WorldWideScience

Sample records for cell proliferative fate

  1. PUF-8, a Pumilio homolog, inhibits the proliferative fate in the Caenorhabditis elegans germline.

    Science.gov (United States)

    Racher, Hilary; Hansen, Dave

    2012-10-01

    Stem cell populations are maintained by keeping a balance between self-renewal (proliferation) and differentiation of dividing stem cells. Within the Caenorhabditis elegans germline, the key regulator maintaining this balance is the canonical Notch signaling pathway, with GLP-1/Notch activity promoting the proliferative fate. We identified the Pumilio homolog, PUF-8, as an inhibitor of the proliferative fate of stem cells in the C. elegans germline. puf-8(0) strongly enhances overproliferation of glp-1(gf) mutants and partially suppresses underproliferation of a weak glp-1(lf) mutant. The germline tumor that is formed in a puf-8(0); glp-1(gf) double mutant is due to a failure of germ cells to enter meiotic prophase. puf-8 likely inhibits the proliferative fate through negatively regulating GLP-1/Notch signaling or by functioning parallel to it.

  2. Cell output, cell cycle duration and neuronal specification: a model of integrated mechanisms of the neocortical proliferative process

    Science.gov (United States)

    Caviness, V. S. Jr; Goto, T.; Tarui, T.; Takahashi, T.; Bhide, P. G.; Nowakowski, R. S.

    2003-01-01

    The neurons of the neocortex are generated over a 6 day neuronogenetic interval that comprises 11 cell cycles. During these 11 cell cycles, the length of cell cycle increases and the proportion of cells that exits (Q) versus re-enters (P) the cell cycle changes systematically. At the same time, the fate of the neurons produced at each of the 11 cell cycles appears to be specified at least in terms of their laminar destination. As a first step towards determining the causal interrelationships of the proliferative process with the process of laminar specification, we present a two-pronged approach. This consists of (i) a mathematical model that integrates the output of the proliferative process with the laminar fate of the output and predicts the effects of induced changes in Q and P during the neuronogenetic interval on the developing and mature cortex and (ii) an experimental system that allows the manipulation of Q and P in vivo. Here we show that the predictions of the model and the results of the experiments agree. The results indicate that events affecting the output of the proliferative population affect both the number of neurons produced and their specification with regard to their laminar fate.

  3. An analysis of the growth of the retinal cell population in embryonic chicks yielding proliferative ratios, numbers of proliferative and non-proliferative cells and cell-cycle times for successive generations of cell cycles.

    Science.gov (United States)

    Morris, V B; Cowan, R

    1995-07-01

    Growth curves of the retinal cell population of embryonic chicks were fitted by a branching-process model of cell population growth, thereby estimating the proliferative ratios and mean cell-cycle times of the generations of cell cycles that underlie retinal growth. The proliferative ratio determines the proportion of cells that divides in the next generation, so the numbers of proliferative and non-proliferative cells in each generation of cell cycles were obtained. The mean cell-cycle times determine the times over which the generations are extant. Assuming growth starts from one cell in generation 0, the proliferative cells reach 3.6 x 10(6) and the non-proliferative cells reach 1.1 x 10(6) by generation 23. The next four generations increase the proliferative cell numbers to 13.9 x 10(6) and produce 20.1 x 10(6) non-proliferative cells. In the next five generations in the end phase of growth, non-proliferative cells are produced in large numbers at an average of 13.9 x 10(6) cells per generation as the retinal lineages are completed. The retinal cell population reaches a maximum estimated here at 98.2 x 10(6) cells. The mean cell-cycle time estimates range between 6.8 and 10.1 h in generations before the end phase of growth and between 10.6 and 17.2 h in generations in the end phase. The retinal cell population growth is limited by the depletion of the proliferative cell population that the production of non-proliferative cells entails. The proliferative ratios and the cell-cycle-time distribution parameters are the likely determinants of retinal growth rates. The results are discussed in relation to other results of spatial and temporal patterns of the cessation of cell cycling in the embryonic chick retina.

  4. Fate mapping of dendritic cells

    Directory of Open Access Journals (Sweden)

    Barbara Ursula Schraml

    2015-05-01

    Full Text Available Dendritic cells (DCs are a heterogeneous group of mononuclear phagocytes with versatile roles in immunity. They are classified predominantly based on phenotypic and functional properties, namely their stellate morphology, expression of the integrin CD11c and major histocompatibility class II molecules, as well as their superior capacity to migrate to secondary lymphoid organs and stimulate naïve T cells. However, these attributes are not exclusive to DCs and often change within inflammatory or infectious environments. This led to debates over cell identification and questioned even the mere existence of DCs as distinct leukocyte lineage. Here, we review experimental approaches taken to fate map DCs and discuss how these have shaped our understanding of DC ontogeny and lineage affiliation. Considering the ontogenetic properties of DCs will help to overcome the inherent shortcomings of purely phenotypic- and function-based approaches to cell definition and will yield a more robust way of DC classification.

  5. Caenorhabditis elegans vulval cell fate patterning

    Science.gov (United States)

    Félix, Marie-Anne

    2012-08-01

    The spatial patterning of three cell fates in a row of competent cells is exemplified by vulva development in the nematode Caenorhabditis elegans. The intercellular signaling network that underlies fate specification is well understood, yet quantitative aspects remain to be elucidated. Quantitative models of the network allow us to test the effect of parameter variation on the cell fate pattern output. Among the parameter sets that allow us to reach the wild-type pattern, two general developmental patterning mechanisms of the three fates can be found: sequential inductions and morphogen-based induction, the former being more robust to parameter variation. Experimentally, the vulval cell fate pattern is robust to stochastic and environmental challenges, and minor variants can be detected. The exception is the fate of the anterior cell, P3.p, which is sensitive to stochastic variation and spontaneous mutation, and is also evolving the fastest. Other vulval precursor cell fates can be affected by mutation, yet little natural variation can be found, suggesting stabilizing selection. Despite this fate pattern conservation, different Caenorhabditis species respond differently to perturbations of the system. In the quantitative models, different parameter sets can reconstitute their response to perturbation, suggesting that network variation among Caenorhabditis species may be quantitative. Network rewiring likely occurred at longer evolutionary scales.

  6. Amniocar as a proliferative medium for mesenchymal cells

    Directory of Open Access Journals (Sweden)

    V. V. Chestkov

    2014-01-01

    Full Text Available Objectives. To develop the Amniocar nutrient medium that contains fetal calf serum (FCS and growth factors cocktail for mass cultivation of human fibroblasts. To study proliferative activity of the medium on cultures of HUVEC cells of mesenchymal origin and mesenchymal stromal cells, as well as on cell culture of human amniotic fluid.Materials and methods. Determination of the rate of accumulation of the cellular mass and cell morphology in the course of cultivation of cells of various histogenesis in the Amniocar medium and nutrient medium that contains 10 % of FCS.Results. It has been demonstrated that the Amniocar medium is prevalent as compared to the standard DMEM medium with 10 % of FCS by 2 to 5 times for cultivation of skin fibroblasts, HUVEC, and mesenchymal stem cells. The Amniocar medium increased the quantity of endothelial cells that enter mitosis and maintained the culture of HUVEC cells with prolonged passaging in vitro. Clonal cultivation of human amniotic fluid cells in the Amniocar medium secured development of colonies of both fibroblast and epithelial type.Conclusions. Proliferative Amniocar medium is efficient for mass cultivation of various cells of mesenchymal origin and can be used for diagnostic purposes in medical genetics, oncology, etc.

  7. Characterization and functionality of proliferative human Sertoli cells.

    Science.gov (United States)

    Chui, Kitty; Trivedi, Alpa; Cheng, C Yan; Cherbavaz, Diana B; Dazin, Paul F; Huynh, Ai Lam Thu; Mitchell, James B; Rabinovich, Gabriel A; Noble-Haeusslein, Linda J; John, Constance M

    2011-01-01

    It has long been thought that mammalian Sertoli cells are terminally differentiated and nondividing postpuberty. For most previous in vitro studies immature rodent testes have been the source of Sertoli cells and these have shown little proliferative ability when cultured. We have isolated and characterized Sertoli cells from human cadaveric testes from seven donors ranging from 12 to 36 years of age. The cells proliferated readily in vitro under the optimized conditions used with a doubling time of approximately 4 days. Nuclear 5-ethynyl-2'-deoxyuridine (EdU) incorporation confirmed that dividing cells represented the majority of the population. Classical Sertoli cell ultrastructural features, lipid droplet accumulation, and immunoexpression of GATA-4, Sox9, and the FSH receptor (FSHr) were observed by electron and fluorescence microscopy, respectively. Flow cytometry revealed the expression of GATA-4 and Sox9 by more than 99% of the cells, and abundant expression of a number of markers indicative of multipotent mesenchymal cells. Low detection of endogenous alkaline phosphatase activity after passaging showed that few peritubular myoid cells were present. GATA-4 and SOX9 expression were confirmed by reverse transcription polymerase chain reaction (RT-PCR), along with expression of stem cell factor (SCF), glial cell line-derived neurotrophic factor (GDNF), and bone morphogenic protein 4 (BMP4). Tight junctions were formed by Sertoli cells plated on transwell inserts coated with fibronectin as revealed by increased transepithelial electrical resistance (TER) and polarized secretion of the immunoregulatory protein, galectin-1. These primary Sertoli cell populations could be expanded dramatically in vitro and could be cryopreserved. The results show that functional human Sertoli cells can be propagated in vitro from testicular cells isolated from adult testis. The proliferative human Sertoli cells should have important applications in studying infertility

  8. Hes4 controls proliferative properties of neural stem cells during retinal ontogenesis.

    Science.gov (United States)

    El Yakoubi, Warif; Borday, Caroline; Hamdache, Johanna; Parain, Karine; Tran, Hong Thi; Vleminckx, Kris; Perron, Muriel; Locker, Morgane

    2012-12-01

    The retina of fish and amphibian contains genuine neural stem cells located at the most peripheral edge of the ciliary marginal zone (CMZ). However, their cell-of-origin as well as the mechanisms that sustain their maintenance during development are presently unknown. We identified Hes4 (previously named XHairy2), a gene encoding a bHLH-O transcriptional repressor, as a stem cell-specific marker of the Xenopus CMZ that is positively regulated by the canonical Wnt pathway and negatively by Hedgehog signaling. We found that during retinogenesis, Hes4 labels a small territory, located first at the pigmented epithelium (RPE)/neural retina (NR) border and later in the retinal margin, that likely gives rise to adult retinal stem cells. We next addressed whether Hes4 might impart this cell subpopulation with retinal stem cell features: inhibited RPE or NR differentiation programs, continuous proliferation, and slow cell cycle speed. We could indeed show that Hes4 overexpression cell autonomously prevents retinal precursor cells from commitment toward retinal fates and maintains them in a proliferative state. Besides, our data highlight for the first time that Hes4 may also constitute a crucial regulator of cell cycle kinetics. Hes4 gain of function indeed significantly slows down cell division, mainly through the lengthening of G1 phase. As a whole, we propose that Hes4 maintains particular stemness features in a cellular cohort dedicated to constitute the adult retinal stem cell pool, by keeping it in an undifferentiated and slowly proliferative state along embryonic retinogenesis.

  9. Asymmetric cell division during T cell development controls downstream fate

    Science.gov (United States)

    Pham, Kim; Shimoni, Raz; Charnley, Mirren; Ludford-Menting, Mandy J.; Hawkins, Edwin D.; Ramsbottom, Kelly; Oliaro, Jane; Izon, David; Ting, Stephen B.; Reynolds, Joseph; Lythe, Grant; Molina-Paris, Carmen; Melichar, Heather; Robey, Ellen; Humbert, Patrick O.; Gu, Min

    2015-01-01

    During mammalian T cell development, the requirement for expansion of many individual T cell clones, rather than merely expansion of the entire T cell population, suggests a possible role for asymmetric cell division (ACD). We show that ACD of developing T cells controls cell fate through differential inheritance of cell fate determinants Numb and α-Adaptin. ACD occurs specifically during the β-selection stage of T cell development, and subsequent divisions are predominantly symmetric. ACD is controlled by interaction with stromal cells and chemokine receptor signaling and uses a conserved network of polarity regulators. The disruption of polarity by deletion of the polarity regulator, Scribble, or the altered inheritance of fate determinants impacts subsequent fate decisions to influence the numbers of DN4 cells arising after the β-selection checkpoint. These findings indicate that ACD enables the thymic microenvironment to orchestrate fate decisions related to differentiation and self-renewal. PMID:26370500

  10. Asymmetric PI3K Signaling Driving Developmental and Regenerative Cell Fate Bifurcation

    Directory of Open Access Journals (Sweden)

    Wen-Hsuan W. Lin

    2015-12-01

    Full Text Available Metazoan sibling cells often diverge in activity and identity, suggesting links between growth signals and cell fate. We show that unequal transduction of nutrient-sensitive PI3K/AKT/mTOR signaling during cell division bifurcates transcriptional networks and fates of kindred cells. A sibling B lymphocyte with stronger signaling, indexed by FoxO1 inactivation and IRF4 induction, undergoes PI3K-driven Pax5 repression and plasma cell determination, while its sibling with weaker PI3K activity renews a memory or germinal center B cell fate. PI3K-driven effector T cell determination silences TCF1 in one sibling cell, while its PI3K-attenuated sibling self-renews in tandem. Prior to bifurcations achieving irreversible plasma or effector cell fate determination, asymmetric signaling during initial divisions specifies a more proliferative, differentiation-prone lymphocyte in tandem with a more quiescent memory cell sibling. By triggering cell division but transmitting unequal intensity between sibling cells, nutrient-sensitive signaling may be a frequent arbiter of cell fate bifurcations during development and repair.

  11. Connecting Mitochondria, Metabolism, and Stem Cell Fate.

    Science.gov (United States)

    Wanet, Anaïs; Arnould, Thierry; Najimi, Mustapha; Renard, Patricia

    2015-09-01

    As sites of cellular respiration and energy production, mitochondria play a central role in cell metabolism. Cell differentiation is associated with an increase in mitochondrial content and activity and with a metabolic shift toward increased oxidative phosphorylation activity. The opposite occurs during reprogramming of somatic cells into induced pluripotent stem cells. Studies have provided evidence of mitochondrial and metabolic changes during the differentiation of both embryonic and somatic (or adult) stem cells (SSCs), such as hematopoietic stem cells, mesenchymal stem cells, and tissue-specific progenitor cells. We thus propose to consider those mitochondrial and metabolic changes as hallmarks of differentiation processes. We review how mitochondrial biogenesis, dynamics, and function are directly involved in embryonic and SSC differentiation and how metabolic and sensing pathways connect mitochondria and metabolism with cell fate and pluripotency. Understanding the basis of the crosstalk between mitochondria and cell fate is of critical importance, given the promising application of stem cells in regenerative medicine. In addition to the development of novel strategies to improve the in vitro lineage-directed differentiation of stem cells, understanding the molecular basis of this interplay could lead to the identification of novel targets to improve the treatment of degenerative diseases.

  12. [Nuclear heterogeneity and proliferative capacity of human adipose derived MSC-like cells].

    Science.gov (United States)

    Lavrov, A V; Smirnichina, S A

    2010-01-01

    Adipose derived stem cells (ADSCs) are MSC-like cells which could be easily used for regenerative medicine. Here, the morphology and proliferative capacity of human ADSCs is discribed. ADSCs were analyzed after one month of cultivation at a density of 10 cells/cm2. 21 colonies were counted. Few atypical cells (huge nuclei and cytoplasm) were found in 9 out of 17 colonies analyzed. ANOVA demonstrated that colonies also differed (P = 0.0025) in nuclei dimensions and scatter in the dimensions in each colony. Nuclei dimensions and cell density logarithms correlated in reverse proportion (-0.7; P = 0.002). Thus, ADSCs were heterogeneous and represented two types of cells: small highly proliferative and large low proliferative cells. Cell heterogeneity observed in some colonies might be due to cells registered at different cell cycle phases. Stable and typical morphology, colony-formation capability and high proliferative capacity of cells indicate visceral adipose tissue as a rich source of ADSCs.

  13. The C. elegans TPR Containing Protein, TRD-1, Regulates Cell Fate Choice in the Developing Germ Line and Epidermis.

    Directory of Open Access Journals (Sweden)

    Samantha Hughes

    Full Text Available Correct cell fate choice is crucial in development. In post-embryonic development of the hermaphroditic Caenorhabitis elegans, distinct cell fates must be adopted in two diverse tissues. In the germline, stem cells adopt one of three possible fates: mitotic cell cycle, or gamete formation via meiosis, producing either sperm or oocytes. In the epidermis, the stem cell-like seam cells divide asymmetrically, with the daughters taking on either a proliferative (seam or differentiated (hypodermal or neuronal fate. We have isolated a novel conserved C. elegans tetratricopeptide repeat containing protein, TRD-1, which is essential for cell fate determination in both the germline and the developing epidermis and has homologs in other species, including humans (TTC27. We show that trd-1(RNAi and mutant animals have fewer seam cells as a result of inappropriate differentiation towards the hypodermal fate. In the germline, trd-1 RNAi results in a strong masculinization phenotype, as well as defects in the mitosis to meiosis switch. Our data suggests that trd-1 acts downstream of tra-2 but upstream of fem-3 in the germline sex determination pathway, and exhibits a constellation of phenotypes in common with other Mog (masculinization of germline mutants. Thus, trd-1 is a new player in both the somatic and germline cell fate determination machinery, suggestive of a novel molecular connection between the development of these two diverse tissues.

  14. Cell fate regulation in early mammalian development

    Science.gov (United States)

    Oron, Efrat; Ivanova, Natalia

    2012-08-01

    Preimplantation development in mammals encompasses a period from fertilization to implantation and results in formation of a blastocyst composed of three distinct cell lineages: epiblast, trophectoderm and primitive endoderm. The epiblast gives rise to the organism, while the trophectoderm and the primitive endoderm contribute to extraembryonic tissues that support embryo development after implantation. In many vertebrates, such as frog or fish, maternally supplied lineage determinants are partitioned within the egg. Cell cleavage that follows fertilization results in polarization of these factors between the individual blastomeres, which become restricted in their developmental fate. In contrast, the mouse oocyte and zygote lack clear polarity and, until the eight-cell stage, individual blastomeres retain the potential to form all lineages. How are cell lineages specified in the absence of a maternally supplied blueprint? This is a fundamental question in the field of developmental biology. The answer to this question lies in understanding the cell-cell interactions and gene networks involved in embryonic development prior to implantation and using this knowledge to create testable models of the developmental processes that govern cell fates. We provide an overview of classic and contemporary models of early lineage development in the mouse and discuss the emerging body of work that highlights similarities and differences between blastocyst development in the mouse and other mammalian species.

  15. The indeterminate cell proliferative disorder: report of a case manifesting as an unusual cutaneous histiocytosis.

    Science.gov (United States)

    Wood, G S; Hu, C H; Beckstead, J H; Turner, R R; Winkelmann, R K

    1985-11-01

    A patient with an unusual, distinctive cutaneous histiocytosis is described. Extensive morphologic, antigenic, and enzymatic studies indicate that this histiocytosis represents a proliferative disorder of cutaneous indeterminate cells. Features that distinguish this disorder from other histiocytoses are discussed.

  16. Stochastic Cell Fate Progression in Embryonic Stem Cells

    Science.gov (United States)

    Zou, Ling-Nan; Doyle, Adele; Jang, Sumin; Ramanathan, Sharad

    2013-03-01

    Studies on the directed differentiation of embryonic stem (ES) cells suggest that some early developmental decisions may be stochastic in nature. To identify the sources of this stochasticity, we analyzed the heterogeneous expression of key transcription factors in single ES cells as they adopt distinct germ layer fates. We find that under sufficiently stringent signaling conditions, the choice of lineage is unambiguous. ES cells flow into differentiated fates via diverging paths, defined by sequences of transitional states that exhibit characteristic co-expression of multiple transcription factors. These transitional states have distinct responses to morphogenic stimuli; by sequential exposure to multiple signaling conditions, ES cells are steered towards specific fates. However, the rate at which cells travel down a developmental path is stochastic: cells exposed to the same signaling condition for the same amount of time can populate different states along the same path. The heterogeneity of cell states seen in our experiments therefore does not reflect the stochastic selection of germ layer fates, but the stochastic rate of progression along a chosen developmental path. Supported in part by the Jane Coffin Childs Fund

  17. Cell fate determination in the Caenorhabditis elegans epidermal lineages

    NARCIS (Netherlands)

    Soete, G.A.J.

    2007-01-01

    The starting point for this work was to use the hypodermal seam of C. elegans as a model system to study cell fate determination. Even though the seam is a relatively simple developmental system, the mechanisms that control cell fate determination in the seam lineages are connected in a highly compl

  18. EMT and MET as paradigms for cell fate switching

    Institute of Scientific and Technical Information of China (English)

    Jiekai Chen; Qingkai Han; Duanqing Pei

    2012-01-01

    Cell fate determination is a major unsolved problem in cell and developmental biology,The discovery of reprogramming by pluripotent factors offers a rational system to investigate the molecular mechanisms associated with cell fate decisions.The idea that reprogramming of fibroblasts starts with a mesenchymal-epithelial transition (MET) suggests that the process is perhaps a reversal of epithelial to mesenchymal transition (EMT) found frequently during early embryogenesis,As such,we believe that investigations into MET-EMT may yield detailed molecular insights into cell fate decisions,not only for the switching between epithelial and mesenchymal cells,but also other cell types.

  19. Integrative modelling of the influence of MAPK network on cancer cell fate decision.

    Directory of Open Access Journals (Sweden)

    Luca Grieco

    2013-10-01

    Full Text Available The Mitogen-Activated Protein Kinase (MAPK network consists of tightly interconnected signalling pathways involved in diverse cellular processes, such as cell cycle, survival, apoptosis and differentiation. Although several studies reported the involvement of these signalling cascades in cancer deregulations, the precise mechanisms underlying their influence on the balance between cell proliferation and cell death (cell fate decision in pathological circumstances remain elusive. Based on an extensive analysis of published data, we have built a comprehensive and generic reaction map for the MAPK signalling network, using CellDesigner software. In order to explore the MAPK responses to different stimuli and better understand their contributions to cell fate decision, we have considered the most crucial components and interactions and encoded them into a logical model, using the software GINsim. Our logical model analysis particularly focuses on urinary bladder cancer, where MAPK network deregulations have often been associated with specific phenotypes. To cope with the combinatorial explosion of the number of states, we have applied novel algorithms for model reduction and for the compression of state transition graphs, both implemented into the software GINsim. The results of systematic simulations for different signal combinations and network perturbations were found globally coherent with published data. In silico experiments further enabled us to delineate the roles of specific components, cross-talks and regulatory feedbacks in cell fate decision. Finally, tentative proliferative or anti-proliferative mechanisms can be connected with established bladder cancer deregulations, namely Epidermal Growth Factor Receptor (EGFR over-expression and Fibroblast Growth Factor Receptor 3 (FGFR3 activating mutations.

  20. Proliferative cell types in embryonic lineages of the central complex of the grasshopper Schistocerca gregaria.

    Science.gov (United States)

    Boyan, George; Williams, Leslie; Legl, Andrea; Herbert, Zsofia

    2010-08-01

    The central complex of the grasshopper Schistocerca gregaria develops to completion during embryogenesis. A major cellular contribution to the central complex is from the w, x, y, z lineages of the pars intercerebralis, each of which comprises over 100 cells, making them by far the largest in the embryonic protocerebrum. Our focus has been to find a cellular mechanism that allows such a large number of cell progeny to be generated within a restricted period of time. Immunohistochemical visualization of the chromosomes of mitotically active cells has revealed an almost identical linear array of proliferative cells present simultaneously in each w, x, y, z lineage at 50% of embryogenesis. This array is maintained relatively unchanged until almost 70% of embryogenesis, after which mitotic activity declines and then ceases. The array is absent from smaller lineages of the protocerebrum not associated with the central complex. The proliferative cells are located apically to the zone of ganglion mother cells and amongst the progeny of the neuroblast. Comparisons of cell morphology, immunoreactivity (horseradish peroxidase, repo, Prospero), location in lineages and spindle orientation have allowed us to distinguish the proliferative cells in an array from neuroblasts, ganglion mother cells, neuronal progeny and glia. Our data are consistent with the proliferative cells being secondary (amplifying) progenitors and originating from a specific subtype of ganglion mother cell. We propose a model of the way that neuroblasts, ganglion mother cells and secondary progenitors together produce the large cell numbers found in central complex lineages.

  1. Notch/gamma-secretase inhibition turns proliferative cells in intestinal crypts and adenomas into goblet cells.

    NARCIS (Netherlands)

    Es, J.H. van; Gijn, M.E. van; Riccio, O.; Born, M. van den; Vooijs, M.; Begthel, H.; Cozijnsen, M.; Robine, S.; Winston, D.J.; Radtke, F.; Clevers, J.C.

    2005-01-01

    The self-renewing epithelium of the small intestine is ordered into stem/progenitor crypt compartments and differentiated villus compartments. Recent evidence indicates that the Wnt cascade is the dominant force in controlling cell fate along the crypt-villus axis. Here we show a rapid, massive conv

  2. The Frequency of Proliferative Stromal Cells in Adipose Tissue Varies Between Inbred Mouse Strains

    Directory of Open Access Journals (Sweden)

    Mo J

    2009-01-01

    Full Text Available Stromal cells derived from adipose tissue (ASCs can proliferate as undifferentiated cells with a fibroblast-like morphology in cell culture, or can be induced to differentiate into a variety of cell types including, adipipogenic, myogenic, neurogenic, osteogenic, chondrogenic and hepatic cells. There is increasing interest to understand the factors controlling the proliferation of ASCs since these cells might provide a readily available source of autologous stem/progenitor cells for cell therapy applications. To explore potential genetic factors that modify the properties of ASCs, we tried to identify relevant properties of ASCs that differ between inbred mouse strains. Plating cells in a modified colony forming assay indicates that the percentage of high proliferative cells among ASCs differs more than 2-fold between 129x1/svj and C57Bl/6J mice. The identification of genetic factors affecting the proliferative capacity of stem cell populations could improve the efficacy of cell therapy.

  3. The differential proliferative ability of satellite cells in Lantang and Landrace pigs.

    Science.gov (United States)

    Wang, Xiu-qi; Yang, Wei-jun; Yang, Zhou; Shu, Gang; Wang, Song-bo; Jiang, Qing-yan; Yuan, Li; Wu, Tong-shan

    2012-01-01

    Here, for the first time, we evaluate the hypothesis that the proliferative abilities of satellite cells (SCs) isolated from Lantang (indigenous Chinese pigs) and Landrace pigs, which differ in muscle characteristics, are different. SCs were isolated from the longissimus dorsi muscle of neonatal Lantang and Landrace pigs. Proliferative ability was estimated by the count and proliferative activity of viable cells using a hemocytometer and MTT assay at different time points after seeding, respectively. Cell cycle information was detected by flow cytometry. Results showed that there was a greater (PLandrace pigs after 72 h of culture. The percentage of cell population in S phase and G(2)/M phases in Lantang pigs were higher (PLandrace pigs. The mRNA abundances of MyoD, Myf5, myogenin and Pax7 in SCs from Lantang pigs were higher (PLandrace pigs. Protein levels of MyoD, myogenin, myostatin, S6K, phosphorylated mTOR and phosphorylated eIF4E were consistent with the corresponding mRNA abundance. Collectively, these findings suggested that SCs in the two breeds present different proliferative abilities, and the proliferative potential of SCs in Lantang pigs is higher than in Landrace pigs.

  4. Cell fate patterning during C. elegans vulval development

    OpenAIRE

    Hill, Russell J.; Sternberg, Paul W.

    1993-01-01

    Precursor cells of the vulva of the C. elegans hermaphrodite choose between two vulval cell fates (1° and 2°) and a non-vulval epidermal fate (3°) in response to three intercellular signals. An inductive signal produced by the anchor cell induces the vulval precursors to assume the 1° and 2° vulval fates. This inductive signal is an EGF-like growth factor encoded by the gene lin-3. An inhibitory signal mediated by lin-15, and which may originate from the surrounding epidermis, prevents the vu...

  5. Influence of pro-angiogenic cytokines on proliferative activity and survival of endothelial cells

    Directory of Open Access Journals (Sweden)

    Solyanik G. I.

    2010-04-01

    Full Text Available Aim. Tumor angiogenesis in contrast to physiological one is characterized by high level of malignant cell production of proangiogenic cytokines, which have different influence on functional activity of endothelial cells. The goal of the study – to carry out a comparative analysis of the influence of a vascular endothelial growth factor (VEGF and an epidermal growth factor (EGF on proliferative activity and survival of endothelial cells upon their confluent and exponential growth. Methods. The proliferative activity of endothelial cells was determined by MTT-test and their viability was detected by the trypane blue exclusion test. Results. It was shown that EGF (irrespectively of the level of serum factors in concentrations higher than 10 ng/ml activated the proliferative activity of confluent endotheliocytes in a concentration-dependent manner by 18–36 % (ð < 0.05 as compared to the control, while this cytokine didn’t affect the endothelial cells in the exponential growth phase. VEGF in wide concentration range didn’t display the mitogenic effect on endotheliocytes in both confluent and exponential growth phases. Furthermore, VEGF in concentrations higher than 100 ng/ml inhibited proliferative activity of confluent endothelial cells by 12 % (ð < 0.05. In case of deficiency of nutrients, EGF and VEGF promoted the survival of endothelial cells, considerably decreasing their death. Conclusions. EGF, in contrast to VEGF, stimulates proliferation and survival of the endothelial cells, whereas VEGF has significant influence only on the survival of the cells

  6. [Proliferative Vitreoretinopathy].

    Science.gov (United States)

    Wiedemann, P; Bringmann, A

    2016-09-01

    Proliferative vitreoretinal retinopathy (PVR) is a very severe complication of vitreoretinal surgery. PVR is characterised by a complex cellular reaction. This corresponds to a vitreoretinal wound healing reaction and leads to tractional retinal detachment fixed by membranes. A rational goal of treatment is the removal of active cells and membranes, particularly the whole vitreous body; this can only be achieved surgically.

  7. Cell fate control in the developing central nervous system

    Energy Technology Data Exchange (ETDEWEB)

    Guérout, Nicolas; Li, Xiaofei; Barnabé-Heider, Fanie, E-mail: Fanie.Barnabe-Heider@ki.se

    2014-02-01

    The principal neural cell types forming the mature central nervous system (CNS) are now understood to be diverse. This cellular subtype diversity originates to a large extent from the specification of the earlier proliferating progenitor populations during development. Here, we review the processes governing the differentiation of a common neuroepithelial cell progenitor pool into mature neurons, astrocytes, oligodendrocytes, ependymal cells and adult stem cells. We focus on studies performed in mice and involving two distinct CNS structures: the spinal cord and the cerebral cortex. Understanding the origin, specification and developmental regulators of neural cells will ultimately impact comprehension and treatments of neurological disorders and diseases. - Highlights: • Similar mechanisms regulate cell fate in different CNS cell types and structures. • Cell fate regulators operate in a spatial–temporal manner. • Different neural cell types rely on the generation of a diversity of progenitor cells. • Cell fate decision is dictated by the integration of intrinsic and extrinsic signals.

  8. Control of stem cell fate by engineering their micro andnanoenvironment

    Institute of Scientific and Technical Information of China (English)

    Michelle F Griffin; Peter E Butler; Alexander M Seifalian; Deepak M Kalaskar

    2015-01-01

    Stem cells are capable of long-term self-renewal anddifferentiation into specialised cell types, making theman ideal candidate for a cell source for regenerativemedicine. The control of stem cell fate has become amajor area of interest in the field of regenerative medicineand therapeutic intervention. Conventional methodsof chemically inducing stem cells into specific lineagesis being challenged by the advances in biomaterialtechnology, with evidence highlighting that materialproperties are capable of driving stem cell fate. Materialsare being designed to mimic the clues stem cells receivein their in vivo stem cell niche including topographicaland chemical instructions. Nanotopographical clues thatmimic the extracellular matrix (ECM) in vivo have shownto regulate stem cell differentiation. The delivery of ECMcomponents on biomaterials in the form of short peptidessequences has also proved successful in directing stem celllineage. Growth factors responsible for controlling stemcell fate in vivo have also been delivered via biomaterialsto provide clues to determine stem cell differentiation. Analternative approach to guide stem cells fate is to providegenetic clues including delivering DNA plasmids andsmall interfering RNAs via scaffolds. This review, aims toprovide an overview of the topographical, chemical andmolecular clues that biomaterials can provide to guidestem cell fate. The promising features and challenges ofsuch approaches will be highlighted, to provide directionsfor future advancements in this exciting area of stem celltranslation for regenerative medicine.

  9. Anti-proliferative action of silibinin on human colon adenomatous cancer HT-29 cells

    OpenAIRE

    Reyhan Akhtar; Mohd Ali; Safrannisa Mahmood; Sankar Nath Sanyal

    2014-01-01

    Background: Silibinin a flavonoid from milk thistle (Silybum marianum) exhibit a variety of pharmacological actions, including anti-proliferative and apoptotic activities against various types of cancers in intact animals and cancer cell lines. In the present study, the effect of silibinin on human colon cancer HT-29 cells was studied. Method: Incubations of cells with different silibinin concentrations (0.783-1,600 μg/ml) for 24, 48 or 72 h showed a progressive decline in cell viability. Res...

  10. Expression of novel genes linked to the androgen-induced, proliferative shutoff in prostate cancer cells.

    Science.gov (United States)

    Geck, P; Szelei, J; Jimenez, J; Lin, T M; Sonnenschein, C; Soto, A M

    1997-01-01

    Androgens control cell numbers in the prostate through three separate pathways: (a) inhibition of cell death, (b) induction of cell proliferation (Step-1) and (c) inhibition of cell proliferation (Step-2, proliferative shutoff). The mechanisms underlying these phenomena are incompletely understood. The human prostate carcinoma LNCaP variants express these pathways as follows: LNCaP-FGC express both steps, LNCaP-LNO expresses Step-2, LNCaP-TAC expresses Step-1, and LNCaP-TJA cells express neither step. These cells facilitated the search for mediators of the androgen-induced proliferative shutoff pathway. Androgen exposure for 24 h or longer induced an irreversible proliferative shutoff in LNCaP-FGC cells. The Wang and Brown approach for identifying differentially expressed mRNAs was used to search for mediators of Step-2. Ten unique inserts were identified and from those ten, three genes were further studied. The basal expression of these genes in shutoff-negative variants was not affected by androgen exposure. They were induced by androgens in shutoff-positive LNCaP variants and the androgen receptor-transfected, shutoff-positive, MCF7-AR1 cells. These genes were induced only in the range of androgen concentrations that elicited the shutoff response. Time course analysis showed that their induction precedes the commitment point by 12-18 h. In addition, they were expressed in the normal prostate during proliferative shutoff. These features suggest that the candidate genes have a role in the regulation cascade for proliferative shutoff.

  11. Epigenetic memory and cell fate reprogramming in plants.

    Science.gov (United States)

    Birnbaum, Kenneth D; Roudier, François

    2017-02-01

    Plants have a high intrinsic capacity to regenerate from adult tissues, with the ability to reprogram adult cell fates. In contrast, epigenetic mechanisms have the potential to stabilize cell identity and maintain tissue organization. The question is whether epigenetic memory creates a barrier to reprogramming that needs to be erased or circumvented in plant regeneration. Early evidence suggests that, while chromatin dynamics impact gene expression in the meristem, a lasting constraint on cell fate is not established until late stages of plant cell differentiation. It is not yet clear whether the plasticity of plant cells arises from the ability of cells to erase identity memory or to deploy cells that may exhibit cellular specialization but still lack an epigenetic restriction on cell fate alteration.

  12. Proteome analysis of proliferative response of bystander cells adjacent to cells exposed to ionizing radiation.

    Science.gov (United States)

    Gerashchenko, Bogdan I; Yamagata, Akira; Oofusa, Ken; Yoshizato, Katsutoshi; de Toledo, Sonia M; Howell, Roger W

    2007-06-01

    Recently (Cytometry 2003, 56A, 71-80), we reported that direct cell-to-cell contact is required for stimulating proliferation of bystander rat liver cells (WB-F344) cocultured with irradiated cells, and neither functional gap junction intercellular communication nor long-range extracellular factors appear to be involved in this proliferative bystander response (PBR). The molecular basis for this response is unknown. Confluent monolayers of WB-F344 cells were exposed to 5-Gray (Gy) of gamma-rays. Irradiated cells were mixed with unirradiated cells and co-cultured for 24 h. Cells were harvested and protein expression was examined using 2-DE. Protein expression was also determined in cultures of unirradiated and 5-Gy irradiated cells. Proteins were identified by MS. Nucleophosmin (NPM)-1, a multifunctional nucleolar protein, was more highly expressed in bystander cells than in either unirradiated or 5-Gy irradiated cells. Enolase-alpha, a glycolytic enzyme, was present in acidic and basic variants in unirradiated cells. In bystander and 5-Gy irradiated cells, the basic variant was weakly expressed, whereas the acidic variant was overwhelmingly present. These data indicate that the presence of irradiated cells can affect NPM-1 and enolase-alpha in adjacent bystander cells. These proteins appear to participate in molecular events related to the PBR and suggest that this response may involve cellular defense, proliferation, and metabolism.

  13. Epithelial cell proliferative activity of Barrett's esophagus : methodology and correlation with traditional cancer risk markers

    NARCIS (Netherlands)

    Peters, F T; Ganesh, S; Kuipers, E J; de Jager-Krikken, A; Karrenbeld, A; Harms, G; Sluiter, W J; Koudstaal, J; Klinkenberg-Knol, E C; Lamers, C B; Kleibeuker, J H

    1998-01-01

    Barrett's esophagus (BE) is a premalignant condition, due to chronic gastroesophageal reflux. Effective antireflux therapy may diminish cancer risk. To evaluate this option an intermediate marker is needed. We developed a methodology for measurement of epithelial cell proliferative activity of Barre

  14. The influence of immunosuppressive drugs on neural stem/progenitor cell fate in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Skardelly, Marco, E-mail: Marco.Skardelly@med.uni-tuebingen.de [Department of Neurosurgery, University Hospital, Leipzig (Germany); Translational Centre for Regenerative Medicine, University of Leipzig, Leipzig (Germany); Glien, Anja; Groba, Claudia; Schlichting, Nadine [Department of Neurosurgery, University Hospital, Leipzig (Germany); Kamprad, Manja [Institute of Clinical Immunology, Medical Faculty, University of Leipzig, Leipzig (Germany); Meixensberger, Juergen [Department of Neurosurgery, University Hospital, Leipzig (Germany); Milosevic, Javorina [Translational Centre for Regenerative Medicine, University of Leipzig, Leipzig (Germany)

    2013-12-10

    In allogenic and xenogenic transplantation, adequate immunosuppression plays a major role in graft survival, especially over the long term. The effect of immunosuppressive drugs on neural stem/progenitor cell fate has not been sufficiently explored. The focus of this study is to systematically investigate the effects of the following four different immunotherapeutic strategies on human neural progenitor cell survival/death, proliferation, metabolic activity, differentiation and migration in vitro: (1) cyclosporine A (CsA), a calcineurin inhibitor; (2) everolimus (RAD001), an mTOR-inhibitor; (3) mycophenolic acid (MPA, mycophenolate), an inhibitor of inosine monophosphate dehydrogenase and (4) prednisolone, a steroid. At the minimum effective concentration (MEC), we found a prominent decrease in hNPCs' proliferative capacity (BrdU incorporation), especially for CsA and MPA, and an alteration of the NAD(P)H-dependent metabolic activity. Cell death rate, neurogenesis, gliogenesis and cell migration remained mostly unaffected under these conditions for all four immunosuppressants, except for apoptotic cell death, which was significantly increased by MPA treatment. - Highlights: • Four immunosuppresants (ISs) were tested in human neural progenitor cells in vitro. • Cyclosporine A and mycophenolic acid showed a prominent anti-proliferative activity • Mycophenolic acid exhibited a significant pro-apoptotic effect. • NAD(P)H-dependent metabolic activity was occasionally induced by ISs. • Neuronal differentiation and migration potential remained unaffected by ISs treatment.

  15. Cell Fate Switch during In Vitro Plant Organogenesis

    Institute of Scientific and Technical Information of China (English)

    Xiang Yu Zhao; Ying Hua Su; Zhi Juan Cheng; Xian Sheng Zhang

    2008-01-01

    Plant mature cells have the capability to reverse their state of differenUation and produce new organs under cultured conditions. Two phases, dedifferentiation and redifferentiation, are commonly characterized during in vitro organogenesis.In these processes, cells undergo fate switch several times regulated by both extrinsic and intrinsic factors, which are associated with reentry to the cell cycle, the balance between euchromatin and heterochromatin, reprogramming of gene expression, and so forth. This short article reviews the advances in the mechanism of organ regeneration from plant somatic cells in molecular, genomic and epigenetic aspects, aiming to provide important information on the mechanism underlying cell fate switch during in vitro plant organogenesis.

  16. Proliferative Effect of sTRAIL on Mouse Pancreatic Beta Cells

    Directory of Open Access Journals (Sweden)

    Sevim Kahraman

    2014-09-01

    Full Text Available Beta cell loss/impairment of function appears as a significant problem in both type 1 and type 2 diabetes. TRAIL (TNF-related apoptosis-inducing ligand was recently correlated with both types of diabetes with a proposed protective effect. TRAIL was also shown to promote survival and proliferation in different cells such as vascular smooth muscle cells and human vascular endothelial cells. Recently, TRAIL was claimed to protect pancreatic beta cells against cytokine-related harm. We hypothesized a proliferative effect for TRAIL on beta cells, and used Min6 mouse pancreatic beta cell line to test our hypothesis.

  17. Anti-proliferative effects of deflazacort on Nb2 cells as quantitated by formazan production.

    Science.gov (United States)

    Adler, R A; Naumann, S A; Mansouri, A; Krieg, R J; Latta, K; Sanders, K M

    1994-01-01

    Prolactin and other lactogenic hormones are mitogenic for the rat T-cell lymphoma line, Nb2. Glucocorticoids have antiproliferative effects on these cells. A limiting feature of experiments utilizing the Nb2 line is their labor-intensive nature. We therefore adapted the commonly used MTT dye proliferation assay for the Nb2 cell line. While rPRL, hPRL, oPRL, hGH, bPL, and to a lesser extent bPRL stimulated the Nb2 cells, hormones without lactogenic activity, rGH and oGH did not. Human serum and rat sera from animals bearing a PRL-secreting tumor stimulated the Nb2 cells in parallel to standards. Glucocorticoids had anti-proliferative effects on Nb2 cells in the presence of half-maximal or maximal PRL doses, as measured by the MTT proliferation assay. It has been claimed that an oxazoline steroid, deflazacort, has anti-inflammatory effects in clinical studies with fewer of the deleterious side-effects common to glucocorticoids. We therefore compared the in vitro anti-proliferative effects of deflazacort with other glucocorticoids. Deflazacort's negative effect on Nb2 cell proliferation was similar to that of cortisol and prednisolone and less than that of dexamethasone. We conclude that the MTT proliferation assay can be used to study both mitogenic and anti-proliferative substances in Nb2 cells. In addition we found that deflazacort acts similarly in vitro to other glucocorticoids.

  18. Tristetraprolin mediates the anti-proliferative effects of metformin in breast cancer cells.

    Science.gov (United States)

    Pandiri, Indira; Chen, Yingqing; Joe, Yeonsoo; Kim, Hyo Jeong; Park, Jeongmin; Chung, Hun Taeg; Park, Jeong Woo

    2016-02-01

    Metformin, which is a drug commonly prescribed to treat type 2 diabetes, has anti-proliferative effects in cancer cells; however, the molecular mechanisms underlying this effect remain largely unknown. The aim is to investigate the role of tristetraprolin (TTP), an AU-rich element-binding protein, in anti-proliferative effects of metformin in cancer cells. p53 wild-type and p53 mutant breast cancer cells were treated with metformin, and expression of TTP and c-Myc was analyzed by semi-quantitative RT-PCR, Western blots, and promoter activity assay. Breast cancer cells were transfected with siRNA against TTP to inhibit TTP expression or c-Myc and, after metformin treatment, analyzed for cell proliferation by MTS assay. Metformin induces the expression of tristetraprolin (TTP) in breast cancer cells in a p53-independent manner. Importantly, inhibition of TTP abrogated the anti-proliferation effect of metformin. We observed that metformin decreased c-Myc levels, and ectopic expression of c-Myc blocked the effect of metformin on TTP expression and cell proliferation. Our data indicate that metformin induces TTP expression by reducing the expression of c-Myc, suggesting a new model whereby TTP acts as a mediator of metformin's anti-proliferative activity in cancer cells.

  19. Suppressor cell activity in a proliferative disorder of T lymphocytes.

    Science.gov (United States)

    Kupa, A; Thomas, M E; Moore, H; Bradley, J; Zola, H; Hooper, M; Harding, P

    1981-06-01

    We report details of the immunological profile of a patient with the candidiasis endocrinopathy syndrome who has developed T-type chronic lymphocytic leukaemia. The patient is anergic to a panel of delayed hypersensitivity skin tests, and has poor in vitro mitogenic responses, but B cell function in vivo is not impaired. Subsequent functional studies have revealed that cells from the patient have a significant suppressive effect in coculture (P less than 0.05) on the responses of healthy donor lymphocytes (NR) to the mitogen phytohaemagglutinin (PHA). A degree of selectivity for the suppressive effect is suggested by the lack of similar effects on coculture responses to the mitogens concanavalin A (Con A) and pokeweed mitogen (PWM). Mitomycin C treatment of the patient's cells reduced their suppressive activity but significant suppression was still observed in the majority of PHA cocultures. The suppressor activity required the presence of the patient's cells in cocultures, as no suppression was observed when the patient's serum or cell culture supernatant were included instead of the patient's cells in NR cultures.

  20. The differential proliferative ability of satellite cells in Lantang and Landrace pigs.

    Directory of Open Access Journals (Sweden)

    Xiu-qi Wang

    Full Text Available Here, for the first time, we evaluate the hypothesis that the proliferative abilities of satellite cells (SCs isolated from Lantang (indigenous Chinese pigs and Landrace pigs, which differ in muscle characteristics, are different. SCs were isolated from the longissimus dorsi muscle of neonatal Lantang and Landrace pigs. Proliferative ability was estimated by the count and proliferative activity of viable cells using a hemocytometer and MTT assay at different time points after seeding, respectively. Cell cycle information was detected by flow cytometry. Results showed that there was a greater (P<0.05 number of SCs in Lantang pigs compared with Landrace pigs after 72 h of culture. The percentage of cell population in S phase and G(2/M phases in Lantang pigs were higher (P<0.05, while in G(0/G(1 phase was lower (P<0.05 in comparison with the Landrace pigs. The mRNA abundances of MyoD, Myf5, myogenin and Pax7 in SCs from Lantang pigs were higher (P<0.05, while those of myostatin, Smad3 and genes in the mammalian target of rapamycin (mTOR pathway (with the exception of 4EBP1 were lower (P<0.05 than the Landrace pigs. Protein levels of MyoD, myogenin, myostatin, S6K, phosphorylated mTOR and phosphorylated eIF4E were consistent with the corresponding mRNA abundance. Collectively, these findings suggested that SCs in the two breeds present different proliferative abilities, and the proliferative potential of SCs in Lantang pigs is higher than in Landrace pigs.

  1. Cell fate in the hand of Plk4

    NARCIS (Netherlands)

    Tanenbaum, Marvin E.; Medema, Rene H.

    2007-01-01

    The transcription factor Hand1 is required for cell-fate determination during placental development. Recent work shows that release of Hand1 from the nucleolus controls differentiation of trophoblast stem cells into trophoblast giant cells, and this switch is controlled by the antagonistic activitie

  2. Towards a statistical mechanics of cell fate decisions.

    Science.gov (United States)

    Garcia-Ojalvo, Jordi; Martinez Arias, Alfonso

    2012-12-01

    The spatiotemporal organization of a developing organism requires carefully orchestrated sequences of cellular differentiation events. These events are triggered by decisions made by individual cells about their fate, which are in turn controlled by gene and protein regulation processes. While these cell fate decisions are subject to stochasticity and are not reproducible at the single-cell level, they result in highly consistent, almost deterministic patterns at the level of the whole cell population. The question of how this macroscopic order arises from a disordered microscopic behaviour is still outstanding, and is reminiscent of problems in physical systems that are readily addressed by statistical mechanics. Here we review recent studies that are beginning to provide the data needed to address this question and discuss conceptual ideas that might be used in a theoretical understanding of cell fate decision processes, emphasizing the challenges that biology poses to the application of statistical mechanics approaches to developmental biology.

  3. Cell fate determination by ubiquitin-dependent regulation of translation

    Science.gov (United States)

    Werner, Achim; Iwasaki, Shintaro; McGourty, Colleen; Medina-Ruiz, Sofia; Teerikorpi, Nia; Fedrigo, Indro; Ingolia, Nicholas T.; Rape, Michael

    2015-01-01

    Metazoan development depends on accurate execution of differentiation programs that allow pluripotent stem cells to adopt specific fates 1. Differentiation requires changes to chromatin architecture and transcriptional networks, yet whether other regulatory events support cell fate determination is less well understood. Here, we have identified the vertebrate-specific ubiquitin ligase CUL3KBTBD8 as an essential regulator of neural crest specification. CUL3KBTBD8 monoubiquitylates NOLC1 and its paralog TCOF1, whose mutation underlies the neurocristopathy Treacher Collins Syndrome 2,3. Ubiquitylation drives formation of a TCOF1-NOLC1 platform that connects RNA polymerase I with ribosome modification enzymes and remodels the translational program of differentiating cells in favor of neural crest specification. We conclude that ubiquitin-dependent regulation of translation is an important feature of cell fate determination. PMID:26399832

  4. Binary cell fate decisions and fate transformation in the Drosophila larval eye.

    Directory of Open Access Journals (Sweden)

    Abhishek Kumar Mishra

    Full Text Available The functionality of sensory neurons is defined by the expression of specific sensory receptor genes. During the development of the Drosophila larval eye, photoreceptor neurons (PRs make a binary choice to express either the blue-sensitive Rhodopsin 5 (Rh5 or the green-sensitive Rhodopsin 6 (Rh6. Later during metamorphosis, ecdysone signaling induces a cell fate and sensory receptor switch: Rh5-PRs are re-programmed to express Rh6 and become the eyelet, a small group of extraretinal PRs involved in circadian entrainment. However, the genetic and molecular mechanisms of how the binary cell fate decisions are made and switched remain poorly understood. We show that interplay of two transcription factors Senseless (Sens and Hazy control cell fate decisions, terminal differentiation of the larval eye and its transformation into eyelet. During initial differentiation, a pulse of Sens expression in primary precursors regulates their differentiation into Rh5-PRs and repression of an alternative Rh6-cell fate. Later, during the transformation of the larval eye into the adult eyelet, Sens serves as an anti-apoptotic factor in Rh5-PRs, which helps in promoting survival of Rh5-PRs during metamorphosis and is subsequently required for Rh6 expression. Comparably, during PR differentiation Hazy functions in initiation and maintenance of rhodopsin expression. Hazy represses Sens specifically in the Rh6-PRs, allowing them to die during metamorphosis. Our findings show that the same transcription factors regulate diverse aspects of larval and adult PR development at different stages and in a context-dependent manner.

  5. Cdc20 control of cell fate during prolonged mitotic arrest

    DEFF Research Database (Denmark)

    Nilsson, Jakob

    2011-01-01

    The fate of cells arrested in mitosis by antimitotic compounds is complex but is influenced by competition between pathways promoting cell death and pathways promoting mitotic exit. As components of both of these pathways are regulated by Cdc20-dependent degradation, I hypothesize that variations...

  6. Cell fate determination in zebrafish embryonic and adult muscle development

    NARCIS (Netherlands)

    Tee, J.M.

    2010-01-01

    We are interested in how the genetic basis of muscle precursor cells determines the outcome of the muscle cell fate, and thus leading to disruption in muscle formation and maintenance. We utilized the zebrafish carrying mutations in both Axin1 and Apc1, resulting in overactivation of the Wnt/beta-ca

  7. FY08 LDRD Final Report Stem Cell Fate Decisions

    Energy Technology Data Exchange (ETDEWEB)

    Hiddessen, A

    2009-03-02

    A detailed understanding of the biological control of fate decisions of stem and progenitor cells is needed to harness their full power for tissue repair and/or regeneration. Currently, internal and external factors that regulate stem cell fate are not fully understood. We aim to engineer biocompatible tools to facilitate the measurement and comparison of the roles and significance of immobilized factors such as extracellular matrix and signaling peptides, synergistic and opposing soluble factors and signals, and cell-to-cell communication, in stem cell fate decisions. Our approach is based on the development of cell microarrays to capture viable stem/progenitor cells individually or in small clusters onto substrate-bound signals (e.g. proteins), combined with conventional antibody and customized subcellular markers made in-house, to facilitate tracking of cell behavior during exposure to relevant signals. Below we describe our efforts, including methods to manipulate a model epithelial stem cell system using a custom subcellular reporter to track and measure cell signaling, arrays with surface chemistry that support viable cells and enable controlled presentation of immobilized signals to cells on the array and fluorescence-based measurement of cell response, and successful on-array tests via conventional immunofluorescence assays that indicate correct cell polarity, localization of junctional proteins, and phenotype, properties which are essential to measuring true cell responses.

  8. A Convenient and Efficient Method to Enrich and Maintain Highly Proliferative Human Fetal Liver Stem Cells.

    Science.gov (United States)

    Guo, Xuan; Wang, Shu; Dou, Ya-ling; Guo, Xiang-fei; Chen, Zhao-li; Wang, Xin-wei; Shen, Zhi-qiang; Qiu, Zhi-gang; Jin, Min; Li, Jun-wen

    2015-06-01

    Pluripotent human hepatic stem cells have broad research and clinical applications, which are, however, restricted by both limited resources and technical difficulties with respect to isolation of stem cells from the adult or fetal liver. In this study, we developed a convenient and efficient method involving a two-step in situ collagenase perfusion, gravity sedimentation, and Percoll density gradient centrifugation to enrich and maintain highly proliferative human fetal liver stem cells (hFLSCs). Using this method, the isolated hFLSCs entered into the exponential growth phase within 10 days and maintained sufficient proliferative activity to permit subculture for at least 20 passages without differentiation. Immunocytochemistry, immunofluorescence, and flow cytometry results showed that these cells expressed stem cell markers, such as c-kit, CD44, epithelial cell adhesion molecule (EpCAM), oval cell marker-6 (OV-6), epithelial marker cytokeratin 18 (CK18), biliary ductal marker CK19, and alpha-fetoprotein (AFP). Gene expression analysis showed that these cells had stable mRNA expression of c-Kit, EpCAM, neural cell adhesion molecule (NCAM), CK19, CK18, AFP, and claudin 3 (CLDN-3) throughout each passage while maintaining low levels of ALB, but with complete absence of cytochrome P450 3A4 (C3A4), phosphoenolpyruvate carboxykinase (PEPCK), telomeric repeat binding factor (TRF), and connexin 26 (CX26) expression. When grown in appropriate medium, these isolated liver stem cells could differentiate into hepatocytes, cholangiocytes, osteoblasts, adipocytes, or endothelial cells. Thus, we have demonstrated a more economical and efficient method to isolate hFLSCs than magnetic-activated cell sorting (MACS). This novel approach may provide an excellent tool to isolate highly proliferative hFLSCs for tissue engineering and regenerative therapies.

  9. ROLE OF THE MORPHOMETRIC PARAMETERS OF INTRATUMORAL MICROVESSELS AND THE PROLIFERATIVE ACTIVITY OF TUMOR CELLS IN RENAL CELL CARCINOMA

    Directory of Open Access Journals (Sweden)

    N. A. Gorban

    2014-08-01

    Full Text Available Tumor cell proliferation and angiogenesis are essential factors for tumor growth, progression, and metastasis.Objective: to assess the relationship between the values of proliferative activity and the morphometric parameters of intratumoral microvessels in metastatic and localized carcinomas of the kidney.Materials and methods. Surgical specimens taken from 54 patients (32 men and 22 women aged 26 to 69 years (mean age 55 ± 1.5 years with the verified diagnosis of clear-cell renal cell carcinoma (RCC were studied.Conclusion. Proliferative activity and angioarchitectonics are an important biological characteristic of a tumor of unequal clinical value in RCC. Metastatic carcinoma has a higher proliferative activity and a low tumor vascularization than those of localized carcinoma.

  10. Cyclin D3 is selectively required for proliferative expansion of germinal center B cells.

    Science.gov (United States)

    Cato, Matthew H; Chintalapati, Suresh K; Yau, Irene W; Omori, Sidne A; Rickert, Robert C

    2011-01-01

    The generation of robust T-cell-dependent humoral immune responses requires the formation and expansion of germinal center structures within the follicular regions of the secondary lymphoid tissues. B-cell proliferation in the germinal center drives ongoing antigen-dependent selection and the generation of high-affinity class-switched plasma and memory B cells. However, the mechanisms regulating B-cell proliferation within this microenvironment are largely unknown. Here, we report that cyclin D3 is uniquely required for germinal center progression. Ccnd3(-/-) mice exhibit a B-cell-intrinsic defect in germinal center maturation and fail to generate an affinity-matured IgG response. We determined that the defect resulted from failed proliferative expansion of GL7(+) IgD(-) PNA(+) B cells. Mechanistically, sustained expression of cyclin D3 was found to be regulated at the level of protein stability and controlled by glycogen synthase kinase 3 in a cyclic AMP-protein kinase A-dependent manner. The specific defect in proliferative expansion of GL7(+) IgD(-) PNA(+) B cells in Ccnd3(-/-) mice defines an underappreciated step in germinal center progression and solidifies a role for cyclin D3 in the immune response, and as a potential therapeutic target for germinal center-derived B-cell malignancies.

  11. Neural Induction, Neural Fate Stabilization, and Neural Stem Cells

    Directory of Open Access Journals (Sweden)

    Sally A. Moody

    2002-01-01

    Full Text Available The promise of stem cell therapy is expected to greatly benefit the treatment of neurodegenerative diseases. An underlying biological reason for the progressive functional losses associated with these diseases is the extremely low natural rate of self-repair in the nervous system. Although the mature CNS harbors a limited number of self-renewing stem cells, these make a significant contribution to only a few areas of brain. Therefore, it is particularly important to understand how to manipulate embryonic stem cells and adult neural stem cells so their descendants can repopulate and functionally repair damaged brain regions. A large knowledge base has been gathered about the normal processes of neural development. The time has come for this information to be applied to the problems of obtaining sufficient, neurally committed stem cells for clinical use. In this article we review the process of neural induction, by which the embryonic ectodermal cells are directed to form the neural plate, and the process of neural�fate stabilization, by which neural plate cells expand in number and consolidate their neural fate. We will present the current knowledge of the transcription factors and signaling molecules that are known to be involved in these processes. We will discuss how these factors may be relevant to manipulating embryonic stem cells to express a neural fate and to produce large numbers of neurally committed, yet undifferentiated, stem cells for transplantation therapies.

  12. Taenia taeniaeformis: fate and proliferation of mucosal cells during gastric hyperplasia in larvae infected rats.

    Science.gov (United States)

    Lagapa, J T; Oku, Y; Nonaka, N; Kamiya, M

    2008-04-01

    Fate and proliferation of gastric mucosal cells during hyperplasia of Taenia taeniaeformis eggs inoculated Wistar rats were investigated using PCNA immunohistochemistry, BrdU labeling and other histopathologic staining techniques. Results revealed marked cell proliferation in gastric corpus and antral mucosa of infected rats as evidenced by increased lengths of proliferative zones and indices of BrdU labeling. The gastropathy in corpus was characterized by massive accumulation of precursors, neck and intermediate cells following significant decreases in numbers of parietal and zymogenic cells. Gastropathy in antrum was described with significant increases in precursors and mucous cells. Our results suggested that T. taeniaeformis-induced gastric hyperplasia was initiated by depletion of parietal cells presumably due to the cestode's ES products. As a result, there was inhibition of zymogenic cell differentiation due to the disruption of normal development pathways of gastric mucosal lineages. These sequences of events were considered to cause the increase in cell proliferation and accumulation of intermediate cells resulting to the hyperplastic lesions.

  13. Long-term nonprogression and broad HIV-1-specific proliferative T-cell responses

    Directory of Open Access Journals (Sweden)

    Nesrina eImami

    2013-03-01

    Full Text Available Complex mechanisms underlying the maintenance of fully functional, proliferative, HIV-1-specific T-cell responses involve processes from early T-cell development through to the final stages of T-cell differentiation and antigen recognition. Virus-specific proliferative CD4 and CD8 T-cell responses, important for the control of infection, are observed in some HIV-1+ patients during early stages of disease, and are maintained in long-term nonprogressing subjects. In the vast majority of HIV-1+ patients, full immune functionality is lost when proliferative HIV-1-specific T-cell responses undergo a variable progressive decline throughout the course of chronic infection. This appears irreparable despite administration of potent combination antiretroviral therapy, which to date is non-curative, necessitating life-long administration and the development of effective, novel, therapeutic interventions. While a sterilising cure, involving clearance of virus from the host, remains a primary aim, a functional cure may be a more feasible goal with considerable impact on worldwide HIV-1 infection. Such an approach would enable long-term co-existence of host and virus in the absence of toxic and costly drugs. Effective immune homeostasis coupled with a balanced response appropriately targeting conserved viral antigens, in a manner that avoids hyperactivation and exhaustion, may prove to be the strongest correlate of durable viral control. This review describes novel concepts underlying full immune functionality in the context of HIV-1 infection, which may be utilised in future strategies designed to improve upon existing therapy. The aim will be to induce long-term nonprogressor or elite controller status in every infected host, through immune-mediated control of viraemia and reduction of viral reservoirs, leading to lower HIV-1 transmission rates.

  14. Cell fate determination during tooth development and regeneration.

    Science.gov (United States)

    Mitsiadis, Thimios A; Graf, Daniel

    2009-09-01

    Teeth arise from sequential and reciprocal interactions between the oral epithelium and the underlying cranial neural crest-derived mesenchyme. Their formation involves a precisely orchestrated series of molecular and morphogenetic events, and gives us the opportunity to discover and understand the nature of the signals that direct cell fates and patterning. For that reason, it is important to elucidate how signaling factors work together in a defined number of cells to generate the diverse and precise patterned structures of the mature functional teeth. Over the last decade, substantial research efforts have been directed toward elucidating the molecular mechanisms that control cell fate decisions during tooth development. These efforts have contributed toward the increased knowledge on dental stem cells, and observation of the molecular similarities that exist between tooth development and regeneration.

  15. Hyper-activation of Notch3 amplifies the proliferative potential of rhabdomyosarcoma cells.

    Directory of Open Access Journals (Sweden)

    Maria De Salvo

    Full Text Available Rhabdomyosarcoma (RMS is a pediatric myogenic-derived soft tissue sarcoma that includes two major histopathological subtypes: embryonal and alveolar. The majority of alveolar RMS expresses PAX3-FOXO1 fusion oncoprotein, associated with the worst prognosis. RMS cells show myogenic markers expression but are unable to terminally differentiate. The Notch signaling pathway is a master player during myogenesis, with Notch1 activation sustaining myoblast expansion and Notch3 activation inhibiting myoblast fusion and differentiation. Accordingly, Notch1 signaling is up-regulated and activated in embryonal RMS samples and supports the proliferation of tumor cells. However, it is unable to control their differentiation properties. We previously reported that Notch3 is activated in RMS cell lines, of both alveolar and embryonal subtype, and acts by inhibiting differentiation. Moreover, Notch3 depletion reduces PAX3-FOXO1 alveolar RMS tumor growth in vivo. However, whether Notch3 activation also sustains the proliferation of RMS cells remained unclear. To address this question, we forced the expression of the activated form of Notch3, Notch3IC, in the RH30 and RH41 PAX3-FOXO1-positive alveolar and in the RD embryonal RMS cell lines and studied the proliferation of these cells. We show that, in all three cell lines tested, Notch3IC over-expression stimulates in vitro cell proliferation and prevents the effects of pharmacological Notch inhibition. Furthermore, Notch3IC further increases RH30 cell growth in vivo. Interestingly, knockdown of Notch canonical ligands JAG1 or DLL1 in RMS cell lines decreases Notch3 activity and reduces cell proliferation. Finally, the expression of Notch3IC and its target gene HES1 correlates with that of the proliferative marker Ki67 in a small cohort of primary PAX-FOXO1 alveolar RMS samples. These results strongly suggest that high levels of Notch3 activation increase the proliferative potential of RMS cells.

  16. Epigenetic control of embryonic stem cell fate

    DEFF Research Database (Denmark)

    Christophersen, Nicolaj Strøyer; Helin, Kristian

    2010-01-01

    Embryonic stem (ES) cells are derived from the inner cell mass of the preimplantation embryo and are pluripotent, as they are able to differentiate into all cell types of the adult organism. Once established, the pluripotent ES cells can be maintained under defined culture conditions, but can also...... be induced rapidly to differentiate. Maintaining this balance of stability versus plasticity is a challenge, and extensive studies in recent years have focused on understanding the contributions of transcription factors and epigenetic enzymes to the "stemness" properties of these cells. Identifying...... the molecular switches that regulate ES cell self-renewal versus differentiation can provide insights into the nature of the pluripotent state and enhance the potential use of these cells in therapeutic applications. Here, we review the latest models for how changes in chromatin methylation can modulate ES cell...

  17. Anti-proliferative activity of Fumaria vaillantii extracts on different cancer cell lines

    Directory of Open Access Journals (Sweden)

    Fatemeh Haji Abbas Tabrizi

    2016-01-01

    Full Text Available Plant-derived natural products are known to have cancer chemo-preventive and chemo-therapeutic properties. Plant extracts or their active constituents are used as folk medicine in traditional therapies by 80% of the world population. The aim of the present study was to determine the anti-proliferative potential of Fumaria vaillantii extracts on three different cancer cell lines including malignant melanoma SKMEL-3, human breast adenocarcinoma MCF-7 and human myelogenous leukemia K562 as well as human gingival fibroblast (HGF as normal cell line. Anti-proliferative activity was evaluated by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT, flowcytometry and annexin methods. Total phenolics and flavonoids were determined by Folin-Ciocalteu and aluminum chloride methods. Chloroform fraction had the lowest IC 50 value at 72 h (0.1 μg/ml in MCF-7 cells. Flowcytometry and annexin-V analysis indicated that the chloroform fraction induced necrosis in MCF-7 cells. In addition, the colorimetric methods showed that the methanolic fraction possessed the highest amount of total phenolics (33.03 ± 0.75 mg/g of dry powder and flavonoids (10.5 ± 2.0 mg/g of dry powder.The collective data demonstrated that F. vaillantii chloroform fraction may contain effective compounds with chemo-therapeutic potential act through an apoptotic independent pathway.

  18. White kidney bean lectin exerts anti-proliferative and apoptotic effects on cancer cells.

    Science.gov (United States)

    Chan, Yau Sang; Xia, Lixin; Ng, Tzi Bun

    2016-04-01

    A 60-kDa glucosamine binding lectin, white kidney bean lectin (WKBL), was purified from Phaseolus vulgaris cv. white kidney beans, by application of anion exchange chromatography on Q-Sepharose, affinity chromatography on Affi-gel blue gel, and FPLC-size exclusion on Superdex 75. The anti-proliferative activity of WKBL on HONE1 cells and HepG2 cells was stronger than the activity on MCF7 cells and WRL68 cells (IC50 values for a 48-h treatment with WKBL on HONE1 cells: 18.8 μM; HepG2 cells: 19.7 μM; MCF7 cells: 26.9 μM; and WRL68 cells: >80 μM). The activity could be reduced by addition of glucosamine, which occupies the binding sites of WKBL, indicating that carbohydrate binding is crucial for the activity. Annexin V-FITC and PI staining, JC-1 staining and Hoechst 33342 staining revealed that apoptosis was induced on WKBL-treated HONE1 cells and HepG2 cells, but not as obviously on MCF7 cells. Cell cycle analysis also showed a slight cell cycle arrest on HONE1 cells after WKBL treatment. Western blotting suggested that WKBL induced apoptosis of HONE1 cells occurred through the extrinsic apoptosis pathway, with detection of increased level of active caspase 3, 8 and 9.

  19. The adult macaque spinal cord central canal zone contains proliferative cells and closely resembles the human.

    Science.gov (United States)

    Alfaro-Cervello, Clara; Cebrian-Silla, Arantxa; Soriano-Navarro, Mario; Garcia-Tarraga, Patricia; Matías-Guiu, Jorge; Gomez-Pinedo, Ulises; Molina Aguilar, Pilar; Alvarez-Buylla, Arturo; Luquin, Maria-Rosario; Garcia-Verdugo, Jose Manuel

    2014-06-01

    The persistence of proliferative cells, which could correspond to progenitor populations or potential cells of origin for tumors, has been extensively studied in the adult mammalian forebrain, including human and nonhuman primates. Proliferating cells have been found along the entire ventricular system, including around the central canal, of rodents, but little is known about the primate spinal cord. Here we describe the central canal cellular composition of the Old World primate Macaca fascicularis via scanning and transmission electron microscopy and immunohistochemistry and identify central canal proliferating cells with Ki67 and newly generated cells with bromodeoxyuridine incorporation 3 months after the injection. The central canal is composed of uniciliated, biciliated, and multiciliated ependymal cells, astrocytes, and neurons. Multiciliated ependymal cells show morphological characteristics similar to multiciliated ependymal cells from the lateral ventricles, and uniciliated and biciliated ependymal cells display cilia with large, star-shaped basal bodies, similar to the Ecc cells described for the rodent central canal. Here we show that ependymal cells with one or two cilia, but not multiciliated ependymal cells, proliferate and give rise to new ependymal cells that presumably remain in the macaque central canal. We found that the infant and adult human spinal cord contains ependymal cell types that resemble those present in the macaque. Interestingly, a wide hypocellular layer formed by bundles of intermediate filaments surrounded the central canal both in the monkey and in the human, being more prominent in the stenosed adult human central canal.

  20. Mitochondrial localization of the low level p53 protein in proliferative cells

    Energy Technology Data Exchange (ETDEWEB)

    Ferecatu, Ioana; Bergeaud, Marie; Rodriguez-Enfedaque, Aida; Le Floch, Nathalie [Laboratoire de Genetique et Biologie Cellulaire - CNRS UMR 8159, Universite de Versailles Saint-Quentin-en-Yvelines, Versailles, France and Laboratoire de Genetique Moleculaire et Physiologique, Ecole Pratique des Hautes Etudes, Versailles (France); Oliver, Lisa [INSERM U601, Universite de Nantes, Faculte de Medecine, Nantes Cedex (France); Rincheval, Vincent; Renaud, Flore [Laboratoire de Genetique et Biologie Cellulaire - CNRS UMR 8159, Universite de Versailles Saint-Quentin-en-Yvelines, Versailles, France and Laboratoire de Genetique Moleculaire et Physiologique, Ecole Pratique des Hautes Etudes, Versailles (France); Vallette, Francois M. [INSERM U601, Universite de Nantes, Faculte de Medecine, Nantes Cedex (France); Mignotte, Bernard [Laboratoire de Genetique et Biologie Cellulaire - CNRS UMR 8159, Universite de Versailles Saint-Quentin-en-Yvelines, Versailles, France and Laboratoire de Genetique Moleculaire et Physiologique, Ecole Pratique des Hautes Etudes, Versailles (France); Vayssiere, Jean-Luc, E-mail: jean-luc.vayssiere@uvsq.fr [Laboratoire de Genetique et Biologie Cellulaire - CNRS UMR 8159, Universite de Versailles Saint-Quentin-en-Yvelines, Versailles, France and Laboratoire de Genetique Moleculaire et Physiologique, Ecole Pratique des Hautes Etudes, Versailles (France)

    2009-10-02

    p53 protein plays a central role in suppressing tumorigenesis by inducing cell cycle arrest or apoptosis through transcription-dependent and -independent mechanisms. Emerging publications suggest that following stress, a fraction of p53 translocates to mitochondria to induce cytochrome c release and apoptosis. However, the localization of p53 under unstressed conditions remains largely unexplored. Here we show that p53 is localized at mitochondria in absence of apoptotic stimuli, when cells are proliferating, localization observed in various cell types (rodent and human). This is also supported by acellular assays in which p53 bind strongly to mitochondria isolated from rat liver. Furthermore, the mitochondria subfractionation study and the alkaline treatment of the mitochondrial p53 revealed that the majority of mitochondrial p53 is present in the membranous compartments. Finally, we identified VDAC, a protein of the mitochondrial outer-membrane, as a putative partner of p53 in unstressed/proliferative cells.

  1. The cell-cycle state of stem cells determines cell fate propensity.

    Science.gov (United States)

    Pauklin, Siim; Vallier, Ludovic

    2013-09-26

    Self-renewal and differentiation of stem cells are fundamentally associated with cell-cycle progression to enable tissue specification, organ homeostasis, and potentially tumorigenesis. However, technical challenges have impaired the study of the molecular interactions coordinating cell fate choice and cell-cycle progression. Here, we bypass these limitations by using the FUCCI reporter system in human pluripotent stem cells and show that their capacity of differentiation varies during the progression of their cell cycle. These mechanisms are governed by the cell-cycle regulators cyclin D1-3 that control differentiation signals such as the TGF-β-Smad2/3 pathway. Conversely, cell-cycle manipulation using a small molecule directs differentiation of hPSCs and provides an approach to generate cell types with a clinical interest. Our results demonstrate that cell fate decisions are tightly associated with the cell-cycle machinery and reveal insights in the mechanisms synchronizing differentiation and proliferation in developing tissues.

  2. Delayed transition to new cell fates during cellular reprogramming.

    Science.gov (United States)

    Cheng, Xianrui; Lyons, Deirdre C; Socolar, Joshua E S; McClay, David R

    2014-07-15

    In many embryos specification toward one cell fate can be diverted to a different cell fate through a reprogramming process. Understanding how that process works will reveal insights into the developmental regulatory logic that emerged from evolution. In the sea urchin embryo, cells at gastrulation were found to reprogram and replace missing cell types after surgical dissections of the embryo. Non-skeletogenic mesoderm (NSM) cells reprogrammed to replace missing skeletogenic mesoderm cells and animal caps reprogrammed to replace all endomesoderm. In both cases evidence of reprogramming onset was first observed at the early gastrula stage, even if the cells to be replaced were removed earlier in development. Once started however, the reprogramming occurred with compressed gene expression dynamics. The NSM did not require early contact with the skeletogenic cells to reprogram, but the animal cap cells gained the ability to reprogram early in gastrulation only after extended contact with the vegetal halves prior to that time. If the entire vegetal half was removed at early gastrula, the animal caps reprogrammed and replaced the vegetal half endomesoderm. If the animal caps carried morpholinos to either hox11/13b or foxA (endomesoderm specification genes), the isolated animal caps failed to reprogram. Together these data reveal that the emergence of a reprogramming capability occurs at early gastrulation in the sea urchin embryo and requires activation of early specification components of the target tissues.

  3. [Immunohistochemical description of proliferative activity and apoptosis of lung squamous cell carcinoma (literature review)].

    Science.gov (United States)

    Филенко, Борис Н; Ройко, Наталия В; Степанчук, Алла П; Проскурня, Сергей А

    2016-01-01

    The analysis of the publications are describe immunohistochemical study of proliferative activity and apoptosis of lung squamous cell carcinoma. Established that the imbalance between proliferation and cell death is a key process in the development of tumors. However, the value of tumor markers in histogenesis and morfogenesis of tumors and forecast their occurrence is not studied enough. Despite the significant amount of scientific literature devoted to this issue, has not yet established a clear link expression of immunohistochemical markers of proliferation and apoptosis with the degree of differentiation of squamous cell lung cancer. Analysis of the literature shows that the morphology of this histogenetics type lung cancer at the cellular, subcellular structural and functional levels are controversial and require detailed investigation.

