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Sample records for biogenesis cell growth

  1. Auxin Transport and Ribosome Biogenesis Mutant/Reporter Lines to Study Plant Cell Growth and Proliferation under Altered Gravity

    Science.gov (United States)

    Valbuena, Miguel A.; Manzano, Ana I.; van Loon, Jack JWA.; Saez-Vasquez, Julio; Carnero-Diaz, Eugenie; Herranz, Raul; Medina, F. J.

    2013-02-01

    We tested different Arabidopsis thaliana strains to check their availability for space use in the International Space Station (ISS). We used mutants and reporter gene strains affecting factors of cell proliferation and cell growth, to check variations induced by an altered gravity vector. Seedlings were grown either in a Random Positioning Machine (RPM), under simulated microgravity (μg), or in a Large Diameter Centrifuge (LDC), under hypergravity (2g). A combination of the two devices (μgRPM+LDC) was also used. Under all gravity alterations, seedling roots were longer than in control 1g conditions, while the levels of the nucleolar protein nucleolin were depleted. Alterations in the pattern of expression of PIN2, an auxin transporter, and of cyclin B1, a cell cycle regulator, were shown. All these alterations are compatible with previous space data, so the use of these strains will be useful in the next experiments in ISS, under real microgravity.

  2. Ribosome biogenesis in replicating cells: Integration of experiment and theory.

    Science.gov (United States)

    Earnest, Tyler M; Cole, John A; Peterson, Joseph R; Hallock, Michael J; Kuhlman, Thomas E; Luthey-Schulten, Zaida

    2016-10-01

    Ribosomes-the primary macromolecular machines responsible for translating the genetic code into proteins-are complexes of precisely folded RNA and proteins. The ways in which their production and assembly are managed by the living cell is of deep biological importance. Here we extend a recent spatially resolved whole-cell model of ribosome biogenesis in a fixed volume [Earnest et al., Biophys J 2015, 109, 1117-1135] to include the effects of growth, DNA replication, and cell division. All biological processes are described in terms of reaction-diffusion master equations and solved stochastically using the Lattice Microbes simulation software. In order to determine the replication parameters, we construct and analyze a series of Escherichia coli strains with fluorescently labeled genes distributed evenly throughout their chromosomes. By measuring these cells' lengths and number of gene copies at the single-cell level, we could fit a statistical model of the initiation and duration of chromosome replication. We found that for our slow-growing (120 min doubling time) E. coli cells, replication was initiated 42 min into the cell cycle and completed after an additional 42 min. While simulations of the biogenesis model produce the correct ribosome and mRNA counts over the cell cycle, the kinetic parameters for transcription and degradation are lower than anticipated from a recent analytical time dependent model of in vivo mRNA production. Describing expression in terms of a simple chemical master equation, we show that the discrepancies are due to the lack of nonribosomal genes in the extended biogenesis model which effects the competition of mRNA for ribosome binding, and suggest corrections to parameters to be used in the whole-cell model when modeling expression of the entire transcriptome. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 735-751, 2016. PMID:27294303

  3. Yeast peroxisomes : function and biogenesis of a versatile cell organelle

    NARCIS (Netherlands)

    van der Klei, IJ; Veenhuis, M

    1997-01-01

    Yeast peroxisomes harbour enzymes involved in the metabolism of specific growth substrates, Sequestration of these enzymes increases the efficiency of such pathways. Currently, 16 genes involved in peroxisome biogenesis have been identified, and analysis of their products suggests novel mechanisms f

  4. Biogenesis and function of T cell-derived exosomes

    Directory of Open Access Journals (Sweden)

    Miguel Angel Alonso

    2016-08-01

    Full Text Available Exosomes are a particular type of extracellular vesicle, characterized by their endosomal origin as intraluminal vesicles present in large endosomes with a multivesicular structure. After these endosomes fuse with the plasma membrane, exosomes are secreted into the extracellular space. The ability of exosomes to carry and selectively deliver bioactive molecules (e.g., lipids, proteins and nucleic acids confers on them the capacity to modulate the activity of receptor cells, even if these cells are located in distant tissues or organs. Since exosomal cargo depends on cell type, a detailed understanding of the mechanisms that regulate the biochemical composition of exosomes is fundamental to a comprehensive view of exosome function. Here, we review the latest advances concerning exosome function and biogenesis in T cells, with particular focus on the mechanism of protein sorting at multivesicular endosomes. Exosomes secreted by specific T-cell subsets can modulate the activity of immune cells, including other T-cell subsets. Ceramide, tetraspanins and MAL have been revealed to be important in exosome biogenesis by T cells. These molecules, therefore, constitute potential molecular targets for artificially modulating exosome production and, hence, the immune response for therapeutic purposes.

  5. Biogenesis and Function of T Cell-Derived Exosomes.

    Science.gov (United States)

    Ventimiglia, Leandro N; Alonso, Miguel A

    2016-01-01

    Exosomes are a particular type of extracellular vesicle, characterized by their endosomal origin as intraluminal vesicles present in large endosomes with a multivesicular structure. After these endosomes fuse with the plasma membrane, exosomes are secreted into the extracellular space. The ability of exosomes to carry and selectively deliver bioactive molecules (e.g., lipids, proteins, and nucleic acids) confers on them the capacity to modulate the activity of receptor cells, even if these cells are located in distant tissues or organs. Since exosomal cargo depends on cell type, a detailed understanding of the mechanisms that regulate the biochemical composition of exosomes is fundamental to a comprehensive view of exosome function. Here, we review the latest advances concerning exosome function and biogenesis in T cells, with particular focus on the mechanism of protein sorting at multivesicular endosomes. Exosomes secreted by specific T-cell subsets can modulate the activity of immune cells, including other T-cell subsets. Ceramide, tetraspanins and MAL have been revealed to be important in exosome biogenesis by T cells. These molecules, therefore, constitute potential molecular targets for artificially modulating exosome production and, hence, the immune response for therapeutic purposes. PMID:27583248

  6. Cell wall structure and biogenesis in Aspergillus species.

    Science.gov (United States)

    Yoshimi, Akira; Miyazawa, Ken; Abe, Keietsu

    2016-09-01

    Aspergillus species are among the most important filamentous fungi from the viewpoints of industry, pathogenesis, and mycotoxin production. Fungal cells are exposed to a variety of environmental stimuli, including changes in osmolality, temperature, and pH, which create stresses that primarily act on fungal cell walls. In addition, fungal cell walls are the first interactions with host cells in either human or plants. Thus, understanding cell wall structure and the mechanism of their biogenesis is important for the industrial, medical, and agricultural fields. Here, we provide a systematic review of fungal cell wall structure and recent findings regarding the cell wall integrity signaling pathways in aspergilli. This accumulated knowledge will be useful for understanding and improving the use of industrial aspergilli fermentation processes as well as treatments for some fungal infections. PMID:27140698

  7. Autophagy induction is a Tor- and Tp53-independent cell survival response in a zebrafish model of disrupted ribosome biogenesis.

    Directory of Open Access Journals (Sweden)

    Yeliz Boglev

    Full Text Available Ribosome biogenesis underpins cell growth and division. Disruptions in ribosome biogenesis and translation initiation are deleterious to development and underlie a spectrum of diseases known collectively as ribosomopathies. Here, we describe a novel zebrafish mutant, titania (tti(s450, which harbours a recessive lethal mutation in pwp2h, a gene encoding a protein component of the small subunit processome. The biochemical impacts of this lesion are decreased production of mature 18S rRNA molecules, activation of Tp53, and impaired ribosome biogenesis. In tti(s450, the growth of the endodermal organs, eyes, brain, and craniofacial structures is severely arrested and autophagy is up-regulated, allowing intestinal epithelial cells to evade cell death. Inhibiting autophagy in tti(s450 larvae markedly reduces their lifespan. Somewhat surprisingly, autophagy induction in tti(s450 larvae is independent of the state of the Tor pathway and proceeds unabated in Tp53-mutant larvae. These data demonstrate that autophagy is a survival mechanism invoked in response to ribosomal stress. This response may be of relevance to therapeutic strategies aimed at killing cancer cells by targeting ribosome biogenesis. In certain contexts, these treatments may promote autophagy and contribute to cancer cells evading cell death.

  8. Key Regulators of Mitochondrial Biogenesis are Increased in Kidneys of Growth Hormone Receptor Knockout (GHRKO) Mice

    OpenAIRE

    Gesing, Adam; Bartke, Andrzej; Wang, Feiya; Karbownik-Lewinska, Malgorzata; Masternak, Michal M.

    2011-01-01

    The growth hormone (GH) receptor knockout mice (GHRKO) are remarkably long-lived and highly insulin sensitive. Alterations in mitochondrial biogenesis are associated with aging and various metabolic derangements. We have previously demonstrated increased gene expression of key regulators of mitochondriogenesis in kidneys, hearts and skeletal muscles of GHRKO mice. The aim of the present study was to quantify the protein levels of the following regulators of mitochondriogenesis: peroxisome pro...

  9. Cockayne syndrome protein A is a transcription factor of RNA polymerase I and stimulates ribosomal biogenesis and growth

    Science.gov (United States)

    Koch, Sylvia; Garcia Gonzalez, Omar; Assfalg, Robin; Schelling, Adrian; Schäfer, Patrick; Scharffetter-Kochanek, Karin; Iben, Sebastian

    2014-01-01

    Mutations in the Cockayne syndrome A (CSA) protein account for 20% of Cockayne syndrome (CS) cases, a childhood disorder of premature aging and early death. Hitherto, CSA has exclusively been described as DNA repair factor of the transcription-coupled branch of nucleotide excision repair. Here we show a novel function of CSA as transcription factor of RNA polymerase I in the nucleolus. Knockdown of CSA reduces pre-rRNA synthesis by RNA polymerase I. CSA associates with RNA polymerase I and the active fraction of the rDNA and stimulates re-initiation of rDNA transcription by recruiting the Cockayne syndrome proteins TFIIH and CSB. Moreover, compared with CSA deficient parental CS cells, CSA transfected CS cells reveal significantly more rRNA with induced growth and enhanced global translation. A previously unknown global dysregulation of ribosomal biogenesis most likely contributes to the reduced growth and premature aging of CS patients. PMID:24781187

  10. PICK1 deficiency impairs secretory vesicle biogenesis and leads to growth retardation and decreased glucose tolerance.

    Directory of Open Access Journals (Sweden)

    Birgitte Holst

    Full Text Available Secretory vesicles in endocrine cells store hormones such as growth hormone (GH and insulin before their release into the bloodstream. The molecular mechanisms governing budding of immature secretory vesicles from the trans-Golgi network (TGN and their subsequent maturation remain unclear. Here, we identify the lipid binding BAR (Bin/amphiphysin/Rvs domain protein PICK1 (protein interacting with C kinase 1 as a key component early in the biogenesis of secretory vesicles in GH-producing cells. Both PICK1-deficient Drosophila and mice displayed somatic growth retardation. Growth retardation was rescued in flies by reintroducing PICK1 in neurosecretory cells producing somatotropic peptides. PICK1-deficient mice were characterized by decreased body weight and length, increased fat accumulation, impaired GH secretion, and decreased storage of GH in the pituitary. Decreased GH storage was supported by electron microscopy showing prominent reduction in secretory vesicle number. Evidence was also obtained for impaired insulin secretion associated with decreased glucose tolerance. PICK1 localized in cells to immature secretory vesicles, and the PICK1 BAR domain was shown by live imaging to associate with vesicles budding from the TGN and to possess membrane-sculpting properties in vitro. In mouse pituitary, PICK1 co-localized with the BAR domain protein ICA69, and PICK1 deficiency abolished ICA69 protein expression. In the Drosophila brain, PICK1 and ICA69 co-immunoprecipitated and showed mutually dependent expression. Finally, both in a Drosophila model of type 2 diabetes and in high-fat-diet-induced obese mice, we observed up-regulation of PICK1 mRNA expression. Our findings suggest that PICK1, together with ICA69, is critical during budding of immature secretory vesicles from the TGN and thus for vesicular storage of GH and possibly other hormones. The data link two BAR domain proteins to membrane remodeling processes in the secretory pathway of

  11. Expression of Key Regulators of Mitochondrial Biogenesis in Growth Hormone Receptor Knockout (GHRKO) Mice is Enhanced but is Not Further Improved by Other Potential Life-Extending Interventions

    OpenAIRE

    Gesing, Adam; Masternak, Michal M.; Wang, Feiya; Joseph, Anna-Maria; Leeuwenburgh, Christiaan; Westbrook, Reyhan; Lewinski, Andrzej; Karbownik-Lewinska, Malgorzata; Bartke, Andrzej

    2011-01-01

    Mitochondrial biogenesis is essential for cell viability. Growth hormone receptor knockout (GHRKO), calorie restriction, and surgical visceral fat removal constitute experimental interventions to delay aging and increase life span. We examined the expression of known regulators of mitochondriogenesis: peroxisome proliferator–activated receptor γ co-activator 1α (PGC-1α), adenosine monophosphate (AMP)–activated protein kinase (AMPK), sirtuin-1 (SIRT-1) and sirtuin-3 (SIRT-3), endothelial nitri...

  12. Mitochondria Biogenesis and Bioenergetics Gene Profiles in Isogenic Prostate Cells with Different Malignant Phenotypes

    OpenAIRE

    Tanya C. Burch; Rhim, Johng S.; Julius O Nyalwidhe

    2016-01-01

    Background. The most significant hallmarks of cancer are directly or indirectly linked to deregulated mitochondria. In this study, we sought to profile mitochondria associated genes in isogenic prostate cell lines with different tumorigenic phenotypes from the same patient. Results. Two isogenic human prostate cell lines RC77N/E (nonmalignant cells) and RC77T/E (malignant cells) were profiled for expression of mitochondrial biogenesis and energy metabolism genes by qRT-PCR using the Human Mit...

  13. Peroxynitrite induced mitochondrial biogenesis following MnSOD knockdown in normal rat kidney (NRK cells

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    Akira Marine

    2014-01-01

    Full Text Available Superoxide is widely regarded as the primary reactive oxygen species (ROS which initiates downstream oxidative stress. Increased oxidative stress contributes, in part, to many disease conditions such as cancer, atherosclerosis, ischemia/reperfusion, diabetes, aging, and neurodegeneration. Manganese superoxide dismutase (MnSOD catalyzes the dismutation of superoxide into hydrogen peroxide which can then be further detoxified by other antioxidant enzymes. MnSOD is critical in maintaining the normal function of mitochondria, thus its inactivation is thought to lead to compromised mitochondria. Previously, our laboratory observed increased mitochondrial biogenesis in a novel kidney-specific MnSOD knockout mouse. The current study used transient siRNA mediated MnSOD knockdown of normal rat kidney (NRK cells as the in vitro model, and confirmed functional mitochondrial biogenesis evidenced by increased PGC1α expression, mitochondrial DNA copy numbers and integrity, electron transport chain protein CORE II, mitochondrial mass, oxygen consumption rate, and overall ATP production. Further mechanistic studies using mitoquinone (MitoQ, a mitochondria-targeted antioxidant and L-NAME, a nitric oxide synthase (NOS inhibitor demonstrated that peroxynitrite (at low micromolar levels induced mitochondrial biogenesis. These findings provide the first evidence that low levels of peroxynitrite can initiate a protective signaling cascade involving mitochondrial biogenesis which may help to restore mitochondrial function following transient MnSOD inactivation.

  14. Enhanced mitochondrial biogenesis contributes to Wnt induced osteoblastic differentiation of C3H10T1/2 cells.

    Science.gov (United States)

    An, Jee Hyun; Yang, Jae-Yeon; Ahn, Byung Yong; Cho, Sun Wook; Jung, Ju Yeon; Cho, Hwa Young; Cho, Young Min; Kim, Sang Wan; Park, Kyong Soo; Kim, Seong Yeon; Lee, Hong Kyu; Shin, Chan Soo

    2010-07-01

    Mitochondria play a key role in cell physiology including cell differentiation and proliferation. We investigated the changes of mitochondrial biogenesis during Wnt-induced osteoblastic differentiation of murine mesenchymal C3H10T1/2 cells. Scanning electron microscopy demonstrated that activation of Wnt signaling by Wnt-3A conditioned medicum (CM) resulted in significant increase in the number of mitochondria in C3H10T1/2 cells. In addition, the induction of alkaline phosphatase (ALP) activities by Wnt-3A CM was accompanied by significant increase in mitochondrial mass (pactivities as well as mitochondrial biogenesis markers. Upregulation of mitochondrial biogenesis by overexpression of mitochondrial transcription factor A (Tfam) significantly enhanced Wnt-induced osteogenesis as measured by ALP activities. In contrast, inhibition of mitochondrial biogenesis by treatment with Zidovudine (AZT) resulted in significant inhibition of ALP activities. Finally, ALP activities in human osteosarcoma cell line devoid of mitochondrial DNA (rho(0) cells) was significantly suppressed both in basal and Wnt-3A stimulated state compared to those from mitochondria-intact cells (rho+ cells). As a mechanism for Wnt-mediated mitochondrial biogenesis, we found that Wnt increased the expression of PGC-1alpha, a critical molecules in mitochondrial biogenesis, through Erk and p38 MAPK pathway independent of beta-catenin signaling. We also found that increased mitochondrial biogenesis is in turn positively regulating TOPflash reporter activity as well as beta-catenin levels. To summarize, mitochodrial biogenesis is upregulated by Wnt signaling and this upregulation contributes to the osteoblastic differentiation of mouse mesenchymal C3H10T1/2 cells. PMID:20399290

  15. Nuclear ribosome biogenesis mediated by the DIM1A rRNA dimethylase is required for organized root growth and epidermal patterning in Arabidopsis.

    Science.gov (United States)

    Wieckowski, Yana; Schiefelbein, John

    2012-07-01

    Position-dependent patterning of hair and non-hair cells in the Arabidopsis thaliana root epidermis is a powerful system to study the molecular basis of cell fate specification. Here, we report an epidermal patterning mutant affecting the ADENOSINE DIMETHYL TRANSFERASE 1A (DIM1A) rRNA dimethylase gene, predicted to participate in rRNA posttranscriptional processing and base modification. Consistent with a role in ribosome biogenesis, DIM1A is preferentially expressed in regions of rapid growth, and its product is nuclear localized with nucleolus enrichment. Furthermore, DIM1A preferentially accumulates in the developing hair cells, and the dim1A point mutant alters the cell-specific expression of the transcriptional regulators GLABRA2, CAPRICE, and WEREWOLF. Together, these findings suggest that establishment of cell-specific gene expression during root epidermis development is dependent upon proper ribosome biogenesis, possibly due to the sensitivity of the cell fate decision to relatively small differences in gene regulatory activities. Consistent with its effect on the predicted S-adenosyl-l-Met binding site, dim1A plants lack the two 18S rRNA base modifications but exhibit normal pre-rRNA processing. In addition to root epidermal defects, the dim1A mutant exhibits abnormal root meristem division, leaf development, and trichome branching. Together, these findings provide new insights into the importance of rRNA base modifications and translation regulation for plant growth and development.

  16. Coordinated Upregulation of Mitochondrial Biogenesis and Autophagy in Breast Cancer Cells: The Role of Dynamin Related Protein-1 and Implication for Breast Cancer Treatment

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    Peng Zou

    2016-01-01

    Full Text Available Overactive mitochondrial fission was shown to promote cell transformation and tumor growth. It remains elusive how mitochondrial quality is regulated in such conditions. Here, we show that upregulation of mitochondrial fission protein, dynamin related protein-1 (Drp1, was accompanied with increased mitochondrial biogenesis markers (PGC1α, NRF1, and Tfam in breast cancer cells. However, mitochondrial number was reduced, which was associated with lower mitochondrial oxidative capacity in breast cancer cells. This contrast might be owing to enhanced mitochondrial turnover through autophagy, because an increased population of autophagic vacuoles engulfing mitochondria was observed in the cancer cells. Consistently, BNIP3 (a mitochondrial autophagy marker and autophagic flux were significantly upregulated, indicative of augmented mitochondrial autophagy (mitophagy. The upregulation of Drp1 and BNIP3 was also observed in vivo (human breast carcinomas. Importantly, inhibition of Drp1 significantly suppressed mitochondrial autophagy, metabolic reprogramming, and cancer cell viability. Together, this study reveals coordinated increase of mitochondrial biogenesis and mitophagy in which Drp1 plays a central role regulating breast cancer cell metabolism and survival. Given the emerging evidence of PGC1α contributing to tumor growth, it will be of critical importance to target both mitochondrial biogenesis and mitophagy for effective cancer therapeutics.

  17. Biogenesis and the growth of DNA-like polymer chains: a computer simulation

    International Nuclear Information System (INIS)

    We study, through computer simulation, a crucial step of Biogenesis, namely the growth of self-replicating codified DNA-like polymers starting from a mixture of oligomers. We have adopted the growth scheme that has been recently proposed by Ferreira and Tsallis which incorporates usual ideas of autocatalysis through complementary pairs and within which a central role is played by the hydrogen-like links (characterized by the probabilities pAT and pCG of chemical bonding of the A-T and C-G pairs respectively) between the two chains of the growing polymer. We find that the average equilibrium polymeric length ξ diverges, for any fixed ratio (1-pAT)/(1-p sub (CG)), as ξ ∝ 1/r1-pAT. Selection of patterns may happen at all stages and in particular at chemical equilibrium. Selection occurs via two different mechanisms: (i) away from the critical point pAT = pCG = 1 if pAT ≠ pCG; (ii) both on and away from the critical point if the initial concentrations of nucleotides (A, T, C and G or their precursors) are different. (author)

  18. Peroxisome biogenesis in mammalian cells: The impact of genes and environment.

    Science.gov (United States)

    Farr, Rebecca L; Lismont, Celien; Terlecky, Stanley R; Fransen, Marc

    2016-05-01

    The initiation and progression of many human diseases are mediated by a complex interplay of genetic, epigenetic, and environmental factors. As all diseases begin with an imbalance at the cellular level, it is essential to understand how various types of molecular aberrations, metabolic changes, and environmental stressors function as switching points in essential communication networks. In recent years, peroxisomes have emerged as important intracellular hubs for redox-, lipid-, inflammatory-, and nucleic acid-mediated signaling pathways. In this review, we focus on how nature and nurture modulate peroxisome biogenesis and function in mammalian cells. First, we review emerging evidence that changes in peroxisome activity can be linked to the epigenetic regulation of cell function. Next, we outline how defects in peroxisome biogenesis may directly impact cellular pathways involved in the development of disease. In addition, we discuss how changes in the cellular microenvironment can modulate peroxisome biogenesis and function. Finally, given the importance of peroxisome function in multiple aspects of health, disease, and aging, we highlight the need for more research in this still understudied field.

  19. Restrictive glycosylphosphatidylinositol anchor synthesis in cwh6/gpi3 yeast cells causes aberrant biogenesis of cell wall proteins.

    OpenAIRE

    Vossen, J.H.; Müller, W. H.; Lipke, P N; Klis, F. M.

    1997-01-01

    We previously reported that the defects in the Saccharomyces cerevisiae cwh6 Calcofluor white-hypersensitive cell wall mutant are caused by a mutation in SPT14/GPI3, a gene involved in glycosylphosphatidylinositol (GPI) anchor biosynthesis. Here we describe the effect of cwh6/spt14/gpi3 on the biogenesis of cell wall proteins. It was found that the release of precursors of cell wall proteins from the endoplasmic reticulum (ER) was retarded. This was accompanied by proliferation of ER structur...

  20. Mitochondria Biogenesis and Bioenergetics Gene Profiles in Isogenic Prostate Cells with Different Malignant Phenotypes

    Directory of Open Access Journals (Sweden)

    Tanya C. Burch

    2016-01-01

    Full Text Available Background. The most significant hallmarks of cancer are directly or indirectly linked to deregulated mitochondria. In this study, we sought to profile mitochondria associated genes in isogenic prostate cell lines with different tumorigenic phenotypes from the same patient. Results. Two isogenic human prostate cell lines RC77N/E (nonmalignant cells and RC77T/E (malignant cells were profiled for expression of mitochondrial biogenesis and energy metabolism genes by qRT-PCR using the Human Mitochondria and the Mitochondrial Energy Metabolism RT2 PCR arrays. Forty-seven genes were differentially regulated between the two cell lines. The interaction and regulatory networks of these genes were generated by Ingenuity Pathway Analysis. UCP2 was the most significantly upregulated gene in primary adenocarcinoma cells in the current study. The overexpression of UCP2 upon malignant transformation was further validated using human prostatectomy clinical specimens. Conclusions. This study demonstrates the overexpression of multiple genes that are involved in mitochondria biogenesis, bioenergetics, and modulation of apoptosis. These genes may play a role in malignant transformation and disease progression. The upregulation of some of these genes in clinical samples indicates that some of the differentially transcribed genes could be the potential targets for therapeutic interventions.

  1. Mitochondria Biogenesis and Bioenergetics Gene Profiles in Isogenic Prostate Cells with Different Malignant Phenotypes.

    Science.gov (United States)

    Burch, Tanya C; Rhim, Johng S; Nyalwidhe, Julius O

    2016-01-01

    Background. The most significant hallmarks of cancer are directly or indirectly linked to deregulated mitochondria. In this study, we sought to profile mitochondria associated genes in isogenic prostate cell lines with different tumorigenic phenotypes from the same patient. Results. Two isogenic human prostate cell lines RC77N/E (nonmalignant cells) and RC77T/E (malignant cells) were profiled for expression of mitochondrial biogenesis and energy metabolism genes by qRT-PCR using the Human Mitochondria and the Mitochondrial Energy Metabolism RT(2) PCR arrays. Forty-seven genes were differentially regulated between the two cell lines. The interaction and regulatory networks of these genes were generated by Ingenuity Pathway Analysis. UCP2 was the most significantly upregulated gene in primary adenocarcinoma cells in the current study. The overexpression of UCP2 upon malignant transformation was further validated using human prostatectomy clinical specimens. Conclusions. This study demonstrates the overexpression of multiple genes that are involved in mitochondria biogenesis, bioenergetics, and modulation of apoptosis. These genes may play a role in malignant transformation and disease progression. The upregulation of some of these genes in clinical samples indicates that some of the differentially transcribed genes could be the potential targets for therapeutic interventions. PMID:27478826

  2. Hippo signaling regulates microprocessor and links cell-density-dependent miRNA biogenesis to cancer.

    Science.gov (United States)

    Mori, Masaki; Triboulet, Robinson; Mohseni, Morvarid; Schlegelmilch, Karin; Shrestha, Kriti; Camargo, Fernando D; Gregory, Richard I

    2014-02-27

    Global downregulation of microRNAs (miRNAs) is commonly observed in human cancers and can have a causative role in tumorigenesis. The mechanisms responsible for this phenomenon remain poorly understood. Here, we show that YAP, the downstream target of the tumor-suppressive Hippo-signaling pathway regulates miRNA biogenesis in a cell-density-dependent manner. At low cell density, nuclear YAP binds and sequesters p72 (DDX17), a regulatory component of the miRNA-processing machinery. At high cell density, Hippo-mediated cytoplasmic retention of YAP facilitates p72 association with Microprocessor and binding to a specific sequence motif in pri-miRNAs. Inactivation of the Hippo pathway or expression of constitutively active YAP causes widespread miRNA suppression in cells and tumors and a corresponding posttranscriptional induction of MYC expression. Thus, the Hippo pathway links contact-inhibition regulation to miRNA biogenesis and may be responsible for the widespread miRNA repression observed in cancer.

  3. Target-dependent biogenesis of cognate microRNAs in human cells.

    Science.gov (United States)

    Bose, Mainak; Bhattacharyya, Suvendra N

    2016-01-01

    Extensive research has established how miRNAs regulate target mRNAs by translation repression and/or endonucleolytic degradation in metazoans. However, information related to the effect of target mRNA on biogenesis and stability of corresponding miRNAs in animals is limited. Here we report regulated biogenesis of cognate miRNAs by their target mRNAs. Enhanced pre-miRNA processing by AGO-associated DICER1 contributes to this increased miRNP formation. The processed miRNAs are loaded onto AGO2 to form functionally competent miRISCs both in vivo and also in a cell-free in vitro system. Thus, we identify an additional layer of posttranscriptional regulation that helps the cell to maintain requisite levels of mature forms of respective miRNAs by modulating their processing in a target-dependent manner, a process happening for miR-122 during stress reversal in human hepatic cells. PMID:27448149

  4. Regulation of Cell Wall Biogenesis in Saccharomyces cerevisiae: The Cell Wall Integrity Signaling Pathway

    OpenAIRE

    Levin, David E.

    2011-01-01

    The yeast cell wall is a strong, but elastic, structure that is essential not only for the maintenance of cell shape and integrity, but also for progression through the cell cycle. During growth and morphogenesis, and in response to environmental challenges, the cell wall is remodeled in a highly regulated and polarized manner, a process that is principally under the control of the cell wall integrity (CWI) signaling pathway. This pathway transmits wall stress signals from the cell surface to...

  5. ADAR1 Activation Drives Leukemia Stem Cell Self-Renewal by Impairing Let-7 Biogenesis.

    Science.gov (United States)

    Zipeto, Maria Anna; Court, Angela C; Sadarangani, Anil; Delos Santos, Nathaniel P; Balaian, Larisa; Chun, Hye-Jung; Pineda, Gabriel; Morris, Sheldon R; Mason, Cayla N; Geron, Ifat; Barrett, Christian; Goff, Daniel J; Wall, Russell; Pellecchia, Maurizio; Minden, Mark; Frazer, Kelly A; Marra, Marco A; Crews, Leslie A; Jiang, Qingfei; Jamieson, Catriona H M

    2016-08-01

    Post-transcriptional adenosine-to-inosine RNA editing mediated by adenosine deaminase acting on RNA1 (ADAR1) promotes cancer progression and therapeutic resistance. However, ADAR1 editase-dependent mechanisms governing leukemia stem cell (LSC) generation have not been elucidated. In blast crisis chronic myeloid leukemia (BC CML), we show that increased JAK2 signaling and BCR-ABL1 amplification activate ADAR1. In a humanized BC CML mouse model, combined JAK2 and BCR-ABL1 inhibition prevents LSC self-renewal commensurate with ADAR1 downregulation. Lentiviral ADAR1 wild-type, but not an editing-defective ADAR1(E912A) mutant, induces self-renewal gene expression and impairs biogenesis of stem cell regulatory let-7 microRNAs. Combined RNA sequencing, qRT-PCR, CLIP-ADAR1, and pri-let-7 mutagenesis data suggest that ADAR1 promotes LSC generation via let-7 pri-microRNA editing and LIN28B upregulation. A small-molecule tool compound antagonizes ADAR1's effect on LSC self-renewal in stromal co-cultures and restores let-7 biogenesis. Thus, ADAR1 activation represents a unique therapeutic vulnerability in LSCs with active JAK2 signaling. PMID:27292188

  6. Direct relationship between the level of p53 stabilization induced by rRNA synthesis-inhibiting drugs and the cell ribosome biogenesis rate.

    Science.gov (United States)

    Scala, F; Brighenti, E; Govoni, M; Imbrogno, E; Fornari, F; Treré, D; Montanaro, L; Derenzini, M

    2016-02-25

    Many drugs currently used in chemotherapy work by hindering the process of ribosome biogenesis. In tumors with functional p53, the inhibition of ribosome biogenesis may contribute to the efficacy of this treatment by inducing p53 stabilization. As the level of stabilized p53 is critical for the induction of cytotoxic effects, it seems useful to highlight those cancer cell characteristics that can predict the degree of p53 stabilization following the treatment with inhibitors of ribosome biogenesis. In the present study we exposed a series of p53 wild-type human cancer cell lines to drugs such as actinomycin D (ActD), doxorubicin, 5-fluorouracil and CX-5461, which hinder ribosomal RNA (rRNA) synthesis. We found that the amount of stabilized p53 was directly related to the level of ribosome biogenesis in cells before the drug treatment. This was due to different levels of inactivation of the ribosomal proteins-MDM2 pathway of p53 digestion. Inhibition of rRNA synthesis always caused cell cycle arrest, independent of the ribosome biogenesis rate of the cells, whereas apoptosis occurred only in cells with a high rDNA transcription rate. The level of p53 stabilization induced by drugs acting in different ways from the inhibition of ribosome biogenesis, such as hydroxyurea (HU) and nutlin-3, was independent of the level of ribosome biogenesis in cells and always lower than that occurring after the inhibition of rRNA synthesis. Interestingly, in cells with a low ribosome biogenesis rate, the combined treatment with ActD and HU exerted an additive effect on p53 stabilization. These results indicated that (i) drugs inhibiting ribosome biogenesis may be highly effective in p53 wild-type cancers with a high ribosome biogenesis rate, as they induce apoptotic cell death, and (ii) the combination of drugs capable of stabilizing p53 through different mechanisms may be useful for treating cancers with a low ribosome biogenesis rate. PMID:25961931

  7. Cilostazol promotes mitochondrial biogenesis in human umbilical vein endothelial cells through activating the expression of PGC-1α

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Luning [Shandong University, 44 Wenhua Xi Road, Jinan, Shandong 250012 (China); Department of Cardiology, Yantaishan Hospital, Yantai, Shandong 264001 (China); Li, Qiang; Sun, Bei; Xu, Zhiying [Department of Cardiology, Yantaishan Hospital, Yantai, Shandong 264001 (China); Ge, Zhiming, E-mail: zhimingge2000@hotmail.com [Department of Cardiology, Qilu Hospital, Shandong University, 44 Wenhua Xi Road, Jinan, Shandong 250012 (China)

    2013-03-29

    Highlights: ► First time to show that cilostazol promotes the expressions of PGC-1α. ► First time to show that cilostazol stimulates mitochondrial biogenesis in HUVECs. ► PKA/CREB pathway mediates the effect of cilostazol on PGC-1α expression. ► Suggesting the roles of cilostazol in mitochondrial dysfunction related disease. -- Abstract: Mitochondrial dysfunction is frequently observed in vascular diseases. Cilostazol is a drug approved by the US Food and Drug Administration for the treatment of intermittent claudication. Cilostazol increases intracellular cyclic adenosine monophosphate (cAMP) levels through inhibition of type III phosphodiesterase. The effects of cilostazol in mitochondrial biogenesis in human umbilical vein endothelial cells (HUVECs) were investigated in this study. Cilostazol treated HUVECs displayed increased levels of ATP, mitochondrial DNA/nuclear DNA ratio, expressions of cytochrome B, and mitochondrial mass, suggesting an enhanced mitochondrial biogenesis induced by cilostazol. The promoted mitochondrial biogenesis could be abolished by Protein kinase A (PKA) specific inhibitor H-89, implying that PKA pathway played a critical role in increased mitochondrial biogenesis after cilostazol treatment. Indeed, expression levels of peroxisome proliferator activator receptor gamma-coactivator 1α (PGC-1α), NRF 1 and mitochondrial transcription factor A (TFAM) were significantly increased in HUVECs after incubation with cilostazol at both mRNA levels and protein levels. Importantly, knockdown of PGC-1α could abolish cilostazol-induced mitochondrial biogenesis. Enhanced expression of p-CREB and PGC-1α induced by cilostazol could be inhibited by H-89. Moreover, the increased expression of PGC-1α induced by cilostazol could be inhibited by downregulation of CREB using CREB siRNA at both mRNA and protein levels. All the results indicated that cilostazol promoted mitochondrial biogenesis through activating the expression of PGC-1α in

  8. The Mkk2 MAPKK Regulates Cell Wall Biogenesis in Cooperation with the Cek1-Pathway in Candida albicans.

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    Elvira Román

    Full Text Available The cell wall integrity pathway (CWI plays an important role in the biogenesis of the cell wall in Candida albicans and other fungi. In the present work, the C. albicans MKK2 gene that encodes the putative MAPKK of this pathway was deleted in different backgrounds and the phenotypes of the resultant mutants were characterised. We show here that Mkk2 mediates the phosphorylation of the Mkc1 MAPK in response to cell wall assembly interfering agents such as zymolyase or tunicamycin and also to oxidative stress. Remarkably, mkk2 and mkc1 mutants display related but distinguishable- cell wall associated phenotypes and differ in the pattern of MAPK phosphorylation under different stress conditions. mkk2 and mkc1 mutants display an altered expression of GSC1, CEK1 and CRH11 genes at different temperatures. Combined deletion of MKK2 with HST7 supports a cooperative role for the Cek1-mediated and CWI pathways in regulating cell wall architecture under vegetative growth. However, and in contrast to Mkc1, Mkk2 does not seem to play a role in the virulence of C. albicans in the mouse systemic model or the Galleria mellonella model of infection.

