cytoprotective action in several cell types such as neurons, lymphocytes and testicular germ cells. Previously, we have shown that HNr is expressed in pituitary cells and that HN inhibited the apoptotic effect of TNF-α in both normal and tumor pituitary cells. The aim of the present study was to identify signaling pathways that mediate the antiapoptotic effect of HN in anterior pituitary cells from ovariectomized rats and in GH3 cells, a somatolactotrope cell line. We assessed the role of STAT3, JNK, Akt and MAPKs as well as proteins of the Bcl-2 family, previously implicated in the antiapoptotic effect of HN. We also evaluated the participation of NF-κB in the antiapoptotic action of HN. STAT3 inhibition reversed the inhibitory effect of HN on TNF-α-induced apoptosis in normal and pituitary tumor cells, indicating that STAT3 signaling pathway mediates the antiapoptotic effect of HN on pituitary cells. Inhibition of NF-κB pathway did not affect action of HN on normal anterior pituitary cells but blocked the cytoprotective effect of HN on TNF-α-induced apoptosis of GH3 cells, suggesting that the NF-κB pathway is involved in HN action in tumor pituitary cells. HN also induced NF-κB-p65 nuclear translocation in these cells. In pituitary tumor cells, JNK and MEK inhibitors also impaired HN cytoprotective action. In addition, HN increased Bcl-2 expression and decreased Bax mitochondrial translocation. Since HN expression in GH3 cells is higher than in normal pituitary cells, we may suggest that through multiple pathways HN could be involved in pituitary tumorigenesis.

  12. Knockdown of apoptosis signal-regulating kinase 1 affects ischaemia-induced astrocyte activation and glial scar formation.

    Science.gov (United States)

    Cheon, So Yeong; Cho, Kyoung Joo; Song, Juhyun; Kim, Gyung Whan

    2016-04-01

    Reactive astrocytes play an essential role in determining the tissue response to ischaemia. Formation of a glial scar can block the neuronal outgrowth that is required for restoration of damaged tissue. Therefore, regulation of astrocyte activation is important; however, the mediator of this process has not been fully elucidated. Apoptosis signal-regulating kinase 1 (ASK1) is an early responder to oxidative stress, and plays a pivotal role in the intracellular signalling pathway of apoptosis, inflammation, and differentiation. To confirm whether ASK1 mediates astrocyte activation and leads to glial scar formation after cerebral ischaemia, we conducted in vivo and in vitro experiments. C57BL/6 mice were subjected to occlusion of the middle cerebral artery, and astrocyte cultures were exposed to oxygen-glucose deprivation. After silencing of ASK1 , astrocyte-associated genes were downregulated, as seen with the use of microarrays. The glial fibrillary acidic protein (GFAP) level was decreased, and correlated with the reduction in the ASK1 level. In astrocytes, reduction in the ASK1 level decreased the activity of the p38 pathway, and the levels of transcription factors for GFAP and GFAP transcripts after hypoxia. In the chronic phase, ASK1 depletion reduced glial scar formation and conserved neuronal structure, which may lead to better functional recovery. These data suggest that ASK1 may be an important mediator of ischaemia-induced astrocyte activation and scar formation, and could provide a potential therapeutic target for treatment after ischaemic stroke. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  13. Effect of Boron on Thymic Cytokine Expression, Hormone Secretion, Antioxidant Functions, Cell Proliferation, and Apoptosis Potential via the Extracellular Signal-Regulated Kinases 1 and 2 Signaling Pathway.

    Science.gov (United States)

    Jin, Erhui; Ren, Man; Liu, Wenwen; Liang, Shuang; Hu, Qianqian; Gu, Youfang; Li, Shenghe

    2017-12-27

    Boron is an essential trace element in animals. Appropriate boron supplementation can promote thymus development; however, a high dose of boron can lead to adverse effects and cause toxicity. The influencing mechanism of boron on the animal body remains unclear. In this study, we examined the effect of boron on cytokine expression, thymosin and thymopoietin secretion, antioxidant function, cell proliferation and apoptosis, and extracellular signal-regulated kinases 1 and 2 (ERK1/2) pathway in the thymus of rats. We found that supplementation with 10 and 20 mg/L boron to the drinking water significantly elevated levels of interleukin 2 (IL-2), interferon γ (IFN-γ), interleukin 4 (IL-4), and thymosin α1 in the thymus of rats (p boron had no apparent effect on many of the above indicators. In contrast, supplementation with 480 and 640 mg/L boron had the opposite effect on the above indicators in rats and elevated levels of pro-inflammatory cytokines, such as interleukin 6 (IL-6), interleukin 1β (IL-1β), and tumor necrosis factor α (TNF-α) (p boron to the drinking water had a U-shaped dose-effect relationship with thymic cytokine expression, hormone secretion, antioxidant function, cell proliferation, and apoptosis. Specifically, supplementation with 10 and 20 mg/L boron promoted thymocyte proliferation and enhanced thymic functions. However, supplementation with 480 and 640 mg/L boron inhibited thymic functions and increased the number of apoptotic thymocytes, suggesting that the effects of boron on thymic functions may be caused via the ERK1/2 signaling pathway.

  14. A Transcriptome Analysis Suggests Apoptosis-Related Signaling Pathways in Hemocytes of Spodoptera litura After Parasitization by Microplitis bicoloratus

    Science.gov (United States)

    Zhang, Yan; Yu, Dongshuai; Yang, Minjun; Yang, Yang; Hu, Jiansheng; Luo, Kaijun

    2014-01-01

    Microplitis bicoloratus parasitism induction of apoptotic DNA fragmentation of host Spodoptera litura hemocytes has been reported. However, how M. bicoloratus parasitism regulates the host signaling pathways to induce DNA fragmentation during apoptosis remains unclear. To address this question, we performed a new RNAseq-based comparative analysis of the hemocytes transcriptomes of non-parasitized and parasitized S. litura. We were able to assemble a total of more than 11.63 Gbp sequence, to yield 20,571 unigenes. At least six main protein families encoded by M. bicoloratus bracovirus are expressed in the parasitized host hemocytes: Ankyrin-repeat, Ben domain, C-type lectin, Egf-like and Mucin-like, protein tyrosine phosphatase. The analysis indicated that during DNA fragmentation and cell death, 299 genes were up-regulated and 2,441 genes were down-regulated. Data on five signaling pathways related with cell death, the gap junctions, Ca2+, PI3K/Akt, NF-κB, ATM/p53 revealed that CypD, which is involved in forming a Permeability Transition Pore Complex (PTPC) to alter mitochondrial membrane permeabilization (MMP), was dramatically up-regulated. The qRT-PCR also provided that the key genes for cell survival were down-regulated under M. bicoloratus parasitism, including those encoding Inx1, Inx2 and Inx3 of the gap junction signaling pathway, p110 subunit of the PI3K/Akt signaling pathway, and the p50 and p65 subunit of the NF-κB signaling pathway. These findings suggest that M. bicoloratus parasitism may regulate host mitochondria to trigger internucleosomal DNA fragmentation. This study will facilitate the identification of immunosuppression-related genes and also improves our understanding of molecular mechanisms underlying polydnavirus-parasitoid-host interaction. PMID:25350281

  15. The role of NgR-Rhoa-Rock signal pathway in retinal ganglion cell apoptosis of early diabetic rats

    Directory of Open Access Journals (Sweden)

    Yun-Jie Fu

    2014-09-01

    Full Text Available AIM: To study the function and mechanism of the NgR-Rhoa-Rock signal pathways which exists in the retinal ganglion cells apoptosis in diabetes mellitus(DMrats. METHODS: Some healthy SD rats were operated by means of single intraperitoneal injection of 1% streptozotocin based on the standard of 50mg/kg wight, after that the blood sugar value was greater than 16.7mmol/L as DM model, then randomly divided into 3 groups, each group was 10 rats. In addition to take 10 healthy SD rats as control group. Four groups of rats were bilaterally eyeball intravitreal injection in turn with NgR-siRNA virus 10μL(siRNA group, NgR-siRNA virus diluted 10μL(DM group, NgR-siRNA virus-negative-control solution 10μL(siRNA blank group, NgR-siRNA virus diluted 10μL(normal control group, and fed normally. During that time, some life indexes like blood glucose, body mass, etc. were measured and recorded. After 12wk, the expression of NgR and Rhoa, HE staining, and TUNNEL staining were detected by Western blot analysis. RESULTS: Western blot analysis: compared with normal control group, the expression of NgR and Rhoa in DM group and siRNA blank group increased significantly(PP>0.05; compared with DM group and siRNA blank group, the expression of those proteins significantly lowered in siRNA group. HE staining: compared with normal control group, some extent ganglion cells arranged disorder, irregular shape, spacing not consistent were all found in three groups of model rats; compared with DM group and siRNA blank group, there was some improvement in siRNA group of ganglion cells about the order and shape size. TUNEL staining: compared with normal control group, there were retinal ganglion cells apoptosis in all of three groups of model rats. Compared with DM group and siRNA blank group, the number of retinal ganglion cells apoptotic cells was less, and the shape of cells had improved significantly in siRNA group. CONCLUSION: In the DM phase, the expression of NgR and

  16. SOST silencing promotes proliferation and invasion and reduces apoptosis of retinoblastoma cells by activating Wnt/β-catenin signaling pathway.

    Science.gov (United States)

    Wu, T; Wang, L-N; Tang, D-R; Sun, F-Y

    2017-07-01

    This study aimed to investigate the effects of SOST and the Wnt/β-catenin signaling pathway on the proliferation, migration, invasion, and apoptosis of human retinoblastoma cells. Fifty-five retinoblastoma and 21 normal retinal tissue samples were collected as the case group and control group, respectively. HXO-RB44 and SO-RB50 cells were selected and assigned into blank, negative control (NC), siRNA 1, siRNA 2, siRNA 3, IWR-1-endo 1, IWR-1-endo 2 and IWR-1-endo 3 groups. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to detect the expression of SOST, Wnt-1, and β-catenin in the collected tissue samples. MTT assay, flow cytometry, transwell assay and the starch test were employed to determine the cell proliferation, cell cycle, apoptosis, invasion and migration after transfection. The qRT-PCR and western blotting were also used to detect the mRNA and protein expressions of SOST, Wnt-1, β-catenin, C-myc, Cyclin D1, MMP-2 and MMP-9. The tumor formation in nude mice was conducted to evaluate the effects of SOST on the growth of a transplanted tumor. Compared with normal retinal tissues, the retinoblastoma tissues exhibited a downregulation of SOST but an upregulation of Wnt-1 and β-catenin. The proliferation, invasion and migration of HXO-RB44 and SO-RB50 cells in the SOST-siRNA group were significantly higher than the cells in the blank and NC groups. The expressions of Wnt-1, β-catenin, C-myc, Cyclin D1, MMP-2 and MMP-9 in the three SOST-siRNA groups were elevated, but the SOST decreased when compared with the blank and NC groups. SOST silencing promoted the growth of transplanted tumors in nude mice. These findings indicate that SOST silencing promotes the proliferation, invasion and migration, and decreases the apoptosis of human retinoblastoma cells by activating the Wnt/β-catenin signaling pathway.

  17. [The role of FOXO3a-Bim signaling in triptolide induced bladder cancer T24 cells apoptosis].

    Science.gov (United States)

    Yang, L L; Wang, X Y; Zheng, L Y; Fang, S J; Xu, M; Zhao, Z W; Ji, J S

    2017-04-18

    Objective: To investigate the role of FOXO3a-Bim signaling in triptolide induced bladder cancer T24 cells apoptosis. Methods: T24 cells were used and divided into control group, triptolide group(50 nmol/L), MK2206 group(50 nmol/L triptolide+ 5 μmol/L MK2206), FOXO3a-siRNA group(50 nmol/L triptolide+ 100 nmol/L FOXO3a-siRNA), Bim-siRNA group (50 nmol/L triptolide+ 100 nmol/L Bim-siRNA). MTT assay was used to analyze the cells growth inhibition.Annexin V/PI staining was implemented to detect cell apoptosis rate, the expression of p-Akt, Akt, p-FOXO3a, FOXO3a, Bim, Bax.Cleaved-caspase 3 was analyzed by Western blot. Results: After treatment with triptolide 25, 50, 100, 250 nmol/L, the cell growth inhibition rates at 24 hours(17%±9%, 24%±5%, 43%±8%, 61%±8%), 48 hours (20%±7%, 34%±6%, 56%±7%, 74%±5%) and 72 hours(32%±8%, 41%±7%, 69%±7%, 84%±3%) were significantly higher than control group respectively.The IC(50) at 24, 48, 72 hours were (113±10), (91±8), (68±5) nmol/L; the cell apoptosis rates at 24 hours (10%±4%, 15%±5%, 29%±8%, 46%±8%), 48 hours (16%±5%, 24%±6%, 40%±7%, 55%±9%) and 72 hours (27%±4%, 38%±5%, 50%±9%, 65%±8%) were significantly increased ( P Bim, Bax, cleaved-caspase 3.The cell inhibition rate in Triptolide group (30%±8%) was significantly higher than that in the control group ( P Bim-siRNA group (11%±6%) were also higher than the control group.Compared with the triptolide group, the inhibition rate in MK2206 group was significantly increased, but decreased in FOXO3a-siRNA group and Bim-siRNA group( P Bim signaling pathway.

  18. Spatial database for intersections.

    Science.gov (United States)

    2015-08-01

    Deciding which intersections in the state of Kentucky warrant safety improvements requires a comprehensive inventory : with information on every intersection in the public roadway network. The Kentucky Transportation Cabinet (KYTC) : had previously c...

  19. INTERSECTIONAL DISCRIMINATION AGAINST CHILDREN

    DEFF Research Database (Denmark)

    Ravnbøl, Camilla Ida

    This paper adds a perspective to existing research on child protection by engaging in a debate on intersectional discrimination and its relationship to child protection. The paper has a twofold objective, (1) to further establish intersectionality as a concept to address discrimination against ch...... children, and (2) to illustrate the importance of addressing intersectionality within rights-based programmes of child protection....

  20. Intersection region I-2

    CERN Multimedia

    CERN PhotoLab

    1972-01-01

    Intersection region I-2 at the ISR showing the small-angle spectrometer at upper left and the large-angle rotating spectrometer on the right. The intersection is behind the wire spark chambers at the centre of the photo. The foil-covered housing appearing above the intersection is part of the "igloo" of the muon spectrometer.

  1. Deburring small intersecting holes

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, L.K.

    1980-08-01

    Deburring intersecting holes is one of the most difficult deburring tasks faced by many industries. Only 14 of the 37 major deburring processes are applicable to most intersecting hole applications. Only five of these are normally applicable to small or miniature holes. Basic process capabilities and techniques used as a function of hole sizes and intersection depths are summarized.

  2. Short-term hypoxia upregulated Mas receptor expression to repress the AT1 R signaling pathway and attenuate Ang II-induced cardiomyocyte apoptosis.

    Science.gov (United States)

    Chang, Ruey-Lin; Chang, Chih-Fen; Ju, Da-Tong; Ho, Tsung-Jung; Chang, Tung-Ti; Lin, Jing-Wei; Li, Jia-Chun; Cheng, Shiu-Min; Day, Cecilia-Hsuan; Viswanadha, Vijaya Padma; Huang, Chih-Yang

    2018-03-01

    Hypertension-stimulated cardiac hypertrophy and apoptosis play critical roles in the progression of heart failure. Our previous study suggested that hypertensive angiotensin II (Ang II) enhanced insulin-like growth factor receptor II (IGF-IIR) expression and cardiomyocyte apoptosis, which are involved JNK activation, sirtuin1 (SIRT1) degradation, and heat-shock transcription factor 1 (HSF1) acetylation. Moreover, previous studies have implied that short-term hypoxia (STH) might exert cardioprotective effects. However, the effects of STH on Ang II-induced cardiomyocyte apoptosis remain unknown. In this study, we found that STH reduced myocardial apoptosis caused by Ang II via upregulation of the Mas receptor (MasR) to inhibit the AT 1 R signaling pathway. STH activates MasR to counteract the Ang II pro-apoptotic signaling cascade by inhibiting IGF-IIR expression via downregulation of JNK activation and reduction of SIRT1 degradation. Hence, HSF could remain deacetylated, and repress IGF-IIR expression. These effects decrease the activation of downstream pro-apoptotic and hypertrophic cascades and protect cardiomyocytes from Ang II-induced injury. In addition, we also found that silencing MasR expression enhanced Ang II-induced cardiac hypertrophy and the apoptosis signaling pathway. These findings suggest a critical role for MasR in cardiomyocyte survival. Altogether, our findings indicate that STH protects cardiomyocytes from Ang II-stimulated apoptosis. The protective effects of STH are associated with the upregulation of MasR to inhibit AT 1 R signaling. STH could be a potential therapeutic strategy for cardiac diseases in hypertensive patients. © 2017 Wiley Periodicals, Inc.

  3. [Inhibitory effect of resveratrol on ischemia reperfusion-induced cardiocyte apoptosis and its relationship with PI3K-Akt signaling pathway].

    Science.gov (United States)

    He, Dongwei; Liu, Xinwei; Pang, Yong; Liu, Liu

    2012-08-01

    To study the effect of resveratol on ischemia reperfusion-induced cardiocyte apoptosis and its relationship with PI3K-Akt signaling pathway. Fifty male SD rats were divided randomly into five groups: the control group (SH group), the ischemia reperfusion group (I/R group), the resveratol pretreatment group (Res group), the resveratol pretreatment + wortmannin group (Res +Wom group) and the ischemia reperfusion + wortmannin group (I/R + Wom group). The myocardial ischemia model was established by ligating left coronary artery for 45 min followed by 120 min reperfution, in order to observe the contents of NOS and NO. Cardiac myocyte apoptosis was determined by terminal deoxynueleotidyl transferase-mediated dUTP nick end labeling (TUNEL). Bcl-2 and Bax proteins were detected by immunohistochemistry. The t-Akt and p-Akt signaling protein expressions were determined by Western blotting analysis. Compared with the I/R groups and the Res + Wom group, the Res group showed significant increase in the expressions of NOS, NO, Bcl-2 protein and p-Akt and notable decrease in cardiocyte apoptosis and Bax/Bcl-2. The difference of above indicators showed a statistical significance (P<0.05). Furthermore, above changes can be blocked by wortmannin, a specific blocker of PI3K-Akt signaling pathway, indicating a statistical significance in their changes (P<0.05). Resveratol can inhibit the ischemia reperfusion-induced cardiocyte apoptosis, in which PI3K-Akt signaling pathway gets involved.

  4. Resolvin D1 Protects Lipopolysaccharide-induced Acute Kidney Injury by Down-regulating Nuclear Factor-kappa B Signal and Inhibiting Apoptosis

    Directory of Open Access Journals (Sweden)

    Yu-Liang Zhao

    2016-01-01

    Conclusion: In LPS-induced AKI, RvD1 could decrease TNF-α level, ameliorate kidney pathological injury, protect kidney function, and improve animal survival by down-regulating NF-κB inflammatory signal as well as inhibiting renal cell apoptosis.

  5. Infección por el virus de la Lengua azul: activación de señales celulares que inducen apoptosis Bluetongue virus infection: signaling pathway activated during apoptosis

    Directory of Open Access Journals (Sweden)

    E. Mortola

    2009-09-01

    Full Text Available El virus de la Lengua azul (VLA es un ARN virus de doble cadena que induce apoptosis tanto en cultivos celulares como en tejidos blanco. Con el fin de dilucidar el mecanismo de apoptosis en la infección por el VLA, en el presente trabajo examinamos en detalle, por la técnica de Western blot, las señales celulares de caspasas, Bax, citocromo c, Smac/DIABLO y factor nuclear kappa B (NF-kB que se activan en la infección viral. Hemos comprobado que luego de la infección in vitro con el VLA, se detectó la activación de la caspasa 8 y con ello el mecanismo extrínseco de la apoptosis. También detectamos por primera vez no sólo la activación de miembros de la familia Bcl-2 (Bax, sino también la liberación del citocromo c y la proteína Smac/DIABLO, confirmando que en la infección por el VLA está involucrado el mecanismo secuencial intrínseco de la apoptosis. Asimismo, demostramos que la infección por el VLA activa el NF-kB y que la apoptosis es sustancialmente reducida mediante la inhibición del mismo. La activación de las señales celulares tales como Bax, citocromo c, Smac/DIABLO y NF-kB presentados en este trabajo, esclarecen los mecanismos apoptóticos durante la infección por el VLA para una mayor comprensión del papel primario que juega la apoptosis en la patogénesis del virus.Bluetongue (BTV is a double-stranded RNA virus that induces apoptosis both in mammalian cell cultures and in target tissues. To elucidate the apoptosis pathways in BTV infection, we have examined in detail the apoptosis mechanism by examination of caspases, Bax, cytochrome c, Smac/DIABLO and NF-kB signalling pathways. In this report, after cell infection with BTV, the activation of caspase 8 was detected, proving the extrinsic receptor binding apoptotic pathway. Apoptosis followed a sequential pathway involving the detection of activated Bcl-2 family members. Furthermore, its translocation to the mitochondria, as well as the release of cytochrome c and

  6. Growth inhibition and apoptosis in cancer cells induced by polyphenolic compounds of Acacia hydaspica: Involvement of multiple signal transduction pathways

    Science.gov (United States)

    Afsar, Tayyaba; Trembley, Janeen H.; Salomon, Christine E.; Razak, Suhail; Khan, Muhammad Rashid; Ahmed, Khalil

    2016-01-01

    Acacia hydaspica R. Parker is known for its medicinal uses in multiple ailments. In this study, we performed bioassay-guided fractionation of cytotoxic compounds from A. hydaspica and investigated their effects on growth and signaling activity in prostate and breast cancer cell lines. Four active polyphenolic compounds were identified as 7-O-galloyl catechin (GC), catechin (C), methyl gallate (MG), and catechin-3-O-gallate (CG). The four compounds inhibited prostate cancer PC-3 cell growth in a dose-dependent manner, whereas CG and MG inhibited breast cancer MDA-MB-231 cell growth. All tested compounds inhibited cell survival and colony growth in both cell lines, and there was evidence of chromatin condensation, cell shrinkage and apoptotic bodies. Further, acridine orange, ethidium bromide, propidium iodide and DAPI staining demonstrated that cell death occurred partly via apoptosis in both PC-3 and MDA-MB-231 cells. In PC-3 cells treatment repressed the expression of anti-apoptotic molecules Bcl-2, Bcl-xL and survivin, coupled with down-regulation of signaling pathways AKT, NFκB, ERK1/2 and JAK/STAT. In MDA-MB-231 cells, treatment induced reduction of CK2α, Bcl-xL, survivin and xIAP protein expression along with suppression of NFκB, JAK/STAT and PI3K pathways. Our findings suggest that certain polyphenolic compounds derived from A. hydaspica may be promising chemopreventive/therapeutic candidates against cancer. PMID:26975752

  7. E2/ER β Enhances Calcineurin Protein Degradation and PI3K/Akt/MDM2 Signal Transduction to Inhibit ISO-Induced Myocardial Cell Apoptosis

    Directory of Open Access Journals (Sweden)

    Kuan-Ho Lin

    2017-04-01

    Full Text Available Secretion of multifunctional estrogen and its receptor has been widely considered as the reason for markedly higher frequency of heart disease in men than in women. 17β-Estradiol (E2, for instance, has been reported to prevent development of cardiac apoptosis via activation of estrogen receptors (ERs. In addition, protein phosphatase such as protein phosphatase 1 (PP1 and calcineurin (PP2B are also involved in cardiac hypertrophy and cell apoptosis signaling. However, the mechanism by which E2/ERβ suppresses apoptosis is not fully understood, and the role of protein phosphatase in E2/ERβ action also needs further investigation. In this study, we observed that E2/ERβ inhibited isoproterenol (ISO-induced myocardial cell apoptosis, cytochrome c release and downstream apoptotic markers. Moreover, we found that E2/ERβ blocks ISO-induced apoptosis in H9c2 cells through the enhancement of calcineurin protein degradation through PI3K/Akt/MDM2 signaling pathway. Our results suggest that supplementation with estrogen and/or overexpression of estrogen receptor β gene may prove to be effective means to treat stress-induced myocardial damage.

  8. Aconitine-induced Ca2+ overload causes arrhythmia and triggers apoptosis through p38 MAPK signaling pathway in rats.

    Science.gov (United States)

    Sun, Gui-Bo; Sun, Hong; Meng, Xiang-Bao; Hu, Jin; Zhang, Qiang; Liu, Bo; Wang, Min; Xu, Hui-Bo; Sun, Xiao-Bo

    2014-08-15

    Aconitine is a major bioactive diterpenoid alkaloid with high content derived from herbal aconitum plants. Emerging evidence indicates that voltage-dependent Na(+) channels have pivotal roles in the cardiotoxicity of aconitine. However, no reports are available on the role of Ca(2+) in aconitine poisoning. In this study, we explored the importance of pathological Ca(2+) signaling in aconitine poisoning in vitro and in vivo. We found that Ca(2+) overload lead to accelerated beating rhythm in adult rat ventricular myocytes and caused arrhythmia in conscious freely moving rats. To investigate effects of aconitine on myocardial injury, we performed cytotoxicity assay in neonatal rat ventricular myocytes (NRVMs), as well as measured lactate dehydrogenase level in the culture medium of NRVMs and activities of serum cardiac enzymes in rats. The results showed that aconitine resulted in myocardial injury and reduced NRVMs viability dose-dependently. To confirm the pro-apoptotic effects, we performed flow cytometric detection, cardiac histology, transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The results showed that aconitine stimulated apoptosis time-dependently. The expression analysis of Ca(2+) handling proteins demonstrated that aconitine promoted Ca(2+) overload through the expression regulation of Ca(2+) handling proteins. The expression analysis of apoptosis-related proteins revealed that pro-apoptotic protein expression was upregulated, and anti-apoptotic protein BCL-2 expression was downregulated. Furthermore, increased phosphorylation of MAPK family members, especially the P-P38/P38 ratio was found in cardiac tissues. Hence, our results suggest that aconitine significantly aggravates Ca(2+) overload and causes arrhythmia and finally promotes apoptotic development via phosphorylation of P38 mitogen-activated protein kinase. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. cAMP/PKA signaling pathway contributes to neuronal apoptosis via regulating IDE expression in a mixed model of type 2 diabetes and Alzheimer's disease.

    Science.gov (United States)

    Li, Huajie; Yang, Song; Wu, Jian; Ji, Lei; Zhu, Linfeng; Cao, Liping; Huang, Jinzhong; Jiang, Qingqing; Wei, Jiang; Liu, Meng; Mao, Keshi; Wei, Ning; Xie, Wei; Yang, Zhilong

    2018-02-01

    Type 2 diabetes (T2D) may play a relevant role in the development of Alzheimer's disease (AD), however, the underlying mechanism was not clear yet. We developed an animal model presenting both AD and T2D, morris water maze (MWM) test and recognition task were performed to trace the cognitive function. Fasting plasma glucose (FPG) and oral glucose tolerance test (OGTT) were determined to trace the metabolism evolution. TUNEL assay and apoptosis-related protein levels were analyzed for the detection of neuronal apoptosis. Cyclic adenosine monophosphate (cAMP) agonist bucladesine or protein kinase (PKA) inhibitor H-89 were used to determine the effects of cAMP/PKA signaling pathway on IDE expression and neuronal apoptosis. The results showed that T2D contributes to the AD progress by accelerating and worsening spatial memory and recognition dysfunctions. Metabolic parameters and glucose tolerance were significantly changed in the presence of the AD and T2D. The significantly induced neuronal apoptosis and increased pro-apoptotic proteins in mice with AD and T2D were also observed. We showed the decreased expression level of IDE and the activating of cAMP/PKA signaling pathway in AD and T2D mice. Further studies indicated that cAMP agonist decreased the expression level of IDE and induced the neuronal apoptosis in mice with AD and T2D; whereas PKA inhibitor H-89 treatment showed the completely opposite results. Our study indicated that, in the T2D and AD mice, cAMP/PKA signaling pathway and IDE may participate in the contribute role of T2D in accelerating the pathological process of AD via causing the accumulation of Aβ and neuronal apoptosis. © 2017 Wiley Periodicals, Inc.

  10. ESC-3 induces apoptosis of human ovarian carcinomas through Wnt/β-catenin and Notch signaling in vitro and in vivo.

    Science.gov (United States)

    Fu, Qi-Rui; Song, Wei; Deng, Yi-Tao; Li, Hua-Liang; Mao, Xiao-Mei; Lin, Chen-Lu; Zheng, Ya-Hui; Chen, Shu-Ming; Chen, Qiong-Hua; Chen, Qing-Xi

    2017-01-01

    Apoptosis, programmed cell death under physiological or pathological conditions, plays a critical role in the tissue homeostasis of eukaryotes. It is desirable to prevent the occurrence and metastasis of cancer through inducing apoptosis. Our previous study demonstrated that apoptosis could be induced by extract from crocodile in human cholangiocarcinoma. ESC-3, a novel cytotoxic compound isolated from the extract induced apoptosis in Mz-ChA-1 cells via the mitochondria-dependent pathway in a dose-dependent manner. In this study, ESC-3 significantly inhibited the proliferation of A2780 cells and arrested the cells at G2/M phase. After exposure to ESC-3, A2780 cells displayed typical morphological changes and the ability of colony-forming was remarkably inhibited. ESC-3 could significantly upregulate the expression of Bax proteins while Bcl-2 protein remained unchanged, resulting in the elevation of Bax/Bcl-2 ratio, which usually could induce apoptosis. The critical protein of Wnt signaling (β-catenin) was significantly downregulated, whereas Hes1, the downstream protein of Notch signaling, was remarkably attenuated through upregulating the expression of P53. In addition, xenograft models demonstrated that ESC-3 effectively suppressed the growth of OvCa tumors (T/C=42%). Western blot analysis of PCNA and VEGF confirmed that ESC-3 could inhibit the growth and metastasis of OvCa tumors. In conclusion, apoptosis could be induced by ESC-3 through Wnt/β-catenin and Notch signaling in vitro and in vivo, and might have therapeutic potential for the treatment of human OvCa.

  11. Statistical modeling of total crash frequency at highway intersections

    Directory of Open Access Journals (Sweden)

    Arash M. Roshandeh

    2016-04-01

    Full Text Available Intersection-related crashes are associated with high proportion of accidents involving drivers, occupants, pedestrians, and cyclists. In general, the purpose of intersection safety analysis is to determine the impact of safety-related variables on pedestrians, cyclists and vehicles, so as to facilitate the design of effective and efficient countermeasure strategies to improve safety at intersections. This study investigates the effects of traffic, environmental, intersection geometric and pavement-related characteristics on total crash frequencies at intersections. A random-parameter Poisson model was used with crash data from 357 signalized intersections in Chicago from 2004 to 2010. The results indicate that out of the identified factors, evening peak period traffic volume, pavement condition, and unlighted intersections have the greatest effects on crash frequencies. Overall, the results seek to suggest that, in order to improve effective highway-related safety countermeasures at intersections, significant attention must be focused on ensuring that pavements are adequately maintained and intersections should be well lighted. It needs to be mentioned that, projects could be implemented at and around the study intersections during the study period (7 years, which could affect the crash frequency over the time. This is an important variable which could be a part of the future studies to investigate the impacts of safety-related works at intersections and their marginal effects on crash frequency at signalized intersections.

  12. Functional role of ALK-related signal cascades on modulation of epithelial-mesenchymal transition and apoptosis in uterine carcinosarcoma.

    Science.gov (United States)

    Inoue, H; Hashimura, M; Akiya, M; Chiba, R; Saegusa, M

    2017-02-14

    Anaplastic lymphoma kinase (ALK), which is a receptor tyrosine kinase, is essentially and transiently expressed in the developing nervous system. Recently, the deregulated expression of full-length ALK has been observed in some primary solid tumors, but little is known about its involvement in the tumorigenesis of uterine carcinosarcomas (UCSs). Here we examined the functional role of the ALK gene in UCSs. Regulation and function of the ALK gene were assessed using two endometrial carcinoma cell lines. Expression of ALK and its related molecules were also investigated using clinical samples of UCSs. In cell lines, ALK promoter activity was significantly increased by transfection of Sox11 and N-myc, which are known to contribute to neuronal properties. Cells stably overexpressing full-length ALK showed an enhancement of EMT properties mediated by TGF-β1 and HGF, along with an increase in phosphorylated (p) Akt and nuclear p65. Overexpression of p65 also led to transactivation of Twist1 gene, known as an EMT inducer. Finally, treatment of the stable ALK-overexpressing cells with doxorubicin resulted in inhibition of apoptosis with progressive increase in the expression ratio of both pAkt and bcl2 relative to total Akt and bax, respectively. In clinical samples, strong cytoplasmic ALK immunoreactivity and mRNA signals without rearrangement or amplification of the ALK locus were frequently observed in UCSs, particularly in the sarcomatous components. Further, ALK IHC score was found to be positively correlated with Sox11, N-myc, Twist1, and bcl2 scores. ALK-related signal cascades containing Akt, NF-κB, Twist1, and bcl2 may participate in initial signaling for divergent sarcomatous differentiation driven from carcinomatous components in UCSs through induction of the EMT process and inhibition of apoptotic features.

  13. Rasagiline prevents cyclosporine A-sensitive superoxide flashes induced by PK11195, the initial signal of mitochondrial membrane permeabilization and apoptosis.

    Science.gov (United States)

    Wu, Yuqiu; Shamoto-Nagai, Masayo; Maruyama, Wakako; Osawa, Toshihiko; Naoi, Makoto

    2016-05-01

    Rasagiline, a neuroprotective inhibitor of type B monoamine oxidase, prevented PK111195-induced apoptosis in SH-SY5Y cells through inhibition of mitochondrial apoptosis signaling (J Neural Transm 120:1539-1551, 2013, J Neural Transm 122:1399-1407, 2015). This paper presents that PK11195 induced superoxide flashes, the transit production burst, mediated by cyclosporine A-sensitive membrane permeability transition. Rasagiline prevented superoxide flashes, calcium efflux, and cell death by PK11195. Regulation of the initial pore formation at the inner mitochondrial membrane was confirmed as the decisive mechanism of neuroprotection by rasagiline.

  14. 6-OHDA-induced apoptosis and mitochondrial dysfunction are mediated by early modulation of intracellular signals and interaction of Nrf2 and NF-κB factors

    International Nuclear Information System (INIS)

    Tobón-Velasco, Julio C.; Limón-Pacheco, Jorge H.; Orozco-Ibarra, Marisol; Macías-Silva, Marina; Vázquez-Victorio, Genaro; Cuevas, Elvis; Ali, Syed F.

    2013-01-01

    6-Hydroxydopamine (6-OHDA) is a neurotoxin that generates an experimental model of Parkinson's disease in rodents and is commonly employed to induce a lesion in dopaminergic pathways. The characterization of those molecular mechanisms linked to 6-OHDA-induced early toxicity is needed to better understand the cellular events further leading to neurodegeneration. The present work explored how 6-OHDA triggers early downstream signaling pathways that activate neurotoxicity in the rat striatum. Mitochondrial function, caspases-dependent apoptosis, kinases signaling (Akt, ERK 1/2, SAP/JNK and p38) and crosstalk between nuclear factor kappa B (NF-κB) and nuclear factor-erythroid-2-related factor 2 (Nrf2) were evaluated at early times post-lesion. We found that 6-OHDA initiates cell damage via mitochondrial complex I inhibition, cytochrome c and apoptosis-inducing factor (AIF) release, as well as activation of caspases 9 and 3 to induce apoptosis, kinase signaling modulation and NF-κB-mediated inflammatory responses, accompanied by inhibition of antioxidant systems regulated by the Nrf2 pathway. Our results suggest that kinases SAP/JNK and p38 up-regulation may play a role in the early stages of 6-OHDA toxicity to trigger intrinsic pathways for apoptosis and enhanced NF-κB activation. In turn, these cellular events inhibit the activation of cytoprotective mechanisms, thereby leading to a condition of general damage

  15. The neurosurvival factor Humanin inhibits beta-cell apoptosis via signal transducer and activator of transcription 3 activation and delays and ameliorates diabetes in nonobese diabetic mice.

    Science.gov (United States)

    Hoang, Phuong T; Park, Patricia; Cobb, Laura J; Paharkova-Vatchkova, Valdislava; Hakimi, Michael; Cohen, Pinchas; Lee, Kuk-Wha

    2010-03-01

    Pancreatic beta-cell apoptosis is important in the pathogenesis and potential treatment of type 1 diabetes mellitus. We investigated whether Humanin, a recently described survival factor for neurons, could improve the survival of beta-cells and delay or treat diabetes in the nonobese diabetic (NOD) model. Humanin reduced apoptosis induced by serum starvation in NIT-1 cells and decreased apoptosis induced by cytokine treatment. Humanin induced signal transducer and activator of transcription 3 and extracellular signal-regulated kinase phosphorylation over a 24-hour time course. Specific inhibition of signal transducer and activator of transcription 3 resulted in nullifying the protective effect of Humanin. Humanin normalized glucose tolerance in NOD mice treated for 6 weeks, and their pancreata revealed decreased lymphocyte infiltration and severity. In addition, Humanin delayed/prevented the onset of diabetes in NOD mice treated for 20 weeks. In summary, Humanin treatment decreases cytokine-induced apoptosis in beta-cells in vitro and improved glucose tolerance and onset of diabetes in NOD mice in vivo. This indicates that Humanin may be useful for islet protection and survival in a spectrum of diabetes-related therapeutics. (c) 2010 Elsevier Inc. All rights reserved.

  16. MEK and TAK1 Regulate Apoptosis in Colon Cancer Cells with KRAS-Dependent Activation of Proinflammatory Signaling.

    Science.gov (United States)

    McNew, Kelsey L; Whipple, William J; Mehta, Anita K; Grant, Trevor J; Ray, Leah; Kenny, Connor; Singh, Anurag

    2016-12-01

    MEK inhibitors have limited efficacy in treating RAS-RAF-MEK pathway-dependent cancers due to feedback pathway compensation and dose-limiting toxicities. Combining MEK inhibitors with other targeted agents may enhance efficacy. Here, codependencies of MEK, TAK1, and KRAS in colon cancer were investigated. Combined inhibition of MEK and TAK1 potentiates apoptosis in KRAS-dependent cells. Pharmacologic studies and cell-cycle analyses on a large panel of colon cancer cell lines demonstrate that MEK/TAK1 inhibition induces cell death, as assessed by sub-G 1 accumulation, in a distinct subset of cell lines. Furthermore, TAK1 inhibition causes G 2 -M cell-cycle blockade and polyploidy in many of the cell lines. MEK plus TAK1 inhibition causes reduced G 2 -M/polyploid cell numbers and additive cytotoxic effects in KRAS/TAK1-dependent cell lines as well as a subset of BRAF-mutant cells. Mechanistically, sensitivity to MEK/TAK1 inhibition can be conferred by KRAS and BMP receptor activation, which promote expression of NF-κB-dependent proinflammatory cytokines, driving tumor cell survival and proliferation. MEK/TAK1 inhibition causes reduced mTOR, Wnt, and NF-κB signaling in TAK1/MEK-dependent cell lines concomitant with apoptosis. A Wnt/NF-κB transcriptional signature was derived that stratifies primary tumors into three major subtypes: Wnt-high/NF-κB-low, Wnt-low/NF-κB-high and Wnt-high/NF-κB-high, designated W, N, and WN, respectively. These subtypes have distinct characteristics, including enrichment for BRAF mutations with serrated carcinoma histology in the N subtype. Both N and WN subtypes bear molecular hallmarks of MEK and TAK1 dependency seen in cell lines. Therefore, N and WN subtype signatures could be utilized to identify tumors that are most sensitive to anti-MEK/TAK1 therapeutics. This study describes a potential therapeutic strategy for a subset of colon cancers that are dependent on oncogenic KRAS signaling pathways, which are currently difficult to

  17. Xingshentongqiao Decoction Mediates Proliferation, Apoptosis, Orexin-A Receptor and Orexin-B Receptor Messenger Ribonucleic Acid Expression and Represses Mitogen-activated Protein Kinase Signaling

    Directory of Open Access Journals (Sweden)

    Yuanli Dong

    2015-01-01

    Full Text Available Background: Hypocretin (HCRT signaling plays an important role in the pathogenesis of narcolepsy and can be significantly influenced by Chinese herbal therapy. Our previous study showed that xingshentongqiao decoction (XSTQ is clinically effective for the treatment of narcolepsy. To determine whether XSTQ improves narcolepsy by modulating HCRT signaling, we investigated its effects on SH-SY5Y cell proliferation, apoptosis, and HCRT receptor 1/2 (orexin receptor 1 [OX1R] and orexin receptor 2 [OX2R] expression. The signaling pathways involved in these processes were also assessed. Methods: The effects of XSTQ on proliferation and apoptosis in SH-SY5Y cells were assessed using cell counting kit-8 and annexin V-fluorescein isothiocyanate assays. OX1R and OX2R expression was assessed by quantitative real-time polymerase chain reaction analysis. Western blotting for mitogen-activated protein kinase (MAPK pathway activation was performed to further assess the signaling mechanism of XSTQ. Results: XSTQ reduced the proliferation and induced apoptosis of SH-SY5Y cells. This effect was accompanied by the upregulation of OX1R and OX2R expression and the reduced phosphorylation of extracellular signal-regulated kinase (Erk 1/2, p38 MAPK and c-Jun N-terminal kinase (JNK. Conclusions: XSTQ inhibits proliferation and induces apoptosis in SH-SY5Y cells. XSTQ also promotes OX1R and OX2R expression. These effects are associated with the repression of the Erk1/2, p38 MAPK, and JNK signaling pathways. These results define a molecular mechanism for XSTQ in regulating HCRT and MAPK activation, which may explain its ability to treat narcolepsy.

  18. Endoplasmic reticulum stress and IRE-1 signaling cause apoptosis in colon cancer cells in response to andrographolide treatment

    OpenAIRE

    Banerjee, Aditi; Ahmed, Hafiz; Yang, Peixin; Czinn, Steven J.; Blanchard, Thomas G.