  4. Anti-proliferative action of silibinin on human colon adenomatous cancer HT-29 cells

    Directory of Open Access Journals (Sweden)

    Reyhan Akhtar

    2014-02-01

    Full Text Available Background: Silibinin a flavonoid from milk thistle (Silybum marianum exhibit a variety of pharmacological actions, including anti-proliferative and apoptotic activities against various types of cancers in intact animals and cancer cell lines. In the present study, the effect of silibinin on human colon cancer HT-29 cells was studied. Method: Incubations of cells with different silibinin concentrations (0.783-1,600 μg/ml for 24, 48 or 72 h showed a progressive decline in cell viability. Results: Loss of cell viability was time dependent and optimum inhibition of cell growth (78% was observed at 72 h. Under inverted microscope, the dead cells were seen as cell aggregates. IC50 (silibinin concentration killing 50% cells values were 180, 110 and 40μg/ml at 24, 48 and 72 h respectively. Conclusion: These findings re-enforce the anticancer potential of silibinin, as reported earlier for various other cancer cell lines (Ramasamy and Agarwal (2008, Cancer Letters, 269: 352-62.

  5. Proliferative and Invasive Effects of Progesterone-Induced Blocking Factor in Human Glioblastoma Cells

    Science.gov (United States)

    Hansberg-Pastor, Valeria

    2017-01-01

    Progesterone-induced blocking factor (PIBF) is a progesterone (P4) regulated protein expressed in different types of high proliferative cells including astrocytomas, the most frequent and aggressive brain tumors. It has been shown that PIBF increases the number of human astrocytoma cells. In this work, we evaluated PIBF regulation by P4 and the effects of PIBF on proliferation, migration, and invasion of U87 and U251 cells, both derived from human glioblastomas. PIBF mRNA expression was upregulated by P4 (10 nM) from 12 to 24 h. Glioblastoma cells expressed two PIBF isoforms, 90 and 57 kDa. The content of the shorter isoform was increased by P4 at 24 h, while progesterone receptor antagonist RU486 (10 μM) blocked this effect. PIBF (100 ng/mL) increased the number of U87 cells on days 4 and 5 of treatment and induced cell proliferation on day 4. Wound-healing assays showed that PIBF increased the migration of U87 (12–48 h) and U251 (24 and 48 h) cells. Transwell invasion assays showed that PIBF augmented the number of invasive cells in both cell lines at 24 h. These data suggest that PIBF promotes proliferation, migration, and invasion of human glioblastoma cells. PMID:28168193

  6. LACHESIS restricts gametic cell fate in the female gametophyte of Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Rita Gross-Hardt

    2007-03-01

    Full Text Available In flowering plants, the egg and sperm cells form within haploid gametophytes. The female gametophyte of Arabidopsis consists of two gametic cells, the egg cell and the central cell, which are flanked by five accessory cells. Both gametic and accessory cells are vital for fertilization; however, the mechanisms that underlie the formation of accessory versus gametic cell fate are unknown. In a screen for regulators of egg cell fate, we isolated the lachesis (lis mutant which forms supernumerary egg cells. In lis mutants, accessory cells differentiate gametic cell fate, indicating that LIS is involved in a mechanism that prevents accessory cells from adopting gametic cell fate. The temporal and spatial pattern of LIS expression suggests that this mechanism is generated in gametic cells. LIS is homologous to the yeast splicing factor PRP4, indicating that components of the splice apparatus participate in cell fate decisions.

  7. ARTEMIS stabilizes the genome and modulates proliferative responses in multipotent mesenchymal cells

    Directory of Open Access Journals (Sweden)

    Tompkins Kathleen

    2010-10-01

    Full Text Available Abstract Background Unrepaired DNA double-stranded breaks (DSBs cause chromosomal rearrangements, loss of genetic information, neoplastic transformation or cell death. The nonhomologous end joining (NHEJ pathway, catalyzing sequence-independent direct rejoining of DSBs, is a crucial mechanism for repairing both stochastically occurring and developmentally programmed DSBs. In lymphocytes, NHEJ is critical for both development and genome stability. NHEJ defects lead to severe combined immunodeficiency (SCID and lymphoid cancer predisposition in both mice and humans. While NHEJ has been thoroughly investigated in lymphocytes, the importance of NHEJ in other cell types, especially with regard to tumor suppression, is less well documented. We previously reported evidence that the NHEJ pathway functions to suppress a range of nonlymphoid tumor types, including various classes of sarcomas, by unknown mechanisms. Results Here we investigate roles for the NHEJ factor ARTEMIS in multipotent mesenchymal stem/progenitor cells (MSCs, as putative sarcomagenic cells of origin. We demonstrate a key role for ARTEMIS in sarcoma suppression in a sensitized mouse tumor model. In this context, we found that ARTEMIS deficiency led to chromosomal damage but, paradoxically, enhanced resistance and proliferative potential in primary MSCs subjected to various stresses. Gene expression analysis revealed abnormally regulated stress response, cell proliferation, and signal transduction pathways in ARTEMIS-defective MSCs. Finally, we identified candidate regulatory genes that may, in part, mediate a stress-resistant, hyperproliferative phenotype in preneoplastic ARTEMIS-deficient MSCs. Conclusions Our discoveries suggest that Art prevents genome damage and restrains proliferation in MSCs exposed to various stress stimuli. We propose that deficiency leads to a preneoplastic state in primary MSCs and is associated with aberrant proliferative control and cellular stress

  8. Fate restriction and multipotency in retinal stem cells.

    Science.gov (United States)

    Centanin, Lázaro; Hoeckendorf, Burkhard; Wittbrodt, Joachim

    2011-12-02

    Stem cells have the capacity to both self-renew and generate postmitotic cells. Long-term tracking of individual clones in their natural environment constitutes the ultimate way to validate postembryonic stem cells. We identify retinal stem cells (RSCs) using the spatiotemporal organization of the fish retina and follow the complete offspring of a single cell during the postnatal life. RSCs generate two tissues of the adult fish retina, the neural retina (NR) and the retinal-pigmented epithelium (RPE). Despite their common embryonic origin and tight coordination during continuous organ growth, we prove that NR and RPE are maintained by dedicated RSCs that contribute in a fate-restricted manner to either one or the other tissue. We show that in the NR, RSCs are multipotent and generate all neuron types and glia. The clonal origin of these different cell types from a multipotent NSC has far-reaching implications for cell type and tissue homeostasis.

  9. The Anti-Proliferative Effect of Inhibitor of Telomerase on Cultured Retinal Pigment Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to provide a new method for treating proliferative vitreoretinopathy (PVR), the effects of anti-proliferation and apoptosis induction of inhibitors of telomerase and heat shock protein 90 (Hsp90) on the cultured retinal pigment epithelial (RPE) cells were investigated. The rate of apoptosis cells was measured by using TUNEL on the cultured RPE cells, the co-cultured RPE cells with inhibitor of telomerase (camptothecin) or the co-cultured RPE cells with inhibitor of Hsp90 (geldanamycin). The cell proliferation status was measured in the above three groups by using MTT method. The rate of apoptosis in the RPE cells co-cultured with camptothecin or geldanamycin was increased remarkably (P<0.05). MTT showed the rate of growth inhibition was 8.4 %, 32.3 % and 72.3 % at the concentrations of camptothecin 1 μmol/L, 5 μmol/L, 10 μmol/L, respectively, and 6.5 %, 30.9 %, 71.9 % at the concentrations of geldanamycin 1 μmol/L, 5 μmol/L, 10 μmol/L, respectively. It was concluded that telomerase and Hsp90 can promote the proliferation of the cultured RPE cells, while the inhibitor of them can induce apoptosis and inhibit the growth of the RPE cells.

  10. Competition in notch signaling with cis enriches cell fate decisions.

    Directory of Open Access Journals (Sweden)

    Pau Formosa-Jordan

    Full Text Available Notch signaling is involved in cell fate choices during the embryonic development of Metazoa. Commonly, Notch signaling arises from the binding of the Notch receptor to its ligands in adjacent cells driving cell-to-cell communication. Yet, cell-autonomous control of Notch signaling through both ligand-dependent and ligand-independent mechanisms is known to occur as well. Examples include Notch signaling arising in the absence of ligand binding, and cis-inhibition of Notch signaling by titration of the Notch receptor upon binding to its ligands within a single cell. Increasing experimental evidences support that the binding of the Notch receptor with its ligands within a cell (cis-interactions can also trigger a cell-autonomous Notch signal (cis-signaling, whose potential effects on cell fate decisions and patterning remain poorly understood. To address this question, herein we mathematically and computationally investigate the cell states arising from the combination of cis-signaling with additional Notch signaling sources, which are either cell-autonomous or involve cell-to-cell communication. Our study shows that cis-signaling can switch from driving cis-activation to effectively perform cis-inhibition and identifies under which conditions this switch occurs. This switch relies on the competition between Notch signaling sources, which share the same receptor but differ in their signaling efficiency. We propose that the role of cis-interactions and their signaling on fine-grained patterning and cell fate decisions is dependent on whether they drive cis-inhibition or cis-activation, which could be controlled during development. Specifically, cis-inhibition and not cis-activation facilitates patterning and enriches it by modulating the ratio of cells in the high-ligand expression state, by enabling additional periodic patterns like stripes and by allowing localized patterning highly sensitive to the precursor state and cell-autonomous bistability

  11. Single-cell RNA-seq and computational analysis using temporal mixture modelling resolves Th1/Tfh fate bifurcation in malaria

    Science.gov (United States)

    Lönnberg, Tapio; Svensson, Valentine; James, Kylie R.; Fernandez-Ruiz, Daniel; Sebina, Ismail; Montandon, Ruddy; Soon, Megan S. F.; Fogg, Lily G.; Nair, Arya Sheela; Liligeto, Urijah; Stubbington, Michael J. T.; Ly, Lam-Ha; Bagger, Frederik Otzen; Zwiessele, Max; Lawrence, Neil D.; Souza-Fonseca-Guimaraes, Fernando; Bunn, Patrick T.; Engwerda, Christian R.; Heath, William R.; Billker, Oliver; Stegle, Oliver; Haque, Ashraful; Teichmann, Sarah A.

    2017-01-01

    Differentiation of naïve CD4+ T cells into functionally distinct T helper subsets is crucial for the orchestration of immune responses. Due to extensive heterogeneity and multiple overlapping transcriptional programs in differentiating T cell populations, this process has remained a challenge for systematic dissection in vivo. By using single-cell transcriptomics and computational analysis using a temporal mixtures of Gaussian processes model, termed GPfates, we reconstructed the developmental trajectories of Th1 and Tfh cells during blood-stage Plasmodium infection in mice. By tracking clonality using endogenous TCR sequences, we first demonstrated that Th1/Tfh bifurcation had occurred at both population and single-clone levels. Next, we identified genes whose expression was associated with Th1 or Tfh fates, and demonstrated a T-cell intrinsic role for Galectin-1 in supporting a Th1 differentiation. We also revealed the close molecular relationship between Th1 and IL-10-producing Tr1 cells in this infection. Th1 and Tfh fates emerged from a highly proliferative precursor that upregulated aerobic glycolysis and accelerated cell cycling as cytokine expression began. Dynamic gene expression of chemokine receptors around bifurcation predicted roles for cell-cell in driving Th1/Tfh fates. In particular, we found that precursor Th cells were coached towards a Th1 but not a Tfh fate by inflammatory monocytes. Thus, by integrating genomic and computational approaches, our study has provided two unique resources, a database www.PlasmoTH.org, which facilitates discovery of novel factors controlling Th1/Tfh fate commitment, and more generally, GPfates, a modelling framework for characterizing cell differentiation towards multiple fates. PMID:28345074

  12. Intracellular Events and Cell Fate in Filovirus Infection

    Directory of Open Access Journals (Sweden)

    Elena Ryabchikova

    2011-08-01

    Full Text Available Marburg and Ebola viruses cause a severe hemorrhagic disease in humans with high fatality rates. Early target cells of filoviruses are monocytes, macrophages, and dendritic cells. The infection spreads to the liver, spleen and later other organs by blood and lymph flow. A hallmark of filovirus infection is the depletion of non-infected lymphocytes; however, the molecular mechanisms leading to the observed bystander lymphocyte apoptosis are poorly understood. Also, there is limited knowledge about the fate of infected cells in filovirus disease. In this review we will explore what is known about the intracellular events leading to virus amplification and cell damage in filovirus infection. Furthermore, we will discuss how cellular dysfunction and cell death may correlate with disease pathogenesis.

  13. Exonuclease 1 is essential for maintaining genomic stability and the proliferative capacity of neural but not hematopoietic stem cells

    Directory of Open Access Journals (Sweden)

    Junling Zhang

    2014-01-01

    Full Text Available Exonuclease 1 (Exo1 has been implicated in the regulation of DNA damage responses in stem cells with dysfunctional telomeres. However, it is unclear whether Exo1-mediated DNA maintenance pathways play a role in the maintenance of genomic stability and the self-renewal of tissue stem cells in mice with functional telomeres. Here, we analyzed the proliferative capacity of neural stem cells (NSCs and hematopoietic stem cells (HSCs from Exo1−/− mice. Our study shows that Exo1 deficiency impairs the maintenance of genomic stability and proliferative capacity in NSCs but not HSCs. In line with these results, we detected a decrease in proliferation and an up-regulation of p21 expression levels in Exo1-deficient NSCs but not Exo1-deficient HSCs. Our data provide experimental evidence that Exo1 deficiency has a differential impact on the homeostasis and proliferative capacity of tissue stem cells in the brain and bone marrow, suggesting that different tissue stem cells utilize distinct mechanisms for maintaining their genomic stability. Our current study provides important insight into the role of Exo1-mediated DNA maintenance pathways in the maintenance of genomic stability and the proliferative capacity of tissue stem cells.

  14. Induction of IgA and sustained deficiency of cell proliferative response in chronic hepatitis C

    Institute of Scientific and Technical Information of China (English)

    Yalena Amador-Ca(n)izares; Liz Alvarez-Lajonchere; Ivis Guerra; Ingrid Rodnguez-Alonso; Gillian Martínez-Donato; Julián Triana; Eddy E González-Horta; Angel Pérez; Santiago Due(n)as-Carrera

    2008-01-01

    AIM: In the present study, antibody and peripheral blood mononuclear cells (PBMC) proliferative responses against hepatitis C virus (HCV) antigens were evaluated in HCV chronically infected patients. METHODS: Paired serum and PBMC samples were taken six months apart from 34 individuals, either treated or not, and tested by enzyme-linked immunosorbent assay (ELISA) and carboxyfluorescein succinimidyl ester staining.RESULTS: Over 70% of the patients showed specific IgG and IgM against capsid, E1 and NS3, while HVR-1 was recognized by half of the patients. An increase in the levels of the anti-capsid IgM (P = 0.027) and IgG (P=0.0006) was observed in six-month samples, compared to baseline. Similarly, a significantly higher percent of patients had detectable IgA reactivity to capsid (P=0.017) and NS3 (P=0.005) after six months, compared to baseline. Particularly, IgA against structural antigens positively correlated with hepatic damage (P=0.036). IgG subclasses evaluation against capsid and NS3 revealed a positive recognition mediated by IgG1 in more than 80% of the individuals. On the contrary, less than 30% of the patients showed a positive proliferative response either of CD4+ or CD8+ T cells, being the capsid poorly recognized. CONCLUSION: These results confirm that while the cellular immune response is narrow and weak, a broad and vigorous humoral response occurs in HCV chronic infection. The observed correlation between IgA and hepatic damage may have diagnostic significance, although it warrants further confirmation.

  15. Origin and fate of the regenerating cells of the kidney.

    Science.gov (United States)

    Eymael, Jennifer; Smeets, Bart

    2016-11-05

    The kidney has the capacity to regenerate itself provided that the damage is limited and the structure of the kidney remains intact. Nevertheless, in disease conditions this potential may be compromised, leading to progression to chronic kidney disease. For development of new therapeutic strategies it is a prerequisite to understand the origin and regulation of the kidney regenerating cells and the processes that underlie maladaptive repair. Because of the complexity of the kidney consisting of a high number of different cell types, it is a complex task to unravel the origin and fate of cells responsible for regeneration. This review summarises the recent and most important advances in identifying regenerating cell populations of the kidney, and highlights the existing controversies.

  16. Identification of a novel, alpha2-fucosylation-dependent uptake system in highly proliferative cells.

    Science.gov (United States)

    Aldi, Silvia; Capone, Antonietta; Giovampaola, Cinzia Della; Ermini, Leonardo; Pianigiani, Elisa; Mariotti, Giancarlo; Rosati, Floriana

    2015-02-01

    In this paper we describe a new structure present in highly proliferative cells and absent in cells with normal growth potential. We used cultured bovine venular endothelial cells (CVEC) as examples of high proliferation, and dermal fibroblasts of a primary culture as examples of normal proliferation. The structure, consisting of tubules radiating from the nuclear region to the tips of cell protrusions, was revealed by its strong positivity to the fucose-binding lectin from Lotus (LTL) that prefers glycans with alpha-1,2-linked fucose. Another fucose-binding lectin that prefers glycans with alpha-1,6-linked fucose was instead found to localize glycans exclusively in Golgi complexes. LTL binding sites were also found at the surface of CVEC in a restricted region close to the nucleus. The role of alpha-1,2-linked fucose in forming or maintaining the tubules was confirmed by the fact that down-regulation of the fucosyltransferases FUT1 and FUT2 resulted in disappearance of the tubular structure. LTL also proved able to penetrate the cells through the tubular structures up to the nuclear region and to inhibit proliferation. Endostatin was also found to massively penetrate the cells in the tubular structures in control cells but not in FUT1/2 depleted cells. In cells of a first passage primary culture of dermal fibroblasts the tubular LTL-positive structure was absent as well as the LTL-positive sites at the external surface, and both fucose-binding lectins were found to exclusively localize glycans in Golgi complexes. Tubules were again found progressively in fibroblasts derived from repeated passages, where faster growing cells predominate. Disappearance of LTL-positivity in Golgi complexes paralleled appearance of LTL-positive tubules. The role of Golgi complexes in forming the tubules is discussed.

  17. Immunochemical expression of proliferative cell nuclear antigen in aging cultured astrocytes

    Directory of Open Access Journals (Sweden)

    M. C. Vanzani

    2003-08-01

    Full Text Available Cell differentiation degree and mitotic activity were sequentially assessed by immunoperoxidase labeling of glial fibrillary acidic protein (GFAP and proliferative cell nuclear antigen (PCNA, respectively, in rat brain cultured astrocytes maintained up to 60 days in vitro (DIV of first subculture, or weekly passaged until their 12th subculture. Cell count was performed through a 0.01 mm2 section reticule and morphometric analysis with a stereological grid. The number of double immunoreactive cells peaked by 2 DIV to achieve its lowest value at 60 DIV. At 24 hs of cell seeding of successive passages, such values peaked by the 6th subculture to gradually decrease thereafter. Increasing cell hypertrophy was found during the long-term first subculture but not after passaging. At the end of the observation period, doubly immunolabeled astrocytes were still recorded, thus evidencing retention of proliferative potential despite aging.El grado de diferenciación celular y la actividad mitótica fueron secuencialmente determinados mediante marcación por inmunoperoxidasa de la proteína gliofibrilar ácida (GFAP y del antígeno nuclear de proliferación celular (PCNA, respectivamente, en cultivos astrocitarios obtenidos de encéfalo de rata y mantenidos hasta 60 días in vitro (DIV de su primer subcultivo, o mediante pasajes semanales hasta el 12do subcultivo. El conteo celular se realizó mediante una retícula de 0.01-mm2 de sección y el análisis morfométrico con una grilla estereológica. El número de células doblemente inmunorreactivas alcanzó valores máximos a los 2 DIV para descender a los menores a los 60 DIV. A las 24 hs de sembrado celular de los sucesivos pasajes, esos valores ascendieron hacia el 6to subcultivo para luego declinar. En cuanto a la hipertrofia celular, se observó en todo el curso del primer subcultivo, pero no durante los posteriores pasajes. Al final del período de observación, todavía se continuaban detectando

  18. Cell fate regulation governed by a repurposed bacterial histidine kinase.

    Directory of Open Access Journals (Sweden)

    W Seth Childers

    2014-10-01

    Full Text Available One of the simplest organisms to divide asymmetrically is the bacterium Caulobacter crescentus. The DivL pseudo-histidine kinase, positioned at one cell pole, regulates cell-fate by controlling the activation of the global transcription factor CtrA via an interaction with the response regulator (RR DivK. DivL uniquely contains a tyrosine at the histidine phosphorylation site, and can achieve these regulatory functions in vivo without kinase activity. Determination of the DivL crystal structure and biochemical analysis of wild-type and site-specific DivL mutants revealed that the DivL PAS domains regulate binding specificity for DivK∼P over DivK, which is modulated by an allosteric intramolecular interaction between adjacent domains. We discovered that DivL's catalytic domains have been repurposed as a phosphospecific RR input sensor, thereby reversing the flow of information observed in conventional histidine kinase (HK-RR systems and coupling a complex network of signaling proteins for cell-fate regulation.

  19. Biocatalytically Oligomerized Epicatechin with Potent and Specific Anti-proliferative Activity for Human Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Ramaswamy Nagarajan

    2008-11-01

    Full Text Available Catechins, naturally occurring flavonoids derived from wine and green tea, are known to exhibit multiple health benefits. Epigallocatechin gallate (EGCG is one of the most widely investigated catechins, but its efficacy in cancer therapy is still inconsistent and limited. The poor stability of EGCG has contributed to the disparity in the reported anti-cancer activity and other beneficial properties. Here we report an innovative enzymatic strategy for the oligomerization of catechins (specifically epicatechin that yields stable, water-soluble oligomerized epicatechins with enhanced and highly specific anti-proliferative activity for human breast cancer cells. This one-pot oxidative oligomerization is carried out in ambient conditions using Horseradish Peroxidase (HRP as a catalyst yielding water-soluble oligo(epicatechins. The oligomerized epicatechins obtained exhibit excellent growth inhibitory effects against human breast cancer cells with greater specificity towards growth-inhibiting cancer cells as opposed to normal cells, achieving a high therapeutic differential. Our studies indicate that water-soluble oligomeric epicatechins surpass EGCG in stability, selectivity and efficacy at lower doses.

  20. Anti-Proliferative Effect of Rosmarinus officinalis L. Extract on Human Melanoma A375 Cells.

    Science.gov (United States)

    Cattaneo, Lucia; Cicconi, Rosella; Mignogna, Giuseppina; Giorgi, Alessandra; Mattei, Maurizio; Graziani, Giulia; Ferracane, Rosalia; Grosso, Alessandro; Aducci, Patrizia; Schininà, M Eugenia; Marra, Mauro

    2015-01-01

    Rosemary (Rosmarinus officinalis L.) has been used since ancient times in traditional medicine, while nowadays various rosemary formulations are increasingly exploited by alternative medicine to cure or prevent a wide range of health disorders. Rosemary's bioproperties have prompted scientific investigation, which allowed us to ascertain antioxidant, anti-inflammatory, cytostatic, and cytotoxic activities of crude extracts or of pure components. Although there is a growing body of experimental work, information about rosemary's anticancer properties, such as chemoprotective or anti-proliferative effects on cancer cells, is very poor, especially concerning the mechanism of action. Melanoma is a skin tumor whose diffusion is rapidly increasing in the world and whose malignancy is reinforced by its high resistance to cytotoxic agents; hence the availability of new cytotoxic drugs would be very helpful to improve melanoma prognosis. Here we report on the effect of a rosemary hydroalcoholic extract on the viability of the human melanoma A375 cell line. Main components of rosemary extract were identified by liquid chromatography coupled to tandem mass spectrometry (LC/ESI-MS/MS) and the effect of the crude extract or of pure components on the proliferation of cancer cells was tested by MTT and Trypan blue assays. The effect on cell cycle was investigated by using flow cytometry, and the alteration of the cellular redox state was evaluated by intracellular ROS levels and protein carbonylation analysis. Furthermore, in order to get information about the molecular mechanisms of cytotoxicity, a comparative proteomic investigation was performed.

  1. Spatially patterned matrix elasticity directs stem cell fate

    Science.gov (United States)

    Yang, Chun; DelRio, Frank W.; Ma, Hao; Killaars, Anouk R.; Basta, Lena P.; Kyburz, Kyle A.; Anseth, Kristi S.

    2016-08-01

    There is a growing appreciation for the functional role of matrix mechanics in regulating stem cell self-renewal and differentiation processes. However, it is largely unknown how subcellular, spatial mechanical variations in the local extracellular environment mediate intracellular signal transduction and direct cell fate. Here, the effect of spatial distribution, magnitude, and organization of subcellular matrix mechanical properties on human mesenchymal stem cell (hMSCs) function was investigated. Exploiting a photodegradation reaction, a hydrogel cell culture substrate was fabricated with regions of spatially varied and distinct mechanical properties, which were subsequently mapped and quantified by atomic force microscopy (AFM). The variations in the underlying matrix mechanics were found to regulate cellular adhesion and transcriptional events. Highly spread, elongated morphologies and higher Yes-associated protein (YAP) activation were observed in hMSCs seeded on hydrogels with higher concentrations of stiff regions in a dose-dependent manner. However, when the spatial organization of the mechanically stiff regions was altered from a regular to randomized pattern, lower levels of YAP activation with smaller and more rounded cell morphologies were induced in hMSCs. We infer from these results that irregular, disorganized variations in matrix mechanics, compared with regular patterns, appear to disrupt actin organization, and lead to different cell fates; this was verified by observations of lower alkaline phosphatase (ALP) activity and higher expression of CD105, a stem cell marker, in hMSCs in random versus regular patterns of mechanical properties. Collectively, this material platform has allowed innovative experiments to elucidate a novel spatial mechanical dosing mechanism that correlates to both the magnitude and organization of spatial stiffness.

  2. Anti-proliferative effect of chalcone derivatives through inactivation of NF-κB in human cancer cells.

    Science.gov (United States)

    Venkateswararao, Eeda; Sharma, Vinay K; Yun, Jieun; Kim, Youngsoo; Jung, Sang-Hun

    2014-07-01

    To investigate the anti-proliferative effect of NF-κB inhibitor, a series of analogs of (E)-1-(2-hydroxy-6-(isopentyloxy)phenyl)-3-(4-hydroxyphenyl)prop-2-en-1-one (5a) were prepared and evaluated for their NF-κB inhibition and anti-proliferative activity against various human cancer cell lines. Compounds (E)-1-(2-(3,3-dimethylbutoxy)-6-hydroxyphenyl)-3-(4-hydroxyphenyl)prop-2-en-1-one (5e) and (E)-4-(3-(2-(3,3-dimethylbutoxy)-6-hydroxyphenyl)-3-oxoprop-1-enyl)benzenesulfonamide (5p) showed good NF-κB inhibition as well as potent anti-proliferative activity. SAR studies showed that all the compounds with potent or moderate NF-κB inhibition displayed good anti-proliferative activity. All the analogs (5b-r) maintained a good correlation between their NF-κB inhibition and anti-proliferative activity though the extent is not directly proportional to each other.

  3. Control of Cell Fate in the Circulatory and Ventilatory Systems

    CERN Document Server

    Thiriet, Marc

    2012-01-01

    The volumes in this authoritative series present a multidisciplinary approach to modeling and simulation of flows in the cardiovascular and ventilatory systems, especially multiscale modeling and coupled simulations. The cardiovascular and respiratory systems are tightly coupled, as their primary function is to supply oxygen to and remove carbon dioxide from the body's cells. Because physiological conduits have deformable and reactive walls, macroscopic flow behavior and prediction must be coupled to nano- and microscopic events in a corrector scheme of regulated mechanisms. Therefore, investigation of flows of blood and air in physiological conduits requires an understanding of the biology, chemistry, and physics of these systems together with the mathematical tools to describe their functioning. Volumes 1 and 2 are devoted to cell organization and fate, as well as activities that are autoregulated and/or controlled by the cell environment. Volume 1 examined cellular features that allow adaptation to env...

  4. Engineering Cell Fate for Tissue Regeneration by In Vivo Transdifferentiation.

    Science.gov (United States)

    de Lázaro, I; Kostarelos, K

    2016-02-01

    Changes in cell identity occur in adult mammalian organisms but are rare and often linked to disease. Research in the last few decades has thrown light on how to manipulate cell fate, but the conversion of a particular cell type into another within a living organism (also termed in vivo transdifferentiation) has only been recently achieved in a limited number of tissues. Although the therapeutic promise of this strategy for tissue regeneration and repair is exciting, important efficacy and safety concerns will need to be addressed before it becomes a reality in the clinical practice. Here, we review the most relevant in vivo transdifferentiation studies in adult mammalian animal models, offering a critical assessment of this potentially powerful strategy for regenerative medicine.

  5. Proliferative effect of whey from cows' milk obtained at two different stages of pregnancy measured in MCF-7 cells.

    Science.gov (United States)

    Nielsen, Tina S; Andersen, Charlotte; Sejrsen, Kris; Purup, Stig

    2012-02-01

    Dietary estrogens may play a role in the etiology of hormone-dependent cancers like breast cancer. Cow's milk contains various endogenous estrogens and feed derived phytoestrogens that potentially contribute to an estrogenic effect of milk in consumers, and therefore we evaluated the effect of milk (whey) in a proliferation assay with estrogen-sensitive MCF-7 human breast cancer cells. Milk samples were obtained from 22 cows representing different stages of pregnancy (first and second half) and whey was produced from the milk. 0·1, 0·25 or 0·5% whey was included in the cell culture medium and after 6 days of treatment cell proliferation was assessed by a colorimetric method with a fluorometer. Whey induced significant (Pwhey at all concentrations tested. There was no difference in the proliferative effect of whey depending on the stage of pregnancy from which the milk was obtained. We did not observe anti-proliferative effects when whey was tested in the presence of 10 pm estradiol in the medium. In conclusion, these results indicate that whey, irrespective of the pregnancy stage from which the milk was obtained induced a significant proliferative response in MCF-7 cells and no anti-proliferative effect, which may be caused, at least in part, by estrogens present in milk. The implications of our findings in relation to for example breast cancer will have to be studied further in other model systems preferentially in vivo.

  6. Evaluation of viability and proliferative activity of human urothelial cells cultured onto xenogenic tissue-engineered extracellular matrices.

    LENUS (Irish Health Repository)

    Davis, Niall F

    2011-04-01

    To evaluate the viability and proliferative activity of human urothelial cells (HUCs) cultured on tissue-engineered extracellular matrix scaffolds and to assess the potential of extracellular matrixes to support the growth of HUCs in their expected in vivo urine environment.

  7. Defined spatiotemporal features of RAS-ERK signals dictate cell fate in MCF-7 mammary epithelial cells

    Science.gov (United States)

    Herrero, Ana; Casar, Berta; Colón-Bolea, Paula; Agudo-Ibáñez, Lorena; Crespo, Piero

    2016-01-01

    Signals conveyed through the RAS-ERK pathway are essential for the determination of cell fate. It is well established that signal variability is achieved in the different microenvironments in which signals unfold. It is also known that signal duration is critical for decisions concerning cell commitment. However, it is unclear how RAS-ERK signals integrate time and space in order to elicit a given biological response. To investigate this, we used MCF-7 cells, in which EGF-induced transient ERK activation triggers proliferation, whereas sustained ERK activation in response to heregulin leads to adipocytic differentiation. We found that both proliferative and differentiating signals emanate exclusively from plasma membrane–disordered microdomains. Of interest, the EGF signal can be transformed into a differentiating stimulus by HRAS overexpression, which prolongs ERK activation, but only if HRAS localizes at disordered membrane. On the other hand, HRAS signals emanating from the Golgi complex induce apoptosis and can prevent heregulin-induced differentiation. Our results indicate that within the same cellular context, RAS can exert different, even antagonistic, effects, depending on its sublocalization. Thus cell destiny is defined by the ability of a stimulus to activate RAS at the appropriate sublocalization for an adequate period while avoiding switching on opposing RAS signals. PMID:27099370

  8. Evaluation of cell proliferative activity after irradiation using immunohistochemical approach and flow cytometry

    Energy Technology Data Exchange (ETDEWEB)

    Tamada, Takashi (Okayama Univ. (Japan). School of Medicine)

    1992-06-01

    To evaluate a proliferative activity of post-irradiated malignant cells, we studied the kinetics of HeLa cells using immunohistochemical approach and flow cytometry. HeLa cells were stained with two proliferation-associated monoclonal antibodies, Ki-67 and anti-DNA polymerase {alpha} antibody. Nucleoli of non-irradiated cells were granularly stained with Ki-67. After irradiation, only the center of nuclei was diffusely stained with Ki-67. One hundred forty-four hours after low-dose irradiation, the staining patterns became the same as the control. On the other hand, after high-dose irradiation, the center of nuclei was weakly stained. DNA polymerase {alpha} was diffusely labelled with nuclei of the control. It was located around the border of nuclei of low-dose irradiated cells like a ring. But after high-dose irradiation, it was granularly distributed in the periphery of nuclei. FITC conjugated Ki-67/PI two parameter analysis was done by a single laser flow cytometer. Twenty-four hours after irradiation, DNA-histograms showed the accumulation to G{sub 2}/M phase and the increase of DNA content of G{sub 2}/M cells, as exposure dose was increased. Two parameter analysis showed the increase of FITC uptake of G{sub 2}/M phase as dose increased. These changes of flow cytometry were remarkably observed after 24 hours' incubation. It was shown that the difference of Ki-67 antigen and DNA polymerase {alpha} appearance depended on the irradiation dose. These findings suggest that immunohistochemical staining with Ki-67 or anti-DNA polymerase {alpha} antibody and flow cytometry using Ki-67 are available to evaluate cell damages after irradiation. (author).

  9. Dynamic transcriptional signature and cell fate analysis reveals plasticity of individual neural plate border cells.

    Science.gov (United States)

    Roellig, Daniela; Tan-Cabugao, Johanna; Esaian, Sevan; Bronner, Marianne E

    2017-03-29

    The 'neural plate border' of vertebrate embryos contains precursors of neural crest and placode cells, both defining vertebrate characteristics. How these lineages segregate from neural and epidermal fates has been a matter of debate. We address this by performing a fine-scale quantitative temporal analysis of transcription factor expression in the neural plate border of chick embryos. The results reveal significant overlap of transcription factors characteristic of multiple lineages in individual border cells from gastrula through neurula stages. Cell fate analysis using a Sox2 (neural) enhancer reveals that cells that are initially Sox2+ cells can contribute not only to neural tube but also to neural crest and epidermis. Moreover, modulating levels of Sox2 or Pax7 alters the apportionment of neural tube versus neural crest fates. Our results resolve a long-standing question and suggest that many individual border cells maintain ability to contribute to multiple ectodermal lineages until or beyond neural tube closure.

  10. 17β-Estradiol Suppresses Cytotoxicity and Proliferative Capacity of Murine Splenic NK1.1+ Cells

    Institute of Scientific and Technical Information of China (English)

    Sha Hao; Pengfei Li; Junli Zhao; Yali Hu; Yayi Hou

    2008-01-01

    In order to clarify the effects of 17β-estradiol(E2)on natural killer(NK)cells and the possibly regulatory mechanisms,we obtained highly purified and viable NK cells from C57BL/6J mouse spleen by a magnetic cell sorter(MACS).These cells were treated with E2 and then their cytotoxicity and proliferative capacity were examined.To further investigate the mechanisms on the effect of E2 on NK cells,expressions of activationassociated markers(CD69,CD122)and inhibitory receptors(CD94,Ly49),and intracellular cytokine production Were analyzed.At last,we performed the cDNA microarray to explore the possible involved genes.We found that E2 could suppress NK cell cytotoxicity and proliferative capacity in vitro.E2 reduced NK cell cytotoxicity and proliferative capacity,which may be through influencing the phenotypes and cytokine expression of NK cells, mainly involving CD94 and IFN-γ.Furthermore,regulation of Stat4,Fyn,Sh2d1a,Eat2,Cd244,Irf1,Runx1,Irf7, Irf5,Esrra and Nr5a1 genes may be related to the cytotoxicity,proliferation and cytokine production of E2-mediated purified NK cells.

  11. 17beta-estradiol suppresses cytotoxicity and proliferative capacity of murine splenic NK1.1+ cells.

    Science.gov (United States)

    Hao, Sha; Li, Pengfei; Zhao, Junli; Hu, Yali; Hou, Yayi

    2008-10-01

    In order to clarify the effects of 17beta-estradiol (E2) on natural killer (NK) cells and the possibly regulatory mechanisms, we obtained highly purified and viable NK cells from C57BL/6J mouse spleen by a magnetic cell sorter (MACS). These cells were treated with E2 and then their cytotoxicity and proliferative capacity were examined. To further investigate the mechanisms on the effect of E2 on NK cells, expressions of activation-associated markers (CD69, CD122) and inhibitory receptors (CD94, Ly49), and intracellular cytokine production were analyzed. At last, we performed the cDNA microarray to explore the possible involved genes. We found that E2 could suppress NK cell cytotoxicity and proliferative capacity in vitro. E2 reduced NK cell cytotoxicity and proliferative capacity, which may be through influencing the phenotypes and cytokine expression of NK cells, mainly involving CD94 and IFN-gamma. Furthermore, regulation of Stat4, Fyn, Sh2d1a, Eat2, Cd244, Irf1, Runx1, Irf7, Irf5, Esrra and Nr5a1 genes may be related to the cytotoxicity, proliferation and cytokine production of E2-mediated purified NK cells.

  12. Relationship between proliferative activity of cancer cells and clinicopathological factors in patients with esophageal squamous cell carcinoma

    Institute of Scientific and Technical Information of China (English)

    Jun-Xing Huang; Wei Yan; Zheng-Xiang Song; Rong-Yu Qian; Ping Chen; Eeva Salminen; Jorma Toppari

    2005-01-01

    AIM: To assess whether the molecular markers of malignant tumors could improve the understanding of tumor characteristics, and to observe the characteristics of expression of cell cycle markers Ki-67 and cydin A in esophageal carcinoma and to analyze the relationship between proliferative activity of cancer cells and clinicopathological factors.METHODS: Seventy of surgically resected esophageal squamous cell carcinoma (SCC) were examined by immunohistochemistry utilizing commercially available antibodies. Nuclear staining was regarded as a positive result. At least 50 fields in each tumor and non-tumor section were evaluated at a medium power (x200) to determine the proportion of tumor cells and the staining intensity of nuclei in the entire sections.RESULTS: Ki-67 and cyclin A were only expressed in base cells of normal esophageal mucosa. The positive immunostaining of nuclei of SCC was significantly higher than that in normal esophageal mucosa (t= 13.32 and t= 7.52,respectively, P<0.01). The distribution of positively stained was more diffuse and stronger in poorly differentiated SCC. Both Ki-67 and cyclin A expressions were related to histological grades of tumors (t = 3.5675 and t = 3.916; t= 2.13, respectively, P<0.05) but not to the sex and age of the patients, tumor size, lymphatic invasion, location, or stage grouping.CONCLUSION: The proliferative activity of cancer cells may be understood by immunohistochemistry of Ki-67 and cyclin A in Chinese patients with esophageal SCC. These cell cycle markers may serve as an indicator of cancer cell proliferation rate. The overexpression of cell cycle markers Ki-67 and cyclin A suggests the poor SCC differentiation in patients with esophageal carcinoma.

  13. Activation of neural progenitor cells in human eyes with proliferative vitreoretinopathy.

    Science.gov (United States)

    Johnsen, Erik O; Frøen, Rebecca C; Albert, Réka; Omdal, Bente K; Sarang, Zsolt; Berta, András; Nicolaissen, Bjørn; Petrovski, Goran; Moe, Morten C

    2012-05-01

    In addition to the ability for self-renewal and functional differentiation, neural stem/progenitor cells (NSCs) can respond to CNS injuries by targeted migration. In lower vertebrates, retinal injury is known to activate NSCs in the ciliary marginal zone (CMZ). Cells expressing markers of NSCs are also present in the ciliary body epithelium (CE) and in Müller glia in the peripheral retina (PR) of the adult human eye. However, these cells seem to be quiescent in the adult human eye and recent reports have shown that CE cells have limited properties of NSCs. In order to further clarify whether NSCs exist in the adult human eye, we tested whether NSC-like cells could be activated in eyes with proliferative vitreoretinopathy (PVR). The PR and CE were studied for NSC-associated markers in human enucleated control eyes and eyes with confirmed PVR, as well as in a mouse model of PVR. Furthermore, cells isolated from vitreous samples obtained during vitrectomies for retinal detachment were directly fixed or cultured in a stem cell-promoting medium and compared to cells cultured from the post-mortem retina and CE. In situ characterization of the normal eyes revealed robust expression of markers present in NSCs (Nestin, Sox2, Pax6) only around peripheral cysts of the proximal pars plana region and the PR, the latter population also staining for the glial marker GFAP. Although there were higher numbers of dividing cells in the CE of PVR eyes than in controls, we did not detect NSC-associated markers in the CE except around the proximal pars plana cysts. In the mice PVR eyes, Nestin activation was also found in the CE. In human PVR eyes, proliferation of both non-glial and glial cells co-staining NSC-associated markers was evident around the ora serrata region. Spheres formed in 7/10 vitreous samples from patients with PVR compared to 2/15 samples from patients with no known PVR, and expressed glial - and NSC-associated markers both after direct fixation and repetitive

  14. Power-Law Modeling of Cancer Cell Fates Driven by Signaling Data to Reveal Drug Effects

    Science.gov (United States)

    Zhang, Fan; Wu, Min; Kwoh, Chee Keong; Zheng, Jie

    2016-01-01

    Extracellular signals are captured and transmitted by signaling proteins inside a cell. An important type of cellular responses to the signals is the cell fate decision, e.g., apoptosis. However, the underlying mechanisms of cell fate regulation are still unclear, thus comprehensive and detailed kinetic models are not yet available. Alternatively, data-driven models are promising to bridge signaling data with the phenotypic measurements of cell fates. The traditional linear model for data-driven modeling of signaling pathways has its limitations because it assumes that the a cell fate is proportional to the activities of signaling proteins, which is unlikely in the complex biological systems. Therefore, we propose a power-law model to relate the activities of all the measured signaling proteins to the probabilities of cell fates. In our experiments, we compared our nonlinear power-law model with the linear model on three cancer datasets with phosphoproteomics and cell fate measurements, which demonstrated that the nonlinear model has superior performance on cell fates prediction. By in silico simulation of virtual protein knock-down, the proposed model is able to reveal drug effects which can complement traditional approaches such as binding affinity analysis. Moreover, our model is able to capture cell line specific information to distinguish one cell line from another in cell fate prediction. Our results show that the power-law data-driven model is able to perform better in cell fate prediction and provide more insights into the signaling pathways for cancer cell fates than the linear model. PMID:27764199

  15. Oncogene-Induced Changes in Mammary Cell Fate and EMT in Breast Tumorigenesis

    Science.gov (United States)

    2015-04-01

    Release; Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Basal-like/ triple negative breast cancers (TNBCs) are characterized by...24 4 1. INTRODUCTION: Basal-like/ triple negative breast cancers (TNBCs) are characterized by distinctive morphologic, genetic, and clinical features...with tumor initiation and cell fate markers. 2. KEYWORDS: IGF1R, triple - negative breast cancer, luminal, myoepithelial, cell fate 3. ACCOMPLISHMENTS

  16. p47phox Directs Murine Macrophage Cell Fate Decisions

    Science.gov (United States)

    Yi, Liang; Liu, Qi; Orandle, Marlene S.; Sadiq-Ali, Sara; Koontz, Sherry M.; Choi, Uimook; Torres-Velez, Fernando J.; Jackson, Sharon H.

    2012-01-01

    Macrophage differentiation and function are pivotal for cell survival from infection and involve the processing of microenvironmental signals that determine macrophage cell fate decisions to establish appropriate inflammatory balance. NADPH oxidase 2 (Nox2)–deficient chronic granulomatous disease (CGD) mice that lack the gp91phox (gp91phox−/−) catalytic subunit show high mortality rates compared with wild-type mice when challenged by infection with Listeria monocytogenes (Lm), whereas p47phox-deficient (p47phox−/−) CGD mice show survival rates that are similar to those of wild-type mice. We demonstrate that such survival results from a skewed macrophage differentiation program in p47phox−/− mice that favors the production of higher levels of alternatively activated macrophages (AAMacs) compared with levels of either wild-type or gp91phox−/− mice. Furthermore, the adoptive transfer of AAMacs from p47phox−/− mice can rescue gp91phox−/− mice during primary Lm infection. Key features of the protective function provided by p47phox−/− AAMacs against Lm infection are enhanced production of IL-1α and killing of Lm. Molecular analysis of this process indicates that p47phox−/− macrophages are hyperresponsive to IL-4 and show higher Stat6 phosphorylation levels and signaling coupled to downstream activation of AAMac transcripts in response to IL-4 stimulation. Notably, restoring p47phox protein expression levels reverts the p47phox-dependent AAMac phenotype. Our results indicate that p47phox is a previously unrecognized regulator for IL-4 signaling pathways that are important for macrophage cell fate choice. PMID:22222227

  17. Proliferative index activity in oral squamous cell carcinoma: indication for postoperative radiotherapy?

    Science.gov (United States)

    Gontarz, M; Wyszyńska-Pawelec, G; Zapała, J; Czopek, J; Lazar, A; Tomaszewska, R

    2014-10-01

    The predictive value of the Ki-67 labelling index and its relationship with radiosensitivity in oral squamous cell carcinoma (SCC) remains controversial. We sought to evaluate whether the expression of Ki-67 antigen found in SCC of the tongue and the floor of the mouth is an indication for postoperative radiotherapy (PORT). The first study group included 34 patients who were treated only with primary surgery, while the second group included 26 patients who underwent primary surgery combined with PORT. The correlation between Ki-67 expression and loco-regional recurrence, as well as the 5-year disease-specific survival, was assessed in the two groups. Cases of high-proliferative tumours showed a significantly higher risk of loco-regional recurrence (P=0.018) and a poorer prognosis (P=0.001) only in the 34 patients treated with surgery alone. In multivariate Cox regression analysis, high Ki-67 expression was an independent predictor of loco-regional recurrence (HR 5.42, P=0.029) and disease-specific survival (HR 9.02, P=0.004). The correlation between Ki-67 expression and the risk of loco-regional recurrence in SCC of the tongue and the floor of the mouth may be useful in the selection of patients at a higher risk of recurrence who would benefit from PORT, despite adequate margins of resection and early stage of the disease.

  18. Divergence of zebrafish and mouse lymphatic cell fate specification pathways

    DEFF Research Database (Denmark)

    van Impel, Andreas; Zhao, Zhonghua; Hermkens, Dorien M A;

    2014-01-01

    . Murine Prox1-null embryos lack lymphatic structures, and sustained expression of Prox1 is indispensable for the maintenance of lymphatic cell fate even at adult stages, highlighting the unique importance of this gene for the lymphatic lineage. Whether this pre-eminent role of Prox1 within the lymphatic...... vasculature is conserved in other vertebrate classes has remained unresolved, mainly owing to the lack of availability of loss-of-function mutants. Here, we re-examine the role of Prox1a in zebrafish lymphangiogenesis. First, using a transgenic reporter line, we show that prox1a is initially expressed...... that the functionally related transcription factors Coup-TFII and Sox18 are also dispensable for lymphangiogenesis. Together, these findings suggest that lymphatic commitment in zebrafish and mice is controlled in fundamentally different ways....

  19. Separation and purification and in vitro anti-proliferative activity of leukemia cell K562 of Galium aparine L. petroleum

    Directory of Open Access Journals (Sweden)

    Guoqing Shi

    2016-05-01

    Full Text Available To explore material basis of in vitro anti-proliferative activity of leukemia cell K562 of petroleum ether phase of product resulting from Galium aparine L. 60% ethanol extraction, the experiment adopts column chromatography combined with thin layer preparation, isolates and purifies petroleum ether, conducts structural identification of obtained single compound and applies MTT method for viability assay of in vitro anti-proliferative activity of leukemia cell K562. Experimental results show that G. aparine L. petroleum ether contains mainly β-sitosterol, daucosterol and dibutyl phthalate and other substances. Under experimental conditions, the three could inhibit the proliferation of leukemia cell K562 with dose-effect and time-effect relationship, of which dibutyl phthalate has strongest activity. Dibutyl phthalate with excellent activity, β-sitosterol with rich content and moderate effect should be the main contributor to its biological activity.

  20. Generation of bivalent chromatin domains during cell fate decisions

    Directory of Open Access Journals (Sweden)

    De Gobbi Marco

    2011-06-01

    Full Text Available Abstract Background In self-renewing, pluripotent cells, bivalent chromatin modification is thought to silence (H3K27me3 lineage control genes while 'poising' (H3K4me3 them for subsequent activation during differentiation, implying an important role for epigenetic modification in directing cell fate decisions. However, rather than representing an equivalently balanced epigenetic mark, the patterns and levels of histone modifications at bivalent genes can vary widely and the criteria for identifying this chromatin signature are poorly defined. Results Here, we initially show how chromatin status alters during lineage commitment and differentiation at a single well characterised bivalent locus. In addition we have determined how chromatin modifications at this locus change with gene expression in both ensemble and single cell analyses. We also show, on a global scale, how mRNA expression may be reflected in the ratio of H3K4me3/H3K27me3. Conclusions While truly 'poised' bivalently modified genes may exist, the original hypothesis that all bivalent genes are epigenetically premarked for subsequent expression might be oversimplistic. In fact, from the data presented in the present work, it is equally possible that many genes that appear to be bivalent in pluripotent and multipotent cells may simply be stochastically expressed at low levels in the process of multilineage priming. Although both situations could be considered to be forms of 'poising', the underlying mechanisms and the associated implications are clearly different.

  1. Mechanical memory and dosing influence stem cell fate

    Science.gov (United States)

    Yang, Chun; Tibbitt, Mark W.; Basta, Lena; Anseth, Kristi S.

    2014-06-01

    We investigated whether stem cells remember past physical signals and whether these can be exploited to dose cells mechanically. We found that the activation of the Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding domain (TAZ) as well as the pre-osteogenic transcription factor RUNX2 in human mesenchymal stem cells (hMSCs) cultured on soft poly(ethylene glycol) (PEG) hydrogels (Young’s modulus E ~ 2 kPa) depended on previous culture time on stiff tissue culture polystyrene (TCPS; E ~ 3 GPa). In addition, mechanical dosing of hMSCs cultured on initially stiff (E ~ 10 kPa) and then soft (E ~ 2 kPa) phototunable PEG hydrogels resulted in either reversible or—above a threshold mechanical dose—irreversible activation of YAP/TAZ and RUNX2. We also found that increased mechanical dosing on supraphysiologically stiff TCPS biases hMSCs towards osteogenic differentiation. We conclude that stem cells possess mechanical memory—with YAP/TAZ acting as an intracellular mechanical rheostat—that stores information from past physical environments and influences the cells’ fate.

  2. Mitophagy-driven mitochondrial rejuvenation regulates stem cell fate

    Science.gov (United States)

    Vazquez-Martin, Alejandro; Van den Haute, Chris; Cufí, Sílvia; Corominas-Faja, Bruna; Cuyàs, Elisabet; Lopez-Bonet, Eugeni; Rodriguez-Gallego, Esther; Fernández-Arroyo, Salvador; Joven, Jorge; Baekelandt, Veerle; Menendez, Javier A.

    2016-01-01

    Our understanding on how selective mitochondrial autophagy, or mitophagy, can sustain the archetypal properties of stem cells is incomplete. PTEN-induced putative kinase 1 (PINK1) plays a key role in the maintenance of mitochondrial morphology and function and in the selective degradation of damaged mitochondria by mitophagy. Here, using embryonic fibroblasts from PINK1 gene-knockout (KO) mice, we evaluated whether mitophagy is a causal mechanism for the control of cell-fate plasticity and maintenance of pluripotency. Loss of PINK1-dependent mitophagy was sufficient to dramatically decrease the speed and efficiency of induced pluripotent stem cell (iPSC) reprogramming. Mitophagy-deficient iPSC colonies, which were characterized by a mixture of mature and immature mitochondria, seemed unstable, with a strong tendency to spontaneously differentiate and form heterogeneous populations of cells. Although mitophagy-deficient iPSC colonies normally expressed pluripotent markers, functional monitoring of cellular bioenergetics revealed an attenuated glycolysis in mitophagy-deficient iPSC cells. Targeted metabolomics showed a notable alteration in numerous glycolysis- and TCA-related metabolites in mitophagy-deficient iPSC cells, including a significant decrease in the intracellular levels of α-ketoglutarate -a key suppressor of the differentiation path in stem cells. Mitophagy-deficient iPSC colonies exhibited a notably reduced teratoma-initiating capacity, but fully retained their pluripotency and multi-germ layer differentiation capacity in vivo. PINK1-dependent mitophagy pathway is an important mitochondrial switch that determines the efficiency and quality of somatic reprogramming. Mitophagy-driven mitochondrial rejuvenation might contribute to the ability of iPSCs to suppress differentiation by directing bioenergetic transition and metabolome remodeling traits. These findings provide new insights into how mitophagy might influence the stem cell decisions to retain

  3. Increased Stiffness in Aged Skeletal Muscle Impairs Muscle Progenitor Cell Proliferative Activity.

    Directory of Open Access Journals (Sweden)

    Grégory Lacraz

    Full Text Available Skeletal muscle aging is associated with a decreased regenerative potential due to the loss of function of endogenous stem cells or myogenic progenitor cells (MPCs. Aged skeletal muscle is characterized by the deposition of extracellular matrix (ECM, which in turn influences the biomechanical properties of myofibers by increasing their stiffness. Since the stiffness of the MPC microenvironment directly impacts MPC function, we hypothesized that the increase in muscle stiffness that occurs with aging impairs the behavior of MPCs, ultimately leading to a decrease in regenerative potential.We showed that freshly isolated individual myofibers from aged mouse muscles contain fewer MPCs overall than myofibers from adult muscles, with fewer quiescent MPCs and more proliferative and differentiating MPCs. We observed alterations in cultured MPC behavior in aged animals, where the proliferation and differentiation of MPCs were lower and higher, respectively. These alterations were not linked to the intrinsic properties of aged myofibers, as shown by the similar values for the cumulative population-doubling values and fusion indexes. However, atomic force microscopy (AFM indentation experiments revealed a nearly 4-fold increase in the stiffness of the MPC microenvironment. We further showed that the increase in stiffness is associated with alterations to muscle ECM, including the accumulation of collagen, which was correlated with higher hydroxyproline and advanced glycation end-product content. Lastly, we recapitulated the impaired MPC behavior observed in aging using a hydrogel substrate that mimics the stiffness of myofibers.These findings provide novel evidence that the low regenerative potential of aged skeletal muscle is independent of intrinsic MPC properties but is related to the increase in the stiffness of the MPC microenvironment.

  4. Fate and degradation of petroleum hydrocarbons in stormwater bioretention cells

    Science.gov (United States)

    LeFevre, Gregory Hallett

    This dissertation describes the investigation of the fate of hydrocarbons in stormwater bioretention areas and those mechanisms that affect hydrocarbon fate in such systems. Seventy-five samples from 58 bioretention areas were collected and analyzed to measure total petroleum hydrocarbon (TPH) residual and biodegradation functional genes. TPH residual in bioretention areas was greater than background sites but low overall (biodegradation. Field soils were capable of mineralizing naphthalene, a polycyclic aromatic hydrocarbon (PAH) when incubated in the laboratory. In an additional laboratory investigation, a column study was initiated to comprehensively determine naphthalene fate in a simulated bioretention cell using a 14C-labeled tracer. Sorption to soil was the greatest sink of naphthalene in the columns, although biodegradation and vegetative uptake were also important loss mechanisms. Little leaching occurred following the first flush, and volatilization was insignificant. Significant enrichment of naphthalene degrading bacteria occurred over the course of the experiment as a result of naphthalene exposure. This was evident from enhanced naphthalene biodegradation kinetics (measured via batch tests), significant increases in naphthalene dioxygenase gene quantities, and a significant correlation observed between naphthalene residual and biodegradation functional genes. Vegetated columns outperformed the unplanted control column in terms of total naphthalene removal and biodegradation kinetics. As a result of these experiments, a final study focused on why planted systems outperform unplanted systems was conducted. Plant root exudates were harvested from hydroponic setups for three types of plants. Additionally, a solution of artificial root exudates (AREs) as prepared. Exudates were digested using soil bacteria to create metabolized exudates. Raw and metabolized exudates were characterized for dissolved organic carbon, specific UV absorbance, spectral slope

  5. Regulation of cell fate and meristem maintenance in Arabidopsis root development

    NARCIS (Netherlands)

    ten Hove, C.A.

    2010-01-01

    Asymmetric cell division is an essential and universal mechanism for generating diversity and pattern in multicellular organisms. Divisions generating daughter cells different in size, shape, identity and function are fundamental to many developmental processes including fate specification, tissue p

  6. How the cell cycle impacts chromatin architecture and influences cell fate

    Directory of Open Access Journals (Sweden)

    Yiqin eMa

    2015-02-01

    Full Text Available Since the earliest observations of cells undergoing mitosis, it has been clear that there is an intimate relationship between the cell cycle and nuclear chromatin architecture. The nuclear envelope and chromatin undergo robust assembly and disassembly during the cell cycle, and transcriptional and post-transcriptional regulation of histone biogenesis and chromatin modification is controlled in a cell cycle-dependent manner. Chromatin binding proteins and chromatin modifications in turn influence the expression of critical cell cycle regulators, the accessibility of origins for DNA replication, DNA repair, and cell fate. In this review we aim to provide an integrated discussion of how the cell cycle machinery impacts nuclear architecture and vice-versa. We highlight recent advances in understanding cell cycle-dependent histone biogenesis and histone modification deposition, how cell cycle regulators control histone modifier activities, the contribution of chromatin modifications to origin firing for DNA replication, and newly identified roles for nucleoporins in regulating cell cycle gene expression, gene expression memory and differentiation. We close with a discussion of how cell cycle status may impact chromatin to influence cell fate decisions, under normal contexts of differentiation as well as in instances of cell fate re-programming.

  7. EBI2 augments Tfh cell fate by promoting interaction with IL-2-quenching dendritic cells.

    Science.gov (United States)

    Li, Jianhua; Lu, Erick; Yi, Tangsheng; Cyster, Jason G

    2016-05-05

    T follicular helper (Tfh) cells are a subset of T cells carrying the CD4 antigen; they are important in supporting plasma cell and germinal centre responses. The initial induction of Tfh cell properties occurs within the first few days after activation by antigen recognition on dendritic cells, although how dendritic cells promote this cell-fate decision is not fully understood. Moreover, although Tfh cells are uniquely defined by expression of the follicle-homing receptor CXCR5 (refs 1, 2), the guidance receptor promoting the earlier localization of activated T cells at the interface of the B-cell follicle and T zone has been unclear. Here we show that the G-protein-coupled receptor EBI2 (GPR183) and its ligand 7α,25-dihydroxycholesterol mediate positioning of activated CD4 T cells at the interface of the follicle and T zone. In this location they interact with activated dendritic cells and are exposed to Tfh-cell-promoting inducible co-stimulator (ICOS) ligand. Interleukin-2 (IL-2) is a cytokine that has multiple influences on T-cell fate, including negative regulation of Tfh cell differentiation. We demonstrate that activated dendritic cells in the outer T zone further augment Tfh cell differentiation by producing membrane and soluble forms of CD25, the IL-2 receptor α-chain, and quenching T-cell-derived IL-2. Mice lacking EBI2 in T cells or CD25 in dendritic cells have reduced Tfh cells and mount defective T-cell-dependent plasma cell and germinal centre responses. These findings demonstrate that distinct niches within the lymphoid organ T zone support distinct cell fate decisions, and they establish a function for dendritic-cell-derived CD25 in controlling IL-2 availability and T-cell differentiation.

  8. Proliferative responses of blood mononuclear cells (BMNC) in a cohort of elderly humans: role of lymphocyte phenotype and cytokine production

    DEFF Research Database (Denmark)

    Bruunsgaard, H.; Pedersen, Agnes Nadelmann; Schroll, M.;

    2000-01-01

    -old humans and in 91 young controls. Decreased proliferation was associated with a reduced number of true naive CD4(+) cells (CD62L(+)CD45RO(-)). Furthermore, a low IL-2-stimulated proliferation was correlated with a decreased PHA response in the elderly cohort, whereas reciprocal interactions of IL-10......- and IL-2-producing cells were of importance in both elderly and young subjects. Accordingly, a minimum of true naive CD4(+) cells was required for a normal proliferative response to PHA, perhaps by providing sufficient IL-2 which is critical for growth of naive as well as memory cells....

  9. GTP depletion synergizes the anti-proliferative activity of chemotherapeutic agents in a cell type-dependent manner

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Tao; Meng, Lingjun [Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology, Texas A and M Health Science Center, Houston, TX 77030 (United States); Tsai, Robert Y.L., E-mail: rtsai@ibt.tamhsc.edu [Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology, Texas A and M Health Science Center, Houston, TX 77030 (United States)

    2011-10-22

    Highlights: {yields} Strong synergy between mycophenolic acid (MPA) and 5-FU in MDA-MB-231 cells. {yields} Cell type-dependent synergy between MPA and anti-proliferative agents. {yields} The synergy of MPA on 5-FU is recapitulated by RNA polymerase-I inhibition. {yields} The synergy of MPA on 5-FU requires the expression of nucleostemin. -- Abstract: Mycophenolic acid (MPA) depletes intracellular GTP by blocking de novo guanine nucleotide synthesis. GTP is used ubiquitously for DNA/RNA synthesis and as a signaling molecule. Here, we made a surprising discovery that the anti-proliferative activity of MPA acts synergistically with specific chemotherapeutic agents in a cell type-dependent manner. In MDA-MB-231 cells, MPA shows an extremely potent synergy with 5-FU but not with doxorubicin or etoposide. The synergy between 5-FU and MPA works most effectively against the highly tumorigenic mammary tumor cells compared to the less tumorigenic ones, and does not work in the non-breast cancer cell types that we tested, with the exception of PC3 cells. On the contrary, MPA shows the highest synergy with paclitaxel but not with 5-FU in SCC-25 cells, derived from oral squamous cell carcinomas. Mechanistically, the synergistic effect of MPA on 5-FU in MDA-MB-231 cells can be recapitulated by inhibiting the RNA polymerase-I activity and requires the expression of nucleostemin. This work reveals that the synergy between MPA and anti-proliferative agents is determined by cell type-dependent factors.

  10. Back and forth between cell fate specification and movement during vertebrate gastrulation.

    Science.gov (United States)

    Heisenberg, Carl-Philipp; Solnica-Krezel, Lilianna

    2008-08-01

    Animal body plan arises during gastrulation and organogenesis by the coordination of inductive events and cell movements. Several signaling pathways, such as BMP, FGF, Hedgehog, Nodal, and Wnt have well-recognized instructive roles in cell fate specification during vertebrate embryogenesis. Growing evidence indicates that BMP, Nodal, and FGF signaling also regulate cell movements, and that they do so through mechanisms distinct from those that specify cell fates. Moreover, pathways controlling cell movements can also indirectly influence cell fate specification by regulating dimensions and relative positions of interacting tissues. The current challenge is to delineate the molecular mechanisms via which the major signaling pathways regulate cell fate specification and movements, and how these two processes are coordinated to ensure normal development.

  11. Ablation of coactivator Med1 switches the cell fate of dental epithelia to that generating hair.

    Directory of Open Access Journals (Sweden)

    Keigo Yoshizaki

    Full Text Available Cell fates are determined by specific transcriptional programs. Here we provide evidence that the transcriptional coactivator, Mediator 1 (Med1, is essential for the cell fate determination of ectodermal epithelia. Conditional deletion of Med1 in vivo converted dental epithelia into epidermal epithelia, causing defects in enamel organ development while promoting hair formation in the incisors. We identified multiple processes by which hairs are generated in Med1 deficient incisors: 1 dental epithelial stem cells lacking Med 1 fail to commit to the dental lineage, 2 Sox2-expressing stem cells extend into the differentiation zone and remain multi-potent due to reduced Notch1 signaling, and 3 epidermal fate is induced by calcium as demonstrated in dental epithelial cell cultures. These results demonstrate that Med1 is a master regulator in adult stem cells to govern epithelial cell fate.

  12. Proliferative effect of whey from cows' milk varying in phyto-oestrogens in human breast and prostate cancer cells.

    Science.gov (United States)

    Nielsen, Tina S; Höjer, Annika; Gustavsson, Anne-Maj; Hansen-Møller, Jens; Purup, Stig

    2012-05-01

    Intake of dietary phyto-oestrogens has received a great deal of attention owing to their potential influence on hormone-sensitive cancers such as breast and prostate cancer. Cows' milk contains phyto-oestrogens and the content varies according to the composition of the feed and the type and amount of legumes used. In this study we evaluated the proliferative effect of milk (whey) with different phyto-oestrogen content in human breast (MCF-7) and prostate cancer cells (PC-3). Milk was obtained from cows fed either a birdsfoot trefoil-timothy silage based ration (B1) or two different red clover silage based diets (R1 and R2) resulting in total phyto-oestrogen contents of 403, 1659 and 1434 ng/ml for the B1, R1 and R2 diets, respectively. Whey was produced from the milk and added to cell culture medium in concentrations up to 10% for MCF-7 cells and 5% for PC-3 cells. Cell proliferation was measured fluorometrically after 7 d for MCF-7 cells and 5 d for PC-3 cells. There was no significant difference in the proliferative effect of whey from the different dietary treatments at any of the whey concentrations tested. An anti-proliferative effect (Pwhey was seen when tested in the presence of 10 pM oestradiol in the medium. This effect was independent of dietary treatment of cows. Whey induced a significant (Pmilk decreased PC-3 cell proliferation, and therefore the stimulatory effect of whey in PC-3 cells is believed to be mediated by other bioactives than equol. In conclusion, our results suggest that using whey in these proliferation assays, it was not possible to discriminate between milk with high or low levels of phyto-oestrogens.

  13. Msx2 in ameloblast cell fate and activity

    Directory of Open Access Journals (Sweden)

    Sylvie eBabajko

    2015-01-01

    Full Text Available While many effectors have been identified in enamel matrix and cells via genetic studies, physiological networks underlying their expression levels and thus the natural spectrum of enamel thickness and degree of mineralization are now just emerging. Several transcription factors are candidates for enamel gene expression regulation and thus the control of enamel quality. Some of these factors, such as MSX2, are mainly confined to the dental epithelium. MSX2 homeoprotein controls several stages of the ameloblast life cycle. This chapter introduces MSX2 and its target genes in the ameloblast and provides an overview of knowledge regarding its effects in vivo in transgenic mouse models. Currently available in vitro data on the role of MSX2 as a transcription factor and its links to other players in ameloblast gene regulation are considered. MSX2 modulations are relevant to the interplay between developmental, hormonal and environmental pathways and in vivo investigations, notably in the rodent incisor, have provided insight into dental physiology. Indeed, in vivo models are particularly promising for investigating enamel formation and MSX2 function in ameloblast cell fate.MSX2 may be central to the temporal-spatial restriction of enamel protein production by the dental epithelium and thus regulation of enamel quality (thickness and mineralization level under physiological and pathological conditions. Studies on MSX2 show that amelogenesis is not an isolated process but is part of the more general physiology of coordinated dental-bone complex growth.

  14. Slit/Robo signaling regulates cell fate decisions in the intestinal stem cell lineage of Drosophila.

    Science.gov (United States)

    Biteau, Benoît; Jasper, Heinrich

    2014-06-26

    In order to maintain tissue homeostasis, cell fate decisions within stem cell lineages have to respond to the needs of the tissue. This coordination of lineage choices with regenerative demand remains poorly characterized. Here, we identify a signal from enteroendocrine cells (EEs) that controls lineage specification in the Drosophila intestine. We find that EEs secrete Slit, a ligand for the Robo2 receptor in intestinal stem cells (ISCs) that limits ISC commitment to the endocrine lineage, establishing negative feedback control of EE regeneration. Furthermore, we show that this lineage decision is made within ISCs and requires induction of the transcription factor Prospero in ISCs. Our work identifies a function for the conserved Slit/Robo pathway in the regulation of adult stem cells, establishing negative feedback control of ISC lineage specification as a critical strategy to preserve tissue homeostasis. Our results further amend the current understanding of cell fate commitment within the Drosophila ISC lineage.

  15. 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.

  16. Slit/Robo Signaling Regulates Cell Fate Decisions in the Intestinal Stem Cell Lineage of Drosophila

    Directory of Open Access Journals (Sweden)

    Benoît Biteau

    2014-06-01

    Full Text Available In order to maintain tissue homeostasis, cell fate decisions within stem cell lineages have to respond to the needs of the tissue. This coordination of lineage choices with regenerative demand remains poorly characterized. Here, we identify a signal from enteroendocrine cells (EEs that controls lineage specification in the Drosophila intestine. We find that EEs secrete Slit, a ligand for the Robo2 receptor in intestinal stem cells (ISCs that limits ISC commitment to the endocrine lineage, establishing negative feedback control of EE regeneration. Furthermore, we show that this lineage decision is made within ISCs and requires induction of the transcription factor Prospero in ISCs. Our work identifies a function for the conserved Slit/Robo pathway in the regulation of adult stem cells, establishing negative feedback control of ISC lineage specification as a critical strategy to preserve tissue homeostasis. Our results further amend the current understanding of cell fate commitment within the Drosophila ISC lineage.

  17. Furanodiene presents synergistic anti-proliferative activity with paclitaxel via altering cell cycle and integrin signaling in 95-D lung cancer cells.

    Science.gov (United States)

    Xu, Wen-Shan; Dang, Yuan-Ye; Chen, Xiu-Ping; Lu, Jin-Jian; Wang, Yi-Tao

    2014-02-01

    Furanodiene (FUR) is a natural terpenoid isolated from Rhizoma Curcumae, a well-known Chinese medicinal herb that presents anti-proliferative activities in several cancer cell lines. Recently, we found that the combined treatment of FUR with paclitaxel (TAX) showed synergetic anti-proliferative activities in 95-D lung cancer cells. Herein, we showed that FUR reduced the cell numbers distributed in mitosis phase induced by TAX while increased those in G1 phase. The protein levels of cyclin D1, cyclin B1, CDK6 and c-Myc were all down-regulated in the group of combined treatment. The dramatically down-regulated expression of integrin β4, focal adhesion kinase and paxillin might partially contribute to the synergic effect. Though FUR alone obviously induced endoplasmic reticulum stress, this signaling pathway may not contribute to the synergetic anti-proliferative effect as the protein expression of CHOP and BIP was similar in FUR alone and combined treatment group.

  18. Insulin Promotes Proliferative Vitality and Invasive Capability of Pancreatic Cancer Cells via Hypoxia-inducible Factor 1α Pathway

    Institute of Scientific and Technical Information of China (English)

    汪理; 周伟; 勾善淼; 王统玲; 刘涛; 王春友

    2010-01-01

    This study examined whether insulin-stimulated hypoxia-inducible factor 1α(HIF-1α) expression plays a crucial role in promoting the proliferative vitality and invasive capability in human pancreatic cancer cells.PANC-1 cells were divided into three groups:Control group,insulin group and insulin+YC-1(a pharmacological inhibitor of HIF-1α) group in terms of different treatments.Cells in the insulin group or insulin+YC-1 group were treated with insulin(0.1,1,10 and 100 nmol/L) alone or combined with 3-(5'-hydr...

  19. Content of endoplasmic reticulum and Golgi complex membranes positively correlates with the proliferative status of brain cells.

    Science.gov (United States)

    Silvestre, David C; Maccioni, Hugo J F; Caputto, Beatriz L

    2009-03-01

    Although the molecular and cellular basis of particular events that lead to the biogenesis of membranes in eukaryotic cells has been described in detail, understanding of the intrinsic complexity of the pleiotropic response by which a cell adjusts the overall activity of its endomembrane system to accomplish these requirements is limited. Here we carried out an immunocytochemical and biochemical examination of the content and quality of the endoplasmic reticulum (ER) and Golgi apparatus membranes in two in vivo situations characterized by a phase of active cell proliferation followed by a phase of declination in proliferation (rat brain tissue at early and late developmental stages) or by permanent active proliferation (gliomas and their most malignant manifestation, glioblastomas multiforme). It was found that, in highly proliferative phases of brain development (early embryo brain cells), the content of ER and Golgi apparatus membranes, measured as total lipid phosphorous content, is higher than in adult brain cells. In addition, the concentration of protein markers of ER and Golgi is also higher in early embryo brain cells and in human glioblastoma multiforme cells than in adult rat brain or in nonpathological human brain cells. Results suggest that the amount of endomembranes and the concentration of constituent functional proteins diminish as cells decline in their proliferative activity.

  20. Myf5 haploinsufficiency reveals distinct cell fate potentials for adult skeletal muscle stem cells.

    Science.gov (United States)

    Gayraud-Morel, Barbara; Chrétien, Fabrice; Jory, Aurélie; Sambasivan, Ramkumar; Negroni, Elisa; Flamant, Patricia; Soubigou, Guillaume; Coppée, Jean-Yves; Di Santo, James; Cumano, Ana; Mouly, Vincent; Tajbakhsh, Shahragim

    2012-04-01

    Skeletal muscle stem cell fate in adult mice is regulated by crucial transcription factors, including the determination genes Myf5 and Myod. The precise role of Myf5 in regulating quiescent muscle stem cells has remained elusive. Here we show that most, but not all, quiescent satellite cells express Myf5 protein, but at varying levels, and that resident Myf5 heterozygous muscle stem cells are more primed for myogenic commitment compared with wild-type satellite cells. Paradoxically however, heterotypic transplantation of Myf5 heterozygous cells into regenerating muscles results in higher self-renewal capacity compared with wild-type stem cells, whereas myofibre regenerative capacity is not altered. By contrast, Pax7 haploinsufficiency does not show major modifications by transcriptome analysis. These observations provide a mechanism linking Myf5 levels to muscle stem cell heterogeneity and fate by exposing two distinct and opposing phenotypes associated with Myf5 haploinsufficiency. These findings have important implications for how stem cell fates can be modulated by crucial transcription factors while generating a pool of responsive heterogeneous cells.

  1. Prolonged antigen presentation by immune complex-binding dendritic cells programs the proliferative capacity of memory CD8 T cells.

    Science.gov (United States)

    León, Beatriz; Ballesteros-Tato, André; Randall, Troy D; Lund, Frances E

    2014-07-28

    The commitment of naive CD8 T cells to effector or memory cell fates can occur after a single day of antigenic stimulation even though virus-derived antigens (Ags) are still presented by DCs long after acute infection is resolved. However, the effects of extended Ag presentation on CD8 T cells are undefined and the mechanisms that regulate prolonged Ag presentation are unknown. We showed that the sustained presentation of two different epitopes from influenza virus by DCs prevented the premature contraction of the primary virus-specific CD8 T cell response. Although prolonged Ag presentation did not alter the number of memory CD8 T cells that developed, it was essential for programming the capacity of these cells to proliferate, produce cytokines, and protect the host after secondary challenge. Importantly, prolonged Ag presentation by DCs was dependent on virus-specific, isotype-switched antibodies (Abs) that facilitated the capture and cross-presentation of viral Ags by FcγR-expressing DCs. Collectively, our results demonstrate that B cells and Abs can regulate the quality and functionality of a subset of antiviral CD8 T cell memory responses and do so by promoting sustained Ag presentation by DCs during the contraction phase of the primary T cell response.

  2. Vertebrate Ctr1 coordinates morphogenesis and progenitor cell fate and regulates embryonic stem cell differentiation

    OpenAIRE

    Haremaki, Tomomi; Fraser, Stuart T.; Kuo, Yien-Ming; Baron, Margaret H.; Weinstein, Daniel C.

    2007-01-01

    Embryogenesis involves two distinct processes. On the one hand, cells must specialize, acquiring fates appropriate to their positions (differentiation); on the other hand, they must physically construct the embryo through coordinated mechanical activity (morphogenesis). In early vertebrate development, fibroblast growth factor (FGF) regulates multiple embryonic events, including germ layer differentiation and morphogenesis; the cellular components that direct FGF signaling to evoke these diff...