  9. Mitochondrial biogenesis: pharmacological approaches.

    Science.gov (United States)

    Valero, Teresa

    2014-01-01

    Organelle biogenesis is concomitant to organelle inheritance during cell division. It is necessary that organelles double their size and divide to give rise to two identical daughter cells. Mitochondrial biogenesis occurs by growth and division of pre-existing organelles and is temporally coordinated with cell cycle events [1]. However, mitochondrial biogenesis is not only produced in association with cell division. It can be produced in response to an oxidative stimulus, to an increase in the energy requirements of the cells, to exercise training, to electrical stimulation, to hormones, during development, in certain mitochondrial diseases, etc. [2]. Mitochondrial biogenesis is therefore defined as the process via which cells increase their individual mitochondrial mass [3]. Recent discoveries have raised attention to mitochondrial biogenesis as a potential target to treat diseases which up to date do not have an efficient cure. Mitochondria, as the major ROS producer and the major antioxidant producer exert a crucial role within the cell mediating processes such as apoptosis, detoxification, Ca2+ buffering, etc. This pivotal role makes mitochondria a potential target to treat a great variety of diseases. Mitochondrial biogenesis can be pharmacologically manipulated. This issue tries to cover a number of approaches to treat several diseases through triggering mitochondrial biogenesis. It contains recent discoveries in this novel field, focusing on advanced mitochondrial therapies to chronic and degenerative diseases, mitochondrial diseases, lifespan extension, mitohormesis, intracellular signaling, new pharmacological targets and natural therapies. It contributes to the field by covering and gathering the scarcely reported pharmacological approaches in the novel and promising field of mitochondrial biogenesis. There are several diseases that have a mitochondrial origin such as chronic progressive external ophthalmoplegia (CPEO) and the Kearns- Sayre syndrome (KSS

  10. Biogenesis and dynamics of mitochondria during the cell cycle: significance of 3'UTRs.

    Directory of Open Access Journals (Sweden)

    Marta Martínez-Diez

    Full Text Available Nowadays, we are facing a renaissance of mitochondria in cancer biology. However, our knowledge of the basic cell biology and on the timing and mechanisms that control the biosynthesis of mitochondrial constituents during progression through the cell cycle of mammalian cells remain largely unknown. Herein, we document the in vivo changes on mitochondrial morphology and dynamics that accompany cellular mitosis, and illustrate the following key points of the biogenesis of mitochondria during progression of liver cells through the cycle: (i the replication of nuclear and mitochondrial genomes is synchronized during cellular proliferation, (ii the accretion of OXPHOS proteins is asynchronously regulated during proliferation being the synthesis of beta-F1-ATPase and Hsp60 carried out also at G2/M and, (iii the biosynthesis of cardiolipin is achieved during the S phase, although full development of the mitochondrial membrane potential (DeltaPsim is attained at G2/M. Furthermore, we demonstrate using reporter constructs that the mechanism regulating the accretion of beta-F1-ATPase during cellular proliferation is controlled at the level of mRNA translation by the 3'UTR of the transcript. The 3'UTR-driven synthesis of the protein at G2/M is essential for conferring to the daughter cells the original phenotype of the parental cell. Our findings suggest that alterations on this process may promote deregulated beta-F1-ATPase expression in human cancer.

  11. Lipid rafts are essential for peroxisome biogenesis in HepG2 cells.

    NARCIS (Netherlands)

    Woudenberg, J.; Rembacz, K.P.; Hoekstra, M.; Pellicoro, A.; Heuvel, F.A. van den; Heegsma, J.; Ijzendoorn, S.C. van; Holzinger, A.; Imanaka, T.; Moshage, H.; Faber, K.N.

    2010-01-01

    Peroxisomes are particularly abundant in the liver and are involved in bile salt synthesis and fatty acid metabolism. Peroxisomal membrane proteins (PMPs) are required for peroxisome biogenesis [e.g., the interacting peroxisomal biogenesis factors Pex13p and Pex14p] and its metabolic function [e.g.,

  12. Lipid Rafts Are Essential for Peroxisome Biogenesis in HepG2 Cells

    NARCIS (Netherlands)

    Woudenberg, Jannes; Rembacz, Krzysztof; Hoekstra, Mark; Pellicoro, Antonella; van den Heuvel, F.A.J.; Heegsma, J.; van IJzendoorn, S.C.D.; Holzinger, A.; Imanaka, T.; Moshage, Albert Johannes (Han); Faber, Klaas Nico

    2010-01-01

    Peroxisomes are particularly abundant in the liver and are involved in bile salt synthesis and fatty acid metabolism. Peroxisomal membrane proteins (PMPs) are required for peroxisome biogenesis [e.g., the interacting peroxisomal biogenesis factors Pex13p and Pex14p] and its metabolic function [e.g.,

  13. Decreased levels of proapoptotic factors and increased key regulators of mitochondrial biogenesis constitute new potential beneficial features of long-lived growth hormone receptor gene-disrupted mice.

    Science.gov (United States)

    Gesing, Adam; Masternak, Michal M; Lewinski, Andrzej; Karbownik-Lewinska, Malgorzata; Kopchick, John J; Bartke, Andrzej

    2013-06-01

    Decreased somatotrophic signaling is among the most important mechanisms associated with extended longevity. Mice homozygous for the targeted disruption of the growth hormone (GH) receptor gene (GH receptor knockout; GHRKO) are obese and dwarf, are characterized by a reduced weight and body size, undetectable levels of GH receptor, high concentration of serum GH, and greatly reduced plasma levels of insulin and insulin-like growth factor-I, and are remarkably long lived. Recent results suggest new features of GHRKO mice that may positively affect longevity-decreased levels of proapoptotic factors and increased levels of key regulators of mitochondrial biogenesis. The alterations in levels of the proapoptotic factors and key regulators of mitochondrial biogenesis were not further improved by two other potential life-extending interventions-calorie restriction and visceral fat removal. This may attribute the primary role to GH resistance in the regulation of apoptosis and mitochondrial biogenesis in GHRKO mice in terms of increased life span. PMID:23197187

  14. PICK1 deficiency impairs secretory vesicle biogenesis and leads to growth retardation and decreased glucose tolerance

    DEFF Research Database (Denmark)

    Holst, Birgitte; Madsen, Kenneth L; Jansen, Anna M;

    2013-01-01

    Secretory vesicles in endocrine cells store hormones such as growth hormone (GH) and insulin before their release into the bloodstream. The molecular mechanisms governing budding of immature secretory vesicles from the trans-Golgi network (TGN) and their subsequent maturation remain unclear. Here...... was rescued in flies by reintroducing PICK1 in neurosecretory cells producing somatotropic peptides. PICK1-deficient mice were characterized by decreased body weight and length, increased fat accumulation, impaired GH secretion, and decreased storage of GH in the pituitary. Decreased GH storage was supported...... dependent expression. Finally, both in a Drosophila model of type 2 diabetes and in high-fat-diet-induced obese mice, we observed up-regulation of PICK1 mRNA expression. Our findings suggest that PICK1, together with ICA69, is critical during budding of immature secretory vesicles from the TGN and thus...

  15. SORCS1 is necessary for normal insulin secretory granule biogenesis in metabolically stressed β cells.

    Science.gov (United States)

    Kebede, Melkam A; Oler, Angie T; Gregg, Trillian; Balloon, Allison J; Johnson, Adam; Mitok, Kelly; Rabaglia, Mary; Schueler, Kathryn; Stapleton, Donald; Thorstenson, Candice; Wrighton, Lindsay; Floyd, Brendan J; Richards, Oliver; Raines, Summer; Eliceiri, Kevin; Seidah, Nabil G; Rhodes, Christopher; Keller, Mark P; Coon, Joshua L; Audhya, Anjon; Attie, Alan D

    2014-10-01

    We previously positionally cloned Sorcs1 as a diabetes quantitative trait locus. Sorcs1 belongs to the Vacuolar protein sorting-10 (Vps10) gene family. In yeast, Vps10 transports enzymes from the trans-Golgi network (TGN) to the vacuole. Whole-body Sorcs1 KO mice, when made obese with the leptin(ob) mutation (ob/ob), developed diabetes. β Cells from these mice had a severe deficiency of secretory granules (SGs) and insulin. Interestingly, a single secretagogue challenge failed to consistently elicit an insulin secretory dysfunction. However, multiple challenges of the Sorcs1 KO ob/ob islets consistently revealed an insulin secretion defect. The luminal domain of SORCS1 (Lum-Sorcs1), when expressed in a β cell line, acted as a dominant-negative, leading to SG and insulin deficiency. Using syncollin-dsRed5TIMER adenovirus, we found that the loss of Sorcs1 function greatly impairs the rapid replenishment of SGs following secretagogue challenge. Chronic exposure of islets from lean Sorcs1 KO mice to high glucose and palmitate depleted insulin content and evoked an insulin secretion defect. Thus, in metabolically stressed mice, Sorcs1 is important for SG replenishment, and under chronic challenge by insulin secretagogues, loss of Sorcs1 leads to diabetes. Overexpression of full-length SORCS1 led to a 2-fold increase in SG content, suggesting that SORCS1 is sufficient to promote SG biogenesis. PMID:25157818

  16. SORCS1 is necessary for normal insulin secretory granule biogenesis in metabolically stressed β cells

    Science.gov (United States)

    Kebede, Melkam A.; Oler, Angie T.; Gregg, Trillian; Balloon, Allison J.; Johnson, Adam; Mitok, Kelly; Rabaglia, Mary; Schueler, Kathryn; Stapleton, Donald; Thorstenson, Candice; Wrighton, Lindsay; Floyd, Brendan J.; Richards, Oliver; Raines, Summer; Eliceiri, Kevin; Seidah, Nabil G.; Rhodes, Christopher; Keller, Mark P.; Coon, Joshua L.; Audhya, Anjon; Attie, Alan D.

    2014-01-01

    We previously positionally cloned Sorcs1 as a diabetes quantitative trait locus. Sorcs1 belongs to the Vacuolar protein sorting-10 (Vps10) gene family. In yeast, Vps10 transports enzymes from the trans-Golgi network (TGN) to the vacuole. Whole-body Sorcs1 KO mice, when made obese with the leptinob mutation (ob/ob), developed diabetes. β Cells from these mice had a severe deficiency of secretory granules (SGs) and insulin. Interestingly, a single secretagogue challenge failed to consistently elicit an insulin secretory dysfunction. However, multiple challenges of the Sorcs1 KO ob/ob islets consistently revealed an insulin secretion defect. The luminal domain of SORCS1 (Lum-Sorcs1), when expressed in a β cell line, acted as a dominant-negative, leading to SG and insulin deficiency. Using syncollin-dsRed5TIMER adenovirus, we found that the loss of Sorcs1 function greatly impairs the rapid replenishment of SGs following secretagogue challenge. Chronic exposure of islets from lean Sorcs1 KO mice to high glucose and palmitate depleted insulin content and evoked an insulin secretion defect. Thus, in metabolically stressed mice, Sorcs1 is important for SG replenishment, and under chronic challenge by insulin secretagogues, loss of Sorcs1 leads to diabetes. Overexpression of full-length SORCS1 led to a 2-fold increase in SG content, suggesting that SORCS1 is sufficient to promote SG biogenesis. PMID:25157818

  17. Effects of dairy consumption on SIRT1 and mitochondrial biogenesis in adipocytes and muscle cells

    Directory of Open Access Journals (Sweden)

    Bruckbauer Antje

    2011-12-01

    Full Text Available Abstract Background Recent data from this laboratory suggest that components of dairy foods may serve as activators of SIRT1 (Silent Information Regulator Transcript 1, and thereby participate in regulation of glucose and lipid metabolism. In this study, an ex-vivo/in-vitro approach was used to examine the integrated effects of dairy diets on SIRT1 activation in two key target tissues (adipose and muscle tissue. Methods Serum from overweight and obese subjects fed low or high dairy diets for 28 days was added to culture medium (similar to conditioned media to treat cultured adipocytes and muscle cells for 48 hours. Results Treatment with high dairy group conditioned media resulted in 40% increased SIRT1 gene expression in both tissues (p Conclusions These data indicate that dairy consumption leads to systemic effects, which may promote mitochondrial biogenesis in key target tissues such as muscle and adipose tissue both by direct activation of SIRT1 as well as by SIRT1-independent pathways.

  18. Evaluation of the effects of Streptococcus mutans chaperones and protein secretion machinery components on cell surface protein biogenesis, competence, and mutacin production.

    Science.gov (United States)

    Crowley, P J; Brady, L J

    2016-02-01

    The respective contributions of components of the protein translocation/maturation machinery to cell surface biogenesis in Streptococcus mutans are not fully understood. Here we used a genetic approach to characterize the effects of deletion of genes encoding the ribosome-associated chaperone RopA (Trigger Factor), the surface-localized foldase PrsA, and the membrane-localized chaperone insertases YidC1 and YidC2, both singly and in combination, on bacterial growth, chain length, self-aggregation, cell surface hydrophobicity, autolysis, and antigenicity of surface proteins P1 (AgI/II, PAc), WapA, GbpC, and GtfD. The single and double deletion mutants, as well as additional mutant strains lacking components of the signal recognition particle pathway, were also evaluated for their effects on mutacin production and genetic competence. PMID:26386361

  19. Syringaresinol induces mitochondrial biogenesis through activation of PPARβ pathway in skeletal muscle cells.

    Science.gov (United States)

    Thach, Trung Thanh; Lee, Chan-Kyu; Park, Hyun Woo; Lee, Sang-Jun; Lee, Sung-Joon

    2016-08-15

    Activation of peroxisome proliferator-activated receptors (PPARs) plays a crucial role in cellular energy metabolism that directly impacts mitochondrial biogenesis. In this study, we demonstrate that syringaresinol, a pharmacological lignan extracted from Panax ginseng berry, moderately binds to and activates PPARβ with KD and EC50 values of 27.62±15.76μM and 18.11±4.77μM, respectively. Subsequently, the expression of peroxisome proliferator-activated receptor γ coactivator-1α together with PPARβ transcriptional targets, mitochondrial carnitine palmitoyltransferase 1 and uncoupling protein 2, was also enhanced in terms of both mRNA and protein levels. The activation of these proteins induced mitochondrial biogenesis by enrichment of mitochondrial replication and density within C2C12 myotubes. Importantly, knockdown of PPARβ reduced the syringaresinol-induced protein expression followed by the significant reduction of mitochondrial biogenesis. Taken together, our results indicate that syringaresinol induces mitochondrial biogenesis by activating PPARβ pathway. PMID:27450788

  20. YUCCA-mediated auxin biogenesis is required for cell fate transition occurring during de novo root organogenesis in Arabidopsis.

    Science.gov (United States)

    Chen, Lyuqin; Tong, Jianhua; Xiao, Langtao; Ruan, Ying; Liu, Jingchun; Zeng, Minhuan; Huang, Hai; Wang, Jia-Wei; Xu, Lin

    2016-07-01

    Many plant organs have the ability to regenerate a new plant after detachment or wounding via de novo organogenesis. During de novo root organogenesis from Arabidopsis thaliana leaf explants, endogenic auxin is essential for the fate transition of regeneration-competent cells to become root founder cells via activation of WUSCHEL-RELATED HOMEOBOX 11 (WOX11). However, the molecular events from leaf explant detachment to auxin-mediated cell fate transition are poorly understood. In this study, we used an assay to determine the concentration of indole-3-acetic acid (IAA) to provide direct evidence that auxin is produced after leaf explant detachment, a process that involves YUCCA (YUC)-mediated auxin biogenesis. Inhibition of YUC prevents expression of WOX11 and fate transition of competent cells, resulting in the blocking of rooting. Further analysis showed that YUC1 and YUC4 act quickly (within 4 hours) in response to wounding after detachment in both light and dark conditions and promote auxin biogenesis in both mesophyll and competent cells, whereas YUC5, YUC8, and YUC9 primarily respond in dark conditions. In addition, YUC2 and YUC6 contribute to rooting by providing a basal auxin level in the leaf. Overall, our study indicates that YUC genes exhibit a division of labour during de novo root organogenesis from leaf explants in response to multiple signals. PMID:27255928

  1. Expression of key regulators of mitochondrial biogenesis in growth hormone receptor knockout (GHRKO) mice is enhanced but is not further improved by other potential life-extending interventions.

    Science.gov (United States)

    Gesing, Adam; Masternak, Michal M; Wang, Feiya; Joseph, Anna-Maria; Leeuwenburgh, Christiaan; Westbrook, Reyhan; Lewinski, Andrzej; Karbownik-Lewinska, Malgorzata; Bartke, Andrzej

    2011-10-01

    Mitochondrial biogenesis is essential for cell viability. Growth hormone receptor knockout (GHRKO), calorie restriction, and surgical visceral fat removal constitute experimental interventions to delay aging and increase life span. We examined the expression of known regulators of mitochondriogenesis: peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α), adenosine monophosphate (AMP)-activated protein kinase (AMPK), sirtuin-1 (SIRT-1) and sirtuin-3 (SIRT-3), endothelial nitric oxide synthase (eNOS), nuclear respiratory factor-1, mitochondrial transcription factor A (TFAM), and mitofusin-2 (MFN-2) in the skeletal muscles and hearts of control and calorie-restricted female GHRKO mice and in the kidneys of male GHRKOs after visceral fat removal or sham surgery. Expression of PGC-1α in skeletal muscles, AMPK, SIRT-1, SIRT-3, eNOS, and MFN-2 in the heart and PGC-1α, AMPK, SIRT-3, eNOS, and MFN-2 in kidneys was increased in GHRKO mice but was not affected by calorie restriction or visceral fat removal. GHRKO mice have increased expression of key regulators of mitochondriogenesis, which is not improved further by calorie restriction or visceral fat removal. PMID:21788651

  2. The neurogenic basic helix-loop-helix transcription factor NeuroD6 enhances mitochondrial biogenesis and bioenergetics to confer tolerance of neuronal PC12-NeuroD6 cells to the mitochondrial stressor rotenone

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Kristin Kathleen; Uittenbogaard, Martine [Department of Anatomy and Regenerative Biology, George Washington University Medical Center, Washington, DC (United States); Chiaramello, Anne, E-mail: achiaram@gwu.edu [Department of Anatomy and Regenerative Biology, George Washington University Medical Center, Washington, DC (United States)

    2012-10-15

    The fundamental question of how and which neuronal specific transcription factors tailor mitochondrial biogenesis and bioenergetics to the need of developing neuronal cells has remained largely unexplored. In this study, we report that the neurogenic basic helix-loop-helix transcription factor NeuroD6 possesses mitochondrial biogenic properties by amplifying the mitochondrial DNA content and TFAM expression levels, a key regulator for mitochondrial biogenesis. NeuroD6-mediated increase in mitochondrial biogenesis in the neuronal progenitor-like PC12-NEUROD6 cells is concomitant with enhanced mitochondrial bioenergetic functions, including increased expression levels of specific subunits of respiratory complexes of the electron transport chain, elevated mitochondrial membrane potential and ATP levels produced by oxidative phosphorylation. Thus, NeuroD6 augments the bioenergetic capacity of PC12-NEUROD6 cells to generate an energetic reserve, which confers tolerance to the mitochondrial stressor, rotenone. We found that NeuroD6 induces an adaptive bioenergetic response throughout rotenone treatment involving maintenance of the mitochondrial membrane potential and ATP levels in conjunction with preservation of the actin network. In conclusion, our results support the concept that NeuroD6 plays an integrative role in regulating and coordinating the onset of neuronal differentiation with acquisition of adequate mitochondrial mass and energetic capacity to ensure energy demanding events, such as cytoskeletal remodeling, plasmalemmal expansion, and growth cone formation. -- Highlights: Black-Right-Pointing-Pointer NeuroD6 induces mitochondrial biogenesis in neuroprogenitor-like cells. Black-Right-Pointing-Pointer NeuroD6 augments the bioenergetic reserve of the neuronal PC12-NeuroD6 cells. Black-Right-Pointing-Pointer NeuroD6 increases the mitochondrial membrane potential and ATP levels. Black-Right-Pointing-Pointer NeuroD6 confers tolerance to rotenone via an adaptive

  3. SOD2 deficient erythroid cells up-regulate transferrin receptor and down-regulate mitochondrial biogenesis and metabolism.

    Directory of Open Access Journals (Sweden)

    Florent M Martin

    Full Text Available BACKGROUND: Mice irradiated and reconstituted with hematopoietic cells lacking manganese superoxide dismutase (SOD2 show a persistent hemolytic anemia similar to human sideroblastic anemia (SA, including characteristic intra-mitochondrial iron deposition. SA is primarily an acquired, clonal marrow disorder occurring in individuals over 60 years of age with uncertain etiology. METHODOLOGY/PRINCIPAL FINDINGS: To define early events in the pathogenesis of this murine model of SA, we compared erythroid differentiation of Sod2⁻/⁻ and normal bone marrow cells using flow cytometry and gene expression profiling of erythroblasts. The predominant transcriptional differences observed include widespread down-regulation of mitochondrial metabolic pathways and mitochondrial biogenesis. Multiple nuclear encoded subunits of complexes I-IV of the electron transport chain, ATP synthase (complex V, TCA cycle and mitochondrial ribosomal proteins were coordinately down-regulated in Sod2⁻/⁻ erythroblasts. Despite iron accumulation within mitochondria, we found increased expression of transferrin receptor, Tfrc, at both the transcript and protein level in SOD2 deficient cells, suggesting deregulation of iron delivery. Interestingly, there was decreased expression of ABCb7, the gene responsible for X-linked hereditary SA with ataxia, a component required for iron-sulfur cluster biogenesis. CONCLUSIONS/SIGNIFICANCE: These results indicate that in erythroblasts, mitochondrial oxidative stress reduces expression of multiple nuclear genes encoding components of the respiratory chain, TCA cycle and mitochondrial protein synthesis. An additional target of particular relevance for SA is iron:sulfur cluster biosynthesis. By decreasing transcription of components of cluster synthesis machinery, both iron utilization and regulation of iron uptake are impacted, contributing to the sideroblastic phenotype.

  4. Monitoring cell growth.

    Science.gov (United States)

    Strober, W

    2001-05-01

    This appendix provides two protocols for monitoring cell growth. Counting cells using a hemacytometer is tedious but it allows one to effectively distinguish live cells from dead cells (using Trypan Blue exclusion). In addition, this procedure is less subject to errors due to cell clumping or heterogeneity of cell size. The use of an electronic cell counter is quicker and easier than counting cells using a hemacytometer. However, an electronic cell counter as currently constructed does not distinguish live from dead cells in a reliable fashion and is subject to error due to the presence of cell clumps. Overall, the electronic cell counter is best reserved for repetitive and rapid counting of fresh peripheral blood cells and should be used with caution when counting cell populations derived from tissues. PMID:18432653

  5. Amla Enhances Mitochondrial Spare Respiratory Capacity by Increasing Mitochondrial Biogenesis and Antioxidant Systems in a Murine Skeletal Muscle Cell Line

    Directory of Open Access Journals (Sweden)

    Hirotaka Yamamoto

    2016-01-01

    Full Text Available Amla is one of the most important plants in Indian traditional medicine and has been shown to improve various age-related disorders while decreasing oxidative stress. Mitochondrial dysfunction is a proposed cause of aging through elevated oxidative stress. In this study, we investigated the effects of Amla on mitochondrial function in C2C12 myotubes, a murine skeletal muscle cell model with abundant mitochondria. Based on cell flux analysis, treatment with an extract of Amla fruit enhanced mitochondrial spare respiratory capacity, which enables cells to overcome various stresses. To further explore the mechanisms underlying these effects on mitochondrial function, we analyzed mitochondrial biogenesis and antioxidant systems, both proposed regulators of mitochondrial spare respiratory capacity. We found that Amla treatment stimulated both systems accompanied by AMPK and Nrf2 activation. Furthermore, we found that Amla treatment exhibited cytoprotective effects and lowered reactive oxygen species (ROS levels in cells subjected to t-BHP-induced oxidative stress. These effects were accompanied by increased oxygen consumption, suggesting that Amla protected cells against oxidative stress by using enhanced spare respiratory capacity to produce more energy. Thus we identified protective effects of Amla, involving activation of mitochondrial function, which potentially explain its various effects on age-related disorders.

  6. Golgi Biogenesis

    OpenAIRE

    Wang, Yanzhuang; Seemann, Joachim

    2011-01-01

    The kinase MEK1 stimulates disassembly of the Golgi at mitosis to facilitate its partitioning into daughter cells. SNARE proteins then promote fusion of the resulting vesicles to regenerate a functional Golgi apparatus at the end of mitosis.

  7. Cellulose biogenesis in Dictyostelium discoideum

    Energy Technology Data Exchange (ETDEWEB)

    Blanton, R.L.

    1993-12-31

    Organisms that synthesize cellulose can be found amongst the bacteria, protistans, fungi, and animals, but it is in plants that the importance of cellulose in function (as the major structural constituent of plant cell walls) and economic use (as wood and fiber) can be best appreciated. The structure of cellulose and its biosynthesis have been the subjects of intense investigation. One of the most important insights gained from these studies is that the synthesis of cellulose by living organisms involves much more than simply the polymerization of glucose into a (1{r_arrow}4)-{beta}-linked polymer. The number of glucoses in a polymer (the degree of polymerization), the crystalline form assumed by the glucan chains when they crystallize to form a microfibril, and the dimensions and orientation of the microfibrils are all subject to cellular control. Instead of cellulose biosynthesis, a more appropriate term might be cellulose biogenesis, to emphasize the involvement of cellular structures and mechanisms in controlling polymerization and directing crystallization and deposition. Dictyostelium discoideum is uniquely suitable for the study of cellulose biogenesis because of its amenability to experimental study and manipulation and the extent of our knowledge of its basic cellular mechanisms (as will be evident from the rest of this volume). In this chapter, I will summarize what is known about cellulose biogenesis in D. discoideum, emphasizing its potential to illuminate our understanding both of D. discoideum development and plant cellulose biogenesis.

  8. Rab3 proteins involved in vesicle biogenesis and priming in embryonic mouse chromaffin cells

    DEFF Research Database (Denmark)

    Schonn, Jean-Sébastien; van Weering, Jan R T; Mohrmann, Ralf;

    2010-01-01

    chromaffin cells by electron microscopy and electrophysiological measurements. We show that in cells from ABCD(-/-) animals large dense core vesicles (LDCVs) are less abundant while the number of morphologically docked granules is normal. By capacitance measurements, we show that deletion of Rab3s reduces...... the size of the releasable vesicle pools but does not alter their fusion kinetics, consistent with an altered function in vesicle priming. The sustained release component has a sigmoid shape in ABCD(-/-) cells when normalized to the releasable pool size, indicating that vesicle priming follows at a higher...... rate after an initial delay. Rescue experiments showed that short-term (4-6 hours) overexpression of Rab3A or Rab3C suffices to rescue vesicle priming and secretion, but it does not restore the number of secretory vesicles. We conclude that Rab3 proteins play two distinct stimulating roles for LDCV...

  9. Genetic interaction maps in Escherichia coli reveal functional crosstalk among cell envelope biogenesis pathways.

    Directory of Open Access Journals (Sweden)

    Mohan Babu

    2011-11-01

    Full Text Available As the interface between a microbe and its environment, the bacterial cell envelope has broad biological and clinical significance. While numerous biosynthesis genes and pathways have been identified and studied in isolation, how these intersect functionally to ensure envelope integrity during adaptive responses to environmental challenge remains unclear. To this end, we performed high-density synthetic genetic screens to generate quantitative functional association maps encompassing virtually the entire cell envelope biosynthetic machinery of Escherichia coli under both auxotrophic (rich medium and prototrophic (minimal medium culture conditions. The differential patterns of genetic interactions detected among > 235,000 digenic mutant combinations tested reveal unexpected condition-specific functional crosstalk and genetic backup mechanisms that ensure stress-resistant envelope assembly and maintenance. These networks also provide insights into the global systems connectivity and dynamic functional reorganization of a universal bacterial structure that is both broadly conserved among eubacteria (including pathogens and an important target.

  10. C. elegans nucleostemin is required for larval growth and germline stem cell division.

    Directory of Open Access Journals (Sweden)

    Michelle M Kudron

    Full Text Available The nucleolus has shown to be integral for many processes related to cell growth and proliferation. Stem cells in particular are likely to depend upon nucleolus-based processes to remain in a proliferative state. A highly conserved nucleolar factor named nucleostemin is proposed to be a critical link between nucleolar function and stem-cell-specific processes. Currently, it is unclear whether nucleostemin modulates proliferation by affecting ribosome biogenesis or by another nucleolus-based activity that is specific to stem cells and/or highly proliferating cells. Here, we investigate nucleostemin (nst-1 in the nematode C. elegans, which enables us to examine nst-1 function during both proliferation and differentiation in vivo. Like mammalian nucleostemin, the NST-1 protein is localized to the nucleolus and the nucleoplasm; however, its expression is found in both differentiated and proliferating cells. Global loss of C. elegans nucleostemin (nst-1 leads to a larval arrest phenotype due to a growth defect in the soma, while loss of nst-1 specifically in the germ line causes germline stem cells to undergo a cell cycle arrest. nst-1 mutants exhibit reduced levels of rRNAs, suggesting defects in ribosome biogenesis. However, NST-1 is generally not present in regions of the nucleolus where rRNA transcription and processing occurs, so this reduction is likely secondary to a different defect in ribosome biogenesis. Transgenic studies indicate that NST-1 requires its N-terminal domain for stable expression and both its G1 GTPase and intermediate domains for proper germ line function. Our data support a role for C. elegans nucleostemin in cell growth and proliferation by promoting ribosome biogenesis.

  11. SORCS1 is necessary for normal insulin secretory granule biogenesis in metabolically stressed β cells

    OpenAIRE

    Kebede, Melkam A.; Angie T Oler; Gregg, Trillian; Balloon, Allison J.; Johnson, Adam; Mitok, Kelly; Rabaglia, Mary; Schueler, Kathryn; Stapleton, Donald; Thorstenson, Candice; Wrighton, Lindsay; Floyd, Brendan J.; Richards, Oliver; Raines, Summer; Eliceiri, Kevin

    2014-01-01

    We previously positionally cloned Sorcs1 as a diabetes quantitative trait locus. Sorcs1 belongs to the Vacuolar protein sorting-10 (Vps10) gene family. In yeast, Vps10 transports enzymes from the trans-Golgi network (TGN) to the vacuole. Whole-body Sorcs1 KO mice, when made obese with the leptinob mutation (ob/ob), developed diabetes. β Cells from these mice had a severe deficiency of secretory granules (SGs) and insulin. Interestingly, a single secretagogue challenge failed to consistently e...

  12. Genome-wide analysis of effectors of peroxisome biogenesis.

    Directory of Open Access Journals (Sweden)

    Ramsey A Saleem

    Full Text Available Peroxisomes are intracellular organelles that house a number of diverse metabolic processes, notably those required for beta-oxidation of fatty acids. Peroxisomes biogenesis can be induced by the presence of peroxisome proliferators, including fatty acids, which activate complex cellular programs that underlie the induction process. Here, we used multi-parameter quantitative phenotype analyses of an arrayed mutant collection of yeast cells induced to proliferate peroxisomes, to establish a comprehensive inventory of genes required for peroxisome induction and function. The assays employed include growth in the presence of fatty acids, and confocal imaging and flow cytometry through the induction process. In addition to the classical phenotypes associated with loss of peroxisomal functions, these studies identified 169 genes required for robust signaling, transcription, normal peroxisomal development and morphologies, and transmission of peroxisomes to daughter cells. These gene products are localized throughout the cell, and many have indirect connections to peroxisome function. By integration with extant data sets, we present a total of 211 genes linked to peroxisome biogenesis and highlight the complex networks through which information flows during peroxisome biogenesis and function.