    2016-01-01

    The plant metabolite andrographolide induces cell cycle arrest and apoptosis in cancer cells. The mechanism(s) by which andrographolide induces apoptosis however, have not been elucidated. The present study was performed to determine the molecular events that promote apoptosis in andrographolide treated cells using T84, HCT116 and COLO 205 colon cancer cell lines. Andrographolide was determined to limit colony formation and Ki67 expression, alter nuclear morphology, increase cytoplasmic histo...

  19. A novel synthetic analogue of ω-3 17,18-epoxyeicosatetraenoic acid activates TNF receptor-1/ASK1/JNK signaling to promote apoptosis in human breast cancer cells.

    Science.gov (United States)

    Dyari, Herryawan Ryadi Eziwar; Rawling, Tristan; Chen, Yongjuan; Sudarmana, William; Bourget, Kirsi; Dwyer, Julie M; Allison, Sarah E; Murray, Michael

    2017-12-01

    A saturated analog of the cytochrome P450-mediated ω-3-17,18-epoxide of ω-3-eicosapentaenoic acid (C20E) activated apoptosis in human triple-negative MDA-MB-231 breast cancer cells. This study evaluated the apoptotic mechanism of C20E. Increased cytosolic cytochrome c expression and altered expression of pro- and antiapoptotic B-cell lymphoma-2 proteins indicated activation of the mitochondrial pathway. Caspase-3 activation by C20E was prevented by pharmacological inhibition and silencing of the JNK and p38 MAP kinases (MAPK), upstream MAPK kinases MKK4 and MKK7, and the upstream MAPK kinase kinase apoptosis signal-regulating kinase 1 (ASK1). Silencing of the death receptor TNF receptor 1 (TNFR1), but not Fas, DR4, or DR5, and the adapters TRADD and TNF receptor-associated factor 2, but not Fas-associated death domain, prevented C20E-mediated apoptosis. B-cell lymphoma-2 homology 3-interacting domain death agonist (Bid) cleavage by JNK/p38 MAPK linked the extrinsic and mitochondrial pathways of apoptosis. In further studies, an antibody against the extracellular domain of TNFR1 prevented apoptosis by TNF-α but not C20E. These findings suggest that C20E acts intracellularly at TNFR1 to activate ASK1-MKK4/7-JNK/p38 MAPK signaling and to promote Bid-dependent mitochondrial disruption and apoptosis. In in vivo studies, tumors isolated from C20E-treated nu/nu mice carrying MDA-MB-231 xenografts showed increased TUNEL staining and decreased Ki67 staining, reflecting increased apoptosis and decreased proliferation, respectively. ω-3-Epoxy fatty acids like C20E could be incorporated into treatments for triple-negative breast cancers.-Dyari, H. R. E., Rawling, T., Chen, Y., Sudarmana, W., Bourget, K., Dwyer, J. M., Allison, S. E., Murray, M. A novel synthetic analogue of ω-3 17,18-epoxyeicosatetraenoic acid activates TNF receptor-1/ASK1/JNK signaling to promote apoptosis in human breast cancer cells. © FASEB.

  20. Curcumin Inhibits Heat-Induced Apoptosis by Suppressing NADPH Oxidase 2 and Activating the Akt/mTOR Signaling Pathway in Bronchial Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Yuan Peng

    2017-04-01

    demonstrates that one of the critical mechanisms underlying curcumin inhibiting heat-induced apoptosis is through suppressing NADPH Oxidase 2 and activating the Akt/mTOR signaling pathway in bronchial epithelial cells.

  1. 4-Hydroxy-2-nonenal Induces Apoptosis by Inhibiting AKT Signaling in Human Osteosarcoma Cells

    Directory of Open Access Journals (Sweden)

    Guang-rong Ji

    2014-01-01

    Full Text Available The onset of lipid peroxidation within cellular membranes is associated with changes in their physiochemical properties and enzymatic dysfunction of the membrane environment. There are increasing bodies of evidence indicating that aldehydic molecules generated endogenously during the process of lipid peroxidation are causally involved in most of the pathophysiological effects associated with oxidative stress in cells and tissues. 4-Hydroxy-2-nonenal (4-HNE, among them, is believed to be largely responsible for cytopathological effects observed during oxidative stress in vivo and has achieved the status of one of the best recognized and most studied of the cytotoxic products of lipid peroxidation. Here, we reported that 4-HNE treatment may induce cell death in MG63 human osteosarcoma cells. The 4-HNE treatment could activate caspase-3 and alter the Bax/Bcl-2 apoptotic signaling. All these changes are due to the inhibition of AKT activity by 4-HNE treatment, and we also found that the p70S6K activity, downstream factors of AKT, was also blocked by 4-HNE. Our results revealed the molecular mechanism of how 4-HNE induces cell death in MG63 human osteosarcoma cells, which contributes to the clinical treatment of cancer therapy.

  2. Inhibition of apoptosis signal-regulating kinase 1 alters the wound epidermis and enhances auricular cartilage regeneration.

    Science.gov (United States)

    Zhang, Qian-Shi; Kurpad, Deepa S; Mahoney, My G; Steinbeck, Marla J; Freeman, Theresa A

    2017-01-01

    Why regeneration does not occur in mammals remains elusive. In lower vertebrates, epimorphic regeneration of the limb is directed by the wound epidermis, which controls blastema formation to promote regrowth of the appendage. Herein, we report that knockout (KO) or inhibition of Apoptosis Signal-regulated Kinase-1 (ASK1), also known as mitogen-activated protein kinase kinase kinase 5 (MAP3K5), after full thickness ear punch in mice prolongs keratinocyte activation within the wound epidermis and promotes regeneration of auricular cartilage. Histological analysis showed the ASK1 KO ears displayed enhanced protein markers associated with blastema formation, hole closure and regeneration of auricular cartilage. At seven days after punch, the wound epidermis morphology was markedly different in the KO, showing a thickened stratum corneum with rounded cell morphology and a reduction of both the granular cell layer and decreased expression of filament aggregating protein. In addition, cytokeratin 6 was expressed in the stratum spinosum and granulosum. Topical application of inhibitors of ASK1 (NQDI-1), the upstream ASK1 activator, calcium activated mitogen kinase 2 (KN93), or the downstream target, c-Jun N-terminal kinase (SP600125) also resulted in enhanced regeneration; whereas inhibition of the other downstream target, the p38 α/β isoforms, (SB203580) had no effect. The results of this investigation indicate ASK1 inhibition prolongs keratinocyte and blastemal cell activation leading to ear regeneration.

  3. Inhibition of apoptosis signal-regulating kinase 1 alters the wound epidermis and enhances auricular cartilage regeneration.

    Directory of Open Access Journals (Sweden)

    Qian-Shi Zhang

    Full Text Available Why regeneration does not occur in mammals remains elusive. In lower vertebrates, epimorphic regeneration of the limb is directed by the wound epidermis, which controls blastema formation to promote regrowth of the appendage. Herein, we report that knockout (KO or inhibition of Apoptosis Signal-regulated Kinase-1 (ASK1, also known as mitogen-activated protein kinase kinase kinase 5 (MAP3K5, after full thickness ear punch in mice prolongs keratinocyte activation within the wound epidermis and promotes regeneration of auricular cartilage. Histological analysis showed the ASK1 KO ears displayed enhanced protein markers associated with blastema formation, hole closure and regeneration of auricular cartilage. At seven days after punch, the wound epidermis morphology was markedly different in the KO, showing a thickened stratum corneum with rounded cell morphology and a reduction of both the granular cell layer and decreased expression of filament aggregating protein. In addition, cytokeratin 6 was expressed in the stratum spinosum and granulosum. Topical application of inhibitors of ASK1 (NQDI-1, the upstream ASK1 activator, calcium activated mitogen kinase 2 (KN93, or the downstream target, c-Jun N-terminal kinase (SP600125 also resulted in enhanced regeneration; whereas inhibition of the other downstream target, the p38 α/β isoforms, (SB203580 had no effect. The results of this investigation indicate ASK1 inhibition prolongs keratinocyte and blastemal cell activation leading to ear regeneration.

  4. MAPK Signal Transduction Pathway Regulation: A Novel Mechanism of Rat HSC-T6 Cell Apoptosis Induced by FUZHENGHUAYU Tablet

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2013-01-01

    Full Text Available FUZHENGHUAYU Tablets have been widely used in the treatment of liver fibrosis in China. Here, we investigate the apoptotic effect of FUZHENGHUAYU Tablet in rat liver stellate cell line HSC-T6. HSC-T6 cells were incubated with control serum or drug serum from rats fed with 0.9% NaCl or FUZHENGHUAYU Tablet, respectively. Cells exposed to drug serum showed higher proportions of early and late apoptotic cells than controls. The mRNA levels of collagens I and III, TGF-β1 and α-SMA were reduced by drug serum compared to control serum. Differentially expressed mRNAs and miRNAs were analyzed by microarray and sequencing, respectively. We identified 334 differentially expressed mRNAs and also 60 GOs and two pathways related to the mRNAs. Seventy-five differentially expressed miRNAs were down-regulated by drug serum and 1963 target genes were predicted. 134 GOs up-regulated in drug serum group were linked to miRNA targets, and drug serum also regulated 43 miRNA signal transduction pathways. Protein levels were evaluated by Western blot. Drug serum down-regulated (phospho-SAPK/JNK/(SAPK/JNK and up-regulated phospho-p38/p38 ratios. The study showed that FUZHENGHUAYU Tablet induced apoptosis in rat HSC-T6 cells possibly in part by activating p38 and inhibiting SAPK/JNK.

  5. Andrographolide, a Novel NF-κB Inhibitor, Induces Vascular Smooth Muscle Cell Apoptosis via a Ceramide-p47phox-ROS Signaling Cascade

    Directory of Open Access Journals (Sweden)

    Yu-Ying Chen

    2013-01-01

    Full Text Available Atherosclerosis is linked with the development of many cardiovascular complications. Abnormal proliferation of vascular smooth muscle cells (VSMCs plays a crucial role in the development of atherosclerosis. Accordingly, the apoptosis of VSMCs, which occurs in the progression of vascular proliferation, may provide a beneficial strategy for managing cardiovascular diseases. Andrographolide, a novel nuclear factor-κB inhibitor, is the most active and critical constituent isolated from the leaves of Andrographis paniculata. Recent studies have indicated that andrographolide is a potential therapeutic agent for treating cancer through the induction of apoptosis. In this study, the apoptosis-inducing activity and mechanisms in andrographolide-treated rat VSMCs were characterized. Andrographolide significantly induced reactive oxygen species (ROS formation, p53 activation, Bax, and active caspase-3 expression, and these phenomena were suppressed by pretreating the cells with N-acetyl-L-cysteine, a ROS scavenger, or diphenylene iodonium, a nicotinamide adenine dinucleotide phosphate (NADPH oxidase (Nox inhibitor. Furthermore, p47phox, a Nox subunit protein, was phosphorylated in andrographolide-treated rat VSMCs. However, pretreatment with 3-O-methyl-sphingomyelin, a neutral sphingomyelinase inhibitor, significantly inhibited andrographolide-induced p47phox phosphorylation as well as Bax and active caspase-3 expression. Our results collectively demonstrate that andrographolide-reduced cell viability can be attributed to apoptosis in VSMCs, and this apoptosis-inducing activity was associated with the ceramide-p47phox-ROS signaling cascade.

  6. Epothilones Suppress Neointimal Thickening in the Rat Carotid Balloon-Injury Model by Inducing Vascular Smooth Muscle Cell Apoptosis through p53-Dependent Signaling Pathway.

    Science.gov (United States)

    Son, Dong Ju; Jung, Jae Chul; Hong, Jin Tae

    2016-01-01

    Microtubule stabilizing agents (MTSA) are known to inhibit vascular smooth muscle cell (VSMC) proliferation and migration, and effectively reduce neointimal hyperplasia and restenosis. Epothilones (EPOs), non-taxane MTSA, have been found to be effective in the inhibition of VSMC proliferation and neointimal formation by cell cycle arrest. However, effect of EPOs on apoptosis in hyper-proliferated VSMCs as a possible way to reduce neointimal formation and its action mechanism related to VSMC viability has not been suited yet. Thus, the purposes of the present study was to investigate whether EPOs are able to inhibit neointimal formation by inducing apoptosis within the region of neointimal hyperplasia in balloon-injured rat carotid artery, as well as underlying action mechanism. Treatment of EPO-B and EPO-D significantly induced apoptotic cell death and mitotic catastrophe in hyper-proliferated VSMCs, resulting in cell growth inhibition. Further, EPOs significantly suppressed VSMC proliferation and induced apoptosis by activation of p53-dependent apoptotic signaling pathway, Bax/cytochrome c/caspase-3. We further demonstrated that the local treatment of carotid arteries with EPOs potently inhibited neointimal lesion formation by induction of apoptosis in rat carotid injury model. Our findings demonstrate a potent anti-neointimal hyperplasia property of EPOs by inducing p53-depedent apoptosis in hyper-proliferated VSMCs.

  7. Andrographolide, a Novel NF- κ B Inhibitor, Induces Vascular Smooth Muscle Cell Apoptosis via a Ceramide-p47phox-ROS Signaling Cascade.

    Science.gov (United States)

    Chen, Yu-Ying; Hsu, Ming-Jen; Sheu, Joen-Rong; Lee, Lin-Wen; Hsieh, Cheng-Ying

    2013-01-01

    Atherosclerosis is linked with the development of many cardiovascular complications. Abnormal proliferation of vascular smooth muscle cells (VSMCs) plays a crucial role in the development of atherosclerosis. Accordingly, the apoptosis of VSMCs, which occurs in the progression of vascular proliferation, may provide a beneficial strategy for managing cardiovascular diseases. Andrographolide, a novel nuclear factor- κ B inhibitor, is the most active and critical constituent isolated from the leaves of Andrographis paniculata. Recent studies have indicated that andrographolide is a potential therapeutic agent for treating cancer through the induction of apoptosis. In this study, the apoptosis-inducing activity and mechanisms in andrographolide-treated rat VSMCs were characterized. Andrographolide significantly induced reactive oxygen species (ROS) formation, p53 activation, Bax, and active caspase-3 expression, and these phenomena were suppressed by pretreating the cells with N-acetyl-L-cysteine, a ROS scavenger, or diphenylene iodonium, a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) inhibitor. Furthermore, p47phox, a Nox subunit protein, was phosphorylated in andrographolide-treated rat VSMCs. However, pretreatment with 3-O-methyl-sphingomyelin, a neutral sphingomyelinase inhibitor, significantly inhibited andrographolide-induced p47phox phosphorylation as well as Bax and active caspase-3 expression. Our results collectively demonstrate that andrographolide-reduced cell viability can be attributed to apoptosis in VSMCs, and this apoptosis-inducing activity was associated with the ceramide-p47phox-ROS signaling cascade.

  8. TNF-α Mediates the Intrinsic and Extrinsic Pathway in Propofol-Induced Neuronal Apoptosis Via PI3K/Akt Signaling Pathway in Rat Prefrontal Cortical Neurons.

    Science.gov (United States)

    Deng, Xiaoyuan; Chen, Bo; Wang, Bin; Zhang, Junfang; Liu, Hongliang

    2017-10-01

    Propofol can cause developing neuronal apoptosis in both in vivo and in vitro studies, and the mechanism is unclear till now. Our previous study has demonstrated that propofol can increase the TNF-α expression in the prefrontal cortex in rat developing brain, the TNF-α antagonist, etanercept, can inhibit propofol-induced neuronal apoptosis, but little is known about how TNF-α mediates that process. This study reveals that propofol at clinically relevant concentrations increases the TNF-α synthesis and release in neurons, and induces neuronal apoptosis; etanercept significantly reduces neuronal apoptosis, the elevation of cleaved caspase-8 and cleaved caspase-9, or the Akt phosphorylation induced by propofol, while the selective PI3K antagonist blocks the neuroprotection of etanercept. Propofol does not change the expression of P2X7 receptor in neurons, and the P2X7 receptor antagonist cannot affect the TNF-α synthesis or release after propofol treatment. These results suggest that propofol can increase the synthesis and release of TNF-α in the primary cultured prefrontal cortical neurons, TNF-α contributes to the intrinsic and extrinsic pathway in propofol-induced neuronal apoptosis via PI3K/Akt signaling pathway, and P2X7R is not involved in the synthesis and release of TNF-α induced by propofol.

  9. Cell surface-bound TIMP3 induces apoptosis in mesenchymal Cal78 cells through ligand-independent activation of death receptor signaling and blockade of survival pathways.

    Directory of Open Access Journals (Sweden)

    Christina Koers-Wunrau

    Full Text Available BACKGROUND: The matrix metalloproteinases (MMPs and their endogenous regulators, the tissue inhibitor of metalloproteinases (TIMPs 1-4 are responsible for the physiological remodeling of the extracellular matrix (ECM. Among all TIMPs, TIMP3 appears to play a unique role since TIMP3 is a secreted protein and, unlike the other TIMP family members, is tightly bound to the ECM. Moreover TIMP3 has been shown to be able to induce apoptotic cell death. As little is known about the underlying mechanisms, we set out to investigate the pro-apoptotic effect of TIMP3 in human mesenchymal cells. METHODOLOGY/PRINCIPAL FINDINGS: Lentiviral overexpression of TIMP3 in mesenchymal cells led to a strong dose-dependent induction of ligand-independent apoptosis as reflected by a five-fold increase in caspase 3 and 7 activity compared to control (pLenti6/V5-GW/lacZ or uninfected cells, whereas exogenous TIMP3 failed to induce apoptosis. Concordantly, increased cleavage of death substrate PARP and the caspases 3 and 7 was observed in TIMP3 overexpressing cultures. Notably, activation of caspase-8 but not caspase-9 was observed in TIMP3-overexpressing cells, indicating a death receptor-dependent mechanism. Moreover, overexpression of TIMP3 led to a further induction of apoptosis after stimulation with TNF-alpha, FasL and TRAIL. Most interestingly, TIMP3-overexpression was associated with a decrease in phosphorylation of cRaf, extracellular signal-regulated protein kinase (Erk1/2, ribosomal S6 kinase (RSK1 and Akt and serum deprivation of TIMP3-overexpressing cells resulted in a distinct enhancement of apoptosis, pointing to an impaired signaling of serum-derived survival factors. Finally, heparinase treatment of heparan sulfate proteoglycans led to the release of TIMP3 from the surface of overexpressing cells and to a significant decrease in apoptosis indicating that the binding of TIMP3 is necessary for apoptosis induction. CONCLUSION: The results demonstrate that

  10. SL4, a chalcone-based compound, induces apoptosis in human cancer cells by activation of the ROS/MAPK signalling pathway.

    Science.gov (United States)

    Wang, L-H; Li, H-H; Li, M; Wang, S; Jiang, X-R; Li, Y; Ping, G-F; Cao, Q; Liu, X; Fang, W-H; Chen, G-L; Yang, J-Y; Wu, C-F

    2015-12-01

    SL4, a chalcone-based compound, exhibits clearly inhibitory effects on HIF-1 and has been shown to effectively suppress tumour invasion and angiogenesis in vitro and in vivo. Here, studies were conducted to determine SL4's anti-apoptotic effects and its underlying mechanisms, in human cancer cells. Cytotoxicity, apoptotic induction and its involved mechanisms of SL4 were investigated using normal cells, cancer cells and mouse xenograft models. The role of reactive oxygen species (ROS) and mitogen-activated protein kinase (MAPK) signalling in SL4-induced apoptosis was explored by manipulating specific scavenger or signalling inhibitors, in cultured cells. SL4 significantly inhibited cell population growth of human cancer cell lines but exhibited lower cytotoxicity against normal cells. In addition, SL4 effectively induced apoptosis of Hep3B and MDA-MB-435 cells by activating procaspase-8, -9 and -3, and down-regulating expression levels of XIAP, but did not affect HIF-1 apoptosis-related targets, Survivin and Bcl-XL. Further study showed that SL4 also reduced mitochondrial membrane potential and promoted generation of ROS. ROS generation and apoptotic induction by SL4 were blocked by NAC, a scavenger of ROS, suggesting SL4-induced apoptosis via ROS accumulation. We also found that MAPKs, JNK and p38, but not ERK1/2, to be critical mediators in SL4-induced apoptosis. SP600125 and SB203580, specific inhibitors of JNK kinase and p38 kinase, significantly retarded apoptosis induced by SL4. Moreover, anti-oxidant NAC blocked activation of JNK and p38 induced by SL4, indicating that ROS may act as upstream signalling of JNK and p38 activation. It is noteworthy that animal studies revealed dramatic reduction (49%) in tumour volume after 11 days SL4 treatment. These data demonstrate that SL4 induced apoptosis in human cancer cells through activation of the ROS/MAPK signalling pathway, suggesting that it may be a novel lead compound, as a cancer drug candidate, with

  11. Polydatin inhibits cell proliferation and induces apoptosis in laryngeal cancer and HeLa cells via suppression of the PDGF/AKT signaling pathway.

    Science.gov (United States)

    Li, Haixia; Shi, Baoyuan; Li, Yanyun; Yin, Fengfang

    2017-07-01

    Polydatin (PD), a stilbene compound extracted from Polygonum cuspidatum, is suggested to possess anti-cancer activities, including inhibition of cell proliferation, cell cycle arrest, and induction of apoptosis. The platelet-derived growth factor (PDGF)/AKT signaling pathway plays complex roles in tumor suppression. However, the effect of PD on the PDGF/AKT signaling pathway in laryngeal cancer and HeLa cells has not been explored. MTT assay and flow cytometry showed that PD inhibited cell proliferation and induced apoptosis in Hep-2 and AMC-HN-8 cells. Western blot analysis indicated that PD inhibited the expression levels of PDGF-B and phosphorylated AKT (p-AKT) in both cells. Treatment of PDGF-B siRNA or PDGFR inhibitor found that after the PDGF signaling was inactivated, p-AKT expression was significantly decreased in Hep-2 cells. Tumor xenograft experiment in nude mice indicated PD significantly inhibited the growth of Hep-2 cells in vivo. In conclusion, PD inhibited cell proliferation and induced apoptosis in laryngeal cancer and HeLa cells via inactivation of the PDGF/AKT signaling pathway. © 2017 Wiley Periodicals, Inc.

  12. Statins induce apoptosis through inhibition of Ras signaling pathways and enhancement of Bim and p27 expression in human hematopoietic tumor cells.

    Science.gov (United States)

    Fujiwara, Daichiro; Tsubaki, Masanobu; Takeda, Tomoya; Tomonari, Yoshika; Koumoto, Yu-Ichi; Sakaguchi, Katsuhiko; Nishida, Shozo

    2017-10-01

    Recently, statins have been demonstrated to improve cancer-related mortality or prognosis in patients of various cancers. However, the details of the apoptosis-inducing mechanisms remain unknown. This study showed that the induction of apoptosis by statins in hematopoietic tumor cells is mediated by mitochondrial apoptotic signaling pathways, which are activated by the suppression of mevalonate or geranylgeranyl pyrophosphate biosynthesis. In addition, statins decreased the levels of phosphorylated extracellular signal-regulated kinase 1/2 and mammalian target of rapamycin through suppressing Ras prenylation. Furthermore, inhibition of extracellular signal-regulated kinase 1/2 and mammalian target of rapamycin by statins induced Bim expression via inhibition of Bim phosphorylation and ubiquitination and cell-cycle arrest at G1 phase via enhancement of p27 expression. Moreover, combined treatment of U0126, a mitogen-activated protein kinase kinase 1/2 inhibitor, and rapamycin, a mammalian target of rapamycin inhibitor, induced Bim and p27 expressions. The present results suggested that statins induce apoptosis by decreasing the mitochondrial transmembrane potential, increasing the activation of caspase-9 and caspase-3, enhancing Bim expression, and inducing cell-cycle arrest at G1 phase through inhibition of Ras/extracellular signal-regulated kinase and Ras/mammalian target of rapamycin pathways. Therefore, our findings support the use of statins as potential anticancer agents or concomitant drugs of adjuvant therapy.

  13. Leukemia-associated gene MLAA-34 reduces arsenic trioxide-induced apoptosis in HeLa cells via activation of the Wnt/β-catenin signaling pathway.

    Science.gov (United States)

    Zhang, Pengyu; Zhao, Xuan; Zhang, Wenjuan; He, Aili; Lei, Bo; Zhang, Wanggang; Chen, Yinxia

    2017-01-01

    Our laboratory previously used the SEREX method in U937 cells and identified a novel leukemia-associated gene MLAA-34, a novel splice variant of CAB39L associated with acute monocytic leukemia, that exhibited anti-apoptotic activities in U937 cells. Whether MLAA-34 has an anti-apoptotic role in other tumor cells has not yet been reported. We explored whether MLAA-34 exhibited anti-apoptotic effects in HeLa cervical cancer cells and the possible mechanism of action. We generated a HeLa cell line stably expressing MLAA-34 and found that MLAA-34 overexpression had no effect on the growth, apoptosis and cell cycle of HeLa cells. However, upon treatment with arsenic trioxide (ATO) to induce apoptosis, the cell viability and colony formation ability of ATO-treated MLAA-34 stable HeLa cells were significantly higher than that of ATO-treated controls, and the apoptosis rate and proportion of G2/M cells also decreased. We found that ATO treatment of HeLa cells resulted in significant decreases in the expression of β-catenin mRNA and protein and the downstream target factors c-Myc, cyclin B1, and cyclin D1 in the Wnt signaling pathway. Notably, ATO-treated MLAA-34 stable HeLa cells showed a significant reduction in the ATO-mediated downregulation of these factors. In addition, MLAA-34 overexpression significantly increased the expression of nuclear β-catenin protein in ATO-treated cells compared with HeLa cells treated only with ATO. Thus, here we have found that the Wnt/β-catenin signaling pathway is involved in ATO-induced apoptosis in HeLa cells. MLAA-34 reduces ATO-induced apoptosis and G2/M arrest, and the anti-apoptotic effect may be achieved by activating the Wnt/β-catenin signaling pathway in HeLa cells.

  14. Ultraviolet (UV and Hydrogen Peroxide Activate Ceramide-ER Stress-AMPK Signaling Axis to Promote Retinal Pigment Epithelium (RPE Cell Apoptosis

    Directory of Open Access Journals (Sweden)

    Jin Yao

    2013-05-01

    Full Text Available Ultraviolet (UV radiation and reactive oxygen species (ROS impair the physiological functions of retinal pigment epithelium (RPE cells by inducing cell apoptosis, which is the main cause of age-related macular degeneration (AMD. The mechanism by which UV/ROS induces RPE cell death is not fully addressed. Here, we observed the activation of a ceramide-endoplasmic reticulum (ER stress-AMP activated protein kinase (AMPK signaling axis in UV and hydrogen peroxide (H2O2-treated RPE cells. UV and H2O2 induced an early ceramide production, profound ER stress and AMPK activation. Pharmacological inhibitors against ER stress (salubrinal, ceramide production (fumonisin B1 and AMPK activation (compound C suppressed UV- and H2O2-induced RPE cell apoptosis. Conversely, cell permeable short-chain C6 ceramide and AMPK activator AICAR (5-amino-1-β-D-ribofuranosyl-imidazole-4-carboxamide mimicked UV and H2O2’s effects and promoted RPE cell apoptosis. Together, these results suggest that UV/H2O2 activates the ceramide-ER stress-AMPK signaling axis to promote RPE cell apoptosis.

  15. Probucol Attenuates Cyclophosphamide-induced Oxidative Apoptosis, p53 and Bax Signal Expression in Rat Cardiac Tissues

    Directory of Open Access Journals (Sweden)

    Yousif A. Asiri

    2010-01-01

    Full Text Available Cyclophosphamide (CP is a widely used drug in cancer chemotherapy and immunosuppression, which could cause toxicity of the normal cells due to its toxic metabolites. Probucol, a cholesterol-lowering drug, acts as potential inhibitor of DNA damage and shows to protect against doxorubicin-induced cardiomyopathy by enhancing the endogenous antioxidant system including glutathione peroxidase, catalase and superoxide dismutase. This study examined the possible protective effects of probucol, a lipid-lowering compound with strong antioxidant properties, against CPinduced cardiotoxicity. This objective could be achieved through studying the gene expression-based on the possible protective effects of probucol against CP-induced cardiac failure in rats. Adult male Wistar albino rats were assigned into four treatment groups: Animals in the first (control and second (probucol groups were injected intraperitoneally with corn oil and probucol (61 mg/kg/day, respectively, for two weeks. Animals in the third (CP and fourth (probucol plus CP groups were injected with the same doses of corn oil and probucol (61 mg/kg/day, respectively, for one week before and one week after a single dose of CP (200 mg/kg, I.P.. The p53, Bax, Bcl2 and oxidative genes signal expression were measured by real time PCR. CP-induced cardiotoxicity was clearly observed by a significant increase in serum creatine phosphokinase isoenzyme (CK-MB (117%, lactate dehydrogenase (LDH (64%, free (69% and esterified cholesterol (42% and triglyceride (69% compared to control group. In cardiac tissues, CP significantly increases the mRNA expression levels of apoptotic genes, p53 with two-fold and Bax with 1.6-fold, and decreases the anti-apoptotic gene Bcl2 with 0.5-fold. Moreover, CP caused downregulation of antioxidant genes, glutathione peroxidase, catalase, and superoxide dismutase and increased the lipid peroxidation and decreased adenosine triphosphate (ATP (40% and ATP/ADP (44% in cardiac

  16. Aconitine-induced Ca2+ overload causes arrhythmia and triggers apoptosis through p38 MAPK signaling pathway in rats

    International Nuclear Information System (INIS)

    Sun, Gui-bo; Sun, Hong; Meng, Xiang-bao; Hu, Jin; Zhang, Qiang; Liu, Bo; Wang, Min; Xu, Hui-bo; Sun, Xiao-bo

    2014-01-01

    Aconitine is a major bioactive diterpenoid alkaloid with high content derived from herbal aconitum plants. Emerging evidence indicates that voltage-dependent Na + channels have pivotal roles in the cardiotoxicity of aconitine. However, no reports are available on the role of Ca 2+ in aconitine poisoning. In this study, we explored the importance of pathological Ca 2+ signaling in aconitine poisoning in vitro and in vivo. We found that Ca 2+ overload lead to accelerated beating rhythm in adult rat ventricular myocytes and caused arrhythmia in conscious freely moving rats. To investigate effects of aconitine on myocardial injury, we performed cytotoxicity assay in neonatal rat ventricular myocytes (NRVMs), as well as measured lactate dehydrogenase level in the culture medium of NRVMs and activities of serum cardiac enzymes in rats. The results showed that aconitine resulted in myocardial injury and reduced NRVMs viability dose-dependently. To confirm the pro-apoptotic effects, we performed flow cytometric detection, cardiac histology, transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The results showed that aconitine stimulated apoptosis time-dependently. The expression analysis of Ca 2+ handling proteins demonstrated that aconitine promoted Ca 2+ overload through the expression regulation of Ca 2+ handling proteins. The expression analysis of apoptosis-related proteins revealed that pro-apoptotic protein expression was upregulated, and anti-apoptotic protein BCL-2 expression was downregulated. Furthermore, increased phosphorylation of MAPK family members, especially the P-P38/P38 ratio was found in cardiac tissues. Hence, our results suggest that aconitine significantly aggravates Ca 2+ overload and causes arrhythmia and finally promotes apoptotic development via phosphorylation of P38 mitogen-activated protein kinase. - Highlights: • Aconitine-induced Ca 2+ overload causes arrhythmia in rats

  17. miR-130b targets NKD2 and regulates the Wnt signaling to promote proliferation and inhibit apoptosis in osteosarcoma cells

    International Nuclear Information System (INIS)

    Li, Zhi; Li, Youjun; Wang, Nan; Yang, Lifeng; Zhao, Wei; Zeng, Xiandong

    2016-01-01

    miR-130b was significantly up-regulated in osteosarcoma (OS) cells. Naked cuticle homolog 2 (NKD2) inhibited tumor growth and metastasis in OS by suppressing Wnt signaling. We used three miRNA target analysis tools to identify potential targets of miR-130b, and found that NKD2 is a potential target of miR-130b. Based on these findings, we hypothesize that miR-130b might target NKD2 and regulate the Wnt signaling to promote OS growth. We detected the expression of miR-130b and NKD2 mRNA and protein by quantitative Real-Time PCR (qRT-PCR) and western blot assays, respectively, and found up-regulation of miR-130b and down-regulation of NKD2 mRNA and protein exist in OS cell lines. MTT and flow cytometry assays showed that miR-130b inhibitors inhibit proliferation and promote apoptosis in OS cells. Furthermore, we showed that NKD2 is a direct target of miR-130b, and miR-130b regulated proliferation and apoptosis of OS cells by targeting NKD2. We further investigated whether miR-130b and NKD2 regulate OS cell proliferation and apoptosis by inhibiting Wnt signaling, and the results confirmed our speculation that miR-130b targets NKD2 and regulates the Wnt signaling to promote proliferation and inhibit apoptosis of OS cells. These findings will offer new clues for OS development and progression, and novel potential therapeutic targets for OS. - Highlights: • miR-130b is up-regulated and NKD2 is down-regulated in osteosarcoma cell lines. • Down-regulation of miR-130b inhibits proliferation of osteosarcoma cells. • Down-regulation of miR-130b promotes apoptosis of osteosarcoma cells. • miR-130b directly targets NKD2. • NKD2 regulates OS cell proliferation and apoptosis by inhibiting the Wnt signaling.

  18. miR-130b targets NKD2 and regulates the Wnt signaling to promote proliferation and inhibit apoptosis in osteosarcoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhi [Department of Human Anatomy and Histoembryology, College of Basic Medical Sciences, Jilin University (China); Li, Youjun, E-mail: liyoujunn@126.com [Department of Human Anatomy and Histoembryology, College of Basic Medical Sciences, Jilin University (China); Wang, Nan; Yang, Lifeng; Zhao, Wei; Zeng, Xiandong [Central Hospital Affiliated to Shenyang Medical College (China)

    2016-03-18

    miR-130b was significantly up-regulated in osteosarcoma (OS) cells. Naked cuticle homolog 2 (NKD2) inhibited tumor growth and metastasis in OS by suppressing Wnt signaling. We used three miRNA target analysis tools to identify potential targets of miR-130b, and found that NKD2 is a potential target of miR-130b. Based on these findings, we hypothesize that miR-130b might target NKD2 and regulate the Wnt signaling to promote OS growth. We detected the expression of miR-130b and NKD2 mRNA and protein by quantitative Real-Time PCR (qRT-PCR) and western blot assays, respectively, and found up-regulation of miR-130b and down-regulation of NKD2 mRNA and protein exist in OS cell lines. MTT and flow cytometry assays showed that miR-130b inhibitors inhibit proliferation and promote apoptosis in OS cells. Furthermore, we showed that NKD2 is a direct target of miR-130b, and miR-130b regulated proliferation and apoptosis of OS cells by targeting NKD2. We further investigated whether miR-130b and NKD2 regulate OS cell proliferation and apoptosis by inhibiting Wnt signaling, and the results confirmed our speculation that miR-130b targets NKD2 and regulates the Wnt signaling to promote proliferation and inhibit apoptosis of OS cells. These findings will offer new clues for OS development and progression, and novel potential therapeutic targets for OS. - Highlights: • miR-130b is up-regulated and NKD2 is down-regulated in osteosarcoma cell lines. • Down-regulation of miR-130b inhibits proliferation of osteosarcoma cells. • Down-regulation of miR-130b promotes apoptosis of osteosarcoma cells. • miR-130b directly targets NKD2. • NKD2 regulates OS cell proliferation and apoptosis by inhibiting the Wnt signaling.

  19. GW627368X inhibits proliferation and induces apoptosis in cervical cancer by interfering with EP4/EGFR interactive signaling.

    Science.gov (United States)

    Parida, S; Pal, I; Parekh, A; Thakur, B; Bharti, R; Das, S; Mandal, M

    2016-03-24

    PGE2, the major product of cyclooxygenases implicated in carcinogenesis, is significantly upregulated in cervical cancer. PGE2 via prostanoid receptor EP4 stimulates proliferation and motility while inhibiting apoptosis and immune surveillance. It promotes angiogenesis by stimulating the production of pro-angiogenic factors. The present study demonstrates GW627368X, a highly selective competitive EP4 antagonist, which hinders cervical cancer progression by inhibiting EP4/epithelial growth factor receptor (EGFR) interactive signaling. GW627368X reduced protein kinase A (PKA) phosphorylation which in turn leads to decreased cAMP response element-binding protein (CREB) activation. Decreased PKA phosphorylation also directly enhanced Bax activity and in part reduced glycogen synthase kinase 3 (GSK3)β phosphorylation. Owing to the interactive signaling between EP4 and EGFR, GW627368X lowered EGFR phosphorylation in turn reducing Akt, mitogen-activated protein kinase (MAPK) and GSK3β activity significantly. Sublethal dose of GW627368X was found to reduce the nuclear translocation of β-catenin in a time dependent manner along with time-dependent decrease in cytoplasmic as well as whole-cell β-catenin. Decreased CREB and β-catenin transcriptional activity restricts the aberrant transcription of key genes like EP4, cyclooxygenase (COX)-2, vascular endothelial growth factor and c-myc, which ultimately control cell survival, proliferation and angiogenesis. Reduced activity of EGFR resulted in enhanced expression of 15-hydroxyprostaglandin dehydrogenase increasing PGE2 degradation thereby blocking a positive feedback loop. In xenograft model, dose-dependent decrease in cancer proliferation was observed characterized by reduction in tumor mass and volume and a marked decrease in Ki67 expression. A diminished CD31 specific staining signified decreased tumor angiogenesis. Reduced expression of pAkt, pMAPK, pEGFR and COX-2 validated in vitro results. GW627368X therefore

  20. Structural Insight into the 14-3-3 Protein-dependent Inhibition of Protein Kinase ASK1 (Apoptosis Signal-regulating kinase 1)

    Czech Academy of Sciences Publication Activity Database

    Petrvalská, Olivia; Košek, Dalibor; Kukačka, Zdeněk; Tošner, Z.; Man, Petr; Večeř, J.; Herman, P.; Obšilová, Veronika; Obšil, Tomáš

    2016-01-01

    Roč. 291, č. 39 (2016), s. 20753-20765 ISSN 0021-9258 R&D Projects: GA ČR(CZ) GA14-10061S Institutional support: RVO:67985823 ; RVO:61388971 Keywords : 14-3-3 protein * apoptosis signal-regulating kinase 1 (ASK1) * fluorescence * nuclear magnetic resonance (NMR) * protein cross-linking * small-angle x-ray scattering (SAXS) Subject RIV: CE - Biochemistry Impact factor: 4.125, year: 2016

  1. Common genomic signaling among initial DNA damage and radiation-induced apoptosis in peripheral blood lymphocytes from locally advanced breast cancer patients

    DEFF Research Database (Denmark)

    Henríquez-Hernández, Luis Alberto; Pinar, Beatriz; Carmona-Vigo, Ruth

    2013-01-01

    PURPOSE: To investigate the genomic signaling that defines sensitive lymphocytes to radiation and if such molecular profiles are consistent with clinical toxicity; trying to disclose the radiobiology mechanisms behind these cellular processes. PATIENTS AND METHODS: Twelve consecutive patients...... suffering from locally advanced breast cancer and treated with high-dose hyperfractionated radiotherapy were recruited. Initial DNA damage was measured by pulsed-field gel electrophoresis and radiation-induced apoptosis was measured by flow cytometry. Gene expression was assessed by DNA microarray. RESULTS...

  2. Singlet oxygen treatment of tumor cells triggers extracellular singlet oxygen generation, catalase inactivation and reactivation of intercellular apoptosis-inducing signaling.

    Science.gov (United States)

    Riethmüller, Michaela; Burger, Nils; Bauer, Georg

    2015-12-01

    Intracellular singlet oxygen generation in photofrin-loaded cells caused cell death without discrimination between nonmalignant and malignant cells. In contrast, extracellular singlet oxygen generation caused apoptosis induction selectively in tumor cells through singlet oxygen-mediated inactivation of tumor cell protective catalase and subsequent reactivation of intercellular ROS-mediated apoptosis signaling through the HOCl and the NO/peroxynitrite signaling pathway. Singlet oxygen generation by extracellular photofrin alone was, however, not sufficient for optimal direct inactivation of catalase, but needed to trigger the generation of cell-derived extracellular singlet oxygen through the interaction between H2O2 and peroxynitrite. Thereby, formation of peroxynitrous acid, generation of hydroxyl radicals and formation of perhydroxyl radicals (HO2(.)) through hydroxyl radical/H2O2 interaction seemed to be required as intermediate steps. This amplificatory mechanism led to the formation of singlet oxygen at a sufficiently high concentration for optimal inactivation of membrane-associated catalase. At low initial concentrations of singlet oxygen, an additional amplification step needed to be activated. It depended on singlet oxygen-dependent activation of the FAS receptor and caspase-8, followed by caspase-8-mediated enhancement of NOX activity. The biochemical mechanisms described here might be considered as promising principle for the development of novel approaches in tumor therapy that specifically direct membrane-associated catalase of tumor cells and thus utilize tumor cell-specific apoptosis-inducing ROS signaling. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Subretinal Fluid Levels of Signal-Transduction Proteins and Apoptosis Molecules in Macula-Off Retinal Detachment Undergoing Scleral Buckle Surgery.

    Science.gov (United States)

    Carpineto, Paolo; Aharrh-Gnama, Agbeanda; Ciciarelli, Vincenzo; Borrelli, Enrico; Petti, Francesco; Aloia, Raffaella; Lamolinara, Alessia; Di Nicola, Marta; Mastropasqua, Leonardo

    2016-12-01

    To evaluate signal transduction and early apoptosis protein levels in subretinal fluid collected during scleral buckling surgery for macula-off rhegmatogenous retinal detachment (RRD). Our aim was to assess both their relation with RRD features and their influence on the posttreatment outcome. Thirty-three eyes of 33 RRD patients scheduled for scleral buckle surgery were enrolled in the study. Undiluted subretinal fluid samples were collected during surgery and analyzed via magnetic bead-based immunoassay. All patients underwent a complete ophthalmologic evaluation at baseline and at each follow-up visit (months 1, 3, and 6). Moreover, both at baseline and at the postsurgery month 6 visit, the patients were tested by means of spectral-domain optical coherence tomography (SD-OCT) in order to evaluate the average ganglion cell-inner plexiform complex thickness, as well as the photoreceptor inner segment/outer segment junction status. Patients' clinical features (retinal detachment size, detachment duration, and occurrence of proliferative vitreoretinopathy) were associated with several early apoptotic factors (caspase-8, caspase-9, and B-cell lymphoma 2 [Bcl-2]-associated death promoter [BAD]). Furthermore, both early apoptosis factors (caspase-8, Bcl-2, and p53) and signal-transduction proteins (ERK 1/2) were found to influence the postsurgery month 3 OCT characteristics. Signal-transduction proteins and early apoptosis proteins are associated with different clinical features and postsurgery outcomes.