  3. T Cell Fate at the Single-Cell Level.

    Science.gov (United States)

    Buchholz, Veit R; Schumacher, Ton N M; Busch, Dirk H

    2016-05-20

    T cell responses display two key characteristics. First, a small population of epitope-specific naive T cells expands by several orders of magnitude. Second, the T cells within this proliferating population take on diverse functional and phenotypic properties that determine their ability to exert effector functions and contribute to T cell memory. Recent technological advances in lineage tracing allow us for the first time to study these processes in vivo at single-cell resolution. Here, we summarize resulting data demonstrating that although epitope-specific T cell responses are reproducibly similar at the population level, expansion potential and diversification patterns of the offspring derived from individual T cells are highly variable during both primary and recall immune responses. In spite of this stochastic response variation, individual memory T cells can serve as adult stem cells that provide robust regeneration of an epitope-specific tissue through population averaging. We discuss the relevance of these findings for T cell memory formation and clinical immunotherapy.

  4. Potential Anti-proliferative and Immunomodulatory Effects of Marine Microalgal Exopolysaccharide on Various Human Cancer Cells and Lymphocytes In Vitro.

    Science.gov (United States)

    Park, Geon-Tae; Go, Ryeo-Eun; Lee, Hae-Miru; Lee, Geum-A; Kim, Cho-Won; Seo, Jeong-Woo; Hong, Won-Kyung; Choi, Kyung-Chul; Hwang, Kyung-A

    2017-02-04

    Marine microalgal exopolysaccharides (EPSs) have drawn great attention due to their biotechnological potentials such as anti-viral, anti-oxidant, anti-lipidemic, anti-proliferative, and immunomodulatory activities, etc. In the present study, the EPS derived from microalgae Thraustochytriidae sp.-derived mutant GA was investigated for its anti-proliferation and immunomodulation. Anti-cancer efficacy of the microalgal EPS was examined for the alterations in cell proliferation and cell cycle-related gene expression that occur in three types of human cancer cell lines, BG-1 ovarian, MCF-7 breast, and SW-620 colon cancer cell lines, by its treatment. Alterations in immunoreactivity by the microalgal EPS were examined by measuring its influence on the growth of T and B lymphocytes and cytokine production of T cells. In cell viability assay, the microalgal EPS inhibited cancer cell growth at the lowest concentration of 10(-11) dilution and in a dose-responsive manner within the range of dilution of 10(-11)~10(-3). In addition, the protein expression of cell cycle progression genes such as cyclin D1 and E in these cancer cell lines was significantly reduced by the microalgal EPS in a dose- and a time-dependant manner. In cell proliferation assay using T and B cells, the microalgal EPS induced B cell proliferation even at the lowest dilution of 10(-11), but not T cells. In cytokine assay, the microalgal EPS decreased the formation of IL-6 and INF-γ at 10(-3) dilution compared to the control and had no significant effects on TNF-α. Collectively, these findings suggest that the EPS derived from microalgae Thraustochytriidae sp. GA has an anti-proliferative activity against cancer cells and an immunomodulatory effect by having an influence on B cell proliferation and cytokine secretion of T cells.

  5. Sox17-Mediated XEN Cell Conversion Identifies Dynamic Networks Controlling Cell-Fate Decisions in Embryo-Derived Stem Cells

    Directory of Open Access Journals (Sweden)

    Angela C.H. McDonald

    2014-10-01

    Full Text Available Little is known about the gene regulatory networks (GRNs distinguishing extraembryonic endoderm (ExEn stem (XEN cells from those that maintain the extensively characterized embryonic stem cell (ESC. An intriguing network candidate is Sox17, an essential transcription factor for XEN derivation and self-renewal. Here, we show that forced Sox17 expression drives ESCs toward ExEn, generating XEN cells that contribute to ExEn when placed back into early mouse embryos. Transient Sox17 expression is sufficient to drive this fate change during which time cells transit through distinct intermediate states prior to the generation of functional XEN-like cells. To orchestrate this conversion process, Sox17 acts in autoregulatory and feedforward network motifs, regulating dynamic GRNs directing cell fate. Sox17-mediated XEN conversion helps to explain the regulation of cell-fate changes and reveals GRNs regulating lineage decisions in the mouse embryo.

  6. Proliferative and anti-proliferative effects of dietary levels of phytoestrogens in rat pituitary GH3/B6/F10 cells - the involvement of rapidly activated kinases and caspases

    OpenAIRE

    Watson Cheryl S; Jeng Yow-Jiun

    2009-01-01

    Abstract Background Phytoestogens are a group of lipophillic plant compounds that can have estrogenic effects in animals; both tumorigenic and anti-tumorigenic effects have been reported. Prolactin-secreting adenomas are the most prevalent form of pituitary tumors in humans and have been linked to estrogen exposures. We examined the proliferative effects of phytoestrogens on a rat pituitary tumor cell line, GH3/B6/F10, originally subcloned from GH3 cells based on its ability to express high l...

  7. IFPA Trophoblast Research Award Lecture: the dynamic role of Bcl-2 family members in trophoblast cell fate.

    Science.gov (United States)

    Ray, J; Jurisicova, A; Caniggia, I

    2009-03-01

    Bcl-2 family members are important regulators of cell fate in normal organ development and in disease status. Pro- and anti-apoptotic members of this family function through a complex network of homo- and hetero-dimers to determine whether a cell lives or dies. Members of the Bcl-2 family are classically recognized for their role in apoptosis, yet emerging evidence has highlighted their importance in the regulation of cell cycle. Cellular proliferation, differentiation and death accompany early placental development of the trophoblast lineage. We have recently reported on the expression and function of two Bcl-2 family members in normal placental development, namely the pro-apoptotic Mtd/Bok, and its anti-apoptotic partner Mcl-1 and have found that their expression is upregulated by low oxygen, a key mediator of trophoblast cell proliferation in early placentation. Interestingly, we have also reported that the expression of the Mtd/Mcl-1 system is altered in preeclampsia, a placental pathology associated with a status of oxidative stress and typically characterized by an immature proliferative trophoblast phenotype and excessive trophoblast cell death. In this pathology levels of pro-apototic Mtd-L and Mtd-P are increased and anti-apoptotic Mcl-1 is cleaved in to a pro-apoptotic isoform. Disruption in Mtd/Mcl-1 expression seen in preeclampsia may contribute to both the increased apoptosis and hyperproliferative nature of this disorder.

  8. Necdin modulates proliferative cell survival of human cells in response to radiation-induced genotoxic stress

    Directory of Open Access Journals (Sweden)

    Lafontaine Julie

    2012-06-01

    Full Text Available Abstract Background The finite replicative lifespan of cells, termed cellular senescence, has been proposed as a protective mechanism against the proliferation of oncogenically damaged cells, that fuel cancer. This concept is further supported by the induction of premature senescence, a process which is activated when an oncogene is expressed in normal primary cells as well as following intense genotoxic stresses. Thus, deregulation of genes that control this process, like the tumor suppressor p53, may contribute to promoting cancer by allowing cells to bypass senescence. A better understanding of the genes that contribute to the establishment of senescence is therefore warranted. Necdin interacts with p53 and is also a p53 target gene, although the importance of Necdin in the p53 response is not clearly understood. Methods In this study, we first investigated Necdin protein expression during replicative senescence and premature senescence induced by gamma irradiation and by the overexpression of oncogenic RasV12. Gain and loss of function experiments were used to evaluate the contribution of Necdin during the senescence process. Results Necdin expression declined during replicative aging of IMR90 primary human fibroblasts or following induction of premature senescence. Decrease in Necdin expression seemed to be a consequence of the establishment of senescence since the depletion of Necdin in human cells did not induce a senescence-like growth arrest nor a flat morphology or SA-β-galactosidase activity normally associated with senescence. Similarly, overexpression of Necdin did not affect the life span of IMR90 cells. However, we demonstrate that in normal human cells, Necdin expression mimicked the effect of p53 inactivation by increasing radioresistance. Conclusion This result suggests that Necdin potentially attenuate p53 signaling in response to genotoxic stress in human cells and supports similar results describing an inhibitory function

  9. Potency and fate specification in CNS stem cell populations in vitro.

    Science.gov (United States)

    Ravin, Rea; Hoeppner, Daniel J; Munno, David M; Carmel, Liran; Sullivan, Jim; Levitt, David L; Miller, Jennifer L; Athaide, Christopher; Panchision, David M; McKay, Ronald D G

    2008-12-01

    To realize the promise of stem cell biology, it is important to identify the precise time in the history of the cell when developmental potential is restricted. To achieve this goal, we developed a real-time imaging system that captures the transitions in fate, generating neurons, astrocytes, and oligodendrocytes from single CNS stem cells in vitro. In the presence of bFGF, tripotent cells normally produce specified progenitors through a bipotent intermediate cell type. Surprisingly, the tripotent state is reset at each passage. The cytokine CNTF is thought to instruct multipotent cells to an astrocytic fate. We demonstrate that CNTF both directs astrogliogenesis from tripotent cells, bypassing two of the three normal bipotent intermediates, and later promotes the expansion of specified astrocytic progenitors. These results show how discrete cell types emerge from a multipotent cell and provide a strong basis for future studies to determine the molecular basis of fate specification.

  10. Stathmin 1 is involved in the highly proliferative phenotype of high-risk myelodysplastic syndromes and acute leukemia cells.

    Science.gov (United States)

    Machado-Neto, João Agostinho; de Melo Campos, Paula; Favaro, Patricia; Lazarini, Mariana; Lorand-Metze, Irene; Costa, Fernando Ferreira; Olalla Saad, Sara Teresinha; Traina, Fabiola

    2014-02-01

    Stathmin 1 is an important cytoplasmic microtubule-destabilizing protein that plays critical roles in proliferation and accurate chromosome segregation through regulation of microtubule dynamics. High levels of Stathmin 1 expression have been reported in leukemia and solid tumors. However, Stathmin 1 has not been studied in myelodysplastic syndrome cells. We, herein, report that significantly higher Stathmin 1 levels were observed in proliferating hematopoietic cells, in high-risk MDS and acute leukemia cells. In addition, Stathmin 1 silencing in U937 and Namalwa leukemia cells reduced cell proliferation and clonogenicity. Our data suggest that Stathmin 1 expression may be related to the highly proliferative phenotype of hematopoietic cells and add new insights into the participation of Stathmin 1 in hematological malignancies.

  11. Dynamic transcriptional signature and cell fate analysis reveals plasticity of individual neural plate border cells

    Science.gov (United States)

    Roellig, Daniela; Tan-Cabugao, Johanna; Esaian, Sevan; Bronner, Marianne E

    2017-01-01

    The ‘neural plate border’ of vertebrate embryos contains precursors of neural crest and placode cells, both defining vertebrate characteristics. How these lineages segregate from neural and epidermal fates has been a matter of debate. We address this by performing a fine-scale quantitative temporal analysis of transcription factor expression in the neural plate border of chick embryos. The results reveal significant overlap of transcription factors characteristic of multiple lineages in individual border cells from gastrula through neurula stages. Cell fate analysis using a Sox2 (neural) enhancer reveals that cells that are initially Sox2+ cells can contribute not only to neural tube but also to neural crest and epidermis. Moreover, modulating levels of Sox2 or Pax7 alters the apportionment of neural tube versus neural crest fates. Our results resolve a long-standing question and suggest that many individual border cells maintain ability to contribute to multiple ectodermal lineages until or beyond neural tube closure. DOI: http://dx.doi.org/10.7554/eLife.21620.001 PMID:28355135

  12. Positional cues specify and maintain aleurone cell fate in maize endosperm development.

    Science.gov (United States)

    Becraft, P W; Asuncion-Crabb, Y

    2000-09-01

    A genetic analysis of maize aleurone development was conducted. Cell lineage was examined by simultaneously marking cells with C1 for anthocyanin pigmentation in the aleurone and wx1 for amylose synthesis in the starchy endosperm. The aleurone and starchy endosperm share a common lineage throughout development indicating that positional cues specify aleurone fate. Mutants in dek1 block aleurone formation at an early stage and cause peripheral endosperm cells to develop as starchy endosperm. Revertant sectors of a transposon-induced dek1 allele showed that peripheral endosperm cells remain competent to differentiate as aleurone cells until late in development. Ds-induced chromosome breakage was used to generate Dek1 loss-of-function sectors. Events occurring until late development caused aleurone cells to switch fate to starchy endosperm indicating that cell fate is not fixed. Thus, positional cues are required to specify and maintain aleurone fate and Dek1 function is required to respond to these cues. An analysis of additional mutants that disrupt aleurone differentiation suggests a hierarchy of gene functions to specify aleurone cell fate and then control aleurone differentiation. These mutants disrupt aleurone differentiation in reproducible patterns suggesting a relationship to endosperm pattern formation.

  13. Anti-proliferative Effects of Androctonus amoreuxi Scorpion and Cerastes cerastes Snake Venoms on Human Prostate Cancer Cells

    Science.gov (United States)

    Akef, Hassan; Kotb, Nahla; Abo-Elmatty, Dina; Salem, Sayed

    2017-01-01

    The present study evaluated the effects of Androctonus amoreuxi scorpion venom, Cerastes cerastes snake venom and their mixture on prostate cancer cells (PC3). An MTT assay was used to determine the anti-proliferative effect of the venoms, while quantitative real time PCR was used to evaluate the expression of apoptosis-related genes (Bax and Bcl-2). Furthermore, colorimetric assays were used to measure the levels of malondialdehyde (MDA) and antioxidant enzymes. Our results show that the venoms significantly reduced PC3 cell viability in a dose-dependent manner. On the other hand, these venoms significantly decreased Bcl-2 gene expression. Additionally, C. cerastes venom significantly reduced Bax gene expression, while A. amoreuxi venom and a mixture of A. amoreuxi & C. cerastes venoms did not alter Bax expression. Consequently, these venoms significantly increased the Bax/Bcl-2 ratio and the oxidative stress biomarker MDA. Furthermore, these venoms also increased the activity levels of the antioxidant enzymes, catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase. Overall, the venoms have cytotoxic and anti-proliferative effects on PC3 cells. PMID:28382285

  14. Anti-proliferative properties of commercial Pelargonium sidoides tincture, with cell-cycle G0/G1 arrest and apoptosis in Jurkat leukaemia cells.

    Science.gov (United States)

    Pereira, Andreia; Bester, Megan; Soundy, Puffy; Apostolides, Zeno

    2016-09-01

    Context Pelargonium sidoides DC (Geraniaceae) is an important medicinal plant indigenous to South Africa and Lesotho. Previous studies have shown that root extracts are rich in polyphenolic compounds with antibacterial, antiviral and immunomodulatory activities. Little is known regarding the anticancer properties of Pelargonium sidoides extracts. Objective This study evaluates the anti-proliferative effects of a Pelargonium sidoides radix mother tincture (PST). Materials and methods The PST was characterized by LC-MS/MS. Anti-proliferative activity was evaluated in the pre-screen panel of the National Cancer Institute (NCI-H460, MCF-7 and SF-268) and the Jurkat leukaemia cell line at concentrations of 0-150 μg/mL. The effect on cell growth was determined with sulphorhodamine B and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays after 72 h. The effect on cell cycle and apoptosis induction in Jurkat cells was determined by flow cytometry with propidium iodide and Annexin V: fluorescein isothiocyanate staining. Results Dihydroxycoumarin sulphates, gallic acid as well as gallocatechin dimers and trimers were characterized in PST by mass spectrometry. Moderate anti-proliferative effects with GI50 values between 40 and 80 μg/mL were observed in the NCI-pre-screen panel. Strong activity observed with Jurkat cells with a GI50 value of 6.2 μg/mL, significantly better than positive control 5-fluorouracil (GI50 value of 9.7 μg/mL). The PST arrested Jurkat cells at the G0/G1 phase of the cell cycle and increased the apoptotic cells from 9% to 21%, while the dead cells increased from 4% to 17%. Conclusion We present evidence that P. sidoides has cancer cell type-specific anti-proliferative effects and may be a source of novel anticancer molecules.

  15. Tenascin-C in the extracellular matrix promotes the selection of highly proliferative and tubulogenesis-defective endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Tercia Rodrigues [Universidade do Estado do Rio de Janeiro (UERJ), Instituto de Biologia Roberto Alcantara Gomes, Departamento de Biologia Celular, Laboratorio de Biologia da Celula Endotelial e da Angiogenese (LabAngio), Rio de Janeiro (Brazil); Universidade Federal do Rio de Janeiro (UFRJ), Programa de Biologia Celular e do Desenvolvimento, Instituto de Ciencias Biomedicas, INNT/INCT/MCT, Rio de Janeiro (Brazil); Carvalho da Fonseca, Anna Carolina [Universidade Federal do Rio de Janeiro (UFRJ), Programa de Biologia Celular e do Desenvolvimento, Instituto de Ciencias Biomedicas, INNT/INCT/MCT, Rio de Janeiro (Brazil); Nunes, Sara Santana; Oliveira da Silva, Aline [Universidade do Estado do Rio de Janeiro (UERJ), Instituto de Biologia Roberto Alcantara Gomes, Departamento de Biologia Celular, Laboratorio de Biologia da Celula Endotelial e da Angiogenese (LabAngio), Rio de Janeiro (Brazil); Dubois, Luiz Gustavo Feijo; Faria, Jane; Kahn, Suzana Assad [Universidade Federal do Rio de Janeiro (UFRJ), Programa de Biologia Celular e do Desenvolvimento, Instituto de Ciencias Biomedicas, INNT/INCT/MCT, Rio de Janeiro (Brazil); Viana, Nathan Bessa [Universidade Federal do Rio de Janeiro, Laboratorio de Pincas Oticas, Coordenacao de Programas de Estudos Avancados, Instituto de Ciencias Biomedicas, Rio de Janeiro (Brazil); Universidade Federal do Rio de Janeiro, Instituto de Fisica, Rio de Janeiro (Brazil); Marcondes, Jorge [Universidade Federal do Rio de Janeiro, Hospital Universitario Clementino Fraga Filho, Servico de Neurocirurgia, Rio de Janeiro (Brazil); Legrand, Chantal [Institut Universitaire d' Hematologie, Universite Paris-Diderot, Paris 7, INSERM U553, Paris (France); Moura-Neto, Vivaldo [Universidade Federal do Rio de Janeiro (UFRJ), Programa de Biologia Celular e do Desenvolvimento, Instituto de Ciencias Biomedicas, INNT/INCT/MCT, Rio de Janeiro (Brazil); and others

    2011-09-10

    The extracellular matrix (ECM) contains important cues for tissue homeostasis and morphogenesis. The matricellular protein tenascin-C (TN-C) is overexpressed in remodeling tissues and cancer. In the present work, we studied the effect of different ECM-which exhibited a significant diversity in their TN-C content-in endothelial survival, proliferation and tubulogenic differentiation: autologous (endothelial) ECM devoid of TN-C, but bearing large amounts of FN; fibroblast ECM, bearing both high TN-C and FN contents; and finally, glioma-derived matrices, usually poor in FN, but very rich in TN-C. HUVECs initially adhered to the immobilized matrix produced by U373 MG glioma cells, but significantly detached and died by anoikis (50 to 80%) after 24 h, as compared with cells incubated with endothelial and fibroblast matrices. Surviving endothelial cells (20 to 50%) became up to 6-fold more proliferative and formed 74-97% less tube-like structures in vitro than cells grown on non-tumoral matrices. An antibody against the EGF-like repeats of tenascin-C (TN-C) partially rescued cells from the tubulogenic defect, indicating that this molecule is responsible for the selection of highly proliferative and tubulogenic defective endothelial cells. Interestingly, by using defined substrata, in conditions that mimic glioma and normal cell ECM composition, we observed that fibronectin (FN) modulates the TN-C-induced selection of endothelial cells. Our data show that TN-C is able to modulate endothelial branching morphogenesis in vitro and, since it is prevalent in matrices of injured and tumor tissues, also suggest a role for this protein in vascular morphogenesis, in these physiological contexts.

  16. Anti-Proliferative and Apoptosis-Inducing Effect of Theabrownin against Non-small Cell Lung Adenocarcinoma A549 Cells

    Science.gov (United States)

    Wu, Feifei; Zhou, Li; Jin, Wangdong; Yang, Weiji; Wang, Ying; Yan, Bo; Du, Wenlin; Zhang, Qiang; Zhang, Lei; Guo, Yonghua; Zhang, Jin; Shan, Letian; Efferth, Thomas

    2016-01-01

    With the highest cancer incidence rate, lung cancer, especially non-small cell lung cancer (NSCLC), is the leading cause of cancer death in the world. Tea (leaves of Camellia sinensis) has been widely used as a traditional beverage beneficial to human health, including anti-NSCLC activity. Theabrownin (TB) is one major kind of tea pigment responsible for the beneficial effects of tea liquor. However, its effect on NSCLC is unknown. The aim of the present study was to evaluate anti-proliferative and apoptosis-inducing effect of TB on NSCLC (A549) cells, using MTT assay, morphological observation (DAPI staining), in situ terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, and annexin-V/PI flow cytometry. Subsequently, the expression of several genes associated with cell proliferation and apoptosis were detected by real time PCR assay to explore its potential underlying mechanism. TB was revealed to inhibit cell proliferation of A549 cells in a concentration-dependent and time-dependent manner. Morphological observation, TUNEL assay and flow cytometric analysis evidenced an apoptosis-inducing effect of TB on A549 cells in a concentration-dependent manner. The real time PCR assay demonstrated that TB down-regulated the expression of TOPO I, TOPO II, and BCL-2, and up-regulated the expression of E2F1, P53, GADD45, BAX, BIM, and CASP 3,7,8,9, which suggests an activation of P53-mediated apoptotic (caspase-dependent) pathway in response to TB treatment. The western blot analysis showed a similar trend for the corresponding protein expression (P53, Bax, Bcl-2, caspase 3,9, and PARP) and further revealed DNA damage as a trigger of the apoptosis (phosphorylation of histone H2A.X). Accordingly, TB can be speculated as a DNA damage inducer and topoisomerase (Topo I and Topo II) inhibitor that can up-regulate P53 expression and subsequently modulate the expression of the downstream genes to induce cell proliferation inhibition and apoptosis of A549 cells

  17. Anti-proliferative and apoptosis-inducing effect of theabrownin against non-small cell lung adenocarcinoma A549 cells

    Directory of Open Access Journals (Sweden)

    Feifei Wu

    2016-12-01

    Full Text Available With the highest cancer incidence rate, lung cancer, especially non-small cell lung cancer (NSCLC, is the leading cause of cancer death in the world. Tea (leaves of Camellia sinensis has been widely used as a traditional beverage beneficial to human health, including anti-NSCLC activity. Theabrownin (TB is one major kind of tea pigment responsible for the beneficial effects of tea liquor. However, its effect on NSCLC is unknown. The aim of the present study was to evaluate anti-proliferative and apoptosis-inducing effect of TB on NSCLC (A549 cells, using MTT assay, morphological observation (DAPI staining, in situ terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL assay, and annexin V/PI flow cytometry. Subsequently, the expression of several genes associated with cell proliferation and apoptosis were detected by real time PCR assay to explore its potential underlying mechanism. TB was revealed to inhibit cell proliferation of A549 cells in a concentration-dependent and time-dependent manner. Morphological observation, TUNEL assay and flow cytometric analysis evidenced an apoptosis-inducing effect of TB on A549 cells in a concentration-dependent manner. The real time PCR assay demonstrated that TB down-regulated the expression of TOPO I, TOPO II, and BCL-2, and up-regulated the expression of E2F1, P53, GADD45, BAX, BIM, and CASP 3,7,8,9, which suggests an activation of P53-mediated apoptotic (caspase-dependent pathway in response to TB treatment. The western blot analysis showed a similar trend for the corresponding protein expression (P53, Bax, Bcl-2, caspase 3,9, and PARP and further revealed DNA damage as a trigger of the apoptosis (phosphorylation of histone H2A.X. Accordingly, TB can be speculated as a DNA damage inducer and topoisomerase (Topo I and Topo II inhibitor that can up-regulate P53 expression and subsequently modulate the expression of the downstream genes to induce cell proliferation inhibition and apoptosis of

  18. Noninvasive Assessment of Cell Fate and Biology in Transplanted Mesenchymal Stem Cells.

    Science.gov (United States)

    Franchi, Federico; Rodriguez-Porcel, Martin

    2017-01-01

    Recently, molecular imaging has become a conditio sine qua non for cell-based regenerative medicine. Developments in molecular imaging techniques, such as reporter gene technology, have increasingly enabled the noninvasive assessment of the fate and biology of cells after cardiovascular applications. In this context, bioluminescence imaging is the most commonly used imaging modality in small animal models of preclinical studies. Here, we present a detailed protocol of a reporter gene imaging approach for monitoring the viability and biology of Mesenchymal Stem Cells transplanted in a mouse model of myocardial ischemia reperfusion injury.

  19. You Are What You Eat: Linking Metabolic Asymmetry and Cell Fate Choice.

    Science.gov (United States)

    Landskron, Lisa; Knoblich, Juergen A

    2016-05-09

    To defend against pathogens, activated immune cells must rapidly produce diverse lymphocyte subtypes. In a recent report in Nature, Verbist et al. (2016) describe how a regulatory loop acting between metabolic and transcriptional programs, centered around the asymmetric cell division machinery and the proto-oncogene c-Myc, establishes distinct T cell fates.

  20. Regulation of monocyte cell fate by blood vessels mediated by Notch signalling.

    Science.gov (United States)

    Gamrekelashvili, Jaba; Giagnorio, Roberto; Jussofie, Jasmin; Soehnlein, Oliver; Duchene, Johan; Briseño, Carlos G; Ramasamy, Saravana K; Krishnasamy, Kashyap; Limbourg, Anne; Kapanadze, Tamar; Ishifune, Chieko; Hinkel, Rabea; Radtke, Freddy; Strobl, Lothar J; Zimber-Strobl, Ursula; Napp, L Christian; Bauersachs, Johann; Haller, Hermann; Yasutomo, Koji; Kupatt, Christian; Murphy, Kenneth M; Adams, Ralf H; Weber, Christian; Limbourg, Florian P

    2016-08-31

    A population of monocytes, known as Ly6C(lo) monocytes, patrol blood vessels by crawling along the vascular endothelium. Here we show that endothelial cells control their origin through Notch signalling. Using combinations of conditional genetic deletion strategies and cell-fate tracking experiments we show that Notch2 regulates conversion of Ly6C(hi) monocytes into Ly6C(lo) monocytes in vivo and in vitro, thereby regulating monocyte cell fate under steady-state conditions. This process is controlled by Notch ligand delta-like 1 (Dll1) expressed by a population of endothelial cells that constitute distinct vascular niches in the bone marrow and spleen in vivo, while culture on recombinant DLL1 induces monocyte conversion in vitro. Thus, blood vessels regulate monocyte conversion, a form of committed myeloid cell fate regulation.

  1. Transfection of oral squamous cell carcinoma with human papillomavirus-16 induces proliferative and morphological changes in vitro

    Directory of Open Access Journals (Sweden)

    O'Malley Susan

    2006-05-01

    Full Text Available Abstract Background Human papillomavirus has been implicated in virtually all cervical cancers and is believed to be the primary etiological factor that transforms cervical epithelia. The presence of HPV in oral cancers suggests that HPV may play a similar role in transforming the oral epithelia. The prevalence of HPV in oral cancers is highly variable, however, presenting problematic issues regarding the etiology of oral cancers, which must be investigated more thoroughly. Past analyses of HPV in cancers of the oral cavity have largely been confined to retrospective studies of cancer patients. The purpose of this study was to examine the potential for HPV16 infection to alter the proliferative phenotype of oral squamous cell carcinoma in vitro. Results This study found that the oral squamous cell carcinoma cell line, CAL27, transfected with HPV16, exhibited significantly increased proliferation, compared with non-transfected CAL27. The increased proliferation was observed under low density conditions, even in the absence of serum. Moreover, these effects were specific to proliferation, adhesion, and morphology, while cell viability was not affected. Conclusion This study represents one of the first investigations of the effects of HPV16 infection on the proliferation, adhesion, and morphology of an oral squamous cell carcinoma cell line in vitro. The finding that HPV16 has the ability to measurably alter adhesion and proliferative potential is significant, indicating that HPV may have multiple influences on precancerous and cancerous lesions and should be explored as a risk factor and mediator of cancer phenotypes. These measurements and observations will be of benefit to researchers interested in elucidating the mechanisms of oral cancer transformation and the factors governing carcinogenesis and progression.

  2. Prolonged Mitosis of Neural Progenitors Alters Cell Fate in the Developing Brain.

    Science.gov (United States)

    Pilaz, Louis-Jan; McMahon, John J; Miller, Emily E; Lennox, Ashley L; Suzuki, Aussie; Salmon, Edward; Silver, Debra L

    2016-01-06

    Embryonic neocortical development depends on balanced production of progenitors and neurons. Genetic mutations disrupting progenitor mitosis frequently impair neurogenesis; however, the link between altered mitosis and cell fate remains poorly understood. Here we demonstrate that prolonged mitosis of radial glial progenitors directly alters neuronal fate specification and progeny viability. Live imaging of progenitors from a neurogenesis mutant, Magoh(+/-), reveals that mitotic delay significantly correlates with preferential production of neurons instead of progenitors, as well as apoptotic progeny. Independently, two pharmacological approaches reveal a causal relationship between mitotic delay and progeny fate. As mitotic duration increases, progenitors produce substantially more apoptotic progeny or neurons. We show that apoptosis, but not differentiation, is p53 dependent, demonstrating that these are distinct outcomes of mitotic delay. Together our findings reveal that prolonged mitosis is sufficient to alter fates of radial glia progeny and define a new paradigm to understand how mitosis perturbations underlie brain size disorders such as microcephaly.

  3. Facile modification of gelatin-based microcarriers with multiporous surface and proliferative growth factors delivery to enhance cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Huang Sha [Department of Oral Histology and Pathology, School of Stomatology, Fourth Military Medical University, Xi' an 710032 (China); Research and Development Center for Tissue Engineering, Fourth Military Medical University, Xi' an 710032 (China); Wang Yijuan [Key Laboratory for Macromolecular Science of Shaanxi Province, Shaanxi Normal University, Xi' an 710062 (China); Deng, Tianzheng [Research and Development Center for Tissue Engineering, Fourth Military Medical University, Xi' an 710032 (China); Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi' an 710032 (China); Jin Fang [Department of Orthodontics, School of Stomatology, Fourth Military Medical University, Xi' an, 710032 (China); Liu Shouxin [Key Laboratory for Macromolecular Science of Shaanxi Province, Shaanxi Normal University, Xi' an 710062 (China); Zhang Yongjie [Department of Oral Histology and Pathology, School of Stomatology, Fourth Military Medical University, Xi' an 710032 (China); Research and Development Center for Tissue Engineering, Fourth Military Medical University, Xi' an 710032 (China); Feng Feng [Research and Development Center for Tissue Engineering, Fourth Military Medical University, Xi' an 710032 (China); Department of Dermatology, Tangdu Hospital, Fourth Military Medical University, Xi' an 710038 (China); Jin Yan [Department of Oral Histology and Pathology, School of Stomatology, Fourth Military Medical University, Xi' an 710032 (China); Research and Development Center for Tissue Engineering, Fourth Military Medical University, Xi' an 710032 (China)], E-mail: yanjin@fmmu.edu.cn

    2008-07-28

    The design of microcarriers plays an important role in the success of cell expansion. The present article provides a facile approach to modify the gelatin-based particles and investigates the feasibility of their acting as microcarriers for cell attachment and growth. Gelatin particles (150-320 {mu}m) were modified by cryogenic treatment and lyophilization to develop the surface with the features of multiporous morphology and were incorporated with proliferative growth factors (bFGF) by adsorption during the post-preparation, which enables them to serve as microcarriers for cells amplification, together with the advantages of larger cell-surface contact area and capability of promoting cell propagation. The microstructure and release assay of the modified microcarriers demonstrated that the pores on surface were uniform and bFGF was released in a controlled manner. Through in vitro fibroblast culture, these features resulted in a prominent increase in the cell attachment rate and cell growth rate relative to the conditions without modification. Although the scanning electron microscopy and optical microscopy analysis results indicated that cells attached, spread, and proliferated on all the microcarriers, cell growth clearly showed a significant correlation with the multiporous structure of microcarriers, in particular on bFGF combined ones. These results validate our previous assumption that the facile modification could improve cell growth on the gelatin-based microcarriers obviously and the novel microcarriers may be a promising candidate in tissue engineering.

  4. Stem cell decisions: a twist of fate or a niche market?

    Science.gov (United States)

    Januschke, Jens; Näthke, Inke

    2014-10-01

    Establishing and maintaining cell fate in the right place at the right time is a key requirement for normal tissue maintenance. Stem cells are at the core of this process. Understanding how stem cells balance self-renewal and production of differentiating cells is key for understanding the defects that underpin many diseases. Both, external cues from the environment and cell intrinsic mechanisms can control the outcome of stem cell division. The role of the orientation of stem cell division has emerged as an important mechanism for specifying cell fate decisions. Although, the alignment of cell divisions can dependent on spatial cues from the environment, maintaining stemness is not always linked to positioning of stem cells in a particular microenvironment or `niche'. Alternate mechanisms that could contribute to cellular memory include differential segregation of centrosomes in asymmetrically dividing cells.

  5. The microRNA-dependent cell fate of multipotent stromal cells differentiating to endothelial cells.

    Science.gov (United States)

    Cha, Min-Ji; Choi, Eunhyun; Lee, Seahyoung; Song, Byeong-Wook; Yoon, Cheesoon; Hwang, Ki-Chul

    2016-02-15

    In the endothelial recovery process, bone marrow-derived MSCs are a potential source of cells for both research and therapy, and their capacities to self-renew and to differentiate into all the cell types in the human body make them a promising therapeutic agent for remodeling cellular differentiation and a valuable resource for the treatment of many diseases. Based on the results provided in a miRNA database, we selected miRNAs with unique targets in cell fate-related signaling pathways. The tested miRNAs targeting GSK-3β (miR-26a), platelet-derived growth factor receptor, and CD133 (miR-26a and miR-29b) induced MSC differentiation into functional ECs, whereas miRNAs targeting VEGF receptor (miR-15, miR-144, miR-145, and miR-329) inhibited MSC differentiation into ECs through VEGF stimulation. In addition, the expression levels of these miRNAs were correlated with in vivo physiological endothelial recovery processes. These findings indicate that the miRNA expression profile is distinct for cells in different stages of differentiation from MSCs to ECs and that specific miRNAs can function as regulators of endothelialization.

  6. Cell-fate determination by ubiquitin-dependent regulation of translation.

    Science.gov (United States)

    Werner, Achim; Iwasaki, Shintaro; McGourty, Colleen A; Medina-Ruiz, Sofia; Teerikorpi, Nia; Fedrigo, Indro; Ingolia, Nicholas T; Rape, Michael

    2015-09-24

    Metazoan development depends on the accurate execution of differentiation programs that allow pluripotent stem cells to adopt specific fates. Differentiation requires changes to chromatin architecture and transcriptional networks, yet whether other regulatory events support cell-fate determination is less well understood. Here we identify the ubiquitin ligase CUL3 in complex with its vertebrate-specific substrate adaptor KBTBD8 (CUL3(KBTBD8)) as an essential regulator of human and Xenopus tropicalis neural crest specification. CUL3(KBTBD8) monoubiquitylates NOLC1 and its paralogue TCOF1, the mutation of which underlies the neurocristopathy Treacher Collins syndrome. Ubiquitylation drives formation of a TCOF1-NOLC1 platform that connects RNA polymerase I with ribosome modification enzymes and remodels the translational program of differentiating cells in favour of neural crest specification. We conclude that ubiquitin-dependent regulation of translation is an important feature of cell-fate determination.

  7. Cell-fate specification in the epidermis: a common patterning mechanism in the root and shoot.

    Science.gov (United States)

    Schiefelbein, John

    2003-02-01

    The specification of epidermal hairs in Arabidopsis provides a useful model for the study of pattern formation in plants. Although the distributions of hair cells in the root and shoot appear quite different, recent studies show that pattern formation in each relies on a common cassette of transcriptional regulators. During development in each organ, neighboring cells compete to express regulators that specify the primary cell fate (including WEREWOLF [WER]/GLABRA1 [GL1], GL3/bHLH, TRANSPARENT TESTA GLABRA [TTG], and GL2), as well as those that prevent their neighbors from adopting this fate (including CAPRICE [CPC] and TRIPTYCHON [TRY]). The basic mechanism of lateral inhibition with feedback that has been uncovered by recent studies provides a conceptual framework for understanding how patterns of cell fate in general may be specified during plant development.

  8. Vacuolar H+-translocating inorganic pyrophosphatase (Vpp1) marks partial aleurone cell fate in cereal endosperm development.

    Science.gov (United States)

    Wisniewski, Jean-Pierre; Rogowsky, Peter M

    2004-10-01

    Cereal endosperm is a model system for cell fate determination in plants. In wild-type plants the outermost endosperm cells adopt aleurone cell fate, while all underlying cells display starchy endosperm cell fate. Mutant analysis showed that cell fate is determined by position rather than lineage. To further characterise the precise cell fate of the outermost cells, we performed a differential screen and isolated the novel marker gene Vpp1 . It encodes a vacuolar H+-translocating inorganic pyrophosphatase (V-PPase) and is mainly expressed in kernels, leaves and tassels. In kernels, its expression is restricted to the aleurone layer with the maximum of expression shifting from the adaxial to the abaxial side during early stages. Together with three other marker genes Vpp1 was then used to analyse the cell fate of the outermost cells in Dap3 , Dap7 , cr4 and dek1 mutants, all of which have aberrant aleurone layers. In the Dap3 and Dap7 mutants the Vpp1 and Ltp2 markers but not the A1 and Zein markers were expressed in patches without aleurone indicating that the outermost cells had some but not all features of aleurone cells and did not simply adopt starchy endosperm cell fate. A similar result was obtained in the cr4 mutant, although Ltp2 expression was less generalised. In other Dap7 patches characterised by multiple aleurone-like cell layers the expression of Vpp1 and Ltp2 confirmed the aleurone cell fate of the cells in the additional cell layers. The analysis of dek1 mutants confirmed the starchy endosperm cell fate of the majority but not all outermost cells. Based on these data we propose a model suggesting a stepwise commitment to aleurone cell fate. Sequential steps are marked by the expression of Vpp1 , the expression of Ltp2 , the acquisition of a regular shape and thick walls and finally pigmentation coupled with A1 expression.

  9. Mammalian aPKC/Par polarity complex mediated regulation of epithelial division orientation and cell fate

    Energy Technology Data Exchange (ETDEWEB)

    Vorhagen, Susanne; Niessen, Carien M., E-mail: carien.niessen@uni-koeln.de

    2014-11-01

    Oriented cell division is a key regulator of tissue architecture and crucial for morphogenesis and homeostasis. Balanced regulation of proliferation and differentiation is an essential property of tissues not only to drive morphogenesis but also to maintain and restore homeostasis. In many tissues orientation of cell division is coupled to the regulation of differentiation producing daughters with similar (symmetric cell division, SCD) or differential fate (asymmetric cell division, ACD). This allows the organism to generate cell lineage diversity from a small pool of stem and progenitor cells. Division orientation and/or the ratio of ACD/SCD need to be tightly controlled. Loss of orientation or an altered ratio can promote overgrowth, alter tissue architecture and induce aberrant differentiation, and have been linked to morphogenetic diseases, cancer and aging. A key requirement for oriented division is the presence of a polarity axis, which can be established through cell intrinsic and/or extrinsic signals. Polarity proteins translate such internal and external cues to drive polarization. In this review we will focus on the role of the polarity complex aPKC/Par3/Par6 in the regulation of division orientation and cell fate in different mammalian epithelia. We will compare the conserved function of this complex in mitotic spindle orientation and distribution of cell fate determinants and highlight common and differential mechanisms in which this complex is used by tissues to adapt division orientation and cell fate to the specific properties of the epithelium.

  10. p53 oligomerization status modulates cell fate decisions between growth, arrest and apoptosis.

    Science.gov (United States)

    Fischer, Nicholas W; Prodeus, Aaron; Malkin, David; Gariépy, Jean

    2016-12-01

    Mutations in the oligomerization domain of p53 are genetically linked to cancer susceptibility in Li-Fraumeni Syndrome. These mutations typically alter the oligomeric state of p53 and impair its transcriptional activity. Activation of p53 through tetramerization is required for its tumor suppressive function by inducing transcriptional programs that lead to cell fate decisions such as cell cycle arrest or apoptosis. How p53 chooses between these cell fate outcomes remains unclear. Here, we use 5 oligomeric variants of p53, including 2 novel p53 constructs, that yield either monomeric, dimeric or tetrameric forms of p53 and demonstrate that they induce distinct cellular activities and gene expression profiles that lead to different cell fate outcomes. We report that dimeric p53 variants are cytostatic and can arrest cell growth, but lack the ability to trigger apoptosis in p53-null cells. In contrast, p53 tetramers induce rapid apoptosis and cell growth arrest, while a monomeric variant is functionally inactive, supporting cell growth. In particular, the expression of pro-arrest CDKN1A and pro-apoptotic P53AIP1 genes are important cell fate determinants that are differentially regulated by the oligomeric state of p53. This study suggests that the most abundant oligomeric species of p53 present in resting cells, namely p53 dimers, neither promote cell growth or cell death and that shifting the oligomeric state equilibrium of p53 in cells toward monomers or tetramers is a key parameter in p53-based cell fate decisions.

  11. Properties and fate of oligodendrocyte progenitor cells in the corpus callosum, motor cortex, and piriform cortex of the mouse.

    Science.gov (United States)

    Clarke, Laura E; Young, Kaylene M; Hamilton, Nicola B; Li, Huiliang; Richardson, William D; Attwell, David

    2012-06-13

    Oligodendrocyte progenitor cells (OPCs) in the postnatal mouse corpus callosum (CC) and motor cortex (Ctx) reportedly generate only oligodendrocytes (OLs), whereas those in the piriform cortex may also generate neurons. OPCs have also been subdivided based on their expression of voltage-gated ion channels, ability to respond to neuronal activity, and proliferative state. To determine whether OPCs in the piriform cortex have inherently different physiological properties from those in the CC and Ctx, we studied acute brain slices from postnatal transgenic mice in which GFP expression identifies OL lineage cells. We whole-cell patch clamped GFP-expressing (GFP(+)) cells within the CC, Ctx, and anterior piriform cortex (aPC) and used prelabeling with 5-ethynyl-2'-deoxyuridine (EdU) to assess cell proliferation. After recording, slices were immunolabeled and OPCs were defined by strong expression of NG2. NG2(+) OPCs in the white and gray matter proliferated and coexpressed PDGFRα and voltage-gated Na(+) channels (I(Na)). Approximately 70% of OPCs were capable of generating regenerative depolarizations. In addition to OLIG2(+) NG2(+) I(Na)(+) OPCs and OLIG2(+) NG2(neg) I(Na)(neg) OLs, we identified cells with low levels of NG2 limited to the soma or the base of some processes. These cells had a significantly reduced I(Na) and a reduced ability to incorporate EdU when compared with OPCs and probably correspond to early differentiating OLs. By combining EdU labeling and lineage tracing using Pdgfrα-CreER(T2) : R26R-YFP transgenic mice, we double labeled OPCs and traced their fate in the postnatal brain. These OPCs generated OLs but did not generate neurons in the aPC or elsewhere at any time that we examined.

  12. Surface position, not signaling from surrounding maternal tissues, specifies aleurone epidermal cell fate in maize.

    Science.gov (United States)

    Gruis, Darren Fred; Guo, Hena; Selinger, David; Tian, Qing; Olsen, Odd-Arne

    2006-07-01

    Maize (Zea mays) endosperm consists of an epidermal-like surface layer of aleurone cells, an underlying body of starchy endosperm cells, and a basal layer of transfer cells. To determine whether surrounding maternal tissues perform a role in specifying endosperm cell fates, a maize endosperm organ culture technique was established whereby the developing endosperm is completely removed from surrounding maternal tissues. Using cell type-specific fluorescence markers, we show that aleurone cell fate specification occurs exclusively in response to surface position and does not require specific, continued maternal signal input. The starchy endosperm and aleurone cell fates are freely interchangeable throughout the lifespan of the endosperm, with internalized aleurone cells converting to starchy endosperm cells and with starchy endosperm cells that become positioned at the surface converting to aleurone cells. In contrast to aleurone and starchy endosperm cells, transfer cells fail to develop in in vitro-grown endosperm, supporting earlier indications that maternal tissue interaction is required to fully differentiate this cell type. Several parameters confirm that the maize endosperm organ cultures described herein retain the main developmental features of in planta endosperm, including fidelity of aleurone mutant phenotypes, temporal and spatial control of cell type-specific fluorescent markers, specificity of cell type transcripts, and control of mitotic cell divisions.

  13. Proliferative and anti-proliferative effects of dietary levels of phytoestrogens in rat pituitary GH3/B6/F10 cells - the involvement of rapidly activated kinases and caspases

    Directory of Open Access Journals (Sweden)

    Watson Cheryl S

    2009-09-01

    Full Text Available Abstract Background Phytoestogens are a group of lipophillic plant compounds that can have estrogenic effects in animals; both tumorigenic and anti-tumorigenic effects have been reported. Prolactin-secreting adenomas are the most prevalent form of pituitary tumors in humans and have been linked to estrogen exposures. We examined the proliferative effects of phytoestrogens on a rat pituitary tumor cell line, GH3/B6/F10, originally subcloned from GH3 cells based on its ability to express high levels of the membrane estrogen receptor-α. Methods We measured the proliferative effects of these phytoestrogens using crystal violet staining, the activation of several mitogen-activated protein kinases (MAPKs and their downstream targets via a quantitative plate immunoassay, and caspase enzymatic activities. Results Four phytoestrogens (coumestrol, daidzein, genistein, and trans-resveratrol were studied over wide concentration ranges. Except trans-resveratrol, all phytoestrogens increased GH3/B6/F10 cell proliferation at some concentration relevant to dietary levels. All four phytoestrogens attenuated the proliferative effects of estradiol when administered simultaneously. All phytoestrogens elicited MAPK and downstream target activations, but with time course patterns that often differed from that of estradiol and each other. Using selective antagonists, we determined that MAPKs play a role in the ability of these phytoestrogens to elicit these responses. In addition, except for trans-resveratrol, a serum removal-induced extrinsic apoptotic pathway was blocked by these phytoestrogens. Conclusion Phytoestrogens can block physiological estrogen-induced tumor cell growth in vitro and can also stimulate growth at high dietary concentrations in the absence of endogenous estrogens; these actions are correlated with slightly different signaling response patterns. Consumption of these compounds should be considered in strategies to control endocrine tumor cell

  14. A blueprint for engineering cell fate: current technologies to reprogram cell identity

    Institute of Scientific and Technical Information of China (English)

    Samantha A Morris; George Q Daley

    2013-01-01

    Human diseases such as heart failure,diabetes,neurodegenerative disorders,and many others result from the deficiency or dysfunction of critical cell types.Strategies for therapeutic tissue repair or regeneration require the in vitro manufacture of clinically relevant quantities of defined cell types.In addition to transplantation therapy,the generation of otherwise inaccessible cells also permits disease modeling,toxicology testing and drug discovery in vitro.In this review,we discuss current strategies to manipulate the identity of abundant and accessible cells by differentiation from an induced pluripotent state or direct conversion between differentiated states.We contrast these approaches with recent advances employing partial reprogramming to facilitate lineage switching,and discuss the mechanisms underlying the engineering of cell fate.Finally,we address the current limitations of the field and how the resulting cell types can be assessed to ensure the production of medically relevant populations.

  15. E series prostaglandins alter the proliferative, apoptotic and migratory properties of T98G human glioma cells in vitro

    Directory of Open Access Journals (Sweden)

    Gomes Renata N

    2012-12-01

    Full Text Available Abstract Background In many types of cancer, prostaglandin E2 (PGE2 is associated with tumour related processes including proliferation, migration, angiogenesis and apoptosis. However in gliomas the role of this prostanoid is poorly understood. Here, we report on the proliferative, migratory, and apoptotic effects of PGE1, PGE2 and Ibuprofen (IBP observed in the T98G human glioma cell line in vitro. Methods T98G human glioma cells were treated with IBP, PGE1 or PGE2 at varying concentrations for 24–72 hours. Cell proliferation, mitotic index and apoptotic index were determined for each treatment. Caspase-9 and caspase-3 activity was measured using fluorescent probes in live cells (FITC-LEHD-FMK and FITC-DEVD-FMK respectively. The migratory capacity of the cells was quantified using a scratch migration assay and a transwell migration assay. Results A significant decrease was seen in cell number (54% in the presence of 50 μM IBP. Mitotic index and bromodeoxyuridine (BrdU incorporation were also decreased 57% and 65%, respectively, by IBP. The apoptotic index was increased (167% and the in situ activity of caspase-9 and caspase-3 was evident in IBP treated cells. The inhibition of COX activity by IBP also caused a significant inhibition of cell migration in the monolayer scratch assay (74% and the transwell migration assay (36%. In contrast, the presence of exogenous PGE1 or PGE2 caused significant increases in cell number (37% PGE1 and 45% PGE2. When mitotic index was measured no change was found for either PG treatment. However, the BrdU incorporation rate was significantly increased by PGE1 (62% and to a greater extent by PGE2 (100%. The apoptotic index was unchanged by exogenous PGs. The addition of exogenous PGs caused an increase in cell migration in the monolayer scratch assay (43% PGE1 and 44% PGE2 and the transwell migration assay (28% PGE1 and 68% PGE2. Conclusions The present study demonstrated that treatments which alter PGE1 and PGE

  16. Mitochondrial function provides instructive signals for activation-induced B-cell fates.

    OpenAIRE

    Jang, Kyoung-Jin; Mano, Hiroto; Aoki, Koji; Hayashi, Tatsunari; Muto, Akihiko; Nambu, Yukiko; Takahashi, Katsu; Itoh, Katsuhiko; Taketani, Shigeru; Stephen L Nutt; Igarashi, Kazuhiko; Shimizu, Akira; Sugai, Manabu

    2015-01-01

    During immune reactions, functionally distinct B-cell subsets are generated by stochastic processes, including class-switch recombination (CSR) and plasma cell differentiation (PCD). In this study, we show a strong association between individual B-cell fates and mitochondrial functions. CSR occurs specifically in activated B cells with increased mitochondrial mass and membrane potential, which augment mitochondrial reactive oxygen species (mROS), whereas PCD occurs in cells with decreased mit...

  17. Anti-proliferative and apoptosis-inducing activity of lycopene against three subtypes of human breast cancer cell lines.

    Science.gov (United States)

    Takeshima, Mikako; Ono, Misaki; Higuchi, Takako; Chen, Chen; Hara, Takayuki; Nakano, Shuji

    2014-03-01

    Although lycopene, a major carotenoid component of tomatoes, has been suggested to attenuate the risk of breast cancer, the underlying preventive mechanism remains to be determined. Moreover, it is not known whether there are any differences in lycopene activity among different subtypes of human breast cancer cells. Using ER/PR positive MCF-7, HER2-positive SK-BR-3 and triple-negative MDA-MB-468 cell lines, we investigated the cellular and molecular mechanism of the anticancer activity of lycopene. Lycopene treatment for 168 consecutive hours exhibited a time-dependent and dose-dependent anti-proliferative activity against these cell lines by arresting the cell cycle at the G0 /G1 phase at physiologically achievable concentrations found in human plasma. The greatest growth inhibition was observed in MDA-MB-468 where the sub-G0 /G1 apoptotic population was significantly increased, with demonstrable cleavage of PARP. Lycopene induced strong and sustained activation of the ERK1/2, with concomitant cyclin D1 suppression and p21 upregulation in these three cell lines. In triple negative cells, lycopene inhibited the phosphorylation of Akt and its downstream molecule mTOR, followed by subsequent upregulation of proapoptotic Bax without affecting anti-apoptotic Bcl-xL. Taken together, these data indicate that the predominant anticancer activity of lycopene in MDA-MB-468 cells suggests a potential role of lycopene for the prevention of triple negative breast cancer.

  18. Autocrine/paracrine proliferative effect of ovarian GH and IGF-I in chicken granulosa cell cultures.

    Science.gov (United States)

    Ahumada-Solórzano, S Marisela; Martínez-Moreno, Carlos G; Carranza, Martha; Ávila-Mendoza, José; Luna-Acosta, José Luis; Harvey, Steve; Luna, Maricela; Arámburo, Carlos

    2016-08-01

    It is known that growth hormone (GH) and its receptor (GHR) are expressed in granulosa cells (GC) and thecal cells during the follicular development in the hen ovary, which suggests GH is involved in autocrine/paracrine actions in the female reproductive system. In this work, we show that the knockdown of local ovarian GH with a specific cGH siRNA in GC cultures significantly decreased both cGH mRNA expression and GH secretion to the media, and also reduced their proliferative rate. Thus, we analyzed the effect of ovarian GH and recombinant chicken GH (rcGH) on the proliferation of pre-hierarchical GCs in primary cultures. Incubation of GCs with either rcGH or conditioned media, containing predominantly a 15-kDa GH isoform, showed that both significantly increased proliferation as determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, proliferating cell nuclear antigen (PCNA) quantification and ((3)H)-thymidine incorporation ((3)H-T) assays in a dose response fashion. Both, locally produced GH and rcGH also induced the phosphorylation of Erk1/2 in GC cultures. Furthermore, GH increased IGF-I synthesis and its release into the GC culture incubation media. These results suggest that GH may act through local IGF-I to induce GC proliferation, since IGF-I immunoneutralization completely abolished the GH-induced proliferative effect. These data suggest that GH and IGF-I may play a role as autocrine/paracrine regulators during the follicular development in the hen ovary at the pre-hierarchical stage.

  19. Steroids are required for epidermal cell fate establishment in Arabidopsis roots.

    Science.gov (United States)

    Kuppusamy, Kavitha T; Chen, Andrew Y; Nemhauser, Jennifer L

    2009-05-12

    The simple structure of Arabidopsis roots provides an excellent model system to study epidermal cell fate specification. Epidermal cells in contact with 2 underlying cortical cells differentiate into hair cells (H cells; trichoblasts), whereas cells that contact only a single cortical cell differentiate into mature hairless cells (N cells; atrichoblasts). This position-dependent patterning, in combination with the constrained orientation of cell divisions, results in hair and nonhair cell files running longitudinally along the root epidermis. Here, we present strong evidence that steroid hormones called brassinosteroids (BRs) are required to maintain position-dependent fate specification in roots. We show that BRs are required for normal expression levels and patterns of WEREWOLF (WER) and GLABRA2 (GL2), master regulators of epidermal patterning. Loss of BR signaling results in loss of hair cells in H positions, likely as a consequence of reduced expression of CAPRICE (CPC), a direct downstream target of WER. Our observations demonstrate that in addition to their well-known role in cell expansion, BRs play an essential role in directing cell fate.

  20. Cell fate in the Arabidopsis root epidermis is determined by competition between WEREWOLF and CAPRICE.

    Science.gov (United States)

    Song, Sang-Kee; Ryu, Kook Hui; Kang, Yeon Hee; Song, Jae Hyo; Cho, Young-Hee; Yoo, Sang-Dong; Schiefelbein, John; Lee, Myeong Min

    2011-11-01

    The root hair and nonhair cells in the Arabidopsis (Arabidopsis thaliana) root epidermis are specified by a suite of transcriptional regulators. Two of these are WEREWOLF (WER) and CAPRICE (CPC), which encode MYB transcription factors that are required for promoting the nonhair cell fate and the hair cell fate, respectively. However, the precise function and relationship between these transcriptional regulators have not been fully defined experimentally. Here, we examine these issues by misexpressing the WER gene using the GAL4-upstream activation sequence transactivation system. We find that WER overexpression in the Arabidopsis root tip is sufficient to cause epidermal cells to adopt the nonhair cell fate through direct induction of GLABRA2 (GL2) gene expression. We also show that GLABRA3 (GL3) and ENHANCER OF GLABRA3 (EGL3), two closely related bHLH proteins, are required for the action of the overexpressed WER and that WER interacts with these bHLHs in plant cells. Furthermore, we find that CPC suppresses the WER overexpression phenotype quantitatively. These results show that WER acts together with GL3/EGL3 to induce GL2 expression and that WER and CPC compete with one another to define cell fates in the Arabidopsis root epidermis.

  1. β‐catenin‐driven binary cell fate decisions in animal development

    Science.gov (United States)

    2016-01-01

    The Wnt/β‐catenin pathway plays key roles during animal development. In several species, β‐catenin is used in a reiterative manner to regulate cell fate diversification between daughter cells following division. This binary cell fate specification mechanism has been observed in animals that belong to very diverse phyla: the nematode Caenorhabditis elegans, the annelid Platynereis, and the ascidian Ciona. It may also play a role in the regulation of several stem cell lineages in vertebrates. While the molecular mechanism behind this binary cell fate switch is not fully understood, it appears that both secreted Wnt ligands and asymmetric cortical factors contribute to the generation of the difference in nuclear β‐catenin levels between daughter cells. β‐Catenin then cooperates with lineage specific transcription factors to induce the expression of novel sets of transcription factors at each round of divisions, thereby diversifying cell fate. WIREs Dev Biol 2016, 5:377–388. doi: 10.1002/wdev.228 For further resources related to this article, please visit the WIREs website. PMID:26952169

  2. Single-cell analysis of mixed-lineage states leading to a binary cell fate choice.

    Science.gov (United States)

    Olsson, Andre; Venkatasubramanian, Meenakshi; Chaudhri, Viren K; Aronow, Bruce J; Salomonis, Nathan; Singh, Harinder; Grimes, H Leighton

    2016-09-29

    Delineating hierarchical cellular states, including rare intermediates and the networks of regulatory genes that orchestrate cell-type specification, are continuing challenges for developmental biology. Single-cell RNA sequencing is greatly accelerating such research, given its power to provide comprehensive descriptions of genomic states and their presumptive regulators. Haematopoietic multipotential progenitor cells, as well as bipotential intermediates, manifest mixed-lineage patterns of gene expression at a single-cell level. Such mixed-lineage states may reflect the molecular priming of different developmental potentials by co-expressed alternative-lineage determinants, namely transcription factors. Although a bistable gene regulatory network has been proposed to regulate the specification of either neutrophils or macrophages, the nature of the transition states manifested in vivo, and the underlying dynamics of the cell-fate determinants, have remained elusive. Here we use single-cell RNA sequencing coupled with a new analytic tool, iterative clustering and guide-gene selection, and clonogenic assays to delineate hierarchical genomic and regulatory states that culminate in neutrophil or macrophage specification in mice. We show that this analysis captured prevalent mixed-lineage intermediates that manifested concurrent expression of haematopoietic stem cell/progenitor and myeloid progenitor cell genes. It also revealed rare metastable intermediates that had collapsed the haematopoietic stem cell/progenitor gene expression programme, instead expressing low levels of the myeloid determinants, Irf8 and Gfi1 (refs 9, 10, 11, 12, 13). Genetic perturbations and chromatin immunoprecipitation followed by sequencing revealed Irf8 and Gfi1 as key components of counteracting myeloid-gene-regulatory networks. Combined loss of these two determinants 'trapped' the metastable intermediate. We propose that mixed-lineage states are obligatory during cell-fate specification

  3. Prolonged effect of fluid flow stress on the proliferative activity of mesothelial cells after abrupt discontinuation of fluid streaming

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Shigehisa, E-mail: aokis@cc.saga-u.ac.jp [Department of Pathology and Microbiology, Faculty of Medicine, Saga University, Saga (Japan); Ikeda, Satoshi [Department of Pathology and Microbiology, Faculty of Medicine, Saga University, Saga (Japan); Takezawa, Toshiaki [Transgenic Animal Research Center, National Institute of Agrobiological Sciences, Ibaraki (Japan); Kishi, Tomoya [Department of Internal Medicine, Saga University, Saga (Japan); Makino, Junichi [Makino Clinic, Saga (Japan); Uchihashi, Kazuyoshi; Matsunobu, Aki [Department of Pathology and Microbiology, Faculty of Medicine, Saga University, Saga (Japan); Noguchi, Mitsuru [Department of Urology, Faculty of Medicine, Saga University, Saga (Japan); Sugihara, Hajime [Department of Physical Therapy, International University of Health and Welfare, Fukuoka (Japan); Toda, Shuji [Department of Pathology and Microbiology, Faculty of Medicine, Saga University, Saga (Japan)

    2011-12-16

    Highlights: Black-Right-Pointing-Pointer Late-onset peritoneal fibrosis leading to EPS remains to be elucidated. Black-Right-Pointing-Pointer Fluid streaming is a potent factor for peritoneal fibrosis in PD. Black-Right-Pointing-Pointer We focused on the prolonged effect of fluid streaming on mesothelial cell kinetics. Black-Right-Pointing-Pointer A history of fluid streaming exposure promoted mesothelial proliferative activity. Black-Right-Pointing-Pointer We have thus identified a potent new factor for late-onset peritoneal fibrosis. -- Abstract: Encapsulating peritoneal sclerosis (EPS) often develops after transfer to hemodialysis and transplantation. Both termination of peritoneal dialysis (PD) and transplantation-related factors are risks implicated in post-PD development of EPS, but the precise mechanism of this late-onset peritoneal fibrosis remains to be elucidated. We previously demonstrated that fluid flow stress induced mesothelial proliferation and epithelial-mesenchymal transition via mitogen-activated protein kinase (MAPK) signaling. Therefore, we speculated that the prolonged bioactive effect of fluid flow stress may affect mesothelial cell kinetics after cessation of fluid streaming. To investigate how long mesothelial cells stay under the bioactive effect brought on by fluid flow stress after removal of the stress, we initially cultured mesothelial cells under fluid flow stress and then cultured the cells under static conditions. Mesothelial cells exposed to fluid flow stress for a certain time showed significantly high proliferative activity compared with static conditions after stoppage of fluid streaming. The expression levels of protein phosphatase 2A, which dephosphorylates MAPK, in mesothelial cells changed with time and showed a biphasic pattern that was dependent on the duration of exposure to fluid flow stress. There were no differences in the fluid flow stress-related bioactive effects on mesothelial cells once a certain time had passed

  4. An emerging molecular mechanism for the neural vs mesodermal cell fate decision

    Institute of Scientific and Technical Information of China (English)

    Roman A Li; Kate G Storey

    2011-01-01

    @@ Understanding how primary cell fates are established and maintained in the vertebrate embryo provides important insights that inform directed in vitro differentiation of embryonic stem cells or adult cells that have undergone induced pluripotency.Neural differentiation is of particular interest as new neural cells may contribute to therapeutic approaches to nervous system injury and diseases and provide in vitro disease models for small molecule screening and for determining personalized drug treatments.

  5. Evaluation of the proliferative activity of immunocompetent cells in the jejunal and iliac lymph nodes of prepubertal female wild boars diagnosed with mixed mycotoxicosis

    Directory of Open Access Journals (Sweden)

    Zielonka Łukasz

    2015-06-01

    Full Text Available The study evaluated the proliferative activity of immunocompetent cells in the jejunal and iliac lymph nodes of prepubertal female wild boars exposed to deoxynivalenol and zearalenone in naturally contaminated feed. The evaluation was performed with the use of the MTT assay and 2 mitogens: lipopolysaccharide (LPS and concanavalin A. Intensified proliferative processes in T and B lymphocytes were revealed. The mitogenic activity of LPS was more expressed in the lymphocytes of both iliac and jejunal lymph nodes in comparison with the control group. Proliferative activity was higher in iliac lymph nodes than in jejunal lymph nodes. A reverse trend was observed in the percentage of live cells, which was higher in jejunal lymph nodes during the evaluation of lymphocyte proliferation.

  6. The fog-3 gene and regulation of cell fate in the germ line of Caenorhabditis elegans

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, R.; Kimble, J. [Univ. of Wisconsin, Madison, WI (United States)

    1995-02-01

    In the nematode Caenorhabditis elegans, germ cells normally adopt one of three fates: mitosis, spermatogenesis or oogenesis. We have identified and characterized the gene fog-3, which is required for germ cells to differentiate as sperm rather than as oocytes. Analysis of double mutants suggests that fog-3 is absolutely required for spermatogenesis and acts at the end of the regulatory hierarchy controlling sex determination for the germ line. By contrast, mutations in fog-3 do not alter the sexual identity of other tissues. We also have characterized the null phenotype of fog-1, another gene required for spermatogenesis; we demonstrate that it too controls the sexual identity of germ cells but not of other tissues. Finally, we have studied the same interaction of these two fog genes with gld-1, a gene required for germ cells to undergo oogenesis rather than mitosis. On the basis of these results, we propose that germ-cell fate might be controlled by a set of inhibitory interactions among genes that specify one of three fates: mitosis, spermatogenesis or oogenesis. Such a regulatory network would link the adoption of one germ-cell fate to the suppression of the other two. 68 refs., 7 figs., 6 tabs.

  7. The roles and regulation of Sertoli cells in fate determinations of spermatogonial stem cells and spermatogenesis.

    Science.gov (United States)

    Hai, Yanan; Hou, Jingmei; Liu, Yun; Liu, Yang; Yang, Hao; Li, Zheng; He, Zuping

    2014-05-01

    Spermatogenesis is a complex process by which spermatogonial stem cells (SSCs) self-renew and differentiate into spermatozoa under the elaborate coordination of testicular microenvironment, namely, niche. Sertoli cells, which locate around male germ cells, are the most critical component of the niche. Significant progress has recently been made by peers and us on uncovering the effects of Sertoli cells on regulating fate determinations of SSCs. Here we addressed the roles and regulation of Sertoli cells in normal and abnormal spermatogenesis. Specifically, we summarized the biological characteristics of Sertoli cells, and we emphasized the roles of Sertoli cells in mediating the self-renewal, differentiation, apoptosis, de-differentiation, and trans-differentiation of SSCs. The association between abnormal function of Sertoli cells and impaired spermatogenesis was discussed. Finally, we highlighted several issues to be addressed for further investigation on the effects and mechanisms of Sertoli cells in spermatogenesis. Since Sertoli cells are the key supportive cells for SSCs and they are very receptive to modification, a better understanding of the roles and regulation of Sertoli cells in SSC biology and spermatogenesis would make it feasible to identify novel targets for gene therapy of male infertility as well as seek more efficient and safer strategies for male contraception.

  8. Innate signals overcome acquired TCR signaling pathway regulation and govern the fate of human CD161(hi) CD8α⁺ semi-invariant T cells.

    Science.gov (United States)

    Turtle, Cameron J; Delrow, Jeff; Joslyn, Rochelle C; Swanson, Hillary M; Basom, Ryan; Tabellini, Laura; Delaney, Colleen; Heimfeld, Shelly; Hansen, John A; Riddell, Stanley R

    2011-09-08

    Type 17 programmed CD161(hi)CD8α(+) T cells contribute to mucosal immunity to bacteria and yeast. In early life, microbial colonization induces proliferation of CD161(hi) cells that is dependent on their expression of a semi-invariant Vα7.2(+) TCR. Although prevalent in adults, CD161(hi)CD8α(+) cells exhibit weak proliferative and cytokine responses to TCR ligation. The mechanisms responsible for the dichotomous response of neonatal and adult CD161(hi) cells, and the signals that enable their effector function, have not been established. We describe acquired regulation of TCR signaling in adult memory CD161(hi)CD8α(+) T cells that is absent in cord CD161(hi) cells and adult CD161(lo) cells. Regulated TCR signaling in CD161(hi) cells was due to profound alterations in TCR signaling pathway gene expression and could be overcome by costimulation through CD28 or innate cytokine receptors, which dictated the fate of their progeny. Costimulation with IL-1β during TCR ligation markedly increased proinflammatory IL-17 production, while IL-12-induced Tc1-like function and restored the response to TCR ligation without costimulation. CD161(hi) cells from umbilical cord blood and granulocyte colony stimulating factor-mobilized leukaphereses differed in frequency and function, suggesting future evaluation of the contribution of CD161(hi) cells in hematopoietic stem cell grafts to transplant outcomes is warranted.

  9. Number and proliferative capacity of osteogenic stem cells are maintained during aging and in patients with osteoporosis

    DEFF Research Database (Denmark)

    Dokkedahl, Karin Stenderup; Justesen, J; Eriksen, E F

    2001-01-01

    Decreased bone formation is an important pathophysiological mechanism responsible for bone loss associated with aging and osteoporosis. Osteoblasts (OBs), originate from mesenchymal stem cells (MSCs) that are present in the bone marrow and form colonies (termed colony-forming units-fibroblastic [......Decreased bone formation is an important pathophysiological mechanism responsible for bone loss associated with aging and osteoporosis. Osteoblasts (OBs), originate from mesenchymal stem cells (MSCs) that are present in the bone marrow and form colonies (termed colony-forming units......-fibroblastic [CFU-Fs]) when cultured in vitro. To examine the effect of aging and osteoporosis on the MSC population, we quantified the number of MSCs and their proliferative capacity in vitro. Fifty-one individuals were studied: 38 normal volunteers (23 young individuals [age, 22-44 years] and 15 old individuals...... [age, 66-74 years]) and 13 patients with osteoporosis (age, 58-83 years). Bone marrow was aspirated from iliac crest; mononuclear cells were enriched in MSCs by magnetic activated cell sorting (MACS) using STRO-1 antibody. Total CFU-F number, size distribution, cell density per CFU-F, number...

  10. The antimalarial amodiaquine causes autophagic-lysosomal and proliferative blockade sensitizing human melanoma cells to starvation- and chemotherapy-induced cell death.

    Science.gov (United States)

    Qiao, Shuxi; Tao, Shasha; Rojo de la Vega, Montserrat; Park, Sophia L; Vonderfecht, Amanda A; Jacobs, Suesan L; Zhang, Donna D; Wondrak, Georg T

    2013-12-01

    Pharmacological inhibition of autophagic-lysosomal function has recently emerged as a promising strategy for chemotherapeutic intervention targeting cancer cells. Repurposing approved and abandoned non-oncological drugs is an alternative approach to the identification and development of anticancer therapeutics, and antimalarials that target autophagic-lysosomal functions have recently attracted considerable attention as candidates for oncological repurposing. Since cumulative research suggests that dependence on autophagy represents a specific vulnerability of malignant melanoma cells, we screened a focused compound library of antimalarials for antimelanoma activity. Here we report for the first time that amodiaquine (AQ), a clinical 4-aminoquinoline antimalarial with unexplored cancer-directed chemotherapeutic potential, causes autophagic-lysosomal and proliferative blockade in melanoma cells that surpasses that of its parent compound chloroquine. Monitoring an established set of protein markers (LAMP1, LC3-II, SQSTM1) and cell ultrastructural changes detected by electron microscopy, we observed that AQ treatment caused autophagic-lysosomal blockade in malignant A375 melanoma cells, a finding substantiated by detection of rapid inactivation of lysosomal cathepsins (CTSB, CTSL, CTSD). AQ-treatment was associated with early induction of energy crisis (ATP depletion) and sensitized melanoma cells to either starvation- or chemotherapeutic agent-induced cell death. AQ displayed potent antiproliferative effects, and gene expression array analysis revealed changes at the mRNA (CDKN1A, E2F1) and protein level (TP53, CDKN1A, CCND1, phospho-RB1 [Ser 780]/[Ser 807/811], E2F1) consistent with the observed proliferative blockade in S-phase. Taken together, our data suggest that the clinical antimalarial AQ is a promising candidate for repurposing efforts that aim at targeting autophagic-lysosomal function and proliferative control in malignant melanoma cells.

  11. Effects of free amino acids on cytokine secretion and proliferative activity of feline T cells in an in vitro study using the cell line MYA-1.

    Science.gov (United States)

    Paßlack, Nadine; Doherr, Marcus G; Zentek, Jürgen

    2016-10-01

    In vitro studies might be an interesting screening method for targeted in vivo studies in the field of immunonutrition and help to reduce and refine animal studies. As the role of amino acids for immune function of cats has not been evaluated in detail so far, the present study aimed at investigating the effects of eight different amino acids (arginine, leucine, isoleucine, valine, glutamine, lysine, threonine and tryptophan) in six concentrations each (0, 0.25, 0.5, 1, 2 and 8x the cat blood level) on cytokine secretion and proliferative activity of feline T cells (MYA-1) in vitro. The results demonstrated that high doses of arginine increased IL-4, IL-10 and TNF-α secretion of T cells, while increasing concentrations of lysine increased IL-10 secretion and proliferative activity of the T cells. High doses of leucine enhanced GM-CSF and IL-10 secretion, while concentrations of threonine in the cell culture media greater than blood concentration also increased GM-CSF and additionally TNF-α secretion of the cells. The effects of glutamine and isoleucine on T cell function were only small. In conclusion, the present in vitro study could evaluate the immunomodulating potential of specific amino acids for feline T cell function. High doses of arginine, lysine, leucine and threonine had a significant impact on cytokine secretion and proliferative activity of the T cells. Targeted in vivo studies should investigate the clinical relevance of dietary supplementation of those amino acids in healthy and diseased cats as a next step.

  12. STUDY ON PERIPHERAL BLOOD MONONUCLEAR CELL(PBMC) PROLIFERATIVE RESPONSES TO DIFFERENT HCV ANTIGENS IN PATIENTS WITH HEPATITIS C

    Institute of Scientific and Technical Information of China (English)

    窦骏; 刘克洲; 陈智; 沃建尔; 何南祥; 徐陈槐; 章明太; 王信子

    1999-01-01

    To explore the cellular immune function in patients with hepatitis C and study the HCV pathogenic mechanism and immune protection effect against HCV infection in host. PBMC proliferative responses in vitro to HCV synthetic peptides (Cp9, Ns4) and recombinant HCV proteins (C,E1 ,E2 ,NS3) were evaluated in 21 patients with chronic hepatitis C and 3 patients with acute hepatitis C. Phenotypic characteristics of proliferating cells in PBMC were detected by FACS after PBMC were stimulated with HCV antigens. Results showed that lymphoproliferative responses of PBMC from patients with hepatitis C to synthetic peptides (Cp9, NS4) and rccombinant proteins (C,E1 ,E2 and NS3) were detected and its stimulation index(SI) were 1.69±0.51, 1. 61±0.54, 1. 68±0.58,1. 49±0.44, 1.44±0.44 and 1. 33±0. 33 respectively. Two out of three patients with acute hepatitis C had efficient lymphoproliferative response to HCV antigens (SI≥2. 1) and their serum HCV-RNA were seroconversion and serum ALT values were returned to normal when studied. Phenotype analysis showed that phenotypic characteristics of proliferating cells was CD4+ lymphocytes and CD8+ lymphocytes proliferative responses was less than that of CD4+ lymphocytes. The results indicate that PBMC from patients with hepatitis C exist proliferative responses to different HCV antigens. CD4+ lymphocytes proliferative response is greater than that of CD8+ lymphocytes. The efficient lymphoproliferative responses to HCV antigens in patients with acute hepatitis C suggests that the patients possibly have a good clinical prognosis.%为探讨丙型肝炎(HC)病人细胞免疫功能和丙型肝炎病毒(HCV)的致病机制及机体对其免疫保护作用,收集24例HC病人(急性3例,慢性21例),用3H-TdR掺入法研究病人外周血单个核细胞(PBMC)对不同HCV抗原增殖反应,并用流式细胞仪(FACS)检测了PBMC中CD4+、CD8+淋巴细胞亚群在HCV抗原刺激后的变化.结果:HC病人PBMC对HCV合成肽CP9,NS

  13. Imatinib mesylate exerts anti-proliferative effects on osteosarcoma cells and inhibits the tumour growth in immunocompetent murine models.

