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Sample records for cells improves cellular

  1. Mesenchymal progenitor cells differentiate into an endothelial phenotype, enhance vascular density and improve heart function in a rat cellular cardiomyoplasty model

    Institute of Scientific and Technical Information of China (English)

    SDAVANI; NMERSIN; BROYER; BKANTELIP; JPKANTELIP

    2004-01-01

    AIM: Cellular cardiomyoplasty is promising for improving postinfarcted cardiac function. Over the past decade, a variety of cell types have been proposed including mononuclear bone marrow cells. The latter contains different lineages including mesenchymal stem cells (MSCs). The aim of this study was to analyse the differentiation pathways of engrafted syngenic mesenchymal progenitor cells (MPCs) obtained in culture from bone marrow

  2. Cell Surface Enzymatic Engineering-Based Approaches to Improve Cellular Therapies

    KAUST Repository

    Abuelela, Ayman F.

    2014-06-06

    The cell surface represents the interface between the cell and its environment. As such, the cell surface controls cell–cell interactions and functions such as adhesion and migration, and will transfer external cues to regulate processes such as survival, death, and differentiation. Redefining the cell surface by temporarily (or permanently) modifying the molecular landscape of the plasma membrane affects the way in which the cell interacts with its environment and influences the information that is relayed into the cell along downstream signaling pathways. This chapter outlines the role of key enzymes, the glycosyltransferases, in posttranslationally modifying proteins and lipids to fine-tune cells, ability to migrate. These enzymes are critical in controlling the formation of a platform structure, sialyl Lewis x (sLex), on circulating cells that plays a central role in the recognition and recruitment by selectin counter receptors on endothelial cells that line blood vessels of tissues throughout the body. By developing methods to manipulate the activity of these enzymes and hence the cell surface structures that result, treatments can be envisioned that direct the migration of therapeutic cells to specific locations throughout the body and also to inhibit metastasis of detrimental cells such as circulating tumor cells.

  3. Cerebral transplantation of encapsulated mesenchymal stem cells improves cellular pathology after experimental traumatic brain injury

    DEFF Research Database (Denmark)

    Heile, Anna M B; Wallrapp, Christine; Klinge, Petra M;

    2009-01-01

    PURPOSE: "Naked" human mesenchymal stem cells (MSC) are neuro-protective in experimental brain injury (TBI). In a controlled cortical impact (CCI) rat model, we investigated whether encapsulated MSC (eMSC) act similarly, and whether efficacy is augmented using cells transfected to produce the neu...

  4. Cellular Cell Bifurcation of Cylindrical Detonations

    Institute of Scientific and Technical Information of China (English)

    HAN Gui-Lai; JIANG Zong-Lin; WANG Chun; ZHANG Fan

    2008-01-01

    Cellular cell pattern evolution of cylindrically-diverging detonations is numerically simulated successfully by solving two-dimensional Euler equations implemented with an improved two-step chemical kinetic model. From the simulation, three cell bifurcation modes are observed during the evolution and referred to as concave front focusing, kinked and wrinkled wave front instability, and self-merging of cellular cells. Numerical research demonstrates that the wave front expansion resulted from detonation front diverging plays a major role in the cellular cell bifurcation, which can disturb the nonlinearly self-sustained mechanism of detonations and finally lead to cell bifurcations.

  5. Improving cellular function and immune protection via layer-by-layer nanocoating of pancreatic islet β-cell spheroids cocultured with mesenchymal stem cells.

    Science.gov (United States)

    Bhaiji, Tasneem; Zhi, Zheng-Liang; Pickup, John C

    2012-06-01

    Islet transplantation as a therapy for type 1 diabetes is currently limited by lack of primary transplant material from human donors and post-transplantation loss of islets caused by adverse immune and nonimmune reactions. This study aimed to develop a novel strategy to create microenvironment for islets via integration of nanoencapsulation with cell cocultures, thereby enhancing their survival and function. The nanoencapsulation was achieved via layer-by-layer deposition of phosphorycholine-modified poly-L-lysine/heparin leading to the formation of nanometer-thick multilayer coating on islets. Spheroids formed by coculturing MIN6 β-cells with mesenchymal stem cells in suspension were used as the tool for testing encapsulation. Coculturing MSCs with MIN6 cells allowed the cell constructs to enhance structural and morphologic stability with improved insulin secretory function and render them less susceptible to inflammatory cytokine-induced apoptosis. Combining nanoencapsulation with coculture of MSCs/MIN6 resulted in higher glucose responsiveness, and lower antibody binding and apoptosis-inducing effects of cytokines. This strategy of nanoencapsulating islet cocultures appears promising to improve cellular delivery of insulin for treating type 1 diabetes. PMID:22447690

  6. Cellular renewal and improvement of local cell effector activity in peritoneal cavity in response to infectious stimuli.

    Directory of Open Access Journals (Sweden)

    Alexandra dos Anjos Cassado

    Full Text Available The peritoneal cavity (PerC is a singular compartment where many cell populations reside and interact. Despite the widely adopted experimental approach of intraperitoneal (i.p. inoculation, little is known about the behavior of the different cell populations within the PerC. To evaluate the dynamics of peritoneal macrophage (MØ subsets, namely small peritoneal MØ (SPM and large peritoneal MØ (LPM, in response to infectious stimuli, C57BL/6 mice were injected i.p. with zymosan or Trypanosoma cruzi. These conditions resulted in the marked modification of the PerC myelo-monocytic compartment characterized by the disappearance of LPM and the accumulation of SPM and monocytes. In parallel, adherent cells isolated from stimulated PerC displayed reduced staining for β-galactosidase, a biomarker for senescence. Further, the adherent cells showed increased nitric oxide (NO and higher frequency of IL-12-producing cells in response to subsequent LPS and IFN-γ stimulation. Among myelo-monocytic cells, SPM rather than LPM or monocytes, appear to be the central effectors of the activated PerC; they display higher phagocytic activity and are the main source of IL-12. Thus, our data provide a first demonstration of the consequences of the dynamics between peritoneal MØ subpopulations by showing that substitution of LPM by a robust SPM and monocytes in response to infectious stimuli greatly improves PerC effector activity.

  7. Improved cellular uptake of antisense Peptide nucleic acids by conjugation to a cell-penetrating Peptide and a lipid domain

    DEFF Research Database (Denmark)

    Shiraishi, Takehiko; Nielsen, Peter E

    2011-01-01

    Unaided cellular uptake of RNA interference agents such as antisense oligonucleotides and siRNA is extremely poor, and in vivo bioavailability is also limited. Thus, effective delivery strategies for such potential drugs are in high demand. Recently, a novel approach using a class of short cationic...

  8. Targeting CD44 expressing cancer cells with anti-CD44 monoclonal antibody improves cellular uptake and antitumor efficacy of liposomal doxorubicin.

    Science.gov (United States)

    Arabi, Leila; Badiee, Ali; Mosaffa, Fatemeh; Jaafari, Mahmoud Reza

    2015-12-28

    Although liposomes improve the safety and pharmacokinetic properties of free drugs, they have not sufficiently enhanced the therapeutic efficacy compared to them. To address this problem, targeted therapy of tumor cells holds great promise to further enhance therapeutic index and decreases off-target effects compared with non-targeted liposomes. In the context of antibody-mediated targeted cancer therapy, we evaluated the anti-tumor activity and therapeutic efficacy of Doxil, and that of Doxil modified with a monoclonal antibody (mAb) against CD44, which is one of the most well-known surface markers associated with Cancer Stem Cells (CSCs). Flow cytometry analyses and confocal laser scanning microscopy results showed significant enhanced cellular uptake of CD44-targeted Doxil (CD44-Doxil) in CD44-positive C-26 cells compared to Doxil. However, CD44-negative NIH-3T3 cells showed a similar uptake and in vitro cytotoxicity with both CD44-Doxil and non-targeted Doxil. In BALB/c mice bearing C-26 murine carcinoma, CD44-Doxil groups exhibited significantly higher doxorubicin concentration (than Doxil) inside the tumor cells, while their circulation time and distribution profile remained comparable. CD44-Doxil at doses of either 10 or 15 mg/kg resulted in superior tumor growth inhibition and higher inclination to tumor, indicating the potential of anti-CD44 mAb targeting in therapeutic efficacy improvement. This study provides proof-of-principle for actively tumor-targeting concept and merits further investigations. PMID:26518722

  9. Cellular heterogeneity and live cell arrays.

    Science.gov (United States)

    Walling, Maureen A; Shepard, Jason R E

    2011-07-01

    In the past decade, the tendency to move from a global, one-size-fits-all treatment philosophy to personalized medicine is based, in part, on the nuanced differences and sub-classifications of disease states. Our knowledge of these varied states stems from not only the ability to diagnose, classify, and perform experiments on cell populations as a whole, but also from new technologies that allow interrogation of cell populations at the individual cell level. Such departures from conventional thinking are driven by the recognition that clonal cell populations have numerous activities that manifest as significant levels of non-genetic heterogeneity. Clonal populations by definition originate from a single genetic origin so are regarded as having a high level of homogeneity as compared to genetically distinct cell populations. However, analysis at the single cell level has revealed a different phenomenon; cells and organisms require an inherent level of non-genetic heterogeneity to function properly, and in some cases, to survive. The growing understanding of this occurrence has lead to the development of methods to monitor, analyze, and better characterize the heterogeneity in cell populations. Following the trend of DNA- and protein microarrays, platforms capable of simultaneously monitoring each cell in a population have been developed. These cellular microarray platforms and other related formats allow for continuous monitoring of single live cells and simultaneously generate individual cell and average population data that are more descriptive and information-rich than traditional bulk methods. These technological advances have helped develop a better understanding of the intricacies associated with biological processes and afforded greater insight into complex biological systems. The associated instruments, techniques, and reagents now allow for highly multiplexed analyses, which enable multiple cellular activities, processes, or pathways to be monitored

  10. Pirin inhibits cellular senescence in melanocytic cells.

    Science.gov (United States)

    Licciulli, Silvia; Luise, Chiara; Scafetta, Gaia; Capra, Maria; Giardina, Giuseppina; Nuciforo, Paolo; Bosari, Silvano; Viale, Giuseppe; Mazzarol, Giovanni; Tonelli, Chiara; Lanfrancone, Luisa; Alcalay, Myriam

    2011-05-01

    Cellular senescence has been widely recognized as a tumor suppressing mechanism that acts as a barrier to cancer development after oncogenic stimuli. A prominent in vivo model of the senescence barrier is represented by nevi, which are composed of melanocytes that, after an initial phase of proliferation induced by activated oncogenes (most commonly BRAF), are blocked in a state of cellular senescence. Transformation to melanoma occurs when genes involved in controlling senescence are mutated or silenced and cells reacquire the capacity to proliferate. Pirin (PIR) is a highly conserved nuclear protein that likely functions as a transcriptional regulator whose expression levels are altered in different types of tumors. We analyzed the expression pattern of PIR in adult human tissues and found that it is expressed in melanocytes and has a complex pattern of regulation in nevi and melanoma: it is rarely detected in mature nevi, but is expressed at high levels in a subset of melanomas. Loss of function and overexpression experiments in normal and transformed melanocytic cells revealed that PIR is involved in the negative control of cellular senescence and that its expression is necessary to overcome the senescence barrier. Our results suggest that PIR may have a relevant role in melanoma progression. PMID:21514450

  11. Tuneable nanoparticle-nanofiber composite substrate for improved cellular adhesion.

    Science.gov (United States)

    Nicolini, Ariana M; Toth, Tyler D; Yoon, Jeong-Yeol

    2016-09-01

    This work presents a novel technique using a reverse potential electrospinning mode for fabricating nanoparticle-embedded composites that can be tailored to represent various fiber diameters, surface morphologies, and functional groups necessary for improved cellular adhesion. Polycaprolactone (PCL) nanofibers were electrospun in both traditional positive (PP) and reverse potential (RP) electrical fields. The fibers were incorporated with 300nm polystyrene (PS) fluorescent particles, which contained carboxyl, amine groups, and surfactants. In the unconventional RP, the charged colloidal particles and surfactants were shown to have an exaggerated effect on Taylor cone morphology and fiber diameter caused by the changes in charge density and surface tension of the bulk solution. The RP mode was shown to lead to a decrease in fiber diameter from 1200±100nm (diameter±SE) for the nanofibers made with PCL alone to 440±80nm with the incorporation of colloidal particles, compared to the PP mode ranging from 530±90nm to 350±50nm, respectively. The nanoparticle-nanofiber composite substrates were cultured with human umbilical vein endothelial cells (HUVECs) and evaluated for cellular viability and adhesion for up to 5 days. Adhesion to the nanofibrous substrates was improved by 180±10% with the addition of carboxylated particles and by 480±60% with the functionalization of an RGD ligand compared to the PCL nanofibers. The novel approach of electrospinning in the RP mode with the addition of colloids in order to alter charge density and surface tension could be utilized towards many applications, one being implantable biomaterials and tissue engineered scaffolds as demonstrated in this work. PMID:27315331

  12. Comparison of Cell formation techniques in Cellular manufacturing using three cell formation algorithms

    Directory of Open Access Journals (Sweden)

    Prabhat Kumar Giri

    2016-01-01

    Full Text Available In the present era of globalization and competitive market, cellular manufacturing has become a vital tool for meeting the challenges of improving productivity, which is the way to sustain growth. Getting best results of cellular manufacturing depends on the formation of the machine cells and part families. This paper examines advantages of ART method of cell formation over array based clustering algorithms, namely ROC-2 and DCA. The comparison and evaluation of the cell formation methods has been carried out in the study. The most appropriate approach is selected and used to form the cellular manufacturing system. The comparison and evaluation is done on the basis of performance measure as grouping efficiency and improvements over the existing cellular manufacturing system is presented.

  13. Cellular radiosensitivity of small-cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Krarup, M; Poulsen, H S; Spang-Thomsen, M

    1997-01-01

    . The multitarget single hit model was applied to calculate the cellular radiosensitivity (D0), the capacity for sublethal damage repair (Dq), and the extrapolation number (n). Values for alpha and beta were determined from best-fit curves according to the linear-quadratic model and these values were applied...... to calculate the surviving fraction after 2-Gy irradiation (SF2). RESULTS: In our investigation, the extrapolation method proved to be inappropriate for the study of in vitro cellular radiosensitivity due to lack of reproducibility. The results obtained by the clonogenic assay showed that the cell lines...

  14. Half-Cell Law of Regular Cellular Detonations

    Institute of Scientific and Technical Information of China (English)

    WANG Chun; JIANG Zong-Lin; GAO Yun-Liang

    2008-01-01

    Numerical simulations illustrate the half-cell law of regular cellular detonations propagating in confined space,i.e., the number of cells always maintains an integral multiple of half cell. The cells adapt themselves larger or smaller to the size of the unconfined space by maintaining the cell scale larger or smaller than the original cells of detonation.

  15. Cellular identity at the single-cell level.

    Science.gov (United States)

    Coskun, Ahmet F; Eser, Umut; Islam, Saiful

    2016-10-20

    A single cell creates surprising heterogeneity in a multicellular organism. While every organismal cell shares almost an identical genome, molecular interactions in cells alter the use of DNA sequences to modulate the gene of interest for specialization of cellular functions. Each cell gains a unique identity through molecular coding across the DNA, RNA, and protein conversions. On the other hand, loss of cellular identity leads to critical diseases such as cancer. Most cell identity dissection studies are based on bulk molecular assays that mask differences in individual cells. To probe cell-to-cell variability in a population, we discuss single cell approaches to decode the genetic, epigenetic, transcriptional, and translational mechanisms for cell identity formation. In combination with molecular instructions, the physical principles behind cell identity determination are examined. Deciphering and reprogramming cellular types impact biology and medicine.

  16. Radiation and chemical interactions producing cellular and subcellular damage and their repair. Coordinated programme on improvement in radiotherapy of cancer using modifiers of radiosensitivity of cells

    International Nuclear Information System (INIS)

    As a result of biochemical studies on the DNA repair of damages induced by ionizing radiation as well as on the radiosensitization with chemicals containing halogen atoms, it was suggested that inhibition of the post-irradiation repair by chemical factors may be useful in improving the radiotherapy. It was possbile to prepare an in vitro repair system in combination with transforming DNA of Bacillus subtilis as well as human placenta extracts; it was shown that certain radiosensitizers worked actually as repair inhibitors in this in vitro system

  17. Improving Quality of Clustering using Cellular Automata for Information retrieval

    Directory of Open Access Journals (Sweden)

    P. K. Sree

    2008-01-01

    Full Text Available Clustering has been widely applied to Information Retrieval (IR on the grounds of its potential improved effectiveness over inverted file search. Clustering is a mostly unsupervised procedure and the majority of the clustering algorithms depend on certain assumptions in order to define the subgroups present in a data set .A clustering quality measure is a function that, given a data set and its partition into clusters, returns a non-negative real number representing the quality of that clustering. Moreover, they may behave in a different way depending on the features of the data set and their input parameters values. Therefore, in most applications the resulting clustering scheme requires some sort of evaluation as regards its validity. The quality of clustering can be enhanced by using a Cellular Automata Classifier for information retrieval. In this study we take the view that if cellular automata with clustering is applied to search results (query-specific clustering, then it has the potential to increase the retrieval effectiveness compared both to that of static clustering and of conventional inverted file search. We conducted a number of experiments using ten document collections and eight hierarchic clustering methods. Our results show that the effectiveness of query-specific clustering with cellular automata is indeed higher and suggest that there is scope for its application to IR.

  18. Cellular bridges: Routes for intercellular communication and cell migration

    OpenAIRE

    Zani, Brett G.; Edelman, Elazer R.

    2010-01-01

    Cell-to-cell communication is the basis of all biology in multicellular organisms, allowing evolution of complex forms and viability in dynamic environments. Though biochemical interactions occur over distances, physical continuity remains the most direct means of cellular interactions. Cellular bridging through thin cytoplasmic channels—plasmodesmata in plants and tunneling nanotubes in animals—creates direct routes for transfer of signals and components, even pathogens, between cells. Recen...

  19. Cell biology of the future: Nanometer-scale cellular cartography.

    Science.gov (United States)

    Taraska, Justin W

    2015-10-26

    Understanding cellular structure is key to understanding cellular regulation. New developments in super-resolution fluorescence imaging, electron microscopy, and quantitative image analysis methods are now providing some of the first three-dimensional dynamic maps of biomolecules at the nanometer scale. These new maps--comprehensive nanometer-scale cellular cartographies--will reveal how the molecular organization of cells influences their diverse and changeable activities.

  20. Cellular pressure and volume regulation and implications for cell mechanics.

    Science.gov (United States)

    Jiang, Hongyuan; Sun, Sean X

    2013-08-01

    In eukaryotic cells, small changes in cell volume can serve as important signals for cell proliferation, death, and migration. Volume and shape regulation also directly impacts the mechanics of cells and tissues. Here, we develop a mathematical model of cellular volume and pressure regulation, incorporating essential elements such as water permeation, mechanosensitive channels, active ion pumps, and active stresses in the cortex. The model can fully explain recent experimental data, and it predicts cellular volume and pressure for several models of cell cortical mechanics. Moreover, we show that when cells are subjected to an externally applied load, such as in an atomic force microscopy indentation experiment, active regulation of volume and pressure leads to a complex cellular response. Instead of the passive mechanics of the cortex, the observed cell stiffness depends on several factors working together. This provides a mathematical explanation of rate-dependent response of cells under force. PMID:23931309

  1. A sub-cellular viscoelastic model for cell population mechanics.

    Directory of Open Access Journals (Sweden)

    Yousef Jamali

    Full Text Available Understanding the biomechanical properties and the effect of biomechanical force on epithelial cells is key to understanding how epithelial cells form uniquely shaped structures in two or three-dimensional space. Nevertheless, with the limitations and challenges posed by biological experiments at this scale, it becomes advantageous to use mathematical and 'in silico' (computational models as an alternate solution. This paper introduces a single-cell-based model representing the cross section of a typical tissue. Each cell in this model is an individual unit containing several sub-cellular elements, such as the elastic plasma membrane, enclosed viscoelastic elements that play the role of cytoskeleton, and the viscoelastic elements of the cell nucleus. The cell membrane is divided into segments where each segment (or point incorporates the cell's interaction and communication with other cells and its environment. The model is capable of simulating how cells cooperate and contribute to the overall structure and function of a particular tissue; it mimics many aspects of cellular behavior such as cell growth, division, apoptosis and polarization. The model allows for investigation of the biomechanical properties of cells, cell-cell interactions, effect of environment on cellular clusters, and how individual cells work together and contribute to the structure and function of a particular tissue. To evaluate the current approach in modeling different topologies of growing tissues in distinct biochemical conditions of the surrounding media, we model several key cellular phenomena, namely monolayer cell culture, effects of adhesion intensity, growth of epithelial cell through interaction with extra-cellular matrix (ECM, effects of a gap in the ECM, tensegrity and tissue morphogenesis and formation of hollow epithelial acini. The proposed computational model enables one to isolate the effects of biomechanical properties of individual cells and the

  2. A novel cell search scheme for OFDM cellular systems

    Institute of Scientific and Technical Information of China (English)

    DING Ming; LUO Han-wen; WU Yun

    2007-01-01

    A novel cell search scheme for OFDM cellular systems is proposed. It is based on one OFDM symbol with several identical slots as preamble, the time domain repetition structure of which can be utilized to accomplish OFDM timing/frequency synchronization. The cell ID is comprised of two parts: a sub-carrier mask index g and a sequence index x. Each sub-carrier mask activates or deactivates some of the sub-carriers, after which a differentially coded sequence is loaded on pairs of the adjacent active sub-carriers. The user equipment (UE) recognizes the mask with index g via power detection of the received frequency domain signal. Then it estimates the index x from differential demodulation followed by detection of the frequency domain sequence. In order to improve the performance, a method of jointly estimating g and x is devised. Simulation results showed that the proposed scheme is able to support a very large number of cell IDs while maintaining a good performance even in bad multi-cell environment.

  3. Multi-cellular logistics of collective cell migration.

    Directory of Open Access Journals (Sweden)

    Masataka Yamao

    Full Text Available During development, the formation of biological networks (such as organs and neuronal networks is controlled by multicellular transportation phenomena based on cell migration. In multi-cellular systems, cellular locomotion is restricted by physical interactions with other cells in a crowded space, similar to passengers pushing others out of their way on a packed train. The motion of individual cells is intrinsically stochastic and may be viewed as a type of random walk. However, this walk takes place in a noisy environment because the cell interacts with its randomly moving neighbors. Despite this randomness and complexity, development is highly orchestrated and precisely regulated, following genetic (and even epigenetic blueprints. Although individual cell migration has long been studied, the manner in which stochasticity affects multi-cellular transportation within the precisely controlled process of development remains largely unknown. To explore the general principles underlying multicellular migration, we focus on the migration of neural crest cells, which migrate collectively and form streams. We introduce a mechanical model of multi-cellular migration. Simulations based on the model show that the migration mode depends on the relative strengths of the noise from migratory and non-migratory cells. Strong noise from migratory cells and weak noise from surrounding cells causes "collective migration," whereas strong noise from non-migratory cells causes "dispersive migration." Moreover, our theoretical analyses reveal that migratory cells attract each other over long distances, even without direct mechanical contacts. This effective interaction depends on the stochasticity of the migratory and non-migratory cells. On the basis of these findings, we propose that stochastic behavior at the single-cell level works effectively and precisely to achieve collective migration in multi-cellular systems.

  4. Cellular Pressure and Volume Regulation and Implications for Cell Mechanics

    OpenAIRE

    Jiang, Hongyuan; Sun, Sean X.

    2013-01-01

    In eukaryotic cells, small changes in cell volume can serve as important signals for cell proliferation, death, and migration. Volume and shape regulation also directly impacts the mechanics of cells and tissues. Here, we develop a mathematical model of cellular volume and pressure regulation, incorporating essential elements such as water permeation, mechanosensitive channels, active ion pumps, and active stresses in the cortex. The model can fully explain recent experimental data, and it pr...

  5. Monkey hybrid stem cells develop cellular features of Huntington's disease

    Directory of Open Access Journals (Sweden)

    Lorthongpanich Chanchao

    2010-02-01

    Full Text Available Abstract Background Pluripotent stem cells that are capable of differentiating into different cell types and develop robust hallmark cellular features are useful tools for clarifying the impact of developmental events on neurodegenerative diseases such as Huntington's disease. Additionally, a Huntington's cell model that develops robust pathological features of Huntington's disease would be valuable for drug discovery research. Results To test this hypothesis, a pluripotent Huntington's disease monkey hybrid cell line (TrES1 was established from a tetraploid Huntington's disease monkey blastocyst generated by the fusion of transgenic Huntington's monkey skin fibroblast and a wild-type non-transgenic monkey oocyte. The TrES1 developed key Huntington's disease cellular pathological features that paralleled neural development. It expressed mutant huntingtin and stem cell markers, was capable of differentiating to neural cells, and developed teratoma in severely compromised immune deficient (SCID mice. Interestingly, the expression of mutant htt, the accumulation of oligomeric mutant htt and the formation of intranuclear inclusions paralleled neural development in vitro , and even mutant htt was ubiquitously expressed. This suggests the development of Huntington's disease cellular features is influenced by neural developmental events. Conclusions Huntington's disease cellular features is influenced by neural developmental events. These results are the first to demonstrate that a pluripotent stem cell line is able to mimic Huntington's disease progression that parallels neural development, which could be a useful cell model for investigating the developmental impact on Huntington's disease pathogenesis.

  6. Cellular memory and, hematopoietic stem cell aging

    NARCIS (Netherlands)

    Kamminga, Leonie M.; de Haan, Gerald

    2006-01-01

    Hematopoietic stem cells (HSCs) balance self-renewal and differentiation in order to sustain lifelong blood production and simultaneously maintain the HSC pool. However, there is clear evidence that HSCs are subject to quantitative and qualitative exhaustion. In this review, we briefly discuss sever

  7. Cell-to-cell communication and cellular environment alter the somatostatin status of delta cells

    International Nuclear Information System (INIS)

    Research highlights: → TGP52 cells display enhanced functionality in pseudoislet form. → Somatostatin content was reduced, but secretion increased in high glucose conditions. → Cellular interactions and environment alter the somatostatin status of TGP52 cells. -- Abstract: Introduction: Somatostatin, released from pancreatic delta cells, is a potent paracrine inhibitor of insulin and glucagon secretion. Islet cellular interactions and glucose homeostasis are essential to maintain normal patterns of insulin secretion. However, the importance of cell-to-cell communication and cellular environment in the regulation of somatostatin release remains unclear. Methods: This study employed the somatostatin-secreting TGP52 cell line maintained in DMEM:F12 (17.5 mM glucose) or DMEM (25 mM glucose) culture media. The effect of pseudoislet formation and culture medium on somatostatin content and release in response to a variety of stimuli was measured by somatostatin EIA. In addition, the effect of pseudoislet formation on cellular viability (MTT and LDH assays) and proliferation (BrdU ELISA) was determined. Results: TGP52 cells readily formed pseudoislets and showed enhanced functionality in three-dimensional form with increased E-cadherin expression irrespective of the culture environment used. However, culture in DMEM decreased cellular somatostatin content (P < 0.01) and increased somatostatin secretion in response to a variety of stimuli including arginine, calcium and PMA (P < 0.001) when compared with cells grown in DMEM:F12. Configuration of TGP52 cells as pseudoislets reduced the proliferative rate and increased cellular cytotoxicity irrespective of culture medium used. Conclusions: Somatostatin secretion is greatly facilitated by cell-to-cell interactions and E-cadherin expression. Cellular environment and extracellular glucose also significantly influence the function of delta cells.

  8. An improved multi-value cellular automata model for heterogeneous bicycle traffic flow

    International Nuclear Information System (INIS)

    This letter develops an improved multi-value cellular automata model for heterogeneous bicycle traffic flow taking the higher maximum speed of electric bicycles into consideration. The update rules of both regular and electric bicycles are improved, with maximum speeds of two and three cells per second respectively. Numerical simulation results for deterministic and stochastic cases are obtained. The fundamental diagrams and multiple states effects under different model parameters are analyzed and discussed. Field observations were made to calibrate the slowdown probabilities. The results imply that the improved extended Burgers cellular automata (IEBCA) model is more consistent with the field observations than previous models and greatly enhances the realism of the bicycle traffic model. - Highlights: • We proposed an improved multi-value CA model with higher maximum speed. • Update rules are introduced for heterogeneous bicycle traffic with maximum speed 2 and 3 cells/s. • Simulation results of the proposed model are consistent with field bicycle data. • Slowdown probabilities of both regular and electric bicycles are calibrated

  9. An improved multi-value cellular automata model for heterogeneous bicycle traffic flow

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Sheng [College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China (China); Qu, Xiaobo [Griffith School of Engineering, Griffith University, Gold Coast, 4222 Australia (Australia); Xu, Cheng [Department of Transportation Management Engineering, Zhejiang Police College, Hangzhou, 310053 China (China); College of Transportation, Jilin University, Changchun, 130022 China (China); Ma, Dongfang, E-mail: mdf2004@zju.edu.cn [Ocean College, Zhejiang University, Hangzhou, 310058 China (China); Wang, Dianhai [College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China (China)

    2015-10-16

    This letter develops an improved multi-value cellular automata model for heterogeneous bicycle traffic flow taking the higher maximum speed of electric bicycles into consideration. The update rules of both regular and electric bicycles are improved, with maximum speeds of two and three cells per second respectively. Numerical simulation results for deterministic and stochastic cases are obtained. The fundamental diagrams and multiple states effects under different model parameters are analyzed and discussed. Field observations were made to calibrate the slowdown probabilities. The results imply that the improved extended Burgers cellular automata (IEBCA) model is more consistent with the field observations than previous models and greatly enhances the realism of the bicycle traffic model. - Highlights: • We proposed an improved multi-value CA model with higher maximum speed. • Update rules are introduced for heterogeneous bicycle traffic with maximum speed 2 and 3 cells/s. • Simulation results of the proposed model are consistent with field bicycle data. • Slowdown probabilities of both regular and electric bicycles are calibrated.

  10. Cellular Magnetic Resonance Imaging: In Vivo Imaging of Melanoma Cells in Lymph Nodes of Mice

    Directory of Open Access Journals (Sweden)

    Paula J Foster

    2008-03-01

    Full Text Available Metastasis is responsible for most deaths due to malignant melanoma. The clinical significance of micrometastases in the lymph is a hotly debated topic, but an improved understanding of the lymphatic spread of cancer remains important for improving cancer survival. Cellular magnetic resonance imaging (MRI is a newly emerging field of imaging research that is expected to have a large impact on cancer research. In this study, we demonstrate the cellular MRI technology required to reliably image the lymphatic system in mice and to detect iron-labeled metastatic melanoma cells within the mouse lymph nodes. Melanoma cells were implanted directly into the inguinal lymph nodes in mice, and micro-MRI was performed using a customized 1.5-T clinical MRI system. We show cell detection of as few as 100 iron-labeled cells within the lymph node, with injections of larger cell numbers producing increasingly obvious regions of signal void. In addition, we show that cellular MRI allows monitoring of the fate of these cells over time as they develop into intranodal tumors. This technology will allow noninvasive investigations of cellular events in cancer metastasis within an entire animal and will facilitate progress in understanding the mechanisms of metastasis within the lymphatic system.

  11. Pseudoislet of hybrid cellular spheroids from commercial cell lines.

    Science.gov (United States)

    Jo, Y H; Nam, B M; Kim, B Y; Nemeno, J G; Lee, S; Yeo, J E; Yang, W; Park, S H; Kim, Y S; Lee, J I

    2013-10-01

    Investigators conducting diabetes-related research have focused on islet transplantation as a radical therapy for type 1 diabetes mellitus. Pancreatic islet isolation, an essential process, is a very demanding work because of the proteolytic enzymes, species, treatment time, and individual difference. Replacement of primary isolated pancreatic islets must be carried out continuously for various in vitro tests, making primary isolated islets a useful tool for cell transplantation research. Hence, we sought to develop pseudoislets from commercial pancreas-derived cell lines. In this study, we used RIN-5F and RIN-m cells, which secrete insulin, somatostatin, or glucagon. To manufacture hybrid cellular spheroids, the cells were cultured under hanging drop plate and nonadhesive plate methods. We observed that hybrid cellular pseudoislets exhibited an oval shape, with sizes ranging from 590 to 1200 μm. Their morphology was similar to naïve islets. Cell line pseudoislets secreted and expressed insulin, glucagon, and somatostatin, as confirmed by reverse transcriptase polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemistry analyses. Thus, the current artificially manufactured biomimetic pseudoislets resembled pancreatic islets of the endocrine system, appearing as cellular aggregates that secreted insulin, glucagon, and somatostatin. Enhanced immunoisolation techniques may lead to the development of new islet sources for pancreatic transplantation through this pseudoislet strategy.

  12. Myosins and cell dynamics in cellular slime molds.

    Science.gov (United States)

    Yumura, Shigehiko; Uyeda, Taro Q P

    2003-01-01

    Myosin is a mechanochemical transducer and serves as a motor for various motile activities such as cell migration, cytokinesis, maintenance of cell shape, phagocytosis, and morphogenesis. Nonmuscle myosin in vivo does not either stay static at specific subcellular regions or construct highly organized structures, such as sarcomere in skeletal muscle cells. The cellular slime mold Dictyostelium discoideum is an ideal "model organism" for the investigation of cell movement and cytokinesis. The advantages of this organism prompted researchers to carry out pioneering cell biological, biochemical, and molecular genetic studies on myosin II, which resulted in elucidation of many fundamental features of function and regulation of this most abundant molecular motor. Furthermore, recent molecular biological research has revealed that many unconventional myosins play various functions in vivo. In this article, how myosins are organized and regulated in a dynamic manner in Dictyostelium cells is reviewed and discussed. PMID:12722951

  13. An efficient Cellular Potts Model algorithm that forbids cell fragmentation

    Science.gov (United States)

    Durand, Marc; Guesnet, Etienne

    2016-11-01

    The Cellular Potts Model (CPM) is a lattice based modeling technique which is widely used for simulating cellular patterns such as foams or biological tissues. Despite its realism and generality, the standard Monte Carlo algorithm used in the scientific literature to evolve this model preserves connectivity of cells on a limited range of simulation temperature only. We present a new algorithm in which cell fragmentation is forbidden for all simulation temperatures. This allows to significantly enhance realism of the simulated patterns. It also increases the computational efficiency compared with the standard CPM algorithm even at same simulation temperature, thanks to the time spared in not doing unrealistic moves. Moreover, our algorithm restores the detailed balance equation, ensuring that the long-term stage is independent of the chosen acceptance rate and chosen path in the temperature space.

  14. Typing of murine cell-surface antigens by cellular radioimmunoassay

    International Nuclear Information System (INIS)

    A cellular radioimmunoassay utilizing 125I-labelled Protein A was used for detecting antigen-antibody complexes on gultaraldehyde fixed cells attached to microtiter plates. This method is rapid, sensitive and specific for revealing H-2 private and public specificities as well as Ia and Lyt antigens. As plates may be kept for months, several reactivities can be tested in one step on a large panel rendering a regular supply of animals unnecessary. (Auth.)

  15. Cellular Deconstruction: Finding Meaning in Individual Cell Variation.

    Science.gov (United States)

    Eberwine, James; Kim, Junhyong

    2015-10-01

    The advent of single cell transcriptome analysis has permitted the discovery of cell-to-cell variation in transcriptome expression of even presumptively identical cells. We hypothesize that this variability reflects a many-to-one relation between transcriptome states and the phenotype of a cell. In this relation, the molecular ratios of the subsets of RNA are determined by the stoichiometric constraints of the cell systems, which underdetermine the transcriptome state. Furthermore, the variability is, in part, induced by the tissue context and is important for system-level function. This theory is analogous to theories of literary deconstruction, where multiple 'signifiers' work in opposition to one another to create meaning. By analogy, transcriptome phenotypes should be defined as subsets of RNAs comprising selected RNA systems where the system-associated RNAs are balanced with each other to produce the associated cellular function. This idea provides a framework for understanding cellular heterogeneity in phenotypic responses to variant conditions, such as disease challenge. PMID:26410403

  16. Dimerization of a cell-penetrating peptide leads to enhanced cellular uptake and drug delivery

    Directory of Open Access Journals (Sweden)

    Jan Hoyer

    2012-10-01

    Full Text Available Over the past 20 years, cell-penetrating peptides (CPPs have gained tremendous interest due to their ability to deliver a variety of therapeutically active molecules that would otherwise be unable to cross the cellular membrane due to their size or hydrophilicity. Recently, we reported on the identification of a novel CPP, sC18, which is derived from the C-terminus of the 18 kDa cationic antimicrobial protein. Furthermore, we demonstrated successful application of sC18 for the delivery of functionalized cyclopentadienyl manganese tricarbonyl (cymantrene complexes to tumor cell lines, inducing high cellular toxicity. In order to increase the potential of the organometallic complexes to kill tumor cells, we were looking for a way to enhance cellular uptake. Therefore, we designed a branched dimeric variant of sC18, (sC182, which was shown to have a dramatically improved capacity to internalize into various cell lines, even primary cells, using flow cytometry and fluorescence microscopy. Cell viability assays indicated increased cytotoxicity of the dimer presumably caused by membrane leakage; however, this effect turned out to be dependent on the specific cell type. Finally, we could show that conjugation of a functionalized cymantrene with (sC182 leads to significant reduction of its IC50 value in tumor cells compared to the respective sC18 conjugate, proving that dimerization is a useful method to increase the drug-delivery potential of a cell-penetrating peptide.

  17. Inter-cell interference mitigation in multi-cellular visible light communications.

    Science.gov (United States)

    Jung, Sun-Young; Kwon, Do-Hoon; Yang, Se-Hoon; Han, Sang-Kook

    2016-04-18

    Inter-cell interference hinders multi-cellular optical wireless communication to support various applications. We proposed and experimentally demonstrated a multicarrier-based cell partitioning scheme, combined with frequency reuse, which could be effective in optical communications although it is inefficient in RF wireless communications. For multicarrier-based cell partitioning, Orthogonal frequency division multiplexing-based multiple access (OFDMA) was employed to accommodate multi-cellular optical wireless communications without a large guard band between adjacent cells and without additional RF components. Moreover, we employed filter bank-based multicarrier (FBMC) to mitigate inter-cell interference generated in OFDMA-based cell partitioning due to asynchronous signals originated from RF path difference. By using FBMC-based cell partitioning, inter-cell interference could be effectively mitigated as well as capacity and spectral efficiency were improved about 1.5 times compared to those of OFDMA. Because no cyclic prefix (CP) is required in FBMC, the improvement factor could be increased if there is a large RF path difference between lighting cells. Moreover, it could be a stronger solution when many neighboring cells exist causing large interference. The proposed multicarrier-based cell partitioning combined with FBMC will effectively support visible light communication (VLC)-based localization-based services (LBS) and indoor positioning system by transparently providing trilateration-based positioning method.

  18. Mitochondria in mesenchymal stem cell biology and cell therapy: From cellular differentiation to mitochondrial transfer.

    Science.gov (United States)

    Hsu, Yi-Chao; Wu, Yu-Ting; Yu, Ting-Hsien; Wei, Yau-Huei

    2016-04-01

    Mesenchymal stem cells (MSCs) are characterized to have the capacity of self-renewal and the potential to differentiate into mesoderm, ectoderm-like and endoderm-like cells. MSCs hold great promise for cell therapies due to their multipotency in vitro and therapeutic advantage of hypo-immunogenicity and lower tumorigenicity. Moreover, it has been shown that MSCs can serve as a vehicle to transfer mitochondria into cells after cell transplantation. Mitochondria produce most of the energy through oxidative phosphorylation in differentiated cells. It has been increasingly clear that the switch of energy supply from glycolysis to aerobic metabolism is essential for successful differentiation of MSCs. Post-translational modifications of proteins have been established to regulate mitochondrial function and metabolic shift during MSCs differentiation. In this article, we review and provide an integrated view on the roles of different protein kinases and sirtuins in the maintenance and differentiation of MSCs. Importantly, we provide evidence to suggest that alteration in the expression of Sirt3 and Sirt5 and relative changes in the acylation levels of mitochondrial proteins might be involved in the activation of mitochondrial function and adipogenic differentiation of adipose-derived MSCs. We summarize their roles in the regulation of mitochondrial biogenesis and metabolism, oxidative responses and differentiation of MSCs. On the other hand, we discuss recent advances in the study of mitochondrial dynamics and mitochondrial transfer as well as their roles in the differentiation and therapeutic application of MSCs to improve cell function in vitro and in animal models. Accumulating evidence has substantiated that the therapeutic potential of MSCs is conferred not only by cell replacement and paracrine effects but also by transferring mitochondria into injured tissues or cells to modulate the cellular metabolism in situ. Therefore, elucidation of the underlying mechanisms

  19. Mitochondria in mesenchymal stem cell biology and cell therapy: From cellular differentiation to mitochondrial transfer.

    Science.gov (United States)

    Hsu, Yi-Chao; Wu, Yu-Ting; Yu, Ting-Hsien; Wei, Yau-Huei

    2016-04-01

    Mesenchymal stem cells (MSCs) are characterized to have the capacity of self-renewal and the potential to differentiate into mesoderm, ectoderm-like and endoderm-like cells. MSCs hold great promise for cell therapies due to their multipotency in vitro and therapeutic advantage of hypo-immunogenicity and lower tumorigenicity. Moreover, it has been shown that MSCs can serve as a vehicle to transfer mitochondria into cells after cell transplantation. Mitochondria produce most of the energy through oxidative phosphorylation in differentiated cells. It has been increasingly clear that the switch of energy supply from glycolysis to aerobic metabolism is essential for successful differentiation of MSCs. Post-translational modifications of proteins have been established to regulate mitochondrial function and metabolic shift during MSCs differentiation. In this article, we review and provide an integrated view on the roles of different protein kinases and sirtuins in the maintenance and differentiation of MSCs. Importantly, we provide evidence to suggest that alteration in the expression of Sirt3 and Sirt5 and relative changes in the acylation levels of mitochondrial proteins might be involved in the activation of mitochondrial function and adipogenic differentiation of adipose-derived MSCs. We summarize their roles in the regulation of mitochondrial biogenesis and metabolism, oxidative responses and differentiation of MSCs. On the other hand, we discuss recent advances in the study of mitochondrial dynamics and mitochondrial transfer as well as their roles in the differentiation and therapeutic application of MSCs to improve cell function in vitro and in animal models. Accumulating evidence has substantiated that the therapeutic potential of MSCs is conferred not only by cell replacement and paracrine effects but also by transferring mitochondria into injured tissues or cells to modulate the cellular metabolism in situ. Therefore, elucidation of the underlying mechanisms

  20. Targeted cellular ablation based on the morphology of malignant cells

    Science.gov (United States)

    Ivey, Jill W.; Latouche, Eduardo L.; Sano, Michael B.; Rossmeisl, John H.; Davalos, Rafael V.; Verbridge, Scott S.

    2015-11-01

    Treatment of glioblastoma multiforme (GBM) is especially challenging due to a shortage of methods to preferentially target diffuse infiltrative cells, and therapy-resistant glioma stem cell populations. Here we report a physical treatment method based on electrical disruption of cells, whose action depends strongly on cellular morphology. Interestingly, numerical modeling suggests that while outer lipid bilayer disruption induced by long pulses (~100 μs) is enhanced for larger cells, short pulses (~1 μs) preferentially result in high fields within the cell interior, which scale in magnitude with nucleus size. Because enlarged nuclei represent a reliable indicator of malignancy, this suggested a means of preferentially targeting malignant cells. While we demonstrate killing of both normal and malignant cells using pulsed electric fields (PEFs) to treat spontaneous canine GBM, we proposed that properly tuned PEFs might provide targeted ablation based on nuclear size. Using 3D hydrogel models of normal and malignant brain tissues, which permit high-resolution interrogation during treatment testing, we confirmed that PEFs could be tuned to preferentially kill cancerous cells. Finally, we estimated the nuclear envelope electric potential disruption needed for cell death from PEFs. Our results may be useful in safely targeting the therapy-resistant cell niches that cause recurrence of GBM tumors.

  1. Cellular and Nuclear Alignment Analysis for Determining Epithelial Cell Chirality.

    Science.gov (United States)

    Raymond, Michael J; Ray, Poulomi; Kaur, Gurleen; Singh, Ajay V; Wan, Leo Q

    2016-05-01

    Left-right (LR) asymmetry is a biologically conserved property in living organisms that can be observed in the asymmetrical arrangement of organs and tissues and in tissue morphogenesis, such as the directional looping of the gastrointestinal tract and heart. The expression of LR asymmetry in embryonic tissues can be appreciated in biased cell alignment. Previously an in vitro chirality assay was reported by patterning multiple cells on microscale defined geometries and quantified the cell phenotype-dependent LR asymmetry, or cell chirality. However, morphology and chirality of individual cells on micropatterned surfaces has not been well characterized. Here, a Python-based algorithm was developed to identify and quantify immunofluorescence stained individual epithelial cells on multicellular patterns. This approach not only produces results similar to the image intensity gradient-based method reported previously, but also can capture properties of single cells such as area and aspect ratio. We also found that cell nuclei exhibited biased alignment. Around 35% cells were misaligned and were typically smaller and less elongated. This new imaging analysis approach is an effective tool for measuring single cell chirality inside multicellular structures and can potentially help unveil biophysical mechanisms underlying cellular chiral bias both in vitro and in vivo. PMID:26294010

  2. Cytotoxicity, cellular uptake, and cellular biotransformations of oxaliplatin in human colon carcinoma cells.

    Science.gov (United States)

    Luo, F R; Wyrick, S D; Chaney, S G

    1998-01-01

    Biotransformation products of platinum anticancer drugs have been suggested to be responsible for drug efficacy and toxicity. This study was designed to determine whether the efficacy of the closely related 1,2-diaminocyclohexane-Pt (dach-Pt) compounds oxaliplatin and ormaplatin were determined primarily by the parent drugs or by one of their biotransformation products. Based on consideration of both in vitro cytotoxicity in human colon carcinoma cells (HT-29) and concentrations following oxaliplatin administration in vivo, our data suggest that the efficacy of oxaliplatin is primarily determined by the plasma levels of the parent drug, with the biotransformation products Pt(dach)Cl2, Pt(dach)(H2O)Cl, and Pt(dach)(H2O)2 making only minor contributions. The stable biotransformation products containing amino acids did not have any significant cytotoxicity. In contrast, our data suggest that the efficacy of ormaplatin is primarily determined by plasma levels of Pt(dach)Cl2. The cytotoxicity of oxaliplatin, Pt(dach)Cl2, and Pt(dach)(H2O)Cl was approximately proportional to their cellular uptake, whereas the cytotoxicity of ormaplatin, Pt(dach)(H2O)2, and Pt(dach)(Met) was less than predicted from their uptake. Treatment of HT-29 cells with equimolar external concentrations of Pt(dach)Cl2 and oxaliplatin resulted in the formation of twofold more Pt-DNA adducts following Pt(dach)Cl2 treatment than following oxaliplatin treatment. However, intracellular Pt(dach)Cl2 levels were 30-fold higher for Pt(dach)Cl2-treated cells than for oxaliplatin-treated cells. These data suggest that intracellular conversion of oxaliplatin to Pt(dach)Cl2 makes only a minor contribution to Pt-DNA adduct formation and the resultant cytotoxicity of oxaliplatin. PMID:10367941

  3. Modeling dynamics of HIV infected cells using stochastic cellular automaton

    Science.gov (United States)

    Precharattana, Monamorn; Triampo, Wannapong

    2014-08-01

    Ever since HIV was first diagnosed in human, a great number of scientific works have been undertaken to explore the biological mechanisms involved in the infection and progression of the disease. Several cellular automata (CA) models have been introduced to gain insights into the dynamics of the disease progression but none of them has taken into account effects of certain immune cells such as the dendritic cells (DCs) and the CD8+ T lymphocytes (CD8+ T cells). In this work, we present a CA model, which incorporates effects of the HIV specific immune response focusing on the cell-mediated immunities, and investigate the interaction between the host immune response and the HIV infected cells in the lymph nodes. The aim of our work is to propose a model more realistic than the one in Precharattana et al. (2010) [10], by incorporating roles of the DCs, the CD4+ T cells, and the CD8+ T cells into the model so that it would reproduce the HIV infection dynamics during the primary phase of HIV infection.

  4. Cellular islet autoimmunity associates with clinical outcome of islet cell transplantation.

    Directory of Open Access Journals (Sweden)

    Volkert A L Huurman

    Full Text Available BACKGROUND: Islet cell transplantation can cure type 1 diabetes (T1D, but only a minority of recipients remains insulin-independent in the following years. We tested the hypothesis that allograft rejection and recurrent autoimmunity contribute to this progressive loss of islet allograft function. METHODOLOGY/PRINCIPAL FINDINGS: Twenty-one T1D patients received cultured islet cell grafts prepared from multiple donors and transplanted under anti-thymocyte globulin (ATG induction and tacrolimus plus mycophenolate mofetil (MMF maintenance immunosuppression. Immunity against auto- and alloantigens was measured before and during one year after transplantation. Cellular auto- and alloreactivity was assessed by lymphocyte stimulation tests against autoantigens and cytotoxic T lymphocyte precursor assays, respectively. Humoral reactivity was measured by auto- and alloantibodies. Clinical outcome parameters--including time until insulin independence, insulin independence at one year, and C-peptide levels over one year--remained blinded until their correlation with immunological parameters. All patients showed significant improvement of metabolic control and 13 out of 21 became insulin-independent. Multivariate analyses showed that presence of cellular autoimmunity before and after transplantation is associated with delayed insulin-independence (p = 0.001 and p = 0.01, respectively and lower circulating C-peptide levels during the first year after transplantation (p = 0.002 and p = 0.02, respectively. Seven out of eight patients without pre-existent T-cell autoreactivity became insulin-independent, versus none of the four patients reactive to both islet autoantigens GAD and IA-2 before transplantation. Autoantibody levels and cellular alloreactivity had no significant association with outcome. CONCLUSIONS/SIGNIFICANCE: In this cohort study, cellular islet-specific autoimmunity associates with clinical outcome of islet cell transplantation under ATG

  5. Improving Quality of Clustering using Cellular Automata for Information retrieval

    OpenAIRE

    Sree, Pokkuluri Kiran; Babu, Inampudi Ramesh

    2014-01-01

    Clustering has been widely applied to Information Retrieval (IR) on the grounds of its potential improved effectiveness over inverted file search. Clustering is a mostly unsupervised procedure and the majority of the clustering algorithms depend on certain assumptions in order to define the subgroups present in a data set .A clustering quality measure is a function that, given a data set and its partition into clusters, returns a non-negative real number representing the quality of that clust...

  6. Overcoming cellular and tissue barriers to improve liposomal drug delivery

    Science.gov (United States)

    Kohli, Aditya G.

    Forty years of liposome research have demonstrated that the anti-tumor efficacy of liposomal therapies is, in part, driven by three parameters: 1) liposome formulation and lipid biophysics, 2) accumulation and distribution in the tumor, and 3) release of the payload at the site of interest. This thesis outlines three studies that improve on each of these delivery steps. In the first study, we engineer a novel class of zwitterlipids with an inverted headgroup architecture that have remarkable biophysical properties and may be useful for drug delivery applications. After intravenous administration, liposomes accumulate in the tumor by the enhanced permeability and retention effect. However, the tumor stroma often limits liposome efficacy by preventing distribution into the tumor. In the second study, we demonstrate that depletion of hyaluronan in the tumor stroma improves the distribution and efficacy of DoxilRTM in murine 4T1 tumors. Once a liposome has distributed to the therapeutic site, it must release its payload over the correct timescale. Few facile methods exist to quantify the release of liposome therapeutics in vivo. In the third study, we outline and validate a simple, robust, and quantitative method for tracking the rate and extent of release of liposome contents in vivo. This tool should facilitate a better understanding of the pharmacodynamics of liposome-encapsulated drugs in animals. This work highlights aspects of liposome behavior that have prevented successful clinical translation and proposes alternative approaches to improve liposome drug delivery.

  7. AdCell: Ad Allocation in Cellular Networks

    CERN Document Server

    Alaei, Saeed; Liaghat, Vahid; Pei, Dan; Saha, Barna

    2011-01-01

    With more than four billion usage of cellular phones worldwide, mobile advertising has become an attractive alternative to online advertisements. In this paper, we propose a new targeted advertising policy for Wireless Service Providers (WSPs) via SMS or MMS- namely {\\em AdCell}. In our model, a WSP charges the advertisers for showing their ads. Each advertiser has a valuation for specific types of customers in various times and locations and has a limit on the maximum available budget. Each query is in the form of time and location and is associated with one individual customer. In order to achieve a non-intrusive delivery, only a limited number of ads can be sent to each customer. Recently, new services have been introduced that offer location-based advertising over cellular network that fit in our model (e.g., ShopAlerts by AT&T) . We consider both online and offline version of the AdCell problem and develop approximation algorithms with constant competitive ratio. For the online version, we assume tha...

  8. Acrylamide inhibits cellular differentiation of human neuroblastoma and glioblastoma cells.

    Science.gov (United States)

    Chen, Jong-Hang; Chou, Chin-Cheng

    2015-08-01

    This study explores human neuroblastoma (SH-SY5Y) and human glioblastoma (U-1240 MG) cellular differentiation changes under exposure to acrylamide (ACR). Differentiation of SH-SY5Y and U-1240 MG cells were induced by retinoic acid (RA) and butyric acid (BA), respectively. Morphological observations and MTT assay showed that the induced cellular differentiation and cell proliferation were inhibited by ACR in a time- and dose-dependent manner. ACR co-treatment with RA attenuated SH-SY5Y expressions of neurofilament protein-L (NF-L), microtubule-associated protein 1b (MAP1b; 1.2 to 0.7, p < 0.001), MAP2c (2.2 to 0.8, p < 0.05), and Janus kinase1 (JAK1; 1.9 to 0.6, p < 0.001), while ACR co-treatment with BA attenuated U-1240 MG expressions of glial fibrillary acidic protein (GFAP), MAP1b (1.2 to 0.6, p < 0.001), MAP2c (1.5 to 0.7, p < 0.01), and JAK1 (2.1 to 0.5, p < 0.001), respectively. ACR also decreased the phosphorylation of extracellular-signal-regulated kinases (ERK) and c-Jun N-terminal kinases (JNK) in U-1240 MG cells, while caffeine reversed this suppression of ERK and JNK phosphorylation caused by ACR treatment. These results showed that RA-induced neurogenesis of SH-SY5Y and BA-induced astrogliogenesis of U-1240 MG cells were attenuated by ACR and were associated with down-regulation of MAPs expression and JAK-STAT signaling.

  9. The Use of Amnion-Derived Cellular Cytokine Solution to Improve Healing in Acute and Chronic Wound Models

    OpenAIRE

    Franz, Michael G.; Payne, Wyatt G.; Xing, Liyu; Naidu, D. K; Salas, R. E; Marshall, Vivienne S.; Trumpower, C. J; Smith, Charlotte A; Steed, David L.; Robson, M. C.

    2008-01-01

    Objective: Growth factors demonstrate mixed results improving wound healing. Amnion-derived multipotent cells release physiologic levels of growth factors and tissue inhibitors of metalloproteinases. This solution was tested in models of acute and chronic wound healing. Methods: Acute model: Sprague-Dawley rats underwent laparotomy incisions. The midline fascia was primed with phosphate-buffered saline, unconditioned media, or amnion-derived cellular cytokine suspension prior to incision. Bre...

  10. Optimization of Cellular Resources Evading Intra and Inter Tier Interference in Femto cells Equipped Macro cell Networks

    CERN Document Server

    Shakhakarmi, Niraj

    2012-01-01

    Cellular network resources are essential to be optimized in Femto cells equipped macro cell networks. This is achieved by increasing the cellular coverage and channel capacity, and reducing power usage and interference between femto cells and macro cells. In this paper, the optimization approach for cellular resources with installed femto cells in macro cell networks has been addressed by deploying smart antennas applications and effect power adaptation method which significantly optimize the cellular coverage, channel capacity, power usage, and intra and inter tier interference. The simulation results also illustrate the outstanding performance of this optimization methodology.

  11. Cell-Penetrating Peptides—Mechanisms of Cellular Uptake and Generation of Delivery Systems

    Directory of Open Access Journals (Sweden)

    Sara Trabulo

    2010-03-01

    Full Text Available The successful clinical application of nucleic acid-based therapeutic strategies has been limited by the poor delivery efficiency achieved by existing vectors. The development of alternative delivery systems for improved biological activity is, therefore, mandatory. Since the seminal observations two decades ago that the Tat protein, and derived peptides, can translocate across biological membranes, cell-penetrating peptides (CPPs have been considered one of the most promising tools to improve non-invasive cellular delivery of therapeutic molecules. Despite extensive research on the use of CPPs for this purpose, the exact mechanisms underlying their cellular uptake and that of peptide conjugates remain controversial. Over the last years, our research group has been focused on the S413-PV cell-penetrating peptide, a prototype of this class of peptides that results from the combination of 13-amino-acid cell penetrating sequence derived from the Dermaseptin S4 peptide with the SV40 large T antigen nuclear localization signal. By performing an extensive biophysical and biochemical characterization of this peptide and its analogs, we have gained important insights into the mechanisms governing the interaction of CPPs with cells and their translocation across biological membranes. More recently, we have started to explore this peptide for the intracellular delivery of nucleic acids (plasmid DNA, siRNA and oligonucleotides. In this review we discuss the current knowledge of the mechanisms responsible for the cellular uptake of cell-penetrating peptides, including the S413-PV peptide, and the potential of peptide-based formulations to mediate nucleic acid delivery.

  12. Network signatures of cellular immortalization in human lymphoblastoid cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Sung-Mi; Jung, So-Young; Nam, Hye-Young; Kim, Hye-Ryun; Lee, Mee-Hee; Kim, Jun-Woo; Han, Bok-Ghee [National Biobank of Korea, Center for Genome Science, Korea National Institute of Health, Osong 363-951 (Korea, Republic of); Jeon, Jae-Pil, E-mail: jaepiljeon@hanmail.net [Division of Brain Diseases, Center for Biomedical Science, Korea National Institute of Health, Osong 363-951 (Korea, Republic of)

    2013-11-15

    Highlights: •We identified network signatures of LCL immortalization from transcriptomic profiles. •More than 41% of DEGs are possibly regulated by miRNAs in LCLs. •MicroRNA target genes in LCLs are involved in apoptosis and immune-related functions. •This approach is useful to find functional miRNA targets in specific cell conditions. -- Abstract: Human lymphoblastoid cell line (LCL) has been used as an in vitro cell model in genetic and pharmacogenomic studies, as well as a good model for studying gene expression regulatory machinery using integrated genomic analyses. In this study, we aimed to identify biological networks of LCL immortalization from transcriptomic profiles of microRNAs and their target genes in LCLs. We first selected differentially expressed genes (DEGs) and microRNAs (DEmiRs) between early passage LCLs (eLCLs) and terminally differentiated late passage LCLs (tLCLs). The in silico and correlation analysis of these DEGs and DEmiRs revealed that 1098 DEG–DEmiR pairs were found to be positively (n = 591 pairs) or negatively (n = 507 pairs) correlated with each other. More than 41% of DEGs are possibly regulated by miRNAs in LCL immortalizations. The target DEGs of DEmiRs were enriched for cellular functions associated with apoptosis, immune response, cell death, JAK–STAT cascade and lymphocyte activation while non-miRNA target DEGs were over-represented for basic cell metabolisms. The target DEGs correlated negatively with miR-548a-3p and miR-219-5p were significantly associated with protein kinase cascade, and the lymphocyte proliferation and apoptosis, respectively. In addition, the miR-106a and miR-424 clusters located in the X chromosome were enriched in DEmiR–mRNA pairs for LCL immortalization. In this study, the integrated transcriptomic analysis of LCLs could identify functional networks of biologically active microRNAs and their target genes involved in LCL immortalization.

  13. Analytical Results to Improve the Capacity of A Cellular System In Frequency Selective Rayleigh Fading Channel

    Directory of Open Access Journals (Sweden)

    Pravindra Kumar

    2010-10-01

    Full Text Available One of the biggest draw back of wireless environment is the limited bandwidth. However, the users sharing this limited bandwidth have been increased considerably by using SDMA technique that can enhancethe capacity of communication system. There are some techniques that can increase the capacity of the cellular system, these are- Spreading Technique, Error Control Coding Technique, Multipath Diversity Technique ( i.e. Rake Receiver, Smart Antenna Technique. In this paper we have used all these technique and examined how thecapacity of cellular system vary with varying the different parameters such as- the value of spreading factor, the number of Rake fingers, the number of interfering cells, value of directivity of Adaptive Antenna at base station. In the results we find that the capacity of a cellular system is varying with these parameters.

  14. Multifunctional non-viral gene vectors with enhanced stability, improved cellular and nuclear uptake capability, and increased transfection efficiency

    Science.gov (United States)

    Yang, Zhe; Jiang, Zhaozhong; Cao, Zhong; Zhang, Chao; Gao, Di; Luo, Xingen; Zhang, Xiaofang; Luo, Huiyan; Jiang, Qing; Liu, Jie

    2014-08-01

    We have developed a new multifunctional, non-viral gene delivery platform consisting of cationic poly(amine-co-ester) (PPMS) for DNA condensation, PEG shell for nanoparticle stabilization, poly(γ-glutamic acid) (γ-PGA) and mTAT (a cell-penetrating peptide) for accelerated cellular uptake, and a nuclear localization signal peptide (NLS) for enhanced intracellular transport of DNA to the nucleus. In vitro study showed that coating of the binary PPMS/DNA polyplex with γ-PGA promotes cellular uptake of the polyplex particles, particularly by γ-glutamyl transpeptidase (GGT)-positive cells through the GGT-mediated endocytosis pathway. Conjugating PEG to the γ-PGA led to the formation of a ternary PPMS/DNA/PGA-g-PEG polyplex with decreased positive charges on the surface of the polyplex particles and substantially higher stability in serum-containing aqueous medium. The cellular uptake rate was further improved by incorporating mTAT into the ternary polyplex system. Addition of the NLS peptide was designed to facilitate intracellular delivery of the plasmid to the nucleus--a rate-limiting step in the gene transfection process. As a result, compared with the binary PPMS/LucDNA polyplex, the new mTAT-quaternary PPMS/LucDNA/NLS/PGA-g-PEG-mTAT system exhibited reduced cytotoxicity, remarkably faster cellular uptake rate, and enhanced transport of DNA to the nucleus. All these advantageous functionalities contribute to the remarkable gene transfection efficiency of the mTAT-quaternary polyplex both in vitro and in vivo, which exceeds that of the binary polyplex and commercial Lipofectamine™ 2000/DNA lipoplex. The multifunctional mTAT-quaternary polyplex system with improved efficiency and reduced cytotoxicity represents a new type of promising non-viral vectors for the delivery of therapeutic genes to treat tumors.We have developed a new multifunctional, non-viral gene delivery platform consisting of cationic poly(amine-co-ester) (PPMS) for DNA condensation, PEG shell

  15. Cellular adhesome screen identifies critical modulators of focal adhesion dynamics, cellular traction forces and cell migration behaviour.

    Science.gov (United States)

    Fokkelman, Michiel; Balcıoğlu, Hayri E; Klip, Janna E; Yan, Kuan; Verbeek, Fons J; Danen, Erik H J; van de Water, Bob

    2016-01-01

    Cancer cells migrate from the primary tumour into surrounding tissue in order to form metastasis. Cell migration is a highly complex process, which requires continuous remodelling and re-organization of the cytoskeleton and cell-matrix adhesions. Here, we aimed to identify genes controlling aspects of tumour cell migration, including the dynamic organization of cell-matrix adhesions and cellular traction forces. In a siRNA screen targeting most cell adhesion-related genes we identified 200+ genes that regulate size and/or dynamics of cell-matrix adhesions in MCF7 breast cancer cells. In a subsequent secondary screen, the 64 most effective genes were evaluated for growth factor-induced cell migration and validated by tertiary RNAi pool deconvolution experiments. Four validated hits showed significantly enlarged adhesions accompanied by reduced cell migration upon siRNA-mediated knockdown. Furthermore, loss of PPP1R12B, HIPK3 or RAC2 caused cells to exert higher traction forces, as determined by traction force microscopy with elastomeric micropillar post arrays, and led to considerably reduced force turnover. Altogether, we identified genes that co-regulate cell-matrix adhesion dynamics and traction force turnover, thereby modulating overall motility behaviour. PMID:27531518

  16. Hetero-cellular prototyping by synchronized multi-material bioprinting for rotary cell culture system.

    Science.gov (United States)

    Snyder, Jessica; Son, Ae Rin; Hamid, Qudus; Wu, Honglu; Sun, Wei

    2016-03-01

    Bottom-up tissue engineering requires methodological progress of biofabrication to capture key design facets of anatomical arrangements across micro, meso and macro-scales. The diffusive mass transfer properties necessary to elicit stability and functionality require hetero-typic contact, cell-to-cell signaling and uniform nutrient diffusion. Bioprinting techniques successfully build mathematically defined porous architecture to diminish resistance to mass transfer. Current limitations of bioprinted cell assemblies include poor micro-scale formability of cell-laden soft gels and asymmetrical macro-scale diffusion through 3D volumes. The objective of this work is to engineer a synchronized multi-material bioprinter (SMMB) system which improves the resolution and expands the capability of existing bioprinting systems by packaging multiple cell types in heterotypic arrays prior to deposition. This unit cell approach to arranging multiple cell-laden solutions is integrated with a motion system to print heterogeneous filaments as tissue engineered scaffolds and nanoliter droplets. The set of SMMB process parameters control the geometric arrangement of the combined flow's internal features and constituent material's volume fractions. SMMB printed hepatocyte-endothelial laden 200 nl droplets are cultured in a rotary cell culture system (RCCS) to study the effect of microgravity on an in vitro model of the human hepatic lobule. RCCS conditioning for 48 h increased hepatocyte cytoplasm diameter 2 μm, increased metabolic rate, and decreased drug half-life. SMMB hetero-cellular models present a 10-fold increase in metabolic rate, compared to SMMB mono-culture models. Improved bioprinting resolution due to process control of cell-laden matrix packaging as well as nanoliter droplet printing capability identify SMMB as a viable technique to improve in vitro model efficacy. PMID:26759993

  17. Whole genome bisulfite sequencing of cell-free DNA and its cellular contributors uncovers placenta hypomethylated domains

    OpenAIRE

    Jensen, Taylor J.; Kim, Sung K; Zhu, Zhanyang; Chin, Christine; Gebhard, Claudia; Lu, Tim; Deciu, Cosmin; Van den Boom, Dirk; Ehrich, Mathias

    2015-01-01

    Background Circulating cell-free fetal DNA has enabled non-invasive prenatal fetal aneuploidy testing without direct discrimination of the maternal and fetal DNA. Testing may be improved by specifically enriching the sample material for fetal DNA. DNA methylation may allow for such a separation of DNA; however, this depends on knowledge of the methylomes of circulating cell-free DNA and its cellular contributors. Results We perform whole genome bisulfite sequencing on a set of unmatched sampl...

  18. Improving solubility, stability, and cellular uptake of resveratrol by nanoencapsulation with chitosan and γ-poly (glutamic acid).

    Science.gov (United States)

    Jeon, Young Ok; Lee, Ji-Soo; Lee, Hyeon Gyu

    2016-11-01

    Resveratrol (RES), a polyphenolic compound found in grape skins, is a potent antioxidant with broad health benefits. However, its utilization in food has been limited by its poor water solubility, instability, and low bioavailability. The purpose of this study is to improve the solubility, stability, and cellular uptake of RES by nanoencapsulation using chitosan (CS) and γ-poly (glutamic acid) (γ-PGA). The size of nanoparticles significantly decreases with a decrease in the CS/γ-PGA ratio (p<0.05). The nanoparticle size with CS/γ-PGA ratio of 5 was 100-150nm. The entrapment efficiency and UV-light protection effect significantly increases (p<0.05), with an increase in the CS and γ-PGA concentration. The solubility of RES increases 3.2 and 4.2 times before and after lyophilization by nanoencapsulation, respectively. Compared with non-nanoencapsulated RES, the nanoencapsulated RES tends to maintain its solubility and antioxidant activity during storage. CS/γ-PGA nanoencapsulation was able to significantly enhance the transport of RES across a Caco-2 cell monolayer (p<0.05). The highest cellular uptake was found for nanoparticles prepared with 0.5mg/mL CS and 0.1mg/mL γ-PGA, which showed the highest solubility and antioxidant activity during storage. Therefore, CS/γ-PGA nanoencapsulation is found to be a potentially valuable technique for improving the solubility, stability, and cellular uptake of RES. PMID:27518454

  19. The Improved Cellular Automata and Its Application in Delineation of Urban Spheres of Influence

    Directory of Open Access Journals (Sweden)

    Yu Deng

    2014-12-01

    Full Text Available The issue of spatial diffusion and pattern division of traditional cellular automata (CA has drawn widespread attention and generated extensive work by scholars. However, there are many deficiencies in traditional configurations of CA neighborhoods, which reduce simulation accuracy. The effect of improved methods of traditional configurations of CA neighborhoods is not obvious, and its interoperability is not strong. Therefore, this paper firstly puts forward the concept of the circular neighborhood of CA constrained by the space metric method based on map algebra, and compares the spatial division pattern and anisotropy of different types of neighborhoods in detail. Then, the CA’s weighted diffusion model is discussed to delineate urban spheres of influence in Henan Province. Finally, Weibo data is used to justify a reasonable delineation of urban spheres of influence and can correctly reflect the state of regional development, further proving that improved cellular automata in algorithms and applications have great significance.

  20. Improved Analysis of Co-Channel Interference in Cellular Communications Systems

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zu-fan; DU Hui-ping; ZHU Wei-le

    2005-01-01

    In terms of the carrier-to-interference-ratio, the performance of co-channel interference in cellular communications systems is studied. The approach is based on an improved analysis, which allows to take into account some area in the desired sector may not be interfered by some co-channel sectors with exact geometrical analysis, instead of the entire sector interfered by some co-channel sectors. Other features, such as power control and the number of interferences are also included.

  1. Cellular uptake of antisense oligonucleotides after complexing or conjugation with cell-penetrating model peptides.

    Science.gov (United States)

    Oehlke, J; Birth, P; Klauschenz, E; Wiesner, B; Beyermann, M; Oksche, A; Bienert, M

    2002-08-01

    The uptake by mammalian cells of phosphorothioate oligonucleotides was compared with that of their respective complexes or conjugates with cationic, cell-penetrating model peptides of varying helix-forming propensity and amphipathicity. An HPLC-based protocol for the synthesis and purification of disulfide bridged conjugates in the 10-100 nmol range was developed. Confocal laser scanning microscopy (CLSM) in combination with gel-capillary electrophoresis and laser induced fluorescence detection (GCE-LIF) revealed cytoplasmic and nuclear accumulationin all cases. The uptake differences between naked oligonucleotides and their respective peptide complexes or conjugates were generally confined to one order of magnitude. No significant influence of the structural properties of the peptide components upon cellular uptake was found. Our results question the common belief that the increased biological activity of oligonucleotides after derivatization with membrane permeable peptides may be primarily due to improved membrane translocation.

  2. An overview on "cellular cannibalism" with special reference to oral squamous cell carcinoma.

    Science.gov (United States)

    Jain, M

    2015-12-01

    Cellular cannibalism has been defined as a large cell engulfing a slightly smaller one within its cytoplasm. It has been described in various cancers like bladder cancer, breast cancer, lung cancer, gastric cancer, oral squamous cell carcinoma. Cellular cannibalism has been well correlated with anaplasia, tumor aggressiveness, grading and metastatic potential. Present review focuses on significance of cannibalism in relation to cancer with special emphasis on oral squamous cell carcinoma. PMID:26710834

  3. Enhanced cellular delivery of cell-penetrating peptide-peptide nucleic acid conjugates by photochemical internalization

    DEFF Research Database (Denmark)

    Shiraishi, Takehiko; Nielsen, Peter E

    2011-01-01

    )) or tetraphenylporphyrin tetrasulfonic acid (TPPS). Cellular uptake of the PNA conjugates were evaluated by using a sensitive cellular method with HeLa pLuc705 cells based on the splicing correction of luciferase gene by targeting antisense oligonucleotides to a cryptic splice site of the mutated luciferase gene....... The cellular efficacy of CPP conjugates were evaluated by measuring luciferase activity as a result of splicing correction and was also confirmed by RT-PCR analysis of luciferase pre-mRNA....

  4. CellFIT: a cellular force-inference toolkit using curvilinear cell boundaries.

    Directory of Open Access Journals (Sweden)

    G Wayne Brodland

    Full Text Available Mechanical forces play a key role in a wide range of biological processes, from embryogenesis to cancer metastasis, and there is considerable interest in the intuitive question, "Can cellular forces be inferred from cell shapes?" Although several groups have posited affirmative answers to this stimulating question, nagging issues remained regarding equation structure, solution uniqueness and noise sensitivity. Here we show that the mechanical and mathematical factors behind these issues can be resolved by using curved cell edges rather than straight ones. We present a new package of force-inference equations and assessment tools and denote this new package CellFIT, the Cellular Force Inference Toolkit. In this approach, cells in an image are segmented and equilibrium equations are constructed for each triple junction based solely on edge tensions and the limiting angles at which edges approach each junction. The resulting system of tension equations is generally overdetermined. As a result, solutions can be obtained even when a modest number of edges need to be removed from the analysis due to short length, poor definition, image clarity or other factors. Solving these equations yields a set of relative edge tensions whose scaling must be determined from data external to the image. In cases where intracellular pressures are also of interest, Laplace equations are constructed to relate the edge tensions, curvatures and cellular pressure differences. That system is also generally overdetermined and its solution yields a set of pressures whose offset requires reference to the surrounding medium, an open wound, or information external to the image. We show that condition numbers, residual analyses and standard errors can provide confidence information about the inferred forces and pressures. Application of CellFIT to several live and fixed biological tissues reveals considerable force variability within a cell population, significant differences

  5. Non-Chemical Distant Cellular Interactions as a potential confounder of Cell Biology Experiments

    Directory of Open Access Journals (Sweden)

    Ashkan eFarhadi

    2014-10-01

    Full Text Available Distant cells can communicate with each other through a variety of methods. Two such methods involve electrical and/or chemical mechanisms. Non-chemical, distant cellular interactions may be another method of communication that cells can use to modify the behavior of other cells that are mechanically separated. Moreover, non-chemical, distant cellular interactions may explain some cases of confounding effects in Cell Biology experiments. In this article, we review non-chemical, distant cellular interactions studies to try to shed light on the mechanisms in this highly unconventional field of cell biology. Despite the existence of several theories that try to explain the mechanism of non-chemical, distant cellular interactions, this phenomenon is still speculative. Among candidate mechanisms, electromagnetic waves appear to have the most experimental support. In this brief article, we try to answer a few key questions that may further clarify this mechanism.

  6. Normalizing for individual cell population context in the analysis of high-content cellular screens

    Directory of Open Access Journals (Sweden)

    Knapp Bettina

    2011-12-01

    Full Text Available Abstract Background High-content, high-throughput RNA interference (RNAi offers unprecedented possibilities to elucidate gene function and involvement in biological processes. Microscopy based screening allows phenotypic observations at the level of individual cells. It was recently shown that a cell's population context significantly influences results. However, standard analysis methods for cellular screens do not currently take individual cell data into account unless this is important for the phenotype of interest, i.e. when studying cell morphology. Results We present a method that normalizes and statistically scores microscopy based RNAi screens, exploiting individual cell information of hundreds of cells per knockdown. Each cell's individual population context is employed in normalization. We present results on two infection screens for hepatitis C and dengue virus, both showing considerable effects on observed phenotypes due to population context. In addition, we show on a non-virus screen that these effects can be found also in RNAi data in the absence of any virus. Using our approach to normalize against these effects we achieve improved performance in comparison to an analysis without this normalization and hit scoring strategy. Furthermore, our approach results in the identification of considerably more significantly enriched pathways in hepatitis C virus replication than using a standard analysis approach. Conclusions Using a cell-based analysis and normalization for population context, we achieve improved sensitivity and specificity not only on a individual protein level, but especially also on a pathway level. This leads to the identification of new host dependency factors of the hepatitis C and dengue viruses and higher reproducibility of results.