  4. Pomegranate Bioactive Constituents Suppress Cell Proliferation and Induce Apoptosis in an Experimental Model of Hepatocellular Carcinoma: Role of Wnt/β-Catenin Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Deepak Bhatia

    2013-01-01

    Full Text Available Hepatocellular carcinoma (HCC is the third leading cause of cancer-related death worldwide, and chemoprevention represents a viable approach in lowering the mortality of this disease. Pomegranate fruit, an abundant source of anti-inflammatory phytochemicals, is gaining tremendous attention for its wide-spectrum health benefits. We previously reported that a characterized pomegranate emulsion (PE prevents diethylnitrosamine (DENA-induced rat hepatocarcinogenesis though inhibition of nuclear factor-kappaB (NF-κB. Since NF-κB concurrently induces Wnt/β-catenin signaling implicated in cell proliferation, cell survival, and apoptosis evasion, we examined antiproliferative, apoptosis-inducing and Wnt/β-catenin signaling-modulatory mechanisms of PE during DENA rat hepatocarcinogenesis. PE (1 or 10 g/kg was administered 4 weeks before and 18 weeks following DENA exposure. There was a significant increase in hepatic proliferation (proliferating cell nuclear antigen and alteration in cell cycle progression (cyclin D1 due to DENA treatment, and PE dose dependently reversed these effects. PE substantially induced apoptosis by upregulating proapoptotic protein Bax and downregulating antiapoptotic protein Bcl-2. PE dose dependently reduced hepatic β-catenin and augmented glycogen synthase kinase-3β expression. Our study provides evidence that pomegranate phytochemicals exert chemoprevention of hepatic cancer through antiproliferative and proapoptotic mechanisms by modulating Wnt/β-catenin signaling. PE, thus, targets two interconnected molecular circuits (canonical NF-κB and Wnt/β-catenin pathways to exert chemoprevention of HCC.

  5. Death Receptor-Induced Apoptosis Signalling Regulation by Ezrin Is Cell Type Dependent and Occurs in a DISC-Independent Manner in Colon Cancer Cells.

    Science.gov (United States)

    Iessi, Elisabetta; Zischler, Luciana; Etringer, Aurélie; Bergeret, Marion; Morlé, Aymeric; Jacquemin, Guillaume; Morizot, Alexandre; Shirley, Sarah; Lalaoui, Najoua; Elifio-Esposito, Selene L; Fais, Stefano; Garrido, Carmen; Solary, Eric; Micheau, Olivier

    2015-01-01

    Ezrin belongs to the ERM (ezrin-radixin-moesin) protein family and has been demonstrated to regulate early steps of Fas receptor signalling in lymphoid cells, but its contribution to TRAIL-induced cell death regulation in adherent cancer cells remains unknown. In this study we report that regulation of FasL and TRAIL-induced cell death by ezrin is cell type dependant. Ezrin is a positive regulator of apoptosis in T-lymphoma cell line Jurkat, but a negative regulator in colon cancer cells. Using ezrin phosphorylation or actin-binding mutants, we provide evidence that negative regulation of death receptor-induced apoptosis by ezrin occurs in a cytoskeleton- and DISC-independent manner, in colon cancer cells. Remarkably, inhibition of apoptosis induced by these ligands was found to be tightly associated with regulation of ezrin phosphorylation on serine 66, the tumor suppressor gene WWOX and activation of PKA. Deficiency in WWOX expression in the liver cancer SK-HEP1 or the pancreatic Mia PaCa-2 cell lines as well as WWOX silencing or modulation of PKA activation by pharmacological regulators, in the colon cancer cell line SW480, abrogated regulation of TRAIL signalling by ezrin. Altogether our results show that death receptor pro-apoptotic signalling regulation by ezrin can occur downstream of the DISC in colon cancer cells.

  6. Aloe-emodin-mediated photodynamic therapy induces autophagy and apoptosis in human osteosarcoma cell line MG‑63 through the ROS/JNK signaling pathway.

    Science.gov (United States)

    Tu, Pinghua; Huang, Qiu; Ou, Yunsheng; Du, Xing; Li, Kaiting; Tao, Yong; Yin, Hang

    2016-06-01

    The present study was carried out to investigate the effect and mechanisms of aloe‑emodin (AE)-mediated photodynamic therapy (AE-PDT) on the human osteosarcoma cell line MG-63. After treatment with AE-PDT, the human osteosarcoma cell line MG-63 was tested for levels of viability, autophagy, reactive oxygen species (ROS) and apoptosis and changes in cell morphology with the Cell Counting Kit-8 (CCK‑8), monodansylcadaverine (MDC) and Hoechst staining and transmission electron microscopy. The expression of proteins including LC-3, cleaved caspase-3, Beclin-1, Bcl-2, p-JNK, t-JNK and β-actin was examined with western blotting. AE-PDT significantly inhibited the viability of the MG-63 cells in an AE-concentration- and PDT energy density-dependent manner. Autophagy and apoptosis of MG-63 cells was substantially promoted in the AE-PDT group compared to the control group, the AE alone group and the light emitting diode (LED) alone group. Inhibition of autophagy by 3-methyladenine (3-MA) (5 mM) and chloroquine (CQ) (15 µM) significantly promoted the apoptosis rate and improved the sensitivity of the MG-63 cells to AE-PDT. AE-PDT was found to induce the expression of ROS and p-JNK. ROS scavenger, N-acetyl-L-cysteine (NAC, 5 mM), was able to hinder the autophagy, apoptosis and phosphorylation of JNK, and JNK inhibitor (SP600125, 10 µM) significantly inhibited the autophagy and apoptosis, and attenuated the sensitivity of MG63 cells to AE-PDT. In conclusion, AE-PDT induced the autophagy and apoptosis of human osteosarcoma cell line MG-63 through the activation of the ROS-JNK signaling pathway. Autophagy may play a protective role during the early stage following treatment of AE-PDT.

  7. Cantharidin Induced Oral Squamous Cell Carcinoma Cell Apoptosis via the JNK-Regulated Mitochondria and Endoplasmic Reticulum Stress-Related Signaling Pathways.

    Directory of Open Access Journals (Sweden)

    Chin-Chuan Su

    Full Text Available Oral cancer is a subtype of head and neck cancer which represents 2.65% of all human malignancies. Most of oral cancer is histopathologically diagnosed as oral squamous cell carcinoma (OSCC. OSCC is characterized by a high degree of local invasion and a high rate of metastasis to the cervical lymph nodes. How to prevention and treatment of OSCC is important and imperative. Here, we investigated the therapeutic effect and molecular mechanism of cantharidin, an active compound isolated from blister beetles, on OSCC in vitro. Results showed that cantharidin significantly decreased cell viability in human tongue squamous carcinoma-derived SAS, CAL-27, and SCC-4 cell lines. The further mechanistic studies were carried out in SAS cells. Cantharidin also significantly increased apoptosis-related signals, including caspase-9, caspase-7 and caspase-3 proteins. Besides, cantharidin decreased mitochondrial transmembrane potential (MMP and induced cytochrome c and apoptosis inducing factor (AIF release. Cantharidin also increased Bax, Bid, and Bak protein expressions and decreased Bcl-2 protein expression. Cantharidin could also increase the endoplasmic reticulum (ER stress signals, including the expressions of phosphorylated eIF-2α and CHOP, but not Grp78 and Grp94. Furthermore, cantharidin reduced pro-caspase-12 protein expression. In signals of mitogen-activated protein kinases, cantharidin increased the phosphorylation of JNK, but not ERK and p38. Transfection of shRNA-JNK to OSCC cells effectively reversed the cantharidin-induced cell apoptotic signals, including the mitochondrial and ER stress-related signaling molecules. Taken together, these findings suggest that cantharidin induces apoptosis in OSCC cells via the JNK-regulated mitochondria and ER stress-related signaling pathways.

  8. Raf-1/CK2 and RhoA/ROCK signaling promote TNF-α-mediated endothelial apoptosis via regulating vimentin cytoskeleton.

    Science.gov (United States)

    Yang, Lifeng; Tang, Lian; Dai, Fan; Meng, Guoliang; Yin, Runting; Xu, Xiaole; Yao, Wenjuan

    2017-08-15

    Both RhoA/ROCK and Raf-1/CK2 pathway play essential roles in cell proliferation, apoptosis, differentiation, and multiple other common cellular functions. We previously reported that vimentin is responsible for TNF-α-induced cell apoptosis. Herein, we investigated the regulation of RhoA/ROCK and Raf-1/CK2 signaling on vimentin filaments and endothelial apoptosis mediated by TNF-α. Treatment with TNF-α significantly induced the activation of RhoA and ROCK, and the expression of ROCK1. RhoA deficiency could obviously inhibit ROCK activation and ROCK1 expression induced by TNF-α. Both RhoA deficiency and ROCK activity inhibition (Y-27632) greatly inhibited endothelial apoptosis and preserved cell viability in TNF-α-induced human umbilical vein endothelial cells (HUVECs). Also vimentin phosphorylation and the remodeling of vimentin or phospho-vimentin induced by TNF-α were obviously attenuated by RhoA suppression and ROCK inhibition. TNF-α-mediated vimentin cleavage was significantly inhibited by RhoA suppression and ROCK inhibition through decreasing the activation of caspase3 and 8. Furthermore, TNF-α treatment greatly enhanced the activation of Raf-1. Suppression of Raf-1 or CK2 by its inhibitor (GW5074 or TBB) blocked vimentin phosphorylation, remodeling and endothelial apoptosis, and preserved cell viability in TNF-α-induced HUVECs. However, Raf-1 inhibition showed no significant effect on TNF-α-induced ROCK expression and activation, suggesting that the regulation of Raf-1/CK2 signaling on vimentin was independent of ROCK. Taken together, these results indicate that both RhoA/ROCK and Raf-1/CK2 pathway are responsible for TNF-α-mediated endothelial cytotoxicity via regulating vimentin cytoskeleton. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Inhibition of phospholipaseD2 increases hypoxia-induced human colon cancer cell apoptosis through inactivating of the PI3K/AKT signaling pathway.

    Science.gov (United States)

    Liu, Maoxi; Fu, Zhongxue; Wu, Xingye; Du, Kunli; Zhang, Shouru; Zeng, Li

    2016-05-01

    Hypoxia is a common feature of solid tumor, and is a direct stress that triggers apoptosis in many human cell types. As one of solid cancer, hypoxia exists in the whole course of colon cancer occurrence and progression. Our previous studies shown that hypoxia induce high expression of phospholipase D2 (PLD2) and survivin in colon cancer cells. However, the correlation between PLD2 and survivin in hypoxic colon cancer cells remains unknown. In this study, we observed significantly elevated PLD2 and survivin expression levels in colon cancer tissues and cells. This is a positive correlation between of them, and co-expression of PLD2 and survivin has a positive correlation with the clinicpatholic features including tumor size, TNM stage, and lymph node metastasis. We also found that hypoxia induced the activity of PLD increased significant mainly caused by PLD2 in colon cancer cells. However, inhibition the activity of PLD2 induced by hypoxia promotes the apoptosis of human colon cancer cells, as well as decreased the expression of apoptosis markers including survivin and bcl2. Moreover, the pharmacological inhibition of PI3K/AKT supported the hypothesis that promotes the apoptosis of hypoxic colon cancer cells by PLD2 activity inhibition may through inactivation of the PI3K/AKT signaling pathway. Furthermore, interference the PLD2 gene expression leaded to the apoptosis of hypoxic colon cancer cells increased and also decreased the expression level of survivin and bcl2 may through inactivation of PI3K/AKT signaling pathway. These results indicated that PLD2 play antiapoptotic role in colon cancer under hypoxic conditions, inhibition of the activity, or interference of PLD2 gene expression will benefit for the treatment of colon cancer patients.

  10. Toyocamycin induces apoptosis via the crosstalk between reactive oxygen species and p38/ERK MAPKs signaling pathway in human prostate cancer PC-3 cells.

    Science.gov (United States)

    Park, Sul-Gi; Kim, Sang-Hun; Kim, Kwang-Youn; Yu, Sun-Nyoung; Choi, Hyeun-Deok; Kim, Young-Wook; Nam, Hyo-Won; Seo, Young-Kyo; Ahn, Soon-Cheol

    2017-02-01

    Toyocamycin, an antibiotic agent isolated from Streptomyces species, has been shown to have anticancer and chemopreventive effects on various cancer cells. Until now, Toyocamycin-induced apoptosis has not been reported to be involved in the regulation between mitogen-activated protein kinases (MAPKs) and reactive oxygen species (ROS) production. Cell viability assay, western blot, cell-cycle arrest, annexin V/propidium iodide assay, reactive oxygen species (ROS) production, mitochondrial membrane potential and intracellular Ca 2+ flux were assayed. We investigated the apoptotic effect of Toyocamycin and the underlying molecular mechanism in prostate cancer PC-3 cells. Toyocamycin treatment resulted in reduced cell viability of PC-3 cells, but not of non-malignant RWPE-1 cells. Toyocamycin enhanced apoptosis, mitochondrial dysfunction, and ROS production in PC-3 cells. In addition, MAPK proteins were activated upon Toyocamycin treatment. The p38 and extracellular signal-regulated kinases (ERK) activities were regulated by ROS-mediated signaling pathway underlying the Toyocamycin-induced apoptosis. Pretreatment with N-acetyl-l-cysteine (NAC) recovered the Toyocamycin-induced mitochondrial dysfunction, ROS, and apoptosis. Additionally, p38 stimulated ROS production and inhibitory effects on ERK activation, while ERK inhibited the ROS production and had no effect on p38 activation. ROS-mediated activation of p38/ERK partially contributes to Toyocamycin-induced apoptosis, and p38/ERK MAPKs regulate the ROS production in PC-3 cells. Copyright © 2016 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  11. Apoptosis Induction of Human Prostate Carcinoma DU145 Cells by Diallyl Disulfide via Modulation of JNK and PI3K/AKT Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Young Hyun Yoo

    2012-11-01

    Full Text Available Diallyl disulfide (DADS, a sulfur compound derived from garlic, has various biological properties, such as anticancer, antiangiogenic and anti-inflammatory effects. However, the mechanisms of action underlying the compound's anticancer activity have not been fully elucidated. In this study, the apoptotic effects of DADS were investigated in DU145 human prostate carcinoma cells. Our results showed that DADS markedly inhibited the growth of the DU145 cells by induction of apoptosis. Apoptosis was accompanied by modulation of Bcl-2 and inhibitor of apoptosis protein (IAP family proteins, depolarization of the mitochondrial membrane potential (MMP, ΔΨm and proteolytic activation of caspases. We also found that the expression of death-receptor 4 (DR4 and Fas ligand (FasL proteins was increased and that the level of intact Bid proteins was down-regulated by DADS. Moreover, treatment with DADS induced phosphorylation of mitogen-activated protein kinases (MAPKs, including extracellular-signal regulating kinase (ERK, p38 MAPK and c-Jun N-terminal kinase (JNK. A specific JNK inhibitor, SP600125, significantly blocked DADS-induced-apoptosis, whereas inhibitors of the ERK (PD98059 and p38 MAPK (SB203580 had no effect. The induction of apoptosis was also accompanied by inactivation of phosphatidylinositol 3-kinase (PI3K/Akt and the PI3K inhibitor LY29004 significantly increased DADS-induced cell death. These findings provide evidence demonstrating that the proapoptotic effect of DADS is mediated through the activation of JNK and the inhibition of the PI3K/Akt signaling pathway in DU145 cells.

  12. Myricetin inhibits Akt survival signaling and induces Bad-mediated apoptosis in a low dose ultraviolet (UV)-B-irradiated HaCaT human immortalized keratinocytes.

    Science.gov (United States)

    Kim, Wanyeon; Yang, Hee Jung; Youn, HyeSook; Yun, Young Ju; Seong, Ki Moon; Youn, BuHyun

    2010-01-01

    Deregulation of cell survival pathways and resistance to apoptosis are generally accepted as crucial aspects of tumorigenesis. As in many tumors, increasing occurrence of human skin cancer and other conflicting effects of solar ultraviolet (UV) radiation enhance the demand for novel chemoprevention agents. Myricetin, a naturally occurring phytochemical, is potent in anti-cancer promoting activity and affords to the chemopreventive potential of several healthy-foods, including fruits and vegetables. We demonstrate here that myricetin inhibits Akt activity to induce apoptosis in a low dose ('repairable dose') UVB-irradiated keratinocytes. Treatment of UVB-irradiated HaCaT cells with an apoptosis-inducing concentration of myricetin (20 microM) resulted in a decrease in phosphorylation of Akt leading to inhibition of its kinase activity. Myricetin treatment also caused a decrease in phosphorylation of Bad (a pro-apoptotic protein), a direct target of Akt in signaling pathway. Interaction between Bad and 14-3-3beta was reduced markedly in UVB-irradiated cells upon a treatment with myricetin. Comparable to these results, myricetin treatment promoted mitochondrial translocation of Bad, loss of the mitochondrial membrane potential, and release of the mitochondrial apoptotic proteins including cytochrome c, Smac, and AIF. Ectopic expression of constitutively active Akt granted statistically significant protection against myricetin-induced apoptosis. In addition, myricetin-induced apoptosis in UVB-irradiated cells was notably attenuated in the presence of caspase inhibitors. Together, these results indicate that myricetin might take on potent chemopreventive activity by inhibiting the Akt-mediated survival signaling axis in UVB-induced skin carcinogenesis.

  13. Induction of apoptosis by a peptide from Porphyra yezoensis: regulation of the insulin-like growth factor I receptor signaling pathway in MCF-7 cells.

    Science.gov (United States)

    Park, Su-Jin; Ryu, Jina; Kim, In-Hye; Choi, Youn-Hee; Nam, Taek-Jeong

    2014-09-01

    This study examined how PPY, a peptide from Porphyra yezoensis, regulates multiple cell growth-related signaling pathways in MCF-7 cells. This study determined that PPY induces cell cycle arrest and inhibits the IGF-IR signaling pathway. Cell proliferation studies revealed that PPY induced cell death in a dose-dependent manner. Expression levels of IGF-IR were decreased in MCF-7 cells by PPY in a dose‑dependent manner. These results indicate that inhibition of the IGF-IR pathway is also involved in PPY induced proliferation of MCF-7 cells. In addition, these data demonstrated that PPY induces cell cycle arrest and activates apoptosis.

  14. Neuronal apoptosis and synaptic density in the dentate gyrus of ischemic rats' response to chronic mild stress and the effects of Notch signaling.

    Directory of Open Access Journals (Sweden)

    Shaohua Wang

    Full Text Available Our previous research highlighted an inconsistency with Notch1 signaling-related compensatory neurogenesis after chronic mild stress (CMS in rodents suffering from cerebral ischemia, which continue to display post-stroke depressive symptoms. Here, we hypothesize that CMS aggrandized ischemia-related apoptosis injury and worsened synaptic integrity via gamma secretase-meditated Notch1 signaling. Adult rats were exposed to a CMS paradigm after left middle cerebral artery occlusion (MCAO. Open-field and sucrose consumption testing were employed to assess depression-like behavior. Gene expression of pro-apoptotic Bax, anti-apoptotic Bcl-2, and synaptic density-related synaptophysin were measured by western blotting and real-time PCR on Day 28 after MCAO surgery. CMS induced depressive behaviors in ischemic rats, which was accompanied by an elevation in Bax/bcl-2 ratio, TUNEL staining in neurons and reduced synaptophysin expression in the dentate gyrus. These collective effects were reversed by the gamma-secretase inhibitor DAPT (N-[N-(3,5-difluorophenacetyl-L-alanyl]-S-phenyl-glycine t-butyl ester. We found that post-stroke stressors made neurons in the dentate gyrus vulnerable to apoptosis, which supports a putative role for Notch signaling in neural integrity, potentially in newborn cells' synaptic deficit with regard to preexisting cells. These findings suggest that post-stroke depression therapeutically benefits from blocking gamma secretase mediated Notch signaling, and whether this signaling pathway could be a therapeutic target needs to be further investigated.

  15. N-Cadherin-Mediated Activation of PI3K/Akt-GSK-3β Signaling Attenuates Nucleus Pulposus Cell Apoptosis Under High-Magnitude Compression

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    Pei Li

    2017-11-01

    Full Text Available Background/Aims: Mechanical overloading-induced nucleus pulposus (NP apoptosis plays an important role in the pathogenesis of intervertebral disc degeneration. N-cadherin (N-CDH-mediated signaling preserves normal NP cell phenotype. This study aims to investigate the effects of N-CDH on NP cell apoptosis under high-magnitude compression and the underlying mechanism behind this process. Methods: Rat NP cells seeded on scaffold were perfusion-cultured using a self-developed perfusion bioreactor for 5 days and experienced different magnitudes (2% and 20% compressive deformation, respectively of compression at a frequency of 1.0 Hz for 4 hours once per day. The un-loaded NP cells were used as controls. Lentivirus-mediated N-CDH overexpression and inhibitor LY294002 were used to further investigate the role of N-CDH and PI3K/Akt pathway under high-magnitude compression, respectively. NP cell apoptosis was evaluated by caspase-3 activity measured using a commercial kit, flow cytometry, and expression of apoptosis-related molecules analyzed by real-time PCR and western blotting assays. Results: High-magnitude compression significantly increased apoptotic NP cells, caspase-3 activity and expression of pro-apoptotic molecules (Bax and caspase-3/cleaved caspase-3, but decreased expression of anti-apoptotic molecule (Bcl-2. High-magnitude compression decreased expression of N-CDH, p-Akt and p-GSK-3β. However, N-CDH overexpression attenuated NP cell apoptosis and increased expression of p-Akt and p-GSK-3β under high-magnitude compression. Further analysis showed that inhibition of the PI3K/Akt pathway suppressed NP cell apoptosis and decreased expression of p-GSK-3β, but had no significant effects on N-CDH expression under high-magnitude compression. Conclusion: N-CDH can attenuate NP cell apoptosis through activating the PI3K/Akt-GSK-3β signaling under high-magnitude compression.

  16. Salidroside improves behavioral and histological outcomes and reduces apoptosis via PI3K/Akt signaling after experimental traumatic brain injury.

    Directory of Open Access Journals (Sweden)

    Szu-Fu Chen

    Full Text Available Traumatic brain injury (TBI induces a complex sequence of apopototic cascades that contribute to secondary tissue damage. The aim of this study was to investigate the effects of salidroside, a phenolic glycoside with potent anti-apoptotic properties, on behavioral and histological outcomes, brain edema, and apoptosis following experimental TBI and the possible involvement of the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt signaling pathway.Mice subjected to controlled cortical impact injury received intraperitoneal salidroside (20, or 50 mg/kg or vehicle injection 10 min after injury. Behavioral studies, histology analysis and brain water content assessment were performed. Levels of PI3K/Akt signaling-related molecules, apoptosis-related proteins, cytochrome C (CytoC, and Smac/DIABLO were also analyzed. LY294002, a PI3K inhibitor, was administered to examine the mechanism of protection. The protective effect of salidroside was also investigated in primary cultured neurons subjected to stretch injury. Treatment with 20 mg/kg salidroside significantly improved functional recovery and reduced brain tissue damage up to post-injury day 28. Salidroside also significantly reduced neuronal death, apoptosis, and brain edema at day 1. These changes were associated with significant decreases in cleaved caspase-3, CytoC, and Smac/DIABLO at days 1 and 3. Salidroside increased phosphorylation of Akt on Ser473 and the mitochondrial Bcl-2/Bax ratio at day 1, and enhanced phosphorylation of Akt on Thr308 at day 3. This beneficial effect was abolished by pre-injection of LY294002. Moreover, delayed administration of salidroside at 3 or 6 h post-injury reduced neuronal damage at day 1. Salidroside treatment also decreased neuronal vulnerability to stretch-induced injury in vitro.Post-injury salidroside improved long-term behavioral and histological outcomes and reduced brain edema and apoptosis following TBI, at least partially via the PI3K/Akt signaling

  17. HSP72 protects cells from ER stress-induced apoptosis via enhancement of IRE1alpha-XBP1 signaling through a physical interaction.

    Directory of Open Access Journals (Sweden)

    Sanjeev Gupta

    2010-07-01

    Full Text Available Endoplasmic reticulum (ER stress is a feature of secretory cells and of many diseases including cancer, neurodegeneration, and diabetes. Adaptation to ER stress depends on the activation of a signal transduction pathway known as the unfolded protein response (UPR. Enhanced expression of Hsp72 has been shown to reduce tissue injury in response to stress stimuli and improve cell survival in experimental models of stroke, sepsis, renal failure, and myocardial ischemia. Hsp72 inhibits several features of the intrinsic apoptotic pathway. However, the molecular mechanisms by which Hsp72 expression inhibits ER stress-induced apoptosis are not clearly understood. Here we show that Hsp72 enhances cell survival under ER stress conditions. The UPR signals through the sensor IRE1alpha, which controls the splicing of the mRNA encoding the transcription factor XBP1. We show that Hsp72 enhances XBP1 mRNA splicing and expression of its target genes, associated with attenuated apoptosis under ER stress conditions. Inhibition of XBP1 mRNA splicing either by dominant negative IRE1alpha or by knocking down XBP1 specifically abrogated the inhibition of ER stress-induced apoptosis by Hsp72. Regulation of the UPR was associated with the formation of a stable protein complex between Hsp72 and the cytosolic domain of IRE1alpha. Finally, Hsp72 enhanced the RNase activity of recombinant IRE1alpha in vitro, suggesting a direct regulation. Our data show that binding of Hsp72 to IRE1alpha enhances IRE1alpha/XBP1 signaling at the ER and inhibits ER stress-induced apoptosis. These results provide a physical connection between cytosolic chaperones and the ER stress response.

  18. HSP72 protects cells from ER stress-induced apoptosis via enhancement of IRE1alpha-XBP1 signaling through a physical interaction.

    LENUS (Irish Health Repository)

    Gupta, Sanjeev

    2010-01-01

    Endoplasmic reticulum (ER) stress is a feature of secretory cells and of many diseases including cancer, neurodegeneration, and diabetes. Adaptation to ER stress depends on the activation of a signal transduction pathway known as the unfolded protein response (UPR). Enhanced expression of Hsp72 has been shown to reduce tissue injury in response to stress stimuli and improve cell survival in experimental models of stroke, sepsis, renal failure, and myocardial ischemia. Hsp72 inhibits several features of the intrinsic apoptotic pathway. However, the molecular mechanisms by which Hsp72 expression inhibits ER stress-induced apoptosis are not clearly understood. Here we show that Hsp72 enhances cell survival under ER stress conditions. The UPR signals through the sensor IRE1alpha, which controls the splicing of the mRNA encoding the transcription factor XBP1. We show that Hsp72 enhances XBP1 mRNA splicing and expression of its target genes, associated with attenuated apoptosis under ER stress conditions. Inhibition of XBP1 mRNA splicing either by dominant negative IRE1alpha or by knocking down XBP1 specifically abrogated the inhibition of ER stress-induced apoptosis by Hsp72. Regulation of the UPR was associated with the formation of a stable protein complex between Hsp72 and the cytosolic domain of IRE1alpha. Finally, Hsp72 enhanced the RNase activity of recombinant IRE1alpha in vitro, suggesting a direct regulation. Our data show that binding of Hsp72 to IRE1alpha enhances IRE1alpha\\/XBP1 signaling at the ER and inhibits ER stress-induced apoptosis. These results provide a physical connection between cytosolic chaperones and the ER stress response.

  19. Escin induces caspase-dependent apoptosis and autophagy through the ROS/p38 MAPK signalling pathway in human osteosarcoma cells in vitro and in vivo.

    Science.gov (United States)

    Zhu, Jian; Yu, Wei; Liu, Bing; Wang, Yitian; Shao, Jianlin; Wang, Junjie; Xia, Kaishun; Liang, Chengzhen; Fang, Weijing; Zhou, Chenhe; Tao, Huimin

    2017-10-12

    Osteosarcoma is one of the most malignant neoplasms in adolescents, and it generally develops multidrug resistance. Escin, a natural mixture of triterpene saponins isolated from Aesculus hippocastanum (horse chestnut), has demonstrated potent anti-tumour potential in vitro and in vivo. In the present study, we found that escin inhibited osteosarcoma proliferation in a dose- and time-dependent manner. Additionally, escin-induced apoptosis was evidenced by the increased expression of caspase-related proteins and the formation of apoptotic bodies. Escin also induced autophagy, with elevated LC3, ATG5, ATG12 and Beclin expression as well as autophagosome formation. Inhibition of escin-induced autophagy promoted apoptosis. Moreover, p38 mitogen-activated protein kinases (MAPKs) and reactive oxygen species (ROS) were activated by escin. A p38 MAPK inhibitor partially attenuated the autophagy and apoptosis triggered by escin, but a ROS scavenger showed a greater inhibitory effect. Finally, the therapeutic efficacy of escin against osteosarcoma was demonstrated in an orthotopic model. Overall, escin counteracted osteosarcoma by inducing autophagy and apoptosis via the activation of the ROS/p38 MAPK signalling pathway; these findings provide evidence for escin as a novel and potent therapeutic for the treatment of osteosarcoma.

  20. Curcumin promotes apoptosis in A549/DDP multidrug-resistant human lung adenocarcinoma cells through an miRNA signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jian, E-mail: zhangjian197011@yahoo.com [Department of Respiratory Medicine, Xijing Hospital, The Fourth Military Medical University, Xi' an 710032 (China); Zhang, Tao [Department of Thoracic Surgery, Tangdu Hospital, The Fourth Military Medical University, Xi' an 710038 (China); Ti, Xinyu; Shi, Jieran; Wu, Changgui; Ren, Xinling [Department of Respiratory Medicine, Xijing Hospital, The Fourth Military Medical University, Xi' an 710032 (China); Yin, Hong, E-mail: yinnhong@yahoo.com [The Medical Image Center, Xijing Hospital, The Fourth Military Medical University, Xi' an 710032 (China)

    2010-08-13

    Research highlights: {yields} Curcumin had anti-cancer effects on A549/DDP multidrug-resistant human lung adenocarcinoma cells {yields} Curcumin promotes apoptosis in A549/DDP cells through a miRNA signaling pathway {yields} Curcumin induces A549/DDP cell apoptosis by downregulating miR-186* {yields} miR-186* may serve as a potential gene therapy target for refractory lung cancer that is sensitive to curcumin -- Abstract: Curcumin extracted from the rhizomes of Curcuma longa L. has been shown to have inhibitory effects on cancers through its anti-proliferative and pro-apoptotic activities. Emerging evidence demonstrates that curcumin can overcome drug resistance to classical chemotherapies. Thus, the mechanisms underlying the anti-tumor activities of curcumin require further study. In our study, we first demonstrated that curcumin had anti-cancer effects on A549/DDP multidrug-resistant human lung adenocarcinoma cells. Further studies showed that curcumin altered miRNA expression; in particular, significantly downregulated the expression of miR-186* in A549/DDP. In addition, transfection of cells with a miR-186* inhibitor promoted A549/DDP apoptosis, and overexpression of miR-186* significantly inhibited curcumin-induced apoptosis in A549/DDP cells. These observations suggest that miR-186* may serve as a potential gene therapy target for refractory lung cancer that is sensitive to curcumin.

  1. Curcumin promotes apoptosis in A549/DDP multidrug-resistant human lung adenocarcinoma cells through an miRNA signaling pathway

    International Nuclear Information System (INIS)

    Zhang, Jian; Zhang, Tao; Ti, Xinyu; Shi, Jieran; Wu, Changgui; Ren, Xinling; Yin, Hong

    2010-01-01

    Research highlights: → Curcumin had anti-cancer effects on A549/DDP multidrug-resistant human lung adenocarcinoma cells → Curcumin promotes apoptosis in A549/DDP cells through a miRNA signaling pathway → Curcumin induces A549/DDP cell apoptosis by downregulating miR-186* → miR-186* may serve as a potential gene therapy target for refractory lung cancer that is sensitive to curcumin -- Abstract: Curcumin extracted from the rhizomes of Curcuma longa L. has been shown to have inhibitory effects on cancers through its anti-proliferative and pro-apoptotic activities. Emerging evidence demonstrates that curcumin can overcome drug resistance to classical chemotherapies. Thus, the mechanisms underlying the anti-tumor activities of curcumin require further study. In our study, we first demonstrated that curcumin had anti-cancer effects on A549/DDP multidrug-resistant human lung adenocarcinoma cells. Further studies showed that curcumin altered miRNA expression; in particular, significantly downregulated the expression of miR-186* in A549/DDP. In addition, transfection of cells with a miR-186* inhibitor promoted A549/DDP apoptosis, and overexpression of miR-186* significantly inhibited curcumin-induced apoptosis in A549/DDP cells. These observations suggest that miR-186* may serve as a potential gene therapy target for refractory lung cancer that is sensitive to curcumin.

  2. Relaxin attenuates aristolochic acid induced human tubular epithelial cell apoptosis in vitro by activation of the PI3K/Akt signaling pathway.

    Science.gov (United States)

    Xie, Xiang-Cheng; Zhao, Ning; Xu, Qun-Hong; Yang, Xiu; Xia, Wen-Kai; Chen, Qi; Wang, Ming; Fei, Xiao

    2017-06-01

    Aristolochic acid nephropathy remains a leading cause of chronic kidney disease (CKD), however few treatment strategies exist. Emerging evidence has shown that H2 relaxin (RLX) possesses powerful antifibrosis and anti-apoptotic properties, therefore we aimed to investigate whether H2 relaxin can be employed to reduce AA-induced cell apoptosis. Human proximal tubular epithelial (HK-2) cells exposed to AA-I were treated with or without administration of H2 RLX. Cell viability was examined using the WST-8 assay. Apoptotic morphologic alterations were observed using the Hoechst 33342 staining method. Apoptosis was detected using flow cytometry. The expression of caspase 3, caspase 8, caspase 9, ERK1/2, Bax, Bcl-2, and Akt proteins was determined by Western blot. Co-treatment with RLX reversed the increased apoptosis observed in the AA-I only treated group. RLX restored expression of phosphorylated Akt which found to be decreased in the AA-I only treated cells. RLX co-treatment led to a decrease in the Bax/Bcl-2 ratio as well as the cleaved form of caspase-3 compared to the AA-I only treated cells. This anti-apoptotic effect of RLX was attenuated by co-administration of the Akt inhibitor LY294002. The present study demonstrated H2 RLX can decrease AA-I induced apoptosis through activation of the PI3K/Akt signaling pathway.

  3. Berberine prevents nitric oxide-induced rat chondrocyte apoptosis and cartilage degeneration in a rat osteoarthritis model via AMPK and p38 MAPK signaling.

    Science.gov (United States)

    Zhou, Yan; Liu, Shi-Qing; Yu, Ling; He, Bin; Wu, Shi-Hao; Zhao, Qi; Xia, Shao-Qiang; Mei, Hong-Jun

    2015-09-01

    Chondrocyte apoptosis is an important mechanism involved in osteoarthritis (OA). Berberine (BBR), a plant alkaloid derived from Chinese medicine, is characterized by multiple pharmacological effects, such as anti-inflammatory and anti-apoptotic activities. This study aimed to evaluate the chondroprotective effect and underlying mechanisms of BBR on sodium nitroprusside (SNP)-stimulated chondrocyte apoptosis and surgically-induced rat OA model. The in vitro results revealed that BBR suppressed SNP-stimulated chondrocyte apoptosis as well as cytoskeletal remodeling, down-regulated expressions of inducible nitric oxide synthase (iNOS) and caspase-3, and up-regulated Bcl-2/Bax ratio and Type II collagen (Col II) at protein levels, which were accompanied by increased adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and decreased phosphorylation of p38 mitogen-activated protein kinase (MAPK). Furthermore, the anti-apoptotic effect of BBR was blocked by AMPK inhibitor Compound C (CC) and adenosine-9-β-D-arabino-furanoside (Ara A), and enhanced by p38 MAPK inhibitor SB203580. In vivo experiment suggested that BBR ameliorated cartilage degeneration and exhibited an anti-apoptotic effect on articular cartilage in a rat OA model, as demonstrated by histological analyses, TUNEL assay and immunohistochemical analyses of caspase-3, Bcl-2 and Bax expressions. These findings suggest that BBR suppresses SNP-stimulated chondrocyte apoptosis and ameliorates cartilage degeneration via activating AMPK signaling and suppressing p38 MAPK activity.

  4. A novel polysaccharide derived from algae extract induces apoptosis and cell cycle arrest in human gastric carcinoma MKN45 cells via ROS/JNK signaling pathway.

    Science.gov (United States)

    Xie, Peiyu; Fujii, Isao; Zhao, Jien; Shinohara, Makoto; Matsukura, Makoto

    2016-10-01

    In recent years, interest in biological activities of compounds from marine organisms has intensified. Cancer is the most principal enemy for human life and health. For the first time, to the best of our knowledge, we investigated a novel algae-derived polysaccharide for its role in inducing apoptosis and cell cycle arrest in human gastric carcinoma MKN45 cells. We found that the novel polysaccharide suppressed MKN45 cell proliferation, induced cell apoptosis and arrested the cells at G2/M phase. Furthermore, we observed that the generation of reactive oxygen species (ROS) and the phosphorylation of Jun N-terminal kinase (JNK), p53, caspase-9 and -3 were induced in the polysaccharide-treated MKN45 cells. In addition, pretreatment with N-acetyl-cysteine (NAC) and SP600125, the inhibitor of ROS and JNK, induced MKN45 cell proliferation, prevented the cell apoptosis and released the cells from cycle arrest. Finally, we found that pretreatment with NAC prevented the JNK, p53, caspase-9 and -3 protein phosphorylation induced by the polysaccharide, however, pretreatment with SP600125 did not affect the generation of ROS, suggesting that ROS is upstream of JNK. Taken together, the novel polysaccharide induced cancer cell apoptosis and arrested cell cycle via ROS/JNK signaling pathway.

  5. Suppression of PTEN/AKT signaling decreases the expression of TUBB3 and TOP2A with subsequent inhibition of cell growth and induction of apoptosis in human breast cancer MCF-7 cells via ATP and caspase-3 signaling pathways.

    Science.gov (United States)

    Yang, Zhenhua; Liu, Ying; Shi, Changzheng; Zhang, Yuqin; Lv, Rongzhao; Zhang, Rong; Wang, Qian; Wang, Yiming

    2017-02-01

    The aim of the present study was to evaluate the effects of PTEN/AKT signaling on TUBB3 and TOP2A expression and on the subsequent cell growth of human breast cancer MCF-7 cells. We found that the disease-free survival (DFS) and overall survival (OS) of breast cancer patients with TUBB3‑positive tumors were lower than these rates in the patients with TUBB3-negative tumors. Meanwhile, DFS and OS of breast cancer patients with TOP2A-positive tumors were also lower than these rates in patients with TOP2A-negative tumors. Suppression of PTEN reduced the protein expression of TUBB3 and TOP2A in MCF-7 cells. Suppression of PTEN also reduced cell proliferation and induced apoptosis and caspase-3 activity in MCF-7 cells. Moreover, an increase in ATP also reduced TUBB3 and TOP2A protein expression, reduced cell proliferation and induced apoptosis and caspase-3 activity in the MCF-7 cells following suppression of PTEN. Suppression of phosphorylation-AKT (p-AKT) reduced the protein expression of TUBB3 and TOP2A in the MCF-7 cells. Suppression of p-AKT also reduced cell proliferation and induced apoptosis and caspase-3 activity in the MCF-7 cells. Then, ATP also reduced TUBB3 and TOP2A protein expression, reduced cell proliferation and induced apoptosis and caspase-3 activity in MCF-7 cells following suppression of p-AKT. These results suggest that PTEN/AKT signaling affects the expression of TUBB3 and TOP2A reducing cell growth and inducing apoptosis of human breast cancer MCF-7 cells through ATP and caspase-3 signaling pathways. TUBB3 and TOP2A may be promising prognostic markers for the efficacy of adjuvant cisplatin-based chemotherapy.

  6. Heat stress prevents lipopolysaccharide-induced apoptosis in pulmonary microvascular endothelial cells by blocking calpain/p38 MAPK signalling.

    Science.gov (United States)

    Liu, Zhi-Feng; Zheng, Dong; Fan, Guo-Chang; Peng, Tianqing; Su, Lei

    2016-08-01

    Pulmonary microvascular endothelial cells (PMECs) injury including apoptosis plays an important role in the pathogenesis of acute lung injury during sepsis. Our recent study has demonstrated that calpain activation contributes to apoptosis in PMECs under septic conditions. This study investigated how calpain activation mediated apoptosis and whether heat stress regulated calpain activation in lipopolysaccharides (LPS)-stimulated PMECs. In cultured mouse primary PMECs, incubation with LPS (1 μg/ml, 24 h) increased active caspase-3 fragments and DNA fragmentation, indicative of apoptosis. These effects of LPS were abrogated by pre-treatment with heat stress (43 °C for 2 h). LPS also induced calpain activation and increased phosphorylation of p38 MAPK. Inhibition of calpain and p38 MAPK prevented apoptosis induced by LPS. Furthermore, inhibition of calpain blocked p38 MAPK phosphorylation in LPS-stimulated PMECs. Notably, heat stress decreased the protein levels of calpain-1/2 and calpain activities, and blocked p38 MAPK phosphorylation in response to LPS. Additionally, forced up-regulation of calpain-1 or calpain-2 sufficiently induced p38 MAPK phosphorylation and apoptosis in PMECs, both of which were inhibited by heat stress. In conclusion, heat stress prevents LPS-induced apoptosis in PMECs. This effect of heat stress is associated with down-regulation of calpain expression and activation, and subsequent blockage of p38 MAPK activation in response to LPS. Thus, blocking calpain/p38 MAPK pathway may be a novel mechanism underlying heat stress-mediated inhibition of apoptosis in LPS-stimulated endothelial cells.