    Directory of Open Access Journals (Sweden)

    Bérengère Gobin

    Full Text Available Osteosarcoma is the most common primary malignant bone tumour characterized by osteoid production and/or osteolytic lesions of bone. A lack of response to chemotherapeutic treatments shows the importance of exploring new therapeutic methods. Imatinib mesylate (Gleevec, Novartis Pharma, a tyrosine kinase inhibitor, was originally developed for the treatment of chronic myeloid leukemia. Several studies revealed that imatinib mesylate inhibits osteoclast differentiation through the M-CSFR pathway and activates osteoblast differentiation through PDGFR pathway, two key cells involved in the vicious cycle controlling the tumour development. The present study investigated the in vitro effects of imatinib mesylate on the proliferation, apoptosis, cell cycle, and migration ability of five osteosarcoma cell lines (human: MG-63, HOS; rat: OSRGA; mice: MOS-J, POS-1. Imatinib mesylate was also assessed as a curative and preventive treatment in two syngenic osteosarcoma models: MOS-J (mixed osteoblastic/osteolytic osteosarcoma and POS-1 (undifferentiated osteosarcoma. Imatinib mesylate exhibited a dose-dependent anti-proliferative effect in all cell lines studied. The drug induced a G0/G1 cell cycle arrest in most cell lines, except for POS-1 and HOS cells that were blocked in the S phase. In addition, imatinib mesylate induced cell death and strongly inhibited osteosarcoma cell migration. In the MOS-J osteosarcoma model, oral administration of imatinib mesylate significantly inhibited the tumour development in both preventive and curative approaches. A phospho-receptor tyrosine kinase array kit revealed that PDGFRα, among 7 other receptors (PDFGFRβ, Axl, RYK, EGFR, EphA2 and 10, IGF1R, appears as one of the main molecular targets for imatinib mesylate. In the light of the present study and the literature, it would be particularly interesting to revisit therapeutic evaluation of imatinib mesylate in osteosarcoma according to the tyrosine-kinase receptor

  14. GSK3 as a sensor determining cell fate in the brain

    Directory of Open Access Journals (Sweden)

    Adam R Cole

    2012-02-01

    Full Text Available Glycogen synthase kinase 3 (GSK3 is an unusual serine/threonine kinase that controls many neuronal functions, including neurite outgrowth, synapse formation, neurotransmission and neurogenesis. It mediates these functions by phosphorylating a wide range of substrates involved in gene transcription, metabolism, apoptosis, cytoskeletal dynamics, signal transduction, lipid membrane dynamics and trafficking, amongst others. This complicated list of diverse substrates generally follow a more simple pattern: substrates negatively regulated by GSK3-mediated phosphorylation favour a proliferative/survival state, while substrates positively regulated by GSK3 favour a more differentiated/functional state. Accordingly, GSK3 activity is higher in differentiated cells than undifferentiated cells and physiological (Wnt, growth factors and pharmacological inhibitors of GSK3 promote the proliferative capacity of embryonic stem cells. In the brain, the level of GSK3 activity influences neural progenitor cell proliferation/differentiation in neuroplasticity and repair, as well as efficient neurotransmission in differentiated adult neurons. While defects in GSK3 activity are unlikely to be the primary cause of neurodegenerative diseases, therapeutic regulation of its activity to promote a proliferative/survival versus differentiated/mature functional environment in the brain could be a powerful strategy for treatment of neurodegenerative and other mental disorders.

  15. An interspecies conserved motif of the mouse immune system-released activating agent (ISRAA) induces proliferative effects on human cells.

    Science.gov (United States)

    Taha, Safa; Fathallah, Mohamed Dahmani; Bakhiet, Moiz

    2014-07-01

    We have recently described an immune system-released activating agent (ISRAA) as a nervous system-induced factor that stimulates immune responses in the mouse spleen. However, the human ISRAA has not yet been identified. In this study, we examined the effects of the mouse ISRAA protein on human peripheral blood mononuclear cells (PBMCs), to observe if the biological activity of this molecule is consistent between the two different species. Mouse ISRAA demonstrated dose-dependent dualistic effects on human cells, as 5 µg exhibited positive apoptosis and 50 pg exhibited significant proliferation (P<0.05). Furthermore, immunosuppressed cells from patients undergoing immunosuppressive therapy demonstrated significant proliferation to 50 pg ISRAA (P<0.05). Studies to compare sequences in different species revealed a preserved motif, exhibiting 72% similarity with the interspecies conserved signal peptide motif of tumor necrosis factor receptor 1 (TNFR1). A mutant ISRAA lacking this motif was produced and tested for its biological effects. The mutant ISRAA demonstrated neither apoptotic nor proliferative effects compared with wild type. Therefore, an interspecies conserved domain of ISRAA constitutes the active site of the molecule, and its effects on immunocompromised cells should be investigated for future therapies in the treatment of immunosuppressive disorders.

  16. The proliferative potential of human cardiac stem cells was unaffected after a long-term cryopreservation of tissue blocks

    Science.gov (United States)

    Iguchi, Nobuo; Cho, Yasunori; Inoue, Masaki; Murakami, Tsutomu; Tabata, Minoru; Takanashi, Shuichiro; Tomoike, Hitonobu

    2017-01-01

    Background Human c-kit-positive cardiac stem cells (CSCs) have been used to treat patients suffering from ischemic cardiomyopathy. This study aimed to investigate whether a long-term storage of cardiac tissues would influence the growth potential of the subsequently isolated CSCs. Methods A total of 34 fresh samples were obtained from various cardiac regions [right atrium (RA), left atrium (LA), and/or left ventricle (LV)] of 21 patients. From 12 of these patients, 18 samples kept frozen for ~2 years were employed to prepare and characterize the CSCs. After confirming the specificity of the cell sorting by c-kit immunolabeling, the growth rate (number of doublings per day), BrdU positivity, and colony forming unit (CFU) were measured in each CSC population; the values were compared among distinct cardiac regions as well as between fresh and frozen tissues from which CSCs were derived. Results Among independent measurements indicating growth potential, the growth rate and BrdU positivity remarkably correlated in freshly prepared CSCs. The cells obtained from every examined region displayed a high proliferative capacity with the growth rate of 0.48±0.19 and the BrdU positivity of 15.0%±7.6%. The right atrial CSCs tended to show a greater growth than those in the other two areas. Similarly, the CSCs were isolated from tissue blocks, cryopreserved for ~2 years, and compared with CSCs derived from the fresh specimens of the same patients. Importantly, we were able to obtain and culture CSCs from every frozen material, and their proliferative potential, represented by the growth rate of 0.47±0.22 and the BrdU positivity of 13.7%±7.9%, was not inferior to that of the freshly prepared cells. Conclusions The long-term cryopreservation of cardiac tissues did not affect the growth potential of the derivative CSCs. Our findings should expand the therapeutic applications of these cells over a longer time span. PMID:28251120

  17. Anti-proliferative and pro-apoptotic effects from sequenced combinations of andrographolide and cisplatin on ovarian cancer cell lines.

    Science.gov (United States)

    Yunos, Nurhanan M; Mutalip, Siti S M; Jauri, Muhammad H; Yu, Jun Q; Huq, Fazlul

    2013-10-01

    Andrographolide (Andro) is a diterpenoid that is isolated from Andrographis paniculata and reported to be active against several cancer cell lines. However, few in-depth studies have been carried out on its effects on ovarian cancer cell lines alone or in combination with cisplatin (Cis), which is commonly used to treat ovarian cancer. The aim of this study was to determine the anti-proliferative and apoptotic effects of Andro administered alone and in combination with Cis in the ovarian A2780 and A2780(cisR) cancer cell lines using five different sequences of administration (Cis/Andro h): 0/0h, 4/0 h, 0/4 h, 24/0 h and 0/24 h. The results were evaluated in terms of medium-effect dose (Dm) and combination indices (CI) using the CalcuSyn software. Unlike Cis, whose activity was lower in the resistant A2780(cisR) cell line than in the parent A2780 cell line, Andro was found to be three times more active in the A2780(cisR) cell line as compared to that in A2780 cell line. Synergism was observed when Cis and Andro were administered using the sequences 0/4 h and 4/0 h. The percentage of apoptotic cell death was found to be greater for the 0/4 h combination of Andro and Cis as compared to those values from single-drug treatments. The results may be clinically significant if confirmed in vivo.

  18. Human mammary progenitor cell fate decisions are productsof interactions with combinatorial microenvironments

    DEFF Research Database (Denmark)

    LaBarge, Mark A.; Nelson, Celeste M.; Villadsen, René

    2009-01-01

    as constellations of signaling molecules; and these were used in conjunction with physiologically relevant 3 dimensional human breast cultures. Both immortalized and primary human breast progenitors were analyzed. We report on the functional ability of those proteins of the mammary gland that maintain quiescence...... combinations of cell-extrinsic mammary gland proteins and ECM molecules that imposed specific cell fates on bipotent human mammary progenitor cells.Micropatterned cell culture surfaces were fabricated to distinguish between the instructive effects of cell-cell versus cell-ECM interactions, as well...

  19. A germline GFP transgenic axolotl and its use to track cell fate: dual origin of the fin mesenchyme during development and the fate of blood cells during regeneration.

    Science.gov (United States)

    Sobkow, Lidia; Epperlein, Hans-Henning; Herklotz, Stephan; Straube, Werner L; Tanaka, Elly M

    2006-02-15

    The development of transgenesis in axolotls is crucial for studying development and regeneration as it would allow for long-term cell fate tracing as well as gene expression analysis. We demonstrate here that plasmid injection into the one-cell stage axolotl embryo generates mosaic transgenic animals that display germline transmission of the transgene. The inclusion of SceI meganuclease in the injections (Thermes, V., Grabher, C., Ristoratore, F., Bourrat, F., Choulika, A., Wittbrodt, J., Joly, J.S., 2002. I-SceI meganuclease mediates highly efficient transgenesis in fish. Mech. Dev. 118, 91-98) resulted in a higher percentage of F0 animals displaying strong expression throughout the body. This represents the first demonstration in the axolotl of germline transmission of a transgene. Using this technique we have generated a germline transgenic animal expressing GFP ubiquitously in all tissues examined. We have used this animal to study cell fate in the dorsal fin during development. We have uncovered a contribution of somite cells to dorsal fin mesenchyme in the axolotl, which was previously assumed to derive solely from neural crest. We have also studied the role of blood during tail regeneration by transplanting the ventral blood-forming region from GFP+ embryos into unlabeled hosts. During tail regeneration, we do not observe GFP+ cells contributing to muscle or nerve, suggesting that during tail regeneration blood stem cells do not undergo significant plasticity.

  20. Single-cell mass spectrometry reveals small molecules that affect cell fates in the 16-cell embryo.

    Science.gov (United States)

    Onjiko, Rosemary M; Moody, Sally A; Nemes, Peter

    2015-05-26

    Spatial and temporal changes in molecular expression are essential to embryonic development, and their characterization is critical to understand mechanisms by which cells acquire different phenotypes. Although technological advances have made it possible to quantify expression of large molecules during embryogenesis, little information is available on metabolites, the ultimate indicator of physiological activity of the cell. Here, we demonstrate that single-cell capillary electrophoresis-electrospray ionization mass spectrometry is able to test whether differential expression of the genome translates to the domain of metabolites between single embryonic cells. Dissection of three different cell types with distinct tissue fates from 16-cell embryos of the South African clawed frog (Xenopus laevis) and microextraction of their metabolomes enabled the identification of 40 metabolites that anchored interconnected central metabolic networks. Relative quantitation revealed that several metabolites were differentially active between the cell types in the wild-type, unperturbed embryos. Altering postfertilization cytoplasmic movements that perturb dorsal development confirmed that these three cells have characteristic small-molecular activity already at cleavage stages as a result of cell type and not differences in pigmentation, yolk content, cell size, or position in the embryo. Changing the metabolite concentration caused changes in cell movements at gastrulation that also altered the tissue fates of these cells, demonstrating that the metabolome affects cell phenotypes in the embryo.

  1. Multiscale microenvironmental perturbation of pluripotent stem cell fate and self-organization

    Science.gov (United States)

    Tabata, Yoji; Lutolf, Matthias P.

    2017-03-01

    The combination of microfluidics with engineered three-dimensional (3D) matrices can bring new insights into the fate regulation of stem cells and their self-organization into organoids. Although there has been progress in 3D stem cell culturing, most existing in vitro methodologies do not allow for mimicking of the spatiotemporal heterogeneity of stimuli that drive morphogenetic processes in vivo. To address this, we present a perfusion-free microchip concept for the in vitro 3D perturbation of stem cell fate. Stem cells are encapsulated in a hydrogel compartment that is flanked by open reservoirs for the diffusion-driven generation of biomolecule gradients. Juxtaposing additional compartments bearing supportive cells enables investigating the influence of long range cell-cell communication. We explore the utility of the microchips in manipulating early fate choices and self-organizing characteristics of 3D-cultured mouse embryonic stem cells (mESCs) under neural differentiation conditions and exposure to gradients of leukemia inhibitory factor (LIF). mESCs respond to LIF gradients in a spatially dependent manner. At higher LIF concentrations, multicellular colonies maintain pluripotency in contrast, at lower concentrations, mESCs develop into apicobasally polarized epithelial cysts. This versatile system can help to systematically explore the role of multifactorial microenvironments in promoting self-patterning of various stem cell types.

  2. Human mammary progenitor cell fate decisions are products of interactions with combinatorial microenvironments

    Energy Technology Data Exchange (ETDEWEB)

    LaBarge, Mark A; Nelson, Celeste M; Villadsen, Rene; Fridriksdottir, Agla; Ruth, Jason R; Stampfer, Martha R; Petersen, Ole W; Bissell, Mina J

    2008-09-19

    In adult tissues, multi-potent progenitor cells are some of the most primitive members of the developmental hierarchies that maintain homeostasis. That progenitors and their more mature progeny share identical genomes, suggests that fate decisions are directed by interactions with extrinsic soluble factors, ECM, and other cells, as well as physical properties of the ECM. To understand regulation of fate decisions, therefore, would require a means of understanding carefully choreographed combinatorial interactions. Here we used microenvironment protein microarrays to functionally identify combinations of cell-extrinsic mammary gland proteins and ECM molecules that imposed specific cell fates on bipotent human mammary progenitor cells. Micropatterned cell culture surfaces were fabricated to distinguish between the instructive effects of cell-cell versus cell-ECM interactions, as well as constellations of signaling molecules; and these were used in conjunction with physiologically relevant 3 dimensional human breast cultures. Both immortalized and primary human breast progenitors were analyzed. We report on the functional ability of those proteins of the mammary gland that maintain quiescence, maintain the progenitor state, and guide progenitor differentiation towards myoepithelial and luminal lineages.

  3. Significantly different proliferative potential of oral mucosal epithelial cells between six animal species.

    Science.gov (United States)

    Kondo, Makoto; Yamato, Masayuki; Takagi, Ryo; Murakami, Daisuke; Namiki, Hideo; Okano, Teruo

    2014-06-01

    There has been an upsurge in regenerative medicine in recent years. In particular, because oral mucosal epithelial cells can be obtained noninvasively, cultured epithelial cell sheets have been used in a number of ectopic transplantations. Additionally, the verification of the properties of experimental animals' cultured cells has accelerated the application of regenerative medicine. In the present study, the properties of oral mucosal epithelial cells were compared between six animal species. The human and pig epithelia were relatively thicker than the epithelia of the other species. The colony-forming efficiency of the rat was the highest, followed by those of the dog, human, rabbit, and pig, whereas the colonies of the mouse cells were all paraclone and uncountable in the colony-forming assay. We also found that the rabbit and pig cells proliferated poorly and were unable to form cell sheets without feeder layers. In contrast, even in the absence of feeder layers and cholera toxin, cultured dog and mouse cells formed contiguous sheets, when the cell seeding density was high. These results indicate that interspecies variation is considerable in oral mucosal epithelial cells and that specific experimental animal or human cells must be chosen according to the intended use.

  4. Differentiation-inducing and anti-proliferative activities of lupeol on canine melanoma cells.

    Science.gov (United States)

    Ogihara, Kikumi; Naya, Yuko; Okamoto, Yoshiharu; Hata, Keishi

    2014-01-01

    Canine melanoma is the most common oral malignant tumor reported in the field of veterinary medicine. We found that lupeol, a lupine triterpene, inhibited mouse melanoma cell growth in vitro and in vivo by inducing cell differentiation. In the present study, we examined the differentiation-inducing activities of lupeol on 4 canine melanoma cells in vitro and in vivo. The induction of canine melanoma cell differentiation by lupeol was confirmed by evaluating some differentiation markers such as tyrosinase with real-time RT-PCR. Furthermore, we transplanted canine melanoma cells into a severe combined immunodeficiency mouse, and studied the anti-progressive effects of lupeol on tumor tissue. The gene expression of microphthalmia-associated transcription factor, tyrosinase, and tyrosinase-related protein-2, which are markers of pigment cell differentiation, was induced in 4 canine oral malignant melanoma cells by lupeol, and the agent markedly inhibited tumor progression in canine melanoma-bearing mice.

  5. Anti-proliferative and apoptotic effects of S1, a tetrandrine derivative, in human gastric cancer BGC-823 cells.

    Science.gov (United States)

    Lei, Rong-Rong; Hu, Hai-Feng; Bai, Fan; Liu, Ying; Wu, Chun-Zhen; Huang, Xiao-Xing; Xie, Li-Ping; Hu, You-Jia

    2016-07-01

    The aim of the study was to investigate the anti-proliferation and apoptosis-inducing effects of S1, a novel tetrandrine derivative, in human gastric cancer BGC-823 cells and explore the possible mechanism of action. The anti-proliferative activity was determined by MTT assay; the induction of cell cycle arrest and apoptosis were detected by flow cytometry. Quantitative real time RT-PCR and Western blotting were used to evaluate the mRNA and protein expression levels in mitochondrial pathway. S1 significantly reduced cell viability and induced a G2/M phase arrest and apoptosis in dose- and time-dependent manner. Further studies showed that S1 increased mRNA and protein expression of Bax and the Bax/Bcl-2 ratio. Moreover, S1 decreased the protein expression of procaspase-9 and procaspase-3, suggesting that the induction of apoptosis may be related to the alteration of the ratio of Bax/Bcl-2 and the activation of caspases. These findings suggested that S1 merits further investigation as a novel therapeutic agent for the treatment of human gastric cancer.

  6. The Proliferative Activity of Mammary Epithelial Cells in Normal Tissue Predicts Breast Cancer Risk in Premenopausal Women.

    Science.gov (United States)

    Huh, Sung Jin; Oh, Hannah; Peterson, Michael A; Almendro, Vanessa; Hu, Rong; Bowden, Michaela; Lis, Rosina L; Cotter, Maura B; Loda, Massimo; Barry, William T; Polyak, Kornelia; Tamimi, Rulla M

    2016-04-01

    The frequency and proliferative activity of tissue-specific stem and progenitor cells are suggested to correlate with cancer risk. In this study, we investigated the association between breast cancer risk and the frequency of mammary epithelial cells expressing p27, estrogen receptor (ER), and Ki67 in normal breast tissue. We performed a nested case-control study of 302 women (69 breast cancer cases, 233 controls) who had been initially diagnosed with benign breast disease according to the Nurses' Health Studies. Immunofluorescence for p27, ER, and Ki67 was performed on tissue microarrays constructed from benign biopsies containing normal mammary epithelium and scored by computational image analysis. We found that the frequency of Ki67(+) cells was positively associated with breast cancer risk among premenopausal women [OR = 10.1, 95% confidence interval (CI) = 2.12-48.0]. Conversely, the frequency of ER(+) or p27(+) cells was inversely, but not significantly, associated with subsequent breast cancer risk (ER(+): OR = 0.70, 95% CI, 0.33-1.50; p27(+): OR = 0.89, 95% CI, 0.45-1.75). Notably, high Ki67(+)/low p27(+) and high Ki67(+)/low ER(+) cell frequencies were significantly associated with a 5-fold higher risk of breast cancer compared with low Ki67(+)/low p27(+) and low Ki67(+)/low ER(+) cell frequencies, respectively, among premenopausal women (Ki67(hi)/p27(lo): OR = 5.08, 95% CI, 1.43-18.1; Ki67(hi)/ER(lo): OR = 4.68, 95% CI, 1.63-13.5). Taken together, our data suggest that the fraction of actively cycling cells in normal breast tissue may represent a marker for breast cancer risk assessment, which may therefore impact the frequency of screening procedures in at-risk women. Cancer Res; 76(7); 1926-34. ©2016 AACR.

  7. Interrogating a cell signalling network sensitively monitors cell fate transition during early differentiation of mouse embryonic stem cells

    Institute of Scientific and Technical Information of China (English)

    LIU; Yi-Hsin; HO; Chih-ming

    2010-01-01

    The different cell types in an animal are often considered to be specified by combinations of transcription factors,and defined by marker gene expression.This paradigm is challenged,however,in stem cell research and application.Using a mouse embryonic stem cell(mESC) culture system,here we show that the expression level of many key stem cell marker genes/transcription factors such as Oct4,Sox2 and Nanog failed to monitor cell status transition during mESC differentiation.On the other hand,the response patterns of cell signalling network to external stimuli,as monitored by the dynamics of protein phosphorylation,changed dramatically.Our results also suggest that an irreversible alternation in the cell signalling network precedes the adjustment of transcription factor levels.This is consistent with the notion that signal transduction events regulate cell fate specification.We propose that interrogating a cell signalling network can assess the cell property more precisely,and provide a sensitive measurement for the early events in cell fate transition.We wish to bring attention to the potential problem of cell identification using a few marker genes,and suggest a novel methodology to address this issue.

  8. Umbelliprenin is cytotoxic against QU-DB large cell lung cancer cell line but anti-proliferative against A549 adenocarcinoma cells

    Directory of Open Access Journals (Sweden)

    Khaghanzadeh Narges

    2012-10-01

    Full Text Available Abstract Background Umbelliprenin is a natural compound, belonging to the class of sesquiterpene coumarins. Recently, umbelliprenin has attracted the researchers' attention for its antitumor activities against skin tumors. Its effect on lung cancer is largely unknown. The aim of our study was to investigate the effects of this natural compound, which is expected to have low adverse effects, on lung cancer. Methods The QU-DB large cell and A549 adenocarcinoma lung cancer cell lines were treated with umbelliprenin. IC50 values were estimated using methyl thiazolely diphenyl-tetrazolium bromide (MTT assay, in which a decrease in MTT reduction can occur as a result of cell death or cell proliferation inhibition. To quantify the rate of cell death at IC50 values, flow cytometry using Annexin V-FITC (for apoptotic cells, and propidium iodide (for necrotic cells dyes were employed. Results Data from three independent MTT experiments in triplicate revealed that IC50 values for QU-DB and A549 were 47 ± 5.3 μM and 52 ± 1.97 μM, respectively. Annexin V/PI staining demonstrated that umbelliprenin treatment at IC50 induced 50% cell death in QU-DB cells, but produced no significant death in A549 cells until increasing the umbelliprenin concentration to IC80. The pattern of cell death was predominantly apoptosis in both cell lines. When peripheral blood mononuclear cells were treated with 50 μM and less concentrations of umbelliprenin, no suppressive effect was observed. Conclusions We found cytotoxic/anti-proliferative effects of umbelliprenin against two different types of lung cancer cell lines.

  9. Umbelliprenin is Cytotoxic against QU-DB Large Cell Lung Cancer Cell Line but Anti-Proliferative against A549 Adenocarcinoma Cells

    Directory of Open Access Journals (Sweden)

    Abbas Ghaderi

    2012-10-01

    Full Text Available Background:Umbelliprenin is a natural compound, belonging to the class of sesquiterpene coumarins.Recently, umbelliprenin has attracted the researchers' attention for its antitumor activitiesagainst skin tumors. Its effect on lung cancer is largely unknown. The aim of our study was to investigate the effects of this natural compound, which is expected to have low adverse effects, on lung cancer.Methods:The QU-DB large cell and A549 adenocarcinoma lung cancer cell lines were treated with umbelliprenin. IC50 values were estimated using methyl thiazolely diphenyl-tetrazolium bromide (MTT assay, in which a decrease in MTT reduction can occur as a result of cell death or cell proliferation inhibition. To quantify the rate of cell death at IC50 values, flow cytometry using Annexin V-FITC (for apoptotic cells, and propidium iodide (for necrotic cells dyes were employed.Results:Data from three independent MTT experiments in triplicate revealed that IC50 values for QUDB and A549 were 47 ± 5.3 μM and 52 ± 1.97 μM, respectively. Annexin V/PI staining demonstrated that umbelliprenin treatment at IC50 induced 50% cell death in QU-DB cells,but produced no significant death in A549 cells until increasing the umbelliprenin concentration to IC80. The pattern of cell death was predominantly apoptosis in both cell lines. When peripheral blood mononuclear cells were treated with 50 μM and lessconcentrations of umbelliprenin, no suppressive effect was observed.Conclusions:We found cytotoxic/anti-proliferative effects of umbelliprenin against two different types of lung cancer cell lines.

  10. Anti-Proliferative Effect of Copper Oxide Nanorods Against Human Cervical Carcinoma Cells.

    Science.gov (United States)

    Pandurangan, Muthuraman; Nagajyothi, P C; Shim, Jaesool; Kim, Doo Hwan

    2016-09-01

    Metal oxide nanoparticles have been widely investigated for its use in the pharmacological field. The present study was aimed to investigate the cytotoxicity of copper oxide nanorods in human cervical carcinoma cells. The effect of copper oxide nanorods on cell viability was determined by sulforhodamine-B (SRB) assay. The fluorescence and confocal microscopy analyzes showed the cell rounding and nuclear fragmentation following exposure of copper oxide nanorods. Reactive oxygen species (ROS) was increased and could initiate membrane lipid peroxidation, which in turn regulate cytokinetic movements of cells. The messenger RNA (mRNA) expression of p53 and caspase 3 was increased, which further confirms the occurrence of apoptosis at the transcriptional level. Furthermore, caspase-3 enzyme activity was increased, which also confirms the occurrence of apoptosis in tumor cells at the translational level. Taking all our experimental results together, it may suggest that the copper oxide nanorods could be a potential anti-tumor agent to inhibit cancer cell proliferation.

  11. Apoptotic neurons induce proliferative responses of progenitor cells in the postnatal neocortex.

    Science.gov (United States)

    Petrenko, Volodymyr; Mihhailova, Jevgenia; Salmon, Patrick; Kiss, Jozsef Z

    2015-11-01

    Apoptotic cell death is the leading cause of neuronal loss after neonatal brain injury. Little is known about the intrinsic capacity of the immature cerebral cortex for replacing dead cells. Here we test the hypothesis that neuronal apoptosis is able to trigger compensatory proliferation in surrounding cells. In order to establish a "pure" apoptotic cell death model and to avoid the confounding effects of broken blood-brain barrier and inflammatory reactions, we used a diphtheria toxin (DT) and diphtheria toxin receptor (DTR) system to induce ablation of layer IV neurons in the rodent somatosensory cortex during the early postnatal period. We found that DT-triggered apoptosis is a slowly progressing event lasting about for 7 days. While dying cells expressed the morphological features of apoptosis, we could not detect immunoreactivity for activated caspase-3 in these cells. Microglia activation and proliferation represented the earliest cellular responses to apoptotic cell death. In addition, we found that induced apoptosis triggered a massive proliferation of undifferentiated progenitor cell pool including Sox2 as well as NG2 cells. The default differentiation pattern of proliferating progenitors appears to be the glial phenotype; we could not find evidence for newly generated neurons in response to apoptotic neuronal death. These results suggest that mitotically active progenitor populations are intrinsically capable to contribute to the repair process of injured cortical tissue and may represent a potential target for neuronal replacement strategies.

  12. Transcriptional control of stem cell fate by E2Fs and Pocket Proteins

    Directory of Open Access Journals (Sweden)

    Lisa Marie Julian

    2015-04-01

    Full Text Available E2F transcription factors and their regulatory partners, the pocket proteins (PPs, have emerged as essential regulators of stem cell fate control in a number of lineages. In mammals, this role extends from both pluripotent stem cells to those encompassing all embryonic germ layers, as well as extra-embryonic lineages. E2F/PP-mediated regulation of stem cell decisions is highly evolutionarily conserved, and is likely a pivotal biological mechanism underlying stem cell homeostasis. This has immense implications for organismal development, tissue maintenance and regeneration. In this article, we discuss the roles of E2F factors and PPs in stem cell populations, focusing on mammalian systems. We discuss emerging findings that position the E2F and PP families as widespread and dynamic epigenetic regulators of cell fate decisions. Additionally, we focus on the ever expanding landscape of E2F/PP target genes, and explore the possibility that E2Fs are not simply regulators of general ‘multi-purpose’ cell fate genes but can execute tissue- and cell type-specific gene regulatory programs.

  13. Relationship between nanotopographical alignment and stem cell fate with live imaging and shape analysis

    Science.gov (United States)

    Newman, Peter; Galenano-Niño, Jorge Luis; Graney, Pamela; Razal, Joselito M.; Minett, Andrew I.; Ribas, João; Ovalle-Robles, Raquel; Biro, Maté; Zreiqat, Hala

    2016-12-01

    The topography of a biomaterial regulates cellular interactions and determine stem cell fate. A complete understanding of how topographical properties affect cell behavior will allow the rational design of material surfaces that elicit specified biological functions once placed in the body. To this end, we fabricate substrates with aligned or randomly organized fibrous nanostructured topographies. Culturing adipose-derived stem cells (ASCs), we explore the dynamic relationship between the alignment of topography, cell shape and cell differentiation to osteogenic and myogenic lineages. We show aligned topographies differentiate cells towards a satellite cell muscle progenitor state - a distinct cell myogenic lineage responsible for postnatal growth and repair of muscle. We analyze cell shape between the different topographies, using fluorescent time-lapse imaging over 21 days. In contrast to previous work, this allows the direct measurement of cell shape at a given time rather than defining the morphology of the underlying topography and neglecting cell shape. We report quantitative metrics of the time-based morphological behaviors of cell shape in response to differing topographies. This analysis offers insights into the relationship between topography, cell shape and cell differentiation. Cells differentiating towards a myogenic fate on aligned topographies adopt a characteristic elongated shape as well as the alignment of cells.

  14. The cAMP analogs have potent anti-proliferative effects on medullary thyroid cancer cell lines.

    Science.gov (United States)

    Dicitore, Alessandra; Grassi, Elisa Stellaria; Caraglia, Michele; Borghi, Maria Orietta; Gaudenzi, Germano; Hofland, Leo J; Persani, Luca; Vitale, Giovanni

    2016-01-01

    The oncogenic activation of the rearranged during transfection (RET) proto-oncogene has a main role in the pathogenesis of medullary thyroid cancer (MTC). Several lines of evidence suggest that RET function could be influenced by cyclic AMP (cAMP)-dependent protein kinase A (PKA) activity. We evaluated the in vitro anti-tumor activity of 8-chloroadenosine-3',5'-cyclic monophosphate (8-Cl-cAMP) and PKA type I-selective cAMP analogs [equimolar combination of the 8-piperidinoadenosine-3',5'-cyclic monophosphate (8-PIP-cAMP) and 8-hexylaminoadenosine-3',5'-cyclic monophosphate (8-HA-cAMP) in MTC cell lines (TT and MZ-CRC-1)]. 8-Cl-cAMP and the PKA I-selective cAMP analogs showed a potent anti-proliferative effect in both cell lines. In detail, 8-Cl-cAMP blocked significantly the transition of TT cell population from G2/M to G0/G1 phase and from G0/G1 to S phase and of MZ-CRC-1 cells from G0/G1 to S phase. Moreover, 8-Cl-cAMP induced apoptosis in both cell lines, as demonstrated by FACS analysis for annexin V-FITC/propidium iodide, the activation of caspase-3 and PARP cleavage. On the other hand, the only effect induced by PKA I-selective cAMP analogs was a delay in G0/G1-S and S-G2/M progression in TT and MZ-CRC-1 cells, respectively. In conclusion, these data demonstrate that cAMP analogs, particularly 8-Cl-cAMP, significantly suppress in vitro MTC proliferation and provide rationale for a potential clinical use of cAMP analogs in the treatment of advanced MTC.

  15. Sildenafil potentiates the proliferative effect of porcine pulmonary artery smooth muscle cells induced by serotonin in vitro

    Institute of Scientific and Technical Information of China (English)

    LI Bing-bing; JIANG Zhen; SHENG Jian-yin; YAO Kang

    2011-01-01

    Background Sildenafil is one of the selective phosphodiesterase 5 inhibitors that has been proven by many investigators to suppress growth factor stimulated (e.g.platelet-derived growth factor (PDGF) or epidermal growth factor (EGF)) proliferation and hypertrophy of pulmonary artery smooth muscle cells (PASMCs) via cGMP/cGKIα pathway.Serotonin promotes cell cycle progression leading to cell mitogenesis and plays a key role in the pathogenesis of pulmonary artery hypertension.The role of sildenafil in proliferation of PASMCs induced by serotonin has not been investigated so far.In this study we explored the underlying mechanism of the effect of sildenafil on serotonin induced proliferation of porcine PASMCs.Methods PASMCs were cells from primary cultures by the explant method from the pulmonary artery of swine and cells at passage 3-5 were used in this study.MTT colorimetric assay and flow cytometry analysis were used to evaluate the cell proliferation and alterations in cell cycle progression respectively.Western blotting analysis was applied to determine the expression of phosphorylated extracellular signal-regulated kinase (ERK),proliferating cell nuclear antigen (PCNA)and mitogen activated protein kinase (MAPK) phosphatase-1 (MKP-1).Results Serotonin (10 μmol/L) induced the upregulation of phosphorylation of ERK1/ERK2 and PCNA,an increase in the percentage of cells in S phase and subsequent cell proliferation.Pretreatment with 1 μmol/L sildenafil potentiated the phosphorylation of ERK1/ERK2,an increase in the percentage of cells in S phase and cell proliferation,compared with serotonin stimulation alone (P <0.05).Furthermore,30-minute pretreatment with 10 μmol/L U0126,specific antagonist for ERK kinase (MEK) prevented the increase in phosphorylation of ERK1/ERK2 and abolished cell cycle progression and the proliferation of PASMCs induced by sildenafil.Conclusion This study shows that sildenafil potentiated the proliferative effect of serotonin on PASMCs

  16. Twist1-positive epithelial cells retain adhesive and proliferative capacity throughout dissemination

    Directory of Open Access Journals (Sweden)

    Eliah R. Shamir

    2016-09-01

    Full Text Available Dissemination is the process by which cells detach and migrate away from a multicellular tissue. The epithelial-to-mesenchymal transition (EMT conceptualizes dissemination in a stepwise fashion, with downregulation of E-cadherin leading to loss of intercellular junctions, induction of motility, and then escape from the epithelium. This gain of migratory activity is proposed to be mutually exclusive with proliferation. We previously developed a dissemination assay based on inducible expression of the transcription factor Twist1 and here utilize it to characterize the timing and dynamics of intercellular adhesion, proliferation and migration during dissemination. Surprisingly, Twist1+ epithelium displayed extensive intercellular junctions, and Twist1– luminal epithelial cells could still adhere to disseminating Twist1+ cells. Although proteolysis and proliferation were both observed throughout dissemination, neither was absolutely required. Finally, Twist1+ cells exhibited a hybrid migration mode; their morphology and nuclear deformation were characteristic of amoeboid cells, whereas their dynamic protrusive activity, pericellular proteolysis and migration speeds were more typical of mesenchymal cells. Our data reveal that epithelial cells can disseminate while retaining competence to adhere and proliferate.

  17. lin-28 controls the succession of cell fate choices via two distinct activities.

    Directory of Open Access Journals (Sweden)

    Bhaskar Vadla

    Full Text Available lin-28 is a conserved regulator of cell fate succession in animals. In Caenorhabditis elegans, it is a component of the heterochronic gene pathway that governs larval developmental timing, while its vertebrate homologs promote pluripotency and control differentiation in diverse tissues. The RNA binding protein encoded by lin-28 can directly inhibit let-7 microRNA processing by a novel mechanism that is conserved from worms to humans. We found that C. elegans LIN-28 protein can interact with four distinct let-7 family pre-microRNAs, but in vivo inhibits the premature accumulation of only let-7. Surprisingly, however, lin-28 does not require let-7 or its relatives for its characteristic promotion of second larval stage cell fates. In other words, we find that the premature accumulation of mature let-7 does not account for lin-28's precocious phenotype. To explain let-7's role in lin-28 activity, we provide evidence that lin-28 acts in two steps: first, the let-7-independent positive regulation of hbl-1 through its 3'UTR to control L2 stage-specific cell fates; and second, a let-7-dependent step that controls subsequent fates via repression of lin-41. Our evidence also indicates that let-7 functions one stage earlier in C. elegans development than previously thought. Importantly, lin-28's two-step mechanism resembles that of the heterochronic gene lin-14, and the overlap of their activities suggests a clockwork mechanism for developmental timing. Furthermore, this model explains the previous observation that mammalian Lin28 has two genetically separable activities. Thus, lin-28's two-step mechanism may be an essential feature of its evolutionarily conserved role in cell fate succession.

  18. Stem cell fate determination during development and regeneration of ectodermal organs

    Directory of Open Access Journals (Sweden)

    Lucia eJimenez-Rojo

    2012-04-01

    Full Text Available The development of ectoderm-derived appendages results in a large variety of highly specialized organs such as hair follicles, mammary glands, salivary glands and teeth. Despite varying in number, shape and function, all these ectodermal organs develop through continuous and reciprocal epithelial-mesenchymal interactions, sharing common morphological and molecular features especially during their embryonic development. Diseases such as ectodermal dysplasias can affect simultaneously these organs, suggesting that they may arise from common multipotent precursors residing in the embryonic ectoderm. During embryogenesis, these putative ectodermal stem cells may adopt different fates and consequently be able to generate a variety of tissue-specific stem cells, which are the sources for the various cell lineages that form the diverse organs. The specification of those common epithelial precursors, as well as their further lineage commitment to tissue-specific stem cells, might be controlled by specific signals. It has been well documented that Notch, Wnt, bone morphogenetic protein (BMP and fibroblast growth factor (FGF signaling pathways regulate cell fate decisions during the various stages of ectodermal organ development. However, the in vivo spatial and temporal dynamics of these signaling pathways are not yet well understood. Improving the current knowledge on the mechanisms involved in stem cell fate determination during organogenesis and homeostasis of ectodermal organs is crucial to develop effective stem cell-based therapies in order to regenerate or replace pathological and damaged tissues.

  19. Modulation of intracellular calcium and proliferative activity of invertebrate and vertebrate cells by ethylene

    Directory of Open Access Journals (Sweden)

    Müller Werner EG

    2001-05-01

    Full Text Available Abstract Background Ethylene is a widely distributed alkene product which is formed enzymatically (e.g., in plants or by photochemical reactions (e.g., in the upper oceanic layers from dissolved organic carbon. This gaseous compound was recently found to induce in cells from the marine sponge Suberites domuncula, an increase in intracellular Ca2+ level ([Ca2+]i and an upregulation of the expression of two genes, the potential ethylene-responsive gene, SDERR, and a Ca2+/calmodulin-dependent protein kinase. Results Here we describe for the first time, that besides sponge cells, mammalian cell lines (mouse NIH-3T3 and human HeLa and SaOS-2 cells respond to ethylene, generated by ethephon, with an immediate and strong, transient increase in [Ca2+]i level, as demonstrated using Fura-2 imaging method. A rise of [Ca2+]i level was also found following exposure to ethylene gas of cells kept under pressure (SaOS-2 cells. The upregulation of [Ca2+]i was associated with an increase in the level of the cell cycle-associated Ki-67 antigen. In addition, we show that the effect of ethephon addition to S. domuncula cells depends on the presence of calcium in the extracellular milieu. Conclusion The results presented in this paper indicate that ethylene, previously known to act as a mediator (hormone in plants only, deserves also attention as a potential signaling molecule in higher vertebrates. Further studies are necessary to clarify the specificity and physiological significance of the effects induced by ethylene in mammalian cells.

  20. Stem-cell dynamics and lineage topology from in vivo fate mapping in the hematopoietic system.

    Science.gov (United States)

    Höfer, Thomas; Barile, Melania; Flossdorf, Michael

    2016-06-01

    In recent years, sophisticated fate-mapping tools have been developed to study the behavior of stem cells in the intact organism. These experimental approaches are beginning to yield a quantitative picture of how cell numbers are regulated during steady state and in response to challenges. Focusing on hematopoiesis and immune responses, we discuss how novel mathematical approaches driven by these fate-mapping data have provided insights into the dynamics and topology of cellular differentiation pathways in vivo. The combination of experiment and theory has allowed to quantify the degree of self-renewal in stem and progenitor cells, shown how native hematopoiesis differs fundamentally from post-transplantation hematopoiesis, and uncovered that the diversification of T lymphocytes during immune responses resembles tissue renewal driven by stem cells.

  1. JAK/STAT signaling regulates tissue outgrowth and male germline stem cell fate in Drosophila

    Institute of Scientific and Technical Information of China (English)

    Shree Ram SINGH; Xiu CHEN; Steven X.HOU

    2005-01-01

    In multicellular organisms, biological activities are regulated by cell signaling. The various signal transduction pathways regulate cell fate, proliferation, migration, and polarity. Miscoordination of the communicative signals will lead to disasters like cancer and other fatal diseases. The JAK/STAT signal transduction pathway is one of the pathways, which was first identified in vertebrates and is highly conserved throughout evolution. Studying the JAK/STAT signal transduction pathway in Drosophila provides an excellent opportunity to understand the molecular mechanism of the cell regulation during development and tumor formation. In this review, we discuss the general overview of JAK/STAT signaling in Drosophila with respect to its functions in the eye development and stem cell fate determination.

  2. Multidimensional nanomaterials for the control of stem cell fate

    Science.gov (United States)

    Chueng, Sy-Tsong Dean; Yang, Letao; Zhang, Yixiao; Lee, Ki-Bum

    2016-09-01

    Current stem cell therapy suffers low efficiency in giving rise to differentiated cell lineages, which can replace the original damaged cells. Nanomaterials, on the other hand, provide unique physical size, surface chemistry, conductivity, and topographical microenvironment to regulate stem cell differentiation through multidimensional approaches to facilitate gene delivery, cell-cell, and cell-ECM interactions. In this review, nanomaterials are demonstrated to work both alone and synergistically to guide selective stem cell differentiation. From three different nanotechnology families, three approaches are shown: (1) soluble microenvironmental factors; (2) insoluble physical microenvironment; and (3) nano-topographical features. As regenerative medicine is heavily invested in effective stem cell therapy, this review is inspired to generate discussions in the potential clinical applications of multi-dimensional nanomaterials.

  3. A novel microtubule inhibitor 4SC-207 with anti-proliferative activity in taxane-resistant cells.

    Directory of Open Access Journals (Sweden)

    Elena Bausch

    Full Text Available Microtubule inhibitors are invaluable tools in cancer chemotherapy: taxanes and vinca alkaloids have been successfully used in the clinic over the past thirty years against a broad range of tumors. However, two factors have limited the effectiveness of microtubule inhibitors: toxicity and resistance. In particular, the latter is highly unpredictable, variable from patient to patient and is believed to be the cause of treatment failure in most cases of metastatic cancers. For these reasons, there is an increasing demand for new microtubule inhibitors that can overcome resistance mechanisms and that, at the same time, have reduced side effects. Here we present a novel microtubule inhibitor, 4SC-207, which shows strong anti-proliferative activity in a large panel of tumor cell lines with an average GI50 of 11 nM. In particular, 4SC-207 is active in multi-drug resistant cell lines, such as HCT-15 and ACHN, suggesting that it is a poor substrate for drug efflux pumps. 4SC-207 inhibits microtubule growth in vitro and in vivo and promotes, in a dose dependent manner, a mitotic delay/arrest, followed by apoptosis or aberrant divisions due to chromosome alignment defects and formation of multi-polar spindles. Furthermore, preliminary data from preclinical studies suggest low propensity towards bone marrow toxicities at concentrations that inhibit tumor growth in paclitaxel-resistant xenograft models. In summary, our results suggest that 4SC-207 may be a potential anti-cancer agent.

  4. Human tumour antigens defined by cytotoxicity and proliferative responses of cultured lymphoid cells

    Science.gov (United States)

    Vose, Brent M.; Bonnard, Guy D.

    1982-03-01

    The long-term goal of many laboratories has been to develop cellular reagents having specific reactivity against human tumour cells. Such immune cells should prove useful for defining the antigenicity of human malignancies and may have important therapeutic potential, as has been clearly shown in some animal models1. Here we describe methods of initiating continued lymphocyte cultures (CLC) having specific anti-tumour reactivity using conditioned media containing interleukin-2 (IL-2).

  5. Anti-Proliferative Effects of Siegesbeckia orientalis Ethanol Extract on Human Endometrial RL-95 Cancer Cells

    Directory of Open Access Journals (Sweden)

    Chi-Chang Chang

    2014-12-01

    Full Text Available Endometrial cancer is a common malignancy of the female genital tract. This study demonstrates that Siegesbeckia orientalis ethanol extract (SOE significantly inhibited the proliferation of RL95-2 human endometrial cancer cells. Treating RL95-2 cells with SOE caused cell arrest in the G2/M phase and induced apoptosis of RL95-2 cells by up-regulating Bad, Bak and Bax protein expression and down-regulation of Bcl-2 and Bcl-xL protein expression. Treatment with SOE increased protein expression of caspase-3, -8 and -9 dose-dependently, indicating that apoptosis was through the intrinsic and extrinsic apoptotic pathways. Moreover, SOE was also effective against A549 (lung cancer, Hep G2 (hepatoma, FaDu (pharynx squamous cancer, MDA-MB-231 (breast cancer, and especially on LNCaP (prostate cancer cell lines. In total, 10 constituents of SOE were identified by Gas chromatography-mass analysis. Caryophyllene oxide and caryophyllene are largely responsible for most cytotoxic activity of SOE against RL95-2 cells. Overall, this study suggests that SOE is a promising anticancer agent for treating endometrial cancer.

  6. Investigation of cell proliferative activity on the surface of the nanocomposite material produced by laser radiation

    Science.gov (United States)

    Zhurbina, N. N.; Kurilova, U. E.; Ickitidze, L. P.; Podgaetsky, V. M.; Selishchev, S. V.; Suetina, I. A.; Mezentseva, M. V.; Eganova, E. M.; Pavlov, A. A.; Gerasimenko, A. Y.

    2016-04-01

    A new method for the formation of composite nanomaterials based on multi-walled and single-walled carbon nanotubes (CNT) on a silicon substrate has been developed. Formation is carried out by ultrasound coating of a silicon substrate by homogenous dispersion of CNTs in the albumin matrix and further irradiation with the continuous laser beam with a wavelength of 810 nm and power of 5.5 watts. The high electrical conductivity of CNTs provides its structuring under the influence of the laser radiation electric field. The result is a scaffold that provides high mechanical strength of nanocomposite material (250 MPa). For in vitro studies of materials biocompatibility a method of cell growth microscopic analysis was developed. Human embryonic fibroblasts (EPP) were used as biological cells. Investigation of the interaction between nanocomposite material and cells was carried out by optical and atomic force microscopy depending on the time of cells incubation. The study showed that after 3 hours incubation EPP were fixed on the substrate surface, avoiding the surface of the composite material. However, after 24 hours of incubation EPP fix on the sample surface and then begin to grow and divide. After 72 hours of incubation, the cells completely fill the sample surface of nanocomposite material. Thus, a nanocomposite material based on CNTs in albumin matrix does not inhibit cell growth on its surface, and favours their growth. The nanocomposite material can be used for creating soft tissue implants

  7. Anti-proliferative effects of Siegesbeckia orientalis ethanol extract on human endometrial RL-95 cancer cells.

    Science.gov (United States)

    Chang, Chi-Chang; Hsu, Hsia-Fen; Huang, Kuo-Hung; Wu, Jing-Mei; Kuo, Shyh-Ming; Ling, Xue-Hua; Houng, Jer-Yiing

    2014-12-01

    Endometrial cancer is a common malignancy of the female genital tract. This study demonstrates that Siegesbeckia orientalis ethanol extract (SOE) significantly inhibited the proliferation of RL95-2 human endometrial cancer cells. Treating RL95-2 cells with SOE caused cell arrest in the G2/M phase and induced apoptosis of RL95-2 cells by up-regulating Bad, Bak and Bax protein expression and down-regulation of Bcl-2 and Bcl-xL protein expression. Treatment with SOE increased protein expression of caspase-3, -8 and -9 dose-dependently, indicating that apoptosis was through the intrinsic and extrinsic apoptotic pathways. Moreover, SOE was also effective against A549 (lung cancer), Hep G2 (hepatoma), FaDu (pharynx squamous cancer), MDA-MB-231 (breast cancer), and especially on LNCaP (prostate cancer) cell lines. In total, 10 constituents of SOE were identified by Gas chromatography-mass analysis. Caryophyllene oxide and caryophyllene are largely responsible for most cytotoxic activity of SOE against RL95-2 cells. Overall, this study suggests that SOE is a promising anticancer agent for treating endometrial cancer.

  8. Self-Organizing Global Gene Expression Regulated through Criticality: Mechanism of the Cell-Fate Change

    Science.gov (United States)

    Tsuchiya, Masa; Giuliani, Alessandro; Hashimoto, Midori; Erenpreisa, Jekaterina; Yoshikawa, Kenichi

    2016-01-01

    Background A fundamental issue in bioscience is to understand the mechanism that underlies the dynamic control of genome-wide expression through the complex temporal-spatial self-organization of the genome to regulate the change in cell fate. We address this issue by elucidating a physically motivated mechanism of self-organization. Principal Findings Building upon transcriptome experimental data for seven distinct cell fates, including early embryonic development, we demonstrate that self-organized criticality (SOC) plays an essential role in the dynamic control of global gene expression regulation at both the population and single-cell levels. The novel findings are as follows: i) Mechanism of cell-fate changes: A sandpile-type critical transition self-organizes overall expression into a few transcription response domains (critical states). A cell-fate change occurs by means of a dissipative pulse-like global perturbation in self-organization through the erasure of initial-state critical behaviors (criticality). Most notably, the reprogramming of early embryo cells destroys the zygote SOC control to initiate self-organization in the new embryonal genome, which passes through a stochastic overall expression pattern. ii) Mechanism of perturbation of SOC controls: Global perturbations in self-organization involve the temporal regulation of critical states. Quantitative evaluation of this perturbation in terminal cell fates reveals that dynamic interactions between critical states determine the critical-state coherent regulation. The occurrence of a temporal change in criticality perturbs this between-states interaction, which directly affects the entire genomic system. Surprisingly, a sub-critical state, corresponding to an ensemble of genes that shows only marginal changes in expression and consequently are considered to be devoid of any interest, plays an essential role in generating a global perturbation in self-organization directed toward the cell-fate change

  9. Synergistic anti-proliferative effects of gambogic acid with docetaxel in gastrointestinal cancer cell lines

    Directory of Open Access Journals (Sweden)

    Zou Zhengyun

    2012-04-01

    Full Text Available Summary Background Gambogic acid has a marked anti-tumor effect for gastric and colorectal cancers in vitro and in vivo. However, recent investigations on gambogic acid have focused mainly on mono-drug therapy, and its potential role in cancer therapy has not been comprehensively illustrated. This study aimed to assess the interaction between gambogic acid and docetaxel on human gastrointestinal cancer cells and to investigate the mechanism of gambogic acid plus docetaxel treatment-induced apoptotic cell death. Methods MTT assay was used to determine IC50 values in BGC-823, MKN-28, LOVO and SW-116 cells after gambogic acid and docetaxel administration. Median effect analysis was applied for determination of synergism and antagonism. Synergistic interaction between gambogic acid and docetaxel was evaluated using the combination index (CI method. Furthermore, cellular apoptosis was analyzed by Annexin-V and propidium iodide (PI double staining. Additionally, mRNA expression of drug-associated genes, i.e., β-tublin III and tau, and the apoptosis-related gene survivin, were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR. Results Gambogic acid provided a synergistic effect on the cytotoxicity induced by docetaxel in all four cell lines. The combined application of gambogic acid and docetaxel enhanced apoptosis in gastrointestinal cancer cells. Moreover, gambogic acid markedly decreased the mRNA expression of docetaxel-related genes, including β-tubulin III, tau and survivin, in BGC-823 cells. Conclusions Gambogic acid plus docetaxel produced a synergistic anti-tumor effect in gastrointestinal cancer cells, suggesting that the drug combination may offer a novel treatment option for patients with gastric and colorectal cancers.

  10. Effect of cyclin G2 on proliferative ability of prostate cancer PC-3 cell.

    Science.gov (United States)

    Cui, D W; Cheng, Y J; Jing, S W; Sun, G G

    2014-04-01

    This study aimed to analyze the expression, clinical significance of cyclin G2 (CCNG2) in prostate carcinoma, and the biological effect in its cell line by CCNG2 overexpression. Immunohistochemistry and Western blot were used to analyze CCNG2 protein expression in 85 cases of prostate cancer and normal tissues to study the relationship between CCNG2 expression and clinical factors. CCNG2 lentiviral vector and empty vector were, respectively, transfected into prostate cancer PC-3 cell line. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect the mRNA level and protein of CCNG2. MTT assay and cell cycle were also conducted as to the influence of the upregulated expression of CCNG2 that might be found on PC-3 cells biological effect. The level of CCNG2 protein expression was found to be significantly lower in prostate cancer tissue than normal tissues (P size (P lymph node metastasis, clinic stage, and Gleason score (P prostate cancer and correlated significantly with lymph node metastasis, clinic stage, and Gleason score, suggesting that CCNG2 may play important roles as a negative regulator to prostate cancer cell.

  11. CXCR4 expression in feline mammary carcinoma cells: evidence of a proliferative role for the SDF-1/CXCR4 axis

    Directory of Open Access Journals (Sweden)

    Ferrari Angelo

    2012-03-01

    Full Text Available Abstract Background Mammary tumours frequently develop in female domestic cats being highly malignant in a large percentage of cases. Chemokines regulate many physiological and pathological processes including organogenesis, chemotaxis of inflammatory cells, as well as tumour progression and metastasization. In particular, the chemokine/receptor pair SDF-1/CXCR4 has been involved in the regulation of metastatic potential of neoplastic cells, including breast cancer. The aim of this study was the immunohistochemical defininition of the expression profile of CXCR4 in primary and metastatic feline mammary carcinomas and the evaluation of the role of SDF-1 in feline mammary tumour cell proliferation. Results A total of 45 mammary surgical samples, including 33 primary tumours (31 carcinomas and 2 adenomas, 6 metastases, and 4 normal mammary tissues were anlyzed. Tumor samples were collected from a total number of 26 animals, as in some cases concurrent occurrence of neoplasm in more than one mammary gland was observed. Tissues were processed for standard histological examination, and all lesions were classified according to the World Health Organization criteria. CXCR4 expression in neoplastic cells was evaluated by immunohistochemistry. The level of CXCR4 immunoreactivity was semi-quantitatively estimated as CXCR4 score evaluating both the number of positive cells and the intensity of staining. Six primary, fibroblast-free primary cultures were obtained from fresh feline mammary carcinomas and characterized by immunofluorescence for CXCR4 and malignant mammary cell marker expression. SDF-1-dependent in vitro proliferative effects were also assayed. CXCR4 expression was observed in 29 out of 31 malignant tissues with a higher CXCR4 score observed in 4 out of 6 metastatic lesions than in the respective primary tumours. In 2 benign lesions analyzed, only the single basaloid adenoma showed a mild positive immunostaining against CXCR4. Normal tissue did

  12. Cell proliferative effect of polyxyloses extracted from the rhizomes of wild turmeric, Curcuma aromatica.

    Science.gov (United States)

    Niyomploy, Ploypat; Thunyakitpisal, Pasutha; Karnchanatat, Aphichart; Sangvanich, Polkit

    2010-08-01

    Hot water-soluble crude polysaccharides were extracted from the rhizomes of wild turmeric, Curcuma aromatica Salisb. (Zingiberaceae), using dry grinding, boiling water extraction, and then ethanol precipitation. The crude polysaccharide extract was then fractionated by DEAE-cellulose ion exchange column chromatography, and subsequently further purified by Superdex G-200 gel filtration column chromatography, giving two relatively abundant polysaccharide fractions, called P11 and P21, and a much less common fraction P22 obtained in insufficient amounts for further analysis. The two main polysaccharide fractions were evaluated for monosaccharide composition by acid hydrolysis and high performance liquid chromatography (HPLC), whilst the molecular weight and functional groups were determined by gel permeable chromatography (GPC) and FT-IR, respectively. Fractions P11 and P21 were found to be polyxyloses with molecular weight-averages of 469,171 and 157,665 Da, respectively. P11 (100 microg/mL) could significantly induce human gingival fibroblast cells proliferation by 30%, while P21 (100 microg/mL) could significantly inhibit gingival fibroblast cells proliferation by 92%. The in vitro human primary gingival fibroblast cell proliferation in cell culture at a concentration of 100 microg/mL.

  13. Evaluation of the proliferative activity of methanol extracts from six medicinal plants in murine spleen cells

    Directory of Open Access Journals (Sweden)

    Rodrigo Hermes Zandonai

    2010-06-01

    Full Text Available A number of natural compounds have been used as immunomodulatory agents, enabling the function of the immune system to be modified by stimulating or suppressing it. There has been increasing interest in the study of therapeutic action of plant extracts regarding their immunomodulatory activity. The aim of this study was to identify and evaluate the action of extracts of the medicinal plants Calophyllum brasiliense, Ipomoea pes-caprae, Matayba elaeagnoides, Maytenus robusta, Rubus imperialis and Vernonia scorpioides on the development of spleen cells from mice, using the in vitro cellular proliferation assay. The cells, obtained by mechanical rupture of mice spleen (5x10(4 cells/mL, were incubated with methanol extracts (10, 50, 100 and 200 µg/mL and phytohemagglutinin (PHA, 5 µg/mL. The basal control for proliferation consisted of cells alone, while the positive control consisted of cells and PHA. The cell culture was kept at 37 ºC in 5% CO2 for 72 hours, and cell proliferation was revealed by the blue tetrazolium reduction assay (MTT. The results were expressed as percentage of growth and were analyzed using the Kruskal-Wallis and Mann-Whitney tests. The C. brasiliense, I. pes-caprae and M. elaeagnoides extracts showed dose-dependent induction of cell proliferation, with a significant increase in cell proliferation (pVárias substâncias de origem natural têm sido utilizadas como agentes imunomoduladores, permitindo modificar a função do sistema imune e propiciando o estudo de atividades terapêuticas de extratos de plantas. Este trabalho objetivou identificar a atividade imunomodulatória dos extratos de seis plantas medicinais da flora brasileira, Calophyllum brasiliense, Ipomoea pes-caprae, Matayba elaeagnoides, Maytenus robusta, Rubus imperialis e Vernonia scorpioides, sobre a proliferação de células esplênicas de camundongos. As células esplênicas murinas obtidas por ruptura mecânica do baço (5x14³ células/mL foram

  14. Notch signaling and ghost cell fate in the calcifying cystig odontogenic tumor

    Directory of Open Access Journals (Sweden)

    Siar CH

    2011-11-01

    Full Text Available Abstract Notch signaling is an evolutionarily conserved mechanism that enables adjacent cells to adopt different fates. Ghost cells (GCs are anucleate cells with homogeneous pale eosinophilic cytoplasm and very pale to clear central areas (previous nucleus sites. Although GCs are present in a variety of odontogenic lesions notably the calcifying cystic odontogenic tumor (GCOT, their nature and process of formation remains elusive. The aim of this study was to investigate the role of Notch signaling in the cell fate specification of GCs in CCOT. Immunohistochemical staining for four Notch receptors (Notch1, Notch2, Notch3 and Notch4 and three ligands (Jagged1, Jagged2 and Delta1 was performed on archival tissues of five CCOT cases. Level of positivity was quantified as negative (0, mild (+, moderate (2+ and strong (3+. Results revealed that GCs demonstrated overexpression for Notch1 and Jagged1 suggesting that Notch1Jagged1 signaling might serve as the main transduction mechanism in cell fate decision for GCs in CCOT. Protein localizations were largely membranous and/or cytoplasmic. Mineralized GCs also stained positive implicating that the calcification process might be associated with upregulation of these molecules. The other Notch receptors and ligands were weak to absent in GCs and tumoral epithelium. Stromal endothelium and fibroblasts were stained variably positive.

  15. A new role of Klumpfuss in establishing cell fate during the GMC asymmetric cell division.

    Science.gov (United States)

    Gabilondo, Hugo; Losada-Pérez, María; Monedero, Ignacio; Torres-Herráez, Arturo; Molina, Isabel; Torroja, Laura; Benito-Sipos, Jonathan

    2014-11-01

    Studies in the Drosophila embryonic NB4-2 lineage have suggested that the transcription factor Klumpfuss (Klu) functions within embryonic neuroblast lineages to differentiate between the identities of two adjacent ganglion mother cells (GMCs). However, because of the limited lineage markers available, these observations have been made only for the NB4-2 lineage. Recent findings have placed this transcription factor in the vanguard of Drosophila neural stem cell biology by demonstrating that Klu is necessary for larval neuroblast growth and self-renewal. Here, we have studied the role of klu in an incipient model in order to address basic mechanisms of neural specification: the Va system. None of the previously reported roles of Klu satisfactorily explain our observations. Unexpectedly, in this lineage, klu is necessary for differentiating between the fates of the two neurons born from a unique GMC; klu mutants produce two B-type cells, rather than one B-type (Notch-OFF) and one A-type (Notch-ON) cell. Additionally, our results demonstrate that Klu operates in the GMC and/or in the newly born neuron, but not in the neuroblast. Unlike in larval neuroblasts in which Klu is an executor of Notch signaling, we have found that Klu does not lie downstream of the Notch pathway in this cell division context.

  16. Anti-Proliferative Effect of an Aqueous Extract of Prunella vulgaris in Vascular Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Sun Mi Hwang

    2013-01-01

    Full Text Available The abnormal proliferation of vascular smooth muscle cells (VSMCs in arterial walls is an important pathogenic factor of vascular disorders such as diabetic atherosclerosis. We have reported the anti-inflammatory effect of an aqueous extract from Prunella vulgaris (APV in vascular endothelial cell. In the present study, APV exhibited inhibitory effects on high glucose-stimulated VSMC proliferation, migration, and invasion activities, inducing G1 cell cycle arrest with downregulation of cyclins and CDKs and upregulation of the CKIs, p21waf1/cip1 and p27kip1. Furthermore, APV dose dependently suppressed the high glucose-induced matrix metalloproteinase activity. High glucose-induced phosphorylation of ERK, p38 MAPK, was decreased by the pretreatment of APV. NF-κB activation by high glucose was attenuated by APV, as an antioxidant. APV attenuated the high glucose-induced decrease of nuclear factor E2-related factor-2 (Nrf2 translocation and heme oxygenase-1 (HO-1 expression. Intracellular cGMP level was also increased by APV treatment. These results demonstrate that APV may inhibit VSMC proliferation via downregulating ROS/NF-κB /ERK/p38 MAPK pathways. In addition, APV has a beneficial effect by the interaction of Nrf2-mediated NO/cGMP with HO-1, suggesting that Prunella vulgaris may be useful in preventing diabetic atherosclerosis.

  17. Evolution of a system sensitive to stochastic noise: P3.p cell fate in Caenorhabditis.

    Science.gov (United States)

    Pénigault, Jean-Baptiste; Félix, Marie-Anne

    2011-09-15

    The C. elegans cell lineage is overall invariant. One rare instance of variability concerns P3.p, the most anterior vulva precursor cell, which may either fuse with the epidermis without dividing, or remain competent to form vulval tissue and divide. Here we examine the evolutionary properties of this stochastic variation in P3.p fate. In the Caenorhabditis genus, high P3.p competence is ancestral and reduction in P3.p competence and division frequency occurred in C. sp. 14 and in a clade of nine species. Within this clade, the frequency of P3.p division further varies within and among species, being intermediate in C. elegans and low in C. briggsae. P3.p fate frequency is sensitive to random mutation accumulation, suggesting that this trait may evolve rapidly because of its sensitivity to mutational impact. P3.p fate depends on LIN-39/Hox5 expression and we find that the peak of LIN-39/Hox5 protein level is displaced posteriorly in C. briggsae compared to C. elegans. However, P3.p fate specification is most sensitive to the dose of EGL-20 and CWN-1, two Wnts that are secreted in a long-range gradient from the posterior end of C. elegans larvae (accompanying article). A half-dose of either of these Wnts is sufficient to affect division frequency in C. elegans N2 to levels similar to those in C. briggsae. Symmetrically, we show that an increase in Wnt dose rescues anterior competence in C. briggsae. We propose that evolutionary variation in the concentration or interpretation of the long-range Wnt gradient may be involved in the rapid evolution of P3.p fate in Caenorhabditis.

  18. Regulation of cell-fate decisions in T lymphocyte differenttiation

    NARCIS (Netherlands)

    M.C. Nawijn (Martijn)

    2000-01-01

    textabstractThe acquisition of protective immunity is essential for survival. Protective itmllunity can be divided in innate immunity and acquired immunity. These two parts of the immune system have evolved to closely interact. Cells of the innate immune system, such as dendritic cells and macrophag

  19. Epigenetic inheritance of cell fates during embryonic development

    Directory of Open Access Journals (Sweden)

    Sirisha eCheedipudi

    2014-02-01

    Full Text Available During embryonic development a large number of widely differing and specialized cell types with identical genomes are generated from a single totipotent zygote. Tissue specific transcription factors cooperate with epigenetic modifiers to establish cellular identity in differentiated cells and epigenetic regulatory mechanisms contribute to the maintenance of distinct chromatin states and cell-type specific gene expression patterns, a phenomenon referred to as epigenetic memory. This is accomplished via the stable maintenance of various epigenetic marks through successive rounds of cell division. Preservation of DNA methylation patterns is a well established mechanism of epigenetic memory, but more recently it has become clear that many other epigenetic modifications can also be maintained following DNA replication and cell division. In this review, we present an overview of the current knowledge regarding the role of histone lysine methylation in the establishment and maintenance of stable epigenetic states.

  20. Elevated Levels of Cytokines Associated with Th2 and Th17 Cells in Vitreous Fluid of Proliferative Diabetic Retinopathy Patients.

    Directory of Open Access Journals (Sweden)

    Masaru Takeuchi

    Full Text Available Macrophages are involved in low-grade inflammation in diabetes, and play pathogenic roles in proliferative diabetic retinopathy (PDR by producing proinflammatory cytokines. T cells as well as other cells are also activated by proinflammatory cytokines, and infiltration into the vitreous of patients with PDR has been shown. In this study, we measured helper T (Th cell-related cytokines in the vitreous of PDR patients to define the characteristics of Th-mediated immune responses associated with PDR. The study group consisted of 25 type 2 diabetic patients (25 eyes with PDR. The control group consisted of 27 patients with epiretinal membrane (ERM, 26 patients with idiopathic macular hole (MH, and 26 patients with uveitis associated with sarcoidosis. Vitreous fluid was obtained at the beginning of vitrectomy, and centrifuging for cellular removals was not performed. Serum was also collected from PDR patients. IL-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, soluble sCD40L, and TNFα in the vitreous and serum samples were measured. Both percent detectable and levels of IL-4, IL-6, IL-17A, IL-21, IL-22, and TNFα in the vitreous were significantly higher than those in the serum in PDR patients. Vitreous levels of these cytokines and IL-31 were significantly higher in PDR than in ERM or MH patients. Vitreous levels of IL-4, IL-17A, IL-22, IL-31, and TNFα in PDR patients were also significantly higher than those of sarcoidosis patients. In PDR patients, vitreous IL-17A level correlated significantly with vitreous levels of IL-22 and IL-31, and especially with IL-4 and TNFα. Although it is unclear whether these cytokines play facilitative roles or inhibitory roles for the progression of PDR, the present study indicated that Th2- and Th17-related immune responses are involved in the pathogenesis of PDR.

  1. Elevated Levels of Cytokines Associated with Th2 and Th17 Cells in Vitreous Fluid of Proliferative Diabetic Retinopathy Patients.

    Science.gov (United States)

    Takeuchi, Masaru; Sato, Tomohito; Tanaka, Atsushi; Muraoka, Tadashi; Taguchi, Manzo; Sakurai, Yutaka; Karasawa, Yoko; Ito, Masataka

    2015-01-01

    Macrophages are involved in low-grade inflammation in diabetes, and play pathogenic roles in proliferative diabetic retinopathy (PDR) by producing proinflammatory cytokines. T cells as well as other cells are also activated by proinflammatory cytokines, and infiltration into the vitreous of patients with PDR has been shown. In this study, we measured helper T (Th) cell-related cytokines in the vitreous of PDR patients to define the characteristics of Th-mediated immune responses associated with PDR. The study group consisted of 25 type 2 diabetic patients (25 eyes) with PDR. The control group consisted of 27 patients with epiretinal membrane (ERM), 26 patients with idiopathic macular hole (MH), and 26 patients with uveitis associated with sarcoidosis. Vitreous fluid was obtained at the beginning of vitrectomy, and centrifuging for cellular removals was not performed. Serum was also collected from PDR patients. IL-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, soluble sCD40L, and TNFα in the vitreous and serum samples were measured. Both percent detectable and levels of IL-4, IL-6, IL-17A, IL-21, IL-22, and TNFα in the vitreous were significantly higher than those in the serum in PDR patients. Vitreous levels of these cytokines and IL-31 were significantly higher in PDR than in ERM or MH patients. Vitreous levels of IL-4, IL-17A, IL-22, IL-31, and TNFα in PDR patients were also significantly higher than those of sarcoidosis patients. In PDR patients, vitreous IL-17A level correlated significantly with vitreous levels of IL-22 and IL-31, and especially with IL-4 and TNFα. Although it is unclear whether these cytokines play facilitative roles or inhibitory roles for the progression of PDR, the present study indicated that Th2- and Th17-related immune responses are involved in the pathogenesis of PDR.

  2. Insulin-independent GLUT4 translocation in proliferative vascular smooth muscle cells involves SM22α.

    Science.gov (United States)

    Zhao, Li-Li; Zhang, Fan; Chen, Peng; Xie, Xiao-Li; Dou, Yong-Qing; Lin, Yan-Ling; Nie, Lei; Lv, Pin; Zhang, Dan-Dan; Li, Xiao-Kun; Miao, Sui-Bing; Yin, Ya-Juan; Dong, Li-Hua; Song, Yu; Shu, Ya-Nan; Han, Mei

    2017-02-01

    The insulin-sensitive glucose transporter 4 (GLUT4) is a predominant facilitative glucose transporter in vascular smooth muscle cells (VSMCs) and is significantly upregulated in rabbit neointima. This study investigated the role of GLUT4 in VSMC proliferation, the cellular mechanism underlying PDGF-BB-stimulated GLUT4 translocation, and effects of SM22α, an actin-binding protein, on this process. Chronic treatment of VSMCs with PDGF-BB significantly elevated GLUT4 expression and glucose uptake. PDGF-BB-induced VSMC proliferation was dependent on GLUT4-mediated glucose uptake. Meanwhile, the response of GLUT4 to insulin decreased in PDGF-BB-stimulated VSMCs. PDGF-BB-induced GLUT4 translocation partially rescued glucose utilization in insulin-resistant cells. Immunofluorescence and western blot analysis revealed that PDGF-BB induced GLUT4 translocation in an actin dynamics-dependent manner. SM22α disruption facilitated GLUT4 translocation and glucose uptake by promoting actin dynamics and cortical actin polymerization. Similar results were observed in VSMCs of SM22α (-/-) mice. The in vivo experiments showed that the glucose level in the neointima induced by ligation was significantly increased in SM22α (-/-) mice, accompanied by increased neointimal thickness, compared with those in wild-type mice. These findings suggest that GLUT4-mediated glucose uptake is involved in VSMC proliferation, and provide a novel link between SM22α and glucose utilization in PDGF-BB-triggered proliferation.

  3. Matrix mechanics and fluid shear stress control stem cells fate in three dimensional microenvironment.

    Science.gov (United States)

    Chen, Guobao; Lv, Yonggang; Guo, Pan; Lin, Chongwen; Zhang, Xiaomei; Yang, Li; Xu, Zhiling

    2013-07-01

    Stem cells have the ability to self-renew and to differentiate into multiple mature cell types during early life and growth. Stem cells adhesion, proliferation, migration and differentiation are affected by biochemical, mechanical and physical surface properties of the surrounding matrix in which stem cells reside and stem cells can sensitively feel and respond to the microenvironment of this matrix. More and more researches have proven that three dimensional (3D) culture can reduce the gap between cell culture and physiological environment where cells always live in vivo. This review summarized recent findings on the studies of matrix mechanics that control stem cells (primarily mesenchymal stem cells (MSCs)) fate in 3D environment, including matrix stiffness and extracellular matrix (ECM) stiffness. Considering the exchange of oxygen and nutrients in 3D culture, the effect of fluid shear stress (FSS) on fate decision of stem cells was also discussed in detail. Further, the difference of MSCs response to matrix stiffness between two dimensional (2D) and 3D conditions was compared. Finally, the mechanism of mechanotransduction of stem cells activated by matrix mechanics and FSS in 3D culture was briefly pointed out.

  4. Sox5 functions as a fate switch in medaka pigment cell development.

    Directory of Open Access Journals (Sweden)

    Yusuke Nagao

    2014-04-01

    Full Text Available Mechanisms generating diverse cell types from multipotent progenitors are crucial for normal development. Neural crest cells (NCCs are multipotent stem cells that give rise to numerous cell-types, including pigment cells. Medaka has four types of NCC-derived pigment cells (xanthophores, leucophores, melanophores and iridophores, making medaka pigment cell development an excellent model for studying the mechanisms controlling specification of distinct cell types from a multipotent progenitor. Medaka many leucophores-3 (ml-3 mutant embryos exhibit a unique phenotype characterized by excessive formation of leucophores and absence of xanthophores. We show that ml-3 encodes sox5, which is expressed in premigratory NCCs and differentiating xanthophores. Cell transplantation studies reveal a cell-autonomous role of sox5 in the xanthophore lineage. pax7a is expressed in NCCs and required for both xanthophore and leucophore lineages; we demonstrate that Sox5 functions downstream of Pax7a. We propose a model in which multipotent NCCs first give rise to pax7a-positive partially fate-restricted intermediate progenitors for xanthophores and leucophores; some of these progenitors then express sox5, and as a result of Sox5 action develop into xanthophores. Our results provide the first demonstration that Sox5 can function as a molecular switch driving specification of a specific cell-fate (xanthophore from a partially-restricted, but still multipotent, progenitor (the shared xanthophore-leucophore progenitor.

  5. Laminins affect T cell trafficking and allograft fate.

    Science.gov (United States)

    Warren, Kristi J; Iwami, Daiki; Harris, Donald G; Bromberg, Jonathan S; Burrell, Bryna E

    2014-05-01

    Lymph nodes (LNs) are integral sites for the generation of immune tolerance, migration of CD4⁺ T cells, and induction of Tregs. Despite the importance of LNs in regulation of inflammatory responses, the LN-specific factors that regulate T cell migration and the precise LN structural domains in which differentiation occurs remain undefined. Using intravital and fluorescent microscopy, we found that alloreactive T cells traffic distinctly into the tolerant LN and colocalize in exclusive regions with alloantigen-presenting cells, a process required for Treg induction. Extracellular matrix proteins, including those of the laminin family, formed regions within the LN that were permissive for colocalization of alloantigen-presenting cells, alloreactive T cells, and Tregs. We identified unique expression patterns of laminin proteins in high endothelial venule basement membranes and the cortical ridge that correlated with alloantigen-specific immunity or immune tolerance. The ratio of laminin α4 to laminin α5 was greater in domains within tolerant LNs, compared with immune LNs, and blocking laminin α4 function or inducing laminin α5 overexpression disrupted T cell and DC localization and transmigration through tolerant LNs. Furthermore, reducing α4 laminin circumvented tolerance induction and induced cardiac allograft inflammation and rejection in murine models. This work identifies laminins as potential targets for immune modulation.