  13. Regulation of ribosome biogenesis in maize embryonic axes during germination.

    Science.gov (United States)

    Villa-Hernández, J M; Dinkova, T D; Aguilar-Caballero, R; Rivera-Cabrera, F; Sánchez de Jiménez, E; Pérez-Flores, L J

    2013-10-01

    Ribosome biogenesis is a pre-requisite for cell growth and proliferation; it is however, a highly regulated process that consumes a great quantity of energy. It requires the coordinated production of rRNA, ribosomal proteins and non-ribosomal factors which participate in the processing and mobilization of the new ribosomes. Ribosome biogenesis has been studied in yeast and animals; however, there is little information about this process in plants. The objective of the present work was to study ribosome biogenesis in maize seeds during germination, a stage characterized for its fast growth, and the effect of insulin in this process. Insulin has been reported to accelerate germination and to induce seedling growth. It was observed that among the first events reactivated just after 3 h of imbibition are the rDNA transcription and the pre-rRNA processing and that insulin stimulates both of them (40-230%). The transcript of nucleolin, a protein which regulates rDNA transcription and pre-rRNA processing, is among the messages stored in quiescent dry seeds and it is mobilized into the polysomal fraction during the first hours of imbibition (6 h). In contrast, de novo ribosomal protein synthesis was low during the first hours of imbibition (3 and 6 h) increasing by 60 times in later stages (24 h). Insulin increased this synthesis (75%) at 24 h of imbibition; however, not all ribosomal proteins were similarly regulated. In this regard, an increase in RPS6 and RPL7 protein levels was observed, whereas RPL3 protein levels did not change even though its transcription was induced. Results show that ribosome biogenesis in the first stages of imbibition is carried out with newly synthesized rRNA and ribosomal proteins translated from stored mRNA. PMID:23806421

  14. Evolution of the holozoan ribosome biogenesis regulon

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    Cole Michael D

    2008-09-01

    Full Text Available Abstract Background The ribosome biogenesis (RiBi genes encode a highly-conserved eukaryotic set of nucleolar proteins involved in rRNA transcription, assembly, processing, and export from the nucleus. While the mode of regulation of this suite of genes has been studied in the yeast, Saccharomyces cerevisiae, how this gene set is coordinately regulated in the larger and more complex metazoan genomes is not understood. Results Here we present genome-wide analyses indicating that a distinct mode of RiBi regulation co-evolved with the E(CG-binding, Myc:Max bHLH heterodimer complex in a stem-holozoan, the ancestor of both Metazoa and Choanoflagellata, the protozoan group most closely related to animals. These results show that this mode of regulation, characterized by an E(CG-bearing core-promoter, is specific to almost all of the known genes involved in ribosome biogenesis in these genomes. Interestingly, this holozoan RiBi promoter signature is absent in nematode genomes, which have not only secondarily lost Myc but are marked by invariant cell lineages typically producing small body plans of 1000 somatic cells. Furthermore, a detailed analysis of 10 fungal genomes shows that this holozoan signature in RiBi genes is not found in hemiascomycete fungi, which evolved their own unique regulatory signature for the RiBi regulon. Conclusion These results indicate that a Myc regulon, which is activated in proliferating cells during normal development as well as during tumor progression, has primordial roots in the evolution of an inducible growth regime in a protozoan ancestor of animals. Furthermore, by comparing divergent bHLH repertoires, we conclude that regulation by Myc but not by other bHLH genes is responsible for the evolutionary maintenance of E(CG sites across the RiBi suite of genes.

  15. Evolution of the holozoan ribosome biogenesis regulon

    Science.gov (United States)

    Brown, Seth J; Cole, Michael D; Erives, Albert J

    2008-01-01

    Background The ribosome biogenesis (RiBi) genes encode a highly-conserved eukaryotic set of nucleolar proteins involved in rRNA transcription, assembly, processing, and export from the nucleus. While the mode of regulation of this suite of genes has been studied in the yeast, Saccharomyces cerevisiae, how this gene set is coordinately regulated in the larger and more complex metazoan genomes is not understood. Results Here we present genome-wide analyses indicating that a distinct mode of RiBi regulation co-evolved with the E(CG)-binding, Myc:Max bHLH heterodimer complex in a stem-holozoan, the ancestor of both Metazoa and Choanoflagellata, the protozoan group most closely related to animals. These results show that this mode of regulation, characterized by an E(CG)-bearing core-promoter, is specific to almost all of the known genes involved in ribosome biogenesis in these genomes. Interestingly, this holozoan RiBi promoter signature is absent in nematode genomes, which have not only secondarily lost Myc but are marked by invariant cell lineages typically producing small body plans of 1000 somatic cells. Furthermore, a detailed analysis of 10 fungal genomes shows that this holozoan signature in RiBi genes is not found in hemiascomycete fungi, which evolved their own unique regulatory signature for the RiBi regulon. Conclusion These results indicate that a Myc regulon, which is activated in proliferating cells during normal development as well as during tumor progression, has primordial roots in the evolution of an inducible growth regime in a protozoan ancestor of animals. Furthermore, by comparing divergent bHLH repertoires, we conclude that regulation by Myc but not by other bHLH genes is responsible for the evolutionary maintenance of E(CG) sites across the RiBi suite of genes. PMID:18816399

  16. Mitochondrial gene therapy improves respiration, biogenesis, and transcription in G11778A Leber's hereditary optic neuropathy and T8993G Leigh's syndrome cells.

    Science.gov (United States)

    Iyer, Shilpa; Bergquist, Kristen; Young, Kisha; Gnaiger, Erich; Rao, Raj R; Bennett, James P

    2012-06-01

    Many incurable mitochondrial disorders result from mutant mitochondrial DNA (mtDNA) and impaired respiration. Leigh's syndrome (LS) is a fatal neurodegenerative disorder of infants, and Leber's hereditary optic neuropathy (LHON) causes blindness in young adults. Treatment of LHON and LS cells harboring G11778A and T8993G mutant mtDNA, respectively, by >90%, with healthy donor mtDNA complexed with recombinant human mitochondrial transcription factor A (rhTFAM), improved mitochondrial respiration by ∼1.2-fold in LHON cells and restored >50% ATP synthase function in LS cells. Mitochondrial replication, transcription, and translation of key respiratory genes and proteins were increased in the short term. Increased NRF1, TFAMB1, and TFAMA expression alluded to the activation of mitochondrial biogenesis as a mechanism for improving mitochondrial respiration. These results represent the development of a therapeutic approach for LHON and LS patients in the near future.

  17. Tgf-β1 inhibits Cftr biogenesis and prevents functional rescue of ΔF508-Cftr in primary differentiated human bronchial epithelial cells.

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    Steven M Snodgrass

    Full Text Available CFTR is an integral transmembrane glycoprotein and a cAMP-activated Cl(- channel. Mutations in the CFTR gene lead to Cystic Fibrosis (CF-an autosomal recessive disease with majority of the morbidity and mortality resulting from airway infection, inflammation, and fibrosis. The most common disease-associated mutation in the CFTR gene-deletion of Phe508 (ΔF508 leads to a biosynthetic processing defect of CFTR. Correction of the defect and delivery of ΔF508-CFTR to the cell surface has been highly anticipated as a disease modifying therapy. Compared to promising results in cultured cell this approach was much less effective in CF patients in an early clinical trial. Although the cause of failure to rescue ΔF508-CFTR in the clinical trial has not been determined, presence of factor(s that interfere with the rescue in vivo could be considered. The cytokine TGF-β1 is frequently elevated in CF patients. TGF-β1 has pleiotropic effects in different disease models and genetic backgrounds and little is known about TGF-β1 effects on CFTR in human airway epithelial cells. Moreover, there are no published studies examining TGF-β1 effects on the functional rescue of ΔF508-CFTR. Here we found that TGF-β1 inhibits CFTR biogenesis by reducing mRNA levels and protein abundance in primary differentiated human bronchial epithelial (HBE cells from non-CF individuals. TGF-β1 inhibits CFTR biogenesis without compromising the epithelial phenotype or integrity of HBE cells. TGF-β1 also inhibits biogenesis and impairs the functional rescue of ΔF508-CFTR in HBE cells from patients homozygous for the ΔF508 mutation. Our data indicate that activation of TGF-β1 signaling may inhibit CFTR function in non-CF individuals and may interfere with therapies directed at correcting the processing defect of ΔF508-CFTR in CF patients.

  18. Bacterial cell wall. MurJ is the flippase of lipid-linked precursors for peptidoglycan biogenesis.

    Science.gov (United States)

    Sham, Lok-To; Butler, Emily K; Lebar, Matthew D; Kahne, Daniel; Bernhardt, Thomas G; Ruiz, Natividad

    2014-07-11

    Peptidoglycan (PG) is a polysaccharide matrix that protects bacteria from osmotic lysis. Inhibition of its biogenesis is a proven strategy for killing bacteria with antibiotics. The assembly of PG requires disaccharide-pentapeptide building blocks attached to a polyisoprene lipid carrier called lipid II. Although the stages of lipid II synthesis are known, the identity of the essential flippase that translocates it across the cytoplasmic membrane for PG polymerization is unclear. We developed an assay for lipid II flippase activity and used a chemical genetic strategy to rapidly and specifically block flippase function. We combined these approaches to demonstrate that MurJ is the lipid II flippase in Escherichia coli. PMID:25013077

  19. Role of the Group B antigen of Streptococcus agalactiae: a peptidoglycan-anchored polysaccharide involved in cell wall biogenesis.

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    Élise Caliot

    Full Text Available Streptococcus agalactiae (Group B streptococcus, GBS is a leading cause of infections in neonates and an emerging pathogen in adults. The Lancefield Group B carbohydrate (GBC is a peptidoglycan-anchored antigen that defines this species as a Group B Streptococcus. Despite earlier immunological and biochemical characterizations, the function of this abundant glycopolymer has never been addressed experimentally. Here, we inactivated the gene gbcO encoding a putative UDP-N-acetylglucosamine-1-phosphate:lipid phosphate transferase thought to catalyze the first step of GBC synthesis. Indeed, the gbcO mutant was unable to synthesize the GBC polymer, and displayed an important growth defect in vitro. Electron microscopy study of the GBC-depleted strain of S. agalactiae revealed a series of growth-related abnormalities: random placement of septa, defective cell division and separation processes, and aberrant cell morphology. Furthermore, vancomycin labeling and peptidoglycan structure analysis demonstrated that, in the absence of GBC, cells failed to initiate normal PG synthesis and cannot complete polymerization of the murein sacculus. Finally, the subcellular localization of the PG hydrolase PcsB, which has a critical role in cell division of streptococci, was altered in the gbcO mutant. Collectively, these findings show that GBC is an essential component of the cell wall of S. agalactiae whose function is reminiscent of that of conventional wall teichoic acids found in Staphylococcus aureus or Bacillus subtilis. Furthermore, our findings raise the possibility that GBC-like molecules play a major role in the growth of most if not all beta-hemolytic streptococci.

  20. Role of cAMP-responsive element-binding protein (CREB)-regulated transcription coactivator 3 (CRTC3) in the initiation of mitochondrial biogenesis and stress response in liver cells.

    Science.gov (United States)

    Than, Tin Aung; Lou, Huan; Ji, Cheng; Win, Sanda; Kaplowitz, Neil

    2011-06-24

    Peroxisome proliferator-activated receptor α, coactivator 1α (PGC-1α) is the master regulator of mitochondrial biogenesis. PGC-1α expression is under the control of the transcription factor, cAMP-responsive element-binding protein (CREB). In searching for candidate transcription factors that mediate mitochondrial stress-initiated mitochondria-to-nucleus signaling in the regulation of mitochondrial biogenesis, we assessed the effect of silencing CREB-regulated transcription co-activators (CRTC). CRTC isoforms are co-activators of CREB-regulated transcription by a CREB phosphorylation-independent pathway. Using cultured HepG2 cells and primary mouse hepatocytes, we determined that mitochondrial stress imposed by the complex I inhibitor rotenone elicited mitochondrial biogenesis, which was dependent on an induction of PGC-1α, which was inhibited by silencing PGC-1α. PGC-1α induction in response to rotenone was inhibited by silencing the expression of CRTC3, which blocked downstream mitochondria biogenesis. In contrast, silencing CRTC2 did not affect the induction of this pathway in response to rotenone. Thus, CRTC3 plays a selective role in mitochondrial biogenesis in response to rotenone.

  1. Biogenesis and fate of the cell-cell adhesion molecule, agglutinin, during gametogenesis and fertilization of Chlamydomonas reinhardtii

    International Nuclear Information System (INIS)

    Fertilization in Chlamydomonas begins with the species-specific recognition and adhesion between gametes of opposite mating types via agglutinin molecules on the flagellar surface. This adhesion generates a cAMP-mediated sexual signal that initiates the subsequent events of call wall release, mating structure activation, and cell fusion. Although flagella of paired gametes remain attached to each other until the zygote forms, the process is dynamic. Engaged agglutinins rapidly become inactivated and turnover, requiring the constant supply of new agglutinins to replace the lost molecules. A population of cell body associated agglutinins has been postulated to the pool of agglutinins recruited during this turnover. Cell body agglutinins, therefore were identified, purified, localized within the cells and compared to flagellar agglutinins. The relationship between these two agglutinin populations was also examined. Cell body agglutinins were biochemically indistinguishable from the flagellar form with respect to their Mr, sedimentation coefficient, and hydrophobicity elution properties. Functionally, however, these molecules were inactive in situ. The calculated surface density of agglutinins in the cell body and flagellar domains was similar and thus could not explain their functional difference, but two domains contiguous and yet distinctive suggested they may be separated by a functional barrier. To test this, a method was developed, using a monoclonal antibody and cycloheximide, that removed the flagellar agglutinins so movement between the domains could be monitored. Mobilization of agglutinins onto the flagella did not occur unless sexual signaling was induced with cAMP and papaverine

  2. crRNA biogenesis

    NARCIS (Netherlands)

    Charpentier, E.; Oost, van der J.; White, M.

    2013-01-01

    Mature crRNAs are key elements in CRISPR-Cas defense against genome invaders. These short RNAs are composed of unique repeat/spacer sequences that guide the Cas protein(s) to the cognate invading nucleic acids for their destruction. The biogenesis of mature crRNAs involves highly precise processing

  3. Linking pseudouridine synthases to growth, development and cell competition.

    Science.gov (United States)

    Tortoriello, Giuseppe; de Celis, José F; Furia, Maria

    2010-08-01

    Eukaryotic pseudouridine synthases direct RNA pseudouridylation and bind H/ACA small nucleolar RNA (snoRNAs), which, in turn, may act as precursors of microRNA-like molecules. In humans, loss of pseudouridine synthase activity causes dyskeratosis congenita (DC), a complex systemic disorder characterized by cancer susceptibility, failures in ribosome biogenesis and telomere stability, and defects in stem cell formation. Considering the significant interest in deciphering the various molecular consequences of pseudouridine synthase failure, we performed a loss of function analysis of minifly (mfl), the pseudouridine synthase gene of Drosophila, in the wing disc, an advantageous model system for studies of cell growth and differentiation. In this organ, depletion of the mfl-encoded pseudouridine synthase causes a severe reduction in size by decreasing both the number and the size of wing cells. Reduction of cell number was mainly attributable to cell death rather than reduced proliferation, establishing that apoptosis plays a key role in the development of the loss of function mutant phenotype. Depletion of Mfl also causes a proliferative disadvantage in mosaic tissues that leads to the elimination of mutant cells by cell competition. Intriguingly, mfl silencing also triggered unexpected effects on wing patterning and cell differentiation, including deviations from normal lineage boundaries, mingling of cells of different compartments, and defects in the formation of the wing margin that closely mimic the phenotype of reduced Notch activity. These results suggest that a component of the pseudouridine synthase loss of function phenotype is caused by defects in Notch signalling.

  4. Genetic and phenotypic heterogeneity in disorders of peroxisome biogenesis--a complementation study involving cell lines from 19 patients.

    Science.gov (United States)

    Roscher, A A; Hoefler, S; Hoefler, G; Paschke, E; Paltauf, F; Moser, A; Moser, H

    1989-07-01

    Disorders of peroxisomal biogenesis include the Zellweger syndrome, neonatal adrenoleukodystrophy, infantile Refsum syndrome, and hyperpipecolic acidemia. These names were assigned before the recognition of the peroxisomal defect and the distinction between phenotypes is uncertain. Recent studies have identified at least four complementation groups, and indicate the presence of at least that number of distinct genotypes. The purpose of the present study was to examine the relationship between genotype and phenotype. We studied cultured skin fibroblasts from 19 patients in whom deficiency of peroxisomes had been established. Complementation analysis was performed with the criterion of complementation being the restoration of the capacity to synthesize plasmalogens when fibroblasts from two patients were fused. Six complementation groups were identified, and consisted of one 13 member group, one two member group, and four groups comprising single cases. The phenotype of each group was examined with respect to age of survival, clinical manifestations, and biochemical alterations. The 13 member group included patients with all of the four currently designated phenotypic entities, while the most common phenotype (Zellweger syndrome) was distributed among five of the six groups. We conclude that the currently used clinical categories do not represent distinct genotypes. Apparently different genes code for a similar phenotype and one defective gene may lead to variant phenotypes. Definitive classification and understanding of these disorders await definition of the specific biochemical defect in each of the genotypes.

  5. Overexpression of human selenoprotein H in neuronal cells enhances mitochondrial biogenesis and function through activation of protein kinase A, protein kinase B, and cyclic adenosine monophosphate response element-binding protein pathway.

    Science.gov (United States)

    Mehta, Suresh L; Mendelev, Natalia; Kumari, Santosh; Andy Li, P

    2013-03-01

    Mitochondrial biogenesis is activated by nuclear encoded transcription co-activator peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), which is regulated by several upstream factors including protein kinase A and Akt/protein kinase B. We have previously shown that selenoprotein H enhances the levels of nuclear regulators for mitochondrial biogenesis, increases mitochondrial mass and improves mitochondrial respiratory rate, under physiological condition. Furthermore, overexpression of selenoprotein H protects neuronal HT22 cells from ultraviolet B irradiation-induced cell damage by lowering reactive oxygen species production, and inhibiting activation of caspase-3 and -9, as well as p53. The objective of this study is to identify the cell signaling pathways by which selenoprotein H initiates mitochondrial biogenesis. We first confirmed our previous observation that selenoprotein H transfected HT22 cells increased the protein levels of nuclear-encoded mitochondrial biogenesis factors, peroxisome proliferator-activated receptor γ coactivator-1α, nuclear respiratory factor 1 and mitochondrial transcription factor A. We then observed that total and phosphorylation of protein kinase A, Akt/protein kinase B and cyclic adenosine monophosphate response element-binding protein (CREB) were significantly increased in selenoprotein H transfected cells compared to vector transfected HT22 cells. To verify whether the observed stimulating effects on mitochondrial biogenesis pathways are caused by selenoprotein H and mediated through CREB, we knocked down selenoprotein H mRNA level using siRNA and inhibited CREB with napthol AS-E phosphate in selenoprotein H transfected cells and repeated the measurements of the aforementioned biomarkers. Our results revealed that silencing of selenoprotein H not only decreased the protein levels of PGC-1α, nuclear respiratory factor 1 and mitochondrial transcription factor A, but also decreased the total and

  6. The Yb body, a major site for Piwi-associated RNA biogenesis and a gateway for Piwi expression and transport to the nucleus in somatic cells.

    Science.gov (United States)

    Qi, Hongying; Watanabe, Toshiaki; Ku, Hsueh-Yen; Liu, Na; Zhong, Mei; Lin, Haifan

    2011-02-01

    Despite exciting progress in understanding the Piwi-interacting RNA (piRNA) pathway in the germ line, less is known about this pathway in somatic cells. We showed previously that Piwi, a key component of the piRNA pathway in Drosophila, is regulated in somatic cells by Yb, a novel protein containing an RNA helicase-like motif and a Tudor-like domain. Yb is specifically expressed in gonadal somatic cells and regulates piwi in somatic niche cells to control germ line and somatic stem cell self-renewal. However, the molecular basis of the regulation remains elusive. Here, we report that Yb recruits Armitage (Armi), a putative RNA helicase involved in the piRNA pathway, to the Yb body, a cytoplasmic sphere to which Yb is exclusively localized. Moreover, co-immunoprecipitation experiments show that Yb forms a complex with Armi. In Yb mutants, Armi is dispersed throughout the cytoplasm, and Piwi fails to enter the nucleus and is rarely detectable in the cytoplasm. Furthermore, somatic piRNAs are drastically diminished, and soma-expressing transposons are desilenced. These observations indicate a crucial role of Yb and the Yb body in piRNA biogenesis, possibly by regulating the activity of Armi that controls the entry of Piwi into the nucleus for its function. Finally, we discovered putative endo-siRNAs in the flamenco locus and the Yb dependence of their expression. These observations further implicate a role for Yb in transposon silencing via both the piRNA and endo-siRNA pathways. PMID:21106531

  7. Direct imaging of RAB27B-enriched secretory vesicle biogenesis in lacrimal acinar cells reveals origins on a nascent vesicle budding site.

    Directory of Open Access Journals (Sweden)

    Lilian Chiang

    Full Text Available This study uses YFP-tagged Rab27b expression in rabbit lacrimal gland acinar cells, which are polarized secretory epithelial cells, to characterize early stages of secretory vesicle trafficking. Here we demonstrate the utility of YFP-Rab27b to delineate new perspectives on the mechanisms of early vesicle biogenesis in lacrimal gland acinar cells, where information is significantly limited. Protocols were developed to deplete the mature YFP-Rab27b-enriched secretory vesicle pool in the subapical region of the cell, and confocal fluorescence microscopy was used to track vesicle replenishment. This analysis revealed a basally-localized organelle, which we termed the "nascent vesicle site," from which nascent vesicles appeared to emerge. Subapical vesicular YFP-Rab27b was co-localized with p150(Glued, a component of the dynactin cofactor of cytoplasmic dynein. Treatment with the microtubule-targeted agent, nocodazole, did not affect release of mature secretory vesicles, although during vesicle repletion it significantly altered nascent YFP-Rab27b-enriched secretory vesicle localization. Instead of moving to the subapical region, these vesicles were trapped at the nascent vesicle site which was adjacent to, if not a sub-compartment of, the trans-Golgi network. Finally, YFP-Rab27b-enriched secretory vesicles which reached the subapical cytoplasm appeared to acquire the actin-based motor protein, Myosin 5C. Our findings show that Rab27b enrichment occurs early in secretory vesicle formation, that secretory vesicles bud from a visually discernable nascent vesicle site, and that transport from the nascent vesicle site to the subapical region requires intact microtubules.

  8. MicroRNA regulation of stem cell differentiation and diseases of the bone and adipose tissue: Perspectives on miRNA biogenesis and cellular transcriptome.

    Science.gov (United States)

    Martin, E C; Qureshi, A T; Dasa, V; Freitas, M A; Gimble, J M; Davis, T A

    2016-05-01

    MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression through targeting and suppression of mRNAs. miRNAs have been under investigation for the past twenty years and there is a large breadth of information on miRNAs in diseases such as cancer and immunology. Only more recently have miRNAs shown promise as a mechanism for intervention with respect to diseases of the bone and adipose tissue. In mesenchymal stem cell (MSC) differentiation, alterations in miRNA expression patterns can differentially promote an osteogenic, adipogenic, or myogenic phenotype. This manuscript reviews the current literature with respect to miRNAs in the context of MSC function with a particular focus on novel avenues for the examination of miRNA associated with bone and adipose tissue biology and disease. Specifically we highlight the need for a greater depth of investigation on MSCs with respect to miRNA biogenesis, processing, strand selection, and heterogeneity. We discuss how these mechanisms facilitate both altered miRNA expression and function.

  9. PEX16: a multifaceted regulator of peroxisome biogenesis

    Directory of Open Access Journals (Sweden)

    Peter eKim

    2013-09-01

    Full Text Available Peroxisomes are formed by two distinct pathways: the growth and fission of mature peroxisomes and de novo synthesis at the endoplasmic reticulum (ER. While many of the molecular mechanisms underlying these two pathways remain to be elucidated, it is generally accepted that their relative contribution to peroxisome formation may vary depending on the species, cell type and/or physiological status of the organism. One pertinent example of the apparent differences in the regulation of peroxisome biogenesis among evolutionarily diverse species is the involvement of the peroxin PEX16. In Yarrowia lipolytica, for instance, PEX16 is an intraperoxisomal peripheral membrane protein that participates in peroxisomal fission. By contrast, Human PEX16 is an integral membrane protein that is thought to function at the ER during the early stages of de novo peroxisome formation and also recruits peroxisomal membrane proteins directly to mature peroxisomes. Similarly, PEX16 in the plant Arabidopsis thaliana is speculated to be a PMP receptor at the ER and peroxisomes, and is also required for the formation of other ER-derived organelles, such as oil and protein bodies. Here we briefly review the current knowledge of Y. lipolytica, human and A. thaliana PEX16 in the context of our overall understanding of peroxisome biogenesis and the role of the ER in this process in these three divergent species.

  10. Oncostatin M regulates membrane traffic and stimulates bile canalicular membrane biogenesis in HepG2 cells

    NARCIS (Netherlands)

    Van der Wouden, Johanna M.; Van IJzendoorn, Sven C.D.; Hoekstra, Dick

    2002-01-01

    Hepatocytes are the major epithelial cells of the liver and they display membrane polarity: the sinusoidal membrane representing the basolateral surface, while the bile canalicular membrane is typical of the apical membrane. In polarized HepG2 cells an endosomal organelle, SAC, fulfills a prominent

  11. The effect of ethidium bromide and chloramphenicol on mitochondrial biogenesis in primary human fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Li-Pin; Ovchinnikov, Dmitry; Wolvetang, Ernst, E-mail: e.wolvetang@uq.edu.au

    2012-05-15

    The expression of mitochondrial components is controlled by an intricate interplay between nuclear transcription factors and retrograde signaling from mitochondria. The role of mitochondrial DNA (mtDNA) and mtDNA-encoded proteins in mitochondrial biogenesis is, however, poorly understood and thus far has mainly been studied in transformed cell lines. We treated primary human fibroblasts with ethidium bromide (EtBr) or chloramphenicol for six weeks to inhibit mtDNA replication or mitochondrial protein synthesis, respectively, and investigated how the cells recovered from these insults two weeks after removal of the drugs. Although cellular growth and mitochondrial gene expression were severely impaired after both inhibitor treatments we observed marked differences in mitochondrial structure, membrane potential, glycolysis, gene expression, and redox status between fibroblasts treated with EtBr and chloramphenicol. Following removal of the drugs we further detected clear differences in expression of both mtDNA-encoded genes and nuclear transcription factors that control mitochondrial biogenesis, suggesting that the cells possess different compensatory mechanisms to recover from drug-induced mitochondrial dysfunction. Our data reveal new aspects of the interplay between mitochondrial retrograde signaling and the expression of nuclear regulators of mitochondrial biogenesis, a process with direct relevance to mitochondrial diseases and chloramphenicol toxicity in humans. -- Highlights: ► Cells respond to certain environmental toxins by increasing mitochondrial biogenesis. ► We investigated the effect of Chloramphenicol and EtBr in primary human fibroblasts. ► Inhibiting mitochondrial protein synthesis or DNA replication elicit different effects. ► We provide novel insights into the cellular responses toxins and antibiotics.

  12. MHC class II-associated proteins in B-cell exosomes and potential functional implications for exosome biogenesis.

    NARCIS (Netherlands)

    Buschow, S.I.; Balkom, B.W.M. van; Aalberts, M.; Heck, A.J.R. van; Wauben, M.; Stoorvogel, W.

    2010-01-01

    Professional antigen-presenting cells secrete major histocompatibility complex class II (MHC II) carrying exosomes with unclear physiological function(s). Exosomes are first generated as the intraluminal vesicles (ILVs) of a specific type of multivesicular body, and are then secreted by fusion of th

  13. Impaired Chloroplast Biogenesis in Immutans, an Arabidopsis Variegation Mutant, Modifies Developmental Programming, Cell Wall Composition and Resistance to Pseudomonas syringae.

    Science.gov (United States)

    Pogorelko, Gennady V; Kambakam, Sekhar; Nolan, Trevor; Foudree, Andrew; Zabotina, Olga A; Rodermel, Steven R

    2016-01-01

    The immutans (im) variegation mutation of Arabidopsis has green- and white- sectored leaves due to action of a nuclear recessive gene. IM codes for PTOX, a plastoquinol oxidase in plastid membranes. Previous studies have revealed that the green and white sectors develop into sources (green tissues) and sinks (white tissues) early in leaf development. In this report we focus on white sectors, and show that their transformation into effective sinks involves a sharp reduction in plastid number and size. Despite these reductions, cells in the white sectors have near-normal amounts of plastid RNA and protein, and surprisingly, a marked amplification of chloroplast DNA. The maintenance of protein synthesis capacity in the white sectors might poise plastids for their development into other plastid types. The green and white im sectors have different cell wall compositions: whereas cell walls in the green sectors resemble those in wild type, cell walls in the white sectors have reduced lignin and cellulose microfibrils, as well as alterations in galactomannans and the decoration of xyloglucan. These changes promote susceptibility to the pathogen Pseudomonas syringae. Enhanced susceptibility can also be explained by repressed expression of some, but not all, defense genes. We suggest that differences in morphology, physiology and biochemistry between the green and white sectors is caused by a reprogramming of leaf development that is coordinated, in part, by mechanisms of retrograde (plastid-to-nucleus) signaling, perhaps mediated by ROS. We conclude that variegation mutants offer a novel system to study leaf developmental programming, cell wall metabolism and host-pathogen interactions. PMID:27050746

  14. Effect of the three-dimensional organization of liver cells on the biogenesis of the γ-glutamyltransferase fraction pattern.

    Science.gov (United States)

    Corti, Alessandro; Fierabracci, Vanna; Caponi, Laura; Paolicchi, Aldo; Lorenzini, Evelina; Campani, Daniela; Belcastro, Eugenia; Franzini, Maria

    2016-07-01

    Context Four gamma-glutamyltransferase (GGT) fractions with different molecular weights (big-, medium-, small- and free-GGT) are detectable in human plasma. Objective Verify if liver cells can release all four GGT fractions and if the spatial cell organization influences their release. Methods Hepatoma (HepG2) and melanoma (Me665/2/60) cells were cultured as monolayers or spheroids. GGT released in culture media was analysed by gel-filtration chromatography. Results HepG2 and Me665/2/60 monolayers released the b-GGT fraction, while significative levels of s-GGT and f-GGT were detectable only in media of HepG2-spheroids. Bile acids alone or in combination with papain promoted the conversion of b-GGT in s-GGT or f-GGT, respectively. Conclusions GGT is usually released as b-GGT, while s-GGT and f-GGT are likely to be produced in the liver extracellular environment by the combined action of bile acids and proteases. PMID:27027926

  15. Homeostatic restitution of cell membranes. Nuclear membrane lipid biogenesis and transport of protein from cytosol to intranuclear spaces.

    Directory of Open Access Journals (Sweden)

    Amalia Slomiany, Maria Grabska, Bronislaw L. Slomiany

    2006-01-01

    Full Text Available Our studies on homeostatic restitution of cellular and subcellular membranes showed that vesicular intracellular transport is engaged in systematic and coordinated replacement of lipids and proteins in the membranes of the secretory, non-dividing epithelial cells (Slomiany et al., J. Physiol. Pharmacol. 2004; 55: 837-860. In this report, we present evidence on the homeostatic restitution of lipids in the biomembranes that constitute nuclear envelopes. We investigated nuclear membranes lipid synthesis by employing purified intact nuclei (IN, the outer nuclear membrane (ONM, the inner nuclear membrane (INM and the cell cytosol (CC. In contrast to Endoplasmic Reticulum (ER which in the presence of CC generates new biomembrane that forms ER vesicles transporting ER products to Golgi, the IN, ONM and INM are not producing transport vesicles. Instead, the newly synthesized lipids remain in the nuclear membranes. The membranes (INM, ONM of IN incubated with CC become enriched with newly synthesized phosphatidylcholine (PC, phosphatidylinositol (PI, phosphatidylinositol phosphates (PIPs and phosphatidic acid (PA. The incubation of separated ONM and INM with CC also enriched the membranes with IN specific lipids identified above. Moreover, the incubation of IN or its membranes with CC afforded retention of numerous CC proteins on the nuclear membrane. Here, we concentrated on 30kDa CC protein that displayed affinity to nuclear membrane PIP2. The 30kDa CC protein bound to PIP2 of IN, INM, and ONM. With IN, initially the PIP2-30kDa CC protein complex was detected on ONM, after 30-120 min of incubation, was found on INM and in nuclear contents. At the same time when the 30 kDa protein was released from INM and found in nuclear contents, the PIP2 of INM and ONM became undetectable, while the lipid extract from the membrane displaced from IN contained labeled PI only. Since ONM is an uninterrupted continuum of ER and INM, we speculate that the synthesis of

  16. The evolution of ERMIONE in mitochondrial biogenesis and lipid homeostasis: An evolutionary view from comparative cell biology.

    Science.gov (United States)

    Wideman, Jeremy G; Muñoz-Gómez, Sergio A

    2016-08-01

    The ER-mitochondria organizing network (ERMIONE) in Saccharomyces cerevisiae is involved in maintaining mitochondrial morphology and lipid homeostasis. ERMES and MICOS are two scaffolding complexes of ERMIONE that contribute to these processes. ERMES is ancient but has been lost in several lineages including animals, plants, and SAR (stramenopiles, alveolates and rhizaria). On the other hand, MICOS is ancient and has remained present in all organisms bearing mitochondrial cristae. The ERMIONE precursor evolved in the α-proteobacterial ancestor of mitochondria which had the central subunit of MICOS, Mic60. The subsequent evolution of ERMIONE and its interactors in eukaryotes reflects the integrative co-evolution of mitochondria and their hosts and the adaptive paths that some lineages have followed in their specialization to certain environments. By approaching the ERMIONE from a perspective of comparative evolutionary cell biology, we hope to shed light on not only its evolutionary history, but also how ERMIONE components may function in organisms other than S. cerevisiae. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon.

  17. The evolution of ERMIONE in mitochondrial biogenesis and lipid homeostasis: An evolutionary view from comparative cell biology.

    Science.gov (United States)

    Wideman, Jeremy G; Muñoz-Gómez, Sergio A

    2016-08-01

    The ER-mitochondria organizing network (ERMIONE) in Saccharomyces cerevisiae is involved in maintaining mitochondrial morphology and lipid homeostasis. ERMES and MICOS are two scaffolding complexes of ERMIONE that contribute to these processes. ERMES is ancient but has been lost in several lineages including animals, plants, and SAR (stramenopiles, alveolates and rhizaria). On the other hand, MICOS is ancient and has remained present in all organisms bearing mitochondrial cristae. The ERMIONE precursor evolved in the α-proteobacterial ancestor of mitochondria which had the central subunit of MICOS, Mic60. The subsequent evolution of ERMIONE and its interactors in eukaryotes reflects the integrative co-evolution of mitochondria and their hosts and the adaptive paths that some lineages have followed in their specialization to certain environments. By approaching the ERMIONE from a perspective of comparative evolutionary cell biology, we hope to shed light on not only its evolutionary history, but also how ERMIONE components may function in organisms other than S. cerevisiae. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon. PMID:26825688

  18. Mitochondrial biogenesis in the pulmonary vasculature during inhalation lung injury and fibrosis

    Science.gov (United States)

    Cell survival and injury repair is facilitated by mitochondrial biogenesis; however, the role of this process in lung repair is unknown. We evaluated mitochondrial biogenesis in the mouse lung in two injuries that cause acute inflammation and in two that cause chronic inflammatio...