  7. Accurate assessment of cell density in low cellular liquid-based cervical cytology

    NARCIS (Netherlands)

    Siebers, A.G.; Laak, J.A.W.M. van der; Huberts-Manders, R.; Vedder, J.E.M.; Bulten, J.

    2013-01-01

    A. G. Siebers, J. A. W. M. van der Laak, R. Huberts-Manders, J. E. M. Vedder and J. Bulten Accurate assessment of cell density in low cellular liquid-based cervical cytology Objective: Scant cellularity is the most important source of unsatisfactory liquid-based cytology. Although still being debate

  8. Quantum Dots Encapsulated with Canine Parvovirus-Like Particles Improving the Cellular Targeted Labeling.

    Directory of Open Access Journals (Sweden)

    Dan Yan

    Full Text Available Quantum dots (QDs have a promising prospect in live-cell imaging and sensing because of unique fluorescence features. QDs aroused significant interest in the bio-imaging field through integrating the fluorescence properties of QDs and the delivery function of biomaterial. The natural tropism of Canine Parvovirus (CPV to the transferrin receptor can target specific cells to increase the targeting ability of QDs in cell imaging. CPV virus-like particles (VLPs from the expression of the CPV-VP2 capsid protein in a prokaryotic expression system were examined to encapsulate the QDs and deliver to cells with an expressed transferrin receptor. CPV-VLPs were used to encapsulate QDs that were modified using 3-mercaptopropionic acid. Gel electrophoresis, fluorescence spectrum, particle size, and transmission electron microscopy verified the conformation of a complex, in which QDs were encapsulated in CPV-VLPs (CPV-VLPs-QDs. When incubated with different cell lines, CPV-VLPs-QDs significantly reduced the cytotoxicity of QDs and selectively labeled the cells with high-level transferrin receptors. Cell-targeted labeling was achieved by utilizing the specific binding between the CPV capsid protein VP2 of VLPs and cellular receptors. CPV-VLPs-QDs, which can mimic the native CPV infection, can recognize and attach to the transferrin receptors on cellular membrane. Therefore, CPV-VLPs can be used as carriers to facilitate the targeted delivery of encapsulated nanomaterials into cells via receptor-mediated pathways. This study confirmed that CPV-VLPs can significantly promote the biocompatibility of nanomaterials and could expand the application of CPV-VLPs in biological medicine.

  9. Dual-drug delivery by porous silicon nanoparticles for improved cellular uptake, sustained release, and combination therapy.

    Science.gov (United States)

    Wang, Chang-Fang; Mäkilä, Ermei M; Kaasalainen, Martti H; Hagström, Marja V; Salonen, Jarno J; Hirvonen, Jouni T; Santos, Hélder A

    2015-04-01

    Dual-drug delivery of antiangiogenic and chemotherapeutic drugs can enhance the therapeutic effect for cancer therapy. Conjugation of methotrexate (MTX) to porous silicon (PSi) nanoparticles (MTX-PSi) with positively charged surface can improve the cellular uptake of MTX and inhibit the proliferation of cancer cells. Herein, MTX-PSi conjugates sustained the release of MTX up to 96 h, and the released fragments including MTX were confirmed by mass spectrometry. The intracellular distribution of the MTX-PSi nanoparticles was confirmed by transmission electron microscopy. Compared to pure MTX, the MTX-PSi achieved similar inhibition of cell proliferation in folate receptor (FR) over-expressing U87 MG cancer cells, and a higher effect in low FR-expressing EA.hy926 cells. Nuclear fragmentation analysis demonstrated programmed cell apoptosis of MTX-PSi in the high/low FR-expressing cancer cells, whereas PSi alone at the same dose had a minor effect on cell apoptosis. Finally, the porous structure of MTX-PSi enabled a successful concomitant loading of another anti-angiogenic hydrophobic drug, sorafenib, and considerably enhanced the dissolution rate of sorafenib. Overall, the MTX-PSi nanoparticles can be used as a platform for combination chemotherapy by simultaneously enhancing the dissolution rate of a hydrophobic drug and sustaining the release of a conjugated chemotherapeutic drug.

  10. An improved assay for antibody dependent cellular cytotoxicity based on time resolved fluorometry.

    Science.gov (United States)

    Patel, A K; Boyd, P N

    1995-07-17

    A new and faster assay for antibody dependent cellular cytotoxicity based on release of europium from target cells is described. This has a number of important advantages over the traditional assays based on release of chromium-51 (51Cr). The new method involves labelling of Wein 133 target cells (B cell non-Hodgkin's lymphoma cells) which express the antigen, CDw52, with the chelate europium diethylenetriaminopentaacetic acid (EuDTPA) according to the method of Blomberg et al. (1986). Labelled cells are sensitised (coated) with the anti-lymphocytic monoclonal antibody, Campath-1H. Human peripheral blood mononuclear cells are added to mediate lysis of EuDTPA labelled Wein 133 cells by ADCC. Release of EuDTPA from lysed cells is determined by mixing supernatants with enhancement solution containing 2-naphthoyl trifluoroacetone, 2-NTA, to form a highly fluorescent chelate which is measured using time resolved fluorometry. Results obtained with the new EuDPTA release assays were comparable to traditional assays based on the release of the radioisotope 51Cr. It is anticipated that this assay will have a widespread application among laboratories performing ADCC assays. The method is non-hazardous and has been used routinely for over 2 years to monitor production and purification of Campath-1H. PMID:7622867

  11. Cellular Phone Towers, Cell Towers, Published in unknown, Norton County Appraisal Office.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Cellular Phone Towers dataset, was produced all or in part from Other information as of unknown. It is described as 'Cell Towers'. Data by this publisher are...

  12. Thermal Pretreatment Improves Viability of Cryopreserved Human Endothelial Cells.

    Science.gov (United States)

    Hofmann, Nicola; Sun, Huan; Chatterjee, Anamika; Saha, Debapriya; Glasmacher, Birgit

    2015-10-01

    A high survival rate of cryopreserved cells requires optimal cooling and thawing rates in the presence of a cryoprotective agent (CPA) or a combination of CPAs in adequate concentrations. One of the most widely used CPAs, dimethyl sulfoxide (Me2SO), however is toxic at high concentrations and has detrimental effects on cellular functions. Additional processing steps are necessary to remove the CPA after thawing, which make the process expensive and time consuming. Therefore it is of great interest to develop new cryoprotective strategies to replace the currently used CPAs or to reduce their concentration. The aim of this study was to investigate if thermal activation of human pulmonary microvascular endothelial cells (HPMEC ST-1.6R), prior to cryopreservation, could improve their post-thaw viability since the resulting heat shock protein expression acts as an intrinsic cellular protection mechanism. The results of this study suggest that both heat and cold shock pretreatments improve cryopreservation outcome of the HPMEC ST-1.6R cells. By re-cultivating cells after heat shock treatment before cryopreservation, a significant increase in cellular membrane integrity and adherence capacity could be achieved. However a combination of thermal activation and cryopreservation with alternative CPAs such as ectoine and L-proline could not further enhance the cell viability. The results of this study showed that pretreatment of endothelial cells with thermal activation could be used to reduce the Me2SO concentration required in order to preserve cell viability after cryopreservation. PMID:26419006

  13. A new method for decreasing cell-load variation in dynamic cellular manufacturing systems

    OpenAIRE

    Aidin Delgoshaei; Mohd Khairol Mohd Ariffin,; Btht Hang Tuah Bin Baharudin; Zulkiflle Leman

    2016-01-01

    Cell load variation is considered a significant shortcoming in scheduling of cellular manufacturing systems. In this article, a new method is proposed for scheduling dynamic cellular manufacturing systems in the presence of bottleneck and parallel machines. The aim of this method is to control cell load variation during the process of determining the best trading off values between in-house manufacturing and outsourcing. A genetic algorithm (GA) is developed because of the high potential of t...

  14. Cellular aging of mitochondrial DNA-depleted cells

    International Nuclear Information System (INIS)

    We have reported that mitochondrial DNA-depleted ρ0 cells are resistant to cell death. Because aged cells have frequent mitochondrial DNA mutations, the resistance of ρ0 cells against cell death might be related to the apoptosis resistance of aged cells and frequent development of cancers in aged individuals. We studied if ρ0 cells have features simulating aged cells. SK-Hep1 hepatoma ρ0 cells showed typical morphology associated with aging such as increased size and elongated appearance. They had increased senescence-associated β-Gal activity, lipofuscin pigment, and plasminogen activator inhibitor-1 expression. Consistent with their decreased proliferation, the expression of mitotic cyclins was decreased and that of cdk inhibitors was increased. Rb hypophosphorylation and decreased telomerase activity were also noted. Features simulating aged cells were also observed in MDA-MB-435 ρ0 cells. These results support the mitochondrial theory of aging, and suggest that ρ0 cells could serve as an in vitro model for aged cells

  15. Strategies to improve homing of mesenchymal stem cells for greater efficacy in stem cell therapy.

    Science.gov (United States)

    Naderi-Meshkin, Hojjat; Bahrami, Ahmad Reza; Bidkhori, Hamid Reza; Mirahmadi, Mahdi; Ahmadiankia, Naghmeh

    2015-01-01

    Stem/progenitor cell-based therapeutic approach in clinical practice has been an elusive dream in medical sciences, and improvement of stem cell homing is one of major challenges in cell therapy programs. Stem/progenitor cells have a homing response to injured tissues/organs, mediated by interactions of chemokine receptors expressed on the cells and chemokines secreted by the injured tissue. For improvement of directed homing of the cells, many techniques have been developed either to engineer stem/progenitor cells with higher amount of chemokine receptors (stem cell-based strategies) or to modulate the target tissues to release higher level of the corresponding chemokines (target tissue-based strategies). This review discusses both of these strategies involved in the improvement of stem cell homing focusing on mesenchymal stem cells as most frequent studied model in cellular therapies.

  16. Photoenzyme probes of photodamage to cells and cellular DNA

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, B. M.

    1979-01-01

    Development of photoenzyme probes for detection of ultraviolet damage to cells and DNA is reviewed with special emphasis on a process using polyethylene glycol to induce cell fusion. Polyethylene glycol is easy to obtain and handle, is gentle to the cells and does not induce latent or productive virus infection; therefore, it may be a general method for insertion of exogenous enzymes into mammalian cells. (PCS)

  17. Potential cellular receptors involved in hepatitis C virus entry into cells

    Directory of Open Access Journals (Sweden)

    Muellhaupt Beat

    2005-04-01

    Full Text Available Abstract Hepatitis C virus (HCV infects hepatocytes and leads to permanent, severe liver damage. Since the genomic sequence of HCV was determined, progress has been made towards understanding the functions of the HCV-encoded proteins and identifying the cellular receptor(s responsible for adsorption and penetration of the virus particle into the target cells. Several cellular receptors for HCV have been proposed, all of which are associated with lipid and lipoprotein metabolism. This article reviews the cellular receptors for HCV and suggests a general model for HCV entry into cells, in which lipoproteins play a crucial role.

  18. Processing and properties of multiscale cellular thermoplastic fiber reinforced composite (CellFRC)

    Science.gov (United States)

    Sorrentino, L.; Cafiero, L.; D'Auria, M.; Iannace, S.

    2015-12-01

    High performance fiber reinforced polymer composites are made by embedding high strength/modulus fibers in a polymeric matrix. They are a class of materials that owe its success to the impressive specific mechanical properties with respect to metals. In many weight-sensitive applications, where high mechanical properties and low mass are required, properties per unit of mass are more important than absolute properties and further weight reduction is desirable. A route to reach this goal could be the controlled induction of porosity into the polymeric matrix, while still ensuring load transfer to the reinforcing fibers and fiber protection from the environment. Cellular lightweight fiber reinforced composites (CellFRC) were prepared embedding gas bubbles of controlled size within a high performance thermoplastic matrix reinforced with continuous fibers. Pores were induced after the composite was first saturated with CO2 and then foamed by using an in situ foaming/shaping technology based on compression moulding with adjustable mould cavities. The presence of micro- or submicro-sized cells in the new CellFRC reduced the apparent density of the structure and led to significant improvements of its impact properties. Both structural and functional performances were further improved through the use of a platelet-like nanofiller (Expanded Graphite) dispersed into the matrix.

  19. Quantitative evaluation of mast cells in cellularly dynamic and adynamic vascular malformations.

    Science.gov (United States)

    Pasyk, K A; Cherry, G W; Grabb, W C; Sasaki, G H

    1984-01-01

    Mast cells were counted in 78 histologic specimens from 70 patients with various vascular malformations showing cellularly dynamic and cellularly adynamic lesions. In growing stages of strawberry hemangiomas, there was an increased number of mast cells (mean 11.0 cells per high-power field in stage III and 23.7 in stage IV), as well as a high number of mast cells in the initial involution of strawberry hemangiomas (stage V, mean 21.0 cells per high-power field). In later involuting stages (stages VI and VII), the number of mast cells decreased (mean 9.3 in stage VI; mean 4.7 in stage VII). In cellularly adynamic lesions, i.e., port wine stains, the mean number of mast cells was 4.8, and in congenital arteriovenous malformations, it was 3.6. In normal skin, the mean number of mast cells was 3.2. In cellular hemangiomas that showed active growth (stages III to IV), the number of mast cells was strikingly low (mean 1.3). It seems that the mast cells are not responsible for the proliferation of the endothelium or for growth of the hemangioma. The markedly increased number of mast cells in the growing stages and initial involuting stage of strawberry hemangiomas parallels the gradual growth of fibrous connective tissue inside the tumor. Mast cells may thus be a precursor of the beginning of the involution of a strawberry hemangioma. PMID:6691077

  20. Multispectral fingerprinting for improved in vivo cell dynamics analysis

    Directory of Open Access Journals (Sweden)

    Cooper Cameron HJ

    2010-09-01

    Full Text Available Abstract Background Tracing cell dynamics in the embryo becomes tremendously difficult when cell trajectories cross in space and time and tissue density obscure individual cell borders. Here, we used the chick neural crest (NC as a model to test multicolor cell labeling and multispectral confocal imaging strategies to overcome these roadblocks. Results We found that multicolor nuclear cell labeling and multispectral imaging led to improved resolution of in vivo NC cell identification by providing a unique spectral identity for each cell. NC cell spectral identity allowed for more accurate cell tracking and was consistent during short term time-lapse imaging sessions. Computer model simulations predicted significantly better object counting for increasing cell densities in 3-color compared to 1-color nuclear cell labeling. To better resolve cell contacts, we show that a combination of 2-color membrane and 1-color nuclear cell labeling dramatically improved the semi-automated analysis of NC cell interactions, yet preserved the ability to track cell movements. We also found channel versus lambda scanning of multicolor labeled embryos significantly reduced the time and effort of image acquisition and analysis of large 3D volume data sets. Conclusions Our results reveal that multicolor cell labeling and multispectral imaging provide a cellular fingerprint that may uniquely determine a cell's position within the embryo. Together, these methods offer a spectral toolbox to resolve in vivo cell dynamics in unprecedented detail.

  1. Cellular Adhesion Tripeptide RGD Inhibits Growth of Human Ileocecal Adenocarcinoma Cells HCT-8 and Induces Apoptosis

    Institute of Scientific and Technical Information of China (English)

    WANG Hua; ZENG Hong-bin; YANG Shao-juan; GAO Shen; HUANG Yi-bing; HOU Rui-zhen; ZHAO Mi-feng; XU Li; ZHANG Xue-zhong

    2007-01-01

    The tripeptide, Arg-Gly-Asp(RGD) motif is an integrin-recognition site found in adhesive proteins present in extracellular matrices(ECM) and in the blood. HCT-8 cells were treated with cellular adhesion tripeptide RGD at various concentrations. MTT assay was performed to examine the growth and proliferation of HCT-8 cells after treatment with RGD for 48 h. Haematoxylin and Eosin(HE) staining and electromicroscope were used to observe the morphology of apoptotic cells. Survivin and flow cytometry were also used to analyze the HCT-8 apoptosis. Cellular adhesion tripeptide RGD significantly inhibits the growth and proliferation of HCT-8 cells in a dose-dependent manner and induces apoptosis of HCT-8. These results indicate that cellular adhesion tripeptide RGD inhibits the growth and proliferation of tumor HCT-8 cell, probably by the aid of inducing apoptosis of HCT-8 cell.

  2. Cellular spectroscopy: applications to cancer stem cell characterization

    Science.gov (United States)

    Wiegand, G.; Xin, H.; Anderson, A.; Mullinax, J.; Jaiswal, K.; Wiegand, A.; Avital, Itzhak

    2011-02-01

    Spectroscopic and light scattering methods were used to gain insight into the existence and characterization of the cancer stem cell. Fundamental technical description of devices used have been reported elsewhere. We included alterations and implementation of these biophotonic instruments as applied to our objectives. We disassociated human tumor and submitted the cells to optical characterization to support our working hypothesis of stem cell origins to cancer and mechanisms. Single cell combined with population based analysis within the Pancreatic cancer system led us to information regarding the polarization state of cells possessing anchor proteins and drug influx pumps. Multispectral imaging combined with flow cytometry enabled us to target rare cells that appear to retain template DNA. rendering them resistant to anti-cancer drug therapy. In this study we describe an optical method that combines high-throughput population pattern and correlates each cell with an individual fluorescent and bright-field image.

  3. Creating new β cells: cellular transmutation by genomic alchemy.

    Science.gov (United States)

    Moss, Larry G

    2013-03-01

    To address insulin insufficiency, diabetes research has long focused on techniques for replacing insulin-producing β cells. Studies in mice have suggested that, under some conditions, α cells possess the capacity to transdifferentiate into β cells, although the mechanisms that drive this conversion are unclear. In this issue, Bramswig et al. analyzed the methylation states of purified human α, β, and acinar cells and found α cells exhibit intrinsic phenotypic plasticity associated with specific histone methylation profiles. In addition to expanding our understanding of this potential source of β cells, this compendium of carefully generated human gene expression and epigenomic data in islet cell subtypes constitutes a truly valuable resource for the field. PMID:23434598

  4. Targeted Nanogel Conjugate for Improved Stability and Cellular Permeability of Curcumin: Synthesis, Pharmacokinetics, and Tumor Growth Inhibition

    Science.gov (United States)

    2015-01-01

    Curcumin (CUR) is a unique natural compound with promising anticancer and anti-inflammatory activities. However, the therapeutic efficacy of curcumin was challenged in clinical trials, mostly due to its low bioavailability, rapid metabolism, and elimination. We designed a nanodrug form of curcumin, which makes it stable and substantially enhances cellular permeability and anticancer activity at standard oral administration. Curcumin was conjugated as an ester to cholesteryl-hyaluronic acid (CHA) nanogel that is capable of targeted delivery to CD44-expressing drug-resistant cancer cells. CHA-CUR nanogels demonstrated excellent solubility and sustained drug release in physiological conditions. It induced apoptosis in cancer cells, suppressing the expression of NF-κB, TNF-α, and COX-2 cellular targets similar to free curcumin. Pharmacokinetic/pharmacodynamic (PK/PD) studies also revealed improved circulation parameters of CHA-CUR at oral, i.p. and i.v. administration routes. CHA-CUR showed targeted tumor accumulation and effective tumor growth inhibition in human pancreatic adenocarcinoma MiaPaCa-2 and aggressive orthotropic murine mammary carcinoma 4T1 animal models. CHA-CUR treatment was well-tolerated and resulted in up to 13-fold tumor suppression, making this nanodrug a potential candidate for cancer prevention and therapeutic treatment. PMID:25072100

  5. Study on Effect of Aloe Glue on Cytogenetics, Cellular Immunity and Cell Proliferation of Human Cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jiahua; WEN Shaluo; XIA Yun; ZHANG Lijun

    2002-01-01

    Objective To provide the scientific evidence for the exploiture of aloe resource. Methods Cytological combined determination was used to study the effect of aloe glue(0.01 ~ 0.3ml) on cytogenetics, cellular immunity and cell proliferation of human cells. Results SCE and MNR in varying dose groups had no significant differences as compared with control group( P > 0.05). LTR was significantly higher than that of control group(P < 0.005). MI was significantly higher than that of control group ( P < 0.05). M3 and PRI in highest dose group had significant differences as compared with control group (P < 0.05). Conclusion Aloe gel had no significant effect on cytogenetics. But it had activating effects on immunity and proliferation of cells.

  6. Stalk cell differentiation without polyketides in the cellular slime mold.

    Science.gov (United States)

    Sato, Yukie G; Suarez, Teresa; Saito, Tamao

    2016-07-01

    Polyketides induce prestalk cell differentiation in Dictyostelium. In the double-knockout mutant of the SteelyA and B polyketide synthases, most of the pstA cells-the major part of the prestalk cells-are lost, and we show by whole mount in situ hybridization that expression of prestalk genes is also reduced. Treatment of the double-knockout mutant with the PKS inhibitor cerulenin gave a further reduction, but some pstA cells still remained in the tip region, suggesting the existence of a polyketide-independent subtype of pstA cells. The double-knockout mutant and cerulenin-treated parental Ax2 cells form fruiting bodies with fragile, single-cell layered stalks after cerulenin treatment. Our results indicate that most pstA cells are induced by polyketides, but the pstA cells at the very tip of the slug are induced in some other way. In addition, a fruiting body with a single-cell layered, vacuolated stalk can form without polyketides. PMID:27305283

  7. Cellular Interrogation: Exploiting Cell-to-Cell Variability to Discriminate Regulatory Mechanisms in Oscillatory Signalling

    Science.gov (United States)

    Gibson, Daniel; Chang, Frederick; Gnad, Florian; Gunawardena, Jeremy

    2016-01-01

    The molecular complexity within a cell may be seen as an evolutionary response to the external complexity of the cell’s environment. This suggests that the external environment may be harnessed to interrogate the cell’s internal molecular architecture. Cells, however, are not only nonlinear and non-stationary, but also exhibit heterogeneous responses within a clonal, isogenic population. In effect, each cell undertakes its own experiment. Here, we develop a method of cellular interrogation using programmable microfluidic devices which exploits the additional information present in cell-to-cell variation, without requiring model parameters to be fitted to data. We focussed on Ca2+ signalling in response to hormone stimulation, which exhibits oscillatory spiking in many cell types and chose eight models of Ca2+ signalling networks which exhibit similar behaviour in simulation. We developed a nonlinear frequency analysis for non-stationary responses, which could classify models into groups under parameter variation, but found that this question alone was unable to distinguish critical feedback loops. We further developed a nonlinear amplitude analysis and found that the combination of both questions ruled out six of the models as inconsistent with the experimentally-observed dynamics and heterogeneity. The two models that survived the double interrogation were mathematically different but schematically identical and yielded the same unexpected predictions that we confirmed experimentally. Further analysis showed that subtle mathematical details can markedly influence non-stationary responses under parameter variation, emphasising the difficulty of finding a “correct” model. By developing questions for the pathway being studied, and designing more versatile microfluidics, cellular interrogation holds promise as a systematic strategy that can complement direct intervention by genetics or pharmacology. PMID:27367445

  8. Murine cellular cytotoxicity to syngeneic and xenogeneic herpes simplex virus-infected cells.

    OpenAIRE

    Kohl, S; Drath, D B; Loo, L S

    1982-01-01

    Cellular cytotoxicity of C57BL/6 adult mice peritoneal cells to xenogeneic (Chang liver) and syngeneic (BL/6-WT3) herpes simplex virus (HSV)-infected cells was analyzed in a 6-h 51Cr release assay. There was no difference in antibody-dependent cellular cytotoxicity to either target. There was no natural killer cytotoxicity to targets with cells from uninfected mice except at very high effector cell ratios. HSV-infected (2 X 10(4) PFU intraperitoneally 1 day previously) mice mediated significa...

  9. Preplay of future place cell sequences by hippocampal cellular assemblies

    OpenAIRE

    Dragoi, George; Tonegawa, Susumu

    2010-01-01

    During spatial exploration, hippocampal neurons show a sequential firing pattern in which individual neurons fire specifically at particular locations along the animal’s trajectory (place cells1, 2). According to the dominant model of hippocampal cell assembly activity, place cell firing order is established for the first time during exploration, to encode the spatial experience, and is subsequently replayed during rest3, 4, 5, 6 or slow-wave sleep7, 8, 9, 10 for consolidation of the encoded ...

  10. Cell-based biosensors: Towards the development of cellular monitoring

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Cell-based biosensors (CBBs), a research hotspot of biosensors, which treat living cells as sensing elements, can detect the functional information of biologically active analytes. They characterize with high sensitivity, excellent selectivity and rapid response, and have been applied in many fields, such as biomedicine, environmental monitoring and pharmaceutical screening. Recently cell-cultured technology, silicon microfabrication technology and genetic technology have promoted exploration of CBBs dramatically. To elucidate the novel research findings and applications of cell- based biosensors, this paper summarizes various research approaches, presents some challenges and proposes the research trends.

  11. Matrix rigidity regulates cancer cell growth and cellular phenotype.

    Directory of Open Access Journals (Sweden)

    Robert W Tilghman

    Full Text Available BACKGROUND: The mechanical properties of the extracellular matrix have an important role in cell growth and differentiation. However, it is unclear as to what extent cancer cells respond to changes in the mechanical properties (rigidity/stiffness of the microenvironment and how this response varies among cancer cell lines. METHODOLOGY/PRINCIPAL FINDINGS: In this study we used a recently developed 96-well plate system that arrays extracellular matrix-conjugated polyacrylamide gels that increase in stiffness by at least 50-fold across the plate. This plate was used to determine how changes in the rigidity of the extracellular matrix modulate the biological properties of tumor cells. The cell lines tested fall into one of two categories based on their proliferation on substrates of differing stiffness: "rigidity dependent" (those which show an increase in cell growth as extracellular rigidity is increased, and "rigidity independent" (those which grow equally on both soft and stiff substrates. Cells which grew poorly on soft gels also showed decreased spreading and migration under these conditions. More importantly, seeding the cell lines into the lungs of nude mice revealed that the ability of cells to grow on soft gels in vitro correlated with their ability to grow in a soft tissue environment in vivo. The lung carcinoma line A549 responded to culture on soft gels by expressing the differentiated epithelial marker E-cadherin and decreasing the expression of the mesenchymal transcription factor Slug. CONCLUSIONS/SIGNIFICANCE: These observations suggest that the mechanical properties of the matrix environment play a significant role in regulating the proliferation and the morphological properties of cancer cells. Further, the multiwell format of the soft-plate assay is a useful and effective adjunct to established 3-dimensional cell culture models.

  12. Cellular plasticity of CD4+ T cells in the intestine

    Directory of Open Access Journals (Sweden)

    Verena eBrucklacher-Waldert

    2014-10-01

    Full Text Available Barrier sites such as the gastrointestinal tract are in constant contact with the environment which contains both beneficial and harmful components. The immune system at the epithelia must make the distinction between these components to balance tolerance, protection and immunopathology. This is achieved via multifaceted immune recognition, highly organised lymphoid structures and the interaction of many types of immune cells. The adaptive immune response in the gut is orchestrated by CD4+ helper T (Th cells which are integral to gut immunity. In recent years it has become apparent that the functional identity of these Th cells is not as fixed as initially thought. Plasticity in differentiated T cell subsets has now been firmly established, in both health and disease. The gut, in particular, utilises CD4+ T cell plasticity to mould CD4+ T cell phenotypes to maintain its finely poised balance of tolerance and inflammation and to encourage biodiversity within the enteric microbiome. In this review we will discuss intestinal helper T cell plasticity and our current understanding of its mechanisms, including our growing knowledge of an evolutionarily ancient symbiosis between microbiota and malleable CD4+ T cell effectors.

  13. Cellular Taxonomy of the Mouse Striatum as Revealed by Single-Cell RNA-Seq.

    Science.gov (United States)

    Gokce, Ozgun; Stanley, Geoffrey M; Treutlein, Barbara; Neff, Norma F; Camp, J Gray; Malenka, Robert C; Rothwell, Patrick E; Fuccillo, Marc V; Südhof, Thomas C; Quake, Stephen R

    2016-07-26

    The striatum contributes to many cognitive processes and disorders, but its cell types are incompletely characterized. We show that microfluidic and FACS-based single-cell RNA sequencing of mouse striatum provides a well-resolved classification of striatal cell type diversity. Transcriptome analysis revealed ten differentiated, distinct cell types, including neurons, astrocytes, oligodendrocytes, ependymal, immune, and vascular cells, and enabled the discovery of numerous marker genes. Furthermore, we identified two discrete subtypes of medium spiny neurons (MSNs) that have specific markers and that overexpress genes linked to cognitive disorders and addiction. We also describe continuous cellular identities, which increase heterogeneity within discrete cell types. Finally, we identified cell type-specific transcription and splicing factors that shape cellular identities by regulating splicing and expression patterns. Our findings suggest that functional diversity within a complex tissue arises from a small number of discrete cell types, which can exist in a continuous spectrum of functional states. PMID:27425622

  14. Cellular Taxonomy of the Mouse Striatum as Revealed by Single-Cell RNA-Seq

    Directory of Open Access Journals (Sweden)

    Ozgun Gokce

    2016-07-01

    Full Text Available The striatum contributes to many cognitive processes and disorders, but its cell types are incompletely characterized. We show that microfluidic and FACS-based single-cell RNA sequencing of mouse striatum provides a well-resolved classification of striatal cell type diversity. Transcriptome analysis revealed ten differentiated, distinct cell types, including neurons, astrocytes, oligodendrocytes, ependymal, immune, and vascular cells, and enabled the discovery of numerous marker genes. Furthermore, we identified two discrete subtypes of medium spiny neurons (MSNs that have specific markers and that overexpress genes linked to cognitive disorders and addiction. We also describe continuous cellular identities, which increase heterogeneity within discrete cell types. Finally, we identified cell type-specific transcription and splicing factors that shape cellular identities by regulating splicing and expression patterns. Our findings suggest that functional diversity within a complex tissue arises from a small number of discrete cell types, which can exist in a continuous spectrum of functional states.

  15. Cellular uptake of a dexamethasone palmitate-low density lipoprotein complex by macrophages and foam cells.

    Science.gov (United States)

    Tauchi, Yoshihiko; Chono, Sumio; Morimoto, Kazuhiro

    2003-04-01

    To evaluate the utility of a dexamethasone palmitate (DP)-low density lipoprotein (LDL) complex to transport drug into foam cells, the cellular uptake of DP-LDL complex by macrophages and foam cells was examined. The DP-LDL complex was prepared by incubation with DP and LDL, and the DP-LDL complex and murine macrophages were incubated. No cellular uptake of the DP-LDL complex by macrophages was found until 6 h after the start of incubation, but this gradually increased from 12 to 48 h. On the other hand, the cellular uptake of the oxidized DP-LDL complex was already apparent at 3 h after the start incubation, and then markedly increased until 48 h incubation along with that of the lipid emulsion (LE) containing DP (DP-LE). The cellular uptake of DP-LE by foam cells was significantly lower than that by macrophages. However, the cellular uptake of DP-LDL complex by foam cells was similar to that by macrophages. These findings suggest that the DP-LDL complex is oxidatively modified, and then incorporated into macrophages and foam cells through the scavenger receptor pathway. Since selective delivery of drugs into foam cells in the early stage of atherosclerosis is a useful protocol for antiatherosclerosis treatment, the DP-LDL complex appears to be a potentially useful drug-carrier complex for future antiatherosclerotic therapy.

  16. Optimizing cell seeding and retention in a three-dimensional bioengineered cardiac ventricle: The two-stage cellularization model.

    Science.gov (United States)

    Patel, Nikita M; Yazdi, Iman K; Tasciotti, Ennio; Birla, Ravi K

    2016-10-01

    Current cell seeding techniques focus on passively directing cells to a scaffold surface with the addition of dynamic culture to encourage cell permeation. In 3D tissue engineered constructs, cell retention efficiency is dependent on the cell delivery method, and biomaterial properties. Passive cell delivery relies on cell migration to the scaffold surface; biomaterial surface properties and porosity determine cell infiltration capacity. As a result, cell retention efficiencies remain low. The development of an effective two-stage cell seeding technique, coupled with perfusion culture, provides the potential to improve cellularization efficiency, and retention. This study, uses a chitosan bioengineered open ventricle (BEOV) scaffold to produce a two-stage perfusion cultured ventricle (TPCV). TPCV were fabricated by direct injection of 10 million primary rat neonatal cardiac cells, followed by wrapping of the outer scaffold surface with a 3D fibrin gel artificial heart muscle patch; TPCV were perfusion cultured for 3 days. The average biopotential output was 1.731 mV. TPCV cell retention following culture was approximately 5%. Cardiac cells were deposited on the scaffold surface and formed intercellular connections. Histological assessment displayed localized cell clusters, with some dissemination, and validated the observed presence of intercellular and gap-junction interactions. The study demonstrates initial effectiveness of our two-stage cell delivery concept, based on function and biological metrics. Biotechnol. Bioeng. 2016;113: 2275-2285. © 2016 Wiley Periodicals, Inc. PMID:27071026

  17. Multiscale modeling of cellular epigenetic states: stochasticity in molecular networks, chromatin folding in cell nuclei, and tissue pattern formation of cells

    Science.gov (United States)

    Liang, Jie; Cao, Youfang; Gürsoy, Gamze; Naveed, Hammad; Terebus, Anna; Zhao, Jieling

    2016-01-01

    Genome sequences provide the overall genetic blueprint of cells, but cells possessing the same genome can exhibit diverse phenotypes. There is a multitude of mechanisms controlling cellular epigenetic states and that dictate the behavior of cells. Among these, networks of interacting molecules, often under stochastic control, depending on the specific wirings of molecular components and the physiological conditions, can have a different landscape of cellular states. In addition, chromosome folding in three-dimensional space provides another important control mechanism for selective activation and repression of gene expression. Fully differentiated cells with different properties grow, divide, and interact through mechanical forces and communicate through signal transduction, resulting in the formation of complex tissue patterns. Developing quantitative models to study these multi-scale phenomena and to identify opportunities for improving human health requires development of theoretical models, algorithms, and computational tools. Here we review recent progress made in these important directions. PMID:27480462

  18. Native cellular fluorescence characteristics of normal and malignant epithelial cells from human larynx

    Science.gov (United States)

    Parmeswearan, Diagaradjane; Ganesan, Singaravelu; Nalini, R.; Aruna, Prakasa R.; Veeraganesh, V.; Alfano, Robert R.

    1997-08-01

    Many applications of native fluorescence spectroscopy of intrinsic biomolecules such as Try, Tyr, Phe, NADH and FAD are reported on both the characterization and the discrimination of malignant tissues from the normal. In the field of diagnostic oncology, extensive studies have been made to distinguish the normal from malignant condition in breast, cervix, colon and bronchus. From the studies made by Alfano and co-workers, it was found that the emission at 340 and 440 nm under UV excitation have shown statistically significant difference between normal and malignant tissues. As tissues are highly complex in nature, it is worth to known whether the changes arise from cells or from other extracellular tissue components, so as to enable us to have better understanding on the transformation mechanism of normal into malignant and to go for an improved approach in the effective optical diagnosis. In this context, the present study addresses the question of whether there are differences in the native cellular fluorescence characteristics between normal and malignant epithelial cells from human larynx. With this aim, the UV fluorescence emission spectra in the wavelength region of excitation between 270 - 310 nm and the excitation spectra for 340 nm emission were measured and analyzed. In order to quantify the altered fluorescence signal between the normal and malignant cells, different ratio parameters were introduced.

  19. Dichotomy of cellular inhibition by small-molecule inhibitors revealed by single-cell analysis

    Science.gov (United States)

    Vogel, Robert M.; Erez, Amir; Altan-Bonnet, Grégoire

    2016-01-01

    Despite progress in drug development, a quantitative and physiological understanding of how small-molecule inhibitors act on cells is lacking. Here, we measure the signalling and proliferative response of individual primary T-lymphocytes to a combination of antigen, cytokine and drug. We uncover two distinct modes of signalling inhibition: digital inhibition (the activated fraction of cells diminishes upon drug treatment, but active cells appear unperturbed), versus analogue inhibition (the activated fraction is unperturbed whereas activation response is diminished). We introduce a computational model of the signalling cascade that accounts for such inhibition dichotomy, and test the model predictions for the phenotypic variability of cellular responses. Finally, we demonstrate that the digital/analogue dichotomy of cellular response as revealed on short (signal transduction) timescales, translates into similar dichotomy on longer (proliferation) timescales. Our single-cell analysis of drug action illustrates the strength of quantitative approaches to translate in vitro pharmacology into functionally relevant cellular settings. PMID:27687249

  20. Cellular and Phenotypic Characterization of Canine Osteosarcoma Cell Lines

    Directory of Open Access Journals (Sweden)

    Marie E. Legare, Jamie Bush, Amanda K. Ashley, Taka Kato, William H. Hanneman

    2011-01-01

    Full Text Available Canine and human osteosarcoma (OSA have many similarities, with the majority of reported cases occurring in the appendicular skeleton, gender predominance noted, high rate of metastasis at the time of presentation, and a lack of known etiology for this devastating disease. Due to poor understanding of the molecular mechanisms underlying OSA, we have characterized seven different OSA canine cell lines: Abrams, D17, Grey, Hughes, Ingles, Jarques, and Marisco and compared them to U2, a human OSA cell line, for the following parameters: morphology, growth, contact inhibition, migrational tendencies, alkaline phosphatase staining, heterologous tumor growth, double-strand DNA breaks, and oxidative damage. All results demonstrated the positive characteristics of the Abrams cell line for use in future studies of OSA. Of particular interest, the robust growth of a subcutaneous tumor and rapid pulmonary metastasis of the Abrams cell line in an immunocompromised mouse shows incredible potential for the future use of Abrams as a canine OSA model. Further investigations utilizing a canine cell model of OSA, such as Abrams, will be invaluable to understanding the molecular events underlying OSA, pharmaceutical inhibition of metastasis, and eventual prevention of this devastating disease.

  1. DNA-damage response network at the crossroads of cell-cycle checkpoints, cellular senescence and apoptosis*

    OpenAIRE

    Schmitt, Estelle; Paquet, Claudie; Beauchemin, Myriam; Bertrand, Richard

    2007-01-01

    Tissue homeostasis requires a carefully-orchestrated balance between cell proliferation, cellular senescence and cell death. Cells proliferate through a cell cycle that is tightly regulated by cyclin-dependent kinase activities. Cellular senescence is a safeguard program limiting the proliferative competence of cells in living organisms. Apoptosis eliminates unwanted cells by the coordinated activity of gene products that regulate and effect cell death. The intimate link between the cell cycl...

  2. Vascularization and cellular isolation potential of a novel electrospun cell delivery vehicle.

    Science.gov (United States)

    Krishnan, Laxminarayanan; Touroo, Jeremy; Reed, Robert; Boland, Eugene; Hoying, James B; Williams, Stuart K

    2014-07-01

    A clinical need exists for a cell delivery device that supports long-term cell viability, cell retention within the device and retrieval of delivered cells if necessary. Previously, cell isolation devices have been based on hollow fiber membranes, porous polymer scaffolds, alginate systems, or micro-machined membranes. We present the development and characterization of a novel dual porosity electrospun membrane based device, which supports cellular infiltration and vascularization of its outer porous layer and maintains cellular isolation within a lumen bounded by an inner low porosity layer. Electrospinning conditions were initially established to support electrospun fiber deposition onto nonconductive silicone surfaces. With these parameters established, devices for in vivo evaluations were produced using nylon as a nonconductive scaffold for deposition of dual porosity electrospun fibers. The outer porous layer supported the development of a penetrating microcirculation and the membrane supported the transfer of insulin from encapsulated sustained release pellets for 4 weeks. Viable cells implanted within the device could be identified after 2 weeks of implantation. Through the successful demonstration of survival and cellular isolation of human epithelial cells within the implanted devices and the ability to use the device to deliver insulin, we have established the utility of this device toward localized cell transplantation. The cell delivery device establishes a platform to test the feasibility of approaches to cell dose control and cell localization at the site of implantation in the clinical use of modified autologous or allogeneic cells. PMID:23913805

  3. An integrated approach for the cell formation and layout design in cellular manufacturing systems

    NARCIS (Netherlands)

    Javadi, Babak; Jolai, Fariborz; Slomp, Jannes; Rabbani, Masoud; Tavakkoli-Moghaddam, Reza

    2013-01-01

    In this paper, a comprehensive model is presented for cell formation and layout design in cellular manufacturing systems (CMS). The proposed model incorporates an extensive coverage of important operational features and especially layout design aspects to determine optimal cell configuration and Int

  4. A single-cell bioluminescence imaging system for monitoring cellular gene expression in a plant body.

    Science.gov (United States)

    Muranaka, Tomoaki; Kubota, Saya; Oyama, Tokitaka

    2013-12-01

    Gene expression is a fundamental cellular process and expression dynamics are of great interest in life science. We succeeded in monitoring cellular gene expression in a duckweed plant, Lemna gibba, using bioluminescent reporters. Using particle bombardment, epidermal and mesophyll cells were transfected with the luciferase gene (luc+) under the control of a constitutive [Cauliflower mosaic virus 35S (CaMV35S)] and a rhythmic [Arabidopsis thaliana CIRCADIAN CLOCK ASSOCIATED 1 (AtCCA1)] promoter. Bioluminescence images were captured using an EM-CCD (electron multiply charged couple device) camera. Luminescent spots of the transfected cells in the plant body were quantitatively measured at the single-cell level. Luminescence intensities varied over a 1,000-fold range among CaMV35S::luc+-transfected cells in the same plant body and showed a log-normal-like frequency distribution. We monitored cellular gene expression under light-dark conditions by capturing bioluminescence images every hour. Luminescence traces of ≥50 individual cells in a frond were successfully obtained in each monitoring procedure. Rhythmic and constitutive luminescence behaviors were observed in cells transfected with AtCCA1::luc+ and CaMV35S::luc+, respectively. Diurnal rhythms were observed in every AtCCA1::luc+-introduced cell with traceable luminescence, and slight differences were detected in their rhythmic waveforms. Thus the single-cell bioluminescence monitoring system was useful for the characterization of cellular gene expression in a plant body.

  5. Cellular response of mucociliary differentiated primary bronchial epithelial cells to diesel exhaust

    NARCIS (Netherlands)

    Zarcone, M.C.; Duistermaat, E.; Schadewijk, A. van; Jedynksa, A.D.; Hiemstra, P.S.; Kooter, I.M.

    2016-01-01

    Cellular response of mucociliary differentiated primary bronchial epithelial cells to diesel exhaust. Am J Physiol Lung Cell Mol Physiol 311: L111–L123, 2016. First published May 17, 2016; doi:10.1152/ajplung.00064.2016.—Diesel emissions are the main source of air pollution in urban areas, and diese

  6. Chromatin structure and cellular radiosensitivity : A comparison of two human tumour cell lines

    NARCIS (Netherlands)

    Woudstra, EC; Roesink, JM; Rosemann, M; Brunsting, JF; Driessen, C; Orta, T; Konings, AWT; Peacock, JH; Kampinga, HH

    1996-01-01

    The role of variation in susceptibility to DNA damage induction was studied as a determinant for cellular radiosensitivity. Comparison of the radiosensitive HX142 and radioresistant RT112 cell lines previously revealed higher susceptibility to X-ray-induced DNA damage in the sensitive cell line usin

  7. Role of p53 in the cellular response following oleic acid accumulation in Chang liver cells.

    Science.gov (United States)

    Park, Eun-Jung; Lee, Ah Young; Chang, Seung-Hee; Yu, Kyeong-Nam; Kim, Jae-Ho; Cho, Myung-Haing

    2014-01-01

    Abnormal accumulation of fatty acids triggers the harmful cellular response called lipotoxicity. In this study, we investigated the cellular response following accumulation of oleic acid (OA), a monounsaturated fatty acid, in human Chang liver cells. OA droplets were distributed freely in the cytoplasm and/or degraded within lysosomes. OA exposure increased ATP production and concomitantly dilated mitochondria. At 24h after OA exposure, cell viability decreased slightly and was coupled with a reduction in mitochondrial Ca(2+) concentration, the alteration in cell viability was also associated with the generation of reactive oxygen species and changes in the cell cycle. Moreover, OA treatment increased the expression of autophagy- and apoptotic cell death-related proteins in a dose-dependent manner. Furthermore, we investigated the role of p53, a tumor suppressor protein, in the cellular response elicited by OA accumulation. OA-induced changes in cell viability and ATP production were rescued to control levels when cells were pretreated with pifithrin-alpha (PTA), a p53 inhibitor. By contrast, the expressions of LC3-II and perilipin, proteins required for lipophagy, were down-regulated by PTA pretreatment. Taken together, our results suggest that p53 plays a key role in the cellular response elicited by OA accumulation in Chang liver cells.

  8. A single-cell bioluminescence imaging system for monitoring cellular gene expression in a plant body.

    Science.gov (United States)

    Muranaka, Tomoaki; Kubota, Saya; Oyama, Tokitaka

    2013-12-01

    Gene expression is a fundamental cellular process and expression dynamics are of great interest in life science. We succeeded in monitoring cellular gene expression in a duckweed plant, Lemna gibba, using bioluminescent reporters. Using particle bombardment, epidermal and mesophyll cells were transfected with the luciferase gene (luc+) under the control of a constitutive [Cauliflower mosaic virus 35S (CaMV35S)] and a rhythmic [Arabidopsis thaliana CIRCADIAN CLOCK ASSOCIATED 1 (AtCCA1)] promoter. Bioluminescence images were captured using an EM-CCD (electron multiply charged couple device) camera. Luminescent spots of the transfected cells in the plant body were quantitatively measured at the single-cell level. Luminescence intensities varied over a 1,000-fold range among CaMV35S::luc+-transfected cells in the same plant body and showed a log-normal-like frequency distribution. We monitored cellular gene expression under light-dark conditions by capturing bioluminescence images every hour. Luminescence traces of ≥50 individual cells in a frond were successfully obtained in each monitoring procedure. Rhythmic and constitutive luminescence behaviors were observed in cells transfected with AtCCA1::luc+ and CaMV35S::luc+, respectively. Diurnal rhythms were observed in every AtCCA1::luc+-introduced cell with traceable luminescence, and slight differences were detected in their rhythmic waveforms. Thus the single-cell bioluminescence monitoring system was useful for the characterization of cellular gene expression in a plant body. PMID:24058151

  9. Detection of silent cells, synchronization and modulatory activity in developing cellular networks.

    Science.gov (United States)

    Hjorth, Johannes J J; Dawitz, Julia; Kroon, Tim; Pires, Johny; Dassen, Valerie J; Berkhout, Janna A; Emperador Melero, Javier; Nadadhur, Aish G; Alevra, Mihai; Toonen, Ruud F; Heine, Vivi M; Mansvelder, Huibert D; Meredith, Rhiannon M

    2016-04-01

    Developing networks in the immature nervous system and in cellular cultures are characterized by waves of synchronous activity in restricted clusters of cells. Synchronized activity in immature networks is proposed to regulate many different developmental processes, from neuron growth and cell migration, to the refinement of synapses, topographic maps, and the mature composition of ion channels. These emergent activity patterns are not present in all cells simultaneously within the network and more immature "silent" cells, potentially correlated with the presence of silent synapses, are prominent in different networks during early developmental periods. Many current network analyses for detection of synchronous cellular activity utilize activity-based pixel correlations to identify cellular-based regions of interest (ROIs) and coincident cell activity. However, using activity-based correlations, these methods first underestimate or ignore the inactive silent cells within the developing network and second, are difficult to apply within cell-dense regions commonly found in developing brain networks. In addition, previous methods may ignore ROIs within a network that shows transient activity patterns comprising both inactive and active periods. We developed analysis software to semi-automatically detect cells within developing neuronal networks that were imaged using calcium-sensitive reporter dyes. Using an iterative threshold, modulation of activity was tracked within individual cells across the network. The distribution pattern of both inactive and active, including synchronous cells, could be determined based on distance measures to neighboring cells and according to different anatomical layers. PMID:26097169

  10. Topology optimization of adaptive fluid-actuated cellular structures with arbitrary polygonal motor cells

    Science.gov (United States)

    Lv, Jun; Tang, Liang; Li, Wenbo; Liu, Lei; Zhang, Hongwu

    2016-05-01

    This paper mainly focuses on the fast and efficient design method for plant bioinspired fluidic cellular materials and structures composed of polygonal motor cells. Here we developed a novel structural optimization method with arbitrary polygonal coarse-grid elements based on multiscale finite element frameworks. The fluidic cellular structures are meshed with irregular polygonal coarse-grid elements according to their natural size and the shape of the imbedded motor cells. The multiscale base functions of solid displacement and hydraulic pressure are then constructed to bring the small-scale information of the irregular motor cells to the large-scale simulations on the polygonal coarse-grid elements. On this basis, a new topology optimization method based on the resulting polygonal coarse-grid elements is proposed to determine the optimal distributions or number of motor cells in the smart cellular structures. Three types of optimization problems are solved according to the usages of the fluidic cellular structures. Firstly, the proposed optimization method is utilized to minimize the system compliance of the load-bearing fluidic cellular structures. Second, the method is further extended to design biomimetic compliant actuators of the fluidic cellular materials due to the fact that non-uniform volume expansions of fluid in the cells can induce elastic action. Third, the optimization problem focuses on the weight minimization of the cellular structure under the constraints for the compliance of the whole system. Several representative examples are investigated to validate the effectiveness of the proposed polygon-based topology optimization method of the smart materials.

  11. An improved cellular automaton model considering the effect of traffic lights and driving behaviour

    Science.gov (United States)

    He, Hong-Di; Lu, Wei-Zhen; Dong, Li-Yun

    2011-04-01

    This paper proposes an improved cellular automaton model to describe the urban traffic flow with the consideration of traffic light and driving behaviour effects. Based on the model, the characteristics of the urban traffic flow on a single-lane road are investigated under three different control strategies, i.e., the synchronized, the green wave and the random strategies. The fundamental diagrams and time-space patterns of the traffic flows are provided for these strategies respectively. It finds that the dynamical transition to the congested flow appears when the vehicle density is higher than a critical level. The saturated flow is less dependent on the cycle time and the strategies of the traffic light control, while the critical vehicle density varies with the cycle time and the strategies. Simulated results indicate that the green wave strategy is proven to be the most effective one among the above three control strategies.

  12. An improved cellular automaton model considering the effect of traffic lights and driving behaviour

    Institute of Scientific and Technical Information of China (English)

    He Hong-Di; Lu Wei-Zhen; Dong Li-Yun

    2011-01-01

    This paper proposes an improved cellular automaton model to describe the urban traffic flow with the consideration of traffic light and driving behaviour effects. Based on the model, the characteristics of the urban traffic flow on a singlelane road are investigated under three different control strategies, i.e., the synchronized, the green wave and the random strategies. The fundamental diagrams and time-space patterns of the traffic flows are provided for these strategies respectively. It finds that the dynamical transition to the congested flow appears when the vehicle density is higher than a critical level. The saturated flow is less dependent on the cycle time and the strategies of the traffic light control,while the critical vehicle density varies with the cycle time and the strategies. Simulated results indicate that the green wave strategy is proven to be the most effective one among the above three control strategies.

  13. Murine cellular cytotoxicity to syngeneic and xenogeneic herpes simplex virus-infected cells.

    Science.gov (United States)

    Kohl, S; Drath, D B; Loo, L S

    1982-12-01

    Cellular cytotoxicity of C57BL/6 adult mice peritoneal cells to xenogeneic (Chang liver) and syngeneic (BL/6-WT3) herpes simplex virus (HSV)-infected cells was analyzed in a 6-h 51Cr release assay. There was no difference in antibody-dependent cellular cytotoxicity to either target. There was no natural killer cytotoxicity to targets with cells from uninfected mice except at very high effector cell ratios. HSV-infected (2 X 10(4) PFU intraperitoneally 1 day previously) mice mediated significantly higher antibody-dependent cellular cytotoxicity and required less antibody (10(-5) versus 10(-2) dilution), fewer cells, and less time to kill than cells from uninfected mice. HSV-infected mice mediated natural killer cytotoxicity but preferentially killed syngeneic HSV-infected cells. Stimulation of cytotoxicity was not virus specific since influenza-infected mice mediated similar levels of cytotoxicity to HSV-infected targets. There was no difference in morphology (95% macrophage) or in the percentage of FcR-positive cells, but infected mice had more peritoneal cells and generated higher levels of superoxide in response to opsonized zymosan or phorbolmyristate acetate. These data demonstrate nonspecific virus-stimulated metabolic and effector cell function which may enhance clearance of virus in an infected host. PMID:6295943

  14. Cellular cardiac electrophysiology modelling with Chaste and CellML

    Directory of Open Access Journals (Sweden)

    Jonathan eCooper

    2015-01-01

    Full Text Available Chaste is an open-source C++ library for computational biology that has well-developed cardiac electrophysiology tissue simulation support. In this paper, we introduce the features available for performing cardiac electrophysiology action potential simulations using a wide range of models from the Physiome repository.The mathematics of the models are described in CellML, with units for all quantities. The primary idea is that the model is defined in one place (the CellML file, and all model code is auto-generated at compile or run time; it never has to be manually edited.We use ontological annotation to identify model variables describing certain biological quantities (membrane voltage, capacitance, etc. to allow us to import any relevant CellML models into the Chaste framework in consistent units, and to interact with them via consistent interfaces. This approach provides a great deal of flexibility for analysing different models of the same system. Chaste provides a wide choice of numerical methods for solving the ordinary differential equations that describe the models. Fixed-timestep explicit and implicit solvers are provided, as discussed in previous work. Here we introduce the Rush--Larsen and Generalised Rush--Larsen integration techniques, made available via symbolic manipulation of the model equations, which are automatically rearranged into the forms required by these approaches. We have also integrated the CVODE solvers, a `gold standard' for stiff systems, and we have developed support for symbolic computation of the Jacobian matrix, yielding further increases in the performance and accuracy of CVODE. We discuss some of the technical details of this work and compare the performance of the available numerical methods.Finally, we discuss how this is generalised in our functional curation framework, which uses a domain-specific language for defining complex experiments as a basis for comparison of model behaviour.

  15. Microencapsulation of stem cells to study cellular interactions.

    Science.gov (United States)

    Moore, Keith; Vandergriff, Adam; Potts, Jay D

    2013-01-01

    Microencapsulation is a technique used in both controlled delivery of materials over time as well as preservation of these materials while delivery is occurring. The range of materials able to be encapsulated is variable, from drugs to living cells. The latter is described here. Electrospray microencapsulation applies a high-voltage field, through which a polymeric material is extruded. A gelling bath, comprising a cross-linking material, is used to create a stable hydrogel containing secondary substances intended for delivery. Control of extrusion parameters, such as flow rate and voltage, allows for specification of diameter and pore sizes of the microcapsules. PMID:23955738

  16. A novel cell traction force microscopy to study multi-cellular system.

    Directory of Open Access Journals (Sweden)

    Xin Tang

    2014-06-01

    Full Text Available Traction forces exerted by adherent cells on their microenvironment can mediate many critical cellular functions. Accurate quantification of these forces is essential for mechanistic understanding of mechanotransduction. However, most existing methods of quantifying cellular forces are limited to single cells in isolation, whereas most physiological processes are inherently multi-cellular in nature where cell-cell and cell-microenvironment interactions determine the emergent properties of cell clusters. In the present study, a robust finite-element-method-based cell traction force microscopy technique is developed to estimate the traction forces produced by multiple isolated cells as well as cell clusters on soft substrates. The method accounts for the finite thickness of the substrate. Hence, cell cluster size can be larger than substrate thickness. The method allows computing the traction field from the substrate displacements within the cells' and clusters' boundaries. The displacement data outside these boundaries are not necessary. The utility of the method is demonstrated by computing the traction generated by multiple monkey kidney fibroblasts (MKF and human colon cancerous (HCT-8 cells in close proximity, as well as by large clusters. It is found that cells act as individual contractile groups within clusters for generating traction. There may be multiple of such groups in the cluster, or the entire cluster may behave a single group. Individual cells do not form dipoles, but serve as a conduit of force (transmission lines over long distances in the cluster. The cell-cell force can be either tensile or compressive depending on the cell-microenvironment interactions.

  17. Pulsed Electromagnetic Field Stimulates Cellular Proliferation in Human Intervertebral Disc Cells

    OpenAIRE

    Lee, Hwan-Mo; Kwon, Un-Hye; Kim, Hyang; Kim, Ho-Joong; Kim, Boram; Park, Jin-Oh; Moon, Eun-Soo; Moon, Seong-Hwan

    2010-01-01

    Purpose The purpose of this study is to investigate the mechanism of cellular proliferation of electromagnetic field (EMF) on human intervertebral disc (IVD) cells. Materials and Methods Human IVD cells were cultured three-dimensionally in alginate beads. EMF was exposed to IVD cells with 650Ω, 1.8 millitesla magnetic flux density, 60 Hz sinusoidal wave. Cultures were divided into a control and EMF group. Cytotoxicity, DNA synthesis and proteoglycan synthesis were measured by MTT assay, [3H]-...

  18. Human Cortical Neural Stem Cells Expressing Insulin-Like Growth Factor-I: A Novel Cellular Therapy for Alzheimer's Disease.

    Science.gov (United States)

    McGinley, Lisa M; Sims, Erika; Lunn, J Simon; Kashlan, Osama N; Chen, Kevin S; Bruno, Elizabeth S; Pacut, Crystal M; Hazel, Tom; Johe, Karl; Sakowski, Stacey A; Feldman, Eva L

    2016-03-01

    Alzheimer's disease (AD) is the most prevalent age-related neurodegenerative disorder and a leading cause of dementia. Current treatment fails to modify underlying disease pathologies and very little progress has been made to develop effective drug treatments. Cellular therapies impact disease by multiple mechanisms, providing increased efficacy compared with traditional single-target approaches. In amyotrophic lateral sclerosis, we have shown that transplanted spinal neural stem cells (NSCs) integrate into the spinal cord, form synapses with the host, improve inflammation, and reduce disease-associated pathologies. Our current goal is to develop a similar "best in class" cellular therapy for AD. Here, we characterize a novel human cortex-derived NSC line modified to express insulin-like growth factor-I (IGF-I), HK532-IGF-I. Because IGF-I promotes neurogenesis and synaptogenesis in vivo, this enhanced NSC line offers additional environmental enrichment, enhanced neuroprotection, and a multifaceted approach to treating complex AD pathologies. We show that autocrine IGF-I production does not impact the cell secretome or normal cellular functions, including proliferation, migration, or maintenance of progenitor status. However, HK532-IGF-I cells preferentially differentiate into gamma-aminobutyric acid-ergic neurons, a subtype dysregulated in AD; produce increased vascular endothelial growth factor levels; and display an increased neuroprotective capacity in vitro. We also demonstrate that HK532-IGF-I cells survive peri-hippocampal transplantation in a murine AD model and exhibit long-term persistence in targeted brain areas. In conclusion, we believe that harnessing the benefits of cellular and IGF-I therapies together will provide the optimal therapeutic benefit to patients, and our findings support further preclinical development of HK532-IGF-I cells into a disease-modifying intervention for AD.

  19. Human Cortical Neural Stem Cells Expressing Insulin-Like Growth Factor-I: A Novel Cellular Therapy for Alzheimer's Disease.

    Science.gov (United States)

    McGinley, Lisa M; Sims, Erika; Lunn, J Simon; Kashlan, Osama N; Chen, Kevin S; Bruno, Elizabeth S; Pacut, Crystal M; Hazel, Tom; Johe, Karl; Sakowski, Stacey A; Feldman, Eva L

    2016-03-01

    Alzheimer's disease (AD) is the most prevalent age-related neurodegenerative disorder and a leading cause of dementia. Current treatment fails to modify underlying disease pathologies and very little progress has been made to develop effective drug treatments. Cellular therapies impact disease by multiple mechanisms, providing increased efficacy compared with traditional single-target approaches. In amyotrophic lateral sclerosis, we have shown that transplanted spinal neural stem cells (NSCs) integrate into the spinal cord, form synapses with the host, improve inflammation, and reduce disease-associated pathologies. Our current goal is to develop a similar "best in class" cellular therapy for AD. Here, we characterize a novel human cortex-derived NSC line modified to express insulin-like growth factor-I (IGF-I), HK532-IGF-I. Because IGF-I promotes neurogenesis and synaptogenesis in vivo, this enhanced NSC line offers additional environmental enrichment, enhanced neuroprotection, and a multifaceted approach to treating complex AD pathologies. We show that autocrine IGF-I production does not impact the cell secretome or normal cellular functions, including proliferation, migration, or maintenance of progenitor status. However, HK532-IGF-I cells preferentially differentiate into gamma-aminobutyric acid-ergic neurons, a subtype dysregulated in AD; produce increased vascular endothelial growth factor levels; and display an increased neuroprotective capacity in vitro. We also demonstrate that HK532-IGF-I cells survive peri-hippocampal transplantation in a murine AD model and exhibit long-term persistence in targeted brain areas. In conclusion, we believe that harnessing the benefits of cellular and IGF-I therapies together will provide the optimal therapeutic benefit to patients, and our findings support further preclinical development of HK532-IGF-I cells into a disease-modifying intervention for AD. PMID:26744412

  20. Olfactory stem cells, a new cellular model for studying molecular mechanisms underlying familial dysautonomia.

    Directory of Open Access Journals (Sweden)

    Nathalie Boone

    Full Text Available BACKGROUND: Familial dysautonomia (FD is a hereditary neuropathy caused by mutations in the IKBKAP gene, the most common of which results in variable tissue-specific mRNA splicing with skipping of exon 20. Defective splicing is especially severe in nervous tissue, leading to incomplete development and progressive degeneration of sensory and autonomic neurons. The specificity of neuron loss in FD is poorly understood due to the lack of an appropriate model system. To better understand and modelize the molecular mechanisms of IKBKAP mRNA splicing, we collected human olfactory ecto-mesenchymal stem cells (hOE-MSC from FD patients. hOE-MSCs have a pluripotent ability to differentiate into various cell lineages, including neurons and glial cells. METHODOLOGY/PRINCIPAL FINDINGS: We confirmed IKBKAP mRNA alternative splicing in FD hOE-MSCs and identified 2 novel spliced isoforms also present in control cells. We observed a significant lower expression of both IKBKAP transcript and IKAP/hELP1 protein in FD cells resulting from the degradation of the transcript isoform skipping exon 20. We localized IKAP/hELP1 in different cell compartments, including the nucleus, which supports multiple roles for that protein. We also investigated cellular pathways altered in FD, at the genome-wide level, and confirmed that cell migration and cytoskeleton reorganization were among the processes altered in FD. Indeed, FD hOE-MSCs exhibit impaired migration compared to control cells. Moreover, we showed that kinetin improved exon 20 inclusion and restores a normal level of IKAP/hELP1 in FD hOE-MSCs. Furthermore, we were able to modify the IKBKAP splicing ratio in FD hOE-MSCs, increasing or reducing the WT (exon 20 inclusion:MU (exon 20 skipping ratio respectively, either by producing free-floating spheres, or by inducing cells into neural differentiation. CONCLUSIONS/SIGNIFICANCE: hOE-MSCs isolated from FD patients represent a new approach for modeling FD to better

  1. Molecular and cellular effects of in vitro shockwave treatment on lymphatic endothelial cells.

    Directory of Open Access Journals (Sweden)

    Sabrina Rohringer

    Full Text Available Extracorporeal shockwave treatment was shown to improve orthopaedic diseases and wound healing and to stimulate lymphangiogenesis in vivo. The aim of this study was to investigate in vitro shockwave treatment (IVSWT effects on lymphatic endothelial cell (LEC behavior and lymphangiogenesis. We analyzed migration, proliferation, vascular tube forming capability and marker expression changes of LECs after IVSWT compared with HUVECs. Finally, transcriptome- and miRNA analyses were conducted to gain deeper insight into the IVSWT-induced molecular mechanisms in LECs. The results indicate that IVSWT-mediated proliferation changes of LECs are highly energy flux density-dependent and LEC 2D as well as 3D migration was enhanced through IVSWT. IVSWT suppressed HUVEC 3D migration but enhanced vasculogenesis. Furthermore, we identified podoplaninhigh and podoplaninlow cell subpopulations, whose ratios changed upon IVSWT treatment. Transcriptome- and miRNA analyses on these populations showed differences in genes specific for signaling and vascular tissue. Our findings help to understand the cellular and molecular mechanisms underlying shockwave-induced lymphangiogenesis in vivo.

  2. Neurogenic plasticity of mesenchymal stem cell, an alluring cellular replacement for traumatic brain injury.

    Science.gov (United States)

    Pati, Soumya; Muthuraju, Sangu; Hadi, Raisah Ab; Huat, Tee Jong; Singh, Shailja; Maletic-Savatic, Mirjana; Abdullah, Jafri Malin; Jaafar, Hasnan

    2016-01-01

    Traumatic brain injury (TBI) imposes horrendous neurophysiological alterations leading to most devastating forms of neuro-disability. Which includes impaired cognition, distorted locomotors activity and psychosomatic disability in both youths and adults. Emerging evidence from recent studies has identified mesenchymal stem cells (MSCs) as one of the promising category of stem cells having excellent neuroregenerative capability in TBI victims. Some of the clinical and animal studies reported that MSCs transplantation could cure neuronal damage as well as improve cognitive and locomotors behaviors in TBI. However, mechanism behind their broad spectrum neuroregenerative potential in TBI has not been reviewed yet. Therefore, in the present article, we present a comprehensive data on the important attributes of MSCs, such as neurotransdifferentiation, neuroprotection, axonal repair and plasticity, maintenance of blood-brain integrity, reduction of reactive oxygen species (ROS) and immunomodulation. We have reviewed in detail the crucial neurogenic capabilities of MSCs in vivo and provided consolidated knowledge regarding their cellular remodeling in TBI for future therapeutic implications. PMID:26763886

  3. Lipid Droplets: A Key Cellular Organelle Associated with Cancer Cell Survival under Normoxia and Hypoxia

    Science.gov (United States)

    Koizume, Shiro; Miyagi, Yohei

    2016-01-01

    The Warburg effect describes the phenomenon by which cancer cells obtain energy from glycolysis even under normoxic (O2-sufficient) conditions. Tumor tissues are generally exposed to hypoxia owing to inefficient and aberrant vasculature. Cancer cells have multiple molecular mechanisms to adapt to such stress conditions by reprogramming the cellular metabolism. Hypoxia-inducible factors are major transcription factors induced in cancer cells in response to hypoxia that contribute to the metabolic changes. In addition, cancer cells within hypoxic tumor areas have reduced access to serum components such as nutrients and lipids. However, the effect of such serum factor deprivation on cancer cell biology in the context of tumor hypoxia is not fully understood. Cancer cells are lipid-rich under normoxia and hypoxia, leading to the increased generation of a cellular organelle, the lipid droplet (LD). In recent years, the LD-mediated stress response mechanisms of cancer cells have been revealed. This review focuses on the production and functions of LDs in various types of cancer cells in relation to the associated cellular environment factors including tissue oxygenation status and metabolic mechanisms. This information will contribute to the current understanding of how cancer cells adapt to diverse tumor environments to promote their survival. PMID:27589734

  4. Sub-cellular force microscopy in single normal and cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Babahosseini, H. [VT MEMS Laboratory, The Bradley Department of Electrical and Computer Engineering, Blacksburg, VA 24061 (United States); Carmichael, B. [Nonlinear Intelligent Structures Laboratory, Department of Mechanical Engineering, University of Alabama, Tuscaloosa, AL 35487-0276 (United States); Strobl, J.S. [VT MEMS Laboratory, The Bradley Department of Electrical and Computer Engineering, Blacksburg, VA 24061 (United States); Mahmoodi, S.N., E-mail: nmahmoodi@eng.ua.edu [Nonlinear Intelligent Structures Laboratory, Department of Mechanical Engineering, University of Alabama, Tuscaloosa, AL 35487-0276 (United States); Agah, M., E-mail: agah@vt.edu [VT MEMS Laboratory, The Bradley Department of Electrical and Computer Engineering, Blacksburg, VA 24061 (United States)

    2015-08-07

    This work investigates the biomechanical properties of sub-cellular structures of breast cells using atomic force microscopy (AFM). The cells are modeled as a triple-layered structure where the Generalized Maxwell model is applied to experimental data from AFM stress-relaxation tests to extract the elastic modulus, the apparent viscosity, and the relaxation time of sub-cellular structures. The triple-layered modeling results allow for determination and comparison of the biomechanical properties of the three major sub-cellular structures between normal and cancerous cells: the up plasma membrane/actin cortex, the mid cytoplasm/nucleus, and the low nuclear/integrin sub-domains. The results reveal that the sub-domains become stiffer and significantly more viscous with depth, regardless of cell type. In addition, there is a decreasing trend in the average elastic modulus and apparent viscosity of the all corresponding sub-cellular structures from normal to cancerous cells, which becomes most remarkable in the deeper sub-domain. The presented modeling in this work constitutes a unique AFM-based experimental framework to study the biomechanics of sub-cellular structures. - Highlights: • The cells are modeled as a triple-layered structure using Generalized Maxwell model. • The sub-domains include membrane/cortex, cytoplasm/nucleus, and nuclear/integrin. • Biomechanics of corresponding sub-domains are compared among normal and cancer cells. • Viscoelasticity of sub-domains show a decreasing trend from normal to cancer cells. • The decreasing trend becomes most significant in the deeper sub-domain.

  5. The effect of ruby laser light on cellular proliferation of epidermal cells.

    Science.gov (United States)

    Liew, S H; Grobbelaar, A O; Gault, D T; Green, C J; Linge, C

    1999-11-01

    In ruby laser-assisted hair removal, microscopic damage is often seen in the basal epidermal cells, where melanosomes are concentrated. It is not known whether this treatment leads to cellular hyperproliferation. It was the aim of this study to investigate this. Ten white patients were treated with the Chromos 694-nm Depilation Ruby Laser, and biopsies taken before and after treatments to assess the presence of cell hyperproliferation, which normally accompanies epidermal damage, with immunohistochemical staining of keratin 16 and Ki67. No evidence of cell hyperproliferation was seen in all specimens examined after ruby laser irradiation. The authors conclude that despite the possible microscopic damages seen in the basal epidermis after laser hair removal, there is no evidence of cellular hyperproliferation. This is in contrast to ultraviolet-irradiated cell damage, in which increased basal cell turnover is seen.

  6. Cellular uptake and cytotoxicity of positively charged chitosan gold nanoparticles in human lung adenocarcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seon Young; Jang, Soo Hwa [Seoul National University, Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Institute for Veterinary Science (Korea, Republic of); Park, Jin; Jeong, Saeromi; Park, Jin Ho; Ock, Kwang Su [Soongsil University, Department of Chemistry (Korea, Republic of); Lee, Kangtaek [Yonsei University, Department of Chemical and Biomolecular Engineering (Korea, Republic of); Yang, Sung Ik [Kyung Hee University, College of Environment and Applied Chemistry (Korea, Republic of); Joo, Sang-Woo, E-mail: sjoo@ssu.ac.kr [Soongsil University, Department of Chemistry (Korea, Republic of); Ryu, Pan Dong; Lee, So Yeong, E-mail: leeso@snu.ac.kr [Seoul National University, Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Institute for Veterinary Science (Korea, Republic of)

    2012-12-15

    Cellular uptake, cytotoxicity, and mechanisms of cytotoxicity of the positively charged Au nanoparticles (NPs) were examined in A549 cells, which are one of the most characterized pulmonary cellular systems. Positively charged Au NPs were prepared by chemical reduction using chitosan. The dimension and surface charge of Au NPs were examined by transmission electron microscopy (TEM), dynamic light scattering, and zeta potential measurements. The uptake of Au NPs into A549 cells was also monitored using TEM and dark-field microscopy (DFM) and z-stack confocal microRaman spectroscopy. DFM live cell imaging was also performed to monitor the entry of chitosan Au NPs in real time. The cytotoxic assay, using both methylthiazol tetrazolium and lactate dehydrogenase assays revealed that positively charged Au NPs decreased cell viability. Flow cytometry, DNA fragmentation, real-time PCR, and western blot analysis suggest that positively charged chitosan Au NPs provoke cell damage through both apoptotic and necrotic pathways.

  7. Cellular uptake and cytotoxicity of positively charged chitosan gold nanoparticles in human lung adenocarcinoma cells

    International Nuclear Information System (INIS)

    Cellular uptake, cytotoxicity, and mechanisms of cytotoxicity of the positively charged Au nanoparticles (NPs) were examined in A549 cells, which are one of the most characterized pulmonary cellular systems. Positively charged Au NPs were prepared by chemical reduction using chitosan. The dimension and surface charge of Au NPs were examined by transmission electron microscopy (TEM), dynamic light scattering, and zeta potential measurements. The uptake of Au NPs into A549 cells was also monitored using TEM and dark-field microscopy (DFM) and z-stack confocal microRaman spectroscopy. DFM live cell imaging was also performed to monitor the entry of chitosan Au NPs in real time. The cytotoxic assay, using both methylthiazol tetrazolium and lactate dehydrogenase assays revealed that positively charged Au NPs decreased cell viability. Flow cytometry, DNA fragmentation, real-time PCR, and western blot analysis suggest that positively charged chitosan Au NPs provoke cell damage through both apoptotic and necrotic pathways.

  8. Cell-permeable intrinsic cellular inhibitors of apoptosis protect and rescue intestinal epithelial cells from radiation-induced cell death

    International Nuclear Information System (INIS)

    One of the important mechanisms for gastrointestinal (GI) injury following high-dose radiation exposure is apoptosis of epithelial cells. X-linked inhibitor of apoptosis (XIAP) and cellular IAP2 (cIAP2) are intrinsic cellular inhibitors of apoptosis. In order to study the effects of exogenously added IAPs on apoptosis in intestinal epithelial cells, we constructed bacterial expression plasmids containing genes of XIAP (full-length, BIR2 domain and BIR3-RING domain with and without mutations of auto-ubiquitylation sites) and cIAP2 proteins fused to a protein-transduction domain (PTD) derived from HIV-1 Tat protein (TAT) and purified these cell-permeable recombinant proteins. When the TAT-conjugated IAPs were added to rat intestinal epithelial cells IEC6, these proteins were effectively delivered into the cells and inhibited apoptosis, even when added after irradiation. Our results suggest that PTD-mediated delivery of IAPs may have clinical potential, not only for radioprotection but also for rescuing the GI system from radiation injuries. (author)

  9. Cell-permeable intrinsic cellular inhibitors of apoptosis protect and rescue intestinal epithelial cells from radiation-induced cell death.

    Science.gov (United States)

    Matsuzaki-Horibuchi, Shiori; Yasuda, Takeshi; Sakaguchi, Nagako; Yamaguchi, Yoshihiro; Akashi, Makoto

    2015-01-01

    One of the important mechanisms for gastrointestinal (GI) injury following high-dose radiation exposure is apoptosis of epithelial cells. X-linked inhibitor of apoptosis (XIAP) and cellular IAP2 (cIAP2) are intrinsic cellular inhibitors of apoptosis. In order to study the effects of exogenously added IAPs on apoptosis in intestinal epithelial cells, we constructed bacterial expression plasmids containing genes of XIAP (full-length, BIR2 domain and BIR3-RING domain with and without mutations of auto-ubiquitylation sites) and cIAP2 proteins fused to a protein-transduction domain (PTD) derived from HIV-1 Tat protein (TAT) and purified these cell-permeable recombinant proteins. When the TAT-conjugated IAPs were added to rat intestinal epithelial cells IEC6, these proteins were effectively delivered into the cells and inhibited apoptosis, even when added after irradiation. Our results suggest that PTD-mediated delivery of IAPs may have clinical potential, not only for radioprotection but also for rescuing the GI system from radiation injuries.