  7. PTHLH coupling upstream negative regulation of fatty acid biosynthesis and Wnt receptor signal to downstream peptidase activity-induced apoptosis network in human hepatocellular carcinoma by systems-theoretical analysis.

    Science.gov (United States)

    Huang, Juxiang; Wang, Lin; Jiang, Minghu; Lin, Hong; Qi, Lianxiu; Diao, Haizhen

    2012-10-01

    Studies were done on the analysis of biological processes in the same high expression (fold change ≥ 2) PTHLH-activated feedback negative regulation-mediated apoptosis gene ontology (GO) network of human hepatocellular carcinoma (HCC) compared with the corresponding low expression activated GO network of no-tumor hepatitis/cirrhotic tissues [hepatitis B virus (HBV) or hepatitis C virus (HCV) infection]. We proposed PTHLH-activated network that upstream included the regulation of apoptosis, signal transduction resulting in induction of apoptosis, signal transduction by p53 class mediator resulting in transcription of p21 class mediator, negative regulation of centriole replication, negative regulation of fatty acid biosynthesis, negative regulation of Wnt receptor signaling pathway, anaphase-promoting complex-dependent proteasomal ubiquitin-dependent protein catabolism, apoptosis, induction of apoptosis, and negative regulation of phosphorylation. Downstream-network negative regulation of peptidase activity, anaphase-promoting complex-dependent proteasomal ubiquitin-dependent protein catabolism, apoptosis, induction of apoptosis and negative regulation of phosphorylation, as a result of coupling upstream negative regulation of fatty acid biosynthesis and Wnt receptor signal to downstream peptidase activity-induced apoptosis in HCC. Our hypothesis was verified by the different PTHLH-activated feedback negative regulation-mediated apoptosis GO network of HCC compared with the corresponding inhibited GO network of no-tumor hepatitis/cirrhotic tissues, or the same compared with the corresponding inhibited GO network of HCC. PTHLH coupling upstream negative regulation of fatty acid biosynthesis and Wnt receptor signal to downstream peptidase activity-induced apoptosis network was constructed that upstream BRCA1, DKK1, BUB1B activated PTHLH, and downstream PTHLH-activated CST6, BUB1B, NTN1, PHLDA2 in HCC from GEO data set using gene regulatory network inference method

  8. Induction of apoptosis in renal cell carcinoma by reactive oxygen species: involvement of extracellular signal-regulated kinase 1/2, p38delta/gamma, cyclooxygenase-2 down-regulation, and translocation of apoptosis-inducing factor.

    LENUS (Irish Health Repository)

    Ambrose, Monica

    2012-02-03

    Renal cell carcinoma (RCC) is the most common malignancy of the kidney. Unfortunately, RCCs are highly refractory to conventional chemotherapy, radiation therapy, and even immunotherapy. Thus, novel therapeutic targets need to be sought for the successful treatment of RCCs. We now report that 6-anilino-5,8-quinolinequinone (LY83583), an inhibitor of cyclic GMP production, induced growth arrest and apoptosis of the RCC cell line 786-0. It did not prove deleterious to normal renal epithelial cells, an important aspect of chemotherapy. To address the cellular mechanism(s), we used both genetic and pharmacological approaches. LY83583 induced a time- and dose-dependent increase in RCC apoptosis through dephosphorylation of mitogen-activated protein kinase kinase 1\\/2 and its downstream extracellular signal-regulated kinases (ERK) 1 and -2. In addition, we observed a decrease in Elk-1 phosphorylation and cyclooxygenase-2 (COX-2) down-regulation. We were surprised that we failed to observe an increase in either c-Jun NH(2)-terminal kinase or p38alpha and -beta mitogen-activated protein kinase activation. In contradiction, reintroduction of p38delta by stable transfection or overexpression of p38gamma dominant negative abrogated the apoptotic effect. Cell death was associated with a decrease and increase in Bcl-x(L) and Bax expression, respectively, as well as release of cytochrome c and translocation of apoptosis-inducing factor. These events were associated with an increase in reactive oxygen species formation. The antioxidant N-acetyl l-cysteine, however, opposed LY83583-mediated mitochondrial dysfunction, ERK1\\/2 inactivation, COX-2 down-regulation, and apoptosis. In conclusion, our results suggest that LY83583 may represent a novel therapeutic agent for the treatment of RCC, which remains highly refractory to antineoplastic agents. Our data provide a molecular basis for the anticancer activity of LY83583.

  9. ERK1/2 signalling protects against apoptosis following endoplasmic reticulum stress but cannot provide long-term protection against BAX/BAK-independent cell death.

    Directory of Open Access Journals (Sweden)

    Nicola J Darling

    Full Text Available Disruption of protein folding in the endoplasmic reticulum (ER causes ER stress. Activation of the unfolded protein response (UPR acts to restore protein homeostasis or, if ER stress is severe or persistent, drive apoptosis, which is thought to proceed through the cell intrinsic, mitochondrial pathway. Indeed, cells that lack the key executioner proteins BAX and BAK are protected from ER stress-induced apoptosis. Here we show that chronic ER stress causes the progressive inhibition of the extracellular signal-regulated kinase (ERK1/2 signalling pathway. This is causally related to ER stress since reactivation of ERK1/2 can protect cells from ER stress-induced apoptosis whilst ERK1/2 pathway inhibition sensitises cells to ER stress. Furthermore, cancer cell lines harbouring constitutively active BRAFV600E are addicted to ERK1/2 signalling for protection against ER stress-induced cell death. ERK1/2 signalling normally represses the pro-death proteins BIM, BMF and PUMA and it has been proposed that ER stress induces BIM-dependent cell death. We found no evidence that ER stress increased the expression of these proteins; furthermore, BIM was not required for ER stress-induced death. Rather, ER stress caused the PERK-dependent inhibition of cap-dependent mRNA translation and the progressive loss of pro-survival proteins including BCL2, BCLXL and MCL1. Despite these observations, neither ERK1/2 activation nor loss of BAX/BAK could confer long-term clonogenic survival to cells exposed to ER stress. Thus, ER stress induces cell death by at least two biochemically and genetically distinct pathways: a classical BAX/BAK-dependent apoptotic response that can be inhibited by ERK1/2 signalling and an alternative ERK1/2- and BAX/BAK-independent cell death pathway.

  10. Notch 1 and 3 receptor signaling modulates vascular smooth muscle cell growth, apoptosis, and migration via a CBF-1/RBP-Jk dependent pathway.

    Science.gov (United States)

    Sweeney, Catherine; Morrow, David; Birney, Yvonne A; Coyle, Seamus; Hennessy, Colm; Scheller, Agnieszka; Cummins, Philip M; Walls, Dermot; Redmond, Eileen M; Cahill, Paul A

    2004-09-01

    Vascular smooth muscle cell (SMC) fate decisions (cell growth, migration, and apoptosis) are fundamental features in the pathogenesis of vascular disease. We investigated the role of Notch 1 and 3 receptor signaling in controlling adult SMC fate in vitro by establishing that hairy enhancer of split (hes-1 and -5) and related hrt's (hrt-1, -2, and -3) are direct downstream target genes of Notch 1 and 3 receptors in SMC and identified an essential role for nuclear protein CBF-1/RBP-Jk in their regulation. Constitutive expression of active Notch 1 and 3 receptors (Notch IC) resulted in a significant up-regulation of CBF-1/RBP-Jk-dependent promoter activity and Notch target gene expression concomitant with significant increases in SMC growth while concurrently inhibiting SMC apoptosis and migration. Moreover, inhibition of endogenous Notch mediated CBF-1/RBP-Jk regulated gene expression with a non-DNA binding mutant of CBF-1, a Notch IC deleted of its delta RAM domain and the Epstein-Barr virus encoded RPMS-1, in conjunction with pharmacological inhibitors of Notch IC receptor trafficking (brefeldin A and monensin), resulted in a significant decrease in cell growth while concomitantly increasing SMC apoptosis and migration. These findings suggest that endogenous Notch receptors and downstream target genes control vascular cell fate in vitro. Notch signaling, therefore, represents a novel therapeutic target for disease states in which changes in vascular cell fate occur in vivo.

  11. Blocking Epidermal Growth Factor Receptor Signaling in HTR-8/SVneo First Trimester Trophoblast Cells Results in Dephosphorylation of PKBα/AKT and Induces Apoptosis

    Directory of Open Access Journals (Sweden)

    J. Bolnick

    2011-01-01

    Full Text Available We identified a major peptide signaling target of EGF/EGFR pathway and explored the consequences of blocking or activating this pathway in the first trimester extravillous trophoblast cells, HTR-8/SVneo. A global analysis of protein phosphorylation was undertaken using novel technology (Kinexus Kinetworks that utilizes SDS-polyacrylamide minigel electrophoresis and multi-lane immunoblotting to permit specific and semiquantitative detection of multiple phosphoproteins. Forty-seven protein phosphorylation sites were queried, and the results reported based on relative phosphorylation at each site. EGF- and Iressa-(gefitinib, ZD1839, an inhibitor of EGFR treated HTR-8/SVneo cells were subjected to immunoblotting and flow cytometry to confirm the phosphoprotein screen and to assess the effects of EGF versus Iressa on cell cycle and apoptosis. EGFR mediates the phosphorylation of important signaling proteins, including PKBα/AKT. This pathway is likely to be central to EGFR-mediated trophoblast survival. Furthermore, EGF treatment induces proliferation and inhibits apoptosis, while Iressa induces apoptosis.

  12. Exposure to Cerium Oxide Nanoparticles Is Associated With Activation of Mitogen-activated Protein Kinases Signaling and Apoptosis in Rat Lungs

    Directory of Open Access Journals (Sweden)

    Kevin M. Rice

    2015-05-01

    Full Text Available Objectives: With recent advances in nanoparticle manufacturing and applications, potential exposure to nanoparticles in various settings is becoming increasing likely. No investigation has yet been performed to assess whether respiratory tract exposure to cerium oxide (CeO2 nanoparticles is associated with alterations in protein signaling, inflammation, and apoptosis in rat lungs. Methods: Specific-pathogen-free male Sprague-Dawley rats were instilled with either vehicle (saline or CeO2 nanoparticles at a dosage of 7.0 mg/kg and euthanized 1, 3, 14, 28, 56, or 90 days after exposure. Lung tissues were collected and evaluated for the expression of proteins associated with inflammation and cellular apoptosis. Results: No change in lung weight was detected over the course of the study; however, cerium accumulation in the lungs, gross histological changes, an increased Bax to Bcl-2 ratio, elevated cleaved caspase-3 protein levels, increased phosphorylation of p38 MAPK, and diminished phosphorylation of ERK-1/2-MAPK were detected after CeO2 instillation (p<0.05. Conclusions: Taken together, these data suggest that high-dose respiratory exposure to CeO2 nanoparticles is associated with lung inflammation, the activation of signaling protein kinases, and cellular apoptosis, which may be indicative of a long-term localized inflammatory response.

  13. Resveratrol suppresses IGF-1 induced human colon cancer cell proliferation and elevates apoptosis via suppression of IGF-1R/Wnt and activation of p53 signaling pathways

    Directory of Open Access Journals (Sweden)

    Radhakrishnan Sridhar

    2010-05-01

    Full Text Available Abstract Background Obesity is a global phenomenon and is associated with various types of cancer, including colon cancer. There is a growing interest for safe and effective bioactive compounds that suppress the risk for obesity-promoted colon cancer. Resveratrol (trans-3, 4', 5,-trihydroxystilbene, a stilbenoid found in the skin of red grapes and peanuts suppresses many types of cancers by regulating cell proliferation and apoptosis through a variety of mechanisms, however, resveratrol effects on obesity-promoted colon cancer are not clearly established. Methods We investigated the anti-proliferative effects of resveratrol on HT-29 and SW480 human colon cancer cells in the presence and absence of insulin like growth factor-1 (IGF-1; elevated during obesity and elucidated the mechanisms of action using IGF-1R siRNA in HT-29 cells which represents advanced colon carcinogenesis. Results Resveratrol (100-150 μM exhibited anti-proliferative properties in HT-29 cells even after IGF-1 exposure by arresting G0/G1-S phase cell cycle progression through p27 stimulation and cyclin D1 suppression. Treatment with resveratrol suppressed IGF-1R protein levels and concurrently attenuated the downstream Akt/Wnt signaling pathways that play a critical role in cell proliferation. Targeted suppression of IGF-1R using IGF-1R siRNA also affected these signaling pathways in a similar manner. Resveratrol treatment induced apoptosis by activating tumor suppressor p53 protein, whereas IGF-1R siRNA treatment did not affect apoptosis. Our data suggests that resveratrol not only suppresses cell proliferation by inhibiting IGF-1R and its downstream signaling pathways similar to that of IGF-1R siRNA but also enhances apoptosis via activation of the p53 pathway. Conclusions For the first time, we report that resveratrol suppresses colon cancer cell proliferation and elevates apoptosis even in the presence of IGF-1 via suppression of IGF-1R/Akt/Wnt signaling pathways and

  14. Resveratrol suppresses IGF-1 induced human colon cancer cell proliferation and elevates apoptosis via suppression of IGF-1R/Wnt and activation of p53 signaling pathways

    International Nuclear Information System (INIS)

    Vanamala, Jairam; Reddivari, Lavanya; Radhakrishnan, Sridhar; Tarver, Chris

    2010-01-01

    Obesity is a global phenomenon and is associated with various types of cancer, including colon cancer. There is a growing interest for safe and effective bioactive compounds that suppress the risk for obesity-promoted colon cancer. Resveratrol (trans-3, 4', 5,-trihydroxystilbene), a stilbenoid found in the skin of red grapes and peanuts suppresses many types of cancers by regulating cell proliferation and apoptosis through a variety of mechanisms, however, resveratrol effects on obesity-promoted colon cancer are not clearly established. We investigated the anti-proliferative effects of resveratrol on HT-29 and SW480 human colon cancer cells in the presence and absence of insulin like growth factor-1 (IGF-1; elevated during obesity) and elucidated the mechanisms of action using IGF-1R siRNA in HT-29 cells which represents advanced colon carcinogenesis. Resveratrol (100-150 μM) exhibited anti-proliferative properties in HT-29 cells even after IGF-1 exposure by arresting G 0 /G 1 -S phase cell cycle progression through p27 stimulation and cyclin D1 suppression. Treatment with resveratrol suppressed IGF-1R protein levels and concurrently attenuated the downstream Akt/Wnt signaling pathways that play a critical role in cell proliferation. Targeted suppression of IGF-1R using IGF-1R siRNA also affected these signaling pathways in a similar manner. Resveratrol treatment induced apoptosis by activating tumor suppressor p53 protein, whereas IGF-1R siRNA treatment did not affect apoptosis. Our data suggests that resveratrol not only suppresses cell proliferation by inhibiting IGF-1R and its downstream signaling pathways similar to that of IGF-1R siRNA but also enhances apoptosis via activation of the p53 pathway. For the first time, we report that resveratrol suppresses colon cancer cell proliferation and elevates apoptosis even in the presence of IGF-1 via suppression of IGF-1R/Akt/Wnt signaling pathways and activation of p53, suggesting its potential role as a

  15. Melatonin Inhibits Neural Cell Apoptosis and Promotes Locomotor Recovery via Activation of the Wnt/β-Catenin Signaling Pathway After Spinal Cord Injury.

    Science.gov (United States)

    Shen, Zhaoliang; Zhou, Zipeng; Gao, Shuang; Guo, Yue; Gao, Kai; Wang, Haoyu; Dang, Xiaoqian

    2017-08-01

    The spinal cord is highly sensitive to spinal cord injury (SCI) by external mechanical damage, resulting in irreversible neurological damage. Activation of the Wnt/β-catenin signaling pathway can effectively reduce apoptosis and protect against SCI. Melatonin, an indoleamine originally isolated from bovine pineal tissue, exerts neuroprotective effects after SCI through activation of the Wnt/β-catenin signaling pathway. In this study, we demonstrated that melatonin exhibited neuroprotective effects on neuronal apoptosis and supported functional recovery in a rat SCI model by activating the Wnt/β-catenin signaling pathway. We found that melatonin administration after SCI significantly upregulated the expression of low-density lipoprotein receptor related protein 6 phosphorylation (p-LRP-6), lymphoid enhancer factor-1 (LEF-1) and β-catenin protein in the spinal cord. Melatonin enhanced motor neuronal survival in the spinal cord ventral horn and improved the locomotor functions of rats after SCI. Melatonin administration after SCI also reduced the expression levels of Bax and cleaved caspase-3 in the spinal cord and the proportion of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) positive cells, but increased the expression level of Bcl-2. These results suggest that melatonin attenuated SCI by activating the Wnt/β-catenin signaling pathway.

  16. Aloin promotes A549 cell apoptosis via the reactive oxygen species‑mitogen activated protein kinase signaling pathway and p53 phosphorylation.

    Science.gov (United States)

    Wan, Li; Zhang, Lin; Fan, Kai; Wang, Jianjun

    2017-11-01

    Aloin has the potential to be a novel anticancer agent in cancer therapies. However, the detailed anticancer effect of Aloin remains to be fully elucidated. The present study analyzed the p53‑dependent mechanisms in response to Aloin treatment. Using the p53‑proficient A549 cells, an Aloin‑induced apoptotic cell model was established, which was used to evaluate the potential underlying molecular mechanisms. The results demonstrated that 200, 300 and 400 µM Aloin induced intrinsic cell apoptosis, which was further confirmed by disruption of the mitochondrial membrane potential, elevation of cytosolic Ca2+ levels, and activation of B‑cell lymphoma 2 (Bcl‑2) homologous antagonist killer, Bcl‑2 X‑associated protein, p53 upregulated modulator of apoptosis and phorbol‑12‑myristate‑13‑acetate‑induced protein 1. Aloin‑induced apoptosis was also accompanied by the induction of p53 phosphorylation on Serine (Ser)15, Threonine 18, Ser20 and Ser392; however, there were no significant differences in the expression of p53 and mouse double minute 2 homolog. Aloin‑induced apoptosis was reactive oxygen species (ROS)‑ and c‑Jun/p38‑dependent, as specific inhibitors for ROS, phosphorylated (p)‑c‑Jun and p‑p38 may attenuate Aloin‑induced A549 cell proliferating inhibition. In conclusion, these results suggested that Aloin may induce apoptosis in A549 cells via the ROS‑mitogen activated protein kinase signaling pathway, with p53 phosphorylation. These results implicate Aloin as a potential therapeutic agent for the treatment of lung cancer.

  17. All-Trans Retinoic Acid Ameliorates Arsenic-Induced Oxidative Stress and Apoptosis in the Rat Uterus by Modulating MAPK Signaling Proteins.

    Science.gov (United States)

    Chatterjee, Aniruddha; Chatterji, Urmi

    2017-11-01

    Exposure to arsenic leads to inhibition of the anti-oxidant defense mechanism of the body. Reactive oxygen species generated in response to arsenic causes reproductive failures in exposed females and also acts as an inducer of apoptosis. As a prospective remedial agent, all-trans retinoic acid (ATRA) was assessed for reversing arsenic-induced oxidative stress and apoptosis. Rats exposed to arsenic for 28 days were allowed to recover naturally or were treated simultaneously with ATRA for 28 days or up to 56 days. Production of H 2 O 2 was detected using 2',7'-dichlorfluorescein diacetate (DCFCA) by flow cytometry. Catalase, superoxide dismutase, glutathione, ALT, and AST were estimated by biochemical assays and Western blot analyses. Detection of apoptosis was performed using annexin V-FITC/propidium iodide. Expressions of p53, p21, cleaved caspase 3, JNK/pJNK, and ERK/pERK levels were estimated using Western blot analysis. Elemental arsenic deposition in the rat uterus and liver was estimated by atomic absorption spectrophotometry. Our results confirmed that ATRA ameliorated sodium arsenite-induced ROS generation, restored redox balance, and prevented apoptosis. Concomitant recovery was observed to be more prominent for ATRA-treated rats as compared to the rats that were allowed to recover naturally for 56 days. Tissue arsenic deposition was significantly reduced in the uterus upon continuous ATRA treatment. The results revealed that ATRA reversed arsenic-induced free radical generation, activated the anti-oxidant defence system, and subsequently repressed p53-dependent apoptosis through inhibition of the MAPK signaling components. J. Cell. Biochem. 118: 3796-3809, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  18. BLM Colorado PLSS Intersected

    Data.gov (United States)

    Department of the Interior — Shapefile Format –The fully intersected data is the atomic level of the PLSS that is similar to the coverage or the smallest pieces used to build the PLSS. Polygons...

  19. Signaling pathways and genes that inhibit pathogen-induced macrophage apoptosis--CREB and NF-kappaB as key regulators.

    Science.gov (United States)

    Park, Jin Mo; Greten, Florian R; Wong, Athena; Westrick, Randal J; Arthur, J Simon C; Otsu, Kinya; Hoffmann, Alexander; Montminy, Marc; Karin, Michael

    2005-09-01

    Certain microbes evade host innate immunity by killing activated macrophages with the help of virulence factors that target prosurvival pathways. For instance, infection of macrophages with the TLR4-activating bacterium Bacillus anthracis triggers an apoptotic response due to inhibition of p38 MAP kinase activation by the bacterial-produced lethal toxin. Other pathogens induce macrophage apoptosis by preventing activation of NF-kappaB, which depends on IkappaB kinase beta (IKKbeta). To better understand how p38 and NF-kappaB maintain macrophage survival, we searched for target genes whose products prevent TLR4-induced apoptosis and a p38-dependent transcription factor required for their induction. Here we describe key roles for transcription factor CREB, a target for p38 signaling, and the plasminogen activator 2 (PAI-2) gene, a target for CREB, in maintenance of macrophage survival.

  20. Furanodienone induces cell cycle arrest and apoptosis by suppressing EGFR/HER2 signaling in HER2-overexpressing human breast cancer cells.

    Science.gov (United States)

    Li, Ying-Wei; Zhu, Guo-Yuan; Shen, Xiao-Ling; Chu, Jian-Hong; Yu, Zhi-Ling; Fong, Wang-Fun

    2011-11-01

    Overexpression of EGFR and HER2 is seen in breast cancers and results in poor prognosis and decreased patient survival. Clinically, EGFR and HER2 are effective therapeutic targets. The objective of this study is to investigate the in vitro effects of furanodienone, an active chemical component isolated from Rhizoma Curcumae, on the activation of EGFR/HER2 signaling, cell cycle, and apoptosis in HER2-overexpressing BT474 and SKBR3 cells. Cell growth was assessed by SRB protein assay. Cell cycle analysis was carried out by flow cytometry, and apoptosis was observed by Annexin V and DAPI staining. Effects of furanodienone on the activation of EGFR/HER2 signaling-related proteins were analyzed by western blotting. Furanodienone inhibited cell growth in BT474 and SKBR3 cells. Furanodienone caused G1 arrest in BT474 cells and induced apoptosis in SKBR3 cells. Furanodienone interfered with EGFR/HER2 signaling in treated cells as shown by decreases in phosphorylated EGFR, HER2, Akt, Gsk3β and an increase in p27(kip1) protein. Accordingly, furanodienone inhibited EGF-induced phosphorylation of EGFR, HER2, Akt, and Gsk3β. EGFR-specific siRNA knockdown did not affect the cell growth inhibitory effect of furanodienone. On the contrary, specific siRNA knockdown of HER2 increased cellular resistance to furanodienone toxicity. In HER-2-deficient MDA-MB-231 cells, the transfection and expression of HER2 increased the sensitivity of cells to furanodienone toxicity. Furanodienone inhibited EGFR/HER2 signaling pathway in BT474 and SKBR3 cells. More importantly, the effect of furanodienone was specifically dependent on HER2, but not EGFR, expression.

  1. Self-Localization at Street Intersections.

    Science.gov (United States)

    Fusco, Giovanni; Shen, Huiying; Coughlan, James M

    2014-05-01

    There is growing interest among smartphone users in the ability to determine their precise location in their environment for a variety of applications related to wayfinding, travel and shopping. While GPS provides valuable self-localization estimates, its accuracy is limited to approximately 10 meters in most urban locations. This paper focuses on the self-localization needs of blind or visually impaired travelers, who are faced with the challenge of negotiating street intersections. These travelers need more precise self-localization to help them align themselves properly to crosswalks, signal lights and other features such as walk light pushbuttons. We demonstrate a novel computer vision-based localization approach that is tailored to the street intersection domain. Unlike most work on computer vision-based localization techniques, which typically assume the presence of detailed, high-quality 3D models of urban environments, our technique harnesses the availability of simple, ubiquitous satellite imagery (e.g., Google Maps) to create simple maps of each intersection. Not only does this technique scale naturally to the great majority of street intersections in urban areas, but it has the added advantage of incorporating the specific metric information that blind or visually impaired travelers need, namely, the locations of intersection features such as crosswalks. Key to our approach is the integration of IMU (inertial measurement unit) information with geometric information obtained from image panorama stitchings. Finally, we evaluate the localization performance of our algorithm on a dataset of intersection panoramas, demonstrating the feasibility of our approach.

  2. Signaling Rho-kinase mediates inflammation and apoptosis in T cells and renal tubules in cisplatin nephrotoxicity.

    Science.gov (United States)

    Nozaki, Yuji; Kinoshita, Koji; Hino, Shoichi; Yano, Tomohiro; Niki, Kaoru; Hirooka, Yasuaki; Kishimoto, Kazuya; Funauchi, Masanori; Matsumura, Itaru

    2015-04-15

    Nephrotoxicity is a frequent complication of cisplatin-induced chemotherapy, in which T cells are known to promote acute kidney injury (AKI). Apoptosis and necrosis of tubules and inflammatory events also contribute to the nephrotoxicity. A delineation of the mechanisms that underlie the inappropriate renal and tubular inflammation can thus provide important insights into potential therapies for cisplatin-induced AKI. Rho-kinases are known to act as molecular switches controlling several critical cellular functions, including cell migration, cytokine production, and apoptosis. Here, we show that the Rho-kinase inhibitor fasudil attenuated cisplatin nephrotoxicity, resulting in less histological damage, improved renal function, and the infiltration of fewer leukocytes into the kidney. Renal nuclear factor-κB activation and apoptosis were reduced, and the expressions of proinflammatory renal cytokine and chemokine mRNA were decreased. Urinary and renal kidney injury molecule-1 (Kim-1) expression was also reduced, a finding that is consistent with diminished kidney injury. In the current study, we also showed that fasudil could be protective of the impaired tubules. In vitro, fasudil reduced the apoptosis (annexin-V+PI cells) and cytokine production (tumor necrosis factor+ cells) in T cells and the apoptosis (annexin-V+PI cells) and tubular damage (Kim-1+ cells) in proximal tubular cells by flow cytometric analysis. As Rho-kinase plays an important role in promoting cisplatin nephrotoxicity, inhibiting Rho-kinase may be a therapeutic strategy for preventing cisplatin-induced AKI. Copyright © 2015 the American Physiological Society.

  3. Regulation of Microglia and Macrophage Polarization via Apoptosis Signal-Regulating Kinase 1 Silencing after Ischemic/Hypoxic Injury

    Directory of Open Access Journals (Sweden)

    So Yeong Cheon

    2017-08-01

    Full Text Available Inflammation is implicated in ischemic stroke and is involved in abnormal homeostasis. Activation of the immune system leads to breakdown of the blood–brain barrier and, thereby, infiltration of immune cells into the brain. Upon cerebral ischemia, infiltrated macrophages and microglia (resident CNS immune cell are activated, change their phenotype to M1 or M2 based on the microenvironment, migrate toward damaged tissue, and are involved in repair or damage. Those of M1 phenotype release pro-inflammatory mediators, which are associated with tissue damage, while those of M2 phenotype release anti-inflammatory mediators, which are related to tissue recovery. Moreover, late inflammation continually stimulates immune cell infiltration and leads to brain infarction. Therefore, regulation of M1/M2 phenotypes under persistent inflammatory conditions after cerebral ischemia is important for brain repair. Herein, we focus on apoptosis signal-regulating kinase 1 (ASK1, which is involved in apoptotic cell death, brain infarction, and production of inflammatory mediators after cerebral ischemia. We hypothesized that ASK1 is involved in the polarization of M1/M2 phenotype and the function of microglia and macrophage during the late stage of ischemia/hypoxia. We investigated the effects of ASK1 in mice subjected to middle cerebral artery occlusion and on BV2 microglia and RAW264.7 macrophage cell lines subjected to oxygen-glucose deprivation. Our results showed that ASK1 silencing effectively reduced Iba-1 or CD11b-positive cells in ischemic areas, suppressed pro-inflammatory cytokines, and increased anti-inflammatory mediator levels at 7 days after cerebral ischemia. In cultured microglia and macrophages, ASK1 inhibition, induced by NQDI-1 drug, decreased the expression and release of M1-associated factors and increased those of M2-associated factors after hypoxia/reperfusion (H/R. At the gene level, ASK1 inhibition suppressed M1-associated genes and

  4. Effect of the Wnt/β-catenin signaling pathway on apoptosis, migration, and invasion of transplanted hepatocellular carcinoma cells after transcatheter arterial chemoembolization in rats.

    Science.gov (United States)

    Wang, Bao-Ming; Li, Nuo

    2018-05-01

    This study aims to investigate the influence of the Wnt/β-catenin signaling pathway on apoptosis, migration, and invasion of transplanted hepatocellular carcinoma (HCC) cells after transcatheter arterial chemoembolization (TACE) in rat models. A total of 80 rats were grouped into sham, TACE, Wnt-C59, and TACE + Wnt-C59 groups (n = 20). Ten days after model establishment, 10 rats in each group were executed to perform pathological examination and follow-up experiment, and the remaining 10 rats in each group were reared to observe the survival condition. RT-qPCR and Western blotting were applied to determine the expressions of Wnt1, β-catenin, cyclin D1, c-met, vimentin, E-cadherin, and vascular endothelial growth factor (VEGF). ELISA was performed to measure the serum alpha-fetoprotein (AFP) content of rats. Flow cytometry was used to evaluate cell apoptosis rate and transwell assay to examine cell migration and invasion. Compared with the TACE group, the Wnt-C59 and TACE + Wnt-C59 groups showed increased apoptosis and survival time (the TACE + Wnt-C59 group > the Wnt-C59 group). Compared with the sham group, the TACE + Wnt-C59 groups showed decreased cancer tissue weight and expressions of Wnt1, β-catenin, cyclin D1, vimentin, c-met, and VEGF, but increased E-cadherin expression. Compared with the TACE group, the Wnt-C59 and TACE + Wnt-C59 groups showed decreased AFP level, migration, and invasion (the TACE + Wnt-C59 group Wnt-C59 group). These findings indicate inhibition of the Wnt/β-catenin signaling pathway improves therapeutic effect on TACE via suppressing migration, invasion, and promoting apoptosis of transplanted HCC cells in rats. © 2017 Wiley Periodicals, Inc.

  5. PCSK9 Promotes oxLDL-Induced PC12 Cell Apoptosis Through the Bcl-2/Bax-Caspase 9/3 Signaling Pathway.

    Science.gov (United States)

    Liu, Lu-Shan; Bai, Xue-Qin; Gao, Ya; Wu, Qi; Ren, Zhong; Li, Qing; Pan, Li-Hong; He, Ni-Ya; Peng, Juan; Tang, Zhi-Han

    2017-01-01

    Hyperlipidemia is a risk factor for neurodegenerative diseases. Proprotein convertase subtilisin / Kexin type 9 (PCSK9) degrades hepatic low-density lipoprotein receptor (LDLR) to regulate lipid metabolism. It is unclear if PCSK9 plays a role in neurodegenerative diseases. This study was designed to determine whether PCSK9 is crucial between hyperlipidemia and Alzheimer's disease. The interrelationship between PCSK9 and neuronal apoptosis was explored in PC12 cells in response to treatment with oxidized low-density lipoprotein (oxLDL). Cultured PC12 cells were serum-starved and incubated with different concentrations of oxLDL for 24 h. Intracytoplasmic lipid droplets were observed by oil red O staining. Morphological assessment of apoptotic cells was performed using Hoechst 33258 staining and flow cytometry analysis. The expression of mRNA and protein was detected by reverse-transcription polymerase chain reaction (RT-PCR) and western blot analyses, respectively. Transfection of small interfering RNA (siRNA) into PC12 cells was conducted using HiperFect Transfection Reagent. Concentrations of Aβ40 and Aβ42 were detected by enzyme-linked immunosorbent assay (ELISA) kit. Intracellular lipid content, the number of apoptotic cells, and PCSK9 expression were increased in PC12 cells after oxLDL treatment. Transfection with PCSK9 siRNA reduced the oxLDL-induced apoptosis of PC12 cells. We further confirmed the involvement of Bcl-2/Bax-Caspase (9, 3) signaling pathway in the regulation of PC12 cells apoptosis.β-Secretase 1, another target gene of PCSK9, was downregulated in PC12 cells in response to oxLDL treatment. Aβ40 and Aβ42 contents were also decreased. PCSK9 promotes oxLDL-induced PC12 cell apoptosis through the Bcl-2/Bax-Caspase 9/3 signaling pathway.

  6. TMEM16A exacerbates renal injury by activating P38/JNK signaling pathway to promote podocyte apoptosis in diabetic nephropathy mice.

    Science.gov (United States)

    Lian, Huan; Cheng, Yi; Wu, Xiaoyan

    2017-05-27

    Diabetic nephropathy (DN) is one of the most common microvascular complication of diabetes mellitus (DM) as well as the main reason resulting in chronic renal failure. Transmembrane protein 16A (TMEM16A) plays an important role in multiple physiological actions. Here we found that it was up-regulated in high-fat diet (HFD)/streptozotocin (STZ)-induced diabetic mice. Moreover, reverse transcription-polymerase chain reaction (RT-PCR) amplification, Western blot detection, Periodic Acid Schiff (PAS) staining and immunohistochemical analysis confirmed that TMEM16A deficiency alleviated renal injury in diabetic mice and TMEM16A knockout diabetic mice were protected from the HFD-induced reduction in Nephrin expression. To understand further the molecular mechanism of its function, podocytes treated with high glucose (HG, 30 mmol/L glucose) in vitro was chosen as a model to study its signal transduction pathway. Nephrin expression level in siRNA-TMEM16A group was significantly higher than that of the HG group (also called Model group). Flow cytometric analysis revealed that podocyte apoptosis in siRNA-TMEM16A group was significantly lower than that of the Model group. RT-PCR and Western blot exhibited that apoptosis-related genes including apoptosis-inducing factor (AIF) and cystinylaspartate specific protease-3/-9 (caspase-3/-9) were dramatically down regulated in siRNA-TMEM16A group, compared with Model group. Phosphorylation levels of P38 and JNK in siRNA-TMEM16A group were lower than that of the Model group. Thus, TMEM16A is one of the critical components of a signal transduction pathway that links renal injury to podocyte apoptosis in DN. Copyright © 2017. Published by Elsevier Inc.

  7. Distinction Between Cell Proliferation and Apoptosis Signals Regulated by Brain-Derived Neurotrophic Factor in Human Periodontal Ligament Cells and Gingival Epithelial Cells.

    Science.gov (United States)

    Kashiwai, Kei; Kajiya, Mikihito; Matsuda, Shinji; Ouhara, Kazuhisa; Takeda, Katsuhiro; Takata, Takashi; Kitagawa, Masae; Fujita, Tsuyoshi; Shiba, Hideki; Kurihara, Hidemi

    2016-07-01

    Previously, we reported that brain-derived neurotrophic factor (BDNF) enhances periodontal tissue regeneration by inducing periodontal ligament cell proliferation in vivo. In addition, the down growth of gingival epithelial cells, which comprises a major obstacle to the regeneration, was not observed. However, the underlying molecular mechanism is still unclear. Therefore, this study aimed to investigate the effect of BDNF on cell proliferation and apoptosis in human periodontal ligament (HPL) cells and human gingival epithelial cells (OBA9 cells) and to explore the molecular mechanism in vitro. HPL cells dominantly expressed a BDNF receptor, TrkB, and BDNF increased cell proliferation and ERK phosphorylation. However, its proliferative effect was diminished by a MEK1/2 inhibitor (U0126) and TrkB siRNA transfection. Otherwise, OBA9 cells showed a higher expression level of p75, which is a pan-neurotrophin receptor, than that of HPL cells. BDNF facilitated not cell proliferation but cell apoptosis and JNK phosphorylation in OBA9 cells. A JNK inhibitor (SP600125) and p75 siRNA transfection attenuated the BDNF-induced cell apoptosis. Moreover, OBA9 cells pretreated with SP600125 or p75 siRNA showed cell proliferation by BDNF stimulation, though it was reduced by U0126 and TrkB siRNA. Interestingly, overexpression of p75 in HPL cells upregulated cell apoptosis and JNK phosphorylation by BDNF treatment. These results indicated that TrkB-ERK signaling regulates BDNF-induced cell proliferation, whereas p75-JNK signaling plays roles in cell apoptotic and cytostatic effect of BDNF. Overall, BDNF activates periodontal ligament cells proliferation and inhibits the gingival epithelial cells growth via the distinct pathway. J. Cell. Biochem. 117: 1543-1555, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  8. miR-122 regulates p53/Akt signalling and the chemotherapy-induced apoptosis in cutaneous T-cell lymphoma.

    Directory of Open Access Journals (Sweden)

    Valentina Manfè

    Full Text Available Advanced cutaneous T-cell lymphoma (CTCL is resistant to chemotherapy and presents a major area of medical need. In view of the known role of microRNAs (miRNAs in the regulation of cellular signalling, we aimed to identify the functionally important miRNA species, which regulate apoptosis in CTCL. Using a recently established model in which apoptosis of CTCL cell lines is induced by Notch-1 inhibition by γ-secretase inhibitors (GSIs, we found that miR-122 was significantly increased in the apoptotic cells. miR-122 up-regulation was not specific for GSI-1 but was also seen during apoptosis induced by chemotherapies including doxorubicin and proteasome blockers (bortezomib, MG132. miR-122 was not expressed in quiescent T-cells, but was detectable in CTCL: in lesional skin in mycosis fungoides and in Sézary cells purified from peripheral blood. In situ hybridization results showed that miR-122 was expressed in the malignant T-cell infiltrate and increased in the advanced stage mycosis fungoides. Surprisingly, miR-122 overexpression decreased the sensitivity to the chemotherapy-induced apoptosis via a signaling circuit involving the activation of Akt and inhibition of p53. We have also shown that induction of miR-122 occurred via p53 and that p53 post-transcriptionally up-regulated miR-122. miR-122 is thus an amplifier of the antiapoptotic Akt/p53 circuit and it is conceivable that a pharmacological intervention in this pathway may provide basis for novel therapies for CTCL.

  9. Prevention of tumour cell apoptosis associated with sustained protein kinase B phosphorylation is more sensitive to regulation by insulin signalling than stimulation of proliferation and extracellular signal-regulated kinase.

    Science.gov (United States)

    Schmid, Christoph; Ghirlanda, Claudia; Niessen, Markus

    2017-08-01

    Insulin controls blood glucose while insulin-like growth factor (IGF) 1 is an important growth factor. Interestingly, both hormones have overlapping bioactivities and can activate the same intracellular signal transduction cascades. Growth control (mainly by IGF1) and metabolic function (predominantly by insulin) are believed to depend on activation of extracellular signal-regulated kinases (ERKs) 1/2 and protein kinase B (Akt/PKB), respectively. Therefore, insulin analogues that are used to normalize blood glucose are tested for their ability to preferentially activate Akt/PKB but not ERK1/2 and mitogenesis. Growth hormone, IGF1, and hyperinsulinemia are associated with increased risk of growth progression of some cancer types. To test if continuous exposure to insulin can favour tumour growth, we studied insulin/IGF1-dependent activation of ERK1/2 and Akt/PKB by Western blotting, inhibition of apoptosis by ELISA, and induction of proliferation by [ 3 H]-thymidine incorporation in Saos-2/B10 osteosarcoma cells. IGF1 and insulin both induced proliferation and prevented apoptosis effectively. Regulation of apoptosis was far more sensitive than regulation of proliferation. IGF1 and insulin activated PKB (Akt/PKB) rapidly and consistently maintained its phosphorylation. Activation of ERK1/2 was only observed in response to IGF1. Loss of p-Akt/PKB (but not of p-ERK1/2) was associated with increased apoptosis, and protection from apoptosis was lost when activation of Akt/PKB was inhibited. These findings in Saos-2/B10 cells were also replicated in the A549 cell line, originally derived from a human lung carcinoma. Therefore, IGF1 and insulin more likely (at lower concentrations) enhance tumour cell survival than proliferation, via activation and maintenance of phosphatidylinositol 3-kinase activity and p-Akt/PKB.