  19. Nonequilibrium mechanisms underlying de novo biogenesis of Golgi cisternae

    CERN Document Server

    Sachdeva, Himani; Rao, Madan

    2016-01-01

    A central issue in cell biology is the physico-chemical basis of organelle biogenesis in intracellular trafficking pathways, its most impressive manifestation being the biogenesis of Golgi cisternae. At a basic level, such morphologically and chemically distinct compartments should arise from an interplay between the molecular transport and chemical maturation. Here, we formulate analytically tractable, minimalist models, that incorporate this interplay between transport and chemical progression in physical space, and explore the conditions for de novo biogenesis of distinct cisternae. We propose new quantitative measures that can discriminate between the various models of transport in a qualitative manner- this includes measures of the dynamics in steady state and the dynamical response to perturbations of the kind amenable to live-cell imaging.

  20. A dynamic model of tomato fruit growth integrating cell division, cell growth and endoreduplication

    NARCIS (Netherlands)

    Fanwoua, J.; Visser, de P.H.B.; Heuvelink, E.; Yin, X.; Struik, P.C.; Marcelis, L.F.M.

    2013-01-01

    In this study, we developed a model of tomato (Solanum lycopersicum L.) fruit growth integrating cell division, cell growth and endoreduplication. The fruit was considered as a population of cells grouped in cell classes differing in their initial cell age and cell mass. The model describes fruit gr

  1. On size and growth of cells

    CERN Document Server

    Boudaoud, A

    2002-01-01

    Understanding how growth induces form is a longstanding biological question. Many studies concentrated on the shapes of plant cells, fungi or bacteria. Some others have shown the importance of the mechanical properties of bacterial walls and plant tissues in pattern formation. Here I sketch a simple physical picture of cell growth. The study is focussed on isolated cells that have walls. They are modeled as thin elastic shells containing a liquid, which pressure drives the growth as generally admitted for bacteria or plant cells. Requiring mechanical equilibrium leads to estimations of typical cell sizes, in quantitative agreement with compiled data including bacteria, cochlear outer hair, fungi, yeast, root hair and giant alga cells.

  2. Decreased Levels of Proapoptotic Factors and Increased Key Regulators of Mitochondrial Biogenesis Constitute New Potential Beneficial Features of Long-lived Growth Hormone Receptor Gene–Disrupted Mice

    OpenAIRE

    Gesing, Adam; Masternak, Michal M.; Lewinski, Andrzej; Karbownik-Lewinska, Malgorzata; Kopchick, John J.; Bartke, Andrzej

    2012-01-01

    Decreased somatotrophic signaling is among the most important mechanisms associated with extended longevity. Mice homozygous for the targeted disruption of the growth hormone (GH) receptor gene (GH receptor knockout; GHRKO) are obese and dwarf, are characterized by a reduced weight and body size, undetectable levels of GH receptor, high concentration of serum GH, and greatly reduced plasma levels of insulin and insulin-like growth factor-I, and are remarkably long lived. Recent results sugges...

  3. Stochastic Gompertz model of tumour cell growth.

    Science.gov (United States)

    Lo, C F

    2007-09-21

    In this communication, based upon the deterministic Gompertz law of cell growth, a stochastic model in tumour growth is proposed. This model takes account of both cell fission and mortality too. The corresponding density function of the size of the tumour cells obeys a functional Fokker--Planck equation which can be solved analytically. It is found that the density function exhibits an interesting "multi-peak" structure generated by cell fission as time evolves. Within this framework the action of therapy is also examined by simply incorporating a therapy term into the deterministic cell growth term.

  4. Thermodynamics of irreversible plant cell growth

    Directory of Open Access Journals (Sweden)

    Mariusz Pietruszka

    2011-04-01

    Full Text Available The time-irreversible cell enlargement of plant cells at a constant temperature results from two independent physical processes, e.g. water absorption and cell wall yielding. In such a model cell growth starts with reduction in wall stress because of irreversible extension of the wall. The water absorption and physical expansion are spontaneous consequences of this initial modification of the cell wall (the juvenile cell vacuolate, takes up water and expands. In this model the irreversible aspect of growth arises from the extension of the cell wall. Such theory expressed quantitatively by time-dependent growth equation was elaborated by Lockhart in the 60's.The growth equation omit however a very important factor, namely the environmental temperature at which the plant cells grow. In this paper we put forward a simple phenomenological model which introduces into the growth equation the notion of temperature. Moreover, we introduce into the modified growth equation the possible influence of external growth stimulator or inhibitor (phytohormones or abiotic factors. In the presence of such external perturbations two possible theoretical solutions have been found: the linear reaction to the application of growth hormones/abiotic factors and the non-linear one. Both solutions reflect and predict two different experimental conditions, respectively (growth at constant or increasing concentration of stimulator/inhibitor. The non-linear solution reflects a common situation interesting from an environmental pollution point of view e.g. the influence of increasing (with time concentration of toxins on plant growth. Having obtained temperature modified growth equations we can draw further qualitative and, especially, quantitative conclusions about the mechanical properties of the cell wall itself. This also concerns a new and interesting result obtained in our model: We have calculated the magnitude of the cell wall yielding coefficient (T [m3 J-1•s-1] in

  5. NUCLEAR PORE COMPLEX BIOGENESIS

    OpenAIRE

    Fernandez-Martinez, Javier; Rout, Michael P.

    2009-01-01

    Nuclear pore complexes (NPCs) are the sole mediators of transport between the nucleus and the cytoplasm. NPCs have a life cycle: they assemble, disassemble, turn over and age. The molecular mechanisms governing these different vital steps are beginning to emerge, suggesting key roles for the core structural scaffold of the NPC and auxiliary factors in the assembly of this large macromolecular complex, and connections between NPC maintenance, NPC turnover, and ageing of the cell.

  6. Growth regulation of cultured human nevus cells.

    Science.gov (United States)

    Mancianti, M L; Györfi, T; Shih, I M; Valyi-Nagy, I; Levengood, G; Menssen, H D; Halpern, A C; Elder, D E; Herlyn, M

    1993-03-01

    Cells isolated from congenital melanocytic nevi and cultured in vitro have growth characteristics that resemble their premalignant stage in situ. A serum-free, chemically defined medium has been developed that allows continuous growth of established nevus cultures for up to several months. Like primary melanoma cells, nevus cells in high-calcium-containing W489 medium require insulin for growth. In contrast to melanoma cells, nevus cells in serum-free medium require the presence of alpha-melanocyte-stimulating hormone, which enhanced intracellular levels of cyclic adenosine monophosphate. In contrast to the requirements of normal human melanocytes from newborn foreskin, congenital nevus cells grow with less dependency on basic fibroblast growth factor (bFGF). Nevus cultures contain bFGF-like activity, and they express bFGF mRNA. Nevic cells of compound nevi also express bFGF mRNA in situ but only in the junctional areas. These results indicate that bFGF plays an important growth regulatory role for nevus cells in vitro and in vivo. PMID:8440904

  7. Tomato fruit growth : integrating cell division, cell growth and endoreduplication by experimentation and modelling

    NARCIS (Netherlands)

    Fanwoua, J.

    2012-01-01

    Keywords: cell division, cell growth, cell endoreduplication, fruit growth, genotype, G×E interaction, model, tomato. Fruit size is a major component of fruit yield and quality of many crops. Variations in fruit size can be tremendous due to genotypic and environmental factors. The mechanisms

  8. Shape of growth cells in directional solidification.

    Science.gov (United States)

    Pocheau, A; Georgelin, M

    2006-01-01

    The purpose of this study is to characterize experimentally the whole shape of the growth cells displayed in directional solidification and its evolution with respect to control parameters. A library of cells is first built up from observation of directional solidification of a succinonitrile alloy in a large range of pulling velocity, cell spacing, and thermal gradient. Cell boundaries are then extracted from these images and fitted by trial functions on their whole profile, from cell tip to cell grooves. A coherent evolution of the fit parameters with the control parameters is evidenced. It enables us to characterize the whole cell shape by a single function involving only two parameters which vary smoothly in the control parameter space. This, in particular, evidences a continuous evolution of the cell geometry at the cell to dendrite transition which denies the existence of a change of branch of solutions at the occurrence of sidebranching. More generally, this global determination of cell shape complemented with a previous determination of the position of cells in the thermal field (the cell tip undercooling) provides a complete characterization of growth solutions and of their evolutions in this system. It thus brings about a relevant framework for testing and improving theoretical and numerical understanding of cell shapes and cell stability in directional solidification.

  9. Beta cell proliferation and growth factors

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis; Svensson, C; Møldrup, Annette;

    1999-01-01

    Formation of new beta cells can take place by two pathways: replication of already differentiated beta cells or neogenesis from putative islet stem cells. Under physiological conditions both processes are most pronounced during the fetal and neonatal development of the pancreas. In adulthood little...... cloned a novel GH/PRL stimulated rat islet gene product, Pref-1 (preadipocyte factor-1). This protein contains six EGF-like motifs and may play a role both in embryonic pancreas differentiation and in beta cell growth and function. In summary, the increasing knowledge about the mechanisms involved...... increase in the beta cell number seems to occur. In pregnancy, however, a marked hyperplasia of the beta cells is observed both in rodents and man. Increased mitotic activity has been seen both in vivo and in vitro in islets exposed to placental lactogen (PL), prolactin (PRL) and growth hormone (GH...

  10. ERES : sites for autophagosome biogenesis and maturation?

    NARCIS (Netherlands)

    Sanchez-Wandelmer, Jana; Ktistakis, Nicholas T; Reggiori, Fulvio

    2015-01-01

    Autophagosomes are the hallmark of autophagy, but despite their central role in this degradative pathway that involves vesicle transport to lysosomes or vacuoles, the mechanism underlying their biogenesis still remains largely unknown. Our current concepts about autophagosome biogenesis are based on

  11. The pituitary growth hormone cell in space

    Science.gov (United States)

    Hymer, Wesley C.; Grindeland, R.

    1989-01-01

    Growth hormone (GH), produced and secreted from specialized cells in the pituitary gland, controls the metabolism of protein, fat, and carbohydrate. It is also probably involved in the regulation of proper function of bone, muscle and immune systems. The behavior of the GH cell system was studied by flying either isolated pituitary cells or live rats. In the latter case, pituitary GH cells are prepared on return to earth and then either transplanted into hypophysectomized rats or placed into cell culture so that function of GH cells in-vivo vs. in-vitro can be compared. The results from three flights to date (STS-8, 1983; SL-3, 1985; Cosmos 1887, 1987) established that the ability of GH cells to release hormone, on return to earth, is compromised. The mechanism(s) responsible for this attenuation response is unknown. However, the data are sufficiently positive to indicate that the nature of the secretory defect resides directly within the GH cells.

  12. Hypoxia Mediated Downregulation of miRNA Biogenesis Promotes Tumor Progression

    OpenAIRE

    Rupaimoole, Rajesha; Wu, Sherry Y.; Pradeep, Sunila; Ivan, Cristina; Pecot, Chad V.; Gharpure, Kshipra M.; Nagaraja, Archana S; Armaiz-Pena, Guillermo N.; McGuire, Michael; Zand, Behrouz; Dalton, Heather J.; Filant, Justyna; Miller, Justin Bottsford; Lu, Chunhua; Sadaoui, Nouara C.

    2014-01-01

    Cancer-related deregulation of miRNA biogenesis has been suggested, but the underlying mechanisms remain elusive. Here, we report a previously unrecognized effect of hypoxia in the downregulation of Drosha and Dicer in cancer cells that leads to dysregulation of miRNA biogenesis and increased tumor progression. We show that hypoxia mediated downregulation of Drosha is dependent on ETS1/ELK1 transcription factors. Moreover, mature miRNA array and deep sequencing studies reveal altered miRNA ma...

  13. Growth of gold nanoparticles in human cells.

    Science.gov (United States)

    Anshup, Anshup; Venkataraman, J Sai; Subramaniam, Chandramouli; Kumar, R Rajeev; Priya, Suma; Kumar, T R Santhosh; Omkumar, R V; John, Annie; Pradeep, T

    2005-12-01

    Gold nanoparticles of 20-100 nm diameter were synthesized within HEK-293 (human embryonic kidney), HeLa (human cervical cancer), SiHa (human cervical cancer), and SKNSH (human neuroblastoma) cells. Incubation of 1 mM tetrachloroaurate solution, prepared in phosphate buffered saline (PBS), pH 7.4, with human cells grown to approximately 80% confluency yielded systematic growth of nanoparticles over a period of 96 h. The cells, stained due to nanoparticle growth, were adherent to the bottom of the wells of the tissue culture plates, with their morphology preserved, indicating that the cell membrane was intact. Transmission electron microscopy of ultrathin sections showed the presence of nanoparticles within the cytoplasm and in the nucleus, the latter being much smaller in dimension. Scanning near field microscopic images confirmed the growth of large particles within the cytoplasm. Normal cells gave UV-visible signatures of higher intensity than the cancer cells. Differences in the cellular metabolism of cancer and noncancer cells were manifested, presumably in their ability to carry out the reduction process. PMID:16316080

  14. Growth arrest in the ribosomopathy, Bowen-Conradi syndrome, is due to dramatically reduced cell proliferation and a defect in mitotic progression.

    Science.gov (United States)

    Armistead, Joy; Patel, Nehal; Wu, Xiaoli; Hemming, Richard; Chowdhury, Biswajit; Basra, Gagandeep Singh; Del Bigio, Marc R; Ding, Hao; Triggs-Raine, Barbara

    2015-05-01

    Bowen-Conradi syndrome (BCS) is a ribosomopathy characterized by severe developmental delay and growth failure that typically leads to death by one year of age. It is caused by a c.257A>G, p.D86G substitution in the ribosomal biogenesis protein, Essential for Mitotic Growth 1 (EMG1). We generated a knock-in of the D86G substitution in mice to characterize the effects of EMG1 deficiency, particularly in the brain, where EMG1 expression is high. Embryos homozygous for the mutation in Emg1 were small for gestational age with neural tube defects, and died between embryonic days 8.5 and 12.5. These embryos exhibited dramatically reduced cell proliferation, which we also detected in autopsy brain tissue and bone marrow of BCS patients, consistent with a requirement for high levels of EMG1 in tissues with rapid cell proliferation. In fibroblasts derived from the BCS mouse embryos, we detected a high proportion of binucleated cells, indicating that a mitotic defect underlies the growth arrest in BCS. These studies add to growing evidence of a link between ribosome biogenesis, mitotic progression, and brain development that is currently unexplored.

  15. The mitochondrial acyl carrier protein (ACP) coordinates mitochondrial fatty acid synthesis with iron sulfur cluster biogenesis.

    Science.gov (United States)

    Van Vranken, Jonathan G; Jeong, Mi-Young; Wei, Peng; Chen, Yu-Chan; Gygi, Steven P; Winge, Dennis R; Rutter, Jared

    2016-01-01

    Mitochondrial fatty acid synthesis (FASII) and iron sulfur cluster (FeS) biogenesis are both vital biosynthetic processes within mitochondria. In this study, we demonstrate that the mitochondrial acyl carrier protein (ACP), which has a well-known role in FASII, plays an unexpected and evolutionarily conserved role in FeS biogenesis. ACP is a stable and essential subunit of the eukaryotic FeS biogenesis complex. In the absence of ACP, the complex is destabilized resulting in a profound depletion of FeS throughout the cell. This role of ACP depends upon its covalently bound 4'-phosphopantetheine (4-PP)-conjugated acyl chain to support maximal cysteine desulfurase activity. Thus, it is likely that ACP is not simply an obligate subunit but also exploits the 4-PP-conjugated acyl chain to coordinate mitochondrial fatty acid and FeS biogenesis. PMID:27540631

  16. Budding yeast colony growth study based on circular granular cell

    Science.gov (United States)

    Aprianti, Devi; Khotimah, S. N.; Viridi, S.

    2016-08-01

    Yeast colony growth can be modelled by using circular granular cells, which can grow and produce buds. The bud growth angle can be set to regulate cell budding pattern. Cohesion force, contact force and Stokes force were adopted to accommodate the behaviour and interactions among cells. Simulation steps are divided into two steps, the explicit step is due to cell growing and implicit step for the cell rearrangement. Only in explicit step that time change was performed. In this study, we examine the influence of cell diameter growth time and reproduction time combination toward the growth of cell number and colony formation. We find a commutative relation between the cell diameter growth time and reproduction time to the specific growth rate. The greater value of the multiplication of the parameters, the smaller specific growth rate is obtained. It also shows a linear correlation between the specific growth rate and colony diameter growth rate.

  17. Bounds on bacterial cell growth rates

    CERN Document Server

    Landy, Jonathan

    2013-01-01

    Recent experiments have shown that rod-like bacteria in nutrient-rich media grow in length at an exponential rate. Here, I point out that it is the elongated shape of these bacteria that allows for this behavior. Further, I show that when a bacterium's growth is limited by some nutrient -- taken in by the cell through a diffusion-to-capture process -- its growth is suppressed: In three-dimensional geometries, the length $L$ is bounded by $\\log L \\lesssim t^{1/2}$, while in two dimensions the length is bounded by a power-law form. Fits of experimental growth curves to these predicted, sub-exponential forms could allow for direct measures of quantities relating to cellular metabolic rates.

  18. Circadian rhythm and cell population growth

    CERN Document Server

    Clairambault, Jean; Lepoutre, Thomas

    2010-01-01

    Molecular circadian clocks, that are found in all nucleated cells of mammals, are known to dictate rhythms of approximately 24 hours (circa diem) to many physiological processes. This includes metabolism (e.g., temperature, hormonal blood levels) and cell proliferation. It has been observed in tumor-bearing laboratory rodents that a severe disruption of these physiological rhythms results in accelerated tumor growth. The question of accurately representing the control exerted by circadian clocks on healthy and tumour tissue proliferation to explain this phenomenon has given rise to mathematical developments, which we review. The main goal of these previous works was to examine the influence of a periodic control on the cell division cycle in physiologically structured cell populations, comparing the effects of periodic control with no control, and of different periodic controls between them. We state here a general convexity result that may give a theoretical justification to the concept of cancer chronothera...

  19. Coordination of plant mitochondrial biogenesis: keeping pace with cellular requirements.

    Directory of Open Access Journals (Sweden)

    Elina eWelchen

    2014-01-01

    Full Text Available Plant mitochondria are complex organelles that carry out numerous metabolic processes related with the generation of energy for cellular functions and the synthesis and degradation of several compounds. Mitochondria are semiautonomous and dynamic organelles changing in shape, number and composition depending on tissue or developmental stage. The biogenesis of functional mitochondria requires the coordination of genes present both in the nucleus and the organelle. In addition, due to their central role, all processes held inside mitochondria must be finely coordinated with those in other organelles according to cellular demands. Coordination is achieved by transcriptional control of nuclear genes encoding mitochondrial proteins by specific transcription factors that recognize conserved elements in their promoter regions. In turn, the expression of most of these transcription factors is linked to developmental and environmental cues, according to the availability of nutrients, light-dark cycles and warning signals generated in response to stress conditions. Among the signals impacting in the expression of nuclear genes, retrograde signals that originate inside mitochondria help to adjust mitochondrial biogenesis to organelle demands. Adding more complexity, several nuclear encoded proteins are dual localized to mitochondria and either chloroplasts or the nucleus. Dual targeting might establish a crosstalk between the nucleus and cell organelles to ensure a fine coordination of cellular activities. In this article, we discuss how the different levels of coordination of mitochondrial biogenesis interconnect to optimize the function of the organelle according to both internal and external demands.

  20. Microprocessor activity controls differential miRNA biogenesis In Vivo.

    Science.gov (United States)

    Conrad, Thomas; Marsico, Annalisa; Gehre, Maja; Orom, Ulf Andersson

    2014-10-23

    In miRNA biogenesis, pri-miRNA transcripts are converted into pre-miRNA hairpins. The in vivo properties of this process remain enigmatic. Here, we determine in vivo transcriptome-wide pri-miRNA processing using next-generation sequencing of chromatin-associated pri-miRNAs. We identify a distinctive Microprocessor signature in the transcriptome profile from which efficiency of the endogenous processing event can be accurately quantified. This analysis reveals differential susceptibility to Microprocessor cleavage as a key regulatory step in miRNA biogenesis. Processing is highly variable among pri-miRNAs and a better predictor of miRNA abundance than primary transcription itself. Processing is also largely stable across three cell lines, suggesting a major contribution of sequence determinants. On the basis of differential processing efficiencies, we define functionality for short sequence features adjacent to the pre-miRNA hairpin. In conclusion, we identify Microprocessor as the main hub for diversified miRNA output and suggest a role for uncoupling miRNA biogenesis from host gene expression.

  1. Mesenchymal stem cell like (MSCl) cells generated from human embryonic stem cells support pluripotent cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Varga, Nora [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary); Vereb, Zoltan; Rajnavoelgyi, Eva [Department of Immunology, Medical and Health Science Centre, University of Debrecen, Debrecen (Hungary); Nemet, Katalin; Uher, Ferenc; Sarkadi, Balazs [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary); Apati, Agota, E-mail: apati@kkk.org.hu [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary)

    2011-10-28

    Highlights: Black-Right-Pointing-Pointer MSC like cells were derived from hESC by a simple and reproducible method. Black-Right-Pointing-Pointer Differentiation and immunosuppressive features of MSCl cells were similar to bmMSC. Black-Right-Pointing-Pointer MSCl cells as feeder cells support the undifferentiated growth of hESC. -- Abstract: Mesenchymal stem cell like (MSCl) cells were generated from human embryonic stem cells (hESC) through embryoid body formation, and isolated by adherence to plastic surface. MSCl cell lines could be propagated without changes in morphological or functional characteristics for more than 15 passages. These cells, as well as their fluorescent protein expressing stable derivatives, efficiently supported the growth of undifferentiated human embryonic stem cells as feeder cells. The MSCl cells did not express the embryonic (Oct4, Nanog, ABCG2, PODXL, or SSEA4), or hematopoietic (CD34, CD45, CD14, CD133, HLA-DR) stem cell markers, while were positive for the characteristic cell surface markers of MSCs (CD44, CD73, CD90, CD105). MSCl cells could be differentiated toward osteogenic, chondrogenic or adipogenic directions and exhibited significant inhibition of mitogen-activated lymphocyte proliferation, and thus presented immunosuppressive features. We suggest that cultured MSCl cells can properly model human MSCs and be applied as efficient feeders in hESC cultures.

  2. The Arabidopsis gene DIG6 encodes a large 60S subunit nuclear export GTPase 1 that is involved in ribosome biogenesis and affects multiple auxin-regulated development processes

    KAUST Repository

    Zhao, Huayan

    2015-08-13

    The circularly permuted GTPase large subunit GTPase 1 (LSG1) is involved in the maturation step of the 60S ribosome and is essential for cell viability in yeast. Here, an Arabidopsis mutant dig6 (drought inhibited growth of lateral roots) was isolated. The mutant exhibited multiple auxin-related phenotypes, which included reduced lateral root number, altered leaf veins, and shorter roots. Genetic mapping combined with next-generation DNA sequencing identified that the mutation occurred in AtLSG1-2. This gene was highly expressed in regions of auxin accumulation. Ribosome profiling revealed that a loss of function of AtLSG1-2 led to decreased levels of monosomes, further demonstrating its role in ribosome biogenesis. Quantitative proteomics showed that the expression of certain proteins involved in ribosome biogenesis was differentially regulated, indicating that ribosome biogenesis processes were impaired in the mutant. Further investigations showed that an AtLSG1-2 deficiency caused the alteration of auxin distribution, response, and transport in plants. It is concluded that AtLSG1-2 is integral to ribosome biogenesis, consequently affecting auxin homeostasis and plant development.

  3. The Biogenesis of Lysosomes and Lysosome-Related Organelles

    Science.gov (United States)

    Luzio, J. Paul; Hackmann, Yvonne; Dieckmann, Nele M.G.; Griffiths, Gillian M.

    2014-01-01

    Lysosomes were once considered the end point of endocytosis, simply used for macromolecule degradation. They are now recognized to be dynamic organelles, able to fuse with a variety of targets and to be re-formed after fusion events. They are also now known to be the site of nutrient sensing and signaling to the cell nucleus. In addition, lysosomes are secretory organelles, with specialized machinery for regulated secretion of proteins in some cell types. The biogenesis of lysosomes and lysosome-related organelles is discussed, taking into account their dynamic nature and multiple roles. PMID:25183830

  4. Mechanisms of pancreatic beta-cell growth and regeneration

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    1989-01-01

    Information about the mechanism of beta-cell growth and regeneration may be obtained by studies of insulinoma cells. In the present study the growth and function of the rat insulinoma cell lines RINm5F and 5AH were evaluated by addition of serum, hormones, and growth factors. It was found...... that transferrin is the only obligatory factor whereas growth hormone, epidermal growth factor, fibroblast growth factor, and TRH had modulating effects. A heat-labile heparin binding serum factor which stimulated thymidine incorporation but not cell proliferation was demonstrated in human serum. Measurements...... of insulin mRNA content showed that the insulinoma cells only contained about 2% of that of normal rat beta-cells. These results are discussed in relation to the role of growth factors, oncogenes, and differentiation in the growth and regeneration of beta-cells....

  5. Biogenesis and architecture of arterivirus replication organelles.

    Science.gov (United States)

    van der Hoeven, Barbara; Oudshoorn, Diede; Koster, Abraham J; Snijder, Eric J; Kikkert, Marjolein; Bárcena, Montserrat

    2016-07-15

    All eukaryotic positive-stranded RNA (+RNA) viruses appropriate host cell membranes and transform them into replication organelles, specialized micro-environments that are thought to support viral RNA synthesis. Arteriviruses (order Nidovirales) belong to the subset of +RNA viruses that induce double-membrane vesicles (DMVs), similar to the structures induced by e.g. coronaviruses, picornaviruses and hepatitis C virus. In the last years, electron tomography has revealed substantial differences between the structures induced by these different virus groups. Arterivirus-induced DMVs appear to be closed compartments that are continuous with endoplasmic reticulum membranes, thus forming an extensive reticulovesicular network (RVN) of intriguing complexity. This RVN is remarkably similar to that described for the distantly related coronaviruses (also order Nidovirales) and sets them apart from other DMV-inducing viruses analysed to date. We review here the current knowledge and open questions on arterivirus replication organelles and discuss them in the light of the latest studies on other DMV-inducing viruses, particularly coronaviruses. Using the equine arteritis virus (EAV) model system and electron tomography, we present new data regarding the biogenesis of arterivirus-induced DMVs and uncover numerous putative intermediates in DMV formation. We generated cell lines that can be induced to express specific EAV replicase proteins and showed that DMVs induced by the transmembrane proteins nsp2 and nsp3 form an RVN and are comparable in topology and architecture to those formed during viral infection. Co-expression of the third EAV transmembrane protein (nsp5), expressed as part of a self-cleaving polypeptide that mimics viral polyprotein processing in infected cells, led to the formation of DMVs whose size was more homogenous and closer to what is observed upon EAV infection, suggesting a regulatory role for nsp5 in modulating membrane curvature and DMV formation. PMID

  6. Green fluorescent protein-tagged sarco(endo)plasmic reticulum Ca2+-ATPase overexpression in Paramecium cells: isoforms, subcellular localization, biogenesis of cortical calcium stores and functional aspects.

    Science.gov (United States)

    Hauser, K; Pavlovic, N; Klauke, N; Geissinger, D; Plattner, H

    2000-08-01

    We have followed the time-dependent transfection of Paramecium cells with a vector containing the gene of green fluorescent protein (GFP) attached to the C-terminus of the PtSERCA1 gene. The outlines of alveolar sacs (ASs) are labelled, as is the endoplasmic reticulum (ER) throughout the cell. When GFP fluorescence is compared with previous anti-PtSERCA1 antibody labelling, the much wider distribution of GFP (ER+ASs) indicates that only a small amount of SERCA molecules is normally retained in the ER. A second isoform, PtSERCA2, also occurs and its C-terminal GFP-tagging results in the same distribution pattern. However, when GFP is inserted in the major cytoplasmic loop, PtSERCA1 and two fusion proteins are mostly retained in the ER, probably because of the presence of the overt C-terminal KKXX ER-retention signal and/or masking of a signal for transfer into ASs. On the overall cell surface, new SERCA molecules seem to be permanently delivered from the ER to ASs by vesicle transport, whereas in the fission zone of dividing cells ASs may form anew. In cells overexpressing PtSERCA1 (with C-terminal GFP) in ASs, [Ca2+]i regulation during exocytosis is not significantly different from controls, probably because their Ca2+ pump has to mediate only slow reuptake.

  7. [Stem cells and growth factors in wound healing].

    Science.gov (United States)

    Pikuła, Michał; Langa, Paulina; Kosikowska, Paulina; Trzonkowski, Piotr

    2015-01-01

    Wound healing is a complex process which depends on the presence of various types of cells, growth factors, cytokines and the elements of extracellular matrix. A wound is a portal of entry for numerous pathogens, therefore during the evolution wound healing process has formed very early, being critical for the survival of every individual. Stem cells, which give rise to their early descendants progenitor cells and subsequently differentiated cells, play a specific role in the process of wound healing. Among the most important cells which take part in wound healing the following cells need to be distinguished: epidermal stem cells, dermal precursor of fibroblasts, adipose-derived stem cells as well as bone marrow cells. The activity of these cells is strictly regulated by various growth factors, inter alia epidermal growth factor (EGF), fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), transforming growth factor (TGF), vascular endothelial growth factor (VEGF). Any disorders in functioning of stem cells and biological activity of growth factors may lead to the defects in wound healing, for instance delayed wound healing or creation of hypertrophic scars. Therefore, knowledge concerning the mechanisms of wound healing is extremely essential from clinical point of view. In this review the current state of the knowledge of the role of stem cells and growth factors in the process of wound healing has been presented. Moreover, some clinical aspects of wound healing as well as the possibility of the therapy based on stem cells and growth factors have included.

  8. Mitochondrial DNA deletion and impairment of mitochondrial biogenesis by reactive oxygen species in ionizing radiation-induced premature senescence

    Energy Technology Data Exchange (ETDEWEB)

    Eom, Hyeon Soo; Jung, U Hee; Jo, Sung Kee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    The aim of this study was to determine whether an increase of ROS level in cellular senescence induced by IR could mediate mtDNA deletion via impairment of mitochondria biogenesis in IMR-90 human lung fibroblast cells. Our results showed that IR induced cellular senescence, intracellular ROS, and mtDNA deletion, and in particular, suppressed the expression of mitochondrial biogenesis genes (NRF-1, TFAM). Furthermore, these IR-induced events were abolished using a potent antioxidant, NAC, which suggests that ROS is a key cause of mtDNA deletion in IR-induced cellular senescence, and that the alteration of mitochondrial biogenesis may mediate these processes

  9. Increased biogenesis of glucagon-containing secretory granules and glucagon secretion in BIG3-knockout mice

    Directory of Open Access Journals (Sweden)

    Hongyu Li

    2015-03-01

    Conclusions: Together with our previous studies, the current data reveal a conserved role for BIG3 in regulating alpha- and beta-cell functions. We propose that BIG3 negatively regulates hormone production at the secretory granule biogenesis stage and that such regulatory mechanism may be used in secretory pathways of other endocrine cells.

  10. A novel mechanism involved in the coupling of mitochondrial biogenesis to oxidative phosphorylation

    Directory of Open Access Journals (Sweden)

    Jelena Ostojić

    2014-01-01

    Full Text Available Mitochondria are essential organelles that are central to a multitude of cellular processes, including oxidative phosphorylation (OXPHOS, which produces most of the ATP in animal cells. Thus it is important to understand not only the mechanisms and biogenesis of this energy production machinery but also how it is regulated in both physiological and pathological contexts. A recent study by Ostojić et al. [Cell Metabolism (2013 18, 567-577] has uncovered a regulatory loop by which the biogenesis of a major enzyme of the OXPHOS pathway, the respiratory complex III, is coupled to the energy producing activity of the mitochondria.

  11. Rosiglitazone induces mitochondrial biogenesis in mouse brain.

    Science.gov (United States)

    Strum, Jay C; Shehee, Ron; Virley, David; Richardson, Jill; Mattie, Michael; Selley, Paula; Ghosh, Sujoy; Nock, Christina; Saunders, Ann; Roses, Allen

    2007-03-01

    Rosiglitazone was found to simulate mitochondrial biogenesis in mouse brain in an apolipoprotein (Apo) E isozyme-independent manner. Rosiglitazone induced both mitochondrial DNA (mtDNA) and estrogen-stimulated related receptor alpha (ESRRA) mRNA, a key regulator of mitochondrial biogenesis. Transcriptomics and proteomics analysis suggested the mitochondria produced in the presence of human ApoE3 and E4 were not as metabolically efficient as those in the wild type or ApoE knockout mice. Thus, we propose that PPARgamma agonism induces neuronal mitochondrial biogenesis and improves glucose utilization leading to improved cellular function and provides mechanistic support for the improvement in cognition observed in treatment of Alzheimer's patients with rosiglitazone.

  12. Pharmacologic inhibition of the CK2-mediated phosphorylation of B23/NPM in cancer cells selectively modulates genes related to protein synthesis, energetic metabolism, and ribosomal biogenesis.

    Science.gov (United States)

    Perera, Yasser; Pedroso, Seidy; Borras-Hidalgo, Orlando; Vázquez, Dania M; Miranda, Jamilet; Villareal, Adelaida; Falcón, Viviana; Cruz, Luis D; Farinas, Hernán G; Perea, Silvio E

    2015-06-01

    B23/NPM is a multifunctional nucleolar protein frequently overexpressed, mutated, or rearranged in neoplastic tissues. B23/NPM is involved in diverse biological processes and is mainly regulated by heteroligomer association and posttranslational modification, phosphorylation being a major posttranslational event. While the role of B23/NPM in supporting and/or driving malignant transformation is widely recognized, the particular relevance of its CK2-mediated phosphorylation remains unsolved. Interestingly, the pharmacologic inhibition of such phosphorylation event by CIGB-300, a clinical-grade peptide drug, was previously associated to apoptosis induction in tumor cell lines. In this work, we sought to identify the biological processes modulated by CIGB-300 in a lung cancer cell line using subtractive suppression hybridization and subsequent functional annotation clustering. Our results indicate that CIGB-300 modulates a subset of genes involved in protein synthesis (ES = 8.4, p NPM in cancer cells, revealing at the same time the potentialities of its pharmacological manipulation for cancer therapy. Finally, this work also suggests several candidate gene biomarkers to be evaluated during the clinical development of the anti-CK2 peptide CIGB-300.