  10. Visualization and cellular hierarchy inference of single-cell data using SPADE.

    Science.gov (United States)

    Anchang, Benedict; Hart, Tom D P; Bendall, Sean C; Qiu, Peng; Bjornson, Zach; Linderman, Michael; Nolan, Garry P; Plevritis, Sylvia K

    2016-07-01

    High-throughput single-cell technologies provide an unprecedented view into cellular heterogeneity, yet they pose new challenges in data analysis and interpretation. In this protocol, we describe the use of Spanning-tree Progression Analysis of Density-normalized Events (SPADE), a density-based algorithm for visualizing single-cell data and enabling cellular hierarchy inference among subpopulations of similar cells. It was initially developed for flow and mass cytometry single-cell data. We describe SPADE's implementation and application using an open-source R package that runs on Mac OS X, Linux and Windows systems. A typical SPADE analysis on a 2.27-GHz processor laptop takes ∼5 min. We demonstrate the applicability of SPADE to single-cell RNA-seq data. We compare SPADE with recently developed single-cell visualization approaches based on the t-distribution stochastic neighborhood embedding (t-SNE) algorithm. We contrast the implementation and outputs of these methods for normal and malignant hematopoietic cells analyzed by mass cytometry and provide recommendations for appropriate use. Finally, we provide an integrative strategy that combines the strengths of t-SNE and SPADE to infer cellular hierarchy from high-dimensional single-cell data. PMID:27310265

  11. Silver Nanoparticle-Mediated Cellular Responses in Various Cell Lines: An in Vitro Model

    Directory of Open Access Journals (Sweden)

    Xi-Feng Zhang

    2016-09-01

    Full Text Available Silver nanoparticles (AgNPs have attracted increased interest and are currently used in various industries including medicine, cosmetics, textiles, electronics, and pharmaceuticals, owing to their unique physical and chemical properties, particularly as antimicrobial and anticancer agents. Recently, several studies have reported both beneficial and toxic effects of AgNPs on various prokaryotic and eukaryotic systems. To develop nanoparticles for mediated therapy, several laboratories have used a variety of cell lines under in vitro conditions to evaluate the properties, mode of action, differential responses, and mechanisms of action of AgNPs. In vitro models are simple, cost-effective, rapid, and can be used to easily assess efficacy and performance. The cytotoxicity, genotoxicity, and biocompatibility of AgNPs depend on many factors such as size, shape, surface charge, surface coating, solubility, concentration, surface functionalization, distribution of particles, mode of entry, mode of action, growth media, exposure time, and cell type. Cellular responses to AgNPs are different in each cell type and depend on the physical and chemical nature of AgNPs. This review evaluates significant contributions to the literature on biological applications of AgNPs. It begins with an introduction to AgNPs, with particular attention to their overall impact on cellular effects. The main objective of this review is to elucidate the reasons for different cell types exhibiting differential responses to nanoparticles even when they possess similar size, shape, and other parameters. Firstly, we discuss the cellular effects of AgNPs on a variety of cell lines; Secondly, we discuss the mechanisms of action of AgNPs in various cellular systems, and try to elucidate how AgNPs interact with different mammalian cell lines and produce significant effects; Finally, we discuss the cellular activation of various signaling molecules in response to AgNPs, and conclude with

  12. Silver Nanoparticle-Mediated Cellular Responses in Various Cell Lines: An in Vitro Model

    Science.gov (United States)

    Zhang, Xi-Feng; Shen, Wei; Gurunathan, Sangiliyandi

    2016-01-01

    Silver nanoparticles (AgNPs) have attracted increased interest and are currently used in various industries including medicine, cosmetics, textiles, electronics, and pharmaceuticals, owing to their unique physical and chemical properties, particularly as antimicrobial and anticancer agents. Recently, several studies have reported both beneficial and toxic effects of AgNPs on various prokaryotic and eukaryotic systems. To develop nanoparticles for mediated therapy, several laboratories have used a variety of cell lines under in vitro conditions to evaluate the properties, mode of action, differential responses, and mechanisms of action of AgNPs. In vitro models are simple, cost-effective, rapid, and can be used to easily assess efficacy and performance. The cytotoxicity, genotoxicity, and biocompatibility of AgNPs depend on many factors such as size, shape, surface charge, surface coating, solubility, concentration, surface functionalization, distribution of particles, mode of entry, mode of action, growth media, exposure time, and cell type. Cellular responses to AgNPs are different in each cell type and depend on the physical and chemical nature of AgNPs. This review evaluates significant contributions to the literature on biological applications of AgNPs. It begins with an introduction to AgNPs, with particular attention to their overall impact on cellular effects. The main objective of this review is to elucidate the reasons for different cell types exhibiting differential responses to nanoparticles even when they possess similar size, shape, and other parameters. Firstly, we discuss the cellular effects of AgNPs on a variety of cell lines; Secondly, we discuss the mechanisms of action of AgNPs in various cellular systems, and try to elucidate how AgNPs interact with different mammalian cell lines and produce significant effects; Finally, we discuss the cellular activation of various signaling molecules in response to AgNPs, and conclude with future perspectives

  13. Silver Nanoparticle-Mediated Cellular Responses in Various Cell Lines: An in Vitro Model.

    Science.gov (United States)

    Zhang, Xi-Feng; Shen, Wei; Gurunathan, Sangiliyandi

    2016-01-01

    Silver nanoparticles (AgNPs) have attracted increased interest and are currently used in various industries including medicine, cosmetics, textiles, electronics, and pharmaceuticals, owing to their unique physical and chemical properties, particularly as antimicrobial and anticancer agents. Recently, several studies have reported both beneficial and toxic effects of AgNPs on various prokaryotic and eukaryotic systems. To develop nanoparticles for mediated therapy, several laboratories have used a variety of cell lines under in vitro conditions to evaluate the properties, mode of action, differential responses, and mechanisms of action of AgNPs. In vitro models are simple, cost-effective, rapid, and can be used to easily assess efficacy and performance. The cytotoxicity, genotoxicity, and biocompatibility of AgNPs depend on many factors such as size, shape, surface charge, surface coating, solubility, concentration, surface functionalization, distribution of particles, mode of entry, mode of action, growth media, exposure time, and cell type. Cellular responses to AgNPs are different in each cell type and depend on the physical and chemical nature of AgNPs. This review evaluates significant contributions to the literature on biological applications of AgNPs. It begins with an introduction to AgNPs, with particular attention to their overall impact on cellular effects. The main objective of this review is to elucidate the reasons for different cell types exhibiting differential responses to nanoparticles even when they possess similar size, shape, and other parameters. Firstly, we discuss the cellular effects of AgNPs on a variety of cell lines; Secondly, we discuss the mechanisms of action of AgNPs in various cellular systems, and try to elucidate how AgNPs interact with different mammalian cell lines and produce significant effects; Finally, we discuss the cellular activation of various signaling molecules in response to AgNPs, and conclude with future perspectives

  14. Development of an Insert Co-culture System of Two Cellular Types in the Absence of Cell-Cell Contact.

    Science.gov (United States)

    Renaud, Justine; Martinoli, Maria-Grazia

    2016-01-01

    The role of secreted soluble factors in the modification of cellular responses is a recurrent theme in the study of all tissues and systems. In an attempt to make straightforward the very complex relationships between the several cellular subtypes that compose multicellular organisms, in vitro techniques have been developed to help researchers acquire a detailed understanding of single cell populations. One of these techniques uses inserts with a permeable membrane allowing secreted soluble factors to diffuse. Thus, a population of cells grown in inserts can be co-cultured in a well or dish containing a different cell type for evaluating cellular changes following paracrine signaling in the absence of cell-cell contact. Such insert co-culture systems offer various advantages over other co-culture techniques, namely bidirectional signaling, conserved cell polarity and population-specific detection of cellular changes. In addition to being utilized in the field of inflammation, cancer, angiogenesis and differentiation, these co-culture systems are of prime importance in the study of the intricate relationships that exist between the different cellular subtypes present in the central nervous system, particularly in the context of neuroinflammation. This article offers general methodological guidelines in order to set up an experiment in order to evaluating cellular changes mediated by secreted soluble factors using an insert co-culture system. Moreover, a specific protocol to measure the neuroinflammatory effects of cytokines secreted by lipopolysaccharide-activated N9 microglia on neuronal PC12 cells will be detailed, offering a concrete understanding of insert co-culture methodology.

  15. Simultaneous characterization of cellular RNA structure and function with in-cell SHAPE-Seq.

    Science.gov (United States)

    Watters, Kyle E; Abbott, Timothy R; Lucks, Julius B

    2016-01-29

    Many non-coding RNAs form structures that interact with cellular machinery to control gene expression. A central goal of molecular and synthetic biology is to uncover design principles linking RNA structure to function to understand and engineer this relationship. Here we report a simple, high-throughput method called in-cell SHAPE-Seq that combines in-cell probing of RNA structure with a measurement of gene expression to simultaneously characterize RNA structure and function in bacterial cells. We use in-cell SHAPE-Seq to study the structure-function relationship of two RNA mechanisms that regulate translation in Escherichia coli. We find that nucleotides that participate in RNA-RNA interactions are highly accessible when their binding partner is absent and that changes in RNA structure due to RNA-RNA interactions can be quantitatively correlated to changes in gene expression. We also characterize the cellular structures of three endogenously expressed non-coding RNAs: 5S rRNA, RNase P and the btuB riboswitch. Finally, a comparison between in-cell and in vitro folded RNA structures revealed remarkable similarities for synthetic RNAs, but significant differences for RNAs that participate in complex cellular interactions. Thus, in-cell SHAPE-Seq represents an easily approachable tool for biologists and engineers to uncover relationships between sequence, structure and function of RNAs in the cell. PMID:26350218

  16. Tracing Dynamics and Clonal Heterogeneity of Cbx7-Induced Leukemic Stem Cells by Cellular Barcoding

    NARCIS (Netherlands)

    Klauke, Karin; Broekhuis, Mathilde J. C.; Weersing, Ellen; Dethmers-Ausema, Albertina; Ritsema, Martha; Gonzalez, Marta Vila; Zwart, Erik; Bystrykh, Leonid V.; de Haan, Gerald

    2015-01-01

    Accurate monitoring of tumor dynamics and leukemic stem cell (LSC) heterogeneity is important for the development of personalized cancer therapies. In this study, we experimentally induced distinct types of leukemia in mice by enforced expression of Cbx7. Simultaneous cellular barcoding allowed for

  17. Embryonic stem cells as an ectodermal cellular model of human p63-related dysplasia syndromes.

    NARCIS (Netherlands)

    Rostagno, P.; Wolchinsky, Z.; Vigano, A.M.; Shivtiel, S.; Zhou, H.; Bokhoven, J.H.L.M. van; Ferone, G.; Missero, C.; Mantovani, R.; Aberdam, D.; Virolle, T.

    2010-01-01

    Heterozygous mutations in the TP63 transcription factor underlie the molecular basis of several similar autosomal dominant ectodermal dysplasia (ED) syndromes. Here we provide a novel cellular model derived from embryonic stem (ES) cells that recapitulates in vitro the main steps of embryonic skin d

  18. Dissecting cellular states and cell state transitions through integrative analysis of epigenetic dynamics

    OpenAIRE

    Ziller, Michael

    2014-01-01

    Understanding how a single genome that is common to all cells in an organism can give rise to many different and highly specialized, cell types has been one of the major questions in biology over the past century and still many aspects remain unanswered. Over the last 15 years, incredible progress has been made in pinpointing the regulatory mechanisms that establish, maintain, and change cellular identities. In particular, the role of histone modifications and DNA methylation in the spatio-te...

  19. Cell fusion induced by ERVWE1 or measles virus causes cellular senescence

    OpenAIRE

    Chuprin, Anna; Gal, Hilah; BIRON-SHENTAL, Tal; Biran, Anat; Amiel, Aliza; Rozenblatt, Shmuel; Krizhanovsky, Valery

    2013-01-01

    Cellular senescence limits proliferation of potentially detrimental cells, preventing tumorigenesis and restricting tissue damage. However, the function of senescence in nonpathological conditions is unknown. Here, Krizhanovsky and colleagues discover a new pathway to activate senescence cell fusion. The authors find that fusion-induced senescence occurs during embryonic development in the placenta. A counterpart of this process is also observed after infection by the measles virus. The resul...

  20. Autophagy and cellular senescence mediated by Sox2 suppress malignancy of cancer cells.

    Directory of Open Access Journals (Sweden)

    Yong-Yeon Cho

    Full Text Available Autophagy is a critical cellular process required for maintaining cellular homeostasis in health and disease states, but the molecular mechanisms and impact of autophagy on cancer is not fully understood. Here, we found that Sox2, a key transcription factor in the regulation of the "stemness" of embryonic stem cells and induced-pluripotent stem cells, strongly induced autophagic phenomena, including intracellular vacuole formation and lysosomal activation in colon cancer cells. The activation occurred through Sox2-mediated ATG10 gene expression and resulted in the inhibition of cell proliferation and anchorage-independent colony growth ex vivo and tumor growth in vivo. Further, we found that Sox2-induced-autophagy enhanced cellular senescence by up-regulating tumor suppressors or senescence factors, including p16(INK4a, p21 and phosphorylated p53 (Ser15. Notably, knockdown of ATG10 in Sox2-expressing colon cancer cells restored cancer cell properties. Taken together, our results demonstrated that regulation of autophagy mediated by Sox2 is a mechanism-driven novel strategy to treat human colon cancers.

  1. Phenotypic characterization of the bone marrow stem cells used in regenerative cellular therapy

    International Nuclear Information System (INIS)

    Regenerative medicine is a novel therapeutic method with broad potential for the treatment of various illnesses, based on the use of bone marrow (BM) stem cells, whose phenotypic characterization is limited. The paper deals with the expression of different cell membrane markers in mononuclear BM cells from 14 patients who underwent autologous cell therapy, obtained by medullary puncture and mobilization to peripheral blood, with the purpose of characterizing the different types of cells present in that heterogeneous cellular population and identifying the adhesion molecules involved in their adhesion. A greater presence was observed of adherent stem cells from the marrow stroma in mononuclear cells obtained directly from the BM; a larger population of CD90+cells in mononuclear cells from CD34-/CD45-peripheral blood with a high expression of molecules CD44 and CD62L, which suggests a greater presence of mesenchymal stem cells (MSC) in mobilized cells from the marrow stroma. The higher levels of CD34+cells in peripheral blood stem cells with a low expression of molecules CD117-and DR-suggests the presence of hematopoietic stem cells, hemangioblasts and progenitor endothelial cells mobilized to peripheral circulation. It was found that mononuclear cells from both the BM and peripheral blood show a high presence of stem cells with expression of adhesion molecule CD44 (MMC marker), probably involved in their migration, settling and differentiation

  2. Protein turnover and cellular autophagy in growing and growth-inhibited 3T3 cells

    Energy Technology Data Exchange (ETDEWEB)

    Papadopoulos, T.; Pfeifer, U. (Univ. of Wuerzburg (West Germany))

    1987-07-01

    The relationship between growth, protein degradation, and cellular autophagy was tested in growing and in growth-inhibited 3T3 cell monolayers. For the biochemical evaluation of DNA and protein metabolism, growth-inhibited 3T3 cell monolayers with high cell density and growing 3T3 cell monolayers with low cell density were labeled simultaneously with ({sup 14}C)thymidine and ({sup 3}H)leucine. The evaluation of the DNA turnover and additional ({sup 3}H)thymidine autoradiography showed that 24 to 5% of 3T3 cells continue to replicate even in the growth-inhibited state, where no accumulation of protein and DNA can be observed. Cell loss, therefore, has to be assumed to compensate for the ongoing cell proliferation. When the data of protein turnover were corrected for cell loss, it was found that the rate constant of protein synthesis in nongrowing monolayers was reduced to half the value found in growing monolayers. Simultaneously, the rate constant of protein degradation in nongrowing monolayers was increased to about 1.5-fold the value of growing monolayers. These data are in agreement with the assumption that cellular autophagy represents a major pathway of regulating protein degradation in 3T3 cells and that the regulation of autophagic protein degradation is of relevance for the transition from a growing to a nongrowing state.

  3. High content analysis at single cell level identifies different cellular responses dependent on nanomaterial concentrations

    Science.gov (United States)

    Manshian, Bella B.; Munck, Sebastian; Agostinis, Patrizia; Himmelreich, Uwe; Soenen, Stefaan J.

    2015-09-01

    A mechanistic understanding of nanomaterial (NM) interaction with biological environments is pivotal for the safe transition from basic science to applied nanomedicine. NM exposure results in varying levels of internalized NM in different neighboring cells, due to variances in cell size, cell cycle phase and NM agglomeration. Using high-content analysis, we investigated the cytotoxic effects of fluorescent quantum dots on cultured cells, where all effects were correlated with the concentration of NMs at the single cell level. Upon binning the single cell data into different categories related to NM concentration, this study demonstrates, for the first time, that quantum dots activate both cytoprotective and cytotoxic mechanisms, resulting in a zero net result on the overall cell population, yet with significant effects in cells with higher cellular NM levels. Our results suggest that future NM cytotoxicity studies should correlate NM toxicity with cellular NM numbers on the single cell level, as conflicting mechanisms in particular cell subpopulations are commonly overlooked using classical toxicological methods.

  4. Nanoparticle-cell interactions: molecular structure of the protein corona and cellular outcomes.

    Science.gov (United States)

    Fleischer, Candace C; Payne, Christine K

    2014-08-19

    The use of nanoparticles (NPs) in biology and medicine requires a molecular-level understanding of how NPs interact with cells in a physiological environment. A critical difference between well-controlled in vitro experiments and in vivo applications is the presence of a complex mixture of extracellular proteins. It has been established that extracellular serum proteins present in blood will adsorb onto the surface of NPs, forming a "protein corona". Our goal was to understand how this protein layer affected cellular-level events, including NP binding, internalization, and transport. A combination of microscopy, which provides spatial resolution, and spectroscopy, which provides molecular information, is necessary to probe protein-NP-cell interactions. Initial experiments used a model system composed of polystyrene NPs functionalized with either amine or carboxylate groups to provide a cationic or anionic surface, respectively. Serum proteins adsorb onto the surface of both cationic and anionic NPs, forming a net anionic protein-NP complex. Although these protein-NP complexes have similar diameters and effective surface charges, they show the exact opposite behavior in terms of cellular binding. In the presence of bovine serum albumin (BSA), the cellular binding of BSA-NP complexes formed from cationic NPs is enhanced, whereas the cellular binding of BSA-NP complexes formed from anionic NPs is inhibited. These trends are independent of NP diameter or cell type. Similar results were obtained for anionic quantum dots and colloidal gold nanospheres. Using competition assays, we determined that BSA-NP complexes formed from anionic NPs bind to albumin receptors on the cell surface. BSA-NP complexes formed from cationic NPs are redirected to scavenger receptors. The observation that similar NPs with identical protein corona compositions bind to different cellular receptors suggested that a difference in the structure of the adsorbed protein may be responsible for the

  5. Cell motility dynamics: a novel segmentation algorithm to quantify multi-cellular bright field microscopy images.

    Directory of Open Access Journals (Sweden)

    Assaf Zaritsky

    Full Text Available Confocal microscopy analysis of fluorescence and morphology is becoming the standard tool in cell biology and molecular imaging. Accurate quantification algorithms are required to enhance the understanding of different biological phenomena. We present a novel approach based on image-segmentation of multi-cellular regions in bright field images demonstrating enhanced quantitative analyses and better understanding of cell motility. We present MultiCellSeg, a segmentation algorithm to separate between multi-cellular and background regions for bright field images, which is based on classification of local patches within an image: a cascade of Support Vector Machines (SVMs is applied using basic image features. Post processing includes additional classification and graph-cut segmentation to reclassify erroneous regions and refine the segmentation. This approach leads to a parameter-free and robust algorithm. Comparison to an alternative algorithm on wound healing assay images demonstrates its superiority. The proposed approach was used to evaluate common cell migration models such as wound healing and scatter assay. It was applied to quantify the acceleration effect of Hepatocyte growth factor/scatter factor (HGF/SF on healing rate in a time lapse confocal microscopy wound healing assay and demonstrated that the healing rate is linear in both treated and untreated cells, and that HGF/SF accelerates the healing rate by approximately two-fold. A novel fully automated, accurate, zero-parameters method to classify and score scatter-assay images was developed and demonstrated that multi-cellular texture is an excellent descriptor to measure HGF/SF-induced cell scattering. We show that exploitation of textural information from differential interference contrast (DIC images on the multi-cellular level can prove beneficial for the analyses of wound healing and scatter assays. The proposed approach is generic and can be used alone or alongside traditional

  6. Molecular and Cellular Mechanisms Involved in the Trypanosoma cruzi/Host Cell Interplay

    Science.gov (United States)

    Romano, Patricia Silvia; Cueto, Juan Agustín; Casassa, Ana Florencia; Vanrell, María Cristina; Gottlieb, Roberta A.; Colombo, María Isabel

    2013-01-01

    Summary The protozoan parasite Trypanosoma cruzi has a complex bi-ological cycle that involves vertebrate and invertebrate hosts. In mammals, the infective trypomastigote form of this parasite can invade several cell types by exploiting phagocytic-like or non-phagocytic mechanisms depending on the class of cell involved. Morphological studies showed that when trypomastigotes contact macrophages, they induce the formation of plasma membrane protrusions that differ from the canonical phagocytosis that occurs in the case of noninfective epimastigotes. In contrast, when trypomastigotes infect epithelial or muscle cells, the cell surface is minimally modified, suggesting the induction of a different class of process. Lysosomal-dependent or -independent T. cruzi invasion of host cells are two different models that describe the molecular and cellular events activated during parasite entry into nonphagocytic cells. In this context, we have previously shown that induction of autophagy in host cells before infection favors T. cruzi invasion. Furthermore, we demonstrate that autophagosomes and the autophagosomal protein LC3 are recruited to the T. cruzi entry sites and that the newly formed T. cruzi parasitophorous vacuole has characteristics of an autophagolysosome. This review summarizes the current knowledge of the molecular and cellular mechanisms of T. cruzi invasion in nonphagocytic cells. Based on our findings, we propose a new model in which T. cruzi takes advantage of the up-regulation of autophagy during starvation to increase its successful colonization of host cells. PMID:22454195

  7. Intrinsic Radiosensitivity and Cellular Characterization of 27 Canine Cancer Cell Lines.

    Science.gov (United States)

    Maeda, Junko; Froning, Coral E; Brents, Colleen A; Rose, Barbara J; Thamm, Douglas H; Kato, Takamitsu A

    2016-01-01

    Canine cancer cell lines have progressively been developed, but are still underused resources for radiation biology research. Measurement of the cellular intrinsic radiosensitivity is important because understanding the difference may provide a framework for further elucidating profiles for prediction of radiation therapy response. Our studies have focused on characterizing diverse canine cancer cell lines in vitro and understanding parameters that might contribute to intrinsic radiosensitivity. First, intrinsic radiosensitivity of 27 canine cancer cell lines derived from ten tumor types was determined using a clonogenic assay. The 27 cell lines had varying radiosensitivities regardless tumor type (survival fraction at 2 Gy, SF2 = 0.19-0.93). In order to understand parameters that might contribute to intrinsic radiosensitivity, we evaluated the relationships of cellular radiosensitivity with basic cellular characteristics of the cell lines. There was no significant correlation of SF2 with S-phase fraction, doubling time, chromosome number, ploidy, or number of metacentric chromosomes, while there was a statistically significant correlation between SF2 and plating efficiency. Next, we selected the five most radiosensitive cell lines as the radiosensitive group and the five most radioresistant cell lines as the radioresistant group. Then, we evaluated known parameters for cell killing by ionizing radiation, including radiation-induced DNA double strand break (DSB) repair and apoptosis, in the radiosensitive group as compared to the radioresistant group. High levels of residual γ-H2AX foci at the sites of DSBs were present in the four out of the five radiosensitive canine cancer cell lines. Our studies suggested that substantial differences in intrinsic radiosensitivity exist in canine cancer cell lines, and radiation-induced DSB repair was related to radiosensitivity, which is consistent with previous human studies. These data may assist further investigations

  8. Uptake rate of cationic mitochondrial inhibitor MKT-077 determines cellular oxygen consumption change in carcinoma cells.

    Directory of Open Access Journals (Sweden)

    John L Chunta

    Full Text Available OBJECTIVE: Since tumor radiation response is oxygen-dependent, radiosensitivity can be enhanced by increasing tumor oxygenation. Theoretically, inhibiting cellular oxygen consumption is the most efficient way to increase oxygen levels. The cationic, rhodacyanine dye-analog MKT-077 inhibits mitochondrial respiration and could be an effective metabolic inhibitor. However, the relationship between cellular MKT-077 uptake and metabolic inhibition is unknown. We hypothesized that rat and human mammary carcinoma cells would take up MKT-077, causing a decrease in oxygen metabolism related to drug uptake. METHODS: R3230Ac rat breast adenocarcinoma cells were exposed to MKT-077. Cellular MKT-077 concentration was quantified using spectroscopy, and oxygen consumption was measured using polarographic electrodes. MKT-077 uptake kinetics were modeled by accounting for uptake due to both the concentration and potential gradients across the plasma and mitochondrial membranes. These kinetic parameters were used to model the relationship between MKT-077 uptake and metabolic inhibition. MKT-077-induced changes in oxygen consumption were also characterized in MDA-MB231 human breast carcinoma cells. RESULTS: Cells took up MKT-077 with a time constant of ∼1 hr, and modeling showed that over 90% of intracellular MKT-077 was bound or sequestered, likely by the mitochondria. The uptake resulted in a rapid decrease in oxygen consumption, with a time constant of ∼30 minutes. Surprisingly the change in oxygen consumption was proportional to uptake rate, not cellular concentration. MKT-077 proved a potent metabolic inhibitor, with dose-dependent decreases of 45-73% (p = 0.003. CONCLUSIONS: MKT-077 caused an uptake rate-dependent decrease in cellular metabolism, suggesting potential efficacy for increasing tumor oxygen levels and radiosensitivity in vivo.

  9. Cellular interactions via conditioned media induce in vivo nephron generation from tubular epithelial cells or mesenchymal stem cells

    International Nuclear Information System (INIS)

    Highlights: •We have attempted in vivo nephron generation using conditioned media. •Vascular and tubular cells do cross-talks on cell proliferation and tubular changes. •Tubular cells suppress these changes in mesenchymal stem cells. •Tubular cells differentiate mesenchymal stem cells into tubular cells. •Nephrons can be created from implanted tubular cells or mesenchymal stem cells. -- Abstract: There are some successful reports of kidney generation by utilizing the natural course of kidney development, namely, the use of an artificially treated metanephros, blastocyst or ureteric bud. Under a novel concept of cellular interactions via conditioned media (CMs), we have attempted in vivo nephron generation from tubular epithelial cells (TECs) or mesenchymal stem cells (MSCs). Here we used 10× CMs of vascular endothelial cells (VECs) and TECs, which is the first to introduce a CM into the field of organ regeneration. We first present stimulative cross-talks induced by these CMs between VECs and TECs on cell proliferation and morphological changes. In MSCs, TEC-CM suppressed these changes, however, induced cytokeratin expression, indicating the differentiation of MSCs into TECs. As a result, glomerular and tubular structures were created following the implantation of TECs or MSCs with both CMs. Our findings suggest that the cellular interactions via CMs might induce in vivo nephron generation from TECs or MSCs. As a promoting factor, CMs could also be applied to the regeneration of other organs and tissues

  10. Cellular interactions via conditioned media induce in vivo nephron generation from tubular epithelial cells or mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Machiguchi, Toshihiko, E-mail: machiguchi.toshihiko.23u@st.kyoto-u.ac.jp; Nakamura, Tatsuo, E-mail: nakamura@frontier.kyoto-u.ac.jp

    2013-06-07

    Highlights: •We have attempted in vivo nephron generation using conditioned media. •Vascular and tubular cells do cross-talks on cell proliferation and tubular changes. •Tubular cells suppress these changes in mesenchymal stem cells. •Tubular cells differentiate mesenchymal stem cells into tubular cells. •Nephrons can be created from implanted tubular cells or mesenchymal stem cells. -- Abstract: There are some successful reports of kidney generation by utilizing the natural course of kidney development, namely, the use of an artificially treated metanephros, blastocyst or ureteric bud. Under a novel concept of cellular interactions via conditioned media (CMs), we have attempted in vivo nephron generation from tubular epithelial cells (TECs) or mesenchymal stem cells (MSCs). Here we used 10× CMs of vascular endothelial cells (VECs) and TECs, which is the first to introduce a CM into the field of organ regeneration. We first present stimulative cross-talks induced by these CMs between VECs and TECs on cell proliferation and morphological changes. In MSCs, TEC-CM suppressed these changes, however, induced cytokeratin expression, indicating the differentiation of MSCs into TECs. As a result, glomerular and tubular structures were created following the implantation of TECs or MSCs with both CMs. Our findings suggest that the cellular interactions via CMs might induce in vivo nephron generation from TECs or MSCs. As a promoting factor, CMs could also be applied to the regeneration of other organs and tissues.

  11. Actual problems of cellular cardiomyoplasty

    Directory of Open Access Journals (Sweden)

    Bulat Kaupov

    2010-04-01

    Full Text Available The paper provides review of cellular technologies used incardiology, describes types of cellular preparations depending onsources of cells and types of compounding cells. The generalmechanisms of therapies with stem cells applications are described.Use of cellular preparations for treatment of cardiovascular diseasesand is improvement of the forecast at patients with heartinsufficiency of various genesis is considered as alternative topractice with organ transplantations. Efforts of biotechnologicallaboratories are directed on search of optimum population of cellsfor application in cardiology and studying of mechanisms andfactors regulating function of cardiac stem cells.

  12. Dexamethasone reduces sensitivity to cisplatin by blunting p53-dependent cellular senescence in non-small cell lung cancer.

    Directory of Open Access Journals (Sweden)

    Haiyan Ge

    Full Text Available INTRODUCTION: Dexamethasone (DEX co-treatment has proved beneficial in NSCLC patients, improving clinical symptoms by the reduction of side effects after chemotherapy. However, recent studies have shown that DEX could render cancer cells more insensitive to cytotoxic drug therapy, but it is not known whether DEX co-treatment could influence therapy-induced senescence (TIS, and unknown whether it is in a p53-dependent or p53-independent manner. METHODS: We examined in different human NSCLC cell lines and detected cellular senescence after cisplatin (DDP treatment in the presence or absence of DEX. The in vivo effect of the combination of DEX and DDP was assessed by tumor growth experiments using human lung cancer cell lines growing as xenograft tumors in nude mice. RESULTS: Co-treatment with DEX during chemotherapy in NSCLC resulted in increased tumor cell viability and inhibition of TIS compared with DDP treated group. DEX co-treatment cells exhibited the decrease of DNA damage signaling pathway proteins, the lower expression of p53 and p21(CIP1, the lower cellular secretory program and down-regulation of NF-κB and its signaling cascade. DEX also significantly reduced DDP sensitivity in vivo. CONCLUSIONS: Our results underscore that DEX reduces chemotherapy sensitivity by blunting therapy induced cellular senescence after chemotherapy in NSCLC, which may, at least in part, in a p53-dependent manner. These data therefore raise concerns about the widespread combined use of gluocorticoids (GCs with antineoplastic drugs in the clinical management of cancer patients.

  13. Frequent biphasic cellular responses of permanent fish cell cultures to deoxynivalenol (DON)

    International Nuclear Information System (INIS)

    Contamination of animal feed with mycotoxins is a major problem for fish feed mainly due to usage of contaminated ingredients for production and inappropriate storage of feed. The use of cereals for fish food production further increases the risk of a potential contamination. Potential contaminants include the mycotoxin deoxynivalenol (DON) which is synthesized by globally distributed fungi of the genus Fusarium. The toxicity of DON is well recognized in mammals. In this study, we confirm cytotoxic effects of DON in established permanent fish cell lines. We demonstrate that DON is capable of influencing the metabolic activity and cell viability in fish cells as determined by different assays to indicate possible cellular targets of this toxin. Evaluation of cell viability by measurement of membrane integrity, mitochondrial activity and lysosomal function after 24 h of exposure of fish cell lines to DON at a concentration range of 0-3000 ng ml-1 shows a biphasic effect on cells although differences in sensitivity occur. The cell lines derived from rainbow trout are particularly sensitive to DON. The focus of this study lies, furthermore, on the effects of DON at different concentrations on production of reactive oxygen species (ROS) in the different fish cell lines. The results show that DON mainly reduces ROS production in all cell lines that were used. Thus, our comparative investigations reveal that the fish cell lines show distinct species-related endpoint sensitivities that also depend on the type of tissue from which the cells were derived and the severity of exposure. - Highlights: → DON uptake by cells is not extensive. → All fish cell lines are sensitive to DON. → DON is most cytotoxic to rainbow trout cells. → Biphasic cellular responses were frequently observed. → Our results are similar to studies on mammalian cell lines.

  14. Facile Synthesis of Biocompatible Fluorescent Nanoparticles for Cellular Imaging and Targeted Detection of Cancer Cells.

    Science.gov (United States)

    Tang, Fu; Wang, Chun; Wang, Xiaoyu; Li, Lidong

    2015-11-18

    In this work, we report the facile synthesis of functional core-shell structured nanoparticles with fluorescence enhancement, which show specific targeting of cancer cells. Biopolymer poly-l-lysine was used to coat the silver core with various shell thicknesses. Then, the nanoparticles were functionalized with folic acid as a targeting agent for folic acid receptor. The metal-enhanced fluorescence effect was observed when the fluorophore (5-(and-6)-carboxyfluorescein-succinimidyl ester) was conjugated to the modified nanoparticle surface. Cellular imaging assay of the nanoparticles in folic acid receptor-positive cancer cells showed their excellent biocompatibility and selectivity. The as-prepared functional nanoparticles demonstrate the efficiency of the metal-enhanced fluorescence effect and provide an alternative approach for the cellular imaging and targeting of cancer cells.

  15. Protein oxidation and aggregation in UVA-irradiated Escherichia coli cells as signs of accelerated cellular senescence.

    Science.gov (United States)

    Bosshard, Franziska; Riedel, Kathrin; Schneider, Thomas; Geiser, Carina; Bucheli, Margarete; Egli, Thomas

    2010-11-01

    Solar disinfection (SODIS) is a simple drinking water treatment method that improves microbiological water quality where other means are unavailable. It makes use of the deleterious effect of solar irradiation on pathogenic microbes and viruses. A positive impact on health has been documented in several epidemiological studies. However, the molecular mechanisms damaging cells during this simple treatment are not yet fully understood. Here we show that protein damage is crucial in the process of inactivation by sunlight. Protein damages in UVA-irradiated Escherichia coli cells have been evaluated by an immunoblot method for carbonylated proteins and an aggregation assay based on semi-quantitative proteomics. A wide spectrum of structural and enzymatic proteins within the cell is affected by carbonylation and aggregation. Vital cellular functions like the transcription and translation apparatus, transport systems, amino acid synthesis and degradation, respiration, ATP synthesis, glycolysis, the TCA cycle, chaperone functions and catalase are targeted by UVA irradiation. The protein damage pattern caused by SODIS strongly resembles the pattern caused by reactive oxygen stress. Hence, sunlight probably accelerates cellular senescence and leads to the inactivation and finally death of UVA-irradiated cells.

  16. Novel cellular genes essential for transformation of endothelial cells by Kaposi's sarcoma-associated herpesvirus.

    Science.gov (United States)

    Raggo, Camilo; Ruhl, Rebecca; McAllister, Shane; Koon, Henry; Dezube, Bruce J; Früh, Klaus; Moses, Ashlee V

    2005-06-15

    Kaposi's sarcoma-associated herpesvirus (KSHV) is involved in the development of lymphoproliferative diseases and Kaposi's sarcoma. The oncogenicity of this virus is reflected in vitro by its ability to transform B cells and endothelial cells. Infection of dermal microvascular endothelial cells (DMVEC) transforms the cells from a cobblestone-like monolayer to foci-forming spindle cells. This transformation is accompanied by dramatic changes in the cellular transcriptome. Known oncogenes, such as c-Kit, are among the KSHV-induced host genes. We previously showed that c-Kit is an essential cellular component of the KSHV-mediated transformation of DMVEC. Here, we test the hypothesis that the transformation process can be used to discover novel oncogenes. When expression of a panel of KSHV-induced cellular transcripts was inhibited with antisense oligomers, we observed inhibition of DMVEC proliferation and foci formation using antisense molecules to RDC1 and Neuritin. We further showed that transformation of KSHV-infected DMVEC was inhibited by small interfering RNA directed at RDC1 or Neuritin. Ectopic expression of Neuritin in NIH 3T3 cells resulted in changes in cell morphology and anchorage-independent growth, whereas RDC1 ectopic expression significantly increased cell proliferation. In addition, both RDC1- and Neuritin-expressing cells formed tumors in nude mice. RDC1 is an orphan G protein-coupled receptor, whereas Neuritin is a growth-promoting protein known to mediate neurite outgrowth. Neither gene has been previously implicated in tumorigenesis. Our data suggest that KSHV-mediated transformation involves exploitation of the hitherto unrealized oncogenic properties of RDC1 and Neuritin. PMID:15958552

  17. Cell damage from radiation-induced bystander effects for different cell densities simulated by a mathematical model via cellular automata

    Energy Technology Data Exchange (ETDEWEB)

    Meireles, Sincler P. de; Santos, Adriano M.; Grynberg, Suely Epsztein, E-mail: spm@cdtn.b, E-mail: amsantos@cdtn.b, E-mail: seg@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Nunes, Maria Eugenia S., E-mail: mariaeugenia@iceb.ufop.b [Universidade Federal de Ouro Preto (UFOP), MG (Brazil)

    2011-07-01

    During recent years, there has been a shift from an approach focused entirely on DNA as the main target of ionizing radiation to a vision that considers complex signaling pathways in cells and among cells within tissues. Several newly recognized responses were classified as the so-called non-target responses in which the biological effects are not directly related to the amount of energy deposited in the DNA of cells that were traversed by radiation. In 1992 the bystander effect was described referring to a series of responses such as death, chromosomal instability or other abnormalities that occur in non-irradiated cells that came into contact with irradiated cells or medium from irradiated cells. In this work, we have developed a mathematical model via cellular automata, to quantify cell death induced by the bystander effect. The model is based on experiments with irradiated cells conditioned medium which suggests that irradiated cells secrete molecules in the medium that are capable of damaging other cells. The computational model consists of two-dimensional cellular automata which is able to simulate the transmission of bystander signals via extrinsic route and via Gap junctions. The model has been validated by experimental results in the literature. The time evolution of the effect and the dose-response curves were obtained in good accordance to them. Simulations were conducted for different values of bystander and irradiated cell densities with constant dose. From this work, we have obtained a relationship between cell density and effect. (author)

  18. Cell damage from radiation-induced bystander effects for different cell densities simulated by a mathematical model via cellular automata

    International Nuclear Information System (INIS)

    During recent years, there has been a shift from an approach focused entirely on DNA as the main target of ionizing radiation to a vision that considers complex signaling pathways in cells and among cells within tissues. Several newly recognized responses were classified as the so-called non-target responses in which the biological effects are not directly related to the amount of energy deposited in the DNA of cells that were traversed by radiation. In 1992 the bystander effect was described referring to a series of responses such as death, chromosomal instability or other abnormalities that occur in non-irradiated cells that came into contact with irradiated cells or medium from irradiated cells. In this work, we have developed a mathematical model via cellular automata, to quantify cell death induced by the bystander effect. The model is based on experiments with irradiated cells conditioned medium which suggests that irradiated cells secrete molecules in the medium that are capable of damaging other cells. The computational model consists of two-dimensional cellular automata which is able to simulate the transmission of bystander signals via extrinsic route and via Gap junctions. The model has been validated by experimental results in the literature. The time evolution of the effect and the dose-response curves were obtained in good accordance to them. Simulations were conducted for different values of bystander and irradiated cell densities with constant dose. From this work, we have obtained a relationship between cell density and effect. (author)

  19. Preparation and evaluation of polymeric microparticulates for improving cellular uptake of gemcitabine

    Directory of Open Access Journals (Sweden)

    Lim JH

    2012-05-01

    Full Text Available Ji-Ho Lim1,*, Sung-Kyun You1,*, Jong-Suep Baek1, Chan-Ju Hwang1, Young-Guk Na1, Sang-Chul Shin2, Cheong-Weon Cho11College of Pharmacy and Institute of Drug Research and Development, Chungnam National University, Gungdong, Yuseonggu, Daejeon, South Korea, 2College of Pharmacy, Chonnam National University, Buggu, Gwangju, South Korea *These authors contributed equally to this workBackground: Gemcitabine must be administered at high doses to elicit the required therapeutic response because of its very short plasma half-life due to rapid metabolism. These high doses can have severe adverse effects.Methods: In this study, polymeric microparticulate systems of gemcitabine were prepared using chitosan as a mucoadhesive polymer and Eudragit L100-55 as an enteric copolymer. The physicochemical and biopharmaceutical properties of the resulting systems were then evaluated.Results: There was no endothermic peak for gemcitabine in any of the polymeric gemcitabine microparticulate systems, suggesting that gemcitabine was bound to chitosan and Eudragit L100-55 and its crystallinity was changed into an amorphous form. The polymeric gemcitabine microparticulate system showed more than 80% release of gemcitabine in 30 minutes in simulated intestinal fluid. When mucin particles were incubated with gemcitabine polymeric microparticulates, the zeta potential of the mucin particles was increased to 1.57 mV, indicating that the polymeric gemcitabine microparticulates were attached to the mucin particles. Furthermore, the F53 polymeric gemcitabine microparticulates having 150 mg of chitosan showed a 3.8-fold increased uptake of gemcitabine into Caco-2 cells over 72 hours compared with gemcitabine solution alone.Conclusion: Overall, these results suggest that polymeric gemcitabine microparticulate systems could be used as carriers to help oral absorption of gemcitabine.Keywords: gemcitabine, polymeric microparticulates, mucoadhesive, enteric coating, cellular uptake

  20. DNA-damage response network at the crossroads of cell-cycle checkpoints,cellular senescence and apoptosis

    Institute of Scientific and Technical Information of China (English)

    SCHMITT Estelle; PAQUET Claudie; BEAUCHEMIN Myriam; BERTRAND Richard

    2007-01-01

    Tissue homeostasis requires a carefully-orchestrated balance between cell proliferation,cellular senescence and cell death.Cells proliferate through a cell cycle that is tightly regulated by cyclin-dependent kinase activities.Cellular senescence is a safeguard program limiting the proliferative competence of cells in living organisms.Apoptosis eliminates unwanted cells by the coordinated activity of gene products that regulate and effect cell death.The intimate link between the cell cycle,cellular senescence,apoptosis regulation,cancer development and tumor responses to cancer treatment has become eminently apparent.Extensive research on tumor suppressor genes,oncogenes,the cell cycle and apoptosis regulatory genes has revealed how the DNA damage-sensing and -signaling pathways,referred to as the DNA-damage response network,are tied to cell proliferation,cell-cycle arrest,cellular senescence and apoptosis.DNA-damage responses are complex,involving "sensor" proteins that sense the damage,and transmit signals to "transducer" proteins,which,in turn,convey the signals to numerous "effector" proteins implicated in specific cellular pathways,including DNA repair mechanisms,cell-cycle checkpoints,cellular senescence and apoptosis.The Bcl-2 family of proteins stands among the most crucial regulators of apoptosis and performs vital functions in deciding whether a cell will live or die after cancer chemotherapy and irradiation.In addition,several studies have now revealed that members of the Bcl-2 family also interface with the cell cycle,DNA repair/recombination and cellular senescence,effects that are generally distinct from their function in apoptosis.In this review,we report progress in understanding the molecular networks that regulate cell-cycle checkpoints,cellular senescence and apoptosis after DNA damage,and discuss the influence of some Bcl-2 family members on cell-cycle checkpoint regulation.

  1. Beyond the Cell: Using Multiscalar Topics to Bring Interdisciplinarity into Undergraduate Cellular Biology Courses.

    Science.gov (United States)

    Weber, Carolyn F

    2016-01-01

    Western science has grown increasingly reductionistic and, in parallel, the undergraduate life sciences curriculum has become disciplinarily fragmented. While reductionistic approaches have led to landmark discoveries, many of the most exciting scientific advances in the late 20th century have occurred at disciplinary interfaces; work at these interfaces is necessary to manage the world's looming problems, particularly those that are rooted in cellular-level processes but have ecosystem- and even global-scale ramifications (e.g., nonsustainable agriculture, emerging infectious diseases). Managing such problems requires comprehending whole scenarios and their emergent properties as sums of their multiple facets and complex interrelationships, which usually integrate several disciplines across multiple scales (e.g., time, organization, space). This essay discusses bringing interdisciplinarity into undergraduate cellular biology courses through the use of multiscalar topics. Discussing how cellular-level processes impact large-scale phenomena makes them relevant to everyday life and unites diverse disciplines (e.g., sociology, cell biology, physics) as facets of a single system or problem, emphasizing their connections to core concepts in biology. I provide specific examples of multiscalar topics and discuss preliminary evidence that using such topics may increase students' understanding of the cell's position within an ecosystem and how cellular biology interfaces with other disciplines. PMID:27146162

  2. Raman Spectroscopy and Microscopy of Individual Cells andCellular Components

    Energy Technology Data Exchange (ETDEWEB)

    Chan, J; Fore, S; Wachsmann-Hogiu, S; Huser, T

    2008-05-15

    Raman spectroscopy provides the unique opportunity to non-destructively analyze chemical concentrations on the submicron length scale in individual cells without the need for optical labels. This enables the rapid assessment of cellular biochemistry inside living cells, and it allows for their continuous analysis to determine cellular response to external events. Here, we review recent developments in the analysis of single cells, subcellular compartments, and chemical imaging based on Raman spectroscopic techniques. Spontaneous Raman spectroscopy provides for the full spectral assessment of cellular biochemistry, while coherent Raman techniques, such as coherent anti-Stokes Raman scattering is primarily used as an imaging tool comparable to confocal fluorescence microscopy. These techniques are complemented by surface-enhanced Raman spectroscopy, which provides higher sensitivity and local specificity, and also extends the techniques to chemical indicators, i.e. pH sensing. We review the strengths and weaknesses of each technique, demonstrate some of their applications and discuss their potential for future research in cell biology and biomedicine.

  3. Agglomeration, sedimentation, and cellular toxicity of alumina nanoparticles in cell culture medium

    International Nuclear Information System (INIS)

    The cytotoxicity of alumina nanoparticles (NPs) was investigated for a wide range of concentration (25–200 μg/mL) and incubation time (0–72 h) using floating cells (THP-1) and adherent cells (J774A.1, A549, and 293). Alumina NPs were gradually agglomerated over time although a significant portion of sedimentation occurred at the early stage within 6 h. A decrease of the viability was found in floating (THP-1) and adherent (J774A.1 and A549) cells in a dose-dependent manner. However, the time-dependent decrease in cell viability was observed only in adherent cells (J774A.1 and A549), which is predominantly related with the sedimentation of alumina NPs in cell culture medium. The uptake of alumina NPs in macrophages and an increased cell-to-cell adhesion in adherent cells were observed. There was no significant change in the viability of 293 cells. This in vitro test suggests that the agglomeration and sedimentation of alumina NPs affected cellular viability depending on cell types such as monocytes (THP-1), macrophages (J774A.1), lung carcinoma cells (A549), and embryonic kidney cells (293).

  4. Immunologic Monitoring of Cellular Responses by Dendritic/Tumor Cell Fusion Vaccines

    Directory of Open Access Journals (Sweden)

    Shigeo Koido

    2011-01-01

    Full Text Available Although dendritic cell (DC- based cancer vaccines induce effective antitumor activities in murine models, only limited therapeutic results have been obtained in clinical trials. As cancer vaccines induce antitumor activities by eliciting or modifying immune responses in patients with cancer, the Response Evaluation Criteria in Solid Tumors (RECIST and WHO criteria, designed to detect early effects of cytotoxic chemotherapy in solid tumors, may not provide a complete assessment of cancer vaccines. The problem may, in part, be resolved by carrying out immunologic cellular monitoring, which is one prerequisite for rational development of cancer vaccines. In this review, we will discuss immunologic monitoring of cellular responses for the evaluation of cancer vaccines including fusions of DC and whole tumor cell.

  5. DAMPs and autophagy: cellular adaptation to injury and unscheduled cell death.

    Science.gov (United States)

    Zhang, Qiuhong; Kang, Rui; Zeh, Herbert J; Lotze, Michael T; Tang, Daolin

    2013-04-01

    Autophagy is a lysosome-mediated catabolic process involving the degradation of intracellular contents (e.g., proteins and organelles) as well as invading microbes (e.g., parasites, bacteria and viruses). Multiple forms of cellular stress can stimulate this pathway, including nutritional imbalances, oxygen deprivation, immunological response, genetic defects, chromosomal anomalies and cytotoxic stress. Damage-associated molecular pattern molecules (DAMPs) are released by stressed cells undergoing autophagy or injury, and act as endogenous danger signals to regulate the subsequent inflammatory and immune response. A complex relationship exists between DAMPs and autophagy in cellular adaption to injury and unscheduled cell death. Since both autophagy and DAMPs are important for pathogenesis of human disease, it is crucial to understand how they interplay to sustain homeostasis in stressful or dangerous environments. PMID:23388380

  6. Ethical Perspectives on Stem Cell-based Cellular Therapies for Neurodegenerative Diseases

    DEFF Research Database (Denmark)

    Ebbesen, Mette; Pedersen, Finn Skou; Andersen, Svend;

    2012-01-01

    The effect of stem cell-based therapies for neurodegenerative diseases such as Alzheimer disease, Huntington disease, and Parkinson disease are currently being investigated. Here we specify possible therapeutic effects and possible side effects for patients and conclude that cellular therapies may....... Beauchamp and James F. Childress is based on these principles. We show that this theory is useful for analyzing complex ethical cases of biomedicine by using cellular therapy for neurodegenerative diseases as a model system. We go through the three steps in an ethical case analysis using Beauchamp...... and Childress’ principles. We explain that the ethical issues of using stem cells for therapies for neurodegenerative diseases often referred to in the literature are related to the moral status of the blastocyst and the developing embryo. We believe that these are to be seen as potential human life...

  7. Techniques to Study Specific Cell-Surface Receptor-Mediated Cellular Vitamin A Uptake

    OpenAIRE

    KAWAGUCHI, RIKI; Sun, Hui

    2010-01-01

    STRA6 is a multitransmembrane domain protein that was recently identified as the cell-surface receptor for plasma retinol binding protein (RBP), the vitamin A carrier protein in the blood. STRA6 binds to RBP with high affinity and mediates cellular uptake of vitamin A from RBP. It is not homologous to any known receptors, transporters, and channels, and it represents a new class of membrane transport protein. Consistent with the diverse physiological functions of vitamin A, STRA6 is widely ex...

  8. A Cooperative Reinforcement Learning Approach for Inter-Cell Interference Coordination in OFDMA Cellular Networks

    OpenAIRE

    Dirani, Mariana; Altman, Zwi

    2010-01-01

    Interference Management International audience Inter-Cell Interference Coordination (ICIC) is commonly identified as a key radio resource management mechanism to enhance system performance of 4G networks. This paper addresses the problem of ICIC in the downlink of cellular OFDMA (LTE and WiMAX) systems in the context of Self-Organizing Networks (SON). The problem is posed as a cooperative Multi-Agent control problem. Each base station is an agent that dynamically changes power masks on ...

  9. DAMPs and autophagy: Cellular adaptation to injury and unscheduled cell death

    OpenAIRE

    Zhang, Qiuhong; Kang, Rui; Zeh, III, Herbert J.; Lotze, Michael T; Tang, Daolin

    2013-01-01

    Autophagy is a lysosome-mediated catabolic process involving the degradation of intracellular contents (e.g., proteins and organelles) as well as invading microbes (e.g., parasites, bacteria and viruses). Multiple forms of cellular stress can stimulate this pathway, including nutritional imbalances, oxygen deprivation, immunological response, genetic defects, chromosomal anomalies and cytotoxic stress. Damage-associated molecular pattern molecules (DAMPs) are released by stressed cells underg...

  10. Indium-111 oxine labelling affects the cellular integrity of haematopoietic progenitor cells

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Bernd; Reinartz, Patrick; Schaefer, Wolfgang M.; Buell, Ulrich [University Hospital, RWTH Aachen University, Department of Nuclear Medicine, Aachen (Germany); Weber, Christian; Schober, Andreas; Zeiffer, Ute; Liehn, Elisa A.; Hundelshausen, Philipp von [University Hospital, RWTH Aachen University, Department of Molecular Cardiovascular Research, Aachen (Germany)

    2007-05-15

    Cell-based therapy by transplantation of progenitor cells has emerged as a promising development for organ repair, but non-invasive imaging approaches are required to monitor the fate of transplanted cells. Radioactive labelling with {sup 111}In-oxine has been used in preclinical trials. This study aimed to validate {sup 111}In-oxine labelling and subsequent in vivo and ex vivo detection of haematopoietic progenitor cells. Murine haematopoietic progenitor cells (10{sup 6}, FDCPmix) were labelled with 0.1 MBq (low dose) or 1.0 MBq (high dose) {sup 111}In-oxine and compared with unlabelled controls. Cellular retention of {sup 111}In, viability and proliferation were determined up to 48 h after labelling. Labelled cells were injected into the cavity of the left or right cardiac ventricle in mice. Scintigraphic images were acquired 24 h later. Organ samples were harvested to determine the tissue-specific activity. Labelling efficiency was 75 {+-} 14%. Cellular retention of incorporated {sup 111}In after 48 h was 18 {+-} 4%. Percentage viability after 48 h was 90 {+-} 1% (control), 58 {+-} 7% (low dose) and 48 {+-} 8% (high dose) (p<0.0001). Numbers of viable cells after 48 h (normalised to 0 h) were 249 {+-} 51% (control), 42 {+-} 8% (low dose) and 32 {+-} 5% (high dose) (p<0.0001). Cells accumulated in the spleen (86.6 {+-} 27.0% ID/g), bone marrow (59.1 {+-} 16.1% ID/g) and liver (30.3 {+-} 9.5% ID/g) after left ventricular injection, whereas most of the cells were detected in the lungs (42.4 {+-} 21.8% ID/g) after right ventricular injection. Radiolabelling of haematopoietic progenitor cells with {sup 111}In-oxine is feasible, with high labelling efficiency but restricted stability. The integrity of labelled cells is significantly affected, with substantially reduced viability and proliferation and limited migration after systemic transfusion. (orig.)

  11. Amorphous calcium carbonate precipitation by cellular biomineralization in mantle cell cultures of Pinctada fucata.

    Directory of Open Access Journals (Sweden)

    Liang Xiang

    Full Text Available The growth of molluscan shell crystals is generally thought to be initiated from the extrapallial fluid by matrix proteins, however, the cellular mechanisms of shell formation pathway remain unknown. Here, we first report amorphous calcium carbonate (ACC precipitation by cellular biomineralization in primary mantle cell cultures of Pinctada fucata. Through real-time PCR and western blot analyses, we demonstrate that mantle cells retain the ability to synthesize and secrete ACCBP, Pif80 and nacrein in vitro. In addition, the cells also maintained high levels of alkaline phosphatase and carbonic anhydrase activity, enzymes responsible for shell formation. On the basis of polarized light microscopy and scanning electron microscopy, we observed intracellular crystals production by mantle cells in vitro. Fourier transform infrared spectroscopy and X-ray diffraction analyses revealed the crystals to be ACC, and de novo biomineralization was confirmed by following the incorporation of Sr into calcium carbonate. Our results demonstrate the ability of mantle cells to perform fundamental biomineralization processes via amorphous calcium carbonate, and these cells may be directly involved in pearl oyster shell formation.

  12. Glucose Oxidase Induces Cellular Senescence in Immortal Renal Cells through ILK by Downregulating Klotho Gene Expression.

    Science.gov (United States)

    Troyano-Suárez, Nuria; del Nogal-Avila, María; Mora, Inés; Sosa, Patricia; López-Ongil, Susana; Rodriguez-Puyol, Diego; Olmos, Gemma; Ruíz-Torres, María Piedad

    2015-01-01

    Cellular senescence can be prematurely induced by oxidative stress involved in aging. In this work, we were searching for novel intermediaries in oxidative stress-induced senescence, focusing our interest on integrin-linked kinase (ILK), a scaffold protein at cell-extracellular matrix (ECM) adhesion sites, and on the Klotho gene. Cultured renal cells were treated with glucose oxidase (GOx) for long time periods. GOx induced senescence, increasing senescence associated β-galactosidase activity and the expression of p16. In parallel, GOx increased ILK protein expression and activity. Ectopic overexpression of ILK in cells increased p16 expression, even in the absence of GOx, whereas downregulation of ILK inhibited the increase in p16 due to oxidative stress. Additionally, GOx reduced Klotho gene expression and cells overexpressing Klotho protein did not undergo senescence after GOx addition. We demonstrated a direct link between ILK and Klotho since silencing ILK expression in cells and mice increases Klotho expression and reduces p53 and p16 expression in renal cortex. In conclusion, oxidative stress induces cellular senescence in kidney cells by increasing ILK protein expression and activity, which in turn reduces Klotho expression. We hereby present ILK as a novel downregulator of Klotho gene expression. PMID:26583057

  13. Disruptive environmental chemicals and cellular mechanisms that confer resistance to cell death.

    Science.gov (United States)

    Narayanan, Kannan Badri; Ali, Manaf; Barclay, Barry J; Cheng, Qiang Shawn; D'Abronzo, Leandro; Dornetshuber-Fleiss, Rita; Ghosh, Paramita M; Gonzalez Guzman, Michael J; Lee, Tae-Jin; Leung, Po Sing; Li, Lin; Luanpitpong, Suidjit; Ratovitski, Edward; Rojanasakul, Yon; Romano, Maria Fiammetta; Romano, Simona; Sinha, Ranjeet K; Yedjou, Clement; Al-Mulla, Fahd; Al-Temaimi, Rabeah; Amedei, Amedeo; Brown, Dustin G; Ryan, Elizabeth P; Colacci, Annamaria; Hamid, Roslida A; Mondello, Chiara; Raju, Jayadev; Salem, Hosni K; Woodrick, Jordan; Scovassi, A Ivana; Singh, Neetu; Vaccari, Monica; Roy, Rabindra; Forte, Stefano; Memeo, Lorenzo; Kim, Seo Yun; Bisson, William H; Lowe, Leroy; Park, Hyun Ho

    2015-06-01

    Cell death is a process of dying within biological cells that are ceasing to function. This process is essential in regulating organism development, tissue homeostasis, and to eliminate cells in the body that are irreparably damaged. In general, dysfunction in normal cellular death is tightly linked to cancer progression. Specifically, the up-regulation of pro-survival factors, including oncogenic factors and antiapoptotic signaling pathways, and the down-regulation of pro-apoptotic factors, including tumor suppressive factors, confers resistance to cell death in tumor cells, which supports the emergence of a fully immortalized cellular phenotype. This review considers the potential relevance of ubiquitous environmental chemical exposures that have been shown to disrupt key pathways and mechanisms associated with this sort of dysfunction. Specifically, bisphenol A, chlorothalonil, dibutyl phthalate, dichlorvos, lindane, linuron, methoxychlor and oxyfluorfen are discussed as prototypical chemical disruptors; as their effects relate to resistance to cell death, as constituents within environmental mixtures and as potential contributors to environmental carcinogenesis. PMID:26106145

  14. Comparison of cellular responses induced by low level light in different cell types

    Science.gov (United States)

    Huang, Ying-Ying; Chen, Aaron C.-H.; Sharma, Sulbha K.; Wu, Qiuhe; Hamblin, Michael R.

    2010-02-01

    Discoveries are rapidly being made in multiple laboratories that shed "light" on the fundamental molecular and cellular mechanisms underlying the use of low level light therapy (LLLT) in vitro, in animal models and in clinical practice. Increases in cellular levels of respiration, in cytochrome c oxidase activity, in ATP levels and in cyclic AMP have been found. Increased expression of reactive oxygen species and release of nitric oxide have also been shown. In order for these molecular changes to have a major effect on cell behavior, it is likely that various transcription factors will be activated, possibly via different signal transduction pathways. In this report we compare and contrast the effects of LLLT in vitro on murine embryonic fibroblasts, primary cortical neurons, cardiomyocytes and bone-marrow derived dendritic cells. We also examined two human cell lines, HeLa cancer cells and HaCaT keratinocytes. The effects of 810-nm near-infra-red light delivered at low and high fluences were addressed. Reactive oxygen species generation, transcription factor activation and ATP increases are reported. The data has led to the hypothesis that cells with a high level of mitochondrial activity (mitochondrial membrane potential) have a higher response to light than cells with low mitochondrial activity.

  15. Cellular responses to low dose heavy-ion exposure in human cell

    International Nuclear Information System (INIS)

    The human lymphoblastoid cell line TK6 was used to study the cellular responses after low-dose (100, 200, 500 mGy) or high-dose (3 Gy) of X rays, C (22 keV.μm-1) and Fe (1000 keV.μm-1) ion exposures, p53 protein induction in individual cells was determined by indirect immunofluorescence staining. Cell-cycle progression after heavy-ion exposure was determined by using a laser scanning cytometer. A characteristic pattern of cell-cycle progression was observed with 3 Gy exposure of Fe ions but not with 100 mGy. Similarly such a pattern with 100 mGy C ion exposure did not match that with 3 Gy. The proportion of p53-induced cells is proportional to the probability of cell being hit by a primary heavy ion. The observed low-dose effect can be reflected in the probability of a hit, although detailed nature about their energy deposition must be considered for more precise estimation of such an effect. New detection methodology must be developed for identification of heavy-ion specific cellular responses. (author)

  16. Genome editing of human pluripotent stem cells to generate human cellular disease models

    Directory of Open Access Journals (Sweden)

    Kiran Musunuru

    2013-07-01

    Full Text Available Disease modeling with human pluripotent stem cells has come into the public spotlight with the awarding of the Nobel Prize in Physiology or Medicine for 2012 to Drs John Gurdon and Shinya Yamanaka for the discovery that mature cells can be reprogrammed to become pluripotent. This discovery has opened the door for the generation of pluripotent stem cells from individuals with disease and the differentiation of these cells into somatic cell types for the study of disease pathophysiology. The emergence of genome-editing technology over the past few years has made it feasible to generate and investigate human cellular disease models with even greater speed and efficiency. Here, recent technological advances in genome editing, and its utility in human biology and disease studies, are reviewed.

  17. A Simple Scheme for Improved Performance of Fixed Outage Rate Cellular System

    Directory of Open Access Journals (Sweden)

    Hussein M.A. Basi

    2004-01-01

    Full Text Available The traffic characteristic of mobile cellular systems is rather distinct from that of a fixed telephone network. However the system planning and design are still carried out with the tools of conventional traffic theory. In the recent days much work is being done in the performance evaluation of mobile or cellular communication systems in order to develop a system with greater efficiency. The useful parameters to estimate the performance of the system are voice quality, frequency spectrum efficiency and Grade of Service (GOS. The grade of service will be affected due to outage of channels. In this study, a new scheme is proposed to reduce lost calls due to channel outage in the fixed rate outage cellular system. In this proposed scheme the call will never dropped but may be delayed. The system performance is evaluated for different conditions and the results are discussed.

  18. Expression weighted cell type enrichments reveal genetic and cellular nature of major brain disorders

    Directory of Open Access Journals (Sweden)

    Nathan Gerald Skene

    2016-01-01

    Full Text Available The cell types that trigger the primary pathology in many brain diseases remain largely unknown. One route to understanding the primary pathological cell type for a particular disease is to identify the cells expressing susceptibility genes. Although this is straightforward for monogenic conditions where the causative mutation may alter expression of a cell type specific marker, methods are required for the common polygenic disorders. We developed the Expression Weighted Cell Type Enrichment (EWCE method that uses single cell transcriptomes to generate the probability distribution associated with a gene list having an average level of expression within a cell type. Following validation, we applied EWCE to human genetic data from cases of epilepsy, Schizophrenia, Autism, Intellectual Disability, Alzheimer’s disease, Multiple Sclerosis and anxiety disorders. Genetic susceptibility primarily affected microglia in Alzheimer’s and Multiple Sclerosis; was shared between interneurons and pyramidal neurons in Autism and Schizophrenia; while intellectual disabilities and epilepsy were attributable to a range of cell-types, with the strongest enrichment in interneurons. We hypothesised that the primary cell type pathology could trigger secondary changes in other cell types and these could be detected by applying EWCE to transcriptome data from diseased tissue. In Autism, Schizophrenia and Alzheimer’s disease we find evidence of pathological changes in all of the major brain cell types. These findings give novel insight into the cellular origins and progression in common brain disorders. The methods can be applied to any tissue and disorder and have applications in validating mouse models.

  19. Effects of brevetoxins on murine myeloma SP2/O cells: aberrant cellular division.

    Science.gov (United States)

    Han, Thomas K; Derby, Melissa; Martin, Dean F; Wright, Scott D; Dao, My Lien

    2003-01-01

    Massive deaths of manatees (Trichechus manatus latirostris) during the red tide seasons have been attributed to brevetoxins produced by the dinoflagellate Karenia brevis (formerly Ptychodiscus breve and Gymnodinium breve). Although these toxins have been found in macrophages and lymphocytes in the lung, liver, and secondary lymphoid tissues of these animals, the molecular mechanisms of brevetoxicosis have not yet been identified. To investigate the effects of brevetoxins on immune cells, a murine myeloma cell line (SP2/O) was used as a model for in vitro studies. By adding brevetoxins to cultures of the SP2/O cells at concentrations ranging from 20 to 600 ng/ml, an apparent increase in proliferation was observed at around 2 hours post challenge as compared to the unchallenged cell cultures. This was followed by a drop in cell number at around 3 hours, suggesting an aberrant effect of brevetoxins on cellular division, the cells generated at 2 hours being apparently short-lived. In situ immunochemical staining of the SP2/O cells at 1 and 2 hour post challenge showed an accumulation of the toxins in the nucleus. A 21-kDa protein was subsequently isolated from the SP2/O cells as having brevetoxin-binding properties, and immunologically identified as p21, a nuclear factor known to down-regulate cellular proliferation through inhibition of cyclin-dependent kinases. These data are the first on a possible effect of brevetoxins on the cell cycle via binding to p21, a phenomenon that needs to be further investigated and validated in normal immune cells. PMID:12745987

  20. Beyond the Cell: Using Multiscalar Topics to Bring Interdisciplinarity into Undergraduate Cellular Biology Courses

    Science.gov (United States)

    Weber, Carolyn F.

    2016-01-01

    Western science has grown increasingly reductionistic and, in parallel, the undergraduate life sciences curriculum has become disciplinarily fragmented. While reductionistic approaches have led to landmark discoveries, many of the most exciting scientific advances in the late 20th century have occurred at disciplinary interfaces; work at these interfaces is necessary to manage the world’s looming problems, particularly those that are rooted in cellular-level processes but have ecosystem- and even global-scale ramifications (e.g., nonsustainable agriculture, emerging infectious diseases). Managing such problems requires comprehending whole scenarios and their emergent properties as sums of their multiple facets and complex interrelationships, which usually integrate several disciplines across multiple scales (e.g., time, organization, space). This essay discusses bringing interdisciplinarity into undergraduate cellular biology courses through the use of multiscalar topics. Discussing how cellular-level processes impact large-scale phenomena makes them relevant to everyday life and unites diverse disciplines (e.g., sociology, cell biology, physics) as facets of a single system or problem, emphasizing their connections to core concepts in biology. I provide specific examples of multiscalar topics and discuss preliminary evidence that using such topics may increase students’ understanding of the cell’s position within an ecosystem and how cellular biology interfaces with other disciplines. PMID:27146162

  1. DNA damage and cellular death in oral mucosa cells of children who have undergone panoramic dental radiography

    Energy Technology Data Exchange (ETDEWEB)

    Angelieri, Fernanda; Oliveira, Gabriela R. de [Sao Paulo Metodista University (UMESP), Department of Orthodontics, Sao Bernardo do Campo, Sao Paulo (Brazil); Sannomiya, Eduardo K. [Sao Paulo Metodista University (UMESP), Department of Dento-Maxillofacial Radiology, Sao Bernardo do Campo, Sao Paulo (Brazil); Ribeiro, Daniel A. [Federal University of Sao Paulo (UNIFESP), Department of Health Sciences, Santos, Sao Paulo (Brazil); Universidade Federal de Sao Paulo (UNIFESP), Departamento de Ciencias da Saude, Santos, Sao Paulo (Brazil)

    2007-06-15

    Despite wide use as a diagnostic tool in medical and dental practice, radiography can induce cytotoxic effects and genetic damage. To evaluate DNA damage (micronucleus) and cellular death (pyknosis, karyolysis and karyorrhexis) in exfoliated buccal mucosa cells taken from healthy children following exposure to radiation during dental radiography. A total of 17 children who had undergone panoramic dental radiography were included. We found no statistically significant differences (P > 0.05) between micronucleated oral mucosa cells in children before and after exposure to radiation. On the other hand, radiation did cause other nuclear alterations closely related to cytotoxicity including karyorrhexis, pyknosis and karyolysis. Taken together, these results indicate that panoramic dental radiography might not induce chromosomal damage, but may be cytotoxic. Overall, the results reinforce the importance of evaluating the health side effects of radiography and contribute to the micronucleus database, which will improve our understanding and practice of this methodology in children. (orig.)

  2. Classification of Cells with Membrane Staining and/or Fixation Based on Cellular Specific Membrane Capacitance and Cytoplasm Conductivity

    OpenAIRE

    Song-Bin Huang; Yang Zhao; Deyong Chen; Shing-Lun Liu; Yana Luo; Tzu-Keng Chiu; Junbo Wang; Jian Chen; Min-Hsien Wu

    2015-01-01

    Single-cell electrical properties (e.g., specific membrane capacitance (Cspecific membrane) and cytoplasm conductivity (σcytoplasm)) have been regarded as potential label-free biophysical markers for the evaluation of cellular status. However, whether there exist correlations between these biophysical markers and cellular status (e.g., membrane-associate protein expression) is still unknown. To further validate the utility of single-cell electrical properties in cell type classification, Cspe...

  3. Multiplex profiling of cellular invasion in 3D cell culture models.

    Directory of Open Access Journals (Sweden)

    Gerald Burgstaller

    Full Text Available To-date, most invasion or migration assays use a modified Boyden chamber-like design to assess migration as single-cell or scratch assays on coated or uncoated planar plastic surfaces. Here, we describe a 96-well microplate-based, high-content, three-dimensional cell culture assay capable of assessing invasion dynamics and molecular signatures thereof. On applying our invasion assay, we were able to demonstrate significant effects on the invasion capacity of fibroblast cell lines, as well as primary lung fibroblasts. Administration of epidermal growth factor resulted in a substantial increase of cellular invasion, thus making this technique suitable for high-throughput pharmacological screening of novel compounds regulating invasive and migratory pathways of primary cells. Our assay also correlates cellular invasiveness to molecular events. Thus, we argue of having developed a powerful and versatile toolbox for an extensive profiling of invasive cells in a 96-well format. This will have a major impact on research in disease areas like fibrosis, metastatic cancers, or chronic inflammatory states.

  4. Dimethylarsenic acid damages cellular DNA and inhibits gap junctional intercellular communication between human skin fibroblast cells

    Institute of Scientific and Technical Information of China (English)

    GuoXB; DengFR

    2002-01-01

    Although arsenic is identified as a human carcinogen,there is currently no accepted mechanism for its action or an established animal model for evaluating the carcinogenic activity of arsenic.To elucidate the mechanism of arsenic arcinogenesis,we investigated the effect of dimethylarsenic acid(DMAA),the main metabolite of inorganic arsenic in humans,on the cellular DNA and gap junctional intercellular communication (GJIC) between human skin fibroblast cells.Single-cell gel electrophoresis (SCGE) assay was used to detect the DNA damage in human skin fibroblast cells exposed to DMAA,and the GJIC between cells was detected by the scrape loading/dye transfer assay.DMAA at concentrations of 0.01-1.0 mmol·L-1 induced DNA damage in a dose-dependent manner,and GJIC between human skin fibroblast cells was significantly inhibited by DMAA at 1.0 mmol·L-1.Our results suggest that both genotoxic and nongenotoxic mechanism are involved in the mechanism of DMAA-induced cellular toxicity.

  5. Cellular distribution of inorganic mercury and its relation to cytotoxicity in bovine kidney cell cultures

    International Nuclear Information System (INIS)

    A bovine kidney cell culture system was used to assess what relationship mercuric chloride (HgCl2) uptake and subcellular distribution had to cytotoxicity. Twenty-four-hour incubations with 0.05-50 μM HgCl2 elicited a concentration-related cytotoxicity. Cellular accumulation of 203Hg was also concentration-related, with 1.0 nmol/106 cells at the IC50. Measurement of Hg uptake over the 24-h exposure period revealed a multiphasic process. Peak accumulation was attained by 1 h and was followed by extrusion and plateauing of intracellular Hg levels. Least-squares regression analysis of the cytotoxicity and cellular uptake data indicated a potential relationship between the Hg uptake and cytotoxicity. However, the subcellular distribution of Hg was not concentration-related. Mitochondria and soluble protein fractions accounted for greater than 65% of the cell-associated Hg at all concentrations. The remaining Hg was distributed between the microsomal (6-10%) and nuclear and cell debris (11-22%) fractions at all concentrations tested. Less than 20% of the total cell-associated Hg was bound with metallothionein-like protein. 31 references, 4 figures, 3 tables

  6. Cellular, Molecular Consequences of Peroxisome Proliferator- Activated Receptor-δ Activation in Ovarian Cancer Cells

    Directory of Open Access Journals (Sweden)

    Sara Vignati

    2006-10-01

    Full Text Available Peroxisome proliferator-activated receptor-δ (PPAR-δ is a ligand-activated transcription factor. In addition to its canonical role in lipid, glucose metabolism, PPAR-δ controls cell proliferation, death, differentiation in several tissues. Here we have examined the expression of PPAR-δ in ovarian tumors, the cellular, molecular consequences of its activation in ovarian cancer cells. PPAR-δ was expressed in a large number of epithelial ovarian tumors, cell lines. The PPAR-δ lig, ciglitazone inhibited the growth, clonogenic survival of ovarian cancer cells, inducing cell cycle arrest, cell death. Growth inhibition by ciglitazone was reversed by the PPAR-δ antagonist GW9662, indicating the involvement of PPAR-δ- dependent mechanisms. Microarray-based gene profiling revealed complex changes in the transcriptional program of ovarian cancer cells on treatment with ciglitazone, identified multiple pathways that may contribute to PPAR-δ ligands' antitumor activity. Genes upregulated by ciglitazone were predominantly associated with metabolic, differentiation, tumorsuppressor pathways, whereas downregulated genes were involved in cell proliferation, cell cycle, cell organization, steroid biosynthesis. Collectively, our data indicate that PPAR-δ activation by selective agonists is a valid strategy for ovarian cancer therapy, prevention, should be tested alone, in combination with other anticancer drugs.

  7. Dynamic culture improves cell reprogramming efficiency.

    Science.gov (United States)

    Sia, Junren; Sun, Raymond; Chu, Julia; Li, Song

    2016-06-01

    Cell reprogramming to pluripotency is an inefficient process and various approaches have been devised to improve the yield of induced pluripotent stem cells. However, the effect of biophysical factors on cell reprogramming is not well understood. Here we showed that, for the first time, dynamic culture with orbital shaking significantly improved the reprogramming efficiency in adherent cells. Manipulating the viscosity of the culture medium suggested that the improved efficiency is mainly attributed to convective mixing rather than hydrodynamic shear stress. Temporal studies demonstrated that the enhancement of reprogramming efficiency required the dynamic culture in the middle but not early phase. In the early phase, fibroblasts had a high proliferation rate, but as the culture became over-confluent in the middle phase, expression of p57 was upregulated to inhibit cell proliferation and consequently, cell reprogramming. Subjecting the over confluent culture to orbital shaking prevented the upregulation of p57, thus improving reprogramming efficiency. Seeding cells at low densities to avoid over-confluency resulted in a lower efficiency, and optimal reprogramming efficiency was attained at a high seeding density with dynamic culture. Our findings provide insight into the underlying mechanisms of how dynamic culture condition regulate cell reprogramming, and will have broad impact on cell engineering for regenerative medicine and disease modeling.