  6. Mark the transition: chromatin modifications and cell fate decision

    Institute of Scientific and Technical Information of China (English)

    Qiang Wu; Huck-Hui Ng

    2011-01-01

    With their unique features of selfrenewal and pluripotency,human embryonic stem (hES) cells are considered to be a nearly unlimited resource for research and clinical applications [1].Accordingly,the transcriptional network specifying and governing human ES cell identity has been extensively studied.OCT4,NANOG and SOX2 form a core transcriptional network that regulates itself as well as a number of target genes [2].This transcriptional network acts together with signaling pathways to maintain ES cell identity [3].Moreover,the last decade has seen tremendous advances in understanding the epigenetic mechanisms underlying ES eell self-renewal and pluripotency.

  7. Retinoic acid, meiosis and germ cell fate in mammals.

    Science.gov (United States)

    Bowles, Josephine; Koopman, Peter

    2007-10-01

    Although mammalian sex is determined genetically, the sex-specific development of germ cells as sperm or oocytes is initiated by cues provided by the gonadal environment. During embryogenesis, germ cells in an ovary enter meiosis, thereby committing to oogenesis. By contrast, germ cells in a testicular environment do not enter meiosis until puberty. Recent findings indicate that the key to this sex-specific timing of meiosis entry is the presence or absence of the signaling molecule retinoic acid. Although this knowledge clarifies a long-standing mystery in reproductive biology, it also poses many new questions, which we discuss in this review.

  8. Concentration Sensing by the Moving Nucleus in Cell Fate Determination: A Computational Analysis.

    Directory of Open Access Journals (Sweden)

    Varun Aggarwal

    Full Text Available During development of the vertebrate neuroepithelium, the nucleus in neural progenitor cells (NPCs moves from the apex toward the base and returns to the apex (called interkinetic nuclear migration at which point the cell divides. The fate of the resulting daughter cells is thought to depend on the sampling by the moving nucleus of a spatial concentration profile of the cytoplasmic Notch intracellular domain (NICD. However, the nucleus executes complex stochastic motions including random waiting and back and forth motions, which can expose the nucleus to randomly varying levels of cytoplasmic NICD. How nuclear position can determine daughter cell fate despite the stochastic nature of nuclear migration is not clear. Here we derived a mathematical model for reaction, diffusion, and nuclear accumulation of NICD in NPCs during interkinetic nuclear migration (INM. Using experimentally measured trajectory-dependent probabilities of nuclear turning, nuclear waiting times and average nuclear speeds in NPCs in the developing zebrafish retina, we performed stochastic simulations to compute the nuclear trajectory-dependent probabilities of NPC differentiation. Comparison with experimentally measured nuclear NICD concentrations and trajectory-dependent probabilities of differentiation allowed estimation of the NICD cytoplasmic gradient. Spatially polarized production of NICD, rapid NICD cytoplasmic consumption and the time-averaging effect of nuclear import/export kinetics are sufficient to explain the experimentally observed differentiation probabilities. Our computational studies lend quantitative support to the feasibility of the nuclear concentration-sensing mechanism for NPC fate determination in zebrafish retina.

  9. Evidence for a critical role of gene occlusion in cell fate restriction

    Institute of Scientific and Technical Information of China (English)

    Jedidiah Gaetz; Wei-Hua Yu; Andy Peng Xiang; Bruce T Lahn; Kayla L Clift; Croydon J Fernandes; Frank Fuxiang Mao; Jae Hyun Lee; Li Zhang; Samuel W Baker; Timothy J Looney; Kara M Foshay

    2012-01-01

    The progressive restriction of cell fate during lineage differentiation is a poorly understood phenomenon despite its ubiquity in multicellular organisms.We recently used a cell fusion assay to define a mode of epigenetic silencing that we termed "occlusion",wherein affected genes are silenced by cis-acting chromatin mechanisms irrespective of whether trans-acting transcriptional activators are present.We hypothesized that occlusion of lineage-inappropriate genes could contribute to cell fate restriction.Here,we test this hypothesis by introducing bacterial artificial chromosomes (BACs),which are devoid of chromatin modifications necessary for occlusion,into mouse fibroblasts.We found that BAC transgenes corresponding to occluded endogenous genes are expressed in most eases,whereas BAC transgenes corresponding to silent but non-occluded endogenous genes are not expressed.This indicates that the cellular milieu in trans supports the expression of most occluded genes in fibroblasts,and that the silent state of these genes is solely the consequence of occlusion in cis.For the BAC corresponding to the occluded myogenic master regulator Myf5,expression of the Myf5 transgene on the BAC triggered fibroblasts to acquire a muscle-like phenotype.These results provide compelling evidence for a critical role of gene occlusion in cell fate restriction.

  10. Highly proliferative primitive fetal liver hematopoietic stem cells are fueled by oxidative metabolic pathways

    Directory of Open Access Journals (Sweden)

    Javed K. Manesia

    2015-11-01

    Full Text Available Hematopoietic stem cells (HSCs in the fetal liver (FL unlike adult bone marrow (BM proliferate extensively, posing different metabolic demands. However, metabolic pathways responsible for the production of energy and cellular building blocks in FL HSCs have not been described. Here, we report that FL HSCs use oxygen dependent energy generating pathways significantly more than their BM counterparts. RNA-Seq analysis of E14.5 FL versus BM derived HSCs identified increased expression levels of genes involved in oxidative phosphorylation (OxPhos and the citric acid cycle (TCA. We demonstrated that FL HSCs contain more mitochondria than BM HSCs, which resulted in increased levels of oxygen consumption and reactive oxygen species (ROS production. Higher levels of DNA repair and antioxidant pathway gene expression may prevent ROS-mediated (genotoxicity in FL HSCs. Thus, we here for the first time highlight the underestimated importance of oxygen dependent pathways for generating energy and building blocks in FL HSCs.

  11. Highly proliferative primitive fetal liver hematopoietic stem cells are fueled by oxidative metabolic pathways.

    Science.gov (United States)

    Manesia, Javed K; Xu, Zhuofei; Broekaert, Dorien; Boon, Ruben; van Vliet, Alex; Eelen, Guy; Vanwelden, Thomas; Stegen, Steve; Van Gastel, Nick; Pascual-Montano, Alberto; Fendt, Sarah-Maria; Carmeliet, Geert; Carmeliet, Peter; Khurana, Satish; Verfaillie, Catherine M

    2015-11-01

    Hematopoietic stem cells (HSCs) in the fetal liver (FL) unlike adult bone marrow (BM) proliferate extensively, posing different metabolic demands. However, metabolic pathways responsible for the production of energy and cellular building blocks in FL HSCs have not been described. Here, we report that FL HSCs use oxygen dependent energy generating pathways significantly more than their BM counterparts. RNA-Seq analysis of E14.5 FL versus BM derived HSCs identified increased expression levels of genes involved in oxidative phosphorylation (OxPhos) and the citric acid cycle (TCA). We demonstrated that FL HSCs contain more mitochondria than BM HSCs, which resulted in increased levels of oxygen consumption and reactive oxygen species (ROS) production. Higher levels of DNA repair and antioxidant pathway gene expression may prevent ROS-mediated (geno)toxicity in FL HSCs. Thus, we here for the first time highlight the underestimated importance of oxygen dependent pathways for generating energy and building blocks in FL HSCs.

  12. Changes in the proliferative activity of hippocampal neural stem cells from manganismus mice

    Institute of Scientific and Technical Information of China (English)

    Guohe Tan; Boning Yang; Guofu Tan; Bo Liang; Jiangu Gong; Xiaodong Ge; Songchao Guo

    2007-01-01

    BACKGROUND: Manganese neurotoxicity presents in the form of not only extracorticospinal tract injury of central nervous system (CNS), but also learning and memory ability damage. So, the mechanism of manganese neurotoxicity will be further studied from the angle ofhippocampus.OBJECTIVE: To observe the effects of manganism on learning and memory ability and the proliferation of neural stem cells (NSCs) in hippocampus of mouse brains, and analyze whether this effect has dose-dependence.DESIGN: Randomized controlled experiment.SETTING: Department of Human Anatomy, and Department of Industrial Hygiene and Occupational Diseases, Guangxi Medical University.MATERIALS: Twenty-eight male Kunming mice, aged 2 weeks, were involved in this experiment. The involved mice were randomized into 4 groups, with 7 in each: control group, low-dose manganism group,middle-dose manganism group and high-dose manganism group. Manganese chloride was purchased from Shantou Chemicals Factory.METHODS: This experiment was carried out in the Experimental Center for Preclinical Medicine, Guangxi Medical University from November 2005 to August 2006. Mice in the low-, middle- and high-dose manganism groups were intraperitoneally injected with 5, 20 and 50 mg/kg per day manganese chloride, once a day, for 2 weeks successively. Mice in the control group were injected with the same amount of stroke-physiological saline solution. Neurobehavioral detection of all the animals was performed in Morris water maze constantly from the 7th day after the first injection of manganese chloride solution. Learning ability was detected in the place navigation test. Mice were trained for 5 consecutive days with four trials per day. The time to find the platform was latency. Memory ability was detected in spatial probe test. Platform was withdrawn on the following day of place navigation. The mice were placed in the water from a random start in the edge of the pool. The number of times they traversed the plateform

  13. Transcription factors regulating B cell fate in the germinal centre.

    Science.gov (United States)

    Recaldin, T; Fear, D J

    2016-01-01

    Diversification of the antibody repertoire is essential for the normal operation of the vertebrate adaptive immune system. Following antigen encounter, B cells are activated, proliferate rapidly and undergo two diversification events; somatic hypermutation (followed by selection), which enhances the affinity of the antibody for its cognate antigen, and class-switch recombination, which alters the effector functions of the antibody to adapt the response to the challenge faced. B cells must then differentiate into antibody-secreting plasma cells or long-lived memory B cells. These activities take place in specialized immunological environments called germinal centres, usually located in the secondary lymphoid organs. To complete the germinal centre activities successfully, a B cell adopts a transcriptional programme that allows it to migrate to specific sites within the germinal centre, proliferate, modify its DNA recombination and repair pathways, alter its apoptotic potential and finally undergo terminal differentiation. To co-ordinate these processes, B cells employ a number of 'master regulator' transcription factors which mediate wholesale transcriptomic changes. These master transcription factors are mutually antagonistic and form a complex regulatory network to maintain distinct gene expression programs. Within this network, multiple points of positive and negative feedback ensure the expression of the 'master regulators', augmented by a number of 'secondary' factors that reinforce these networks and sense the progress of the immune response. In this review we will discuss the different activities B cells must undertake to mount a successful T cell-dependent immune response and describe how a regulatory network of transcription factors controls these processes.

  14. Ptf1a triggers GABAergic neuronal cell fates in the retina

    Directory of Open Access Journals (Sweden)

    Parain Karine

    2007-10-01

    Full Text Available Abstract Background In recent years, considerable knowledge has been gained on the molecular mechanisms underlying retinal cell fate specification. However, hitherto studies focused primarily on the six major retinal cell classes (five types of neurons of one type of glial cell, and paid little attention to the specification of different neuronal subtypes within the same cell class. In particular, the molecular machinery governing the specification of the two most abundant neurotransmitter phenotypes in the retina, GABAergic and glutamatergic, is largely unknown. In the spinal cord and cerebellum, the transcription factor Ptf1a is essential for GABAergic neuron production. In the mouse retina, Ptf1a has been shown to be involved in horizontal and most amacrine neurons differentiation. Results In this study, we examined the distribution of neurotransmitter subtypes following Ptf1a gain and loss of function in the Xenopus retina. We found cell-autonomous dramatic switches between GABAergic and glutamatergic neuron production, concomitant with profound defects in the genesis of amacrine and horizontal cells, which are mainly GABAergic. Therefore, we investigated whether Ptf1a promotes the fate of these two cell types or acts directly as a GABAergic subtype determination factor. In ectodermal explant assays, Ptf1a was found to be a potent inducer of the GABAergic subtype. Moreover, clonal analysis in the retina revealed that Ptf1a overexpression leads to an increased ratio of GABAergic subtypes among the whole amacrine and horizontal cell population, highlighting its instructive capacity to promote this specific subtype of inhibitory neurons. Finally, we also found that within bipolar cells, which are typically glutamatergic interneurons, Ptf1a is able to trigger a GABAergic fate. Conclusion Altogether, our results reveal for the first time in the retina a major player in the GABAergic versus glutamatergic cell specification genetic pathway.

  15. Fate of cerium dioxide nanoparticles in endothelial cells: exocytosis

    Energy Technology Data Exchange (ETDEWEB)

    Strobel, Claudia, E-mail: Claudia.Strobel@med.uni-jena.de [Jena University Hospital – Friedrich Schiller University Jena, Department of Experimental Radiology, Institute of Diagnostic and Interventional Radiology (Germany); Oehring, Hartmut [Jena University Hospital – Friedrich Schiller University Jena, Institute of Anatomy II (Germany); Herrmann, Rudolf [University of Augsburg, Department of Physics (Germany); Förster, Martin [Jena University Hospital – Friedrich Schiller University Jena, Department of Internal Medicine I, Division of Pulmonary Medicine and Allergy/Immunology (Germany); Reller, Armin [University of Augsburg, Department of Physics (Germany); Hilger, Ingrid, E-mail: ingrid.hilger@med.uni-jena.de [Jena University Hospital – Friedrich Schiller University Jena, Department of Experimental Radiology, Institute of Diagnostic and Interventional Radiology (Germany)

    2015-05-15

    Although cytotoxicity and endocytosis of nanoparticles have been the subject of numerous studies, investigations regarding exocytosis as an important mechanism to reduce intracellular nanoparticle accumulation are rather rare and there is a distinct lack of knowledge. The current study investigated the behavior of human microvascular endothelial cells to exocytose cerium dioxide (CeO{sub 2}) nanoparticles (18.8 nm) by utilization of specific inhibitors [brefeldin A; nocodazole; methyl-β-cyclodextrin (MβcD)] and different analytical methods (flow cytometry, transmission electron microscopy, inductively coupled plasma mass spectrometry). Overall, it was found that endothelial cells were able to release CeO{sub 2} nanoparticles via exocytosis after the migration of nanoparticle containing endosomes toward the plasma membrane. The exocytosis process occurred mainly by fusion of vesicular membranes with plasma membrane resulting in the discharge of vesicular content to extracellular environment. Nevertheless, it seems to be likely that nanoparticles present in the cytosol could leave the cells in a direct manner. MβcD treatment led to the strongest inhibition of the nanoparticle exocytosis indicating a significant role of the plasma membrane cholesterol content in the exocytosis process. Brefeldin A (inhibitor of Golgi-to-cell-surface-transport) caused a higher inhibitory effect on exocytosis than nocodazole (inhibitor of microtubules). Thus, the transfer from distal Golgi compartments to the cell surface influenced the exocytosis process of the CeO{sub 2} nanoparticles more than the microtubule-associated transport. In conclusion, endothelial cells, which came in contact with nanoparticles, e.g., after intravenously applied nano-based drugs, can regulate their intracellular nanoparticle amount, which is necessary to avoid adverse nanoparticle effects on cells.

  16. Putting it all on pigmentation: Heuristics of a bold and stochastic cell fate decision.

    Science.gov (United States)

    Xing, Jianhua; Lee, Robin E C

    2015-10-06

    Gradients of transmembrane potential coordinate cell-fate decisions and patterning during embryogenesis and wound-healing. Bioelectrical signaling may also be more important for adult pathologies than currently recognized. In this issue of Science Signaling, Lobikin et al. describe a role for bioelectric signals during the development of Xenopus leavis embryos to instruct an organism-level response reminiscent of neoplastic progression in melanoma.

  17. Anti-proliferative effects of raw and steamed extracts of Panax notoginseng and its ginsenoside constituents on human liver cancer cells

    Directory of Open Access Journals (Sweden)

    Neo Soek-Ying

    2011-01-01

    Full Text Available Abstract Background Panax notoginseng is a potential source of anticancer compounds. This study aims to investigate the effects of steaming on the chemical profile of P. notoginseng and the anti-proliferative effects of P. notoginseng on liver cancer cells. Methods Samples of powdered raw P. notoginseng roots were steamed for various durations. Extracts of the raw and steamed samples were subjected to ultra-high pressure liquid chromatography/mass spectrometry (UHPLC-MS analysis for chemical profiling. The anti-proliferative effects on three human liver cancer cells, namely SNU449, SNU182 and HepG2, were evaluated using colorimetric WST-1 assay. Results Steaming changed chromatographic and pharmacological profiles of P. notoginseng, causing differences in activities such as inhibition of cancer growth. Steamed P. notoginseng exhibited greater anti-proliferative effects against liver cancer cells (SNU449, SNU182 and HepG2 than its raw form; steaming up to 24 hours increased bioactivities. Steaming increased the concentrations of ginsenoside Rh2, Rk1, Rk3 and 20S-Rg3 and enhanced growth inhibition of liver cancer cells. Conclusion Steaming changes the chemical profile as well as anti-cancer biological activities of P. notoginseng. Steamed P. notoginseng contains potential compounds for the treatment of liver cancer.

  18. GLD-4-mediated translational activation regulates the size of the proliferative germ cell pool in the adult C. elegans germ line.

    Science.gov (United States)

    Millonigg, Sophia; Minasaki, Ryuji; Nousch, Marco; Novak, Jakub; Eckmann, Christian R

    2014-09-01

    To avoid organ dysfunction as a consequence of tissue diminution or tumorous growth, a tight balance between cell proliferation and differentiation is maintained in metazoans. However, cell-intrinsic gene expression mechanisms controlling adult tissue homeostasis remain poorly understood. By focusing on the adult Caenorhabditis elegans reproductive tissue, we show that translational activation of mRNAs is a fundamental mechanism to maintain tissue homeostasis. Our genetic experiments identified the Trf4/5-type cytoplasmic poly(A) polymerase (cytoPAP) GLD-4 and its enzymatic activator GLS-1 to perform a dual role in regulating the size of the proliferative zone. Consistent with a ubiquitous expression of GLD-4 cytoPAP in proliferative germ cells, its genetic activity is required to maintain a robust proliferative adult germ cell pool, presumably by regulating many mRNA targets encoding proliferation-promoting factors. Based on translational reporters and endogenous protein expression analyses, we found that gld-4 activity promotes GLP-1/Notch receptor expression, an essential factor of continued germ cell proliferation. RNA-protein interaction assays documented also a physical association of the GLD-4/GLS-1 cytoPAP complex with glp-1 mRNA, and ribosomal fractionation studies established that GLD-4 cytoPAP activity facilitates translational efficiency of glp-1 mRNA. Moreover, we found that in proliferative cells the differentiation-promoting factor, GLD-2 cytoPAP, is translationally repressed by the stem cell factor and PUF-type RNA-binding protein, FBF. This suggests that cytoPAP-mediated translational activation of proliferation-promoting factors, paired with PUF-mediated translational repression of differentiation factors, forms a translational control circuit that expands the proliferative germ cell pool. Our additional genetic experiments uncovered that the GLD-4/GLS-1 cytoPAP complex promotes also differentiation, forming a redundant translational circuit with

  19. GLD-4-mediated translational activation regulates the size of the proliferative germ cell pool in the adult C. elegans germ line.

    Directory of Open Access Journals (Sweden)

    Sophia Millonigg

    2014-09-01

    Full Text Available To avoid organ dysfunction as a consequence of tissue diminution or tumorous growth, a tight balance between cell proliferation and differentiation is maintained in metazoans. However, cell-intrinsic gene expression mechanisms controlling adult tissue homeostasis remain poorly understood. By focusing on the adult Caenorhabditis elegans reproductive tissue, we show that translational activation of mRNAs is a fundamental mechanism to maintain tissue homeostasis. Our genetic experiments identified the Trf4/5-type cytoplasmic poly(A polymerase (cytoPAP GLD-4 and its enzymatic activator GLS-1 to perform a dual role in regulating the size of the proliferative zone. Consistent with a ubiquitous expression of GLD-4 cytoPAP in proliferative germ cells, its genetic activity is required to maintain a robust proliferative adult germ cell pool, presumably by regulating many mRNA targets encoding proliferation-promoting factors. Based on translational reporters and endogenous protein expression analyses, we found that gld-4 activity promotes GLP-1/Notch receptor expression, an essential factor of continued germ cell proliferation. RNA-protein interaction assays documented also a physical association of the GLD-4/GLS-1 cytoPAP complex with glp-1 mRNA, and ribosomal fractionation studies established that GLD-4 cytoPAP activity facilitates translational efficiency of glp-1 mRNA. Moreover, we found that in proliferative cells the differentiation-promoting factor, GLD-2 cytoPAP, is translationally repressed by the stem cell factor and PUF-type RNA-binding protein, FBF. This suggests that cytoPAP-mediated translational activation of proliferation-promoting factors, paired with PUF-mediated translational repression of differentiation factors, forms a translational control circuit that expands the proliferative germ cell pool. Our additional genetic experiments uncovered that the GLD-4/GLS-1 cytoPAP complex promotes also differentiation, forming a redundant

  20. Microspore embryogenesis: reprogramming cell fate from pollen to embryo development

    NARCIS (Netherlands)

    Hui Li,

    2014-01-01

    Microspore embryogenesis is an expression of plant cell totipotency that leads to the production of haploid embryos. Besides being a widely exploited plant breeding tool, microspore embryogenesis is also a fascinating system that can be used to obtain a deeper mechanistic understanding of plant toti

  1. Influence of dietary supplementation with flaxseed and lactobacilli on the mucosal morphology and proliferative cell rate in the jejunal mucosa of piglets after weaning.

    Science.gov (United States)

    Jonecova, Zuzana; Toth, Stefan; Ciccocioppo, Rachele; Rodrigo, Luis; Kruzliak, Peter; Nemcova, Radomira

    2015-06-01

    The aim of the study was to investigate the influence of flaxseed and lactobacilli supplementation to the diet of piglets during the time period between 10 days before and 21 days after weaning. The morphometry of the jejunal mucosa and proliferative ratio of both epithelial and lamina propria cells were compared with those found in a group of piglets fed with the usual diet added with sunflower oil during the same time period. The addition of flaxseed oil to the diet significantly increased the crypt depth in comparison with both groups supplemented with sunflower (P lactobacilli showed significantly lower proliferative activity in the connective tissue cells from weaning up to 7 days after weaning (P < 0.05 all) in comparison with the flaxseed group.

  2. Oriented growth and transdifferentiation of mesenchymal stem cells towards a Schwann cell fate on micropatterned substrates.

    Science.gov (United States)

    Sharma, Anup D; Zbarska, Svitlana; Petersen, Emma M; Marti, Mustafa E; Mallapragada, Surya K; Sakaguchi, Donald S

    2016-03-01

    While Schwann cells (SCs) have a significant role in peripheral nerve regeneration, their use in treatments has been limited because of lack of a readily available source. To address this issue, this study focused on the effect of guidance cues by employing micropatterned polymeric films to influence the alignment, morphology and transdifferentiation of bone marrow-derived rat mesenchymal stem cells (MSCs) towards a Schwann cell-like fate. Two different types of polymers, biocompatible polystyrene (PS) and biodegradable poly(lactic acid) (PLA) were used to fabricate patterned films. Percentages of transdifferentiated MSCs (tMSCs) immunolabeled with SC markers (α-S100β and α-p75(NTR)) were found to be similar on patterned versus smooth PS and PLA substrates. However, patterning had a significant effect on the alignment and elongation of the tMSCs. More than 80% of the tMSCs were oriented in the direction of microgrooves (0°-20°), while cells on the smooth substrates were randomly oriented. The aspect ratio [AR, ratio of length (in direction of microgrooves) and breadth (in direction perpendicular to microgrooves)] of the tMSCs on patterned substrates had a value of approximately five, as compared to cells on smooth substrates where the AR was one. Understanding responses to these cues in vitro helps us in understanding the behavior and interaction of the cells with the 3D environment of the scaffolds, facilitating the application of these concepts to designing effective nerve guidance conduits for peripheral nerve regeneration.

  3. The C. elegans LIM homeobox gene lin-11 specifies multiple cell fates during vulval development.

    Science.gov (United States)

    Gupta, Bhagwati P; Wang, Minqin; Sternberg, Paul W

    2003-06-01

    LIM homeobox family members regulate a variety of cell fate choices during animal development. In C. elegans, mutations in the LIM homeobox gene lin-11 have previously been shown to alter the cell division pattern of a subset of the 2 degrees lineage vulval cells. We demonstrate multiple functions of lin-11 during vulval development. We examined the fate of vulval cells in lin-11 mutant animals using five cellular markers and found that lin-11 is necessary for the patterning of both 1 degrees and 2 degrees lineage cells. In the absence of lin-11 function, vulval cells fail to acquire correct identity and inappropriately fuse with each other. The expression pattern of lin-11 reveals dynamic changes during development. Using a temporally controlled overexpression system, we show that lin-11 is initially required in vulval cells for establishing the correct invagination pattern. This process involves asymmetric expression of lin-11 in the 2 degrees lineage cells. Using a conditional RNAi approach, we show that lin-11 regulates vulval morphogenesis. Finally, we show that LDB-1, a NLI/Ldb1/CLIM2 family member, interacts physically with LIN-11, and is necessary for vulval morphogenesis. Together, these findings demonstrate that temporal regulation of lin-11 is crucial for the wild-type vulval patterning.

  4. Laminopathies disrupt epigenomic developmental programs and cell fate.

    Science.gov (United States)

    Perovanovic, Jelena; Dell'Orso, Stefania; Gnochi, Viola F; Jaiswal, Jyoti K; Sartorelli, Vittorio; Vigouroux, Corinne; Mamchaoui, Kamel; Mouly, Vincent; Bonne, Gisèle; Hoffman, Eric P

    2016-04-20

    The nuclear envelope protein lamin A is encoded by thelamin A/C(LMNA) gene, which can contain missense mutations that cause Emery-Dreifuss muscular dystrophy (EDMD) (p.R453W). We fused mutated forms of the lamin A protein to bacterial DNA adenine methyltransferase (Dam) to define euchromatic-heterochromatin (epigenomic) transitions at the nuclear envelope during myogenesis (using DamID-seq). Lamin A missense mutations disrupted appropriate formation of lamin A-associated heterochromatin domains in an allele-specific manner-findings that were confirmed by chromatin immunoprecipitation-DNA sequencing (ChIP-seq) in murine H2K cells and DNA methylation studies in fibroblasts from muscular dystrophy patient who carried a distinctLMNAmutation (p.H222P). Observed perturbations of the epigenomic transitions included exit from pluripotency and cell cycle programs [euchromatin (open, transcribed) to heterochromatin (closed, silent)], as well as induction of myogenic loci (heterochromatin to euchromatin). In muscle biopsies from patients with either a gain- or change-of-functionLMNAgene mutation or a loss-of-function mutation in theemeringene, both of which cause EDMD, we observed inappropriate loss of heterochromatin formation at theSox2pluripotency locus, which was associated with persistent mRNA expression ofSox2 Overexpression ofSox2inhibited myogenic differentiation in human immortalized myoblasts. Our findings suggest that nuclear envelopathies are disorders of developmental epigenetic programming that result from altered formation of lamina-associated domains.

  5. Fate study of water-borne gram positive vegetative bacterial cells with Raman microscopy

    Science.gov (United States)

    Guicheteau, Jason; Tripathi, Ashish; Minter, Jennifer; Wilcox, Phillip; Christesen, Steven

    2010-04-01

    We present an initial bacterial fate study of Gram positive vegetative cells suspended in water and stored at ambient room temperature via Raman spectroscopy monitoring. Two types of cells were considered for this study: vegetative cells of Bacillus cereus, Bacillus thuringiensis which contain the polyhydroxybutyric acid (PHBA) as an energy storage compound and Bacillus subtlilis cells which do not. The cells were cultured specifically for this project. Immediately following the culturing phase, the bacteria were extracted, cleaned and at the onset of the study were suspended in de-ionized water and stored at room temperature. Aliquots of suspensions were deposited onto aluminum slides at different times and allowed to dry for Raman analysis. Spectra from multiple regions of each dried spot and each deposit time were acquired along with the bright-field and fluorescence images. Results were examined to investigate the effect of suspension time on the spectral signatures as well as the fate behavior of the three types of cells investigated. The cells were monitored daily for over a 14 period during which time the onset of starvation induced sporulation was observed.

  6. Polish natural bee honeys are anti-proliferative and anti-metastatic agents in human glioblastoma multiforme U87MG cell line.

    Directory of Open Access Journals (Sweden)

    Justyna Moskwa

    Full Text Available Honey has been used as food and a traditional medicament since ancient times. However, recently many scientists have been concentrating on the anti-oxidant, anti-proliferative, anti-inflammatory and other properties of honey. In this study, we investigated for the first time an anticancer effect of different honeys from Poland on tumor cell line - glioblastoma multiforme U87MG. Anti-proliferative activity of honeys and its interferences with temozolomide were determined by a cytotoxicity test and DNA binding by [H3]-thymidine incorporation. A gelatin zymography was used to conduct an evaluation of metalloproteinases (MMP-2 and MMP-9 expression in U87MG treatment with honey samples. The honeys were previously tested qualitatively (diastase activity, total phenolic content, lead and cadmium content. The data demonstrated that the examined honeys have a potent anti-proliferative effect on U87MG cell line in a time- and dose-dependent manner, being effective at concentrations as low as 0.5% (multifloral light honey - viability 53% after 72 h of incubation. We observed that after 48 h, combining honey with temozolomide showed a significantly higher inhibitory effect than the samples of honey alone. We observed a strong inhibition of MMP-2 and MMP-9 for the tested honeys (from 20 to 56% and from 5 to 58% compared to control, respectively. Our results suggest that Polish honeys have an anti-proliferative and anti-metastatic effect on U87MG cell line. Therefore, natural bee honey can be considered as a promising adjuvant treatment for brain tumors.

  7. The Let-60 Locus Controls the Switch between Vulval and Nonvulval Cell Fates in Caenorhabditis Elegans

    Science.gov (United States)

    Han, M.; Aroian, R. V.; Sternberg, P. W.

    1990-01-01

    During induction of the Caenorhabditis elegans hermaphrodite vulva by the anchor cell of the gonad, six multipotent vulval precursor cells (VPCs) have two distinct fates: three VPCs generate the vulva and the other three VPCs generate nonspecialized hypodermis. Genes that control the fates of the VPCs in response to the anchor cell signal are defined by mutations that cause all six VPCs to generate vulval tissue (Multivulva or Muv) or that cause all six VPCs to generate hypodermis (Vulvaless or Vul). Seven dominant Vul mutations were isolated as dominant suppressors of a lin-15 Muv mutation. These mutations are dominant alleles of the gene let-60, previously identified only by recessive lethal mutations. Our genetic studies of these dominant Vul recessive lethal mutations, recessive lethal mutations, intragenic revertants of the dominant Vul mutations, and the closely mapping semidominant multivulva lin-34 mutations suggest that: (1) loss-of-function mutations of let-60 are recessive lethal at a larval stage, but they also cause a Vul phenotype if the lethality is rescued maternally by a lin-34 gain-of-function mutation. (2) The dominant Vul alleles of let-60 are dominant negative mutations whose gene products compete with wild-type activity. (3) lin-34 semidominant Muv alleles are either gain-of-function mutations of let-60 or gain-of-function mutations of an intimately related gene that elevates let-60 activity. We propose that let-60 activity controls VPC fates. In a wild-type animal, reception by a VPC of inductive signal activates let-60, and it generates into a vulval cell type; in absence of inductive signal, let-60 activity is low and the VPC generates hypodermal cells. Our genetic interaction studies suggest that let-60 acts downstream of let-23 and lin-15 and upstream of lin-1 and lin-12 in the genetic pathway specifying the switch between vulval and nonvulval cell types. PMID:2076820

  8. The binding, transport and fate of aluminium in biological cells.

    Science.gov (United States)

    Exley, Christopher; Mold, Matthew J

    2015-04-01

    Aluminium is the most abundant metal in the Earth's crust and yet, paradoxically, it has no known biological function. Aluminium is biochemically reactive, it is simply that it is not required for any essential process in extant biota. There is evidence neither of element-specific nor evolutionarily conserved aluminium biochemistry. This means that there are no ligands or chaperones which are specific to its transport, there are no transporters or channels to selectively facilitate its passage across membranes, there are no intracellular storage proteins to aid its cellular homeostasis and there are no pathways which evolved to enable the metabolism and excretion of aluminium. Of course, aluminium is found in every compartment of every cell of every organism, from virus through to Man. Herein we have investigated each of the 'silent' pathways and metabolic events which together constitute a form of aluminium homeostasis in biota, identifying and evaluating as far as is possible what is known and, equally importantly, what is unknown about its uptake, transport, storage and excretion.

  9. GATA3 induces human T-cell commitment by restraining Notch activity and repressing NK-cell fate

    Science.gov (United States)

    Van de Walle, Inge; Dolens, Anne-Catherine; Durinck, Kaat; De Mulder, Katrien; Van Loocke, Wouter; Damle, Sagar; Waegemans, Els; De Medts, Jelle; Velghe, Imke; De Smedt, Magda; Vandekerckhove, Bart; Kerre, Tessa; Plum, Jean; Leclercq, Georges; Rothenberg, Ellen V.; Van Vlierberghe, Pieter; Speleman, Frank; Taghon, Tom

    2016-01-01

    The gradual reprogramming of haematopoietic precursors into the T-cell fate is characterized by at least two sequential developmental stages. Following Notch1-dependent T-cell lineage specification during which the first T-cell lineage genes are expressed and myeloid and dendritic cell potential is lost, T-cell specific transcription factors subsequently induce T-cell commitment by repressing residual natural killer (NK)-cell potential. How these processes are regulated in human is poorly understood, especially since efficient T-cell lineage commitment requires a reduction in Notch signalling activity following T-cell specification. Here, we show that GATA3, in contrast to TCF1, controls human T-cell lineage commitment through direct regulation of three distinct processes: repression of NK-cell fate, upregulation of T-cell lineage genes to promote further differentiation and restraint of Notch activity. Repression of the Notch1 target gene DTX1 hereby is essential to prevent NK-cell differentiation. Thus, GATA3-mediated positive and negative feedback mechanisms control human T-cell lineage commitment. PMID:27048872

  10. Using cell fate attractors to uncover transcriptional regulation of HL60 neutrophil differentiation

    Directory of Open Access Journals (Sweden)

    Kauffman Stuart A

    2009-02-01

    Full Text Available Abstract Background The process of cellular differentiation is governed by complex dynamical biomolecular networks consisting of a multitude of genes and their products acting in concert to determine a particular cell fate. Thus, a systems level view is necessary for understanding how a cell coordinates this process and for developing effective therapeutic strategies to treat diseases, such as cancer, in which differentiation plays a significant role. Theoretical considerations and recent experimental evidence support the view that cell fates are high dimensional attractor states of the underlying molecular networks. The temporal behavior of the network states progressing toward different cell fate attractors has the potential to elucidate the underlying molecular mechanisms governing differentiation. Results Using the HL60 multipotent promyelocytic leukemia cell line, we performed experiments that ultimately led to two different cell fate attractors by two treatments of varying dosage and duration of the differentiation agent all-trans-retinoic acid (ATRA. The dosage and duration combinations of the two treatments were chosen by means of flow cytometric measurements of CD11b, a well-known early differentiation marker, such that they generated two intermediate populations that were poised at the apparently same stage of differentiation. However, the population of one treatment proceeded toward the terminally differentiated neutrophil attractor while that of the other treatment reverted back toward the undifferentiated promyelocytic attractor. We monitored the gene expression changes in the two populations after their respective treatments over a period of five days and identified a set of genes that diverged in their expression, a subset of which promotes neutrophil differentiation while the other represses cell cycle progression. By employing promoter based transcription factor binding site analysis, we found enrichment in the set of divergent

  11. Predicting pancreas cell fate decisions and reprogramming with a hierarchical multi-attractor model.

    Directory of Open Access Journals (Sweden)

    Joseph Xu Zhou

    Full Text Available Cell fate reprogramming, such as the generation of insulin-producing β cells from other pancreas cells, can be achieved by external modulation of key transcription factors. However, the known gene regulatory interactions that form a complex network with multiple feedback loops make it increasingly difficult to design the cell reprogramming scheme because the linear regulatory pathways as schemes of causal influences upon cell lineages are inadequate for predicting the effect of transcriptional perturbation. However, sufficient information on regulatory networks is usually not available for detailed formal models. Here we demonstrate that by using the qualitatively described regulatory interactions as the basis for a coarse-grained dynamical ODE (ordinary differential equation based model, it is possible to recapitulate the observed attractors of the exocrine and β, δ, α endocrine cells and to predict which gene perturbation can result in desired lineage reprogramming. Our model indicates that the constraints imposed by the incompletely elucidated regulatory network architecture suffice to build a predictive model for making informed decisions in choosing the set of transcription factors that need to be modulated for fate reprogramming.

  12. Pax6- and Six3-mediated induction of lens cell fate in mouse and human ES cells.

    Directory of Open Access Journals (Sweden)

    Raymond M Anchan

    Full Text Available Embryonic stem (ES cells provide a potentially useful in vitro model for the study of in vivo tissue differentiation. We used mouse and human ES cells to investigate whether the lens regulatory genes Pax6 and Six3 could induce lens cell fate in vitro. To help assess the onset of lens differentiation, we derived a new mES cell line (Pax6-GFP mES that expresses a GFP reporter under the control of the Pax6 P0 promoter and lens ectoderm enhancer. Pax6 or Six3 expression vectors were introduced into mES or hES cells by transfection or lentiviral infection and the differentiating ES cells analyzed for lens marker expression. Transfection of mES cells with Pax6 or Six3 but not with other genes induced the expression of lens cell markers and up-regulated GFP reporter expression in Pax6-GFP mES cells by 3 days post-transfection. By 7 days post-transfection, mES cell cultures exhibited a>10-fold increase over controls in the number of colonies expressing γA-crystallin, a lens fiber cell differentiation marker. RT-PCR and immunostaining revealed induction of additional lens epithelial or fiber cell differentiation markers including Foxe3, Prox1, α- and β-crystallins, and Tdrd7. Moreover, γA-crystallin- or Prox1-expressing lentoid bodies formed by 30 days in culture. In hES cells, Pax6 or Six3 lentiviral vectors also induced lens marker expression. mES cells that express lens markers reside close to but are distinct from the Pax6 or Six3 transduced cells, suggesting that the latter induce nearby undifferentiated ES cells to adopt a lens fate by non-cell autonomous mechanisms. In sum, we describe a novel mES cell GFP reporter line that is useful for monitoring induction of lens fate, and demonstrate that Pax6 or Six3 is sufficient to induce ES cells to adopt a lens fate, potentially via non-cell autonomous mechanisms. These findings should facilitate investigations of lens development.

  13. Sr-substituted bone cements direct mesenchymal stem cells, osteoblasts and osteoclasts fate

    Science.gov (United States)

    Panseri, Silvia; Dapporto, Massimiliano; Tampieri, Anna; Sprio, Simone

    2017-01-01

    Strontium-substituted apatitic bone cements enriched with sodium alginate were developed as a potential modulator of bone cells fate. The biological impact of the bone cement were investigated in vitro through the study of the effect of the nanostructured apatitic composition and the doping of strontium on mesenchymal stem cells, pre-osteoblasts and osteoclasts behaviours. Up to 14 days of culture the bone cells viability, proliferation, morphology and gene expression profiles were evaluated. The results showed that different concentrations of strontium were able to evoke a cell-specific response, in fact an inductive effect on mesenchymal stem cells differentiation and pre-osteoblasts proliferation and an inhibitory effect on osteoclasts activity were observed. Moreover, the apatitic structure of the cements provided a biomimetic environment suitable for bone cells growth. Therefore, the combination of biological features of this bone cement makes it as promising biomaterials for tissue regeneration. PMID:28196118

  14. Level of reactive oxygen species induced by p21Waf1/CIP1 is critical for the determination of cell fate.

    Science.gov (United States)

    Inoue, Takafumi; Kato, Kiyoko; Kato, Hidenori; Asanoma, Kazuo; Kuboyama, Ayumi; Ueoka, Yousuke; Yamaguchi, Shin-ichiro; Ohgami, Tatsuhiro; Wake, Norio

    2009-07-01

    p21(WAF(1)/)(CIP(1)) is a well-known cell cycle regulatory protein which is overexpressed in several cancer cell lines, and known to determine cell fate. We generated three recombinant adenovirus vectors that expressed either the full-length p21 (Ad-p21F), a p21 mutant with a deletion of the C-terminal proliferative cell nuclear antigen (PCNA) binding domain (Ad-p21N), or a p21 mutant with a deletion of the N-terminal cyclin-dependent kinase binding domain (Ad-p21C). We transfected these vectors into five cancer cell lines. Premature senescence was induced in all of the lines only following transfection with Ad-p21N and Ad-p21F. In addition, apoptosis was also induced in LoVo and HCT116 cells that harbored wild-type p53 and the reactive oxygen species (ROS) level was higher than in senescent cells. Finally, the induction of apoptosis was inhibited by using siRNA to downregulate p53. This observation implies that there is a feedback signaling loop involving p21/ROS/p53 in apoptotic responses. It appears to be, at least in part, driven by high levels of p21 protein. Next, we investigated the cell death effect of endogenous p21 protein on cell fate using sodium butyrate (NaB). Treatment with 1 mM NaB or 2 to 5 mM NaB induced senescence or apoptosis, respectively. The level of intracellular ROS in 5 mM NaB treated cells was 2-fold higher, compared with that in 1 mM NaB treated cells. We also demonstrated that DNA damage response signals including ataxia telangiectasia mutated, gammaH2AX, and p38 MAPK were involved in NaB-induced cell death. The magnitude of intracellular ROS levels in response to p21 elicited either senescence or apoptosis in the cancer cell lines.

  15. The Adipocyte-Derived Hormone Leptin Has Proliferative Actions on Androgen-Resistant Prostate Cancer Cells Linking Obesity to Advanced Stages of Prostate Cancer

    Directory of Open Access Journals (Sweden)

    M. Raschid Hoda

    2012-01-01

    Full Text Available Background. Because obesity may be a risk factor for prostate cancer, we investigated proliferative effects of adipocytes-derived hormone leptin on human prostate cancer cells and assessed the role of mitogen-activated protein kinase (MAPK signaling pathway in mediating these actions. Material and Methods. Three human prostate cancer cell lines were treated with increasing doses of recombinant leptin. Cell growth was measured under serum-free conditions using a spectrophotometric assay. Further, Western blotting was applied to detect the phosphorylation of an ERK1/2, and a specific inhibitor of MAPK (PD98059; 40 μM was used. Results. In both androgen-resistant cell lines DU145 and PC-3, cell growth was dose-dependently increased by leptin after 24 hrs and 48 hrs of incubation, whereas leptin’s proliferative effects on androgen-sensitive cell line LNCaP was less pronounced. Further, leptin caused dose-dependent ERK1/2 phosphorylation in both androgen-resistant cell lines, and pretreatment of these cells with PD98059 inhibited these responses. Conclusions. Leptin may be a potential link between obesity and risk of progression of prostate cancer. Thus, studies on leptin and obesity association to prostate cancer should differentiate patients according to androgen sensitivity.

  16. Notch signaling differentially regulates the cell fate of early endocrine precursor cells and their maturing descendants in the mouse pancreas and intestine.

    Science.gov (United States)

    Li, Hui Joyce; Kapoor, Archana; Giel-Moloney, Maryann; Rindi, Guido; Leiter, Andrew B

    2012-11-15

    Notch signaling inhibits differentiation of endocrine cells in the pancreas and intestine. In a number of cases, the observed inhibition occurred with Notch activation in multipotential cells, prior to the initiation of endocrine differentiation. It has not been established how direct activation of Notch in endocrine precursor cells affects their subsequent cell fate. Using conditional activation of Notch in cells expressing Neurogenin3 or NeuroD1, we examined the effects of Notch in both organs, on cell fate of early endocrine precursors and maturing endocrine-restricted cells, respectively. Notch did not preclude the differentiation of a limited number of endocrine cells in either organ when activated in Ngn3(+) precursor cells. In addition, in the pancreas most Ngn3(+) cells adopted a duct but not acinar cell fate; whereas in intestinal Ngn3(+) cells, Notch favored enterocyte and goblet cell fates, while selecting against endocrine and Paneth cell differentiation. A small fraction of NeuroD1(+) cells in the pancreas retain plasticity to respond to Notch, giving rise to intraislet ductules as well as cells with no detectable pancreatic lineage markers that appear to have limited ultrastructural features of both endocrine and duct cells. These results suggest that Notch directly regulates cell fate decisions in multipotential early endocrine precursor cells. Some maturing endocrine-restricted NeuroD1(+) cells in the pancreas switch to the duct lineage in response to Notch, indicating previously unappreciated plasticity at such a late stage of endocrine differentiation.

  17. Sex determination. foxl3 is a germ cell-intrinsic factor involved in sperm-egg fate decision in medaka.

    Science.gov (United States)

    Nishimura, Toshiya; Sato, Tetsuya; Yamamoto, Yasuhiro; Watakabe, Ikuko; Ohkawa, Yasuyuki; Suyama, Mikita; Kobayashi, Satoru; Tanaka, Minoru

    2015-07-17

    Sex determination is an essential step in the commitment of a germ cell to a sperm or egg. However, the intrinsic factors that determine the sexual fate of vertebrate germ cells are unknown. Here, we show that foxl3, which is expressed in germ cells but not somatic cells in the gonad, is involved in sperm-egg fate decision in medaka fish. Adult XX medaka with disrupted foxl3 developed functional sperm in the expanded germinal epithelium of a histologically functional ovary. In chimeric medaka, mutant germ cells initiated spermatogenesis in female wild-type gonad. These results indicate that a germ cell-intrinsic cue for the sperm-egg fate decision is present in medaka and that spermatogenesis can proceed in a female gonadal environment.

  18. Gastrin: a distinct fate of neurogenin3 positive progenitor cells in the embryonic pancreas.

    Directory of Open Access Journals (Sweden)

    Yaron Suissa

    Full Text Available Neurogenin3(+ (Ngn3(+ progenitor cells in the developing pancreas give rise to five endocrine cell types secreting insulin, glucagon, somatostatin, pancreatic polypeptide and ghrelin. Gastrin is a hormone produced primarily by G-cells in the stomach, where it functions to stimulate acid secretion by gastric parietal cells. Gastrin is expressed in the embryonic pancreas and is common in islet cell tumors, but the lineage and regulators of pancreatic gastrin(+ cells are not known. We report that gastrin is abundantly expressed in the embryonic pancreas and disappears soon after birth. Some gastrin(+ cells in the developing pancreas co-express glucagon, ghrelin or pancreatic polypeptide, but many gastrin(+ cells do not express any other islet hormone. Pancreatic gastrin(+ cells express the transcription factors Nkx6.1, Nkx2.2 and low levels of Pdx1, and derive from Ngn3(+ endocrine progenitor cells as shown by genetic lineage tracing. Using mice deficient for key transcription factors we show that gastrin expression depends on Ngn3, Nkx2.2, NeuroD1 and Arx, but not Pax4 or Pax6. Finally, gastrin expression is induced upon differentiation of human embryonic stem cells to pancreatic endocrine cells expressing insulin. Thus, gastrin(+ cells are a distinct endocrine cell type in the pancreas and an alternative fate of Ngn3+ cells.

  19. Machine learning classification of cell-specific cardiac enhancers uncovers developmental subnetworks regulating progenitor cell division and cell fate specification.

    Science.gov (United States)

    Ahmad, Shaad M; Busser, Brian W; Huang, Di; Cozart, Elizabeth J; Michaud, Sébastien; Zhu, Xianmin; Jeffries, Neal; Aboukhalil, Anton; Bulyk, Martha L; Ovcharenko, Ivan; Michelson, Alan M

    2014-02-01

    The Drosophila heart is composed of two distinct cell types, the contractile cardial cells (CCs) and the surrounding non-muscle pericardial cells (PCs), development of which is regulated by a network of conserved signaling molecules and transcription factors (TFs). Here, we used machine learning with array-based chromatin immunoprecipitation (ChIP) data and TF sequence motifs to computationally classify cell type-specific cardiac enhancers. Extensive testing of predicted enhancers at single-cell resolution revealed the added value of ChIP data for modeling cell type-specific activities. Furthermore, clustering the top-scoring classifier sequence features identified novel cardiac and cell type-specific regulatory motifs. For example, we found that the Myb motif learned by the classifier is crucial for CC activity, and the Myb TF acts in concert with two forkhead domain TFs and Polo kinase to regulate cardiac progenitor cell divisions. In addition, differential motif enrichment and cis-trans genetic studies revealed that the Notch signaling pathway TF Suppressor of Hairless [Su(H)] discriminates PC from CC enhancer activities. Collectively, these studies elucidate molecular pathways used in the regulatory decisions for proliferation and differentiation of cardiac progenitor cells, implicate Su(H) in regulating cell fate decisions of these progenitors, and document the utility of enhancer modeling in uncovering developmental regulatory subnetworks.

  20. Dynamic Pax6 expression during the neurogenic cell cycle influences proliferation and cell fate choices of retinal progenitors

    Directory of Open Access Journals (Sweden)

    Yang Xian-Jie

    2009-08-01

    Full Text Available Abstract Background The paired homeobox protein Pax6 is essential for proliferation and pluripotency of retinal progenitors. However, temporal changes in Pax6 protein expression associated with the generation of various retinal neurons have not been characterized with regard to the cell cycle. Here, we examine the dynamic changes of Pax6 expression among chicken retinal progenitors as they progress through the neurogenic cell cycle, and determine the effects of altered Pax6 levels on retinogenesis. Results We provide evidence that during the preneurogenic to neurogenic transition, Pax6 protein levels in proliferating progenitor cells are down-regulated. Neurogenic retinal progenitors retain a relatively low level of Pax6 protein, whereas postmitotic neurons either elevate or extinguish Pax6 expression in a cell type-specific manner. Cell imaging and cell cycle analyses show that neurogenic progenitors in the S phase of the cell cycle contain low levels of Pax6 protein, whereas a subset of progenitors exhibits divergent levels of Pax6 protein upon entering the G2 phase of the cell cycle. We also show that M phase cells contain varied levels of Pax6, and some correlate with the onset of early neuronal marker expression, forecasting cell cycle exit and cell fate commitment. Furthermore, either elevating or knocking down Pax6 attenuates cell proliferation and results in increased cell death. Reducing Pax6 decreases retinal ganglion cell genesis and enhances cone photoreceptor and amacrine interneuron production, whereas elevating Pax6 suppresses cone photoreceptor and amacrine cell fates. Conclusion These studies demonstrate for the first time quantitative changes in Pax6 protein expression during the preneurogenic to neurogenic transition and during the neurogenic cell cycle. The results indicate that Pax6 protein levels are stringently controlled in proliferating progenitors. Maintaining a relatively low Pax6 protein level is necessary for S phase

  1. Synthesis of 17β-N-arylcarbamoylandrost-4-en-3-one derivatives and their anti-proliferative effect on human androgen-sensitive LNCaP cell line.

    Science.gov (United States)

    Cortés-Benítez, Francisco; Cabeza, Marisa; Ramírez-Apan, María Teresa; Alvarez-Manrique, Berenice; Bratoeff, Eugene

    2016-10-04

    In this study, we report the synthesis and anti-proliferative effect of a set of eight androst-4-ene-3-one derivatives with different arylcarbamoyl groups at C-17. The novel compounds were prepared from commercially available 3β-hydroxy-5-pregnen-20-one and evaluated against the androgen-sensitive human prostate adenocarcinoma LNCaP cell line. The cancerous cells were exposed to 50 μM of each compound and the proliferating agent testosterone (T) or dihydrotestosterone (DHT). The most potent compounds from this assay were further tested against the androgen-insensitive PC3 cell line. We also demonstrate the activity of these compounds on rat peripheral blood mononuclear cells for comparison. Both 17β-N-[3,5-bis(trifluoromethyl)phenylcarbamoyl]androst-4-ene-3-one (6f) and 17β-N-(1,3-thiazol-2-ylcarbamoyl)androst-4-ene-3-one (6g) exhibited a higher growth inhibitory effect than commercially available drugs finasteride, flutamide and ketoconazole on LNCaP cells in the presence and absence of androgens. In addition, 6f and 6g demonstrated high potency on PC3 cells suggesting an androgen-independent anti-proliferative effect. Moreover, the novel compounds showed a small effect on rat mononuclear cells, an indication of low toxicity.

  2. Sequoia regulates cell fate decisions in the external sensory organs of adult Drosophila.

    Science.gov (United States)

    Andrews, Hillary K; Giagtzoglou, Nikolaos; Yamamoto, Shinya; Schulze, Karen L; Bellen, Hugo J

    2009-06-01

    The adult Drosophila external sensory organ (ESO), comprising the hair, socket, neuron, sheath and glia cells, arises through the asymmetric division of sensory organ precursor cells (SOPs). In a mosaic screen designed to identify new components in ESO development, we isolated mutations in sequoia, which encodes a putative zinc-finger transcription factor that has previously been shown to have a role in dendritogenesis. Here, we show that adult clones mutant for seq exhibit a loss of hair cells and a gain of socket cells. We propose that the seq mutant phenotype arises, in part, owing to the loss of several crucial transcription factors known to be important in peripheral nervous system development such as D-Pax2, Prospero and Hamlet. Thus, Sequoia is a new upstream regulator of genes that orchestrates cell fate specification during development of the adult ESO lineage.

  3. The developmental fate of green fluorescent mouse embryonic germ cells in chimeric embryos

    Institute of Scientific and Technical Information of China (English)

    XUXIN; SUMIOSUGANO; 等

    1999-01-01

    Primordial germ cells (PGCs),as precursors of mammalian germ lineage,have been gaining more attention as a new resource of pluripotent stem cells,which bring a great possibility to study developmental events of germ cell in vitro and at animal level.EG4 cells derived from 10.5 days post coitum (dpc) PGCs of 129/svJ strain mouse were established and maintained in an undifferentiated state.With an attempt to study the differentiation capability of EG4 cells with a reporter protein:green fluorescence protein,and the possible application of EG4 cells in the research of germ cell development,we have generated several EG4-GFP cell lines expressing enhanced green fluorescence protein (EGFP) and still maintaining typical characteristics of pluripotent stem cells.Then,the differentiation of EG4-GFP cells in vitro as well as their developmental fate in chimeric embryos which were produced by aggregating EG4-GFP cells to 8-cell stage embryos were studied.The results showed that EG4 cells carrying green fluorescence have a potential use in the research of germ cell development and other related studies.

  4. Fibrosarcoma versus fibromatoses and cellular nodular fasciitis. A comparative study of their proliferative activity using proliferating cell nuclear antigen, DNA flow cytometry, and p53.

    Science.gov (United States)

    Oshiro, Y; Fukuda, T; Tsuneyoshi, M

    1994-07-01

    We analyzed the proliferative activities, immunoreactivity of the p53 protein, and aneuploidy in patients with benign and malignant fibrous lesions, including 19 with nodular fasciitis (cellular type) (6-88 years old, mean 42.9), 11 with abdominal fibromatoses (22-74 years old, mean 37.9), 13 with extraabdominal fibromatoses (2-38 years old, mean 19.5), and 23 with fibrosarcomas (adult type: 16-71 years old, mean 47.3; infantile type: 3 months to 9 years, mean 2.9) using immunohistochemistry to determine proliferating cell nuclear antigen (PC10) and p53 protein (CM1) as well as performing DNA flow cytometry. The proliferating cell nuclear antigen (PCNA) score was measured as the ratio of PCNA-positive nuclear size/total nuclear size determined by an image analysis computer system. The distribution pattern of the PCNA-positive cells was uneven in each instance of nodular fasciitis, in contrast to the distribution in abdominal fibromatosis, extraabdominal fibromatosis, and fibrosarcoma. Both fibrosarcoma (28.4 +/- 20.0) and nodular fasciitis (33.6 +/- 20.9) exhibited a larger value and a greater variation in the PCNA score than did either abdominal (13.5 +/- 14.5) or extraabdominal fibromatosis (19.9 +/- 21.5). Abdominal fibromatosis exhibited a smaller value and less variation in the score. In short, the PCNA score did not correlate with the malignant potential. The proliferative index (S + G2 + M fraction) in fibrosarcoma was significantly higher than in either nodular fasciitis or abdominal fibromatosis. Aneuploidy was detected in five cases (26%) of fibrosarcoma, while six (26%) fibrosarcomas showed p53 positivity. Furthermore, p53-positive patients had a worse survival (0.01 < p < 0.05), and p53 positivity correlated with the proliferative index (p < 0.01). In conclusion, the PCNA score simply indicates the proliferative activity independent of malignant potential. On the other hand, p53 positivity, proliferative index, and aneuploidy are all indicators of

  5. BRAF Mutation Is Associated With a Specific Cell Type With Features Suggestive of Senescence in Ovarian Serous Borderline (Atypical Proliferative) Tumors

    DEFF Research Database (Denmark)

    Zeppernick, Felix; Ardighieri, Laura; Hannibal, Charlotte G

    2014-01-01

    Serous borderline tumor also known as atypical proliferative serous tumor (APST) is the precursor of ovarian low-grade serous carcinoma (LGSC). In this study, we correlated the morphologic and immunohistochemical phenotypes of 71 APSTs and 18 LGSCs with the mutational status of KRAS and BRAF......, the most common molecular genetic changes in these neoplasms. A subset of cells characterized by abundant eosinophilic cytoplasm (EC), discrete cell borders, and bland nuclei was identified in all (100%) 25 BRAF-mutated APSTs but in only 5 (10%) of 46 APSTs without BRAF mutations (P... LGSCs, EC cells were found in only 2, and both contained BRAF mutations. The EC cells were present admixed with cuboidal and columnar cells lining the papillae and appeared to be budding from the surface, resulting in individual cells and clusters of detached cells "floating" above the papillae...

  6. Emergence of Form from Function - Mechanical Engineering Approaches to Probe the Role of Stem Cell Mechanoadaptation in Sealing Cell Fate.

    Science.gov (United States)

    Knothe Tate, Melissa L; Gunning, Peter W; Sansalone, Vittorio

    2016-10-14

    Stem cell "mechanomics" refers to the effect of mechanical cues on stem cell and matrix biology, where cell shape and fate are intrinsic manifestations of form and function. Before specialization, the stem cell itself serves as a sensor and actuator; its structure emerges from its local mechanical milieu as the cell adapts over time. Coupling of novel spatiotemporal imaging and computational methods allows for linking of the energy of adaptation to the structure, biology and mechanical function of the cell. Cutting edge imaging methods enable probing of mechanisms by which stem cells' emergent anisotropic architecture and fate commitment occurs. A novel cell-scale model provides a mechanistic framework to describe stem cell growth and remodeling through mechanical feedback; making use of a generalized virtual power principle, the model accounts for the rate of doing work or the rate of using energy to effect the work. This coupled approach provides a basis to elucidate mechanisms underlying the stem cell's innate capacity to adapt to mechanical stimuli as well as the role of mechanoadaptation in lineage commitment. An understanding of stem cell mechanoadaptation is key to deciphering lineage commitment, during prenatal development, postnatal wound healing, and engineering of tissues.

  7. Putting things in place for fertilization: discovering roles for importin proteins in cell fate and spermatogenesis

    Directory of Open Access Journals (Sweden)

    Kate L. Loveland

    2015-01-01

    Full Text Available Importin proteins were originally characterized for their central role in protein transport through the nuclear pores, the only intracellular entry to the nucleus. This vital function must be tightly regulated to control access by transcription factors and other nuclear proteins to genomic DNA, to achieve appropriate modulation of cellular behaviors affecting cell fate. Importin-mediated nucleocytoplasmic transport relies on their specific recognition of cargoes, with each importin binding to distinct and overlapping protein subsets. Knowledge of importin function has expanded substantially in regard to three key developmental systems: embryonic stem cells, muscle cells and the germ line. In the decade since the potential for regulated nucleocytoplasmic transport to contribute to spermatogenesis was proposed, we and others have shown that the importins that ferry transcription factors into the nucleus perform additional roles, which control cell fate. This review presents key findings from studies of mammalian spermatogenesis that reveal potential new pathways by which male fertility and infertility arise. These studies of germline genesis illuminate new ways in which importin proteins govern cellular differentiation, including via directing proteins to distinct intracellular compartments and by determining cellular stress responses.

  8. Microbe-associated immunomodulatory metabolites: Influence on T cell fate and function.

    Science.gov (United States)

    Castro, C N; Freitag, J; Berod, L; Lochner, M; Sparwasser, T

    2015-12-01

    During the past two decades, a growing interest surrounding the interaction between microbe-associated molecular patterns (MAMPs) and pattern recognition receptors has occurred. This attention is now driven alongside bacterial-derived metabolites, which impact immune cell differentiation and function. Hence, this review introduces the term meta-MAMP as a means to classify the microbial derived-metabolites, which influence the immune response by affecting specific cellular processes. We discuss two prominent examples of meta-MAMPs: the first, rapamycin (isolated from Streptomyces), was discovered in the 1970s and since then has been thoroughly studied. The second, soraphen A (isolated from Myxobacteria), was discovered in the early 1990s but only recently identified as a promising immunomodulator. Both meta-MAMPs are similar in their remarkable capacity to modulate T cell fate by targeting key metabolic pathways triggered upon T cell activation. In this context, we highlight the progress made in the field of immunometabolism and the possibility of modulating metabolic pathways such as cellular fatty acid metabolism as a strategy for immunomodulation. We focus on the use of microbial metabolites as auspicious agents for T cell fate modulation.

  9. Early perturbation in mitochondria redox homeostasis in response to environmental stress predicts cell fate in diatoms.

    Science.gov (United States)

    van Creveld, Shiri Graff; Rosenwasser, Shilo; Schatz, Daniella; Koren, Ilan; Vardi, Assaf

    2015-02-01

    Diatoms are ubiquitous marine photosynthetic eukaryotes that are responsible for about 20% of global photosynthesis. Nevertheless, little is known about the redox-based mechanisms that mediate diatom sensing and acclimation to environmental stress. Here we used a redox-sensitive green fluorescent protein sensor targeted to various subcellular organelles in the marine diatom Phaeodactylum tricornutum, to map the spatial and temporal oxidation patterns in response to environmental stresses. Specific organelle oxidation patterns were found in response to various stress conditions such as oxidative stress, nutrient limitation and exposure to diatom-derived infochemicals. We found a strong correlation between the mitochondrial glutathione (GSH) redox potential (EGSH) and subsequent induction of cell death in response to the diatom-derived unsaturated aldehyde 2E,4E/Z-decadienal (DD), and a volatile halocarbon (BrCN) that mediate trophic-level interactions in marine diatoms. Induction of cell death in response to DD was mediated by oxidation of mitochondrial EGSH and was reversible by application of GSH only within a narrow time frame. We found that cell fate can be accurately predicted by a distinct life-death threshold of mitochondrial EGSH (-335 mV). We propose that compartmentalized redox-based signaling can integrate the input of diverse environmental cues and will determine cell fate decisions as part of algal acclimation to stress conditions.

  10. Neuronal cell fate diversification controlled by sub-temporal action of Kruppel

    Science.gov (United States)

    Stratmann, Johannes; Gabilondo, Hugo; Benito-Sipos, Jonathan; Thor, Stefan

    2016-01-01

    During Drosophila embryonic nervous system development, neuroblasts express a programmed cascade of five temporal transcription factors that govern the identity of cells generated at different time-points. However, these five temporal genes fall short of accounting for the many distinct cell types generated in large lineages. Here, we find that the late temporal gene castor sub-divides its large window in neuroblast 5–6 by simultaneously activating two cell fate determination cascades and a sub-temporal regulatory program. The sub-temporal program acts both upon itself and upon the determination cascades to diversify the castor window. Surprisingly, the early temporal gene Kruppel acts as one of the sub-temporal genes within the late castor window. Intriguingly, while the temporal gene castor activates the two determination cascades and the sub-temporal program, spatial cues controlling cell fate in the latter part of the 5–6 lineage exclusively act upon the determination cascades. DOI: http://dx.doi.org/10.7554/eLife.19311.001 PMID:27740908

  11. Involvement of C2H2 zinc finger proteins in the regulation of epidermal cell fate determination in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    An Yan; Minjie Wu; Yongqin Zhao; Aidong Zhang; Bohan Liu; John Schiefelbein; Yinbo Gan

    2014-01-01

    Cell fate determination is a basic developmental process during the growth of multicellular organisms. Trichomes and root hairs of Arabidopsis are both readily accessible structures originating from the epidermal cells of the aerial tissues and roots respectively, and they serve as excellent models for understanding the molecular mecha-nisms controlling cell fate determination and cell morphogen-esis. The regulation of trichome and root hair formation is a complex program that consists of the integration of hormonal signals with a large number of transcriptional factors, including MYB and bHLH transcriptional factors. Studies during recent years have uncovered an important role of C2H2 type zinc finger proteins in the regulation of epidermal cell fate determination. Here in this minireview we briefly summarize the involvement of C2H2 zinc finger proteins in the control of trichome and root hair formation in Arabidopsis.

  12. Ectopic expression of Cvh (Chicken Vasa homologue) mediates the reprogramming of chicken embryonic stem cells to a germ cell fate.

    Science.gov (United States)

    Lavial, Fabrice; Acloque, Hervé; Bachelard, Elodie; Nieto, M Angela; Samarut, Jacques; Pain, Bertrand

    2009-06-01

    When they are derived from blastodermal cells of the pre-primitive streak in vitro, the pluripotency of Chicken Embryonic Stem Cells (cESC) can be controlled by the cPouV and Nanog genes. These cESC can differentiate into derivatives of the three germ layers both in vitro and in vivo, but they only weakly colonize the gonads of host embryos. By contrast, non-cultured blastodermal cells and long-term cultured chicken primordial germ cells maintain full germline competence. This restriction in the germline potential of the cESC may result from either early germline determination in the donor embryos or it may occur as a result of in vitro culture. We are interested in understanding the genetic determinants of germline programming. The RNA binding protein Cvh (Chicken Vasa Homologue) is considered as one such determinant, although its role in germ cell physiology is still unclear. Here we show that the exogenous expression of Cvh, combined with appropriate culture conditions, induces cESC reprogramming towards a germ cell fate. Indeed, these cells express the Dazl, Tudor and Sycp3 germline markers, and they display improved germline colonization and adopt a germ cell fate when injected into recipient embryos. Thus, our results demonstrate that Vasa can drive ES cell differentiation towards the germ cell lineage, both in vitro and in vivo.

  13. Dominant effects of Δ40p53 on p53 function and melanoma cell fate

    OpenAIRE

    2013-01-01

    The p53 gene encodes 12 distinct isoforms some of which can alter p53 activity in the absence of genomic alteration. Endogenous p53 isoforms have been identified in cancers; however, the function of these isoforms remains unclear. In melanoma, the frequency of p53 mutations is relatively low compared to other cancers suggesting that these isoforms may play a larger role in regulating p53 activity. We hypothesized that p53 function and therefore cell fate might be altered by the presence of Δ4...

  14. The strength of indecisiveness: oscillatory behavior for better cell fate determination.

    Science.gov (United States)

    Lahav, Galit

    2004-12-21

    Oscillatory behavior is very common in many cellular responses. Recently, two pathways involved in response to cell stress, the p53 and nuclear factor kappa B signaling pathways, have been found to show oscillatory behavior. At first sight, there would seem to be no reason for signaling pathways of this type to require oscillations. Recent single-cell studies indicate that oscillatory behavior may be used to allow repeated testing for the continued existence of a signal. I argue that oscillations increase cellular response sensitivity and flexibility by allowing the cell to integrate the results of many periodical evaluations of the signal before making an eventual decision about cell fate, thus reducing the risk of premature commitment.

  15. Cell fate after mitotic arrest in different tumor cells is determined by the balance between slippage and apoptotic threshold

    Energy Technology Data Exchange (ETDEWEB)

    Galán-Malo, Patricia; Vela, Laura; Gonzalo, Oscar; Calvo-Sanjuán, Rubén; Gracia-Fleta, Lucía; Naval, Javier; Marzo, Isabel, E-mail: imarzo@unizar.es

    2012-02-01

    Microtubule poisons and other anti-mitotic drugs induce tumor death but the molecular events linking mitotic arrest to cell death are still not fully understood. We have analyzed cell fate after mitotic arrest produced by the microtubule-destabilizing drug vincristine in a panel of human tumor cell lines showing different response to vincristine. In Jurkat, RPMI 8226 and HeLa cells, apoptosis was triggered shortly after vincristine-induced mitotic arrest. However, A549 cells, which express a great amount of Bcl-x{sub L} and undetectable amounts of Bak, underwent mitotic slippage prior to cell death. However, when Bcl-x{sub L} gene was silenced in A549 cells, vincristine induced apoptosis during mitotic arrest. Another different behavior was found in MiaPaca2 cells, where vincristine caused death by mitotic catastrophe that switched to apoptosis when cyclin B1 degradation was prevented by proteasome inhibition. Overexpression of Bcl-x{sub L} or silencing Bax and Bak expression delayed the onset of apoptosis in Jurkat and RPMI 8226 cells, enabling mitotic slippage and endoreduplication. In HeLa cells, overexpression of Bcl-x{sub L} switched cell death from apoptosis to mitotic catastrophe. Mcl-1 offered limited protection to vincristine-induced cell death and Mcl-1 degradation was not essential for vincristine-induced death. All these results, taken together, indicate that the Bcl-x{sub L}/Bak ratio and the ability to degrade cyclin B1 determine cell fate after mitotic arrest in the different tumor cell types. Highlights: ► Vincristine induces cell death by apoptosis or mitotic catastrophe. ► Apoptosis-proficient cells die by apoptosis during mitosis upon vincristine treatment. ► p53wt apoptosis-deficient cells undergo apoptosis from a G1-like tetraploid state. ► p53mt apoptosis-deficient cells can survive and divide giving rise to 8N cells.

  16. Estrogen receptor coregulators and pioneer factors: The orchestrators of mammary gland cell fate and development

    Directory of Open Access Journals (Sweden)

    Bramanandam eManavathi

    2014-08-01

    Full Text Available The 17-beta estradiol (E2, a steroid hormone, which play critical role in various cellular processes such as cell proliferation, differentiation, migration and apoptosis, is essential for reproduction and mammary gland development. E2 actions are mediated by two classical nuclear hormone receptors, estrogen receptor alpha and beta (ERs. The activity of ERs depends on the coordinate activity of ligand binding, posttranslational modification, and importantly their interaction with their partner proteins called ‘coregulators’. Because majority of breast cancers are ERalpha positive and coregulators are proved to be crucial for ER transcriptional activity, an increased interest in the field has led to the identification of a large number of coregulators. In the last decade, gene knockout studies using mouse models provided impetus to our further understanding of the role of these coregulators in mammary gland development. Several coregulators appear to be critical for terminal end bud formation, ductal branching and alveologenesis during mammary gland development. The emerging studies support that, in addition to these coregulators, the other ER partner proteins ‘pioneering factors’ also seems to contribute significantly to E2 signaling and mammary cell fate. This review discusses emerging themes in coregulator- and pioneering factor-mediated action on ER functions, particularly their role in mammary gland cell fate and development.

  17. Improved Proliferative Capacity of NP-Like Cells Derived from Human Mesenchymal Stromal Cells and Neuronal Transdifferentiation by Small Molecules.

    Science.gov (United States)

    Aguilera-Castrejon, Alejandro; Pasantes-Morales, Herminia; Montesinos, Juan José; Cortés-Medina, Lorena V; Castro-Manrreza, Marta E; Mayani, Héctor; Ramos-Mandujano, Gerardo

    2017-02-01

    Neural progenitors (NP), found in fetal and adult brain, differentiate into neurons potentially able to be used in cell replacement therapies. This approach however, raises technical and ethical problems which limit their potential therapeutic use. Alternately, NPs can be obtained by transdifferentiation of non-neural somatic cells evading these difficulties. Human bone marrow mesenchymal stromal cells (MSCs) are suggested to transdifferentiate into NP-like cells, which however, have a low proliferation capacity. The present study demonstrates the requisite of cell adhesion for proliferation and survival of NP-like cells and re-evaluates some neuronal features after differentiation by standard procedures. Mature neuronal markers, though, were not detected by these procedures. A chemical differentiation approach was used in this study to convert MSCs-derived NP-like cells into neurons by using a cocktail of six molecules, CHIR99021, I-BET151, RepSox, DbcAMP, forskolin and Y-27632, defined after screening combinations of 22 small molecules. Direct transdifferentiation of MSCs into neuronal cells was obtained with the small molecule cocktail, without requiring the NP-like intermediate stage.

  18. SCARECROW-LIKE23 and SCARECROW jointly specify endodermal cell fate but distinctly control SHORT-ROOT movement.

    Science.gov (United States)

    Long, Yuchen; Goedhart, Joachim; Schneijderberg, Martinus; Terpstra, Inez; Shimotohno, Akie; Bouchet, Benjamin P; Akhmanova, Anna; Gadella, Theodorus W J; Heidstra, Renze; Scheres, Ben; Blilou, Ikram

    2015-11-01

    Intercellular signaling through trafficking of regulatory proteins is a widespread phenomenon in plants and can deliver positional information for the determination of cell fate. In the Arabidopsis root meristem, the cell fate determinant SHORT-ROOT (SHR), a GRAS domain transcription factor, acts as a signaling molecule from the stele to the adjacent layer to specify endodermal cell fate. Upon exiting the stele, SHR activates another GRAS domain transcription factor, SCARCROW (SCR), which, together with several BIRD/INDETERMINATE DOMAIN proteins, restricts movement of SHR to define a single cell layer of endodermis. Here we report that endodermal cell fate also requires the joint activity of both SCR and its closest homologue SCARECROW-LIKE23 (SCL23). We show that SCL23 protein moves with zonation-dependent directionality. Within the meristem, SCL23 exhibits short-ranged movement from ground tissue to vasculature. Away from the meristem, SCL23 displays long-range rootward movement into meristematic vasculature and a bidirectional radial spread, respectively. As a known target of SHR and SCR, SCL23 also interacts with SCR and SHR and can restrict intercellular outspread of SHR without relying on nuclear retention as SCR does. Collectively, our data show that SCL23 is a mobile protein that controls movement of SHR and acts redundantly with SCR to specify endodermal fate in the root meristem.

  19. Optogenetic Control of Nodal Signaling Reveals a Temporal Pattern of Nodal Signaling Regulating Cell Fate Specification during Gastrulation.

    Science.gov (United States)

    Sako, Keisuke; Pradhan, Saurabh J; Barone, Vanessa; Inglés-Prieto, Álvaro; Müller, Patrick; Ruprecht, Verena; Čapek, Daniel; Galande, Sanjeev; Janovjak, Harald; Heisenberg, Carl-Philipp

    2016-07-19

    During metazoan development, the temporal pattern of morphogen signaling is critical for organizing cell fates in space and time. Yet, tools for temporally controlling morphogen signaling within the embryo are still scarce. Here, we developed a photoactivatable Nodal receptor to determine how the temporal pattern of Nodal signaling affects cell fate specification during zebrafish gastrulation. By using this receptor to manipulate the duration of Nodal signaling in vivo by light, we show that extended Nodal signaling within the organizer promotes prechordal plate specification and suppresses endoderm differentiation. Endoderm differentiation is suppressed by extended Nodal signaling inducing expression of the transcriptional repressor goosecoid (gsc) in prechordal plate progenitors, which in turn restrains Nodal signaling from upregulating the endoderm differentiation gene sox17 within these cells. Thus, optogenetic manipulation of Nodal signaling identifies a critical role of Nodal signaling duration for organizer cell fate specification during gastrulation.

  20. Optogenetic Control of Nodal Signaling Reveals a Temporal Pattern of Nodal Signaling Regulating Cell Fate Specification during Gastrulation

    Directory of Open Access Journals (Sweden)

    Keisuke Sako

    2016-07-01

    Full Text Available During metazoan development, the temporal pattern of morphogen signaling is critical for organizing cell fates in space and time. Yet, tools for temporally controlling morphogen signaling within the embryo are still scarce. Here, we developed a photoactivatable Nodal receptor to determine how the temporal pattern of Nodal signaling affects cell fate specification during zebrafish gastrulation. By using this receptor to manipulate the duration of Nodal signaling in vivo by light, we show that extended Nodal signaling within the organizer promotes prechordal plate specification and suppresses endoderm differentiation. Endoderm differentiation is suppressed by extended Nodal signaling inducing expression of the transcriptional repressor goosecoid (gsc in prechordal plate progenitors, which in turn restrains Nodal signaling from upregulating the endoderm differentiation gene sox17 within these cells. Thus, optogenetic manipulation of Nodal signaling identifies a critical role of Nodal signaling duration for organizer cell fate specification during gastrulation.