  10. Isoorientin induces apoptosis through mitochondrial dysfunction and inhibition of PI3K/Akt signaling pathway in HepG2 cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Li; Wang, Jing; Xiao, Haifang; Xiao, Chunxia; Wang, Yutang; Liu, Xuebo, E-mail: xueboliu@yahoo.com.cn

    2012-11-15

    Isoorientin (ISO) is a flavonoid compound that can be extracted from several plant species, such as Phyllostachys pubescens, Patrinia, and Drosophyllum lusitanicum; however, its biological activity remains poorly understood. The present study investigated the effects and putative mechanism of apoptosis induced by ISO in human hepatoblastoma cancer (HepG2) cells. The results showed that ISO induced cell death in a dose-dependent manner in HepG2 cells, but no toxicity in human liver cells (HL-7702) and buffalo rat liver cells (BRL-3A) treated with ISO at the indicated concentrations. ISO-induced cell death included apoptosis which characterized by the appearance of nuclear shrinkage, the cleavage of poly (ADP-ribose) polymerase (PARP) and DNA fragmentation. ISO significantly (p < 0.01) increased the Bax/Bcl-2 ratio, disrupted the mitochondrial membrane potential (MMP), increased the release of cytochrome c, activated caspase-3, and enhanced intracellular levels of reactive oxygen species (ROS) and nitric oxide (NO). In addition, ISO effectively inhibited the phosphorylation of Akt and increased FoxO4 expression. The PI3K/Akt inhibitor LY294002 enhanced the apoptosis-inducing effect of ISO. However, LY294002 markedly quenched ROS and NO generation and diminished the protein expression of heme peroxidase enzyme (HO-1) and inducible nitric oxide synthase (iNOS). Furthermore, the addition of a ROS inhibitor (N-acetyl cysteine, NAC) or iNOS inhibitor (N-[3-(aminomethyl) benzyl] acetamidine, dihydrochloride, 1400W) significantly diminished the apoptosis induced by ISO and also blocked the phosphorylation of Akt. These results demonstrated for the first time that ISO induces apoptosis in HepG2 cells and indicate that this apoptosis might be mediated through mitochondrial dysfunction and PI3K/Akt signaling pathway, and has no toxicity in normal liver cells, suggesting that ISO may have good potential as a therapeutic and chemopreventive agent for liver cancer. Highlights:

  11. Isoorientin induces apoptosis through mitochondrial dysfunction and inhibition of PI3K/Akt signaling pathway in HepG2 cancer cells

    International Nuclear Information System (INIS)

    Yuan, Li; Wang, Jing; Xiao, Haifang; Xiao, Chunxia; Wang, Yutang; Liu, Xuebo

    2012-01-01

    Isoorientin (ISO) is a flavonoid compound that can be extracted from several plant species, such as Phyllostachys pubescens, Patrinia, and Drosophyllum lusitanicum; however, its biological activity remains poorly understood. The present study investigated the effects and putative mechanism of apoptosis induced by ISO in human hepatoblastoma cancer (HepG2) cells. The results showed that ISO induced cell death in a dose-dependent manner in HepG2 cells, but no toxicity in human liver cells (HL-7702) and buffalo rat liver cells (BRL-3A) treated with ISO at the indicated concentrations. ISO-induced cell death included apoptosis which characterized by the appearance of nuclear shrinkage, the cleavage of poly (ADP-ribose) polymerase (PARP) and DNA fragmentation. ISO significantly (p < 0.01) increased the Bax/Bcl-2 ratio, disrupted the mitochondrial membrane potential (MMP), increased the release of cytochrome c, activated caspase-3, and enhanced intracellular levels of reactive oxygen species (ROS) and nitric oxide (NO). In addition, ISO effectively inhibited the phosphorylation of Akt and increased FoxO4 expression. The PI3K/Akt inhibitor LY294002 enhanced the apoptosis-inducing effect of ISO. However, LY294002 markedly quenched ROS and NO generation and diminished the protein expression of heme peroxidase enzyme (HO-1) and inducible nitric oxide synthase (iNOS). Furthermore, the addition of a ROS inhibitor (N-acetyl cysteine, NAC) or iNOS inhibitor (N-[3-(aminomethyl) benzyl] acetamidine, dihydrochloride, 1400W) significantly diminished the apoptosis induced by ISO and also blocked the phosphorylation of Akt. These results demonstrated for the first time that ISO induces apoptosis in HepG2 cells and indicate that this apoptosis might be mediated through mitochondrial dysfunction and PI3K/Akt signaling pathway, and has no toxicity in normal liver cells, suggesting that ISO may have good potential as a therapeutic and chemopreventive agent for liver cancer. Highlights:

  12. Cordyceps militaris Fraction induces apoptosis and G2/M Arrest via c-Jun N-Terminal kinase signaling pathway in oral squamous carcinoma KB Cells

    Science.gov (United States)

    Xie, Wangshi; Zhang, Zhang; Song, Liyan; Huang, Chunhua; Guo, Zhongyi; Hu, Xianjing; Bi, Sixue; Yu, Rongmin

    2018-01-01

    signaling pathway and promoted the nuclear localization of c-JunCMF regulated the apoptosis- and cell cycle-related proteins in a manner dependent on JNK/c-Jun pathway. Abbreviations used: CMF: Cordyceps militaris fraction; OSCC: Oral squamous cell carcinoma; JNK: c-Jun N-terminal kinase. PMID:29576711

  13. Evaluating safety and operation of high-speed intersections.

    Science.gov (United States)

    2010-03-01

    This Final Report reviews a research effort to evaluate the safety and operations of high-speed intersections in the State of : Oregon. In particular, this research effort focuses on four-leg, signalized intersections with speed limits of 45 mph or :...

  14. Methylcobalamin promotes proliferation and migration and inhibits apoptosis of C2C12 cells via the Erk1/2 signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Michio [Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Tanaka, Hiroyuki, E-mail: tanahiro-osk@umin.ac.jp [Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Okada, Kiyoshi [Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kuroda, Yusuke [Department of Orthopaedic Surgery, Kansai Rosai Hospital, 3-1-69 Inabaso, Amagasaki, Hyogo 660-8511 (Japan); Nishimoto, Shunsuke; Murase, Tsuyoshi; Yoshikawa, Hideki [Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2014-01-17

    Highlights: •Methylcobalamin activated the Erk1/2 signaling pathway in C2C12 cells. •Methylcobalamin promoted the proliferation and migration in C2C12 cells. •C2C12 cell apoptosis during differentiation was inhibited by methylcobalamin. -- Abstract: Methylcobalamin (MeCbl) is a vitamin B12 analog that has some positive effects on peripheral nervous disorders. Although some previous studies revealed the effects of MeCbl on neurons, its effect on the muscle, which is the final target of motoneuron axons, remains to be elucidated. This study aimed to determine the effect of MeCbl on the muscle. We found that MeCbl promoted the proliferation and migration of C2C12 myoblasts in vitro and that these effects are mediated by the Erk1/2 signaling pathway without affecting the activity of the Akt signaling pathway. We also demonstrated that MeCbl inhibits C2C12 cell apoptosis during differentiation. Our results suggest that MeCbl has beneficial effects on the muscle in vitro. MeCbl administration may provide a novel therapeutic approach for muscle injury or degenerating muscle after denervation.

  15. Mitochondria transmit apoptosis signalling in cardiomyocyte-like cells and isolated hearts exposed to experimental ischemia-reperfusion injury

    Czech Academy of Sciences Publication Activity Database

    Neužil, Jiří; Widen, C.; Gellert, N.; Swettenham, E.; Zobalová, Renata; Dong, J. F.; Wang, X. F.; Lidebjer, C.; Dalen, H.; Headrick, J.P.; Witting, P. K.

    2007-01-01

    Roč. 12, č. 3 (2007), s. 148-162 ISSN 1351-0002 Institutional research plan: CEZ:AV0Z50520514; CEZ:AV0Z50520701 Keywords : kardiomyocyty * superoxide * apoptosis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.600, year: 2007

  16. miR-122 regulates p53/Akt signalling and the chemotherapy-induced apoptosis in cutaneous T-cell lymphoma

    DEFF Research Database (Denmark)

    Manfè, Valentina; Biskup, Edyta; Rosbjerg, Anne

    2012-01-01

    R-122 was expressed in the malignant T-cell infiltrate and increased in the advanced stage mycosis fungoides. Surprisingly, miR-122 overexpression decreased the sensitivity to the chemotherapy-induced apoptosis via a signaling circuit involving the activation of Akt and inhibition of p53. We have also...... shown that induction of miR-122 occurred via p53 and that p53 post-transcriptionally up-regulated miR-122. miR-122 is thus an amplifier of the antiapoptotic Akt/p53 circuit and it is conceivable that a pharmacological intervention in this pathway may provide basis for novel therapies for CTCL....

  17. Brucein D, a Naturally Occurring Tetracyclic Triterpene Quassinoid, Induces Apoptosis in Pancreatic Cancer through ROS-Associated PI3K/Akt Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Zheng-Quan Lai

    2017-12-01

    Full Text Available Brucein D (BD, a major active quassinoid in Brucea javanica, has exhibited pronounced anticancer activities. However, the biologic mechanisms have not been fully explored. In this study, BD exhibited more potent cytotoxic effect on pancreatic cancer (PanCa cell lines, while exerted weaker cytotoxic effects on GES-1 cells (non-tumorigenic. BD was shown to elicit apoptosis through inducing both the intrinsic and extrinsic mitochondria-mediated caspase activations. Furthermore, the BD-induced apoptotic effects were dependent on the accumulated reactive oxygen species (ROS and inactivation of PI3K/Akt signaling pathway. Pretreatment with tempol completely prevented the cellular apoptosis induced by BD, and recovered the inactivation of AKT, which suggested ROS essentially involved in BD-elicited apoptosis and down-regulation of PI3K/Akt pathway. In addition, the results obtained from orthotopic xenograft in nude mice were congruent with those of the in vitro investigations. These results support the notion that BD held good potential to be further developed into an effective pharmaceutical agent for the treatment of PanCa.

  18. A polypeptide from Chlamys farreri inhibits UVB-induced HaCaT cells apoptosis via the Apaf-1/caspase-9 and Smac/XIAP signaling pathway

    Science.gov (United States)

    Liu, Xiaojin; Wang, Wencheng; Wang, Hongjiang; Zhang, Lanlan; Liu, Leqian; Wang, Yuejun; Wang, Chunbo

    2009-09-01

    A novel marine active polypeptide (PCF), isolated from the gonochoric Chinese scallop, Chlamys farreri, has potential antioxidant and anti-apoptotic activity against ultraviolet irradiation. We investigated whether UVB-induced HaCaT cell apoptosis occurs via the mitochondrial pathways Apaf-1/caspase-9 and Smac/XIAP/caspase-3. We then investigated the molecular mechanisms controlling the anti-apoptotic effect of PCF. Pre-treatment with PCF and caspase-9 inhibitor significantly inhibited UVB-induced apoptosis in HaCaT cells based on a DNA fragmentation assay and Hoechst 33258 staining. The expression of Apaf-1 and the cleavage of procaspase-9 were dose-dependently reduced by 1.42-5.96 mmol/L PCF pretreatment in UVB-irradiated HaCaT cells. This was followed by inhibition of cleavage of procaspase-3, whose activation induced cell apoptosis. Meanwhile, PCF significantly and dose-dependently enhanced the activation of ATPase. Furthermore, we demonstrated that PCF strongly inhibited the release of Smac from the mitochondria to cytosol by reducing the degradation of XIAP dose-dependently. We conclude that the protective effect of PCF against UVB irradiation in HaCaT cells may be attributed to the inhibition of the Apaf-1/caspase-9 and Smac/XIAP/caspase-3 apoptotic signaling pathways.

  19. Graphene oxide and reduced graphene oxide induced neural pheochromocytoma-derived PC12 cell lines apoptosis and cell cycle alterations via the ERK signaling pathways.

    Science.gov (United States)

    Kang, Yiyuan; Liu, Jia; Wu, Junrong; Yin, Qian; Liang, Huimin; Chen, Aijie; Shao, Longquan

    2017-01-01

    Given the novel applications of graphene materials in biomedical and electronics industry, the health hazards of these particles have attracted extensive worldwide attention. Although many studies have been performed on graphene material-induced toxic effects, toxicological data for the effect of graphene materials on the nervous system are lacking. In this study, we focused on the biological effects of graphene oxide (GO) and reduced graphene oxide (rGO) materials on PC12 cells, a type of traditional neural cell line. We found that GO and rGO exerted significant toxic effects on PC12 cells in a dose- and time-dependent manner. Moreover, apoptosis appeared to be a response to toxicity. A potent increase in the number of PC12 cells at G0/G1 phase after GO and rGO exposure was detected by cell cycle analysis. We found that phosphorylation levels of ERK signaling molecules, which are related to cell cycle regulation and apoptosis, were significantly altered after GO and rGO exposure. In conclusion, our results show that GO has more potent toxic effects than rGO and that apoptosis and cell cycle arrest are the main toxicity responses to GO and rGO treatments, which are likely due to ERK pathway regulation.

  20. Chronic hepatitis C virus infection triggers spontaneous differential expression of biosignatures associated with T cell exhaustion and apoptosis signaling in peripheral blood mononucleocytes.

    Science.gov (United States)

    Barathan, Muttiah; Gopal, Kaliappan; Mohamed, Rosmawati; Ellegård, Rada; Saeidi, Alireza; Vadivelu, Jamuna; Ansari, Abdul W; Rothan, Hussin A; Ravishankar Ram, M; Zandi, Keivan; Chang, Li Y; Vignesh, Ramachandran; Che, Karlhans F; Kamarulzaman, Adeeba; Velu, Vijayakumar; Larsson, Marie; Kamarul, Tunku; Shankar, Esaki M

    2015-04-01

    Persistent hepatitis C virus (HCV) infection appears to trigger the onset of immune exhaustion to potentially assist viral persistence in the host, eventually leading to hepatocellular carcinoma. The role of HCV on the spontaneous expression of markers suggestive of immune exhaustion and spontaneous apoptosis in immune cells of chronic HCV (CHC) disease largely remain elusive. We investigated the peripheral blood mononuclear cells of CHC patients to determine the spontaneous recruitment of cellular reactive oxygen species (cROS), immunoregulatory and exhaustion markers relative to healthy controls. Using a commercial QuantiGenePlex(®) 2.0 assay, we determined the spontaneous expression profile of 80 different pro- and anti-apoptotic genes in persistent HCV disease. Onset of spontaneous apoptosis significantly correlated with the up-regulation of cROS, indoleamine 2,3-dioxygenase (IDO), cyclooxygenase-2/prostaglandin H synthase (COX-2/PGHS), Foxp3, Dtx1, Blimp1, Lag3 and Cd160. Besides, spontaneous differential surface protein expression suggestive of T cell inhibition viz., TRAIL, TIM-3, PD-1 and BTLA on CD4+ and CD8+ T cells, and CTLA-4 on CD4+ T cells was also evident. Increased up-regulation of Tnf, Tp73, Casp14, Tnfrsf11b, Bik and Birc8 was observed, whereas FasLG, Fas, Ripk2, Casp3, Dapk1, Tnfrsf21, and Cflar were moderately up-regulated in HCV-infected subjects. Our observation suggests the spontaneous onset of apoptosis signaling and T cell exhaustion in chronic HCV disease.

  1. MicroRNA-Mediated Down-Regulation of Apoptosis Signal-Regulating Kinase 1 (ASK1 Attenuates the Apoptosis of Human Mesenchymal Stem Cells (MSCs Transplanted into Infarcted Heart

    Directory of Open Access Journals (Sweden)

    Chang Youn Lee

    2016-10-01

    Full Text Available Stem cell therapy using adult stem cells, such as mesenchymal stem cells (MSCs has produced some promising results in treating the damaged heart. However, the low survival rate of MSCs after transplantation is still one of the crucial factors that limit the therapeutic effect of stem cells. In the damaged heart, oxidative stress due to reactive oxygen species (ROS production can cause the death of transplanted MSCs. Apoptosis signal-regulating kinase 1 (ASK1 has been implicated in the development of oxidative stress-related pathologic conditions. Thus, we hypothesized that down-regulation of ASK1 in human MSCs (hMSCs might attenuate the post-transplantation death of MSCs. To test this hypothesis, we screened microRNAs (miRNAs based on a miRNA-target prediction database and empirical data and investigated the anti-apoptotic effect of selected miRNAs on human adipose-derived stem cells (hASCs and on rat myocardial infarction (MI models. Our data indicated that miRNA-301a most significantly suppressed ASK1 expression in hASCs. Apoptosis-related genes were significantly down-regulated in miRNA-301a-enriched hASCs exposed to hypoxic conditions. Taken together, these data show that miRNA-mediated down-regulation of ASK1 protects MSCs during post-transplantation, leading to an increase in the efficacy of MSC-based cell therapy.

  2. Similar to spironolactone, oxymatrine is protective in aldosterone-induced cardiomyocyte injury via inhibition of calpain and apoptosis-inducing factor signaling.

    Directory of Open Access Journals (Sweden)

    Ting-Ting Xiao

    Full Text Available Accumulating evidence indicates that oxymatrine (OMT possesses variously pharmacological properties, especially on the cardiovascular system. We previously demonstrated that activated calpain/apoptosis-inducing factor (AIF-mediated pathway was the key molecular mechanism in aldosterone (ALD induces cardiomyocytes apoptosis. In the present study, we extended the experimentation by investigating the effect of OMT on cardiomyocytes exposed to ALD, as compared to spironolactone (Spiro, a classical ALD receptor antagonist. Cardiomyocytes were pre-incubated with OMT, Spiro or vehicle for 1 h, and then, cardiomyocytes were exposed to ALD 24 h. The cell injury was evaluated by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay and lactate dehydrogenase (LDH leakage ratio. Apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL assay, annexin V/PI staining, and relative caspase-3 activity assay. Furthermore, expression of pro-apoptotic proteins including truncated Bid (tBid, calpain and AIF were evaluated by western blot analysis. ALD stimulation increased cardiomyocytes apoptosis, caspase-3 activity and protein expression of calpain, tBid and AIF in the cytosol (p<0.05. Pre-incubated with cardiomyocytes injury and increased caspase-3 activity were significantly attenuated (p<0.05. Furthermore, OMT suppressed ALD-induced high expression of calpain and AIF. And these effects of OMT could be comparable to Spiro. These findings indicated that OMT might be a potential cardioprotective-agent against excessive ALD-induced cardiotoxicity, at least in part, mediated through inhibition of calpain/AIF signaling.

  3. Effect of orexin A on apoptosis in BGC-823 gastric cancer cells via OX1R through the AKT signaling pathway.

    Science.gov (United States)

    Wen, Jing; Zhao, Yuyan; Shen, Yang; Guo, Lei

    2015-05-01

    Orexins are a class of peptides involved in the regulation of food intake, energy homeostasis, the sleep‑wake cycle and gastrointestinal function. Recent studies have demonstrated that orexin A may influence apoptosis and proliferation in numerous types of cancer cells. However, the effect of orexin A on gastric cancer cells and its mechanisms of action remain elusive. In the present study, BGC‑823 gastric cancer cells were treated with orexin A (10‑10‑10‑6 M) in vitro and the expression levels of orexin receptor 1 (OX1R) protein in cells was then determined. The proliferation, viability and apoptosis of BGC‑823 cells were detected. In addition, BGC‑823 cells were treated with AKT inhibitor PF‑04691502 or OX1R‑specific antagonist SB334867 in combination with orexin A, in order to examine the activation of AKT and caspase‑3. The results showed that orexin A (10‑10‑10‑6 M) stimulated the OX1R protein expression in BGC‑823 cells, which improved the proliferation and viability of the cells as well as protected them from apoptosis. Phosphorylated AKT protein was significantly increased in BGC‑823 cells following treatment with orexin A. Moreover, 10‑8 M orexin A reduced the proapoptotic activity of caspase‑3 (by ≤30%). The OX1R antagonist SB334867 (10‑6 M) and AKT antagonist PF‑04691502 (10‑6 M), when used individually or in combination, abolished the effect of orexin A (10‑8 M) on BGC-823 cells. In conclusion, the results of the present study demonstrated that orexin A inhibited gastric cancer cell apoptosis via OX1R through the AKT signaling pathway.

  4. Aqueous extract of Tribulus terrestris Linn induces cell growth arrest and apoptosis by down-regulating NF-κB signaling in liver cancer cells.

    Science.gov (United States)

    Kim, Hye Jin; Kim, Jin Chul; Min, Jung Sun; Kim, Mi-Jee; Kim, Ji Ae; Kor, Myung Ho; Yoo, Hwa Seung; Ahn, Jeong Keun

    2011-06-14

    A medicinal herb Tribulus terrestris Linn has been used to treat various diseases including hepatocellular carcinoma. The aim of the present study was to investigate the anticancer activity of Tribulus terrestris Linn (TT) in liver cancer cells. The antitumor activity of aqueous TT extract was analyzed by testing the cytotoxicity and the effect on clonogenecity in HepG2 cells. Apoptosis and cell cycle arrest induced by TT were dissected by flow cytometry and its inhibitory effect on NF-κB activity was determined by analyzing the expression levels of NF-κB/IκB subunit proteins. The suppression of NF-κB-regulated gene expression by TT was assessed by RT-PCR. TT extract repressed clonogenecity and proliferation, induced apoptosis, and enhanced accumulation in the G0/G1 phase of liver cancer cells. It also turned out that TT extract inhibited NF-κB-dependent reporter gene expression and NF-κB subunit p50 expression, while it enhanced the cellular level of IκBα by inhibiting the phosphorylation and degradation of IκBα. In addition, IKK activity was inhibited in a dose-dependent manner. Furthermore, TT extract suppressed the transcription of genes associated with cell cycle regulation, anti-apoptosis, and invasion. These data showed that TT extract blocks proliferation and induces apoptosis in human liver cancer cells through the inhibition of NF-κB signaling. Aqueous TT extract can be used as an anticancer drug for hepatocellular carcinoma patients. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  5. Driver eye-scanning behavior at intersections at night.

    Science.gov (United States)

    2009-10-01

    This research project analyzed drivers eye scanning behavior at night when approaching signalized : and unsignalized intersections using the data from a head-mounted eye-tracking system during open road : driving on a prescribed route. During the ...

  6. Intersectionality - an intercategorical approach

    DEFF Research Database (Denmark)

    Emerek, Ruth

    2017-01-01

    their intersection may give misleading results. Secondly, the pitfalls of a narrow focus on a single section of categories are discussed by means of an example of educational attainment for categories of gender and ancestry. Finally, using the example of a study of the gender pay gap, it is shown how a breakdown......The aim of this article is to demonstrate how to empirically uncover intersectional complexity by simple methods. The article is based on three examples of intercategorical complexity. Firstly, by discussing gender mainstreaming, it is shown that a narrow focus on categories without...

  7. ISR Intersection 1

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    The experimental apparatus used at intersection 1 by the CERN-Bologna Collaboration (experiment R105). It consists of two almost identical magnetic spectrometers centered at 90 degrees on opposite sides of the intersection region. In each spectrometer one can see magnetostrictive wire spark chambers, a magnet, more chambers and various hodoscopes of scintillation counters. Gas Cerenkov counters (almost invisible in the picture) are located in the gap of each magnet. On the left hand side, a matrix of 119 lead glass Cerenkov counters is located behind some concrete and iron shielding.

  8. MiR-155 promotes cell proliferation and inhibits apoptosis by PTEN signaling pathway in the psoriasis.

    Science.gov (United States)

    Xu, Longjiang; Leng, Hong; Shi, Xin; Ji, Jiang; Fu, Jinxiang; Leng, Hong

    2017-06-01

    MicroRNAs (miRNAs) have been demonstrated to contribute to malignant progression in psoriasis development. The purposes of the study was to evaluated the effects of miRNA-155 on cell proliferation, migration and apoptosis in psoriasis development via PTEN singaling pathway and identify its direct target protein. Quantitative real-time RT-PCR (qRT-PCR) was performed to examine the level of miR-155 in psoriasis cells, miR-155 was downregulated in a psoriasis cell line Hacat by transfected with small interfering RNA (siRNA), respectively. Cell survival was detected by the MTT assay and colony formation assay. Cell migration and invasion were measured via wound-healing assayand transwell assay. In addition, cell cycle and apoptosis about psoriasis cells was measured by flow cytometry. In this study, qRT-PCR assay showed that the expressions of miR-155 mRNA in psoriasis tissues were significantly higher than that in normal tissues. The assays about cell growth and proliferation showed that miR-155 knockdown led to a significant decrease in cell proliferation which was determined by MTT assay and colony formation assay compared to those of Lv-NC cells. Flow cytometry analysis showed that depletion of miR-155 could cause cell cycle change and the number of apoptotic cells was significantly increased in Lv-miR155 cells compared with control cells. In addition, the expression of several apoptosis-related factors were dramatically changed, such as PTEN, PIP 3 , AKT, p-AKT, Bax and Bcl-2. Our findings indicate that down-regulation of miR-155 significantly inhibits proliferation, migration, invasion and promotes apoptosis through PTEN singaling pathway in psoriasis cells. miR-155 might function as an oncogene miRNA in the progress of psoriasis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  9. Evaluating lane-by-lane gap-out based signal control for isolated intersection under stop-line, single and multiple advance detection systems

    Directory of Open Access Journals (Sweden)

    Chandan Keerthi Kancharla

    2016-12-01

    Full Text Available In isolated intersection’s actuated signal control, inductive loop detector layout plays a crucial role in providingthe vehicle information to the signal controller. Based on vehicle actuations at the detector, the green time is extended till a pre-defined threshold gap-out occurs. The Federal Highway Administration (FHWA proposed various guidelines for detec-tor layouts on low-speed and high-speed approaches. This paper proposes single and multiple advance detection schemes for low-speed traffic movements, that utilizes vehicle actuations from advance detectors located upstream of the stop-line, which are able to detect spill-back queues. The proposed detection schemes operate with actuated signal control based on lane-by-lane gap-out criteria. The performance of the proposed schemes is compared with FHWA’s stop-line and single advance detection schemes in the VISSIM simulation tool. Results have shown that the proposed single advance detection schemes showed improved performance in reducing travel time delay and average number of stops per vehicle under low volumes while the multiple advance detection scheme performed well under high volumes.

  10. Role of the PKCβII/JNK signaling pathway in acute glucose fluctuation-induced apoptosis of rat vascular endothelial cells.

    Science.gov (United States)

    Wu, Na; Shen, Haitao; Wang, Yanjun; He, Bing; Zhang, Yongyan; Bai, Yu; Du, Runyu; Du, Qiang; Han, Ping

    2017-08-01

    The purpose of this study was to investigate the mechanism of vascular endothelial cell apoptosis induced by acute blood glucose fluctuation. Thirty rats were assigned to three groups: normal saline (SAL group), constant high glucose (CHG group) and acute blood glucose fluctuation (AFG) group. Other forty rats were assigned to SAL group, AFG group, LY group (PKCβ inhibitor LY333531 was injected intragastrically to the rats who were under acute blood glucose fluctuation) and SP group (JNK inhibitor SP600125 was injected intraperitoneally to the rats who were under acute blood glucose fluctuation). Oxidative stress and inflammatory cytokines were detected. TUNEL was performed to detect apoptosis. Pro-caspase-3, caspase-3 p17, JNK, PKC-βII and insulin signaling-related protein expression were tested by Western blotting. After administration of LY333531, AFG-induced membrane translocation of PKCβII protein was inhibited, but SP600125 failed to affect AFG-induced PKCβII membrane translocation. After administration of LY333531, the AFG-induced increase in JNK activity was significantly compromised. LY333531 inhibited AFG-induced oxidative stress. However, SP600125 only slightly inhibited AFG-induced oxidative stress reaction (P > 0.05). Both LY333531 and SP600125 can reverse AFG-induced endothelial cell apoptosis increase, inflammatory cytokines levels rise and insulin signaling impairment. It is necessary to actively control blood glucose and avoid significant glucose fluctuation. PKCβII/JNK may serve as a target, and inhibitors of PKCβII/JNK may be used to help prevent cardiovascular diseases in patients with poor glucose control or significant glucose fluctuation.

  11. Secoisolariciresinol diglucoside prevents the oxidative stress-induced apoptosis of myocardial cells through activation of the JAK2/STAT3 signaling pathway.

    Science.gov (United States)

    Huang, Guiqiong; Huang, Xiaofang; Liu, Min; Hua, Yue; Deng, Bo; Jin, Wen; Yan, Wen; Tan, Zhangbin; Wu, Yifen; Liu, Bin; Zhou, Yingchun

    2018-06-01

    Myocardial cell apoptosis mediated by oxidative stress has previously been identified as a key process in ischemic heart disease. Secoisolariciresinol diglucoside (SDG), a polyphenolic plant lignan primarily found in flaxseed, has been demonstrated to effectively protect myocardial cells from apoptosis. In the present study, the role of the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) was investigated in mediating the protective effect of SDG. Findings of the present study revealed that treatment with H2O2 reduced cell viability and induced apoptosis in H9C2 rat cardiomyocytes. However, SDG was able to reduce the effect of H2O2 in a dose‑dependent manner. H2O2 reduced the expression level of phosphorylated STAT3 and inhibited the levels of B‑cell lymphoma‑extra‑large and induced myeloid leukemia cell differentiation protein, which are the STAT3 target genes. Conversely, SDG rescued phosphorylation of STAT3 and increased the levels of STAT3 target genes. Treatment with SDG alone led to a dose‑dependent increased phosphorylation of JAK2 and STAT3, without activating Src. Furthermore, the anti‑apoptotic effects of SDG were partially abolished by a JAK2/STAT3 inhibitor. In addition, molecular docking revealed that SDG may bind to the protein kinase domain of JAK2, at a binding energy of ‑8.258 kcal/mol. Molecular dynamics simulations revealed that JAK2‑SDG binding was stable. In conclusion, activation of the JAK2/STAT3 signaling pathway contributed to the anti‑apoptotic activity of SDG, which may be a potential JAK2 activator.

  12. Long-term blue light exposure induces RGC-5 cell death in vitro: involvement of mitochondria-dependent apoptosis, oxidative stress, and MAPK signaling pathways.

    Science.gov (United States)

    Huang, Chen; Zhang, Pei; Wang, Wei; Xu, Yongsheng; Wang, Minshu; Chen, Xiaoyong; Dong, Xuran

    2014-06-01

    The mechanism of blue light-induced retinal ganglion cell (RGC) injury is poorly understood. In this study, we established a patented light-emitting diode-based system to study the effects of long-term blue light exposure under culture conditions on RGC-5 cells. Long-term blue light exposure significantly reduced cell viability in a time-dependent manner and induced apoptosis and necrosis in RGC-5 cells. Long-term blue light exposure marked an increase in the expression of Bax and active Caspase-3 (p17), which was accompanied by Bcl-2 down-regulation, and displayed features of the mitochondria-dependent apoptosis pathway. Blue light exposure also increased the generation of reactive oxygen species (ROS), and was a strong inducer of ROS-sensitive protein nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression. Moreover, blue light exposure constitutively activated p38 mitogen-activated protein kinases and c-Jun NH2-terminal kinase (JNK), as well as induced the phosphorylation of extracellular signal-regulated kinase in the early phase, in blue light-exposed RGC-5 cells. The protein expression of c-jun and c-fos was further enhanced after RGC-5 cells were exposed to blue light. Taken together, these findings indicated that blue light induced RGC-5 cell line death in dependence upon exposure duration. The potential mechanisms for this phenomenon might be via activated mitochondria-dependent apoptosis, increased ROS production and protein expressions of Nrf2 and HO-1, and activated JNK/p38 MAPK signaling pathways.

  13. 20(S-Protopanaxadiol-Induced Apoptosis in MCF-7 Breast Cancer Cell Line through the Inhibition of PI3K/AKT/mTOR Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Hong Zhang

    2018-04-01

    Full Text Available 20(S-Protopanaxadiol (PPD is one of the major active metabolites of ginseng. It has been reported that 20(S-PPD shows a broad spectrum of antitumor effects. Our research study aims were to investigate whether apoptosis of human breast cancer MCF-7 cells could be induced by 20(S-PPD by targeting the Phosphatidylinositol 3-kinase/Protein kinase B/Mammalian target of rapamycin (PI3K/AKT/mTOR signal pathway in vitro and in vivo. Cell cycle analysis was performed by Propidium Iodide (PI staining. To overexpress and knock down the expression of mTOR, pcDNA3.1-mTOR and mTOR small interfering RNA (siRNA transient transfection assays were used, respectively. Cell viability and apoptosis were evaluated by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT-test and Annexin V /PI double-staining after transfection. The antitumor effect in vivo was determined by the nude mice xenograft assay. After 24 h of incubation, treatment with 20(S-PPD could upregulate phosphorylated-Phosphatase and tensin homologue deleted on chromosome 10 (p-PTEN expression and downregulate PI3K/AKT/mTOR-pathway protein expression. Moreover, G0/G1 cell cycle arrest in MCF-7 cells could be induced by 20(S-PPD treatment at high concentrations. Furthermore, overexpression or knockdown of mTOR could inhibit or promote the apoptotic effects of 20(S-PPD. In addition, tumor volumes were partially reduced by 20(S-PPD at 100 mg/kg in a MCF-7 xenograft model. Immunohistochemical staining indicated a close relationship between the inhibition of tumor growth and the PI3K/AKT/mTOR signal pathway. PI3K/AKT/mTOR pathway-mediated apoptosis may be one of the potential mechanisms of 20(S-PPD treatment.

  14. Targeting miR-29 induces apoptosis of osteosarcoma MG-63 cells via regulation of TGF-β1/PUMA signal.

    Science.gov (United States)

    Wang, C-Y; Ren, J-B; Liu, M; Yu, L

    2016-09-01

    Recent studies have shown that high miR-29 expression was associated with poor prognosis in patients with osteosarcoma (OS). However, the exact role and mechanisms of miR-29 in human OS remains speculative. Here, we identify a connection between miR-29 and TGF-β1/PUMA signaling in this context. MG-63 cells were treated with anti-miR-29 for 48 h. Cell growth and apoptosis in vitro were detected by MTT, colony formation and flow cytometry assay. The effect of the miR-29 inhibitor on the growth of MG-63 cells was also evaluated in a MG-63 mouse model. Human recombinant TGF-β1 (rh TGF-β1) and PUMA siRNA transfection were used to assess the signal pathway. miR-29, TGF-β1, PUMA, and caspase-3 protein expression were detected by Western blotting assay and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) assays. Knockdown of miR-29 resulted in 80% decrease of miR-29 compared to the negative control. Knockdown of miR-29 significantly downregulated TGF-β1 and upregulated PUMA expression, and decreased MG-63 cell growth by 70%, impaired colony formation by approximately 80%, and increased MG-63 cell apoptosis by 40%. Knockdown of PUMA reversed miR-29 silencing-induced proliferation and apoptosis of MG-63 cells. Restoration of TGF-β1 decreased PUMA expression. In murine engraftment models of MG-63, we showed that knockdown of miR-29 was able to reduce tumor growth. This was accompanied by decreased levels of TGF-β1 and increased levels of PUMA in these tumors. Targeting miR-29 exhibits significant in vivo and in vitro anti-tumor activities in OS through a novel mechanism resulting in inhibition of TGF-β1 expression and inducing PUMA expression.

  15. CD-200 induces apoptosis and inhibits Bcr-Abl signaling in imatinib-resistant chronic myeloid leukemia with T315I mutation.

    Science.gov (United States)

    Fang, Zhenghuan; Jung, Kyung Hee; Yan, Hong Hua; Kim, Soo Jung; Son, Mi Kwon; Rumman, Marufa; Lee, Hyunseung; Kim, Ki Woon; Yoo, Hye-Dong; Hong, Soon-Sun

    2015-07-01

    Chronic myeloid leukemia (CML) is characterized by a constitutively active Bcr-Abl tyrosine kinase. Although Imatinib has been proven to be an effective drug against CML, its resistance has been observed with disease relapse due to T315I predominant point mutation. Liriodendron tulipifera L., one of the fastest growing hardwood tree species, exerts antioxidant activity and anti-inflammatory effects. However, its anticancer effect has been minimally reported. In this study, we extracted CD-200 from Liriodendron tulipifera L. and investigated its effect on cell survival or apoptosis in CML cells with Bcr-Abl/T315I (BaF3/T315I) as well as wild-type Bcr-Abl (BaF3/WT). CD-200 inhibited cell proliferation in the BaF3/WT cells, and also in the BaF3/T315I cells with Imatinib resistance. Moreover, it strongly inhibited Bcr-Abl signaling pathways in a dose-dependent manner. Also, it significantly increased the sub-G1 phase and the expression of cleaved PARP and caspase-3, as well as the TUNEL-positive apoptotic cells. In addition, we observed that CD-200 induced apoptosis with a loss of mitochondrial membrane potential by decreasing the expression of Mcl-1 and survivin. Furthermore, CD-200 showed a significant inhibition in tumor growth, compared to Imatinib in BaF3/T315I mouse xenograft models. Taken together, our study demonstrates that CD-200 exhibits apoptosis induction and anti-proliferative effect by blocking the Bcr-Abl signaling pathways in the Bcr-Abl/T315I with resistance to Imatinib. We suggest that CD-200 may be a natural product to target Bcr-Abl and overcome Imatinib resistance in CML patients.

  16. Salidroside induces apoptosis in human ovarian cancer SKOV3 and A2780 cells through the p53 signaling pathway.

    Science.gov (United States)

    Yu, Ge; Li, Na; Zhao, Yan; Wang, Wei; Feng, Xiao-Ling

    2018-05-01

    Salidroside is one of the most potent compounds extracted from the plant Rhodiola rosea , and its cardiovascular protective effects have been studied extensively. However, the role of salidroside in human ovarian carcinoma remains unknown. The aim of the current study was to investigate the effects of salidroside on the proliferation and apoptosis of SKOV3 and A2780 cells using MTT assay and acridine orange/ethidium bromide staining. Salidroside activated caspase-3 and upregulated the levels of apoptosis-inducing factor, Bcl-2-associated X and Bcl-2-associated death promoter (Bad) proteins. Furthermore, salidroside downregulated the levels of Bcl-2, p-Bad and X-linked inhibitor of apoptosis proteins. Salidroside activated the caspase-dependent pathway in SKOV3 and A2780 cells, upregulating p53, p21 Cip1/Waf1 and p16 INK4a . These results suggest that the p53/p21 Cip1/Waf1 /p16 INK4a pathway may serve a key function in salidroside-mediated effects on SKOV3 and A2780 cells. The current findings indicate that salidroside may be a promising novel drug candidate for ovarian cancer therapy.

  17. Cell cycle and apoptosis regulatory proteins, proliferative markers, cell signaling molecules, CD209, and decorin immunoreactivity in low-grade myxofibrosarcoma and myxoma.

    Science.gov (United States)

    Cates, Justin M M; Memoli, Vincent A; Gonzalez, Raul S

    2015-08-01

    The histologic differential diagnosis between intramuscular myxoma and low-grade myxofibrosarcoma can be quite difficult in some cases. To identify a diagnostic immunohistochemical marker, we compared the staining profiles of 19 different antigens, including cell cycle proteins, apoptosis proteins, and proliferative markers, and selected other signaling and structural proteins in these two tumors. Ten cases each of intramuscular myxoma and low-grade myxofibrosarcoma were stained with antibodies directed against apoptosis regulatory proteins (Bcl2, activated caspase-3, phospho-H2A.X, and cleaved PARP), cell cycle regulatory proteins (Rb1, Cyclin-A, CDKN1B, and Cdt1), proliferative markers (KI67, MCM2, phospho-histone H3, and geminin), cell signalling molecules (c-Myc, EGF, EGFR, PLA2G4A, and HSP90), a dendritic cell marker (CD209), and the extracellular matrix proteoglycan decorin. Staining patterns of myxoma and myxofibrosarcoma were compared using Fisher's exact test and the Mann-Whitney test. For each potential diagnostic marker studied, the proportions of cases scored as positive on both dichotomous or ordinal scales were not significantly different between myxoma and myxofibrosarcoma. Myxoma and myxofibrosarcoma share a common immunophenotype for each of the markers studied. Distinction between these tumors is still predominantly based on morphologic criteria.

  18. Ciliary neurotrophic factor (CNTF) signals through STAT3-SOCS3 pathway and protects rat pancreatic islets from cytokine-induced apoptosis.

    Science.gov (United States)

    Rezende, Luiz F; Vieira, André S; Negro, Alessandro; Langone, Francesco; Boschero, Antonio C

    2009-04-01

    CNTF is a cytokine that promotes survival and/or differentiation in many cell types, including rat pancreatic islets. In this work, we studied the mechanism of CNTF signal in neonatal rats pancreatic islets isolated by the collagenase method and cultured for 3 days in RPMI medium without (CTL) or with 1 nM of CNTF. The medium contained, when necessary, specific inhibitors of the PI3K, MAPK and JAK/STAT3 pathways. mRNA expression (RT-PCR) and protein phosphorylation (Western blot) of Akt, ERK1/2 and STAT3, and SOCS-3 (RT-PCR and Western blot), as well as glucose-stimulated insulin secretion (GSIS) (Radioimmunoassay), were analyzed. Our results showed that Akt, ERK1 and STAT3 mRNA expression, as well as phosphorylated Akt and ERK1/2, was not affected by CNTF treatment. CNTF increased cytoplasmatic and nuclear phosphorylated STAT3, and the SOCS3 mRNA and protein expression. In addition, CNTF lowered apoptosis and impaired GSIS. These effects were blocked by the JAK inhibitor, AG490 and by the STAT3 inhibitor Curcumin, but not by the MAPK inhibitor, PD98059, nor by the PI3K inhibitor, Wortmannin. In conclusion, CNTF signals through the JAK2/STAT3 cascade, increases SOCS3 expression, impairs GSIS and protects neonatal pancreatic rat islets from cytokine-induced apoptosis. These findings indicate that CNTF may be a potential therapeutic tool against Type 1 and/or Type 2 diabetes.

  19. Human Chorionic Gonadotropin Protects Vascular Endothelial Cells from Oxidative Stress by Apoptosis Inhibition, Cell Survival Signalling Activation and Mitochondrial Function Protection

    Directory of Open Access Journals (Sweden)

    Daniela Surico

    2015-07-01

    Full Text Available Background/Aim: Previous reports have made it hypothetically possible that human chorionic gonadotropin (hCG could protect against the onset of pregnancy-related pathological conditions by acting as an antioxidant. In the present study we planned to examine the effects of hCG against oxidative stress in human umbilical vein endothelial cells (HUVEC. Methods: HUVEC were subjected to peroxidation by hydrogen peroxide. The modulation of nitric oxide (NO release by hCG and its effects on cell viability, glutathione (GSH levels, mitochondrial membrane potential and mitochondrial transition pore opening (MPTP were examined by specific dyes. Endothelial and inducible NO synthase (eNOS and iNOS, Akt and extracellular -signal-regulated kinases 1/2 (ERK1/2 activation and markers of apoptosis were analyzed by Western Blot. Results: In HUVEC, hCG reduced NO release by modulating eNOS and iNOS. Moreover, hCG protected HUVEC against oxidative stress by preventing GSH reduction and apoptosis, by maintaining Akt and ERK1/2 activation and by keeping mitochondrial function. Conclusion: The present results have for the first time shown protective effects exerted by hCG on vascular endothelial function, which would be achieved by modulation of NO release, antioxidant and antiapoptotic actions and activation of cell survival signalling. These findings could have clinical implications in the management of pregnancy-related disorders.