  8. Accelerated cellular senescence phenotype of GAPDH-depleted human lung carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Phadke, Manali; Krynetskaia, Natalia [Temple University School of Pharmacy, Philadelphia, PA 19140 (United States); Mishra, Anurag [Jayne Haines Center for Pharmacogenomics, Temple University School of Pharmacy, Philadelphia, PA 19140 (United States); Krynetskiy, Evgeny, E-mail: ekrynets@temple.edu [Temple University School of Pharmacy, Philadelphia, PA 19140 (United States); Jayne Haines Center for Pharmacogenomics, Temple University School of Pharmacy, Philadelphia, PA 19140 (United States)

    2011-07-29

    Highlights: {yields} We examined the effect of glyceraldehyde 3-phosphate (GAPDH) depletion on proliferation of human carcinoma A549 cells. {yields} GAPDH depletion induces accelerated senescence in tumor cells via AMPK network, in the absence of DNA damage. {yields} Metabolic and genetic rescue experiments indicate that GAPDH has regulatory functions linking energy metabolism and cell cycle. {yields} Induction of senescence in LKB1-deficient lung cancer cells via GAPDH depletion suggests a novel strategy to control tumor cell proliferation. -- Abstract: Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is a pivotal glycolytic enzyme, and a signaling molecule which acts at the interface between stress factors and the cellular apoptotic machinery. Earlier, we found that knockdown of GAPDH in human carcinoma cell lines resulted in cell proliferation arrest and chemoresistance to S phase-specific cytotoxic agents. To elucidate the mechanism by which GAPDH depletion arrests cell proliferation, we examined the effect of GAPDH knockdown on human carcinoma cells A549. Our results show that GAPDH-depleted cells establish senescence phenotype, as revealed by proliferation arrest, changes in morphology, SA-{beta}-galactosidase staining, and more than 2-fold up-regulation of senescence-associated genes DEC1 and GLB1. Accelerated senescence following GAPDH depletion results from compromised glycolysis and energy crisis leading to the sustained AMPK activation via phosphorylation of {alpha} subunit at Thr172. Our findings demonstrate that GAPDH depletion switches human tumor cells to senescent phenotype via AMPK network, in the absence of DNA damage. Rescue experiments using metabolic and genetic models confirmed that GAPDH has important regulatory functions linking the energy metabolism and the cell cycle networks. Induction of senescence in LKB1-deficient non-small cell lung cancer cells via GAPDH depletion suggests a novel strategy to control tumor cell proliferation.

  9. Planes, Trains, and Automobiles: Perspectives on CAR T Cells and Other Cellular Therapies for Hematologic Malignancies.

    Science.gov (United States)

    Gill, Saar

    2016-08-01

    Hematologic oncologists now have at their disposal (or a referral away) a myriad of new options to get from point A (a patient with relapsed or poor-risk disease) to point B (potential tumor eradication and long-term disease-free survival). In this perspective piece, we discuss the putative mechanisms of action and the relative strengths and weaknesses of currently available cellular therapy approaches. Notably, while many of these approaches have been published in high impact journals, with the exception of allogeneic stem cell transplantation and of checkpoint inhibitors (PD1/PDL1 or CTLA4 blockade), the published clinical trials have mostly been early phase, uncontrolled studies. Therefore, many of the new cellular therapy approaches have yet to demonstrate incontrovertible evidence of enhanced overall survival compared with controls. Nonetheless, the science behind these is sure to advance our understanding of cancer immunology and ultimately to bring us closer to our goal of curing cancer.

  10. Planes, Trains, and Automobiles: Perspectives on CAR T Cells and Other Cellular Therapies for Hematologic Malignancies.

    Science.gov (United States)

    Gill, Saar

    2016-08-01

    Hematologic oncologists now have at their disposal (or a referral away) a myriad of new options to get from point A (a patient with relapsed or poor-risk disease) to point B (potential tumor eradication and long-term disease-free survival). In this perspective piece, we discuss the putative mechanisms of action and the relative strengths and weaknesses of currently available cellular therapy approaches. Notably, while many of these approaches have been published in high impact journals, with the exception of allogeneic stem cell transplantation and of checkpoint inhibitors (PD1/PDL1 or CTLA4 blockade), the published clinical trials have mostly been early phase, uncontrolled studies. Therefore, many of the new cellular therapy approaches have yet to demonstrate incontrovertible evidence of enhanced overall survival compared with controls. Nonetheless, the science behind these is sure to advance our understanding of cancer immunology and ultimately to bring us closer to our goal of curing cancer. PMID:27136938

  11. Role of cellular prion proteins in the function of macrophages and dendritic cells.

    Science.gov (United States)

    Nitta, Kayako; Sakudo, Akikazu; Masuyama, Jun; Xue, Guangai; Sugiura, Katsuaki; Onodera, Takashi

    2009-01-01

    The cellular isoform of prion proteins (PrPC) is expressed in hematopoietic stem cells, granulocytes, T and B lymphocyte natural killer cells, platelets, monocytes, dendritic cells, and follicular dendritic cells, which may act as carrier cells for the spread of its abnormal isoform (PrPSc) before manifesting transmissible spongiform encephalopathies (TSEs). In particular, macrophages and dendritic cells seem to be involved in the replication of PrPSc after ingestion. In addition, information on the role of PrPC during phagocytotic activity in these cells has been obtained. A recent study showed that resident macrophages from ZrchI PrP gene (Prnp)-deficient (Prnp-/-) mice show augmented phagocytotic activity compared to Prnp+/+ counterparts. In contrast, our study suggests that Rikn Prnp-/- peritoneal macrophages show pseudopodium extension arrest and up-regulation of phagocytotic activity compared to Prnp+/+ cells. Although reports regarding phagocytotic activity in resident and peritoneal macrophages are inconsistent between ZrchI and Rikn Prnp-/- mice, it seems plausible that PrPC in macrophages could contribute to maintain the immunological environment. This review will introduce the recent progress in understanding the functions of PrPC in macrophages and dendritic cells under physiological conditions and its involvement in the pathogenesis of prion diseases. PMID:19275736

  12. Impact of photocatalysis on fungal cells: depiction of cellular and molecular effects on Saccharomyces cerevisiae.

    Science.gov (United States)

    Thabet, Sana; Simonet, France; Lemaire, Marc; Guillard, Chantal; Cotton, Pascale

    2014-12-01

    We have investigated the antimicrobial effects of photocatalysis on the yeast model Saccharomyces cerevisiae. To accurately study the antimicrobial mechanisms of the photocatalytic process, we focused our investigations on two questions: the entry of the nanoparticles in treated cells and the fate of the intracellular environment. Transmission electronic microscopy did not reveal any entry of nanoparticles within the cells, even for long exposure times, despite degradation of the cell wall space and deconstruction of cellular compartments. In contrast to proteins located at the periphery of the cells, intracellular proteins did not disappear uniformly. Disappearance or persistence of proteins from the pool of oxidized intracellular isoforms was not correlated to their functions. Altogether, our data suggested that photocatalysis induces the establishment of an intracellular oxidative environment. This hypothesis was sustained by the detection of an increased level of superoxide ions (O2°(-)) in treated cells and by greater cell cultivability for cells expressing oxidant stress response genes during photocatalytic exposure. The increase in intracellular ROS, which was not connected to the entry of nanoparticles within the cells or to a direct contact with the plasma membrane, could be the result of an imbalance in redox status amplified by chain reactions. Moreover, we expanded our study to other yeast and filamentous fungi and pointed out that, in contrast to the laboratory model S. cerevisiae, some environmental strains are very resistant to photocatalysis. This could be related to the cell wall composition and structure.

  13. CELLULAR AND POPULATION PLASTICITY OF HELPER CD4 T CELL RESPONSES

    Directory of Open Access Journals (Sweden)

    Gesham eMagombedze

    2013-08-01

    Full Text Available Vertebrates are constantly exposed to pathogens, and the adaptive immunity has most likely evolved to control and clear such infectious agents. CD4 T cells are the major players in the adaptive immune response to pathogens. Following recognition of pathogen-derived antigens naïve CD4 T cells differentiate into effectors which then control pathogen replication either directly by killing pathogen-infected cells or by assisting with generation of cytotoxic T lymphocytes or pathogen-specific antibodies. Pathogen-specific effector CD4 T cells are highly heterogeneous in terms of cytokines they produce. Three major subtypes of effector CD4 T cells have been identified: T-helper 1 (Th1 cells producing IFN-g and TNF-α, Th2 cells producing IL-4 and IL-10, and Th17 cells producing IL-17. How this heterogeneity is maintained and what regulates changes in effector T cell composition during chronic infections remains poorly understood. In this review we discuss recent advances in our understanding of CD4 T cell differentiation in response to microbial infections. We propose that a change in the phenotype of pathogen-specific effector CD4 T cells during chronic infections, for example, from Th1 to Th2 response as observed in Mycobacteriumavium ssp. paratuberculosis (MAP infection of ruminants, can be achieved by conversion of T cells from one effector subset to another (cellular plasticity or due to differences in kinetics (differentiation, proliferation, death of different effector T cell subsets (population plasticity. We also shortly review mathematical models aimed at describing CD4 T cell differentiation and outline areas for future experimental and theoretical research.

  14. Analyzing the Influence of Mobile Phone Use of Drivers on Traffic Flow Based on an Improved Cellular Automaton Model

    OpenAIRE

    Yao Xiao; Jing Shi

    2015-01-01

    This paper aimed to analyze the influence of drivers’ behavior of phone use while driving on traffic flow, including both traffic efficiency and traffic safety. An improved cellular automaton model was proposed to simulate traffic flow with distracted drivers based on the Nagel-Schreckenberg model. The driving characters of drivers using a phone were first discussed and a value representing the probability to use a phone while driving was put into the CA model. Simulation results showed that ...

  15. Improved Zirconia Oxygen-Separation Cell

    Science.gov (United States)

    Walsh, John V.; Zwissler, James G.

    1988-01-01

    Cell structure distributes feed gas more evenly for more efficent oxygen production. Multilayer cell structure containing passages, channels, tubes, and pores help distribute pressure evenly over zirconia electrolytic membrane. Resulting more uniform pressure distribution expected to improve efficiency of oxygen production.

  16. A SELF-ORGANIZED RESOURCE ALLOCATION USING INTER-CELL INTERFERENCE COORDINATION (ICIC IN RELAY-ASSISTED CELLULAR NETWORKS

    Directory of Open Access Journals (Sweden)

    Mahima Mehta

    2011-06-01

    Full Text Available In a multi-cell scenario, the inter-cell interference (ICI is detrimental in achieving the intended system performance, in particular for the edge users. There is paucity of work available in literature on ICI coordination (ICIC for relay-assisted cellular networks (RACN. In this paper, we do a survey on the ICIC schemes in cellular networks and RACN. We then propose a self-organized resource allocation plan for RACN to improve the edge user’s performance by ICIC. We compare the performance of reuse-1, reuse-3, soft frequency reuse (SFR scheme, proposed plan with and without relays. The performance metrics for comparison are edge user’s spectral efficiency, their signal-to-interference-and-noise ratio (SINR and system’s area spectral efficiency. We show by the simulation results that our proposed plan performs better than the existing resource allocation schemes in static allocation scenario. Next, we propose to make our resource allocation plan dynamic and self-organized. The distinct features of our proposed plan are: One, it achieves a trade-off between the system’s area spectral efficiency and the edge user’s spectral efficiency performance. Secondly, it introduces a novel concept of interfering neighbor set to achieve ICIC by local interaction between the entities.

  17. Locally-Delivered T-Cell-Derived Cellular Vehicles Efficiently Track and Deliver Adenovirus Delta24-RGD to Infiltrating Glioma

    Directory of Open Access Journals (Sweden)

    Rutger K. Balvers

    2014-08-01

    Full Text Available Oncolytic adenoviral vectors are a promising alternative for the treatment of glioblastoma. Recent publications have demonstrated the advantages of shielding viral particles within cellular vehicles (CVs, which can be targeted towards the tumor microenvironment. Here, we studied T-cells, often having a natural capacity to target tumors, for their feasibility as a CV to deliver the oncolytic adenovirus, Delta24-RGD, to glioblastoma. The Jurkat T-cell line was assessed in co-culture with the glioblastoma stem cell (GSC line, MGG8, for the optimal transfer conditions of Delta24-RGD in vitro. The effect of intraparenchymal and tail vein injections on intratumoral virus distribution and overall survival was addressed in an orthotopic glioma stem cell (GSC-based xenograft model. Jurkat T-cells were demonstrated to facilitate the amplification and transfer of Delta24-RGD onto GSCs. Delta24-RGD dosing and incubation time were found to influence the migratory ability of T-cells towards GSCs. Injection of Delta24-RGD-loaded T-cells into the brains of GSC-bearing mice led to migration towards the tumor and dispersion of the virus within the tumor core and infiltrative zones. This occurred after injection into the ipsilateral hemisphere, as well as into the non-tumor-bearing hemisphere. We found that T-cell-mediated delivery of Delta24-RGD led to the inhibition of tumor growth compared to non-treated controls, resulting in prolonged survival (p = 0.007. Systemic administration of virus-loaded T-cells resulted in intratumoral viral delivery, albeit at low levels. Based on these findings, we conclude that T-cell-based CVs are a feasible approach to local Delta24-RGD delivery in glioblastoma, although efficient systemic targeting requires further improvement.

  18. Nitric oxide-releasing prodrug triggers cancer cell death through deregulation of cellular redox balance

    Directory of Open Access Journals (Sweden)

    Anna E. Maciag

    2013-01-01

    Full Text Available JS-K is a nitric oxide (NO-releasing prodrug of the O2-arylated diazeniumdiolate family that has demonstrated pronounced cytotoxicity and antitumor properties in a variety of cancer models both in vitro and in vivo. The current study of the metabolic actions of JS-K was undertaken to investigate mechanisms of its cytotoxicity. Consistent with model chemical reactions, the activating step in the metabolism of JS-K in the cell is the dearylation of the diazeniumdiolate by glutathione (GSH via a nucleophilic aromatic substitution reaction. The resulting product (CEP/NO anion spontaneously hydrolyzes, releasing two equivalents of NO. The GSH/GSSG redox couple is considered to be the major redox buffer of the cell, helping maintain a reducing environment under basal conditions. We have quantified the effects of JS-K on cellular GSH content, and show that JS-K markedly depletes GSH, due to JS-K's rapid uptake and cascading release of NO and reactive nitrogen species. The depletion of GSH results in alterations in the redox potential of the cellular environment, initiating MAPK stress signaling pathways, and inducing apoptosis. Microarray analysis confirmed signaling gene changes at the transcriptional level and revealed alteration in the expression of several genes crucial for maintenance of cellular redox homeostasis, as well as cell proliferation and survival, including MYC. Pre-treating cells with the known GSH precursor and nucleophilic reducing agent N-acetylcysteine prevented the signaling events that lead to apoptosis. These data indicate that multiplicative depletion of the reduced glutathione pool and deregulation of intracellular redox balance are important initial steps in the mechanism of JS-K's cytotoxic action.

  19. Effect of verapamil on cellular uptake of Tc-99m MIBI and tetrofosmin on several cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Hyun; Yoo, Jung Ah; Bae, Jin Ho; Jeong, Shin Young; Suh, Myung Rang; Ahn, Byeong Cheol; Lee, Kyu Bo; Lee, Jae Tae [School of Medicine, Kyungpook National Univ., Daegu (Korea, Republic of)

    2004-02-01

    Cellular uptake of {sup 99}mTc-sestamibi (MIBI) and {sup 99}mTc-tetrofosmin (TF) is low in cancer cells expressing multidrug resistance(MDR) by p-glycoprotein(Pgp) or multidrug related protein(MRP). Verapamil is known to increase cellular uptake of MIBI in MDR cancer cells, but is recently reported to have different effects on tracer uptake in certain cancer cells. This study was prepared to evaluate effects of verapamil on cellular uptake of MIBI and TF in several cancer cells. Cellular uptakes of Tc-99m MIBI and TF were measured in erythroleukemia K562 cell, breast cancer MCF7 cell, and human ovarian cancer SK-OV-3 cells, and data were compared with those of doxorubicin-resistant K562(Ad) cells. RT-PCR and Western blot analysis were used for the detection of mdr1 mRNA and Pgp expression, and to observe changes in isotypes of PKC enzyme. Effects of verapamil on MIBI and TF uptake were evaluated at different concentrations upto 200 {mu}M at 1*10{sup 6} cells/{sup m}l at 37.deg.C. Radioactivity in supernatant and pellet was measured with gamma counter to calculate cellular uptake ratio. Toxicity of verapamil was measured with MTT assay. Cellular uptakes of MIBI and TF were increased by time in four cancer cells studied. Co-incubation with verapamil resulted in an increase in uptake of MIBI and TF in K562(Adr) cell at a concentration of 100 {mu}M and the maximal increase at 50 {mu}M was 10-times to baseline. In contrast, uptakes of MIBI and TF in K562, MCF7m SK-OV3 cells were decreased with verapamil treatment at a concentration over 1 {mu}M. With a concentration of 200 {mu}M verapamil, respectively. Cellular uptakes of MIBI and TF in MCF7 and SK-OV-3 cells were not changed with 10{mu}M, but were also decreased with verapamil higher than 10{mu}M, resulting 40% and 5% of baseline at 50 {mu}M. MTT assay of four cells revealed that K562, MCF7, SK-OV3 were not damaged with verapamil at 200 {mu}M. Although verapamil increases uptake of MIBI and TF in MDR cancer cells

  20. Analysis on Traffic Conflicts of Two-lane Highway Based on Improved Cellular Automation Model

    Directory of Open Access Journals (Sweden)

    Xiru Tang

    2013-06-01

    Full Text Available Based on microscopic traffic characteristics of two-lane highway and different driving characteristics for drivers, the characteristics of drivers and vehicle structure are introduced into Cellular Automation model for establishing new Cellular Automation model of two-lane highway. Through computer simulation, the paper analyzes the effect of the promotion of different vehicles, drivers and arrival rates on traffic conflicts of two-lane highway, which gets the relationship between the parameters such as road traffic and velocity variance and collision. The results indicate that the frequency of traffic conflicts has close relationship with the product of traffic flow and velocity variation. When the traffic flow and velocity variation are great, the frequency of the conflict is the greatest, and when the traffic flow and velocity variation are little, the frequency of the conflict is the least.

  1. Activation of human natural killer cells by the soluble form of cellular prion protein

    International Nuclear Information System (INIS)

    Cellular prion protein (PrPC) is widely expressed in various cell types, including cells of the immune system. However, the specific roles of PrPC in the immune system have not been clearly elucidated. In the present study, we investigated the effects of a soluble form of recombinant PrPC protein on human natural killer (NK) cells. Recombinant soluble PrPC protein was generated by fusion of human PrPC with the Fc portion of human IgG1 (PrPC-Fc). PrPC-Fc binds to the surface of human NK cells, particularly to CD56dim NK cells. PrPC-Fc induced the production of cytokines and chemokines and the degranulation of granzyme B from NK cells. In addition, PrPC-Fc facilitated the IL-15-induced proliferation of NK cells. PrPC-Fc induced phosphorylation of ERK-1/2 and JNK in NK cells, and inhibitors of the ERK or the JNK pathways abrogated PrPC-Fc-induced cytokine production in NK cells. In conclusion, the soluble form of recombinant PrPC-Fc protein activates human NK cells via the ERK and JNK signaling pathways. - Highlights: • Recombinant soluble PrPC (PrPC-Fc) was generated by fusion of human PrPC with IgG1 Fc portion. • PrPC-Fc protein induces the production of cytokines and degranulation from human NK cells. • PrPC-Fc protein enhances the IL-15-induced proliferation of human NK cells. • PrPC-Fc protein activates human NK cells via the ERK and JNK signaling pathways

  2. Regulatory subunits of PKA define an axis of cellular proliferation/differentiation in ovarian cancer cells

    Directory of Open Access Journals (Sweden)

    Hall John C

    2008-09-01

    Full Text Available Abstract Background The regulatory subunit of cAMP-dependent protein kinase (PKA exists in two isoforms, RI and RII, which distinguish the PKA isozymes, type I (PKA-I and type II (PKA-II. Evidence obtained from a variety of different experimental approaches has shown that the relative levels of type I and type II PKA in cells can play a major role in determining the balance between cell growth and differentiation. In order to characterize the effect of PKA type I and type II regulatory subunits on gene transcription at a global level, the PKA regulatory subunit genes for RIα and RIIβ were stably transfected into cells of the ovarian cancer cell line (OVCAR8. Results RIα transfected cells exhibit hyper-proliferative growth and RIIβ transfected cells revert to a relatively quiescent state. Profiling by microarray revealed equally profound changes in gene expression between RIα, RIIβ, and parental OVCAR cells. Genes specifically up-regulated in RIα cells were highly enriched for pathways involved in cell growth while genes up-regulated in RIIβ cells were enriched for pathways involved in differentiation. A large group of genes (~3600 was regulated along an axis of proliferation/differentiation between RIα, parental, and RIIβ cells. RIα/wt and RIIβ/wt gene regulation was shown by two separate and distinct gene set analytical methods to be strongly cross-correlated with a generic model of cellular differentiation. Conclusion Overexpression of PKA regulatory subunits in an ovarian cancer cell line dramatically influences the cell phenotype. The proliferation phenotype is strongly correlated with recently identified clinical biomarkers predictive of poor prognosis in ovarian cancer suggesting a possible pivotal role for PKA regulation in disease progression.

  3. Activation of human natural killer cells by the soluble form of cellular prion protein

    Energy Technology Data Exchange (ETDEWEB)

    Seong, Yeon-Jae [Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, KAIST, Daejeon (Korea, Republic of); Hafis Clinic, Seoul (Korea, Republic of); Sung, Pil Soo; Jang, Young-Soon; Choi, Young Joon [Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, KAIST, Daejeon (Korea, Republic of); Park, Bum-Chan [Aging Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Park, Su-Hyung [Laboratory of Translational Immunology and Vaccinology, Graduate School of Medical Science and Engineering, KAIST, Daejeon (Korea, Republic of); Park, Young Woo [Aging Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Shin, Eui-Cheol, E-mail: ecshin@kaist.ac.kr [Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, KAIST, Daejeon (Korea, Republic of)

    2015-08-21

    Cellular prion protein (PrP{sup C}) is widely expressed in various cell types, including cells of the immune system. However, the specific roles of PrP{sup C} in the immune system have not been clearly elucidated. In the present study, we investigated the effects of a soluble form of recombinant PrP{sup C} protein on human natural killer (NK) cells. Recombinant soluble PrP{sup C} protein was generated by fusion of human PrP{sup C} with the Fc portion of human IgG{sub 1} (PrP{sup C}-Fc). PrP{sup C}-Fc binds to the surface of human NK cells, particularly to CD56{sup dim} NK cells. PrP{sup C}-Fc induced the production of cytokines and chemokines and the degranulation of granzyme B from NK cells. In addition, PrP{sup C}-Fc facilitated the IL-15-induced proliferation of NK cells. PrP{sup C}-Fc induced phosphorylation of ERK-1/2 and JNK in NK cells, and inhibitors of the ERK or the JNK pathways abrogated PrP{sup C}-Fc-induced cytokine production in NK cells. In conclusion, the soluble form of recombinant PrP{sup C}-Fc protein activates human NK cells via the ERK and JNK signaling pathways. - Highlights: • Recombinant soluble PrP{sup C} (PrP{sup C}-Fc) was generated by fusion of human PrP{sup C} with IgG1 Fc portion. • PrP{sup C}-Fc protein induces the production of cytokines and degranulation from human NK cells. • PrP{sup C}-Fc protein enhances the IL-15-induced proliferation of human NK cells. • PrP{sup C}-Fc protein activates human NK cells via the ERK and JNK signaling pathways.

  4. The cytotoxicity of polycationic iron oxide nanoparticles: Common endpoint assays and alternative approaches for improved understanding of cellular response mechanism

    Directory of Open Access Journals (Sweden)

    Hoskins Clare

    2012-04-01

    Full Text Available Abstract Background Iron oxide magnetic nanoparticles (MNP's have an increasing number of biomedical applications. As such in vitro characterisation is essential to ensure the bio-safety of these particles. Little is known on the cellular interaction or effect on membrane integrity upon exposure to these MNPs. Here we synthesised Fe3O4 and surface coated with poly(ethylenimine (PEI and poly(ethylene glycol (PEG to achieve particles of varying surface positive charges and used them as model MNP's to evaluate the relative utility and limitations of cellular assays commonly applied for nanotoxicity assessment. An alternative approach, atomic force microscopy (AFM, was explored for the analysis of membrane structure and cell morphology upon interacting with the MNPs. The particles were tested in vitro on human SH-SY5Y, MCF-7 and U937 cell lines for reactive oxygen species (ROS production and lipid peroxidation (LPO, LDH leakage and their overall cytotoxic effect. These results were compared with AFM topography imaging carried out on fixed cell lines. Results Successful particle synthesis and coating were characterised using FTIR, PCS, TEM and ICP. The particle size from TEM was 30 nm (−16.9 mV which increased to 40 nm (+55.6 mV upon coating with PEI and subsequently 50 nm (+31.2 mV with PEG coating. Both particles showed excellent stability not only at neutral pH but also in acidic environment of pH 4.6 in the presence of sodium citrate. The higher surface charge MNP-PEI resulted in increased cytotoxic effect and ROS production on all cell lines compared with the MNP-PEI-PEG. In general the effect on the cell membrane integrity was observed only in SH-SY5Y and MCF-7 cells by MNP-PEI determined by LDH leakage and LPO production. AFM topography images showed consistently that both the highly charged MNP-PEI and the less charged MNP-PEI-PEG caused cell morphology changes possibly due to membrane disruption and cytoskeleton remodelling. Conclusions

  5. Cellular and molecular remodelling of a host cell for vertical transmission of bacterial symbionts

    Science.gov (United States)

    Luan, Jun-Bo; Shan, Hong-Wei; Isermann, Philipp; Huang, Jia-Hsin; Lammerding, Jan; Liu, Shu-Sheng; Douglas, Angela E.

    2016-01-01

    Various insects require intracellular bacteria that are restricted to specialized cells (bacteriocytes) and are transmitted vertically via the female ovary, but the transmission mechanisms are obscure. We hypothesized that, in the whitefly Bemisia tabaci, where intact bacteriocytes (and not isolated bacteria) are transferred to oocytes, the transmission mechanism would be evident as cellular and molecular differences between the nymph (pre-adult) and adult bacteriocytes. We demonstrate dramatic remodelling of bacteriocytes at the developmental transition from nymph to adulthood. This transition involves the loss of cell–cell adhesion, high division rates to constant cell size and onset of cell mobility, enabling the bacteriocytes to crawl to the ovaries. These changes are accompanied by cytoskeleton reorganization and changes in gene expression: genes functioning in cell–cell adhesion display reduced expression and genes involved in cell division, cell motility and endocytosis/exocytosis have elevated expression in adult bacteriocytes, relative to nymph bacteriocytes. This study demonstrates, for the first time, how developmentally orchestrated remodelling of gene expression and correlated changes in cell behaviour underpin the capacity of bacteriocytes to mediate the vertical transmission and persistence of the symbiotic bacteria on which the insect host depends. PMID:27358364

  6. Comparative Iron Oxide Nanoparticle Cellular Dosimetry and Response in Mice by the Inhalation and Liquid Cell Culture Exposure Routes

    Energy Technology Data Exchange (ETDEWEB)

    Teeguarden, Justin G.; Mikheev, Vladimir B.; Minard, Kevin R.; Forsythe, William C.; Wang, Wei; Sharma, Gaurav; Karin, Norman J.; Tilton, Susan C.; Waters, Katrina M.; Asgharian, Bahman; Price, Owen; Pounds, Joel G.; Thrall, Brian D.

    2014-01-01

    testing the rapidly growing number of nanomaterials requires large scale use of in vitro systems under the presumption that these systems are sufficiently predictive or descriptive of responses in in vivo systems for effective use in hazard ranking. We hypothesized that improved relationships between in vitro and in vivo models of experimental toxicology for nanomaterials would result from placing response data in vitro and in vivo on the same dose scale, the amount of material associated with cells (target cell dose). Methods: Balb/c mice were exposed nose-only to an aerosol of 12.8 nm (68.6 nm CMD, 19.9 mg/m3, 4 hours) super paramagnetic iron oxide particles, target cell doses were calculated and biomarkers of response anchored with histological evidence were identified by global transcriptomics. Representative murine epithelial and macrophage cell types were exposed in vitro to the same material in liquid suspension for four hours and levels nanoparticle regulated cytokine transcripts identified in vivo were quantified as a function of measured nanoparticle cellular dose. Results. Target tissue doses of 0.009-0.4 μg SPIO/cm2 lung led to an inflammatory response in the alveolar region characterized by interstitial inflammation and macrophage infiltration. In vitro, higher target tissue doses of ~1.2-4 μg SPIO/ cm2 of cells were required to induce transcriptional regulation of markers of inflammation, CXCL2 CCL3, in C10 lung epithelial cells. Estimated in vivo macrophage SPIO nanoparticle doses ranged from 1-100 pg/cell, and induction of inflammatory markers was observed in vitro in macrophages at doses of 8-35 pg/cell. Conclusions: Application of target tissue dosimetry revealed good correspondence between target cell doses triggering inflammatory processes in vitro and in vivo in the alveolar macrophage population, but not in the epithelial cells of the alveolar region. These findings demonstrate the potential for target tissue dosimetry to enable the more

  7. Preparation of cell-sized water-in-oil droplets for in vitro reconstitution of biological processes in cellular compartments

    OpenAIRE

    sprotocols

    2015-01-01

    This protocol presents a method for encapsulation of purified proteins into cell-sized water-in-oil droplets surrounded by a phospholipid monolayer, which can be broadly applied to studies to reconstitute biological processes in cellular compartments.

  8. Precision automation of cell type classification and sub-cellular fluorescence quantification from laser scanning confocal images

    Directory of Open Access Journals (Sweden)

    Hardy Craig Hall

    2016-02-01

    Full Text Available While novel whole-plant phenotyping technologies have been successfully implemented into functional genomics and breeding programs, the potential of automated phenotyping with cellular resolution is largely unexploited. Laser scanning confocal microscopy has the potential to close this gap by providing spatially highly resolved images containing anatomic as well as chemical information on a subcellular basis. However, in the absence of automated methods, the assessment of the spatial patterns and abundance of fluorescent markers with subcellular resolution is still largely qualitative and time-consuming. Recent advances in image acquisition and analysis, coupled with improvements in microprocessor performance, have brought such automated methods within reach, so that information from thousands of cells per image for hundreds of images may be derived in an experimentally convenient time-frame. Here, we present a MATLAB-based analytical pipeline to 1 segment radial plant organs into individual cells, 2 classify cells into cell type categories based upon random forest classification, 3 divide each cell into sub-regions, and 4 quantify fluorescence intensity to a subcellular degree of precision for a separate fluorescence channel. In this research advance, we demonstrate the precision of this analytical process for the relatively complex tissues of Arabidopsis hypocotyls at various stages of development. High speed and robustness make our approach suitable for phenotyping of large collections of stem-like material and other tissue types.

  9. A generic screening platform for inhibitors of virus induced cell fusion using cellular electrical impedance.

    Science.gov (United States)

    Watterson, Daniel; Robinson, Jodie; Chappell, Keith J; Butler, Mark S; Edwards, David J; Fry, Scott R; Bermingham, Imogen M; Cooper, Matthew A; Young, Paul R

    2016-01-01

    Fusion of the viral envelope with host cell membranes is an essential step in the life cycle of all enveloped viruses. Despite such a clear target for antiviral drug development, few anti-fusion drugs have progressed to market. One significant hurdle is the absence of a generic, high-throughput, reproducible fusion assay. Here we report that real time, label-free measurement of cellular electrical impedance can quantify cell-cell fusion mediated by either individually expressed recombinant viral fusion proteins, or native virus infection. We validated this approach for all three classes of viral fusion and demonstrated utility in quantifying fusion inhibition using antibodies and small molecule inhibitors specific for dengue virus and respiratory syncytial virus. PMID:26976324

  10. Cancer stem cell overexpression of nicotinamide N-methyltransferase enhances cellular radiation resistance

    DEFF Research Database (Denmark)

    D’Andrea, Filippo P.; Safwat, Akmal; Kassem, Moustapha;

    2011-01-01

    found the genes involved in cancer, proliferation, DNA repair and cell death. ConclusionsThe higher radiation resistance in clone CE8 is likely due to NNMT overexpression. The higher levels of NNMT could affect the cellular damage resistance through depletion of the accessible amounts of nicotinamide...... that could explain cancer stem cell radiation resistance. MethodsTumorigenic mesenchymal cancer stem cell clones BB3 and CE8 were irradiated at varying doses and assayed for clonogenic surviving fraction. Altered gene expression before and after 2Gy was assessed by Affymetric exon chip analysis and further...... validated with q-RT-PCR using TaqMan probes. ResultsThe CE8 clone was more radiation resistant than the BB3 clone. From a pool of 15 validated genes with altered expression in the CE8 clone, we found the enzyme nicotinamide N-methyltransferase (NNMT) more than 5-fold upregulated. In-depth pathway analysis...

  11. Effects of Cisplatin in Neuroblastoma Rat Cells: Damage to Cellular Organelles

    Science.gov (United States)

    Santin, Giada; Scietti, Luigi; Veneroni, Paola; Barni, Sergio; Bernocchi, Graziella; Bottone, Maria Grazia

    2012-01-01

    Cisplatin (cisPt) is a chemotherapy agent used as a treatment for several types of cancer. The main cytotoxic effect of cisplatin is generally accepted to be DNA damage. Recently, the mechanism by which cisPt generates the cascade of events involved in the apoptotic process has been demonstrated. In particular it has been shown that some organelles are cisPt target and are involved in cell death. This paper aims to describe the morphological and functional changes of the Golgi apparatus and lysosomes during apoptosis induced in neuronal rat cells (B50) by cisplatin. The results obtained show that the cellular organelles are the target of cisPt, so their damage can induce cell death. PMID:22505928

  12. Classification of Cells with Membrane Staining and/or Fixation Based on Cellular Specific Membrane Capacitance and Cytoplasm Conductivity

    Directory of Open Access Journals (Sweden)

    Song-Bin Huang

    2015-01-01

    Full Text Available Single-cell electrical properties (e.g., specific membrane capacitance (Cspecific membrane and cytoplasm conductivity (σcytoplasm have been regarded as potential label-free biophysical markers for the evaluation of cellular status. However, whether there exist correlations between these biophysical markers and cellular status (e.g., membrane-associate protein expression is still unknown. To further validate the utility of single-cell electrical properties in cell type classification, Cspecific membrane and σcytoplasm of single PC-3 cells with membrane staining and/or fixation were analyzed and compared in this study. Four subtypes of PC-3 cells were prepared: untreated PC-3 cells, PC-3 cells with anti-EpCAM staining, PC-3 cells with fixation, and fixed PC-3 cells with anti-EpCAM staining. In experiments, suspended single cells were aspirated through microfluidic constriction channels with raw impedance data quantified and translated to Cspecific membrane and σcytoplasm. As to experimental results, significant differences in Cspecific membrane were observed for both live and fixed PC-3 cells with and without membrane staining, indicating that membrane staining proteins can contribute to electrical properties of cellular membranes. In addition, a significant decrease in σcytoplasm was located for PC-3 cells with and without fixation, suggesting that cytoplasm protein crosslinking during the fixation process can alter the cytoplasm conductivity. Overall, we have demonstrated how to classify single cells based on cellular electrical properties.

  13. Improved biolistic transfection of hair cells.

    Directory of Open Access Journals (Sweden)

    Hongyu Zhao

    Full Text Available Transient transfection of hair cells has proven challenging. Here we describe modifications to the Bio-Rad Helios Gene Gun that, along with an optimized protocol, improve transfection of bullfrog, chick, and mouse hair cells. The increased penetrating power afforded by our method allowed us to transfect mouse hair cells from the basal side, through the basilar membrane; this configuration protects hair bundles from damage during the procedure. We characterized the efficiency of transfection of mouse hair cells with fluorescently-tagged actin fusion protein using both the optimized procedure and a published procedure; while the efficiency of the two methods was similar, the morphology of transfected hair cells was improved with the new procedure. In addition, using the improved method, we were able to transfect hair cells in the bullfrog sacculus and chick cochlea for the first time. We used fluorescent-protein fusions of harmonin b (USH1C and PMCA2 (ATP2B2; plasma-membrane Ca(2+-ATPase isoform 2 to examine protein distribution in hair cells. While PMCA2-EGFP localization was similar to endogenous PMCA2 detected with antibodies, high levels of harmonin-EGFP were found at stereocilia tapers in bullfrog and chick, but not mouse; by contrast, harmonin-EGFP was concentrated in stereocilia tips in mouse hair cells.

  14. BAF180 regulates cellular senescence and hematopoietic stem cell homeostasis through p21.

    Science.gov (United States)

    Lee, Hyemin; Dai, Fangyan; Zhuang, Li; Xiao, Zhen-Dong; Kim, Jongchan; Zhang, Yilei; Ma, Li; You, M James; Wang, Zhong; Gan, Boyi

    2016-04-12

    BAF180 (also called PBRM1), a subunit of the SWI/SNF complex, plays critical roles in the regulation of chromatin remodeling and gene transcription, and is frequently mutated in several human cancers. However, the role of mammalian BAF180 in tumor suppression and tissue maintenance in vivo remains largely unknown. Here, using a conditional somatic knockout approach, we explored the cellular and organismal functions of BAF180 in mouse. BAF180 deletion in primary mouse embryonic fibroblasts (MEFs) triggers profound cell cycle arrest, premature cellular senescence, without affecting DNA damage response or chromosomal integrity. While somatic deletion of BAF180 in adult mice does not provoke tumor development, BAF180 deficient mice exhibit defects in hematopoietic system characterized by progressive reduction of hematopoietic stem cells (HSCs), defective long-term repopulating potential, and hematopoietic lineage developmental aberrations. BAF180 deletion results in elevated p21 expression in both MEFs and HSCs. Mechanistically, we showed that BAF180 binds to p21 promoter, and BAF180 deletion enhances the binding of modified histones associated with transcriptional activation on p21 promoter. Deletion of p21 rescues cell cycle arrest and premature senescence in BAF180 deficient MEFs, and partially rescues hematopoietic defects in BAF180 deficient mice. Together, our study identifies BAF180 as a critical regulator of cellular senescence and HSC homeostasis, which is at least partially regulated through BAF180-mediated suppression of p21 expression. Our results also suggest that senescence triggered by BAF180 inactivation may serve as a failsafe mechanism to restrain BAF180 deficiency-associated tumor development, providing a conceptual framework to further understand BAF180 function in tumor biology.

  15. Aldolase B knockdown prevents high glucose-induced methylglyoxal overproduction and cellular dysfunction in endothelial cells.

    Directory of Open Access Journals (Sweden)

    Jianghai Liu

    Full Text Available We used cultured endothelial cells as a model to examine whether up-regulation of aldolase B and enhanced methylglyoxal (MG formation play an important role in high glucose-induced overproduction of advanced glycosylation endproducts (AGEs, oxidative stress and cellular dysfunction. High glucose (25 mM incubation up-regulated mRNA levels of aldose reductase (an enzyme converting glucose to fructose and aldolase B (a key enzyme that catalyzes MG formation from fructose and enhanced MG formation in human umbilical vein endothelial cells (HUVECs and HUVEC-derived EA. hy926 cells. High glucose-increased MG production in EA. hy926 cells was completely prevented by siRNA knockdown of aldolase B, but unaffected by siRNA knockdown of aldolase A, an enzyme responsible for MG formation during glycolysis. In addition, inhibition of cytochrome P450 2E1 or semicarbazide-sensitive amine oxidase which produces MG during the metabolism of lipid and proteins, respectively, did not alter MG production. Both high glucose (25 mM and MG (30, 100 µM increased the formation of N(ε-carboxyethyl-lysine (CEL, a MG-induced AGE, oxidative stress (determined by the generation of oxidized DCF, H(2O(2, protein carbonyls and 8-oxo-dG, O-GlcNAc modification (product of the hexosamine pathway, membrane protein kinase C activity and nuclear translocation of NF-κB in EA. hy926 cells. However, the above metabolic and signaling alterations induced by high glucose were completely prevented by knockdown of aldolase B and partially by application of aminoguanidine (a MG scavenger or alagebrium (an AGEs breaker. In conclusion, efficient inhibition of aldolase B can prevent high glucose-induced overproduction of MG and related cellular dysfunction in endothelial cells.

  16. Multiple steady states with distinct cellular metabolism in continuous culture of mammalian cells.

    Science.gov (United States)

    Europa, A F; Gambhir, A; Fu, P C; Hu, W S

    2000-01-01

    Mammalian cells have the ability to proliferate under different nutrient environments by utilizing different combinations of the nutrients, especially glucose and the amino acids. Under the conditions often used in in vitro cultivation, the cells consume glucose and amino acids in great excess of what is needed for making up biomass and products. They also produce large amounts of metabolites with lactate, ammonia, and some non-essential amino acids such as alanine as the most dominant ones. By controlling glucose and glutamine at low levels, cellular metabolism can be altered and can result in reduced glucose and glutamine consumption as well as in reduced metabolite formation. Using a fed-batch reactor to manipulate glucose at a low level (as compared to a typical batch culture), cell metabolism was altered to a state with substantially reduced lactate production. The culture was then switched to a continuous mode and allowed to reach a steady-state. At this steady-state, the concentrations of cells and antibody were substantially higher than a control culture that was initiated from a batch culture without first altering cellular metabolism. The lactate and other metabolite concentrations were also substantially reduced as compared to the control culture. This newly observed steady-state was achieved at the same dilution rate and feed medium as the control culture. The paths leading to the two steady-states, however, were different. These results demonstrate steady-state multiplicity. At this new steady-state, not only was glucose metabolism altered, but the metabolism of amino acids was altered as well. The amino acid metabolism in the new steady-state was more balanced, and the excretion of non-essential amino acids and ammonia was substantially lower. This approach of reaching a more desirable steady-state with higher concentrations of cells and product opens a new avenue for high-density- and high-productivity-cell culture.

  17. Differential Cellular and Molecular Effects of Butyrate and Trichostatin A on Vascular Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Kasturi Ranganna

    2012-09-01

    Full Text Available The histone deacetylase (HDAC inhibitors, butyrate and trichostatin A (TSA, are epigenetic histone modifiers and proliferation inhibitors by downregulating cyclin D1, a positive cell cycle regulator, and upregulating p21Cip1 and INK family of proteins, negative cell cycle regulators. Our recent study indicated cyclin D1 upregulation in vascular smooth muscle cells (VSMC that are proliferation-arrested by butyrate. Here we investigate whether cyclin D1 upregulation is a unique response of VSMC to butyrate or a general response to HDAC inhibitors (HDACi by evaluating the effects of butyrate and TSA on VSMC. While butyrate and TSA inhibit VSMC proliferation via cytostatic and cytotoxic effects, respectively, they downregulate cdk4, cdk6, and cdk2, and upregulate cyclin D3, p21Cip1 and p15INK4B, and cause similar effects on key histone H3 posttranslational modifications. Conversely, cyclin D1 is upregulated by butyrate and inhibited by TSA. Assessment of glycogen synthase 3-dependent phosphorylation, subcellular localization and transcription of cyclin D1 indicates that differential effects of butyrate and TSA on cyclin D1 levels are linked to disparity in cyclin D1 gene expression. Disparity in butyrate- and TSA-induced cyclin D1 may influence transcriptional regulation of genes that are associated with changes in cellular morphology/cellular effects that these HDACi confer on VSMC, as a transcriptional modulator.

  18. A new adenovirus based vaccine vector expressing an Eimeria tenella derived TLR agonist improves cellular immune responses to an antigenic target.

    Directory of Open Access Journals (Sweden)

    Daniel M Appledorn

    Full Text Available BACKGROUND: Adenoviral based vectors remain promising vaccine platforms for use against numerous pathogens, including HIV. Recent vaccine trials utilizing Adenovirus based vaccines expressing HIV antigens confirmed induction of cellular immune responses, but these responses failed to prevent HIV infections in vaccinees. This illustrates the need to develop vaccine formulations capable of generating more potent T-cell responses to HIV antigens, such as HIV-Gag, since robust immune responses to this antigen correlate with improved outcomes in long-term non-progressor HIV infected individuals. METHODOLOGY/PRINCIPAL FINDINGS: In this study we designed a novel vaccine strategy utilizing an Ad-based vector expressing a potent TLR agonist derived from Eimeria tenella as an adjuvant to improve immune responses from a [E1-]Ad-based HIV-Gag vaccine. Our results confirm that expression of rEA elicits significantly increased TLR mediated innate immune responses as measured by the influx of plasma cytokines and chemokines, and activation of innate immune responding cells. Furthermore, our data show that the quantity and quality of HIV-Gag specific CD8(+ and CD8(- T-cell responses were significantly improved when coupled with rEA expression. These responses also correlated with a significantly increased number of HIV-Gag derived epitopes being recognized by host T cells. Finally, functional assays confirmed that rEA expression significantly improved antigen specific CTL responses, in vivo. Moreover, we show that these improved responses were dependent upon improved TLR pathway interactions. CONCLUSION/SIGNIFICANCE: The data presented in this study illustrate the potential utility of Ad-based vectors expressing TLR agonists to improve clinical outcomes dependent upon induction of robust, antigen specific immune responses.

  19. Cellular compartments cause multistability and allow cells to process more information

    DEFF Research Database (Denmark)

    Harrington, Heather A; Feliu, Elisenda; Wiuf, Carsten;

    2013-01-01

    outcomes for cellular-decision making. We combine different mathematical techniques to provide a heuristic procedure to determine if a system has the capacity for multiple steady states, and find conditions that ensure that multiple steady states cannot occur. Notably, we find that introducing species...... is capable of multistationarity (multiple response states), and is thus directly linked to the amount of information that the signaling molecules can represent in the nucleus. Multistationarity provides a mechanism for switching between different response states in cell signaling systems and enables multiple...

  20. Early Passage Dependence of Mesenchymal Stem Cell Mechanics Influences Cellular Invasion and Migration.

    Science.gov (United States)

    Spagnol, Stephen T; Lin, Wei-Chun; Booth, Elizabeth A; Ladoux, Benoit; Lazarus, Hillard M; Dahl, Kris Noel

    2016-07-01

    The cellular structures and mechanical properties of human mesenchymal stem cells (hMSCs) vary significantly during culture and with differentiation. Previously, studies to measure mechanics have provided divergent results using different quantitative parameters and mechanical models of deformation. Here, we examine hMSCs prepared for clinical use and subject them to mechanical testing conducive to the relevant deformability associated with clinical injection procedures. Micropipette aspiration of hMSCs shows deformation as a viscoelastic fluid, with little variation from cell to cell within a population. After two passages, hMSCs deform as viscoelastic solids. Further, for clinical applicability during stem cell migration in vivo, we investigated the ability of hMSCs to invade into micropillar arrays of increasing confinement from 12 to 8 μm spacing between adjacent micropillars. We find that hMSC samples with reduced deformability and cells that are more solid-like with passage are more easily able to enter the micropillar arrays. Increased cell fluidity is an advantage for injection procedures and optimization of cell selection based on mechanical properties may enhance efficacy of injected hMSC populations. However, the ability to invade and migrate within tight interstitial spaces appears to be increased with a more solidified cytoskeleton, likely from increased force generation and contractility. Thus, there may be a balance between optimal injection survival and in situ tissue invasion. PMID:26581348

  1. Cellular Telephone

    Institute of Scientific and Technical Information of China (English)

    杨周

    1996-01-01

    Cellular phones, used in automobiles, airliners, and passenger trains, are basically low-power radiotelephones. Calls go through radio transmitters that are located within small geographical units called cells. Because each cell’s signals are too weak to interfere with those of other cells operating on the same fre-

  2. An integrated cellular model to evaluate cytotoxic effects in mammalian cell lines.

    Science.gov (United States)

    Fernández Freire, P; Peropadre, A; Pérez Martín, J M; Herrero, O; Hazen, M J

    2009-12-01

    The ever growing anthropogenic pressure to the environment has lead in 2007 to the revision of the existing legislation and the approval of the new European law regarding the production and importation of chemicals, known as REACH. This new legal framework supports the development of alternative methods to animal experimentation encouraging the improvement and/or design of new methodological strategies for the toxicological evaluation of chemical compounds. Even though cytotoxicity studies are a reductionist approach to acute toxicity in vivo, they offer the best agreement between obtaining relevant information about the mechanism of toxic action and the use of alternative methods. Following this trend, this work presents an integrated cellular strategy in order to know the toxicity and mechanism of action of chemical compounds, using simple and reproducible in vitro systems. The experimental procedures are performed in two steps. The first one involves the systematic analysis of the main cellular targets using proliferation, viability and morphological probes. The second step relies upon the results obtained in the first step, including specific assays that focus on the mechanism of toxic action and the cellular response. The benefits of this strategy are exemplified with two real cases: pentachlorophenol and rotenone. PMID:19540333

  3. Nanocoating of single cells: from maintenance of cell viability to manipulation of cellular activities.

    Science.gov (United States)

    Park, Ji Hun; Yang, Sung Ho; Lee, Juno; Ko, Eun Hyea; Hong, Daewha; Choi, Insung S

    2014-04-01

    The chronological progresses in single-cell nanocoating are described. The historical developments in the field are divided into biotemplating, cytocompatible nanocoating, and cells in nano-nutshells, depending on the main research focuses. Each subfield is discussed in conjunction with the others, regarding how and why to manipulate living cells by nanocoating at the single-cell level. PMID:24452932

  4. Space experiment "Cellular Responses to Radiation in Space (CellRad)": Hardware and biological system tests.

    Science.gov (United States)

    Hellweg, Christine E; Dilruba, Shahana; Adrian, Astrid; Feles, Sebastian; Schmitz, Claudia; Berger, Thomas; Przybyla, Bartos; Briganti, Luca; Franz, Markus; Segerer, Jürgen; Spitta, Luis F; Henschenmacher, Bernd; Konda, Bikash; Diegeler, Sebastian; Baumstark-Khan, Christa; Panitz, Corinna; Reitz, Günther

    2015-11-01

    One factor contributing to the high uncertainty in radiation risk assessment for long-term space missions is the insufficient knowledge about possible interactions of radiation with other spaceflight environmental factors. Such factors, e.g. microgravity, have to be considered as possibly additive or even synergistic factors in cancerogenesis. Regarding the effects of microgravity on signal transduction, it cannot be excluded that microgravity alters the cellular response to cosmic radiation, which comprises a complex network of signaling pathways. The purpose of the experiment "Cellular Responses to Radiation in Space" (CellRad, formerly CERASP) is to study the effects of combined exposure to microgravity, radiation and general space flight conditions on mammalian cells, in particular Human Embryonic Kidney (HEK) cells that are stably transfected with different plasmids allowing monitoring of proliferation and the Nuclear Factor κB (NF-κB) pathway by means of fluorescent proteins. The cells will be seeded on ground in multiwell plate units (MPUs), transported to the ISS, and irradiated by an artificial radiation source after an adaptation period at 0 × g and 1 × g. After different incubation periods, the cells will be fixed by pumping a formaldehyde solution into the MPUs. Ground control samples will be treated in the same way. For implementation of CellRad in the Biolab on the International Space Station (ISS), tests of the hardware and the biological systems were performed. The sequence of different steps in MPU fabrication (cutting, drilling, cleaning, growth surface coating, and sterilization) was optimized in order to reach full biocompatibility. Different coatings of the foil used as growth surface revealed that coating with 0.1 mg/ml poly-D-lysine supports cell attachment better than collagen type I. The tests of prototype hardware (Science Model) proved its full functionality for automated medium change, irradiation and fixation of cells. Exposure of

  5. Effects of transport inhibitors on the cellular uptake of carboxylated polystyrene nanoparticles in different cell lines.

    Directory of Open Access Journals (Sweden)

    Tiago dos Santos

    Full Text Available Nanotechnology is expected to play a vital role in the rapidly developing field of nanomedicine, creating innovative solutions and therapies for currently untreatable diseases, and providing new tools for various biomedical applications, such as drug delivery and gene therapy. In order to optimize the efficacy of nanoparticle (NP delivery to cells, it is necessary to understand the mechanisms by which NPs are internalized by cells, as this will likely determine their ultimate sub-cellular fate and localisation. Here we have used pharmacological inhibitors of some of the major endocytic pathways to investigate nanoparticle uptake mechanisms in a range of representative human cell lines, including HeLa (cervical cancer, A549 (lung carcinoma and 1321N1 (brain astrocytoma. Chlorpromazine and genistein were used to inhibit clathrin and caveolin mediated endocytosis, respectively. Cytochalasin A and nocodazole were used to inhibit, respectively, the polymerisation of actin and microtubule cytoskeleton. Uptake experiments were performed systematically across the different cell lines, using carboxylated polystyrene NPs of 40 nm and 200 nm diameters, as model NPs of sizes comparable to typical endocytic cargoes. The results clearly indicated that, in all cases and cell types, NPs entered cells via active energy dependent processes. NP uptake in HeLa and 1321N1 cells was strongly affected by actin depolymerisation, while A549 cells showed a stronger inhibition of NP uptake (in comparison to the other cell types after microtubule disruption and treatment with genistein. A strong reduction of NP uptake was observed after chlorpromazine treatment only in the case of 1321N1 cells. These outcomes suggested that the same NP might exploit different uptake mechanisms to enter different cell types.

  6. Assessment of Membrane Fluidity Fluctuations during Cellular Development Reveals Time and Cell Type Specificity

    KAUST Repository

    Noutsi, Pakiza

    2016-06-30

    Cell membrane is made up of a complex structure of lipids and proteins that diffuse laterally giving rise to what we call membrane fluidity. During cellular development, such as differentiation cell membranes undergo dramatic fluidity changes induced by proteins such as ARC and Cofilin among others. In this study we used the generalized polarization (GP) property of fluorescent probe Laurdan using two-photon microscopy to determine membrane fluidity as a function of time and for various cell lines. A low GP value corresponds to a higher fluidity and a higher GP value is associated with a more rigid membrane. Four different cell lines were monitored such as hN2, NIH3T3, HEK293 and L6 cells. Membrane fluidity was measured at 12h, 72h and 92 h. Our results show significant changes in membrane fluidity among all cell types at different time points. GP values tend to increase significantly within 92 h in hN2 cells and 72 h in NIH3T3 cells and only at 92 h in HEK293 cells. L6 showed a marked decrease in membrane fluidity at 72 h and starts to increase at 92 h. As expected, NIH3T3 cells have more rigid membrane at earlier time points. On the other hand, neurons tend to have the highest membrane fluidity at early time points emphasizing its correlation with plasticity and the need for this malleability during differentiation. This study sheds light on the involvement of membrane fluidity during neuronal differentiation and development of other cell lines.

  7. Assessment of Membrane Fluidity Fluctuations during Cellular Development Reveals Time and Cell Type Specificity.

    Science.gov (United States)

    Noutsi, Pakiza; Gratton, Enrico; Chaieb, Sahraoui

    2016-01-01

    Cell membrane is made up of a complex structure of lipids and proteins that diffuse laterally giving rise to what we call membrane fluidity. During cellular development, such as differentiation cell membranes undergo dramatic fluidity changes induced by proteins such as ARC and Cofilin among others. In this study we used the generalized polarization (GP) property of fluorescent probe Laurdan using two-photon microscopy to determine membrane fluidity as a function of time and for various cell lines. A low GP value corresponds to a higher fluidity and a higher GP value is associated with a more rigid membrane. Four different cell lines were monitored such as hN2, NIH3T3, HEK293 and L6 cells. Membrane fluidity was measured at 12h, 72h and 92 h. Our results show significant changes in membrane fluidity among all cell types at different time points. GP values tend to increase significantly within 92 h in hN2 cells and 72 h in NIH3T3 cells and only at 92 h in HEK293 cells. L6 showed a marked decrease in membrane fluidity at 72 h and starts to increase at 92 h. As expected, NIH3T3 cells have more rigid membrane at earlier time points. On the other hand, neurons tend to have the highest membrane fluidity at early time points emphasizing its correlation with plasticity and the need for this malleability during differentiation. This study sheds light on the involvement of membrane fluidity during neuronal differentiation and development of other cell lines. PMID:27362860

  8. Multi-color fluorescence imaging of sub-cellular dynamics of cancer cells in live mice

    Science.gov (United States)

    Hoffman, Robert M.

    2006-02-01

    We have genetically engineered dual-color fluorescent cells with one color in the nucleus and the other in the cytoplasm that enables real-time nuclear-cytoplasmic dynamics to be visualized in living cells in the cytoplasm in vivo as well as in vitro. To obtain the dual-color cells, red fluorescent protein (RFP) was expressed of the cancer cells, and green fluorescent protein (GFP) linked to histone H2B was expressed in the nucleus. Mitotic cells were visualized by whole-body imaging after injection in the mouse ear. Common carotid artery or heart injection of dual-color cells and a reversible skin flap enabled the external visualization of the dual-color cells in microvessels in the mouse where extreme elongation of the cell body as well as the nucleus occurred. The migration velocities of the dual-color cancer cells in the capillaries were measured by capturing individual images of the dual-color fluorescent cells over time. Human HCT-116-GFP-RFP colon cancer and mouse mammary tumor (MMT)-GFP-RFP cells were injected in the portal vein of nude mice. Extensive clasmocytosis (destruction of the cytoplasm) of the HCT-116-GFP-RFP cells occurred within 6 hours. The data suggest rapid death of HCT-116-GFP-RFP cells in the portal vein. In contrast, MMT-GFP-RFP cells injected into the portal vein mostly survived and formed colonies in the liver. However, when the host mice were pretreated with cyclophosphamide, the HCT-116-GFP-RFP cells also survived and formed colonies in the liver after portal vein injection. These results suggest that a cyclophosphamide-sensitive host cellular system attacked the HCT-116-GFP-RFP cells but could not effectively kill the MMT-GFP-RFP cells. With the ability to continuously image cancer cells at the subcellular level in the live animal, our understanding of the complex steps of metastasis will significantly increase. In addition, new drugs can be developed to target these newly visible steps of metastasis.

  9. Resveratrol induces cellular senescence with attenuated mono-ubiquitination of histone H2B in glioma cells

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Zhen; Xu, Michael S.; Barnett, Tamara L. [Nevada Cancer Institute, Las Vegas, NV 89135 (United States); Xu, C. Wilson, E-mail: wxu@nvcancer.org [Nevada Cancer Institute, Las Vegas, NV 89135 (United States)

    2011-04-08

    Research highlights: {yields} Resveratrol induces cellular senescence in glioma cell. {yields} Resveratrol inhibits mono-ubiquitination of histone H2B at K120. {yields} Depletion of RNF20, phenocopies the inhibitory effects of resveratrol. {yields} Mono-ubiquitination of histone H2B at K120 is a novel target of resveratrol. {yields} RNF20 inhibits cellular senescence in proliferating glioma cells. -- Abstract: Resveratrol (3,4',5-trihydroxy-trans-stilbene), a polyphenol naturally occurring in grapes and other plants, has cancer chemo-preventive effects and therapeutic potential. Although resveratrol modulates multiple pathways in tumor cells, how resveratrol or its affected pathways converge on chromatin to mediate its effects is not known. Using glioma cells as a model, we showed here that resveratrol inhibited cell proliferation and induced cellular hypertrophy by transforming spindle-shaped cells to enlarged, irregular and flatten-shaped ones. We further showed that resveratrol-induced hypertrophic cells expressed senescence-associated-{beta}-galactosidase, suggesting that resveratrol-induced cellular senescence in glioma cells. Consistent with these observations, we demonstrated that resveratrol inhibited clonogenic efficiencies in vitro and tumor growth in a xenograft model. Furthermore, we found that acute treatment of resveratrol inhibited mono-ubiquitination of histone H2B at K120 (uH2B) in breast, prostate, pancreatic, lung, brain tumor cells as well as primary human cells. Chronic treatment with low doses of resveratrol also inhibited uH2B in the resveratrol-induced senescent glioma cells. Moreover, we showed that depletion of RNF20, a ubiquitin ligase of histone H2B, inhibited uH2B and induced cellular senescence in glioma cells in vitro, thereby recapitulated the effects of resveratrol. Taken together, our results suggest that uH2B is a novel direct or indirect chromatin target of resveratrol and RNF20 plays an important role in inhibiting cellular

  10. Pb-induced cellular defense system in the root meristematic cells of Allium sativum L

    Directory of Open Access Journals (Sweden)

    Liu Donghua

    2010-03-01

    Full Text Available Abstract Background Electron microscopy (EM techniques enable identification of the main accumulations of lead (Pb in cells and cellular organelles and observations of changes in cell ultrastructure. Although there is extensive literature relating to studies on the influence of heavy metals on plants, Pb tolerance strategies of plants have not yet been fully explained. Allium sativum L. is a potential plant for absorption and accumulation of heavy metals. In previous investigations the effects of different concentrations (10-5 to 10-3 M of Pb were investigated in A. sativum, indicating a significant inhibitory effect on shoot and root growth at 10-3 to 10-4 M Pb. In the present study, we used EM and cytochemistry to investigate ultrastructural alterations, identify the synthesis and distribution of cysteine-rich proteins induced by Pb and explain the possible mechanisms of the Pb-induced cellular defense system in A. sativum. Results After 1 h of Pb treatment, dictyosomes were accompanied by numerous vesicles within cytoplasm. The endoplasm reticulum (ER with swollen cisternae was arranged along the cell wall after 2 h. Some flattened cisternae were broken up into small closed vesicles and the nuclear envelope was generally more dilated after 4 h. During 24-36 h, phenomena appeared such as high vacuolization of cytoplasm and electron-dense granules in cell walls, vacuoles, cytoplasm and mitochondrial membranes. Other changes included mitochondrial swelling and loss of cristae, and vacuolization of ER and dictyosomes during 48-72 h. In the Pb-treatment groups, silver grains were observed in cell walls and in cytoplasm, suggesting the Gomori-Swift reaction can indirectly evaluate the Pb effects on plant cells. Conclusions Cell walls can immobilize some Pb ions. Cysteine-rich proteins in cell walls were confirmed by the Gomori-Swift reaction. The morphological alterations in plasma membrane, dictyosomes and ER reflect the features of detoxification

  11. Identification of genes that regulate multiple cellular processes/responses in the context of lipotoxicity to hepatoma cells

    Directory of Open Access Journals (Sweden)

    Yedwabnick Matthew

    2007-10-01

    Full Text Available Abstract Background In order to devise efficient treatments for complex, multi-factorial diseases, it is important to identify the genes which regulate multiple cellular processes. Exposure to elevated levels of free fatty acids (FFAs and tumor necrosis factor alpha (TNF-α alters multiple cellular processes, causing lipotoxicity. Intracellular lipid accumulation has been shown to reduce the lipotoxicity of saturated FFA. We hypothesized that the genes which simultaneously regulate lipid accumulation as well as cytotoxicity may provide better targets to counter lipotoxicity of saturated FFA. Results As a model system to test this hypothesis, human hepatoblastoma cells (HepG2 were exposed to elevated physiological levels of FFAs and TNF-α. Triglyceride (TG accumulation, toxicity and the genomic responses to the treatments were measured. Here, we present a framework to identify such genes in the context of lipotoxicity. The aim of the current study is to identify the genes that could be altered to treat or ameliorate the cellular responses affected by a complex disease rather than to identify the causal genes. Genes that regulate the TG accumulation, cytotoxicity or both were identified by a modified genetic algorithm partial least squares (GA/PLS analysis. The analyses identified NADH dehydrogenase and mitogen activated protein kinases (MAPKs as important regulators of both cytotoxicity and lipid accumulation in response to FFA and TNF-α exposure. In agreement with the predictions, inhibiting NADH dehydrogenase and c-Jun N-terminal kinase (JNK reduced cytotoxicity significantly and increased intracellular TG accumulation. Inhibiting another MAPK pathway, the extracellular signal regulated kinase (ERK, on the other hand, improved the cytotoxicity without changing TG accumulation. Much greater reduction in the toxicity was observed upon inhibiting the NADH dehydrogenase and MAPK (which were identified by the dual-response analysis, than for the

  12. Sodium Glucose Cotransporter 2 (SGLT2) Plays as a Physiological Glucose Sensor and Regulates Cellular Contractility in Rat Mesangial Cells

    OpenAIRE

    Masanori Wakisaka; Tetsuhiko Nagao; Mototaka Yoshinari

    2016-01-01

    Purpose Mesangial cells play an important role in regulating glomerular filtration by altering their cellular tone. We report the presence of a sodium glucose cotransporter (SGLT) in rat mesangial cells. This study in rat mesangial cells aimed to evaluate the expression and role of SGLT2. Methods The SGLT2 expression in rat mesangial cells was assessed by Western blotting and reverse transcription-polymerase chain reaction (RT-PCR). Changes in the mesangial cell surface area at different gluc...

  13. Highlighting a Need to Distinguish Cell Cycle Signatures from Cellular Responses to Chemotherapeutics in SR-FTIR Spectroscopy

    OpenAIRE

    C Hughes, M D Brown, P Dumas, N W Clarke, K R Flower and P Gardner

    2012-01-01

    Previous research has seen difficulties in establishing clear discrimination by principal component analysis (PCA) between drug-treated cells analysed by single point SR-FTIR spectroscopy, relative to multisampling cell monolayers by conventional FTIR. It is suggested that the issue arises due to signal mixing between cellular-response signatures and cell cycle phase contributions in individual cells. Consequently, chemometric distinction of cell spectra treated with multiple drugs is difficu...

  14. Cellular heredity in haploid cultures of somatic cells. Progress report, August 1978-September 1979

    International Nuclear Information System (INIS)

    During the past year we have continued our studies of the relation of ultraviolet mutagenesis to DNA repair in cultures of the haploid frog cell line ICR 2A. Our method of irradiation of cells in suspension was improved by construction of an improved detector with major sensitivity to the 254 nm Hg resonance line, to give better estimates of actual exposure of the cells. Using this method, dose-response and dose-fractionation studies on irradiation of ouabain resistance were carried out. The uv induction of this phenotype in the ICR 2A cell line was found to be less than that necessary for adequate analysis of dose-response curves. Cell fusion experiments using frog and mouse cells revealed an enhancement of mutagenesis in the mouse parent that will be explored in further work

  15. Cellular heredity in haploid cultures of somatic cells. Progress report, August 1978-September 1979

    International Nuclear Information System (INIS)

    During the past year, studies were continued on the relation of ultraviolet mutagenesis to DNA repair in cultures of the haploid frog cell line ICR 2A. The method of irradiation of cells in suspension was improved by construction of an improved detector with major sensitivity to the 254 nm Hg resonance line, to give better estimates of actual exposure of the cells. Using this method, dose-response and dose-fractionation studies on irradiation of ouabain resistance were carried out. The uv induction of this phenotype in the ICR 2A cell line was found to be less than that necessary for adequate analysis of dose-response curves. Cell fusion experiments using frog and mouse cells revealed an enhancement of mutagenesis in the mouse parent that will be explored in further work

  16. Cellular radiosensitivity of primary and metastatic human uveal melanoma cell lines

    NARCIS (Netherlands)

    G.J.M.J. van den Aardweg (Gerard J. M.); N.C. Naus (Nicole); A.C. Verhoeven; J.E.M.M. de Klein (Annelies); G.P.M. Luyten (Gré)

    2002-01-01

    textabstractPURPOSE: To investigate the radiosensitivity of uveal melanoma cell lines by a clonogenic survival assay, to improve the efficiency of the radiation regimen. METHODS: Four primary and four metastatic human uveal melanoma cell lines were cultured in the presence of condi

  17. EXPRESSION OF CELLULAR ADHESION MOLECULES IN LANGERHANS CELL HISTIOCYTOSIS AND NORMAL LANGERHANS CELLS

    NARCIS (Netherlands)

    DEGRAAF, JH; TAMMINGA, RYJ; KAMPS, WA; TIMENS, W

    1995-01-01

    Langerhans cell histiocytosis (LCH) is characterized by lesions with an accumulation and/or proliferation of Langerhans cells (LCs). Little is known of the etiology and pathogenesis of LCH. Although the relation between the LCH cell and normal LCs is currently uncertain, the localizations of the LCH

  18. A Simple BODIPY-Based Viscosity Probe for Imaging of Cellular Viscosity in Live Cells.

    Science.gov (United States)

    Su, Dongdong; Teoh, Chai Lean; Gao, Nengyue; Xu, Qing-Hua; Chang, Young-Tae

    2016-01-01

    Intracellular viscosity is a fundamental physical parameter that indicates the functioning of cells. In this work, we developed a simple boron-dipyrromethene (BODIPY)-based probe, BTV, for cellular mitochondria viscosity imaging by coupling a simple BODIPY rotor with a mitochondria-targeting unit. The BTV exhibited a significant fluorescence intensity enhancement of more than 100-fold as the solvent viscosity increased. Also, the probe showed a direct linear relationship between the fluorescence lifetime and the media viscosity, which makes it possible to trace the change of the medium viscosity. Furthermore, it was demonstrated that BTV could achieve practical applicability in the monitoring of mitochondrial viscosity changes in live cells through fluorescence lifetime imaging microscopy (FLIM). PMID:27589762

  19. Direct fuel cell product design improvement

    Energy Technology Data Exchange (ETDEWEB)

    Maru, H.C.; Farooque, M. [Energy Research Corp., Danbury, CT (United States)

    1996-12-31

    Significant milestones have been attained towards the technology development field testing and commercialization of direct fuel cell power plant since the 1994 Fuel Cell Seminar. Under a 5-year cooperative agreement with the Department of Energy signed in December 1994, Energy Research Corporation (ERC) has been developing the design for a MW-scale direct fuel cell power plant with input from previous technology efforts and the Santa Clara Demonstration Project. The effort encompasses product definition in consultation with the Fuel Cell Commercialization Group, potential customers, as well as extensive system design and packaging. Manufacturing process improvements, test facility construction, cell component scale up, performance and endurance improvements, stack engineering, and critical balance-of-plant development are also addressed. Major emphasis of this product design improvement project is on increased efficiency, compactness and cost reduction to establish a competitive place in the market. A 2.85 MW power plant with an efficiency of 58% and a footprint of 420 m{sup 2} has been designed. Component and subsystem testing is being conducted at various levels. Planning and preparation for verification of a full size prototype unit are in progress. This paper presents the results obtained since the last fuel cell seminar.

  20. Cellular adhesion molecules on endothelial cells participate in radiation-mediated inflammation

    International Nuclear Information System (INIS)

    Purpose: The acute and subacute clinical manifestations of ionizing radiation mimic the inflammatory response to a number of stimuli. During the early stages of the inflammatory response, endothelial cells rapidly and transiently express a number of glycoproteins such as E-selectin, P-selectin, ICAM-1 and VCAM-1 which influence leucocyte adhesion. We quantified the expression of these cellular adhesion molecules (CAMs) in irradiated endothelial cells in order to determine whether these glycoproteins participate in radiation-mediated inflammation. Methods: Primary cultures of human umbilical vein endothelial cells (HUVEC) and HMEC cells were grown to 90% confluence and irradiated with a GE Maxitron x-ray generator. The cells were incubated with primary IgG1 antibody (mouse anti-human ICAM-1, VCAM-1, P-selectin and E-selectin and incubated with FITC-conjugated secondary antibody (goat anti-mouse IgG1). Fluorescence-activated cell sorting (FACS) analysis was utilized for quantitation of receptor expression of each CAM on irradiated endothelial cells. Electrophoretic mobility gel shift assays of nuclear protein extracts from irradiated HUVEC cells were performed using the E-selectin NFkB binding sequence (5'AGCTTAGAGGGGATTTCCGAGAGGA-3'). The E-selectin promoter was ligated to the growth hormone reporter. Plasmids pE-sel(-587 +35)GH or pE-sel(-587 +35)GH Δ NFκB (5 μg) was transfected into HMEC or HUVEC cells by use of lipofection. Transfectants were incubated for 16 h after transfection followed by treatment with 10 Gy (1 Gy/min, GE Maxitron) of ionizing radiation, and or with TNF or IL-1. Leukocyte adhesion to irradiated endothelial cells was quantified by HL-60 binding. Results: The log fluorescence of cells incubated with the antibody to E-selectin shifted by 32% at 4 h after irradiation. In comparison, a shift of 35% occurred 20 h after irradiation for cells incubated with the antibody to ICAM. However, there was no significant increase in P-selectin or VCAM

  1. Improvements to parallel plate flow chambers to reduce reagent and cellular requirements

    Directory of Open Access Journals (Sweden)

    Larson Richard S

    2001-09-01

    Full Text Available Abstract Background The parallel plate flow chamber has become a mainstay for examination of leukocytes under physiologic flow conditions. Several design modifications have occurred over the years, yet a comparison of these different designs has not been performed. In addition, the reagent requirements of many designs prohibit the study of rare leukocyte populations and require large amounts of reagents. Results In this study, we evaluate modifications to a newer parallel plate flow chamber design in comparison to the original parallel plate flow chamber described by Lawrence et al. We show that modifications in the chamber size, internal tubing diameters, injection valves, and a recirculation design may dramatically reduce the cellular and reagent requirements without altering measurements. Conclusions These modifications are simple and easily implemented so that study of rare leukocyte subsets using scarce or expensive reagents can occur.

  2. Improved micromorph tandem cell performance through enhanced top cell currents

    Energy Technology Data Exchange (ETDEWEB)

    Platz, R.; Vaucher, N.P.; Fischer, D.; Meier, J.; Shah, A. [Univ. de Neuchatel (Switzerland). Inst. de Microtechnique

    1997-12-31

    Two approaches to increasing the current in the amorphous silicon top cell of an amorphous silicon/microcrystalline silicon (a-Si:H/{micro}c-Si:H) tandem cell are presented. The goal is to raise the stabilized efficiency of such cells. The deposition of the amorphous top cell at higher than standard substrate temperature is shown to reduce the optical gap of the i-layer and to increase the current which is generated with a given i-layer thickness. Furthermore, a selectively reflecting ZnO interface layer between the component cells is presented as a viable tool for enhancing the current generation in the top cell by selective reflection of light. The authors present a micromorph tandem cell containing the amorphous top cell deposited at high substrate temperature, and additionally the ZnO mirror layer. A top cell thickness of 150 nm is shown to be sufficient to provide a current density of 13mA/cm{sup 2} in the top cell. Finally, the influence of such thin top cells on the stabilized efficiency of the tandem cell is investigated by experiment and by means of semi-empirical modeling. Model and experiment confirm that such reduced-gap top cells, together with current enhancement due to the mirror layer, have a high potential for improving the stabilized efficiency of micromorph tandem cells.

  3. Improved Gene Targeting through Cell Cycle Synchronization.

    Directory of Open Access Journals (Sweden)

    Vasiliki Tsakraklides

    Full Text Available Gene targeting is a challenge in organisms where non-homologous end-joining is the predominant form of recombination. We show that cell division cycle synchronization can be applied to significantly increase the rate of homologous recombination during transformation. Using hydroxyurea-mediated cell cycle arrest, we obtained improved gene targeting rates in Yarrowia lipolytica, Arxula adeninivorans, Saccharomyces cerevisiae, Kluyveromyces lactis and Pichia pastoris demonstrating the broad applicability of the method. Hydroxyurea treatment enriches for S-phase cells that are active in homologous recombination and enables previously unattainable genomic modifications.

  4. Feasibility study of a mini fuel cell to detect interference from a cellular phone

    Science.gov (United States)

    Abdullah, M. O.; Gan, Y. K.

    Fuel cells produce electricity without involving combustion processes. They generate no noise, vibration or air pollution and are therefore suitable for use in many vibration-free power-generating applications. In this study, a mini alkaline fuel cell signal detector system has been designed, constructed and tested. The initial results have shown the applicability of such system for used as an indicator of signal disturbance from cellular phones. A small disturbance even at 4 mV cm -1, corresponding to an amplitude of 12-18 mG in terms of electromagnetic field, can be well detected by such a device. Subsequently, a thermodynamics model has been developed to provide a parametric study by simulation to show the likely performance of the fuel cell alone in other environments. As such the model can provide many useful generic design data for alkaline fuel cells. Two general conclusions can be drawn from the present theoretical study: (i) fuel cell performance increases with temperature, pressure and correction factor, C f; (ii) the temperature factor (E/ T) increases with increasing temperature and with increasing pressure factor.