  13. Serine Protease Autotransporters of Enterobacteriaceae (SPATEs: Biogenesis and Function

    Directory of Open Access Journals (Sweden)

    Nathalie Dautin

    2010-05-01

    Full Text Available Serine Protease Autotransporters of Enterobacteriaceae (SPATEs constitute a large family of proteases secreted by Escherichia coli and Shigella. SPATEs exhibit two distinct proteolytic activities. First, a C-terminal catalytic site triggers an intra-molecular cleavage that releases the N-terminal portion of these proteins in the extracellular medium. Second, the secreted N-terminal domains of SPATEs are themselves proteases; each contains a canonical serine-protease catalytic site. Some of these secreted proteases are toxins, eliciting various effects on mammalian cells. Here, we discuss the biogenesis of SPATEs and their function as toxins.

  14. Polarized membrane traffic and cell polarity development is dependent on dihydroceramide synthase-regulated sphinganine turnover

    NARCIS (Netherlands)

    van Ijzendoorn, SCD; van der Wouden, JM; Liebisch, G; Schmitz, G; Hoekstra, D

    2004-01-01

    Sphingoid bases have been implicated in various cellular processes including cell growth, apoptosis and cell differentiation. Here, we show that the regulated turnover of sphingoid bases is crucial for cell polarity development, i.e., the biogenesis of apical plasma membrane domains, in well-differe

  15. Beyond growth: novel functions for bacterial cell wall hydrolases.

    Science.gov (United States)

    Wyckoff, Timna J; Taylor, Jennifer A; Salama, Nina R

    2012-11-01

    The peptidoglycan cell wall maintains turgor pressure and cell shape of most bacteria. Cell wall hydrolases are essential, together with synthases, for growth and daughter cell separation. Recent work in diverse organisms has uncovered new cell wall hydrolases that act autonomously or on neighboring cells to modulate invasion of prey cells, cell shape, innate immune detection, intercellular communication, and competitor lysis. The hydrolases involved in these processes catalyze the cleavage of bonds throughout the sugar and peptide moities of peptidoglycan. Phenotypes associated with these diverse hydrolases reveal new functions of the bacterial cell wall beyond growth and division.

  16. A liaison between mTOR signaling, ribosome biogenesis and cancer.

    Science.gov (United States)

    Gentilella, Antonio; Kozma, Sara C; Thomas, George

    2015-07-01

    The ability to translate genetic information into functional proteins is considered a landmark in evolution. Ribosomes have evolved to take on this responsibility and, although there are some differences in their molecular make-up, both prokaryotes and eukaryotes share a common structural architecture and similar underlying mechanisms of protein synthesis. Understanding ribosome function and biogenesis has been the focus of extensive research since the early days of their discovery. In the last decade however, new and unexpected roles have emerged that place deregulated ribosome biogenesis and protein synthesis at the crossroads of pathological settings, particularly cancer, revealing a set of novel cellular checkpoints. Moreover, it is also becoming evident that mTOR signaling, which regulates an array of anabolic processes, including ribosome biogenesis, is often exploited by cancer cells to sustain proliferation through the upregulation of global protein synthesis. The use of pharmacological agents that interfere with ribosome biogenesis and mTOR signaling has proven to be an effective strategy to control cancer development clinically. Here we discuss the most recent findings concerning the underlying mechanisms by which mTOR signaling controls ribosome production and the potential impact of ribosome biogenesis in tumor development. This article is part of a Special Issue entitled: Translation and Cancer. PMID:25735853

  17. Expanding antitumor therapeutic windows by targeting cancer-specific nicotinamide adenine dinucleotide phosphate-biogenesis pathways

    Directory of Open Access Journals (Sweden)

    Chakrabarti G

    2015-03-01

    Full Text Available Gaurab Chakrabarti,1,2,4 David E Gerber,3,4 David A Boothman1,2,4 1Department of Pharmacology, 2Department of Radiation Oncology, 3Division of Hematology and Oncology, 4Harold C Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, TX, USA Abstract: Nicotinamide adenine dinucleotide phosphate (NADPH biogenesis is an essential mechanism by which both normal and cancer cells maintain redox balance. While antitumor approaches to treat cancers through elevated reactive oxygen species (ROS are not new ideas, depleting specific NADPH-biogenesis pathways that control recovery and repair pathways are novel, viable approaches to enhance cancer therapy. However, to elicit efficacious therapies exploiting NADPH-biogenic pathways, it is crucial to understand and specifically define the roles of NADPH-biogenesis pathways used by cancer cells for survival or recovery from cell stress. It is equally important to select NADPH-biogenic pathways that are expendable or not utilized in normal tissue to avoid unwanted toxicity. Here, we address recent literature that demonstrates specific tumor-selective NADPH-biogenesis pathways that can be exploited using agents that target specific cancer cell pathways normally not utilized in normal cells. Defining NADPH-biogenesis profiles of specific cancer-types should enable novel strategies to exploit these therapeutic windows for increased efficacy against recalcitrant neoplastic disease, such as pancreatic cancers. Accomplishing the goal of using ROS as a weapon against cancer cells will also require agents, such as NQO1 bioactivatable drugs, that selectively induce elevated ROS levels in cancer cells, while normal cells are protected. Keywords: reactive oxygen species (ROS, NQO1-bioactivatable drugs, nicotinamide adenine dinucleotide phosphate (NADPH, glutathione (GSH, biogenic pathways, antioxidant

  18. Computationally driven, quantitative experiments discover genes required for mitochondrial biogenesis.

    Directory of Open Access Journals (Sweden)

    David C Hess

    2009-03-01

    Full Text Available Mitochondria are central to many cellular processes including respiration, ion homeostasis, and apoptosis. Using computational predictions combined with traditional quantitative experiments, we have identified 100 proteins whose deficiency alters mitochondrial biogenesis and inheritance in Saccharomyces cerevisiae. In addition, we used computational predictions to perform targeted double-mutant analysis detecting another nine genes with synthetic defects in mitochondrial biogenesis. This represents an increase of about 25% over previously known participants. Nearly half of these newly characterized proteins are conserved in mammals, including several orthologs known to be involved in human disease. Mutations in many of these genes demonstrate statistically significant mitochondrial transmission phenotypes more subtle than could be detected by traditional genetic screens or high-throughput techniques, and 47 have not been previously localized to mitochondria. We further characterized a subset of these genes using growth profiling and dual immunofluorescence, which identified genes specifically required for aerobic respiration and an uncharacterized cytoplasmic protein required for normal mitochondrial motility. Our results demonstrate that by leveraging computational analysis to direct quantitative experimental assays, we have characterized mutants with subtle mitochondrial defects whose phenotypes were undetected by high-throughput methods.

  19. Fibroblast growth factor 8 increases breast cancer cell growth by promoting cell cycle progression and by protecting against cell death

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Emeli M., E-mail: Emeli.Nilsson@med.lu.se [Department of Laboratory Medicine, Tumour Biology, Lund University, CRC, Building 91, Plan 10, Entrance 72, UMAS, 205 02 Malmoe (Sweden); Brokken, Leon J.S., E-mail: Leon.Brokken@med.lu.se [Department of Laboratory Medicine, Tumour Biology, Lund University, CRC, Building 91, Plan 10, Entrance 72, UMAS, 205 02 Malmoe (Sweden); Haerkoenen, Pirkko L., E-mail: Pirkko.Harkonen@med.lu.se [Department of Laboratory Medicine, Tumour Biology, Lund University, CRC, Building 91, Plan 10, Entrance 72, UMAS, 205 02 Malmoe (Sweden)

    2010-03-10

    Fibroblast growth factor 8 (FGF-8) is expressed in a large proportion of breast cancers, whereas its level in normal mammary gland epithelium is low. Previous studies have shown that FGF-8b stimulates breast cancer cell growth in vitro and in vivo. To explore the mechanisms by which FGF-8b promotes growth, we studied its effects on cell cycle regulatory proteins and signalling pathways in mouse S115 and human MCF-7 breast cancer cells. We also studied the effect of FGF-8b on cell survival. FGF-8b induced cell cycle progression and up-regulated particularly cyclin D1 mRNA and protein in S115 cells. Silencing cyclin D1 with siRNA inhibited most but not all FGF-8b-induced proliferation. Inhibition of the FGF-8b-activated ERK/MAPK pathway decreased FGF-8b-stimulated proliferation. Blocking the constitutively active PI3K/Akt and p38 MAPK pathways also lowered FGF-8b-induced cyclin D1 expression and proliferation. Corresponding results were obtained in MCF-7 cells. In S115 and MCF-7 mouse tumours, FGF-8b increased cyclin D1 and Ki67 levels. Moreover, FGF-8b opposed staurosporine-induced S115 cell death which effect was blocked by inhibiting the PI3K/Akt pathway but not the ERK/MAPK pathway. In conclusion, our results suggest that FGF-8b increases breast cancer cell growth both by stimulating cell cycle progression and by protecting against cell death.

  20. Two-component signal transduction pathways regulating growth and cell cycle progression in a bacterium: a system-level analysis.

    Directory of Open Access Journals (Sweden)

    Jeffrey M Skerker

    2005-10-01

    Full Text Available Two-component signal transduction systems, comprised of histidine kinases and their response regulator substrates, are the predominant means by which bacteria sense and respond to extracellular signals. These systems allow cells to adapt to prevailing conditions by modifying cellular physiology, including initiating programs of gene expression, catalyzing reactions, or modifying protein-protein interactions. These signaling pathways have also been demonstrated to play a role in coordinating bacterial cell cycle progression and development. Here we report a system-level investigation of two-component pathways in the model organism Caulobacter crescentus. First, by a comprehensive deletion analysis we show that at least 39 of the 106 two-component genes are required for cell cycle progression, growth, or morphogenesis. These include nine genes essential for growth or viability of the organism. We then use a systematic biochemical approach, called phosphotransfer profiling, to map the connectivity of histidine kinases and response regulators. Combining these genetic and biochemical approaches, we identify a new, highly conserved essential signaling pathway from the histidine kinase CenK to the response regulator CenR, which plays a critical role in controlling cell envelope biogenesis and structure. Depletion of either cenK or cenR leads to an unusual, severe blebbing of cell envelope material, whereas constitutive activation of the pathway compromises cell envelope integrity, resulting in cell lysis and death. We propose that the CenK-CenR pathway may be a suitable target for new antibiotic development, given previous successes in targeting the bacterial cell wall. Finally, the ability of our in vitro phosphotransfer profiling method to identify signaling pathways that operate in vivo takes advantage of an observation that histidine kinases are endowed with a global kinetic preference for their cognate response regulators. We propose that this

  1. Cell growth characterization using multi-electrode bioimpedance spectroscopy

    International Nuclear Information System (INIS)

    Cell growth characterization during culturing is an important issue in a variety of biomedical applications. In this study an electrical bioimpedance spectroscopy-based multi-electrode culture monitoring system was developed to characterize cell growth. A PC12 cell line was cultured for the cell growth study. The bioimpedance variations for PC12 cell growth within the initial 12 h were measured over a range between 1 kHz and 4 MHz at three different medium concentrations. Within this frequency range, the largest bioimpedance value was 1.9 times the smallest bioimpedance value. The phase angle decreased over the range from 1 to 10 kHz when cells were growing. Then, the phase angle approached a constant over the frequency range between 10 kHz and 2 MHz. Thereafter, the phase angle increased rapidly from 20 to 52 degrees during cell culturing between 8 and 12 h at 4 MHz. The maximum cell number after culturing for 12 h increased by 25.8% for the control sites with poly-D-lysine (PDL) pastes. For the normal growth factor, the cell number increased up to 4.78 times from 8 to 12 h, but only 0.96 and 1.60 times for the other two medium growth factors. The correlation coefficients between impedance and cell number were 0.868 (coating with PDL), and 0.836 (without PDL) for the normal concentration medium. Thus, impedance may be used as an index for cell growth characterization. (paper)

  2. Cell growth characterization using multi-electrode bioimpedance spectroscopy

    Science.gov (United States)

    Lu, Yi-Yu; Huang, Ji-Jer; Huang, Yu-Jie; Cheng, Kuo-Sheng

    2013-03-01

    Cell growth characterization during culturing is an important issue in a variety of biomedical applications. In this study an electrical bioimpedance spectroscopy-based multi-electrode culture monitoring system was developed to characterize cell growth. A PC12 cell line was cultured for the cell growth study. The bioimpedance variations for PC12 cell growth within the initial 12 h were measured over a range between 1 kHz and 4 MHz at three different medium concentrations. Within this frequency range, the largest bioimpedance value was 1.9 times the smallest bioimpedance value. The phase angle decreased over the range from 1 to 10 kHz when cells were growing. Then, the phase angle approached a constant over the frequency range between 10 kHz and 2 MHz. Thereafter, the phase angle increased rapidly from 20 to 52 degrees during cell culturing between 8 and 12 h at 4 MHz. The maximum cell number after culturing for 12 h increased by 25.8% for the control sites with poly-D-lysine (PDL) pastes. For the normal growth factor, the cell number increased up to 4.78 times from 8 to 12 h, but only 0.96 and 1.60 times for the other two medium growth factors. The correlation coefficients between impedance and cell number were 0.868 (coating with PDL), and 0.836 (without PDL) for the normal concentration medium. Thus, impedance may be used as an index for cell growth characterization.

  3. Transcriptional coactivator PGC-1alpha promotes peroxisomal remodeling and biogenesis.

    Science.gov (United States)

    Bagattin, Alessia; Hugendubler, Lynne; Mueller, Elisabetta

    2010-11-23

    Mitochondria and peroxisomes execute some analogous, nonredundant functions including fatty acid oxidation and detoxification of reactive oxygen species, and, in response to select metabolic cues, undergo rapid remodeling and division. Although these organelles share some components of their division machinery, it is not known whether a common regulator coordinates their remodeling and biogenesis. Here we show that in response to thermogenic stimuli, peroxisomes in brown fat tissue (BAT) undergo selective remodeling and expand in number and demonstrate that ectopic expression of the transcriptional coactivator PGC-1α recapitulates these effects on the peroxisomal compartment, both in vitro and in vivo. Conversely, β-adrenergic stimulation of PGC-1α(-/-) cells results in blunted induction of peroxisomal gene expression. Surprisingly, PPARα was not required for the induction of critical biogenesis factors, suggesting that PGC-1α orchestrates peroxisomal remodeling through a PPARα-independent mechanism. Our data suggest that PGC-1α is critical to peroxisomal physiology, establishing a role for this factor as a fundamental orchestrator of cellular adaptation to energy demands.

  4. Outer membrane lipoprotein biogenesis: Lol is not the end.

    Science.gov (United States)

    Konovalova, Anna; Silhavy, Thomas J

    2015-10-01

    Bacterial lipoproteins are lipid-anchored proteins that contain acyl groups covalently attached to the N-terminal cysteine residue of the mature protein. Lipoproteins are synthesized in precursor form with an N-terminal signal sequence (SS) that targets translocation across the cytoplasmic or inner membrane (IM). Lipid modification and SS processing take place at the periplasmic face of the IM. Outer membrane (OM) lipoproteins take the localization of lipoproteins (Lol) export pathway, which ends with the insertion of the N-terminal lipid moiety into the inner leaflet of the OM. For many lipoproteins, the biogenesis pathway ends here. We provide examples of lipoproteins that adopt complex topologies in the OM that include transmembrane and surface-exposed domains. Biogenesis of such lipoproteins requires additional steps beyond the Lol pathway. In at least one case, lipoprotein sequences reach the cell surface by being threaded through the lumen of a beta-barrel protein in an assembly reaction that requires the heteropentomeric Bam complex. The inability to predict surface exposure reinforces the importance of experimental verification of lipoprotein topology and we will discuss some of the methods used to study OM protein topology. PMID:26370942

  5. Analysis of photosystem II biogenesis in cyanobacteria.

    Science.gov (United States)

    Heinz, Steffen; Liauw, Pasqual; Nickelsen, Jörg; Nowaczyk, Marc

    2016-03-01

    Photosystem II (PSII), a large multisubunit membrane protein complex found in the thylakoid membranes of cyanobacteria, algae and plants, catalyzes light-driven oxygen evolution from water and reduction of plastoquinone. Biogenesis of PSII requires coordinated assembly of at least 20 protein subunits, as well as incorporation of various organic and inorganic cofactors. The stepwise assembly process is facilitated by numerous protein factors that have been identified in recent years. Further analysis of this process requires the development or refinement of specific methods for the identification of novel assembly factors and, in particular, elucidation of the unique role of each. Here we summarize current knowledge of PSII biogenesis in cyanobacteria, focusing primarily on the impact of methodological advances and innovations. This article is part of a Special Issue entitled Organization and dynamics of bioenergetic systems in bacteria, edited by Conrad Mullineaux.

  6. Oil Body Biogenesis during Brassica napus Embryogenesis

    Institute of Scientific and Technical Information of China (English)

    Yu-Qing He; Yan Wu

    2009-01-01

    Although the oil body is known to be an important membrane enclosed compartment for oil storage in seeds, we have little understanding about its biogenesis during embryogenesis. In the present study we investigated the oil body emergence and variations in Brassica napus cv. Topas. The results demonstrate that the oil bodies could be detected already at the heart stage, at the same time as the embryos began to tum green, and the starch grains accumulated in the chloroplast stroma. In comparison, we have studied the development of oil bodies between Arabidopsis thaliana wild type (Col) and the low-seed-oil mutant wrinkled1-3. We observed that the oil body development in the embryos of Col is similar to that of B. napus cv. Topas, and that the size of the oil bodies was obviously smaller in the embryos of wrinkled1-3. Our results suggest that the oil body biogenesis might be coupled with the embryo chloroplast.

  7. The circadian clock coordinates ribosome biogenesis.

    Directory of Open Access Journals (Sweden)

    Céline Jouffe

    Full Text Available Biological rhythms play a fundamental role in the physiology and behavior of most living organisms. Rhythmic circadian expression of clock-controlled genes is orchestrated by a molecular clock that relies on interconnected negative feedback loops of transcription regulators. Here we show that the circadian clock exerts its function also through the regulation of mRNA translation. Namely, the circadian clock influences the temporal translation of a subset of mRNAs involved in ribosome biogenesis by controlling the transcription of translation initiation factors as well as the clock-dependent rhythmic activation of signaling pathways involved in their regulation. Moreover, the circadian oscillator directly regulates the transcription of ribosomal protein mRNAs and ribosomal RNAs. Thus the circadian clock exerts a major role in coordinating transcription and translation steps underlying ribosome biogenesis.

  8. Ribosome biogenesis during skeletal muscle hypertrophy

    OpenAIRE

    von Walden, Ferdinand

    2014-01-01

    Muscle adaptation to chronic resistance exercise (RE) is the result of a cumulative effect on gene expression and protein content. Following a bout of RE, muscle protein synthesis increases and, if followed by consecutive bouts (training), protein accretion and muscle hypertrophy develops. The protein synthetic capacity of the muscle is dictated by ribosome content. Therefore, the general aim of this thesis is to investigate the regulation of ribosome biogenesis during skeletal muscle hypertr...

  9. Explaining tomato fruit growth by a multi-scale model on regulation of cell division, cell growth and carbohydrate dynamics

    NARCIS (Netherlands)

    Visser, de P.H.B.; Kromdijk, W.; Okello, R.C.; Fanwoua, J.; Struik, P.C.; Yin, X.; Heuvelink, E.; Marcelis, L.F.M.

    2012-01-01

    A multi-scale approach to model tomato fruit growth is proposed, in order to account for the interaction between gene functioning and growth conditions, and, ultimately, to explain the fruit phenotype of various genotypes in diverse growth environments. There is particular focus on: (I) cell divisio

  10. Growth kinetics of Thiobacillus ferrooxidans in bioelectrochemical cell

    Institute of Scientific and Technical Information of China (English)

    李宏煦; 王淀佐; 邱冠周; 胡岳华

    2004-01-01

    Thiobacillus ferrooxidans might be the most important bacteria used in biometallurgy. The foundation way of its growth process is oxidizing ferrous in order to obtain energy needed for metabolism, but the variation of ferrous concentration and mixed potential of the culture media would have crucial effect on the bacteria growth.Based on the characteristics of Thiobacillus ferrooxidans growth and redox potential of ferric and ferrous, an electrochemical cell was designed conventionally to study growth rule and the relationship between redox potential and bacteria growth was built up, and some growth kinetics of Thiobacillus ferrooxidans were elucidated. It demonstrates that the variation of open potential of electrochemical cell △E shows the growth tendency of Thiobacillus ferrooxidans, at the initial growth stage, the value of △E increases slowly, when at logistic growth stage, it increases drastically, and the growth rate of bacteria is linear with the oxidation rate of ferrous. The bacteria growth kinetics model is proposed using Monod and Michealis-Menten equation, and the kinetics parameters are got. The consistence of the measured and the calculated results proves that it is proper to use the proposed kinetics model and the electrochemical cell method to describe the growth rule of Thiobacillus ferrooxidans.

  11. MHC class II molecules regulate growth in human T cells

    DEFF Research Database (Denmark)

    Nielsen, M; Odum, Niels; Bendtzen, K;

    1994-01-01

    modulate several T cell responses. Here, we studied further the role of class II molecules in the regulation of T cell growth. Costimulation of class II molecules by immobilized HLA-DR mAb significantly enhanced interleukin (IL)-2-supported T cell growth of the majority of CD4+, CD45RAlow, ROhigh T cell......-like) as well as T cells producing both cytokines (THO-like) responded to class II mAb. The costimulatory effect was not restricted to IL-2-driven T cell growth, since TCR/CD3-induced T cell activation was also enhanced by HLA-DR mAb. Moreover, class II costimulation potentiated CD28-mAb-induced T cell...

  12. Growth of children with Langerhans cell histiocytosis

    NARCIS (Netherlands)

    A.C.J. van den Hoek (A. C J); A. Karstens (A.); R.M. Egeler (Maarten); K. Hählen (Karel)

    1995-01-01

    textabstractConclusion: GH deficiency is not a common manifestation of LCH in childhood and GH provocation tests are only indicated when there is a poor or decelerating growth rate. In our patients the number of organs involved and/or the treatment modality did not influence the growth in all but on

  13. Dihydroartemisinin is an inhibitor of ovarian cancer cell growth

    Institute of Scientific and Technical Information of China (English)

    Yang JIAO; Chun-min GE; Qing-hui MENG; Jian-ping CAO; Jian TONG; Sai-jun FAN

    2007-01-01

    Aim: To investigate the anticancer activity of dihydroartemisinin (DHA), a deriva-tive of antimalaria drug artemisinin in a panel of human ovarian cancer cell lines. Methods: Cell growth was determined by the MTT viability assay. Apoptosis and cell cycle progression were evaluated by a DNA fragmentation gel electro-phoresis, flow cytometry assay, and TUNEL assay; protein and mRNA expression were analyzed by Western blotting and RT-PCR assay. Results: Artemisinin and its derivatives, including artesunate, arteether, artemether, arteannuin, and DHA, exhibit anticancer growth activities in human ovarian cancer cells. Among them, DHA is the most effective in inhibiting cell growth. Ovarian cancer cell lines are more sensitive (5-10-fold) to DHA treatment compared to normal ovarian cell lines. DHA at micromolar dose levels exhibits a dose- and time-dependent cyto-toxicity in ovarian cancer cell lines. Furthermore, DHA induced apoptosis and G2 cell cycle arrest, accompanied by a decrease of Bcl-xL and Bcl-2 and an increase of Bax and Bad. Conclusion: The promising results show for the first time that DHA inhibits the growth of human ovarian cancer cells. The selective inhibition of ovarian cancer cell growth, apoptosis induction, and G2 arrest provide in vitro evidence for further studies of DHA as a possible anticancer drug in the clinical treatment of ovarian cancer.

  14. Another brick in the cell wall: biosynthesis dependent growth model.

    Directory of Open Access Journals (Sweden)

    Adelin Barbacci

    Full Text Available Expansive growth of plant cell is conditioned by the cell wall ability to extend irreversibly. This process is possible if (i a tensile stress is developed in the cell wall due to the coupling effect between turgor pressure and the modulation of its mechanical properties through enzymatic and physicochemical reactions and if (ii new cell wall elements can be synthesized and assembled to the existing wall. In other words, expansive growth is the result of coupling effects between mechanical, thermal and chemical energy. To have a better understanding of this process, models must describe the interplay between physical or mechanical variable with biological events. In this paper we propose a general unified and theoretical framework to model growth in function of energy forms and their coupling. This framework is based on irreversible thermodynamics. It is then applied to model growth of the internodal cell of Chara corallina modulated by changes in pressure and temperature. The results describe accurately cell growth in term of length increment but also in term of cell pectate biosynthesis and incorporation to the expanding wall. Moreover, the classical growth model based on Lockhart's equation such as the one proposed by Ortega, appears as a particular and restrictive case of the more general growth equation developed in this paper.

  15. Growth-stimulatory effect of resveratrol in human cancer cells.

    Science.gov (United States)

    Fukui, Masayuki; Yamabe, Noriko; Kang, Ki Sung; Zhu, Bao Ting

    2010-08-01

    Earlier studies have shown that resveratrol could induce death in several human cancer cell lines in culture. Here we report our observation that resveratrol can also promote the growth of certain human cancer cells when they are grown either in culture or in athymic nude mice as xenografts. At relatively low concentrations (cells, but this effect was not observed in several other human cell lines tested. Analysis of cell signaling molecules showed that resveratrol induced the activation of JNK, p38, Akt, and NF-kappaB signaling pathways in these cells. Further analysis using pharmacological inhibitors showed that only the NF-kappaB inhibitor (BAY11-7082) abrogated the growth-stimulatory effect of resveratrol in cultured cells. In athymic nude mice, resveratrol at 16.5 mg/kg body weight enhanced the growth of MDA-MB-435s xenografts compared to the control group, while resveratrol at the 33 mg/kg body weight dose did not have a similar effect. Additional analyses confirmed that resveratrol stimulated cancer cell growth in vivo through activation of the NF-kappaB signaling pathway. Taken together, these observations suggest that resveratrol at low concentrations could stimulate the growth of certain types of human cancer cells in vivo. This cell type-specific mitogenic effect of resveratrol may also partly contribute to the procarcinogenic effect of alcohol consumption (rich in resveratrol) in the development of certain human cancers.

  16. Influence of O polysaccharides on biofilm development and outer membrane vesicle biogenesis in Pseudomonas aeruginosa PAO1.

    Science.gov (United States)

    Murphy, Kathleen; Park, Amber J; Hao, Youai; Brewer, Dyanne; Lam, Joseph S; Khursigara, Cezar M

    2014-04-01

    Pseudomonas aeruginosa is a common opportunistic human pathogen known for its ability to adapt to changes in its environment during the course of infection. These adaptations include changes in the expression of cell surface lipopolysaccharide (LPS), biofilm development, and the production of a protective extracellular exopolysaccharide matrix. Outer membrane vesicles (OMVs) have been identified as an important component of the extracellular matrix of P. aeruginosa biofilms and are thought to contribute to the development and fitness of these bacterial communities. The goal of this study was to examine the relationships between changes in the cell surface expression of LPS O polysaccharides, biofilm development, and OMV biogenesis in P. aeruginosa. We compared wild-type P. aeruginosa PAO1 with three chromosomal knockouts. These knockouts have deletions in the rmd, wbpM, and wbpL genes that produce changes in the expression of common polysaccharide antigen (CPA), O-specific antigen (OSA), or both. Our results demonstrate that changes in O polysaccharide expression do not significantly influence OMV production but do affect the size and protein content of OMVs derived from both CPA(-) and OSA(-) cells; these mutant cells also exhibited different physical properties from wild-type cells. We further examined biofilm growth of the mutants and determined that CPA(-) cells could not develop into robust biofilms and exhibit changes in cell morphology and biofilm matrix production. Together these results demonstrate the importance of O polysaccharide expression on P. aeruginosa OMV composition and highlight the significance of CPA expression in biofilm development. PMID:24464462

  17. Endothelial cell-derived interleukin-6 regulates tumor growth

    International Nuclear Information System (INIS)

    Endothelial cells play a complex role in the pathobiology of cancer. This role is not limited to the making of blood vessels to allow for influx of oxygen and nutrients required for the high metabolic demands of tumor cells. Indeed, it has been recently shown that tumor-associated endothelial cells secrete molecules that enhance tumor cell survival and cancer stem cell self-renewal. The hypothesis underlying this work is that specific disruption of endothelial cell-initiated signaling inhibits tumor growth. Conditioned medium from primary human dermal microvascular endothelial cells (HDMEC) stably transduced with silencing RNA for IL-6 (or controls) was used to evaluate the role of endothelial-derived IL-6 on the activation of key signaling pathways in tumor cells. In addition, these endothelial cells were co-transplanted with tumor cells into immunodefficient mice to determine the impact of endothelial cell-derived IL-6 on tumor growth and angiogenesis. We observed that tumor cells adjacent to blood vessels show strong phosphorylation of STAT3, a key mediator of tumor progression. In search for a possible mechanism for the activation of the STAT3 signaling pathway, we observed that silencing interleukin (IL)-6 in tumor-associated endothelial cells inhibited STAT3 phosphorylation in tumor cells. Notably, tumors vascularized with IL-6-silenced endothelial cells showed lower intratumoral microvessel density, lower tumor cell proliferation, and slower growth than tumors vascularized with control endothelial cells. Collectively, these results demonstrate that IL-6 secreted by endothelial cells enhance tumor growth, and suggest that cancer patients might benefit from targeted approaches that block signaling events initiated by endothelial cells

  18. Regulatory Multidimensionality of Gas Vesicle Biogenesis in Halobacterium salinarum NRC-1

    Directory of Open Access Journals (Sweden)

    Andrew I. Yao

    2011-01-01

    Full Text Available It is becoming clear that the regulation of gas vesicle biogenesis in Halobacterium salinarum NRC-1 is multifaceted and appears to integrate environmental and metabolic cues at both the transcriptional and posttranscriptional levels. The mechanistic details underlying this process, however, remain unclear. In this manuscript, we quantify the contribution of light scattering made by both intracellular and released gas vesicles isolated from Halobacterium salinarum NRC-1, demonstrating that each form can lead to distinct features in growth curves determined by optical density measured at 600 nm (OD600. In the course of the study, we also demonstrate the sensitivity of gas vesicle accumulation in Halobacterium salinarum NRC-1 on small differences in growth conditions and reevaluate published works in the context of our results to present a hypothesis regarding the roles of the general transcription factor tbpD and the TCA cycle enzyme aconitase on the regulation of gas vesicle biogenesis.

  19. A Neutral Theory of Biogenesis

    Science.gov (United States)

    Ferracin, Alessandro

    1981-12-01

    The selective Darwinian theory of chemical evolution is critically reviewed and the tentative conclusion is reached that neither the theoretical analyses nor the experiments with phages can really prove it. An alternative proposal is put forth which considers the possibility that the biogenetic process has been driven by stochastic forces, e.g. it took place in the absence of Darwinian selection which, in turn, started only when the first protocells came into existence. The dynamics of the early self-organization of living structures should be understood in terms of self-assembly. The complexification of living matter is thus not represented as a gradual phenomenon but as a series of abrupt and relatively fast transitions consisting in the aggregation of pre-systems which had evolved by their own. The shift towards new and variegated states proposed by the bifurcation theory are not considered particularly relevant for reasons reported in the text, nor is it believed that dissipation can entirely account for the order observed in living cells.

  20. Ribosomal protein methyltransferases in the yeast Saccharomyces cerevisiae: Roles in ribosome biogenesis and translation.

    Science.gov (United States)

    Al-Hadid, Qais; White, Jonelle; Clarke, Steven

    2016-02-12

    A significant percentage of the methyltransferasome in Saccharomyces cerevisiae and higher eukaryotes is devoted to methylation of the translational machinery. Methylation of the RNA components of the translational machinery has been studied extensively and is important for structure stability, ribosome biogenesis, and translational fidelity. However, the functional effects of ribosomal protein methylation by their cognate methyltransferases are still largely unknown. Previous work has shown that the ribosomal protein Rpl3 methyltransferase, histidine protein methyltransferase 1 (Hpm1), is important for ribosome biogenesis and translation elongation fidelity. In this study, yeast strains deficient in each of the ten ribosomal protein methyltransferases in S. cerevisiae were examined for potential defects in ribosome biogenesis and translation. Like Hpm1-deficient cells, loss of four of the nine other ribosomal protein methyltransferases resulted in defects in ribosomal subunit synthesis. All of the mutant strains exhibited resistance to the ribosome inhibitors anisomycin and/or cycloheximide in plate assays, but not in liquid culture. Translational fidelity assays measuring stop codon readthrough, amino acid misincorporation, and programmed -1 ribosomal frameshifting, revealed that eight of the ten enzymes are important for translation elongation fidelity and the remaining two are necessary for translation termination efficiency. Altogether, these results demonstrate that ribosomal protein methyltransferases in S. cerevisiae play important roles in ribosome biogenesis and translation.

  1. Possible dual regulatory circuits involving AtS6K1 in the regulation of plant cell cycle and growth.

    Science.gov (United States)

    Shin, Yun-jeong; Kim, Sunghan; Du, Hui; Choi, Soonyoung; Verma, Desh Pal S; Cheon, Choong-Ill

    2012-05-01

    The role of Arabidopsis S6 Kinase 1 (AtS6K1), a downstream target of TOR kinase, in controlling plant growth and ribosome biogenesis was characterized after generating transgenic plants expressing AtS6K1 under auxin-inducible promoter. Down regulation of selected cell cycle regulatory genes upon auxin treatment was observed in the transgenic plants, confirming the negative regulatory role of AtS6K1 in the plant cell cycle progression reported earlier. Callus tissues established from these transgenic plants grew to larger cell masses with more number of enlarged cells than untransformed control, demonstrating functional implication of AtS6K1 in the control of plant cell size. The observed negative correlation between the expression of AtS6K1 and the cell cycle regulatory genes, however, was completely reversed in protoplasts generated from the transgenic plants expressing AtS6K1, suggesting a possible existence of dual regulatory mechanism of the plant cell cycle regulation mediated by AtS6K1. An alternative method of kinase assay, termed "substrate-mediated kinase pull down", was employed to examine the additional phosphorylation on other domains of AtS6K1 and verified the phosphorylation of both amino- and carboxy-terminal domains, which is a novel finding regarding the phosphorylation target sites on plant S6Ks by upstream regulatory kinases. In addition, this kinase assay under the stress conditions revealed the salt- and sugar-dependencies of AtS6K1 phosphorylations.