  20. Ubiquitin specific peptidase 5 mediates Histidine-rich protein Hpn induced cell apoptosis in hepatocellular carcinoma through P14-P53 signaling.

    Science.gov (United States)

    Liu, Yi; Wang, Wei-Mao; Zou, Li-Yi; Li, Li; Feng, Lu; Pan, Ming-Zhu; Lv, Min-Yi; Cao, Ying; Wang, Hua; Kung, Hsiang-Fu; Pang, Jian-Xin; Fu, Wei-Ming; Zhang, Jin-Fang

    2017-06-01

    Hpn is a small histidine-rich cytoplasmic protein from Helicobacter pylori and has been recognized as a high-risk factor for several cancers including gastric cancer, colorectal cancer, and MALT lymphoma. However, the relationship between Hpn and cancers remains elusive. In this study, we discovered that Hpn protein effectively suppressed cell growth and induced apoptosis in hepatocellular carcinoma (HCC). A two-dimensional gel electrophoresis and mass spectrometry-based comparative proteomics was performed to find the molecular targets of Hpn in HCC cells. It was identified that twelve proteins were differentially expressed, with USP5 being one of the most significantly downregulated protein. The P14 ARF -P53 signaling was activated by USP5 knockdown in HCC cells. Furthermore, USP5 overexpression significantly rescued the suppressive effect of Hpn on the viability of HCC cells. In conclusion, our study suggests that Hpn plays apoptosis-inducing roles through suppressing USP5 expression and activating the P14 ARF -P53 signaling. Therefore, Hpn may be a potential candidate for developing novel anti-HCC drugs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. α-Lactose Improves the Survival of Septic Mice by Blockade of TIM-3 Signaling to Prevent NKT Cell Apoptosis and Attenuate Cytokine Storm.

    Science.gov (United States)

    Yao, Yao; Deng, Hai; Li, Pingfei; Zhang, Jian; Zhang, Junbo; Wang, Deping; Li, Songbo; Luo, Yixing; Wei, Zhengping; Bi, Guoyu; Yang, Xiang-Ping; Tang, Zhao-Hui

    2017-03-01

    Sepsis is the leading cause of death among critically ill patients and natural killer T (NKT) cell activation is essential to induce inflammatory cytokine cascade in sepsis. However, little is known about what regulates the NKT cell function during sepsis. Herein, we showed that T-cell immunoglobulin and mucin domain 3 (Tim-3) expression in NKT cells is elevated in experimental mice during sepsis. Tim-3 expression was positively correlated with NKT cell activation and apoptosis. In sepsis, interleukin (IL)-12 secreted by dendritic cell exposure to lipopolysaccharide increased the expression of Tim-3 in NKT cells. Administration of α-lactose to block Tim-3 signaling pathway significantly improved the survival of septic mice, concomitant with reduced IL-12 production by dendritic cells, reduced Tim-3 expression, prevented NKT cell apoptosis, and attenuated production of inflammatory cytokines. Collectively, Tim-3 signaling in NKT cells plays a critical role in the immunopathogenesis of sepsis. Thus, α-lactose could be a promising immunomodulatory agent in the treatment of sepsis.

  2. PMS1077 sensitizes TNF-α induced apoptosis in human prostate cancer cells by blocking NF-κB signaling pathway.

    Directory of Open Access Journals (Sweden)

    Jie Shi

    Full Text Available Our previous studies have demonstrated that PMS1077, a platelet-activating factor (PAF antagonist, could induce apoptosis of Raji cells. However, the mechanism of action has not yet been determined. The nuclear transcription factor-kappa B (NF-κB signaling pathway plays a critical role in tumor cell survival, proliferation, invasion, metastasis, and angiogenesis, so we determined the effects of PMS1077 and its structural analogs on tumor necrosis factor-α (TNF-α induced activation of NF-κB signaling. In this study, we found that PMS1077 inhibited TNF-α induced expression of the NF-κB regulated reporter gene in a dose dependent manner. Western blot assay indicated that PMS1077 suppressed the TNF-α induced inhibitor of κB-α (IκB-α phosphorylation, IκB-α degradation, and p65 phosphorylation. PMS1077 consistently blocked TNF-α induced p65 nuclear translocation as demonstrated in the immunofluorescence assay used. Docking studies by molecular modeling predicted that PMS1077 might interact directly with the IκB kinase-β (IKK-β subunit. These results suggested that PMS1077 might suppress the activation of NF-κB by targeting IKK-β involved in the NF-κB signaling pathway. Finally, we showed that PMS1077 sensitized cells to TNF-α induced apoptosis by suppressing the expression of NF-κB regulated anti-apoptotic genes. Our results reveal a novel function of PMS1077 on the NF-κB signaling pathway and imply that PMS1077 can be considered as an anti-tumor lead compound.

  3. without intersecting short cycles

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... ... Lecture Workshops · Refresher Courses · Symposia. Home; Journals; Proceedings – Mathematical Sciences; Volume 126; Issue 2. (3, 1)*-Choosability of graphs of nonnegative characteristic without intersecting short cycles. Haihui Zhang. Research Article Volume 126 Issue 2 May 2016 pp 159-165 ...

  4. Considering Intersectionality in Multiculturalism

    Science.gov (United States)

    Clark, Madeline

    2015-01-01

    The intersection of feminist theory and multiculturalism is discussed. Although Frisby makes several strong points, there are several aspects of his definition of multiculturalism that are simplistic. Expansion of ideas borrowed from feminism has potential to increase the nuance and accuracy of the conceptualization of multiculturalism.

  5. Particle-nuclear intersections

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    With the traditional distinctions between particle and nuclear physics becoming increasing blurred, the Fifth Conference on the Intersections of Particle and Nuclear Physics, held from May 31 to June 6 in St. Petersburg, Florida, brought together particle and nuclear physicists to discuss common research efforts and to define and plan a united approach

  6. Intersection of Feature Models

    NARCIS (Netherlands)

    van den Broek, P.M.

    In this paper, we present an algorithm for the construction of the intersection of two feature models. The feature models are allowed to have "requires" and "excludes" constraints, and should be parent-compatible. The algorithm is applied to the problem of combining feature models from stakeholders

  7. Intersectionality and Liberal Education

    Science.gov (United States)

    Butler, Johnella E.

    2017-01-01

    Intersectionality--an integrated approach to analyzing the complex, matrix-like interconnections among patterns of discrimination based on race, gender, and other social identities, with the goal of highlighting how resulting inequalities are experienced--has many implications for exploring the relationship between knowledge and experience and for…

  8. Intersection I-1

    CERN Multimedia

    CERN PhotoLab

    1971-01-01

    Intersection I-1 of the ISR in August 1971 showing the 90 degree large acceptance spectrometer of the Saclay-Strasbourg Collaboration which is studying the momentum spectra of electrons at large angles. On the left of the crossing region can be seen the track used by the CERN-Bucharest-Cracow-Tata Collaboration to bring nuclear emulsions into the ISR.

  9. Bak compensated for Bax in p53-null cells to release cytochrome c for the initiation of mitochondrial signaling during Withanolide D-induced apoptosis.

    Directory of Open Access Journals (Sweden)

    Susmita Mondal

    Full Text Available The goal of cancer chemotherapy to induce multi-directional apoptosis as targeting a single pathway is unable to decrease all the downstream effect arises from crosstalk. Present study reports that Withanolide D (WithaD, a steroidal lactone isolated from Withania somnifera, induced cellular apoptosis in which mitochondria and p53 were intricately involved. In MOLT-3 and HCT116p53+/+ cells, WithaD induced crosstalk between intrinsic and extrinsic signaling through Bid, whereas in K562 and HCT116p53-/- cells, only intrinsic pathway was activated where Bid remain unaltered. WithaD showed pronounced activation of p53 in cancer cells. Moreover, lowered apoptogenic effect of HCT116p53-/- over HCT116p53+/+ established a strong correlation between WithaD-mediated apoptosis and p53. WithaD induced Bax and Bak upregulation in HCT116p53+/+, whereas increase only Bak expression in HCT116p53-/- cells, which was coordinated with augmented p53 expression. p53 inhibition substantially reduced Bax level and failed to inhibit Bak upregulation in HCT116p53+/+ cells confirming p53-dependent Bax and p53-independent Bak activation. Additionally, in HCT116p53+/+ cells, combined loss of Bax and Bak (HCT116Bax-Bak- reduced WithaD-induced apoptosis and completely blocked cytochrome c release whereas single loss of Bax or Bak (HCT116Bax-Bak+/HCT116Bax+Bak- was only marginally effective after WithaD treatment. In HCT116p53-/- cells, though Bax translocation to mitochondria was abrogated, Bak oligomerization helped the cells to release cytochrome c even before the disruption of mitochondrial membrane potential. WithaD also showed in vitro growth-inhibitory activity against an array of p53 wild type and null cancer cells and K562 xenograft in vivo. Taken together, WithaD elicited apoptosis in malignant cells through Bax/Bak dependent pathway in p53-wild type cells, whereas Bak compensated against loss of Bax in p53-null cells.

  10. Effects of MicroRNA-206 on Osteosarcoma Cell Proliferation, Apoptosis, Migration and Invasion by Targeting ANXA2 Through the AKT Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Bao-Long Pan

    2018-02-01

    Full Text Available Background/Aims: This study aimed to investigate the mechanism by which microRNA-206 (miR-206 affects the proliferation, apoptosis, migration and invasion of osteosarcoma (OS cells by targeting ANXA2 via the AKT signaling pathway. Methods: A total of 132 OS tissues and 120 osteochondroma tissues were examined in this study. The targeting relationship between miR-206 and ANXA2 was verified with a dual-luciferase reporter assay. The miR-206 expression and ANXA2, AKT, PARP, FASN, Survivin, Bax, Mcl-1 and Bcl-1 mRNA and protein expression in the above two groups were examined by qRT-PCR and western blotting. The cultured OS cells were divided into 6 groups: a blank group, negative control (NC group, miR-206 mimic group, miR-206 inhibitor group, si-ANXA2 group and miR-206 inhibitor + si-ANXA2 group. Cell cycle and apoptosis were assessed by flow cytometry, cell migration was examined with a wound-healing assay, and cell invasion was assessed with a Transwell assay. Pearson correlation analysis was used to determine the correlation between ANXA2 mRNA expression and miR-206 expression in OS. Results: OS tissues exhibited increased mRNA and protein expression of ANXA2, AKT, PARP, FASN, Survivin, Mcl-1 and Bcl-2; decreased miR-206 expression; and decreased Bax mRNA and protein expression. ANXA2 mRNA expression was strongly negatively correlated with miR-206 expression in OS. ANXA2 was found to be a miR-206 target gene. In the miR-206 mimic group and the si-ANXA2 group, the mRNA and protein expression of ANXA2, AKT, PARP, FASN, Survivin, Mcl-1 and Bcl-1 decreased markedly, cell proliferation was inhibited, apoptosis was promoted, higher cell growth in G1 phase and decreased growth in S phase was detected, and decreased cell migration and invasion were observed compared with those in the blank group. Conclusion: The current results demonstrate that miR-206 overexpression inhibits OS cell proliferation, migration and invasion and promotes apoptosis through

  11. Effects of microRNA-24 targeting C-myc on apoptosis, proliferation and cytokine expressions in chondrocytes of rats with osteoarthritis via MAPK signaling pathway.

    Science.gov (United States)

    Wu, Yuan-Hao; Liu, Wei; Zhang, Lei; Liu, Xiao-Ya; Wang, Yi; Xue, Bin; Liu, Bin; Duan, Ran; Zhang, Bo; Ji, Yang

    2017-11-16

    To investigate whether microRNA-24 (miR-24) targeting C-myc affects chondrocytes of rats with osteoarthritis (OA) via the MAPK signaling pathway. Thirty rats were assigned as a sham group and an OA group (established as OA rat models by cutting the anterior cruciate ligaments and removing 1/3 medial meniscus). TUNEL staining and immunohistochemistry were conducted for cell apoptosis index (AI) and positive expression rate of C-myc protein. Enzyme-linked immuno sorbent assay (ELISA) was carried out for serum level of IL-1β and TNF-α. Primary chondrocytes were assigned into the blank, negative control (NC), miR-24 mimics, miR-24 inhibitors, siRNA-C-myc, and miR-24 inhibitors + siRNA-C-myc groups. The expressions of miR-24, C-myc, p38, ERK, JNK, IL-1β, and TNF-α in tissues and cells were detected using reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and Western blotting. CCK8 assay and flow cytometry were performed for cell proliferation and apoptosis. The OA group showed higher IL-1β, TNF-α, AI, and C-myc than the sham group. C-myc is a target gene of miR-24. Compared with the blank group, the miR-24 mimics and siRNA-C-myc groups showed reduced expression of C-myc, IL-1β, TNF-α, p38, p-p38, ERK, p-ERK, JNK, and p-JNK, apoptosis rate yet increased cell proliferation; however, the miR-24 inhibitors group exhibited an opposite trend. The miR-24 inhibitors + siRNA-C-myc group presented a same tendency compared to the siRNA-C-myc group. Upregulated miR-24 downregulates C-myc could suppress apoptosis and promote proliferation of chondrocytes to prevent the occurrence and subsequent progression of OA via inactivating the MAPK signaling pathway. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  12. PTEN enhances TNF-induced apoptosis through modulation of nuclear factor-κB signaling pathway in human glioma cells

    International Nuclear Information System (INIS)

    Koul, Dimpy; Takada, Yasunari; Shen, Ruijun; Aggarwal, Bharat B.; Yung, W.K. Alfred

    2006-01-01

    The PTEN tumor suppressor gene modulates cell growth and survival known to be regulated by the activation of the transcription factor NFκB, suggesting PTEN might affect the NFκB activation pathway. We found that PTEN inhibited NFκB activation induced by TNF. The suppression of NFκB activation correlated with sequential inhibition of the tumor necrosis factor-induced expression of NFκB-regulated anti-apoptotic (IAP1, IAP2, Bcl-2, Bcl-xL, cFLIP, Bfl-1/A1, and survivin) gene products. Downregulation of the antiapoptotic genes by PTEN increased TNF-induced apoptosis, as indicated by caspase activation, TUNEL, annexin staining, and esterase assay. We conclude that the ectopic expression of PTEN enhances TNF-induced apoptosis and downregulates the proliferation of glioma cells through the suppression of various molecules including NFκB, and various mediators of cellular survival and proliferation, and that this targets might be essential for its central role in the growth and survival of glioma cancer cells

  13. Cycloartane triterpenoids from Cimicifuga yunnanensis induce apoptosis of breast cancer cells (MCF7) via p53-dependent mitochondrial signaling pathway.

    Science.gov (United States)

    Fang, Zhong-Ze; Nian, Yin; Li, Wei; Wu, Jing-Jing; Ge, Guang-Bo; Dong, Pei-Pei; Zhang, Yan-Yan; Qiu, Ming-Hua; Liu, Lei; Yang, Ling

    2011-01-01

    The present study was carried out to investigate the antitumor activity of five cycloartane triterpenoids isolated from Cimicifuga yunnanensis on the breast cancer cell line MCF7 and its corresponding drug resistant subline R-MCF7, including cimigenol-3-O-β-D-xylopyranoside (compound 1), 25-O-acetylcimigenol-3-O-β-D-xylopyranoside (compound 2), 25-chlorodeoxycimigenol-3-O-β-D-xylopyranoside (compound 3), 25-O-acetylcimigenol-3-O-α-L-arabinopyranoside (compound 4) and 23-O-acetylcimigenol-3-O-β-D-xylopyranoside (compound 5). The results showed that compounds 2-5 have relatively high antitumor activity on both MCF7 and R-MCF7 cells. The involvement of apoptosis as a major cause of cycloartane triterpenoids-induced cell death was further confirmed. The results of RT-PCR showed that compounds 2-5 increased the expression of p53 and bax, which led to the loss of mitochondrial potential and then resulted in the activation of caspase-7. These findings collectively demonstrated that compounds 2-5 induced apoptosis of MCF7 via p53-dependent mitochondrial pathway. Copyright © 2010 John Wiley & Sons, Ltd.

  14. The role of Pten/Akt signaling pathway involved in BPA-induced apoptosis of rat Sertoli cells.

    Science.gov (United States)

    Wang, Chengmin; Fu, Wenjuan; Quan, Chao; Yan, Maosheng; Liu, Changjiang; Qi, Suqin; Yang, Kedi

    2015-07-01

    Bisphenol-A (BPA), one of endocrine-disrupting chemicals, is a male reproductive toxicant. Previous studies have revealed the direct cytotoxicity of BPA in many cultured cells, such as mitotic aneuploidy in embryonic cells and somatic cells, and apoptosis in neurons and testicular Sertoli cells. To understand the action of BPA and assess its risk, the Pten/Akt pathway was investigated in cultured Sertoli cells to elucidate the mechanism of the reproductive effects of BPA. The results showed that over 50 μM BPA treatment could decrease the viability of Sertoli cells and cause more apoptosis. In addition, BPA could induce the increase in mRNA levels of Pten and Akt. The protein level of Pten was increased; however, the protein levels of phospho-Akt and procaspase-3 were decreased after BPA exposure. Taken together, observed results suggested that the Pten/Akt pathway might be involved in the apoptotic effects of BPA on Sertoli cells. © 2014 Wiley Periodicals, Inc.

  15. Umbilical cord-derived mesenchymal stem cells alleviated inflammation and inhibited apoptosis in interstitial cystitis via AKT/mTOR signaling pathway.

    Science.gov (United States)

    Xie, Juncong; Liu, Bolong; Chen, Jialiang; Xu, Yuancheng; Zhan, Hailun; Yang, Fei; Li, Wenbiao; Zhou, Xiangfu

    2018-01-01

    Interstitial cystitis (IC) is a bladder syndrome characterized by pelvic pain and urinary frequency without infection or other identifiable pathology. There are no effective treatments to cure IC. This study investigated the effects of human umbilical cord-derived mesenchymal stem cells (UC-MSCs) injection on IC rat model. Furthermore, we used a coculture system to find the possible molecular mechanism on the human uroepithelial cells (SV-HUC-1), which was the cell model of IC. A rat model of IC was established via systemic injection with cyclophosphamide (CYP) and a cell model of IC was induced by being exposed to tumor necrosis factor (TNF)-α (10 ng/ml). After one week, UC-MSCs injection significantly ameliorated the bladder voiding function in IC rat model. And the Histo- and immunohistochemical analyses showed that UC-MSCs can repair impaired bladder, reduce mast cell infiltration and inhibit apoptosis of urothelium. ELISA results showed that UC-MSCs can decrease IL-1β, IL-6 and TNF-α in bladder. In the coculture system, UC-MSCs can promote proliferation of impaired SV-HUC-1 cells, and inhibit apoptosis. However, while knocked down EGF secreted by UC-MSCs with siRNA, the effects would be weaken. Western blot showed that UC-MSCs increase protein expression levels of p-AKT and p-mTOR in SV-HUC-1 cells, and decrease the levels of cleaved caspase-3. Taken together, we provide evidence that UC-MSCs therapy can successfully alleviate IC in a preclinical animal Model and cell model by alleviating inflammation, promoting proliferation and inhibiting apoptosis. In addition, we demonstrate that the AKT/mTOR signaling pathway was activated. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Effects of mobile phone distraction on pedestrians' crossing behavior and visual attention allocation at a signalized intersection: An outdoor experimental study.

    Science.gov (United States)

    Jiang, Kang; Ling, Feiyang; Feng, Zhongxiang; Ma, Changxi; Kumfer, Wesley; Shao, Chen; Wang, Kun

    2018-03-28

    With the rapid growth in mobile phone use worldwide, traffic safety experts have begun to consider the impact of mobile phone distractions on pedestrian crossing safety. This study sought to investigate how mobile phone distractions (music distraction, phone conversation distraction and text distraction) affect the behavior of pedestrians while they are crossing the street. An outdoor-environment experiment was conducted among 28 college student pedestrians. Two HD videos and an eye tracker were employed to record and analyze crossing behavior and visual attention allocation. The results of the research showed that the three mobile phone distractions cause different levels of impairment to pedestrians' crossing performance, with the greatest effect from text distraction, followed by phone conversation distraction and music distraction. Pedestrians distracted by music initiate crossing later, have increased pupil diameter, and reduce their scanning frequency, fixation points and fixation times toward traffic signal area priorities. In addition to the above effects, pedestrians distracted by phone conversation cross the street more slowly, direct fewer fixation points to the right traffic area, and spend less fixation time and lower average fixation duration on the left traffic area. Moreover, pedestrians distracted by texting look left and right less often and switch, distribute and maintain less visual attention on the traffic environment. These findings may inform researchers, policy makers, and pedestrians. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Effects of MicroRNA-19b on the Proliferation, Apoptosis, and Migration of Wilms' Tumor Cells Via the PTEN/PI3K/AKT Signaling Pathway.

    Science.gov (United States)

    Liu, Ge-Liang; Yang, Han-Jie; Liu, Bo; Liu, Tian

    2017-10-01

    Wilms' tumor (WT) is a most common renal cancer that occurs among children, and microRNA-19b (miR-19b) usually participates in various human cancers. Importantly, the PTEN/PI3K/Akt signaling pathway plays a key role in cell apoptosis, growth and proliferation. Thus, our present study aims to investigate the effect of miR-19b on the PTEN/PI3K/Akt signaling pathway during WT cell proliferation, migration, and apoptosis. WT tissues and adjacent normal tissues from WT patients were collected. qRT-PCR was applied to detect miR-19b expression in both the WT tissues and the adjacent normal tissues, immunohistochemistry was applied to detect the protein expressions of PTEN, P13K, and p-Akt, SK-NEP-1 cells were divided into the blank, negative control (NC), miR-19b mimics and miR-19b inhibitors groups. MTT assay, propidium iodide (PI) staining, Annexin-V/PI double-staining, Transwell assay and Western blotting were performed to examine cell proliferation, cycle, apoptosis, migration, and invasion, and the protein expressions of PTEN, P13K, Akt, and p-Akt. Increased miR-19b expression, positive expression rates of P13K and Akt, decreased PTEN expression rate, a negative correlation between PTEN expression and tumor lymph node metastasis, and a positive correlation between the expression of P13K and Akt and the clinical stages were observed in the WT tissues. The miR-19b inhibitors group exhibited decreased cell proliferation, cell cycle progression, migration and invasion, and protein expressions of PI3K and p-Akt but increased PTEN protein expression compared with the blank and NC groups. Thus, inhibition of miR-19b suppresses the progression of WT by modulating the PTEN/PI3K/AKT signaling pathway. J. Cell. Biochem. 118: 3424-3434, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  18. Effect of Momordica charantia protein on proliferation, apoptosis and the AKT signal transduction pathway in the human endometrial carcinoma Ishikawa H cell line in vitro

    Science.gov (United States)

    Gu, Hang-Zhi; Lin, Rong-Rong; Wang, Han-Chu; Zhu, Xue-Jie; Hu, Yan; Zheng, Fei-Yun

    2017-01-01

    Endometrial carcinoma (EC) is one of the most common female malignancies, and there is an urgent requirement to explore new therapeutic strategies. In the present study, Ishikawa H cells were treated with Momordica charantia protein (MCP30). The cell morphology, growth inhibition rate, cell cycle distribution, and expression of phosphate and tensin homolog, P-AKT and AKT were measured. DNA fragmentation analysis and Annexin V-fluorescein isothiocyanate/propidium iodide double staining assay were used to analyze cell apoptosis. MCP30 decreased the viability of Ishikawa H cells in a dose- and time-dependent manner. The early apoptotic rates of Ishikawa H cells treated with MCP30 at 666.67 pM reached to 16.07±0.15%, following 72 h of treatment. DNA ladder was observed in cells treated with 333.33 and 666.67 pM MCP30 following 72 h of treatment. MCP30 blocks Ishikawa H cells from progressing between the S-phase and the G2/M-phase in a time- and concentration-dependent manner. Western blotting revealed that MCP30 treatment decreased the levels of P-AKT in a dose-dependent manner. It was revealed that MCP30 decreases cell proliferation, and induces apoptosis and S-phase cell cycle arrest through the AKT signaling pathway in Ishikawa H cells. PMID:28521410

  19. Effect of fluoride exposure on mRNA expression of cav1.2 and calcium signal pathway apoptosis regulators in PC12 cells.

    Science.gov (United States)

    Liao, Qiuxia; Zhang, Rui; Wang, Xiaoyu; Nian, Weiwei; Ke, Lulu; Ouyang, Wei; Zhang, Zigui

    2017-09-01

    This study investigated the effects of fluoride exposure on the mRNA expression of Cav1.2 calcium signaling pathway and apoptosis regulatory molecules in PC12 cells. The viability of PC12 cell receiving high fluoride (5.0mM) and low fluoride (0.5mM) alone or fluoride combined with L-type calcium channel (LTCC) agonist/inhibitor (5umol/L FPL6417/2umol/L nifedipine) was detected using cell counting kit-8 at different time points (2, 4, 6, 8, 12, 10, and 24h). Changes in the cell configuration were observed after exposing the cells to fluoride for 24h. The expression levels of molecules related to the LTCC were examined, particularly, Cav1.2, c-fos, CAMK II, Bax, and Bcl-2. Fluoride poisoning induced severe cell injuries, such as decreased PC12 cell activity, enhanced cell apoptosis, high c-fos, CAMKII, and Bax mRNA expression levels. Bcl-2 expression level was also reduced. Meanwhile, high fluoride, high fluoride with FPL64176, and low fluoride with FPL64176 enhanced the Cav1.2 expression level. In contrast, low fluoride, high fluoride with nifedipine, and low fluoride with nifedipine reduced the Cav1.2 expression level. Thus, Cav1.2 may be an important molecular target for the fluorosis treatment, and the LTCC inhibitor nifedipine may be an effective drug for fluorosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Blueberry and malvidin inhibit cell cycle progression and induce mitochondrial-mediated apoptosis by abrogating the JAK/STAT-3 signalling pathway.

    Science.gov (United States)

    Baba, Abdul Basit; Nivetha, Ramesh; Chattopadhyay, Indranil; Nagini, Siddavaram

    2017-11-01

    Blueberries, a rich source of anthocyanins have attracted considerable attention as functional foods that confer immense health benefits including anticancer properties. Herein, we assessed the potential of blueberry and its major constituent malvidin to target STAT-3, a potentially druggable oncogenic transcription factor with high therapeutic index. We demonstrate that blueberry abrogates the JAK/STAT-3 pathway and modulates downstream targets that influence cell proliferation and apoptosis in a hamster model of oral oncogenesis. Further, we provide mechanistic evidence that blueberry and malvidin function as STAT-3 inhibitors in the oral cancer cell line SCC131. Blueberry and malvidin suppressed STAT-3 phosphorylation and nuclear translocation thereby inducing cell cycle arrest and mitochondrial-mediated apoptosis. However, the combination of blueberry and malvidin with the STAT-3 inhibitor S3I-201 was more efficacious in STAT-3 inhibition relative to single agents. The present study has provided leads for the development of novel combinations of compounds that can serve as inhibitors of STAT-mediated oncogenic signalling. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Multiwalled carbon nanotube buckypaper induces cell cycle arrest and apoptosis in human leukemia cell lines through modulation of AKT and MAPK signaling pathways.

    Science.gov (United States)

    Dinicola, Simona; Masiello, Maria Grazia; Proietti, Sara; Coluccia, Pierpaolo; Fabrizi, Gianmarco; Palombo, Alessandro; Micciulla, Federico; Bistarelli, Silvia; Ricci, Giulia; Catizone, Angela; De Toma, Giorgio; Bizzarri, Mariano; Bellucci, Stefano; Cucina, Alessandra

    2015-10-01

    MWCNT buckypaper (BP) shows physico-chemical and mechanical properties that make it potentially useful as a substrate in nano-bio interface research including in tissue engineering. When used as a scaffold material, BP comes into contact with host cells and surrounding tissues; therefore it is critical to determine its biocompatibility and interaction with living systems. The aim of this study was to investigate BP effects on cell growth, apoptosis and reactive oxygen species (ROS) production in three human leukemia cell lines HL-60, U-937 and K-562. BP was able to induce both the reduction of cell proliferation, associated with an arrest in G0/G1 phase of cell cycle and the increase of apoptosis in leukemic cell lines, thus exerting both cytostatic and cytotoxic effects. The growth inhibitory effect was likely mediated by the decrease of cyclins D, E, A, B1 levels and CDK4 expression; meanwhile, the apoptotic effect, not mediated by ROS production, was presumably due to the combined action of the survival and pro-apoptotic AKT and MAPK signal transduction pathways. These results raised the issue of biocompatibility of MWCNT BP for the creation of carbon nanotubes based scaffolds to utilize as prostheses in tissue engineering. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Autonomous Intersection Management

    Science.gov (United States)

    2009-12-01

    and analyzing my algorithms for correctness and rigor. Third, Tarun Nimmagadda, for creating the first mixed simulation using my simulator. In addition...Agent Systems, 10(2):131–164, March 2005. [Beeson et al., 2008] Patrick Beeson, Jack O’Quin, Bartley Gillan, Tarun Nimma- gadda, Mickey Ristroph, David...autonomous vehicles at intersections. IEEE Intelligent Systems, 13(3):82–86, May 1998. [Nimmagadda, 2009] Tarun Nimmagadda. Building an autonomous ground

  3. Outlook from the intersections

    International Nuclear Information System (INIS)

    Haxton, W.C.

    1994-01-01

    I review a number of the physics themes of the Fifth Conference on the Intersections of Particle and Nuclear Physics, discussing the significance and promise of current work at the interface of these fields. Some of thee themes are: pattern of quark and boson masses; solar neutrino problem; lepton flavor violation tests; atomic dipole moments studies; Δs=0 weak interaction between nucleons; and strongly-interacting many-body problems

  4. Deletion of the N-terminus of IKKγ induces apoptosis in keratinocytes and impairs the AKT/PTEN signaling pathway

    International Nuclear Information System (INIS)

    Leis, Hugo; Sanchis, Ana; Perez, Paloma

    2007-01-01

    The regulatory subunit IKKγ/NEMO is crucial for skin development and function and although devoid of kinase activity, loss of IKKγ function completely abolishes the activation of NF-κB by all pro-inflammatory cytokines. To inhibit the IκB kinase (IKK) complex in keratinocytes, we have used a dominant negative approach by generating stable transfectants of an N-terminal deletion of IKKγ (IKKγ-DN97) that uncouples formation of the IKK complex. Expression of this mutant in PB keratinocytes (PB-IKKγ-DN97) delayed growth kinetics, caused morphological changes and dramatically augmented apoptosis even in the absence of pro-apoptotic stimuli, as determined by cell morphology, TUNEL and caspase-3 cleavage. Moreover, in PB-IKKγ-DN97 cells, TNF-α and IL-1 treatment failed to induce degradation of IκBα, phosphorylation of p65 on Ser 536 and nuclear translocation which, consequently, reduced κB-binding activity. In PB-IKKγ-DN97 cells, accumulation of IκBα correlated with a downregulation of AKT activity and an increase of PTEN protein levels whereas pro-apoptotic p53 target genes Bax and Puma were upregulated. These effects were most likely mediated through IKK since coexpression of the wild-type form of IKKγ in keratinocytes partially reversed apoptosis and reduced PTEN expression. Thus, our data suggest a negative cross-talk mechanism involving PTEN and NF-κB, critical for the anti-apoptotic role of NF-κB in keratinocytes

  5. Apoptosis and necrosis induced by novel realgar quantum dots in human endometrial cancer cells via endoplasmic reticulum stress signaling pathway

    Directory of Open Access Journals (Sweden)

    Wang H

    2015-08-01

    Full Text Available Huan Wang,1–3 Zhengyun Liu,4 Ying Gou,3 Yu Qin,4 Yaze Xu,5 Jie Liu,4 Jin-Zhu Wu6 1Research Center for Medicine and Biology, 2Guizhou Provincial College-based Key Lab for Tumor Prevention and Treatment with Distinctive Medicines, 3Department of Microbiology, 4Key Lab for Basic Pharmacology of Ministry of Education, 5Pharmacy School, Zunyi Medical College, Zunyi, 6Department of Chemistry, School of Science, Harbin Institute of Technology, Harbin, People’s Republic of China Abstract: Realgar (AS4S4 has been used in traditional medicines for malignancy, but the poor water solubility is still a major hindrance to its clinical use. Realgar quantum dots (RQDs were therefore synthesized with improved water solubility and bioavailability. Human endometrial cancer JEC cells were exposed to various concentrations of RQDs to evaluate their anticancer effects and to explore mechanisms by the MTT assay, transmission electron microscopy (TEM, flow cytometry, real-time reverse transcriptase polymerase chain reaction (RT-PCR and Western blot analysis. Results revealed that the highest photoluminescence quantum yield of the prepared RQDs was up to approximately 70%, with the average size of 5.48 nm. RQDs induced antiproliferative activity against JEC cells in a concentration-dependent manner. In light microscopy and TEM examinations, RQDs induced vacuolization and endoplasmic reticulum (ER dilation in JEC cells in a concentration-dependent manner. ER stress by RQDs were further confirmed by increased expression of GADD153 and GRP78 at both mRNA and protein levels. ER stress further led to JEC cell apoptosis and necrosis, as evidenced by flow cytometry and mitochondrial membrane potential detection. Our findings demonstrated that the newly synthesized RQDs were effective against human endometrial cancer cells. The underlying mechanism appears to be, at least partly, due to ER stress leading to apoptotic cell death and necrosis. Keywords: realgar, quantum dots

  6. Novel reciprocal regulation of cAMP signaling and apoptosis by orphan G-protein-coupled receptor GPRC5A gene expression

    International Nuclear Information System (INIS)

    Hirano, Minoru; Zang, Liqing; Oka, Takehiko; Ito, Yoshiyuki; Shimada, Yasuhito; Nishimura, Yuhei; Tanaka, Toshio

    2006-01-01

    GPRC5A is a member of G-protein-coupled receptors, which was originally identified as an all-trans-retinoic acid-induced gene. Although recent studies reported that this gene was highly expressed in the cancer cell lines and that GPRC5A might positively regulate cell proliferation, its mechanism remains unknown. We investigated the upstream and downstream signaling of GPRC5A and its biological function, and found that cAMP signaling is the novel GPRC5A induction pathway. When GPRC5A gene was overexpressed, intracellular cAMP concentration was decreased, and Gsα gene expression was downregulated. On the other hand, RNA interference of GPRC5A increased mRNA levels of Gsα and intracellular cAMP, reduced cell number, and induced apoptosis. Conversely, cell number was increased by GPRC5A overexpression. We first report the novel negative feedback model of cAMP signaling through GPRC5A gene expression. This evidence explains one of the mechanisms of the GPRC5A-regulated cell growth in some cancer cell lines

  7. Naringenin induces mitochondria-mediated apoptosis and endoplasmic reticulum stress by regulating MAPK and AKT signal transduction pathways in endometriosis cells.

    Science.gov (United States)

    Park, Sunwoo; Lim, Whasun; Bazer, Fuller W; Song, Gwonhwa

    2017-12-01

    Does the flavonoid naringenin inhibit proliferation of human endometriosis cells? Naringenin suppresses proliferation and increases apoptosis via depolarization of mitochondrial membrane potential and generation of reactive oxygen species (ROS) in human endometriosis cells. For management of endometriosis, hormonal therapy is commonly used to decrease production of estrogens by the ovaries, but that has limitations including undesirable side effects with long-term therapies. To overcome these limitations, it is important to discover novel compounds which have no adverse effects, but inhibit expression of target molecules involved in the pathogenesis of endometriosis. Well-established endometriosis cell lines (VK2/E6E7 and End1/E6E7) were purchased from the American Type Culture Collection. Effects of naringenin on VK2/E6E7 and End1/E6E7 cells were assessed in diverse assays in a dose- and time-dependent manner. Effects of naringenin on viability, apoptosis (Annexin V expression, propidium iodide staining, TUNEL and invasion assays), mitochondria-mediated apoptosis, production of ROS and endoplasmic reticulum (ER) stress proteins of VK2/E6E7 and End1/E6E7 cells were determined. Signal transduction pathways in VK2/E6E7 and End1/E6E7 cells in response to naringenin were determined by western blot analyses. In the present study, we demonstrated that naringenin suppressed proliferation and increased apoptosis through depolarization of mitochondrial membrane potential and inducing pro-apoptotic proteins, Bax and Bak, in both endometriosis cell lines. In addition, naringenin increased ROS, ER stress, through activation of eIF2α and IRE1α, GADD153 and GRP78 proteins in a dose-dependent manner. Furthermore, the induction of apoptosis by naringenin involved activation of MAPK and inactivation of PI3K pathways in VK2/E6E7 and End1/E6E7 cells. Lack of in vivo animal studies is a major limitation of this research. Effectiveness of naringenin to induce apoptosis of human

  8. Changes in immune cell signalling, apoptosis and stress response functions in mice returned from the BION-M1 mission in space.

    Science.gov (United States)

    Novoselova, E G; Lunin, S M; Khrenov, M O; Parfenyuk, S B; Novoselova, T V; Shenkman, B S; Fesenko, E E

    2015-04-01

    To explore the effect of the spaceflight environment on immunity in animals, C57/BL6 mice flown on a 30-day space high-orbit satellite mission (BION-M1) were analyzed. Cytokine response in mice was measured in tandem with the following parameters: the synthesis of inducible forms of the heat shock proteins HSP72 and HSP90α; activity of the NF-κB, IFR3, and SAPK/JNK signalling pathways; and TLR4 expression. In addition, apoptosis in the thymus was measured by caspase-3 and ph-p53/p53 ratio testing. In response to flight environment exposure, mice had a reduction in spleen and thymus masses and decreased splenic and thymic lymphocyte counts. Plasma concentration of IL-6 and IFN-γ but not TNF-α was decreased in C57BL6 mice. The NF-κB activity in splenic lymphocytes through the canonical pathway involving IκB degradation was significantly increased at 12h after landing. One week after landing, however, the activity of NF-κB was markedly decreased below even the control values. Non-canonical NF-κB activity increased during the whole observation period. The activities of SAPK/JNK and IRF-3 were invariable at 12h but significantly increased 7 days after landing. The expression of Hsp72 and Hsp90α was somewhat increased 12h (Hsp72) and 7 days (Hsp90α). TLR4 expression in splenic cells was significantly increased only at 12h, returning to normal 7 days after landing. To assess the apoptosis in thymus lymphocytes, caspase-3 and levels of p53 protein along with its phosphorylated form were measured in thymic lymphocytes. The results indicated that the high-orbit spaceflight environment caused an increase in the level of p53 but more notably in the activated, phosphorylated form of the p53 protein. The calculated ratio of the active to inactive forms of the protein (ph-53/p53) 12h after landing increased by more than twofold, indicating the apparent induction of apoptosis in thymus cells. Interestingly, 7 days after the landing, this ratio was not restored, but

  9. Association of apoptosis with the inhibition of extracellular signal-regulated protein kinase activity in the tumor necrosis factor alpha-resistant ovarian carcinoma cell line UCI 101.

    Science.gov (United States)

    Yazlovitskaya, E M; Pelling, J C; Persons, D L

    1999-05-01

    Tumor necrosis factor-alpha (TNF alpha) can function as both an autocrine and a paracrine growth factor and may therefore play a role in ovarian tumor progression. TNF alpha initiates multiple cellular responses, many of which are mediated through the mitogen-activated protein kinase pathways, which transduce signals from the TNF alpha receptors through the cytoplasm to the nucleus, resulting in regulation of gene expression. We examined the role of c-jun N-terminal kinase 1 (JNK1) and extracellular signal-regulated protein kinase (ERK) 1 and 2 in the cellular growth response to TNF alpha in the ovarian carcinoma cell line UCI 101. JNK1 activity was increased to a maximum level ninefold above the basal level after 10-20 min of treatment with 10 ng/mL TNF alpha. A maximum threefold induction of ERK1/2 activity was observed after 1 min of treatment. At concentrations up to 100 ng/mL, TNF alpha had neither a stimulatory nor an inhibitory effect on growth of UCI 101 cells. However, inhibition of TNF alpha-induced ERK1/2 activity by the MAP/ERK kinase 1 inhibitor PD 98059 resulted in 60% inhibition of cell growth in TNF alpha-treated UCI 101 cells. This decrease in cell growth was accompanied by apoptosis, as demonstrated by the presence of a 180-bp DNA ladder. Thus, the inhibition of TNF alpha-induced ERK1/2 activity was associated with induction of apoptosis in the TNF alpha-resistant cell line UCI 101. Inhibition of TNF alpha-induced ERK1/2 activity was accompanied by a subsequent transient increase in TNF alpha-induced JNK1 activity. The significance of this increase with respect to apoptosis induction remains to be determined. These findings demonstrated that ERK1/2 activity can modulate cellular sensitivity to TNF alpha and suggested that the balance between the levels of ERK1/2 and JNK1 activation may be critical in the cellular growth response to TNF alpha.

  10. Ginkgo biloba extract mitigates liver fibrosis and apoptosis by regulating p38 MAPK, NF-κB/IκBα, and Bcl-2/Bax signaling

    Directory of Open Access Journals (Sweden)

    Wang YY

    2015-12-01

    Full Text Available Yuanyuan Wang, Rong Wang, Yujie Wang, Ruqin Peng, Yan Wu, Yongfang Yuan Department of Pharmacy, Shanghai 9th People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China Background: Liver fibrosis is the consequence of diverse liver injuries and can eventually develop into liver cirrhosis. Ginkgo biloba extract (GBE is an extract from dried ginkgo leaves that has many pharmacological effects because of its various ingredients and has been shown to be hepatoprotective. Purpose and methods: Aimed to investigate the underlying protective mechanisms of GBE on carbon tetrachloride (CCl4-induced liver fibrosis in rats. Male Sprague Dawley rats were randomly divided into four groups: control group (C, model group (M, low-dose group (L, and high-dose group (H. Liver fibrosis was induced by CCl4 groups M, L, and H: group C was administered saline. In addition, GBE at different doses was used to treat groups L and H. Results: The results of hematoxylin and eosin staining, Masson’s trichrome staining, a liver function index, and a liver fibrosis index showed that GBE application noticeably mitigated fibrosis and improved the function of the liver. The western blotting and immunohistochemistry analyses indicated that GBE reduced liver fibrosis not only by inhibiting p38 MAPK and NF-κBp65 via inhibition of IκBα degradation but also by inhibiting hepatocyte apoptosis via downregulation of Bax, upregulation of Bcl-2, and subsequent inhibition of caspase-3 activation. Inflammation-associated factors and hepatic stellate cell (HSC-activation markers further demonstrated that GBE could effectively inhibit HSC activation and inflammation as a result of its regulation of p38 MAPK and nuclear factor-kappa B/IκBα signaling. Conclusion: Our findings indicated a novel role for GBE in the treatment of liver fibrosis. The potential mechanisms may be associated with the following signaling pathways: 1 the p38 MAPK

  11. Ranking the types of intersections for assessing the safety of pedestrians using TOPSIS method

    Directory of Open Access Journals (Sweden)

    Călin ŞERBU

    2014-11-01

    Full Text Available Every year, more than 1500 accidents with pedestrian occur in the intersections in Romania. The number of accidents involving pedestrians in roundabouts intersections type increased approximately three times in 2013 compared to 2009 in Romania. This alarming increase led to the need of assessing the safety of pedestrians in intersections with or without safety systems. The safety systems for pedestrians and drivers include: the road marking, the pedestrian crossings marking, signal intersections with road signs, traffic lights or pedestrian safety barriers. We propose to assess the types of intersections with TOPSIS method.