  5. Feasibility study of a mini fuel cell to detect interference from a cellular phone

    Energy Technology Data Exchange (ETDEWEB)

    Abdullah, M.O.; Gan, Y.K. [Mechanical and Manufacturing System Engineering, Faculty of Engineering, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak (Malaysia)

    2006-04-21

    Fuel cells produce electricity without involving combustion processes. They generate no noise, vibration or air pollution and are therefore suitable for use in many vibration-free power-generating applications. In this study, a mini alkaline fuel cell signal detector system has been designed, constructed and tested. The initial results have shown the applicability of such system for used as an indicator of signal disturbance from cellular phones. A small disturbance even at 4mVcm{sup -1}, corresponding to an amplitude of 12-18mG in terms of electromagnetic field, can be well detected by such a device. Subsequently, a thermodynamics model has been developed to provide a parametric study by simulation to show the likely performance of the fuel cell alone in other environments. As such the model can provide many useful generic design data for alkaline fuel cells. Two general conclusions can be drawn from the present theoretical study: (i) fuel cell performance increases with temperature, pressure and correction factor, C{sub f}; (ii) the temperature factor (E/T) increases with increasing temperature and with increasing pressure factor. (author)

  6. Time- and polarization-resolved cellular autofluorescence towards quantitative biochemistry on living cells

    Science.gov (United States)

    Alfveby, John; TImerman, Randi; Soto Velasquez, Monica P.; Wickramasinghe, Dhanushka W. P. M.; Bartusek, Jillian; Heikal, Ahmed A.

    2014-09-01

    Native coenzymes such as the reduced nicotinamide adenine dinucleotide (NADH) and oxidized flavin adenine dinucleotide play pivotal roles in energy metabolism and a myriad of biochemical reactions in living cells/tissues. These coenzymes are naturally fluorescent and, therefore, have the potential to serve as intrinsic biomarkers for mitochondrial activities, programmed cell death (apoptosis), oxidative stress, aging, and neurodegenerative disease. In this contribution, we employ two-photon fluorescence lifetime imaging microscopy (FLIM) and time-resolved anisotropy imaging of intracellular NADH for quantitative, non-invasive biochemistry on living cells in response to hydrogenperoxide- induced oxidative stress. In contrast with steady-state one-photon, UV-excited autofluorescence, two-photon FLIM is sensitive to both molecular conformation and stimuli-induced changes in the local environment in living cells with minimum photodamage and inherently enhanced spatial resolution. On the other hand, time-resolved, two-photon anisotropy imaging of cellular autofluorescence allows for quantitative assessment of binding state and environmental restrictions on the tumbling mobility of intrinsic NADH. Our measurements reveal that free and enzyme-bound NADH exist at equilibrium, with a dominant autofluorescence contribution of the bound fraction in living cells. Parallel studies on NADH-enzyme binding in controlled environments serve as a point of reference in analyzing autofluorescence in living cells. These autofluorescence-based approaches complement the conventional analytical biochemistry methods that require the destruction of cells/tissues, while serving as an important step towards establishing intracellular NADH as a natural biomarker for monitoring changes in energy metabolism and redox state of living cells in response to environmental hazards.

  7. Entrainment of the mammalian cell cycle by the circadian clock: modeling two coupled cellular rhythms.

    Directory of Open Access Journals (Sweden)

    Claude Gérard

    2012-05-01

    Full Text Available The cell division cycle and the circadian clock represent two major cellular rhythms. These two periodic processes are coupled in multiple ways, given that several molecular components of the cell cycle network are controlled in a circadian manner. For example, in the network of cyclin-dependent kinases (Cdks that governs progression along the successive phases of the cell cycle, the synthesis of the kinase Wee1, which inhibits the G2/M transition, is enhanced by the complex CLOCK-BMAL1 that plays a central role in the circadian clock network. Another component of the latter network, REV-ERBα, inhibits the synthesis of the Cdk inhibitor p21. Moreover, the synthesis of the oncogene c-Myc, which promotes G1 cyclin synthesis, is repressed by CLOCK-BMAL1. Using detailed computational models for the two networks we investigate the conditions in which the mammalian cell cycle can be entrained by the circadian clock. We show that the cell cycle can be brought to oscillate at a period of 24 h or 48 h when its autonomous period prior to coupling is in an appropriate range. The model indicates that the combination of multiple modes of coupling does not necessarily facilitate entrainment of the cell cycle by the circadian clock. Entrainment can also occur as a result of circadian variations in the level of a growth factor controlling entry into G1. Outside the range of entrainment, the coupling to the circadian clock may lead to disconnected oscillations in the cell cycle and the circadian system, or to complex oscillatory dynamics of the cell cycle in the form of endoreplication, complex periodic oscillations or chaos. The model predicts that the transition from entrainment to 24 h or 48 h might occur when the strength of coupling to the circadian clock or the level of growth factor decrease below critical values.

  8. NR4A2 is regulated by gastrin and influences cellular responses of gastric adenocarcinoma cells.

    Directory of Open Access Journals (Sweden)

    Kristine Misund

    Full Text Available The peptide hormone gastrin is known to play a role in differentiation, growth and apoptosis of cells in the gastric mucosa. In this study we demonstrate that gastrin induces Nuclear Receptor 4A2 (NR4A2 expression in the adenocarcinoma cell lines AR42J and AGS-GR, which both possess the gastrin/CCK2 receptor. In vivo, NR4A2 is strongly expressed in the gastrin responsive neuroendocrine ECL cells in normal mucosa, whereas gastric adenocarcinoma tissue reveals a more diffuse and variable expression in tumor cells. We show that NR4A2 is a primary early transient gastrin induced gene in adenocarcinoma cell lines, and that NR4A2 expression is negatively regulated by inducible cAMP early repressor (ICER and zinc finger protein 36, C3H1 type-like 1 (Zfp36l1, suggesting that these gastrin regulated proteins exert a negative feedback control of NR4A2 activated responses. FRAP analyses indicate that gastrin also modifies the nucleus-cytosol shuttling of NR4A2, with more NR4A2 localized to cytoplasm upon gastrin treatment. Knock-down experiments with siRNA targeting NR4A2 increase migration of gastrin treated adenocarcinoma AGS-GR cells, while ectopically expressed NR4A2 increases apoptosis and hampers gastrin induced invasion, indicating a tumor suppressor function of NR4A2. Collectively, our results uncover a role of NR4A2 in gastric adenocarcinoma cells, and suggest that both the level and the localization of NR4A2 protein are of importance regarding the cellular responses of these cells.

  9. Rhizobacterial Strain Bacillus megaterium BOFC15 Induces Cellular Polyamine Changes that Improve Plant Growth and Drought Resistance.

    Science.gov (United States)

    Zhou, Cheng; Ma, Zhongyou; Zhu, Lin; Xiao, Xin; Xie, Yue; Zhu, Jian; Wang, Jianfei

    2016-01-01

    Plant-growth-promoting rhizobacteria can improve plant growth, development, and stress adaptation. However, the underlying mechanisms are still largely unclear. We investigated the effects of Bacillus megaterium BOFC15 on Arabidopsis plants. BOFC15 produced and secreted spermidine (Spd), a type of polyamine (PA) that plays an important role in plant growth. Moreover, BOFC15 induced changes in the cellular PAs of plants that promoted an increase of free Spd and spermine levels. However, these effects were remarkably abolished by the addition of dicyclohexylamine (DCHA), a Spd biosynthetic inhibitor. Additionally, the inoculation with BOFC15 remarkably increased plant biomass, improved root system architecture, and augmented photosynthetic capacity. Inoculated plants also displayed stronger ability to tolerate drought stress than non-inoculated (control) plants. Abscisic acid (ABA) content was notably higher in the inoculated plants than in the control plants under drought stress and polyethylene glycol (PEG)-induced stress conditions. However, the BOFC15-induced ABA synthesis was markedly inhibited by DCHA. Thus, microbial Spd participated in the modulation of the ABA levels. The Spd-producing BOFC15 improved plant drought tolerance, which was associated with altered cellular ABA levels and activated adaptive responses. PMID:27338359

  10. Rhizobacterial Strain Bacillus megaterium BOFC15 Induces Cellular Polyamine Changes that Improve Plant Growth and Drought Resistance

    Directory of Open Access Journals (Sweden)

    Cheng Zhou

    2016-06-01

    Full Text Available Plant-growth-promoting rhizobacteria can improve plant growth, development, and stress adaptation. However, the underlying mechanisms are still largely unclear. We investigated the effects of Bacillus megaterium BOFC15 on Arabidopsis plants. BOFC15 produced and secreted spermidine (Spd, a type of polyamine (PA that plays an important role in plant growth. Moreover, BOFC15 induced changes in the cellular PAs of plants that promoted an increase of free Spd and spermine levels. However, these effects were remarkably abolished by the addition of dicyclohexylamine (DCHA, a Spd biosynthetic inhibitor. Additionally, the inoculation with BOFC15 remarkably increased plant biomass, improved root system architecture, and augmented photosynthetic capacity. Inoculated plants also displayed stronger ability to tolerate drought stress than non-inoculated (control plants. Abscisic acid (ABA content was notably higher in the inoculated plants than in the control plants under drought stress and polyethylene glycol (PEG-induced stress conditions. However, the BOFC15-induced ABA synthesis was markedly inhibited by DCHA. Thus, microbial Spd participated in the modulation of the ABA levels. The Spd-producing BOFC15 improved plant drought tolerance, which was associated with altered cellular ABA levels and activated adaptive responses.

  11. Rhizobacterial Strain Bacillus megaterium BOFC15 Induces Cellular Polyamine Changes that Improve Plant Growth and Drought Resistance

    Science.gov (United States)

    Zhou, Cheng; Ma, Zhongyou; Zhu, Lin; Xiao, Xin; Xie, Yue; Zhu, Jian; Wang, Jianfei

    2016-01-01

    Plant-growth-promoting rhizobacteria can improve plant growth, development, and stress adaptation. However, the underlying mechanisms are still largely unclear. We investigated the effects of Bacillus megaterium BOFC15 on Arabidopsis plants. BOFC15 produced and secreted spermidine (Spd), a type of polyamine (PA) that plays an important role in plant growth. Moreover, BOFC15 induced changes in the cellular PAs of plants that promoted an increase of free Spd and spermine levels. However, these effects were remarkably abolished by the addition of dicyclohexylamine (DCHA), a Spd biosynthetic inhibitor. Additionally, the inoculation with BOFC15 remarkably increased plant biomass, improved root system architecture, and augmented photosynthetic capacity. Inoculated plants also displayed stronger ability to tolerate drought stress than non-inoculated (control) plants. Abscisic acid (ABA) content was notably higher in the inoculated plants than in the control plants under drought stress and polyethylene glycol (PEG)-induced stress conditions. However, the BOFC15-induced ABA synthesis was markedly inhibited by DCHA. Thus, microbial Spd participated in the modulation of the ABA levels. The Spd-producing BOFC15 improved plant drought tolerance, which was associated with altered cellular ABA levels and activated adaptive responses. PMID:27338359

  12. Identification of human genes involved in cellular responses to ionizing radiation: molecular and cellular studies of gene encoding the p68 helicase in mammalian cells

    International Nuclear Information System (INIS)

    Cells submitted to genotoxic factors -like IR- activate several and important mechanisms such as repair, cell cycle arrest or 'apoptosis' to maintain genetic integrity. So, the damaged cells will induce many and different genes. The human transcriptome analysis by 'SSH' method in a human breast carcinoma cell line MCF7 γ-irradiated versus not irradiated, allowed to identify about one hundred genes. Among of these genes, we have focused our study on a radio-induced gene encoding the p68 helicase. In the conditions of irradiation used, our results show that the kinetic and the regulation of this gene expression differs between the nature of radiations used. Indeed, in γ-irradiated mammalian cells, ATM, a protein kinase activated by DSB and IR, is required to induce quickly P68 gene via the important transcription factor p53 stabilized by IR. In the case of UVC-irradiated cells, the P68 gene induction is late and the intracellular signalling pathway that lead to this induction is independent from the p53 protein. Finally, we show that the p68 protein under-expression is responsible for an increased radiosensitivity of MCF7 cells. Consequently, we can postulate that the p68 protein is involved in cellular responses to radiations to reduce the increased radiosensitivity of cells exposed to γ-rays. (author)

  13. Cellular Programming and Reprogramming: Sculpting Cell Fate for the Production of Dopamine Neurons for Cell Therapy

    Directory of Open Access Journals (Sweden)

    Julio C. Aguila

    2012-01-01

    success of clinical applications depends on our ability to steer pluripotent stem cells towards the right neuronal identity. In Parkinson disease, the loss of dopamine neurons is more pronounced in the ventrolateral population that projects to the sensorimotor striatum. Because synapses are highly specific, only neurons with this precise identity will contribute, upon transplantation, to the synaptic reconstruction of the dorsal striatum. Thus, understanding the developmental cell program of the mesostriatal dopamine neurons is critical for the identification of the extrinsic signals and cell-intrinsic factors that instruct and, ultimately, determine cell identity. Here, we review how extrinsic signals and transcription factors act together during development to shape midbrain cell fates. Further, we discuss how these same factors can be applied in vitro to induce, select, and reprogram cells to the mesostriatal dopamine fate.

  14. The Rho GTPase Cdc42 regulates hair cell planar polarity and cellular patterning in the developing cochlea

    OpenAIRE

    Anna Kirjavainen; Maarja Laos; Tommi Anttonen; Ulla Pirvola

    2015-01-01

    Hair cells of the organ of Corti (OC) of the cochlea exhibit distinct planar polarity, both at the tissue and cellular level. Planar polarity at tissue level is manifested as uniform orientation of the hair cell stereociliary bundles. Hair cell intrinsic polarity is defined as structural hair bundle asymmetry; positioning of the kinocilium/basal body complex at the vertex of the V-shaped bundle. Consistent with strong apical polarity, the hair cell apex displays prominent actin and microtubul...

  15. Metalloproteinases and tissue inhibitor of metalloproteinases in mesothelial cells. Cellular differentiation influences expression.

    Science.gov (United States)

    Marshall, B C; Santana, A; Xu, Q P; Petersen, M J; Campbell, E J; Hoidal, J R; Welgus, H G

    1993-04-01

    Mesothelial cells play a critical role in the remodeling process that follows serosal injury. Although mesothelial cells are known to synthesize a variety of extracellular matrix components including types I, III, and IV collagens, their potential to participate in matrix degradation has not been explored. We now report that human pleural and peritoneal mesothelial cells express interstitial collagenase, 72- and 92-kD gelatinases (type IV collagenases), and the counterregulatory tissue inhibitor of metalloproteinases (TIMP). Our initial characterization of the mesothelial cell metalloenzymes and TIMP has revealed: (a) they are likely identical to corresponding molecules secreted by other human cells; (b) they are secreted rather than stored in an intracellular pool; (c) a primary site of regulation occurs at a pretranslational level; (d) phorbol myristate acetate, via activation of protein kinase C, upregulates expression of collagenase, 92-kD gelatinase, and TIMP, but has no effect on expression of 72-kD gelatinase; and (e) lipopolysaccharide fails to upregulate the biosynthesis of either metalloproteinases or TIMP. Of particular interest is the observation that the state of cellular differentiation has a striking influence on the expression of metalloenzymes and TIMP, such that epitheloid cells display a more matrix-degradative phenotype (increased 92-kD gelatinase and decreased TIMP) than their fibroblastoid counterparts. We speculate that mesothelial cells directly participate in the extracellular matrix turnover that follows serosal injury via elaboration of metalloproteinases and TIMP. Additionally, the reactive cuboidal mesothelium which is characteristic of the early response to serosal injury may manifest a matrix-degenerative phenotype favoring normal repair rather than fibrosis.

  16. Midkine secretion protects Hep3B cells from cadmium induced cellular damage

    Institute of Scientific and Technical Information of China (English)

    Nuray Yazihan; Haluk Ataoglu; Ethem Akcil; Burcu Yener; Bulent Salman; Cengiz Aydin

    2008-01-01

    AIM:To evaluate role of midkine secretion during Cadmium (Cd) exposure in the human hepatocyte cell line Hep3B cells.METHODS: Different dosages of Cd (0.5-1-5-10 μg/mL) were applied to Hep3B cells and their effects to apoptosis, lactate dehydrogenase (LDH) leakage and midkine secretion were evaluated as time dependent manner. Same experiments were repeated with exogenously applied midkine (250-5000 pg/mL) and/or 5μg/mL Cd.RESULTS: Cd exposure induced prominent apoptosis and LDH leakage beginning from lower dosages at the 48th h. Cd induced midkine secretion with higher dosages (P < 0.001), (control, Cd 0.5-1-5-10μg/mL respectively: 1123±73, 1157±63, 1242±90, 1886± 175, 1712±166 pg/mL). Exogenous 500-5000 pg/mL midkine application during 5 μg/mL Cd toxicity prevented caspase-3 activation (control, Cd toxicity, 250, 500, 1000, 2500, 5000 pg/mL midkine+ Cd toxicity, respectively:374±64, 1786±156, 1545±179, 1203±113, 974±116, 646±56, 556±63 cfu) LDH leakage and cell death in Hep3B cells (P < 0.001).CONCLUSION: Our results showed that midkine secretion from Hep3B cells during Cd exposure protects liver cells from Cd induced cellular damage. Midkine has anti-apoptotic and cytoprotective role during Cd toxicity. Further studies are needed to explain the mechanism of midkine secretion and cytoprotective role of midkine during Cd exposure. Midkine may be a promising theurapatic agent in different toxic hepatic diseases.

  17. Analysis of tanshinone IIA induced cellular apoptosis in leukemia cells by genome-wide expression profiling

    Directory of Open Access Journals (Sweden)

    Liu Chang

    2012-01-01

    Full Text Available Abstract Background Tanshinone IIA (Tan IIA is a diterpene quinone extracted from the root of Salvia miltiorrhiza, a Chinese traditional herb. Although previous studies have reported the anti-tumor effects of Tan IIA on various human cancer cells, the underlying mechanisms are not clear. The current study was undertaken to investigate the molecular mechanisms of Tan IIA's apoptotic effects on leukemia cells in vitro. Methods The cytotoxicity of Tan IIA on different types of leukemia cell lines was evaluated by the 3-[4,5-dimethylthiazol-2,5]-diphenyl tetrazolium bromide (MTT assay on cells treated without or with Tan IIA at different concentrations for different time periods. Cellular apoptosis progression with and without Tan IIA treatment was analyzed by Annexin V and Caspase 3 assays. Gene expression profiling was used to identify the genes regulated after Tan IIA treatment and those differentially expressed among the five cell lines. Confirmation of these expression regulations was carried out using real-time quantitative PCR and ELISA. The antagonizing effect of a PXR inhibitor L-SFN on Tan IIA treatment was tested using Colony Forming Unit Assay. Results Our results revealed that Tan IIA had different cytotoxic activities on five types of leukemia cells, with the highest toxicity on U-937 cells. Tan IIA inhibited the growth of U-937 cells in a time- and dose-dependent manner. Annexin V and Caspase-3 assays showed that Tan IIA induced apoptosis in U-937 cells. Using gene expression profiling, 366 genes were found to be significantly regulated after Tan IIA treatment and differentially expressed among the five cell lines. Among these genes, CCL2 was highly expressed in untreated U-937 cells and down-regulated significantly after Tan IIA treatment in a dose-dependent manner. RT-qPCR analyses validated the expression regulation of 80% of genes. Addition of L- sulforaphane (L-SFN, an inhibitor of Pregnane × receptor (PXR significantly

  18. Dysfunction of nucleus accumbens-1 activates cellular senescence and inhibits tumor cell proliferation and oncogenesis.

    Science.gov (United States)

    Zhang, Yi; Cheng, Yan; Ren, Xingcong; Hori, Tsukasa; Huber-Keener, Kathryn J; Zhang, Li; Yap, Kai Lee; Liu, David; Shantz, Lisa; Qin, Zheng-Hong; Zhang, Suping; Wang, Jianrong; Wang, Hong-Gang; Shih, Ie-Ming; Yang, Jin-Ming

    2012-08-15

    Nucleus accumbens-1 (NAC1), a nuclear factor belonging to the BTB/POZ gene family, has emerging roles in cancer. We report here that NAC1 acts as a negative regulator of cellular senescence in transformed and nontransformed cells, and dysfunction of NAC1 induces senescence and inhibits its oncogenic potential. We show that NAC1 deficiency markedly activates senescence and inhibits proliferation in tumor cells treated with sublethal doses of γ-irradiation. In mouse embryonic fibroblasts from NAC1 knockout mice, following infection with a Ras virus, NAC1-/- cells undergo significantly more senescence and are either nontransformed or less transformed in vitro and less tumorigenic in vivo when compared with NAC1+/+ cells. Furthermore, we show that the NAC1-caused senescence blunting is mediated by ΔNp63, which exerts its effect on senescence through p21, and that NAC1 activates transcription of ΔNp63 under stressful conditions. Our results not only reveal a previously unrecognized function of NAC1, the molecular pathway involved and its impact on pathogenesis of tumor initiation and development, but also identify a novel senescence regulator that may be exploited as a potential target for cancer prevention and treatment.

  19. Cellular Heterogeneity in the Level of mtDNA Heteroplasmy in Mouse Embryonic Stem Cells

    Directory of Open Access Journals (Sweden)

    Jitesh Neupane

    2015-11-01

    Full Text Available Variation in the level of mtDNA heteroplasmy in adult tissues is commonly seen in patients with a mixture of wild-type and mutant mtDNA. A mixture of different mtDNA variants may influence such variation and cause mtDNA segregation bias. We analyzed cellular heterogeneity in embryonic stem cells (ESCs derived from a polymorphic mouse model containing NZB and BALB mtDNA genotypes. In ESCs, inter-colony heterogeneity varied up to 61%, whereas intra-colony heterogeneity varied up to 100%. Three out of five cell lines displayed nearly homoplasmic BALB and NZB mtDNA haplotypes in differentiated single cells. The proportion of NZB mtDNA genotype increased with progressive passaging (0.39%; p = 0.002. These results demonstrate the bimodal segregation of mtDNA haplotypes, indicating the occurrence of tissues with variable levels of heteroplasmies in individuals with mtDNA mutations. Furthermore, proliferation of one mtDNA genotype over another may pose the risk of accumulating mutant mtDNAs during subsequent cell divisions.

  20. Cellular Heterogeneity in the Level of mtDNA Heteroplasmy in Mouse Embryonic Stem Cells.

    Science.gov (United States)

    Neupane, Jitesh; Ghimire, Sabitri; Vandewoestyne, Mado; Lu, Yuechao; Gerris, Jan; Van Coster, Rudy; Deroo, Tom; Deforce, Dieter; Vansteelandt, Stijn; De Sutter, Petra; Heindryckx, Björn

    2015-11-17

    Variation in the level of mtDNA heteroplasmy in adult tissues is commonly seen in patients with a mixture of wild-type and mutant mtDNA. A mixture of different mtDNA variants may influence such variation and cause mtDNA segregation bias. We analyzed cellular heterogeneity in embryonic stem cells (ESCs) derived from a polymorphic mouse model containing NZB and BALB mtDNA genotypes. In ESCs, inter-colony heterogeneity varied up to 61%, whereas intra-colony heterogeneity varied up to 100%. Three out of five cell lines displayed nearly homoplasmic BALB and NZB mtDNA haplotypes in differentiated single cells. The proportion of NZB mtDNA genotype increased with progressive passaging (0.39%; p = 0.002). These results demonstrate the bimodal segregation of mtDNA haplotypes, indicating the occurrence of tissues with variable levels of heteroplasmies in individuals with mtDNA mutations. Furthermore, proliferation of one mtDNA genotype over another may pose the risk of accumulating mutant mtDNAs during subsequent cell divisions.

  1. CellLab-CTS 2015: continuous-time stochastic cellular automaton modeling using Landlab

    Science.gov (United States)

    Tucker, Gregory E.; Hobley, Daniel E. J.; Hutton, Eric; Gasparini, Nicole M.; Istanbulluoglu, Erkan; Adams, Jordan M.; Siddartha Nudurupati, Sai

    2016-02-01

    CellLab-CTS 2015 is a Python-language software library for creating two-dimensional, continuous-time stochastic (CTS) cellular automaton models. The model domain consists of a set of grid nodes, with each node assigned an integer state code that represents its condition or composition. Adjacent pairs of nodes may undergo transitions to different states, according to a user-defined average transition rate. A model is created by writing a Python code that defines the possible states, the transitions, and the rates of those transitions. The code instantiates, initializes, and runs one of four object classes that represent different types of CTS models. CellLab-CTS provides the option of using either square or hexagonal grid cells. The software provides the ability to treat particular grid-node states as moving particles, and to track their position over time. Grid nodes may also be assigned user-defined properties, which the user can update after each transition through the use of a callback function. As a component of the Landlab modeling framework, CellLab-CTS models take advantage of a suite of Landlab's tools and capabilities, such as support for standardized input and output.

  2. HPV16 E2 could act as down-regulator in cellular genes implicated in apoptosis, proliferation and cell differentiation

    Directory of Open Access Journals (Sweden)

    Valencia-Hernández Armando

    2011-05-01

    Full Text Available Abstract Background Human Papillomavirus (HPV E2 plays several important roles in the viral cycle, including the transcriptional regulation of the oncogenes E6 and E7, the regulation of the viral genome replication by its association with E1 helicase and participates in the viral genome segregation during mitosis by its association with the cellular protein Brd4. It has been shown that E2 protein can regulate negative or positively the activity of several cellular promoters, although the precise mechanism of this regulation is uncertain. In this work we constructed a recombinant adenoviral vector to overexpress HPV16 E2 and evaluated the global pattern of biological processes regulated by E2 using microarrays expression analysis. Results The gene expression profile was strongly modified in cells expressing HPV16 E2, finding 1048 down-regulated genes, and 581 up-regulated. The main cellular pathway modified was WNT since we found 28 genes down-regulated and 15 up-regulated. Interestingly, this pathway is a convergence point for regulating the expression of genes involved in several cellular processes, including apoptosis, proliferation and cell differentiation; MYCN, JAG1 and MAPK13 genes were selected to validate by RT-qPCR the microarray data as these genes in an altered level of expression, modify very important cellular processes. Additionally, we found that a large number of genes from pathways such as PDGF, angiogenesis and cytokines and chemokines mediated inflammation, were also modified in their expression. Conclusions Our results demonstrate that HPV16 E2 has regulatory effects on cellular gene expression in HPV negative cells, independent of the other HPV proteins, and the gene profile observed indicates that these effects could be mediated by interactions with cellular proteins. The cellular processes affected suggest that E2 expression leads to the cells in to a convenient environment for a replicative cycle of the virus.

  3. Sub-cellular trafficking of phytochemicals explored using auto-fluorescent compounds in maize cells

    Directory of Open Access Journals (Sweden)

    Grotewold Erich

    2003-12-01

    Full Text Available Abstract Background Little is known regarding the trafficking mechanisms of small molecules within plant cells. It remains to be established whether phytochemicals are transported by pathways similar to those used by proteins, or whether the expansion of metabolic pathways in plants was associated with the evolution of novel trafficking pathways. In this paper, we exploited the induction of green and yellow auto-fluorescent compounds in maize cultured cells by the P1 transcription factor to investigate their targeting to the cell wall and vacuole, respectively. Results We investigated the accumulation and sub-cellular localization of the green and yellow auto-fluorescent compounds in maize BMS cells expressing the P1 transcription factor from an estradiol inducible promoter. We established that the yellow fluorescent compounds accumulate inside the vacuole in YFBs that resemble AVIs. The green fluorescent compounds accumulate initially in the cytoplasm in large spherical GFBs. Cells accumulating GFBs also contain electron-dense structures that accumulate initially in the ER and which later appear to fuse with the plasma membrane. Structures resembling the GFBs were also observed in the periplasmic space of plasmolized cells. Ultimately, the green fluorescence accumulates in the cell wall, in a process that is insensitive to the Golgi-disturbing agents BFA and monensin. Conclusions Our results suggest the presence of at least two distinct trafficking pathways, one to the cell wall and the other to the vacuole, for different auto-fluorescent compounds induced by the same transcription factor in maize BMS cells. These compartments represent two of the major sites of accumulation of phenolic compounds characteristic of maize cells. The secretion of the green auto-fluorescent compounds occurs by a pathway that does not involve the TGN, suggesting that it is different from the secretion of most proteins, polysaccharides or epicuticular waxes. The

  4. Comparative evaluation of nano-CuO crossing Caco-2 cell monolayers and cellular uptake

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Gao; Lianqin, Zhu, E-mail: lianqinz1963@163.com; Fenghua, Zhu [Qingdao Agricultural University, College of Animal Science and Veterinary Medicine (China); Fang, Zheng [Dezhou University, College of Agriculture (China); Mingming, Song; Kai, Huang [Qingdao Agricultural University, College of Animal Science and Veterinary Medicine (China)

    2015-04-15

    Different concentrations of CuSO{sub 4}, micro-CuO, and nano-CuO were added to Caco-2 cell monolayers to study the absorption and transport characteristics in this epithelial cell model. Nano-CuO nanoparticles had a diameter of 10–20 nm. Inhibitors of endocytosis were used to explore whether nano-CuO could enter the Caco-2 cell in the form of nanoparticles, and to ascertain the endocytotic pathway that is involved in the transport process. The apparent permeability coefficient (P{sub app}) of CuSO{sub 4} and nano-CuO increased with the Cu concentration in the culture medium (p < 0.05). The micro-CuO of different concentrations had no significant impact on the P{sub app} value of Caco-2 cells (p > 0.05). When the Cu concentration in the culture medium was in the range 31.25–500 μM, the P{sub app} value of Caco-2 cells incubated with nano-CuO was significantly higher than that obtained with CuSO{sub 4}. The latter was also significantly higher than that when cells were incubated with micro-CuO (p < 0.05). The amount of Cu transport increased with the increase of CuSO{sub 4} concentration in the culture medium. After 90 min, the amount of transport began to saturate, and the transport rate of Cu declined with the increase of CuSO{sub 4} concentration. For the cells incubated with nano-CuO, the amount of Cu transport increased with the increase of nano-CuO concentration, but did not show an obvious saturation with the extension of transport time. Nano-CuO could enter the Caco-2 cell in the form of nanoparticles, and were found in the cytoplasm, vesicles, lysosomes, and cell nuclei. Several inhibitors of endocytosis effectively prevented the entry of nano-CuO into the Caco-2 cells. It was concluded that nano-CuO particles can enter the Caco-2 cells through several cellular endocytotic pathways.

  5. Stem cell-like ALDHbright cellular states in EGFR-mutant non-small cell lung cancer

    Science.gov (United States)

    Corominas-Faja, Bruna; Oliveras-Ferraros, Cristina; Cuyàs, Elisabet; Segura-Carretero, Antonio; Joven, Jorge; Martin-Castillo, Begoña; Barrajón-Catalán, Enrique; Micol, Vicente; Bosch-Barrera, Joaquim; Menendez, Javier A

    2013-01-01

    The enrichment of cancer stem cell (CSC)-like cellular states has not previously been considered to be a causative mechanism in the generalized progression of EGFR-mutant non-small cell lung carcinomas (NSCLC) after an initial response to the EGFR tyrosine kinase inhibitor erlotinib. To explore this possibility, we utilized a pre-clinical model of acquired erlotinib resistance established by growing NSCLC cells containing a TKI-sensitizing EGFR exon 19 deletion (ΔE746-A750) in the continuous presence of high doses of erlotinib. Genome-wide analyses using Agilent 44K Whole Human Genome Arrays were evaluated via bioinformatics analyses through GSEA-based screening of the KEGG pathway database to identify the molecular circuitries that were over-represented in the transcriptomic signatures of erlotinib-refractory cells. The genomic spaces related to erlotinib resistance included a preponderance of cell cycle genes (E2F1, -2, CDC2, -6) and DNA replication-related genes (MCM4, -5, -6, -7), most of which are associated with early lung development and poor prognosis. In addition, metabolic genes such as ALDH1A3 (a candidate marker for lung cancer cells with CSC-like properties) were identified. Thus, we measured the proportion of erlotinib-resistant cells expressing very high levels of aldehyde dehydrogenase (ALDH) activity attributed to ALDH1/3 isoforms. Using flow cytometry and the ALDEFLUOR® reagent, we confirmed that erlotinib-refractory cell populations contained drastically higher percentages (>4500%) of ALDHbright cells than the parental erlotinib-responsive cells. Notably, strong decreases in the percentages of ALDHbright cells were observed following incubation with silibinin, a bioactive flavonolignan that can circumvent erlotinib resistance in vivo. The number of lung cancer spheres was drastically suppressed by silibinin in a dose-dependent manner, thus confirming the ability of this agent to inhibit the self-renewal of erlotinib-refractory CSC-like cells

  6. Cysteine modified polyaniline films improve biocompatibility for two cell lines

    International Nuclear Information System (INIS)

    This work focuses on one of the most exciting application areas of conjugated conducting polymers, which is cell culture and tissue engineering. To improve the biocompatibility of conducting polymers we present an easy method that involves the modification of the polymer backbone using L-cysteine. In this publication, we show the synthesis of polyaniline (PANI) films supported onto Polyethylene terephthalate (PET) films, and modified using cysteine (PANI-Cys) in order to generate a biocompatible substrate for cell culture. The PANI-Cys films are characterized by Fourier Transform infrared and UV–visible spectroscopy. The changes in the hydrophilicity of the polymer films after and before the modification were tested using contact angle measurements. After modification the contact angle changes from 86° ± 1 to 90° ± 1, suggesting a more hydrophylic surface. The adhesion properties of LM2 and HaCaT cell lines on the surface of PANI-Cys films in comparison with tissue culture plastic (TCP) are studied. The PANI-Cys film shows better biocompatibility than PANI film for both cell lines. The cell morphologies on the TCP and PANI-Cys film were examined by florescence and Atomic Force Microscopy (AFM). Microscopic observations show normal cellular behavior when PANI-Cys is used as a substrate of both cell lines (HaCaT and LM2) as when they are cultured on TCP. The ability of these PANI-Cys films to support cell attachment and growth indicates their potential use as biocompatible surfaces and in tissue engineering. - Highlights: • A new surface PANI-Cys was produced on films of polyethylene terephthalate. • The relationship between surface characteristics and biocompatibility is analyzed. • The PANI-Cys film presents good biocompatibility for two cell lines

  7. Cysteine modified polyaniline films improve biocompatibility for two cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Yslas, Edith I., E-mail: eyslas@exa.unrc.edu.ar [Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Agencia Postal Nro3, X580BYA Río Cuarto (Argentina); Cavallo, Pablo; Acevedo, Diego F.; Barbero, César A. [Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal Nro3, X580BYA Río Cuarto (Argentina); Rivarola, Viviana A. [Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Agencia Postal Nro3, X580BYA Río Cuarto (Argentina)

    2015-06-01

    This work focuses on one of the most exciting application areas of conjugated conducting polymers, which is cell culture and tissue engineering. To improve the biocompatibility of conducting polymers we present an easy method that involves the modification of the polymer backbone using L-cysteine. In this publication, we show the synthesis of polyaniline (PANI) films supported onto Polyethylene terephthalate (PET) films, and modified using cysteine (PANI-Cys) in order to generate a biocompatible substrate for cell culture. The PANI-Cys films are characterized by Fourier Transform infrared and UV–visible spectroscopy. The changes in the hydrophilicity of the polymer films after and before the modification were tested using contact angle measurements. After modification the contact angle changes from 86° ± 1 to 90° ± 1, suggesting a more hydrophylic surface. The adhesion properties of LM2 and HaCaT cell lines on the surface of PANI-Cys films in comparison with tissue culture plastic (TCP) are studied. The PANI-Cys film shows better biocompatibility than PANI film for both cell lines. The cell morphologies on the TCP and PANI-Cys film were examined by florescence and Atomic Force Microscopy (AFM). Microscopic observations show normal cellular behavior when PANI-Cys is used as a substrate of both cell lines (HaCaT and LM2) as when they are cultured on TCP. The ability of these PANI-Cys films to support cell attachment and growth indicates their potential use as biocompatible surfaces and in tissue engineering. - Highlights: • A new surface PANI-Cys was produced on films of polyethylene terephthalate. • The relationship between surface characteristics and biocompatibility is analyzed. • The PANI-Cys film presents good biocompatibility for two cell lines.

  8. Prostaglandin E2 promotes cellular recovery from established nephrotoxic serum nephritis in mice, prosurvival, and regenerative effects on glomerular cells

    OpenAIRE

    Kvirkvelia, Nino; McMenamin, Malgorzata; Chaudhary, Kapil; Bartoli, Manuela; Madaio, Michael P.

    2013-01-01

    We postulated that prostaglandin E2 (PGE2), which exhibits regulatory functions to control immune-mediated inflammation, fibrosis, oxidative stress, and tissue/cellular regeneration, has the potential to improve the course of nephritis. Therefore, the therapeutic potential of prostanoid on established nephritis in mice was evaluated focusing on its role on renal cellular recovery, with emphasis on its cytoprotecting and growth-promoting effects. Acute nephritis was induced in mice by single i...

  9. Increased SHP-1 expression results in radioresistance, inhibition of cellular senescence, and cell cycle redistribution in nasopharyngeal carcinoma cells

    International Nuclear Information System (INIS)

    Radioresistance is the main limit to the efficacy of radiotherapy in nasopharyngeal carcinoma (NPC). SHP-1 is involved in cancer progression, but its role in radioresistance and senescence of NPC is not well understood. This study aimed to assess the role of SHP-1 in the radioresistance and senescence of NPC cells. SHP-1 was knocked-down and overexpressed in CNE-1 and CNE-2 cells using lentiviruses. Cells were irradiated to observe their radiosensitivity by colony forming assay. BrdU incorporation assay and flow cytometry were used to monitor cell cycle. A β-galactosidase assay was used to assess senescence. Western blot was used to assess SHP-1, p21, p53, pRb, Rb, H3K9Me3, HP1γ, CDK4, cyclin D1, cyclin E, and p16 protein expressions. Compared with CNE-1-scramble shRNA cells, SHP-1 downregulation resulted in increased senescence (+107 %, P < 0.001), increased radiosensitivity, higher proportion of cells in G0/G1 (+33 %, P < 0.001), decreased expressions of CDK4 (−44 %, P < 0.001), cyclin D1 (−41 %, P = 0.001), cyclin E (−97 %, P < 0.001), Rb (−79 %, P < 0.001), and pRb (−76 %, P = 0.001), and increased expression of p16 (+120 %, P = 0.02). Furthermore, SHP-1 overexpression resulted in radioresistance, inhibition of cellular senescence, and cell cycle arrest in the S phase. Levels of p53 and p21 were unchanged in both cell lines (all P > 0.05). SHP-1 has a critical role in radioresistance, cell cycle progression, and senescence of NPC cells. Down-regulating SHP-1 may be a promising therapeutic approach for treating patients with NPC

  10. Scotblood 2015: Improving and delivering blood products, novel cellular therapies, and celebrating patients and donor engagement within transfusion services.

    Science.gov (United States)

    Colligan, David; McGowan, Neil; Seghatchian, Jerard

    2016-08-01

    Blood Transfusion Services are striving to continually improve the efficacy and quality of their blood products whilst also simultaneously diversifying into novel cellular products. For this to be successful the relationships between the various arms of the organisation must be strong and interlinked. As new technologies impact on the products that blood transfusion services supply it should be noted that the interaction between the service and its donor base is also affected by advancing technologies. Social media has fundamentally altered the way in which the public can access information and news, as such blood services must engage and interact appropriately with these new forms of media. As a reflection of these challenges the Scotblood 2015 programme was focussed on service and product improvement, donor engagement and people centred transfusion. This commentary comprises summaries of the presentations, based in part on the abstracts provided by the speakers. PMID:27524267

  11. Tracing dynamics and clonal heterogeneity of Cbx7-induced leukemic stem cells by cellular barcoding.

    Science.gov (United States)

    Klauke, Karin; Broekhuis, Mathilde J C; Weersing, Ellen; Dethmers-Ausema, Albertina; Ritsema, Martha; González, Marta Vilà; Zwart, Erik; Bystrykh, Leonid V; de Haan, Gerald

    2015-01-13

    Accurate monitoring of tumor dynamics and leukemic stem cell (LSC) heterogeneity is important for the development of personalized cancer therapies. In this study, we experimentally induced distinct types of leukemia in mice by enforced expression of Cbx7. Simultaneous cellular barcoding allowed for thorough analysis of leukemias at the clonal level and revealed high and unpredictable tumor complexity. Multiple LSC clones with distinct leukemic properties coexisted. Some of these clones remained dormant but bore leukemic potential, as they progressed to full-blown leukemia after challenge. LSC clones could retain multilineage differentiation capacities, where one clone induced phenotypically distinct leukemias. Beyond a detailed insight into CBX7-driven leukemic biology, our model is of general relevance for the understanding of tumor dynamics and clonal evolution.

  12. Tracing Dynamics and Clonal Heterogeneity of Cbx7-Induced Leukemic Stem Cells by Cellular Barcoding

    Directory of Open Access Journals (Sweden)

    Karin Klauke

    2015-01-01

    Full Text Available Accurate monitoring of tumor dynamics and leukemic stem cell (LSC heterogeneity is important for the development of personalized cancer therapies. In this study, we experimentally induced distinct types of leukemia in mice by enforced expression of Cbx7. Simultaneous cellular barcoding allowed for thorough analysis of leukemias at the clonal level and revealed high and unpredictable tumor complexity. Multiple LSC clones with distinct leukemic properties coexisted. Some of these clones remained dormant but bore leukemic potential, as they progressed to full-blown leukemia after challenge. LSC clones could retain multilineage differentiation capacities, where one clone induced phenotypically distinct leukemias. Beyond a detailed insight into CBX7-driven leukemic biology, our model is of general relevance for the understanding of tumor dynamics and clonal evolution.

  13. Managing magnetic nanoparticle aggregation and cellular uptake: a precondition for efficient stem-cell differentiation and MRI tracking.

    Science.gov (United States)

    Fayol, Delphine; Luciani, Nathalie; Lartigue, Lenaic; Gazeau, Florence; Wilhelm, Claire

    2013-02-01

    The labeling of stem cells with iron oxide nanoparticles is increasingly used to enable MRI cell tracking and magnetic cell manipulation, stimulating the fields of tissue engineering and cell therapy. However, the impact of magnetic labeling on stem-cell differentiation is still controversial. One compromising factor for successful differentiation may arise from early interactions of nanoparticles with cells during the labeling procedure. It is hypothesized that the lack of control over nanoparticle colloidal stability in biological media may lead to undesirable nanoparticle localization, overestimation of cellular uptake, misleading MRI cell tracking, and further impairment of differentiation. Herein a method is described for labeling mesenchymal stem cells (MSC), in which the physical state of citrate-coated nanoparticles (dispersed versus aggregated) can be kinetically tuned through electrostatic and magnetic triggers, as monitored by diffusion light scattering in the extracellular medium and by optical and electronic microscopy in cells. A set of statistical cell-by-cell measurements (flow cytometry, single-cell magnetophoresis, and high-resolution MRI cellular detection) is used to independently quantify the nanoparticle cell uptake and the effects of nanoparticle aggregation. Such aggregation confounds MRI cell detection as well as global iron quantification and has adverse effects on chondrogenetic differentiation. Magnetic labeling conditions with perfectly stable nanoparticles-suitable for obtaining differentiation-capable magnetic stem cells for use in cell therapy-are subsequently identified. PMID:23184893

  14. Effects of ethanol on hepatic cellular replication and cell cycle progression

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Ethanol is a hepatotoxin. It appears that the liver is the target of ethanol induced toxicity primarily because it is the major site of ethanol metabolism. Metabolism of ethanol results in a number of biochemical changes that are thought to mediate the toxicity associated with ethanol abuse. These include the production of acetaldehyde and reactive oxygen species, as well as an accumulation of nicotinamide adenine dinucleotide(NADH). These biochemical changes are associated with the accumulation of fat and mitochondrial dysfunction in the liver. If these changes are severe enough they can themselves cause hepatotoxicity, or they can sensitize the liver to more severe damage by other hepatotoxins.Whether liver damage is the result of ethanol metabolism or some other hepatotoxin, recovery of the liver from damage requires replacement of cells that have been destroyed. It is now apparent that ethanol metabolism not only causes hepatotoxicity but also impairs the replication of normal hepatocytes. This impairment has been shown to occur at both the G1/S, and the G2/M transitions of the cell cycle. These impairments may be the result of activation of the checkpoint kinases, which can mediate cell cycle arrest at both of these transitions.Conversely, because ethanol metabolism results in a number of biochemical changes, there may be a number of mechanisms by which ethanol metabolism impairs cellular replication. It is the goal of this article to review the mechanisms by which ethanol metabolism mediates impairment of hepatic replication.

  15. An Integrated Model for Production Planning and Cell Formation in Cellular Manufacturing Systems

    Directory of Open Access Journals (Sweden)

    Reza Raminfar

    2013-01-01

    Full Text Available Cellular manufacturing (CM is a production approach directed towards reducing costs, as well as increasing system's flexibility in today's small-to-medium lot production environment. Many structural and operational issues should be considered for a successful CM design and implementation such as cell formation (CF, production planning, and facility layout. Most researchers have addressed these issues sequentially or independently, instead of jointly optimizing a combination of these issues. In order to attain better results to ensure that the system will be capable of remaining efficient in unknown future situations, these issues should be addressed simultaneously. In this paper, a mathematical model is developed using an integrated approach for production planning and cell formation problems in a CM. A set of numerical examples are provided from existing the literature in order to test and illustrate the proposed model. In order to evaluate and verify the performance of the proposed model, it is compared with a well-known cell formation methods (rank order clustering and direct clustering analysis, using group capability index (GCI measure. The results and comparisons indicate that the proposed model has a significantly higher and satisfactory performance and it is reliable for the design and the analysis of CM systems.

  16. Aiolos transcription factor controls cell death in T cells by regulating Bcl-2 expression and its cellular localization.

    Science.gov (United States)

    Romero, F; Martínez-A, C; Camonis, J; Rebollo, A

    1999-01-01

    We searched for proteins that interact with Ras in interleukin (IL)-2-stimulated or IL-2-deprived cells, and found that the transcription factor Aiolos interacts with Ras. The Ras-Aiolos interaction was confirmed in vitro and in vivo by co-immunoprecipitation. Indirect immunofluorescence shows that IL-2 controls the cellular distribution of Aiolos and induces its tyrosine phosphorylation, required for dissociation from Ras. We also identified functional Aiolos-binding sites in the Bcl-2 promoter, which are able to activate the luciferase reporter gene. Mutation of Aiolos-binding sites within the Bcl-2 promoter inhibits transactivation of the reporter gene luciferase, suggesting direct control of Bcl-2 expression by Aiolos. Co-transfection experiments confirm that Aiolos induces Bcl-2 expression and prevents apoptosis in IL-2-deprived cells. We propose a model for the regulation of Bcl-2 expression via Aiolos. PMID:10369681

  17. Malignant monoblasts can function as effector cells in natural killer cell and antibody-dependent cellular cytotoxicity assays

    DEFF Research Database (Denmark)

    Hokland, P; Hokland, M; Ellegaard, J

    1981-01-01

    This is the first report describing natural killer (NK) and antibody-dependent cellular cytotoxicity (ADCC) of malignant monoblasts. Pure acute monoblastic leukemia was diagnosed in bone marrow aspirations from two patients by use of conventional cytochemical methods as well as multiple immunolog...... no modulation was seen in ADCC. These findings are discussed in the light of our present knowledge of lymphoid NK cells. Udgivelsesdato: 1981-May...... techniques including detection of ALL antigens and terminal transferase. The malignant cells were subsequently found to be potent effectors in NK and ADCC assays. Addition of partially purified alpha-interferon to the in vitro cultures was found to have an enhancing effect on NK activity, whereas...

  18. Beyond the antigen receptor: editing the genome of T-cells for cancer adoptive cellular therapies

    Directory of Open Access Journals (Sweden)

    Angharad eLloyd

    2013-08-01

    Full Text Available Recent early-stage clinical trials evaluating the adoptive transfer of patient CD8+ T-cells re-directed with antigen receptors recognising tumours have shown very encouraging results. These reports provide strong support for further development of the therapeutic concept as a curative cancer treatment. In this respect combining the adoptive transfer of tumour-specific T-cells with therapies that increase their anti-tumour capacity is viewed as a promising strategy to improve treatment outcome. The ex-vivo genetic engineering step that underlies T-cell re-direction offers a unique angle to combine antigen receptor delivery with the targeting of cell intrinsic pathways that restrict T-cell effector functions. Recent progress in genome editing technologies such as protein- and RNA-guided endonucleases raise the possibility of disrupting gene expression in T-cells in order to enhance effector functions or to bypass tumour immune suppression. This approach would avoid the systemic administration of compounds that disrupt immune homeostasis, potentially avoiding autoimmune adverse effects, and could improve the efficacy of T-cell based adoptive therapies.

  19. Arbutin encapsulated micelles improved transdermal delivery and suppression of cellular melanin production

    OpenAIRE

    Liang, Ke; Xu, Keming; Bessarab, Dmitri; Obaje, Jonathan; Xu, Chenjie

    2016-01-01

    Background Hyperpigmentation is a skin disorder characterized by elevated production of melanin. Current treatment approaches mainly rely on the application of skin lightening chemicals, most of which have safety issues. Efficacy of delivery of the active ingredients to the target organ has also been a challenge. Transdermal based drug delivery platform has been shown to improve drug bioavailability, avoiding the hepatic first pass metabolism, decrease gastrointestinal side effects, and event...

  20. Drug-Loaded Nanoparticles from 'Ershiwuwei Shanhu' Pill Induced Cellular Swelling of SH-SY5Y Neuroblastoma Cells.

    Science.gov (United States)

    Liu, Yali; Song, Xiaoping; Zheng, Siting; Luo, Yuandai; Wang, Leyu; Huang, Fukai; Qiu, Xiaozhong

    2016-03-01

    Drug-loaded nanoparticles from 'Ershiwuwei Shanhu' Pill (ESP) inducing cellular swelling of the SH-SY5Y neuroblastoma cells were investigated. Electron microscope was used to observe nanoparticles existing in the freeze-dried supernatant of 'Ershiwuwei Shanhu' Pill. Drug-free nanoparticles were obtained from the solution of drug-loaded nanoparticles via dialysis. The size and zeta potential of two kinds of nanoparticles were tested by granularmetric analysis and surface charge analysis. Results showed that nanoparticles could penetrate into cellular nucleus and caused cell swelling. CCK8 analysis implied that low concentration of drug-free nanoparticles from 'Ershiwuwei Shanhu' Pill can induce cell proliferation of the SH-SY5Y neuroblastoma cells, while drug-loaded nanoparticles can reduce cell viability through NF-κB pathway. Drug-loaded nanoparticles existed in 'Ershiwuwei Shanhu' pill might play a vital role during pharmacotherapy, which served as nanocarriers in delivering drugs into cells.

  1. Cyclophilin A as a potential genetic adjuvant to improve HIV-1 Gag DNA vaccine immunogenicity by eliciting broad and long-term Gag-specific cellular immunity in mice

    Science.gov (United States)

    Hou, Jue; Zhang, Qicheng; Liu, Zheng; Wang, Shuhui; Li, Dan; Liu, Chang; Liu, Ying; Shao, Yiming

    2016-01-01

    Previous research has shown that host Cyclophilin A (CyPA) can promote dendritic cell maturation and the subsequent innate immune response when incorporated into an HIV-1 Gag protein to circumvent the resistance of dendritic cells to HIV-1 infection. This led us to hypothesize that CyPA may improve HIV-1 Gag-specific vaccine immunogenicity via binding with Gag antigen. The adjuvant effect of CyPA was evaluated using a DNA vaccine with single or dual expression cassettes. Mouse studies indicated that CyPA specifically and markedly promoted HIV-1 Gag-specific cellular immunity but not an HIV-1 Env-specific cellular response. The Gag/CyPA dual expression cassettes stimulated a greater Gag-specific cellular immune response, than Gag immunization alone. Furthermore, CyPA induced a broad Gag-specific T cell response and strong cellular immunity that lasted up to 5 months. In addition, CyPA skewed to cellular rather than humoral immunity. To investigate the mechanisms of the adjuvant effect, site-directed mutagenesis in CyPA, including active site residues H54Q and F60A resulted in mutants that were co-expressed with Gag in dual cassettes. The immune response to this vaccine was analyzed in vivo. Interestingly, the wild type CyPA markedly increased Gag cellular immunity, but the H54Q and F60A mutants drastically reduced CyPA adjuvant activation. Therefore, we suggest that the adjuvant effect of CyPA was based on Gag-CyPA-specific interactions. Herein, we report that Cyclophilin A can augment HIV-1 Gag-specific cellular immunity as a genetic adjuvant in multiplex DNA immunization strategies, and that activity of this adjuvant is specific, broad, long-term, and based on Gag-CyPA interaction. PMID:26305669

  2. Magnolol Affects Cellular Proliferation, Polyamine Biosynthesis and Catabolism-Linked Protein Expression and Associated Cellular Signaling Pathways in Human Prostate Cancer Cells in vitro

    Directory of Open Access Journals (Sweden)

    Brendan T. McKeown

    2015-01-01

    Full Text Available Background: Prostate cancer is the most commonly diagnosed form of cancer in men in Canada and the United States. Both genetic and environmental factors contribute to the development and progression of many cancers, including prostate cancer. Context and purpose of this study: This study investigated the effects of magnolol, a compound found in the roots and bark of the magnolia tree Magnolia officinalis, on cellular proliferation and proliferation-linked activities of PC3 human prostate cancer cells in vitro. Results: PC3 cells exposed to magnolol at a concentration of 80 μM for 6 hours exhibited decreased protein expression of ornithine decarboxylase, a key regulator in polyamine biosynthesis, as well as affecting the expression of other proteins involved in polyamine biosynthesis and catabolism. Furthermore, protein expression of the R2 subunit of ribonucleotide reductase, a key regulatory protein associated with DNA synthesis, was significantly decreased. Finally, the MAPK (mitogen-activated protein kinase, PI3K (phosphatidylinositol 3-kinase, NFκB (nuclear factor of kappa-light-chain-enhancer of activated B cells and AP-1 (activator protein 1 cellular signaling pathways were assayed to determine which, if any, of these pathways magnolol exposure would alter. Protein expressions of p-JNK-1 and c-jun were significantly increased while p-p38, JNK-1/2, PI3Kp85, p-PI3Kp85, p-Akt, NFκBp65, p-IκBα and IκBα protein expressions were significantly decreased. Conclusions: These alterations further support the anti-proliferative effects of magnolol on PC3 human prostate cancer cells in vitro and suggest that magnolol may have potential as a novel anti-prostate cancer agent.

  3. Role of cell cycle on the cellular uptake and dilution of nanoparticles in a cell population

    NARCIS (Netherlands)

    Kim, Jong Ah; Åberg, Christoffer; Salvati, Anna; Dawson, Kenneth A

    2012-01-01

    Nanoparticles are considered a primary vehicle for targeted therapies because they can pass biological barriers and enter and distribute within cells by energy-dependent pathways(1-3). So far, most studies have shown that nanoparticle properties, such as size(4-6) and surface(7,8), can influence how

  4. Real-time monitoring of cellular dynamics using a microfluidic cell culture system with integrated electrode array and potentiostat

    DEFF Research Database (Denmark)

    Zor, Kinga; Vergani, M.; Heiskanen, Arto;

    2011-01-01

    A versatile microfluidic, multichamber cell culture and analysis system with an integrated electrode array and potentiostat suitable for electrochemical detection and microscopic imaging is presented in this paper. The system, which allows on-line electrode cleaning and modification, was developed...... for real-time monitoring of cellular dynamics, exemplified in this work by monitoring of redox metabolism inside living yeast cells and dopamine release from PC12 cells....

  5. Application of Local Activity Theory of Cellular Neural Network with Two Ports to the Coupled Lorenz-Cell Model

    Institute of Scientific and Technical Information of China (English)

    MIN LeQuan; YU Na

    2002-01-01

    Some criteria for the local activity theory in two-port cellular neural network cells with three local state variables are applied to a coupled Lorenz-cell model. The numerical simulation exhibited that emergence may exist if the selected cell parameters are nearby or on the edge of chaos domain. The local activity theory has provided a new tool of studying the complexity of high dimensional coupled nonlinear physical systems.

  6. Micro 3D cell culture systems for cellular behavior studies: Culture matrices, devices, substrates, and in-situ sensing methods.

    Science.gov (United States)

    Choi, Jonghoon; Lee, Eun Kyu; Choo, Jaebum; Yuh, Junhan; Hong, Jong Wook

    2015-09-01

    Microfabricated systems equipped with 3D cell culture devices and in-situ cellular biosensing tools can be a powerful bionanotechnology platform to investigate a variety of biomedical applications. Various construction substrates such as plastics, glass, and paper are used for microstructures. When selecting a construction substrate, a key consideration is a porous microenvironment that allows for spheroid growth and mimics the extracellular matrix (ECM) of cell aggregates. Various bio-functionalized hydrogels are ideal candidates that mimic the natural ECM for 3D cell culture. When selecting an optimal and appropriate microfabrication method, both the intended use of the system and the characteristics and restrictions of the target cells should be carefully considered. For highly sensitive and near-cell surface detection of excreted cellular compounds, SERS-based microsystems capable of dual modal imaging have the potential to be powerful tools; however, the development of optical reporters and nanoprobes remains a key challenge. We expect that the microsystems capable of both 3D cell culture and cellular response monitoring would serve as excellent tools to provide fundamental cellular behavior information for various biomedical applications such as metastasis, wound healing, high throughput screening, tissue engineering, regenerative medicine, and drug discovery and development. PMID:26358782

  7. Treatment Analysis in a Cancer Stem Cell Context Using a Tumor Growth Model Based on Cellular Automata.

    Directory of Open Access Journals (Sweden)

    Ángel Monteagudo

    Full Text Available Cancer can be viewed as an emergent behavior in terms of complex system theory and artificial life, Cellular Automata (CA being the tool most used for studying and characterizing the emergent behavior. Different approaches with CA models were used to model cancer growth. The use of the abstract model of acquired cancer hallmarks permits the direct modeling at cellular level, where a cellular automaton defines the mitotic and apoptotic behavior of cells, and allows for an analysis of different dynamics of the cellular system depending on the presence of the different hallmarks. A CA model based on the presence of hallmarks in the cells, which includes a simulation of the behavior of Cancer Stem Cells (CSC and their implications for the resultant growth behavior of the multicellular system, was employed. This modeling of cancer growth, in the avascular phase, was employed to analyze the effect of cancer treatments in a cancer stem cell context. The model clearly explains why, after treatment against non-stem cancer cells, the regrowth capability of CSCs generates a faster regrowth of tumor behavior, and also shows that a continuous low-intensity treatment does not favor CSC proliferation and differentiation, thereby allowing an unproblematic control of future tumor regrowth. The analysis performed indicates that, contrary to the current attempts at CSC control, trying to make CSC proliferation more difficult is an important point to consider, especially in the immediate period after a standard treatment for controlling non-stem cancer cell proliferation.

  8. Targeting Cells With MR Imaging Probes: Cellular Interaction And Intracellular Magnetic Iron Oxide Nanoparticles Uptake In Brain Capillary Endothelial and Choroidal Plexus Epithelial Cells

    Science.gov (United States)

    Cambianica, I.; Bossi, M.; Gasco, P.; Gonzalez, W.; Idee, J. M.; Miserocchi, G.; Rigolio, R.; Chanana, M.; Morjan, I.; Wang, D.; Sancini, G.

    2010-10-01

    Magnetic iron oxide nanoparticles (NPs) are considered for various diagnostic and therapeutic applications in brain including their use as contrast agent for magnetic resonance imaging. In delivery application, the critical step is the transport across cell layers and the internalization of NPs into specific cells, a process often limited by poor targeting specificity and low internalization efficiency. The development of the models of brain endothelial cells and choroidal plexus epithelial cells in culture has allowed us to investigate into these mechanisms. Our strategy is aimed at exploring different routes to the entrapment of iron oxide NPs in these brain related cells. Here we demonstrated that not only cells endowed with a good phagocytic activity like activated macrophages but also endothelial brain capillary and choroidal plexus epithelial cells do internalize iron oxide NPs. Our study of the intracellular trafficking of NPs by TEM, and confocal microscopy revealed that NPs are mainly internalized by the endocytic pathway. Iron oxide NPs were dispersed in water and coated with 3,4-dihydroxyl-L-phenylalanine (L-DOPA) using standard procedures. Magnetic lipid NPs were prepared by NANOVECTOR: water in oil in water (W/O/W) microemulsion process has been applied to directly coat different iron based NPs by lipid layer or to encapsulate them into Solid Lipid Nanoparticles (SLNs). By these coating/loading the colloidal stability was improved without strong alteration of the particle size distribution. Magnetic lipid NPs could be reconstituted after freeze drying without appreciable changes in stability. L-DOPA coated NPs are stable in PBS and in MEM (Modified Eagle Medium) medium. The magnetic properties of these NPs were not altered by the coating processes. We investigated the cellular uptake, cytotoxicity, and interaction of these NPs with rat brain capillary endothelial (REB4) and choroidal plexus epithelial (Z310) cells. By means of widefield, confocal

  9. miR-196a Ameliorates Cytotoxicity and Cellular Phenotype in Transgenic Huntington's Disease Monkey Neural Cells.

    Science.gov (United States)

    Kunkanjanawan, Tanut; Carter, Richard L; Prucha, Melinda S; Yang, Jinjing; Parnpai, Rangsun; Chan, Anthony W S

    2016-01-01

    Huntington's disease (HD) is an inherited neurodegenerative disorder caused by the expansion of polyglutamine (polyQ) tract that leads to motor, cognitive and psychiatric impairment. Currently there is no cure for HD. A transgenic HD nonhuman primate (HD-NHP) model was developed with progressive development of clinical and pathological features similar to human HD, which suggested the potential preclinical application of the HD-NHP model. Elevated expression of miR-196a was observed in both HD-NHP and human HD brains. Cytotoxicity and apoptosis were ameliorated by the overexpression of miR-196a in HD-NHP neural progenitor cells (HD-NPCs) and differentiated neural cells (HD-NCs). The expression of apoptosis related gene was also down regulated. Mitochondrial morphology and activity were improved as indicated by mitotracker staining and the upregulation of CBP and PGC-1α in HD-NPCs overexpressing miR-196a. Here we demonstrated the amelioration of HD cellular phenotypes in HD-NPCs and HD-NCs overexpressing miR-196a. Our results also suggested the regulatory role of miR-196a in HD pathogenesis that may hold the key for understanding molecular regulation in HD and developing novel therapeutics. PMID:27631085

  10. miR-196a Ameliorates Cytotoxicity and Cellular Phenotype in Transgenic Huntington’s Disease Monkey Neural Cells

    Science.gov (United States)

    Carter, Richard L.; Prucha, Melinda S.; Yang, Jinjing; Parnpai, Rangsun; Chan, Anthony W. S.

    2016-01-01

    Huntington’s disease (HD) is an inherited neurodegenerative disorder caused by the expansion of polyglutamine (polyQ) tract that leads to motor, cognitive and psychiatric impairment. Currently there is no cure for HD. A transgenic HD nonhuman primate (HD-NHP) model was developed with progressive development of clinical and pathological features similar to human HD, which suggested the potential preclinical application of the HD-NHP model. Elevated expression of miR-196a was observed in both HD-NHP and human HD brains. Cytotoxicity and apoptosis were ameliorated by the overexpression of miR-196a in HD-NHP neural progenitor cells (HD-NPCs) and differentiated neural cells (HD-NCs). The expression of apoptosis related gene was also down regulated. Mitochondrial morphology and activity were improved as indicated by mitotracker staining and the upregulation of CBP and PGC-1α in HD-NPCs overexpressing miR-196a. Here we demonstrated the amelioration of HD cellular phenotypes in HD-NPCs and HD-NCs overexpressing miR-196a. Our results also suggested the regulatory role of miR-196a in HD pathogenesis that may hold the key for understanding molecular regulation in HD and developing novel therapeutics. PMID:27631085

  11. Positive and negative regulatory mechanisms for fine-tuning cellularity and functions of medullary thymic epithelial cells

    Directory of Open Access Journals (Sweden)

    Taishin eAkiyama

    2015-09-01

    Full Text Available Self-tolerant T cells and regulatory T cells develop in the thymus. A wide variety of cell-cell interactions in the thymus is required for the differentiation, proliferation, and repertoire selection of T cells. Various secreted and cell surface molecules expressed in thymic epithelial cells mediate these processes. Moreover, cytokines expressed by cells of hematopoietic origin regulate the cellularity of thymic epithelial cells (TECs. Tumor necrosis factor (TNF family RANK ligand, lymphotoxin, and CD40 ligand, expressed in T cells and innate lymphoid cells (ILCs, promote the differentiation and proliferation of medullary TECs (mTECs that play critical roles in the induction of immune tolerance. A recent study suggests that interleukin-22 (IL-22 produced by ILCs promotes regeneration of TECs after irradiation. Intriguingly, TGF-β and osteoprotegerin limit cellularity of mTECs, thereby attenuating regulatory T cell generation. We will review recent insights into the molecular basis for cell-cell interactions regulating differentiation and proliferation of mTECs and also discuss about a perspective on use of mathematical models for understanding this complicated system.

  12. Cellular and molecular markers in monitoring the fate of lymphoid cell culture from Penaeus monodon Fabricius (1798).

    Science.gov (United States)

    Puthumana, Jayesh; Jose, Seena; Philip, Rosamma; Singh, I S Bright

    2015-12-01

    Lymphoid cell culture from penaeid shrimps has gained much acceptance as an in vitro platform to facilitate research on the development of prophylaxis, and therapeutic strategies against viruses and for cell line development. However, lymphoid cells can be used as platform for in vitro research, only if they are in metabolically and mitotically active state in vitro with unaltered cell surface receptors. Through this study, we addressed the response of lymphoid cells to a new microenvironment at cellular and molecular levels; including the study of mitotic events, DNA synthesis, expression profile of cell cycle genes, cytoskeleton organization, metabolic activity and viral susceptibility. The S-phase entry and synthesis of new DNA was recorded by immunoflourescent technique. Cdc2, CycA, CycB, EF-1α and BUB3 genes involved in cell cycle were studied in both the cells and tissue, of which EF-1α showed an elevated expression in cells in vitro (∼ 19.7%). Cytoskeleton network of the cell was examined by studying the organization of actin filaments. As the markers for metabolic status, mitochondrial dehydrogenase, protein synthesis and glucose assimilation by the cells were also assessed. Viral susceptibility of the cell was determined using WSSV to confirm the preservation of cellular receptors. This study envisages to strengthen the shrimp cell line research and to bring forth lymphoid cell culture system as a 'model' in vitro system for shrimp and crustaceans altogether.

  13. Effects of in vitro Brevetoxin Exposure on Apoptosis and Cellular Metabolism in a Leukemic T Cell Line (Jurkat

    Directory of Open Access Journals (Sweden)

    John W. Sleasman

    2008-06-01

    Full Text Available Harmful algal blooms (HABs of the toxic dinoflagellate, Karenia brevis, produce red tide toxins, or brevetoxins. Significant health effects associated with red tide toxin exposure have been reported in sea life and in humans, with brevetoxins documented within immune cells from many species. The objective of this research was to investigate potential immunotoxic effects of brevetoxins using a leukemic T cell line (Jurkat as an in vitro model system. Viability, cell proliferation, and apoptosis assays were conducted using brevetoxin congeners PbTx-2, PbTx-3, and PbTx-6. The effects of in vitro brevetoxin exposure on cell viability and cellular metabolism or proliferation were determined using trypan blue and MTT (1-(4,5-dimethylthiazol-2-yl-3,5- diphenylformazan, respectively. Using MTT, cellular metabolic activity was decreased in Jurkat cells exposed to 5 - 10 μg/ml PbTx-2 or PbTx-6. After 3 h, no significant effects on cell viability were observed with any toxin congener in concentrations up to 10 μg/ml. Viability decreased dramatically after 24 h in cells treated with PbTx-2 or -6. Apoptosis, as measured by caspase-3 activity, was significantly increased in cells exposed to PbTx-2 or PbTx-6. In summary, brevetoxin congeners varied in effects on Jurkat cells, with PbTx-2 and PbTx-6 eliciting greater cellular effects compared to PbTx-3.

  14. Reversibility of cellular aging by reprogramming through an embryonic-like state : a new paradigm for human cell rejuvenation

    Directory of Open Access Journals (Sweden)

    Jean-Marc Lemaitre

    2014-01-01

    Full Text Available Direct reprogramming of somatic cells into induced pluripotent stem cells (iPSCs provides a unique opportunity to derive patient-specific stem cells with potential application in autologous tissue replacement therapies and without the ethical concerns of Embryonic Stem Cells (hESC. However, this strategy still suffers from several hurdles that need to be overcome before clinical applications. Among them, cellular senescence, which contributes to aging and restricted longevity, has been described as a barrier to the derivation of iPSCs. This suggests that aging might be an important limitation for therapeutic purposes for elderly individuals. Senescence is characterized by an irreversible cell cycle arrest in response to various forms of stress, including activation of oncogenes, shortened telomeres, DNA damage, oxidative stress, and mitochondrial dysfunction. To overcome this barrier, we developed an optimized 6-factor-based reprogramming protocol that is able to cause efficient reversing of cellular senescence and reprogramming into iPSCs. We demonstrated that iPSCs derived from senescent and centenarian fibroblasts have reset telomere size, gene expression profiles, oxidative stress, and mitochondrial metabolism, and are indistinguishable from hESC. Finally, we demonstrate that re-differentiation led to rejuvenated cells with a reset cellular physiology, defining a new paradigm for human cell rejuvenation. We discuss the molecular mechanisms involved in cell reprogramming of senescent cells

  15. Cell-directed assembly on an integrated nanoelectronic/nanophotonic device for probing cellular responses on the nanoscale.

    Energy Technology Data Exchange (ETDEWEB)

    Brinker, C. Jeffrey; Dunphy, Darren Robert; Ashley, Carlee E. (University of New Mexico, Albuquerque, NM); Fan, Hongyou; Lopez, DeAnna (University of New Mexico, Albuquerque, NM); Simpson, Regina Lynn; Tallant, David Robert; Burckel, David Bruce; Baca, Helen Kennicott (University of New Mexico, Albuquerque, NM); Carnes, Eric C. (University of New Mexico, Albuquerque, NM); Singh, Seema

    2006-01-01

    Our discovery that the introduction of living cells (Saccharomyces cerevisiae) alters dramatically the evaporation driven self-assembly of lipid-silica nanostructures suggested the formation of novel bio/nano interfaces useful for cellular interrogation at the nanoscale. This one year ''out of the box'' LDRD focused on the localization of metallic and semi-conducting nanocrystals at the fluid, lipid-rich interface between S. cerevisiae and the surrounding phospholipid-templated silica nanostructure with the primary goal of creating Surface Enhanced Raman Spectroscopy (SERS)-active nanostructures and platforms for cellular integration into electrode arrays. Such structures are of interest for probing cellular responses to the onset of disease, understanding of cell-cell communication, and the development of cell-based bio-sensors. As SERS is known to be sensitive to the size and shape of metallic (principally gold and silver) nanocrystals, various sizes and shapes of nanocrystals were synthesized, functionalized and localized at the cellular surface by our ''cell-directed assembly'' approach. Laser scanning confocal microscopy, SEM, and in situ grazing incidence small angle x-ray scattering (GISAXS) experiments were performed to study metallic nanocrystal localization. Preliminary Raman spectroscopy studies were conducted to test for SERS activity. Interferometric lithography was used to construct high aspect ratio cylindrical holes on patterned gold substrates and electro-deposition experiments were performed in a preliminary attempt to create electrode arrays. A new printing procedure was also developed for cellular integration into nanostructured platforms that avoids solvent exposure and may mitigate osmotic stress. Using a different approach, substrates comprised of self-assembled nanoparticles in a phospholipid templated silica film were also developed. When printed on top of these substrates, the cells integrate

  16. Sodium Glucose Cotransporter 2 (SGLT2 Plays as a Physiological Glucose Sensor and Regulates Cellular Contractility in Rat Mesangial Cells.

    Directory of Open Access Journals (Sweden)

    Masanori Wakisaka

    Full Text Available Mesangial cells play an important role in regulating glomerular filtration by altering their cellular tone. We report the presence of a sodium glucose cotransporter (SGLT in rat mesangial cells. This study in rat mesangial cells aimed to evaluate the expression and role of SGLT2.The SGLT2 expression in rat mesangial cells was assessed by Western blotting and reverse transcription-polymerase chain reaction (RT-PCR. Changes in the mesangial cell surface area at different glucose concentrations and the effects of extracellular Na+ and Ca2+ and of SGLT and Na+/Ca2+ exchanger (NCX inhibitors on cellular size were determined. The cellular sizes and the contractile response were examined during a 6-day incubation with high glucose with or without phlorizin, an SGLT inhibitor.Western blotting revealed an SGLT2 band, and RT-PCR analysis of SGLT2 revealed the predicted 422-bp band in both rat mesangial and renal proximal tubular epithelial cells. The cell surface area changed according to the extracellular glucose concentration. The glucose-induced contraction was abolished by the absence of either extracellular Na+ or Ca2+ and by SGLT and NCX inhibitors. Under the high glucose condition, the cell size decreased for 2 days and increased afterwards; these cells did not contract in response to angiotensin II, and the SGLT inhibitor restored the abolished contraction.These data suggest that SGLT2 is expressed in rat mesangial cells, acts as a normal physiological glucose sensor and regulates cellular contractility in rat mesangial cells.

  17. Comparative transcriptome analyses indicate enhanced cellular protection against FMDV in PK15 cells pretreated with IFN-γ.

    Science.gov (United States)

    Fu, Yin; Zhu, Zesen; Chang, Huiyun; Liu, Zaixin; Liu, Jing; Chen, Huiyong

    2016-07-25

    Interferon gamma (IFN-γ) can induce a host antiviral response to foot and mouth disease virus (FMDV) in vivo and in vitro. To elucidate the mechanism of IFN-γ anti FMDV infection in host cells, high-throughput RNA sequencing was analyzed for systemic changes in gene expression profiles in PK15 cells infected by FMDV with or without IFN-γ pretreatment. More than 25 million reads, covering 1.2-1.5 Gb, were analyzed from each experiment panel. FMDV challenge altered the transcription of genes involved in positively and negatively regulating cell death or apoptosis; however, the expected immune suppression response was not obvious. IFN-γ pretreatment combined with FMDV infection normalized the increase in apoptosis. Furthermore, the transcription factors required for IFN-γ functioning, STAT1 and IRF1 were up-regulated by IFN-γ pretreatment and stimulated downstream IFN-stimulated genes (ISGs). These induced ISGs are mainly responsible for antigen processing, antigen presentation or antiviral defense. Interestingly, a synergistic effect on some ISGs, including OAS1, OAS2, MX1, MX2, RIG-I and IFIT1, was observed in the combined treatment compared to the IFN-γ treatment alone. The suggested effects identified by RNA sequencing were consistent with cellular morphology changes and confirmed by related protein markers. This is the first report exploring transcriptome alterations introduced by FMDV infection with or without IFN-γ pretreatment. The identified key host genes that control cell survival in vitro broaden our comprehensive understanding of how IFN-γ inhibits FMDV infection and may shed light on developing improved FMD control approaches. PMID:27018244

  18. Cellular Behavior of Human Adipose-Derived Stem Cells on Wettable Gradient Polyethylene Surfaces

    Directory of Open Access Journals (Sweden)

    Hyun Hee Ahn

    2014-01-01

    Full Text Available Appropriate surface wettability and roughness of biomaterials is an important factor in cell attachment and proliferation. In this study, we investigated the correlation between surface wettability and roughness, and biological response in human adipose-derived stem cells (hADSCs. We prepared wettable and rough gradient polyethylene (PE surfaces by increasing the power of a radio frequency corona discharge apparatus with knife-type electrodes over a moving sample bed. The PE changed gradually from hydrophobic and smooth surfaces to hydrophilic (water contact angle, 90° to ~50° and rough (80 to ~120 nm surfaces as the power increased. We found that hADSCs adhered better to highly hydrophilic and rough surfaces and showed broadly stretched morphology compared with that on hydrophobic and smooth surfaces. The proliferation of hADSCs on hydrophilic and rough surfaces was also higher than that on hydrophobic and smooth surfaces. Furthermore, integrin beta 1 gene expression, an indicator of attachment, and heat shock protein 70 gene expression were high on hydrophobic and smooth surfaces. These results indicate that the cellular behavior of hADSCs on gradient surface depends on surface properties, wettability and roughness.