  1. BMP-SHH signaling network controls epithelial stem cell fate via regulation of its niche in the developing tooth.

    Science.gov (United States)

    Li, Jingyuan; Feng, Jifan; Liu, Yang; Ho, Thach-Vu; Grimes, Weston; Ho, Hoang Anh; Park, Shery; Wang, Songlin; Chai, Yang

    2015-04-20

    During embryogenesis, ectodermal stem cells adopt different fates and form diverse ectodermal organs, such as teeth, hair follicles, mammary glands, and salivary glands. Interestingly, these ectodermal organs differ in their tissue homeostasis, which leads to differential abilities for continuous growth postnatally. Mouse molars lose the ability to grow continuously, whereas incisors retain this ability. In this study, we found that a BMP-Smad4-SHH-Gli1 signaling network may provide a niche supporting transient Sox2+ dental epithelial stem cells in mouse molars. This mechanism also plays a role in continuously growing mouse incisors. The differential fate of epithelial stem cells in mouse molars and incisors is controlled by this BMP/SHH signaling network, which partially accounts for the different postnatal growth potential of molars and incisors. Collectively, our study highlights the importance of crosstalk between two signaling pathways, BMP and SHH, in regulating the fate of epithelial stem cells during organogenesis.

  2. Gene Regulatory Network Analysis Reveals Differences in Site-specific Cell Fate Determination in Mammalian Brain

    Directory of Open Access Journals (Sweden)

    Gokhan eErtaylan

    2014-12-01

    Full Text Available Neurogenesis - the generation of new neurons - is an ongoing process that persists in the adult mammalian brain of several species, including humans. In this work we analyze two discrete brain regions: the subventricular zone (SVZ lining the walls of the lateral ventricles; and the subgranular zone (SGZ of the dentate gyrus of the hippocampus in mice and shed light on the SVZ and SGZ specific neurogenesis. We propose a computational model that relies on the construction and analysis of region specific gene regulatory networks from the publicly available data on these two regions. Using this model a number of putative factors involved in neuronal stem cell (NSC identity and maintenance were identified. We also demonstrate potential gender and niche-derived differences based on cell surface and nuclear receptors via Ar, Hif1a and Nr3c1.We have also conducted cell fate determinant analysis for SVZ NSC populations to Olfactory Bulb interneurons and SGZ NSC populations to the granule cells of the Granular Cell Layer. We report thirty-one candidate cell fate determinant gene pairs, ready to be validated. We focus on Ar - Pax6 in SVZ and Sox2 - Ncor1 in SGZ. Both pairs are expressed and localized in the suggested anatomical structures as shown by in situ hybridization and found to physically interact.Finally, we conclude that there are fundamental differences between SGZ and SVZ neurogenesis. We argue that these regulatory mechanisms are linked to the observed differential neurogenic potential of these regions. The presence of nuclear and cell surface receptors in the region specific regulatory circuits indicate the significance of niche derived extracellular factors, hormones and region specific factors such as the oxygen sensitivity, dictating SGZ and SVZ specific neurogenesis.

  3. Single-Cell Profiling of Epigenetic Modifiers Identifies PRDM14 as an Inducer of Cell Fate in the Mammalian Embryo

    Directory of Open Access Journals (Sweden)

    Adam Burton

    2013-11-01

    Full Text Available Cell plasticity or potency is necessary for the formation of multiple cell types. The mechanisms underlying this plasticity are largely unknown. Preimplantation mouse embryos undergo drastic changes in cellular potency, starting with the totipotent zygote through to the formation of the pluripotent inner cell mass (ICM and differentiated trophectoderm in the blastocyst. Here, we set out to identify and functionally characterize chromatin modifiers that define the transitions of potency and cell fate in the mouse embryo. Using a quantitative microfluidics approach in single cells, we show that developmental transitions are marked by distinctive combinatorial profiles of epigenetic modifiers. Pluripotent cells of the ICM are distinct from their differentiated trophectoderm counterparts. We show that PRDM14 is heterogeneously expressed in 4-cell-stage embryos. Forced expression of PRDM14 at the 2-cell stage leads to increased H3R26me2 and can induce a pluripotent ICM fate. Our results shed light on the epigenetic networks that govern cellular potency and identity in vivo.

  4. Dissecting chronic lymphocytic leukemia microenvironment signals in patients with unmutated disease: microRNA-22 regulates phosphatase and tensin homolog/AKT/FOXO1 pathway in proliferative leukemic cells.

    Science.gov (United States)

    Palacios, Florencia; Prieto, Daniel; Abreu, Cecilia; Ruiz, Santiago; Morande, Pablo; Fernández-Calero, Tamara; Libisch, Gabriela; Landoni, Ana Inés; Oppezzo, Pablo

    2015-05-01

    Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of clonal B cells arrested in G0/G1 stages that coexist with proliferative B cells. We identified one of these proliferative subsets in the peripheral blood from patients with unmutated disease (UM). Aiming to characterize the molecular mechanism underlying this proliferative behavior, we performed gene expression analysis of the mRNA and microRNAs in this leukemic subpopulation and compared results with those for the quiescent counterpart. Our results suggest that proliferation of this subset mainly depends on microRNA-22 overexpression, which induces phosphatase and tensin homolog (PTEN) down-regulation and phosphoinositide 3-kinase (PI3K)/AKT pathway activation. These results underline the role of the PI3K/AKT pathway at the origin of this proliferative pool in patients with UM CLL and provide additional rationale for the use of PI3K inhibitors.

  5. AID-induced remodeling of immunoglobulin genes and B cell fate.

    Science.gov (United States)

    Laffleur, Brice; Denis-Lagache, Nicolas; Péron, Sophie; Sirac, Christophe; Moreau, Jeanne; Cogné, Michel

    2014-03-15

    Survival and phenotype of normal and malignant B lymphocytes are critically dependent on constitutive signals by the B cell receptor (BCR) for antigen. In addition, either antigen ligation of the BCR or various mitogenic stimuli result in B cell activation and induction of activation-induced deaminase (AID). AID activity can in turn mediate somatic hypermutation (SHM) of immunoglobulin (Ig) V regions and also deeply remodel the Ig heavy chain locus through class switch recombination (CSR) or locus suicide recombination (LSR). In addition to changes linked to affinity for antigen, modifying the class/isotype (i.e. the structure and function) of the BCR or suddenly deleting BCR expression also modulates the fate of antigen-experienced B cells.

  6. SCARECROW, SCR-LIKE 23 and SHORT-ROOT control bundle sheath cell fate and function in Arabidopsis thaliana.

    Science.gov (United States)

    Cui, Hongchang; Kong, Danyu; Liu, Xiuwen; Hao, Yueling

    2014-04-01

    Bundle sheath (BS) cells form a single cell layer surrounding the vascular tissue in leaves. In C3 plants, photosynthesis occurs in both the BS and mesophyll cells, but the BS cells are the major sites of photosynthesis in C4 plants, whereas the mesophyll cells are only involved in CO2 fixation. Because C4 plants are more efficient photosynthetically, introduction of the C4 mechanism into C3 plants is considered a key strategy to improve crop yield. One prerequisite for such C3-to-C4 engineering is the ability to manipulate the number and physiology of the BS cells, but the molecular basis of BS cell-fate specification remains unclear. Here we report that mutations in three GRAS family transcription factors, SHORT-ROOT (SHR), SCARECROW (SCR) and SCARECROW-LIKE 23 (SCL23), affect BS cell fate in Arabidopsis thaliana. SCR and SCL23 are expressed specifically in the BS cells and act redundantly in BS cell-fate specification, but their expression pattern and function diverge at later stages of leaf development. Using ChIP-chip experiments and sugar assays, we show that SCR is primarily involved in sugar transport whereas SCL23 functions in mineral transport. SHR is also essential for BS cell-fate specification, but it is expressed in the central vascular tissue. However, the SHR protein moves into the BS cells, where it directly regulates SCR and SCL23 expression. SHR, SCR and SCL23 homologs are present in many plant species, suggesting that this developmental pathway for BS cell-fate specification is likely to be evolutionarily conserved.

  7. A BMP regulatory network controls ectodermal cell fate decisions at the neural plate border.

    Science.gov (United States)

    Reichert, Sabine; Randall, Rebecca A; Hill, Caroline S

    2013-11-01

    During ectodermal patterning the neural crest and preplacodal ectoderm are specified in adjacent domains at the neural plate border. BMP signalling is required for specification of both tissues, but how it is spatially and temporally regulated to achieve this is not understood. Here, using a transgenic zebrafish BMP reporter line in conjunction with double-fluorescent in situ hybridisation, we show that, at the beginning of neurulation, the ventral-to-dorsal gradient of BMP activity evolves into two distinct domains at the neural plate border: one coinciding with the neural crest and the other abutting the epidermis. In between is a region devoid of BMP activity, which is specified as the preplacodal ectoderm. We identify the ligands required for these domains of BMP activity. We show that the BMP-interacting protein Crossveinless 2 is expressed in the BMP activity domains and is under the control of BMP signalling. We establish that Crossveinless 2 functions at this time in a positive-feedback loop to locally enhance BMP activity, and show that it is required for neural crest fate. We further demonstrate that the Distal-less transcription factors Dlx3b and Dlx4b, which are expressed in the preplacodal ectoderm, are required for the expression of a cell-autonomous BMP inhibitor, Bambi-b, which can explain the specific absence of BMP activity in the preplacodal ectoderm. Taken together, our data define a BMP regulatory network that controls cell fate decisions at the neural plate border.

  8. DMPD: Nitric oxide and cell viability in inflammatory cells: a role for NO inmacrophage function and fate. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15691589 Nitric oxide and cell viability in inflammatory cells: a role for NO inmac...(.png) (.svg) (.html) (.csml) Show Nitric oxide and cell viability in inflammatory cells: a role for NO inma...ty in inflammatory cells: a role for NO inmacrophage function and fate. Authors Bosca L, Zeini M, Traves PG,

  9. The WEREWOLF MYB protein directly regulates CAPRICE transcription during cell fate specification in the Arabidopsis root epidermis.

    Science.gov (United States)

    Ryu, Kook Hui; Kang, Yeon Hee; Park, Young-hwan; Hwang, Ildoo; Schiefelbein, John; Lee, Myeong Min

    2005-11-01

    The Arabidopsis root epidermis is composed of two types of cells, hair cells and non-hair cells, and their fate is determined in a position-dependent manner. WEREWOLF (WER), a R2R3 MYB protein, has been shown genetically to function as a master regulator to control both of the epidermal cell fates. To directly test the proposed role of WER in this system, we examined its subcellular localization and defined its transcriptional activation properties. We show that a WER-GFP fusion protein is functional and accumulates in the nucleus of the N-position cells in the Arabidopsis root epidermis, as expected for a transcriptional regulator. We also find that a modified WER protein with a strong activation domain (WER-VP16) promotes the formation of both epidermal cell types, supporting the view that WER specifies both cell fates. In addition, we used the glucocorticoid receptor (GR) inducible system to show that CPC transcription is regulated directly by WER. Using EMSA, we found two WER-binding sites (WBSs; WBSI and WBSII) in the CPC promoter. WER-WBSI binding was confirmed in vivo using the yeast one-hybrid assay. Binding between the WER protein and both WBSs (WBSI and WBSII), and the importance of the two WBSs in CPC promoter activity were confirmed in Arabidopsis. These results provide experimental support for the proposed role of WER as an activator of gene transcription during the specification of both epidermal cell fates.

  10. A gene expression atlas of a bicoid-depleted Drosophila embryo reveals early canalization of cell fate.

    Science.gov (United States)

    Staller, Max V; Fowlkes, Charless C; Bragdon, Meghan D J; Wunderlich, Zeba; Estrada, Javier; DePace, Angela H

    2015-02-01

    In developing embryos, gene regulatory networks drive cells towards discrete terminal fates, a process called canalization. We studied the behavior of the anterior-posterior segmentation network in Drosophila melanogaster embryos by depleting a key maternal input, bicoid (bcd), and measuring gene expression patterns of the network at cellular resolution. This method results in a gene expression atlas containing the levels of mRNA or protein expression of 13 core patterning genes over six time points for every cell of the blastoderm embryo. This is the first cellular resolution dataset of a genetically perturbed Drosophila embryo that captures all cells in 3D. We describe the technical developments required to build this atlas and how the method can be employed and extended by others. We also analyze this novel dataset to characterize the degree and timing of cell fate canalization in the segmentation network. We find that in two layers of this gene regulatory network, following depletion of bcd, individual cells rapidly canalize towards normal cell fates. This result supports the hypothesis that the segmentation network directly canalizes cell fate, rather than an alternative hypothesis whereby cells are initially mis-specified and later eliminated by apoptosis. Our gene expression atlas provides a high resolution picture of a classic perturbation and will enable further computational modeling of canalization and gene regulation in this transcriptional network.

  11. Conversion of neurons and glia to external-cell fates in the external sensory organs of Drosophila hamlet mutants by a cousin-cousin cell-type respecification.

    Science.gov (United States)

    Moore, Adrian W; Roegiers, Fabrice; Jan, Lily Y; Jan, Yuh-Nung

    2004-03-15

    The Drosophila external sensory organ forms in a lineage elaborating from a single precursor cell via a stereotypical series of asymmetric divisions. HAMLET transcription factor expression demarcates the lineage branch that generates two internal cell types, the external sensory neuron and thecogen. In HAMLET mutant organs, these internal cells are converted to external cells via an unprecedented cousin-cousin cell-fate respecification event. Conversely, ectopic HAMLET expression in the external cell branch leads to internal cell production. The fate-determining signals NOTCH and PAX2 act at multiple stages of lineage elaboration and HAMLET acts to modulate their activity in a branch-specific manner.

  12. Polycomb protein EZH2 regulates cancer cell fate decision in response to DNA damage.

    Science.gov (United States)

    Wu, Z; Lee, S T; Qiao, Y; Li, Z; Lee, P L; Lee, Y J; Jiang, X; Tan, J; Aau, M; Lim, C Z H; Yu, Q

    2011-11-01

    Polycomb protein histone methyltransferase enhancer of Zeste homologe 2 (EZH2) is frequently overexpressed in human malignancy and is implicated in cancer cell proliferation and invasion. However, it is largely unknown whether EZH2 has a role in modulating DNA damage response. Here, we show that EZH2 is an important determinant of cell fate decision in response to genotoxic stress. EZH2 depletion results in abrogation of both cell cycle G1 and G2/M checkpoints, directing DNA damage response toward predominant apoptosis in both p53-proficient and p53-deficient cancer cells, but not in normal cells. Mechanistically, EZH2 regulates DNA damage response in p53 wild-type cells mainly through transcriptional repression of FBXO32, which binds to and directs p21 for proteasome-mediated degradation, whereas it affects p53-deficient cells through regulating Chk1 activation by a distinct mechanism. Furthermore, pharmacological depletion of EZH2 phenocopies the effects of EZH2 knockdown on cell cycle checkpoints and apoptosis. These data unravel a crucial role of EZH2 in determining the cancer cell outcome following DNA damage and suggest that therapeutic targeting oncogenic EZH2 might serve as a strategy for improving conventional chemotherapy in a given malignancy.

  13. Modulated DISP3/PTCHD2 expression influences neural stem cell fate decisions

    Science.gov (United States)

    Konířová, Jana; Oltová, Jana; Corlett, Alicia; Kopycińska, Justyna; Kolář, Michal; Bartůněk, Petr; Zíková, Martina

    2017-01-01

    Neural stem cells (NSCs) are defined by their dual ability to self-renew through mitotic cell division or differentiate into the varied neural cell types of the CNS. DISP3/PTCHD2 is a sterol-sensing domain-containing protein, highly expressed in neural tissues, whose expression is regulated by thyroid hormone. In the present study, we used a mouse NSC line to investigate what effect DISP3 may have on the self-renewal and/or differentiation potential of the cells. We demonstrated that NSC differentiation triggered significant reduction in DISP3 expression in the resulting astrocytes, neurons and oligodendrocytes. Moreover, when DISP3 expression was disrupted, the NSC “stemness” was suppressed, leading to a larger population of cells undergoing spontaneous neuronal differentiation. Conversely, overexpression of DISP3 resulted in increased NSC proliferation. When NSCs were cultured under differentiation conditions, we observed that the lack of DISP3 augmented the number of NSCs differentiating into each of the neural cell lineages and that neuronal morphology was altered. In contrast, DISP3 overexpression resulted in impaired cell differentiation. Taken together, our findings imply that DISP3 may help dictate the NSC cell fate to either undergo self-renewal or switch to the terminal differentiation cell program. PMID:28134287

  14. Naturally-acquired influenza-specific CD4+ T-cell proliferative responses are impaired in HIV-infected African adults.

    Directory of Open Access Journals (Sweden)

    Kondwani C Jambo

    Full Text Available BACKGROUND: Seasonal influenza has been associated with greater morbidity and mortality in AIDS patients. Highly-active antiretroviral therapy (HAART has led to some reduction in influenza-related complications but the nature of naturally-acquired T-cell immunity to influenza virus in an African setting, and how this changes with immune reconstitution following HAART is unknown. We measured influenza-specific CD4(+ T-cell immunity in unimmunized HIV-infected Malawian adults and then investigated immune reconstitution following HAART. METHODS: Peripheral blood mononuclear cells were isolated from HIV-infected and HIV-uninfected Malawian adults. CFSE proliferation and CD154 expression flow cytometry-based assays were used to measure influenza-specific CD4(+ T-cell immunity. RESULTS: We found lower naturally-acquired proliferative influenza-specific CD4(+ T-cell responses in AIDS patients that was also present in asymptomatic HIV-infected adults with relatively high CD4 counts (>350 cells/µl. Influenza-specific CD4(+ T-cell immune reconstitution in HIV-infected patients on HAART for 12 months was poor despite a marked reduction in viral load and an increase in CD4 count. This poor immune reconstitution was characterised by a low influenza-specific proliferative CD4(+ T-cell response and reduced proportions of CD154-expressing influenza-specific CD4(+ T-cells in peripheral blood. CONCLUSION: Our data suggest that asymptomatic HIV-infected adults may also be at risk of influenza-related complications and that HAART alone may not circumvent this risk in AIDS patients. This study highlights the need to identify possible interventions early in HIV infection to reduce the risk of influenza and to intensify influenza surveillance in these susceptible African populations.

  15. Anti-Proliferative and Pro-Apoptotic Activities of 4-Methyl-2,6-bis(1-phenylethyl)phenol in Cancer Cells

    Science.gov (United States)

    Sung, Nak Yoon; Kim, Seung Cheol; Kim, Yun Hwan; Kim, Gihyeon; Lee, Yunmi; Sung, Gi-Ho; Kim, Ji Hye; Yang, Woo Seok; Kim, Mi Seon; Baek, Kwang-Soo; Kim, Jong-Hoon; Cho, Jae Youl

    2016-01-01

    It has been found that 4-isopropyl-2,6-bis(1-phenylethyl)phenol (KTH-13), a novel compound isolated from Cordyceps bassiana, is able to suppress tumor cell proliferation by inducing apoptosis. To mass-produce this compound, we established a total synthesis method. Using those conditions, we further synthesized various analogs with structural similarity to KTH-13. In this study, we aimed to test their anti-cancer activity by measuring anti-proliferative and pro-apoptotic activities. Of 8 compounds tested, 4-methyl-2,6-bis(1-phenylethyl)phenol (KTH-13-Me) exhibited the strongest anti-proliferative activity toward MDA-MB 231 cells. KTH-13-Me also similarly suppressed the survival of various cancer cell lines, including C6 glioma, HCT-15, and LoVo cells. Treatment of KTH-13-Me induced several apoptotic signs in C6 glioma cells, such as morphological changes, induction of apoptotic bodies, and nuclear fragmentation and chromatin condensation. Concordantly, early-apoptotic cells were also identified by staining with FITC-Annexin V/PI. Moreover, KTH-13-Me highly enhanced the activation of caspase-3 and caspase-9, and decreased the protein level of Bcl-2. In addition, the phosphorylation levels of Src and STAT3 were diminished in KTH-13-Me-treated C6 cells. Therefore, these results suggest that KTH-13-Me can be developed as a novel anti-cancer drug capable of blocking proliferation, inducing apoptosis, and blocking cell survival signaling in cancer cells. PMID:27068261

  16. The neural stem cell fate determinant TRIM32 regulates complex behavioral traits

    Directory of Open Access Journals (Sweden)

    Anna-Lena eHillje

    2015-03-01

    Full Text Available In mammals, new neurons are generated throughout the entire lifespan in two restricted areas of the brain, the dentate gyrus (DG of the hippocampus and the subventricular zone (SVZ – olfactory bulb (OB system. In both regions newborn neurons display unique properties that clearly distinguish them from mature neurons. Enhanced excitability and increased synaptic plasticity enables them to add specific properties to information processing by modulating the existing local circuitry of already established mature neurons. Hippocampal neurogenesis has been suggested to play a role in spatial-navigation learning, spatial memory and spatial pattern separation. Cumulative evidences implicate that adult-born OB neurons contribute to learning processes and odor memory. We recently demonstrated that the cell fate determinant TRIM32 is upregulated in differentiating neuroblasts of the SVZ-OB system in the adult mouse brain. The absence of TRIM32 leads to increased progenitor cell proliferation and less cell death. Both effects accumulate in an overproduction of adult-generated OB neurons. Here, we present novel data from behavioral studies showing that such an enhancement of OB neurogenesis not necessarily leads to increased olfactory performance but in contrast even results in impaired olfactory capabilities. In addition, we show at the cellular level that TRIM32 protein levels increase during differentiation of neural stem cells. At the molecular level, several metabolic intermediates that are connected to glycolysis, glycine or cysteine metabolism are deregulated in TRIM32 knockout mice brain tissue. These metabolomics pathways are directly or indirectly linked to anxiety or depression like behavior. In summary, our study provides comprehensive data on how the impairment of neurogenesis caused by the loss of the cell fate determinant TRIM32 causes a decrease of olfactory performance as well as a deregulation of metabolomic pathways that are linked to

  17. Moving epithelia: Tracking the fate of mammalian limbal epithelial stem cells.

    Science.gov (United States)

    Di Girolamo, Nick

    2015-09-01

    Lineage tracing allows the destiny of a stem cell (SC) and its progeny to be followed through time. In order to track their long-term fate, SC must be permanently marked to discern their distribution, division, displacement and differentiation. This information is essential for unravelling the mysteries that govern their replenishing activity while they remain anchored within their niche microenvironment. Modern-day lineage tracing uses inducible genetic recombination to illuminate cells within embryonic, newborn and adult tissues, and the advent of powerful high-resolution microscopy has enabled the behaviour of labelled cells to be monitored in real-time in a living organism. The simple structural organization of the mammalian cornea, including its accessibility and transparency, renders it the ideal tissue to study SC fate using lineage tracing assisted by non-invasive intravital microscopy. Despite more than a century of research devoted to understanding how this tissue is maintained and repaired, many limitations and controversies continue to plague the field, including uncertainties about the specificity of current SC markers, the number of SC within the cornea, their mode of division, their location, and importantly the signals that dictate cell migration. This communication will highlight historical discoveries as well as recent developments in the corneal SC field; more specifically how the progeny of these cells are mobilised to replenish this dynamic tissue during steady-state, disease and transplantation. Also discussed is how insights gleaned from animal studies can be used to advance our knowledge of the fundamental mechanisms that govern modelling and remodelling of the human cornea in health and disease.

  18. Expression of an activated rasD gene changes cell fate decisions during Dictyostelium development.

    Science.gov (United States)

    Louis, S A; Spiegelman, G B; Weeks, G

    1997-02-01

    It has been previously demonstrated that the expression of an activated rasD gene in wild-type Dictyostelium cells results in formation of aggregates with multitips, instead of the normal single tips, and a block in further development. In an attempt to better understand the role of activated RasD development, we examined cell-type-specific gene expression in a strain stably expressing high levels of RasD[G12T]. We found that the expression of prestalk cell-specific genes ecmA and tagB was markedly enhanced, whereas the expression of the prespore cell-specific gene cotC was reduced to very low levels. When the fate of cells in the multitipped aggregate was monitored with an ecmA/lacZ fusion, it appeared that most of the cells eventually adopted prestalk gene expression characteristics. When mixtures of the [G12T]rasD cells and Ax3 cells were induced to differentiate, chimeric pseudoplasmodia were not formed. Thus, although the [G12T]rasD transformant had a marked propensity to form prestalk cells, it could not supply the prestalk cell population when mixed with wild-type cells. Both stalk and spore cell formation occurred in low cell density monolayers of the [G12T]rasD strain, suggesting that at least part of the inhibition of stalk and spore formation during multicellular development involved inhibitory cell interactions within the cell mass. Models for the possible role of rasD in development are discussed.

  19. Phosphorylation of the Polarity Protein BASL Differentiates Asymmetric Cell Fate through MAPKs and SPCH.

    Science.gov (United States)

    Zhang, Ying; Guo, Xiaoyu; Dong, Juan

    2016-11-07

    Cell polarization is commonly used for the regulation of stem cell asymmetric division in both animals and plants. Stomatal development in Arabidopsis, a process that produces breathing pores in the epidermis, requires asymmetric cell division to differentiate highly specialized guard cells while maintaining a stem cell population [1, 2]. The BREAKING OF ASYMMETRY IN THE STOMATAL LINEAGE (BASL) protein exhibits a polarized localization pattern in the cell and is required for differential cell fates resulting from asymmetric cell division [3]. The polarization of BASL is made possible by a positive feedback loop with a canonical mitogen-activated protein kinase (MAPK) pathway that recruits the MAPKK kinase YODA (YDA) and MAPK 6 (MPK6) to the cortical polarity site [4]. Here, we study BASL intracellular dynamics and show that the membrane-associated BASL is slowly replenished at the cortical polarity site and that the mobility is tightly linked to its phosphorylation status. Because BASL polarity is only exhibited by one daughter cell after an asymmetric cell division, we study how BASL differentially functions in the two daughter cells. The YDA MAPK cascade transduces upstream ligand-receptor signaling [5-13] to the transcription factor SPEECHLESS (SPCH), which controls stomatal initiation and is directly suppressed by MPK3/6-mediated phosphorylation [14, 15]. We show that BASL polarization leads to elevated nuclear MPK6 signaling and lowered SPCH abundance in one of the two daughter cells. Therefore, two daughter cells are differentiated by BASL polarity-mediated differential suppression of SPCH, which may provide developmental plasticity in plant stem cell asymmetric cell division (ACD).

  20. An interplay between extracellular signalling and the dynamics of the exit from pluripotency drives cell fate decisions in mouse ES cells

    Directory of Open Access Journals (Sweden)

    David A. Turner

    2014-06-01

    Full Text Available Embryonic Stem cells derived from the epiblast tissue of the mammalian blastocyst retain the capability to differentiate into any adult cell type and are able to self-renew indefinitely under appropriate culture conditions. Despite the large amount of knowledge that we have accumulated to date about the regulation and control of self-renewal, efficient directed differentiation into specific tissues remains elusive. In this work, we have analysed in a systematic manner the interaction between the dynamics of loss of pluripotency and Activin/Nodal, BMP4 and Wnt signalling in fate assignment during the early stages of differentiation of mouse ES cells in culture. During the initial period of differentiation, cells exit from pluripotency and enter an Epi-like state. Following this transient stage, and under the influence of Activin/Nodal and BMP signalling, cells face a fate choice between differentiating into neuroectoderm and contributing to Primitive Streak fates. We find that Wnt signalling does not suppress neural development as previously thought and that it aids both fates in a context dependent manner. Our results suggest that as cells exit pluripotency they are endowed with a primary neuroectodermal fate and that the potency to become endomesodermal rises with time. We suggest that this situation translates into a “race for fates” in which the neuroectodermal fate has an advantage.

  1. Protein Kinase B Controls Transcriptional Programs that Direct Cytotoxic T Cell Fate but Is Dispensable for T Cell Metabolism

    Science.gov (United States)

    Macintyre, Andrew N.; Finlay, David; Preston, Gavin; Sinclair, Linda V.; Waugh, Caryll M.; Tamas, Peter; Feijoo, Carmen; Okkenhaug, Klaus; Cantrell, Doreen A.

    2011-01-01

    Summary In cytotoxic T cells (CTL), Akt, also known as protein kinase B, is activated by the T cell antigen receptor (TCR) and the cytokine interleukin 2 (IL-2). Akt can control cell metabolism in many cell types but whether this role is important for CTL function has not been determined. Here we have shown that Akt does not mediate IL-2- or TCR-induced cell metabolic responses; rather, this role is assumed by other Akt-related kinases. There is, however, a nonredundant role for sustained and strong activation of Akt in CTL to coordinate the TCR- and IL-2-induced transcriptional programs that control expression of key cytolytic effector molecules, adhesion molecules, and cytokine and chemokine receptors that distinguish effector versus memory and naive T cells. Akt is thus dispensable for metabolism, but the strength and duration of Akt activity dictates the CTL transcriptional program and determines CTL fate. PMID:21295499

  2. Bar represses dPax2 and decapentaplegic to regulate cell fate and morphogenetic cell death in Drosophila eye.

    Directory of Open Access Journals (Sweden)

    Jongkyun Kang

    Full Text Available The coordinated regulation of cell fate and cell survival is crucial for normal pattern formation in developing organisms. In Drosophila compound eye development, crystalline arrays of hexagonal ommatidia are established by precise assembly of diverse cell types, including the photoreceptor cells, cone cells and interommatidial (IOM pigment cells. The molecular basis for controlling the number of cone and IOM pigment cells during ommatidial pattern formation is not well understood. Here we present evidence that BarH1 and BarH2 homeobox genes are essential for eye patterning by inhibiting excess cone cell differentiation and promoting programmed death of IOM cells. Specifically, we show that loss of Bar from the undifferentiated retinal precursor cells leads to ectopic expression of Prospero and dPax2, two transcription factors essential for cone cell specification, resulting in excess cone cell differentiation. We also show that loss of Bar causes ectopic expression of the TGFβ homolog Decapentaplegic (Dpp posterior to the morphogenetic furrow in the larval eye imaginal disc. The ectopic Dpp expression is not responsible for the formation of excess cone cells in Bar loss-of-function mutant eyes. Instead, it causes reduction in IOM cell death in the pupal stage by antagonizing the function of pro-apoptotic gene reaper. Taken together, this study suggests a novel regulatory mechanism in the control of developmental cell death in which the repression of Dpp by Bar in larval eye disc is essential for IOM cell death in pupal retina.

  3. Genetic control of murine T cell proliferative responses to Mycobacterium leprae. V. Evidence for cross-reactivity between host antigens and Mycobacterium leprae

    Energy Technology Data Exchange (ETDEWEB)

    Harris, D.P.; Jones, A.G.; Wade, S.; Krahenbuhl, J.L.; Gillis, T.P.; Watson, J.D.

    1988-09-01

    T cell proliferative responses to Mycobacterium leprae were measured by immunization of mice at the base of the tail with Ag and challenging lymphocytes from draining lymph nodes in culture with M. leprae. C57BL/10J and B10.BR mice were identified as low responder mice and the congenic strains B10.M, B10.Q, and B10.AKM as high responders whereas F1 (high x low) hybrid mice were found to be low responders. The cellular basis of low responsiveness did not appear to result from a defect in Ag-presenting cells or the activation of suppressor T cells by M. leprae. The influence of the environment in which T cells developed on responsiveness to M. leprae was analyzed in chimeric mice prepared by irradiating F1(C57BL/10J x B10.M) mice and reconstituting with bone marrow from C57BL/10J, B10.M, or F1 donors. Six weeks later, chimeric mice were immunized with M. leprae, lymph node cells were subsequently prepared, and H-2 phenotyped and challenged in culture with M. leprae Ag. T cell proliferative responses were found to be low in all cases, similar to those observed using lymph node cells from F1 hybrid mice. These results suggested that high responder B10.M lymphocytes developing in the irradiated F1 mice became tolerized to antigenic determinants found on M. leprae. This implied cross-reactive epitopes existed between some mouse strains and M. leprae. Low responsiveness to M. leprae in low responder and F1 hybrid mice may result from tolerance to H-2-encoded Ag that show cross-reactivity with M. leprae.

  4. Eya1 controls cell polarity, spindle orientation, cell fate and Notch signaling in distal embryonic lung epithelium.

    Science.gov (United States)

    El-Hashash, Ahmed H K; Turcatel, Gianluca; Al Alam, Denise; Buckley, Sue; Tokumitsu, Hiroshi; Bellusci, Saverio; Warburton, David

    2011-04-01

    Cell polarity, mitotic spindle orientation and asymmetric division play a crucial role in the self-renewal/differentiation of epithelial cells, yet little is known about these processes and the molecular programs that control them in embryonic lung distal epithelium. Herein, we provide the first evidence that embryonic lung distal epithelium is polarized with characteristic perpendicular cell divisions. Consistent with these findings, spindle orientation-regulatory proteins Insc, LGN (Gpsm2) and NuMA, and the cell fate determinant Numb are asymmetrically localized in embryonic lung distal epithelium. Interfering with the function of these proteins in vitro randomizes spindle orientation and changes cell fate. We further show that Eya1 protein regulates cell polarity, spindle orientation and the localization of Numb, which inhibits Notch signaling. Hence, Eya1 promotes both perpendicular division as well as Numb asymmetric segregation to one daughter in mitotic distal lung epithelium, probably by controlling aPKCζ phosphorylation. Thus, epithelial cell polarity and mitotic spindle orientation are defective after interfering with Eya1 function in vivo or in vitro. In addition, in Eya1(-/-) lungs, perpendicular division is not maintained and Numb is segregated to both daughter cells in mitotic epithelial cells, leading to inactivation of Notch signaling. As Notch signaling promotes progenitor cell identity at the expense of differentiated cell phenotypes, we test whether genetic activation of Notch could rescue the Eya1(-/-) lung phenotype, which is characterized by loss of epithelial progenitors, increased epithelial differentiation but reduced branching. Indeed, genetic activation of Notch partially rescues Eya1(-/-) lung epithelial defects. These findings uncover novel functions for Eya1 as a crucial regulator of the complex behavior of distal embryonic lung epithelium.

  5. Increased Connexin 43 Expression Improves the Migratory and Proliferative Ability of H9c2 Cells by Wnt-3a Overexpression

    Institute of Scientific and Technical Information of China (English)

    Xiaoyu LIU; Wen LIU; Ling YANG; Beili XIA; Jinyan LI; Ji ZUO; Xiaotian LI

    2007-01-01

    The change of connexin 43 (Cx43) expression and the biological behaviors of Cx43 in rat heart cell line H9c2, expressing Wnt-3a (wingless-type MMTV integration site family, member 3A), were evaluated in the present study. Plasmid pcDNA3.1/Wnt-3a was constructed and transferred into H9c2 cells.The cell model Wnt-3a+-H9c2 steadily expressing Wnt-3a was obtained. Compared with H9c2 and pcDNA3.1-H9c2 cells, the expression of Cx43 in Wnt-3a+-H9c2 cells was clearly increased, the proliferation of Wnt-3a+-H9c2 cells was significantly changed, and cell migration abilities were also improved (P<0.05).In comparison with H9c2 and pcDNA3.1-H9c2 cells, the G2 phase of the cell cycle increased by 11% in Wnt-3a+-H9c2 cells. Thus, Wnt-3a overexpression is associated with an increase in Cx43 expression and altered migratory and proliferative activity in H9c2 cells. Cx43 might be one of the downstream target genes regulated by Wnt-3a.

  6. Role of PUF-8/PUF protein in stem cell control, sperm-oocyte decision and cell fate reprogramming.

    Science.gov (United States)

    Datla, Udaya Sree; Scovill, Natasha Carol; Brokamp, Austin J; Kim, Eunsuk; Asch, Adam S; Lee, Myon-Hee

    2014-10-01

    Pumilio and FBF (PUF) proteins are conserved stem cell regulators that maintain germline stem cells (GSCs) in worms and flies. Moreover, they are also present in vertebrate stem cells. The nematode Caenorhabditis elegans has multiple PUF proteins with specialized roles. Among them, PUF-8 protein controls multiple cellular processes, including proliferation, differentiation, sperm-oocyte decision, and cell fate reprogramming, depending on the genetic context in the C. elegans germline. In this review, we describe the possible mechanisms of how PUF-8 protein systematically controls multiple cellular processes in the C. elegans germline. Since PUF proteins are evolutionarily conserved, we suggest that a similar mechanism may be involved in controlling stem cell regulation and differentiation in other organisms, including humans.

  7. The neural crest stem cells: control of neural crest cell fate and plasticity by endothelin-3

    Directory of Open Access Journals (Sweden)

    ELISABETH DUPIN

    2001-12-01

    Full Text Available How the considerable diversity of neural crest (NC-derived cell types arises in the vertebrate embryo has long been a key question in developmental biology. The pluripotency and plasticity of differentiation of the NC cell population has been fully documented and it is well-established that environmental cues play an important role in patterning the NC derivatives throughout the body. Over the past decade, in vivo and in vitro cellular approaches have unravelled the differentiation potentialities of single NC cells and led to the discovery of NC stem cells. Although it is clear that the final fate of individual cells is in agreement with their final position within the embryo, it has to be stressed that the NC cells that reach target sites are pluripotent and further restrictions occur only late in development. It is therefore a heterogenous collection of cells that is submitted to local environmental signals in the various NC-derived structures. Several factors were thus identified which favor the development of subsets of NC-derived cells in vitro. Moreover, the strategy of gene targeting in mouse has led at identifying new molecules able to control one or several aspects of NC cell differentiation in vivo. Endothelin peptides (and endothelin receptors are among those. The conjunction of recent data obtained in mouse and avian embryos and reviewed here contributes to a better understanding of the action of the endothelin signaling pathway in the emergence and stability of NC-derived cell phenotypes.O modo como a diversidade dos tipos celulares derivados da crista neural (CN surge, no embrião de vertebrado, tem sido uma pergunta chave na biologia do desenvolvimento. A pluripotência e a plasticidade na diferenciação da população de células da CN têm sido intensivamente documentadas, ficando deste modo estabelecido que os factores ambientais têm um papel importante na correta diferenciação dos derivados da CN no organismo. Na d

  8. Thidiazuron Triggers Morphogenesis in Rosa canina L. Protocorm-Like Bodies by Changing Incipient Cell Fate

    Science.gov (United States)

    Kou, Yaping; Yuan, Cunquan; Zhao, Qingcui; Liu, Guoqin; Nie, Jing; Ma, Zhimin; Cheng, Chenxia; Teixeira da Silva, Jaime A.; Zhao, Liangjun

    2016-01-01

    Thidiazuron (N-phenyl-N′-1,2,3-thiadiazol-5-ylurea; TDZ) is an artificial plant growth regulator that is widely used in plant tissue culture. Protocorm-like bodies (PLBs) induced by TDZ serve as an efficient and rapid in vitro regeneration system in Rosa species. Despite this, the mechanism of PLB induction remains relatively unclear. TDZ, which can affect the level of endogenous auxins and cytokinins, converts the cell fate of rhizoid tips and triggers PLB formation and plantlet regeneration in Rosa canina L. In callus-rhizoids, which are rhizoids that co-develop from callus, auxin and a Z-type cytokinin accumulated after applying TDZ, and transcription of the auxin transporter gene RcPIN1 was repressed. The expression of RcARF4, RcRR1, RcCKX2, RcCKX3, and RcLOG1 increased in callus-rhizoids and rhizoid tips while the transcription of an auxin response factor (RcARF1) and auxin transport proteins (RcPIN2, RcPIN3) decreased in callus-rhizoids but increased in rhizoid tips. In situ hybridization of rhizoids showed that RcWUS and RcSERK1 were highly expressed in columella cells and root stem cells resulting in the conversion of cell fate into shoot apical meristems or embryogenic callus. In addition, transgenic XVE::RcWUS lines showed repressed RcWUS overexpression while RcWUS had no effect on PLB morphogenesis. Furthermore, higher expression of the root stem cell marker RcWOX5 and root stem cell maintenance regulator genes RcPLT1 and RcPLT2 indicated the presence of a dedifferentiation developmental pathway in the stem cell niche of rhizoids. Viewed together, our results indicate that different cells in rhizoid tips acquired regeneration competence after induction by TDZ. A novel developmental pathway containing different cell types during PLB formation was identified by analyzing the endogenous auxin and cytokinin content. This study also provides a deeper understanding of the mechanisms underlying in vitro regeneration in Rosa. PMID:27200031

  9. Forced expression of Hnf1b/Foxa3 promotes hepatic fate of embryonic stem cells.

    Science.gov (United States)

    Yahoo, Neda; Pournasr, Behshad; Rostamzadeh, Jalal; Hakhamaneshi, Mohammad Saeed; Ebadifar, Asghar; Fathi, Fardin; Baharvand, Hossein

    2016-05-20

    Embryonic stem (ES) cell-derived hepatocytes have the potential to be used for basic research, regenerative medicine, and drug discovery. Recent reports demonstrated that in addition to conventional differentiation inducers such as chemical compounds and cytokines, overexpression of lineage-specific transcription factors could induce ES cells to differentiate to a hepatic fate. Here, we hypothesized that lentivirus-mediated inducible expression of hepatic lineage transcription factors could enhance mouse ES cells to hepatocyte-like cells. We screened the effects of candidate transcription factors Hnf1b, Hnf1a, Hnf4a, Foxa1, Foxa3 and Hex, and determined that the combination of Hnf1b/Foxa3 promoted expression of several hepatic lineage-specific markers and proteins, in addition to glycogen storage, ICG uptake, and secretion of albumin and urea. The differentiated cells were engraftable and expressed albumin when transplanted into a carbon tetrachloride-injured mouse model. These results demonstrated the crucial role of Hnf1b and Foxa3 in hepatogenesis in vitro and provided a valuable tool for the efficient differentiation of HLCs from ES cells.

  10. Matrix stiffness determines the fate of nucleus pulposus-derived stem cells.

    Science.gov (United States)

    Navaro, Yosi; Bleich-Kimelman, Nadav; Hazanov, Lena; Mironi-Harpaz, Iris; Shachaf, Yonatan; Garty, Shai; Smith, Yoav; Pelled, Gadi; Gazit, Dan; Seliktar, Dror; Gazit, Zulma

    2015-05-01

    Intervertebral disc (IVD) degeneration and consequent low-back pain present a major medical challenge. Nucleus pulposus-derived stem cells (NP-SCs) may lead to a novel therapy for this severe disease. It was recently shown that survival and function of mature NP cells are regulated in part by tissue stiffness. We hypothesized that modification of matrix stiffness will influence the ability of cultured NP-SCs to proliferate, survive, and differentiate into mature NP cells. NP-SCs were subcultured in three-dimensional matrices of varying degrees of stiffness as measured by the material's shear storage modulus. Cell survival, activity, and rate of differentiation toward the chondrogenic or osteogenic lineage were analyzed. NP-SCs were found to proliferate and differentiate in all matrices, irrespective of matrix stiffness. However, matrices with a low shear storage modulus (G' = 1 kPa) promoted significantly more proliferation and chondrogenic differentiation, whereas matrices with a high modulus (G' = 2 kPa) promoted osteogenic differentiation. Imaging performed via confocal and scanning electron microscopes validated cell survival and highlighted stiffness-dependent cell-matrix interactions. These results underscore the effect of the matrix modulus on the fate of NP-SCs. This research may facilitate elucidation of the complex cross-talk between NP-SCs and their surrounding matrix in healthy as well as pathological conditions.

  11. Human stem cells from single blastomeres reveal pathways of embryonic or trophoblast fate specification.

    Science.gov (United States)

    Zdravkovic, Tamara; Nazor, Kristopher L; Larocque, Nicholas; Gormley, Matthew; Donne, Matthew; Hunkapillar, Nathan; Giritharan, Gnanaratnam; Bernstein, Harold S; Wei, Grace; Hebrok, Matthias; Zeng, Xianmin; Genbacev, Olga; Mattis, Aras; McMaster, Michael T; Krtolica, Ana; Valbuena, Diana; Simón, Carlos; Laurent, Louise C; Loring, Jeanne F; Fisher, Susan J

    2015-12-01

    Mechanisms of initial cell fate decisions differ among species. To gain insights into lineage allocation in humans, we derived ten human embryonic stem cell lines (designated UCSFB1-10) from single blastomeres of four 8-cell embryos and one 12-cell embryo from a single couple. Compared with numerous conventional lines from blastocysts, they had unique gene expression and DNA methylation patterns that were, in part, indicative of trophoblast competence. At a transcriptional level, UCSFB lines from different embryos were often more closely related than those from the same embryo. As predicted by the transcriptomic data, immunolocalization of EOMES, T brachyury, GDF15 and active β-catenin revealed differential expression among blastomeres of 8- to 10-cell human embryos. The UCSFB lines formed derivatives of the three germ layers and CDX2-positive progeny, from which we derived the first human trophoblast stem cell line. Our data suggest heterogeneity among early-stage blastomeres and that the UCSFB lines have unique properties, indicative of a more immature state than conventional lines.

  12. Proliferative retinopathy predicts nephropathy

    DEFF Research Database (Denmark)

    Karlberg, Charlotte; Falk, Christine; Green, Anders;

    2012-01-01

    We wanted to examine proliferative retinopathy as a marker of incident nephropathy in a 25-year follow-up study of a population-based cohort of Danish type 1 diabetic patients and to examine cross-sectional associations between nephropathy and retinopathy in long-term surviving patients of the same...... photographs at follow-up. Single spot urine was used to evaluate nephropathy at both examinations. Proliferative retinopathy was present in 29 patients (15.8%) at baseline. At follow-up, these patients were more likely to macroalbuminuria (20.7% vs. 6.5%) than patients without proliferative retinopathy...... at baseline. In a multivariate logistic regression adjusted for baseline age, sex, duration of diabetes, smoking, HbA(1,) systolic and diastolic blood pressure, odds ratio of nephropathy (micro- and macroalbuminuria combined) was 2.98 (95% confidence interval 1.18-7.51, p = 0.02) for patients...

  13. Duration of culture and sonic hedgehog signaling differentially specify PV versus SST cortical interneuron fates from embryonic stem cells.

    Science.gov (United States)

    Tyson, Jennifer A; Goldberg, Ethan M; Maroof, Asif M; Xu, Qing; Petros, Timothy J; Anderson, Stewart A

    2015-04-01

    Medial ganglionic eminence (MGE)-derived GABAergic cortical interneurons (cINs) consist of multiple subtypes that are involved in many cortical functions. They also have a remarkable capacity to migrate, survive and integrate into cortical circuitry after transplantation into postnatal cortex. These features have engendered considerable interest in generating distinct subgroups of interneurons from pluripotent stem cells (PSCs) for the study of interneuron fate and function, and for the development of cell-based therapies. Although advances have been made, the capacity to generate highly enriched pools of subgroup fate-committed interneuron progenitors from PSCs has remained elusive. Previous studies have suggested that the two main MGE-derived interneuron subgroups--those expressing somatostatin (SST) and those expressing parvalbumin (PV)--are specified in the MGE from Nkx2.1-expressing progenitors at higher or lower levels of sonic hedgehog (Shh) signaling, respectively. To further explore the role of Shh and other factors in cIN fate determination, we generated a reporter line such that Nkx2.1-expressing progenitors express mCherry and postmitotic Lhx6-expressing MGE-derived interneurons express GFP. Manipulations of Shh exposure and time in culture influenced the subgroup fates of ESC-derived interneurons. Exposure to higher Shh levels, and collecting GFP-expressing precursors at 12 days in culture, resulted in the strongest enrichment for SST interneurons over those expressing PV, whereas the strongest enrichment for PV interneurons was produced by lower Shh and by collecting mCherry-expressing cells after 17 days in culture. These findings confirm that fate determination of cIN subgroups is crucially influenced by Shh signaling, and provide a system for the further study of interneuron fate and function.

  14. Fss/Tbx6 is required for central dermomyotome cell fate in zebrafish

    Directory of Open Access Journals (Sweden)

    Stefanie Elisabeth Windner

    2012-06-01

    The dermomyotome is a pool of progenitor cells on the surface of the myotome. In zebrafish, dermomyotome precursors (anterior border cells, ABCs can be first identified in the anterior portion of recently formed somites. They must be prevented from undergoing terminal differentiation during segmentation, even while mesodermal cells around them respond to signaling cues and differentiate. T-box containing transcription factors regulate many aspects of mesoderm fate including segmentation and somite patterning. The fused somites (fss gene is the zebrafish ortholog of tbx6. We demonstrate that in addition to its requirement for segmentation, fss/tbx6 is also required for the specification of ABCs and subsequently the central dermomyotome. The absence of Tbx6-dependent central dermomyotome cells in fss/tbx6 mutants is spatially coincident with a patterning defect in the myotome. Using transgenic fish with a heat-shock inducible tbx6 gene in the fss/tbx6 mutant background, we further demonstrate that ubiquitous fss/tbx6 expression has spatially distinct effects on recovery of the dermomyotome and segment boundaries, suggesting that the mechanism of Fss/Tbx6 action is distinct with respect to dermomyotome development and segmentation. We propose that Fss/Tbx6 is required for preventing myogenic differentiation of central dermomyotome precursors before and after segmentation and that central dermomyotome cells represent a genetically and functionally distinct subpopulation within the zebrafish dermomyotome.

  15. The selector gene Pax7 dictates alternate pituitary cell fates through its pioneer action on chromatin remodeling

    NARCIS (Netherlands)

    Budry, L.; Balsalobre, A.; Gauthier, Y.; Khetchoumian, K.; L'Honore, A.; Vallette-Kasic, S.; Brue, T; Figarella-Branger, D.; Meij, B.P.; Drouin, J.

    2012-01-01

    Genes Dev. 2012 Oct 15;26(20):2299-310. doi: 10.1101/gad.200436.112. The selector gene Pax7 dictates alternate pituitary cell fates through its pioneer action on chromatin remodeling. Budry L, Balsalobre A, Gauthier Y, Khetchoumian K, L'honoré A, Vallette S, Brue T, Figarella-Branger D, Meij B, Drou

  16. A peroxisome proliferator-activated receptor ligand MCC-555 imparts anti-proliferative response in pancreatic cancer cells by PPARgamma-independent up-regulation of KLF4

    Energy Technology Data Exchange (ETDEWEB)

    Min, Kyung-Won [Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996 (United States); Zhang, Xiaobo [Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996 (United States); College of Animal Science and Technology, Northwest A and F University, Yangling, Shaanxi, 712100 (China); Imchen, Temjenmongla [Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996 (United States); Baek, Seung Joon, E-mail: sbaek2@utk.edu [Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996 (United States)

    2012-09-01

    MCC-555 is a novel PPARα/γ dual ligand of the thiazolidinedione class and was recently developed as an anti-diabetic drug with unique properties. MCC-555 also has anti-proliferative activity through growth inhibition and apoptosis induction in several cancer cell types. Our group has shown that MCC-555 targets several proteins in colorectal tumorigenesis including nonsteroidal anti-inflammatory drug (NSAID)-activated gene (NAG-1) which plays an important role in chemoprevention responsible for chemopreventive compounds. NAG-1 is a member of the TGF-β superfamily and is involved in tumor progression and development; however, NAG-1's roles in pancreatic cancer have not been studied. In this report, we found that MCC-555 alters not only NAG-1 expression, but also p21 and cyclin D1 expression. NAG-1 and p21 expression was not blocked by PPARγ-specific antagonist GW9662, suggesting that MCC-555-induced NAG-1 and p21 expression is independent of PPARγ activation. However, decreasing cyclin D1 by MCC-555 seems to be affected by PPARγ activation. Further, we found that the GC box located in the NAG-1 promoter play an important role in NAG-1 transactivation by MCC-555. Subsequently, we screened several transcription factors that may bind to the GC box region in the NAG-1 promoter and found that KLF4 potentially binds to this region. Expression of KLF4 precedes NAG-1 and p21 expression in the presence of MCC-555, whereas blocking KLF4 expression using specific KLF4 siRNA showed that both NAG-1 and p21 expression by MCC-555 was blocked. In conclusion, MCC-555's actions on anti-proliferation involve both PPARγ-dependent and -independent pathways, thereby enhancing anti-tumorigenesis in pancreatic cancer cells. -- Highlights: ► PPARα/γ ligand MCC-555 exhibits anti-proliferative activity in pancreatic cancer cells. ► MCC-555 affects KLF4 expression following by NAG-1 and p21 expression in a PPARγ independent manner. ► MCC-555 also affects cyclin D1 down

  17. Revealing the fate of cell surface human P-glycoprotein (ABCB1): The Lysosomal Degradation Pathway

    Science.gov (United States)

    Katayama, Kazuhiro; Kapoor, Khyati; Ohnuma, Shinobu; Patel, Atish; Swaim, William; Ambudkar, Indu S.; Ambudkar, Suresh V.

    2015-01-01

    P-glycoprotein (P-gp) transports a variety of chemically dissimilar amphipathic compounds including anticancer drugs. Although mechanisms of P-gp drug transport are widely studied, the pathways involving its internalization are poorly understood. The present study is aimed at elucidating the pathways involved in degradation of cell surface P-gp. The fate of P-gp at the cell surface was determined by biotinylating cell surface proteins followed by flow cytometry and Western blotting. Our data shows that the half-life of endogenously expressed P-gp is 26.7 ± 1.1 h in human colorectal cancer HCT-15 cells. Treatment of cells with Bafilomycin A1 (BafA1) a vacuolar H+ ATPase inhibitor increased the half-life of P-gp at the cell surface to 36.1± 0.5 h. Interestingly, treatment with the proteasomal inhibitors MG132, MG115 or lactacystin alone did not alter the half-life of the protein. When cells were treated with both lysosomal and proteasomal inhibitors (BafA1 and MG132), the half-life was further prolonged to 39-50 h. Functional assays done with rhodamine 123 or calcein-AM, fluorescent substrates of P-gp, indicated that the transport function of P-gp was not affected by either biotinylation or treatment with BafA1 or proteasomal inhibitors. Immunofluorescence studies done with the antibody against lysosomal marker LAMP1 and the P-gp-specific antibody UIC2 in permeabilized cells indicated that intracellular P-gp is primarily localized in the lysosomal compartment. Our results suggest that the lysosomal degradation system could be targeted to increase the sensitivity of P-gp expressing cancer cells towards chemotherapeutic drugs. PMID:26057472

  18. Revealing the fate of cell surface human P-glycoprotein (ABCB1): The lysosomal degradation pathway.

    Science.gov (United States)

    Katayama, Kazuhiro; Kapoor, Khyati; Ohnuma, Shinobu; Patel, Atish; Swaim, William; Ambudkar, Indu S; Ambudkar, Suresh V

    2015-10-01

    P-glycoprotein (P-gp) transports a variety of chemically dissimilar amphipathic compounds including anticancer drugs. Although mechanisms of P-gp drug transport are widely studied, the pathways involving its internalization are poorly understood. The present study is aimed at elucidating the pathways involved in degradation of cell surface P-gp. The fate of P-gp at the cell surface was determined by biotinylating cell surface proteins followed by flow cytometry and Western blotting. Our data shows that the half-life of endogenously expressed P-gp is 26.7±1.1 h in human colorectal cancer HCT-15 cells. Treatment of cells with Bafilomycin A1 (BafA1) a vacuolar H+ ATPase inhibitor increased the half-life of P-gp at the cell surface to 36.1±0.5 h. Interestingly, treatment with the proteasomal inhibitors MG132, MG115 or lactacystin alone did not alter the half-life of the protein. When cells were treated with both lysosomal and proteasomal inhibitors (BafA1 and MG132), the half-life was further prolonged to 39-50 h. Functional assays done with rhodamine 123 or calcein-AM, fluorescent substrates of P-gp, indicated that the transport function of P-gp was not affected by either biotinylation or treatment with BafA1 or proteasomal inhibitors. Immunofluorescence studies done with the antibody against lysosomal marker LAMP1 and the P-gp-specific antibody UIC2 in permeabilized cells indicated that intracellular P-gp is primarily localized in the lysosomal compartment. Our results suggest that the lysosomal degradation system could be targeted to increase the sensitivity of P-gp- expressing cancer cells towards chemotherapeutic drugs.

  19. Anti Proliferative and Pro Apoptotic Effects of Flavonoid Quercetin Are Mediated by CB1 Receptor in Human Colon Cancer Cell Lines.

    Science.gov (United States)

    Refolo, Maria Grazia; D'Alessandro, Rosalba; Malerba, Natascia; Laezza, Chiara; Bifulco, Maurizio; Messa, Caterina; Caruso, Maria Gabriella; Notarnicola, Maria; Tutino, Valeria

    2015-12-01

    Quercetin, the major constituent of flavonoid and widely present in fruits and vegetables, is an attractive compound for cancer prevention due to its beneficial anti proliferative effects, showing a crucial role in the regulation of apoptosis and cell cycle signaling. In vitro studies have demonstrated that quercetin specifically influences colon cancer cell proliferation. Our experiments, using human colon adenocarcinoma cells, confirmed the anti proliferative effect of quercetin and gave intriguing new insight in to the knowledge of the mechanisms involved. We observed a significant increase in the expression of the endocannabinoids receptor (CB1-R) after quercetin treatment. CB1-R can be considered an estrogen responsive receptor and quercetin, having a structure similar to that of the estrogens, can interact with CB1-R leading to the regulation of cell growth. In order to clarify the contribution of the CB1-R to the quercetin action, we investigated some of the principal molecular pathways that are inhibited or activated by this natural compound. In particular we detected the inhibition of the major survival signals like the PI3K/Akt/mTOR and an induction of the pro apoptotic JNK/JUN pathways. Interestingly, the metabolism of β-catenin was modified by flavonoid both directly and through activated CB1-R. In all the experiments done, the quercetin action has proven to be reinforced by anandamide (Met-F-AEA), a CB1-R agonist, and partially counteracted by SR141716, a CB1-R antagonist. These findings open new perspectives for anticancer therapeutic strategies.

  20. A Blockade of IGF Signaling Sensitizes Human Ovarian Cancer Cells to the Anthelmintic Niclosamide-Induced Anti-Proliferative and Anticancer Activities

    Directory of Open Access Journals (Sweden)

    Youlin Deng

    2016-08-01

    Full Text Available Background/Aims: Ovarian cancer is the most lethal gynecologic malignancy, and there is an unmet clinical need to develop new therapies. Although showing promising anticancer activity, Niclosamide may not be used as a monotherapy. We seek to investigate whether inhibiting IGF signaling potentiates Niclosamide's anticancer efficacy in human ovarian cancer cells. Methods: Cell proliferation and migration are assessed. Cell cycle progression and apoptosis are analyzed by flow cytometry. Inhibition of IGF signaling is accomplished by adenovirus-mediated expression of siRNAs targeting IGF-1R. Cancer-associated pathways are assessed using pathway-specific reporters. Subcutaneous xenograft model is used to determine anticancer activity. Results: We find that Niclosamide is highly effective on inhibiting cell proliferation, cell migration, and cell cycle progression, and inducing apoptosis in human ovarian cancer cells, possibly by targeting multiple signaling pathways involved in ELK1/SRF, AP-1, MYC/MAX and NFkB. Silencing IGF-1R exert a similar but weaker effect than that of Niclosamide's. However, silencing IGF-1R significantly sensitizes ovarian cancer cells to Niclosamide-induced anti-proliferative and anticancer activities both in vitro and in vivo. Conclusion: Niclosamide as a repurposed anticancer agent may be more efficacious when combined with agents that target other signaling pathways such as IGF signaling in the treatment of human cancers including ovarian cancer.

  1. Adaptation of HepG2 cells to silver nanoparticles-induced stress is based on the pro-proliferative and anti-apoptotic changes in gene expression.

    Science.gov (United States)

    Brzóska, Kamil; Męczyńska-Wielgosz, Sylwia; Stępkowski, Tomasz M; Kruszewski, Marcin

    2015-05-01

    Silver nanoparticles (AgNPs) are one of the most widely used nanomaterials due to their antibacterial properties. Owing to the recent boost in the usage of AgNPs-containing products, human exposure to AgNPs is increasing, highlighting the need for careful evaluation of AgNPs toxicity in humans. We used two cellular models, hepatic HepG2 and epithelial A549 cell lines, to study the mechanism of AgNPs-induced toxicity at the cellular level. These two cell lines differ significantly in their response to AgNPs treatment. In the case of A549 cells, a minor decrease in viability and increase in the extent of DNA breakage were observed. A markedly different response to AgNPs was observed in HepG2 cells. In short term, a massive induction of DNA breakage was observed, suggesting that the basal activity of antioxidant defence in these cells was not sufficient to effectively protect them from the nanoparticle-induced oxidative stress. After prolonged exposure, the extent of DNA breakage decreased to the level observed in the control cells proving that a successful adaptation to the new conditions had taken place. The cells that were unable to adapt must have died, as revealed by the Neutral Red assay that indicated less than half viable cells after 24-h treatment with 100 µg/ml of 20nm AgNPs. The gene expression analysis revealed that the observed adaptation was underlain by a pro-proliferative, anti-apoptotic signal leading to up-regulation of the genes promoting proliferation and inflammatory response (EGR1, FOS, JUN, HK2, IL4, MMP10, VEGFA, WISP1, CEBPB, IL8, SELPLG), genes coding the anti-apoptotic proteins (BCL2A1, CCL2) and factors involved in the response to stress (HSPB1, GADD45A). Such a selection of highly resistant population of cells should be taken into account in the case of medical applications of nanoparticles since the sustained proliferative signalling and resistance to cell death are hallmarks of cancer, acquired by the cells in the process of

  2. Signaling regulating inner ear development: cell fate determination, patterning, morphogenesis, and defects.

    Science.gov (United States)

    Nakajima, Yuji

    2015-02-01

    The membranous labyrinth of the inner ear is a highly complex organ that detects sound and balance. Developmental defects in the inner ear cause congenital hearing loss and balance disorders. The membranous labyrinth consists of three semicircular ducts, the utricle, saccule, and endolymphatic ducts, and the cochlear duct. These complex structures develop from the simple otic placode, which is established in the cranial ectoderm adjacent to the neural crest at the level of the hindbrain at the early neurula stage. During development, the otic placode invaginates to form the otic vesicle, which subsequently gives rise to neurons for the vestibulocochlear ganglion, the non-sensory and sensory epithelia of the membranous labyrinth that includes three ampullary crests, two maculae, and the organ of Corti. Combined paracrine and autocrine signals including fibroblast growth factor, Wnt, retinoic acid, hedgehog, and bone morphogenetic protein regulate fate determination, axis formation, and morphogenesis in the developing inner ear. Juxtacrine signals mediated by Notch pathways play a role in establishing the sensory epithelium, which consists of mechanosensory hair cells and supporting cells. The highly differentiated organ of Corti, which consists of uniformly oriented inner/outer hair cells and specific supporting cells, develops during fetal development. Developmental alterations/arrest causes congenital malformations in the inner ear in a spatiotemporal-restricted manner. A clearer understanding of the mechanisms underlying inner ear development is important not only for the management of patients with congenital inner ear malformations, but also for the development of regenerative therapy for impaired function.

  3. Medial HOXA genes demarcate haematopoietic stem cell fate during human development

    Science.gov (United States)

    Dou, Diana R.; Calvanese, Vincenzo; Sierra, Maria I.; Nguyen, Andrew T.; Minasian, Arazin; Saarikoski, Pamela; Sasidharan, Rajkumar; Ramirez, Christina M.; Zack, Jerome A.; Crooks, Gay M.; Galic, Zoran; Mikkola, Hanna K.A.

    2016-01-01

    Pluripotent stem cells (PSC) may provide a potential source of haematopoietic stem/progenitor cells (HSPCs) for transplantation; however, unknown molecular barriers prevent the self-renewal of PSC-HSPCs. Using two-step differentiation, human embryonic stem cells (hESCs) differentiated in vitro into multipotent haematopoietic cells that had CD34+CD38−/loCD90+CD45+GPI-80+ foetal liver (FL) HSC immunophenotype, but displayed poor expansion potential and engraftment ability. Transcriptome analysis of immunophenotypic hESC-HSPCs revealed that, despite their molecular resemblance to FL-HSPCs, medial HOXA genes remained suppressed. Knockdown of HOXA7 disrupted FL-HSPC function and caused transcriptome dysregulation that resembled hESC-derived progenitors. Overexpression of medial HOXA genes prolonged FL-HSPC maintenance but was insufficient to confer self-renewal to hESC-HSPCs. Stimulation of retinoic acid signalling during endothelial-to-haematopoietic transition induced the HOXA cluster and other HSC/definitive haemogenic endothelium genes, and prolonged HSPC maintenance in culture. Thus, retinoic acid signalling-induced medial HOXA gene expression marks the establishment of the definitive HSC fate and controls HSC identity and function. PMID:27183470

  4. Activin and GDF11 collaborate in feedback control of neuroepithelial stem cell proliferation and fate

    Science.gov (United States)

    Gokoffski, Kimberly K.; Wu, Hsiao-Huei; Beites, Crestina L.; Kim, Joon; Kim, Euiseok J.; Matzuk, Martin M.; Johnson, Jane E.; Lander, Arthur D.; Calof, Anne L.

    2011-01-01

    Studies of the olfactory epithelium model system have demonstrated that production of neurons is regulated by negative feedback. Previously, we showed that a locally produced signal, the TGFβ superfamily ligand GDF11, regulates the genesis of olfactory receptor neurons by inhibiting proliferation of the immediate neuronal precursors (INPs) that give rise to them. GDF11 is antagonized by follistatin (FST), which is also produced locally. Here, we show that Fst–/– mice exhibit dramatically decreased neurogenesis, a phenotype that can only be partially explained by increased GDF11 activity. Instead, a second FST-binding factor, activin βB (ACTβB), inhibits neurogenesis by a distinct mechanism: whereas GDF11 inhibits expansion of INPs, ACTβB inhibits expansion of stem and early progenitor cells. We present data supporting the concept that these latter cells, previously considered two distinct types, constitute a dynamic stem/progenitor population in which individual cells alternate expression of Sox2 and/or Ascl1. In addition, we demonstrate that interplay between ACTβB and GDF11 determines whether stem/progenitor cells adopt a glial versus neuronal fate. Altogether, the data indicate that the transition between stem cells and committed progenitors is neither sharp nor irreversible and that GDF11, ACTβB and FST are crucial components of a circuit that controls both total cell number and the ratio of neuronal versus glial cells in this system. Thus, our findings demonstrate a close connection between the signals involved in the control of tissue size and those that regulate the proportions of different cell types. PMID:21852401

  5. The MYB23 gene provides a positive feedback loop for cell fate specification in the Arabidopsis root epidermis.

    Science.gov (United States)

    Kang, Yeon Hee; Kirik, Victor; Hulskamp, Martin; Nam, Kyoung Hee; Hagely, Katherine; Lee, Myeong Min; Schiefelbein, John

    2009-04-01

    The specification of cell fates during development requires precise regulatory mechanisms to ensure robust cell type patterns. Theoretical models of pattern formation suggest that a combination of negative and positive feedback mechanisms are necessary for efficient specification of distinct fates in a field of differentiating cells. Here, we examine the role of the R2R3-MYB transcription factor gene, AtMYB23 (MYB23), in the establishment of the root epidermal cell type pattern in Arabidopsis thaliana. MYB23 is closely related to, and is positively regulated by, the WEREWOLF (WER) MYB gene during root epidermis development. Furthermore, MYB23 is able to substitute for the function of WER and to induce its own expression when controlled by WER regulatory sequences. We also show that the MYB23 protein binds to its own promoter, suggesting a MYB23 positive feedback loop. The localization of MYB23 transcripts and MYB23-green fluorescent protein (GFP) fusion protein, as well as the effect of a chimeric MYB23-SRDX repressor construct, links MYB23 function to the developing non-hair cell type. Using mutational analyses, we find that MYB23 is necessary for precise establishment of the root epidermal pattern, particularly under conditions that compromise the cell specification process. These results suggest that MYB23 participates in a positive feedback loop to reinforce cell fate decisions and ensure robust establishment of the cell type pattern in the Arabidopsis root epidermis.

  6. Effect of Exposing Low-Frequency Electric Fields on the Proliferative Capacity and Morphological Features of Olfactory Ensheathing Cells in vitro

    Institute of Scientific and Technical Information of China (English)

    WANG Meng-hang; LI Ping; FAN Yu-bo

    2014-01-01

    Olfactory ensheathing cells (OECs) transplanted into the damaged spinal cord may be considered as a valuable remedy explorations for spinal cord repair. The proliferation of transplanted olfactory ensheathing cells depends on various environmental factors and effective cues, which may include electrical fields (EFs). In this study, we investigated the proliferative capacity, morphologic alterations of olfactory ensheathing cells derived from neonate rat that occurd when exposed to two EFs of 20 Hz, 50 mV and 20 Hz, 100 mV for 6 h. For both EF treatments, the MTT results revealed that the cellular proliferation of exposed group during the last 6 h of the experiment was statistically higher than that of control group. Then, we investigated morphological structure changes in the cells stained by Coomassie brilliant blue. Compared with control group, most of cells were present at intensively proliferating appearance including the microfilaments were long and thick and the accumulated appearance of cells. It is conceivable that electrical fields as a new approach may promote the growth and proliferation of OECs and may be engineered to control the survival of transplanted OECs in injured spinal cord. Although our results have been suggesting that EFs may be non-chemical strategies for cell proliferation, the fundamental mechanisms remain to be elucidated.

  7. Feedbacks, Bifurcations, and Cell Fate Decision-Making in the p53 System

    Science.gov (United States)

    Bogdał, Marta N.; Lipniacki, Tomasz

    2016-01-01

    The p53 transcription factor is a regulator of key cellular processes including DNA repair, cell cycle arrest, and apoptosis. In this theoretical study, we investigate how the complex circuitry of the p53 network allows for stochastic yet unambiguous cell fate decision-making. The proposed Markov chain model consists of the regulatory core and two subordinated bistable modules responsible for cell cycle arrest and apoptosis. The regulatory core is controlled by two negative feedback loops (regulated by Mdm2 and Wip1) responsible for oscillations, and two antagonistic positive feedback loops (regulated by phosphatases Wip1 and PTEN) responsible for bistability. By means of bifurcation analysis of the deterministic approximation we capture the recurrent solutions (i.e., steady states and limit cycles) that delineate temporal responses of the stochastic system. Direct switching from the limit-cycle oscillations to the “apoptotic” steady state is enabled by the existence of a subcritical Neimark—Sacker bifurcation in which the limit cycle loses its stability by merging with an unstable invariant torus. Our analysis provides an explanation why cancer cell lines known to have vastly diverse expression levels of Wip1 and PTEN exhibit a broad spectrum of responses to DNA damage: from a fast transition to a high level of p53 killer (a p53 phosphoform which promotes commitment to apoptosis) in cells characterized by high PTEN and low Wip1 levels to long-lasting p53 level oscillations in cells having PTEN promoter methylated (as in, e.g., MCF-7 cell line). PMID:26928575

  8. Data integration for identification of important transcription factors of STAT6-mediated cell fate decisions.

    Science.gov (United States)

    Jargosch, M; Kröger, S; Gralinska, E; Klotz, U; Fang, Z; Chen, W; Leser, U; Selbig, J; Groth, D; Baumgrass, R

    2016-06-24

    Data integration has become a useful strategy for uncovering new insights into complex biological networks. We studied whether this approach can help to delineate the signal transducer and activator of transcription 6 (STAT6)-mediated transcriptional network driving T helper (Th) 2 cell fate decisions. To this end, we performed an integrative analysis of publicly available RNA-seq data of Stat6-knockout mouse studies together with STAT6 ChIP-seq data and our own gene expression time series data during Th2 cell differentiation. We focused on transcription factors (TFs), cytokines, and cytokine receptors and delineated 59 positively and 41 negatively STAT6-regulated genes, which were used to construct a transcriptional network around STAT6. The network illustrates that important and well-known TFs for Th2 cell differentiation are positively regulated by STAT6 and act either as activators for Th2 cells (e.g., Gata3, Atf3, Satb1, Nfil3, Maf, and Pparg) or as suppressors for other Th cell subpopulations such as Th1 (e.g., Ar), Th17 (e.g., Etv6), or iTreg (e.g., Stat3 and Hif1a) cells. Moreover, our approach reveals 11 TFs (e.g., Atf5, Creb3l2, and Asb2) with unknown functions in Th cell differentiation. This fact together with the observed enrichment of asthma risk genes among those regulated by STAT6 underlines the potential value of the data integration strategy used here. Thus, our results clearly support the opinion that data integration is a useful tool to delineate complex physiological processes.

  9. Quantifying Waddington landscapes and paths of non-adiabatic cell fate decisions for differentiation, reprogramming and transdifferentiation

    Science.gov (United States)

    Li, Chunhe; Wang, Jin

    2013-01-01

    Cellular differentiation, reprogramming and transdifferentiation are determined by underlying gene regulatory networks. Non-adiabatic regulation via slow binding/unbinding to the gene can be important in these cell fate decision-making processes. Based on a stem cell core gene network, we uncovered the stem cell developmental landscape. As the binding/unbinding speed decreases, the landscape topography changes from bistable attractors of stem and differentiated states to more attractors of stem and other different cell states as well as substates. Non-adiabaticity leads to more differentiated cell types and provides a natural explanation for the heterogeneity observed in the experiments. We quantified Waddington landscapes with two possible cell fate decision mechanisms by changing the regulation strength or regulation timescale (non-adiabaticity). Transition rates correlate with landscape topography through barrier heights between different states and quantitatively determine global stability. We found the optimal speeds of these cell fate decision-making processes. We quantified biological paths and predict that differentiation and reprogramming go through an intermediate state (IM1), whereas transdifferentiation goes through another intermediate state (IM2). Some predictions are confirmed by recent experimental studies. PMID:24132204

  10. Mutant huntingtin regulates EGF receptor fate in non-neuronal cells lacking wild-type protein.

    Science.gov (United States)

    Melone, Mariarosa A B; Calarco, Anna; Petillo, Orsolina; Margarucci, Sabrina; Colucci-D'Amato, Luca; Galderisi, Umberto; Koverech, Guido; Peluso, Gianfranco

    2013-01-01

    Huntingtin (htt) is a scaffold protein localized at the subcellular level and is involved in coordinating the activity of several protein for signaling and intracellular transport. The emerging properties of htt in intracellular trafficking prompted us to study the role of mutant htt (polyQ-htt) in the intracellular fate of epidermal growth factor receptor (EGFR), whose activity seems to be strictly regulated by htt. In particular, to evaluate whether protein trafficking dysfunction occurs in non-neuronal cells in the absence of functional htt, we monitored the EGFR protein in fibroblasts from homozygotic HD patients and their healthy counterpart. We found that polyQ-htt controls EGFR degradation and recycling. Lack of wild-type htt caused alteration of the ubiquitination cycle, formation of EGFR-incorporating high-molecular weight protein aggregates and abnormal EGFR distribution in endosomes of the degradation and recycling pathways after EGF stimulation. PolyQ-htt-induced alteration of EGFR trafficking affected cell migration and proliferation, at least in part, through inhibition of ERK signaling. To our knowledge the data here reported represent the first signaling and phenotypic characterization of polyQ-htt involvement in the modulation of growth factor stimulation in non-neuronal cells.

  11. Genomic DISC1 Disruption in hiPSCs Alters Wnt Signaling and Neural Cell Fate

    Directory of Open Access Journals (Sweden)

    Priya Srikanth

    2015-09-01

    Full Text Available Genetic and clinical association studies have identified disrupted in schizophrenia 1 (DISC1 as a candidate risk gene for major mental illness. DISC1 is interrupted by a balanced chr(1;11 translocation in a Scottish family in which the translocation predisposes to psychiatric disorders. We investigate the consequences of DISC1 interruption in human neural cells using TALENs or CRISPR-Cas9 to target the DISC1 locus. We show that disruption of DISC1 near the site of the translocation results in decreased DISC1 protein levels because of nonsense-mediated decay of long splice variants. This results in an increased level of canonical Wnt signaling in neural progenitor cells and altered expression of fate markers such as Foxg1 and Tbr2. These gene expression changes are rescued by antagonizing Wnt signaling in a critical developmental window, supporting the hypothesis that DISC1-dependent suppression of basal Wnt signaling influences the distribution of cell types generated during cortical development.