  2. Targeting Btk with ibrutinib inhibit gastric carcinoma cells growth

    Science.gov (United States)

    Wang, Jin Dao; Chen, Xiao Ying; Ji, Ke Wei; Tao, Feng

    2016-01-01

    Bruton’s tyrosine kinase (Btk) is a member of the Tec-family non-receptor tyrosine kinases family. It has previously been reported to be expressed in B cells and has an important role in B-cell malignancies. While the roles of Btk in the pathogenesis of certain B-cell malignancies are well established, the functions of Btk in gastric carcinoma have never been investigated. Herein, we found that Btk is over-expressed in gastric carcinoma tissues and gastric cancer cells. Knockdown of Btk expression selectively inhibits the growth of gastric cancer cells, but not that of the normal gastric mucosa epithelial cell, which express very little Btk. Inhibition of Btk by its inhibitor ibrutinib has an additive inhibitory effect on gastric cancer cell growth. Treatment of gastric cancer cells, but not immortalized breast epithelial cells with ibrutinib results in effective cell killing, accompanied by the attenuation of Btk signals. Ibrutinib also induces apoptosis in gastric carcinoma cells as well as is a chemo-sensitizer for docetaxel (DTX), a standard of care for gastric carcinoma patients. Finally, ibrutinib markedly reduces tumor growth and increases tumor cell apoptosis in the tumors formed in mice inoculated with the gastric carcinoma cells. Given these promising preclinical results for ibrutinib in gastric carcinoma, a strategy combining Btk inhibitor warrants attention in gastric cancer. PMID:27508020

  3. Catalase regulates cell growth in HL60 human promyelocytic cells: evidence for growth regulation by H(2)O(2).

    Science.gov (United States)

    Hachiya, Misao; Akashi, Makoto

    2005-03-01

    Reactive oxygen species (ROS) including hydrogen peroxide (H(2)O(2)) are generated constitutively in mammalian cells. Because of its relatively long life and high permeability across membranes, H(2)O(2) is thought to be an important second messenger. Generation of H(2)O(2) is increased in response to external insults, including radiation. Catalase is located at the peroxisome and scavenges H(2)O(2). In this study, we investigated the role of catalase in cell growth using the H(2)O(2)-resistant variant HP100-1 of human promyelocytic HL60 cells. HP100-1 cells had an almost 10-fold higher activity of catalase than HL60 cells without differences in levels of glutathione peroxidase, manganese superoxide dismutase (MnSOD), and copper-zinc SOD (CuZnSOD). HP100-1 cells had higher proliferative activity than HL60 cells. Treatment with catalase or the introduction of catalase cDNA into HL60 cells stimulated cell growth. Exposure of HP100-1 cells to a catalase inhibitor resulted in suppression of cell growth with concomitant increased levels of intracellular H(2)O(2). Moreover, exogenously added H(2)O(2) or depletion of glutathione suppressed cell growth in HL60 cells. Extracellular signal regulated kinase 1/2 (ERK1/2) was constitutively phosphorylated in HP100-1 cells but not in HL60 cells. Inhibition of the ERK1/2 pathway suppressed the growth of HP100-1 cells, but inhibition of p38 mitogen-activated protein kinase (p38MAPK) did not affect growth. Moreover, inhibition of catalase blocked the phosphorylation of ERK1/2 but not of p38MAPK in HP100-1 cells. Thus our results suggest that catalase activates the growth of HL60 cells through dismutation of H(2)O(2), leading to activation of the ERK1/2 pathway; H(2)O(2) is an important regulator of growth in HL60 cells.

  4. Purification and cultivation of human pituitary growth hormone secreting cells

    Science.gov (United States)

    Hymer, W. C.

    1984-01-01

    A multiphase study was conducted to examine the properties of growth hormone cells. Topics investigated included: (1) to determine if growth hormone (GH) cells contained within the rat pituitary gland can be separated from the other hormone producing cell types by continuous flow electrophoresis (CFE); (2) to determine what role, if any, gravity plays in the electrophoretic separation of GH cells; (3) to compare in vitro GH release from rat pituitary cells previously exposed to microgravity conditions vs release from cells not exposed to microgravity; (4) to determine if the frequency of different hormone producing pituitary cell types contained in cell suspensions can be quantitated by flow cytometry; and (5) to determine if GH contained within the human post mortem pituitary gland can be purified by CFE. Specific experimental procedures and results are included.

  5. Tracking the Biogenesis and Inheritance of Subpellicular Microtubule in Trypanosoma brucei with Inducible YFP-α-Tubulin

    Directory of Open Access Journals (Sweden)

    Omar Sheriff

    2014-01-01

    Full Text Available The microtubule cytoskeleton forms the most prominent structural system in Trypanosoma brucei, undergoing extensive modifications during the cell cycle. Visualization of tyrosinated microtubules leads to a semiconservative mode of inheritance, whereas recent studies employing microtubule plus end tracking proteins have hinted at an asymmetric pattern of cytoskeletal inheritance. To further the knowledge of microtubule synthesis and inheritance during T. brucei cell cycle, the dynamics of the microtubule cytoskeleton was visualized by inducible YFP-α-tubulin expression. During new flagellum/flagellum attachment zone (FAZ biogenesis and cell growth, YFP-α-tubulin was incorporated mainly between the old and new flagellum/FAZ complexes. Cytoskeletal modifications at the posterior end of the cells were observed with EB1, a microtubule plus end binding protein, particularly during mitosis. Additionally, the newly formed microtubules segregated asymmetrically, with the daughter cell inheriting the new flagellum/FAZ complex retaining most of the new microtubules. Together, our results suggest an intimate connection between new microtubule formation and new FAZ assembly, consequently leading to asymmetric microtubule inheritance and cell division.

  6. Myristoylated CIL-7 regulates ciliary extracellular vesicle biogenesis.

    Science.gov (United States)

    Maguire, Julie E; Silva, Malan; Nguyen, Ken C Q; Hellen, Elizabeth; Kern, Andrew D; Hall, David H; Barr, Maureen M

    2015-08-01

    The cilium both releases and binds to extracellular vesicles (EVs). EVs may be used by cells as a form of intercellular communication and mediate a broad range of physiological and pathological processes. The mammalian polycystins (PCs) localize to cilia, as well as to urinary EVs released from renal epithelial cells. PC ciliary trafficking defects may be an underlying cause of autosomal dominant polycystic kidney disease (PKD), and ciliary-EV interactions have been proposed to play a central role in the biology of PKD. In Caenorhabditis elegans and mammals, PC1 and PC2 act in the same genetic pathway, act in a sensory capacity, localize to cilia, and are contained in secreted EVs, suggesting ancient conservation. However, the relationship between cilia and EVs and the mechanisms generating PC-containing EVs remain an enigma. In a forward genetic screen for regulators of C. elegans PKD-2 ciliary localization, we identified CIL-7, a myristoylated protein that regulates EV biogenesis. Loss of CIL-7 results in male mating behavioral defects, excessive accumulation of EVs in the lumen of the cephalic sensory organ, and failure to release PKD-2::GFP-containing EVs to the environment. Fatty acylation, such as myristoylation and palmitoylation, targets proteins to cilia and flagella. The CIL-7 myristoylation motif is essential for CIL-7 function and for targeting CIL-7 to EVs. C. elegans is a powerful model with which to study ciliary EV biogenesis in vivo and identify cis-targeting motifs such as myristoylation that are necessary for EV-cargo association and function. PMID:26041936

  7. Human telomerase: biogenesis, trafficking, recruitment, and activation.

    Science.gov (United States)

    Schmidt, Jens C; Cech, Thomas R

    2015-06-01

    Telomerase is the ribonucleoprotein enzyme that catalyzes the extension of telomeric DNA in eukaryotes. Recent work has begun to reveal key aspects of the assembly of the human telomerase complex, its intracellular trafficking involving Cajal bodies, and its recruitment to telomeres. Once telomerase has been recruited to the telomere, it appears to undergo a separate activation step, which may include an increase in its repeat addition processivity. This review covers human telomerase biogenesis, trafficking, and activation, comparing key aspects with the analogous events in other species.

  8. Connective Tissue Growth Factor Expression in Human Bronchial Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    Amrita DOSANJH

    2006-01-01

    Connective tissue growth factor (CTGF) is a cysteine-rich protein that promotes extracellular matrix deposition. CTGF is selectively induced by transforming growth factor β and des-Arg kallidin in lung fibroblasts and increases steady-state mRNA levels of α type I collagen, 5α-integrin and fibronectin in fibroblasts. Bronchial epithelial cells have been proposed to functionally interact with lung fibroblasts. We therefore investigated if bronchial epithelial cells are able to synthesize CTGF. Human bronchial epithelial cells were grown to subconfluence in standard growth media. Proliferating cells grown in small airway growth media were harvested following starvation for up to 24 h. Expression of CTGF transcripts was measured by PCR. Immunocytochemistry was also completed using a commercially available antibody.The cells expressed readily detectable CTGF transcripts. Starvation of these cells resulted in a quantitative decline of CTGF transcripts. Direct sequencing of the PCR product identified human CTGF. Immunocytochemistry confirmed intracellular CTGF in the cells and none in negative control cells. We conclude that bronchial epithelial cells could be a novel source of CTGF. Bronchial epithelial cell-derived CTGF could thus directly influence the deposition of collagen in certain fibrotic lung diseases.

  9. Insulin-like growth factor binding protein-5 influences pancreatic cancer cell growth

    Institute of Scientific and Technical Information of China (English)

    Sarah K Johnson; Randy S Haun

    2009-01-01

    AIM: To investigate the functional significance of insulin-like growth factor binding protein-5 (IGFBP-5) overexpression in pancreatic cancer (PaC).METHODS: The effects of IGFBP-5 on cell growth were assessed by stable transfection of BxPC-3 and PANC-1 cell lines and measuring cell number and DNA synthesis. Alterations in the cell cycle were assessed by flow cytometry and immunoblot analyses.Changes in cell survival and signal transduction were evaluated after mitogen activated protein kinase and phosphatidylinositol 3-kinase (PI3K) inhibitor treatment.RESULTS: After serum depr ivat ion, IGFBP-5 expression increased both cell number and DNA synthesis in BxPC-3 cells, but reduced cell number in PANC-1 cells. Consistent with this observation, cell cycle analysis of IGFBP-5-expressing cells revealed accelerated cell cycle progression in BxPC-3 and G2/M arrest of PANC-1 cells. Signal transduction analysis revealed that Akt activation was increased in BxPC-3, but reduced in PANC-1 cells that express IGFBP-5. Inhibition of PI3K with LY294002 suppressed extracellular signal-regulated kinase-1 and -2 (ERK1/2) activation in BxPC-3, but enhanced ERK1/2 activation in PANC-1 cells that express IGFBP-5. When MEK1/2 was blocked, Akt activation remained elevated in IGFBP-5 expressing PaC cells; however, inhibition of PI3K or MEK1/2 abrogated IGFBP-5-mediated cell survival.CONCLUSION: These results indicate that IGFBP-5 expression affects the cell cycle and survival signal pathways and thus it may be an important mediator of PaC cell growth.

  10. TOR and paradigm change: cell growth is controlled.

    Science.gov (United States)

    Hall, Michael N

    2016-09-15

    This year marks the 25th anniversary of the discovery of target of rapamycin (TOR), a highly conserved kinase and central controller of cell growth. In this Retrospective, I briefly describe the discovery of TOR and the subsequent elucidation of its cellular role. I place particular emphasis on an article by Barbet et al. from 1996, the first suggesting that TOR controls cell growth in response to nutrients.

  11. TOR and paradigm change: cell growth is controlled.

    Science.gov (United States)

    Hall, Michael N

    2016-09-15

    This year marks the 25th anniversary of the discovery of target of rapamycin (TOR), a highly conserved kinase and central controller of cell growth. In this Retrospective, I briefly describe the discovery of TOR and the subsequent elucidation of its cellular role. I place particular emphasis on an article by Barbet et al. from 1996, the first suggesting that TOR controls cell growth in response to nutrients. PMID:27634743

  12. Critical telomerase activity for uncontrolled cell growth.

    Science.gov (United States)

    Wesch, Neil L; Burlock, Laura J; Gooding, Robert J

    2016-01-01

    The lengths of the telomere regions of chromosomes in a population of cells are modelled using a chemical master equation formalism, from which the evolution of the average number of cells of each telomere length is extracted. In particular, the role of the telomere-elongating enzyme telomerase on these dynamics is investigated. We show that for biologically relevant rates of cell birth and death, one finds a critical rate, R crit, of telomerase activity such that the total number of cells diverges. Further, R crit is similar in magnitude to the rates of mitosis and cell death. The possible relationship of this result to replicative immortality and its associated hallmark of cancer is discussed. PMID:27500377

  13. Critical telomerase activity for uncontrolled cell growth

    Science.gov (United States)

    Wesch, Neil L.; Burlock, Laura J.; Gooding, Robert J.

    2016-08-01

    The lengths of the telomere regions of chromosomes in a population of cells are modelled using a chemical master equation formalism, from which the evolution of the average number of cells of each telomere length is extracted. In particular, the role of the telomere-elongating enzyme telomerase on these dynamics is investigated. We show that for biologically relevant rates of cell birth and death, one finds a critical rate, R crit, of telomerase activity such that the total number of cells diverges. Further, R crit is similar in magnitude to the rates of mitosis and cell death. The possible relationship of this result to replicative immortality and its associated hallmark of cancer is discussed.

  14. Molecular mobility of scaffolds' biopolymers influences cell growth.

    Science.gov (United States)

    Podlipec, Rok; Gorgieva, Selestina; Jurašin, Darija; Urbančič, Iztok; Kokol, Vanja; Strancar, Janez

    2014-09-24

    Understanding biocompatibility of materials and scaffolds is one of the main challenges in the field of tissue engineering and regeneration. The complex nature of cell-biomaterial interaction requires extensive preclinical functionality testing by studying specific cell responses to different biomaterial properties, from morphology and mechanics to surface characteristics at the molecular level. Despite constant improvements, a more general picture of biocompatibility is still lacking and tailormade scaffolds are not yet available. The scope of our study was thus the investigation of the correlation of fibroblast cell growth on different gelatin scaffolds with their morphological, mechanical as well as surface molecular properties. The latter were thoroughly investigated via polymer molecular mobility studied by site-directed spin labeling and electron paramagnetic resonance spectroscopy (EPR) for the first time. Anisotropy of the rotational motion of the gelatin side chain mobility was identified as the most correlated quantity with cell growth in the first days after adhesion, while weaker correlations were found with scaffold viscoelasticity and no correlations with scaffold morphology. Namely, the scaffolds with highly mobile or unrestricted polymers identified with the cell growth being five times less efficient (N(cells) = 60 ± 25 mm(-2)) as compared to cell growth on the scaffolds with considerable part of polymers with the restricted rotational motion (N(cells) = 290 ± 25 mm(-2)). This suggests that molecular mobility of scaffold components could play an important role in cell response to medical devices, reflecting a new aspect of the biocompatibility concept.

  15. Unravelling the mechanisms regulating muscle mitochondrial biogenesis.

    Science.gov (United States)

    Hood, David A; Tryon, Liam D; Carter, Heather N; Kim, Yuho; Chen, Chris C W

    2016-08-01

    Skeletal muscle is a tissue with a low mitochondrial content under basal conditions, but it is responsive to acute increases in contractile activity patterns (i.e. exercise) which initiate the signalling of a compensatory response, leading to the biogenesis of mitochondria and improved organelle function. Exercise also promotes the degradation of poorly functioning mitochondria (i.e. mitophagy), thereby accelerating mitochondrial turnover, and preserving a pool of healthy organelles. In contrast, muscle disuse, as well as the aging process, are associated with reduced mitochondrial quality and quantity in muscle. This has strong negative implications for whole-body metabolic health and the preservation of muscle mass. A number of traditional, as well as novel regulatory pathways exist in muscle that control both biogenesis and mitophagy. Interestingly, although the ablation of single regulatory transcription factors within these pathways often leads to a reduction in the basal mitochondrial content of muscle, this can invariably be overcome with exercise, signifying that exercise activates a multitude of pathways which can respond to restore mitochondrial health. This knowledge, along with growing realization that pharmacological agents can also promote mitochondrial health independently of exercise, leads to an optimistic outlook in which the maintenance of mitochondrial and whole-body metabolic health can be achieved by taking advantage of the broad benefits of exercise, along with the potential specificity of drug action. PMID:27470593

  16. Human vascular smooth muscle cells both express and respond to heparin-binding growth factor I (endothelial cell growth factor).

    OpenAIRE

    Winkles, J A; Friesel, R; Burgess, W H; Howk, R; Mehlman, T; Weinstein, R.; T. MACIAG

    1987-01-01

    The control of vascular endothelial and smooth muscle cell proliferation is important in such processes as tumor angiogenesis, wound healing, and the pathogenesis of atherosclerosis. Class I heparin-binding growth factor (HBGF-I) is a potent mitogen and chemoattractant for human endothelial cells in vitro and will induce angiogenesis in vivo. RNA gel blot hybridization experiments demonstrate that cultured human vascular smooth muscle cells, but not human umbilical vein endothelial cells, exp...

  17. Biogenesis of inner membrane proteins in Escherichia coli.

    Science.gov (United States)

    Luirink, Joen; Yu, Zhong; Wagner, Samuel; de Gier, Jan-Willem

    2012-06-01

    The inner membrane proteome of the model organism Escherichia coli is composed of inner membrane proteins, lipoproteins and peripherally attached soluble proteins. Our knowledge of the biogenesis of inner membrane proteins is rapidly increasing. This is in particular true for the early steps of biogenesis - protein targeting to and insertion into the membrane. However, our knowledge of inner membrane protein folding and quality control is still fragmentary. Furthering our knowledge in these areas will bring us closer to understand the biogenesis of individual inner membrane proteins in the context of the biogenesis of the inner membrane proteome of Escherichia coli as a whole. This article is part of a Special Issue entitled: Biogenesis/Assembly of Respiratory Enzyme Complexes.

  18. In vitro effects of recombinant human growth hormone on growth of human gastric cancer cell line BGC823 cells

    Institute of Scientific and Technical Information of China (English)

    Jia-Yong Chen; Dao-Ming Liang; Ping Gan; Yi Zhang; Jie Lin

    2004-01-01

    AIM: To study the effects of recombinant human growth hormone (rhGH) on growth of human gastric cancer cell line in vitro.METHODS: Experiment was divided into control group,rhGH group, oxaliplatin (L-OHP) group and rhGH+L-OHP group. Cell inhibitory rate, cell cycle, cell proliferation index (PI) and DNA inhibitory rate of human gastric cancer line BGC823, at different concentrations of rhGH treatment were studied by cell culture, MTT assay and flow cytometry.RESULTS: The distinctly accelerated effects of rhGH on multiplication of BGC823 cell line were not found in vitro.There was no statistical significance between rhGH group and control group, or between rhGH+L-OHP group and LOHP group (P>0.05). The cell growth curve did not rise.Cell inhibitory rate and cells arrested in G0-G1 phase were obviously increased. Meanwhile, cells in S phase and PI were distinctly decreased and DNA inhibitory rate was obviously increased in rhGH+L-OHP group in comparison with control group and rhGH group, respectively (P<0.01).Cell inhibitory rate showed an increasing trend and PI showed a decreasing trend in rhGH+L-OHP group compared with L-OHP group.CONCLUSION: In vitro rhGH does not accelerate the multiplication of human gastric cancer cells. It may increase the therapeutic efficacy when it is used in combination with anticancer drugs.

  19. Virtual microstructural leaf tissue generation based on cell growth modeling

    NARCIS (Netherlands)

    Abera, M.K.; Retta, M.A.; Verboven, P.; Nicolai, B.M.; Berghuijs, H.; Struik, P.

    2016-01-01

    A cell growth algorithm for virtual leaf tissue generation is presented based on the biomechanics of plant cells in tissues. The algorithm can account for typical differences in epidermal layers, palisade mesophyll layer and spongy mesophyll layer which have characteristic differences in the shap

  20. Nerve Growth Factor in Cancer Cell Death and Survival

    International Nuclear Information System (INIS)

    One of the major challenges for cancer therapeutics is the resistance of many tumor cells to induction of cell death due to pro-survival signaling in the cancer cells. Here we review the growing literature which shows that neurotrophins contribute to pro-survival signaling in many different types of cancer. In particular, nerve growth factor, the archetypal neurotrophin, has been shown to play a role in tumorigenesis over the past decade. Nerve growth factor mediates its effects through its two cognate receptors, TrkA, a receptor tyrosine kinase and p75NTR, a member of the death receptor superfamily. Depending on the tumor origin, pro-survival signaling can be mediated by TrkA receptors or by p75NTR. For example, in breast cancer the aberrant expression of nerve growth factor stimulates proliferative signaling through TrkA and pro-survival signaling through p75NTR. This latter signaling through p75NTR promotes increased resistance to the induction of cell death by chemotherapeutic treatments. In contrast, in prostate cells the p75NTR mediates cell death and prevents metastasis. In prostate cancer, expression of this receptor is lost, which contributes to tumor progression by allowing cells to survive, proliferate and metastasize. This review focuses on our current knowledge of neurotrophin signaling in cancer, with a particular emphasis on nerve growth factor regulation of cell death and survival in cancer

  1. Signaling Pathways in Exosomes Biogenesis, Secretion and Fate

    Directory of Open Access Journals (Sweden)

    Carla Emiliani

    2013-03-01

    Full Text Available Exosomes are small extracellular vesicles (30–100 nm derived from the endosomal system, which have raised considerable interest in the last decade. Several studies have shown that they mediate cell-to-cell communication in a variety of biological processes. Thus, in addition to cell-to-cell direct interaction or secretion of active molecules, they are now considered another class of signal mediators. Exosomes can be secreted by several cell types and retrieved in many body fluids, such as blood, urine, saliva and cerebrospinal fluid. In addition to proteins and lipids, they also contain nucleic acids, namely mRNA and miRNA. These features have prompted extensive research to exploit them as a source of biomarkers for several pathologies, such as cancer and neurodegenerative disorders. In this context, exosomes also appear attractive as gene delivery vehicles. Furthermore, exosome immunomodulatory and regenerative properties are also encouraging their application for further therapeutic purposes. Nevertheless, several issues remain to be addressed: exosome biogenesis and secretion mechanisms have not been clearly understood, and physiological functions, as well as pathological roles, are far from being satisfactorily elucidated.

  2. Mutation of EMG1 causing Bowen-Conradi syndrome results in reduced cell proliferation rates concomitant with G2/M arrest and 18S rRNA processing delay.

    Science.gov (United States)

    Armistead, Joy; Hemming, Richard; Patel, Nehal; Triggs-Raine, Barbara

    2014-06-01

    Bowen-Conradi syndrome (BCS) is a lethal autosomal recessive disorder caused by a D86G substitution in the protein, Essential for Mitotic Growth 1 (EMG1). EMG1 is essential for 18S rRNA maturation and 40S ribosome biogenesis in yeast, but no studies of its role in ribosome biogenesis have been done in mammals. To assess the effect of the EMG1 mutation on cell growth and ribosomal biogenesis in humans, we employed BCS patient cells. The D86G substitution did not interfere with EMG1 nucleolar localization. In BCS patient lymphoblasts, cells accumulated in G2/M, resulting in reduced proliferation rates; however, patient fibroblasts showed normal proliferation. The rate of 18S rRNA processing was consistently delayed in patient cells, although this did not lead to a difference in the levels of 40S ribosomes, or a change in protein synthesis rates. These results demonstrate that as in yeast, EMG1 in mammals has a role in ribosome biogenesis. The obvious phenotype in lymphoblasts compared to fibroblasts suggests a greater need for EMG1 in rapidly dividing cells. Tissue-specific effects have been seen in other ribosomal biogenesis disorders, and it seems likely that the impact of EMG1 deficiency would be larger in the rapidly proliferating cells of the developing embryo.

  3. Mutation of EMG1 causing Bowen–Conradi syndrome results in reduced cell proliferation rates concomitant with G2/M arrest and 18S rRNA processing delay

    Directory of Open Access Journals (Sweden)

    Joy Armistead

    2014-06-01

    Full Text Available Bowen–Conradi syndrome (BCS is a lethal autosomal recessive disorder caused by a D86G substitution in the protein, Essential for Mitotic Growth 1 (EMG1. EMG1 is essential for 18S rRNA maturation and 40S ribosome biogenesis in yeast, but no studies of its role in ribosome biogenesis have been done in mammals. To assess the effect of the EMG1 mutation on cell growth and ribosomal biogenesis in humans, we employed BCS patient cells. The D86G substitution did not interfere with EMG1 nucleolar localization. In BCS patient lymphoblasts, cells accumulated in G2/M, resulting in reduced proliferation rates; however, patient fibroblasts showed normal proliferation. The rate of 18S rRNA processing was consistently delayed in patient cells, although this did not lead to a difference in the levels of 40S ribosomes, or a change in protein synthesis rates. These results demonstrate that as in yeast, EMG1 in mammals has a role in ribosome biogenesis. The obvious phenotype in lymphoblasts compared to fibroblasts suggests a greater need for EMG1 in rapidly dividing cells. Tissue-specific effects have been seen in other ribosomal biogenesis disorders, and it seems likely that the impact of EMG1 deficiency would be larger in the rapidly proliferating cells of the developing embryo.

  4. Pumpkin seed extract: Cell growth inhibition of hyperplastic and cancer cells, independent of steroid hormone receptors.

    Science.gov (United States)

    Medjakovic, Svjetlana; Hobiger, Stefanie; Ardjomand-Woelkart, Karin; Bucar, Franz; Jungbauer, Alois

    2016-04-01

    Pumpkin seeds have been known in folk medicine as remedy for kidney, bladder and prostate disorders since centuries. Nevertheless, pumpkin research provides insufficient data to back up traditional beliefs of ethnomedical practice. The bioactivity of a hydro-ethanolic extract of pumpkin seeds from the Styrian pumpkin, Cucurbita pepo L. subsp. pepo var. styriaca, was investigated. As pumpkin seed extracts are standardized to cucurbitin, this compound was also tested. Transactivational activity was evaluated for human androgen receptor, estrogen receptor and progesterone receptor with in vitro yeast assays. Cell viability tests with prostate cancer cells, breast cancer cells, colorectal adenocarcinoma cells and a hyperplastic cell line from benign prostate hyperplasia tissue were performed. As model for non-hyperplastic cells, effects on cell viability were tested with a human dermal fibroblast cell line (HDF-5). No transactivational activity was found for human androgen receptor, estrogen receptor and progesterone receptor, for both, extract and cucurbitin. A cell growth inhibition of ~40-50% was observed for all cell lines, with the exception of HDF-5, which showed with ~20% much lower cell growth inhibition. Given the receptor status of some cell lines, a steroid-hormone receptor independent growth inhibiting effect can be assumed. The cell growth inhibition for fast growing cells together with the cell growth inhibition of prostate-, breast- and colon cancer cells corroborates the ethnomedical use of pumpkin seeds for a treatment of benign prostate hyperplasia. Moreover, due to the lack of androgenic activity, pumpkin seed applications can be regarded as safe for the prostate.

  5. Effect of transforming growth factor-β1 on human intrahepatic cholangiocarcinoma cell growth

    Institute of Scientific and Technical Information of China (English)

    Tetsuya Shimizu; Takashi Tajiri; Shigeki Yokomuro; Yoshiaki Mizuguchi; Yutaka Kawahigashi; Yasuo Arima; Nobuhiko Taniai; Yasuhiro Mamada; Hiroshi Yoshida; Koho Akimaru

    2006-01-01

    AIM: To elucidate the biological effects of transforming growth factor-β1 (TGF-β1) on intrahepatic cholangiocarcinoma (ICC).METHODS: We investigated the effects of TGF-β1 on human ICC cell lines (HuCCT1, MEC, and HuH-28) by monitoring the influence of TGF-β1 on tumor growth and interleukin-6 (IL-6) expression in ICC cells.RESULTS: All three human ICC cell lines produced TGF-β1 and demonstrated accelerated growth in the presence of TGF-β1 with no apoptotic effect. Studies on HuCCT1 revealed a TGF-β1-induced stimulation of the expression of TGF-β1, as well as a decrease in TGF-β1 mRNA expression induced by neutralizing anti-TGF-β1 antibody. These results indicate that TGF-β1 stimulates the production and function of TGF-β1 in an autocrine fashion. Further, IL-6 secretion was observed in all three cell lines and exhibited an inhibitory response to neutralizing anti-TGF-β1 antibody. Experiments using HuCCT1 revealed a TGF-β1-induced acceleration of IL-6 protein expression and mRNA levels. These findings demonstrate a functional interaction between TGF-β1 and IL-6. All three cell lines proliferated in the presence of IL-6. In contrast, TGF-β1 induced no growth effect in HuCCT1 in the presence of small interfering RNA against a specific cell surface receptor of IL-6 and signal transducer and activator of transcription-3.CONCLUSION: ICC cells produce TGF-β1 and confer a TGF-β1-induced growth effect in an autocrine fashion.TGF-β1 activates IL-6 production, and the functional interaction between TGF-β1 and IL-6 contributes to ICC cell growth by TGF-β1.

  6. Preparing T Cell Growth Factor from Rat Splenocytes

    OpenAIRE

    Beeton, Christine; Chandy, K. George

    2007-01-01

    Maintenance of antigen-specific T cell lines or clones in culture requires rounds of antigen-induced activation separated by phases of cell expansion 1,2. Addition of interleukin 2 to the culture media during the expansion phase is necessary to prevent cell death and sufficient to maintain short-term T cell lines but has been shown to increase Th1 polarization 3. Replacement of interleukin 2 by T cell growth factor (TCGF) which contains a mix of cytokines is more effective than interleukin 2...

  7. eIF1A augments Ago2-mediated Dicer-independent miRNA biogenesis and RNA interference

    Science.gov (United States)

    Yi, Tingfang; Arthanari, Haribabu; Akabayov, Barak; Song, Huaidong; Papadopoulos, Evangelos; Qi, Hank H.; Jedrychowski, Mark; Güttler, Thomas; Guo, Cuicui; Luna, Rafael E.; Gygi, Steven P.; Huang, Stephen A.; Wagner, Gerhard

    2015-05-01

    MicroRNA (miRNA) biogenesis and miRNA-guided RNA interference (RNAi) are essential for gene expression in eukaryotes. Here we report that translation initiation factor eIF1A directly interacts with Ago2 and promotes Ago2 activities in RNAi and miR-451 biogenesis. Biochemical and NMR analyses demonstrate that eIF1A binds to the MID domain of Ago2 and this interaction does not impair translation initiation. Alanine mutation of the Ago2-facing Lys56 in eIF1A impairs RNAi activities in human cells and zebrafish. The eIF1A-Ago2 assembly facilitates Dicer-independent biogenesis of miR-451, which mediates erythrocyte maturation. Human eIF1A (heIF1A), but not heIF1A(K56A), rescues the erythrocyte maturation delay in eif1axb knockdown zebrafish. Consistently, miR-451 partly compensates erythrocyte maturation defects in zebrafish with eif1axb knockdown and eIF1A(K56A) expression, supporting a role of eIF1A in miRNA-451 biogenesis in this model. Our results suggest that eIF1A is a novel component of the Ago2-centred RNA-induced silencing complexes (RISCs) and augments Ago2-dependent RNAi and miRNA biogenesis.

  8. Meloxicam inhibits the growth of colorectal cancer cells.

    Science.gov (United States)

    Goldman, A P; Williams, C S; Sheng, H; Lamps, L W; Williams, V P; Pairet, M; Morrow, J D; DuBois, R N

    1998-12-01

    Cyclooxygenase-2 has been reported to play an important role in colorectal carcinogenesis. The effects of meloxicam (a COX-2 inhibitor) on the growth of two colon cancer cell lines that express COX-2 (HCA-7 and Moser-S) and a COX-2 negative cell line (HCT-116) were evaluated. The growth rate of these cells was measured following treatment with meloxicam. HCA-7 and Moser-S colony size were significantly reduced following treatment with meloxicam; however, there was no significant change in HCT-116 colony size with treatment. In vivo studies were performed to evaluate the effect of meloxicam on the growth of HCA-7 cells when xenografted into nude mice. We observed a 51% reduction in tumor size after 4 weeks of treatment. Analysis of COX-1 and COX-2 protein levels in HCA-7 tumor lysates revealed a slight decrease in COX-2 expression levels in tumors taken from mice treated with meloxicam and no detectable COX-1 expression. Here we report that meloxicam significantly inhibited HCA-7 colony and tumor growth but had no effect on the growth of the COX-2 negative HCT-116 cells. PMID:9886578

  9. Human vascular smooth muscle cells both express and respond to heparin-binding growth factor I (endothelial cell growth factor)

    Energy Technology Data Exchange (ETDEWEB)

    Winkles, J.A.; Friesel, R.; Burgess, W.H.; Howk, R.; Mehlman, T.; Weinstein, R.; Maciag, T.

    1987-10-01

    The control of vascular endothelial and muscle cell proliferation is important in such processes as tumor angiogenesis, wound healing, and the pathogenesis of atherosclerosis. Class I heparin-binding growth factor (HBGF-I) is a potent mitogen and chemoattractant for human endothelial cells in vitro and will induce angiogenesis in vivo. RNA gel blot hybridization experiments demonstrate that cultured human vascular smooth muscle cells, but not human umbilical cells also synthesize an HBGF-I mRNA. Smooth muscle cells also synthesize an HBGF-I-like polypeptide since (i) extract prepared from smooth muscle cells will compete with /sup 125/I-labeled HBGF-I for binding to the HBGF-I cell surface receptor, and (ii) the competing ligand is eluted from heparin-Sepharose affinity resin at a NaCl concentration similar to that required by purified bovine brain HBGF-I and stimulates endothelial cell proliferation in vitro. Furthermore, like endothelial cells, smooth muscle cells possess cell-surface-associated HBGF-I receptors and respond to HBGF-I as a mitogen. These results indicate the potential for an additional autocrine component of vascular smooth muscle cell growth control and establish a vessel wall source of HBGF-I for endothelial cell division in vivo.

  10. Total triterpenoids from Ganoderma Lucidum suppresses prostate cancer cell growth by inducing growth arrest and apoptosis.