  19. Elemental mapping by synchrotron radiation X-Ray microfluorescence in cellular spheroid of prostate tumor cells

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, R.G.; Anjos, M.J.; Lopes, R.T., E-mail: roberta@lin.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Lab. de Instrumentacao Nuclear; Santos, C.A.N. [Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Duque de Caxias, RJ (Brazil). Lab. de Biotecnologia; Palumbo Junior, A.; Souza, P.A.V.R.; Nasciutti, L.E. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Ciencias Biomedicas; Pereira, G.R. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Lab. de Ensaios Nao Destrutivos, Corrosao e Soldagem

    2013-08-15

    Prostate cancer is the sixth most common type of cancer and the third most common in males in Western industrialized countries. Cellular spheroid serves as excellent physiologic tumor models as they mimic avascular tumors and micrometastases. Trace elements play a significant role in biological processes. They are capable of affecting human health by competing with essential elements for available binding sites and by the activation or inhibition of reactions between metabolic enzymes. It is well known that zinc levels in the peripheral zone of dorsal and lateral lobes of the prostate are almost 10 times higher than in other soft tissues. Prostate tumor cells were isolated of the prostate tissue samples that were collected from patients submitted to surgery. The measurements were performed in XRF beam line at the Synchrotron Light National Laboratory (LNLS) in Campinas, Brazil. The results showed that all elements were heterogeneously distributed in different areas of the spheroids analyzed. P, S and Cl showed similar elemental distribution in all the samples analyzed while K, Ca, Fe, and Cu showed different elemental distribution. In all spheroids analyzed, Zn presented more intense distributions in the central region of the spheroid. The relationship between the function of Zn in the secretory epithelial cells and the carcinogenic process suggests that more studies on elemental mapping in spheroids are necessary. (author)

  20. Self-organization of yeast cells on modified polymer surfaces after dewetting: new perspectives in cellular patterning

    Energy Technology Data Exchange (ETDEWEB)

    Carnazza, S [Department of Microbiological, Genetic and Molecular Sciences, University of Messina, Messina (Italy); Satriano, S [Department of Chemical Sciences, University of Catania, Catania (Italy); Guglielmino, S [Department of Microbiological, Genetic and Molecular Sciences, University of Messina, Messina (Italy)

    2006-08-23

    In recent years, biological micro-electro-mechanical systems (commonly referred to as BioMEMS) have found widespread use, becoming increasingly prevalent in diagnostics and therapeutics. Cell-based sensors are nowadays gaining increasing attention, due to cellular built-in natural selectivity and physiologically relevant response to biologically active chemicals. On the other hand, surrogate microbial systems, including yeast models, have become a useful alternative to animal and mammalian cell systems for high-throughput screening for the identification of new pharmacological agents. A main obstacle in biosensor device fabrication is the need for localized geometric confinement of cells, without losing cell viability and sensing capability. Here we illustrate a new approach for cellular patterning using dewetting processes to control cell adhesion and spatial confinement on modified surfaces. By the control of simple system parameters, a rich variety of morphologies, ranging through hexagonal arrays, polygonal networks, bicontinuous structures, and elongated fingers, can be obtained.

  1. Analyzing the Influence of Mobile Phone Use of Drivers on Traffic Flow Based on an Improved Cellular Automaton Model

    Directory of Open Access Journals (Sweden)

    Yao Xiao

    2015-01-01

    Full Text Available This paper aimed to analyze the influence of drivers’ behavior of phone use while driving on traffic flow, including both traffic efficiency and traffic safety. An improved cellular automaton model was proposed to simulate traffic flow with distracted drivers based on the Nagel-Schreckenberg model. The driving characters of drivers using a phone were first discussed and a value representing the probability to use a phone while driving was put into the CA model. Simulation results showed that traffic flow rate was significantly reduced if some drivers used a phone compared to no phone use. The flow rate and velocity decreased as the proportion of drivers using a phone increased. While, under low density, the risk of traffic decreased first and then increased as the distracted drivers increased, the distracted behavior of drivers, like using a phone, could reduce the flow rate by 5 percent according to the simulation.

  2. Prednisolone succinate-glucosamine conjugate: Synthesis, characterization and in vitro cellular uptake by kidney cell lines

    Institute of Scientific and Technical Information of China (English)

    Yan Lin; Xun Sun; Tao Gong; Zhi Rong Zhang

    2012-01-01

    Prednisolone succinate-glucosamine (PSG) conjugate,a prodrug for prednisolone,was synthesized and confirmed by NMR and MS spectrum.The stabilities of the prodrug in PBS (pH 2.50,5.00,7.20,and 7.89) were studied.Cytotoxicity and uptake assay of the prodrug were perfomed on HK-2 and MDCK cell lines.The results showed that compared with prednisolone,the PSG not only did not increase the cytotoxicity but also improved the uptake to 2.2 times of prednisolone by the cells.Thus,it indicated that glucosamine might be a potential carrier for kidney-targeting delivery of prednisolone.

  3. Induction of vascular endothelial phenotype and cellular proliferation from human cord blood stem cells cultured in simulated microgravity

    Science.gov (United States)

    Chiu, Brian; Z-M Wan, Jim; Abley, Doris; Akabutu, John

    2005-05-01

    Recent studies have demonstrated that stem cells derived from adult hematopoietic tissues are capable of trans-differentiation into non-hematopoietic cells, and that the culture in microgravity ( μg) may modulate the proliferation and differentiation. We investigated the application of μg to human umbilical cord blood stem cells (CBSC) in the induction of vascular endothelial phenotype expression and cellular proliferation. CD34+ mononuclear cells were isolated from waste human umbilical cord blood samples and cultured in simulated μg for 14 days. The cells were seeded in rotary wall vessels (RWV) with or without microcarrier beads (MCB) and vascular endothelial growth factor was added during culture. Controls consisted of culture in 1 G. The cell cultures in RWV were examined by inverted microscopy. Cell counts, endothelial cell and leukocyte markers performed by flow-cytometry and FACS scan were assayed at days 1, 4, 7 and at the termination of the experiments. Culture in RWV revealed significantly increased cellular proliferation with three-dimensional (3D) tissue-like aggregates. At day 4, CD34+ cells cultured in RWV bioreactor without MCB developed vascular tubular assemblies and exhibited endothelial phenotypic markers. These data suggest that CD34+ human umbilical cord blood progenitors are capable of trans-differentiation into vascular endothelial cell phenotype and assemble into 3D tissue structures. Culture of CBSC in simulated μg may be potentially beneficial in the fields of stem cell biology and somatic cell therapy.

  4. Cellular interaction between fixed and living cells; transfer of radioactive materials from living cells to fixed cells

    Energy Technology Data Exchange (ETDEWEB)

    Sakiyama, H.; Otsu, H.; Kanegasaki, S.

    1979-06-01

    Transfer of radioactive materials to fixed cells from an overlying layer of living cells has been examined to determine whether fixed cells can act as acceptors of glycosyltransferases of living cells. After the incubation of living cells were removed by EDTA treatment, and the radioactivity associated with the fixed cells was determined. Lipids, proteins and carbohydrates were found to be transfered from the living cells to the fixed cells. The amount of radioactivity transferred to the fixed cells was dependent on the number of both fixed and living cells and increased with the time of incubation. When fixed cells were treated with chloroform-methanol before the addition of living cells, the transfer of both lipids and proteins to the fixed cells decreased drastically, but only a slight decrease in carbohydrate transfer was observed. Most of the radioactive materials transferred from living cells labeled with glucosamine or fucose to chloroform-methanol-treated fixed cells were solubilized by trypsin but not by the detergents tested. Approximately 55% of the materials transferred from the cells labeled with glucosamine could be solubilized by hyaluronidase and chondroitinase, and the rest was solubilized by neuraminidase and a glycosidase mixture. The treatment of chloroform-methanol-extracted fixed cells with trypsin caused a significant decrease in the transfer from cells labeled with glucosamine. When nucleotide sugars were used as the radioactive precursor, no significant amount of radioactivity was transferred to the fixed cells.

  5. Acute dyskerin depletion triggers cellular senescence and renders osteosarcoma cells resistant to genotoxic stress-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Ping; Mobasher, Maral E.; Alawi, Faizan, E-mail: falawi@upenn.edu

    2014-04-18

    Highlights: • Dyskerin depletion triggers cellular senescence in U2OS osteosarcoma cells. • Dyskerin-depleted cells are resistant to apoptosis induced by genotoxic stress. • Chromatin relaxation sensitizes dyskerin-depleted cells to apoptosis. - Abstract: Dyskerin is a conserved, nucleolar RNA-binding protein implicated in an increasing array of fundamental cellular processes. Germline mutation in the dyskerin gene (DKC1) is the cause of X-linked dyskeratosis congenita (DC). Conversely, wild-type dyskerin is overexpressed in sporadic cancers, and high-levels may be associated with poor prognosis. It was previously reported that acute loss of dyskerin function via siRNA-mediated depletion slowed the proliferation of transformed cell lines. However, the mechanisms remained unclear. Using human U2OS osteosarcoma cells, we show that siRNA-mediated dyskerin depletion induced cellular senescence as evidenced by proliferative arrest, senescence-associated heterochromatinization and a senescence-associated molecular profile. Senescence can render cells resistant to apoptosis. Conversely, chromatin relaxation can reverse the repressive effects of senescence-associated heterochromatinization on apoptosis. To this end, genotoxic stress-induced apoptosis was suppressed in dyskerin-depleted cells. In contrast, agents that induce chromatin relaxation, including histone deacetylase inhibitors and the DNA intercalator chloroquine, sensitized dyskerin-depleted cells to apoptosis. Dyskerin is a core component of the telomerase complex and plays an important role in telomere homeostasis. Defective telomere maintenance resulting in premature senescence is thought to primarily underlie the pathogenesis of X-linked DC. Since U2OS cells are telomerase-negative, this leads us to conclude that loss of dyskerin function can also induce cellular senescence via mechanisms independent of telomere shortening.

  6. Cellular Barcoding Links B-1a B Cell Potential to a Fetal Hematopoietic Stem Cell State at the Single-Cell Level

    DEFF Research Database (Denmark)

    Kristiansen, Trine A; Jaensson Gyllenbäck, Elin; Zriwil, Alya;

    2016-01-01

    Hematopoietic stem cells (HSCs) undergo a functional switch in neonatal mice hallmarked by a decrease in self-renewing divisions and entry into quiescence. Here, we investigated whether the developmental attenuation of B-1a cell output is a consequence of a shift in stem cell state during ontogeny....... Using cellular barcoding for in vivo single-cell fate analyses, we found that fetal liver definitive HSCs gave rise to both B-1a and B-2 cells. Whereas B-1a potential diminished in all HSCs with time, B-2 output was maintained. B-1a and B-2 plasticity could be reinitiated in a subset of adult HSCs...... by ectopic expression of the RNA binding protein LIN28B, a key regulator of fetal hematopoiesis, and this coincided with the clonal reversal to fetal-like elevated self-renewal and repopulation potential. These results anchor the attenuation of B-1a cell output to fetal HSC behavior and demonstrate...

  7. Cellular Modulation of Polymeric Device Surfaces: Promise of Adult Stem Cells for Neuro-Prosthetics

    OpenAIRE

    Richter, Anja; Kruse, Charli; Moser, Andreas; Hofmann, Ulrich G.; Danner, Sandra

    2011-01-01

    Minimizing the foreign body response is seen as one critical research strategy for implants especially when designed for immune-privileged organs like the brain. The context of this work is to improve deep brain stimulating devices used in a consistently growing spectrum of psychomotor and psychiatric diseases mainly in form of stiff electrodes. Based on the compliance match hypothesis of biocompatibility we present another step forward using flexible implant materials covered with brain cell...

  8. Cellular angiofibroma: analysis of 25 cases emphasizing its relationship to spindle cell lipoma and mammary-type myofibroblastoma

    NARCIS (Netherlands)

    Flucke, U.E.; Krieken, J.H. van; Mentzel, T.

    2011-01-01

    Cellular angiofibroma represents a rare benign mesenchymal tumor, occurring mainly in the superficial soft tissue of the genital region. The involvement of 13q14 in some cases confirmed the morphological suggested link with spindle cell lipoma and mammary-type myofibroblastoma. We analyzed the clini

  9. Cellular trafficking determines the exon skipping activity of Pip6a-PMO in mdx skeletal and cardiac muscle cells

    OpenAIRE

    Lehto, Taavi; Castillo Alvarez, Alejandra; Gauck, Sarah; Gait, Michael J.; Coursindel, Thibault; Matthew J A Wood; Lebleu, Bernard; Boisguerin, Prisca

    2013-01-01

    Cell-penetrating peptide-mediated delivery of phosphorodiamidate morpholino oligomers (PMOs) has shown great promise for exon-skipping therapy of Duchenne Muscular Dystrophy (DMD). Pip6a-PMO, a recently developed conjugate, is particularly efficient in a murine DMD model, although mechanisms responsible for its increased biological activity have not been studied. Here, we evaluate the cellular trafficking and the biological activity of Pip6a-PMO in skeletal muscle cells and primary cardiomyoc...

  10. Cyclic RGD peptide-modified liposomal drug delivery system: enhanced cellular uptake in vitro and improved pharmacokinetics in rats

    Directory of Open Access Journals (Sweden)

    Chen Z

    2012-07-01

    Full Text Available Zhongya Chen,1,2 Jiaxin Deng,1,2 Yan Zhao,1,2 Tao Tao1,21National Pharmaceutical Engineering Research Center, 2Shanghai Institute of Pharmaceutical Industry, China State Institute of Pharmaceutical Industry, Shanghai, People's Republic of ChinaBackground: Integrins αvβ3 and αvβ5, both of which specifically recognize the Arg-Gly-Asp (RGD motif, are overexpressed on many solid tumors and in tumor neovasculature. Thus, coupling the RGD motif to the liposomal surface for achieving active targeting can be a promising strategy for the treatment of tumors.Methods: Cyclo(Arg-Gly-Asp-D-Phe-Cys (cRGD was covalently coupled with the liposomal membrane surface, followed by coating with poly(ethylene glycol (PEG using the post-insertion technique. The coupling efficiency of cRGD was determined. Doxorubicin as a model anticancer drug was loaded into liposomes using an ammonium sulfate gradient method to investigate the encapsulation efficiency, cellular uptake by the integrin-overexpressing human glioma cell line U87MG in vitro, and pharmacokinetic properties in Sprague-Dawley rats.Results: cRGD was conjugated to the liposomal surface by a thiol-maleimide coupling reaction. The coupling efficiency reached 98%. The encapsulation efficiency of doxorubicin in liposomes was more than 98%. The flow cytometry test result showed that cRGD-modified liposomes (RGD-DXRL-PEG had higher cell uptake by U87MG cells, compared with nontargeted liposomes (DXRL-PEG. The cellular uptake was significantly inhibited in the presence of excess free cRGD. Both the targeted (t1/2 = 24.10 hours and non-targeted (t1/2 = 25.32 hours liposomes showed long circulating properties in rat plasma. The area under the curve of the targeted and nontargeted liposomes was 6.4-fold and 8.3-fold higher than that of doxorubicin solution, respectively.Conclusion: This study indicates preferential targeting and long circulating properties for cRGD-modified liposomes in vivo, which could be used as

  11. Uptake of dexamethasone incorporated into liposomes by macrophages and foam cells and its inhibitory effect on cellular cholesterol ester accumulation.

    Science.gov (United States)

    Chono, Sumio; Morimoto, Kazuhiro

    2006-09-01

    To confirm the efficacy of dexamethasone incorporated into liposomes in the treatment of atherosclerosis, the uptake of dexamethasone-liposomes by macrophages and foam cells and its inhibitory effect on cellular cholesterol ester accumulation in these cells were investigated in-vitro. Dexamethasone-liposomes were prepared with egg yolk phosphatidylcholine, cholesterol and dicetylphosphate in a lipid molar ratio of 7/2/1 by the hydration method. This was adjusted to three different particle sizes to clarify the influence of particle size on the uptake by the macrophages and foam cells, and the inhibitory effect on cellular cholesterol ester accumulation. The distribution of particle sizes of dexamethasone-liposomes were 518.7+/-49.5 nm (L500), 202.2+/-23.1 nm (L200), and 68.6+/-6.5 nm (L70), respectively. For each size, dexamethasone concentration and dexamethasone/lipid molar ratio in dexamethasone-liposome suspension were 1 mg dexamethasone mL-1 and 0.134 mol dexamethasone mol-1 total lipids, respectively. The zeta potential was approximately -70 mV for all sizes. Dexamethasone-liposomes or free dexamethasone were added to the macrophages in the presence of oxidized low density lipoprotein (oxLDL) and foam cells, and then incubated at 37 degrees C. The uptake amount of dexamethasone by the macrophages and foam cells after a 24-h incubation was L500>L200>free dexamethasone>L70. The macrophages in the presence of oxLDL and foam cells were incubated with dexamethasone-liposomes or free dexamethasone for 24 h at 37 degrees C to evaluate the inhibitory effect on the cellular cholesterol ester accumulation. The cellular cholesterol ester level in the macrophages treated with oxLDL was significantly increased compared with that in macrophages without additives. L500, L200 and free dexamethasone significantly inhibited this cholesterol ester accumulation. L500, L200 and free dexamethasone also significantly reduced cellular cholesterol ester accumulation in foam cells. In

  12. Epigallocatechin-3-gallate affects the growth of LNCaP cells via membrane fluidity and distribution of cellular zinc

    Institute of Scientific and Technical Information of China (English)

    Jun-guo YANG; Hai-ning YU; Shi-li SUN; Lan-cui ZHANG; Guo-qing HE; Undurti N. DAS; Hui RUAN; Sheng-rong SHEN

    2009-01-01

    Objective: To evaluate effects of epigallocatechin-3-gallate (EGCG) on the viability, membrane properties, and zinc distribution, with and without the presence of Zn2+, in human prostate carcinoma LNCaP cells. Methods: We examined changes in cellular morphology and membrane fluidity of LNCaP cells, distribution of cellular zinc, and the incorporated portion of EGCG after treatments with EGCG, Zn2+, and EGCG+Zn2+. Results: We observed an alteration in cellular morphology and a decrease in membrane fluidity of LNCaP cells after treatment with EGCG or Zn2+. The proportion of EGCG incorporated into liposomes treated with the mixture of EGCG and Zn2+ at the ratio of 1:l was 90.57%, which was significantly higher than that treated with EGCG alone (30.33%). Electron spin resonance (ESR) studies and determination of fatty acids showed that the effects of EGCG on the membrane fluidity of LNCaP were decreased by Zn2+. EGCG accelerated the accumulation of zinc in the mitochondria and cytosol as observed by atomic absorption spectrometer. Conclusion: These results show that EGCG interacted with cell membrane,decreased the membrane fluidity of LNCaP cells, and accelerated zinc accumulation in the mitochondria and cytosol, which could be the mechanism by which EGCG inhibits proliferation of LNCaP cells. In addition, high concentrations of Zn2+ could attenuate the actions elicited by EGCG.

  13. An improved method for quantification of extra domain A-containing cellular fibronectin (EDAcFN) in different body fluids.

    Science.gov (United States)

    Ylätupa, S; Mertaniemi, P; Haglund, C; Partanen, P

    1995-01-31

    A quantitative direct enzyme immunoassay for the extra domain A-containing isoform of cellular fibronectin (EDAcFN) was established for screening of large series of blood samples and various body fluids of different pH and viscosity. The method is based on the monoclonal antibody DH1 recognizing the extra domain A in cellular fibronectin (EDAcFN). Studies on the effect of dilution of plasma and serum samples in this direct assay indicated that the measured concentration of cFN in the samples greatly depend on the ratio of sample dilution. The linearity of the assay was improved with sample dilution and the optimal dilution was 1:5. Stored diluted samples retained their cFN content at +4 degrees C, and -20 degrees C and -70 degrees C for months in contrast to samples stored undiluted. With this direct EIA the detection limit was 0.05 micrograms/ml and the linear portion of the standard curve could be extended above 30 micrograms/ml. Thus, the cFN concentration of blood samples could be measured reliably without inhibition also in samples with very high concentration of cFN. This is particularly important when measuring blood samples from cancer patients, since these samples may contain more than 20 micrograms/ml EDAcFN. The assay was standardized for blood samples but, due to the possibility of sample dilution, it also enabled reliable quantification of EDAcFN in various other body fluids. Undiluted some of the samples with non-neutral pH (urine, bile) or with high viscosity (seminal plasma) interfered with the assay. In addition to blood samples, the EDAcFN concentration was determined in samples of urine, bile, amniotic fluid, cervicovaginal secretions, seminal fluid, cerebrospinal fluid, bronchoalveolar lavage fluid, pleural fluid and saliva. Thereby, this modified method was shown to be applicable to various body fluids. PMID:7758225

  14. Proteomic profiling of cellular targets of lipopolysaccharide-induced signalling in Nicotiana tabacum BY-2 cells.

    Science.gov (United States)

    Gerber, Isak B; Laukens, Kris; De Vijlder, Thomas; Witters, Erwin; Dubery, Ian A

    2008-11-01

    Plants constantly monitor for pathogen challenge and utilize a diverse array of adaptive defense mechanisms, including differential protein regulation, during pathogen attack. A proteomic analysis of Nicotiana tabacum BY-2 cells was performed in order to investigate the dynamic changes following perception of bacterial lipopolysaccharides. A multiplexed proteome analysis, employing two-dimensional difference-in-gel-electrophoresis with CyDye DIGE fluors, as well as Ruthenium II tris (bathophenanthroline disulfonate) fluorescence staining and Pro-Q Diamond phosphoprotein-specific gel staining, monitored over 1500 proteins and resulted in the identification of 88 differentially regulated proteins and phosphoproteins responsive to LPS(B.cep.)-elicitation. Functional clustering of the proteins both at the level of their abundance and phosphorylation status, revealed 9 proteins involved in transport, ion homeostasis and signal transduction. A large number of responsive proteins were found to be involved in metabolism- and energy-related processes (36), representing various metabolic pathways. Another abundant category corresponded to proteins classified as molecular chaperones and involved in protein destination/targeting (12). Other categories of proteins found to be LPS(B.cep.)-responsive and differentially regulated include cell structure- and cytoskeletal rearrangement proteins (8) and proteins involved in transcription and translation as well as degradation (11). The results indicate that LPS(B.cep.) induces metabolic reprogramming and changes in cellular activities supporting protein synthesis, -folding, vesicle trafficking and secretion; accompanied by changes to the cytoskeleton and proteosome function. Many of the identified proteins are known to be interconnected at various levels through a complex web of activation/deactivation, complex formation, protein-protein interactions, and chaperoning reactions. The presented data offers novel insights and further

  15. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    Energy Technology Data Exchange (ETDEWEB)

    H.C. Maru; M. Farooque

    2005-03-01

    The program was designed to advance the carbonate fuel cell technology from full-size proof-of-concept field test to the commercial design. DOE has been funding Direct FuelCell{reg_sign} (DFC{reg_sign}) development at FuelCell Energy, Inc. (FCE, formerly Energy Research Corporation) from an early state of development for stationary power plant applications. The current program efforts were focused on technology and system development, and cost reduction, leading to commercial design development and prototype system field trials. FCE, in Danbury, CT, is a world-recognized leader for the development and commercialization of high efficiency fuel cells that can generate clean electricity at power stations, or at distributed locations near the customers such as hospitals, schools, universities, hotels and other commercial and industrial applications. FCE has designed three different fuel cell power plant models (DFC300A, DFC1500 and DFC3000). FCE's power plants are based on its patented DFC{reg_sign} technology, where a hydrocarbon fuel is directly fed to the fuel cell and hydrogen is generated internally. These power plants offer significant advantages compared to the existing power generation technologies--higher fuel efficiency, significantly lower emissions, quieter operation, flexible siting and permitting requirements, scalability and potentially lower operating costs. Also, the exhaust heat by-product can be used for cogeneration applications such as high-pressure steam, district heating and air conditioning. Several sub-MW power plants based on the DFC design are currently operating in Europe, Japan and the US. Several one-megawatt power plant design was verified by operation on natural gas at FCE. This plant is currently installed at a customer site in King County, WA under another US government program and is currently in operation. Because hydrogen is generated directly within the fuel cell module from readily available fuels such as natural gas and

  16. Structure of modified [epsilon]-polylysine micelles and their application in improving cellular antioxidant activity of curcuminoids

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Hailong; Li, Ji; Shi, Ke; Huang, Qingrong (Rutgers)

    2015-10-15

    The micelle structure of octenyl succinic anhydride modified {var_epsilon}-polylysine (M-EPL), an anti-microbial surfactant prepared from natural peptide {var_epsilon}-polylysine in aqueous solution has been studied using synchrotron small-angle X-ray scattering (SAXS). Our results revealed that M-EPLs formed spherical micelles with individual size of 24-26 {angstrom} in aqueous solution which could further aggregate to form a larger dimension with averaged radius of 268-308 {angstrom}. Furthermore, M-EPL micelle was able to encapsulate curcuminoids, a group of poorly-soluble bioactive compounds from turmeric with poor oral bioavailability, and improve their water solubility. Three loading methods, including solvent evaporation, dialysis, and high-speed homogenization were compared. The results indicated that the dialysis method generated the highest loading capacity and curcuminoids water solubility. The micelle encapsulation was confirmed as there were no free curcuminoid crystals detected in the differential scanning calorimetry analysis. It was also demonstrated that M-EPL encapsulation stabilized curcuminoids against hydrolysis at pH 7.4 and the encapsulated curcuminoids showed elevated cellular antioxidant activity compared with free curcuminoids. This work suggested that M-EPL could be used as new biopolymer micelles for delivering poorly soluble drugs/phytochemicals and improving their bioactivities.

  17. The Rho GTPase Cdc42 regulates hair cell planar polarity and cellular patterning in the developing cochlea

    Directory of Open Access Journals (Sweden)

    Anna Kirjavainen

    2015-03-01

    Full Text Available Hair cells of the organ of Corti (OC of the cochlea exhibit distinct planar polarity, both at the tissue and cellular level. Planar polarity at tissue level is manifested as uniform orientation of the hair cell stereociliary bundles. Hair cell intrinsic polarity is defined as structural hair bundle asymmetry; positioning of the kinocilium/basal body complex at the vertex of the V-shaped bundle. Consistent with strong apical polarity, the hair cell apex displays prominent actin and microtubule cytoskeletons. The Rho GTPase Cdc42 regulates cytoskeletal dynamics and polarization of various cell types, and, thus, serves as a candidate regulator of hair cell polarity. We have here induced Cdc42 inactivation in the late-embryonic OC. We show the role of Cdc42 in the establishment of planar polarity of hair cells and in cellular patterning. Abnormal planar polarity was displayed as disturbances in hair bundle orientation and morphology and in kinocilium/basal body positioning. These defects were accompanied by a disorganized cell-surface microtubule network. Atypical protein kinase C (aPKC, a putative Cdc42 effector, colocalized with Cdc42 at the hair cell apex, and aPKC expression was altered upon Cdc42 depletion. Our data suggest that Cdc42 together with aPKC is part of the machinery establishing hair cell planar polarity and that Cdc42 acts on polarity through the cell-surface microtubule network. The data also suggest that defects in apical polarization are influenced by disturbed cellular patterning in the OC. In addition, our data demonstrates that Cdc42 is required for stereociliogenesis in the immature cochlea.

  18. Proteomic analysis of cellular response induced by multi-walled carbon nanotubes exposure in A549 cells.

    Directory of Open Access Journals (Sweden)

    Li Ju

    Full Text Available The wide application of multi-walled carbon nanotubes (MWCNT has raised serious concerns about their safety on human health and the environment. However, the potential harmful effects of MWCNT remain unclear and contradictory. To clarify the potentially toxic effects of MWCNT and to elucidate the associated underlying mechanisms, the effects of MWCNT on human lung adenocarcinoma A549 cells were examined at both the cellular and the protein level. Cytotoxicity and genotoxicity were examined, followed by a proteomic analysis (2-DE coupled with LC-MS/MS of the cellular response to MWCNT. Our results demonstrate that MWCNT induces cytotoxicity in A549 cells only at relatively high concentrations and longer exposure time. Within a relatively low dosage range (30 µg/ml and short time period (24 h, MWCNT treatment does not induce significant cytotoxicity, cell cycle changes, apoptosis, or DNA damage. However, at these low doses and times, MWCNT treatment causes significant changes in protein expression. A total of 106 proteins show altered expression at various time points and dosages, and of these, 52 proteins were further identified by MS. Identified proteins are involved in several cellular processes including proliferation, stress, and cellular skeleton organization. In particular, MWCNT treatment causes increases in actin expression. This increase has the potential to contribute to increased migration capacity and may be mediated by reactive oxygen species (ROS.

  19. An evaluation of the mechanism of ABCA7 on cellular lipid release in ABCA7-HEC293 cell

    Institute of Scientific and Technical Information of China (English)

    WU Cheng-ai; WANG Na; ZHAO Dan-hui

    2013-01-01

    Background ABCA7 is a member of the ABCA subfamily that shows a high degree of homology to ABCA1 and,like ABCA1,mediates cellular cholesterol and phospholipid release by apolipoproteins when transfected in vitro.However,expression of ABCA7 has been shown to be downregulated by increased cellular cholesterol while ABCA1 was upregulated.Methods The underlying mechanism for this effect was examined in ABCA1 or ABCA7-transfected HEC293.Lipid content in the medium and cells was determined by enzymatic assays.Gene expression was quantitated by real time PCR,and protein content was determined by Western blotting.Results While ABCA7 mRNA was decreased by 25-hydroxycholesterol treatment,ABCA1 was apparently increased.Treatment with the synthetic LXR agonist T0901317 (T09) upregulated ABCA1 expression and apoAI-mediated cellular lipid release in ABCA1-transfected HEC293 cells,but ABCA7 expression and cellular lipid release in ABCA7-transfected HEC293 cells showed no obvious changes.Conclusion The ABCA7 gene is regulated by sterol in a direction opposite to that of ABCA1.

  20. The cellular uptake mechanism, intracellular transportation, and exocytosis of polyamidoamine dendrimers in multidrug-resistant breast cancer cells.

    Science.gov (United States)

    Zhang, Jie; Liu, Dan; Zhang, Mengjun; Sun, Yuqi; Zhang, Xiaojun; Guan, Guannan; Zhao, Xiuli; Qiao, Mingxi; Chen, Dawei; Hu, Haiyang

    2016-01-01

    Polyamidoamine dendrimers, which can deliver drugs and genetic materials to resistant cells, are attracting increased research attention, but their transportation behavior in resistant cells remains unclear. In this paper, we performed a systematic analysis of the cellular uptake, intracellular transportation, and efflux of PAMAM-NH2 dendrimers in multidrug-resistant breast cancer cells (MCF-7/ADR cells) using sensitive breast cancer cells (MCF-7 cells) as the control. We found that the uptake rate of PAMAM-NH2 was much lower and exocytosis of PAMAM-NH2 was much greater in MCF-7/ADR cells than in MCF-7 cells due to the elimination of PAMAM-NH2 from P-glycoprotein and the multidrug resistance-associated protein in MCF-7/ADR cells. Macropinocytosis played a more important role in its uptake in MCF-7/ADR cells than in MCF-7 cells. PAMAM-NH2 aggregated and became more degraded in the lysosomal vesicles of the MCF-7/ADR cells than in those of the MCF-7 cells. The endoplasmic reticulum and Golgi complex were found to participate in the exocytosis rather than endocytosis process of PAMAM-NH2 in both types of cells. Our findings clearly showed the intracellular transportation process of PAMAM-NH2 in MCF-7/ADR cells and provided a guide of using PAMAM-NH2 as a drug and gene vector in resistant cells. PMID:27536106

  1. Oligonol suppresses lipid accumulation and improves insulin resistance in a palmitate-induced in HepG2 hepatocytes as a cellular steatosis model

    OpenAIRE

    Park, Jae-Yeo; Kim, Younghwa; Im, Jee Ae; Lee, Hyangkyu

    2015-01-01

    Background Oligonol is a low molecular weight form of polyphenol polymers derived from lychee fruits. Several studies suggest that Oligonol has an anti-obesity effect. Since obesity is tightly associated with insulin resistance, we investigated a possible remission effect of Oligonol on lipid accumulation and insulin resistance in human hepatic HepG2 cells. Methods HepG2 cells were treated with palmitate for 24 h to induce cellular hepatic steatosis and insulin resistance. The cells were then...

  2. Cellular Damage in Diabetic Wounded Fibroblast Cells following Phototherapy at 632.8, 830, and 1064 nm

    International Nuclear Information System (INIS)

    This study aimed to establish if laser irradiation induces cellular and genetic damage. Background. Phototherapy has been shown to induce wound healing in diabetic wounds, however little information is known regarding light-induced damage. Methods. Diabetic wounded fibroblasts were irradiated with 5 or 16 J/cm2 at 632.8, 830, and 1064 nm. Damage was assessed by measuring membrane and DNA damages. Cellular migration was determined by microscopy. Results. Cells irradiated with 5J/cm2 at 632.8 and 830 nm showed a significant decrease in DNA damage while all cells irradiated with a fluence of 16 J/cm2 showed an increase in membrane and DNA damages. Conclusion. This study showed that the comet assay and LDH release were sensitive enough to pick up changes in laser-irradiated cells. This study also showed that cellular and genetic damage inflicted on diabetic wounded cells was dependent on dose and wavelength and that cells are able to recover and respond.

  3. The regeneration of epidermal cells of Saintpaulia leaves as a new plant-tissue system for cellular radiation biology.

    Science.gov (United States)

    Engels, F M; van der Laan, F M; Leenhouts, H P; Chadwick, K H

    1980-09-01

    Investigation of the nucleus of epidermal cells of the petioles of Saintpaulia leaves by cytofluorimetry revealed that all cells are in a non-cycling pre DNA synthesis phase. Cultivation of dissected leaves results in a synchronous regeneration process of a defined number of cells. Five days after onset of cultivation the cells reach the first mitosis. The nuclear development during the regeneration process is described. Irradiation of the leaves results in a directly visible inhibition of this regenerating capability which is used to quantify cell survival in a tissue. The data show that the radiation response has a similar shape to that of the survival of single cells in culture. This response can be observed before the first mitosis of the cells and its application as a new plant tissue system for cellular radiation research is discussed. PMID:7012060

  4. Cellular uptake but low permeation of human calcitonin-derived cell penetrating peptides and Tat(47-57) through well-differentiated epithelial models

    DEFF Research Database (Denmark)

    Tréhin, Rachel; Krauss, Ulrike; Beck-Sickinger, Annette G;

    2004-01-01

    To investigate whether cell penetrating peptides (CPP) derived from human calcitonin (hCT) possess, in addition to cellular uptake, the capacity to deliver their cargo through epithelial barriers.......To investigate whether cell penetrating peptides (CPP) derived from human calcitonin (hCT) possess, in addition to cellular uptake, the capacity to deliver their cargo through epithelial barriers....

  5. Possible improvement of solar cell efficiency

    International Nuclear Information System (INIS)

    We present the development of a new solar cell prototype in order to improve photovoltaic efficiency. In this model we show that the material can have three successive incident ray absorptions instead of two currently, by varying the incidence angle, the aperture between the summits of two neighbouring pyramids and their height. This study concerns in particular the photovoltaic parameters such as the spectral response. This model was checked for angles varying between 54 and 60 deg and for pyramid heights between 5 and 10 μm. For these values of incidence angle, the apertures between the summits of two neighbouring pyramids varied respectively from 14.54 to 11.54 μm for a pyramid angle height of 10 μm

  6. Modulation by retinoic acid of cellular, surface-exposed, and secreted glycoconjugates in cultured human sarcoma cells.

    Science.gov (United States)

    Meromsky, L; Lotan, R

    1984-02-01

    The effect of beta-all-trans-retinoic acid (RA) on the synthesis of cellular, cell surface, and secreted glycoconjugates by human Hs705 chondrosarcoma and Hs791 osteosarcoma cells was investigated in vitro. Untreated and RA-treated cells were labeled either metabolically with radioactive precursors or by oxidation of externally exposed cell membrane glycoprotein(s) (GP) by treatment with NalO4 or neuraminidase and galactose oxidase followed by reduction with NaB[3H]4. The cells were solubilized and analyzed by polyacrylamide gel electrophoresis followed by fluorography. RA enhanced the labeling of sialic acid and galactose residues on the GP of relative molecular weight(s) (Mr) in the range 95,000-300,000 on the surfaces of both cell types. [3H]glycosamine incorporation into GP with Mr of 100,000, 150,000, and 190,000 in both cell lines was also stimulated. In the Hs705 cells there was also an increase in the labeling of a 290,000-Mr GP. In contrast, [3H]glucosamine incorporation into glycoconjugates greater than 400,000 Mr in both the cells and the conditioned medium of Hs705 cells decreased. The latter glycoconjugates were susceptible to hyaluronidase and chondroitinases. [3H]glucosamine incorporation into a secreted 230,000-Mr GP, identified as fibronectin, was also reduced. Analyses of conditioned media of cells labeled with [35S]methionine or [14C]proline demonstrated that RA decreased the secretion of procollagen chains and fibronectin. Immunofluorescence revealed that RA alters the distribution of cell-associated fibronectin. These results demonstrated that RA increases the glycosylation of specific cellular and cell surface GP and decreases the production of secreted GP and glycosaminoglycans by the sarcoma cells.

  7. Evaluation of in-vitro cytotoxicity and cellular uptake efficiency of zidovudine-loaded solid lipid nanoparticles modified with Aloe Vera in glioma cells.

    Science.gov (United States)

    K S, Joshy; Sharma, Chandra P; Kalarikkal, Nandakumar; Sandeep, K; Thomas, Sabu; Pothen, Laly A

    2016-09-01

    Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66±12.22nm and modified solid lipid nanoparticles showed an average size of 265.61±80.44nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV. PMID:27207037

  8. Comparison of the colony formation and crystal violet cell proliferation assays to determine cellular radiosensitivity in a repair-deficient MCF10A cell line

    Energy Technology Data Exchange (ETDEWEB)

    Vandersickel, Veerle [Department of Basic Medical Sciences, Ghent University, Campus Heymans, De Pintelaan 185 (6B3), 9000 Gent (Belgium); Slabbert, Jacobus [NRF iThemba LABS (Laboratory for Accelerated Based Sciences), PO box 722, 7129 Somerset West (South Africa); Thierens, Hubert [Department of Basic Medical Sciences, Ghent University, Campus Heymans, De Pintelaan 185 (6B3), 9000 Gent (Belgium); Vral, Anne, E-mail: anne.Vral@UGent.b [Department of Basic Medical Sciences, Ghent University, Campus Heymans, De Pintelaan 185 (6B3), 9000 Gent (Belgium)

    2011-01-15

    Colony formation as measured by the in vitro clonogenic assay is a very important endpoint to determine cellular radiosensitivity and tumor response to radiotherapy. In the framework of assessing in vitro cellular radiosensitivity, proliferation assays could represent an attractive alternative to the clonogenic assay for cell lines that do not form proper colonies. In the present study, we compared cellular radiosensitivity measurements obtained by the crystal violet (CV) cell proliferation assay and the standard colony formation assay in repair-deficient and-proficient human MCF10A cell lines. Compared to the clonogenic assay, the CV cell proliferation assay yielded higher surviving fractions for the same radiation dose. This is reflected in larger mean inactivation dose values - a parameter that reflects the area under the survival curve. However, as the dose modifying factors obtained by both assays are comparable, the CV cell proliferation assay can be used to compare the in vitro cellular radiosensitivity of cell lines that lack the ability to form well-defined colonies.

  9. Cellular and Molecular Consequences of Peroxisome Proliferator-Activated Receptor-γ Activation in Ovarian Cancer Cells1*

    OpenAIRE

    Vignati, Sara; Albertini, Veronica; Rinaldi, Andrea; Kwee, Ivo; RIVA Cristina; Oldrini, Rita; Capella, Carlo; Bertoni, Francesco; Carbone, Giuseppina M; Catapano, Carlo V.

    2006-01-01

    Peroxisome proliferator-activated receptor-γ (PPAR-γ) is a ligand-activated transcription factor. In addition to its canonical role in lipid and glucose metabolism, PPAR-γ controls cell proliferation, death, and differentiation in several tissues. Here we have examined the expression of PPAR-γ in ovarian tumors and the cellular and molecular consequences of its activation in ovarian cancer cells. PPAR-γ was expressed in a large number of epithelial ovarian tumors and cell lines. The PPAR-γ li...

  10. Fast intracellular dissolution and persistent cellular uptake of silver nanoparticles in CHO-K1 cells: implication for cytotoxicity

    DEFF Research Database (Denmark)

    Jiang, Xiumei; Miclaus, Teodora; Wang, Liming;

    2015-01-01

    Toxicity of silver nanoparticles (Ag NPs) has been reported both in vitro and in vivo. However, the intracellular stability and chemical state of Ag NPs are still not very well studied. In this work, we systematically investigated the cellular uptake pathways, intracellular dissolution and chemical...... species, and cytotoxicity of Ag NPs (15.9 ± 7.6 nm) in Chinese hamster ovary cell subclone K1 cells, a cell line recommended by the OECD for genotoxicity studies. Quantification of intracellular nanoparticle uptake and ion release was performed through inductively coupled plasma mass spectrometry. X...

  11. Transcriptional control of fungal cell cycle and cellular events by Fkh2, a forkhead transcription factor in an insect pathogen

    OpenAIRE

    Wang, Juan-juan; Qiu, Lei; Cai, Qing; Ying, Sheng-Hua; Feng, Ming-Guang

    2015-01-01

    Transcriptional control of the cell cycle by forkhead (Fkh) transcription factors is likely associated with fungal adaptation to host and environment. Here we show that Fkh2, an ortholog of yeast Fkh1/2, orchestrates cell cycle and many cellular events of Beauveria bassiana, a filamentous fungal insect pathogen. Deletion of Fkh2 in B. bassiana resulted in dramatic down-regulation of the cyclin-B gene cluster and hence altered cell cycle (longer G2/M and S, but shorter G0/G1, phases) in unicel...

  12. Myocardin inhibits cellular proliferation by inhibiting NF-κB(p65)-dependent cell cycle progression

    OpenAIRE

    Tang, Ru-hang; Zheng, Xi-Long; Callis, Thomas E.; Stansfield, William E.; He, Jiayin; Baldwin, Albert S.; Wang, Da-Zhi; Selzman, Craig H.

    2008-01-01

    We previously reported the importance of the serum response factor (SRF) cofactor myocardin in controlling muscle gene expression as well as the fundamental role for the inflammatory transcription factor NF-κB in governing cellular fate. Inactivation of myocardin has been implicated in malignant tumor growth. However, the underlying mechanism of myocardin regulation of cellular growth remains unclear. Here we show that NF-κB(p65) represses myocardin activation of cardiac and smooth muscle gen...

  13. Relief of delayed oxidative stress by ascorbic acid can suppress radiation-induced cellular senescence in mammalian fibroblast cells.

    Science.gov (United States)

    Kobashigawa, Shinko; Kashino, Genro; Mori, Hiromu; Watanabe, Masami

    2015-03-01

    Ionizing radiation-induced cellular senescence is thought to be caused by nuclear DNA damage that cannot be repaired. However, here we found that radiation induces delayed increase of intracellular oxidative stress after irradiation. We investigated whether the relief of delayed oxidative stress by ascorbic acid would suppress the radiation-induced cellular senescence in Syrian golden hamster embryo (SHE) cells. We observed that the level of oxidative stress was drastically increased soon after irradiation, then declined to the level in non-irradiated cells, and increased again with a peak on day 3 after irradiation. We found that the inductions of cellular senescence after X-irradiation were reduced along with suppression of the delayed induction of oxidative stress by treatment with ascorbic acid, but not when oxidative stress occurred immediately after irradiation. Moreover, treatment of ascorbic acid inhibited p53 accumulation at 3 days after irradiation. Our data suggested a delayed increase of intracellular oxidative stress levels plays an important role in the process of radiation-induced cellular senescence by p53 accumulation.

  14. An improved Cellular Automata model to simulate the behavior of high density crowd and validation by experimental data

    Science.gov (United States)

    Feliciani, Claudio; Nishinari, Katsuhiro

    2016-06-01

    In this article we present an improved version of the Cellular Automata floor field model making use of a sub-mesh system to increase the maximum density allowed during simulation and reproduce phenomena observed in dense crowds. In order to calibrate the model's parameters and to validate it we used data obtained from an empirical observation of bidirectional pedestrian flow. A good agreement was found between numerical simulation and experimental data and, in particular, the double outflow peak observed during the formation of deadlocks could be reproduced in numerical simulations, thus allowing the analysis of deadlock formation and dissolution. Finally, we used the developed high density model to compute the flow-ratio dependent fundamental diagram of bidirectional flow, demonstrating the instability of balanced flow and predicting the bidirectional flow behavior at very high densities. The model we presented here can be used to prevent dense crowd accidents in the future and to investigate the dynamics of the accidents which already occurred in the past. Additionally, fields such as granular and active matter physics may benefit from the developed framework to study different collective phenomena.

  15. In vivo and in vitro analysis of age-associated changes and somatic cellular senescence in renal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Birgit Berkenkamp

    Full Text Available Acute kidney injury is a major clinical problem and advanced age is associated with ineffective renal regeneration and poor functional outcome. Data from kidney injury models suggest that a loss of tubular epithelial proliferation contributes to a decrease in renal repair capacity with aging, but aging can also lead to a higher severity of inflammation and damage which may influence repair. In this study we tested intrinsic age-dependent changes in tubular epithelial proliferation in young and old mice, by injecting low-dose lead acetate as a non-injurious mitogen. In parallel, we explored in vitro techniques of studying cellular senescence in primary tubular epithelial cells (PTEC. Lead acetate induced tubular epithelial proliferation at a significantly higher rate in young as compared to old mice. Old kidneys showed significantly more senescence as demonstrated by increased p16 (INK4a, senescence associated β-galactosidase, and γH2AX(+/Ki-67(- cells. This was paralleled in old kidneys by a higher number of Cyclin D1 positive tubular cells. This finding was corroborated by a positive correlation between Cyclin D1 positivity and age in human renal biopsies. When tubular cells were isolated from mouse kidneys they rapidly lost their age-associated differences under culture conditions. However, senescence was readily induced in PTEC by γ-irradiation representing a future model for study of cellular senescence in the renal epithelium. Together, our data indicate that the tubular epithelium of aged kidney has an intrinsically reduced proliferative capacity probably due to a higher load of senescent cells. Moreover, stress induced models of cellular senescence are preferable for study of the renal epithelium in vitro. Finally, the positive correlation of Cyclin D1 with age and cellular senescence in PTEC needs further evaluation as to a functional role of renal epithelial aging.

  16. Expression kinetics of hepatic progenitor markers in cellular models of human liver development recapitulating hepatocyte and biliary cell fate commitment.

    Science.gov (United States)

    Chaudhari, Pooja; Tian, Lipeng; Deshmukh, Abhijeet; Jang, Yoon-Young

    2016-09-01

    Due to the limitations of research using human embryos and the lack of a biological model of human liver development, the roles of the various markers associated with liver stem or progenitor cell potential in humans are largely speculative, and based on studies utilizing animal models and certain patient tissues. Human pluripotent stem cell-based in vitro multistage hepatic differentiation systems may serve as good surrogate models for mimicking normal human liver development, pathogenesis and injury/regeneration studies. Here, we describe the implications of various liver stem or progenitor cell markers and their bipotency (i.e. hepatocytic- and biliary-epithelial cell differentiation), based on the pluripotent stem cell-derived model of human liver development. Future studies using the human cellular model(s) of liver and biliary development will provide more human relevant biological and/or pathological roles of distinct markers expressed in heterogeneous liver stem/progenitor cell populations.

  17. Role of vascular endothelial growth factor in the stimulation of cellular invasion and signaling of breast cancer cells.

    Science.gov (United States)

    Price, D J; Miralem, T; Jiang, S; Steinberg, R; Avraham, H

    2001-03-01

    The expression of vascular endothelial growth factor (VEGF) by breast tumors has been previously correlated with a poor prognosis in the pathogenesis of breast cancer. Furthermore, VEGF secretion is a prerequisite for tumor development. Although most of the effects of VEGF have been shown to be attributable to the stimulation of endothelial cells, we present evidence here that breast tumor cells are capable of responding to VEGF. We show that VEGF stimulation of T-47D breast cancer cells leads to changes in cellular signaling and invasion. VEGF increases the cellular invasion of T-47D breast cancer cells on Matrigel/ fibronectin-coated transwell membranes by a factor of two. Northern analysis for the expression of the known VEGF receptors shows the presence of moderate levels of Flt-1 and low levels of Flk-1/KDR mRNAs in a variety of breast cancer cell lines. T-47D breast cancer cells bind 125I-labeled VEGF with a Kd of 13 x 10(-9) M. VEGF induces the activation of the extracellular regulated kinases 1,2 as well as activation of phosphatidylinositol 3'-kinase, Akt, and Forkhead receptor L1. These findings in T-47D breast cancer cells strongly suggest an autocrine role for VEGF contributing to the tumorigenic phenotype.

  18. Specific cellular accumulation of photofrin-II in EC cells promotes photodynamic treatment efficacy in esophageal cancer.

    Science.gov (United States)

    Gao, Shegan; Liang, Shuo; Ding, Kaili; Qu, Zhifeng; Wang, Ying; Feng, Xiaoshan

    2016-06-01

    Photodynamic therapy (PDT), which uses a light-sensitive compound and laser irradiation, is a light-based oncological treatment modality. PDT offers an alternative, less invasive treatment for various malignant tumors, such as esophageal cancer (EC), through a photochemical reaction induced by photofrin-II or other oncotropic photosensitizers without severe complications. Previous studies has shown that cancerous tissues accumulated more photosensitizers than paired normal tissues, however, whether it is cellular or vascular mechanisms remains unknown. Herein, in vivo and in vitro examinations were performed to study the mechanisms by which photofrin-II effectively and specifically killed EC cells. In this study, EC tissue of patients treated with photofrin-II, human ESCC cellline SHEEC and parental normal cellline SHEE, primary culture cells of EC tissue were used. The concentration of photofrin-II in cells were evaluated by high-performance liquid chromatography (HPLC). The results exhibited that accumulation of photofrin-II in cancerous cells were significantly higher than that in non-cancerous cells (p<0.05) under certain dose and time period of incubation of photofrin-II. In summary, our study showed that, photofrin-II specifically accumulated in EC cells in vivo and in vitro after controlling for vascular factors, which provided strong evidence that maybe the cellular factor is the main mechanism by which photofrin-II-mediated PDT selectively caused EC cells death. PMID:26829562

  19. Serratia marcescens suppresses host cellular immunity via the production of an adhesion-inhibitory factor against immunosurveillance cells.

    Science.gov (United States)

    Ishii, Kenichi; Adachi, Tatsuo; Hamamoto, Hiroshi; Sekimizu, Kazuhisa

    2014-02-28

    Injection of a culture supernatant of Serratia marcescens into the bloodstream of the silkworm Bombyx mori increased the number of freely circulating immunosurveillance cells (hemocytes). Using a bioassay with live silkworms, serralysin metalloprotease was purified from the culture supernatant and identified as the factor responsible for this activity. Serralysin inhibited the in vitro attachment of both silkworm hemocytes and murine peritoneal macrophages. Incubation of silkworm hemocytes or murine macrophages with serralysin resulted in degradation of the cellular immune factor BmSPH-1 or calreticulin, respectively. Furthermore, serralysin suppressed in vitro phagocytosis of bacteria by hemocytes and in vivo bacterial clearance in silkworms. Disruption of the ser gene in S. marcescens attenuated its host killing ability in silkworms and mice. These findings suggest that serralysin metalloprotease secreted by S. marcescens suppresses cellular immunity by decreasing the adhesive properties of immunosurveillance cells, thereby contributing to bacterial pathogenesis.

  20. Cross acclimation between heat and hypoxia: Heat acclimation improves cellular tolerance and exercise performance in acute normobaric hypoxia

    Directory of Open Access Journals (Sweden)

    Ben James Lee

    2016-03-01

    Full Text Available Background. The potential for cross acclimation between environmental stressors is not well understood. Thus the aim of this investigation was to determine the effect of fixed-workload heat or hypoxic acclimation on cellular, physiological and performance responses during post acclimation hypoxic exercise in humans. Method. Twenty-one males (age 22 ± 5 years; stature 1.76 ± 0.07m; mass 71.8 ± 7.9kg; V ̇O2 peak 51 ± 7mL.kg-1.min-1 completed a cycling hypoxic stress test (HST and self-paced 16.1km time trial (TT before (HST1, TT1, and after (HST2, TT2 a series of 10 daily 60 min training sessions (50% N V ̇O2peak in control (CON, n = 7; 18°C, 35%RH, hypoxic (HYP, n = 7; or hot (HOT, n = 7; 40°C, 25% RH conditions. Results. TT performance in hypoxia was improved following both acclimation treatments, HYP (-3:16 ± 3:10 mins:sec; p = 0.0006 and HOT (-2:02 ± 1:02 mins:sec; p = 0.005, but unchanged after CON (+0:31 ± 1:42 mins:sec. Resting monocyte heat shock protein 72 (mHSP72 increased prior to HST2 in HOT (62 ± 46% and HYP (58 ± 52%, but was unchanged after CON (9 ± 46%, leading to an attenuated mHSP72 response to hypoxic exercise in HOT and HYP HST2 compared to HST1 (p < 0.01. Changes in extracellular hypoxia-inducible factor 1-α followed a similar pattern to those of mHSP72. Physiological strain index (PSI was attenuated in HOT (HST1 = 4.12 ± 0.58, HST2 = 3.60 ± 0.42; p = 0.007 as a result of a reduced HR (HST1 = 140 ± 14 b.min-1; HST2 131 ± 9 b.min-1 p = 0.0006 and Trectal (HST1 = 37.55 ± 0.18°C; HST2 37.45 ± 0.14°C; p = 0.018 during exercise. Whereas PSI did not change in HYP (HST1 = 4.82 ± 0.64, HST2 4.83 ± 0.63. Conclusion. Heat acclimation improved cellular and systemic physiological tolerance to steady state exercise in moderate hypoxia. Additionally we show, for the first time, that heat acclimation improved cycling time trial performance to a magnitude similar to that achieved by hypoxic acclimation.

  1. Reconstitution of the cellular response to DNA damage in vitro using damage-activated extracts from mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Roper, Katherine; Coverley, Dawn, E-mail: dc17@york.ac.uk

    2012-03-10

    In proliferating mammalian cells, DNA damage is detected by sensors that elicit a cellular response which arrests the cell cycle and repairs the damage. As part of the DNA damage response, DNA replication is inhibited and, within seconds, histone H2AX is phosphorylated. Here we describe a cell-free system that reconstitutes the cellular response to DNA double strand breaks using damage-activated cell extracts and naieve nuclei. Using this system the effect of damage signalling on nuclei that do not contain DNA lesions can be studied, thereby uncoupling signalling and repair. Soluble extracts from G1/S phase cells that were treated with etoposide before isolation, or pre-incubated with nuclei from etoposide-treated cells during an in vitro activation reaction, restrain both initiation and elongation of DNA replication in naieve nuclei. At the same time, H2AX is phosphorylated in naieve nuclei in a manner that is dependent upon the phosphatidylinositol 3-kinase-like protein kinases. Notably, phosphorylated H2AX is not focal in naieve nuclei, but is evident throughout the nucleus suggesting that in the absence of DNA lesions the signal is not amplified such that discrete foci can be detected. This system offers a novel screening approach for inhibitors of DNA damage response kinases, which we demonstrate using the inhibitors wortmannin and LY294002. -- Highlights: Black-Right-Pointing-Pointer A cell free system that reconstitutes the response to DNA damage in the absence of DNA lesions. Black-Right-Pointing-Pointer Damage-activated extracts impose the cellular response to DNA damage on naieve nuclei. Black-Right-Pointing-Pointer PIKK-dependent response impacts positively and negatively on two separate fluorescent outputs. Black-Right-Pointing-Pointer Can be used to screen for inhibitors that impact on the response to damage but not on DNA repair. Black-Right-Pointing-Pointer LY294002 and wortmannin demonstrate the system's potential as a pathway focused screening

  2. [Cellular distribution and behavior of metallothionein in mammalian cells following exposure to silver nanoparticles and silver ions].

    Science.gov (United States)

    Miyayama, Takamitsu; Arai, Yuta; Suzuki, Noriyuki; Hirano, Seishiro

    2014-01-01

    Silver nanoparticles (AgNPs) are commercially used mainly as antibacterial reagents in wound dressing and deodorant powders. However, the mechanisms underlying Ag toxicity in mammals are not fully understood. In the present study, we assessed cellular distribution and toxicity of AgNPs and AgNO3 in mouse macrophage cell line (J774.1) and those of AgNO3 in human bronchial epithelial cell line (BEAS-2B) focusing on behavior of metallothionein (MT). J774.1 cells were exposed to 0-100 μg Ag/mL AgNPs or AgNO3 and BEAS-2B cells were exposed to 0-100 μM AgNO3 for 24 h. The cytotoxicity was assayed by a modified MTT method. The cellular concentration and distribution of Ag were evaluated by inductively coupled plasma-mass spectorometry (ICP-MS) and laser scanning microscopy. Distribution of Ag to MT and other proteins was determined using HPLC-ICP-MS. Most AgNPs were found in lysosomes in J774.1 at 3 h after post exposure. Ag was distributed to high molecular weight proteins in AgNPs-exposed cells, while most Ag was bound to MT in AgNO3-exposed cells. In AgNO3-exposed BEAS-2B cells cellular Ag concentration and Ag-bound MT (Ag-MT) were sharply increased up to 3 h and then decreased. ROS production appeared to cause relocation of MT-bound Ag to mitochondria, which evoked inhibition of electron transport chain. AgNPs were sequestered by high-molecular weight proteins rather than MT, probably because they were taken up by lysosomes before induction of MT.

  3. Reconstitution of the cellular response to DNA damage in vitro using damage-activated extracts from mammalian cells

    International Nuclear Information System (INIS)

    In proliferating mammalian cells, DNA damage is detected by sensors that elicit a cellular response which arrests the cell cycle and repairs the damage. As part of the DNA damage response, DNA replication is inhibited and, within seconds, histone H2AX is phosphorylated. Here we describe a cell-free system that reconstitutes the cellular response to DNA double strand breaks using damage-activated cell extracts and naïve nuclei. Using this system the effect of damage signalling on nuclei that do not contain DNA lesions can be studied, thereby uncoupling signalling and repair. Soluble extracts from G1/S phase cells that were treated with etoposide before isolation, or pre-incubated with nuclei from etoposide-treated cells during an in vitro activation reaction, restrain both initiation and elongation of DNA replication in naïve nuclei. At the same time, H2AX is phosphorylated in naïve nuclei in a manner that is dependent upon the phosphatidylinositol 3-kinase-like protein kinases. Notably, phosphorylated H2AX is not focal in naïve nuclei, but is evident throughout the nucleus suggesting that in the absence of DNA lesions the signal is not amplified such that discrete foci can be detected. This system offers a novel screening approach for inhibitors of DNA damage response kinases, which we demonstrate using the inhibitors wortmannin and LY294002. -- Highlights: ► A cell free system that reconstitutes the response to DNA damage in the absence of DNA lesions. ► Damage-activated extracts impose the cellular response to DNA damage on naïve nuclei. ► PIKK-dependent response impacts positively and negatively on two separate fluorescent outputs. ► Can be used to screen for inhibitors that impact on the response to damage but not on DNA repair. ► LY294002 and wortmannin demonstrate the system's potential as a pathway focused screening approach.

  4. Multi-cellular rosettes in the mouse visceral endoderm facilitate the ordered migration of anterior visceral endoderm cells.

    Directory of Open Access Journals (Sweden)

    Georgios Trichas

    2012-02-01

    Full Text Available The visceral endoderm (VE is a simple epithelium that forms the outer layer of the egg-cylinder stage mouse embryo. The anterior visceral endoderm (AVE, a specialised subset of VE cells, is responsible for specifying anterior pattern. AVE cells show a stereotypic migratory behaviour within the VE, which is responsible for correctly orientating the anterior-posterior axis. The epithelial integrity of the VE is maintained during the course of AVE migration, which takes place by intercalation of AVE and other VE cells. Though a continuous epithelial sheet, the VE is characterised by two regions of dramatically different behaviour, one showing robust cell movement and intercalation (in which the AVE migrates and one that is static, with relatively little cell movement and mixing. Little is known about the cellular rearrangements that accommodate and influence the sustained directional movement of subsets of cells (such as the AVE within epithelia like the VE. This study uses an interdisciplinary approach to further our understanding of cell movement in epithelia. Using both wild-type embryos as well as mutants in which AVE migration is abnormal or arrested, we show that AVE migration is specifically linked to changes in cell packing in the VE and an increase in multi-cellular rosette arrangements (five or more cells meeting at a point. To probe the role of rosettes during AVE migration, we develop a mathematical model of cell movement in the VE. To do this, we use a vertex-based model, implemented on an ellipsoidal surface to represent a realistic geometry for the mouse egg-cylinder. The potential for rosette formation is included, along with various junctional rearrangements. Simulations suggest that while rosettes are not essential for AVE migration, they are crucial for the orderliness of this migration observed in embryos. Our simulations are similar to results from transgenic embryos in which Planar Cell Polarity (PCP signalling is disrupted

  5. Cellular Architecture of Treponema pallidum: Novel Flagellum, Periplasmic Cone, and Cell Envelope as Revealed by Cryo-Electron Tomography

    OpenAIRE

    Liu, Jun; Howell, Jerrilyn K.; Bradley, Sherille D.; Zheng, Yesha; Zhou, Z. Hong; Norris, Steven J

    2010-01-01

    High resolution cryo-electron tomography (cryo-ET) was utilized to visualize Treponema pallidum, the causative agent of syphilis, at the molecular level. Three-dimensional (3-D) reconstructions from 304 infectious organisms revealed unprecedented cellular structures of this unusual member in the spirochetal family. High resolution cryo-ET reconstructions provided the detailed structures of the cell envelope, which is significantly different from that of gram-negative bacteria. The 4 nm lipid ...

  6. Revisions to Exceptions Applicable to Certain Human Cells, Tissues, and Cellular and Tissue-Based Products. Final rule.

    Science.gov (United States)

    2016-06-22

    : The Food and Drug Administration (FDA or Agency or we) is issuing this final rule to amend certain regulations regarding donor eligibility, including the screening and testing of donors of particular human cells, tissues, and cellular and tissue-based products (HCT/Ps), and related labeling. This final rule is in response to our enhanced understanding in this area and in response to comments from stakeholders regarding the importance of embryos to individuals and couples seeking access to donated embryos.

  7. Increased cellular uptake of biocompatible superparamagnetic iron oxide nanoparticles into malignant cells by an external magnetic field.

    Science.gov (United States)

    Prijic, Sara; Scancar, Janez; Romih, Rok; Cemazar, Maja; Bregar, Vladimir B; Znidarsic, Andrej; Sersa, Gregor

    2010-07-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) are used as delivery systems for different therapeutics including nucleic acids for magnetofection-mediated gene therapy. The aim of our study was to evaluate physicochemical properties, biocompatibility, cellular uptake and trafficking pathways of the custom-synthesized SPIONs for their potential use in magnetofection. Custom-synthesized SPIONs were tested for size, shape, crystalline composition and magnetic behavior using a transmission electron microscope, X-ray diffractometer and magnetometer. SPIONs were dispersed in different aqueous media to obtain ferrofluids, which were tested for pH and stability using a pH meter and zetameter. Cytotoxicity was determined using the MTS and clonogenic assays. Cellular uptake and trafficking pathways were qualitatively evaluated by transmission electron microscopy and quantitatively by inductively coupled plasma atomic emission spectrometry. SPIONs were composed of an iron oxide core with a diameter of 8-9 nm, coated with a 2-nm-thick layer of silica. SPIONs, dispersed in 0.9% NaCl solution, resulted in a stable ferrofluid at physiological pH for several months. SPIONs were not cytotoxic in a broad range of concentrations and were readily internalized into different cells by endocytosis. Exposure to neodymium-iron-boron magnets significantly increased the cellular uptake of SPIONs, predominantly into malignant cells. The prepared SPIONs displayed adequate physicochemical and biomedical properties for potential use in magnetofection. Their cellular uptake was dependent on the cell type, and their accumulation within the cells was dependent on the duration of exposure to an external magnetic field. PMID:20602230

  8. Cellular uptake of 125I-mIBG and of 111In-pentetreotide by human neuroblastoma cells in culture

    International Nuclear Information System (INIS)

    Aim. Neuroblastoma have various prognosis, leading or not to heavy therapeutics. MIBG scan is the reference for assessment of the disease extent, but somatostatin analogs are promising as somatostatin receptors expression might indicate neuroendocrine tumoral cell differentiation. The aim of our study was to establish an experimental model to assess cellular uptake of 125I-meta-iodo-benzyl-guanidine (125I-mIBG) and of 111In pentetreotide (111In-OCT), by neuroblastoma cells culture. Material and methods. We compared the uptake of these tracers by SK-N-SH human neuroblastoma cell line in monolayer culture. After cell characterization, toxicity of ligands and of their competitive inhibitors was studied. Experiments with separate incubation of each tracer, using different times and concentrations, determined optimal conditions, which were then applied to simultaneous incubation studies. Results. Total uptakes after simultaneous 3 h-incubation with 125I-mIBG (106 M) and 111In-OCT (108 M) (respectively 3.5 % and 0.03 % of administered activity per 105 cells) were not different from total uptake with separate incubation. Conclusions. Our results confirms the validity of the methodology which is now under use to study the influence of cell differentiation on cellular uptake. (authors)

  9. Detection and Analysis of Cell Cycle-Associated APC/C-Mediated Cellular Ubiquitylation In Vitro and In Vivo.

    Science.gov (United States)

    Cedeño, Cesyen; La Monaca, Esther; Esposito, Mara; Gutierrez, Gustavo J

    2016-01-01

    The anaphase-promoting complex or cyclosome (APC/C) is one of the major orchestrators of the cell division cycle in mammalian cells. The APC/C acts as a ubiquitin ligase that triggers sequential ubiquitylation of a significant number of substrates which will be eventually degraded by proteasomes during major transitions of the cell cycle. In this chapter, we present accessible methodologies to assess both in in vitro conditions and in cellular systems ubiquitylation reactions mediated by the APC/C. In addition, we also describe techniques to evidence the changes in protein stability provoked by modulation of the activity of the APC/C. Finally, specific methods to analyze interactors or posttranslational modifications of particular APC/C subunits are also discussed. Given the crucial role played by the APC/C in the regulation of the cell cycle, this review only focuses on its action and effects in actively proliferating cells. PMID:27613041

  10. Increased cellular hypoxia and reduced proliferation of both normal and leukaemic cells during progression of acute myeloid leukaemia in rats

    DEFF Research Database (Denmark)

    Jensen, P O; Mortensen, B T; Hodgkiss, R J;

    2000-01-01

    The microenvironmental changes in the bone marrow, spleen and liver during progression of the transplantable promyelocytic leukaemia in the Brown Norwegian rat (BNML) have been studied. We used flow cytometry to estimate cellular hypoxia and proliferation based on in vivo pulse...... in the bone marrow and liver, reaching a level of 65-87% in these organs at day 32. At day 32, the NITP+ fraction of RM124+ cells had increased significantly in the bone marrow and spleen to 88% and 90%, respectively. The corresponding fractions of NITP+ normal cells reached 63% and 65%, respectively. From......-labelling with a mixture of 2-nitroimidazole linked to theophylline (NITP) and bromodeoxyuridine (BrdUrd). The leukaemic cells were identified with the RM124 antibody. In rats inoculated with leukaemic cells the fraction of RM124+ cells was significantly increased from day 20 onwards in the spleen and from day 27...

  11. Improved cell activity on biodegradable photopolymer scaffolds using titanate nanotube coatings

    International Nuclear Information System (INIS)

    The development of bioactive materials is in the premise of tissue engineering. For several years, surface functionalization of scaffolds has been one of the most promising approaches to stimulate cellular activity and finally improve implant success. Herein, we describe the development of a bioactive composite scaffold composed of a biodegradable photopolymer scaffold and titanate nanotubes (TNTs). The biodegradable photopolymer scaffolds were fabricated by applying mask-projection excimer laser photocuring at 308 nm. TNTs were synthesized and then spin-coated on the porous scaffolds. Upon culturing fibroblast cells on scaffolds, we found that nanotubes coating affects cell viability and proliferation demonstrating that TNT coatings enhance cell growth on the scaffolds by further improving their surface topography. - Highlights: • Biodegradable scaffolds were produced by mask-assisted UV laser photocuring. • Titanate nanotube deposition was carried out without binding compounds or additives. • Titanate nanotube coatings enhanced cell viability and proliferation

  12. Improved cell activity on biodegradable photopolymer scaffolds using titanate nanotube coatings

    Energy Technology Data Exchange (ETDEWEB)

    Beke, S., E-mail: szabolcs.beke@iit.it [Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova (Italy); Barenghi, R. [IEIIT, National Research Council (CNR), Via De Marini 6, 16149 Genova (Italy); Farkas, B.; Romano, I. [Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova (Italy); Kőrösi, L. [Department of Biotechnology, Nanophage Therapy Center, Enviroinvest Corporation, Kertváros u. 2, H-7632 Pécs (Hungary); Scaglione, S. [IEIIT, National Research Council (CNR), Via De Marini 6, 16149 Genova (Italy); Brandi, F. [Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova (Italy); Istituto Nazionale di Ottica, CNR, Via G. Moruzzi 1, 56124-Pisa (Italy)

    2014-11-01

    The development of bioactive materials is in the premise of tissue engineering. For several years, surface functionalization of scaffolds has been one of the most promising approaches to stimulate cellular activity and finally improve implant success. Herein, we describe the development of a bioactive composite scaffold composed of a biodegradable photopolymer scaffold and titanate nanotubes (TNTs). The biodegradable photopolymer scaffolds were fabricated by applying mask-projection excimer laser photocuring at 308 nm. TNTs were synthesized and then spin-coated on the porous scaffolds. Upon culturing fibroblast cells on scaffolds, we found that nanotubes coating affects cell viability and proliferation demonstrating that TNT coatings enhance cell growth on the scaffolds by further improving their surface topography. - Highlights: • Biodegradable scaffolds were produced by mask-assisted UV laser photocuring. • Titanate nanotube deposition was carried out without binding compounds or additives. • Titanate nanotube coatings enhanced cell viability and proliferation.

  13. pH effect on cellular uptake of Sn(IV) chlorine e6 dichloride trisodium salt by cancer cells in vitro.

    Science.gov (United States)

    Al-Khaza'leh, Khaled A; Omar, Khalid; Jaafar, M S

    2011-01-01

    The effects of pH value and presence of serum in an incubation medium on photosensitizer drug cellular uptake in MCF7 cancer cells have been investigated. The results showed that the presence of serum in an incubation medium reduced the drug cellular uptake at all pH values. It has been found that decreasing on pH values of the incubation medium increased the cellular uptake of the drug, demonstrating selective uptake of the sensitizer. The HepG2 liver cancer cells exhibited more drug cellular uptake than CCD-18CO normal colon cells, which assessed the selectivity uptake of photosensitizer on cancerous cells. The concentration of photosensitizer measured in 10(6) cells showed a good correlation to the incubation time. Fluorescence and absorption spectroscopy been have used to examine the cells. PMID:22210969

  14. Calcium citrate improves the epithelial-to-mesenchymal transition induced by acidosis in proximal tubular cells

    Directory of Open Access Journals (Sweden)

    Maria José Rodriguez Cabalgante

    2012-12-01

    Full Text Available INTRODUCTION: Epithelial-to-mesenchymal transition (EMT is a key event in renal fibrosis. The aims of the study were to evaluate acidosis induced EMT, transforming-growth-factor (TGF β1 role and citrate effect on it. METHODS: HK2 cells (ATCC 2290 were cultured in DMEM/HAM F12 medium, pH 7.4. At 80% confluence, after 24 hr under serum free conditions, cells were distributed in three groups (24 hours: A Control: pH 7.4, B Acidosis: pH 7.0 and C Calcium citrate (0.2 mmol/L + pH 7.0. Change (Δ of intracellular calcium concentration, basal and after Angiotensin II (10-6M exposition, were measured to evaluate cellular performance. EMT was evaluated by the expression of α-smooth muscle actin (α-SMA and E-cadherin by immunocytochemistry and/or Western blot. TGF-β1 secretion was determined by ELISA in cell supernatant. RESULTS: At pH 7.0 HK2 cells significantly reduced E-cadherin and increased α-SMA expression (EMT. Supernatant TGF-β1 levels were higher than in control group. Calcium citrate decreased acidosis induced EMT and improved cells performance, without reduction of TGF-β production. CONCLUSIONS: Acidosis induces EMT and secretion of TGF-β1 in tubular proximal cells in culture and citrate improves cellular performance and ameliorates acidosis induced EMT.

  15. Awakened by cellular stress: isolation and characterization of a novel population of pluripotent stem cells derived from human adipose tissue.

    Directory of Open Access Journals (Sweden)

    Saleh Heneidi

    Full Text Available Advances in stem cell therapy face major clinical limitations, particularly challenged by low rates of post-transplant cell survival. Hostile host factors of the engraftment microenvironment such as hypoxia, nutrition deprivation, pro-inflammatory cytokines, and reactive oxygen species can each contribute to unwanted differentiation or apoptosis. In this report, we describe the isolation and characterization of a new population of adipose tissue (AT derived pluripotent stem cells, termed Multilineage Differentiating Stress-Enduring (Muse Cells, which are isolated using severe cellular stress conditions, including long-term exposure to the proteolytic enzyme collagenase, serum deprivation, low temperatures and hypoxia. Under these conditions, a highly purified population of Muse-AT cells is isolated without the utilization of cell sorting methods. Muse-AT cells grow in suspension as cell spheres reminiscent of embryonic stem cell clusters. Muse-AT cells are positive for the pluripotency markers SSEA3, TR-1-60, Oct3/4, Nanog and Sox2, and can spontaneously differentiate into mesenchymal, endodermal and ectodermal cell lineages with an efficiency of 23%, 20% and 22%, respectively. When using specific differentiation media, differentiation efficiency is greatly enhanced in Muse-AT cells (82% for mesenchymal, 75% for endodermal and 78% for ectodermal. When compared to adipose stem cells (ASCs, microarray data indicate a substantial up-regulation of Sox2, Oct3/4, and Rex1. Muse-ATs also exhibit gene expression patterns associated with the down-regulation of genes involved in cell death and survival, embryonic development, DNA replication and repair, cell cycle and potential factors related to oncogenecity. Gene expression analysis indicates that Muse-ATs and ASCs are mesenchymal in origin; however, Muse-ATs also express numerous lymphocytic and hematopoietic genes, such as CCR1 and CXCL2, encoding chemokine receptors and ligands involved in stem cell

  16. Cellular Interactions and Biological Responses to Titanium Dioxide Nanoparticles in HepG2 and BEAS-2B Cells: Role of Cell Culture Media

    Science.gov (United States)

    ABSTRACT We have shown previously that the composition of the biological medium used in vitro can affect the cellular interaction and biological response of titanium dioxide nanoparticles (nano-TiO2) in human lung epithelial cells. However, it is unclear if these effects are co...