  12. The adaptor protein NTAL enhances proximal signaling and potentiates corticosteroid-induced apoptosis in T-ALL

    Czech Academy of Sciences Publication Activity Database

    Svojgr, K.; Kalina, T.; Kanderová, V.; Skopcová, Tereza; Brdička, Tomáš; Zuna, J.

    2012-01-01

    Roč. 40, č. 5 (2012), s. 379-385 ISSN 0301-472X R&D Projects: GA MŠk 2B06064 Institutional support: RVO:68378050 Keywords : acute lymphoblastic leukemia * TCR signaling * NTAL * ERK Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.907, year: 2012

  13. Intersectional embodiment and power

    DEFF Research Database (Denmark)

    Elg, Camilla; Jensen, Sune Qvotrup

    on the embodiment of social dispositions and the social formation of the individual as body inherent in Bourdieu's work have not yet gained weight in this development within ‘difference research'. It might not come to much surprise as the radical sociology of embodiment implicit in the theory of habitus does...... not seem to gain much attention in social stratification research in general. In our paper we will present our work on an embodied approach to intersectionality, which is inspired by Pierre Bourdieu and other thinkers of embodiment. We will argue for the importance of a focus on the embodiment of social...

  14. Effects of high-orbit spaceflight on signaling cascades and apoptosis in immune cells from mice flied on board the BION-M1 satellite

    Science.gov (United States)

    Novoselova, Elena; Shenkman, Boris; Lunin, Sergey; Parfenyuk, Svetlana; Novoselova, Tatyana; Fesenko, Eugeny

    The study was designed to evaluate immune cell activity in male C57bl mice after a 30-day high-orbit spaceflight (550 km, higher than conventional manned spaceflights) on board the BION-M1 satellite (Roskosmos Program, Russia). For the present study, thymus, spleens and plasma samples were collected from mice 12 h after landing and, additionally, 7 days subsequently. Assessing the activity of NF-kappaB signaling cascade by measuring Rel A (p65) protein phosphorylation in splenic lymphocytes, we showed that the NF-kappaB activity was significantly increased at 12 h after landing. Contrariwise, one week after landing, the NF-kappaB activity was markedly decreased, even below to the control values. Interestingly, after landing there were no significant changes in SAPK/JNK cascade activity in splenic lymphocytes as well as in the expression of transcription factor IRF3 in thymus cells. To assess the apoptosis status in thymus lymphocytes, levels of p53 protein and its phosphorylated form were measured in thymic lymphocytes. It is known that p53 plays an important role in the cellular response to DNA damage, genomic aberrations, and other characteristic of apoptosis. The results showed that the high-orbit spaceflight environment caused some increase in level of p53 protein, but most notably, activated phosphorylated form of p53 protein. Calculated ratio of active and inactive forms of the protein (ph-p53/p53) 12 h after landing increased by more than 2-fold, indicating the apparent induction of apoptosis in thymus cells. Interestingly, 7 days after the landing, this ratio was not restored, but rather increased: the specified ratio was 4 times higher as compared to the ground-based control. We can conclude that response to the prolonged high-orbit spaceflight is not like the classic "stress response", which is usually observed under various stressful factors. It is known that the stress response is surely accompanied by increased SAPK/JNK cascade activity as well as the

  15. Measuring user awareness at signalized intersections

    NARCIS (Netherlands)

    Vreeswijk, Jacob Dirk; van Berkum, Eric C.; van Arem, Bart

    2013-01-01

    Drivers have limited awareness of changes in trip attributes or the performance of the traffic system. Due to non-utilitarian behavior and perceptual biases a distinctive amount of changes go unnoticed or are valued incorrectly, which makes drivers indifferent to changing traffic conditions to a

  16. Knockdown of KLK11 reverses oxaliplatin resistance by inhibiting proliferation and activating apoptosis via suppressing the PI3K/AKT signal pathway in colorectal cancer cell

    Directory of Open Access Journals (Sweden)

    Zhang Y

    2018-02-01

    Full Text Available Yiyi Zhang,* Zongbin Xu,* Yanwu Sun,* Pan Chi, Xingrong Lu Department of Colorectal Surgery, Fujian Medical University Union Hospital, Fuzhou, People’s Republic of China *These authors contributed equally to this work Introduction: Kallikrein 11 (KLK11 plays a crucial role in drug-resistance to oxaliplatin (L-OHP in the treatment of metastatic colorectal cancer (mCRC. The study aimed to investigate the role of KLK11 in chemoresistance, and to clarify the mechanism underlying reverse of L-OHP resistance by knockdown of KLK11.Materials and Methods: Resistance to oxaliplatin was induced in HCT-8 (HCT-8/L-OHP colorectal adenocarcinoma cell lines by exposing cells to increasing concentrations of L-OHP. MTT, RT-qPCR, and Western blot were used to evaluate the resistance to L-OHP. We then knocked down KLK11 in HCT-8/L-OHP cells to explore the mechanism through which KLK11 reverses L-OHP resistance. The mRNA and protein expression of KLK11 in tissues from mCRC patients were detected by RT-qPCR and immunohistochemistry.Results: The drug resistance index (RI of HCT-8/L-OHP cell line to L-OHP, 5-Fluorouracil (5-FU, Irinotecan (CPT-11, Vincristine (VCR and Cis-diamminedichloroplatinum (CDDP were 10, 5.35, 3.23, 1.28, and 6.64, respectively. Increased expression of multi-drug resistant genes ABCC1, ABCB1, GSTP1 and ERCC1 were detected in HCT-8/L-OHP cell line. Moreover, the activated PI3K/AKT pathway was related to L-OHP-resistance. Knockdown of KLK11 in HCT-8/L-OHP cell reversed L-OHP-resistance by inhibiting cell growth and activating apoptosis via suppressing the PI3K/AKT signaling pathway. Moreover, high expression of KLK11 in chemoresistant-patients was associated with lymph node metastases and histopathology.Conclusion: KLK11 was highly expressed in chemoresistant-patients and L-OHP-resistant cell lines. Moreover, L-OHP resistance was associated with activated PI3K/AKT signal pathway. Knockdown of KLK11 can reverse L-OHP resistance by blocking PI3K

  17. EGCG protects against homocysteine-induced human umbilical vein endothelial cells apoptosis by modulating mitochondrial-dependent apoptotic signaling and PI3K/Akt/eNOS signaling pathways.

    Science.gov (United States)

    Liu, Shumin; Sun, Zhengwu; Chu, Peng; Li, Hailong; Ahsan, Anil; Zhou, Ziru; Zhang, Zonghui; Sun, Bin; Wu, Jingjun; Xi, Yalin; Han, Guozhu; Lin, Yuan; Peng, Jinyong; Tang, Zeyao

    2017-05-01

    Homocysteine (Hcy) induced vascular endothelial injury leads to the progression of endothelial dysfunction in atherosclerosis. Epigallocatechin gallate (EGCG), a natural dietary antioxidant, has been applied to protect against atherosclerosis. However, the underlying protective mechanism of EGCG has not been clarified. The present study investigated the mechanism of EGCG protected against Hcy-induced human umbilical vein endothelial cells (HUVECs) apoptosis. Methyl thiazolyl tetrazolium assay (MTT), transmission electron microscope, fluorescent staining, flow cytometry, western blot were used in this study. The study has demonstrated that EGCG suppressed Hcy-induced endothelial cell morphological changes and reactive oxygen species (ROS) generation. Moreover, EGCG dose-dependently prevented Hcy-induced HUVECs cytotoxicity and apoptotic biochemical changes such as reducing mitochondrial membrane potential (MMP), decreasing Bcl-2/Bax protein ratio and activating caspase-9 and 3. In addition, EGCG enhanced the protein ratio of p-Akt/Akt, endothelial nitric oxide synthase (eNOS) activation and nitric oxide (NO) formation in injured cells. In conclusion, the present study shows that EGCG prevents Hcy-induced HUVECs apoptosis via modulating mitochondrial apoptotic and PI3K/Akt/eNOS signaling pathways. Furthermore, the results indicate that EGCG is likely to represent a potential therapeutic strategy for atherosclerosis associated with Hyperhomocysteinemia (HHcy).

  18. Stress-induced nuclear import of apoptosis signal-regulating kinase 1 is mediated by karyopherin α2/β1 heterodimer.

    Science.gov (United States)

    Sturchler, Emmanuel; Feurstein, Daniel; Chen, Weimin; McDonald, Patricia; Duckett, Derek

    2013-03-01

    The apoptosis signal-regulating kinase 1 (ASK1) is activated in response to a wide variety of extracellular stressors. Consequently, dysregulation of ASK1 is associated with multiple pathologies. Here, we show that ASK1 translocates from the cytoplasm to the nucleus in HEK293 cells and human cardiomyocytes in response to hydrogen peroxide (H(2)O(2)) or angiotensin respectively. Immunoprecipitation and mass spectrometry experiments reveal that ASK1 physically interacts with the karyopherin α2/β1 heterodimer in response to stress and genetic knockdown experiments confirm that this association mediates H(2)O(2)-induced ASK1 nuclear translocation. In addition, we have identified a nuclear localization signal (NLS)-like motif within the primary amino acid sequence of ASK1 composed of two clusters of basic amino acids separated by an intervening 16 amino acid spacer, KR[ACANDLLVDEFLKVSS]KKKK. Mutation of the downstream lysine cluster markedly reduces the H(2)O(2)-induced ASK1-karyopherin α2/β1 interaction and inhibits ASK1 nuclear translocation. Furthermore, we demonstrate that nuclear ASK1 is active and participates in H(2)O(2)-induced ASK1-mediated cell death. Collectively, our findings have identified a functional interaction between ASK1 and the karyopherin α2/β1 heterodimer and have also revealed a novel mechanism by which nuclear trafficking regulates the apoptotic function of ASK1 in response to stress. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Alpha-mangostin induces apoptosis through activation of reactive oxygen species and ASK1/p38 signaling pathway in cervical cancer cells.

    Science.gov (United States)

    Lee, Chien-Hsing; Ying, Tsung-Ho; Chiou, Hui-Ling; Hsieh, Shu-Ching; Wen, Shiua-Hua; Chou, Ruey-Hwang; Hsieh, Yi-Hsien

    2017-07-18

    Alpha-mangostin, a natural xanthonoid, has been reported to possess the anti-cancer property in various types of human cancer. However, its effects and mechanism of α-mangostin in cervical cancer remain unclear. We found that α-mangostin effectively inhibited cell viability, resulted in loss of mitochondrial membrane potential (MMP), release of cytochrome C, increase of Bax, decrease of Bcl-2, and activation of caspase-9/caspase-3 cascade in cervical cancer cells. Alpha-mangostin elevated the contents of reactive oxygen species (ROS) to activate p38. Disrupting ASK1/p38 signaling pathway by a specific inhibitor of p38, or by the siRNAs against ASK1, MKK3/6, or p38, significantly abolished α-mangostin-induced cell death and apoptotic responses. Moreover, α-mangostin also repressed tumor growth in accordance with increased levels of p-ASK1, p-p38, cleaved-PARP and cleaved-caspase-3 in the tumor mass from the mouse xenograft model of cervical cancer. In the current study, we provided first evidence to demonstrate that dietary antioxidant α-mangostin could inhibit the tumor growth of cervical cancer cells through enhancing ROS amounts to activate ASK1/p38 signaling pathway and damage the integrity of mitochondria and thereby induction of apoptosis in cervical cancer cells.

  20. Cutaneous RANK-RANKL Signaling Upregulates CD8-Mediated Antiviral Immunity during Herpes simplex Virus Infection by Preventing Virus-Induced Langerhans Cell Apoptosis.

    Science.gov (United States)

    Klenner, Lars; Hafezi, Wali; Clausen, Björn E; Lorentzen, Eva U; Luger, Thomas A; Beissert, Stefan; Kühn, Joachim E; Loser, Karin

    2015-11-01

    Herpes simplex virus-type 1 (HSV-1) causes the majority of cutaneous viral infections. Viral infections are controlled by the immune system, and CD8(+) cytotoxic T-lymphocytes (CTLs) have been shown to be crucial during the clearance of HSV-1 infections. Although epidermal Langerhans cells (LCs) are the first dendritic cells (DCs) to come into contact with the virus, it has been shown that the processing of viral antigens and the differentiation of antiviral CTLs are mediated by migratory CD103(+) dermal DCs and CD8α(+) lymph node-resident DCs. In vivo regulatory T-cells (Tregs) are implicated in the regulation of antiviral immunity and we have shown that signaling via the receptor activator of NF-κB (RANK) and its ligand RANKL mediates the peripheral expansion of Tregs. However, in addition to expanding Tregs, RANK-RANKL interactions are involved in the control of antimicrobial immunity by upregulating the priming of CD4(+) effector T cells in LCMV infection or by the generation of parasite-specific CD8(+) T cells in Trypanosoma cruzi infection. Here, we demonstrate that cutaneous RANK-RANKL signaling is critical for the induction of CD8-mediated antiviral immune responses during HSV-1 infection of the skin by preventing virus-induced LC apoptosis, improving antigen transport to regional lymph nodes, and increasing the CTL priming capacity of lymph node DCs.

  1. Gadolinium chloride elicits apoptosis in human osteosarcoma U-2 OS cells through extrinsic signaling, intrinsic pathway and endoplasmic reticulum stress.

    Science.gov (United States)

    Tsai, Yuh-Feng; Huang, Ching-Wen; Chiang, Jo-Hua; Tsai, Fuu-Jen; Hsu, Yuan-Man; Lu, Chi-Cheng; Hsiao, Chen-Yu; Yang, Jai-Sing

    2016-12-01

    Gadolinium (Gd) compounds are important as magnetic resonance imaging (MRI) contrast agents, and are potential anticancer agents. However, no report has shown the effect of gadolinium chloride (GdCl3) on osteosarcoma in vitro. The present study investigated the apoptotic mechanism of GdCl3 on human osteosarcoma U-2 OS cells. Our results indicated that GdCl3 significantly reduced cell viability of U-2 OS cells in a concentration-dependent manner. GdCl3 led to apoptotic cell shrinkage and DNA fragmentation in U-2 OS cells as revealed by morphologic changes and TUNEL staining. Colorimetric assay analyses also showed that activities of caspase-3, caspase-8, caspase-9 and caspase-4 occurred in GdCl3-treated U-2 OS cells. Pretreatment of cells with pan-caspase inhibitor (Z-VAD-FMK) and specific inhibitors of caspase-3/-8/-9 significantly reduced cell death caused by GdCl3. The increase of cytoplasmic Ca2+ level, ROS production and the decrease of mitochondria membrane potential (ΔΨm) were observed by flow cytometric analysis in U-2 OS cells after GdCl3 exposure. Western blot analyses demonstrated that the levels of Fas, FasL, cytochrome c, Apaf-1, GADD153 and GRP78 were upregulated in GdCl3-treated U-2 OS cells. In conclusion, death receptor, mitochondria-dependent and endoplasmic reticulum (ER) stress pathways contribute to GdCl3-induced apoptosis in U-2 OS cells. GdCl3 might have potential to be used in treatment of osteosarcoma patients.

  2. An assessment of norepinephrine mediated hypertrophy to apoptosis transition in cardiac cells: a signal for cell death.

    Science.gov (United States)

    Jain, Aditi; Atale, Neha; Kohli, Shrey; Bhattacharya, Susinjan; Sharma, Manish; Rani, Vibha

    2015-01-05

    Heart is an organ which is under a constant work load that generates numerous stress responses. Heart failure is associated with increased plasma norepinephrine (NE) and hypertrophic cell death. Within the current study we try to understand the concentration dependent molecular switch from hypertrophy to apoptosis under stress. The effect of increasing concentration of NE on cell death was studied using MTT assay based on which further experimental conditions were decided. Trypan Blue staining and TUNEL assay were done at selected concentrations of NE. Cellular and nuclear morphology at these concentrations was studied using Haematoxylin-Eosin, DAPI and PI stains. The molecular switch between hypertrophy and cell death was studied by expression analysis of β-MyHC and TNF-α. Rhodamine and DCFH-DA staining were done to evaluate the role of mitochondria and ROS under these conditions. Role of caspases under these transitions was also evaluated. NE shows steep falls in cell viability at 50 μM and 100 μM concentrations. The cellular and nuclear morphology is altered at these concentrations along with alterations at molecular level showing a shift from hypertrophy towards cell death. Altered mitochondrial membrane potential and increase in ROS support this which leads to caspase dependent activation of cell death. We show that at 50 μM NE, there occurs a transition from cellular hypertrophy towards death. This could be beneficial to prevent hypertrophy induced cardiac cell death and evaluating cardio protective therapeutic targets in vitro. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  3. FSHR and LHR Expression and Signaling as Well as Maturation and Apoptosis of Cumulus-Oocyte Complexes Following Treatment with FSH Receptor Binding Inhibitor in Sheep

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    Suocheng Wei

    2017-09-01

    Full Text Available Background/Aims: Currently, it remains unknown whether FSH receptor binding inhibitor (FRBI influences follicular development and reproduction functions in humans and animals. The present study aimed to investigate FRBI effects on in vitro maturation (IVM and apoptosis of cumulus-oocyte complexes (COCs of sheep, to determine the effect of FRBI on mRNA and protein levels of FSHR and LHR in COCs, and to elucidate the signal pathway of FRBI effects. Methods: COCs were in vitro cultured for 24h in the IVM media supplemented with varying concentrations of FRBI (0, 10, 20, 30 and 40µg/mL and FSH (10IU/mL. The harvested COCs were observed under an inverted microscope and maturation rates of COCs were determined. Real time RT-PCR and Western blotting were utilized to detect mRNA and protein levels of FSHR and LHR. The concentrations of FSH, LH and caspase-3 were determined using especial ELISA kits for sheep, respectively. Results: Maturation rates of COCs decreased gradually as FRBI concentrations increased from 0 to 40µg/mL, reaching a bottom value of 23.76% of the FRBI-4 group. The maximal apoptosis rate was detected in the FRBI-4 group. IP3 contents of FRBI-3 and FRBI-4 groups were reduced as compared to control group (CG and FSH groups (P<0.05. Levels of FSHR protein of FRBI-3 and FRBI-4 groups as well as LHR protein of FRBI-4 group were significantly less than that of CG and FSH group. FSH contents of four FRBI treatment groups were gradually decreased along with the supplementation doses of FRBI. Caspase-3 contents of FRBI groups were reduced with a maximum reduction of the FRBI-2 group. Conclusion: Our results revealed supplement of FRBI into IVM media could dose-dependently decrease the maturation rate and increase apoptosis rate of sheep COCs. A lower dose of FRBI treatment slightly promoted IP3 production, but a higher dose of FRBI reduced IP3 production. FRBI suppressed the mRNA and protein expression levels of FSHR and LHR in sheep COCs

  4. Apoptosis induced by knockdown of uPAR and MMP-9 is mediated by inactivation of EGFR/STAT3 signaling in medulloblastoma.

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    Ramaprasada Rao Kotipatruni

    Full Text Available Medulloblastoma is a highly invasive cancer of central nervous system diagnosed mainly in children. Matrix metalloproteinase-9 (MMP-9 and urokinase plasminogen activator receptor (uPAR are over expressed in several cancers and well established for their roles in tumor progression. The present study is aimed to determine the consequences of targeting these molecules on medulloblastoma progression.Radiation is one of the foremost methods applied for treating cancer and considerable evidence showed that radiation elevated uPAR and MMP-9 expression in medulloblastoma cell. Therefore efforts are made to target these molecules in non-irradiated and irradiated medulloblastoma cells. Our results showed that siRNA-mediated knockdown of uPAR and MMP-9, either alone or in combination with radiation modulated a series of events leading to apoptosis. Down regulation of uPAR and MMP-9 inhibited the expression of anti-apoptotic molecules like Bcl-2, Bcl-xL, survivin, XIAP and cIAPI; activated BID cleavage, enhanced the expression of Bak and translocated cyctochrome C to cytosol. Capsase-3 and -9 activities were also increased in uPAR- and MMP-9-downregulated cells. The apoptosis induced by targeting MMP-9 and uPAR was initiated by inhibiting epidermal growth factor receptor (EGFR mediated activation of STAT3 and NF-κB related signaling molecules. Silencing uPAR and MMP-9 inhibited DNA binding activity of STAT3 and also reduced the recruitment of STAT3 protein at the promoter region of Bcl-2 and survivin genes. Our results suggest that inhibiting uPAR and MMP-9 reduced the expression of anti-apoptotic molecules by inactivating the transcriptional activity of STAT3. In addition, treating pre-established medulloblastoma with siRNAs against uPAR and MMP-9 both alone or in combination with radiation suppressed uPAR, MMP-9, EGFR, STAT3 expression and induced Bak activation leading to apoptosis.Taken together, our results illustrated that RNAi mediated targeting of

  5. Vitamin E synthetic derivate-TPGS-selectively induces apoptosis in jurkat t cells via oxidative stress signaling pathways: implications for acute lymphoblastic leukemia.

    Science.gov (United States)

    Ruiz-Moreno, Cristian; Jimenez-Del-Rio, Marlene; Sierra-Garcia, Ligia; Lopez-Osorio, Betty; Velez-Pardo, Carlos

    2016-09-01

    D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) is a water-soluble derivative of natural vitamin E commonly used as a drug delivery agent. Recently, TPGS alone has been reported to induce cell death in lung, breast and prostate cancer. However, the effect of TPGS on cancer cell viability remains unclear. Thus, this study was aimed to evaluate the cytotoxic effect of TPGS on human periphral blood lymphocytes (PBL) and on T cell acute lymphocytic leukemia (ALL) Jurkat clone E6-1 cells and its possible mechanism of action. PBL and Jurkat cells were treated with TPGS (10, 20, 40, 60, and 80 μM), and morphological changes in the cell nucleus, mitochondrial membrane potential (ΔΨm), and intracellular reactive oxygen species levels were determined by immune-fluorescence microscopy and flow cytometry. Cellular apoptosis markers were also evaluated by immunocytochemistry. In this study, TPGS induced apoptotic cell death in Jurkat cells, but not in PBL, in a dose-response manner with increasing nuclear DNA fragmentation, increasing cell cycle arrest, and decreasing ΔΨm. Additionally, TPGS increased dichlorofluorescein fluorescence intensity, indicative of H2O2 production, in a dose-independent fashion. TPGS increased DJ-1 Cys(106)-sulfonate, as a marker of intracellular stress and induced the activation of NF-κB, p53 and c-Jun transcription factors. Additionally, it increased the expression of apoptotic markers Bcl-2 related pro-apoptotic proteins Bax and PUMAand activated caspase-3. The antioxidant N-acetyl-L-cysteine and known pharmacological inhibitors protected the cells from the TPGS induced effects. In conclusion, TPGS selectively induces apoptosis in Jurkat cells through two independent but complementary H2O2-mediated signaling pathways. Our findings support the use of TPGS as a potential treatment for ALL.

  6. Osteopontin Promotes Cell Migration and Invasion, and Inhibits Apoptosis and Autophagy in Colorectal Cancer by activating the p38 MAPK Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Ren-hong Huang

    2017-04-01

    Full Text Available Background: Osteopontin (OPN is highly expressed in colorectal cancer (CRC and is associated with disease progression in vivo. High levels of OPN have been demonstrated to predict low survival rates in CRC. Autophagy is a process of self-digestion, which is thought to play a significant role in carcinogenesis. However, the mechanisms of OPN's effects on CRC cell autophagy have not been elucidated. Therefore, we aimed to investigate possible mechanisms of OPN's effects on CRC autophagy. Methods: HCT116 cell proliferation, apoptosis, and migration and invasion ability were identified by cell counting k¡t-8 assay, flow cytometry, wound healing assay, and transwell chamber invasion assay, respectively. The ratios of proteins LC3-II/LC3-I, P62, and Atg7 were analyzed by Western-blot. Expressions of Beclin-1, Atg4b, Bnip3, and Vps34, both in transcriptional and translational levels, were analyzed and compared by RT-PCR and Western blot. Immunofluorescence and co-focusing experiments were used to investigate the formation of autophagosomes. Results: The results showed that OPN can promote cell proliferation, migration, and invasion, as well as inhibit cell apoptosis. It was also demonstrated that OPN could inhibit cell autophagy. Further experiments revealed that the inhibitory effect of OPN on autophagy could be reversed by blocking the p38 MAPK pathway in HCT116 cells. Conclusion: OPN is involved in HCT116 cell progression and is capable of inhibiting cell autophagy possibly by activating the p38 MAPK signaling pathway, implying that OPN could be a potential novel molecular therapeutic biomarker in patients with CRC.

  7. The microRNA-302b-inhibited insulin-like growth factor-binding protein 2 signaling pathway induces glioma cell apoptosis by targeting nuclear factor IA.

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    Chin-Cheng Lee

    Full Text Available MicroRNAs are small noncoding RNAs that post-transcriptionally control the expression of genes involved in glioblastoma multiforme (GBM development. Although miR-302b functions as a tumor suppressor, its role in GBM is still unclear. Therefore, this study comprehensively explored the roles of miR-302b-mediated gene networks in GBM cell death. We found that miR-302b levels were significantly higher in primary astrocytes than in GBM cell lines. miR-302b overexpression dose dependently reduced U87-MG cell viability and induced apoptosis through caspase-3 activation and poly(ADP ribose polymerase degradation. A transcriptome microarray revealed 150 downregulated genes and 380 upregulated genes in miR-302b-overexpressing cells. Nuclear factor IA (NFIA, higher levels of which were significantly related to poor survival, was identified as a direct target gene of miR-302b and was involved in miR-302b-induced glioma cell death. Higher NFIA levels were observed in GBM cell lines and human tumor sections compared with astrocytes and non-tumor tissues, respectively. NFIA knockdown significantly enhanced apoptosis. We found high levels of insulin-like growth factor-binding protein 2 (IGFBP2, another miR-302b-downregulated gene, in patients with poor survival. We verified that NFIA binds to the IGFBP2 promoter and transcriptionally enhances IGFBP2 expression levels. We identified that NFIA-mediated IGFBP2 signaling pathways are involved in miR-302b-induced glioma cell death. The identification of a regulatory loop whereby miR-302b inhibits NFIA, leading to a decrease in expression of IGFBP-2, may provide novel directions for developing therapies to target glioblastoma tumorigenesis.

  8. Caspases: An apoptosis mediator

    Directory of Open Access Journals (Sweden)

    Tapan Kumar Palai

    2015-03-01

    Full Text Available The process of programmed cell death, or apoptosis, is generally characterized by distinct morphological characteristics and energy - dependent biochemical mechanisms. Apoptosis is a widely conserved phenomenon helping many processes, including normal cell turnover, proper development and functioning of the immune system, hormone dependent atrophy etc. Inappropriate apoptosis (either low level or high level leads to many developmental abnormalities like, neurodegenerative diseases, ischemic damage, autoimmune disorders and many types of cancer. To use cells for therapeutic purposes through generating cell lines, it is critical to study the cell cycle machinery and signalling pathways that controls cell death and apoptosis. Apoptotic pathways provide a fundamental protective mechanism that decreases cellular sensitivity to damaging events and allow proper developmental process in multi-cellular organisms. Major mediator of apoptosis is a family of proteins known as caspases. There are mainly fourteen types of caspases but out of them only ten caspasese have got essential role in controlling the process of apoptosis. These ten caspases have been categorized into either initiator caspases (caspase 2, 8, 9, 10 or executioner caspases (caspase 3, 6, 7. Although various types of caspases have been identified so far, the exact mechanisms of action of these groups of proteins is still to be fully understood. The aim of this review is to provide a detail overview of role of different caspases in regulating the process of apoptosis.

  9. Study of Bioreductive Anticancer Agent RH-1-Induced Signals Leading the Wild-Type p53-Bearing Lung Cancer A549 Cells to Apoptosis.

    Science.gov (United States)

    Stulpinas, Aurimas; Imbrasaitė, Aušra; Krestnikova, Natalija; Šarlauskas, Jonas; Čėnas, Narimantas; Kalvelytė, Audronė Valerija

    2016-01-19

    Aziridinylquinone RH-1 (2,5-diaziridinyl-3-hydroxymethyl-6-methyl-cyclohexa-2,5-diene-1,4-dione) is a potential anticancer agent. RH-1 action is associated with quinone oxidoreductase (NQO1) which reduces this diaziridinylbenzoquinone into DNA-alkylating hydroquinone and is overexpressed in many tumors. Another suggested mechanism of RH-1 toxicity is the formation of reactive oxygen species (ROS) arising from its redox cycling. In order to improve anticancer action of this and similar antitumor quinones, we investigated the involvement of different signaling molecules in cytotoxicity induced by RH-1 by using wild-type tumor suppressor p53 bearing nonsmall cell lung carcinoma A549 cells as a model. Gradual and prolonged increase of mitogen-activated protein kinases (MAPK) ERK, P38, and JNK phosphorylation was observed during 24-h RH-1 treatment. In parallel, activation of DNA damage-sensing ATM kinase, upregulation, and phosphorylation of TP53 (human p53) took place. Inhibition studies revealed that RH-1-induced A549 apoptosis involved the NQO1-ATM-p53 signaling pathway and ROS generation. TP53 participated in ROS- and DNA damage-induced cell death differently. Moreover, MAP kinase JNK was another TP53 activator and death inducer in A549 cells. At the same time, rapid and prolonged activation of AKT kinase during RH-1 treatment was found, and it proved to be antiapoptotic kinase in our model system. Therefore, we identified that different and opposite cell death regulating signaling pathways, which may counteract one another, are induced in cancer cells during chemotherapeutic RH-1 treatment.

  10. Development of an in-vehicle intersection collision countermeasure

    Science.gov (United States)

    Pierowicz, John A.

    1997-02-01

    Intersection collisions constitute approximately twenty-six percent of all accidents in the United States. Because of their complexity, and demands on the perceptual and decision making abilities of the driver, intersections present an increased risk of collisions between automobiles. This situation provides an opportunity to apply advanced sensor and processing capabilities to prevent these collisions. A program to determine the characteristics of intersection collisions and identify potential countermeasures will be described. This program, sponsored by the National Highway Traffic Safety Administration, utilized accident data to develop a taxonomy of intersection crashes. This taxonomy was used to develop a concept for an intersection collision avoidance countermeasure. The concept utilizes in-vehicle position, dynamic status, and millimeter wave radar system and an in-vehicle computer system to provide inputs to an intersection collision avoidance algorithm. Detection of potential violation of traffic control device, or proceeding into the intersection with inadequate gap will lead to the presentation of a warning to the driver. These warnings are presented to the driver primarily via a head-up display and haptic feedback. Roadside to vehicle communication provides information regarding phased traffic signal information. Active control of the vehicle's brake and steering systems are described. Progress in the development of the systems will be presented along with the schedule of future activities.

  11. MHC class I cross-talk with CD2 and CD28 induces specific intracellular signalling and leads to growth retardation and apoptosis via a p56(lck)-dependent mechanism

    DEFF Research Database (Denmark)

    Ruhwald, M; Pedersen, Anders Elm; Claesson, M H

    1999-01-01

    Ligation of the major histocompatibility complex class I molecules (MHC-I) on human T lymphoma cells (Jurkat) initiates p56(lck)-dependent intracellular signalling events (phosphotyrosine kinase activity; [Ca(2+)](i)) and leads to augmented growth inhibition and apoptosis. MHC-I ligation in concert...... of apoptosis. In parallel experiments with the p56(lck)-negative Jurkat mutant cell, JCaM1.6, cross-linking neither influenced cell signalling nor cellular growth functions, indicating a cardinal role of the src kinases in signal transduction via MHC-I, CD2 and CD28 molecules. The results presented here...... with ligation of CD2 or CD28 augments, changes or modifies the pattern of activation. Ligation of MHC-I and CD2 alone resulted in growth inhibition, whereas CD28 ligation alone had no effect on cell proliferation. Ligation of MHC-I together with CD2 augmented growth inhibition and enhanced the level...

  12. Scattering Amplitudes from Intersection Theory.

    Science.gov (United States)

    Mizera, Sebastian

    2018-04-06

    We use Picard-Lefschetz theory to prove a new formula for intersection numbers of twisted cocycles associated with a given arrangement of hyperplanes. In a special case when this arrangement produces the moduli space of punctured Riemann spheres, intersection numbers become tree-level scattering amplitudes of quantum field theories in the Cachazo-He-Yuan formulation.

  13. Intersectionality and Critical Race Parenting

    Science.gov (United States)

    DePouw, Christin

    2018-01-01

    This conceptual article employs critical race theory (CRT) as a theoretical framework to explore the importance of intersectionality in critical race parenting. In particular, I focus on intersectionality to understand better how Whiteness and racial power play out in intimate relationships within the family, particularly between White parents and…

  14. Induction of cell cycle arrest and apoptosis in caspase-3 deficient MCF-7 cells by Dillenia suffruticosa root extract via multiple signalling pathways

    Science.gov (United States)

    2014-01-01

    Background Dillenia suffruticosa root dichloromethane extract (DCM-DS) has been reported to exhibit strong cytotoxicity towards breast cancer cells. The present study was designed to investigate the cell cycle profile, mode of cell death and signalling pathways of DCM-DS-treated human caspase-3 deficient MCF-7 breast cancer cells. Methods Dillenia suffruticosa root was extracted by sequential solvent extraction. The anti-proliferative activity of DCM-DS was determined by using MTT assay. The mode of cell death was evaluated by using inverted light microscope and Annexin-V/PI-flow cytometry analysis. Cell cycle analysis and measurement of intracellular reactive oxygen species (ROS) were performed by using flow cytometry. MCF-7 cells were co-treated with antioxidants α-tocopherol and ascorbic acid to evaluate whether the cell death was mainly due to oxidative stress. GeXP-based multiplex system was employed to investigate the expression of apoptotic, growth and survival genes in MCF-7 cells. Western blot analysis was performed to confirm the expression of the genes. Results DCM-DS was cytotoxic to the MCF-7 cells in a time-and dose-dependent manner. The IC50 values of DCM-DS at 24, 48 and 72 hours were 20.3 ± 2.8, 17.8 ± 1.5 and 15.5 ± 0.5 μg/mL, respectively. Cell cycle analysis revealed that DCM-DS induced G0/G1 and G2/M phase cell cycle arrest in MCF-7 cells at low concentration (12.5 and 25 μg/mL) and high concentration (50 μg/mL), respectively. Although Annexin-V/PI-flow cytometry analysis has confirmed that DCM-DS induced apoptosis in MCF-7 cells, the distinct characteristics of apoptosis such as membrane blebbing, chromatin condensation, nuclear fragmentation and formation of apoptotic bodies were not observed under microscope. DCM-DS induced formation of ROS in MCF-7 cells. Nevertheless, co-treatment with antioxidants did not attenuate the cell death at low concentration of DCM-DS. The pro-apoptotic gene JNK was up-regulated whereby

  15. Small molecule ErbB inhibitors decrease proliferative signaling and promote apoptosis in philadelphia chromosome-positive acute lymphoblastic leukemia.

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    Mary E Irwin

    Full Text Available The presence of the Philadelphia chromosome in patients with acute lymphoblastic leukemia (Ph(+ALL is a negative prognostic indicator. Tyrosine kinase inhibitors (TKI that target BCR/ABL, such as imatinib, have improved treatment of Ph(+ALL and are generally incorporated into induction regimens. This approach has improved clinical responses, but molecular remissions are seen in less than 50% of patients leaving few treatment options in the event of relapse. Thus, identification of additional targets for therapeutic intervention has potential to improve outcomes for Ph+ALL. The human epidermal growth factor receptor 2 (ErbB2 is expressed in ~30% of B-ALLs, and numerous small molecule inhibitors are available to prevent its activation. We analyzed a cohort of 129 ALL patient samples using reverse phase protein array (RPPA with ErbB2 and phospho-ErbB2 antibodies and found that activity of ErbB2 was elevated in 56% of Ph(+ALL as compared to just 4.8% of Ph(-ALL. In two human Ph+ALL cell lines, inhibition of ErbB kinase activity with canertinib resulted in a dose-dependent decrease in the phosphorylation of an ErbB kinase signaling target p70S6-kinase T389 (by 60% in Z119 and 39% in Z181 cells at 3 µM. Downstream, phosphorylation of S6-kinase was also diminished in both cell lines in a dose-dependent manner (by 91% in both cell lines at 3 µM. Canertinib treatment increased expression of the pro-apoptotic protein Bim by as much as 144% in Z119 cells and 49% in Z181 cells, and further produced caspase-3 activation and consequent apoptotic cell death. Both canertinib and the FDA-approved ErbB1/2-directed TKI lapatinib abrogated proliferation and increased sensitivity to BCR/ABL-directed TKIs at clinically relevant doses. Our results suggest that ErbB signaling is an additional molecular target in Ph(+ALL and encourage the development of clinical strategies combining ErbB and BCR/ABL kinase inhibitors for this subset of ALL patients.

  16. Galactose protects hepatocytes against TNF-α-induced apoptosis by promoting activation of the NF-κB signaling pathway in acute liver failure.

    Science.gov (United States)

    Liu, Yanmin; Zhu, Liuluan; Liang, Shuntao; Yao, Shanshan; Li, Rui; Liu, Sanhai; Ma, Yaluan; Zhou, Xiaobing; Zhang, Jinliang; Zeng, Hui; Wang, Xianbo

    2015-05-01

    Saccharides are reported to protect hepatocytes from acute liver injury through distinct mechanisms. To date, the protective role of galactose against acute liver injury induced by lipopolysaccharide (LPS) and D-galactosamine (D-GalN) has been attributed to competition with D-GalN. Here, we showed that in addition to its effects on LPS/D-GalN and tumor necrosis factor alpha (TNF-α)/D-GalN models, galactose improves hepatic injury in mice challenged with LPS alone or TNF-α/actinomycin D. Consistent with this result, galactose enhanced the viability of TNF-α-stimulated Chang Liver and Hu7.5 hepatic cell lines. Specifically, galactose prevented TNF-α-induced apoptosis of hepatocytes through promoting phosphorylation of nuclear factor kappa B (NF-κB) p65. Additionally, galactose enhanced expression of the anti-apoptotic genes, c-IAP1 and A20, and inhibited cleavage of caspase-8 and caspase-3. These findings collectively suggest that galactose prevents TNF-α-induced liver injury through activation of the NF-κB signaling pathway. Considering that monosaccharides protect against liver injury via distinct mechanisms, these compounds may represent a promising clinical approach to treat acute liver failure.