    Science.gov (United States)

    Wang, Tao; Xie, Zi-ping; Huang, Zhan-sen; Li, Hao; Wei, An-yang; Di, Jin-ming; Xiao, Heng-jun; Zhang, Zhi-gang; Cai, Liu-hong; Tao, Xin; Qi, Tao; Chen, Di-ling; Chen, Jun

    2015-10-01

    In this study, one immortalized human normal prostatic epithelial cell line (BPH) and four human prostate cancer cell lines (LNCaP, 22Rv1, PC-3, and DU-145) were treated with Ganoderma Lucidum triterpenoids (GLT) at different doses and for different time periods. Cell viability, apoptosis, and cell cycle were analyzed using flow cytometry and chemical assays. Gene expression and binding to DNA were assessed using real-time PCR and Western blotting. It was found that GLT dose-dependently inhibited prostate cancer cell growth through induction of apoptosis and cell cycle arrest at G1 phase. GLT-induced apoptosis was due to activation of Caspases-9 and -3 and turning on the downstream apoptotic events. GLT-induced cell cycle arrest (mainly G1 arrest) was due to up-regulation of p21 expression at the early time and down-regulation of cyclin-dependent kinase 4 (CDK4) and E2F1 expression at the late time. These findings demonstrate that GLT suppresses prostate cancer cell growth by inducing growth arrest and apoptosis, which might suggest that GLT or Ganoderma Lucidum could be used as a potential therapeutic drug for prostate cancer.

  11. Total triterpenoids from Ganoderma Lucidum suppresses prostate cancer cell growth by inducing growth arrest and apoptosis.

    Science.gov (United States)

    Wang, Tao; Xie, Zi-ping; Huang, Zhan-sen; Li, Hao; Wei, An-yang; Di, Jin-ming; Xiao, Heng-jun; Zhang, Zhi-gang; Cai, Liu-hong; Tao, Xin; Qi, Tao; Chen, Di-ling; Chen, Jun

    2015-10-01

    In this study, one immortalized human normal prostatic epithelial cell line (BPH) and four human prostate cancer cell lines (LNCaP, 22Rv1, PC-3, and DU-145) were treated with Ganoderma Lucidum triterpenoids (GLT) at different doses and for different time periods. Cell viability, apoptosis, and cell cycle were analyzed using flow cytometry and chemical assays. Gene expression and binding to DNA were assessed using real-time PCR and Western blotting. It was found that GLT dose-dependently inhibited prostate cancer cell growth through induction of apoptosis and cell cycle arrest at G1 phase. GLT-induced apoptosis was due to activation of Caspases-9 and -3 and turning on the downstream apoptotic events. GLT-induced cell cycle arrest (mainly G1 arrest) was due to up-regulation of p21 expression at the early time and down-regulation of cyclin-dependent kinase 4 (CDK4) and E2F1 expression at the late time. These findings demonstrate that GLT suppresses prostate cancer cell growth by inducing growth arrest and apoptosis, which might suggest that GLT or Ganoderma Lucidum could be used as a potential therapeutic drug for prostate cancer. PMID:26489631

  12. [RNA interference: biogenesis molecular mechanisms and its applications in cervical cancer].

    Science.gov (United States)

    Peralta-Zaragoza, Oscar; Bermúdez-Morales, Víctor Hugo; Madrid-Marina, Vicente

    2010-01-01

    RNAi (RNA interference) is a natural process by which eukaryotic cells silence gene expression through small interference RNAs (siRNA) which are complementary to messenger RNA (mRNA). In this process, the siRNA that are 21-25 nucleotides long and are known as microRNA (miRNA), either associate with the RNA-induced silencing complex (RISC), which targets and cleaves the complementary mRNAs by the endonucleolytic pathway, or repress the translation. It is also possible to silence exogenous gene expression during viral infections by using DNA templates to transcribe siRNA with properties that are identical to those of bioactive microRNA. Persistent human papillomavirus (HPV) infection is the main etiological agent during cervical cancer development and the HPV E6 and E7 oncogenes, which induce cellular transformation and immortalization, represent strategic targets to be silenced with siRNA. In several in vitro and in vivo studies, it has been demonstrated that the introduction of siRNA directed against the E6 and E7 oncogenes in human tumoral cervical cells transformed by HPV, leads to the efficient silencing of HPV E6 and E7 oncogene expression, which induces the accumulation of the products of the p53 and pRb tumor suppressor genes and activates the mechanism of programmed cell death by apoptosis; thus, the progression of the tumoral growth process may be prevented. The goal of this review is to analyze the microRNA biogenesis process in the silencing of gene expression and to discuss the different protocols for the use of siRNA as a potential gene therapy strategy for the treatment of cervical cancer. PMID:20415061

  13. Hydrodynamic effects on cell growth in agitated microcarrier bioreactors

    Science.gov (United States)

    Cherry, Robert S.; Papoutsakis, E. Terry

    1988-01-01

    The net growth rate of bovine embryonic kidney cells in microcarrier bioreactor is the result of a variable death rate imposed on a cell culture trying to grow at a constant intrinsic growth rate. The death rate is a function of the agitation conditions in the system, and increases at higher agitation because of increasingly energetic interactions of the cell covered microcarriers with turbulent eddies in the fluid. At very low agitation rates bead-bead bridging becomes important; the large clumps formed by bridging can interact with larger eddies than single beads, leading to a higher death rate at low agitation. The growth and death rate were correlated with a dimensionless eddy number which compares eddy forces to the buoyant force on the bead.

  14. The role of stem cells in midgut growth and regeneration.

    Science.gov (United States)

    Hakim, R S; Baldwin, K M; Loeb, M

    2001-06-01

    The Manduca sexta (L.) [Lepidoptera: Sphingidae] and Heliothis virescens (F.) [Lepidoptera: Noctuidae] midguts consist of a pseudostratified epithelium surrounded by striated muscle and tracheae. This epithelium contains goblet, columnar, and basal stem cells. The stem cells are critically important in that they are capable of massive proliferation and differentiation. This growth results in a fourfold enlargement of the midgut at each larval molt. The stem cells are also responsible for limited cell replacement during repair. While the characteristics of the stem cell population vary over the course of an instar, stem cells collected early in an instar and those collected late can start in vitro cultures. Cultures of larval stem, goblet, and columnar cells survive in vitro for several mo through proliferation and differentiation of the stem cells. One of the two polypeptide differentiation factors which have been identified and characterized from the culture medium has now been shown to be present in midgut in vivo. Thus the ability to examine lepidopteran midgut stem cell growth in vitro and in vivo is proving to be effective in determining the basic features of stem cell action and regulation. PMID:11515964

  15. Reactive Oxygen Species-Mediated Control of Mitochondrial Biogenesis

    Directory of Open Access Journals (Sweden)

    Edgar D. Yoboue

    2012-01-01

    Full Text Available Mitochondrial biogenesis is a complex process. It necessitates the contribution of both the nuclear and the mitochondrial genomes and therefore crosstalk between the nucleus and mitochondria. It is now well established that cellular mitochondrial content can vary according to a number of stimuli and physiological states in eukaryotes. The knowledge of the actors and signals regulating the mitochondrial biogenesis is thus of high importance. The cellular redox state has been considered for a long time as a key element in the regulation of various processes. In this paper, we report the involvement of the oxidative stress in the regulation of some actors of mitochondrial biogenesis.

  16. Purification and cultivation of human pituitary growth hormone secreting cells

    Science.gov (United States)

    Hymer, W. C.

    1979-01-01

    Efforts were directed towards maintenance of actively secreting human pituitary growth hormone cells (somatotrophs) in vitro. The production of human growth hormone (hGH) by this means would be of benefit for the treatment of certain human hypopituitary diseases such as dwarfism. One of the primary approaches was the testing of agents which may logically be expected to increase hGH release. The progress towards this goal is summarized. Results from preliminary experiments dealing with electrophoresis of pituitary cell for the purpose of somatotroph separation are described.

  17. Growth and Plating of Cell Suspension Cultures of Datura Innoxia

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen

    1974-01-01

    Suspension cultures of Datura innoxia Mill, were successfully grown on a modified Murashige and Skoog medium with 2,4–D, NAA or BAP as growth substances, provided the micronutrient levels were reduced to 1/10. Normal amounts of micronutrients were toxic. Attempts to identify the toxic elements did...... malate) or on NO3−-N alone. Dry weight yield was proportional to the amount of nitrate-N added (47 mg/mg N). Filtered suspension cultures containing single cells (plating cultures) could be grown in agar in petri dishes when NAA or 2,4-D were used as growth substances. Cells grew at densities above 500...

  18. Bacterial cell curvature through mechanical control of cell growth

    DEFF Research Database (Denmark)

    Cabeen, M.; Charbon, Godefroid; Vollmer, W.;

    2009-01-01

    The cytoskeleton is a key regulator of cell morphogenesis. Crescentin, a bacterial intermediate filament-like protein, is required for the curved shape of Caulobacter crescentus and localizes to the inner cell curvature. Here, we show that crescentin forms a single filamentous structure...

  19. Two-dimension tissue growth model based on circular granular cells for cells with small overlap

    CERN Document Server

    Viridi, Sparisoma; Aprianti, Devi; Haris, Luman; Haryanto, Freddy

    2014-01-01

    Tissue growth can be modeled in two dimension by only using circular granular cells, which can grow and produce child. Linear spring-dashpot model is used to bind the cells with a cut-off interaction range of 1.1 times sum of radii of interacted cells. Simulation steps must be divided into explicit and implicit ones due to cell growing stage and cell position rearrangement. This division is aimed to avoid simulation problem. Only in the explicit steps time changes is performed. Large cells overlap is chosen as termination condition of tissue growth. Only some cells configuration can growth to infinite time without encountering the large cells overlap. These configurations, and the other also, are presented in this work.

  20. Immunoreactive transforming growth factor alpha and epidermal growth factor in oral squamous cell carcinomas

    DEFF Research Database (Denmark)

    Therkildsen, M H; Poulsen, Steen Seier; Bretlau, P

    1993-01-01

    Forty oral squamous cell carcinomas have been investigated immunohistochemically for the presence of transforming growth factor alpha (TGF-alpha) and epidermal growth factor (EGF). The same cases were recently characterized for the expression of EGF-receptors. TGF-alpha was detected...... with a monoclonal mouse antibody and EGF with polyclonal rabbit antiserum. Thirty-five of the tumours were positive for TGF-alpha and 26 of the tumours for EGF. None of the poorly differentiated tumours was positive for EGF, but they all were for TGF-alpha. In sections including normal differentiated oral mucosa......, the cells above the basal cell layer were positive for both TGF-alpha and EGF. The same staining pattern was observed in oral mucosa obtained from healthy persons. In moderately to well differentiated carcinomas, the immunoreactivity was mainly confined to the cytologically more differentiated cells, thus...

  1. Rapamycin promotes Schwann cell migration and nerve growth factor secretion

    Institute of Scientific and Technical Information of China (English)

    Fang Liu; Haiwei Zhang; Kaiming Zhang; Xinyu Wang; Shipu Li; Yixia Yin

    2014-01-01

    Rapamycin, similar to FK506, can promote neural regeneration in vitro. We assumed that the mechanisms of action of rapamycin and FK506 in promoting peripheral nerve regeneration were similar. This study compared the effects of different concentrations of rapamycin and FK506 on Sc hwann cells and investigated effects and mechanisms of rapamycin on improving peripheral nerve regeneration. Results demonstrated that the lowest rapamycin concentration (1.53 nmol/L) more signiifcantly promoted Schwann cell migration than the highest FK506 concentration (100μmol/L). Rapamycin promoted the secretion of nerve growth factors and upregulated growth-associated protein 43 expression in Schwann cells, but did not signiifcantly affect Schwann cell proliferation. Therefore, rapamycin has potential application in peripheral nerve regeneration therapy.

  2. A novel cell growth-promoting factor identified in a B cell leukemia cell line, BALL-1

    International Nuclear Information System (INIS)

    A novel leukemia cell growth-promoting activity has been identified in the culture supernatant from a human B cell leukemia cell line, BALL-1. The supernatant from unstimulated cultures of the BALL-1 cells significantly promoted the growth of 16 out of 24 leukemia/lymphoma cell lines of different lineages (T, B and non-lymphoid) in a minimal concentration of fetal bovine serum (FBS), and 5 out of 12 cases of fresh leukemia cells in FBS-free medium. The growth-promoting sieve filtration and dialysis. The MW of the factor was less than 10 kDa. The growth-promoting activity was heat and acid stable and resistant to trypsin treatment. The factor isolated from the BALL-1 supernatant was distinct from known polypeptide growth factors with MW below 10 kDa, such as epidermal growth factor, transforming growth factor α, insulin-like growth factor I (IGF-I), IGF-II and insulin, as determine by specific antibodies and by cell-growth-promoting tests. The factor is the BALL-1 supernatant did not promote the proliferation of normal human fresh peripheral blood lymphocytes or mouse fibroblast cell line, BALB/C 3T3. In addition to the BALL-1 supernatant, a similar growth-promoting activity was found in the culture supernatant from 13 of 17 leukemia/lymphoma cell lines tested. The activity in these culture supernatant promoted the growth of leukemia/lymphoma cell lines in autocrine and/or paracrine fashions. These observations suggest that the low MW cell growth-promoting activity found in the BALL-1 culture supernatant is mediated by a novel factor which may be responsible for the clonal expansion of particular leukemic clones. (author)

  3. Insulin-like Growth Factor Binding Protein 7 Mediates Glioma Cell Growth and Migration

    Directory of Open Access Journals (Sweden)

    Wei Jiang

    2008-12-01

    Full Text Available Insulin-like growth factor binding protein 7 (IGFBP-7 is the only member of the IGFBP superfamily that binds strongly to insulin, suggesting that IGFBP-7 may have different functions from other IGFBPs. Unlike other IGFBPs, the expression and functions of IGFBP-7 in glioma tumors have not been reported. Using cDNA microarray analysis, we found that expression of IGFBP-7 correlated with the grade of glioma tumors and the overall patient survival. This finding was further validated by real-time reverse transcription-polymerase chain reaction and Western blot analysis. We used RNAi to examine the role of IGFBP-7 in glioma cells, inhibiting IGFBP-7 expression by short interfering RNA transfection. Cell proliferation was suppressed after IGFBP-7 expression was inhibited for 5 days, and glioma cell growth was stimulated consistently by the addition of recombinant IGFBP-7 protein. Moreover, glioma cell migration was attenuated by IGFBP-7 depletion but enhanced by IGFBP-7 overexpression and addition. Overexpression of AKT1 in IGFBP-7-overxpressed cells attenuated the IGFBP-7-promoted migration and further enhanced inhibition of IGFBP-7 depletion on the migration. Phosphorylation of AKT and Erk1/2 was also inversely regulated by IGFBP-7 expression. These two factors together suggest that IGFBP-7 can regulate glioma cell migration through the AKT-ERK pathway, thereby playing an important role in glioma growth and migration.

  4. Targeting the erythropoietin receptor on glioma cells reduces tumour growth

    International Nuclear Information System (INIS)

    Hypoxia has been shown to be one of the major events involved in EPO expression. Accordingly, EPO might be expressed by cerebral neoplastic cells, especially in glioblastoma, known to be highly hypoxic tumours. The expression of EPOR has been described in glioma cells. However, data from the literature remain descriptive and controversial. On the basis of an endogenous source of EPO in the brain, we have focused on a potential role of EPOR in brain tumour growth. In the present study, with complementary approaches to target EPO/EPOR signalling, we demonstrate the presence of a functional EPO/EPOR system on glioma cells leading to the activation of the ERK pathway. This EPO/EPOR system is involved in glioma cell proliferation in vitro. In vivo, we show that the down-regulation of EPOR expression on glioma cells reduces tumour growth and enhances animal survival. Our results support the hypothesis that EPOR signalling in tumour cells is involved in the control of glioma growth.

  5. Targeting the erythropoietin receptor on glioma cells reduces tumour growth

    Energy Technology Data Exchange (ETDEWEB)

    Peres, Elodie A.; Valable, Samuel [CERVOxy team ' Hypoxia and cerebrovascular pathophysiology' , UMR 6232 CI-NAPS, Universite de Caen Basse-Normandie, Universite Paris-Descartes, CNRS, CEA. G.I.P. CYCERON, Caen (France); Guillamo, Jean-Sebastien [CERVOxy team ' Hypoxia and cerebrovascular pathophysiology' , UMR 6232 CI-NAPS, Universite de Caen Basse-Normandie, Universite Paris-Descartes, CNRS, CEA. G.I.P. CYCERON, Caen (France); Departement de Neurologie, CHU de Caen (France); Marteau, Lena [CERVOxy team ' Hypoxia and cerebrovascular pathophysiology' , UMR 6232 CI-NAPS, Universite de Caen Basse-Normandie, Universite Paris-Descartes, CNRS, CEA. G.I.P. CYCERON, Caen (France); Bernaudin, Jean-Francois [Service d' Histologie-Biologie Tumorale, ER2UPMC, Universite Paris 6, Hopital Tenon, Paris (France); Roussel, Simon [CERVOxy team ' Hypoxia and cerebrovascular pathophysiology' , UMR 6232 CI-NAPS, Universite de Caen Basse-Normandie, Universite Paris-Descartes, CNRS, CEA. G.I.P. CYCERON, Caen (France); Lechapt-Zalcman, Emmanuele [CERVOxy team ' Hypoxia and cerebrovascular pathophysiology' , UMR 6232 CI-NAPS, Universite de Caen Basse-Normandie, Universite Paris-Descartes, CNRS, CEA. G.I.P. CYCERON, Caen (France); Service d' Anatomie Pathologique, CHU de Caen (France); Bernaudin, Myriam [CERVOxy team ' Hypoxia and cerebrovascular pathophysiology' , UMR 6232 CI-NAPS, Universite de Caen Basse-Normandie, Universite Paris-Descartes, CNRS, CEA. G.I.P. CYCERON, Caen (France); Petit, Edwige, E-mail: epetit@cyceron.fr [CERVOxy team ' Hypoxia and cerebrovascular pathophysiology' , UMR 6232 CI-NAPS, Universite de Caen Basse-Normandie, Universite Paris-Descartes, CNRS, CEA. G.I.P. CYCERON, Caen (France)

    2011-10-01

    Hypoxia has been shown to be one of the major events involved in EPO expression. Accordingly, EPO might be expressed by cerebral neoplastic cells, especially in glioblastoma, known to be highly hypoxic tumours. The expression of EPOR has been described in glioma cells. However, data from the literature remain descriptive and controversial. On the basis of an endogenous source of EPO in the brain, we have focused on a potential role of EPOR in brain tumour growth. In the present study, with complementary approaches to target EPO/EPOR signalling, we demonstrate the presence of a functional EPO/EPOR system on glioma cells leading to the activation of the ERK pathway. This EPO/EPOR system is involved in glioma cell proliferation in vitro. In vivo, we show that the down-regulation of EPOR expression on glioma cells reduces tumour growth and enhances animal survival. Our results support the hypothesis that EPOR signalling in tumour cells is involved in the control of glioma growth.

  6. Inhibition of Cell Growth and Telomerase Activity in Osteosarcoma Cells by DN-hTERT

    Institute of Scientific and Technical Information of China (English)

    XU Tao; RAO Yaojian; ZHU Wentao; GUO Fengjin

    2006-01-01

    In order to study the effects of dominant negative human telomerase reverse transcriptase (DN-hTERT) on cell growth and telomerase activity in osteosarcoma cell line MG63, MG63 cells were transfected with DN-hTERT-IRES2-EGFP9 (DN) or IRES2-EGF (I, blank vector) with lipofectamine 2000. The stably transfected cells were selected with G-418. Cell growth properties were examined under a fluorescence microscope. The hTERT mRNA expression was detected by reverse transcription-polymerase chain reaction (RT-PCR). Telomerase activities were measured by TRAP-ELISE. The tumorigenicity was studied with tumor xenografts by subcutaneous injection of cancer cells into nude mice. The results showed that cell growth was suppressed in MG63 cells transfected with DN-hTERT. The hTERT mRNA was increased in N-hTERT transfected-MG63 cells (MG63/DN). The telomerase activity was 2.45±0.11 in MG63/DN cells, while 3.40±0.12 in the cells transfected with blank vector (MG63/I), (P<0.05); DN-hTERT-expressing clones did not form tumors in 2 weeks, but the ratio of tumorigenesis was 30 % in nude mice bearing MG63/I (P<0.01). It was concluded that DN-hTERT could specifically inhibit the cell growth and telomerase activity in MG63 cells.

  7. The ribosome biogenesis factor Nol11 is required for optimal rDNA transcription and craniofacial development in Xenopus.

    Directory of Open Access Journals (Sweden)

    John N Griffin

    2015-03-01

    Full Text Available The production of ribosomes is ubiquitous and fundamental to life. As such, it is surprising that defects in ribosome biogenesis underlie a growing number of symptomatically distinct inherited disorders, collectively called ribosomopathies. We previously determined that the nucleolar protein, NOL11, is essential for optimal pre-rRNA transcription and processing in human tissue culture cells. However, the role of NOL11 in the development of a multicellular organism remains unknown. Here, we reveal a critical function for NOL11 in vertebrate ribosome biogenesis and craniofacial development. Nol11 is strongly expressed in the developing cranial neural crest (CNC of both amphibians and mammals, and knockdown of Xenopus nol11 results in impaired pre-rRNA transcription and processing, increased apoptosis, and abnormal development of the craniofacial cartilages. Inhibition of p53 rescues this skeletal phenotype, but not the underlying ribosome biogenesis defect, demonstrating an evolutionarily conserved control mechanism through which ribosome-impaired craniofacial cells are removed. Excessive activation of this mechanism impairs craniofacial development. Together, our findings reveal a novel requirement for Nol11 in craniofacial development, present the first frog model of a ribosomopathy, and provide further insight into the clinically important relationship between specific ribosome biogenesis proteins and craniofacial cell survival.

  8. Regulated growth of diatom cells on self-assembled monolayers

    Directory of Open Access Journals (Sweden)

    Kobayashi Koichi

    2007-03-01

    Full Text Available Abstract We succeeded in regulating the growth of diatom cells on chemically modified glass surfaces. Glass surfaces were functionalized with -CF3, -CH3, -COOH, and -NH2 groups using the technique of self-assembled monolayers (SAM, and diatom cells were subsequently cultured on these surfaces. When the samples were rinsed after the adhesion of the diatom cells on the modified surfaces, the diatoms formed two dimensional arrays; this was not possible without the rinsing treatment. Furthermore, we examined the number of cells that grew and their motility by time-lapse imaging in order to clarify the interaction between the cells and SAMs. We hope that our results will be a basis for developing biodevices using living photosynthetic diatom cells.

  9. Systems-biology dissection of eukaryotic cell growth

    OpenAIRE

    Andrews Justen; Przytycka Teresa M

    2010-01-01

    Abstract A recent article in BMC Biology illustrates the use of a systems-biology approach to integrate data across the transcriptome, proteome and metabolome of budding yeast in order to dissect the relationship between nutrient conditions and cell growth. See research article http://jbiol.com/content/6/2/4 and http://www.biomedcentral.com/1741-7007/8/68

  10. Extracellular Streptomyces lividans vesicles: composition, biogenesis and antimicrobial activity

    Science.gov (United States)

    Schrempf, Hildgund; Merling, Philipp

    2015-01-01

    We selected Streptomyces lividans to elucidate firstly the biogenesis and antimicrobial activities of extracellular vesicles that a filamentous and highly differentiated Gram-positive bacterium produces. Vesicle types range in diameter from 110 to 230 nm and 20 to 60 nm, respectively; they assemble to clusters, and contain lipids and phospholipids allowing their in situ imaging by specific fluorescent dyes. The presence of the identified secondary metabolite undecylprodigiosin provokes red fluorescence of a portion of the heterogeneous vesicle populations facilitating in vivo monitoring. Protuberances containing vesicles generate at tips, and alongside of substrate hyphae, and enumerate during late vegetative growth to droplet-like exudates. Owing to in situ imaging in the presence and absence of a green fluorescent vancomycin derivative, we conclude that protuberances comprising vesicles arise at sites with enhanced levels of peptidoglycan subunits [pentapeptide of lipid II (C55)-linked disaccharides], and reduced levels of polymerized and cross-linked peptidoglycan within hyphae. These sites correlate with enhanced levels of anionic phospholipids and lipids. Vesicles provoke pronounced damages of Aspergillus proliferans, Verticillium dahliae and induced clumping and distortion of Escherichia coli. These harmful effects are likely attributable to the action of the identified vesicular compounds including different enzyme types, components of signal transduction cascades and undecylprodigiosin. Based on our pioneering findings, we highlight novel clues with environmental implications and application potential. PMID:25851532

  11. 14,15-EET promotes mitochondrial biogenesis and protects cortical neurons against oxygen/glucose deprivation-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lai; Chen, Man; Yuan, Lin; Xiang, Yuting [Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing (China); Zheng, Ruimao, E-mail: rmzheng@pku.edu.cn [Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing (China); Zhu, Shigong, E-mail: sgzhu@bjmu.edu.cn [Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing (China)

    2014-07-18

    Highlights: • 14,15-EET inhibits OGD-induced apoptosis in cortical neurons. • Mitochondrial biogenesis of cortical neurons is promoted by 14,15-EET. • 14,15-EET preserves mitochondrial function of cortical neurons under OGD. • CREB mediates effect of 14,15-EET on mitochondrial biogenesis and function. - Abstract: 14,15-Epoxyeicosatrienoic acid (14,15-EET), a metabolite of arachidonic acid, is enriched in the brain cortex and exerts protective effect against neuronal apoptosis induced by ischemia/reperfusion. Although apoptosis has been well recognized to be closely associated with mitochondrial biogenesis and function, it is still unclear whether the neuroprotective effect of 14,15-EET is mediated by promotion of mitochondrial biogenesis and function in cortical neurons under the condition of oxygen–glucose deprivation (OGD). In this study, we found that 14,15-EET improved cell viability and inhibited apoptosis of cortical neurons. 14,15-EET significantly increased the mitochondrial mass and the ratio of mitochondrial DNA to nuclear DNA. Key makers of mitochondrial biogenesis, peroxisome proliferator activator receptor gamma-coactivator 1 alpha (PGC-1α), nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM), were elevated at both mRNA and protein levels in the cortical neurons treated with 14,15-EET. Moreover, 14,15-EET markedly attenuated the decline of mitochondrial membrane potential, reduced ROS, while increased ATP synthesis. Knockdown of cAMP-response element binding protein (CREB) by siRNA blunted the up-regulation of PGC-1α and NRF-1 stimulated by 14,15-EET, and consequently abolished the neuroprotective effect of 14,15-EET. Our results indicate that 14,15-EET protects neurons from OGD-induced apoptosis by promoting mitochondrial biogenesis and function through CREB mediated activation of PGC-1α and NRF-1.

  12. Effect of acute exercise on prostate cancer cell growth.

    Directory of Open Access Journals (Sweden)

    Helene Rundqvist

    Full Text Available Physical activity is associated with reduced risk of several cancers, including aggressive prostate cancer. The mechanisms mediating the effects are not yet understood; among the candidates are modifications of endogenous hormone levels. Long-term exercise is known to reduce serum levels of growth stimulating hormones. In contrast, the endocrine effects of acute endurance exercise include increased levels of mitogenic factors such as GH and IGF-1. It can be speculated that the elevation of serum growth factors may be detrimental to prostate cancer progression into malignancy. The incentive of the current study is to evaluate the effect of acute exercise serum on prostate cancer cell growth. We designed an exercise intervention where 10 male individuals performed 60 minutes of bicycle exercise at increasing intensity. Serum samples were obtained before (rest serum and after completed exercise (exercise serum. The established prostate cancer cell line LNCaP was exposed to exercise or rest serum. Exercise serum from 9 out of 10 individuals had a growth inhibitory effect on LNCaP cells. Incubation with pooled exercise serum resulted in a 31% inhibition of LNCaP growth and pre-incubation before subcutaneous injection into SCID mice caused a delay in tumor formation. Serum analyses indicated two possible candidates for the effect; increased levels of IGFBP-1 and reduced levels of EGF. In conclusion, despite the fear of possible detrimental effects of acute exercise serum on tumor cell growth, we show that even the short-term effects seem to add to the overall beneficial influence of exercise on neoplasia.

  13. On the Non-observability of Recent Biogenesis

    OpenAIRE

    Lineweaver, Charles H.; Davis, Tamara M.

    2003-01-01

    In a previous paper we addressed the question "Does the Rapid Appearance of Life on Earth Suggest that Life is Common in the Universe?" The non-observability of recent biogenesis is a self-selection effect that needs to be considered if inferences are to be drawn from the rapidity of terrestrial biogenesis. We discuss several approaches that have been proposed to take this effect into account.

  14. Two-dimensional diffusion limited system for cell growth

    International Nuclear Information System (INIS)

    A new cell system, the ''sandwich'' system, was developed to supplement multicellular spheroids as tumor analogues. Sandwiches allow new experimental approaches to questions of diffusion, cell cycle effects and radiation resistance in tumors. In this thesis the method for setting up sandwiches is described both theoretically and experimentally followed by its use in x-ray irradiation studies. In the sandwich system, cells are grown in a narrow gap between two glass slides. Where nutrients and waste products can move into or out of the local environment of the cells only by diffusing through the narrow gap between the slides. Due to the competition between cells, self-created gradients of nutrients and metabolic products are set up resulting in a layer of cells which resembles a living spheroid cross section. Unlike the cells of the spheroid, however, cells in all regions of the sandwich are visible. Therefore, the relative sizes of the regions and their time-dependent growth can be monitored visually without fixation or sectioning. The oxygen and nutrient gradients can be ''turned off'' at any time without disrupting the spatial arrangement of the cells by removing the top slide of the assembly and subsequently turned back on if desired. Removal of the top slide also provides access to all the cells, including those near the necrotic center, of the sandwich. The cells can then be removed for analysis outside the sandwich system. 61 refs., 17 figs

  15. Two-dimensional diffusion limited system for cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Hlatky, L.

    1985-11-01

    A new cell system, the ''sandwich'' system, was developed to supplement multicellular spheroids as tumor analogues. Sandwiches allow new experimental approaches to questions of diffusion, cell cycle effects and radiation resistance in tumors. In this thesis the method for setting up sandwiches is described both theoretically and experimentally followed by its use in x-ray irradiation studies. In the sandwich system, cells are grown in a narrow gap between two glass slides. Where nutrients and waste products can move into or out of the local environment of the cells only by diffusing through the narrow gap between the slides. Due to the competition between cells, self-created gradients of nutrients and metabolic products are set up resulting in a layer of cells which resembles a living spheroid cross section. Unlike the cells of the spheroid, however, cells in all regions of the sandwich are visible. Therefore, the relative sizes of the regions and their time-dependent growth can be monitored visually without fixation or sectioning. The oxygen and nutrient gradients can be ''turned off'' at any time without disrupting the spatial arrangement of the cells by removing the top slide of the assembly and subsequently turned back on if desired. Removal of the top slide also provides access to all the cells, including those near the necrotic center, of the sandwich. The cells can then be removed for analysis outside the sandwich system. 61 refs., 17 figs.

  16. Cell lineages, growth and repair of the mouse heart.

    Science.gov (United States)

    Lescroart, Fabienne; Meilhac, Sigolène M

    2012-01-01

    The formation of the heart involves diversification of lineages which differentiate into distinct cardiac cell types or contribute to different regions such as the four cardiac chambers. The heart is the first organ to form in the embryo. However, in parallel with the growth of the organism, before or after birth, the heart has to adapt its size to maintain pumping efficiency. The adult heart has only a mild regeneration potential; thus, strategies to repair the heart after injury are based on the mobilisation of resident cardiac stem cells or the transplantation of external sources of stem cells. We discuss current knowledge on these aspects and raise questions for future research.

  17. Suppressing The Growth Of Dendrites In Secondary Li Cells

    Science.gov (United States)

    Davies, Evan D.; Perrone, David E.; Shen, David H.

    1996-01-01

    Proposed technique for suppressing growth of lithium dendrites in rechargeable lithium electrochemical power cells involves periodic interruption of steady charging current with short, high-current discharge pulses. Technique applicable to lithium cells of several different types, including Li/TiS(2), Li/NbSe(3), Li/CoO(2), Li/MoS(2), Li/Vo(x), and Li/MnO(2). Cells candidates for use in spacecraft, military, communications, automotive, and other applications in which high-energy-density rechargeable batteries needed.

  18. Pumpkin seed extract: Cell growth inhibition of hyperplastic and cancer cells, independent of steroid hormone receptors.

    Science.gov (United States)

    Medjakovic, Svjetlana; Hobiger, Stefanie; Ardjomand-Woelkart, Karin; Bucar, Franz; Jungbauer, Alois

    2016-04-01

    Pumpkin seeds have been known in folk medicine as remedy for kidney, bladder and prostate disorders since centuries. Nevertheless, pumpkin research provides insufficient data to back up traditional beliefs of ethnomedical practice. The bioactivity of a hydro-ethanolic extract of pumpkin seeds from the Styrian pumpkin, Cucurbita pepo L. subsp. pepo var. styriaca, was investigated. As pumpkin seed extracts are standardized to cucurbitin, this compound was also tested. Transactivational activity was evaluated for human androgen receptor, estrogen receptor and progesterone receptor with in vitro yeast assays. Cell viability tests with prostate cancer cells, breast cancer cells, colorectal adenocarcinoma cells and a hyperplastic cell line from benign prostate hyperplasia tissue were performed. As model for non-hyperplastic cells, effects on cell viability were tested with a human dermal fibroblast cell line (HDF-5). No transactivational activity was found for human androgen receptor, estrogen receptor and progesterone receptor, for both, extract and cucurbitin. A cell growth inhibition of ~40-50% was observed for all cell lines, with the exception of HDF-5, which showed with ~20% much lower cell growth inhibition. Given the receptor status of some cell lines, a steroid-hormone receptor independent growth inhibiting effect can be assumed. The cell growth inhibition for fast growing cells together with the cell growth inhibition of prostate-, breast- and colon cancer cells corroborates the ethnomedical use of pumpkin seeds for a treatment of benign prostate hyperplasia. Moreover, due to the lack of androgenic activity, pumpkin seed applications can be regarded as safe for the prostate. PMID:26976217

  19. Automated inference procedure for the determination of cell growth parameters

    Science.gov (United States)

    Harris, Edouard A.; Koh, Eun Jee; Moffat, Jason; McMillen, David R.

    2016-01-01

    The growth rate and carrying capacity of a cell population are key to the characterization of the population's viability and to the quantification of its responses to perturbations such as drug treatments. Accurate estimation of these parameters necessitates careful analysis. Here, we present a rigorous mathematical approach for the robust analysis of cell count data, in which all the experimental stages of the cell counting process are investigated in detail with the machinery of Bayesian probability theory. We advance a flexible theoretical framework that permits accurate estimates of the growth parameters of cell populations and of the logical correlations between them. Moreover, our approach naturally produces an objective metric of avoidable experimental error, which may be tracked over time in a laboratory to detect instrumentation failures or lapses in protocol. We apply our method to the analysis of cell count data in the context of a logistic growth model by means of a user-friendly computer program that automates this analysis, and present some samples of its output. Finally, we note that a traditional least squares fit can provide misleading estimates of parameter values, because it ignores available information with regard to the way in which the data have actually been collected.