  17. Involvement of oxygen reactive species in the cellular response of carcinoma cells to irradiation

    International Nuclear Information System (INIS)

    After a presentation of oxygen reactive species and their sources, the author describes the enzymatic and non-enzymatic anti-oxidative defenses, the physiological roles of oxygen reactive species, the oxidative stress, the water radiolysis, the anti-oxidative enzymes and the effects of ionizing radiations. The author then reports an investigation on the contribution of oxygen reactive species in the cellular response to irradiation, and an investigation on the influence of the breathing chain on the persistence of a radio-induced oxidative stress. He also reports a research on molecular mechanisms involved in the cellular radio-sensitivity

  18. Positively charged and pH self-buffering quantum dots for efficient cellular uptake by charge mediation and monitoring cell membrane permeability

    Energy Technology Data Exchange (ETDEWEB)

    Wang Suhua; Song Haipeng; Huang Dejian [Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543 (Singapore); Ong Weiyi [Department of Anatomy, National University of Singapore, 119260 (Singapore); Han Mingyong, E-mail: chmhdj@nus.edu.s [Institute of Materials Research and Engineering, 3 Research Link, 117602 (Singapore)

    2009-10-21

    Positively charged and pH self-buffering quantum dots (Tren-QDs) were achieved by surface functionalization with tris(2-aminoethyl)amine (Tren) derivatives, which are attached to the inorganic cores of QDs through bidentate chelating of dithiocarbamates. The Tren-QDs exhibit pH buffering capability by absorbing or releasing protons due to the surface polyamine groups as the surrounding pH fluctuates. Such self-buffering capability stabilizes the photoluminescence of the Tren-QDs against acid. The Tren-QDs bear positive charges through protonation of the surface polyamine groups under physiological conditions and the surface positive charges improve their cellular uptake efficiency by charge mediation, which has been demonstrated by BV-2 microglia cells. The photoluminescence of Tren-QDs shows a selective Stern-Volmer response to copper ions and this property has been preliminarily evaluated for investigating the BV-2 cell membrane structure by monitoring the photoluminescence of intracellular Tren-QDs.

  19. Positively charged and pH self-buffering quantum dots for efficient cellular uptake by charge mediation and monitoring cell membrane permeability

    Science.gov (United States)

    Wang, Suhua; Song, Haipeng; Ong, Wei Yi; Han, Ming Yong; Huang, Dejian

    2009-10-01

    Positively charged and pH self-buffering quantum dots (Tren-QDs) were achieved by surface functionalization with tris(2-aminoethyl)amine (Tren) derivatives, which are attached to the inorganic cores of QDs through bidentate chelating of dithiocarbamates. The Tren-QDs exhibit pH buffering capability by absorbing or releasing protons due to the surface polyamine groups as the surrounding pH fluctuates. Such self-buffering capability stabilizes the photoluminescence of the Tren-QDs against acid. The Tren-QDs bear positive charges through protonation of the surface polyamine groups under physiological conditions and the surface positive charges improve their cellular uptake efficiency by charge mediation, which has been demonstrated by BV-2 microglia cells. The photoluminescence of Tren-QDs shows a selective Stern-Volmer response to copper ions and this property has been preliminarily evaluated for investigating the BV-2 cell membrane structure by monitoring the photoluminescence of intracellular Tren-QDs.

  20. Positively charged and pH self-buffering quantum dots for efficient cellular uptake by charge mediation and monitoring cell membrane permeability

    International Nuclear Information System (INIS)

    Positively charged and pH self-buffering quantum dots (Tren-QDs) were achieved by surface functionalization with tris(2-aminoethyl)amine (Tren) derivatives, which are attached to the inorganic cores of QDs through bidentate chelating of dithiocarbamates. The Tren-QDs exhibit pH buffering capability by absorbing or releasing protons due to the surface polyamine groups as the surrounding pH fluctuates. Such self-buffering capability stabilizes the photoluminescence of the Tren-QDs against acid. The Tren-QDs bear positive charges through protonation of the surface polyamine groups under physiological conditions and the surface positive charges improve their cellular uptake efficiency by charge mediation, which has been demonstrated by BV-2 microglia cells. The photoluminescence of Tren-QDs shows a selective Stern-Volmer response to copper ions and this property has been preliminarily evaluated for investigating the BV-2 cell membrane structure by monitoring the photoluminescence of intracellular Tren-QDs.

  1. Cellular uptake mechanism and comparative evaluation of antineoplastic effects of paclitaxel–cholesterol lipid emulsion on triple-negative and non-triple-negative breast cancer cell lines

    Science.gov (United States)

    Ye, Jun; Xia, Xuejun; Dong, Wujun; Hao, Huazhen; Meng, Luhua; Yang, Yanfang; Wang, Renyun; Lyu, Yuanfeng; Liu, Yuling

    2016-01-01

    There is no effective clinical therapy for triple-negative breast cancers (TNBCs), which have high low-density lipoprotein (LDL) requirements and express relatively high levels of LDL receptors (LDLRs) on their membranes. In our previous study, a novel lipid emulsion based on a paclitaxel–cholesterol complex (PTX-CH Emul) was developed, which exhibited improved safety and efficacy for the treatment of TNBC. To date, however, the cellular uptake mechanism and intracellular trafficking of PTX-CH Emul have not been investigated. In order to offer powerful proof for the therapeutic effects of PTX-CH Emul, we systematically studied the cellular uptake mechanism and intracellular trafficking of PTX-CH Emul and made a comparative evaluation of antineoplastic effects on TNBC (MDA-MB-231) and non-TNBC (MCF7) cell lines through in vitro and in vivo experiments. The in vitro antineoplastic effects and in vivo tumor-targeting efficiency of PTX-CH Emul were significantly more enhanced in MDA-MB-231-based models than those in MCF7-based models, which was associated with the more abundant expression profile of LDLR in MDA-MB-231 cells. The results of the cellular uptake mechanism indicated that PTX-CH Emul was internalized into breast cancer cells through the LDLR-mediated internalization pathway via clathrin-coated pits, localized in lysosomes, and then released into the cytoplasm, which was consistent with the internalization pathway and intracellular trafficking of native LDL. The findings of this paper further confirm the therapeutic potential of PTX-CH Emul in clinical applications involving TNBC therapy. PMID:27601899

  2. Cellular uptake mechanism and comparative evaluation of antineoplastic effects of paclitaxel-cholesterol lipid emulsion on triple-negative and non-triple-negative breast cancer cell lines.

    Science.gov (United States)

    Ye, Jun; Xia, Xuejun; Dong, Wujun; Hao, Huazhen; Meng, Luhua; Yang, Yanfang; Wang, Renyun; Lyu, Yuanfeng; Liu, Yuling

    2016-01-01

    There is no effective clinical therapy for triple-negative breast cancers (TNBCs), which have high low-density lipoprotein (LDL) requirements and express relatively high levels of LDL receptors (LDLRs) on their membranes. In our previous study, a novel lipid emulsion based on a paclitaxel-cholesterol complex (PTX-CH Emul) was developed, which exhibited improved safety and efficacy for the treatment of TNBC. To date, however, the cellular uptake mechanism and intracellular trafficking of PTX-CH Emul have not been investigated. In order to offer powerful proof for the therapeutic effects of PTX-CH Emul, we systematically studied the cellular uptake mechanism and intracellular trafficking of PTX-CH Emul and made a comparative evaluation of antineoplastic effects on TNBC (MDA-MB-231) and non-TNBC (MCF7) cell lines through in vitro and in vivo experiments. The in vitro antineoplastic effects and in vivo tumor-targeting efficiency of PTX-CH Emul were significantly more enhanced in MDA-MB-231-based models than those in MCF7-based models, which was associated with the more abundant expression profile of LDLR in MDA-MB-231 cells. The results of the cellular uptake mechanism indicated that PTX-CH Emul was internalized into breast cancer cells through the LDLR-mediated internalization pathway via clathrin-coated pits, localized in lysosomes, and then released into the cytoplasm, which was consistent with the internalization pathway and intracellular trafficking of native LDL. The findings of this paper further confirm the therapeutic potential of PTX-CH Emul in clinical applications involving TNBC therapy. PMID:27601899

  3. Effects of toxic cellular stresses and divalent cations on the human P2X7 cell death receptor

    OpenAIRE

    Dutot, Mélody; Liang, Hong; Pauloin, Thierry; Brignole-Baudouin, Françoise; Baudouin, Christophe; Warnet, Jean-Michel; Rat, Patrice

    2008-01-01

    Purpose The purpose of this study was to investigate responses to toxic cellular stresses in different human ocular epithelia. Methods Reactivity with a specific anti-P2X7 antibody was studied using confocal fluorescence microscopy on conjunctival, corneal, lens, and retinal cell lines as well as using impression cytology on human ocular cells. Activation of the P2X7 receptor by selective agonists (ATP and benzoylbenzoyl-ATP) and inhibition by antagonists (oATP, KN-62, and PPADS) were evaluat...

  4. Integrated cellular systems

    Science.gov (United States)

    Harper, Jason C.

    The generation of new three-dimensional (3D) matrices that enable integration of biomolecular components and whole cells into device architectures, without adversely altering their morphology or activity, continues to be an expanding and challenging field of research. This research is driven by the promise that encapsulated biomolecules and cells can significantly impact areas as diverse as biocatalysis, controlled delivery of therapeutics, environmental and industrial process monitoring, early warning of warfare agents, bioelectronics, photonics, smart prosthetics, advanced physiological sensors, portable medical diagnostic devices, and tissue/organ replacement. This work focuses on the development of a fundamental understanding of the biochemical and nanomaterial mechanisms that govern the cell directed assembly and integration process. It was shown that this integration process relies on the ability of cells to actively develop a pH gradient in response to evaporation induced osmotic stress, which catalyzes silica condensation within a thin 3D volume surrounding the cells, creating a functional bio/nano interface. The mechanism responsible for introducing functional foreign membrane-bound proteins via proteoliposome addition to the silica-lipid-cell matrix was also determined. Utilizing this new understanding, 3D cellular immobilization capabilities were extended using sol-gel matrices endowed with glycerol, trehalose, and media components. The effects of these additives, and the metabolic phase of encapsulated S. cerivisiase cells, on long-term viability and the rate of inducible gene expression was studied. This enabled the entrapment of cells within a novel microfluidic platform capable of simultaneous colorimetric, fluorescent, and electrochemical detection of a single analyte, significantly improving confidence in the biosensor output. As a complementary approach, multiphoton protein lithography was utilized to engineer 3D protein matrices in which to

  5. Performance improvement of silicon solar cells by nanoporous silicon coating

    Directory of Open Access Journals (Sweden)

    Dzhafarov T. D.

    2012-04-01

    Full Text Available In the present paper the method is shown to improve the photovoltaic parameters of screen-printed silicon solar cells by nanoporous silicon film formation on the frontal surface of the cell using the electrochemical etching. The possible mechanisms responsible for observed improvement of silicon solar cell performance are discussed.

  6. Adult Bone Marrow: Which Stem Cells for Cellular Therapy Protocols in Neurodegenerative Disorders?

    OpenAIRE

    Sabine Wislet-Gendebien; Emerence Laudet; Virginie Neirinckx; Bernard Rogister

    2012-01-01

    The generation of neuronal cells from stem cells obtained from adult bone marrow is of significant clinical interest in order to design new cell therapy protocols for several neurological disorders. The recent identification in adult bone marrow of stem cells derived from the neural crests (NCSCs) might explain the neuronal phenotypic plasticity shown by bone marrow cells. However, little information is available about the nature of these cells compared to mesenchymal stem cells (MSCs). In th...

  7. A systemic approach to explore the flexibility of energy stores at the cellular scale: Examples from muscle cells.

    Science.gov (United States)

    Taghipoor, Masoomeh; van Milgen, Jaap; Gondret, Florence

    2016-09-01

    Variations in energy storage and expenditure are key elements for animals adaptation to rapidly changing environments. Because of the multiplicity of metabolic pathways, metabolic crossroads and interactions between anabolic and catabolic processes within and between different cells, the flexibility of energy stores in animal cells is difficult to describe by simple verbal, textual or graphic terms. We propose a mathematical model to study the influence of internal and external challenges on the dynamic behavior of energy stores and its consequence on cell energy status. The role of the flexibility of energy stores on the energy equilibrium at the cellular level is illustrated through three case studies: variation in eating frequency (i.e., glucose input), level of physical activity (i.e., ATP requirement), and changes in cell characteristics (i.e., maximum capacity of glycogen storage). Sensitivity analysis has been performed to highlight the most relevant parameters of the model; model simulations have then been performed to illustrate how variation in these key parameters affects cellular energy balance. According to this analysis, glycogen maximum accumulation capacity and homeostatic energy demand are among the most important parameters regulating muscle cell metabolism to ensure its energy equilibrium. PMID:27338303

  8. Cellular development of the human cochlea and the regenerative potential of hair follicle bulge stem cells

    NARCIS (Netherlands)

    Locher, heiko

    2015-01-01

    The embryonic development of the human cochlea (the organ of hearing) has been investigated for over one hundred years. However, little is still known about the development on a cellular and protein level, which is important to better understand etiologies and pathologies of various types of sensori

  9. Cellular cooperation during in vivo anti-hapten antibody responses. I. The effect of cell number on the response

    International Nuclear Information System (INIS)

    Cellular interactions in adoptive secondary anti-hapten antibody responses to the hapten 2,4-dinitrophenyl (DNP) have been studied. It was shown that DNP-specific B cells must interact with carrier specific helper T cells to give optimal responses. Independent titration of B cell and helper cell activity in adoptive anti-DNP antibody responses gave the following results: Doubling the number of transferred B cells approximately doubled the subsequent antibody response. Doubling the number of helper cells leads to nearly 4 times as much anti-DNP antibody, measured 7 days after boosting (''premium effect''). This marked effect of helper cell number on the antibody response is thought to be due primarily to the interaction of two populations of carrier-specific cells in the helper effect, or to the interaction of two activities of a single population of helper cells, namely clone activation and clone expansion. Only a very small proportion of the premium effect given by helper cells could be attributed to increases in antibody affinity. (U.S.)

  10. A medaka model of cancer allowing direct observation of transplanted tumor cells in vivo at a cellular-level resolution.

    Science.gov (United States)

    Hasegawa, Sumitaka; Maruyama, Kouichi; Takenaka, Hikaru; Furukawa, Takako; Saga, Tsuneo

    2009-08-18

    The recent success with small fish as an animal model of cancer with the aid of fluorescence technique has attracted cancer modelers' attention because it would be possible to directly visualize tumor cells in vivo in real time. Here, we report a medaka model capable of allowing the observation of various cell behaviors of transplanted tumor cells, such as cell proliferation and metastasis, which were visualized easily in vivo. We established medaka melanoma (MM) cells stably expressing GFP and transplanted them into nonirradiated and irradiated medaka. The tumor cells were grown at the injection sites in medaka, and the spatiotemporal changes were visualized under a fluorescence stereoscopic microscope at a cellular-level resolution, and even at a single-cell level. Tumor dormancy and metastasis were also observed. Interestingly, in irradiated medaka, accelerated tumor growth and metastasis of the transplanted tumor cells were directly visualized. Our medaka model provides an opportunity to visualize in vivo tumor cells "as seen in a culture dish" and would be useful for in vivo tumor cell biology. PMID:19666513

  11. Enhanced cellular responses and distinct gene profiles in human fetoplacental artery endothelial cells under chronic low oxygen.

    Science.gov (United States)

    Jiang, Yi-Zhou; Wang, Kai; Li, Yan; Dai, Cai-Feng; Wang, Ping; Kendziorski, Christina; Chen, Dong-Bao; Zheng, Jing

    2013-12-01

    Fetoplacental endothelial cells are exposed to oxygen levels ranging from 2% to 8% in vivo. However, little is known regarding endothelial function within this range of oxygen because most laboratories use ambient air (21% O2) as a standard culture condition (SCN). We asked whether human umbilical artery endothelial cells (HUAECs) that were steadily exposed to the physiological chronic normoxia (PCN, 3% O2) for ∼20-25 days differed in their proliferative and migratory responses to FGF2 and VEGFA as well as in their global gene expression compared with those in the SCN. We observed that PCN enhanced FGF2- and VEGFA-stimulated cell proliferation and migration. In oxygen reversal experiments (i.e., when PCN cells were exposed to SCN for 24 h and vice versa), we found that preexposure to 21% O2 decreased the migratory ability, but not the proliferative ability, of the PCN-HUAECs in response to FGF2 and VEGFA. These PCN-enhanced cellular responses were associated with increased protein levels of HIF1A and NOS3, but not FGFR1, VEGFR1, and VEGFR2. Microarray analysis demonstrated that PCN up-regulated 74 genes and down-regulated 86, 14 of which were directly regulated by hypoxia-inducible factors as evaluated using in silico analysis. Gene function analysis further indicated that the PCN-regulated genes were highly related to cell proliferation and migration, consistent with the results from our functional assays. Given that PCN significantly alters cellular responses to FGF2 and VEGFA as well as transcription in HUAECs, it is likely that we may need to reexamine the current cellular and molecular mechanisms controlling fetoplacental endothelial functions, which were largely derived from endothelial models established under ambient O2.

  12. Cellular internalization of LiNbO3 nanocrystals for second harmonic imaging and the effects on stem cell differentiation

    Science.gov (United States)

    Li, Jianhua; Qiu, Jichuan; Guo, Weibo; Wang, Shu; Ma, Baojin; Mou, Xiaoning; Tanes, Michael; Jiang, Huaidong; Liu, Hong

    2016-03-01

    Second harmonic generation (SHG) nanocrystals have recently been reported to label cancer cells and other functional cell lines due to their unique double-frequency property. In this paper, we report for the first time the use of lithium niobate (LiNbO3, LN) nanocrystals as SHG labels for imaging stem cells. Rat mesenchymal stem cells (rMSCs) were labeled with LN nanocrystals in order to study the cellular internalization of the nanocrystals and the influence on stem cell differentiation. The results showed that LN nanocrystals were endocytosed by the rMSCs and the distribution of the internalized nanoparticles demonstrated a high consistency with the orientation of the actin filaments. Besides, LN-labeled rMSCs showed a concentration-dependent viability. Most importantly, rMSCs labeled with 50 μg per mL of LN nanocrystals retained their ability to differentiate into both osteogenic and adipogenic lineages. The results prove that LN nanocrystals can be used as a cytocompatible, near-infrared (NIR) light driven cell label for long-term imaging, without hindering stem cell differentiation. This work will promote the use of LN nanocrystals to broader applications like deep-tissue tracking, remote drug delivery and stem cell therapy.Second harmonic generation (SHG) nanocrystals have recently been reported to label cancer cells and other functional cell lines due to their unique double-frequency property. In this paper, we report for the first time the use of lithium niobate (LiNbO3, LN) nanocrystals as SHG labels for imaging stem cells. Rat mesenchymal stem cells (rMSCs) were labeled with LN nanocrystals in order to study the cellular internalization of the nanocrystals and the influence on stem cell differentiation. The results showed that LN nanocrystals were endocytosed by the rMSCs and the distribution of the internalized nanoparticles demonstrated a high consistency with the orientation of the actin filaments. Besides, LN-labeled rMSCs showed a concentration

  13. IL-12 directs further maturation of ex vivo differentiated NK cells with improved therapeutic potential.

    Directory of Open Access Journals (Sweden)

    Dorit Lehmann

    Full Text Available The possibility to modulate ex vivo human NK cell differentiation towards specific phenotypes will contribute to a better understanding of NK cell differentiation and facilitate tailored production of NK cells for immunotherapy. In this study, we show that addition of a specific low dose of IL-12 to an ex vivo NK cell differentiation system from cord blood CD34(+ stem cells will result in significantly increased proportions of cells with expression of CD62L as well as KIRs and CD16 which are preferentially expressed on mature CD56(dim peripheral blood NK cells. In addition, the cells displayed decreased expression of receptors such as CCR6 and CXCR3, which are typically expressed to a lower extent by CD56(dim than CD56(bright peripheral blood NK cells. The increased number of CD62L and KIR positive cells prevailed in a population of CD33(+NKG2A(+ NK cells, supporting that maturation occurs via this subtype. Among a series of transcription factors tested we found Gata3 and TOX to be significantly downregulated, whereas ID3 was upregulated in the IL-12-modulated ex vivo NK cells, implicating these factors in the observed changes. Importantly, the cells differentiated in the presence of IL-12 showed enhanced cytokine production and cytolytic activity against MHC class I negative and positive targets. Moreover, in line with the enhanced CD16 expression, these cells exhibited improved antibody-dependent cellular cytotoxicity for B-cell leukemia target cells in the presence of the clinically applied antibody rituximab. Altogether, these data provide evidence that IL-12 directs human ex vivo NK cell differentiation towards more mature NK cells with improved properties for potential cancer therapies.

  14. Hormonal and cellular factors affecting immature sertoli cells radiosensitivity in rat fetus

    International Nuclear Information System (INIS)

    Immature Sertoli cells population was studied after irradiation either in hypophysectomised (decapited) or in germ cell free foetus (busulfan treated embryo). Decapitation did not modify the 10 % reduction of immature Sertoli cells after 1.5 Gy irradiation. But, without germ cells, immature Sertoli cells were more radiosensitive

  15. A METHOD OF IMPROVING THE PRODUCTION OF BIOMASS OR A DESIRED PRODUCT FROM A CELL

    DEFF Research Database (Denmark)

    1998-01-01

    the F¿1? ATPase or portions thereof is expressed, may be selected from prokaryotes and eukaryotes. In particular the DNA encoding F¿1? or a portion thereof may be derived from bacteria and eukaryotic microorganisms such as yeasts, other fungi and cell lines of higher organisms and be selected from......The production of biomass or a desired product from a cell can be improved by inducing conversion of ATP to ADP without primary effects on other cellular metabolites or functions which is achieved by expressing an uncoupled ATPase activity in said cell and incubating the cell with a suitable...... substrate to produce said biomass or product. This is conveniently done by expressing in said cell the soluble part (F¿1?) of the membrane bound (F¿0?F¿1? type) H?+¿-ATPase or a portion of F¿1? exhibiting ATPase activity. The organism from which the F¿1? ATPase or portions thereof is derived, or in which...

  16. Cellular uptake and imaging studies of glycosylated silica nanoprobe (GSN in human colon adenocarcinoma (HT 29 cell line

    Directory of Open Access Journals (Sweden)

    Mehravi B

    2013-08-01

    Full Text Available Bita Mehravi,1 Mohsen Ahmadi,1 Massoud Amanlou,2 Ahmad Mostaar,1 Mehdi Shafiee Ardestani,3 Negar Ghalandarlaki41Biomedical Engineering and Medical Physics Department, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 2Department of Medicinal Chemistry, Faculty of Pharmacy and Drug Design and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran; 3Department of Radiopharmacy, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran; 4Department of Biological Science, School of Science, Science and Research branch, Islamic Azad University, Tehran, IranPurpose: In recent years, molecular imaging by magnetic resonance imaging (MRI has gained prominence in the detection of tumor cells. The scope of this study is on molecular imaging and on the cellular uptake study of a glycosylated silica nanoprobe (GSN.Methods: In this study, intracellular uptake (HT 29 cell line of GSN was analyzed quantitatively and qualitatively with inductively coupled plasma atomic emission spectroscopy, flow cytometry, and fluorescent microscopy. In vitro and in vivo relaxometry of this nanoparticle was determined using a 3 Tesla MRI; biodistribution of GSN and Magnevist® were measured in different tissues.Results: Results suggest that the cellular uptake of GSN was about 70%. The r1 relaxivity of this nanoparticle in the cells was measured to be 12.9 ± 1.6 mM-1 s-1 and on a per lanthanide gadolinium (Gd3+ basis. Results also indicate an average cellular uptake of 0.7 ± 0.009 pg Gd3+ per cell. It should be noted that 3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay demonstrated that the cells were effectively labeled without cytotoxicity, and that using MRI for quantitative estimation of delivery and uptake of targeted contrast agents and early detection of human colon cancer cells using targeted contrast agents, is feasible.Conclusion: These results showed that GSN provided a

  17. Epigallocatechin-3-gallate prevents oxidative stress-induced cellular senescence in human mesenchymal stem cells via Nrf2

    Science.gov (United States)

    Shin, Joo-Hyun; Jeon, Hyo-Jin; Park, Jihye; Chang, Mi-Sook

    2016-01-01

    Human mesenchymal stem cells (hMSCs) have great therapeutic potential due to their high plasticity, immune privileged status and ease of preparation, as well as a lack of ethical barriers to their use. However, their ultimate usefulness is limited by cellular senescence occurring secondary to increased cellular levels of reactive oxygen species (ROS) during their propagation in culture. The underlying molecular mechanisms responsible for this process in hMSCs remain unclear. An antioxidant polyphenol epigallocatechin-3-gallate (EGCG) found in green tea, is known to activate nuclear factor-erythroid 2-related factor 2 (Nrf2), a master transcriptional regulator of antioxidant genes. Herein, we examined the EGCG-mediated antioxidant mechanism in hMSCs exposed to ROS which involves Nrf2 activation. The H2O2-exposed hMSCs showed cellular senescence with significantly increased protein levels of acetyl-p53 and p21 in comparison with the untreated hMSCs, and these effects were prevented by pre-treatment with EGCG. By contrast, in Nrf2-knockdown hMSCs, EGCG lost its antioxidant effect, exhibiting high levels of acetyl-p53 and p21 following EGCG pre-treatment and H2O2 exposure. This indicates that Nrf2 and p53/p21 may be involved in the anti-senescent effect of EGCG in hMSCs. Taken together, these findings indicate the important role of EGCG in preventing oxidative stress-induced cellular senescence in hMSCs through Nrf2 activation, which has applications for the massive production of more suitable hMSCs for cell-based therapy. PMID:27498709

  18. Pummelo Protects Doxorubicin-Induced Cardiac Cell Death by Reducing Oxidative Stress, Modifying Glutathione Transferase Expression, and Preventing Cellular Senescence

    Directory of Open Access Journals (Sweden)

    L. Chularojmontri

    2013-01-01

    Full Text Available Citrus flavonoids have been shown to reduce cardiovascular disease (CVD risks prominently due to their antioxidant effects. Here we investigated the protective effect of pummelo (Citrus maxima, CM fruit juice in rat cardiac H9c2 cells against doxorubicin (DOX- induced cytotoxicity. Four antioxidant compositions (ascorbic acid, hesperidin, naringin, and gallic acid were determined by HPLC. CM significantly increased cardiac cell survival from DOX toxicity as evaluated by MTT assay. Reduction of cellular oxidative stress was monitored by the formation of DCF fluorescent product and total glutathione (GSH levels. The changes in glutathione-S-transferase (GST activity and expression were determined by enzyme activity assay and Western blot analysis, respectively. Influence of CM on senescence-associated β-galactosidase activity (SA-β-gal was also determined. The mechanisms of cytoprotection involved reduction of intracellular oxidative stress, maintaining GSH availability, and enhanced GST enzyme activity and expression. DOX-induced cellular senescence was also attenuated by long-term CM treatment. Thus, CM fruit juice can be promoted as functional fruit to protect cells from oxidative cell death, enhance the phase II GSTP enzyme activity, and decrease senescence phenotype population induced by cardiotoxic agent such as DOX.

  19. Development of a Cell-penetrating Peptide that Exhibits Responsive Changes in its Secondary Structure in the Cellular Environment.

    Science.gov (United States)

    Yamashita, Hiroko; Kato, Takuma; Oba, Makoto; Misawa, Takashi; Hattori, Takayuki; Ohoka, Nobumichi; Tanaka, Masakazu; Naito, Mikihiko; Kurihara, Masaaki; Demizu, Yosuke

    2016-01-01

    Cell-penetrating peptides (CPP) are received a lot of attention as an intracellular delivery tool for hydrophilic molecules such as drugs, proteins, and DNAs. We designed and synthesized nona-arginine analogues 1-5 [FAM-β-Ala-(l-Arg-l-Arg-l-Pro)3-(Gly)3-NH2 (1), FAM-β-Ala-(l-Arg-l-Arg-l-Pro(NH2))3-(Gly)3-NH2 (2), FAM-β-Ala-(l-Arg-l-Arg-l-Pro(Gu))3-(Gly)3-NH2 (3), FAM-β-Ala-(l-Arg)2-(l-Pro(Gu))2-(l-Arg)4-l-Pro(Gu)-(Gly)3-NH2 (4), and FAM-β-Ala-(l-Arg)6-(l-Pro(Gu))3-(Gly)3-NH2 (5)] containing l-proline (l-Pro) or cationic proline derivatives (l-Pro(NH2) and l-Pro(Gu)), and investigated their cell-penetrating abilities. Interestingly, only peptide 3 having the side-chain guanidinyl l-Pro(Gu) exhibited a secondary structural change in cellular environment. Specifically, peptide 3 formed a random structure in hydrophilic conditions, whereas it formed a helical structure under amphipathic conditions. Furthermore, during cellular permeability tests, peptide 3 demonstrated greater cell-penetrating activity than other peptides and effectively transported plasmid DNA into HeLa cells. Thus, l-Pro(Gu)-containing peptide 3 may be a useful candidate as a gene delivery carrier. PMID:27609319

  20. Development of a Cell-penetrating Peptide that Exhibits Responsive Changes in its Secondary Structure in the Cellular Environment

    Science.gov (United States)

    Yamashita, Hiroko; Kato, Takuma; Oba, Makoto; Misawa, Takashi; Hattori, Takayuki; Ohoka, Nobumichi; Tanaka, Masakazu; Naito, Mikihiko; Kurihara, Masaaki; Demizu, Yosuke

    2016-01-01

    Cell-penetrating peptides (CPP) are received a lot of attention as an intracellular delivery tool for hydrophilic molecules such as drugs, proteins, and DNAs. We designed and synthesized nona-arginine analogues 1–5 [FAM-β-Ala-(l-Arg-l-Arg-l-Pro)3-(Gly)3-NH2 (1), FAM-β-Ala-(l-Arg-l-Arg-l-ProNH2)3-(Gly)3-NH2 (2), FAM-β-Ala-(l-Arg-l-Arg-l-ProGu)3-(Gly)3-NH2 (3), FAM-β-Ala-(l-Arg)2-(l-ProGu)2-(l-Arg)4-l-ProGu-(Gly)3-NH2 (4), and FAM-β-Ala-(l-Arg)6-(l-ProGu)3-(Gly)3-NH2 (5)] containing l-proline (l-Pro) or cationic proline derivatives (l-ProNH2 and l-ProGu), and investigated their cell-penetrating abilities. Interestingly, only peptide 3 having the side-chain guanidinyl l-ProGu exhibited a secondary structural change in cellular environment. Specifically, peptide 3 formed a random structure in hydrophilic conditions, whereas it formed a helical structure under amphipathic conditions. Furthermore, during cellular permeability tests, peptide 3 demonstrated greater cell-penetrating activity than other peptides and effectively transported plasmid DNA into HeLa cells. Thus, l-ProGu-containing peptide 3 may be a useful candidate as a gene delivery carrier. PMID:27609319

  1. Natural killer cell cytotoxicity of breast cancer targets is enhanced by two distinct mechanisms of antibody-dependent cellular cytotoxicity against LFA-3 and HER2/neu.

    Science.gov (United States)

    Cooley, S; Burns, L J; Repka, T; Miller, J S

    1999-10-01

    Treatment of advanced breast cancer with autologous stem cell transplantation is limited by a high probability of disease relapse. In clinical trials, interleukin 2 (IL-2) alone can expand natural killer (NK) cells in vivo and increase their cytotoxic activity against breast cancer cell lines, but this increase is modest. Understanding the mechanisms that mediate NK cell lysis of breast cancer targets may lead to improvements of current immunotherapy strategies. NK cells from normal donors or patients receiving subcutaneous IL-2 were tested in cytotoxicity assays against five breast cancer cell lines. The role of adhesion molecules and antibodies that interact through Fc receptors on NK cells was explored. NK cell lysis of breast cancer targets is variable and is partially dependent on recognition through ICAM-1 and CD18. While blocking CD2 slightly decreased cytotoxicity, contrary to expectations, an antibody against CD58 (the ligand for CD2), failed to block killing and instead mediated an increased cytotoxicity that correlated with target density of CD58. The CD58 antibody-enhanced killing was dependent not only on FcRgammaIII but also on CD2 and ICAM-1/CD18. To further elucidate the mechanism of this CD58 antibody-dependent cellular cytotoxicity (ADCC), another antibody was tested. Trastuzumab (Herceptin), a humanized antibody against HER2/neu, mediated potent ADCC against all the HER2/neu positive breast cancer targets. Unlike CD58 antibody-mediated ADCC, Herceptin ADCC was minimally affected by blocking antibodies to CD2 or ICAM-1/CD18, which suggests a different mechanism of action. This study shows that multiple mechanisms are involved in NK cell lysis of breast cancer targets, that none of the targets are inherently resistant to killing, and that two distinct mechanisms of ADCC can target immunotherapy to breast cancer cells. PMID:10517495

  2. Functionalized Graphitic Supports for Improved Fuel Cell Catalyst Stability Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Physical Sciences Inc. (PSI) together with the University of Connecticut (UCONN) proposes to demonstrate the improved fuel cell catalyst support durability offered...

  3. Epithelial Cell Transforming 2 and Aurora Kinase B Modulate Formation of Stress Granule-Containing Transcripts from Diverse Cellular Pathways in Astrocytoma Cells.

    Science.gov (United States)

    Weeks, Adrienne; Agnihotri, Sameer; Lymer, Jennifer; Chalil, Alan; Diaz, Roberto; Isik, Semra; Smith, Christian; Rutka, James T

    2016-06-01

    Stress granules are small RNA-protein granules that modify the translational landscape during cellular stress to promote survival. The RhoGTPase RhoA is implicated in the formation of RNA stress granules. Our data demonstrate that the cytokinetic proteins epithelial cell transforming 2 and Aurora kinase B (AurkB) are localized to stress granules in human astrocytoma cells. AurkB and its downstream target histone-3 are phosphorylated during arsenite-induced stress. Chemical (AZD1152-HQPA) and siRNA inhibition of AurkB results in fewer and smaller stress granules when analyzed using high-throughput fluorescent-based cellomics assays. RNA immunoprecipitation with the known stress granule aggregates TIAR and G3BP1 was performed on astrocytoma cells, and subsequent analysis revealed that astrocytoma stress granules harbor unique mRNAs for various cellular pathways, including cellular migration, metabolism, translation, and transcriptional regulation. Human astrocytoma cell stress granules contain mRNAs that are known to be involved in glioma signaling and the mammalian target of rapamycin pathway. These data provide evidence that RNA stress granules are a novel form of epigenetic regulation in astrocytoma cells, which may be targetable by chemical inhibitors and enhance astrocytoma susceptibility to conventional therapy, such as radiation and chemotherapy. PMID:27106762

  4. Preliminary analysis of cellular sociology of co-cultured glioma initiating cells and macrophages in vitro

    Institute of Scientific and Technical Information of China (English)

    Mingxia Zhang; Xingliang Dai; Xiaonan Li; Qiang Huang; Jun Dong; Junjie Chen; Lin Wang; Xiaoyan Ji; Lin Yang; Yujing Sheng; Hairui Liu; Haiyang Wang; Aidong Wang

    2016-01-01

    Objective:Real-time monitoring of cytokine secretion at the single immunocyte level, based on the concept of immune cells, sociology has been recently reported. However, the relationships between glioma-initiating cells (GICs) and host immune cells and their mutual interactions in the tumor microenvironment have not been directly observed and remain unclear. Methods:The dual fluorescence tracing technique was applied to label the co-cultured GICs and host macrophages (Mø), and the interactions between the two types of cells were observed using a live cell imaging system. Fusion cells in the co-culture system were monocloned and proliferated in vitro and their social interactions were observed and recorded. Results:Using real-time dynamic observation of target cells, 6 types of intercellular conjunction microtubes were found to function in the transfer of intercellular information between GICs and Mø;GICs and host Mø can fuse into hybrid cells after several rounds of mutual interactions, and then these fusion cells fused with each other;Fusion cells generated offspring cells through symmetrical and asymmetrical division or underwent apoptosis. A“cell in cell” phenomenon was observed in the fusion cells, which was often followed by cell release, namely entosis. Conclusions:Preliminary studies revealed the patterns of cell conjunction via microtubes between GICs and host Mø and the processes of cell fusion, division, and entosis. The results revealed malignant transformation of host Mø, induced by GICs, suggesting complex social relationships among tumor-immune cells in gliomas.

  5. Characterisation of the p53-mediated cellular responses evoked in primary mouse cells following exposure to ultraviolet radiation.

    Directory of Open Access Journals (Sweden)

    Gillian D McFeat

    Full Text Available Exposure to ultraviolet (UV light can cause significant damage to mammalian cells and, although the spectrum of damage produced varies with the wavelength of UV, all parts of the UV spectrum are recognised as being detrimental to human health. Characterising the cellular response to different wavelengths of UV therefore remains an important aim so that risks and their moderation can be evaluated, in particular in relation to the initiation of skin cancer. The p53 tumour suppressor protein is central to the cellular response that protects the genome from damage by external agents such as UV, thus reducing the risk of tumorigenesis. In response to a variety of DNA damaging agents including UV light, wild-type p53 plays a role in mediating cell-cycle arrest, facilitating apoptosis and stimulating repair processes, all of which prevent the propagation of potentially mutagenic defects. In this study we examined the induction of p53 protein and its influence on the survival of primary mouse fibroblasts exposed to different wavelengths of UV light. UVC was found to elevate p53 protein and its sequence specific DNA binding capacity. Unexpectedly, UVA treatment failed to induce p53 protein accumulation or sequence specific DNA binding. Despite this, UVA exposure of wild-type cells induced a p53 dependent G1 cell cycle arrest followed by a wave of p53 dependent apoptosis, peaking 12 hours post-insult. Thus, it is demonstrated that the elements of the p53 cellular response evoked by exposure to UV radiation are wavelength dependent. Furthermore, the interrelationship between various endpoints is complex and not easily predictable. This has important implications not only for understanding the mode of action of p53 but also for the use of molecular endpoints in quantifying exposure to different wavelengths of UV in the context of human health protection.

  6. From Cells to Islands: An unified Model of Cellular Parallel Genetic Algorithms

    CERN Document Server

    Simoncini, David; Verel, Sébastien; Clergue, Manuel

    2008-01-01

    This paper presents the Anisotropic selection scheme for cellular Genetic Algorithms (cGA). This new scheme allows to enhance diversity and to control the selective pressure which are two important issues in Genetic Algorithms, especially when trying to solve difficult optimization problems. Varying the anisotropic degree of selection allows swapping from a cellular to an island model of parallel genetic algorithm. Measures of performances and diversity have been performed on one well-known problem: the Quadratic Assignment Problem which is known to be difficult to optimize. Experiences show that, tuning the anisotropic degree, we can find the accurate trade-off between cGA and island models to optimize performances of parallel evolutionary algorithms. This trade-off can be interpreted as the suitable degree of migration among subpopulations in a parallel Genetic Algorithm.

  7. Gene expression profiling bovine ovarian follicular and luteal cells provides insight into cellular identities and functions

    Science.gov (United States)

    After ovulation, somatic cells of the ovarian follicle (theca and granulosa cells) become the small and large luteal cells of the corpus luteum. Aside from known cell type-specific receptors and steroidogenic enzymes, little is known about the differences in the gene expression profiles of these fou...

  8. Gastric Lgr5(+) stem cells are the cellular origin of invasive intestinal-type gastric cancer in mice.

    Science.gov (United States)

    Li, Xiu-Bin; Yang, Guan; Zhu, Liang; Tang, Yu-Ling; Zhang, Chong; Ju, Zhenyu; Yang, Xiao; Teng, Yan

    2016-07-01

    The cellular origin of gastric cancer remains elusive. Leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5) is the first identified marker of gastric stem cells. However, the role of Lgr5(+) stem cells in driving malignant gastric cancer is not fully validated. Here, we deleted Smad4 and PTEN in murine gastric Lgr5(+) stem cells by the inducible Cre-LoxP system and marked mutant Lgr5(+) stem cells and their progeny with Cre-reporter Rosa26(tdTomato). Rapid onset and progression from microadenoma and macroscopic adenoma to invasive intestinal-type gastric cancer (IGC) were found in the gastric antrum with the loss of Smad4 and PTEN. In addition, invasive IGC developed at the murine gastro-forestomach junction, where a few Lgr5(+) stem cells reside. In contrast, Smad4 and PTEN deletions in differentiated cells, including antral parietal cells, pit cells and corpus Lgr5(+) chief cells, failed to initiate tumor growth. Furthermore, mutant Lgr5(+) cells were involved in IGC growth and progression. In the TCGA (The Cancer Genome Atlas) database, an increase in LGR5 expression was manifested in the human IGC that occurred at the gastric antrum and gastro-esophageal junction. In addition, the concurrent deletion of SMAD4 and PTEN, as well as their reduced expression and deregulated downstream pathways, were associated with human IGC. Thus, we demonstrated that gastric Lgr5(+) stem cells were cancer-initiating cells and might act as cancer-propagating cells to contribute to malignant progression. PMID:27091432

  9. An improved hydrothermal diamond anvil cell.

    Science.gov (United States)

    Li, Jiankang; Bassett, W A; Chou, I-Ming; Ding, Xin; Li, Shenghu; Wang, Xinyan

    2016-05-01

    A new type of HDAC-V hydrothermal diamond anvil cell (HDAC-VT) has been designed to meet the demands of X-ray research including X-Ray Fluorescence, X-ray Absorption Spectroscopy, and small angle X-ray scattering. The earlier version of HDAC-V that offered a large rectangular solid angle used two posts and two driver screws on both sides of a rectangular body. The new version HDAC-VT in a triangular shape has two alternative guide systems, either three posts inserted into bushings suitable for small anvil faces or linear ball bearings suitable for large anvil faces. The HDAC-VT having three driver screws offers the advantage of greater control and stability even though it sacrifices some of the size of solid angle. The greater control allows better sealing of samples, while greater stability results in longer survival for anvils and ceramic parts. This improved design retains several beneficial features of the original HDAC-V as well. These include the small collar that surrounds the heater and sample chamber forming an Ar + H2 gas chamber to protect diamonds and their heating parts from being oxidized. Three linear ball bearings, when used, fit to the three posts prevent seizing that can result from deterioration of lubricant at high temperatures. Positioning the posts and bearings outside of the gas chamber as in HDAC-V also prevents seizing and possible deformation due to overheating. In order to control the heating rate precisely with computer software, we use Linkam T95 and have replaced the Linkam 1400XY heating stage with the HDAC-VT allowing the HDAC to be heated to 950 °C at a rate from 0.01 °C/min to 50 °C/min. We have used the HDAC-VT and Linkam T95 to observe in situ nucleation and growth of zabuyelite in aqueous fluid and to homogenize melt inclusions in quartz from three porphyry deposits in Shanxi, China. PMID:27250393

  10. Bioconjugated gold nanoparticles enhance cellular uptake: A proof of concept study for siRNA delivery in prostate cancer cells.

    Science.gov (United States)

    Guo, Jianfeng; O'Driscoll, Caitriona M; Holmes, Justin D; Rahme, Kamil

    2016-07-25

    The chemistry of gold nanoparticles (AuNPs) facilitates surface modifications and thus these bioengineered NPs have been investigated as a means of delivering a variety of therapeutic cargos to treat cancer. In this study we have developed AuNPs conjugated with targeting ligands to enhance cell-specific uptake in prostate cancer cells, with a purpose of providing efficient non-viral gene delivery systems in the treatment of prostate cancer. As a consequence, two novel AuNPs were synthesised namely AuNPs-PEG-Tf (negatively charged AuNPs with the transferrin targeting ligands) and AuNPs-PEI-FA (positively charged AuNPs with the folate-receptor targeting ligands). Both bioconjugated AuNPs demonstrated low cytotoxicity in prostate cancer cells. The attachment of the targeting ligand Tf to AuNPs successfully achieved receptor-mediated cellular uptake in PC-3 cells, a prostate cancer cell line highly expressing Tf receptors. The AuNPs-PEI-FA effectively complexed small interfering RNA (siRNA) through electrostatic interaction. At the cellular level the AuNPs-PEI-FA specifically delivered siRNA into LNCaP cells, a prostate cancer cell line overexpressing prostate specific membrane antigen (PSMA, exhibits a hydrolase enzymic activity with a folate substrate). Following endolysosomal escape the AuNPs-PEI-FA.siRNA formulation produced enhanced endogenous gene silencing compared to the non-targeted formulation. Our results suggest both formulations have potential as non-viral gene delivery vectors in the treatment of prostate cancer. PMID:27188645

  11. Thermal conductivity of biological cells at cellular level and correlation with disease state

    Science.gov (United States)

    Park, Byoung Kyoo; Woo, Yunho; Jeong, Dayeong; Park, Jaesung; Choi, Tae-Youl; Simmons, Denise Perry; Ha, Jeonghong; Kim, Dongsik

    2016-06-01

    This paper reports the thermal conductivity k of matched pair cell lines: two pairs of a normal and a cancer cell, one pair of a primary and metastatic cell. The 3ω method with a nanoscale thermal sensor was used to measure k at the single-cell level. To observe the difference in k between normal and cancer cells, the measurements were conducted for Hs 578Bst/Hs 578 T (human breast cells) and TE 353.Sk/TE 354.T (human skin cells). Then k of WM-115/WM-266-4, a primary and metastatic pair of human skin cell, was measured to find the effect of disease progression on k. The measured k data for normal and disease cell samples show statistically meaningful differences. In all cases, k decreased as the disease progressed. This work shows that thermal-analysis schemes, such as the 3ω method, have a potential to detect diseases at the cell level.

  12. Adult Bone Marrow: Which Stem Cells for Cellular Therapy Protocols in Neurodegenerative Disorders?

    Directory of Open Access Journals (Sweden)

    Sabine Wislet-Gendebien

    2012-01-01

    Full Text Available The generation of neuronal cells from stem cells obtained from adult bone marrow is of significant clinical interest in order to design new cell therapy protocols for several neurological disorders. The recent identification in adult bone marrow of stem cells derived from the neural crests (NCSCs might explain the neuronal phenotypic plasticity shown by bone marrow cells. However, little information is available about the nature of these cells compared to mesenchymal stem cells (MSCs. In this paper, we will review all information available concerning NCSC from adult tissues and their possible use in regenerative medicine. Moreover, as multiple recent studies showed the beneficial effect of bone marrow stromal cells in neurodegenerative diseases, we will discuss which stem cells isolated from adult bone marrow should be more suitable for cell replacement therapy.

  13. Adult bone marrow: which stem cells for cellular therapy protocols in neurodegenerative disorders?

    Science.gov (United States)

    Wislet-Gendebien, Sabine; Laudet, Emerence; Neirinckx, Virginie; Rogister, Bernard

    2012-01-01

    The generation of neuronal cells from stem cells obtained from adult bone marrow is of significant clinical interest in order to design new cell therapy protocols for several neurological disorders. The recent identification in adult bone marrow of stem cells derived from the neural crests (NCSCs) might explain the neuronal phenotypic plasticity shown by bone marrow cells. However, little information is available about the nature of these cells compared to mesenchymal stem cells (MSCs). In this paper, we will review all information available concerning NCSC from adult tissues and their possible use in regenerative medicine. Moreover, as multiple recent studies showed the beneficial effect of bone marrow stromal cells in neurodegenerative diseases, we will discuss which stem cells isolated from adult bone marrow should be more suitable for cell replacement therapy. PMID:22319243

  14. Immunohistochemical characterization of cell types expressing the cellular prion protein in the small intestine of cattle and mice.

    Science.gov (United States)

    Miyazawa, Kohtaro; Kanaya, Takashi; Tanaka, Sachi; Takakura, Ikuro; Watanabe, Kouichi; Ohwada, Shyuichi; Kitazawa, Haruki; Rose, Michael T; Sakaguchi, Suehiro; Katamine, Shigeru; Yamaguchi, Takahiro; Aso, Hisashi

    2007-03-01

    The gastrointestinal tract is thought to be the main site of entry for the pathological isoform of the prion protein (PrP(Sc)). Prion diseases are believed to result from a conformational change of the cellular prion protein (PrP(c)) to PrP(Sc). Therefore, PrP(c) expression is a prerequisite for the infection and spread of the disease to the central nervous system. However, the distribution of PrP(c) in the gut is still a matter of controversy. We therefore investigated the localization of PrP(c) in the bovine and murine small intestine. In cattle, most PrP(c) positive epithelial cells were detected in the duodenum, while a few positive cells were found in the jejunum. PrP(c) was expressed in serotonin producing cells. In bovine Peyer's patches, PrP(c) was distributed in extrafollicular areas, but not in the germinal centre of the jejunum and ileum. PrP(c) was expressed in myeloid lineage cells such as myeloid dendritic cells and macrophages. In mice, PrP(c) was expressed in some epithelial cells throughout the small intestine as well as in cells such as follicular dendritic cell in the germinal centre of Peyer's patches. In this study, we demonstrate that there are a number of differences in the localization of PrP(c) between the murine and bovine small intestines. PMID:17165097

  15. Synergistic effect of topography, surface chemistry and conductivity of the electrospun nanofibrous scaffold on cellular response of PC12 cells.

    Science.gov (United States)

    Tian, Lingling; Prabhakaran, Molamma P; Hu, Jue; Chen, Menglin; Besenbacher, Flemming; Ramakrishna, Seeram

    2016-09-01

    Electrospun nanofibrous nerve implants is a promising therapy for peripheral nerve injury, and its performance can be tailored by chemical cues, topographical features as well as electrical properties. In this paper, a surface modified, electrically conductive, aligned nanofibrous scaffold composed of poly (lactic acid) (PLA) and polypyrrole (Ppy), referred to as o-PLAPpy_A, was fabricated for nerve regeneration. The morphology, surface chemistry and hydrophilicity of nanofibers were characterized by Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and water contact angle, respectively. The effects of these nanofibers on neuronal differentiation using PC12 cells were evaluated. A hydrophilic surface was created by Poly-ornithine coating, which was able to provide a better environment for cell attachment, and furthermore aligned fibers were proved to be able to guide PC12 cells grow along the fiber direction and be beneficial for neurite outgrowth. The cellular response of PC12 cells to pulsed electrical stimulation was evaluated by NF 200 and alpha tubulin expression, indicating that electrical stimulation with a voltage of 40mV could enhance the neurite outgrowth. The PC12 cells stimulated with electrical shock showed greater level of neurite outgrowth and smaller cell body size. Moreover, the PC12 cells under electrical stimulation showed better viability. In summary, the o-PLAPpy_A nanofibrous scaffold supported the attachment, proliferation and differentiation of PC12 cells in the absence of electrical stimulation, which could be potential candidate for nerve regeneration applications. PMID:27232305

  16. Cellular Redox Status Regulates Emodin-Induced Radiosensitization of Nasopharyngeal Carcinoma Cells In Vitro and In Vivo

    Directory of Open Access Journals (Sweden)

    Huaxin Hou

    2013-01-01

    Full Text Available Here, we report that regulation of cellular redox status is required for radiosensitization of nasopharyngeal carcinoma (NPC cells by emodin. We evaluated emodin’s radiosensitivity-enhancing ability by using NPC cells in vitro and xenografts in vivo. A clonogenic assay was performed to evaluate NPC cell survival and to determine dose modification factors. Flow cytometry, western blot analysis, and in vivo radiation-induced tumor regrowth delay assays were performed to characterize emodin’s effects. Exposure of CNE-1 NPC cells to emodin enhanced their radiosensitivity. HIF-1α expression significantly increased under hypoxic conditions but did not change after treatment with emodin alone. Emodin downregulated mRNA and protein expression of HIF-1α. Cells exposed to radiation and emodin underwent significant cell cycle arrest at the G2/M phase. The percentage of apoptotic cells and reactive oxygen species (ROS levels were significantly higher in the group exposed to emodin and radiation hypoxic group than in the other groups. Compared to the CNE-1 xenografts exposed to radiation alone, CNE-1 xenografts exposed to radiation with emodin showed significantly enhanced radiation effects. Our data suggest that emodin effectively enhanced the radiosensitivity of CNE-1 cells in vitro and in vivo. The mechanism appears to involve ROS generation and ROS-mediated inhibition of HIF-1α expression.

  17. Development of a cell culture surface conversion technique using alginate thin film for evaluating effect upon cellular differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Nakashima, Y., E-mail: yuta-n@mech.kumamoto-u.ac.jp [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 096-8555 (Japan); Graduate School of Science and Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube 755-8611 (Japan); Tsusu, K.; Minami, K. [Graduate School of Science and Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube 755-8611 (Japan); Nakanishi, Y. [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 096-8555 (Japan)

    2014-06-15

    Here, we sought to develop a cell culture surface conversion technique that would not damage living cells. An alginate thin film, formed on a glass plate by spin coating of sodium alginate solution and dipping into calcium chloride solution, was used to inhibit adhesion of cells. The film could be removed by ethylenediaminetetraacetate (EDTA) at any time during cell culture, permitting observation of cellular responses to conversion of the culture surface in real time. Additionally, we demonstrated the validity of the alginate thin film coating method and the performance of the film. The thickness of the alginate thin film was controlled by varying the rotation speed during spin coating. Moreover, the alginate thin film completely inhibited the adhesion of cultured cells to the culture surface, irrespective of the thickness of the film. When the alginate thin film was removed from the culture surface by EDTA, the cultured cells adhered to the culture surface, and their morphology changed. Finally, we achieved effective differentiation of C2C12 myoblasts into myotube cells by cell culture on the convertible culture surface, demonstrating the utility of our novel technique.

  18. The surfactant protein C mutation A116D alters cellular processing, stress tolerance, surfactant lipid composition, and immune cell activation

    Directory of Open Access Journals (Sweden)

    Zarbock Ralf

    2012-03-01

    Full Text Available Abstract Background Surfactant protein C (SP-C is important for the function of pulmonary surfactant. Heterozygous mutations in SFTPC, the gene encoding SP-C, cause sporadic and familial interstitial lung disease (ILD in children and adults. Mutations mapping to the BRICHOS domain located within the SP-C proprotein result in perinuclear aggregation of the proprotein. In this study, we investigated the effects of the mutation A116D in the BRICHOS domain of SP-C on cellular homeostasis. We also evaluated the ability of drugs currently used in ILD therapy to counteract these effects. Methods SP-CA116D was expressed in MLE-12 alveolar epithelial cells. We assessed in vitro the consequences for cellular homeostasis, immune response and effects of azathioprine, hydroxychloroquine, methylprednisolone and cyclophosphamide. Results Stable expression of SP-CA116D in MLE-12 alveolar epithelial cells resulted in increased intracellular accumulation of proSP-C processing intermediates. SP-CA116D expression further led to reduced cell viability and increased levels of the chaperones Hsp90, Hsp70, calreticulin and calnexin. Lipid analysis revealed decreased intracellular levels of phosphatidylcholine (PC and increased lyso-PC levels. Treatment with methylprednisolone or hydroxychloroquine partially restored these lipid alterations. Furthermore, SP-CA116D cells secreted soluble factors into the medium that modulated surface expression of CCR2 or CXCR1 receptors on CD4+ lymphocytes and neutrophils, suggesting a direct paracrine effect of SP-CA116D on neighboring cells in the alveolar space. Conclusions We show that the A116D mutation leads to impaired processing of proSP-C in alveolar epithelial cells, alters cell viability and lipid composition, and also activates cells of the immune system. In addition, we show that some of the effects of the mutation on cellular homeostasis can be antagonized by application of pharmaceuticals commonly applied in ILD therapy

  19. Salvia fruticosa reduces intrinsic cellular and H2O2-induced DNA oxidation in HEK 293 cells; assessment using flow cytometry

    Directory of Open Access Journals (Sweden)

    Saleem Bani Hani

    2014-05-01

    Conclusions: The results from this study suggest that the water-soluble extract of S. fruticosa leaves protects against both H2O2-induced and intrinsic cellular DNA oxidation in human embryonic kidney 293 cells.

  20. Cellular Phone Towers, Cell Towers in Lowndes County, GA, Published in 2008, 1:1200 (1in=100ft) scale, Southern Georgia Regional Commission.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Cellular Phone Towers dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from Other information as of 2008. It is described as 'Cell...

  1. Cellular Phone Towers, Cell Towers - downloaded from the FCC website, Published in 2010, 1:2400 (1in=200ft) scale, Effingham County Board Of Commissioners.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Cellular Phone Towers dataset, published at 1:2400 (1in=200ft) scale, was produced all or in part from Other information as of 2010. It is described as 'Cell...

  2. Soybean extracts increase cell surface ZIP4 abundance and cellular zinc levels: a potential novel strategy to enhance zinc absorption by ZIP4 targeting.

    Science.gov (United States)

    Hashimoto, Ayako; Ohkura, Katsuma; Takahashi, Masakazu; Kizu, Kumiko; Narita, Hiroshi; Enomoto, Shuichi; Miyamae, Yusaku; Masuda, Seiji; Nagao, Masaya; Irie, Kazuhiro; Ohigashi, Hajime; Andrews, Glen K; Kambe, Taiho

    2015-12-01

    Dietary zinc deficiency puts human health at risk, so we explored strategies for enhancing zinc absorption. In the small intestine, the zinc transporter ZIP4 functions as an essential component of zinc absorption. Overexpression of ZIP4 protein increases zinc uptake and thereby cellular zinc levels, suggesting that food components with the ability to increase ZIP4 could potentially enhance zinc absorption via the intestine. In the present study, we used mouse Hepa cells, which regulate mouse Zip4 (mZip4) in a manner indistinguishable from that in intestinal enterocytes, to screen for suitable food components that can increase the abundance of ZIP4. Using this ZIP4-targeting strategy, two such soybean extracts were identified that were specifically able to decrease mZip4 endocytosis in response to zinc. These soybean extracts also effectively increased the abundance of apically localized mZip4 in transfected polarized Caco2 and Madin-Darby canine kidney cells and, moreover, two apically localized mZip4 acrodermatitis enteropathica mutants. Soybean components were purified from one extract and soyasaponin Bb was identified as an active component that increased both mZip4 protein abundance and zinc levels in Hepa cells. Finally, we confirmed that soyasaponin Bb is capable of enhancing cell surface endogenous human ZIP4 in human cells. Our results suggest that ZIP4 targeting may represent a new strategy to improve zinc absorption in humans.

  3. HAMLET kills tumor cells by apoptosis: structure, cellular mechanisms, and therapy.

    Science.gov (United States)

    Gustafsson, Lotta; Hallgren, Oskar; Mossberg, Ann-Kristin; Pettersson, Jenny; Fischer, Walter; Aronsson, Annika; Svanborg, Catharina

    2005-05-01

    New cancer treatments should aim to destroy tumor cells without disturbing normal tissue. HAMLET (human alpha-lactalbumin made lethal to tumor cells) offers a new molecular approach to solving this problem, because it induces apoptosis in tumor cells but leaves normal differentiated cells unaffected. After partial unfolding and binding to oleic acid, alpha-lactalbumin forms the HAMLET complex, which enters tumor cells and freezes their metabolic machinery. The cells proceed to fragment their DNA, and they disintegrate with apoptosis-like characteristics. HAMLET kills a wide range of malignant cells in vitro and maintains this activity in vivo in patients with skin papillomas. In addition, HAMLET has striking effects on human glioblastomas in a rat xenograft model. After convection-enhanced delivery, HAMLET diffuses throughout the brain, selectively killing tumor cells and controlling tumor progression without apparent tissue toxicity. HAMLET thus shows great promise as a new therapeutic with the advantage of selectivity for tumor cells and lack of toxicity.

  4. Cell adhesion-mediated radioresistance (CAM-RR). Extracellular matrix-dependent improvement of cell survival in human tumor and normal cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, N.; Meineke, V. [Inst. of Radiobiology, Medical Academy of the German Armed Forces, Munich (Germany)

    2003-05-01

    Background: Cell-extracellular matrix (ECM) contact is thought to have great impact on cellular mechanisms resulting in increased cell survival upon exposure to ionizing radiation. Several human tumor cell lines and normal human fibroblastic cell strains of different origin, all of them expressing the wide-spread and important integrin subunit {beta}1, were irradiated, and clonogenic cell survival, {beta}1-integrin cell surface expression, and adhesive functionality were investigated. Material and Methods: Human tumor cell lines A172 (glioblastoma), PATU8902 (pancreas carcinoma), SKMES1 (lung carcinoma), A549 (lung carcinoma), and IPC298 (melanoma) as well as normal human skin (HSF1) and lung fibroblasts (CCD32) and human keratinocytes (HaCaT) were irradiated with 0-8 Gy. Besides colony formation assays, {beta}1-integrin cell surface expression by flow cytometry and adhesive functionality by adhesion assays were analyzed. Results: All cell lines showed improved clonogenic survival after irradiation in the presence of fibronectin as compared to plastic. Irradiated cells exhibited a significant, dose-dependent increase in {beta}1-integrin cell surface expression following irradiation. As a parameter of the adhesive functionality of the {beta}1-integrin, a radiation-dependent elevation of cell adhesion to fibronectin in comparison with adhesion to plastic was demonstrated. Conclusion: The in vitro cellular radiosensitivity is highly influenced by fibronectin according to the phenomenon of cell adhesion-mediated radioresistance. Additionally, our emerging data question the results of former and current in vitro cytotoxicity studies performed in the absence of an ECM. These findings might also be important for the understanding of malignant transformation, anchorage-independent cell growth, optimization of radiotherapeutic regimes and the prevention of normal tissue side effects on the basis of experimental radiobiological data. (orig.)

  5. Improved cellular activity of antisense peptide nucleic acids by conjugation to a cationic peptide-lipid (CatLip) domain

    DEFF Research Database (Denmark)

    Koppelhus, Uffe; Shiraishi, Takehiko; Zachar, Vladimir;

    2008-01-01

    for future in vivo applications. We find that simply conjugating a lipid domain (fatty acid) to the cationic peptide (a CatLip conjugate) increases the biological effect of the corresponding PNA (CatLip) conjugates in a luciferase cellular antisense assay up to 2 orders of magnitude. The effect increases...

  6. The mannose receptor LY75 (DEC205/CD205) modulates cellular phenotype and metastatic potential of ovarian cancer cells.

    Science.gov (United States)

    Faddaoui, Adnen; Bachvarova, Magdalena; Plante, Marie; Gregoire, Jean; Renaud, Marie-Claude; Sebastianelli, Alexandra; Gobeil, Stephane; Morin, Chantale; Macdonald, Elizabeth; Vanderhyden, Barbara; Bachvarov, Dimcho

    2016-03-22

    The molecular basis of epithelial ovarian cancer (EOC) dissemination is still poorly understood. Previously, we identified the mannose receptor LY75 gene as hypomethylated in high-grade (HG) serous EOC tumors, compared to normal ovarian tissues. LY75 represents endocytic receptor expressed on dendritic cells and so far, has been primarily studied for its role in antigen processing and presentation. Here we demonstrate that LY75 is overexpressed in advanced EOC and that LY75 suppression induces mesenchymal-to-epithelial transition (MET) in EOC cell lines with mesenchymal morphology (SKOV3 and TOV112), accompanied by reduction of their migratory and invasive capacity in vitro and enhanced tumor cell colonization and metastatic growth in vivo. LY75 knockdown in SKOV3 cells also resulted in predominant upregulation of functional pathways implicated in cell proliferation and metabolism, while pathways associated with cell signaling and adhesion, complement activation and immune response were mostly suppressed. Moreover, LY75 suppression had an opposite effect on EOC cell lines with epithelial phenotype (A2780s and OV2008), by directing epithelial-to-mesenchymal transition (EMT) associated with reduced capacity for in vivo EOC cell colonization, as similar/identical signaling pathways were reversely regulated, when compared to mesenchymal LY75 knockdown EOC cells.To our knowledge, this is the first report of a gene displaying such pleiotropic effects in sustaining the cellular phenotype of EOC cells and points to novel functions of this receptor in modulating EOC dissemination. Our data also support previous findings regarding the superior capacity of epithelial cancer cells in metastatic colonization of distant sites, compared to cancer cells with mesenchymal-like morphology. PMID:26871602

  7. The mannose receptor LY75 (DEC205/CD205) modulates cellular phenotype and metastatic potential of ovarian cancer cells.

    Science.gov (United States)

    Faddaoui, Adnen; Bachvarova, Magdalena; Plante, Marie; Gregoire, Jean; Renaud, Marie-Claude; Sebastianelli, Alexandra; Gobeil, Stephane; Morin, Chantale; Macdonald, Elizabeth; Vanderhyden, Barbara; Bachvarov, Dimcho

    2016-03-22

    The molecular basis of epithelial ovarian cancer (EOC) dissemination is still poorly understood. Previously, we identified the mannose receptor LY75 gene as hypomethylated in high-grade (HG) serous EOC tumors, compared to normal ovarian tissues. LY75 represents endocytic receptor expressed on dendritic cells and so far, has been primarily studied for its role in antigen processing and presentation. Here we demonstrate that LY75 is overexpressed in advanced EOC and that LY75 suppression induces mesenchymal-to-epithelial transition (MET) in EOC cell lines with mesenchymal morphology (SKOV3 and TOV112), accompanied by reduction of their migratory and invasive capacity in vitro and enhanced tumor cell colonization and metastatic growth in vivo. LY75 knockdown in SKOV3 cells also resulted in predominant upregulation of functional pathways implicated in cell proliferation and metabolism, while pathways associated with cell signaling and adhesion, complement activation and immune response were mostly suppressed. Moreover, LY75 suppression had an opposite effect on EOC cell lines with epithelial phenotype (A2780s and OV2008), by directing epithelial-to-mesenchymal transition (EMT) associated with reduced capacity for in vivo EOC cell colonization, as similar/identical signaling pathways were reversely regulated, when compared to mesenchymal LY75 knockdown EOC cells.To our knowledge, this is the first report of a gene displaying such pleiotropic effects in sustaining the cellular phenotype of EOC cells and points to novel functions of this receptor in modulating EOC dissemination. Our data also support previous findings regarding the superior capacity of epithelial cancer cells in metastatic colonization of distant sites, compared to cancer cells with mesenchymal-like morphology.

  8. HIV-Specific ADCC Improves After Antiretroviral Therapy and Correlates With Normalization of the NK Cell Phenotype

    DEFF Research Database (Denmark)

    Jensen, Sanne S; Hartling, Hans J; Tingstedt, Jeanette L;

    2015-01-01

    BACKGROUND: Natural killer (NK) cell phenotype and function have recently gained much attention as playing crucial roles in antibody-dependent cellular cytotoxicity (ADCC). We investigated NK cell function, as measured by ADCC, in HIV-1-positive individuals before and 6 months after highly active...... antiretroviral therapy (HAART) initiation. METHOD: The ability of antibodies and NK cells to mediate ADCC was investigated separately and in combination in an autologous model. The NK cell subset distribution and NK cell phenotype (ie, expression of maturation and activation markers within NK cell subsets) were....... For individuals with no increase in ADCC after 6 months of HAART, the frequency of NK cells expressing NKp46 was downregulated. The ability of antibodies to mediate ADCC alone and in combination in an autologous model was not improved. CONCLUSIONS: HAART improves the ability of NK cells to mediate ADCC after 6...

  9. Recent advances in interactions of designed nanoparticles and cells with respect to cellular uptake, intracellular fate, degradation and cytotoxicity

    Science.gov (United States)

    Deng, Jun; Gao, Changyou

    2016-10-01

    The unique features of nanomaterials have led to their rapid development in the biomedical field. In particular, functionalized nanoparticles (NPs) are extensively used in the delivery of drugs and genes, bio-imaging and diagnosis. Hence, the interaction between NPs and cells is one of the most important issues towards understanding the true nature of the NP-mediated biological effects. Moreover, the intracellular safety concern of the NPs as a result of intracellular NP degradation remains to be clarified in detail. This review presents recent advances in the interactions of designed NPs and cells. The focus includes the governing factors on cellular uptake and the intracellular fate of NPs, and the degradation of NPs and its influence on nanotoxicity. Some basic consideration is proposed for optimizing the NP-cell interaction and designing NPs of better biocompatiblity for biomedical application.

  10. PLGA nanoparticles codeliver paclitaxel and Stat3 siRNA to overcome cellular resistance in lung cancer cells

    Directory of Open Access Journals (Sweden)

    Su WP

    2012-08-01

    Full Text Available Wen-Pin Su,1,2 Fong-Yu Cheng,3 Dar-Bin Shieh,3–6 Chen-Sheng Yeh,5–7 Wu-Chou Su1,2,81Graduate Institute of Clinical Medicine, College of Medicine, National Cheng Kung University; 2Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University; 3Institute of Oral Medicine, College of Medicine, National Cheng Kung University; 4Department of Stomatology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University; 5Advanced Optoelectronic Technology Center; 6Center for Frontier Materials and Micro/Nano Science and Technology, and 7Department of Chemistry, National Cheng Kung University; 8Cancer Center, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.Abstract: Background: Effective cancer chemotherapy remains an important issue in cancer treatment, and signal transducer and activator of transcription-3 (Stat3 activation leads to cellular resistance of anticancer agents. Polymers are ideal vectors to carry both chemotherapeutics and small interfering ribonucleic acid (siRNA to enhance antitumor efficacy. In this paper, poly(lactic-co-glycolic acid (PLGA nanoparticles loaded with paclitaxel and Stat3 siRNA were successfully synthesized, and their applications in cancer cells were investigated.Methods: Firstly, paclitaxel was enclosed by PLGA nanoparticles through solvent evaporation. They were then coated with cationic polyethylenimine polymer (PLGA-PEI-TAX, enabling it to carry Stat3 siRNA on its surface through electrostatic interactions (PLGA-PEI-TAX-S3SI. The size, zeta potential, deliver efficacy, and release profile of the PLGA nanocomplexes were characterized in vitro. The cellular uptake, intracellular nanoparticle trajectory, and subsequent cellular events were evaluated after treatment with various PLGA nanocomplexes in human lung cancer A549 cells and A549-derived paclitaxel

  11. Cellular Mechanism of Newly Synthesized Indoledione Derivative-induced Immunological Death of Tumor Cell

    OpenAIRE

    Oh, Su-Jin; Ryu, Chung-Kyu; Baek, So-Young; Lee, Hyunah

    2011-01-01

    Background EY-6 is one of the newly synthesized indoledione derivatives to induce tumor cell-specific cell death. In this study, we investigated the mechanism of immunological death induced by EY-6 at mouse colon cancer cell as well as at the normal immune cell represented by dendritic cell. Methods C57BL/6 mouse syngeneic colon cancer cell MC38 was treated with EY-6, and analyzed by MTT for viability test, flow cytometry for confirming surface expressing molecules and ELISA for detection of ...

  12. Optical quantification of cellular mass, volume and density of circulating tumor cells identified in an ovarian cancer patient

    Directory of Open Access Journals (Sweden)

    Kevin Gregory Phillips

    2012-07-01

    Full Text Available Clinical studies have demonstrated that circulating tumor cells (CTCs are present in the blood of cancer patients with known metastatic disease across the major types of epithelial malignancies. Recent studies have shown that the concentration of CTCs in the blood is prognostic of overall survival in breast, prostate, colorectal and non-small cell lung cancer. This study characterizes CTCs identified using the high-definition (HD-CTC assay in an ovarian cancer patient with stage IIIC disease. We characterized the physical properties of 31 HD-CTCs and 50 normal leukocytes from a single blood draw taken just prior to the initial debulking surgery. We utilized a non-interferometric quantitative phase microscopy technique using brightfield imagery to measure cellular dry mass. Next we used a quantitative differential interference contrast microscopy technique to measure cellular volume. These techniques were combined to determine cellular dry mass density. We found that HD-CTCs were more massive than leukocytes: 33.6 ± 3.2 pg (HD-CTC compared to 18.7 ± 0.6 pg (leukocytes, p < 0.001; had greater volumes: 518.3 ± 24.5 fL (HD-CTC compared to 230.9 ± 78.5 fL (leukocyte, p<0.001; and possessed a decreased dry mass density with respect to leukocytes: 0.065 ± 0.006 pg/fL (HD-CTC compared to 0.085 ± 0.004 pg/fL (leukocyte, p < 0.006. Quantification of HD-CTC dry mass content and volume provide key insights into the fluid dynamics of cancer, and may provide the rationale for strategies to isolate, monitor or target CTCs based on their physical properties. The parameters reported here can also be incorporated into blood cell flow models to better understand metastasis.

  13. Cellular High-energy Cavitation Trauma - description of a novel in vitro trauma model in three different cell types.

    Directory of Open Access Journals (Sweden)

    Yuli eCao

    2016-02-01

    Full Text Available The mechanisms involved in traumatic brain injury (TBI have yet to be fully characterized. One mechanism that, especially in high energy trauma, could be of importance is cavitation. Cavitation can be described as a process of vaporization, bubble generation and bubble implosion as a result of a decrease and subsequent increase in pressure. Cavitation as an injury mechanism is difficult to visualize and model due to its short duration and limited spatial distribution. One strategy to analyze the cellular response of cavitation is to employ suitable in vitro models. The flyer plate is an in vitro high energy trauma model that includes cavitation as a trauma mechanism. A copper fragment is accelerated by means of a laser, hits the bottom of a cell culture well causing cavitation and shock waves inside the well and cell medium. We have found the flyer plate model to be efficient, reproducible and easy to control. In this study we have used the model to analyze the cellular response to microcavitation in SH-SY5Y neuroblastoma, Caco-2, and C6 glioma cell lines. Mitotic activity in neuroblastoma and glioma was investigated with BrdU staining, and cell numbers were calculated using automated time-lapse imaging. We found variations between cell types and between different zones surrounding the lesion with these methods. It was also shown that the injured cell cultures released S-100B in a dose dependent manner. Using gene expression microarray a number of gene families of potential interest were found to be strongly, but differently regulated in neuroblastoma and glioma at 24 hr post trauma. The data from the gene expression arrays may be used to identify new candidates for biomarkers in cavitation trauma. We conclude that our model is useful for studies of trauma in vitro and that it could be applied in future treatment studies.

  14. Cellular High-Energy Cavitation Trauma – Description of a Novel In Vitro Trauma Model in Three Different Cell Types

    Science.gov (United States)

    Cao, Yuli; Risling, Mårten; Malm, Elisabeth; Sondén, Anders; Bolling, Magnus Frödin; Sköld, Mattias K.

    2016-01-01

    The mechanisms involved in traumatic brain injury have yet to be fully characterized. One mechanism that, especially in high-energy trauma, could be of importance is cavitation. Cavitation can be described as a process of vaporization, bubble generation, and bubble implosion as a result of a decrease and subsequent increase in pressure. Cavitation as an injury mechanism is difficult to visualize and model due to its short duration and limited spatial distribution. One strategy to analyze the cellular response of cavitation is to employ suitable in vitro models. The flyer-plate model is an in vitro high-energy trauma model that includes cavitation as a trauma mechanism. A copper fragment is accelerated by means of a laser, hits the bottom of a cell culture well causing cavitation, and shock waves inside the well and cell medium. We have found the flyer-plate model to be efficient, reproducible, and easy to control. In this study, we have used the model to analyze the cellular response to microcavitation in SH-SY5Y neuroblastoma, Caco-2, and C6 glioma cell lines. Mitotic activity in neuroblastoma and glioma was investigated with BrdU staining, and cell numbers were calculated using automated time-lapse imaging. We found variations between cell types and between different zones surrounding the lesion with these methods. It was also shown that the injured cell cultures released S-100B in a dose-dependent manner. Using gene expression microarray, a number of gene families of potential interest were found to be strongly, but differently regulated in neuroblastoma and glioma at 24 h post trauma. The data from the gene expression arrays may be used to identify new candidates for biomarkers in cavitation trauma. We conclude that our model is useful for studies of trauma in vitro and that it could be applied in future treatment studies. PMID:26869990

  15. Cellular High-Energy Cavitation Trauma - Description of a Novel In Vitro Trauma Model in Three Different Cell Types.

    Science.gov (United States)

    Cao, Yuli; Risling, Mårten; Malm, Elisabeth; Sondén, Anders; Bolling, Magnus Frödin; Sköld, Mattias K

    2016-01-01

    The mechanisms involved in traumatic brain injury have yet to be fully characterized. One mechanism that, especially in high-energy trauma, could be of importance is cavitation. Cavitation can be described as a process of vaporization, bubble generation, and bubble implosion as a result of a decrease and subsequent increase in pressure. Cavitation as an injury mechanism is difficult to visualize and model due to its short duration and limited spatial distribution. One strategy to analyze the cellular response of cavitation is to employ suitable in vitro models. The flyer-plate model is an in vitro high-energy trauma model that includes cavitation as a trauma mechanism. A copper fragment is accelerated by means of a laser, hits the bottom of a cell culture well causing cavitation, and shock waves inside the well and cell medium. We have found the flyer-plate model to be efficient, reproducible, and easy to control. In this study, we have used the model to analyze the cellular response to microcavitation in SH-SY5Y neuroblastoma, Caco-2, and C6 glioma cell lines. Mitotic activity in neuroblastoma and glioma was investigated with BrdU staining, and cell numbers were calculated using automated time-lapse imaging. We found variations between cell types and between different zones surrounding the lesion with these methods. It was also shown that the injured cell cultures released S-100B in a dose-dependent manner. Using gene expression microarray, a number of gene families of potential interest were found to be strongly, but differently regulated in neuroblastoma and glioma at 24 h post trauma. The data from the gene expression arrays may be used to identify new candidates for biomarkers in cavitation trauma. We conclude that our model is useful for studies of trauma in vitro and that it could be applied in future treatment studies. PMID:26869990

  16. In vitro evaluation of the cellular effect of indium tin oxide nanoparticles using the human lung adenocarcinoma A549 cells.