  17. gef Gene Expression in MCF-7 Breast Cancer Cells is Associated with a Better Prognosis and Induction of Apoptosis by p53-Mediated Signaling Pathway

    Science.gov (United States)

    Boulaiz, Houria; Álvarez, Pablo J.; Prados, Jose; Marchal, Juan; Melguizo, Consolación; Carrillo, Esmeralda; Peran, Macarena; Rodríguez, Fernando; Ramírez, Alberto; Ortíz, Raúl; Aránega, Antonia

    2011-01-01

    Breast cancer research has developed rapidly in the past few decades, leading to longer survival times for patients and opening up the possibility of developing curative treatments for advanced breast cancer. Our increasing knowledge of the biological pathways associated with the progression and development of breast cancer, alongside the failure of conventional treatments, has prompted us to explore gene therapy as an alternative therapeutic strategy. We previously reported that gef gene from E. coli has shown considerable cytotoxic effects in breast cancer cells. However, its action mechanism has not been elucidated. Indirect immunofluorescence technique using flow cytometry and immunocytochemical analysis were used to detect breast cancer markers: estrogen (ER) and progesterone (PR) hormonal receptors, human epidermal growth factor receptor-2 proto-oncogene (c-erbB-2), ki-67 antigen and p53 protein. gef gene induces an increase in ER and PR expressions and a decrease in ki-67 and c-erbB-2 gene expressions, indicating a better prognosis and response to treatment and a longer disease-free interval and survival. It also increased p53 expression, suggesting that gef-induced apoptosis is regulated by a p53-mediated signaling pathway. These findings support the hypothesis that the gef gene offers a new approach to gene therapy in breast cancer. PMID:22174609

  18. A novel synthetic Asiatic acid derivative induces apoptosis and inhibits proliferation and mobility of gastric cancer cells by suppressing STAT3 signaling pathway

    Directory of Open Access Journals (Sweden)

    Wang G

    2016-12-01

    Full Text Available Gang Wang,1 Yue Jing,2 Lingsen Cao,3 Changchang Gong,1 Zhunan Gong,1,3 Xiangrong Cao3 1Center for New Drug Research and Development, College of Life Science, Nanjing Normal University, 2Central Laboratory of Stomatology, Nanjing Stomatological Hospital, Medical School of Nanjing University, 3Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, People’s Republic of China Abstract: Activation of the transcription factor, signal transducers and activators of transcription 3 (STAT3, has been linked to the proliferation and migration of a variety of human cancer cells. These actions occur via the upregulation or downregulation of cell survival and tumor suppressor genes, respectively. Importantly, agents that can suppress STAT3 activation have the potential for use in the prevention and treatment of various cancers. In this study, an Asiatic acid (AA derivative, N-(2α,3β,23-acetoxyurs-12-en-28-oyl-L-proline methyl ester (AA-PMe, is reported to dose dependently suppress constitutive STAT3 activation in gastric cancer cells. This inhibition was mediated by blockade of Janus-activated kinase 2. Additionally, AA-PMe regulated the expression of STAT3-modulated gene products, including cyclin D1, Bax, Bcl-2, c-Myc, and matrix metalloproteinase (MMP-2 and MMP-9. Finally, transfection with both a STAT3 mimic and an inhibitor reversed the AA-PMe-driven modulation of STAT3 downstream gene products. Overall, these results suggest that AA-PMe is a novel blocker of STAT3 activation and has the potential for the prevention and treatment of gastric cancer. Keywords: gastric cancer, signal transducer and activator of transcription 3, Asiatic acid derivative, cell cycle, apoptosis, invasion

  19. Physician Education: Apoptosis.

    Science.gov (United States)

    Kataoka; Tsuruo

    1996-01-01

    apoptosis include those that cause DNA damage such as radiation and anticancer drugs, those that are mediated by the TNF receptor and Fas receptor (the so-called "death signal receptors"), and the deprivation of cytokines that supply survival signals such as IL-3 and erythropoietin. The tumor suppressor gene p53 plays a very important role in apoptosis induced by damage to DNA. This has been demonstrated by studying resistance to apoptosis of cells derived from p53 knockout mice [2]. Other than the irritations that induce apoptosis, molecules that have been strongly implicated as major players in the drama of apoptosis include the Bcl-2 family proteins and the IL-1 converting enzyme (ICE) and its homolog proteases (caspase family). Both groups of proteins show homology with proteins that affect cell death in nematodes. It is believed that molecules that contribute to cell death have been well conserved in multicellular organisms all the way from the relatively primitive nematodes to mammals including humans. It was discovered that Bcl-2 suppressed apoptosis induced in IL-3 dependent cells by deprivation of IL-3 [3]. It has since become the gene around which apoptosis research revolves. Recently, it has become clear that cell death involving the Bcl-2 protein is under the control of similar proteins from the same family [4]. It is interesting that the phenomenon of cell death may be regulated by the balance of the molecules involved in it. APOPTOSIS ABNORMALITIES AND DISEASE: Physiological cell death plays a major role in the growth and permanent maintenance of the human body [5]. In the process of forming the nervous system, neurons that do not form proper connections die. Physiological cell death also accompanies the removal of virus-infected cells by cytotoxic T cells, the elimination of autoreactive immune cells, the formation of the gut, the reconstitution of cartilage and bone, etc. When physiological cell death that normally should occur is inhibited, inappropriate

  20. Methylselenium and Prostate Cancer Apoptosis

    National Research Council Canada - National Science Library

    Lu, Junxuan

    2007-01-01

    The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of prostate cancer (PCa...

  1. Methylselenium and Prostate Cancer Apoptosis

    National Research Council Canada - National Science Library

    Lu, Junxuan

    2005-01-01

    The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of prostate cancer (PCa...

  2. Methylselenium and Prostate Cancer Apoptosis

    National Research Council Canada - National Science Library

    Lu, Junxuan

    2006-01-01

    The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of prostate cancer (PCa...

  3. Methylselenium and Prostate Cancer Apoptosis

    National Research Council Canada - National Science Library

    Lu, Junxuan

    2004-01-01

    The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of PCa cells by methyl selenium (Se)/selenol...

  4. Methylselenium and Prostate Cancer Apoptosis

    National Research Council Canada - National Science Library

    Lu, Junxuan

    2008-01-01

    The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of prostate cancer (PCa...

  5. Methylselenium and Prostate Cancer Apoptosis

    National Research Council Canada - National Science Library

    Lu, Junxuan

    2003-01-01

    The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of PCa cells by methyl selenium (Se...

  6. Intersectional perspective in elderly care

    Directory of Open Access Journals (Sweden)

    Marta Cuesta

    2016-05-01

    Full Text Available Earlier research has shown that power relationships at workplaces are constructed by power structures. Processes related to power always influence the working conditions for (in this study in elderly care the working groups involved. Power structures are central for intersectional analysis, in the sense that the intersectional perspective highlights aspects such as gender and ethnicity (subjective dimensions and interrelates them to processes of power (objective dimension. This qualitative study aims to explore in what way an intersectional perspective could contribute to increased knowledge of power structures in a nursing home where the employees were mostly immigrants from different countries. By using reflexive dialogues related to an intersectional perspective, new knowledge which contributes to the employees’ well-being could develop. Narrative analysis was the method used to conduct this study. Through a multi-stage focus group on six occasions over 6 months, the staff were engaged in intersectional and critical reflections about power relationship with the researchers, by identifying patterns in their professional activities that could be connected to their subjectivities (gender, ethnicity, etc.. The result of this study presents three themes that express the staff's experiences and connect these experiences to structural discrimination. 1 Intersectionality, knowledge, and experiences of professionalism; 2 Intersectionality, knowledge, and experiences of collaboration; and 3 Intersectionality, knowledge, and experiences of discrimination. The result demonstrates that an intersectional perspective reinforces the involved abilities, during the conversations, into being clear about, for example, their experiences of discrimination, and consequently developing a better understanding of their professionalism and collaboration. Such deeper reflections became possible through a process of consciousness raising, strengthening the employee

  7. Intersectional perspective in elderly care.

    Science.gov (United States)

    Cuesta, Marta; Rämgård, Margareta

    2016-01-01

    Earlier research has shown that power relationships at workplaces are constructed by power structures. Processes related to power always influence the working conditions for (in this study in elderly care) the working groups involved. Power structures are central for intersectional analysis, in the sense that the intersectional perspective highlights aspects such as gender and ethnicity (subjective dimensions) and interrelates them to processes of power (objective dimension). This qualitative study aims to explore in what way an intersectional perspective could contribute to increased knowledge of power structures in a nursing home where the employees were mostly immigrants from different countries. By using reflexive dialogues related to an intersectional perspective, new knowledge which contributes to the employees' well-being could develop. Narrative analysis was the method used to conduct this study. Through a multi-stage focus group on six occasions over 6 months, the staff were engaged in intersectional and critical reflections about power relationship with the researchers, by identifying patterns in their professional activities that could be connected to their subjectivities (gender, ethnicity, etc.). The result of this study presents three themes that express the staff's experiences and connect these experiences to structural discrimination. 1) Intersectionality, knowledge, and experiences of professionalism; 2) Intersectionality, knowledge, and experiences of collaboration; and 3) Intersectionality, knowledge, and experiences of discrimination. The result demonstrates that an intersectional perspective reinforces the involved abilities, during the conversations, into being clear about, for example, their experiences of discrimination, and consequently developing a better understanding of their professionalism and collaboration. Such deeper reflections became possible through a process of consciousness raising, strengthening the employee's self

  8. Taurine exerts hypoglycemic effect in alloxan-induced diabetic rats, improves insulin-mediated glucose transport signaling pathway in heart and ameliorates cardiac oxidative stress and apoptosis

    International Nuclear Information System (INIS)

    Das, Joydeep; Vasan, Vandana; Sil, Parames C.

    2012-01-01

    Hyperlipidemia, inflammation and altered antioxidant profiles are the usual complications in diabetes mellitus. In the present study, we investigated the therapeutic potential of taurine in diabetes associated cardiac complications using a rat model. Rats were made diabetic by alloxan (ALX) (single i.p. dose of 120 mg/kg body weight) and left untreated or treated with taurine (1% w/v, orally, in water) for three weeks either from the day of ALX exposure or after the onset of diabetes. Animals were euthanized after three weeks. ALX-induced diabetes decreased body weight, increased glucose level, decreased insulin content, enhanced the levels of cardiac damage markers and altered lipid profile in the plasma. Moreover, it increased oxidative stress (decreased antioxidant enzyme activities and GSH/GSSG ratio, increased xanthine oxidase enzyme activity, lipid peroxidation, protein carbonylation and ROS generation) and enhanced the proinflammatory cytokines levels, activity of myeloperoxidase and nuclear translocation of NFκB in the cardiac tissue of the experimental animals. Taurine treatment could, however, result to a decrease in the elevated blood glucose and proinflammatory cytokine levels, diabetes-evoked oxidative stress, lipid profiles and NFκB translocation. In addition, taurine increased GLUT 4 translocation to the cardiac membrane by enhanced phosphorylation of IR and IRS1 at tyrosine and Akt at serine residue in the heart. Results also suggest that taurine could protect cardiac tissue from ALX induced apoptosis via the regulation of Bcl2 family and caspase 9/3 proteins. Taken together, taurine supplementation in regular diet could play a beneficial role in regulating diabetes and its associated complications in the heart. Highlights: ► Taurine controls blood glucose via protection of pancreatic β cells in diabetic rat. ► Taurine controls blood glucose via increasing the insulin level in diabetic rat. ► Taurine improves cardiac AKT/GLUT4 signaling

  9. Aconitine-induced Ca{sup 2+} overload causes arrhythmia and triggers apoptosis through p38 MAPK signaling pathway in rats

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Gui-bo; Sun, Hong; Meng, Xiang-bao [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China); Hu, Jin; Zhang, Qiang; Liu, Bo [Academy of Chinese Medical Sciences of Jilin Province, Changchun, Jilin 130021 (China); Wang, Min [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China); Xu, Hui-bo, E-mail: xhb_6505@163.com [Academy of Chinese Medical Sciences of Jilin Province, Changchun, Jilin 130021 (China); Sun, Xiao-bo, E-mail: sun_xiaobo163@163.com [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China)

    2014-08-15

    Aconitine is a major bioactive diterpenoid alkaloid with high content derived from herbal aconitum plants. Emerging evidence indicates that voltage-dependent Na{sup +} channels have pivotal roles in the cardiotoxicity of aconitine. However, no reports are available on the role of Ca{sup 2+} in aconitine poisoning. In this study, we explored the importance of pathological Ca{sup 2+} signaling in aconitine poisoning in vitro and in vivo. We found that Ca{sup 2+} overload lead to accelerated beating rhythm in adult rat ventricular myocytes and caused arrhythmia in conscious freely moving rats. To investigate effects of aconitine on myocardial injury, we performed cytotoxicity assay in neonatal rat ventricular myocytes (NRVMs), as well as measured lactate dehydrogenase level in the culture medium of NRVMs and activities of serum cardiac enzymes in rats. The results showed that aconitine resulted in myocardial injury and reduced NRVMs viability dose-dependently. To confirm the pro-apoptotic effects, we performed flow cytometric detection, cardiac histology, transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The results showed that aconitine stimulated apoptosis time-dependently. The expression analysis of Ca{sup 2+} handling proteins demonstrated that aconitine promoted Ca{sup 2+} overload through the expression regulation of Ca{sup 2+} handling proteins. The expression analysis of apoptosis-related proteins revealed that pro-apoptotic protein expression was upregulated, and anti-apoptotic protein BCL-2 expression was downregulated. Furthermore, increased phosphorylation of MAPK family members, especially the P-P38/P38 ratio was found in cardiac tissues. Hence, our results suggest that aconitine significantly aggravates Ca{sup 2+} overload and causes arrhythmia and finally promotes apoptotic development via phosphorylation of P38 mitogen-activated protein kinase. - Highlights: • Aconitine-induced Ca

  10. Tannoid principles of Emblica officinalis attenuated aluminum chloride induced apoptosis by suppressing oxidative stress and tau pathology via Akt/GSK-3βsignaling pathway.

    Science.gov (United States)

    Justin Thenmozhi, Arokiasamy; Dhivyabharathi, Mathiyazahan; Manivasagam, Thamilarasan; Essa, Musthafa Mohamed

    2016-12-24

    Fruits of Phyllanthus emblica Linn. or Emblica officinalis Gaertn. (Phyllanthaceae) are used in Ayurveda, Siddha, Unani, Arabic, Tibetan and various other folk medicinal systems to promote intelligence and memory. Recent study from our lab indicated the neuroprotective effect of tannoids principles of Emblica officinalis (EoT) against memory loss caused by aluminum chloride (AlCl 3 ) intoxication through attenuating acetylcholine esterase activity and the expression of amyloid β protein biosynthesis related markers. However the molecular mechanism of EoT has not yet been fully elucidated. The aim of the present study was to further investigate the neuroprotective mechanisms of EoT against AlCl 3 -induced cognitive deficits, tau hyperphosphorylation, oxidative stress and apoptosis. Rats were treated with AlCl 3 for 60 days to induce biochemical and physiological abnormalities similar to AD patients. AD rats were treated with EoT (100mg/kg., bw. oral) for 60 days. For the examination of neuroprotective effect of EoT, behavior analysis, biochemical estimations and western blot were performed in the hippocampus and cortex of control, EoT treated and untreated AD rats. Intraperitoneal injections of AlCl 3 (100mg/kg., b.w.) for 60 days enhanced the learning and memory deficits, levels of TBARS and diminished the levels of reduced glutathione and activities of enzymatic antioxidants as compared to control group. Moreover toxicity of AlCl 3 is accompanied by the enhanced expressions of Bax, caspases-3,-9, cytosolic cytochrome c (cyto c), and pTau along with diminished expressions of Bcl-2, mitochondrial cyto c, pGSK-3β and pAkt. Coadministration of EoT nullified the cognitive deficits, biochemical abnormalities and apoptosis induced by AlCl 3 treatment. Moreover EoT prevents tau hyperphosphorylation by targeting the GSK-3β/Akt signaling pathway. This study confirms that EoT would be used as a potential drug candidate for AD and other tau pathology-related neuronal

  11. Taurine exerts hypoglycemic effect in alloxan-induced diabetic rats, improves insulin-mediated glucose transport signaling pathway in heart and ameliorates cardiac oxidative stress and apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Das, Joydeep; Vasan, Vandana; Sil, Parames C., E-mail: parames@bosemain.boseinst.ac.in

    2012-01-15

    Hyperlipidemia, inflammation and altered antioxidant profiles are the usual complications in diabetes mellitus. In the present study, we investigated the therapeutic potential of taurine in diabetes associated cardiac complications using a rat model. Rats were made diabetic by alloxan (ALX) (single i.p. dose of 120 mg/kg body weight) and left untreated or treated with taurine (1% w/v, orally, in water) for three weeks either from the day of ALX exposure or after the onset of diabetes. Animals were euthanized after three weeks. ALX-induced diabetes decreased body weight, increased glucose level, decreased insulin content, enhanced the levels of cardiac damage markers and altered lipid profile in the plasma. Moreover, it increased oxidative stress (decreased antioxidant enzyme activities and GSH/GSSG ratio, increased xanthine oxidase enzyme activity, lipid peroxidation, protein carbonylation and ROS generation) and enhanced the proinflammatory cytokines levels, activity of myeloperoxidase and nuclear translocation of NFκB in the cardiac tissue of the experimental animals. Taurine treatment could, however, result to a decrease in the elevated blood glucose and proinflammatory cytokine levels, diabetes-evoked oxidative stress, lipid profiles and NFκB translocation. In addition, taurine increased GLUT 4 translocation to the cardiac membrane by enhanced phosphorylation of IR and IRS1 at tyrosine and Akt at serine residue in the heart. Results also suggest that taurine could protect cardiac tissue from ALX induced apoptosis via the regulation of Bcl2 family and caspase 9/3 proteins. Taken together, taurine supplementation in regular diet could play a beneficial role in regulating diabetes and its associated complications in the heart. Highlights: ► Taurine controls blood glucose via protection of pancreatic β cells in diabetic rat. ► Taurine controls blood glucose via increasing the insulin level in diabetic rat. ► Taurine improves cardiac AKT/GLUT4 signaling

  12. Promotion versus suppression of rat colon carcinogenesis by chlorophyllin and chlorophyll: modulation of apoptosis, cell proliferation, and {beta}-catenin/Tcf signaling

    Energy Technology Data Exchange (ETDEWEB)

    Blum, Carmen A.; Xu Meirong; Orner, Gayle A.; Dario Diaz, G.; Li Qingjie; Dashwood, Wan Mohaiza; Bailey, George S.; Dashwood, Roderick H

    2003-03-01

    ), whereas chlorophyllin had no effect and copper promoted the number of small ACF induced by IQ. The results suggest that further investigation of the dose-response for suppression versus promotion by chlorophyll and chlorophyllin is warranted, including studies of the {beta}-catenin/Tcf signaling pathway and its influence on cell proliferation and apoptosis in the colonic crypt.

  13. Interference of Apoptosis by Hepatitis B Virus.

    Science.gov (United States)

    Lin, Shaoli; Zhang, Yan-Jin

    2017-08-18

    Hepatitis B virus (HBV) causes liver diseases that have been a consistent problem for human health, leading to more than one million deaths every year worldwide. A large proportion of hepatocellular carcinoma (HCC) cases across the world are closely associated with chronic HBV infection. Apoptosis is a programmed cell death and is frequently altered in cancer development. HBV infection interferes with the apoptosis signaling to promote HCC progression and viral proliferation. The HBV-mediated alteration of apoptosis is achieved via interference with cellular signaling pathways and regulation of epigenetics. HBV X protein (HBX) plays a major role in the interference of apoptosis. There are conflicting reports on the HBV interference of apoptosis with the majority showing inhibition of and the rest reporting induction of apoptosis. In this review, we described recent studies on the mechanisms of the HBV interference with the apoptosis signaling during the virus infection and provided perspective.

  14. Interference of Apoptosis by Hepatitis B Virus

    Science.gov (United States)

    2017-01-01

    Hepatitis B virus (HBV) causes liver diseases that have been a consistent problem for human health, leading to more than one million deaths every year worldwide. A large proportion of hepatocellular carcinoma (HCC) cases across the world are closely associated with chronic HBV infection. Apoptosis is a programmed cell death and is frequently altered in cancer development. HBV infection interferes with the apoptosis signaling to promote HCC progression and viral proliferation. The HBV-mediated alteration of apoptosis is achieved via interference with cellular signaling pathways and regulation of epigenetics. HBV X protein (HBX) plays a major role in the interference of apoptosis. There are conflicting reports on the HBV interference of apoptosis with the majority showing inhibition of and the rest reporting induction of apoptosis. In this review, we described recent studies on the mechanisms of the HBV interference with the apoptosis signaling during the virus infection and provided perspective. PMID:28820498

  15. Intersectional perspectives on intimate technology

    DEFF Research Database (Denmark)

    Søndergaard, Marie Louise Juul; Hansen, Lone Koefoed

    In this text, we discuss if and how an intersectional perspective on design may be critically practiced from a privileged position. More precisely, we ask how intersectional perspectives on race, gender and class may be useful in reflecting on and critically intervening in a privileged, Northern ...... European culture. Our discussion is motivated by considerations into what impact culture and context have on the practice, representation, and reception of critique....

  16. Fluid shear stress suppresses TNF-α-induced apoptosis in MC3T3-E1 cells: Involvement of ERK5-AKT-FoxO3a-Bim/FasL signaling pathways

    International Nuclear Information System (INIS)

    Bin, Geng; Bo, Zhang; Jing, Wang; Jin, Jiang; Xiaoyi, Tan; Cong, Chen; Liping, An; Jinglin, Ma; Cuifang, Wang; Yonggang, Chen; Yayi, Xia

    2016-01-01

    TNF-α is known to induce osteoblasts apoptosis, whereas mechanical stimulation has been shown to enhance osteoblast survival. In the present study, we found that mechanical stimulation in the form of fluid shear stress (FSS) suppresses TNF-α induced apoptosis in MC3T3-E1 cells. Extracellular signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase (MAPK) family that has been implicated in cell survival. We also demonstrated that FSS imposed by flow chamber in vitro leads to a markedly activation of ERK5, which was shown to be protective against TNF-α-induced apoptosis, whereas the transfection of siRNA against ERK5 (ERK5-siRNA) reversed the FSS-medicated anti-apoptotic effects. An initial FSS-mediated activation of ERK5 that phosphorylates AKT to increase its activity, and a following forkhead box O 3a (FoxO3a) was phosphorylated by activated AKT. Phosphorylated FoxO3a is sequestered in the cytoplasm, and prevents it from translocating to nucleus where it can increase the expression of FasL and Bim. The inhibition of AKT-FoxO3a signalings by a PI3K (PI3-kinase)/AKT inhibitor (LY294002) or the transfection of ERK5-siRNA led to the nuclear translocation of non-phosphorylated FoxO3a, and increased the protein expression of FasL and Bim. In addition, the activation of caspase-3 by TNF-α was significantly inhibited by aforementioned FSS-medicated mechanisms. In brief, the activation of ERK5-AKT-FoxO3a signaling pathways by FSS resulted in a decreased expression of FasL and Bim and an inhibition of caspase-3 activation, which exerts a protective effect that prevents osteoblasts from apoptosis. - Highlights: • Fluid shear stress inhibits osteoblast apoptosis induced by TNF-α. • Inhibition of ERK5 activity by transfection of ERK5 siRNA blocks FSS-mediated anti-apoptotic effect in osteoblast. • Activated ERK5-AKT-FoxO3a-Bim/FasL signaling pathways by FSS is required to protect osteoblast from apoptosis.

  17. Fluid shear stress suppresses TNF-α-induced apoptosis in MC3T3-E1 cells: Involvement of ERK5-AKT-FoxO3a-Bim/FasL signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Bin, Geng; Bo, Zhang; Jing, Wang; Jin, Jiang; Xiaoyi, Tan; Cong, Chen; Liping, An; Jinglin, Ma; Cuifang, Wang; Yonggang, Chen [The Second Hospital of Lanzhou University, #82 Cuiyingmen, Lanzhou, 730000 Gansu (China); Orthopaedics Key Laboratory of Gansu Province, Lanzhou, 730000 Gansu (China); Yayi, Xia, E-mail: xiayayildey@163.com [The Second Hospital of Lanzhou University, #82 Cuiyingmen, Lanzhou, 730000 Gansu (China); Orthopaedics Key Laboratory of Gansu Province, Lanzhou, 730000 Gansu (China)

    2016-05-01

    TNF-α is known to induce osteoblasts apoptosis, whereas mechanical stimulation has been shown to enhance osteoblast survival. In the present study, we found that mechanical stimulation in the form of fluid shear stress (FSS) suppresses TNF-α induced apoptosis in MC3T3-E1 cells. Extracellular signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase (MAPK) family that has been implicated in cell survival. We also demonstrated that FSS imposed by flow chamber in vitro leads to a markedly activation of ERK5, which was shown to be protective against TNF-α-induced apoptosis, whereas the transfection of siRNA against ERK5 (ERK5-siRNA) reversed the FSS-medicated anti-apoptotic effects. An initial FSS-mediated activation of ERK5 that phosphorylates AKT to increase its activity, and a following forkhead box O 3a (FoxO3a) was phosphorylated by activated AKT. Phosphorylated FoxO3a is sequestered in the cytoplasm, and prevents it from translocating to nucleus where it can increase the expression of FasL and Bim. The inhibition of AKT-FoxO3a signalings by a PI3K (PI3-kinase)/AKT inhibitor (LY294002) or the transfection of ERK5-siRNA led to the nuclear translocation of non-phosphorylated FoxO3a, and increased the protein expression of FasL and Bim. In addition, the activation of caspase-3 by TNF-α was significantly inhibited by aforementioned FSS-medicated mechanisms. In brief, the activation of ERK5-AKT-FoxO3a signaling pathways by FSS resulted in a decreased expression of FasL and Bim and an inhibition of caspase-3 activation, which exerts a protective effect that prevents osteoblasts from apoptosis. - Highlights: • Fluid shear stress inhibits osteoblast apoptosis induced by TNF-α. • Inhibition of ERK5 activity by transfection of ERK5 siRNA blocks FSS-mediated anti-apoptotic effect in osteoblast. • Activated ERK5-AKT-FoxO3a-Bim/FasL signaling pathways by FSS is required to protect osteoblast from apoptosis.

  18. A novel oncolytic adenovirus targeting Wnt signaling effectively inhibits cancer-stem like cell growth via metastasis, apoptosis and autophagy in HCC models.

    Science.gov (United States)

    Zhang, Jian; Lai, Weijie; Li, Qiang; Yu, Yang; Jin, Jin; Guo, Wan; Zhou, Xiumei; Liu, Xinyuan; Wang, Yigang

    2017-09-16

    Cancer stem cells (CSCs), which are highly differentiated and self-renewing, play an important role in the occurrence, therapeutic resistant and metastasis of hepatacellular carcinoma (HCC). Oncolytic adenoviruses have targeted killing effect on tumor cells, and are invoked as candidate drugs for cancer treatment. We designed a dual-regulated oncolytic adenovirus Ad.wnt-E1A(△24bp)-TSLC1 that targets Wnt and Rb signaling pathways respectively, and carries the tumor suppressor gene, TSLC1. Previous studies have demonstrated that oncolytic adenovirus mediated TSLC1can target liver cancer and exhibit significant cytotoxicity. However, whether Ad.wnt-E1A(△24bp)-TSLC1 can effectively eliminate liver CSCs remains to be explored. We first used the spheroid culture to enrich the liver CSCs-like cells, and detected the self-renewal capacity, differentiation, drug resistance and tumorigenicity. The results showed that Ad-wnt-E1A(△24bp)-TSLC1 could effectively lead to autophagic death. In addition, recombinant adenovirus effectively induced the apoptosis, inhibit metastasis of hepatic CSCs-like cells in vivo. Further animal experiments indicated that Ad-wnt-E1A(△24bp)-TSLC1could effectively inhibit the growth of transplanted tumor of hepatic CSCs and prolong the survival time of mice. Therefore, the novel oncolytic adenovirus Ad.wnt-E1A(△24bp)-TSLC1 has potential application as a therapeutic target for HCC stem cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Modeling the dynamics of driver's dilemma zone perception using machine learning methods for safer intersection control.

    Science.gov (United States)

    2014-04-01

    The "dilemma zone" (DZ) is defined as the area where drivers approaching a signalized intersection must decide to either proceed or stop at the onset of the yellow indication. Drivers that might perceive themselves to be too close to an intersection ...

  20. ISR intersection I-2

    CERN Multimedia

    CERN PhotoLab

    1972-01-01

    Towards the left one sees, on top of ISR beam 1, the front section of the 30-metre-long, small-angle spectrometer from the CERN-Holland-Lancaster-Manchester single-particle production experiment. It consists of two special septum magnets carrying up to 20 kA each. These magnets are necessary to force charged particles produced at small angles away from the ISR beam. They are followed by two threshold Cerenkov counters and (not visible) three more bending magnets and a 6-metre-long Cerenkov counter. Particle identification follows from the Cerenkov signals after determination of the particle trajectory through the spectrometer with magnetostrictive spark chambers. The positions of the first magnets and Cerenkov counters can be changed by remote control. In front one sees the electronics which determines the traversal of a charged particle from scintillator counter signals and gives the "fire" signal for the spark chambers.

  1. Sustainable intersection control to accommodate urban freight mobility.

    Science.gov (United States)

    2009-08-01

    In this research, we studied green extension of a two-phased vehicleactuated signal at an isolated : intersection between two one-way streets. The green phase is extended by a preset time interval, referred to : as critical gap, from the time of a...

  2. Inhibition of B-Raf/MEK/ERK signaling suppresses DR5 expression and impairs response of cancer cells to DR5-mediated apoptosis and T cell-induced killing.

    Science.gov (United States)

    Oh, Y-T; Deng, J; Yue, P; Owonikoko, T K; Khuri, F R; Sun, S-Y

    2016-01-28

    Inhibition of B-Raf/MEK/ERK signaling is an effective therapeutic strategy against certain types of cancers such as melanoma and thyroid cancer. While demonstrated to be effective anticancer agents, B-Raf or MEK inhibitors have also been associated with early tumor progression and development of secondary neoplasms. The ligation of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) with its receptor, death receptor 5 (DR5), leading to induction of apoptosis, offers a promising anticancer strategy. Importantly, this is also a natural immunosurveillance mechanism against cancer development. We previously demonstrated that activated B-Raf/MEK/ERK signaling positively regulates DR5 expression. Hence, our current work sought to address whether B-Raf/MEK/ERK inhibition and the consequent suppression of DR5 expression impede cancer cell response to DR5 activation-induced apoptosis and activated immune cell-induced killing. We found that both B-Raf (for example, PLX4032) and MEK inhibitors (for example, AZD6244 and PD0325901) effectively inhibited ERK1/2 phosphorylation and reduced DR5 levels in both human thyroid cancer and melanoma cells. Similar to the observed effect of genetic knockdown of the B-Raf gene, pre-treatment of cancer cell lines with either B-Raf or MEK inhibitors attenuated or abolished cellular apoptotic response induced by TRAIL or the DR5 agonistic antibody AMG655 or cell killing by activated T cells. Our findings clearly show that inhibition of B-Raf/MEK/ERK signaling suppresses DR5 expression and impairs DR5 activation-induced apoptosis and T cell-mediated killing of cancer cells. These findings suggest a potential negative impact of B-Raf or MEK inhibition on TRAIL- or DR5-mediated anticancer therapy and on TRAIL/DR5-mediated immune-clearance of cancer cells.

  3. The JNK- and AKT/GSK3β- Signaling Pathways Converge to Regulate Puma Induction and Neuronal Apoptosis Induced by Trophic Factor Deprivation

    Science.gov (United States)

    Karajgikar, Meera; Hamilton, Alison; Ferguson, Stephen S.; Cregan, Sean P.

    2012-01-01

    The AKT, GSK3 and JNK family kinases have been implicated in neuronal apoptosis associated with neuronal development and several neurodegenerative conditions. However, the mechanisms by which these kinase pathways regulate apoptosis remain unclear. In this study we have investigated the role of these kinases in neuronal cell death using an established model of trophic factor deprivation induced apoptosis in cerebellar granule neurons. BCL-2 family proteins are known to be central regulators of apoptosis and we have determined that the pro-apoptotic family member Puma is transcriptionally up-regulated in trophic factor deprived neurons and that Puma induction is required for apoptosis in vitro and in vivo. Importantly, we demonstrate that Puma induction is dependent on both JNK activation and AKT inactivation. AKT is known to regulate a number of downstream pathways, however we have determined that PI3K-AKT inactivation induces Puma expression through a GSK3β-dependent mechanism. Finally we demonstrate that the JNK and AKT/GSK3β pathways converge to regulate FoxO3a-mediated transcriptional activation of Puma. In summary we have identified a novel and critical link between the AKT, GSK3β and JNK kinases and the regulation of Puma induction and suggest that this may be pivotal to the regulation of neuronal apoptosis in neurodegenerative conditions. PMID:23056511

  4. Morin impedes Yap nuclear translocation and fosters apoptosis through suppression of Wnt/β-catenin and NF-κB signaling in Mst1 overexpressed HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Perumal, NaveenKumar [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu (India); Perumal, MadanKumar [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu (India); Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas 75390 (United States); Kannan, Anbarasu [Department of Cellular and Molecular Biology, The University of Texas Health Science Center, Tyler, Texas (United States); Subramani, Kumar [Centre for Biotechnology, Anna University, Chennai 600025, Tamil Nadu (India); Halagowder, Devaraj [Department of Zoology, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu (India); Sivasithamparam, NiranjaliDevaraj, E-mail: profniranjali@gmail.com [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu (India)

    2017-06-15

    Recent clinical and experimental evidences strongly acclaim Yes-associated protein (Yap), a key oncogenic driver in liver carcinogenesis, as a therapeutic target. Of the known multiple schemes to inhibit Yap activity, activation of Mammalian Sterile 20-like Kinase 1 (Mst1), an upstream regulator of Yap, appears to be a promising one. In this study, we hypothesize that morin, a bioflavonoid, mediates its anti-cancer effect through the activation of Mst1/hippo signaling in liver cancer cells. To test this hypothesis, both full length Mst1 (F-Mst1) and kinase active N-terminal Mst1 (N-Mst1)-overexpressed HepG2 cells were used. Exposure of F-Mst1 overexpressed HepG2 cells to morin activated Mst1 by caspase-3 cleavage and thereby inhibited Yap nuclear translocation and fostered apoptosis. Morin suppressed NF-κB p65 and Wnt/β-catenin signaling through Mst1 activation via cleavage and phosphorylation, leading to cell death. Annexin-V/PI staining further confirmed the induction of apoptosis in morin treated F-Mst1 overexpressed cells. The present study shows that morin targets cell survival molecules such as NF-κB p65 and β-catenin through activation of hippo signaling. Therefore, morin could be considered as a potential anti-cancer agent against liver cancer. - Highlights: • Morin induced cytotoxicity in cultured HepG2 cells. • Morin activated hippo pathway via Mst1 activation in transfected HepG2 cells. • Morin suppressed Wnt/β-catenin signaling and induced G0/G1 cell cycle arrest. • Morin inhibited NF-κB signaling through Mst1 activation in transfected HepG2 cells. • Morin potentiates apoptosis through Mst1-JNK-caspase mediated mechanism in HepG2 cells.

  5. Wogonoside inhibits cell growth and induces mitochondrial-mediated autophagy-related apoptosis in human colon cancer cells through the PI3K/AKT/mTOR/p70S6K signaling pathway.

    Science.gov (United States)

    Han, Chengzheng; Xing, Guozheng; Zhang, Mengying; Zhong, Min; Han, Zhen; He, Chiyi; Liu, Xiaoping

    2018-04-01

    Wogonoside, the main effective constituent of traditional Chinese medicine Scutellaria , belongs to the glucuronide family, with various functions, including detoxification, anti-inflammation and nourishing gallbladder, lowering blood pressure, diuresis and anti-allergic reactions. However, the effects of wogonoside on human colon cancer cells remain unclear. The present study aimed to investigate the anticancer effect of wogonoside on human colon cancer cells in vitro and its anticancer mechanisms. The results demonstrated that wogonoside significantly inhibited cell growth, induced apoptosis and mitochondrial-mediated autophagy of colon cancer cells. Furthermore, the results revealed that wogonoside significantly increased caspase-3 and caspase-9 expression levels, induced apoptosis regulator Bax/Bcl-2 and microtubule-associated protein 1A/1B-light chain 3 protein expression, suppressed the phosphatidylinositol 3 kinase (PI3K)/RAC-α serine/threonine-protein kinase (Akt)/mechanistic target of rapamycin (mTOR)/p70 S6 kinase (p70S6K) signaling pathway and induced p62 protein expression in colon cancer cells. In conclusion, these results demonstrated that wogonoside inhibits cell growth and induces mitochondrial mediated autophagy-related apoptosis in human colon cancer cells through modulation of the PI3K/Akt/mTOR/p70S6K signaling pathway.

  6. Apoptosis-induced effects of extract from Artemisia annua Linné by modulating PTEN/p53/PDK1/Akt/ signal pathways through PTEN/p53-independent manner in HCT116 colon cancer cells.

    Science.gov (United States)

    Kim, Eun Ji; Kim, Guen Tae; Kim, Bo Min; Lim, Eun Gyeong; Kim, Sang-Yong; Kim, Young Min

    2017-04-28

    The extracts from Artemisia annua Linné (AAE) has been known to possess various functions including anti-bacterial, anti-virus and anti-oxidant effects. However, the mechanism of those effects of AAE is not well known. Pursuantly, we determined the apoptotic effects of extract of AAE in HCT116 cell. In this study, we suggested that AAE may exert cancer cell apoptosis through PTEN/PDK1/Akt/p53signal pathway and mitochondria-mediated apoptotic proteins. We measured 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, lactate dehydrogenase (LDH) assay, Hoechst 33342 staining, Annexin V-PI staining, Mitopotential assay, immunofluorescence (IF) and Western blotting. Accordingly, our study showed that AAE treatment to HCT116 cells resulted in inhibition of PDK1, Akt, MDM2, Bcl-2, and pro-caspase 3 as well as activation of PTEN, p53-upregulated modulator of apoptosis (PUMA), Bax and Bak expression. Also we measured in vivo assay that xenograft model, H&E assay, TUNEL assay and IHC. AAE induced apoptosis via PTEN/p53/PDK1/Akt signal pathways through PTEN/p53-independent manner. AAE inhibit cell viability and increase LDH release in HCT116 colon cancer cell. Also, AAE increase apoptotic bodies, caspase -3,7 activation and reduces mitochondria membrane potential. AAE regulates cytochrome c translocation to the cytoplasm and Bax translocation to the mitochondrial membrane in an Immunofluorescence staining and increase PTEN and p53 expression in an in vivo tumor xenograft model. To elucidate the role of the PTEN/p53/PDK1/Akt signal pathways in cancer control, we conditionally inactivated PTEN/p53/PDK1/Akt signal pathways. We used inhibitors of PTEN, p53, PDK1, Akt. In consequence, these results indicate that AAE induced apoptosis by means of a mitochondrial event through the regulation of proteins such as Bax, Bak and cytochrome c in PDK1/Akt signaling pathways via PTEM/p53-independent manner. We confirmed the apoptotic effect of extracts of AAE by

  7. Sulforaphane induces apoptosis in T24 human urinary bladder cancer cells through a reactive oxygen species-mediated mitochondrial pathway: the involvement of endoplasmic reticulum stress and the Nrf2 signaling pathway.

    Science.gov (United States)

    Jo, Guk Heui; Kim, Gi-Young; Kim, Wun-Jae; Park, Kun Young; Choi, Yung Hyun

    2014-10-01

    Sulforaphane, a naturally occurring isothiocyanate found in cruciferous vegetables, has received a great deal of attention because of its ability to inhibit cell proliferation and induce apoptosis in cancer cells. In this study, we investigated the anticancer activity of sulforaphane in the T24 human bladder cancer line, and explored its molecular mechanism of action. Our results showed that treatment with sulforaphane inhibited cell viability and induced apoptosis in T24 cells in a concentration-dependent manner. Sulforaphane-induced apoptosis was associated with mitochondria dysfunction, cytochrome c release and Bcl-2/Bax dysregulation. Furthermore, the increased activity of caspase-9 and -3, but not caspase-8, was accompanied by the cleavage of poly ADP-ribose polymerase, indicating the involvement of the mitochondria-mediated intrinsic apoptotic pathway. Concomitant with these changes, sulforaphane triggered reactive oxygen species (ROS) generation, which, along with the blockage of sulforaphane-induced loss of mitochondrial membrane potential and apoptosis, was strongly attenuated by the ROS scavenger N-acetyl-L-cysteine. Furthermore, sulforaphane was observed to activate endoplasmic reticulum (ER) stress and the nuclear factor-E2-related factor-2 (Nrf2) signaling pathway, as demonstrated by the upregulation of ER stress‑related proteins, including glucose-regulated protein 78 and C/EBP-homologous protein, and the accumulation of phosphorylated Nrf2 proteins in the nucleus and induction of heme oxygenase-1 expression, respectively. Taken together, these results demonstrate that sulforaphane has antitumor effects against bladder cancer cells through an ROS-mediated intrinsic apoptotic pathway, and suggest that ER stress and Nrf2 may represent strategic targets for sulforaphane-induced apoptosis.

  8. Phloretin induces apoptosis in H-Ras MCF10A human breast tumor cells through the activation of p53 via JNK and p38 mitogen-activated protein kinase signaling.

    Science.gov (United States)

    Kim, Mi-Sung; Kwon, Jung Yeon; Kang, Nam Joo; Lee, Ki Won; Lee, Hyong Joo

    2009-08-01

    Mutations in Ras play a critical role in the development of human cancers, including breast cancer. We investigated the possible antiproliferative effects of the naturally occurring dihydrochalcone phloretin [2',4',6'-trihydroxy-3-(4-hydroxyphenyl)-propiophenone] on H-Ras-transformed MCF10A human breast epithelial (H-Ras MCF10A) cells. Phloretin suppressed H-Ras MCF10A cell proliferation in a dose-dependent manner and induced nuclear condensation in the cells, indicating that phloretin-induced cell death occurs mainly via the induction of apoptosis. Prominent upregulation of p53 and Bax and cleavage of poly (ADP)-ribose polymerase were also detected in the phloretin-treated cells. Finally, phloretin markedly increased caspase-3 activity as well as JNK and p38 mitogen-activated protein kinase signaling. Our findings suggest that the phloretin-induced apoptosis of breast tumor cells contributes to the chemopreventive potential of phloretin against breast cancer.

  9. The methanol-ethyl acetate partitioned fraction from Chinese olive fruits inhibits cancer cell proliferation and tumor growth by promoting apoptosis through the suppression of the NF-κB signaling pathway.

    Science.gov (United States)

    Hsieh, Shu-Chen; Hsieh, Wang-Ju; Chiang, An-Na; Su, Nan-Wei; Yeh, Yu-Te; Liao, Yi-Chun

    2016-12-07

    Chinese olives (Canarium album L.) have historically been used for medicinal purposes rather than commercially for oil. In this report, we reveal that the methanol-ethyl acetate partitioned fraction from Chinese olive fruits (MEO), of which ellagic acid accounted for 12%, exhibited profound anti-proliferative activities in the human colon cancer cell line, HCT116. Additionally, oral administration of MEO remarkably inhibited the tumor growth of subcutaneously implanted CT26 cells, a mouse colon carcinoma cell line, in BALB/c mice. Treatment with MEO induced a significant increase in the percentage of apoptotic cells and resulted in poly(ADP-ribose) polymerase (PARP) cleavage, suggesting that MEO inhibits cancer cell proliferation by promoting apoptosis. Our study also showed that MEO exerted the most potent effect on the inhibition of NF-κB-mediated signaling among the partitioned fractions from Chinese olives. This process employed the use of reporter-based bio-platforms that are capable of detecting the activation of NF-κB. In addition, phosphorylation of NF-κB signaling-associated proteins, IKKα/β, IκBα, and p65, was reduced in MEO-incubated cancer cells, indicating that MEO suppresses NF-κB activation. Moreover, MEO treatment significantly suppressed lipopolysaccharide (LPS)-induced cancer cell proliferation, demonstrating that MEO promotes cancer cell apoptosis through the inhibition of the NF-κB signaling pathway. In summary, our findings demonstrate that the methanol-ethyl acetate partitioned fraction from Chinese olive fruits inhibits cancer cell proliferation and tumor growth by promoting apoptosis through the suppression of NF-κB signaling. Therefore, the Chinese olive fruit has promising potential in cancer treatment.