  12. Specification of osteoblast cell fate by canonical Wnt signaling requires Bmp2.

    Science.gov (United States)

    Salazar, Valerie S; Ohte, Satoshi; Capelo, Luciane P; Gamer, Laura; Rosen, Vicki

    2016-12-01

    Enhanced BMP or canonical Wnt (cWnt) signaling are therapeutic strategies employed to enhance bone formation and fracture repair, but the mechanisms each pathway utilizes to specify cell fate of bone-forming osteoblasts remain poorly understood. Among all BMPs expressed in bone, we find that singular deficiency of Bmp2 blocks the ability of cWnt signaling to specify osteoblasts from limb bud or bone marrow progenitors. When exposed to cWnts, Bmp2-deficient cells fail to progress through the Runx2/Osx1 checkpoint and thus do not upregulate multiple genes controlling mineral metabolism in osteoblasts. Cells lacking Bmp2 after induction of Osx1 differentiate normally in response to cWnts, suggesting that pre-Osx1(+) osteoprogenitors are an essential source and a target of BMP2. Our analysis furthermore reveals Grainyhead-like 3 (Grhl3) as a transcription factor in the osteoblast gene regulatory network induced during bone development and bone repair, which acts upstream of Osx1 in a BMP2-dependent manner. The Runx2/Osx1 transition therefore receives crucial regulatory inputs from BMP2 that are not compensated for by cWnt signaling, and this is mediated at least in part by induction and activation of Grhl3.

  13. Stimulative Effects of Low Intensity He-Ne Laser Irradiation on the Proliferative Potential and Cell-Cycle Progression of Myoblasts in Culture

    Directory of Open Access Journals (Sweden)

    Cui-Ping Zhang

    2014-01-01

    Full Text Available Low intensity laser irradiation (LILI was found to promote the regeneration of skeletal muscle in vivo but the cellular mechanisms are not fully understood. Myoblasts, normally quiescent and inactivated in adult skeletal muscle, are a type of myogenic progenitor cells and considered as the major candidates responsible for muscle regeneration. The aim of the present study was to study the effect of LILI on the growth potential and cell-cycle progression of the cultured myoblasts. Primary myoblasts isolated from rat hind legs were cultured in nutrient-deficient medium for 36 hours and then irradiated by helium-neon laser at a certain energy density. Immunohistochemical and flow cytometric analysis revealed that laser irradiation could increase the expression of cellular proliferation marker and the amount of cell subpopulations in the proliferative phase as compared with the nonirradiated control group. Meanwhile, the expressions of cell-cycle regulatory proteins in the laser-treated myoblasts were markedly upregulated as compared to the unirradiated cells, indicating that LILI could promote the reentry of quiescent myoblasts into the cell division cycle. These results suggest that LILI at certain fluences could promote their proliferation, thus contributing to the skeletal muscle regeneration following trauma and myopathic diseases.

  14. BRAF mutation is associated with a specific cell-type with features suggestive of senescence in ovarian serous borderline (atypical proliferative) tumors

    Science.gov (United States)

    Zeppernick, Felix; Ardighieri, Laura; Hannibal, Charlotte G.; Vang, Russell; Junge, Jette; Kjaer, Susanne K.; Zhang, Rugang; Kurman, Robert J.; Shih, Ie-Ming

    2014-01-01

    Serous borderline tumor (SBT) also known as atypical proliferative serous tumor (APST) is the precursor of ovarian low-grade serous carcinoma (LGSC). In this study, we correlated the morphologic and immunohistochemical phenotypes of 71 APSTs and 18 LGSCs with the mutational status of KRAS and BRAF, the most common molecular genetic changes in these neoplasms. A subset of cells characterized by abundant eosinophilic cytoplasm (EC), discrete cell borders and bland nuclei was identified in all (100%) 25 BRAF mutated APSTs but in only 5 (10%) of 46 APSTs without BRAF mutations (p<0.0001). Among the 18 LGSCs, EC cells were found in only 2 and both contained BRAF mutations. The EC cells were present admixed with cuboidal and columnar cells lining the papillae and appeared to be budding from the surface, resulting in individual cells and clusters of detached cells “floating” above the papillae. Immunohistochemistry showed that the EC cells always expressed p16, a senescence-associated marker, and had a significantly lower Ki-67 labeling index than adjacent cuboidal and columnar cells (p=0.02). In vitro studies supported the interpretation that these cells were undergoing senescence as the same morphologic features could be reproduced in cultured epithelial cells by ectopic expression of BRAFV600E. Senescence was further established by markers such as SA-β-gal staining, expression of p16 and p21, and reduction in DNA synthesis. In conclusion, this study sheds light on the pathogenesis of this unique group of ovarian tumors by showing that BRAF mutation is associated with cellular senescence and the presence of a specific cell type characterized by abundant eosinophilic cytoplasm. This “oncogene-induced senescence” phenotype may represent a mechanism that prevents impedes progression of APSTs to LGSC. PMID:25188864

  15. Quantifying Cell Fate Decisions for Differentiation and Reprogramming of a Human Stem Cell Network: Landscape and Biological Paths

    Science.gov (United States)

    Li, Chunhe; Wang, Jin

    2013-01-01

    Cellular reprogramming has been recently intensively studied experimentally. We developed a global potential landscape and kinetic path framework to explore a human stem cell developmental network composed of 52 genes. We uncovered the underlying landscape for the stem cell network with two basins of attractions representing stem and differentiated cell states, quantified and exhibited the high dimensional biological paths for the differentiation and reprogramming process, connecting the stem cell state and differentiated cell state. Both the landscape and non-equilibrium curl flux determine the dynamics of cell differentiation jointly. Flux leads the kinetic paths to be deviated from the steepest descent gradient path, and the corresponding differentiation and reprogramming paths are irreversible. Quantification of paths allows us to find out how the differentiation and reprogramming occur and which important states they go through. We show the developmental process proceeds as moving from the stem cell basin of attraction to the differentiation basin of attraction. The landscape topography characterized by the barrier heights and transition rates quantitatively determine the global stability and kinetic speed of cell fate decision process for development. Through the global sensitivity analysis, we provided some specific predictions for the effects of key genes and regulation connections on the cellular differentiation or reprogramming process. Key links from sensitivity analysis and biological paths can be used to guide the differentiation designs or reprogramming tactics. PMID:23935477

  16. Erucin, a new promising cancer chemopreventive agent from rocket salads, shows anti-proliferative activity on human lung carcinoma A549 cells.

    Science.gov (United States)

    Melchini, A; Costa, C; Traka, M; Miceli, N; Mithen, R; De Pasquale, R; Trovato, A

    2009-07-01

    Erucin (ER) is a dietary isothiocyanate present in cruciferous vegetables, such as rocket salads (Erucasativa Mill., Diplotaxis sp.), that has been recently considered a promising cancer chemopreventive phytochemical. Biological activity of ER was investigated on human lung adenocarcinoma A549 cells, analyzing its effects on molecular pathways involved in apoptosis and cell cycle arrest, such as PARP-1 cleavage, p53 and p21 protein expression. Our results show that ER affects the A549 cell proliferation, enhancing significantly p53 and p21 protein expression in a dose-dependent manner (pinduction of p53, p21 and PARP-1 cleavage may participate in the anti-proliferative activity of ER in human lung adenocarcinoma A549 cells. Comparison of data with those obtained with the isothiocyanate sulforaphane (SF), structurally related to ER, underlines the strong relationship between structural analogy of ITCs and their biological activity. The ability of dietary compounds to modulate molecular mechanisms that affect cancer cell proliferation is certainly a key point of the cancer prevention potential by functional foods.

  17. Multiple bidirectional alterations of phenotype and changes in proliferative potential during the in vitro and in vivo passage of clonal mast cell populations derived from mouse peritoneal mast cells

    Energy Technology Data Exchange (ETDEWEB)

    Kanakura, Y.; Thompson, H.; Nakano, T.; Yamamura, T.; Asai, H.; Kitamura, Y.; Metcalfe, D.D.; Galli, S.J.

    1988-09-01

    Mouse peritoneal mast cells (PMC) express a connective tissue-type mast cell (CTMC) phenotype, including reactivity with the heparin-binding fluorescent dye berberine sulfate and incorporation of (35S) sulfate predominantly into heparin proteoglycans. When PMC purified to greater than 99% purity were cultured in methylcellulose with IL-3 and IL-4, approximately 25% of the PMC formed colonies, all of which contained both berberine sulfate-positive and berberine sulfate-negative mast cells. When these mast cells were transferred to suspension culture, they generated populations that were 100% berberine sulfate-negative, a characteristic similar to that of mucosal mast cells (MMC), and that synthesized predominantly chondroitin sulfate (35S) proteoglycans. When ''MMC-like'' cultured mast cells derived from WBB6F1-+/+ PMC were injected into the peritoneal cavities of mast cell-deficient WBB6F1-W/Wv mice, the adoptively transferred mast cell population became 100% berberine sulfate-positive. In methylcellulose culture, these ''second generation PMC'' formed clonal colonies containing both berberine sulfate-positive and berberine sulfate-negative cells, but exhibited significantly less proliferative ability than did normal +/+ PMC. Thus, clonal mast cell populations initially derived from single PMC exhibited multiple and bidirectional alterations between CTMC-like and MMC-like phenotypes. However, this process was associated with a progressive diminution of the mast cells' proliferative ability.

  18. Surface Chemistry of Nanoscale Mineralized Collagen Regulates Periodontal Ligament Stem Cell Fate.

    Science.gov (United States)

    Fu, Yu; Liu, Shuai; Cui, Sheng-Jie; Kou, Xiao-Xing; Wang, Xue-Dong; Liu, Xiao-Mo; Sun, Yue; Wang, Gao-Nan; Liu, Yan; Zhou, Yan-Heng

    2016-06-29

    The interplay between stem cells and their extracellular microenvironment is of critical importance to the stem cell-based therapeutics in regenerative medicine. Mineralized collagen is the main component of bone extracellular matrix, but the effect of interfacial properties of mineralized collagen on subsequent cellular behaviors is unclear. This study examined the role of surface chemistry of nanoscale mineralized collagen on human periodontal ligament stem cell (hPDLSC) fate decisions. The intrafibrillarly mineralized collagen (IMC), fabricated by a biomimetic bottom-up approach, showed a bonelike hierarchy with nanohydroxyapatites (HAs) periodically embedded within fibrils. The infrared spectrum of the IMC showed the presence of phosphate, carbonate, amide I and II bands; and infrared mapping displayed uniform and higher spatial distribution of mineralization in the IMC. However, the distribution of the phosphate group differed far from that of the amide I group in the extrafibrillarly mineralized collagen (EMC), in which flowerlike HA clusters randomly depositing around the surface of the fibrils. Moreover, a large quantity of extrafibrillar HAs covered up the C═O stretch and N-H in-plane bend, resulting in substantial reduction of amide I and II bands. Cell experiments demonstrated that the hPDLSCs seeded on the IMC exhibited a highly branched, osteoblast-like polygonal shape with extended pseudopodia and thick stress fiber formation; while cells on the EMC displayed a spindle shape with less branch points and thin actin fibril formation. Furthermore, the biocompatibility of EMC was much lower than that of IMC. Interestingly, even without osteogenic induction, mRNA levels of major osteogenic differentiation genes were highly expressed in the IMC during cultivation time. These data suggest that the IMC with a similar nanotopography and surface chemistry to natural mineralized collagen directs hPDLSCs toward osteoblast differentiation, providing a promising

  19. IRE1α Signaling Pathways Involved in Mammalian Cell Fate Determination

    Directory of Open Access Journals (Sweden)

    Jie Wu

    2016-02-01

    Full Text Available A diverse array of cellular stresses can lead to accumulation of misfolded or unfolded proteins in endoplasmic reticulum (ER, which subsequently elicits ER stress. Inositol-requiring enzyme 1α (IRE1α is the most sensitive of the three unfolded protein response (UPR branches which are triggered to cope with ER stress in mammalian cells. IRE1α signaling is quite context-specific on account of many adaptor and modulator proteins that directly interact with it, including heat shock proteins (HSPs, RING finger protein 13 (RNF13, poly (ADP-ribose polymerase 16 (PARP16, Bax/Bak, and Bax inhibitor-1 (BI-1. The activated IRE1α triggers different downstream pathways depending on the UPRosome formed by distinct modulator proteins. At the initial phase of ER stress, IRE1α-XBP1 axis functions as an adaptive response. While ER stress sustains or intensifies, signals shift to apoptotic responses. Furthermore, IRE1α signaling can be exploited to the development of a wide range of prevalent human diseases, with cancer the most characterized. Here we provide an overview of recent insights into the complex IRE1α signaling network which makes IRE1α an intriguing cell fate switch. Besides, the functional relevance is presented since IRE1α activation also participates in some other physiological processes beyond protein-folding status.

  20. A transcription factor network controls cell migration and fate decisions in the developing zebrafish pineal complex

    Science.gov (United States)

    Clanton, Joshua A.; Dean, Benjamin J.; Gamse, Joshua T.

    2016-01-01

    The zebrafish pineal complex consists of four cell types (rod and cone photoreceptors, projection neurons and parapineal neurons) that are derived from a single pineal complex anlage. After specification, parapineal neurons migrate unilaterally away from the rest of the pineal complex whereas rods, cones and projection neurons are non-migratory. The transcription factor Tbx2b is important for both the correct number and migration of parapineal neurons. We find that two additional transcription factors, Flh and Nr2e3, negatively regulate parapineal formation. Flh induces non-migratory neuron fates and limits the extent of parapineal specification, in part by activation of Nr2e3 expression. Tbx2b is positively regulated by Flh, but opposes Flh action during specification of parapineal neurons. Loss of parapineal neuron specification in Tbx2b-deficient embryos can be partially rescued by loss of Nr2e3 or Flh function; however, parapineal migration absolutely requires Tbx2b activity. We conclude that cell specification and migration in the pineal complex are regulated by a network of at least three transcription factors. PMID:27317804

  1. Aurora A Kinase Regulates Mammary Epithelial Cell Fate by Determining Mitotic Spindle Orientation in a Notch-Dependent Manner

    Directory of Open Access Journals (Sweden)

    Joseph L. Regan

    2013-07-01

    Full Text Available Cell fate determination in the progeny of mammary epithelial stem/progenitor cells remains poorly understood. Here, we have examined the role of the mitotic kinase Aurora A (AURKA in regulating the balance between basal and luminal mammary lineages. We find that AURKA is highly expressed in basal stem cells and, to a lesser extent, in luminal progenitors. Wild-type AURKA expression promoted luminal cell fate, but expression of an S155R mutant reduced proliferation, promoted basal fate, and inhibited serial transplantation. The mechanism involved regulation of mitotic spindle orientation by AURKA and the positioning of daughter cells after division. Remarkably, this was NOTCH dependent, as NOTCH inhibitor blocked the effect of wild-type AURKA expression on spindle orientation and instead mimicked the effect of the S155R mutant. These findings directly link AURKA, NOTCH signaling, and mitotic spindle orientation and suggest a mechanism for regulating the balance between luminal and basal lineages in the mammary gland.

  2. The effect of nutritional status and muscle fiber type on myogenic satellite cell fate and apoptosis.

    Science.gov (United States)

    Powell, D J; McFarland, D C; Cowieson, A J; Muir, W I; Velleman, S G

    2014-01-01

    Satellite cells (SC) are multipotential stem cells that can be induced by nutrition to alter their cellular developmental fate, which may vary depending on their fiber type origin. The objective of the current study was to determine the effect of restricting protein synthesis on inducing adipogenic transdifferentiation and apoptosis of SC originating from fibers of the fast glycolytic pectoralis major (p. major) and fast oxidative and glycolytic biceps femoris (b. femoris) muscles of the chicken. The availability of the essential sulfur amino acids Met and Cys was restricted to regulate protein synthesis during SC proliferation and differentiation. The SC were cultured and treated with 1 of 6 Met/Cys concentrations: 60/192, 30/96 (control), 7.5/24, 3/9.6, 1/3.2, or 0/0 mg/L. Reductions in Met/Cys concentrations from the control level resulted in increased lipid staining and expression of the adipogenic marker genes peroxisome proliferator-activated receptor gamma and stearoyl-CoA desaturase during differentiation in the p. major SC. Although b. femoris SC had increased lipid staining at lower Met/Cys concentrations, there was no increase in expression of either adipogenic gene. For both muscle types, SC Met/Cys, concentration above the control increased the expression of peroxisome proliferator-activated receptor gamma and stearoyl-CoA desaturase during differentiation. As Met/Cys concentration was decreased during proliferation, a dose-dependent decline in all apoptotic cells occurred except for early apoptotic cells in the p. major, which had no treatment effect (P nutrition on SC transdifferentiation to an adipogenic lineage and apoptosis, and the effect of fiber type on this response in an in vitro context.

  3. The Caenorhabditis elegans PcG-like gene sop-2 regulates the temporal and sexual specificities of cell fates.

    Science.gov (United States)

    Cai, Qingchun; Sun, Yinyan; Huang, Xinxin; Guo, Cong; Zhang, Yuxia; Zhu, Zuoyan; Zhang, Hong

    2008-03-01

    How spatial, temporal, and sexual specific cues are integrated to specify distinct cell fates during multicellular organism development is largely unknown. Here we demonstrate that the Caenorhabditis elegans PcG-like gene sop-2 determines the temporal and sexual specificities of a row of hypodermal seam cells, in addition to specifying their positional identities. Loss-of-function of sop-2 causes premature expression of adult fates at larval stages. sop-2 acts upstream of lin-29 in the heterochronic pathway and genetically interacts with other heterochronic genes in specifying the temporal fates of seam cells at different larval stages. We show that the number of ALG-1-containing P bodies is increased in seam cells in sop-2 mutants. Furthermore, the microRNA-mediated repression of a heterochronic gene reporter is enhanced in sop-2 mutants. Mutations in sop-2 also cause partial hermaphrodite-to-male sexual transformations. The homeotic transformations, heterochronic defects, and sexual transformations can occur concomitantly in sop-2 mutants. In summary, our studies reveal that sop-2 integrates spatial, temporal, and sexual cues during C. elegans development.

  4. Neuronal Cell Fate Specification by the Convergence of Different Spatiotemporal Cues on a Common Terminal Selector Cascade.

    Directory of Open Access Journals (Sweden)

    Hugo Gabilondo

    2016-05-01

    Full Text Available Specification of the myriad of unique neuronal subtypes found in the nervous system depends upon spatiotemporal cues and terminal selector gene cascades, often acting in sequential combinatorial codes to determine final cell fate. However, a specific neuronal cell subtype can often be generated in different parts of the nervous system and at different stages, indicating that different spatiotemporal cues can converge on the same terminal selectors to thereby generate a similar cell fate. However, the regulatory mechanisms underlying such convergence are poorly understood. The Nplp1 neuropeptide neurons in the Drosophila ventral nerve cord can be subdivided into the thoracic-ventral Tv1 neurons and the dorsal-medial dAp neurons. The activation of Nplp1 in Tv1 and dAp neurons depends upon the same terminal selector cascade: col>ap/eya>dimm>Nplp1. However, Tv1 and dAp neurons are generated by different neural progenitors (neuroblasts with different spatiotemporal appearance. Here, we find that the same terminal selector cascade is triggered by Kr/pdm>grn in dAp neurons, but by Antp/hth/exd/lbe/cas in Tv1 neurons. Hence, two different spatiotemporal combinations can funnel into a common downstream terminal selector cascade to determine a highly related cell fate.

  5. Telomerase expression extends the proliferative life-span and maintains the osteogenic potential of human bone marrow stromal cells

    DEFF Research Database (Denmark)

    Simonsen, Janne Lytoft; Rosada, Cecilia; Serakinci, Nedime;

    2002-01-01

    Human bone marrow stromal cells (hMSCs) were stably transduced by a retroviral vector containing the gene for the catalytic subunit of human telomerase (hTERT). Transduced cells (hMSC-TERTs) had telomerase activity, and the mean telomere length was increased as compared with that of control cells......, did not form tumors, and had a normal karyotype. When implanted subcutaneously in immunodeficient mice, the transduced cells formed more bone than did normal cells. These results suggest that ectopic expression of telomerase in hMSCs prevents senescence-associated impairment of osteoblast functions....

  6. Induction of autophagy by dimethyl cardamonin is associated with proliferative arrest in human colorectal carcinoma HCT116 and LOVO cells.

    Science.gov (United States)

    Ko, Hyeonseok; Kim, Young-Joo; Amor, Evangeline C; Lee, Jong Wha; Kim, Han-Cheon; Kim, Hee Ju; Yang, Hyun Ok

    2011-09-01

    Dimethyl cardamonin (2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone; DMC) is a naturally occurring chalcone, and it is the major compound isolated from the leaves of Syzygium samarangense (Blume) Merr. & L.M. Perry (Myrtaceae). Experiments were conducted to determine the effects of DMC on cell proliferation, cell-cycle distribution, and programmed cell death in cultures of human colorectal carcinoma HCT116 and LOVO cells. Results showed that DMC inhibited HCT116 and LOVO cell proliferation and induced G(2) /M cell cycle arrest, which was associated with the conversion of microtubule associated protein light chain 3 (LC3)-I-LC3-II, an autophagosome marker, and the incorporation of monodansylcadaverine (MDC), a marker for the acidic compartment of autolysosomes or acidic vesicular organelles. The treatment of HCT116 and LOVO cells using a combination of DMC with an autophagy inhibitor, such as 3-methyladenine (3-MA), beclin 1 siRNA, or atg5 siRNA, suppressed the effect of DMC-mediated anti-proliferation. These results imply that DMC can suppress colorectal carcinoma HCT116 and LOVO cell proliferation through a G(2) /M phase cell-cycle delay, and can induce autophagy, the hallmark of Type II programmed cell death (PCD). Taken together, our results suggest that DMC may be an effective chemotherapeutic agent for HCT116 and LOVO colorectal carcinoma cells.

  7. HIPPO pathway members restrict SOX2 to the inner cell mass where it promotes ICM fates in the mouse blastocyst.

    Directory of Open Access Journals (Sweden)

    Eryn Wicklow

    2014-10-01

    Full Text Available Pluripotent epiblast (EPI cells, present in the inner cell mass (ICM of the mouse blastocyst, are progenitors of both embryonic stem (ES cells and the fetus. Discovering how pluripotency genes regulate cell fate decisions in the blastocyst provides a valuable way to understand how pluripotency is normally established. EPI cells are specified by two consecutive cell fate decisions. The first decision segregates ICM from trophectoderm (TE, an extraembryonic cell type. The second decision subdivides ICM into EPI and primitive endoderm (PE, another extraembryonic cell type. Here, we investigate the roles and regulation of the pluripotency gene Sox2 during blastocyst formation. First, we investigate the regulation of Sox2 patterning and show that SOX2 is restricted to ICM progenitors prior to blastocyst formation by members of the HIPPO pathway, independent of CDX2, the TE transcription factor that restricts Oct4 and Nanog to the ICM. Second, we investigate the requirement for Sox2 in cell fate specification during blastocyst formation. We show that neither maternal (M nor zygotic (Z Sox2 is required for blastocyst formation, nor for initial expression of the pluripotency genes Oct4 or Nanog in the ICM. Rather, Z Sox2 initially promotes development of the primitive endoderm (PE non cell-autonomously via FGF4, and then later maintains expression of pluripotency genes in the ICM. The significance of these observations is that 1 ICM and TE genes are spatially patterned in parallel prior to blastocyst formation and 2 both the roles and regulation of Sox2 in the blastocyst are unique compared to other pluripotency factors such as Oct4 or Nanog.

  8. Advanced imaging approaches for regenerative medicine: Emerging technologies for monitoring stem cell fate in vitro and in vivo.

    Science.gov (United States)

    Kupfer, Molly E; Ogle, Brenda M

    2015-10-01

    The future of regenerative medicine relies on our ability to control stem cell fate in order to produce functional tissues. Stem cells are the preferred cell source for tissue engineering endeavors and regenerative medicine therapies due to their high potency and capacity for expansion. However, their potency also makes them very difficult to control, as they are in a constant state of flux. Therefore, in order to advance research in regenerative medicine, it is necessary to be able to monitor cell state and phenotype both in vitro and in vivo. This review will detail the imaging technologies currently in use to monitor stem cell phenotype, migration, and differentiation. In addition to providing examples of the most recent work in this area, we will also discuss the future of imaging technologies for regenerative medicine, and how current imaging modalities might be utilized to image specific cell functionality in order to track stem cell fate. The research area of imaging stem cells is progressing toward identifying mature and differentiating cells not only by phenotypic markers, but also by visualizing cell function. Many of the cutting-edge modalities detailed in this review have the potential to be harnessed toward this goal.

  9. Anti-proliferative effect of biogenic gold nanoparticles against breast cancer cell lines (MDA-MB-231 & MCF-7)

    Science.gov (United States)

    K. S., Uma Suganya; Govindaraju, K.; Ganesh Kumar, V.; Prabhu, D.; Arulvasu, C.; Stalin Dhas, T.; Karthick, V.; Changmai, Niranjan

    2016-05-01

    Breast cancer is a major complication in women and numerous approaches are being developed to overcome this problem. In conventional treatments such as chemotherapy and radiotherapy the post side effects cause an unsuitable effect in treatment of cancer. Hence, it is essential to develop a novel strategy for the treatment of this disease. In the present investigation, a possible route for green synthesis of gold nanoparticles (AuNPs) using leaf extract of Mimosa pudica and its anticancer efficacy in the treatment of breast cancer cell lines is studied. The synthesized nanoparticles were found to be effective in killing cancer cells (MDA-MB-231 & MCF-7) which were studied using various anticancer assays (MTT assay, cell morphology determination, cell cycle analysis, comet assay, Annexin V-FITC/PI staining and DAPI staining). Cell morphological analysis showed the changes occurred in cancer cells during the treatment with AuNPs. Cell cycle analysis revealed apoptosis in G0/G1 to S phase. Similarly in Comet assay, there was an increase in tail length in treated cells in comparison with the control. Annexin V-FITC/PI staining assay showed prompt fluorescence in treated cells indicating the translocation of phosphatidylserine from the inner membrane. PI and DAPI staining showed the DNA damage in treated cells.

  10. Anti-proliferative effect of biogenic gold nanoparticles against breast cancer cell lines (MDA-MB-231 & MCF-7)

    Energy Technology Data Exchange (ETDEWEB)

    Uma Suganya, K.S. [Centre for Ocean Research, Sathyabama University, Chennai 600119 (India); Govindaraju, K., E-mail: govindtu@gmail.com [Centre for Ocean Research, Sathyabama University, Chennai 600119 (India); Ganesh Kumar, V. [Centre for Ocean Research, Sathyabama University, Chennai 600119 (India); Prabhu, D.; Arulvasu, C. [Department of Zoology, University of Madras, Guindy campus, Chennai 600 025 (India); Stalin Dhas, T.; Karthick, V.; Changmai, Niranjan [Centre for Ocean Research, Sathyabama University, Chennai 600119 (India)

    2016-05-15

    Highlights: • Biosynthesis of stable and well dispersed predominantly spherical gold nanoparticles of size around ∼12.5 nm. • Anticancer assessment of gold nanoparticles on MDA-MB-231 and MCF-7 cell lines. • AuNPs were found non toxic to normal HMEC cells. • Flow cytometry results revealed significant arrest in cell proliferation in early G0/G1 to S phase. - Abstract: Breast cancer is a major complication in women and numerous approaches are being developed to overcome this problem. In conventional treatments such as chemotherapy and radiotherapy the post side effects cause an unsuitable effect in treatment of cancer. Hence, it is essential to develop a novel strategy for the treatment of this disease. In the present investigation, a possible route for green synthesis of gold nanoparticles (AuNPs) using leaf extract of Mimosa pudica and its anticancer efficacy in the treatment of breast cancer cell lines is studied. The synthesized nanoparticles were found to be effective in killing cancer cells (MDA-MB-231 & MCF-7) which were studied using various anticancer assays (MTT assay, cell morphology determination, cell cycle analysis, comet assay, Annexin V-FITC/PI staining and DAPI staining). Cell morphological analysis showed the changes occurred in cancer cells during the treatment with AuNPs. Cell cycle analysis revealed apoptosis in G{sub 0}/G{sub 1} to S phase. Similarly in Comet assay, there was an increase in tail length in treated cells in comparison with the control. Annexin V-FITC/PI staining assay showed prompt fluorescence in treated cells indicating the translocation of phosphatidylserine from the inner membrane. PI and DAPI staining showed the DNA damage in treated cells.

  11. Controlling Cell Functions and Fate with Surfaces and Hydrogels: The Role of Material Features in Cell Adhesion and Signal Transduction

    Directory of Open Access Journals (Sweden)

    Maurizio Ventre

    2016-03-01

    Full Text Available In their natural environment, cells are constantly exposed to a cohort of biochemical and biophysical signals that govern their functions and fate. Therefore, materials for biomedical applications, either in vivo or in vitro, should provide a replica of the complex patterns of biological signals. Thus, the development of a novel class of biomaterials requires, on the one side, the understanding of the dynamic interactions occurring at the interface of cells and materials; on the other, it requires the development of technologies able to integrate multiple signals precisely organized in time and space. A large body of studies aimed at investigating the mechanisms underpinning cell-material interactions is mostly based on 2D systems. While these have been instrumental in shaping our understanding of the recognition of and reaction to material stimuli, they lack the ability to capture central features of the natural cellular environment, such as dimensionality, remodelling and degradability. In this work, we review the fundamental traits of material signal sensing and cell response. We then present relevant technologies and materials that enable fabricating systems able to control various aspects of cell behavior, and we highlight potential differences that arise from 2D and 3D settings.

  12. Transcriptional Regulation of Δ6-Desaturase by Peroxisome Proliferative-Activated Receptor δ Agonist in Human Pancreatic Cancer Cells: Role of MEK/ERK1/2 Pathway

    Directory of Open Access Journals (Sweden)

    Maryam Darabi

    2013-01-01

    Full Text Available The Δ6-desaturase (Δ6D, also known as fatty acid desaturase 2, is a regulatory enzyme in de novo fatty acid synthesis, which has been linked to obesity and diabetes. The aim of the present study was to investigate the effect of peroxisome proliferative-activated receptor δ (PPARδ agonist and MEK/ERK1/2-dependent pathway on the expression of Δ6D in human pancreatic carcinoma cell line PANC-1. PANC-1 cells cultured in RPMI-1640 were exposed to the commonly used ERK1/2 pathway inhibitor PD98059 and PPARδ agonist GW0742. Changes in mRNA and protein expression of Δ6D were then determined using real-time RT-PCR and Western blot, respectively. The expression of Δ6D (P40%, P25%, P<0.05 pretreatment. PPARδ and MEK/ERK1/2 signaling pathways affect differentially the expression of Δ6D in pancreatic cancer cells. Furthermore, there may be an inhibitory crosstalk between these two regulatory pathways on the mRNA expression of Δ6D and subsequently on Δ6D protein expression.

  13. SMI of Bcl-2 TW-37 is active across a spectrum of B-cell tumors irrespective of their proliferative and differentiation status.

    Science.gov (United States)

    Al-Katib, Ayad M; Sun, Yuan; Goustin, Anton Scott; Azmi, Asfar Sohail; Chen, Ben; Aboukameel, Amro; Mohammad, Ramzi M

    2009-02-16

    The Bcl-2 family of proteins is critical to the life and death of malignant B-lymphocytes. Interfering with their activity using small-molecule inhibitors (SMI) is being explored as a new therapeutic strategy for treating B-cell tumors. We evaluated the efficacy of TW-37, a non-peptidic SMI of Bcl-2 against a range spectrum of human B-cell lines, fresh patient samples and animal xenograft models. Multiple cytochemical and molecular approaches such as acridine orange/ethidium bromide assay for apoptosis, co-immunoprecipitation of complexes and western blot analysis, caspase luminescent activity assay and apoptotic DNA fragmentation assay were used to demonstrate the effect of TW-37 on different B-cell lines, patient derived samples, as well as in animal xenograft models. Nanomolar concentrations of TW-37 were able to induce apoptosis in both fresh samples and established cell lines with IC50 in most cases of 165-320 nM. Apoptosis was independent of proliferative status or pathological classification of B-cell tumor. TW-37 was able to block Bim-Bcl-XL and Bim-Mcl-1 heterodimerization and induced apoptosis via activation of caspases -9, -3, PARP and DNA fragmentation. TW-37 administered to tumor-bearing SCID mice led to significant tumor growth inhibition (T/C), tumor growth delay (T-C) and Log10kill, when used at its maximum tolerated dose (40 mg/kg x 3 days) via tail vein. TW-37 failed to induce changes in the Bcl-2 proteins levels suggesting that assessment of baseline Bcl-2 family proteins can be used to predict response to the drug. These findings indicate activity of TW-37 across the spectrum of human B-cell tumors and support the concept of targeting the Bcl-2 system as a therapeutic strategy regardless of the stage of B-cell differentiation.

  14. Synthesis of new diarylamides with pyrimidinyl pyridine scaffold and evaluation of their anti-proliferative effect on cancer cell lines.

    Science.gov (United States)

    Abdelazem, Ahmed Z; Al-Sanea, Mohammad M; Park, Hyun-Mee; Lee, So Ha

    2016-02-15

    A new series of diarylamides, having a pyrimidinyl pyridine scaffold, was designed and synthesized. The target compounds were synthesized in three steps. A selected group from the target compounds was tested over a panel of 60 cancer cell lines at a single dose concentration of 10 μM, and the most active compound, 5j, was further tested in a five-dose testing mode to determine its IC50 value over the 60 cell lines. In single-dose testing mode, compound 5j showed the highest growth inhibition against the NCI-60 cancer cell lines, while other tested compounds showed a weak to moderate inhibitory activity against a range of different cancer cell lines. In five-dose testing mode, compound 5j showed strong inhibitory activity in micro molar range against many cancer cell lines. Its major activity was against melanoma cancer cell lines. Therefore, compound 5j is a promising hit compound targeting this severe form of cancer.

  15. Immunophenotypic features by multiparameter flow cytometry can help distinguish low grade B-cell lymphomas with plasmacytic differentiation from plasma cell proliferative disorders with an unrelated clonal B-cell process.

    Science.gov (United States)

    Rosado, Flavia G; Morice, William G; He, Rong; Howard, Matthew T; Timm, Michael; McPhail, Ellen D

    2015-05-01

    Highly sensitive flow cytometry studies may incidentally identify B cell clones when used to assess plasma cell clonality in bone marrows. Clinical history, which can help differentiate related clones (low grade B cell lymphoma with plasmacytic differentiation/LBCL-PD) from unrelated ones (plasma cell proliferative disorder (PCPD) with an unrelated B cell clone), is often unavailable in referred specimens. We sought to identify morphologic or phenotypic features that would help predict the significance of these clones in the absence of history. We included only cases with identical light chain B and plasma cell clones, as determined by 6-color flow cytometry with additional DNA ploidy analysis, in which the relationship between clones could be established by review of medical records. There were 26 cases; 18 were related (14 were Waldenstrom macroglobulinemia) and eight were unrelated (seven multiple myeloma). Features seen exclusively in LBCL-PD include CD19+/CD45+ clonal plasma cell phenotype (66·7%, P = 0·0022) and morphologic features such as paratrabecular bone marrow involvement, increased mast cells, and plasma cells surrounding B-cell nodules. Aneuploidy was identified exclusively in PCPD cases (75%, P = 0·000028). We conclude that CD19+/CD45+ clonal plasma cell phenotype and aneuploidy are useful in distinguishing related clones (LBCL-PD) from unrelated clones (PCPD).

  16. Notch-HES1 signaling axis controls hemato-endothelial fate decisions of human embryonic and induced pluripotent stem cells.

    Science.gov (United States)

    Lee, Jung Bok; Werbowetski-Ogilvie, Tamra E; Lee, Jong-Hee; McIntyre, Brendan A S; Schnerch, Angelique; Hong, Seok-Ho; Park, In-Hyun; Daley, George Q; Bernstein, Irwin D; Bhatia, Mickie

    2013-08-15

    Notch signaling regulates several cellular processes including cell fate decisions and proliferation in both invertebrates and mice. However, comparatively less is known about the role of Notch during early human development. Here, we examined the function of Notch signaling during hematopoietic lineage specification from human pluripotent stem cells of both embryonic and adult fibroblast origin. Using immobilized Notch ligands and small interfering RNA to Notch receptors we have demonstrated that Notch1, but not Notch2, activation induced hairy and enhancer of split 1 (HES1) expression and generation of committed hematopoietic progenitors. Using gain- and loss-of-function approaches, this was shown to be attributed to Notch-signaling regulation through HES1, which dictated cell fate decisions from bipotent precursors either to the endothelial or hematopoietic lineages at the clonal level. Our study reveals a previously unappreciated role for the Notch pathway during early human hematopoiesis, whereby Notch signaling via HES1 represents a toggle switch of hematopoietic vs endothelial fate specification.

  17. Dynamics of defense responses and cell fate change during Arabidopsis-Pseudomonas syringae interactions.

    Directory of Open Access Journals (Sweden)

    Safae Hamdoun

    picture of dynamic changes of defense phenotypes and cell fate determination during Arabidopsis-P. syringae interactions, contributing to a better understanding of plant defense mechanisms.

  18. Pro-apoptotic and anti-proliferative effects of corn silk extract on human colon cancer cell lines

    Science.gov (United States)

    Guo, Hao; Guan, Hong; Yang, Wenqin; Liu, Han; Hou, Huiling; Chen, Xue; Liu, Zhenyan; Zang, Chuangang; Liu, Yuchao; Liu, Jicheng

    2017-01-01

    Corn silk is an economically and nutritionally significant natural product as it represents a staple food for a large proportion of the world population. This study investigated the anticancer activity of corn silk extract in human colon cancer cells and human gastric cancer cells. Following treatment with corn silk extract, certain apoptosis-related events were observed, including inhibition of cell proliferation, loss of mitochondrial membrane potential (ΔΨm), release of Ca2+ and release of cytochrome c from the mitochondria into the cytosol. Our results revealed that corn silk extract inhibited the proliferation of cancer cells and increased the level of apoptosis in a concentration-dependent manner. Western blot analysis revealed that corn silk extract upregulated the levels of Bax, cytochrome c, caspase-3 and caspase-9, but downregulated the levels of B-cell lymphoma 2. These results suggest that corn silk extract may induce apoptosis through the mitochondria-mediated pathway.

  19. Immune gene expression profiling of Proliferative Kidney Disease in rainbow trout Oncorhynchus mykiss reveals a dominance of anti-inflammatory, antibody and T helper cell-like activities.

    Science.gov (United States)

    Gorgoglione, Bartolomeo; Wang, Tiehui; Secombes, Christopher J; Holland, Jason W

    2013-07-16

    The myxozoan Tetracapsuloides bryosalmonae is the causative agent of Proliferative Kidney Disease (PKD) targeting primarily the kidney of infected fish where it causes a chronic lymphoid immunopathology. Although known to be associated with suppression of some cellular aspects of innate immunity and a prominent lymphocytic hyperplasia, there remains a considerable knowledge gap in our understanding of the underlying immune mechanisms driving PKD pathogenesis. To provide further insights, the expression profiles of a panel of innate/inflammatory and adaptive immune molecules were examined in rainbow trout Oncorhynchus mykiss following a natural exposure to the parasite. Relative to controls, fish with early to advanced stages of kidney pathology exhibited up-regulation of the inflammatory cytokines interleukin (IL)-6 and IL-11, although remaining refractory towards genes indicative of macrophage activity. Antimicrobial peptides (AMPs) and anti-inflammatory markers, including cathelicidin (CATH) and IL-10 were markedly up-regulated during clinical disease. Up-regulation of adaptive immune molecules, including cell markers and antibody genes reflect the lymphocytic dominance of this disease and the likely importance of lymphocyte subsets in PKD pathogenesis. Up-regulation of T helper (TH) cell-like response genes and transcription factors implies that T. bryosalmonae may elicit a complex interplay between TH cell subsets. This work, for the first time in the study of fish-myxozoan interactions, suggests that PKD pathogenesis is shaped by an anti-inflammatory phenotype, a profound B cell/antibody response and dysregulated TH cell-like activities. A better understanding of the functional roles of fish immune cells and molecules in PKD pathogenesis may facilitate future development of control measures against this disease.

  20. The apical complex protein Pals1 is required to maintain cerebellar progenitor cells in a proliferative state.

    Science.gov (United States)

    Park, Jun Young; Hughes, Lucinda J; Moon, Uk Yeol; Park, Raehee; Kim, Sang-Bae; Tran, Khoi; Lee, Ju-Seog; Cho, Seo-Hee; Kim, Seonhee

    2016-01-01

    Through their biased localization and function within the cell, polarity complex proteins are necessary to establish the cellular asymmetry required for tissue organization. Well-characterized germinal zones, mitogenic signals and cell types make the cerebellum an excellent model for addressing the crucial function of polarity complex proteins in the generation and organization of neural tissues. Deletion of the apical polarity complex protein Pals1 in the developing cerebellum results in a remarkably undersized cerebellum with disrupted layers in poorly formed folia and strikingly reduced granule cell production. We demonstrate that Pals1 is not only essential for cerebellum organogenesis, but also for preventing premature differentiation and thus maintaining progenitor pools in cerebellar germinal zones, including cerebellar granule neuron precursors in the external granule layer. In the Pals1 mouse mutants, the expression of genes that regulate the cell cycle was diminished, correlating with the loss of the proliferating cell population of germinal zones. Furthermore, enhanced Shh signaling through activated Smo cannot overcome impaired cerebellar cell generation, arguing for an epistatic role of Pals1 in proliferation capacity. Our study identifies Pals1 as a novel intrinsic factor that regulates the generation of cerebellar cells and Pals1 deficiency as a potential inhibitor of overactive mitogenic signaling.

  1. Cytotoxic Compounds from Juglans sinensis Dode Display Anti-Proliferative Activity by Inducing Apoptosis in Human Cancer Cells.

    Science.gov (United States)

    Lee, Yoo Jin; Cui, Jun; Lee, Jun; Han, Ah-Reum; Lee, Eun Byul; Jang, Ho Hee; Seo, Eun Kyoung

    2016-01-01

    Phytochemical investigation of the bark of Juglans sinensis Dode (Juglandaceae) led to the isolation of two active compounds, 8-hydroxy-2-methoxy-1,4-naphthoquinone (1) and 5-hydroxy-2-methoxy-1,4-naphthoquinone (2), together with 15 known compounds 3-17. All compounds were isolated from this plant for the first time. The structures of 1 and 2 were elucidated by spectroscopic data analysis, including 1D and 2D NMR experiments. Compounds 1-17 were tested for their cytotoxicity against the A549 human lung cancer cell line; compounds 1 and 2 exhibited significant cytotoxicity and additionally had potent cytotoxicity against six human cancer cell lines, MCF7 (breast cancer), SNU423 (liver cancer), SH-SY5Y (neuroblastoma), HeLa (cervical cancer), HCT116 (colorectal cancer), and A549 (lung cancer). In particular, breast, colon, and lung cancer cells were more sensitive to the treatment using compound 1. In addition, compounds 1 and 2 showed strong cytotoxic activity towards human breast cancer cells MCF7, HS578T, and T47D, but not towards MCF10A normal-like breast cells. They also inhibited the colony formation of MCF7, A549, and HCT116 cells in a dose-dependent manner. Flow cytometry analysis revealed that the percentage of apoptotic cells significantly increased in MCF7 cells upon the treatment with compounds 1 and 2. The mechanism of cell death caused by compounds 1 and 2 may be attributed to the upregulation of Bax and downregulation of Bcl2. These findings suggest that compounds 1 and 2 may be regarded as potential therapeutic agents against cancer.

  2. Suspension culture of pluripotent stem cells: effect of shear on stem cell fate.

    Science.gov (United States)

    Keller, Kevin C; Rodrigues, Beatriz; zur Nieden, Nicole I

    2014-01-01

    Despite significant promise, the routine usage of suspension cell culture to manufacture stem cell-derived differentiated cells has progressed slowly. Suspension culture is an innovative way of either expanding or differentiating cells and sometimes both are combined into a single bioprocess. Its advantages over static 2D culturing include a homogeneous and controllable culture environment and producing a large quantity of cells in a fraction of time. This feature makes suspension cell culture ideal for use in stem cell research and eventually ideal in the large-scale production of differentiated cells for regenerative medicine. Because of their tremendous differentiation capacities and unlimited growth properties, pluripotent stem cells (PSCs) in particular are considered potential sources for future cell-replacement therapies. Currently, expansion of PSCs is accomplished in 2D, which only permits a limited amount of cell growth per culture flask before cells need to be passaged. However, before stem cells can be applied clinically, several aspects of their expansion, such as directed growth, but also differentiation, need to be better controlled. This review will summarize recent advantages in suspension culture of PSCs, while at the same time highlighting current challenges.

  3. CYP24 inhibition preserves 1α,25-dihydroxyvitamin D3 anti-proliferative signaling in lung cancer cells

    OpenAIRE

    Zhang, Qiuhong; Kanterewicz, Beatriz; Buch, Shama; Petkovich, Martin; Parise, Robert; Beumer,Jan; Yan LIN; Diergaarde, Brenda; Hershberger, Pamela A.

    2012-01-01

    Human lung tumors aberrantly express the 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3)-catabolizing enzyme, CYP24. We hypothesized that CYP24 reduces 1,25(OH)2D3-mediated transcription and allows lung cancer cells to escape its growth-inhibitory action. To test this, H292 lung cancer cells and the CYP24-selective inhibitor CTA091 were utilized. In H292 cells, CTA091 reduces 1,25(OH)2D3 catabolism, significantly increases 1,25(OH)2D3-mediated growth inhibition, and increases 1,25(OH)2D3 effects on i...

  4. Bistable cell fate specification as a result of stochastic fluctuations and collective spatial cell behaviour.

    Directory of Open Access Journals (Sweden)

    Daniel Stockholm

    Full Text Available BACKGROUND: In culture, isogenic mammalian cells typically display enduring phenotypic heterogeneity that arises from fluctuations of gene expression and other intracellular processes. This diversity is not just simple noise but has biological relevance by generating plasticity. Noise driven plasticity was suggested to be a stem cell-specific feature. RESULTS: Here we show that the phenotypes of proliferating tissue progenitor cells such as primary mononuclear muscle cells can also spontaneously fluctuate between different states characterized by the either high or low expression of the muscle-specific cell surface molecule CD56 and by the corresponding high or low capacity to form myotubes. Although this capacity is a cell-intrinsic property, the cells switch their phenotype under the constraints imposed by the highly heterogeneous microenvironment created by their own collective movement. The resulting heterogeneous cell population is characterized by a dynamic equilibrium between "high CD56" and "low CD56" phenotype cells with distinct spatial distribution. Computer simulations reveal that this complex dynamic is consistent with a context-dependent noise driven bistable model where local microenvironment acts on the cellular state by encouraging the cell to fluctuate between the phenotypes until the low noise state is found. CONCLUSIONS: These observations suggest that phenotypic fluctuations may be a general feature of any non-terminally differentiated cell. The cellular microenvironment created by the cells themselves contributes actively and continuously to the generation of fluctuations depending on their phenotype. As a result, the cell phenotype is determined by the joint action of the cell-intrinsic fluctuations and by collective cell-to-cell interactions.

  5. Development of transplant vasculopathy in aortic allografts correlates with neointimal smooth muscle cell proliferative capacity and fibrocyte frequency

    NARCIS (Netherlands)

    Onuta, Geanina; van Ark, Joris; Rienstra, Heleen; Boer, Mark Walther; Klatter, Flip A.; Bruggeman, Cathrien A.; Zeebregts, Clark J.; Rozing, Jan; Hillebrands, Jan-Luuk

    2010-01-01

    Objective: Transplant vasculopathy consists of neointima formation in graft vasculature resulting from vascular smooth muscle cell recruitment and proliferation. Variation in the severity of vasculopathy has been demonstrated. Genetic predisposition is suggested as a putative cause of this variation

  6. Anti-proliferative effect of rhein, an anthraquinone isolated from Cassia species, on Caco-2 human adenocarcinoma cells.

    Science.gov (United States)

    Aviello, Gabriella; Rowland, Ian; Gill, Christopher I; Acquaviva, Angela Maria; Capasso, Francesco; McCann, Mark; Capasso, Raffaele; Izzo, Angelo A; Borrelli, Francesca

    2010-07-01

    In recent years, the use of anthraquinone laxatives, in particular senna, has been associated with damage to the intestinal epithelial layer and an increased risk of developing colorectal cancer. In this study, we evaluated the cytotoxicity of rhein, the active metabolite of senna, on human colon adenocarcinoma cells (Caco-2) and its effect on cell proliferation. Cytotoxicity studies were performed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), neutral red (NR) and trans-epithelial electrical resistance (TEER) assays whereas (3)H-thymidine incorporation and Western blot analysis were used to evaluate the effect of rhein on cell proliferation. Moreover, for genoprotection studies Comet assay and oxidative biomarkers measurement (malondialdehyde and reactive oxygen species) were used. Rhein (0.1-10 microg/ml) had no significant cytotoxic effect on proliferating and differentiated Caco-2 cells. Rhein (0.1 and 1 microg/ml) significantly reduced cell proliferation as well as mitogen-activated protein (MAP) kinase activation; by contrast, at high concentration (10 microg/ml) rhein significantly increased cell proliferation and extracellular-signal-related kinase (ERK) phosphorylation. Moreover, rhein (0.1-10 microg/ml): (i) did not adversely affect the integrity of tight junctions and hence epithelial barrier function; (ii) did not induce DNA damage, rather it was able to reduce H(2)O(2)-induced DNA damage and (iii) significantly inhibited the increase in malondialdehyde and reactive oxygen species (ROS) levels induced by H(2)O(2)/Fe(2+). Rhein was devoid of cytotoxic and genotoxic effects in colon adenocarcinoma cells. Moreover, at concentrations present in the colon after a human therapeutic dosage of senna, rhein inhibited cell proliferation via a mechanism that seems to involve directly the MAP kinase pathway. Finally, rhein prevents the DNA damage probably via an anti-oxidant mechanism.

  7. Cold Atmospheric Plasma Treatment Induces Anti-Proliferative Effects in Prostate Cancer Cells by Redox and Apoptotic Signaling Pathways.

    Directory of Open Access Journals (Sweden)

    Martin Weiss

    Full Text Available One of the promising possibilities of the clinical application of cold plasma, so-called cold atmospheric plasma (CAP, is its application on malignant cells and cancer tissue using its anti-neoplastic effects, primarily through the delivery of reactive oxygen and nitrogen species (ROS, RNS. In this study, we investigated the impact of CAP on cellular proliferation and consecutive molecular response mechanisms in established prostate cancer (PC cell lines. PC cells showed a significantly reduced cell growth following CAP treatment as a result of both an immediate increase of intracellular peroxide levels and through the induction of apoptosis indicated by annexin V assay, TUNEL assay, and the evaluation of changes in nuclear morphology. Notably, co-administration of N-acetylcysteine (NAC completely neutralized CAP effects by NAC uptake and rapid conversion to glutathione (GSH. Vitamin C could not counteract the CAP induced effects on cell growth. In summary, relatively short treatments with CAP of 10 seconds were sufficient to induce a significant inhibition of cancer proliferation, as observed for the first time in urogenital cancer. Therefore, it is important to understand the mode of CAP related cell death and clarify and optimize CAP as cancer therapy. Increased levels of peroxides can alter redox-regulated signaling pathways and can lead to growth arrest and apoptosis. We assume that the general intracellular redox homeostasis, especially the levels of cellular GSH and peroxidases such as peroxiredoxins affect the outcome of the CAP treatment.

  8. Cold Atmospheric Plasma Treatment Induces Anti-Proliferative Effects in Prostate Cancer Cells by Redox and Apoptotic Signaling Pathways.

    Science.gov (United States)

    Weiss, Martin; Gümbel, Denis; Hanschmann, Eva-Maria; Mandelkow, Robert; Gelbrich, Nadine; Zimmermann, Uwe; Walther, Reinhard; Ekkernkamp, Axel; Sckell, Axel; Kramer, Axel; Burchardt, Martin; Lillig, Christopher H; Stope, Matthias B

    2015-01-01

    One of the promising possibilities of the clinical application of cold plasma, so-called cold atmospheric plasma (CAP), is its application on malignant cells and cancer tissue using its anti-neoplastic effects, primarily through the delivery of reactive oxygen and nitrogen species (ROS, RNS). In this study, we investigated the impact of CAP on cellular proliferation and consecutive molecular response mechanisms in established prostate cancer (PC) cell lines. PC cells showed a significantly reduced cell growth following CAP treatment as a result of both an immediate increase of intracellular peroxide levels and through the induction of apoptosis indicated by annexin V assay, TUNEL assay, and the evaluation of changes in nuclear morphology. Notably, co-administration of N-acetylcysteine (NAC) completely neutralized CAP effects by NAC uptake and rapid conversion to glutathione (GSH). Vitamin C could not counteract the CAP induced effects on cell growth. In summary, relatively short treatments with CAP of 10 seconds were sufficient to induce a significant inhibition of cancer proliferation, as observed for the first time in urogenital cancer. Therefore, it is important to understand the mode of CAP related cell death and clarify and optimize CAP as cancer therapy. Increased levels of peroxides can alter redox-regulated signaling pathways and can lead to growth arrest and apoptosis. We assume that the general intracellular redox homeostasis, especially the levels of cellular GSH and peroxidases such as peroxiredoxins affect the outcome of the CAP treatment.

  9. Age-dependent alterations of the hippocampal cell composition and proliferative potential in the hAβPPSwInd-J20 mouse.

    Science.gov (United States)

    Fu, YuHong; Rusznák, Zoltán; Kwok, John B J; Kim, Woojin Scott; Paxinos, George

    2014-01-01

    The J20 mouse expresses human mutant amyloid-β protein precursor (hAβPPSwInd) and is an established transgenic model of Alzheimer's disease (AD). From the age of 5 months, amyloid-β (Aβ) deposits appear in the hippocampus with concomitant increase of AD-associated features. Although changes occurring after the appearance of Aβ deposits have been extensively studied, very little is known about alterations that occur prior to 5 months. The present study aimed to identify changes in the cellular composition and proliferative potential of the J20 hippocampus using 1-18-month-old mice. Neuronal, non-neuronal, Ki-67+, and TUNEL+ cell numbers were counted with the isotropic fractionator method. Age-dependent changes of the expression of microglia-, astrocyte-, and neurogenesis-specific markers were sought in the entire hippocampus. Several transgene-associated changes were revealed before the appearance of Aβ deposits. The number of proliferating cells decreased whereas the number of microglia clusters increased as early as 4 weeks of age. The neurogenesis was also impaired in the dentate gyrus of 7-11-week-old J20 mice. A statistically significant negative correlation was found between the number of proliferating cells and age in both populations, but the time course of the age-dependence was steeper in wild-type than in J20 mice. Negative age-dependence was noted when the number of cells committed to apoptosis was examined. Our results indicate that overexpression of mutant hAβPP initiates a cascade of pathologic events well before the appearance of visible Aβ plaques. Accordingly, early signs of AD include reduced cell proliferation, impaired neurogenesis, and increased activity of microglia in the hippocampus.

  10. Hepatic expression of the proliferative marker Ki-67 and p53 protein in HBV or HCV cirrhosis in relation to dysplastic liver cell changes and hepatocellular carcinoma.

    Science.gov (United States)

    Koskinas, J; Petraki, K; Kavantzas, N; Rapti, I; Kountouras, D; Hadziyannis, S

    2005-11-01

    To evaluate hepatic expression of the nuclear proliferative marker Ki-67 and the p53 oncoprotein in hepatitis B virus (HBV)/HCV cirrhosis in relation to dysplastic liver cell changes and hepatocellular carcinoma (HCC). We studied needle liver biopsies from 107 patients with cirrhosis and no HCC (52 HBV, 55 HCV) who had been assessed for protocol studies, and 57 cirrhotic patients with HCC (40 HBV, 17 HCV). We evaluated small and large cell dysplastic changes along with the expression of Ki-67 and p53 by immunohistochemistry. The labelling index (LI) was defined as the proportion (%) of positive-stained nuclei of the 500 measured. Large and small cell dysplastic changes were observed in 12 and 9% of specimens respectively. Only small cell changes were associated with Ki-67 expression. Ki-67 LI was 5.50 +/- 5.7 in cirrhosis (13.90 +/- 3.84 in those with small cell dysplastic changes vs 4.64 +/- 4.98 in those without, P cirrhosis with HCC (P cirrhosis. Expression of p53 was observed in 30% of the non-tumorous and in 53% of the neoplastic tissue obtained from patients with HCC, with no differences between HCV and HBV. Ki-67 and p53 expression was associated with the tumour grade (P < 0.001). Our observations clearly demonstrate the association between the proliferation activity and the morphological changes in the cirrhotic liver from the non-dysplastic to dysplastic lesion to HCC. They also support the hypothesis that p53 alterations are a rather late event in carcinogenesis and related to HCC grade. And finally, they suggest that the final steps of hepatocarcinogenesis are common and independent of the aetiology of the chronic viral infection.

  11. Proliferative sickle cell retinopathy associated with sickle cell trait and gestational diabetes: case report Retinopatia falciforme proliferativa associada a traço falciforme e diabetes gestacional: relato de caso

    Directory of Open Access Journals (Sweden)

    Jefferson Augusto Santana Ribeiro

    2009-06-01

    Full Text Available Proliferative sickle cell retinopathy is an uncommon complication in individuals with sickle cell trait (AS. However, the risk for proliferative retinopathy development is increased in patients with AS hemoglobinopathy associated with systemic conditions or ocular trauma. A case of a patient with AS hemoglobinopathy who developed proliferative sickle cell retinopathy after the occurrence of gestational diabetes and pregnancy-induced hypertension is reported. Hemoglobin electrophoresis revealed presence of A2 5.0%, S 35.0% and A 53.2%. The present case emphasizes the importance of evaluating systemic comorbidities in patients with sickle cell trait during pregnancy since sickle cell retinopathy can progress rapidly, as well as the importance of regular eye fundus examination in these patients.Retinopatia falciforme proliferativa é uma complicação incomum em indivíduos com traço falciforme, havendo, porém, risco aumentado de desenvolver retinopatia proliferativa em pacientes com hemoglobinopatia AS associada a condições sistêmicas ou trauma ocular. Neste artigo será apresentado um caso de paciente com diabetes gestacional, hipertensão arterial sistêmica associada à gravidez e traço falciforme. Eletroforese de hemoglobinas revelou a presença de A2 5,0%, S 35,0% e A 53,2%. Este caso ressalta a importância da avaliação de comorbidades sistêmicas em pacientes com traço falciforme no período gestacional, uma vez que pode ocorrer rápida progressão da retinopatia falciforme, devendo-se realizar também exames regulares do fundo de olho nestes pacientes.

  12. Molecular analysis of ex-vivo CD133+ GBM cells revealed a common invasive and angiogenic profile but different proliferative signatures among high grade gliomas

    Directory of Open Access Journals (Sweden)

    Garcia Juan L

    2010-08-01

    of samples: those discriminated by tumour location and, the most importantly, the group discriminated by their proliferative potential; Conclusions Primary glioblastomas could be sub-classified according to the properties of their CD133+ cells. The molecular characterization of these potential stem cell populations could be critical to find new therapeutic targets and to develop an effective therapy for these tumours with very dismal prognosis.

  13. Transcriptome analysis of soybean leaf abscission identifies transcriptional regulators of organ polarity and cell fate

    Directory of Open Access Journals (Sweden)

    Joonyup eKim

    2016-02-01

    Full Text Available Abscission, organ separation, is a developmental process that is modulated by endogenous and environmental factors. To better understand the molecular events underlying the progression of abscission in soybean, an agriculturally important legume, we performed RNA sequencing (RNA-seq of RNA isolated from the leaf abscission zones (LAZ and petioles (Non-AZ, NAZ after treating stem/petiole explants with ethylene for 0, 12, 24, 48, and 72 h. As expected, expression of several families of cell wall modifying enzymes and many pathogenesis-related (PR genes specifically increased in the LAZ as abscission progressed. Here, we focus on the 5,206 soybean genes we identified as encoding transcription factors (TFs. Of the 5,206 TFs, 1,088 were differentially up- or down-regulated more than 8-fold in the LAZ over time, and, within this group, 188 of the TFs were differentially regulated more than 8-fold in the LAZ relative to the NAZ. These 188 abscission-specific TFs include several TFs containing domains for homeobox, MYB, Zinc finger, bHLH, AP2, NAC, WRKY, YABBY, and auxin-related motifs. To discover the connectivity among the TFs and highlight developmental processes that support organ separation, the 188 abscission-specific TFs were then clustered based on a >4-fold up- or down-regulation in two consecutive time points (i.e., 0 h and 12 h, 12 h and 24 h, 24 h and 48 h, or 48 h and 72 h. By requiring a sustained change in expression over two consecutive time intervals and not just one or several time intervals, we could better tie changes in TFs to a particular process or phase of abscission. The greatest number of TFs clustered into the 0 h and 12 h group. Transcriptional network analysis for these abscission-specific TFs indicated that most of these TFs are known as key determinants in the maintenance of organ polarity, lateral organ growth and cell fate. The abscission-specific expression of these TFs prior to the onset of abscission and their

  14. Transcriptome Analysis of Soybean Leaf Abscission Identifies Transcriptional Regulators of Organ Polarity and Cell Fate.

    Science.gov (United States)

    Kim, Joonyup; Yang, Jinyoung; Yang, Ronghui; Sicher, Richard C; Chang, Caren; Tucker, Mark L

    2016-01-01

    Abscission, organ separation, is a developmental process that is modulated by endogenous and environmental factors. To better understand the molecular events underlying the progression of abscission in soybean, an agriculturally important legume, we performed RNA sequencing (RNA-seq) of RNA isolated from the leaf abscission zones (LAZ) and petioles (Non-AZ, NAZ) after treating stem/petiole explants with ethylene for 0, 12, 24, 48, and 72 h. As expected, expression of several families of cell wall modifying enzymes and many pathogenesis-related (PR) genes specifically increased in the LAZ as abscission progressed. Here, we focus on the 5,206 soybean genes we identified as encoding transcription factors (TFs). Of the 5,206 TFs, 1,088 were differentially up- or down-regulated more than eight-fold in the LAZ over time, and, within this group, 188 of the TFs were differentially regulated more than eight-fold in the LAZ relative to the NAZ. These 188 abscission-specific TFs include several TFs containing domains for homeobox, MYB, Zinc finger, bHLH, AP2, NAC, WRKY, YABBY, and auxin-related motifs. To discover the connectivity among the TFs and highlight developmental processes that support organ separation, the 188 abscission-specific TFs were then clustered based on a >four-fold up- or down-regulation in two consecutive time points (i.e., 0 and 12 h, 12 and 24 h, 24 and 48 h, or 48 and 72 h). By requiring a sustained change in expression over two consecutive time intervals and not just one or several time intervals, we could better tie changes in TFs to a particular process or phase of abscission. The greatest number of TFs clustered into the 0 and 12 h group. Transcriptional network analysis for these abscission-specific TFs indicated that most of these TFs are known as key determinants in the maintenance of organ polarity, lateral organ growth, and cell fate. The abscission-specific expression of these TFs prior to the onset of abscission and their functional

  15. Proliferative effect of whey from cow's milk obtained at two different stages of pregnancy measured in MCF-7 cells

    DEFF Research Database (Denmark)

    Nielsen, Tina S; Andersen, Charlotte; Sejrsen, Kristen

    2012-01-01

    (whey) in a proliferation assay with estrogen-sensitive MCF-7 human breast cancer cells. Milk samples were obtained from 22 cows representing different stages of pregnancy (first and second half) and whey was produced from the milk. 0·1, 0·25 or 0·5% whey was included in the cell culture medium......Dietary estrogens may play a role in the etiology of hormone-dependent cancers like breast cancer. Cow's milk contains various endogenous estrogens and feed derived phytoestrogens that potentially contribute to an estrogenic effect of milk in consumers, and therefore we evaluated the effect of milk...... and after 6 days of treatment cell proliferation was assessed by a colorimetric method with a fluorometer. Whey induced significant (P...

  16. Anti-proliferative effect of a compound isolated from Cassia auriculata against human colon cancer cell line HCT 15.

    Science.gov (United States)

    Esakkirajan, M; Prabhu, N M; Arulvasu, C; Beulaja, M; Manikandan, R; Thiagarajan, R; Govindaraju, K; Prabhu, D; Dinesh, D; Babu, G; Dhanasekaran, G

    2014-01-01

    The compound was isolated from leaves of Cassia auriculata and its structure was characterized using high-performance liquid chromatography (HPLC), liquid chromatography mass spectrometry (LC-MS), UV-vis spectroscopy (UV-vis), fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance spectroscopy (NMR). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, cytotoxicity, nuclear morphology and lactate dehydrogenase assay of isolated compound was tested against human colon cancer cell line HCT 15. The isolated compound, 4-(4-chlorobenzyl)-2,3,4,5,6,7-hexahydro-7-(2-ethoxyphenyl)benzo[h][1,4,7]triazecin-8(1H)-one at 25μg/ml concentration and by 48h showed 50% inhibition of human colon cancer cells (HCT 15). The results suggest that isolated compound from C. auriculata has potential to prevent colon cancer cell line.

  17. A Gap Junction Protein, Inx2, Modulates Calcium Flux to Specify Border Cell Fate during Drosophila oogenesis

    Science.gov (United States)

    Ghosh, Ritabrata; Deshpande, Girish

    2017-01-01

    Intercellular communication mediated by gap junction (GJ) proteins is indispensable during embryogenesis, tissue regeneration and wound healing. Here we report functional analysis of a gap junction protein, Innexin 2 (Inx2), in cell type specification during Drosophila oogenesis. Our data reveal a novel involvement of Inx2 in the specification of Border Cells (BCs), a migratory cell type, whose identity is determined by the cell autonomous STAT activity. We show that Inx2 influences BC fate specification by modulating STAT activity via Domeless receptor endocytosis. Furthermore, detailed experimental analysis has uncovered that Inx2 also regulates a calcium flux that transmits across the follicle cells. We propose that Inx2 mediated calcium flux in the follicle cells stimulates endocytosis by altering Dynamin (Shibire) distribution which is in turn critical for careful calibration of STAT activation and, thus for BC specification. Together our data provide unprecedented molecular insights into how gap junction proteins can regulate cell-type specification. PMID:28114410

  18. Sequence of neuron origin and neocortical laminar fate: relation to cell cycle of origin in the developing murine cerebral wall

    Science.gov (United States)

    Takahashi, T.; Goto, T.; Miyama, S.; Nowakowski, R. S.; Caviness, V. S. Jr

    1999-01-01

    Neurons destined for each region of the neocortex are known to arise approximately in an "inside-to-outside" sequence from a pseudostratified ventricular epithelium (PVE). This sequence is initiated rostrolaterally and propagates caudomedially. Moreover, independently of location in the PVE, the neuronogenetic sequence in mouse is divisible into 11 cell cycles that occur over a 6 d period. Here we use a novel "birth hour" method that identifies small cohorts of neurons born during a single 2 hr period, i.e., 10-20% of a single cell cycle, which corresponds to approximately 1.5% of the 6 d neuronogenetic period. This method shows that neurons arising with the same cycle of the 11 cycle sequence in mouse have common laminar fates even if they arise from widely separated positions on the PVE (neurons of fields 1 and 40) and therefore arise at different embryonic times. Even at this high level of temporal resolution, simultaneously arising cells occupy more than one cortical layer, and there is substantial overlap in the distributions of cells arising with successive cycles. We demonstrate additionally that the laminar representation of cells arising with a given cycle is little if at all modified over the early postnatal interval of histogenetic cell death. We infer from these findings that cell cycle is a neuronogenetic counting mechanism and that this counting mechanism is integral to subsequent processes that determine cortical laminar fate.

  19. Persistent Exposure to Porphyromonas gingivalis Promotes Proliferative and Invasion Capabilities, and Tumorigenic Properties of Human Immortalized Oral Epithelial Cells

    Science.gov (United States)

    Geng, Fengxue; Liu, Junchao; Guo, Yan; Li, Chen; Wang, Hongyang; Wang, Hongyan; Zhao, Haijiao; Pan, Yaping

    2017-01-01

    Recent epidemiological studies revealed a significant association between oral squamous cell carcinoma (OSCC) and Porphyromonas gingivalis, a major pathogen of periodontal disease. As a keystone pathogen of periodontitis, P. gingivalis is known not only to damage local periodontal tissues, but also to evade the host immune system and eventually affect systemic health. However, its role in OSCC has yet to be defined. To explore the underlying effect of chronic P. gingivalis infection on OSCC and to identify relevant biomarkers as promising targets for therapy and prevention, we established a novel model by exposing human immortalized oral epithelial cells (HIOECs) to P. gingivalis at a low multiplicity of infection (MOI) for 5–23 weeks. The P. gingivalis infected HIOECs were monitored for tumor biological alteration by proliferation, wound healing, transwell invasion, and gelatin zymography assays. Microarray and proteomic analyses were performed on HIOECs infected with P. gingivalis for 15 weeks, and some selected data were validated by quantitative real-time PCR and (or) western blot on cells infected for 15 and 23 weeks. Persistent exposure to P. gingivalis caused cell morphological changes, increased proliferation ability with higher S phase fraction in the cell cycle, and promoted cell migratory and invasive properties. In combining results of bioinformatics analyses and validation assays, tumor-related genes such as NNMT, FLI1, GAS6, lncRNA CCAT1, PDCD1LG2, and CD274 may be considered as the key regulators in tumor-like transformation in response to long-time exposure of P. gingivalis. In addition, some useful clinical biomarkers and novel proteins were also presented. In conclusion, P. gingivalis could promote tumorigenic properties of HIOECs, indicating that chronic P. gingivalis infection may be considered as a potential risk factor for oral cancer. The key regulators detected from the present model might be used in monitoring the development of OSCC with

  20. Planar cell polarity effector gene Intu regulates cell fate-specific differentiation of keratinocytes through the primary cilia.

    Science.gov (United States)

    Dai, D; Li, L; Huebner, A; Zeng, H; Guevara, E; Claypool, D J; Liu, A; Chen, J

    2013-01-01

    Genes involved in the planar cell polarity (PCP) signaling pathway are essential for a number of developmental processes in mammals, such as convergent extension and ciliogenesis. Tissue-specific PCP effector genes of the PCP signaling pathway are believed to mediate PCP signals in a tissue- and cell type-specific manner. However, how PCP signaling controls the morphogenesis of mammalian tissues remains unclear. In this study, we investigated the role of inturned (Intu), a tissue-specific PCP effector gene, during hair follicle formation in mice. Tissue-specific disruption of Intu in embryonic epidermis resulted in hair follicle morphogenesis arrest because of the failure of follicular keratinocyte to differentiate. Targeting Intu in the epidermis resulted in almost complete loss of primary cilia in epidermal and follicular keratinocytes, and a suppressed hedgehog signaling pathway. Surprisingly, the epidermal stratification and differentiation programs and barrier function were not affected. These results demonstrate that tissue-specific PCP effector genes of the PCP signaling pathway control the differentiation of keratinocytes through the primary cilia in a cell fate- and context-dependent manner, which may be critical in orchestrating the propagation and interpretation of polarity signals established by the core PCP components.

  1. Influences of LIN-12/Notch and POP-1/TCF on the Robustness of Ventral Uterine Cell Fate Specification in Caenorhabditis elegans Gonadogenesis.

    Science.gov (United States)

    Sallee, Maria D; Aydin, Taner; Greenwald, Iva

    2015-10-19

    The prospective ventral uterus of the hermaphrodite gonad primordium consists of two pairs of sister cells, with each pair consisting of a proximal "α" cell and a distal "β" cell. All four cells initially are competent to become the anchor cell (AC), a unique cell type that acts as the organizer of subsequent uterine and vulval development. However, the β cells soon lose this competence and always become ventral uterine precursor cells (VUs), whereas the α cells maintain their AC competence longer, until lin-12/Notch-mediated interactions between them specify one as the AC and the other as a VU. Here, we investigate this asymmetry in developmental potential and VU fate specification between the α and β sister cells. We find evidence that lin-12 activity contributes to the robustness of βVU fate at elevated temperature, that the Caenorhabditis elegans Notch paralog glp-1 is not functionally redundant with lin-12 in specifying βVU fate, and that the activity of POP-1, the sole C. elegans TCF ortholog, influences βVU fate. We propose a model for how Wnt and LIN-12/Notch signaling together lead to robust specification of the βVU fate.

  2. Influence of interferon preparations on the proliferative capacity of human and mouse bone marrow cells in vitro

    NARCIS (Netherlands)

    E. van 't Hull (Eveline); B. Löwenberg (Bob); M. de Vries (Marco); H. Schellekens (Huub)

    1978-01-01

    textabstractThe toxicity of interferon to bone marrow was studied by the use of in vitro colony forming assays for hemopoietic cells. In the same study the relative inhibitory effects of two clinically common interferon preparations, leukocyte and fibroblast interferons, were compared with regard to

  3. Anti-Proliferative Activity of λ-Carrageenan Through the Induction of Apoptosis in Human Breast Cancer Cells

    Science.gov (United States)

    Jazzara, Marie; Ghannam, Ahmed; Soukkarieh, Chadi; Murad, Hossam

    2016-01-01

    Background Sulfated Polysaccharides (SPs) possess spectrum of pharmacological and therapeutic properties that could attributed to their origins variation, chemical structures and biological activities. Various studies have shown the impact of SPs on proliferation in different cancer cell lines. Objectives In this study, we have evaluated the biological effects of λ-carrageenan, a highly SP, extracted from the red seaweed Laurencia papillosa, on MDA-MB-231 cancer cell line. Materials and Methods MDA-MB-231 cells have treated with λ-carrageenan, the viability and apoptosis have assessed by the appropriate florescent probes on flow cytometer. The expression levels of mRNA of apoptotic genes have detected by real-time PCR analysis. Results Our results have indicated that the signaling pathway of λ-carrageenan inhibited the proliferation of MDA-MB-231 cells by up-regulating the pro-apoptotic genes caspase-8, caspase-9, caspase-3 which have been resulting the increased levels of active caspase-3 protein. Furthermore, This SP had that capacity to disrupt the mitochondrial function by altering the bax/bcl-2 ratio of expression which has considered an important element in apoptosis induction. Conclusions The presented results have signposted that λ-carrageenan was a promising bioactive polymer which could be a potential candidate in preventing or treating breast cancer. PMID:27761203

  4. DeltaNp63alpha repression of the Notch1 gene supports the proliferative capacity of normal human keratinocytes and cervical cancer cells.

    Science.gov (United States)

    Yugawa, Takashi; Narisawa-Saito, Mako; Yoshimatsu, Yuki; Haga, Kei; Ohno, Shin-ichi; Egawa, Nagayasu; Fujita, Masatoshi; Kiyono, Tohru

    2010-05-15

    The p53 family member p63 is a master regulator of epithelial development. One of its isoforms, DeltaNp63alpha, is predominantly expressed in the basal cells of stratified epithelia and plays a fundamental role in control of regenerative potential and epithelial integrity. In contrast to p53, p63 is rarely mutated in human cancers, but it is frequently overexpressed in squamous cell carcinomas (SCC). However, its functional relevance to tumorigenesis remains largely unclear. We previously identified the Notch1 gene as a novel transcriptional target of p53. Here, we show that DeltaNp63alpha functions as a transcriptional repressor of the Notch1 gene through the p53-responsive element. Knockdown of p63 caused upregulation of Notch1 expression and marked reduction in proliferation and clonogenicity of both normal human keratinocytes and cervical cancer cell lines overexpressing DeltaNp63alpha. Concomitant silencing of Notch1 significantly rescued this phenotype, indicating the growth defect induced by p63 deficiency to be, at least in part, attributable to Notch1 function. Conversely, overexpression of DeltaNp63alpha decreased basal levels of Notch1, increased proliferative potential of normal human keratinocytes, and inhibited both p53-dependent and p53-independent induction of Notch1 and differentiation markers upon genotoxic stress and serum exposure, respectively. These results suggest that DeltaNp63alpha maintains the self-renewing capacity of normal human keratinocytes and cervical cancer cells partly through transcriptional repression of the Notch1 gene and imply a novel pathogenetical significance of frequently observed overexpression of DeltaNp63alpha together with p53 inactivation in SCCs.