    Science.gov (United States)

    Tabei, Yosuke; Sonoda, Akinari; Nakajima, Yoshihiro; Biju, Vasudevanpillai; Makita, Yoji; Yoshida, Yasukazu; Horie, Masanori

    2015-05-01

    Indium tin oxide (ITO) is widely used in liquid crystal displays (LCDs) or plasma and mobile phone displays. Elevated production and usage of ITO in such displays have led to increased concerns over the safety of industrial workers exposed to particulate aerosols produced during cutting, grinding and polishing of these materials. However, the cellular effects of ITO nanoparticles (NPs) are still unclear, although it has been reported that micro-scale ITO particles induce cytotoxicity. The aim of this study was to examine the potential of ITO NPs to induce cytotoxicity, oxidative stress, and DNA damage using human lung adenocarcinoma A549 cells. Here, stable dispersions of a medium containing ITO NPs were obtained using pre-adsorption and centrifugal fractionation methods, and the A549 cells were incubated in this medium. The ITO NPs showed low cytotoxic effects as shown by the WST-1 and LDH assays. Transmission electron microscopy observations showed the cellular uptake of ITO NPs. The ITO NPs increased the intracellular level of reactive oxygen species and the expression of the heme oxygenase 1 gene. Further, the results of alkaline comet assays showed that ITO NPs induced DNA damage. Thus, these results suggest that ITO NPs possess a genotoxic potential on human lung adenocarcinoma A549 cells.

  17. Phenylpyrazole insecticides induce cytotoxicity by altering mechanisms involved in cellular energy supply in the human epithelial cell model Caco-2.

    Science.gov (United States)

    Vidau, Cyril; Brunet, Jean-Luc; Badiou, Alexandra; Belzunces, Luc P

    2009-06-01

    Phenylpyrazoles are relatively new insecticides designed to manage problematic insect resistance and public health hazards encountered with older pesticide families. In vitro cytotoxicity induced by the phenylpyrazole insecticides, Ethiprol and Fipronil, and Fipronil metabolites, sulfone and sulfide, was studied in Caco-2 cells. This cellular model was chosen because it made possible to mimic the primary site of oral exposure to xenobiotics, the intestinal epithelium. Assessment of the barrier function of Caco-2 epithelium was assessed by TEER measurement and showed a major loss of barrier integrity after exposure to Fipronil and its metabolites, but not to Ethiprol. The disruption of the epithelial barrier was attributed to severe ATP depletion independent of cell viability, as revealed by LDH release. The origin of energetic metabolism failure was investigated and revealed a transient enhancement of tetrazolium salt reduction and an increase in lactate production by Caco-2 cells, suggesting an increase in glucose metabolism by pesticides. Cellular symptoms observed in these experiments lead us to hypothesize that phenylpyrazole insecticides interacted with mitochondria.

  18. Gene Expression Profile Changes and Cellular Responses to Bleomycin-Induced DNA Damage in Human Fibroblast Cells in Space

    Science.gov (United States)

    Lu, Tao; Zhang, Ye; Kidane, Yared; Feiveson, Alan; Stodieck, Louis; Karouia, Fathi; Rohde, Larry; Wu, Honglu

    2016-01-01

    Living organisms are constantly exposed to space radiation that consists of energetic protons and other heavier charged particles. In addition, DNA in space can be damaged by toxic chemicals or reactive oxygen species generated due to increased levels of environmental and psychological stresses. Understanding the impact of spaceflight factors, microgravity in particular, on cellular responses to DNA damage affects the accuracy of the radiation risk assessment for astronauts and the mutation rate in microorganisms. Although possible synergistic effects of space radiation and microgravity have been investigated since the early days of the human space program, the published results were mostly conflicting and inconsistent. To investigate the effects of spaceflight on cellular responses to DNA damage, confluent human fibroblast cells (AG1522) flown on the International Space Station (ISS) were treated with bleomycin for three hours in the true microgravity environment, which induced DNA damages including double-strand breaks (DSB). Damages in the DNA were quantified by immunofluorescence staining for ?-H2AX, which showed similar percentages of different types of stained cells between flight and ground. However, there was a slight shift in the distribution of the ?-H2AX foci number in the flown cells with countable foci. Comparison of the cells in confluent and in exponential growth conditions indicated that the proliferation rate between flight and the ground may be responsible for such a shift. A microarray analysis of gene expressions in response to bleomycin treatment was also performed. Comparison of the responsive pathways between the flown and ground cells showed similar responses with the p53 network being the top upstream regulator. Similar responses at the RNA level between different gravity conditions were also observed with a PCR array analysis containing a set of genes involved in DNA damage signaling; with BBC3, CDKN1A, PCNA and PPM1D being significantly

  19. Pressuromodulation at the cell membrane as the basis for small molecule hormone and peptide regulation of cellular and nuclear function.

    Science.gov (United States)

    Sarin, Hemant

    2015-11-26

    Building on recent knowledge that the specificity of the biological interactions of small molecule hydrophiles and lipophiles across microvascular and epithelial barriers, and with cells, can be predicted on the basis of their conserved biophysical properties, and the knowledge that biological peptides are cell membrane impermeant, it has been further discussed herein that cellular, and thus, nuclear function, are primarily regulated by small molecule hormone and peptide/factor interactions at the cell membrane (CM) receptors. The means of regulating cellular, and thus, nuclear function, are the various forms of CM Pressuromodulation that exist, which include Direct CM Receptor-Mediated Stabilizing Pressuromodulation, sub-classified as Direct CM Receptor-Mediated Stabilizing Shift Pressuromodulation (Single, Dual or Tri) or Direct CM Receptor-Mediated Stabilizing Shift Pressuromodulation (Single, Dual or Tri) cum External Cationomodulation (≥3+ → 1+); which are with respect to acute CM receptor-stabilizing effects of small biomolecule hormones, growth factors or cytokines, and also include Indirect CM- or CM Receptor-Mediated Pressuromodulation, sub-classified as Indirect 1ary CM-Mediated Shift Pressuromodulation (Perturbomodulation), Indirect 2ary CM Receptor-Mediated Shift Pressuromodulation (Tri or Quad Receptor Internal Pseudo-Cationomodulation: SS 1+), Indirect 3ary CM Receptor-Mediated Shift Pressuromodulation (Single or Dual Receptor Endocytic External Cationomodulation: 2+) or Indirect (Pseudo) 3ary CM Receptor-Mediated Shift Pressuromodulation (Receptor Endocytic Hydroxylocarbonyloetheroylomodulation: 0), which are with respect to sub-acute CM receptor-stabilizing effects of small biomolecules, growth factors or cytokines. As a generalization, all forms of CM pressuromodulation decrease CM and nuclear membrane (NM) compliance (whole cell compliance), due to pressuromodulation of the intracellular microtubule network and increases the exocytosis of pre

  20. Peptide nucleic acid (PNA) cell penetrating peptide (CPP) conjugates as carriers for cellular delivery of antisense oligomers

    DEFF Research Database (Denmark)

    Shiraishi, Takehiko; Nielsen, Peter E

    2012-01-01

    splicing correction of the mutated luciferase gene in the HeLa pLuc705 cell line, reporting cellular (nuclear) uptake of the antisense PNA via luciferase activity measurement. Carrier CPP-PNA constructs were studied in terms of construct modification (with octaarginine and/or decanoic acid) and carrier PNA...... that the carrier might facilitate endosomal escape. Furthermore, 50% downregulation of luciferase expression at 60 nM siRNA was obtained using this carrier CPP-PNA delivery strategy (with CQ co-treatment) for a single stranded antisense RNA targeting normal luciferase mRNA. These results indicated that CPP...

  1. Heterozygous inactivation of the Nf1 gene in myeloid cells enhances neointima formation via a rosuvastatin-sensitive cellular pathway.

    Science.gov (United States)

    Stansfield, Brian K; Bessler, Waylan K; Mali, Raghuveer; Mund, Julie A; Downing, Brandon; Li, Fang; Sarchet, Kara N; DiStasi, Matthew R; Conway, Simon J; Kapur, Reuben; Ingram, David A

    2013-03-01

    Mutations in the NF1 tumor suppressor gene cause Neurofibromatosis type 1 (NF1). Neurofibromin, the protein product of NF1, functions as a negative regulator of Ras activity. Some NF1 patients develop cardiovascular disease, which represents an underrecognized disease complication and contributes to excess morbidity and mortality. Specifically, NF1 patients develop arterial occlusion resulting in tissue ischemia and sudden death. Murine studies demonstrate that heterozygous inactivation of Nf1 (Nf1(+/-)) in bone marrow cells enhances neointima formation following arterial injury. Macrophages infiltrate Nf1(+/-) neointimas, and NF1 patients have increased circulating inflammatory monocytes in their peripheral blood. Therefore, we tested the hypothesis that heterozygous inactivation of Nf1 in myeloid cells is sufficient for neointima formation. Specific ablation of a single copy of the Nf1 gene in myeloid cells alone mobilizes a discrete pro-inflammatory murine monocyte population via a cell autonomous and gene-dosage dependent mechanism. Furthermore, lineage-restricted heterozygous inactivation of Nf1 in myeloid cells is sufficient to reproduce the enhanced neointima formation observed in Nf1(+/-) mice when compared with wild-type controls, and homozygous inactivation of Nf1 in myeloid cells amplified the degree of arterial stenosis after arterial injury. Treatment of Nf1(+/-) mice with rosuvastatin, a stain with anti-inflammatory properties, significantly reduced neointima formation when compared with control. These studies identify neurofibromin-deficient myeloid cells as critical cellular effectors of Nf1(+/-) neointima formation and propose a potential therapeutic for NF1 cardiovascular disease. PMID:23197650

  2. The importance of cellular internalization of antibody-targeted carbon nanotubes in the photothermal ablation of breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Marches, Radu; Vitetta, Ellen S [Cancer Immunobiology Center, University of Texas Southwestern Medical Center, Dallas, TX 75390 (United States); Mikoryak, Carole; Draper, Rockford K [Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, TX 75080 (United States); Wang, Ru-Hung; Pantano, Paul, E-mail: ellen.vitetta@utsouthwestern.edu [Department of Chemistry, University of Texas at Dallas, Richardson, TX 75080 (United States)

    2011-03-04

    Single-walled carbon nanotubes (CNTs) convert absorbed near infrared (NIR) light into heat. The use of CNTs in the NIR-mediated photothermal ablation of tumor cells is attractive because the penetration of NIR light through normal tissues is optimal and the side effects are minimal. Targeted thermal ablation with minimal collateral damage can be achieved by using CNTs attached to tumor-specific monoclonal antibodies (MAbs). However, the role that the cellular internalization of CNTs plays in the subsequent sensitivity of the target cells to NIR-mediated photothermal ablation remains undefined. To address this issue, we used CNTs covalently coupled to an anti-Her2 or a control MAb and tested their ability to bind, internalize, and photothermally ablate Her2{sup +} but not Her2{sup -} breast cancer cell lines. Using flow cytometry, immunofluorescence, and confocal Raman microscopy, we observed the gradual time-dependent receptor-mediated endocytosis of anti-Her2-CNTs whereas a control MAb-CNT conjugate did not bind to the cells. Most importantly, the Her2{sup +} cells that internalized the MAb-CNTs were more sensitive to NIR-mediated photothermal damage than cells that could bind to, but not internalize the MAb-CNTs. These results suggest that both the targeting and internalization of MAb-CNTs might result in the most effective thermal ablation of tumor cells following their exposure to NIR light.

  3. Gall-forming root-knot nematodes hijack key plant cellular functions to induce multinucleate and hypertrophied feeding cells.

    Science.gov (United States)

    Favery, Bruno; Quentin, Michaël; Jaubert-Possamai, Stéphanie; Abad, Pierre

    2016-01-01

    Among plant-parasitic nematodes, the root-knot nematodes (RKNs) of the Meloidogyne spp. are the most economically important genus. RKN are root parasitic worms able to infect nearly all crop species and have a wide geographic distribution. During infection, RKNs establish and maintain an intimate relationship with the host plant. This includes the creation of a specialized nutritional structure composed of multinucleate and hypertrophied giant cells, which result from the redifferentiation of vascular root cells. Giant cells constitute the sole source of nutrients for the nematode and are essential for growth and reproduction. Hyperplasia of surrounding root cells leads to the formation of the gall or root-knot, an easily recognized symptom of plant infection by RKNs. Secreted effectors produced in nematode salivary glands and injected into plant cells through a specialized feeding structure called the stylet play a critical role in the formation of giant cells. Here, we describe the complex interactions between RKNs and their host plants. We highlight progress in understanding host plant responses, focusing on how RKNs manipulate key plant processes and functions, including cell cycle, defence, hormones, cellular scaffold, metabolism and transport.

  4. Cellular plasticity : the good, the bad, and the ugly? Microenvironmental influences on progenitor cell therapy

    NARCIS (Netherlands)

    Moonen, Jan-Renier A. J.; Harmsen, Martin C.; Krenning, Guido

    2012-01-01

    Progenitor cell based therapies have emerged for the treatment of ischemic cardiovascular diseases where there is insufficient endogenous repair. However, clinical success has been limited, which challenges the original premise that transplanted progenitor cells would orchestrate repair. In this rev

  5. Cellular heredity in haploid cultures of somatic cells, March 1968-April 1981. Final report

    International Nuclear Information System (INIS)

    An account is given of the development and application to cell-culture genetics of unique haploid cell lines from frog embryo developed in this laboratory. Since 1968, the main aim of this project has been to develop the haploid cell system for studies of mutagenesis in culture, particularly by ultraviolet radiation. In the course of this work we isolated chromosomally stable cell lines, derived and characterized a number of variants, and adapted cell hybridization and other methods to this material. Particular emphasis was placed on ultraviolet photobiology, including studies of cell survival, mutagenesis, and pathways of repair of uv-damaged DNA. Although at present less widely used for genetic experiments than mammalian cell lines, the frog cells offer the advantages of authentic haploidy and a favorable repertory of DNA repair pathways for study of uv mutagenesis

  6. Arginine vasopressin increases cellular free calcium concentration and adenosine 3',5'-monophosphate production in rat renal papillary collecting tubule cells in culture

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, S.; Okada, K.; Saito, T.

    1988-09-01

    The role of calcium (Ca) in the cellular action of arginine vasopressin (AVP) was examined in rat renal papillary collecting tubule cells in culture. AVP increased both the cellular free Ca concentration ((Ca2+)i) using fura-2, and cAMP production in a dose-dependent manner. AVP-induced cellular Ca mobilization was totally blocked by the antagonist to the antidiuretic action of AVP, and somewhat weakened by the antagonist to the vascular action of AVP. 1-Deamino-8-D-AVP (dDAVP). an antidiuretic analog of AVP, also increased (Ca2+) significantly. Cellular Ca mobilization was not obtained with cAMP, forskolin (a diterpene activator of adenylate cyclase), or phorbol-12-myristate-13-acetate. The early phase of (Ca2+)i depended on the intracellular Ca pool, since an AVP-induced rise in (Ca2+)i was obtained in cells pretreated with Ca-free medium containing 1 mM EGTA, verapamil, or cobalt, which blocked cellular Ca uptake. Also, AVP increased /sup 45/Ca2+ influx during the initial 10 min, which initiated the sustained phase of cellular Ca mobilization. However, cellular cAMP production induced by AVP during the 10-min observation period was diminished in the cells pretreated with Ca-free medium, verapamil, or cobalt, but was still significantly higher than the basal level. This was also diminished by a high Ca concentration in medium. These results indicate that 1) AVP concomitantly regulates cellular free Ca as well as its second messenger cAMP production; 2) AVP-induced elevation of cellular free Ca is dependent on both the cellular Ca pool and extracellular Ca; and 3) there is an optimal level of extracellular Ca to modulate the AVP action in renal papillary collecting tubule cells.

  7. Single-cell bioelectrical impedance platform for monitoring cellular response to drug treatment

    OpenAIRE

    Asphahani, Fareid; Wang, Kui; Thein, Myo; Veiseh, Omid; Yung, Sandy; Xu, Jian; Zhang, Miqin

    2011-01-01

    The response of cells to a chemical or biological agent in terms of their impedance changes in real-time is a useful mechanism that can be utilized for a wide variety of biomedical and environmental applications. The use of a single-cell based analytical platform could be an effective approach to acquiring more sensitive cell impedance measurements, particularly in applications where only diminutive changes in impedance are expected. Here, we report the development of an on-chip cell impedanc...

  8. pH effect on cellular uptake of Sn(IV) chlorine e6 dichloride trisodium salt by cancer cells in vitro

    OpenAIRE

    Al-Khaza’leh, Khaled A.; Omar, Khalid; M. S. Jaafar

    2010-01-01

    The effects of pH value and presence of serum in an incubation medium on photosensitizer drug cellular uptake in MCF7 cancer cells have been investigated. The results showed that the presence of serum in an incubation medium reduced the drug cellular uptake at all pH values. It has been found that decreasing on pH values of the incubation medium increased the cellular uptake of the drug, demonstrating selective uptake of the sensitizer. The HepG2 liver cancer cells exhibited more drug cellula...

  9. Micropatterned co-culture of hepatocyte spheroids layered on non-parenchymal cells to understand heterotypic cellular interactions

    International Nuclear Information System (INIS)

    Microfabrication and micropatterning techniques in tissue engineering offer great potential for creating and controlling cellular microenvironments including cell–matrix interactions, soluble stimuli and cell–cell interactions. Here, we present a novel approach to generate layered patterning of hepatocyte spheroids on micropatterned non-parenchymal feeder cells using microfabricated poly(ethylene glycol) (PEG) hydrogels. Micropatterned PEG-hydrogel-treated substrates with two-dimensional arrays of gelatin circular domains (ϕ = 100 μm) were prepared by photolithographic method. Only on the critical structure of PEG hydrogel with perfect protein rejection, hepatocytes were co-cultured with non-parenchymal cells to be led to enhanced hepatocyte functions. Then, we investigated the mechanism of the functional enhancement in co-culture with respect to the contributions of soluble factors and direct cell–cell interactions. In particular, to elucidate the influence of soluble factors on hepatocyte function, hepatocyte spheroids underlaid with fibroblasts (NIH/3T3 mouse fibroblasts) or endothelial cells (BAECs: bovine aortic endothelial cells) were compared with physically separated co-culture of hepatocyte monospheroids with NIH3T3 or BAEC using trans-well culture systems. Our results suggested that direct heterotypic cell-to-cell contact and soluble factors, both of these between hepatocytes and fibroblasts, significantly enhanced hepatocyte functions. In contrast, direct heterotypic cell-to-cell contact between hepatocytes and endothelial cells only contributed to enhance hepatocyte functions. This patterning technique can be a useful experimental tool for applications in basic science, drug screening and tissue engineering, as well as in the design of artificial liver devices. (paper)

  10. The Effect of Cellular Stress on T and B Cell Memory Pathways in Immunized and Unimmunized BALB/c Mice*

    Science.gov (United States)

    Wang, Yufei; Rahman, Durdana; Mistry, Mukesh; Lehner, Thomas

    2016-01-01

    Immunological memory is a fundamental function of vaccination. The antigenic breakdown products of the vaccine may not persist, and undefined tonic stimulation has been proposed to maintain the specific memory. We have suggested that cellular stress agents to which the immune cells are constantly exposed may be responsible for tonic stimulation. Here we have studied four stress agents: sodium arsenite, an oxidative agent; Gramicidin, eliciting K+ efflux and calcium influx; dithiocarbamate, a metal ionophore; and aluminum hydroxide (alum), an immunological adjuvant. The aims of this study are to extend these investigations to T and B cell responses of unimmunized and ovalbumin (OVA)-immunized BALB/c mice, and furthermore, to ascertain whether stress is involved in optimal expression of memory B cells, as demonstrated in CD4+ T cells. Examination of the homeostatic pathway defined by IL-15/IL-15R (IL-15 receptor) interaction and the inflammasome pathway defined by the IL-1-IL-1R interaction between dendritic cells (DC) and CD4+ T cells suggests that both pathways are involved in the development of optimal expression of CD4+CD45RO+ memory T cells in unimmunized and OVA-immunized BALB/c mice. Furthermore, significant direct correlation was found between CD4+CD44+ memory T cells and both IL-15 of the homeostatic and IL-1β of the inflammasome pathways. However, CD19+CD27+ memory B cells in vivo seem to utilize only the IL-15/IL-15R homeostatic pathway, although the proliferative responses are enhanced by the stress agents. Altogether, stress agents may up-regulate unimmunized and OVA-immunized CD4+CD44+ memory T cells by the homeostatic and inflammasome pathways. However, the CD19+CD27+ memory B cells utilize only the homeostatic pathway. PMID:27502276

  11. LANGERHANS CELL HISTIOCYTOSIS - EXPRESSION OF LEUKOCYTE CELLULAR ADHESION MOLECULES SUGGESTS ABNORMAL HOMING AND DIFFERENTIATION

    NARCIS (Netherlands)

    DEGRAAF, JH; TAMMINGA, RYJ; KAMPS, WA; TIMENS, W

    1994-01-01

    Langerhans' cell histiocytosis (LCH) is characterized by an accumulation of cells with a Langerhans' cell (LC) phenotype. Most patients present with solitary skin or bone lesions, but multi-organ lesions may appear Twenty-two LCH-tissue sections from 13 children and adolescents, with lesions at diff

  12. EFFECT OF DESTRUCTION OF NTS AND PVN ON NEIGUAN (PC 6)ELECTROACUPUNCTURE-INDUCED IMPROVEMENT OF ISCHEMIC MYOCARDIAL CELLULAR MEMBRANE POTENTIALS IN RABBITS

    Institute of Scientific and Technical Information of China (English)

    CHEN Ze-bin; WANG Shu-ju; WANG Ya-wen; WU Xu-ping; WANG Hua

    2005-01-01

    Objective:To observe the influence of electrolytic destruction of nucleus solitary tract (NTS) and hypothalamic paraventricular nucleus (PVN) on the effect of electroacupuncture (EA) in improving ischemic myocardia cellular transmembrane action potential (TMAP). Methods: 38 Japanese breed big-ear white rabbits (anesthetized with 20% Urethane, 4mL/kg) were randomly divided into acute myocardial ischemia (AMI) group (n=8), PVN destruction group (n=12) and PVN+NTS destruction group (n=18). AMI model was established by occlusion of the descending anterior branch (DAB) of the coronary artery. TMAP of myocytes was recorded by using a glass microelectrode which was fixed to a suspending spring silver wire. Bilateral "Neiguan"(PC 6) in all the 3 groups were punctured and stimulated electrically by using parameters of continuous waves, frequency ECG-ST elevated significantly while APA lowered, APD50 and APD90 shortened of 7 Hz, intensity of 6 mA and duration of 30 minutes. Results: After AMI,clearly in comparison with those of pre-AMI in the 3 groups. Compared with AMI group, ECG-ST values of PVN destruction group and PVN+NTS destruction group were significantly higher (P<0.05~0.01), while APA, APD50 and APD90 all significantly lower in all the recording time courses(P<0.05). The facts displayed that electrolytic destruction of PVN and PVN+NTS could produce ischemic myocardial injury and reduce the protective effect of EA on ischemic myocardial cells. Comparison between PVN destruction and PVN+NTS groups showed that all the 4 indexes of the later group were evidently worse than those of the former group (P<0.05), suggesting after destruction of these two nuclei, the effect of EA was worsened further. Conclusion: Electrolytic destruction of PVN and NTS weakens the protective effect of EA on ischemic myocardial cells, both NTS and PVN take part in the effect of EA of "Neiguan"(PC 6) Point in improving ischemic myocardium.

  13. Effect of passage number on cellular response DNA-damaging agents: cell survival and gene expression

    Energy Technology Data Exchange (ETDEWEB)

    Chang-Liu, Chin-Mei; Wolschak, G.E.

    1996-03-01

    The effect of different passage numbers on plating efficiency, doubling time, cell growth, and radiation sensitivity was assessed in Syrian hamster embryo (SHE) cells. Changes in gene expression after UV or {gamma}-ray irradiation at different passage numbers were also examined. The SHE cells were maintained in culture medium for up to 64 passages. Cells were exposed to {sup 60}Co {gamma} rays or 254-m UV radiation. Differential display of cDNAs and Northern blots were used for the study of gene expression. With increasing passage number, SHE cells demonstrated decreased doubling time, increased plating efficiency, and a decreased yield in the number of cells per plate. Between passages 41 and 48 a ``crisis`` period was evident during which time cell growth in high serum (20%) was no longer optimal, and serum concentrations were reduced (to 10%) to maintain cell growth. Sensitivity to ionizing radiation was no different between early- and intermediate-passage cells. However, after UV exposure at low passages (passage 3), confluent cells were more sensitive to the killing effects of UV than were log-phase cells. At intermediate passages (passages 43, 48), confluent cells were slightly more radioresistant- than were log-phase cells. By passage 64, however, both confluent and log-phase cells showed similar patterns of UV sensitivity. Expression of {gamma}-actin, PCNA, and p53 transcripts did not change following UV exposure. p53 mRNA was induced following {gamma}-ray exposure of the intermediate (passage 45) epithelial cells. Differential display, however, revealed changes in expression of several transcripts following exposure to ionizing and ultraviolet radiations. The observed differences in radiation sensitivity associated with increasing passage number may be influenced by radiation-induced gene expression. We are conducting experiments to identify these genes.

  14. Large-Scale Culture and Genetic Modification of Human Natural Killer Cells for Cellular Therapy.

    Science.gov (United States)

    Lapteva, Natalia; Parihar, Robin; Rollins, Lisa A; Gee, Adrian P; Rooney, Cliona M

    2016-01-01

    Recent advances in methods for the ex vivo expansion of human natural killer (NK) cells have facilitated the use of these powerful immune cells in clinical protocols. Further, the ability to genetically modify primary human NK cells following rapid expansion allows targeting and enhancement of their immune function. We have successfully adapted an expansion method for primary NK cells from peripheral blood mononuclear cells or from apheresis products in gas permeable rapid expansion devices (G-Rexes). Here, we describe an optimized protocol for rapid and robust NK cell expansion as well as a method for highly efficient retroviral transduction of these ex vivo expanded cells. These methodologies are good manufacturing practice (GMP) compliant and could be used for clinical-grade product manufacturing. PMID:27177667

  15. NAD⁺ repletion improves mitochondrial and stem cell function and enhances life span in mice.

    Science.gov (United States)

    Zhang, Hongbo; Ryu, Dongryeol; Wu, Yibo; Gariani, Karim; Wang, Xu; Luan, Peiling; D'Amico, Davide; Ropelle, Eduardo R; Lutolf, Matthias P; Aebersold, Ruedi; Schoonjans, Kristina; Menzies, Keir J; Auwerx, Johan

    2016-06-17

    Adult stem cells (SCs) are essential for tissue maintenance and regeneration yet are susceptible to senescence during aging. We demonstrate the importance of the amount of the oxidized form of cellular nicotinamide adenine dinucleotide (NAD(+)) and its effect on mitochondrial activity as a pivotal switch to modulate muscle SC (MuSC) senescence. Treatment with the NAD(+) precursor nicotinamide riboside (NR) induced the mitochondrial unfolded protein response and synthesis of prohibitin proteins, and this rejuvenated MuSCs in aged mice. NR also prevented MuSC senescence in the mdx (C57BL/10ScSn-Dmd(mdx)/J) mouse model of muscular dystrophy. We furthermore demonstrate that NR delays senescence of neural SCs and melanocyte SCs and increases mouse life span. Strategies that conserve cellular NAD(+) may reprogram dysfunctional SCs and improve life span in mammals. PMID:27127236

  16. Perfluorinated chemicals: Differential toxicity, inhibition of aromatase activity and alteration of cellular lipids in human placental cells

    Energy Technology Data Exchange (ETDEWEB)

    Gorrochategui, Eva; Pérez-Albaladejo, Elisabet [Department of Environmental Chemistry, IDAEA–CSIC, 08034 Barcelona, Catalonia (Spain); Casas, Josefina [Department of Biomedicinal Chemistry, IQAC–CSIC, 08034 Barcelona, Catalonia (Spain); Lacorte, Sílvia, E-mail: slbqam@cid.csic.es [Department of Environmental Chemistry, IDAEA–CSIC, 08034 Barcelona, Catalonia (Spain); Porte, Cinta, E-mail: cinta.porte@cid.csic.es [Department of Environmental Chemistry, IDAEA–CSIC, 08034 Barcelona, Catalonia (Spain)

    2014-06-01

    The cytotoxicity of eight perfluorinated chemicals (PFCs), namely, perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorododecanoic acid (PFDoA), perfluorobutanesulfonate (PFBS), perfluorohexanesulfonate (PFHxS) and perfluorooctanesulfonate (PFOS) was assessed in the human placental choriocarcinoma cell line JEG-3. Only the long chain PFCs – PFOS, PFDoA, PFNA, PFOA – showed significant cytotoxicity in JEG-3 cells with EC50 values in the range of 107 to 647 μM. The observed cytotoxicity was to some extent related to a higher uptake of the longer chain PFCs by cells (PFDoA > PFOS ≫ PFNA > PFOA > PFHxA). Moreover, this work evidences a high potential of PFOS, PFOA and PFBS to act as aromatase inhibitors in placental cells with IC50s in the range of 57–80 μM, the inhibitory effect of PFBS being particularly important despite the rather low uptake of the compound by cells. Finally, exposure of JEG-3 cells to a mixture of the eight PFCs (0.6 μM each) led to a relative increase (up to 3.4-fold) of several lipid classes, including phosphatidylcholines (PCs), plasmalogen PC and lyso plasmalogen PC, which suggests an interference of PFCs with membrane lipids. Overall, this work highlights the ability of the PFC mixture to alter cellular lipid pattern at concentrations well below those that generate toxicity, and the potential of the short chain PFBS, often considered a safe substitute of PFOS, to significantly inhibit aromatase activity in placental cells. - Highlights: • Eight perfluorinated chemicals of different chain lengths have been selected. • Long chain ones – PFOS, PFDoA, PFNA, PFOA – were cytotoxic in placenta cells. • The uptake of long chain perfluorinated chemicals by cells was comparatively higher. • PFOS, PFOA and the short chain PFBS significantly inhibited aromatase activity. • A mixture of perfluorinated chemicals significantly altered placenta cell

  17. Cell-centred model for the simulation of curved cellular monolayers

    Science.gov (United States)

    Mosaffa, Payman; Asadipour, Nina; Millán, Daniel; Rodríguez-Ferran, Antonio; J Muñoz, Jose

    2015-12-01

    This paper presents a cell-centred model for the simulation of planar and curved multicellular soft tissues. We propose a computational model that includes stress relaxation due to cell reorganisation (intercellular connectivity changes) and cytoskeleton remodelling (intracellular changes). Cells are represented by their cell centres, and their mechanical interaction is modelled through active non-linear elastic laws with a dynamically changing resting length. Special attention is paid to the handling of connectivity changes between cells, and the relaxation that the tissues exhibit under these topological changes. Cell-cell connectivity is computed by resorting to a Delaunay triangulation, which is combined with a mapping technique in order to obtain triangulations on curved manifolds. Our numerical results show that even a linear elastic cell-cell interaction model may induce a global non-linear response due to the reorganisation of the cell connectivity. This plastic-like behaviour is combined with a non-linear rheological law where the resting length depends on the elastic strain, mimicking the global visco-elastic response of tissues. The model is applied to simulate the elongation of planar and curved monolayers.

  18. Cellular contractility and extracellular matrix stiffness regulate matrix metalloproteinase activity in pancreatic cancer cells.

    Science.gov (United States)

    Haage, Amanda; Schneider, Ian C

    2014-08-01

    The pathogenesis of cancer is often driven by local invasion and metastasis. Recently, mechanical properties of the tumor microenvironment have been identified as potent regulators of invasion and metastasis, while matrix metalloproteinases (MMPs) are classically known as significant enhancers of cancer cell migration and invasion. Here we have been able to sensitively measure MMP activity changes in response to specific extracellular matrix (ECM) environments and cell contractility states. Cells of a pancreatic cancer cell line, Panc-1, up-regulate MMP activities between 3- and 10-fold with increased cell contractility. Conversely, they down-regulate MMP activities when contractility is blocked to levels seen with pan-MMP activity inhibitors. Similar, albeit attenuated, responses are seen in other pancreatic cancer cell lines, BxPC-3 and AsPC-1. In addition, MMP activity was modulated by substrate stiffness, collagen gel concentration, and the degree of collagen cross-linking, when cells were plated on collagen gels ranging from 0.5 to 5 mg/ml that span the physiological range of substrate stiffness (50-2000 Pa). Panc-1 cells showed enhanced MMP activity on stiffer substrates, whereas BxPC-3 and AsPC-1 cells showed diminished MMP activity. In addition, eliminating heparan sulfate proteoglycans using heparinase completely abrogated the mechanical induction of MMP activity. These results demonstrate the first functional link between MMP activity, contractility, and ECM stiffness and provide an explanation as to why stiffer environments result in enhanced cell migration and invasion.

  19. Sponge cell reaggregation: Cellular structure and morphogenetic potencies of multicellular aggregates.

    Science.gov (United States)

    Lavrov, Andrey I; Kosevich, Igor A

    2016-02-01

    Sponges (phylum Porifera) are one of the most ancient extant multicellular animals and can provide valuable insights into origin and early evolution of Metazoa. High plasticity of cell differentiations and anatomical structure is characteristic feature of sponges. Present study deals with sponge cell reaggregation after dissociation as the most outstanding case of sponge plasticity. Dynamic of cell reaggregation and structure of multicellular aggregates of three demosponge species (Halichondria panicea (Pallas, 1766), Haliclona aquaeductus (Sсhmidt, 1862), and Halisarca dujardinii Johnston, 1842) were studied. Sponge tissue dissociation was performed mechanically. Resulting cell suspensions were cultured at 8-10°C for at least 5 days. Structure of multicellular aggregates was studied by light, transmission and scanning electron microscopy. Studied species share common stages of cell reaggregation-primary multicellular aggregates, early-stage primmorphs and primmorphs, but the rate of reaggregation varies considerably among species. Only cells of H. dujardinii are able to reconstruct functional and viable sponge after primmorphs formation. Sponge reconstruction in this species occurs due to active cell locomotion. Development of H. aquaeductus and H. panicea cells ceases at the stages of early primmorphs and primmorphs, respectively. Development of aggregates of these species is most likely arrested due to immobility of the majority of cells inside them. However, the inability of certain sponge species to reconstruct functional and viable individuals during cell reaggregation may be not a permanent species-specific characteristic, but depends on various factors, including the stage of the life cycle and experimental conditions. PMID:26863993

  20. Cellular uptake of {sup 212}BiOCl by Ehrlich ascites cells: A dosimetric analysis

    Energy Technology Data Exchange (ETDEWEB)

    Roeske, J.C.; Whitlock, J.L.; Harper, P.V.; Rotmensch, J. [Univ. of Chicago, IL (United States); Stinchcomb, T.G. [DePaul Univ., Chicago, IL (United States). Dept. of Physics; Schwartz, J.L. [Univ. of Washington, Seattle, WA (United States). Dept. of Radiation Oncology; Hines, J.J. [Argonne National Lab., IL (United States). Chemistry Div.

    1999-01-01

    Bi-212 is an alpha-emitting radionuclide being investigated as a therapeutic agent in the intraperitoneal treatment of micrometastatic ovarian carcinoma. In evaluating a new therapeutic modality, cell-survival studies are often used as a means of quantifying the biological effects of radiation. In this analysis, Ehrlich ascites cells were irradiated under conditions similar to therapy in various concentrations of Bi-212. Immediately following irradiation, a cell survival assay was performed in which cells were plated and colonies were counted after 10--14 days. Both a macrodosimetric and a microdosimetric approach were used in analyzing these data. These models used as input the fraction of activity within the cell and in solution, the distribution of cell sizes, and the variation of LET along individual alpha-particle tracks. The results indicate that the energy deposited within the nucleus varies significantly among individual cells. There is a small fraction of cell nuclei which receive no hits, while the remaining cells receive energy depositions which can differ significantly from the mean value. These dosimetric parameters are correlated with measured cell survival and will be a useful predictor of outcome for therapeutic doses.

  1. Evaluation of Cellular Toxicity for Cisplatin, Arsenic And Acetaminophen in the Cancer and Normal Cell Line

    Directory of Open Access Journals (Sweden)

    S Saeedi Saravi

    2007-12-01

    Full Text Available Introduction: Cell culture is a process in which the cells ware isolated from original tissue, dispersed in liquid media and then placed in culture plate where the cells adhere together and propagate. Today, this method is used for assessment of cell toxicity, its mechanisms and effect of different compounds on intracellular components. Methods: Clonogenic assay was used for assessment of cell toxicity and amount of cell death after a specific time during which cells were exposed to different compounds. Thus, IC50 in caner cell lines (HePG2, SKOV3 and A549 and normal cell (LLCPK1, CHO and HGF1 was assessed after exposure to cisplatin, acetaminophen and arsenic. Results: Results showed that acetaminophen has maximum resistance and minimum sensitivity in CHO line with IC50=16.7±1.06 HePG2 with IC50=18.6±1.29. On the other hand, cisplatin showed minimum resistance and maximum sensitivity in HePG2 with IC50 = 0.87±0.07 and HGF1 with IC50 = 1.6±0.21 and lastly, arsenic showed minimum resistance and maximum sensitivity in A549 with IC50 = 4.59±0.29 and LLCPK1 with IC50= 1±0.37. Discussion: According to the evaluated IC50, there were differences between results of sensitivity of cell lines exposed to the three drugs (P<0.05. Entirely, resistance in cancer cell lines was lower than normal cells. The results showed the importance of cell defensive mechanisms encountering different substances like glutathione.

  2. Analytical analysis of slow and fast pressure waves in a two-dimensional cellular solid with fluid-filled cells.

    Science.gov (United States)

    Dorodnitsyn, Vladimir; Van Damme, Bart

    2016-06-01

    Wave propagation in cellular and porous media is widely studied due to its abundance in nature and industrial applications. Biot's theory for open-cell media predicts the existence of two simultaneous pressure waves, distinguished by its velocity. A fast wave travels through the solid matrix, whereas a much slower wave is carried by fluid channels. In closed-cell materials, the slow wave disappears due to a lack of a continuous fluid path. However, recent finite element (FE) simulations done by the authors of this paper also predict the presence of slow pressure waves in saturated closed-cell materials. The nature of the slow wave is not clear. In this paper, an equivalent unit cell of a medium with square cells is proposed to permit an analytical description of the dynamics of such a material. A simplified FE model suggests that the fluid-structure interaction can be fully captured using a wavenumber-dependent spring support of the vibrating cell walls. Using this approach, the pressure wave behavior can be calculated with high accuracy, but with less numerical effort. Finally, Rayleigh's energy method is used to investigate the coexistence of two waves with different velocities. PMID:27369159

  3. Luciferase mRNA Transfection of Antigen Presenting Cells Permits Sensitive Nonradioactive Measurement of Cellular and Humoral Cytotoxicity

    Directory of Open Access Journals (Sweden)

    Tana A. Omokoko

    2016-01-01

    Full Text Available Immunotherapy is rapidly evolving as an effective treatment option for many cancers. With the emerging fields of cancer vaccines and adoptive cell transfer therapies, there is an increasing demand for high-throughput in vitro cytotoxicity assays that efficiently analyze immune effector functions. The gold standard 51Cr-release assay is very accurate but has the major disadvantage of being radioactive. We reveal the development of a versatile and nonradioactive firefly luciferase in vitro transcribed (IVT RNA-based assay. Demonstrating high efficiency, consistency, and excellent target cell viability, our optimized luciferase IVT RNA is used to transfect dividing and nondividing primary antigen presenting cells. Together with the long-lasting expression and minimal background, the direct measurement of intracellular luciferase activity of living cells allows for the monitoring of killing kinetics and displays paramount sensitivity. The ability to cotransfect the IVT RNA of the luciferase reporter and the antigen of interest into the antigen presenting cells and its simple read-out procedure render the assay high-throughput in nature. Results generated were comparable to the 51Cr release and further confirmed the assay’s ability to measure antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. The assay’s combined simplicity, practicality, and efficiency tailor it for the analysis of antigen-specific cellular and humoral effector functions during the development of novel immunotherapies.

  4. Accumulation of intra-cellular polyphosphate in Chlorella vulgaris cells is related to indole-3-acetic acid produced by Azospirillum brasilense.

    Science.gov (United States)

    Meza, Beatriz; de-Bashan, Luz E; Hernandez, Juan-Pablo; Bashan, Yoav

    2015-06-01

    Accumulation of intra-cellular phosphate, as polyphosphate, was measured when the microalga Chlorella vulgaris was immobilized in alginate with either of two wild-type strains of the microalgae growth-promoting bacterium Azospirillum brasilense or their corresponding IAA-attenuated mutants. Wild type strains of A. brasilense induced higher amounts of intra-cellular phosphate in Chlorella than their respective mutants. Calculations comparing intra-cellular phosphate accumulation by culture or net accumulation by the cell and the amount of IAA that was produced by each of these strains revealed that higher IAA was linked to higher accumulations of intra-cellular phosphate. Application of four levels of exogenous IAA reported for A. brasilense and their IAA-attenuated mutants to cultures of C. vulgaris enhanced accumulation of intra-cellular phosphate; the higher the content of IAA per culture or per single cell, the higher was the amount of accumulated phosphate. When an IAA-attenuated mutant was complemented with exogenous IAA, accumulation of intra-cellular phosphate at the culture level was even higher than phosphate accumulation with the respective wild type strains. When calculating the net accumulation of intra-cellular phosphate in the complementation experiment, net intra-cellular phosphate induced by the IAA-attenuated mutant was completely restored and was similar to the wild strains. We propose that IAA produced by A. brasilense is linked to polyphosphate accumulation in C. vulgaris.

  5. Curcumin inhibits cellular cholesterol accumulation by regulating SREBP-1/caveolin-1 signaling pathway in vascular smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    Hao-yu YUAN; Shuang-yu KUANG; Xing ZHENG; Hong-yan LING; Yun-bo YANG; Peng-ke YAN; Kai LI; Duan-fang LIAO

    2008-01-01

    Aim: To investigate the protective effect and the possible mechanism of curcumin on anti-atherosclerosis. Methods: Morphological changes of atherosclerotic le-sions taken from apoE knockout (apoE-/-) mice were determined by hematoxylin-eosin staining. Intracellular lipid droplets and lipid levels were assayed by oil red O staining and HPLC. The protein expression of caveolin-1 was quantified by West-ern blotting. Translocation and the expression of sterol response element-bind-ing protein-1 (SREBP-1) were indirectly detected by an immunofluorescence analysis. Results: The administration of 20 mg.kg-1.d-1 curcumin to apoE-/1 mice for 4 months induced a 50% reduction of atherosclerotic lesions and yielded a 5-fold increase in the caveolin-1 expression level as compared to the model group. Rat vascular smooth muscle cells (VSMC) pretreated with 50 mg.L-1 ox-lipid den-sity lipoprotein(ox-LDL) for 48 h increased cellular lipid contents, and stimulated SREBP-1 translocation, but decreased the caveolin-1 expression level. Lipid-loaded cells exposed to curcumin at various concentrations (12.5, 25, and 50 μmol.L-1) for different durations (0, 6, 12, 24, and 48 h) significantly diminished the number and area of cellular lipid droplets, total cholesterol, cholesterol ester, and free choles-terol accompanying the elevation of the caveolin-1 expression level (approximately 3-fold); the translocation of SREBP-1 from the cytoplasm to the nucleus was inhibited compared with the models. Lipid-loaded VSMC exposed to N-acetyl-Leu-Leu-norleucinal, a SREBP-1 protease inhibitor, showed increased nuclear trans-location of SREBP-1, reduced caveolin-1 expression level, and upregulated cellu-lar lipid levels. Conclusion: Curcumin inhibits ox-LDL-induced cholesterol accu-mulation in cultured VSMC through increasing the caveolin-1 expression via the inhibition of nuclear translocation of SREBP-1.

  6. A new flow-regulating cell type in the Demosponge Tethya wilhelma - functional cellular anatomy of a leuconoid canal system.

    Directory of Open Access Journals (Sweden)

    Jörg U Hammel

    Full Text Available Demosponges possess a leucon-type canal system which is characterized by a highly complex network of canal segments and choanocyte chambers. As sponges are sessile filter feeders, their aquiferous system plays an essential role in various fundamental physiological processes. Due to the morphological and architectural complexity of the canal system and the strong interdependence between flow conditions and anatomy, our understanding of fluid dynamics throughout leuconoid systems is patchy. This paper provides comprehensive morphometric data on the general architecture of the canal system, flow measurements and detailed cellular anatomical information to help fill in the gaps. We focus on the functional cellular anatomy of the aquiferous system and discuss all relevant cell types in the context of hydrodynamic and evolutionary constraints. Our analysis is based on the canal system of the tropical demosponge Tethya wilhelma, which we studied using scanning electron microscopy. We found a hitherto undescribed cell type, the reticuloapopylocyte, which is involved in flow regulation in the choanocyte chambers. It has a highly fenestrated, grid-like morphology and covers the apopylar opening. The minute opening of the reticuloapopylocyte occurs in an opened, intermediate and closed state. These states permit a gradual regulation of the total apopylar opening area. In this paper the three states are included in a theoretical study into flow conditions which aims to draw a link between functional cellular anatomy, the hydrodynamic situation and the regular body contractions seen in T. wilhelma. This provides a basis for new hypotheses regarding the function of bypass elements and the role of hydrostatic pressure in body contractions. Our study provides insights into the local and global flow conditions in the sponge canal system and thus enhances current understanding of related physiological processes.

  7. A new flow-regulating cell type in the Demosponge Tethya wilhelma - functional cellular anatomy of a leuconoid canal system.

    Science.gov (United States)

    Hammel, Jörg U; Nickel, Michael

    2014-01-01

    Demosponges possess a leucon-type canal system which is characterized by a highly complex network of canal segments and choanocyte chambers. As sponges are sessile filter feeders, their aquiferous system plays an essential role in various fundamental physiological processes. Due to the morphological and architectural complexity of the canal system and the strong interdependence between flow conditions and anatomy, our understanding of fluid dynamics throughout leuconoid systems is patchy. This paper provides comprehensive morphometric data on the general architecture of the canal system, flow measurements and detailed cellular anatomical information to help fill in the gaps. We focus on the functional cellular anatomy of the aquiferous system and discuss all relevant cell types in the context of hydrodynamic and evolutionary constraints. Our analysis is based on the canal system of the tropical demosponge Tethya wilhelma, which we studied using scanning electron microscopy. We found a hitherto undescribed cell type, the reticuloapopylocyte, which is involved in flow regulation in the choanocyte chambers. It has a highly fenestrated, grid-like morphology and covers the apopylar opening. The minute opening of the reticuloapopylocyte occurs in an opened, intermediate and closed state. These states permit a gradual regulation of the total apopylar opening area. In this paper the three states are included in a theoretical study into flow conditions which aims to draw a link between functional cellular anatomy, the hydrodynamic situation and the regular body contractions seen in T. wilhelma. This provides a basis for new hypotheses regarding the function of bypass elements and the role of hydrostatic pressure in body contractions. Our study provides insights into the local and global flow conditions in the sponge canal system and thus enhances current understanding of related physiological processes.

  8. Application of Allogeneic Fibroblast Cells in Cellular Therapy of Recessive Dystrophic Epidermolysis Bullosa

    Directory of Open Access Journals (Sweden)

    Zare

    2015-09-01

    Full Text Available Context Connective tissue cells include fibroblasts, chondrocytes, adipocyte, and osteocytes. These cells are specialized for the secretion of collagenous extracellular matrix and are responsible for the architectural framework of the human body. Evidence Acquisition Connective tissue cells play a central role in supporting as well as repairing tissues and organs. Fibroblast cell therapy could be used for the treatment of burn wounds, scars, diabetic foot ulcers, acne scars and skin aging. This review focused on biology of fibroblasts and their role in cell therapy of recessive dystrophic epidermolysis bullosa (RDEB. Results Fibroblasts are known to play a pivotal role in skin structure and integrity, and dermal fibroblasts are believed to promote skin regeneration and rejuvenation via collagen production. Conclusions Fibroblasts can be used in transplantations to ameliorate an immune system response, in order to reduce antigen production. Human fibroblasts suppress ongoing mixed lymphocyte reactions (MLRs between lymphocyte cells from two individuals, and supernatant materials from fibroblast cultures suppress MLRs.

  9. Method of constructing an improved electrochemical cell

    Science.gov (United States)

    Grimes, Patrick G.; Einstein, Harry

    1984-10-09

    An electrochemical cell construction features a novel co-extruded plastic electrode in an interleaved construction with a novel integral separator-spacer. Also featured is a leak and impact resistant construction for preventing the spill of corrosive materials in the event of rupture.

  10. Single-Cell Cytokine Profiling to Investigate Cellular Functional Diversity in Hematopoietic Malignancies.

    Science.gov (United States)

    Chen, Jonathan J; Kwak, Minsuk; Fan, Rong

    2016-01-01

    Single-cell analysis of cytokine production is increasingly recognized as an important method to understand the inflammatory microenvironment and hematopoietic disease state. Certain cytokines are critical to the regulation of lineage specification, and the aberrant production of these cytokines can contribute to lineage reprogramming. Here, we describe of a platform combining subnanoliter microchambers and a high-density antibody barcode array for the study of single-cell cytokine secretions in hematopoietic cancer cell populations. PMID:27581152

  11. Investigation of Dendrimer-based nanoparticles cellular uptake and cell tracking in a semiautomated microfluidic platform

    OpenAIRE

    Carvalho, Mariana Rodrigues; Maia, Fátima Raquel; Reis, R. L.; Oliveira, J. M.

    2016-01-01

    A microfluidic device such as Kima Pump and Vena8 biochip is able to realize functions that are not easily imaginable in conventional biological analysis, such as highly parallel, sophisticated high-throughput analysis and single-cell analysis in a well-defined manner [1]. Cancer cell tracking within the microfluidic model will be achieved by grafting fluorescent label probe Fluorescein-5(6)-isothiocyanate (FITC) to dendrimer nanoparticles allowing cell visualization by immunofluorescen...

  12. Longevity of guard cell chloroplasts in falling leaves: implication for stomatal function and cellular aging

    Energy Technology Data Exchange (ETDEWEB)

    Zeiger, E.; Schwartz, A.

    1982-11-12

    Guard cell chloroplasts in senescing leaves from 12 species of perennial trees and three species of annual plants survived considerably longer than their mesophyll counterparts. In Ginkgo biloba, stomata from yellow leaves opened during the day and closed at night; guard cell chloroplasts from these leaves showed fluorescence transients associated with electron transport and photophosphorylation. These findings indicate that guard cell chloroplasts are highly conserved throughout the life-span of the leaf and that leaves retain stomatal control during senescence.

  13. Cellular mechanisms of alpha herpesvirus egress: live cell fluorescence microscopy of pseudorabies virus exocytosis.

    OpenAIRE

    Hogue, Ian B.; Jens B Bosse; Jiun-Ruey Hu; Thiberge, Stephan Y.; Enquist, Lynn W.

    2014-01-01

    Egress of newly assembled herpesvirus particles from infected cells is a highly dynamic process involving the host secretory pathway working in concert with viral components. To elucidate the location, dynamics, and molecular mechanisms of alpha herpesvirus egress, we developed a live-cell fluorescence microscopy method to visualize the final transport and exocytosis of pseudorabies virus (PRV) particles in non-polarized epithelial cells. This method is based on total internal reflection fluo...

  14. Hijacking the Cellular Mail: Exosome Mediated Differentiation of Mesenchymal Stem Cells

    OpenAIRE

    Raghuvaran Narayanan; Chun-Chieh Huang; Sriram Ravindran

    2016-01-01

    Bone transplantation is one of the most widely performed clinical procedures. Consequently, bone regeneration using mesenchymal stem cells and tissue engineering strategies is one of the most widely researched fields in regenerative medicine. Recent scientific consensus indicates that a biomimetic approach is required to achieve proper regeneration of any tissue. Exosomes are nanovesicles secreted by cells that act as messengers that influence cell fate. Although exosomal function has been st...

  15. Cellular characterization of cells from the Fanconi anemia complementation group, FA-D1/BRCA2

    Energy Technology Data Exchange (ETDEWEB)

    Godthelp, Barbara C. [Department of Toxicogenetics, Leiden University Medical Center, Building 2, Postzone S-6-P, P.O. Box 9600, 2300 RC, Leiden (Netherlands); Buul, Paul P.W. van [Department of Toxicogenetics, Leiden University Medical Center, Building 2, Postzone S-6-P, P.O. Box 9600, 2300 RC, Leiden (Netherlands); Jaspers, Nicolaas G.J. [Department of Cell Biology and Genetics, Erasmus University, P.O. Box 1738, 3000 DR Rotterdam (Netherlands); Elghalbzouri-Maghrani, Elhaam [Department of Toxicogenetics, Leiden University Medical Center, Building 2, Postzone S-6-P, P.O. Box 9600, 2300 RC, Leiden (Netherlands); Duijn-Goedhart, Annemarie van [Department of Toxicogenetics, Leiden University Medical Center, Building 2, Postzone S-6-P, P.O. Box 9600, 2300 RC, Leiden (Netherlands); Arwert, Fre [Department of Clinical Genetics and Human Genetics, Free University Medical Center, Amsterdam (Netherlands); Joenje, Hans [Department of Clinical Genetics and Human Genetics, Free University Medical Center, Amsterdam (Netherlands); Zdzienicka, Malgorzata Z. [Department of Toxicogenetics, Leiden University Medical Center, Building 2, Postzone S-6-P, P.O. Box 9600, 2300 RC, Leiden (Netherlands) and Department of Molecular Cell Genetics, Collegium Medicum, N.Copernicus University, Bydgoszcz (Poland)]. E-mail: M.Z.Zdzienicka@LUMC.nl

    2006-10-10

    Fanconi anemia (FA) is an inherited cancer-susceptibility disorder, characterized by genomic instability and hypersensitivity to DNA cross-linking agents. The discovery of biallelic BRCA2 mutations in the FA-D1 complementation group allows for the first time to study the characteristics of primary BRCA2-deficient human cells. FANCD1/BRCA2-deficient fibroblasts appeared hypersensitive to mitomycin C (MMC), slightly sensitive to methyl methane sulfonate (MMS), and like cells derived from other FA complementation groups, not sensitive to X-ray irradiation. However, unlike other FA cells, FA-D1 cells were slightly sensitive to UV irradiation. Despite the observed lack of X-ray sensitivity in cell survival, significant radioresistant DNA synthesis (RDS) was observed in the BRCA2-deficient fibroblasts but also in the FANCA-deficient fibroblasts, suggesting an impaired S-phase checkpoint. FA-D1/BRCA2 cells displayed greatly enhanced levels of spontaneous as well as MMC-induced chromosomal aberrations (Canada), similar to cells deficient in homologous recombination (HR) and non-D1 FA cells. In contrast to Brca2-deficient rodent cells, FA-D1/BRCA2 cells showed normal sister chromatid exchange (SCE) levels, both spontaneous as well as after MMC treatment. Hence, these data indicate that human cells with biallelic BRCA2 mutations display typical features of both FA- and HR-deficient cells, which suggests that FANCD1/BRCA2 is part of the integrated FA/BRCA DNA damage response pathway but also controls other functions outside the FA pathway.

  16. Stem cell therapy and cellular engineering for treatment of neuronal dysfunction in Huntington's disease.

    Science.gov (United States)

    Choi, Kyung-Ah; Hwang, Insik; Park, Hang-soo; Oh, Seung-Ick; Kang, Seongman; Hong, Sunghoi

    2014-07-01

    Huntington's disease (HD) is a fatal inherited neurodegenerative disorder characterized by progressive loss of neurons in the striatum, a sub-cortical region of the forebrain. The sub-cortical region of the forebrain is associated with the control of movement and behavior, thus HD initially presents with coordination difficulty and cognitive decline. Recent reprogramming technologies, including induced pluripotent stem cells (iPSCs) and induced neural stem cells (iNSCs), have created opportunities to understand the pathological cascades that underlie HD and to develop new treatments for this currently incurable neurological disease. The ultimate objectives of stem cell-based therapies for HD are to replace lost neurons and to prevent neuronal dysfunction and death. In this review, we examine the current understanding of the molecular and pathological mechanisms involved in HD. We discuss disease modeling with HD-iPSCs derived from the somatic cells of patients, which could provide an invaluable platform for understanding HD pathogenesis. We speculate about the benefits and drawbacks of using iNSCs as an alternative stem cell source for HD treatment. Finally, we discuss cell culture and engineering systems that promote the directed differentiation of pluripotent stem cell-derived NSCs into a striatal DARPP32(+) GABAergic MSN phenotype for HD. In conclusion, this review summarizes the potentials of cell reprogramming and engineering technologies relevant to the development of cell-based therapies for HD.

  17. Do Cells Sense Stress or Strain? Measurement of Cellular Orientation Can Provide a Clue☆

    OpenAIRE

    De, Rumi; Zemel, Assaf; Safran, Samuel A.

    2008-01-01

    We predict theoretically the steady-state orientation of cells subject to dynamical stresses that vary more quickly than the cell relaxation time. We show that the orientation is a strong function of the Poisson's ratio, ν, of the matrix when cell activity is governed by the matrix strain; if cell activity is governed by the matrix stress, the orientation depends only weakly on ν. These results can be used to differentiate systems in which the strain or the stress determine the setpoint for t...

  18. Glucose restriction induces transient G2 cell cycle arrest extending cellular chronological lifespan.

    Science.gov (United States)

    Masuda, Fumie; Ishii, Mahiro; Mori, Ayaka; Uehara, Lisa; Yanagida, Mitsuhiro; Takeda, Kojiro; Saitoh, Shigeaki

    2016-01-01

    While glucose is the fundamental source of energy in most eukaryotes, it is not always abundantly available in natural environments, including within the human body. Eukaryotic cells are therefore thought to possess adaptive mechanisms to survive glucose-limited conditions, which remain unclear. Here, we report a novel mechanism regulating cell cycle progression in response to abrupt changes in extracellular glucose concentration. Upon reduction of glucose in the medium, wild-type fission yeast cells undergo transient arrest specifically at G2 phase. This cell cycle arrest is dependent on the Wee1 tyrosine kinase inhibiting the key cell cycle regulator, CDK1/Cdc2. Mutant cells lacking Wee1 are not arrested at G2 upon glucose limitation and lose viability faster than the wild-type cells under glucose-depleted quiescent conditions, suggesting that this cell cycle arrest is required for extension of chronological lifespan. Our findings indicate the presence of a novel cell cycle checkpoint monitoring glucose availability, which may be a good molecular target for cancer therapy. PMID:26804466

  19. Modeling of Cell/Dendrite Transition During Directional Solidification of Ti-AI Alloy Using Cellular Automaton Method

    Institute of Scientific and Technical Information of China (English)

    WANG Kuang-fei; LI Bang-sheng; MI Guo-fa; GUO Jing-jie; FU Heng-zhi

    2008-01-01

    Solute diffusion controlled solidification model was used to simulate the initial stage cellular to dendrite transition of Ti44AI alloys during directional solidification at different velocities. The simulation results show that during this process, a mixed structure composed of cells and dendrites was observed, where secondary dendrites are absent at facing surface with parallel closely spaced dendrites, which agrees with the previous experimental observa-tion. The dendrite spacings are larger than cellular spacings at a given rate, and the columnar grain spacing sharply increases to a maximum as solidification advance to coexistence zone. In addition, simulation also revealed that decreasing the numbers of the seed causes the trend of unstable dendrite transition to increase. Finally, the main influence factors affecting cell/dendrite transition were analyzed, which could be the change of growth rates resulting in slight fluctuations of liquid composition occurred at growth front. The simulation results are in reasonable agreement with the results of previous theoretical models and experimental observation at low cooling rates.

  20. DNA damage induction and/or repair as mammalian cell biomarker for the prediction of cellular radiation response

    Science.gov (United States)

    Baumstark-Khan, C.

    DNA damage and its repair processes are key factors in cancer induction and also in the treatment of malignancies. Cancer prevention during extended space missions becomes a topic of great importance for space radiobiology. The knowledge of individual responsiveness would allow the protection strategy to be tailored optimally in each case. Radiobiological analysis of cultured cells derived from tissue explants from individuals has shown that measurement of the surviving fraction after 2 Gy (SF2) may be used to predict the individual responsiveness. However, clonogenic assays are timeconsuming, thus alternative assays for the determination of radiore-sponse are being sought. For that reason CHO cell strains having different repair capacities were used for examining whether DNA strand break repair is a suitable experimental design to allow predictive statements. Cellular survival (CFA assay) and DNA strand breaks (total DNA strand breaks: FADU technique; DSBs: non-denaturing elution) were determined in parallel immediately after irradiation as well as after a 24 hour recovery period according to dose. There were no correlations between the dose-response curves of the initial level of DNA strand breaks and parameters that describe clonogenic survival curves (SF2). A good correlation exists between intrinsic cellular radioresistance and the extent of residual DNA strand breaks.

  1. Effect of solid distribution on elastic properties of open-cell cellular solids using numerical and experimental methods.

    Science.gov (United States)

    Zargarian, A; Esfahanian, M; Kadkhodapour, J; Ziaei-Rad, S

    2014-09-01

    Effect of solid distribution between edges and vertices of three-dimensional cellular solid with an open-cell structure was investigated both numerically and experimentally. Finite element analysis (FEA) with continuum elements and appropriate periodic boundary condition was employed to calculate the elastic properties of cellular solids using tetrakaidecahedral (Kelvin) unit cell. Relative densities between 0.01 and 0.1 and various values of solid fractions were considered. In order to validate the numerical model, three scaffolds with the relative density of 0.08, but different amounts of solid in vertices, were fabricated via 3-D printing technique. Good agreement was observed between numerical simulation and experimental results. Results of numerical simulation showed that, at low relative densities (<0.03), Young׳s modulus increased by shifting materials away from edges to vertices at first and then decreased after reaching a critical point. However, for the high values of relative density, Young׳s modulus increased monotonically. Mechanisms of such a behavior were discussed in detail. Results also indicated that Poisson׳s ratio decreased by increasing relative density and solid fraction in vertices. By fitting a curve to the data obtained from the numerical simulation and considering the relative density and solid fraction in vertices, empirical relations were derived for Young׳s modulus and Poisson׳s ratio. PMID:24956160

  2. The Multiplicity of Cellular Infection Changes Depending on the Route of Cell Infection in a Plant Virus

    Science.gov (United States)

    Gutiérrez, Serafín; Pirolles, Elodie; Yvon, Michel; Baecker, Volker; Michalakis, Yannis

    2015-01-01

    ABSTRACT The multiplicity of cellular infection (MOI) is the number of virus genomes of a given virus species that infect individual cells. This parameter chiefly impacts the severity of within-host population bottlenecks as well as the intensity of genetic exchange, competition, and complementation among viral genotypes. Only a few formal estimations of the MOI currently are available, and most theoretical reports have considered this parameter as constant within the infected host. Nevertheless, the colonization of a multicellular host is a complex process during which the MOI may dramatically change in different organs and at different stages of the infection. We have used both qualitative and quantitative approaches to analyze the MOI during the colonization of turnip plants by Turnip mosaic virus. Remarkably, different MOIs were observed at two phases of the systemic infection of a leaf. The MOI was very low in primary infections from virus circulating within the vasculature, generally leading to primary foci founded by a single genome. Each lineage then moved from cell to cell at a very high MOI. Despite this elevated MOI during cell-to-cell progression, coinfection of cells by lineages originating in different primary foci is severely limited by the rapid onset of a mechanism inhibiting secondary infection. Thus, our results unveil an intriguing colonization pattern where individual viral genomes initiate distinct lineages within a leaf. Kin genomes then massively coinfect cells, but coinfection by two distinct lineages is strictly limited. IMPORTANCE The MOI is the size of the viral population colonizing cells and defines major phenomena in virus evolution, like the intensity of genetic exchange and the size of within-host population bottlenecks. However, few studies have quantified the MOI, and most consider this parameter as constant during infection. Our results reveal that the MOI can depend largely on the route of cell infection in a systemically

  3. Roles for glycosylation of cell surface receptors involved in cellular immune recognition.

    Science.gov (United States)

    Rudd, P M; Wormald, M R; Stanfield, R L; Huang, M; Mattsson, N; Speir, J A; DiGennaro, J A; Fetrow, J S; Dwek, R A; Wilson, I A

    1999-10-22

    The majority of cell surface receptors involved in antigen recognition by T cells and in the orchestration of the subsequent cell signalling events are glycoproteins. The length of a typical N-linked sugar is comparable with that of an immunoglobulin domain (30 A). Thus, by virtue of their size alone, oligosaccharides may be expected to play a significant role in the functions and properties of the cell surface proteins to which they are attached. A databank of oligosaccharide structures has been constructed from NMR and crystallographic data to aid in the interpretation of crystal structures of glycoproteins. As unambiguous electron density can usually only be assigned to the glycan cores, the remainder of the sugar is then modelled into the crystal lattice by superimposing the appropriate oligosaccharide from the database. This approach provides insights into the roles that glycosylation might play in cell surface receptors, by providing models that delineate potential close packing interactions on the cell surface. It has been proposed that the specific recognition of antigen by T cells results in the formation of an immunological synapse between the T cell and the antigen-presenting cell. The cell adhesion glycoproteins, such as CD2 and CD48, help to form a cell junction, providing a molecular spacer between opposing cells. The oligosaccharides located on the membrane proximal domains of CD2 and CD48 provide a scaffold to orient the binding faces, which leads to increased affinity. In the next step, recruitment of the peptide major histocompatibility complex (pMHC) by the T-cell receptors (TCRs) requires mobility on the membrane surface. The TCR sugars are located such that they could prevent non-specific aggregation. Importantly, the sugars limit the possible geometry and spacing of TCR/MHC clusters which precede cell signalling. We postulate that, in the final stage, the sugars could play a general role in controlling the assembly and stabilisation of the

  4. The cellular state determines the effect of melatonin on the survival of mixed cerebellar cell culture.

    Directory of Open Access Journals (Sweden)

    Daiane Gil Franco

    Full Text Available The constitutive activation of nuclear factor-κB (NF-κB, a key transcription factor involved in neuroinflammation, is essential for the survival of neurons in situ and of cerebellar granule cells in culture. Melatonin is known to inhibit the activation of NF-κB and has a cytoprotective function. In this study, we evaluated whether the cytoprotective effect of melatonin depends on the state of activation of a mixed cerebellar culture that is composed predominantly of granule cells; we tested the effect of melatonin on cultured rat cerebellar cells stimulated or not with lipopolysaccharide (LPS. The addition of melatonin (0.1 nM-1 µM reduced the survival of naïve cells while inhibiting LPS-induced cell death. Melatonin (100 nM transiently (15 min inhibited the nuclear translocation of both NF-κB dimers (p50/p50, p50/RelA and, after 60 min, increased the activation of p50/RelA. Melatonin-induced p50/RelA activity in naïve cells resulted in the transcription of inducible nitric oxide synthase (iNOS and the production of NO. Otherwise, in cultures treated with LPS, melatonin blocked the LPS-induced activation of p50/RelA and the reduction in p50/p50 levels and inhibited iNOS expression and NO synthesis. Therefore, melatonin in vehicle-treated cells induces cell death, while it protects against LPS-induced cytotoxicity. In summary, we confirmed that melatonin is a neuroprotective drug when cerebellar cells are challenged; however, melatonin can also lead to cell death when the normal balance of the NF-κB pathway is disturbed. Our data provide a mechanistic basis for understanding the influence of cell context on the final output response of melatonin.

  5. Measurement temperature increment of open-celled cellular Zn-22Al-2Cu alloy

    Science.gov (United States)

    Guzmán, R.; Santos, A.

    2016-08-01

    Thermo-mechanical properties of cellular materials, “metallic foams” make them very attractive in a variety of engineering applications. During plastic deformation of closedcell metallic foams, part of plastic work is converted into heat. The generated heat increases may be quantified using an infrared camera measuring radiation emitted on the surface of the metallic foam. Experimental tests were carried out under quasi-static loading conditions using Zn-22Al-2Cu (zinalco) foams featuring different pore sizes, and densities between 30% to 50% maintaining constant volume. The goal of this study was to analyse the effect of heat generation during quasistatic compression of metallic foams at constant strain rate. Some conclusions on the mechanical behaviour were obtained in terms of temperature increase, the nominal stress-strain curves and relative density.

  6. Combined Cell Culture-Biosensing Platform Using Vertically Aligned Patterned Peptide Nanofibers for Cellular Studies

    DEFF Research Database (Denmark)

    Taskin, Mehmet B.; Sasso, Luigi; Dimaki, Maria;

    2013-01-01

    This Article presents the development of a combined cell culture–biosensing platform using vertically aligned self-assembled peptide nanofibers. Peptide nanofibers were patterned on a microchip containing gold microelectrodes to provide the cells with a 3D environment enabling them to grow...

  7. A Cellular Potts Model simulating cell migration on and in matrix environments

    NARCIS (Netherlands)

    Scianna, M.; Preziosi, L.; Wolf, K.A.

    2013-01-01

    Cell migration on and through extracellular matrix is fundamental in a wide variety of physiological and pathological phenomena, and is exploited in scaffold-based tissue engineering. Migration is regulated by a number of extracellular matrix- or cell-derived biophysical parameters, such as matrix f

  8. Strategies for selecting recombinant CHO cell lines for cGMP manufacturing: improving the efficiency of cell line generation.

    Science.gov (United States)

    Porter, Alison J; Racher, Andrew J; Preziosi, Richard; Dickson, Alan J

    2010-01-01

    Transfectants with a wide range of cellular phenotypes are obtained during the process of cell line generation. For the successful manufacture of a therapeutic protein, a means is required to identify a cell line with desirable growth and productivity characteristics from this phenotypically wide-ranging transfectant population. This identification process is on the critical path for first-in-human studies. We have stringently examined a typical selection strategy used to isolate cell lines suitable for cGMP manufacturing. One-hundred and seventy-five transfectants were evaluated as they progressed through the different assessment stages of the selection strategy. High producing cell lines, suitable for cGMP manufacturing, were identified. However, our analyses showed that the frequency of isolation of the highest producing cell lines was low and that ranking positions were not consistent between each assessment stage, suggesting that there is potential to improve upon the strategy. Attempts to increase the frequency of isolation of the 10 highest producing cell lines, by in silico analysis of alternative selection strategies, were unsuccessful. We identified alternative strategies with similar predictive capabilities to the typical selection strategy. One alternate strategy required fewer cell lines to be progressed at the assessment stages but the stochastic nature of the models means that cell line numbers are likely to change between programs. In summary, our studies illuminate the potential for improvement to this and future selection strategies, based around use of assessments that are more informative or that reduce variance, paving the way to improved efficiency of generation of manufacturing cell lines. PMID:20623584

  9. Nanostructured upconverters for improved solar cell performance

    Science.gov (United States)

    MacQueen, Rowan W.; Schulze, Tim F.; Khoury, Tony; Cheng, Yuen Yap; Stannowski, Bernd; Lips, Klaus; Crossley, Maxwel J.; Schmidt, Timothy

    2013-09-01

    Triplet-triplet annihilation photon upconversion (TTA-UC) is a promising candidate for mitigating sub-band gap absorption losses in solar cells. In TTA-UC, sensitiser dyes absorb sub-band gap photons, cross to a triplet state, and transfer triplet excitons to emitter dyes. Two triplet-excited emitters can undergo TTA, raising one emitter to a higher-energy bright singlet state. The quadratic efficiency of TTA-UC at device-relevant light intensities motivates a push towards the higher chromophore densities achievable in the solid phase. We have begun this process by tethering tetrakisquinoxalino palladium porphyrin to 20nm silica nanoparticles using peptide chemistry techniques, achieving a total-volume concentration of 1.5mM. The phosphorescence kinetics of the tethered porphyrins was measured to quantify quenching by rubrene emitter. Upconverter performance was measured in a solar cell enhancement experiment.

  10. Cellular recovery from electroporation using synchronisation modulation as a rescue model for electrically injured cells.

    Science.gov (United States)

    Dando, Robin; Chen, Wei

    2008-12-01

    Electroporation of the plasma membrane resulting in a decrement in transmembrane potential is offered as a model in the study of the rescuing effects of the synchronisation modulation technique by electrically activating sodium potassium adenosine triphosphatase. Living cells were first electrically damaged by a pulsed intensive electric field, resulting in cell membrane electroporation, ion leakages and membrane potential depolarisation. Their recovery rate in natural conditions was compared with that of cells in a synchronisation modulation electric field. Fluorescence readings were taken using confocal microscopy and a potentiometric dye. Significantly more rapid recovery was observed after synchronisation modulation, with cell membranes actually polarised to levels higher than the original resting potential, a feature never seen in naturally recovering cells.

  11. Selective COX-2 inhibitor, NS-398, suppresses cellular proliferation in human hepatocellular carcinoma cell lines via cell cycle arrest

    Institute of Scientific and Technical Information of China (English)

    Ji Yeon Baek; Wonhee Hur; Jin Sang Wang; Si Hyun Bae; Seung Kew Yoon

    2007-01-01

    AIM: To investigate the growth inhibitory mechanism of NS-398, a selective cyclooxygenase-2 (COX-2) inhibitor,in two hepatocellular carcinoma (HCC) cell lines (HepG2and Huh7).METHODS: HepG2 and Huh7 cells were treated with NS-398. Its effects on cell viability, cell proliferation,cell cycles, and gene expression were respectively evaluated by water-soluble tetrazolium salt (WST-1)assay, 4'-6-diamidino-2-phenylindole (DAPI) staining,flow cytometer analysis, and Western blotting,with dimethyl sulfoxide (DMSO) as positive control.RESULTS: NS-398 showed dose- and time-dependent growth-inhibitory effects on the two cell lines.Proliferating cell nuclear antigen (PCNA) expressions in HepG2 and Huh7 cells, particularly in Huh7 cells were inhibited in a time- and dose-independent manner.NS-398 caused cell cycle arrest in the G1 phase with cell accumulation in the sub-G1 phase in HepG2 and Huh7cell lines. No evidence of apoptosis was observed in two cell lines.CONCLUSION: NS-398 reduces cell proliferation by inducing cell cycle arrest in HepG2 and Huh7 cell lines,and COX-2 inhibitors may have potent chemoprevention effects on human hepatocellular carcinoma.

  12. Nucleoside drugs induce cellular differentiation by caspase-dependent degradation of stem cell factors.

    Directory of Open Access Journals (Sweden)

    Tanja Musch

    Full Text Available BACKGROUND: Stem cell characteristics are an important feature of human cancer cells and play a major role in the therapy resistance of tumours. Strategies to target cancer stem cells are thus of major importance for cancer therapy. Differentiation therapy by nucleoside drugs represents an attractive approach for the elimination of cancer stem cells. However, even if it is generally assumed that the activity of these drugs is mediated by their ability to modulate epigenetic pathways, their precise mode of action remains to be established. We therefore analysed the potential of three nucleoside analogues to induce differentiation of the embryonic cancer stem cell line NTERA 2 D1 and compared their effect to the natural ligand retinoic acid. METHODOLOGY/PRINCIPAL FINDINGS: All nucleoside analogues analyzed, but not retinoic acid, triggered proteolytic d