  5. The Epstein-Barr Virus-encoded miR-BART22 targets MAP3K5 to promote host cell proliferative and invasive abilities in nasopharyngeal carcinoma

    Science.gov (United States)

    Chen, Ruichao; Zhang, Minfeng; Li, Qiulian; Xiong, Hanzhen; Liu, Shaoyan; Fang, Weiyi; Zhang, Qianbing; Liu, Zhen; Xu, Xuehu; Jiang, Qingping

    2017-01-01

    miR-BART22, a new discovered Epstein-Barr virus (EBV) miRNA, is abundant in Nasopharyngeal carcinoma (NPC). It has been reported that miR-BART22 promoted the tumor development by down-modulating EBV LMP2 expression to evade the host immune response. But its cell target genes have still been obscure. We have reported an inverse correlation between the BART-22 and MAP3K5 protein expression in NPC tissues and NPC cell lines. Meanwhile, MAP3K5 protein expression level was significantly decreased in primary NPC tissues compared with nasopharyngitis when MAP3K5 mRNA expression was consistent in two group tissues. According to our data and target prediction by miRnada, we assume MAP3K5 is an important target gene of NPC. MAP3K5, also named apoptosis signal-regulating kinase1 (ASK1), is an important early answer gene in P38MAPK pathway and an apoptosis-related gene. In present study, MAP3K5 was verified the target gene of miR-BART22 by luciferase assay. miRBART-22 decreased MAP3K5 protein level. Moreover, it also decreased MAP3K5 downstream gene MAP2K4 expression in P38MAPK pathway, and even their activated phosphorylation forms. Additionally, we found stable transfection of miR-BAT22 could improve tumor cells' proliferative and invasive abilities in NPC cell line 5-8F. The data highlight the role of the EBV miR-BART22 in regulating genes involving in apoptosis and some important pathways to promote cancer development. And it also raises the possibility that inhibitors of miR-BART22 can be as a therapeutic strategy for NPC and other EBV-infected tumors treatment. PMID:28243335

  6. Floor plate-derived sonic hedgehog regulates glial and ependymal cell fates in the developing spinal cord.

    Science.gov (United States)

    Yu, Kwanha; McGlynn, Sean; Matise, Michael P

    2013-04-01

    Cell fate specification in the CNS is controlled by the secreted morphogen sonic hedgehog (Shh). At spinal cord levels, Shh produced by both the notochord and floor plate (FP) diffuses dorsally to organize patterned gene expression in dividing neural and glial progenitors. Despite the fact that two discrete sources of Shh are involved in this process, the individual contribution of the FP, the only intrinsic source of Shh throughout both neurogenesis and gliogenesis, has not been clearly defined. Here, we have used conditional mutagenesis approaches in mice to selectively inactivate Shh in the FP (Shh(FP)) while allowing expression to persist in the notochord, which underlies the neural tube during neurogenesis but not gliogenesis. We also inactivated Smo, the common Hh receptor, in neural tube progenitors. Our findings confirm and extend prior studies suggesting an important requirement for Shh(FP) in specifying oligodendrocyte cell fates via repression of Gli3 in progenitors. Our studies also uncover a connection between embryonic Shh signaling and astrocyte-mediated reactive gliosis in adults, raising the possibility that this pathway is involved in the development of the most common cell type in the CNS. Finally, we find that intrinsic spinal cord Shh signaling is required for the proper formation of the ependymal zone, the epithelial cell lining of the central canal that is also an adult stem cell niche. Together, our studies identify a crucial late embryonic role for Shh(FP) in regulating the specification and differentiation of glial and epithelial cells in the mouse spinal cord.

  7. Hippo pathway effectors control cardiac progenitor cell fate by acting as dynamic sensors of substrate mechanics and nanostructure.

    Science.gov (United States)

    Mosqueira, Diogo; Pagliari, Stefania; Uto, Koichiro; Ebara, Mitsuhiro; Romanazzo, Sara; Escobedo-Lucea, Carmen; Nakanishi, Jun; Taniguchi, Akiyoshi; Franzese, Ornella; Di Nardo, Paolo; Goumans, Marie José; Traversa, Enrico; Pinto-do-Ó, Perpetua; Aoyagi, Takao; Forte, Giancarlo

    2014-03-25

    Stem cell responsiveness to extracellular matrix (ECM) composition and mechanical cues has been the subject of a number of investigations so far, yet the molecular mechanisms underlying stem cell mechano-biology still need full clarification. Here we demonstrate that the paralog proteins YAP and TAZ exert a crucial role in adult cardiac progenitor cell mechano-sensing and fate decision. Cardiac progenitors respond to dynamic modifications in substrate rigidity and nanopattern by promptly changing YAP/TAZ intracellular localization. We identify a novel activity of YAP and TAZ in the regulation of tubulogenesis in 3D environments and highlight a role for YAP/TAZ in cardiac progenitor proliferation and differentiation. Furthermore, we show that YAP/TAZ expression is triggered in the heart cells located at the infarct border zone. Our results suggest a fundamental role for the YAP/TAZ axis in the response of resident progenitor cells to the modifications in microenvironment nanostructure and mechanics, thereby contributing to the maintenance of myocardial homeostasis in the adult heart. These proteins are indicated as potential targets to control cardiac progenitor cell fate by materials design.

  8. Hippo pathway effectors control cardiac progenitor cell fate by acting as dynamic sensors of substrate mechanics and nanostructure

    KAUST Repository

    Mosqueira, Diogo

    2014-03-25

    Stem cell responsiveness to extracellular matrix (ECM) composition and mechanical cues has been the subject of a number of investigations so far, yet the molecular mechanisms underlying stem cell mechano-biology still need full clarification. Here we demonstrate that the paralog proteins YAP and TAZ exert a crucial role in adult cardiac progenitor cell mechano-sensing and fate decision. Cardiac progenitors respond to dynamic modifications in substrate rigidity and nanopattern by promptly changing YAP/TAZ intracellular localization. We identify a novel activity of YAP and TAZ in the regulation of tubulogenesis in 3D environments and highlight a role for YAP/TAZ in cardiac progenitor proliferation and differentiation. Furthermore, we show that YAP/TAZ expression is triggered in the heart cells located at the infarct border zone. Our results suggest a fundamental role for the YAP/TAZ axis in the response of resident progenitor cells to the modifications in microenvironment nanostructure and mechanics, thereby contributing to the maintenance of myocardial homeostasis in the adult heart. These proteins are indicated as potential targets to control cardiac progenitor cell fate by materials design. © 2014 American Chemical Society.

  9. Pomegranate Ellagitannin-Derived Compounds Exhibit Anti-proliferative and Anti-aromatase Activity in Breast Cancer Cells In Vitro

    OpenAIRE

    Adams, Lynn S.; Zhang, Yanjun; Seeram, Navindra P.; Heber, David; Chen, Shiuan

    2010-01-01

    Estrogen stimulates the proliferation of breast cancer cells and the growth of estrogen-responsive tumors. The aromatase enzyme, which converts androgen to estrogen, plays a key role in breast carcinogenesis. The pomegranate fruit, a rich source of ellagitannins (ETs), has attracted recent attention due to its anti-cancer and anti-atherosclerotic properties. On consumption, pomegranate ETs hydrolyze, releasing ellagic acid (EA) which is then converted to 3,8-dihydroxy-6H-dibenzo[b,d]pyran-6-o...

  10. Brm inhibits the proliferative response of keratinocytes and corneal epithelial cells to ultraviolet radiation-induced damage.

    Directory of Open Access Journals (Sweden)

    Nur Mohammad Monsur Hassan

    Full Text Available Ultraviolet radiation (UV from sunlight is the primary cause of skin and ocular neoplasia. Brahma (BRM is part of the SWI/SNF chromatin remodeling complex. It provides energy for rearrangement of chromatin structure. Previously we have found that human skin tumours have a hotspot mutation in BRM and that protein levels are substantially reduced. Brm-/- mice have enhanced susceptibility to photocarcinogenesis. In these experiments, Brm-/- mice, with both or a single Trp53 allele were exposed to UV for 2 or 25 weeks. In wild type mice the central cornea and stroma became atrophic with increasing time of exposure while the peripheral regions became hyperplastic, presumably as a reparative process. Brm-/-, Trp53+/-, and particularly the Brm-/- Trp53+/- mice had an exaggerated hyperplastic regeneration response in the corneal epithelium and stroma so that the central epithelial atrophy or stromal loss was reduced. UV induced hyperplasia of the epidermis and corneal epithelium, with an increase in the number of dividing cells as determined by Ki-67 expression. This response was considerably greater in both the Brm-/- Trp53+/+ and Brm-/- Trp53+/- mice indicating that Brm protects from UV-induced enhancement of cell division, even with loss of one Trp53 allele. Cell division was disorganized in Brm-/- mice. Rather than being restricted to the basement membrane region, dividing cells were also present in the suprabasal regions of both tissues. Brm appears to be a tumour suppressor gene that protects from skin and ocular photocarcinogenesis. These studies indicate that Brm protects from UV-induced hyperplastic growth in both cutaneous and corneal keratinocytes, which may contribute to the ability of Brm to protect from photocarcinogenesis.

  11. Isolation of a glucosamine binding leguminous lectin with mitogenic activity towards splenocytes and anti-proliferative activity towards tumor cells.

    Directory of Open Access Journals (Sweden)

    Yau Sang Chan

    Full Text Available A dimeric 64-kDa glucosamine-specific lectin was purified from seeds of Phaseolus vulgaris cv. "brown kidney bean." The simple 2-step purification protocol involved affinity chromatography on Affi-gel blue gel and gel filtration by FPLC on Superdex 75. The lectin was absorbed on Affi-gel blue gel and desorbed using 1M NaCl in the starting buffer. Gel filtration on Superdex 75 yielded a major absorbance peak that gave a single 32-kDa band in SDS-PAGE. Hemagglutinating activity was completely preserved when the ambient temperature was in the range of 20 °C-60 °C. However, drastic reduction of the activity occurred at temperatures above 65 °C. Full hemagglutinating activity of the lectin was observed at an ambient pH of 3 to 12. About 50% activity remained at pH 0-2, and only residual activity was observed at pH 13-14. Hemagglutinating activity of the lectin was inhibited by glucosamine. The brown kidney bean lectin elicited maximum mitogenic activity toward murine splenocytes at 2.5 µM. The mitogenic activity was nearly completely eliminated in the presence of 250 mM glucosamine. The lectin also increased mRNA expression of the cytokines IL-2, TNF-α and IFN-γ. The lectin exhibited antiproliferative activity toward human breast cancer (MCF7 cells, hepatoma (HepG2 cells and nasopharyngeal carcinoma (CNE1 and CNE2 cells with IC(50 of 5.12 µM, 32.85 µM, 3.12 µM and 40.12 µM respectively after treatment for 24 hours. Flow cytometry with Annexin V and propidum iodide staining indicated apoptosis of MCF7 cells. Hoechst 33342 staining also indicated formation of apoptotic bodies in MCF7 cells after exposure to brown kidney bean lectin. Western blotting revealed that the lectin-induced apoptosis involved ER stress and unfolded protein response.

  12. Isolation of a glucosamine binding leguminous lectin with mitogenic activity towards splenocytes and anti-proliferative activity towards tumor cells.

    Science.gov (United States)

    Chan, Yau Sang; Wong, Jack Ho; Fang, Evandro Fei; Pan, Wenliang; Ng, Tzi Bun

    2012-01-01

    A dimeric 64-kDa glucosamine-specific lectin was purified from seeds of Phaseolus vulgaris cv. "brown kidney bean." The simple 2-step purification protocol involved affinity chromatography on Affi-gel blue gel and gel filtration by FPLC on Superdex 75. The lectin was absorbed on Affi-gel blue gel and desorbed using 1M NaCl in the starting buffer. Gel filtration on Superdex 75 yielded a major absorbance peak that gave a single 32-kDa band in SDS-PAGE. Hemagglutinating activity was completely preserved when the ambient temperature was in the range of 20 °C-60 °C. However, drastic reduction of the activity occurred at temperatures above 65 °C. Full hemagglutinating activity of the lectin was observed at an ambient pH of 3 to 12. About 50% activity remained at pH 0-2, and only residual activity was observed at pH 13-14. Hemagglutinating activity of the lectin was inhibited by glucosamine. The brown kidney bean lectin elicited maximum mitogenic activity toward murine splenocytes at 2.5 µM. The mitogenic activity was nearly completely eliminated in the presence of 250 mM glucosamine. The lectin also increased mRNA expression of the cytokines IL-2, TNF-α and IFN-γ. The lectin exhibited antiproliferative activity toward human breast cancer (MCF7) cells, hepatoma (HepG2) cells and nasopharyngeal carcinoma (CNE1 and CNE2) cells with IC(50) of 5.12 µM, 32.85 µM, 3.12 µM and 40.12 µM respectively after treatment for 24 hours. Flow cytometry with Annexin V and propidum iodide staining indicated apoptosis of MCF7 cells. Hoechst 33342 staining also indicated formation of apoptotic bodies in MCF7 cells after exposure to brown kidney bean lectin. Western blotting revealed that the lectin-induced apoptosis involved ER stress and unfolded protein response.

  13. Asymmetric cell division and its role in cell fate determination in the green alga Tetraselmis indica

    Indian Academy of Sciences (India)

    Mani Arora; Arga Chandrashekar Anil; Karl Burgess; Jane Delany; Ehsan Mesbahi

    2015-12-01

    The prasinophytes (early diverging Chlorophyta), consisting of simple unicellular green algae, occupy a critical position at the base of the green algal tree of life, with some of its representatives viewed as the cell form most similar to the first green alga, the `ancestral green flagellate'. Relatively large-celled unicellular eukaryotic phytoflagellates (such as Tetraselmis and Scherffelia), traditionally placed in Prasinophyceae but now considered as members of Chlorodendrophyceae (core Chlorophyta), have retained some primitive characteristics of prasinophytes. These organisms share several ultrastructural features with the other core chlorophytes (Trebouxiophyceae, Ulvophyceae and Chlorophyceae). However, the role of Chlorodendrophycean algae as the evolutionary link between cellular individuality and cellular cooperation has been largely unstudied. Here, we show that clonal populations of a unicellular chlorophyte, Tetraselmis indica, consist of morphologically and ultrastructurally variant cells which arise through asymmetric cell division. These cells also differ in their physiological properties. The structural and physiological differences in the clonal cell population correlate to a certain extent with the longevity and function of cells.

  14. 59. Protectivc effect of melatonin on genetic damage by chemical mutagen and the influence on cell prolife-ration kenetics

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: In this study, we observed the effect of melatonin on the frequency of sister chromatid exchange, micronucleus formation of binuclear cell in lymphocyte from human peripheral blood in vitro, micronucleus formation of mouse bone marrow polycychromatic erythrocyte in vivo, which were induced by chemical mutagen, and lymphocyte proliferation kenetics in vitro. Methods: ① Lymphocytes were cultured in vitro in the presence of 0.01,0.10,1.00 mmol/L melatonin, mitomycin C(MMC) (positive control), 0.5% ethanol (negative control)and 0.01,0.10,1.00 mmol/L melatonin plus MMC for 72 h at 37℃±1℃. Lymphocytes were examined for the frequence of SCE, mitotic index, cell proliferation cycle, cell cycle ratio and proliferation index. ② Lymphocytes were cultured in vitro in the presence of 0.01,0.10,1.00 mmol/L melatonin, mitomycin C(MMC) (positive control), 0.5% ethanol (negative control) and 0.01,0.10,1.00 mmol/L melatonin plus MMC for 44 h at 37℃±1℃. Then each culture was given cytochalasin B, which was cultured to 72 h. Binuclear lymphocytes were examined for the micronucleus rate. ③ The mice were administered with 0.1, 1.0,10.0 mg/kg*bw melatonin and distillated water (negative control) respectively for 7 d, then were given melatonin plus cyclophosphamide (CP) (positive control) for 2 d since the eighth day. The rate of micronulclei of mouse bone marrow polycychromatic erythrocyte was examined. Results: ① The frequences of sister chromatid exchange of lymphocytes which were cultured in the presence of 0.01,0.10,1.00 mmol/L melatonin compared with negative control exhibited no statistical significance. ② The SCE of cells treated with melatonin plus MMC compared with positive control were markedly decreased. ③ The mitotic indices of lymphocytes cultured in the presence of 0.10,1.00 mmol/L melatonin were lower than negative control. The proliferation index was significant lower than negative control only in the culture exposed to 1.00 mmol

  15. Mammary gland development: cell fate specification, stem cells and the microenvironment.

    Science.gov (United States)

    Inman, Jamie L; Robertson, Claire; Mott, Joni D; Bissell, Mina J

    2015-03-15

    The development of the mammary gland is unique: the final stages of development occur postnatally at puberty under the influence of hormonal cues. Furthermore, during the life of the female, the mammary gland can undergo many rounds of expansion and proliferation. The mammary gland thus provides an excellent model for studying the 'stem/progenitor' cells that allow this repeated expansion and renewal. In this Review, we provide an overview of the different cell types that constitute the mammary gland, and discuss how these cell types arise and differentiate. As cellular differentiation cannot occur without proper signals, we also describe how the tissue microenvironment influences mammary gland development.

  16. Exposure to parabens at the concentration of maximal proliferative response increases migratory and invasive activity of human breast cancer cells in vitro.

    Science.gov (United States)

    Khanna, Sugandha; Dash, Philip R; Darbre, Philippa D

    2014-09-01

    Alkyl esters of p-hydroxybenzoic acid (parabens) are widely used as preservatives in personal care products, foods and pharmaceuticals. Their oestrogenic activity, their measurement in human breast tissue and their ability to drive proliferation of oestrogen-responsive human breast cancer cells has opened a debate on their potential to influence breast cancer development. As proliferation is not the only hallmark of cancer cells, we have investigated the effects of exposure to parabens at concentrations of maximal proliferative response on migratory and invasive properties using three oestrogen-responsive human breast cancer cell lines (MCF-7, T-47-D, ZR-75-1). Cells were maintained short-term (1 week) or long-term (20 ± 2 weeks) in phenol-red-free medium containing 5% charcoal-stripped serum with no addition, 10(-8)  M 17β-oestradiol, 1-5 × 10(-4)  M methylparaben, 10(-5)  M n-propylparaben or 10(-5)  M n-butylparaben. Long-term exposure (20 ± 2 weeks) of MCF-7 cells to methylparaben, n-propylparaben or n-butylparaben increased migration as measured using a scratch assay, time-lapse microscopy and xCELLigence technology: invasive properties were found to increase in matrix degradation assays and migration through matrigel on xCELLigence. Western immunoblotting showed an associated downregulation of E-cadherin and β-catenin in the long-term paraben-exposed cells which could be consistent with a mechanism involving epithelial to mesenchymal transition. Increased migratory activity was demonstrated also in long-term paraben-exposed T-47-D and ZR-75-1 cells using a scratch assay and time-lapse microscopy. This is the first report that in vitro, parabens can influence not only proliferation but also migratory and invasive properties of human breast cancer cells.

  17. C. elegans EVI1 proto-oncogene, EGL-43, is necessary for Notch-mediated cell fate specification and regulates cell invasion.

    Science.gov (United States)

    Hwang, Byung Joon; Meruelo, Alejandro D; Sternberg, Paul W

    2007-02-01

    During C. elegans development, LIN-12 (Notch) signaling specifies the anchor cell (AC) and ventral uterine precursor cell (VU) fates from two equivalent pre-AC/pre-VU cells in the hermaphrodite gonad. Once specified, the AC induces patterned proliferation of vulva via expression of LIN-3 (EGF) and then invades into the vulval epithelium. Although these cellular processes are essential for the proper organogenesis of vulva and appear to be temporally regulated, the mechanisms that coordinate the processes are not well understood. We computationally identified egl-43 as a gene likely to be expressed in the pre-AC/pre-VU cells and the AC, based on the presence of an enhancer element similar to the one that transcribes lin-3 in the same cells. Genetic epistasis analyses reveal that egl-43 acts downstream of or parallel to lin-12 in AC/VU cell fate specification at an early developmental stage, and functions downstream of fos-1 as well as upstream of zmp-1 and him-4 to regulate AC invasion at a later developmental stage. Characterization of the egl-43 regulatory region suggests that EGL-43 is a direct target of LIN-12 and HLH-2 (E12/47), which is required for the specification of the VU fate during AC/VU specification. EGL-43 also regulates basement membrane breakdown during AC invasion through a FOS-1-responsive regulatory element that drives EGL-43 expression in the AC and VU cells at the later stage. Thus, egl-43 integrates temporally distinct upstream regulatory events and helps program cell fate specification and cell invasion.

  18. Expression of activated Ras during Dictyostelium development alters cell localization and changes cell fate.

    Science.gov (United States)

    Jaffer, Z M; Khosla, M; Spiegelman, G B; Weeks, G

    2001-03-01

    There is now a body of evidence to indicate that Ras proteins play important roles in development. Dictyostelium expresses several ras genes and each appears to perform a distinct function. Previous data had indicated that the overexpression of an activated form of the major developmentally regulated gene, rasD, caused a major aberration in morphogenesis and cell type determination. We now show that the developmental expression of an activated rasG gene under the control of the rasD promoter causes a similar defect. Our results indicate that the expression of activated rasG in prespore cells results in their transdifferentiation into prestalk cells, whereas activated rasG expression in prestalk causes gross mislocalization of the prestalk cell populations.

  19. Estrogenic potency of benzophenone UV filters in breast cancer cells: proliferative and transcriptional activity substantiated by docking analysis.

    Directory of Open Access Journals (Sweden)

    Gwenneg Kerdivel

    Full Text Available The results from recent studies show that some benzophenones (BPs and their hydroxylated metabolites can function as weak estrogens (E2 in the environment. However, little is known about the structure-activity relationship of these molecules. We have examined the effects of exposure to ten different BPs on the proliferation of estrogen receptor (ER-positive breast cancer cells and on the transcriptional activity of E2-target genes. We analyzed two genes that are tightly linked with estrogen-mediated proliferation, the CXCL12 and amphiregulin genes and two classical estrogen-responsive genes, the pS2 and progesterone receptor. Significant differences in the BPs efficiency to induce cell proliferation and endogenous E2-target gene expressions were observed. Using ERE-, Sp1-, AP1- and C3-reporter genes that contain different ER-binding sites in their promoter, we also showed significant differences in the BPs efficiency in activation of the ER transactivation. Together, our analyzes showed that the most active molecule is 4-hydroxy-BP. Docking analysis of the interaction of BPs in the ligand-binding pocket of ERα suggests that the minimum structural requirement for the estrogenic activity of BPs is a hydroxyl (OH group in the phenyl A-ring that allows interaction with Glu-353, Arg-394 or Phe-404, which enhances the stability between BPs and ERα. Our modeling also indicates a loss of interaction between the OH groups of the phenyl B-ring and His-524. In addition, the presence of some OH groups in the phenyl B-ring can create repulsion forces, which may constrain helix 12 in an unfavorable position, explaining the differential estrogenic effects of BPs. These results, together with our analysis of BPs for their potency in activation of cell proliferation and ER-mediated transcription, report an improved understanding of the mechanism and structure-activity relationship of BPs.

  20. Dynamical modeling of the cell cycle and cell fate emergence in Caulobacter crescentus.

    Directory of Open Access Journals (Sweden)

    César Quiñones-Valles

    Full Text Available The division of Caulobacter crescentus, a model organism for studying cell cycle and differentiation in bacteria, generates two cell types: swarmer and stalked. To complete its cycle, C. crescentus must first differentiate from the swarmer to the stalked phenotype. An important regulator involved in this process is CtrA, which operates in a gene regulatory network and coordinates many of the interactions associated to the generation of cellular asymmetry. Gaining insight into how such a differentiation phenomenon arises and how network components interact to bring about cellular behavior and function demands mathematical models and simulations. In this work, we present a dynamical model based on a generalization of the Boolean abstraction of gene expression for a minimal network controlling the cell cycle and asymmetric cell division in C. crescentus. This network was constructed from data obtained from an exhaustive search in the literature. The results of the simulations based on our model show a cyclic attractor whose configurations can be made to correspond with the current knowledge of the activity of the regulators participating in the gene network during the cell cycle. Additionally, we found two point attractors that can be interpreted in terms of the network configurations directing the two cell types. The entire network is shown to be operating close to the critical regime, which means that it is robust enough to perturbations on dynamics of the network, but adaptable to environmental changes.

  1. Dynamical modeling of the cell cycle and cell fate emergence in Caulobacter crescentus.

    Science.gov (United States)

    Quiñones-Valles, César; Sánchez-Osorio, Ismael; Martínez-Antonio, Agustino

    2014-01-01

    The division of Caulobacter crescentus, a model organism for studying cell cycle and differentiation in bacteria, generates two cell types: swarmer and stalked. To complete its cycle, C. crescentus must first differentiate from the swarmer to the stalked phenotype. An important regulator involved in this process is CtrA, which operates in a gene regulatory network and coordinates many of the interactions associated to the generation of cellular asymmetry. Gaining insight into how such a differentiation phenomenon arises and how network components interact to bring about cellular behavior and function demands mathematical models and simulations. In this work, we present a dynamical model based on a generalization of the Boolean abstraction of gene expression for a minimal network controlling the cell cycle and asymmetric cell division in C. crescentus. This network was constructed from data obtained from an exhaustive search in the literature. The results of the simulations based on our model show a cyclic attractor whose configurations can be made to correspond with the current knowledge of the activity of the regulators participating in the gene network during the cell cycle. Additionally, we found two point attractors that can be interpreted in terms of the network configurations directing the two cell types. The entire network is shown to be operating close to the critical regime, which means that it is robust enough to perturbations on dynamics of the network, but adaptable to environmental changes.

  2. Apoptosis mediated anti-proliferative effect of compound isolated from Cassia auriculata leaves against human colon cancer cell line

    Science.gov (United States)

    Esakkirajan, M.; Prabhu, N. M.; Manikandan, R.; Beulaja, M.; Prabhu, D.; Govindaraju, K.; Thiagarajan, R.; Arulvasu, C.; Dhanasekaran, G.; Dinesh, D.; Babu, G.

    2014-06-01

    A compound was isolated from Cassia auriculata leaves and characterized by high-performance liquid chromatography (HPLC), liquid chromatography mass spectrometry (LC-MS), UV-vis spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance spectroscopy (NMR). The in vitro anticancer effect of the compound isolated from C. auriculata was evaluated in human colon cancer cells HCT 15 by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cytotoxicity, nuclear morphology analysis and measurement of lactate dehydrogenase. The isolated compound 4-(2,5 dichlorobenzyl)-2,3,4,5,6,7 hexahydro7(4 methoxyphenyl)benzo[h][1,4,7] triazecin8(1H)-one showed 50% inhibition of HCT 15 cells when tested at 20 μg/ml after 24 h incubation. Cytotoxicity, nuclear morphology and lactate dehydrogenase assays clearly show potent anticancer activity of the isolated compound against colon cancer. Thus, the in vitro findings suggest that the compound isolated from C. auriculata leaves have potent anti-cancer properties with possible clinical applications.

  3. Tetraploidization or autophagy: The ultimate fate of senescent human endometrial stem cells under ATM or p53 inhibition.

    Science.gov (United States)

    Borodkina, Aleksandra V; Shatrova, Alla N; Deryabin, Pavel I; Grukova, Anastasiya A; Nikolsky, Nikolay N; Burova, Elena B

    2016-01-01

    Previously we demonstrated that endometrium-derived human mesenchymal stem cells (hMESCs) via activation of the ATM/p53/p21/Rb pathway enter the premature senescence in response to oxidative stress. Down regulation effects of the key components of this signaling pathway, particularly ATM and p53, on a fate of stressed hMESCs have not yet been investigated. In the present study by using the specific inhibitors Ku55933 and Pifithrin-α, we confirmed implication of both ATM and p53 in H(2)O(2)-induced senescence of hMESCs. ATM or p53 down regulation was shown to modulate differently the cellular fate of H(2)O(2)-treated hMESCs. ATM inhibition allowed H(2)O(2)-stimulated hMESCs to escape the permanent cell cycle arrest due to loss of the functional ATM/p53/p21/Rb pathway, and induced bypass of mitosis and re-entry into S phase, resulting in tetraploid cells. On the contrary, suppression of the p53 transcriptional activity caused a pronounced cell death of H(2)O(2)-treated hMESCs via autophagy induction. The obtained data clearly demonstrate that down regulation of ATM or p53 shifts senescence of human endometrial stem cells toward tetraploidization or autophagy.

  4. Neurogenin 2 Converts Mesenchymal Stem Cells into a Neural Precursor Fate and Improves Functional Recovery after Experimental Stroke

    Directory of Open Access Journals (Sweden)

    Feng Cheng

    2014-03-01

    Full Text Available Background: Neurogenin2 (Ngn2 is a proneural gene that directs neuronal differentiation of progenitor cells during development. Here, we investigated whether Ngn2 can reprogram MSCs to adopt a neural precursor fate and enhance the therapeutic effects of MSCs after experimental stroke. Methods: In vitro, MSCs were transfected with lenti-GFP or lenti-Ngn2. Following neuronal induction, cells were identified by immunocytochemistry, Western blot and electrophysiological analyses. In a stroke model induced by transient right middle cerebral artery occlusion (MCAO, PBS, GFP-MSCs or Ngn2-MSCs were injected 1 day after MCAO. Behavioral tests, neurological and immunohistochemical assessments were performed. Results: In vitro, Ngn2-MSCs expressed neural stem cells markers (Pax6 and nestin and lost the potential to differentiate into mesodermal cell types. Following neural induction, Ngn2-MSCs expressed higher levels of neuron-specific proteins MAP2, Tuj1 and NeuN, and also expressed voltage-gated Na+ channel, which was absent in GFP-MSCs. In vivo, after transplantation, Ngn2-MSCs significantly reduced apoptotic cells, decreased infarct volume, and increased the expression of VEGF and BDNF. Finally, Ngn2-MSCs treated animals showed the highest functional recovery among the three groups. Conclusions: Ngn2 was sufficient to convert MSCs into a neural precursor fate and transplantation of Ngn2-MSCs was advantageous for the treatment of stroke rats.

  5. Combination of low O(2) concentration and mesenchymal stromal cells during culture of cord blood CD34(+) cells improves the maintenance and proliferative capacity of hematopoietic stem cells.

    Science.gov (United States)

    Hammoud, Mohammad; Vlaski, Marija; Duchez, Pascale; Chevaleyre, Jean; Lafarge, Xavier; Boiron, Jean-Michel; Praloran, Vincent; Brunet De La Grange, Philippe; Ivanovic, Zoran

    2012-06-01

    The physiological approach suggests that an environment associating the mesenchymal stromal cells (MSC) and low O(2) concentration would be most favorable for the maintenance of hematopoietic stem cells (HSCs) in course of ex vivo expansion of hematopoietic grafts. To test this hypothesis, we performed a co-culture of cord blood CD34(+) cells with or without MSC in presence of cytokines for 10 days at 20%, 5%, and 1.5% O(2) and assessed the impact on total cells, CD34(+) cells, committed progenitors (colony-forming cells-CFC) and stem cells activity (pre-CFC and Scid repopulating cells-SRC). Not surprisingly, the expansion of total cells, CD34(+) cells, and CFC was higher in co-culture and at 20% O(2) compared to simple culture and low O(2) concentrations, respectively. However, co-culture at low O(2) concentrations provided CD34(+) cell and CFC amplification similar to classical culture at 20% O(2) . Interestingly, low O(2) concentrations ensured a better pre-CFC and SRC preservation/expansion in co-culture. Indeed, SRC activity in co-culture at 1.5% O(2) was higher than in freshly isolated CD34(+) cells. Interleukin-6 production by MSC at physiologically low O(2) concentrations might be one of the factors mediating this effect. Our data demonstrate that association of co-culture and low O(2) concentration not only induces sufficient expansion of committed progenitors (with respect to the classical culture), but also ensures a better maintenance/expansion of hematopoietic stem cells (HSCs), pointing to the oxygenation as a physiological regulatory factor but also as a cell engineering tool.

  6. A cell cycle kinase with tandem sensory PAS domains integrates cell fate cues

    Science.gov (United States)

    Mann, Thomas H.; Seth Childers, W.; Blair, Jimmy A.; Eckart, Michael R.; Shapiro, Lucy

    2016-01-01

    All cells must integrate sensory information to coordinate developmental events in space and time. The bacterium Caulobacter crescentus uses two-component phospho-signalling to regulate spatially distinct cell cycle events through the master regulator CtrA. Here, we report that CckA, the histidine kinase upstream of CtrA, employs a tandem-PAS domain sensor to integrate two distinct spatiotemporal signals. Using CckA reconstituted on liposomes, we show that one PAS domain modulates kinase activity in a CckA density-dependent manner, mimicking the stimulation of CckA kinase activity that occurs on its transition from diffuse to densely packed at the cell poles. The second PAS domain interacts with the asymmetrically partitioned second messenger cyclic-di-GMP, inhibiting kinase activity while stimulating phosphatase activity, consistent with the selective inactivation of CtrA in the incipient stalked cell compartment. The integration of these spatially and temporally regulated signalling events within a single signalling receptor enables robust orchestration of cell-type-specific gene regulation. PMID:27117914

  7. A general model for binary cell fate decision gene circuits with degeneracy: indeterminacy and switch behavior in the absence of cooperativity.

    Directory of Open Access Journals (Sweden)

    Mircea Andrecut

    Full Text Available BACKGROUND: The gene regulatory circuit motif in which two opposing fate-determining transcription factors inhibit each other but activate themselves has been used in mathematical models of binary cell fate decisions in multipotent stem or progenitor cells. This simple circuit can generate multistability and explains the symmetric "poised" precursor state in which both factors are present in the cell at equal amounts as well as the resolution of this indeterminate state as the cell commits to either cell fate characterized by an asymmetric expression pattern of the two factors. This establishes the two alternative stable attractors that represent the two fate options. It has been debated whether cooperativity of molecular interactions is necessary to produce such multistability. PRINCIPAL FINDINGS: Here we take a general modeling approach and argue that this question is not relevant. We show that non-linearity can arise in two distinct models in which no explicit interaction between the two factors is assumed and that distinct chemical reaction kinetic formalisms can lead to the same (generic dynamical system form. Moreover, we describe a novel type of bifurcation that produces a degenerate steady state that can explain the metastable state of indeterminacy prior to cell fate decision-making and is consistent with biological observations. CONCLUSION: The general model presented here thus offers a novel principle for linking regulatory circuits with the state of indeterminacy characteristic of multipotent (stem cells.

  8. A General Model for Binary Cell Fate Decision Gene Circuits with Degeneracy: Indeterminacy and Switch Behavior in the Absence of Cooperativity

    Science.gov (United States)

    Andrecut, Mircea; Halley, Julianne D.; Winkler, David A.; Huang, Sui

    2011-01-01

    Background The gene regulatory circuit motif in which two opposing fate-determining transcription factors inhibit each other but activate themselves has been used in mathematical models of binary cell fate decisions in multipotent stem or progenitor cells. This simple circuit can generate multistability and explains the symmetric “poised” precursor state in which both factors are present in the cell at equal amounts as well as the resolution of this indeterminate state as the cell commits to either cell fate characterized by an asymmetric expression pattern of the two factors. This establishes the two alternative stable attractors that represent the two fate options. It has been debated whether cooperativity of molecular interactions is necessary to produce such multistability. Principal Findings Here we take a general modeling approach and argue that this question is not relevant. We show that non-linearity can arise in two distinct models in which no explicit interaction between the two factors is assumed and that distinct chemical reaction kinetic formalisms can lead to the same (generic) dynamical system form. Moreover, we describe a novel type of bifurcation that produces a degenerate steady state that can explain the metastable state of indeterminacy prior to cell fate decision-making and is consistent with biological observations. Conclusion The general model presented here thus offers a novel principle for linking regulatory circuits with the state of indeterminacy characteristic of multipotent (stem) cells. PMID:21625586

  9. Multiplex Quantitative Histologic Analysis of Human Breast Cancer Cell Signaling and Cell Fate

    Science.gov (United States)

    2010-05-01

    P. Lewis , B. S. Manjunath, and S. K. Fisher, “Automated tool for the detection of cell nuclei in digital microscopic images: Application to retinal...set model and some applications to Mumford -Shah image segmentation,” IEEE Trans. Image Process., vol. 15, no. 5, pp. 1171–1181, May 2006. [37] N. R

  10. Hydrogel formulation determines cell fate of fetal and adult neural progenitor cells

    Directory of Open Access Journals (Sweden)

    Emily R. Aurand

    2014-01-01

    Full Text Available Hydrogels provide a unique tool for neural tissue engineering. These materials can be customized for certain functions, i.e. to provide cell/drug delivery or act as a physical scaffold. Unfortunately, hydrogel complexities can negatively impact their biocompatibility, resulting in unintended consequences. These adverse effects may be combated with a better understanding of hydrogel chemical, physical, and mechanical properties, and how these properties affect encapsulated neural cells. We defined the polymerization and degradation rates and compressive moduli of 25 hydrogels formulated from different concentrations of hyaluronic acid (HA and poly(ethylene glycol (PEG. Changes in compressive modulus were driven primarily by the HA concentration. The in vitro biocompatibility of fetal-derived (fNPC and adult-derived (aNPC neural progenitor cells was dependent on hydrogel formulation. Acute survival of fNPC benefited from hydrogel encapsulation. NPC differentiation was divergent: fNPC differentiated into mostly glial cells, compared with neuronal differentiation of aNPC. Differentiation was influenced in part by the hydrogel mechanical properties. This study indicates that there can be a wide range of HA and PEG hydrogels compatible with NPC. Additionally, this is the first study comparing hydrogel encapsulation of NPC derived from different aged sources, with data suggesting that fNPC and aNPC respond dissimilarly within the same hydrogel formulation.

  11. The KDM5 family is required for activation of pro-proliferative cell cycle genes during adipocyte differentiation

    DEFF Research Database (Denmark)

    Brier, Ann-Sofie B; Loft, Anne; Madsen, Jesper G S;

    2016-01-01

    The KDM5 family of histone demethylases removes the H3K4 tri-methylation (H3K4me3) mark frequently found at promoter regions of actively transcribed genes and is therefore generally considered to contribute to corepression. In this study, we show that knockdown (KD) of all expressed members...... of the KDM5 family in white and brown preadipocytes leads to deregulated gene expression and blocks differentiation to mature adipocytes. KDM5 KD leads to a considerable increase in H3K4me3 at promoter regions; however, these changes in H3K4me3 have a limited effect on gene expression per se. By contrast......, genome-wide analyses demonstrate that KDM5A is strongly enriched at KDM5-activated promoters, which generally have high levels of H3K4me3 and are associated with highly expressed genes. We show that KDM5-activated genes include a large set of cell cycle regulators and that the KDM5s are necessary...

  12. Neutrophil elastase cleavage of the gC1q domain impairs the EMILIN1-α4β1 integrin interaction, cell adhesion and anti-proliferative activity

    Science.gov (United States)

    Maiorani, Orlando; Pivetta, Eliana; Capuano, Alessandra; Modica, Teresa Maria Elisa; Wassermann, Bruna; Bucciotti, Francesco; Colombatti, Alfonso; Doliana, Roberto; Spessotto, Paola

    2017-01-01

    The extracellular matrix glycoprotein EMILIN1 exerts a wide range of functions mainly associated with its gC1q domain. Besides providing functional significance for adhesion and migration, the direct interaction between α4β1 integrin and EMILIN1-gC1q regulates cell proliferation, transducing net anti-proliferative effects. We have previously demonstrated that EMILIN1 degradation by neutrophil elastase (NE) is a specific mechanism leading to the loss of functions disabling its regulatory properties. In this study we further analysed the proteolytic activity of NE, MMP-3, MMP-9, and MT1-MMP on EMILIN1 and found that MMP-3 and MT1-MMP partially cleaved EMILIN1 but without affecting the functional properties associated with the gC1q domain, whereas NE was able to fully impair the interaction of gC1q with the α4β1 integrin by cleaving this domain outside of the E933 integrin binding site. By a site direct mutagenesis approach we mapped the bond between S913 and R914 residues and selected the NE-resistant R914W mutant still able to interact with the α4β1 integrin after NE treatment. Functional studies showed that NE impaired the EMILIN1-α4β1 integrin interaction by cleaving the gC1q domain in a region crucial for its proper structural conformation, paving the way to better understand NE effects on EMILIN1-cell interaction in pathological context. PMID:28074935

  13. An APC:WNT counter-current-like mechanism regulates cell division along the colonic crypt axis: a mechanism that explains how APC mutations induce proliferative abnormalities that drive colon cancer development.

    Directory of Open Access Journals (Sweden)

    Bruce M Boman

    2013-11-01

    Full Text Available APC normally down-regulates WNT signaling in human colon, and APC mutations cause proliferative abnormalities in premalignant crypts leading to colon cancer, but the mechanisms are unclear at the level of spatial and functional organization of the crypt. Accordingly, we postulated a counter-current-like mechanism based on gradients of factors (APC;WNT that regulate colonocyte proliferation along the crypt axis. During crypt renewal, stem cells (SCs at the crypt bottom generate non-SC daughter cells that proliferate and differentiate while migrating upwards. The APC concentration is low at the crypt bottom and high at the top (where differentiated cells reside. WNT signaling, in contrast, is high at the bottom (where SCs reside and low at the top. Given that WNT and APC gradients are counter to one another, we hypothesized that a counter-current-like mechanism exists. Since both APC and WNT signaling components (e.g. survivin are required for mitosis, this mechanism establishes a zone in the lower crypt where conditions are optimal for maximal cell division and mitosis orientation (symmetric versus asymmetric. APC haploinsufficiency diminishes the APC gradient, shifts the proliferative zone upwards, and increases symmetric division, which causes SC overpopulation. In homozygote mutant crypts, these changes are exacerbated. Thus, APC-mutation-induced changes in the counter-current-like mechanism cause expansion of proliferative populations (SCs, rapidly-proliferating cells during tumorigenesis. We propose this mechanism also drives crypt fission, functions in the crypt cycle, and underlies adenoma development. Novel chemoprevention approaches designed to normalize the two gradients and readjust the proliferative zone downwards, might thwart progression of these premalignant changes.

  14. Lactic acid fermentation of germinated barley fiber and proliferative function of colonic epithelial cells in loperamide-induced rats.

    Science.gov (United States)

    Jeon, Jeong Ryae; Choi, Joon Hyuk

    2010-08-01

    To develop a functional food from the dietary fiber fraction of germinated barley (Hordeum vulgare L.) (GBF), lactic acid fermentation was attempted using Lactobacillus acidophilus, Streptococcus thermophilus, and Bifidobacterium bifidus. The quality characteristics of the lactic acid-fermented product and its effect on gastrointestinal function in an animal model were examined. The anaerobic fermentation of 1% and 2% GBF yielded lactic acid bacteria at 8.9 +/- 1.0 x 10(8) and 1.6 +/- 0.2 x 10(9) colony-forming units/mL, and it was considered acceptable for consumption by sensory assessment. To determine the effect on gastrointestinal function, Sprague-Dawley rats were fed with three types of diets: a normal chow diet and chow diets supplemented with 10% lactic acid bacteria or a yogurt fermented with 2% GBF (GBFY). The rats fed GBFY for 6 weeks gained less body weight, excreted more fecal mass, and had improved gastrointestinal transit as examined with barium sulfate. The effect of GBFY on colonic epithelial proliferation was investigated through loperamide (LPM)-induced constipation in rats. The rats fed with GBFY for 6 weeks were intraperitoneally administered LPM twice daily for 7 days. GBFY supplementation decreased fecal excretion and moisture content in feces and depleted goblet cells as observed by hematoxylin and eosin stain. However, the rats supplemented with GBFY prior to the LPM administration had enhanced bowel movement, mucin secretion, and production of short-chain fatty acids compared with values for the LPM-alone group. Immunohistochemistry revealed that the GBFY supplement increased the numbers of nuclei stained positively for Ki-67 and extended from the base to the middle zone of crypts. These results indicate that GBFY alleviates constipation via the proliferation of the colonic crypts in LPM-administered rats.

  15. Resveratrol Increases Anti-Proliferative Activity of Bestatin Through Downregulating P-Glycoprotein Expression Via Inhibiting PI3K/Akt/mTOR Pathway in K562/ADR Cells.

    Science.gov (United States)

    Wang, Li; Wang, Changyuan; Jia, Yongming; Liu, Zhihao; Shu, Xiaohong; Liu, Kexin

    2016-05-01

    Multidrug resistance (MDR) is a major obstacle in the clinical therapy of hematological malignancies. P-glycoprotein (P-gp) overexpression results in reduction of intracellular drug concentration with a consequence that the cytotoxicity of anti-tumor drugs is decreased, which leads to MDR in K562/ADR cells. In this study, we found that resveratrol enhanced the anti-proliferative activity of bestatin in K562/ADR cells. Co-treatment with resveratrol, IC50 values of bestatin in K562/ADR cells significantly decreased and activation of caspase-3 and caspase-8 increased, which indicated that resveratrol potentiated bestatin-induced apoptosis. Resveratrol increased the intracellular concentration of bestatin through inhibiting P-gp function and downregulating P-gp expression at mRNA and protein levels, which increased anti-proliferative activity of bestatin in K562/ADR cells. Resveratrol decreased the phosphorylation of Akt and mTOR but did not affect the phosphorylations of JNK or ERK1/2. These results demonstrated that resveratrol could increase the anti-proliferative activity of bestatin through downregulating P-gp expression via suppressing the PI3K/Akt/mTOR signaling pathway.

  16. Mammary-Stem-Cell-Based Somatic Mouse Models Reveal Breast Cancer Drivers Causing Cell Fate Dysregulation

    Directory of Open Access Journals (Sweden)

    Zheng Zhang

    2016-09-01

    Full Text Available Cancer genomics has provided an unprecedented opportunity for understanding genetic causes of human cancer. However, distinguishing which mutations are functionally relevant to cancer pathogenesis remains a major challenge. We describe here a mammary stem cell (MaSC organoid-based approach for rapid generation of somatic genetically engineered mouse models (GEMMs. By using RNAi and CRISPR-mediated genome engineering in MaSC-GEMMs, we have discovered that inactivation of Ptpn22 or Mll3, two genes mutated in human breast cancer, greatly accelerated PI3K-driven mammary tumorigenesis. Using these tumor models, we have also identified genetic alterations promoting tumor metastasis and causing resistance to PI3K-targeted therapy. Both Ptpn22 and Mll3 inactivation resulted in disruption of mammary gland differentiation and an increase in stem cell activity. Mechanistically, Mll3 deletion enhanced stem cell activity through activation of the HIF pathway. Thus, our study has established a robust in vivo platform for functional cancer genomics and has discovered functional breast cancer mutations.

  17. Dynamics of p53: A Master Decider of Cell Fate.

    Science.gov (United States)

    Luo, Qingyin; Beaver, Jill M; Liu, Yuan; Zhang, Zunzhen

    2017-02-09

    Cellular stress-induced temporal alterations-i.e., dynamics-are typically exemplified  by the dynamics of p53 that serve as a master to determine cell fate. p53 dynamics were initially  identified as the variations of p53 protein levels. However, a growing number of studies have  shown that p53 dynamics are also manifested in variations in the activity, spatial location, and  posttranslational modifications of p53 proteins, as well as the interplay among all p53 dynamical  features. These are essential in determining a specific outcome of cell fate. In this review, we  discuss the importance of the multifaceted features of p53 dynamics and their roles in the cell fate  decision process, as well as their potential applications in p53-based cancer therapy. The review  provides new insights into p53 signaling pathways and their potentials in the development of new  strategies in p53-based cancer therapy.

  18. Switch Enhancers Interpret TGF-β and Hippo Signaling to Control Cell Fate in Human Embryonic Stem Cells

    Directory of Open Access Journals (Sweden)

    Tobias A. Beyer

    2013-12-01

    Full Text Available A small toolkit of morphogens is used repeatedly to direct development, raising the question of how context dictates interpretation of the same cue. One example is the transforming growth factor β (TGF-β pathway that in human embryonic stem cells fulfills two opposite functions: pluripotency maintenance and mesendoderm (ME specification. Using proteomics coupled to analysis of genome occupancy, we uncover a regulatory complex composed of transcriptional effectors of the Hippo pathway (TAZ/YAP/TEAD, the TGF-β pathway (SMAD2/3, and the pluripotency regulator OCT4 (TSO. TSO collaborates with NuRD repressor complexes to buffer pluripotency gene expression while suppressing ME genes. Importantly, the SMAD DNA binding partner FOXH1, a major specifier of ME, is found near TSO elements, and upon fate specification we show that TSO is disrupted with subsequent SMAD-FOXH1 induction of ME. These studies define switch-enhancer elements and provide a framework to understand how cellular context dictates interpretation of the same morphogen signal in development.

  19. Neuronal cell fate decisions:  O2 and CO2 sensing neurons require egl-13/Sox5

    DEFF Research Database (Denmark)

    Gramstrup Petersen, Jakob; Pocock, Roger David John

    2013-01-01

    We recently conducted a study that aimed to describe the differentiation mechanisms used to generate O2 and CO2 sensing neurons in C. elegans. We identified egl-13/Sox5 to be required for the differentiation of both O2 and CO2 sensing neurons. We found that egl-13 functions cell autonomously...... to drive O2 and CO2 sensing neuron fate and is therefore essential for O2 and CO2 sensing-induced behaviors. Through systematic dissection of the egl-13 promoter we identified upstream regulators of egl-13 and proposed a model of how differentiation of O2 and CO2 sensing neurons is regulated...

  20. hESC Differentiation toward an Autonomic Neuronal Cell Fate Depends on Distinct Cues from the Co-Patterning Vasculature

    Directory of Open Access Journals (Sweden)

    Lisette M. Acevedo

    2015-06-01

    Full Text Available To gain insight into the cellular and molecular cues that promote neurovascular co-patterning at the earliest stages of human embryogenesis, we developed a human embryonic stem cell model to mimic the developing epiblast. Contact of ectoderm-derived neural cells with mesoderm-derived vasculature is initiated via the neural crest (NC, not the neural tube (NT. Neurovascular co-patterning then ensues with specification of NC toward an autonomic fate requiring vascular endothelial cell (EC-secreted nitric oxide (NO and direct contact with vascular smooth muscle cells (VSMCs via T-cadherin-mediated homotypic interactions. Once a neurovascular template has been established, NT-derived central neurons then align themselves with the vasculature. Our findings reveal that, in early human development, the autonomic nervous system forms in response to distinct molecular cues from VSMCs and ECs, providing a model for how other developing lineages might coordinate their co-patterning.

  1. The anti-proliferative effect of L-carnosine correlates with a decreased expression of hypoxia inducible factor 1 alpha in human colon cancer cells.

    Directory of Open Access Journals (Sweden)

    Barbara Iovine

    Full Text Available In recent years considerable attention has been given to the use of natural substances as anticancer drugs. The natural antioxidant dipeptide L-carnosine belongs to this class of molecules because it has been proved to have a significant anticancer activity both in vitro and in vivo. Previous studies have shown that L-carnosine inhibits the proliferation of human colorectal carcinoma cells by affecting the ATP and Reactive Oxygen Species (ROS production. In the present study we identified the Hypoxia-Inducible Factor 1α (HIF-1α as a possible target of L-carnosine in HCT-116 cell line. HIF-1α protein is over-expressed in multiple types of human cancer and is the major cause of resistance to drugs and radiation in solid tumours. Of particular interest are experimental data supporting the concept that generation of ROS provides a redox signal for HIF-1α induction, and it is known that some antioxidants are able to suppress tumorigenesis by inhibiting HIF-1α. In the current study we found that L-carnosine reduces the HIF-1α protein level affecting its stability and decreases the HIF-1 transcriptional activity. In addition, we demonstrated that L-carnosine is involved in ubiquitin-proteasome system promoting HIF-1α degradation. Finally, we compared the antioxidant activity of L-carnosine with that of two synthetic anti-oxidant bis-diaminotriazoles (namely 1 and 2, respectively. Despite these three compounds have the same ability in reducing intracellular ROS, 1 and 2 are more potent scavengers and have no effect on HIF-1α expression and cancer cell proliferation. These findings suggest that an analysis of L-carnosine antioxidant pathway will clarify the mechanism underlying the anti-proliferative effects of this dipeptide on colon cancer cells. However, although the molecular mechanism by which L-carnosine down regulates or inhibits the HIF-1α activity has not been yet elucidated, this ability may be promising in treating hypoxia

  2. Proliferative multifocal leukoplakia better name that proliferative verrucous leukoplakia

    OpenAIRE

    Aguirre-Urizar Jose M

    2011-01-01

    Abstract In this letter I propose the name "Proliferative Multifocal Leukoplakia" with the goal of reducing under-diagnosis of this disease, improve the early diagnosis, try to make an early therapy and control, and prevent its malignant transformation.

  3. 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.

  4. Early postnatal respiratory viral infection alters hippocampal neurogenesis, cell fate, and neuron morphology in the neonatal piglet.

    Science.gov (United States)

    Conrad, Matthew S; Harasim, Samantha; Rhodes, Justin S; Van Alstine, William G; Johnson, Rodney W

    2015-02-01

    Respiratory viral infections are common during the neonatal period in humans, but little is known about how early-life infection impacts brain development. The current study used a neonatal piglet model as piglets have a gyrencephalic brain with growth and development similar to human infants. Piglets were inoculated with porcine reproductive and respiratory syndrome virus (PRRSV) to evaluate how chronic neuroinflammation affects hippocampal neurogenesis and neuron morphology. Piglets in the neurogenesis study received one bromodeoxyuridine injection on postnatal day (PD) 7 and then were inoculated with PRRSV. Piglets were sacrificed at PD 28 and the number of BrdU+ cells and cell fate were quantified in the dentate gyrus. PRRSV piglets showed a 24% reduction in the number of newly divided cells forming neurons. Approximately 15% of newly divided cells formed microglia, but this was not affected by sex or PRRSV. Additionally, there was a sexual dimorphism of new cell survival in the dentate gyrus where males had more cells than females, and PRRSV infection caused a decreased survival in males only. Golgi impregnation was used to characterize dentate granule cell morphology. Sholl analysis revealed that PRRSV caused a change in inner granule cell morphology where the first branch point was extended further from the cell body. Males had more complex dendritic arbors than females in the outer granule cell layer, but this was not affected by PRRSV. There were no changes to dendritic spine density or morphology distribution. These findings suggest that early-life viral infection can impact brain development.

  5. Differential cytotoxicity of [123I]IUdR, [125I]IUdR and [131I]IUdR to human glioma cells in monolayer or spheroid culture: effect of proliferative heterogeneity and radiation cross-fire.

    OpenAIRE

    1998-01-01

    Radioiodinated iododeoxyuridine (IUdR) is a novel, cycle-specific agent that has potential for the treatment of residual malignant glioma after surgery. As only cells in S-phase incorporate IUdR into DNA, a major limitation to this therapy is likely to be proliferative heterogeneity of the tumour cell population. Using a clonogenic end point, we have compared the toxicities of three radioiodoanalogues of IUdR--[123I]IUdR, [125I]IUdR and [131I]IUdR--to the human glioma cell line UVW, cultured ...

  6. Aging alters bone-fat reciprocity by shifting in vivo mesenchymal precursor cell fate towards an adipogenic lineage.

    Science.gov (United States)

    Singh, Lakshman; Brennan, Tracy A; Russell, Elizabeth; Kim, Jung-Hoon; Chen, Qijun; Brad Johnson, F; Pignolo, Robert J

    2016-04-01

    Bone marrow derived mesenchymal progenitor cells (MPCs) play an important role in bone homeostasis. Age-related changes occur in bone resulting in a decrease in bone density and a relative increase in adipocity. Although in vitro studies suggest the existence of an age-related lineage switch between osteogenic and adipogenic fates, stem cell and microenvironmental contributions to this process have not been elucidated in vivo. In order to study the effects of MPC and microenvironmental aging on functional engraftment and lineage switching, transplantation studies were performed under non-myeloablative conditions in old recipients, with donor MPCs derived from young and old green fluorescent protein (GFP) transgenic mice. Robust engraftment by young MPCs or their progeny was observed in the marrow, bone-lining region and in the matrix of young recipients; however, significantly lower engraftment was seen at the same sites in old recipients transplanted with old MPCs. Differentiation of transplanted MPCs strongly favored adipogenesis over osteogenesis in old recipients irrespective of MPC donor age, suggesting that microenvironmental alterations that occur with in vivo aging are predominately responsible for MPC lineage switching. These data indicate that aging alters bone-fat reciprocity and differentiation of mesenchymal progenitors towards an adipogenic fate.

  7. Comparative Study of Green Sub- and Supercritical Processes to Obtain Carnosic Acid and Carnosol-Enriched Rosemary Extracts with in Vitro Anti-Proliferative Activity on Colon Cancer Cells.

    Science.gov (United States)

    Sánchez-Camargo, Andrea Del Pilar; García-Cañas, Virginia; Herrero, Miguel; Cifuentes, Alejandro; Ibáñez, Elena

    2016-12-07

    In the present work, four green processes have been compared to evaluate their potential to obtain rosemary extracts with in vitro anti-proliferative activity against two colon cancer cell lines (HT-29 and HCT116). The processes, carried out under optimal conditions, were: (1) pressurized liquid extraction (PLE, using an hydroalcoholic mixture as solvent) at lab-scale; (2) Single-step supercritical fluid extraction (SFE) at pilot scale; (3) Intensified two-step sequential SFE at pilot scale; (4) Integrated PLE plus supercritical antisolvent fractionation (SAF) at pilot scale. Although higher extraction yields were achieved by using PLE (38.46% dry weight), this extract provided the lowest anti-proliferative activity with no observed cytotoxic effects at the assayed concentrations. On the other hand, extracts obtained using the PLE + SAF process provided the most active rosemary extracts against both colon cancer cell lines, with LC50 ranging from 11.2 to 12.4 µg/mL and from 21.8 to 31.9 µg/mL for HCT116 and HT-29, respectively. In general, active rosemary extracts were characterized by containing carnosic acid (CA) and carnosol (CS) at concentrations above 263.7 and 33.9 mg/g extract, respectively. Some distinct compounds have been identified in the SAF extracts (rosmaridiphenol and safficinolide), suggesting their possible role as additional contributors to the observed strong anti-proliferative activity of CA and CS in SAF extracts.

  8. Comparative Study of Green Sub- and Supercritical Processes to Obtain Carnosic Acid and Carnosol-Enriched Rosemary Extracts with in Vitro Anti-Proliferative Activity on Colon Cancer Cells

    Directory of Open Access Journals (Sweden)

    Andrea del Pilar Sánchez-Camargo

    2016-12-01

    Full Text Available In the present work, four green processes have been compared to evaluate their potential to obtain rosemary extracts with in vitro anti-proliferative activity against two colon cancer cell lines (HT-29 and HCT116. The processes, carried out under optimal conditions, were: (1 pressurized liquid extraction (PLE, using an hydroalcoholic mixture as solvent at lab-scale; (2 Single-step supercritical fluid extraction (SFE at pilot scale; (3 Intensified two-step sequential SFE at pilot scale; (4 Integrated PLE plus supercritical antisolvent fractionation (SAF at pilot scale. Although higher extraction yields were achieved by using PLE (38.46% dry weight, this extract provided the lowest anti-proliferative activity with no observed cytotoxic effects at the assayed concentrations. On the other hand, extracts obtained using the PLE + SAF process provided the most active rosemary extracts against both colon cancer cell lines, with LC50 ranging from 11.2 to 12.4 µg/mL and from 21.8 to 31.9 µg/mL for HCT116 and HT-29, respectively. In general, active rosemary extracts were characterized by containing carnosic acid (CA and carnosol (CS at concentrations above 263.7 and 33.9 mg/g extract, respectively. Some distinct compounds have been identified in the SAF extracts (rosmaridiphenol and safficinolide, suggesting their possible role as additional contributors to the observed strong anti-proliferative activity of CA and CS in SAF extracts.

  9. Cell-to-cell signaling influences the fate of prostate cancer stem cells and their potential to generate more aggressive tumors.

    Directory of Open Access Journals (Sweden)

    Luisa Salvatori

    Full Text Available An increasing number of malignancies has been shown to be initiated and propelled by small subpopulations of cancer stem cells (CSC. However, whether tumor aggressiveness is driven by CSC and by what extent this property may be relevant within the tumor mass is still unsettled. To address this issue, we isolated a rare tumor cell population on the basis of its CD44(+CD24(- phenotype from the human androgen-independent prostate carcinoma cell line DU145 and established its CSC properties. The behavior of selected CSC was investigated with respect to the bulk DU145 cells. The injection of CSC in nude mice generated highly vascularized tumors infiltrating the adjacent tissues, showing high density of neuroendocrine cells and expressing low levels of E-cadherin and β-catenin as well as high levels of vimentin. On the contrary, when a comparable number of unsorted DU145 cells were injected the resulting tumors were less aggressive. To investigate the different features of tumors in vivo, the influence of differentiated tumor cells on CSC was examined in vitro by growing CSC in the absence or presence of conditioned medium from DU145 cells. CSC grown in permissive conditions differentiated into cell populations with features similar to those of cells held in aggressive tumors generated from CSC injection. Differently, conditioned medium induced CSC to differentiate into a cell phenotype comparable to cells of scarcely aggressive tumors originated from bulk DU145 cell injection. These findings show for the first time that CSC are able to generate differentiated cells expressing either highly or scarcely aggressive phenotype, thus influencing prostate cancer progression. The fate of CSC was determined by signals released from tumor environment. Moreover, using microarray analysis we selected some molecules which could be involved in this cell-to-cell signaling, hypothesizing their potential value for prognostic or therapeutic applications.

  10. Proliferative histiocytic disorders of canine skin.

    Science.gov (United States)

    Middleton, D J

    1997-06-01

    Proliferative histiocytic disorders of canine skin present a clinical spectrum from the innocuous self-limiting solitary dermal lesion of cutaneous histiocytoma, through the recurrent deep dermal nodules of cutaneous histiocytosis to the generally fatal condition of Bernese Mountain Dogs termed systemic histiocytosis, in which visceral involvement is commonly encountered. Immunocytochemical characterization of the constituent histiocytic cells and accompanying lymphoid infiltrate using canine species specific reagents has elucidated considerably the mechanism by which these conditions exhibit their various biologic behaviours.

  11. MicroRNA-126-mediated control of cell fate in B-cell myeloid progenitors as a potential alternative to transcriptional factors.

    Science.gov (United States)

    Okuyama, Kazuki; Ikawa, Tomokatsu; Gentner, Bernhard; Hozumi, Katsuto; Harnprasopwat, Ratanakanit; Lu, Jun; Yamashita, Riu; Ha, Daon; Toyoshima, Takae; Chanda, Bidisha; Kawamata, Toyotaka; Yokoyama, Kazuaki; Wang, Shusheng; Ando, Kiyoshi; Lodish, Harvey F; Tojo, Arinobu; Kawamoto, Hiroshi; Kotani, Ai

    2013-08-13

    Lineage specification is thought to be largely regulated at the level of transcription, where lineage-specific transcription factors drive specific cell fates. MicroRNAs (miR), vital to many cell functions, act posttranscriptionally to decrease the expression of target mRNAs. MLL-AF4 acute lymphocytic leukemia exhibits both myeloid and B-cell surface markers, suggesting that the transformed cells are B-cell myeloid progenitor cells. Through gain- and loss-of-function experiments, we demonstrated that microRNA 126 (miR-126) drives B-cell myeloid biphenotypic leukemia differentiation toward B cells without changing expression of E2A immunoglobulin enhancer-binding factor E12/E47 (E2A), early B-cell factor 1 (EBF1), or paired box protein 5, which are critical transcription factors in B-lymphopoiesis. Similar induction of B-cell differentiation by miR-126 was observed in normal hematopoietic cells in vitro and in vivo in uncommitted murine c-Kit(+)Sca1(+)Lineage(-) cells, with insulin regulatory subunit-1 acting as a target of miR-126. Importantly, in EBF1-deficient hematopoietic progenitor cells, which fail to differentiate into B cells, miR-126 significantly up-regulated B220, and induced the expression of B-cell genes, including recombination activating genes-1/2 and CD79a/b. These data suggest that miR-126 can at least partly rescue B-cell development independently of EBF1. These experiments show that miR-126 regulates myeloid vs. B-cell fate through an alternative machinery, establishing the critical role of miRNAs in the lineage specification of multipotent mammalian cells.

  12. Opposing regulation of PROX1 by interleukin-3 receptor and NOTCH directs differential host cell fate reprogramming by Kaposi sarcoma herpes virus.

    Directory of Open Access Journals (Sweden)

    Jaehyuk Yoo

    Full Text Available Lymphatic endothelial cells (LECs are differentiated from blood vascular endothelial cells (BECs during embryogenesis and this physiological cell fate specification is controlled by PROX1, the master regulator for lymphatic development. When Kaposi sarcoma herpes virus (KSHV infects host cells, it activates the otherwise silenced embryonic endothelial differentiation program and reprograms their cell fates. Interestingly, previous studies demonstrated that KSHV drives BECs to acquire a partial lymphatic phenotype by upregulating PROX1 (forward reprogramming, but stimulates LECs to regain some BEC-signature genes by downregulating PROX1 (reverse reprogramming. Despite the significance of this KSHV-induced bidirectional cell fate reprogramming in KS pathogenesis, its underlying molecular mechanism remains undefined. Here, we report that IL3 receptor alpha (IL3Rα and NOTCH play integral roles in the host cell type-specific regulation of PROX1 by KSHV. In BECs, KSHV upregulates IL3Rα and phosphorylates STAT5, which binds and activates the PROX1 promoter. In LECs, however, PROX1 was rather downregulated by KSHV-induced NOTCH signal via HEY1, which binds and represses the PROX1 promoter. Moreover, PROX1 was found to be required to maintain HEY1 expression in LECs, establishing a reciprocal regulation between PROX1 and HEY1. Upon co-activation of IL3Rα and NOTCH, PROX1 was upregulated in BECs, but downregulated in LECs. Together, our study provides the molecular mechanism underlying the cell type-specific endothelial fate reprogramming by KSHV.

  13. Analysis on Pathogenesis of 50 Cases of Bladder Proliferative Lesions

    Institute of Scientific and Technical Information of China (English)

    陈志强; 蓝儒竹; 叶章群; 杨为民

    2003-01-01

    In order to study the pathogenesis, clinical and pathological characteristics of prolifera-tive lesions of the bladder, 50 cases of proliferative lesions of the bladder from 150 patients withcomplaints of frequency, urgency, hematuria and dysuria were subjected to cystoscopic biopsy ofthe suspicious foci in the bladder. In combination with the symptoms, urine routine and urodynam-ics, the relationship of proliferative lesions of the bladder to the inflammation and obstruction of thelower urinary tract was analyzed. Of the 50 cases of proliferative bladder lesions, 44 cases (88%)had lower urinary tract infection and 29 (58%) lower urinary tract obstruction. The patients withlower urinary tract obstruction were all complicated with infection. Three cases were associatedwith transitional cell carcinoma. Malignant cells were detected in 1 case by urinary cytologic exami-nation. Proliferative lesions of the bladder, especially those without other obvious mucosa changesunder cystoscopy, are common histological variants of urothelium in the patients with chronic in-flammation and obstruction of the lower urinary tract. Chronic inflammation and obstruction of thelower urinary tract might be the causes for proliferative lesions of the bladder. It is suggested thatdifferent treatments should be applied according to the scope and histological type of the prolifera-tive lesions.

  14. A role for interleukin-1β in determining the lineage fate of embryonic rat hippocampal neural precursor cells.

    Science.gov (United States)

    Green, Holly F; Treacy, Eimear; Keohane, Aoife K; Sullivan, Aideen M; O'Keeffe, Gerard W; Nolan, Yvonne M

    2012-03-01

    Neurogenesis occurs in the hippocampus of the developing and adult brain due to the presence of multipotent stem cells and restricted precursor cells at different stages of differentiation. It has been proposed that they may be of potential benefit for use in cell transplantation approaches for neurodegenerative disorders and trauma. Prolonged release of interleukin-1β (IL-1β) from activated microglia has a deleterious effect on hippocampal neurons and is implicated in the impaired neurogenesis and cognitive dysfunction associated with aging, Alzheimer's disease and depression. This study assessed the effect of IL-1β on the proliferation and differentiation of embryonic rat hippocampal NPCs in vitro. We show that IL-1R1 is expressed on proliferating NPCs and that IL-1β treatment decreases cell proliferation and neurosphere growth. When NPCs were differentiated in the presence of IL-1β, a significant reduction in the percentages of newly-born neurons and post-mitotic neurons and a significant increase in the percentage of astrocytes was observed in these cultures. These effects were attenuated by IL-1 receptor antagonist. These data reveal that IL-1β exerts an anti-proliferative, anti-neurogenic and pro-gliogenic effect on embryonic hippocampal NPCs, which is mediated by IL-1R1. The present results emphasise the consequences of an inflammatory environment during NPC development, and indicate that strategies to inhibit IL-1β signalling may be necessary to facilitate effective cell transplantation approaches or in conditions where endogenous hippocampal neurogenesis is impaired.

  15. Imaging long-term fate of intramyocardially implanted mesenchymal stem cells in a porcine myocardial infarction model.

    Directory of Open Access Journals (Sweden)

    Emerson C Perin

    Full Text Available The long-term fate of stem cells after intramyocardial delivery is unknown. We used noninvasive, repetitive PET/CT imaging with [(18F]FEAU to monitor the long-term (up to 5 months spatial-temporal dynamics of MSCs retrovirally transduced with the sr39HSV1-tk gene (sr39HSV1-tk-MSC and implanted intramyocardially in pigs with induced acute myocardial infarction. Repetitive [(18F]FEAU PET/CT revealed a biphasic pattern of sr39HSV1-tk-MSC dynamics; cell proliferation peaked at 33-35 days after injection, in periinfarct regions and the major cardiac lymphatic vessels and lymph nodes. The sr39HSV1-tk-MSC-associated [(18F]FEAU signals gradually decreased thereafter. Cardiac lymphography studies using PG-Gd-NIRF813 contrast for MRI and near-infrared fluorescence imaging showed rapid clearance of the contrast from the site of intramyocardial injection through the subepicardial lymphatic network into the lymphatic vessels and periaortic lymph nodes. Immunohistochemical analysis of cardiac tissue obtained at 35 and 150 days demonstrated several types of sr39HSV1-tk expressing cells, including fibro-myoblasts, lymphovascular cells, and microvascular and arterial endothelium. In summary, this study demonstrated the feasibility and sensitivity of [(18F]FEAU PET/CT imaging for long-term, in-vivo monitoring (up to 5 months of the fate of intramyocardially injected sr39HSV1-tk-MSC cells. Intramyocardially transplanted MSCs appear to integrate into the lymphatic endothelium and may help improve myocardial lymphatic system function after MI.

  16. Control of flowering and cell fate by LIF2, an RNA binding partner of the polycomb complex component LHP1.

    Directory of Open Access Journals (Sweden)

    David Latrasse

    Full Text Available Polycomb Repressive Complexes (PRC modulate the epigenetic status of key cell fate and developmental regulators in eukaryotes. The chromo domain protein like heterochromatin protein1 (LHP1 is a subunit of a plant PRC1-like complex in Arabidopsis thaliana and recognizes histone H3 lysine 27 trimethylation, a silencing epigenetic mark deposited by the PRC2 complex. We have identified and studied an LHP1-Interacting Factor2 (LIF2. LIF2 protein has RNA recognition motifs and belongs to the large hnRNP protein family, which is involved in RNA processing. LIF2 interacts in vivo, in the cell nucleus, with the LHP1 chromo shadow domain. Expression of LIF2 was detected predominantly in vascular and meristematic tissues. Loss-of-function of LIF2 modifies flowering time, floral developmental homeostasis and gynoecium growth determination. lif2 ovaries have indeterminate growth and produce ectopic inflorescences with severely affected flowers showing proliferation of ectopic stigmatic papillae and ovules in short-day conditions. To look at how LIF2 acts relative to LHP1, we conducted transcriptome analyses in lif2 and lhp1 and identified a common set of deregulated genes, which showed significant enrichment in stress-response genes. By comparing expression of LHP1 targets in lif2, lhp1 and lif2 lhp1 mutants we showed that LIF2 can either antagonize or act with LHP1. Interestingly, repression of the FLC floral transcriptional regulator in lif2 mutant is accompanied by an increase in H3K27 trimethylation at the locus, without any change in LHP1 binding, suggesting that LHP1 is targeted independently from LIF2 and that LHP1 binding does not strictly correlate with gene expression. LIF2, involved in cell identity and cell fate decision, may modulate the activity of LHP1 at specific loci, during specific developmental windows or in response to environmental cues that control cell fate determination. These results highlight a novel link between plant RNA

  17. Unique molecular signatures influencing the biological function and fate of post-natal stem cells isolated from different sources.

    Science.gov (United States)

    Abu Kasim, Noor Hayaty; Govindasamy, Vijayendran; Gnanasegaran, Nareshwaran; Musa, Sabri; Pradeep, Padmaja Jayaprasad; Srijaya, Thekkeparambil Chandrabose; Aziz, Zeti Adura Che Ab

    2015-12-01

    The discovery of mesenchymal stem cells (MSCs) from a myriad of tissues has triggered the initiative of establishing tailor-made stem cells for disease-specific therapy. Nevertheless, lack of understanding on the inherent differential propensities of these cells may restrict their clinical outcome. Therefore, a comprehensive study was done to compare the proliferation, differentiation, expression of cell surface markers and gene profiling of stem cells isolated from different sources, viz. bone marrow, Wharton's jelly, adipose tissue and dental pulp. We found that although all MSCs were phenotypically similar to each other, Wharton's jelly (WJ) MSCs and dental pulp stem cells (DPSCs) were highly proliferative as compared to bone marrow (BM) MSCs and adipose tissue (AD) MSCs. Moreover, indistinguishable cell surface characteristics and differentiation capacity were confirmed to be similar among all cell types. Based on gene expression profiling, we postulate that BM-MSCs constitutively expressed genes related to inflammation and immunodulation, whereas genes implicated in tissue development were highly expressed in AD-MSCs. Furthermore, the transcriptome profiling of WJ-MSCs and DPSCs revealed an inherent bias towards the neuro-ectoderm lineage. Based on our findings, we believe that there is no unique master mesenchymal stem cell that is appropriate to treat all target diseases. More precisely, MSCs from different sources exhibit distinct and unique gene expression signatures that make them competent to give rise to specific lineages rather than others. Therefore, stem cells should be subjected to rigorous characterization and utmost vigilance needs to be adopted in order to choose the best cellular source for a particular disease.

  18. Restoration of p53 Expression in Human Cancer Cell Lines Upregulates the Expression of Notch1: Implications for Cancer Cell Fate Determination after Genotoxic Stress

    Directory of Open Access Journals (Sweden)

    Fatouma Alimirah

    2007-05-01

    Full Text Available Following genotoxic stress, transcriptional activation of target genes by p53 tumor suppressor is critical in cell fate determination. Here we report that the restoration of p53 function in human cancer cell lines that are deficient in p53 function upregulated the expression of Notch1. Interestingly, the expression of wild-type p53 in human prostate and breast cancer cell lines correlated well with increased expression of Notch1. Furthermo