  20. Mitochondrial DNA deletion and impairment of mitochondrial biogenesis are mediated by reactive oxygen species in ionizing radiation-induced premature senescence

    Energy Technology Data Exchange (ETDEWEB)

    Eom, Hyeon Soo; Jung, U Hee; Jo, Sung Kee [Radiation Biotechnology Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Young Sang [College of Natural Sciences, Chungnam National University, Daejeon (Korea, Republic of)

    2011-09-15

    Mitochondrial DNA (mtDNA) deletion is a well-known marker for oxidative stress and aging, and contributes to harmful effects in cultured cells and animal tissues. mtDNA biogenesis genes (NRF-1, TFAM) are essential for the maintenance of mtDNA, as well as the transcription and replication of mitochondrial genomes. Considering that oxidative stress is known to affect mitochondrial biogenesis, we hypothesized that ionizing radiation (IR)-induced reactive oxygen species (ROS) causes mtDNA deletion by modulating the mitochondrial biogenesis, thereby leading to cellular senescence. Therefore, we examined the effects of IR on ROS levels, cellular senescence, mitochondrial biogenesis, and mtDNA deletion in IMR-90 human lung fibroblast cells. Young IMR-90 cells at population doubling (PD) 39 were irradiated at 4 or 8 Gy. Old cells at PD55, and H2O2-treated young cells at PD 39, were compared as a positive control. The IR increased the intracellular ROS level, senescence-associated {beta}-galactosidase (SA-{beta}-gal) activity, and mtDNA common deletion (4977 bp), and it decreased the mRNA expression of NRF-1 and TFAM in IMR-90 cells. Similar results were also observed in old cells (PD 55) and H{sub 2}O{sub 2}-treated young cells. To confirm that a increase in ROS level is essential for mtDNA deletion and changes of mitochondrial biogenesis in irradiated cells, the effects of N-acetylcysteine (NAC) were examined. In irradiated and H{sub 2}O{sub 2}-treated cells, 5 mM NAC significantly attenuated the increases of ROS, mtDNA deletion, and SA-{beta}-gal activity, and recovered from decreased expressions of NRF-1 and TFAM mRNA. These results suggest that ROS is a key cause of IR-induced mtDNA deletion, and the suppression of the mitochondrial biogenesis gene may mediate this process.

  1. Cybrid models of Parkinson's disease show variable mitochondrial biogenesis and genotype-respiration relationships.

    Science.gov (United States)

    Keeney, Paula M; Dunham, Lisa D; Quigley, Caitlin K; Morton, Stephanie L; Bergquist, Kristen E; Bennett, James P

    2009-12-01

    Sporadic Parkinson's disease (sPD) is a nervous system-wide disease that presents with a bradykinetic movement disorder and frequently progresses to include depression and cognitive impairment. Cybrid models of sPD are based on expression of sPD platelet mitochondrial DNA (mtDNA) in neural cells and demonstrate some similarities to sPD brains. In sPD and CTL cybrids we characterized aspects of mitochondrial biogenesis, mtDNA genomics, composition of the respirasome and the relationships among isolated mitochondrial and intact cell respiration. Cybrid mtDNA levels varied and correlated with expression of PGC-1 alpha, a transcriptional co-activator regulator of mitochondrial biogenesis. Levels of mtDNA heteroplasmic mutations were asymmetrically distributed across the mitochondrial genome; numbers of heteroplasmies were more evenly distributed. Neither levels nor numbers of heteroplasmies distinguished sPD from CTL. sPD cybrid mitochondrial ETC subunit protein levels were not altered. Isolated mitochondrial complex I respiration rates showed limited correlation with whole cell complex I respiration rates in both sPD and CTL cybrids. Intact cell respiration during the normoxic-anoxic transition yielded K(m) values for oxygen that directly related to respiration rates in CTL but not in sPD cell lines. Both sPD and CTL cybrid cells are substantially heterogeneous in mitochondrial genomic and physiologic properties. Our results suggest that mtDNA depletion may occur in sPD neurons and could reflect impairment of mitochondrial biogenesis. Cybrids remain a valuable model for some aspects of sPD but their heterogeneity mitigates against a simple designation of sPD phenotype in this cell model.

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

    Directory of Open Access Journals (Sweden)

    Robert W Tilghman

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

  3. Roles of CUP-5, the Caenorhabditis elegans orthologue of human TRPML1, in lysosome and gut granule biogenesis

    Directory of Open Access Journals (Sweden)

    Fares Hanna

    2010-06-01

    Full Text Available Abstract Background CUP-5 is a Transient Receptor Potential protein in C. elegans that is the orthologue of mammalian TRPML1. Loss of TRPML1 results in the lysosomal storage disorder Mucolipidosis type IV. Loss of CUP-5 results in embryonic lethality and the accumulation of enlarged yolk granules in developing intestinal cells. The embryonic lethality of cup-5 mutants is rescued by mutations in mrp-4, which is required for gut granule differentiation. Gut granules are intestine-specific lysosome-related organelles that accumulate birefringent material. This link between CUP-5 and gut granules led us to determine the roles of CUP-5 in lysosome and gut granule biogenesis in developing intestinal cells. Results We show that CUP-5 protein localizes to lysosomes, but not to gut granules, in developing intestinal cells. Loss of CUP-5 results in defects in endo-lysosomal transport in developing intestinal cells of C. elegans embryos. This ultimately leads to the appearance of enlarged terminal vacuoles that show defective lysosomal degradation and that have lysosomal and endosomal markers. In contrast, gut granule biogenesis is normal in the absence of CUP-5. Furthermore, loss of CUP-5 does not result in inappropriate fusion or mixing of content between lysosomes and gut granules. Conclusions Using an in vivo model of MLIV, we show that there is a defect in lysosomal transport/biogenesis that is earlier than the presumed function of TRPML1 in terminal lysosomes. Our results indicate that CUP-5 is required for the biogenesis of lysosomes but not of gut granules. Thus, cellular phenotypes in Mucolipidosis type IV are likely not due to defects in lysosome-related organelle biogenesis, but due to progressive defects in lysosomal transport that lead to severe lysosomal dysfunction.

  4. Distribution and number of epidermal growth factor receptors in skin is related to epithelial cell growth

    DEFF Research Database (Denmark)

    Green, M R; Basketter, D A; Couchman, J R;

    1983-01-01

    an undetectable or sharply reduced number of EGF receptors. The EGF receptor number and receptor affinity of epidermal basal cells freshly isolated from rats of increasing age has also been determined. We find that receptor affinity remains unchanged (3.3 nM) but that basal cell surface receptor number decreases...... markedly with age. This decrease in receptor number is similar in trend to the known drop in basal cell [3H]thymidine labelling index which occurs over the same time period. The data suggest that the distribution of EGF receptors and EGF cell surface receptor number in skin are important in the spatial...... receptors are detected on the epithelial cells overlying the basement membranes of the epidermis, sebaceous gland, and regions of the hair follicle all of which have proliferative capacity. In marked contrast, tissues which have started to differentiate and lost their growth potential, carry either...

  5. Phosphorylation of αSNAP is Required for Secretory Organelle Biogenesis in Toxoplasma gondii.

    Science.gov (United States)

    Stewart, Rebecca J; Ferguson, David J P; Whitehead, Lachlan; Bradin, Clare H; Wu, Hong J; Tonkin, Christopher J

    2016-02-01

    Upon infection, apicomplexan parasites quickly invade host cells and begin a replicative cycle rapidly increasing in number over a short period of time, leading to tissue lysis and disease. The secretory pathway of these highly polarized protozoan parasites tightly controls, in time and space, the biogenesis of specialized structures and organelles required for invasion and intracellular survival. In other systems, regulation of protein trafficking can occur by phosphorylation of vesicle fusion machinery. Previously, we have shown that Toxoplasma gondii αSNAP - a protein that controls the disassembly of cis-SNARE complexes--is phosphorylated. Here, we show that this post-translational modification is required for the correct function of αSNAP in controlling secretory traffic. We demonstrate that during intracellular development conditional expression of a non-phosphorylatable form of αSNAP results in Golgi fragmentation and vesiculation of all downstream secretory organelles. In addition, we show that the vestigial plastid (termed apicoplast), although reported not to be reliant on Golgi trafficking for biogenesis, is also affected upon overexpression of αSNAP and is much more sensitive to the levels of this protein than targeting to other organelles. This work highlights the importance of αSNAP and its phosphorylation in Toxoplasma organelle biogenesis and exposes a hereto fore-unexplored mechanism of regulation of vesicle fusion during secretory pathway trafficking in apicomplexan parasites.

  6. Ribosome Biogenesis Factor Bmsl-like Is Essential for Liver Development in Zebrafish

    Institute of Scientific and Technical Information of China (English)

    Yong Wang; Yue Luo; Yunhan Hong; Jinrong Peng; Lijan Lo

    2012-01-01

    Ribosome biogenesis in the nucleolus requires numerous nucleolar proteins and small non-coding RNAs.Among them is ribosome biogenesis factor Bmsl,which is highly conserved from yeast to human.In yeast,Bmsl initiates ribosome biogenesis through recruiting Rcll to pre-ribosomes.However,little is known about the biological function of Bmsl in vertebrates.Here we report that Bmsl plays an essential role in zebrafish liver development.We identified a zebrafish bmsllsq163 mutant which carries a T to A mutation in the gene bmsl-like (bmsll).This mutation results in L152 to Q152 substitution in a GTPase motif in Bmsll.Surprisingly,bmsllsq163 mutation confers hypoplasia specifically in the liver,exocrine pancreas and intestine after 3 days post-fertilization (dpf).Consistent with the bmsllsq163 mutant phenotypes,whole-mount in situ hybridization (WISH) on wild type embryos showed that bmsll transcripts are abundant in the entire digestive tract and its accessory organs.Immunostaining for phospho-Histone 3 (P-H3) and TUNEL assay revealed that impairment of hepatoblast proliferation rather than cell apoptosis is one of the consequences of bmsllsq163 giving rise to an underdeveloped liver.Therefore,our findings demonstrate that Bmsll is necessary for zebrafish liver development.

  7. Microprocessor Activity Controls Differential miRNA Biogenesis In Vivo

    Directory of Open Access Journals (Sweden)

    Thomas Conrad

    2014-10-01

    Full Text Available In miRNA biogenesis, pri-miRNA transcripts are converted into pre-miRNA hairpins. The in vivo properties of this process remain enigmatic. Here, we determine in vivo transcriptome-wide pri-miRNA processing using next-generation sequencing of chromatin-associated pri-miRNAs. We identify a distinctive Microprocessor signature in the transcriptome profile from which efficiency of the endogenous processing event can be accurately quantified. This analysis reveals differential susceptibility to Microprocessor cleavage as a key regulatory step in miRNA biogenesis. Processing is highly variable among pri-miRNAs and a better predictor of miRNA abundance than primary transcription itself. Processing is also largely stable across three cell lines, suggesting a major contribution of sequence determinants. On the basis of differential processing efficiencies, we define functionality for short sequence features adjacent to the pre-miRNA hairpin. In conclusion, we identify Microprocessor as the main hub for diversified miRNA output and suggest a role for uncoupling miRNA biogenesis from host gene expression.

  8. Purification and Cultivation of Human Pituitary Growth Hormones Secreting Cells

    Science.gov (United States)

    Hymer, W. C.; Todd, P.; Grindeland, R.; Lanham, W.; Morrison, D.

    1985-01-01

    The rat and human pituitary gland contains a mixture of hormone producing cell types. The separation of cells which make growth hormone (GH) is attempted for the purpose of understanding how the hormone molecule is made within the pituitary cell; what form(s) it takes within the cell; and what form(s) GH assumes as it leaves the cell. Since GH has a number of biological targets (e.g., muscle, liver, bone), the assessment of the activities of the intracellular/extracellular GH by new and sensitive bioassays. GH cells contained in the mixture was separated by free flow electrophoresis. These experiments show that GH cells have different electrophoretic mobilities. This is relevant to NASA since a lack of GH could be a prime causative factor in muscle atrophy. Further, GH has recently been implicated in the etiology of motion sickness in space. Continous flow electrophoresis experiment on STS-8 showed that GH cells could be partially separated in microgravity. However, definitive cell culture studies could not be done due to insufficient cell recoveries.

  9. Wall relaxation and the driving forces for cell expansive growth

    Science.gov (United States)

    Cosgrove, D. J.

    1987-01-01

    When water uptake by growing cells is prevented, the turgor pressure and the tensile stress in the cell wall are reduced by continued wall loosening. This process, termed in vivo stress relaxation, provides a new way to study the dynamics of wall loosening and to measure the wall yield threshold and the physiological wall extensibility. Stress relaxation experiments indicate that wall stress supplies the mechanical driving force for wall yielding. Cell expansion also requires water absorption. The driving force for water uptake during growth is created by wall relaxation, which lowers the water potential of the expanding cells. New techniques for measuring this driving force show that it is smaller than believed previously; in elongating stems it is only 0.3 to 0.5 bar. This means that the hydraulic resistance of the water transport pathway is small and that rate of cell expansion is controlled primarily by wall loosening and yielding.

  10. Tissue specific roles for the ribosome biogenesis factor Wdr43 in zebrafish development.

    Directory of Open Access Journals (Sweden)

    Chengtian Zhao

    2014-01-01

    Full Text Available During vertebrate craniofacial development, neural crest cells (NCCs contribute to most of the craniofacial pharyngeal skeleton. Defects in NCC specification, migration and differentiation resulting in malformations in the craniofacial complex are associated with human craniofacial disorders including Treacher-Collins Syndrome, caused by mutations in TCOF1. It has been hypothesized that perturbed ribosome biogenesis and resulting p53 mediated neuroepithelial apoptosis results in NCC hypoplasia in mouse Tcof1 mutants. However, the underlying mechanisms linking ribosome biogenesis and NCC development remain poorly understood. Here we report a new zebrafish mutant, fantome (fan, which harbors a point mutation and predicted premature stop codon in zebrafish wdr43, the ortholog to yeast UTP5. Although wdr43 mRNA is widely expressed during early zebrafish development, and its deficiency triggers early neural, eye, heart and pharyngeal arch defects, later defects appear fairly restricted to NCC derived craniofacial cartilages. Here we show that the C-terminus of Wdr43, which is absent in fan mutant protein, is both necessary and sufficient to mediate its nucleolar localization and protein interactions in metazoans. We demonstrate that Wdr43 functions in ribosome biogenesis, and that defects observed in fan mutants are mediated by a p53 dependent pathway. Finally, we show that proper localization of a variety of nucleolar proteins, including TCOF1, is dependent on that of WDR43. Together, our findings provide new insight into roles for Wdr43 in development, ribosome biogenesis, and also ribosomopathy-induced craniofacial phenotypes including Treacher-Collins Syndrome.

  11. miR-526a regulates apoptotic cell growth in human carcinoma cells.

    Science.gov (United States)

    Yang, Xiaoli; Wang, Cui; Xu, Changzhi; Yan, Zhifeng; Wei, Congwen; Guan, Kai; Ma, Shengli; Cao, Ye; Liu, Liping; Zou, Deyong; He, Xiang; Zhang, Buchang; Ma, Qingjun; Zheng, Zirui

    2015-09-01

    MicroRNAs (miRNAs) play vital roles in the regulation of cell cycle, cell growth, apoptosis, and tumorigenesis. Our previous studies showed that miR-526a positively regulated innate immune response by suppressing CYLD expression, however, the functional relevance of miR-526a expression and cell growth remains to be evaluated. In this study, miR-526a overexpression was found to promote cancer cell proliferation, migration, and anchor-independent colony formation. The molecular mechanism(s) of miR-526a-mediated growth stimulation is associated with rapid cell cycle progression and inhibition of cell apoptosis by targeting CYLD. Taken together, these results provide evidence to show the stimulatory role of miR-526a in tumor migration and invasion through modulation of the canonical NF-κB signaling pathway. PMID:26002288

  12. Endothelial AMPK activation induces mitochondrial biogenesis and stress adaptation via eNOS-dependent mTORC1 signaling.

    Science.gov (United States)

    Li, Chunying; Reif, Michaella M; Craige, Siobhan M; Kant, Shashi; Keaney, John F

    2016-05-01

    Metabolic stress sensors like AMP-activated protein kinase (AMPK) are known to confer stress adaptation and promote longevity in lower organisms. This study demonstrates that activating the metabolic stress sensor AMP-activated protein kinase (AMPK) in endothelial cells helps maintain normal cellular function by promoting mitochondrial biogenesis and stress adaptation. To better define the mechanisms whereby AMPK promotes endothelial stress resistance, we used 5-aminoimidazole-4-carboxamide riboside (AICAR) to chronically activate AMPK and observed stimulation of mitochondrial biogenesis in wild type mouse endothelium, but not in endothelium from endothelial nitric oxide synthase knockout (eNOS-null) mice. Interestingly, AICAR-enhanced mitochondrial biogenesis was blocked by pretreatment with the mammalian target of rapamycin complex 1 (mTORC1) inhibitor, rapamycin. Further, AICAR stimulated mTORC1 as determined by phosphorylation of its known downstream effectors in wild type, but not eNOS-null, endothelial cells. Together these data indicate that eNOS is needed to couple AMPK activation to mTORC1 and thus promote mitochondrial biogenesis and stress adaptation in the endothelium. These data suggest a novel mechanism for mTORC1 activation that is significant for investigations in vascular dysfunction. PMID:26989010

  13. 42% 500X Bi-Facial Growth Concentrator Cells

    Science.gov (United States)

    Wojtczuk, S.; Chiu, P.; Zhang, X.; Pulver, D.; Harris, C.; Siskavich, B.

    2011-12-01

    Data are presented from three-junction concentrator photovoltaic cells using a new cell architecture (1.9 eV InGaP top cell lattice-matched to a 1.42 eV GaAs middle cells on one side of a infrared-transparent GaAs wafer with a lattice-mismatched 0.95 eV InGaAs bottom cell grown isolated on the wafer backside). The cell uses a new epitaxial bifacial growth (BFG) technique. The impetus is to replace the 0.67 eV Ge bottom cell in the standard three junction InGaP/GaAs/Ge tandems with a higher bandgap 0.95 eV InGaAs cell that boosts the bottom cell voltage by about 40% while maintaining a simple high-yield cell process without use of complex large area epitaxial liftoff or wafer bonding steps used to make similar cell stacks. Efficiency was independently-verified by NREL for a 1 cm×1 cm cell (42.3% at 406 suns, with Voc 3.452V, 87.1% FF and 1xJsc of 14.07 mA/cm2, at 25 °C AM1.5D, 100 mW/cm2), which was the world record at the time of the CPV-7 conference. No degradation was seen during concentrated solar operation after a 2000 hr 165C burn-in and PbSn solder tests. Average efficiency of 1 cm2 cells designed for 500 suns at 1018 suns was 40.5% (Spire test, 25 °C, spectrally corrected flash simulator). Measured efficiency temperature coefficient for gen2 cells is -0.06%/°C, similar to InGaP/GaAs/Ge tandems.

  14. Autophagy contributes to gefitinib-induced glioma cell growth inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Cheng-Yi [Department of Surgery, Fong-Yuan Hospital, Taichung 420, Taiwan (China); Graduate Institute of Pharmaceutical Science and Technology, Central Taiwan University of Science and Technology, Taichung 406, Taiwan (China); Kuan, Yu-Hsiang [Department of Pharmacology, School of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Pharmacy, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Ou, Yen-Chuan; Li, Jian-Ri [Division of Urology, Taichung Veterans General Hospital, Taichung 407, Taiwan (China); Wu, Chih-Cheng [Department of Anesthesiology, Taichung Veterans General Hospital, Taichung 407, Taiwan (China); Department of Financial and Computational Mathematics, Providence University, Taichung 433, Taiwan (China); Pan, Pin-Ho [Department of Pediatrics, Tungs’ Taichung MetroHarbor Hospital, Taichung 435, Taiwan (China); Chen, Wen-Ying [Department of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan (China); Huang, Hsuan-Yi [Department of Surgery, Fong-Yuan Hospital, Taichung 420, Taiwan (China); Chen, Chun-Jung, E-mail: cjchen@vghtc.gov.tw [Department of Medical Research, Taichung Veterans General Hospital, Taichung 407, Taiwan (China); Institute of Biomedical Sciences, National Chung Hsing University, Taichung 402, Taiwan (China); Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung 402, Taiwan (China); Center for General Education, Tunghai University, Taichung 407, Taiwan (China); Department of Nursing, HungKuang University, Taichung 433, Taiwan (China)

    2014-09-10

    Epidermal growth factor receptor tyrosine kinase inhibitors, including gefitinib, have been evaluated in patients with malignant gliomas. However, the molecular mechanisms involved in gefitinib-mediated anticancer effects against glioma are incompletely understood. In the present study, the cytostatic potential of gefitinib was demonstrated by the inhibition of glioma cell growth, long-term clonogenic survival, and xenograft tumor growth. The cytostatic consequences were accompanied by autophagy, as evidenced by monodansylcadaverine staining of acidic vesicle formation, conversion of microtubule-associated protein-1 light chain 3-II (LC3-II), degradation of p62, punctate pattern of GFP-LC3, and conversion of GFP-LC3 to cleaved-GFP. Autophagy inhibitor 3-methyladenosine and chloroquine and genetic silencing of LC3 or Beclin 1 attenuated gefitinib-induced growth inhibition. Gefitinib-induced autophagy was not accompanied by the disruption of the Akt/mammalian target of rapamycin signaling. Instead, the activation of liver kinase-B1/AMP-activated protein kinase (AMPK) signaling correlated well with the induction of autophagy and growth inhibition caused by gefitinib. Silencing of AMPK suppressed gefitinib-induced autophagy and growth inhibition. The crucial role of AMPK activation in inducing glioma autophagy and growth inhibition was further supported by the actions of AMP mimetic AICAR. Gefitinib was shown to be capable of reducing the proliferation of glioma cells, presumably by autophagic mechanisms involving AMPK activation. - Highlights: • Gefitinib causes cytotoxic and cytostatic effect on glioma. • Gefitinib induces autophagy. • Gefitinib causes cytostatic effect through autophagy. • Gefitinib induces autophagy involving AMPK.

  15. Autophagy contributes to gefitinib-induced glioma cell growth inhibition

    International Nuclear Information System (INIS)

    Epidermal growth factor receptor tyrosine kinase inhibitors, including gefitinib, have been evaluated in patients with malignant gliomas. However, the molecular mechanisms involved in gefitinib-mediated anticancer effects against glioma are incompletely understood. In the present study, the cytostatic potential of gefitinib was demonstrated by the inhibition of glioma cell growth, long-term clonogenic survival, and xenograft tumor growth. The cytostatic consequences were accompanied by autophagy, as evidenced by monodansylcadaverine staining of acidic vesicle formation, conversion of microtubule-associated protein-1 light chain 3-II (LC3-II), degradation of p62, punctate pattern of GFP-LC3, and conversion of GFP-LC3 to cleaved-GFP. Autophagy inhibitor 3-methyladenosine and chloroquine and genetic silencing of LC3 or Beclin 1 attenuated gefitinib-induced growth inhibition. Gefitinib-induced autophagy was not accompanied by the disruption of the Akt/mammalian target of rapamycin signaling. Instead, the activation of liver kinase-B1/AMP-activated protein kinase (AMPK) signaling correlated well with the induction of autophagy and growth inhibition caused by gefitinib. Silencing of AMPK suppressed gefitinib-induced autophagy and growth inhibition. The crucial role of AMPK activation in inducing glioma autophagy and growth inhibition was further supported by the actions of AMP mimetic AICAR. Gefitinib was shown to be capable of reducing the proliferation of glioma cells, presumably by autophagic mechanisms involving AMPK activation. - Highlights: • Gefitinib causes cytotoxic and cytostatic effect on glioma. • Gefitinib induces autophagy. • Gefitinib causes cytostatic effect through autophagy. • Gefitinib induces autophagy involving AMPK

  16. Cell proliferation along vascular islands during microvascular network growth

    Directory of Open Access Journals (Sweden)

    Kelly-Goss Molly R

    2012-06-01

    Full Text Available Abstract Background Observations in our laboratory provide evidence of vascular islands, defined as disconnected endothelial cell segments, in the adult microcirculation. The objective of this study was to determine if vascular islands are involved in angiogenesis during microvascular network growth. Results Mesenteric tissues, which allow visualization of entire microvascular networks at a single cell level, were harvested from unstimulated adult male Wistar rats and Wistar rats 3 and 10 days post angiogenesis stimulation by mast cell degranulation with compound 48/80. Tissues were immunolabeled for PECAM and BRDU. Identification of vessel lumens via injection of FITC-dextran confirmed that endothelial cell segments were disconnected from nearby patent networks. Stimulated networks displayed increases in vascular area, length density, and capillary sprouting. On day 3, the percentage of islands with at least one BRDU-positive cell increased compared to the unstimulated level and was equal to the percentage of capillary sprouts with at least one BRDU-positive cell. At day 10, the number of vascular islands per vascular area dramatically decreased compared to unstimulated and day 3 levels. Conclusions These results show that vascular islands have the ability to proliferate and suggest that they are able to incorporate into the microcirculation during the initial stages of microvascular network growth.

  17. Glycan Sulfation Modulates Dendritic Cell Biology and Tumor Growth

    Directory of Open Access Journals (Sweden)

    Roland El Ghazal

    2016-05-01

    Full Text Available In cancer, proteoglycans have been found to play roles in facilitating the actions of growth factors, and effecting matrix invasion and remodeling. However, little is known regarding the genetic and functional importance of glycan chains displayed by proteoglycans on dendritic cells (DCs in cancer immunity. In lung carcinoma, among other solid tumors, tumor-associated DCs play largely subversive/suppressive roles, promoting tumor growth and progression. Herein, we show that targeting of DC glycan sulfation through mutation in the heparan sulfate biosynthetic enzyme N-deacetylase/N-sulfotransferase-1 (Ndst1 in mice increased DC maturation and inhibited trafficking of DCs to draining lymph nodes. Lymphatic-driven DC migration and chemokine (CCL21-dependent activation of a major signaling pathway required for DC migration (as measured by phospho-Akt were sensitive to Ndst1 mutation in DCs. Lewis lung carcinoma tumors in mice deficient in Ndst1 were reduced in size. Purified CD11c+ cells from the tumors, which contain the tumor-infiltrating DC population, showed a similar phenotype in mutant cells. These features were replicated in mice deficient in syndecan-4, the major heparan sulfate proteoglycan expressed on the DC surface: Tumors were growth-impaired in syndecan-4–deficient mice and were characterized by increased infiltration by mature DCs. Tumors on the mutant background also showed greater infiltration by NK cells and NKT cells. These findings indicate the genetic importance of DC heparan sulfate proteoglycans in tumor growth and may guide therapeutic development of novel strategies to target syndecan-4 and heparan sulfate in cancer.

  18. Glycan Sulfation Modulates Dendritic Cell Biology and Tumor Growth.

    Science.gov (United States)

    El Ghazal, Roland; Yin, Xin; Johns, Scott C; Swanson, Lee; Macal, Monica; Ghosh, Pradipta; Zuniga, Elina I; Fuster, Mark M

    2016-05-01

    In cancer, proteoglycans have been found to play roles in facilitating the actions of growth factors, and effecting matrix invasion and remodeling. However, little is known regarding the genetic and functional importance of glycan chains displayed by proteoglycans on dendritic cells (DCs) in cancer immunity. In lung carcinoma, among other solid tumors, tumor-associated DCs play largely subversive/suppressive roles, promoting tumor growth and progression. Herein, we show that targeting of DC glycan sulfation through mutation in the heparan sulfate biosynthetic enzyme N-deacetylase/N-sulfotransferase-1 (Ndst1) in mice increased DC maturation and inhibited trafficking of DCs to draining lymph nodes. Lymphatic-driven DC migration and chemokine (CCL21)-dependent activation of a major signaling pathway required for DC migration (as measured by phospho-Akt) were sensitive to Ndst1 mutation in DCs. Lewis lung carcinoma tumors in mice deficient in Ndst1 were reduced in size. Purified CD11c+ cells from the tumors, which contain the tumor-infiltrating DC population, showed a similar phenotype in mutant cells. These features were replicated in mice deficient in syndecan-4, the major heparan sulfate proteoglycan expressed on the DC surface: Tumors were growth-impaired in syndecan-4-deficient mice and were characterized by increased infiltration by mature DCs. Tumors on the mutant background also showed greater infiltration by NK cells and NKT cells. These findings indicate the genetic importance of DC heparan sulfate proteoglycans in tumor growth and may guide therapeutic development of novel strategies to target syndecan-4 and heparan sulfate in cancer.

  19. Teroxirone inhibited growth of human non-small cell lung cancer cells by activating p53

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jing-Ping; Lin, Kai-Han; Liu, Chun-Yen; Yu, Ya-Chu; Wu, Pei-Tsun [Department of Life Science, National Taiwan Normal University, Taipei, Taiwan (China); Chiu, Chien-Chih [Department of Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Su, Chun-Li [Department of Human Development and Family Studies, National Taiwan Normal University, Taipei, Taiwan (China); Chen, Kwun-Min [Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan (China); Fang, Kang, E-mail: kangfang@ntnu.edu.tw [Department of Life Science, National Taiwan Normal University, Taipei, Taiwan (China)

    2013-11-15

    In this work, we demonstrated that the growth of human non-small-cell-lung-cancer cells H460 and A549 cells can be inhibited by low concentrations of an epoxide derivative, teroxirone, in both in vitro and in vivo models. The cytotoxicity was mediated by apoptotic cell death through DNA damage. The onset of ultimate apoptosis is dependent on the status of p53. Teroxirone caused transient elevation of p53 that activates downstream p21 and procaspase-3 cleavage. The presence of caspase-3 inhibitor reverted apoptotic phenotype. Furthermore, we showed the cytotoxicity of teroxirone in H1299 cells with stable ectopic expression of p53, but not those of mutant p53. A siRNA-mediated knockdown of p53 expression attenuated drug sensitivity. The in vivo experiments demonstrated that teroxirone suppressed growth of xenograft tumors in nude mice. Being a potential therapeutic agent by restraining cell growth through apoptotic death at low concentrations, teroxirone provides a feasible perspective in reversing tumorigenic phenotype of human lung cancer cells. - Highlights: • Teroxirone repressed tumor cell growth in nude mice of human lung cancer cells. • The apoptotic cell death reverted by caspase-3 inhibitor is related to p53 status. • Teroxirone provides a good candidate for lung cancer treatment.

  20. Oligodendroglial membrane dynamics in relation to myelin biogenesis.

    Science.gov (United States)

    Ozgen, Hande; Baron, Wia; Hoekstra, Dick; Kahya, Nicoletta

    2016-09-01

    In the central nervous system, oligodendrocytes synthesize a specialized membrane, the myelin membrane, which enwraps the axons in a multilamellar fashion to provide fast action potential conduction and to ensure axonal integrity. When compared to other membranes, the composition of myelin membranes is unique with its relatively high lipid to protein ratio. Their biogenesis is quite complex and requires a tight regulation of sequential events, which are deregulated in demyelinating diseases such as multiple sclerosis. To devise strategies for remedying such defects, it is crucial to understand molecular mechanisms that underlie myelin assembly and dynamics, including the ability of specific lipids to organize proteins and/or mediate protein-protein interactions in healthy versus diseased myelin membranes. The tight regulation of myelin membrane formation has been widely investigated with classical biochemical and cell biological techniques, both in vitro and in vivo. However, our knowledge about myelin membrane dynamics, such as membrane fluidity in conjunction with the movement/diffusion of proteins and lipids in the membrane and the specificity and role of distinct lipid-protein and protein-protein interactions, is limited. Here, we provide an overview of recent findings about the myelin structure in terms of myelin lipids, proteins and membrane microdomains. To give insight into myelin membrane dynamics, we will particularly highlight the application of model membranes and advanced biophysical techniques, i.e., approaches which clearly provide an added value to insight obtained by classical biochemical techniques. PMID:27141942

  1. Controlled Cell Growth and Cell Migration in Periodic Mesoporous Organosilica/Alginate Nanocomposite Hydrogels.

    Science.gov (United States)

    Seda Kehr, Nermin; Riehemann, Kristina

    2016-01-21

    Nanocomposite (NC) hydrogels with different periodic mesoporous organosilica (PMO) concentrations and a NC hydrogel bilayer with various PMO concentrations inside the layers of the hydrogel matrix are prepared. The effect of the PMO concentration on cell growth and migration of cells is reported. The cells migrate in the bilayer NC hydrogel towards higher PMO concentrations and from cell culture plates to NC hydrogel scaffolds. PMID:26648333

  2. Methyl Jasmonate Represses Growth and Affects Cell Cycle Progression in Cultured Taxus Cells

    OpenAIRE

    Patil, Rohan A.; Lenka, Sangram K.; Normanly, Jennifer; Walker, Elsbeth L.; Roberts, Susan C.

    2014-01-01

    Methyl jasmonate (MeJA) elicitation is an effective strategy to induce and enhance synthesis of the anticancer agent paclitaxel (Taxol®) in Taxus cell suspension cultures; however, concurrent decreases in growth are often observed, which is problematic for large scale bioprocessing. Here, increased accumulation of paclitaxel in Taxus cuspidata suspension cultures with MeJA elicitation was accompanied by a concomitant decrease in cell growth, evident within the first three days post-elicitatio...

  3. Reciprocal regulation of protein synthesis and carbon metabolism for thylakoid membrane biogenesis.

    Directory of Open Access Journals (Sweden)

    Alexandra-Viola Bohne

    Full Text Available Metabolic control of gene expression coordinates the levels of specific gene products to meet cellular demand for their activities. This control can be exerted by metabolites acting as regulatory signals and/or a class of metabolic enzymes with dual functions as regulators of gene expression. However, little is known about how metabolic signals affect the balance between enzymatic and regulatory roles of these dual functional proteins. We previously described the RNA binding activity of a 63 kDa chloroplast protein from Chlamydomonas reinhardtii, which has been implicated in expression of the psbA mRNA, encoding the D1 protein of photosystem II. Here, we identify this factor as dihydrolipoamide acetyltransferase (DLA2, a subunit of the chloroplast pyruvate dehydrogenase complex (cpPDC, which is known to provide acetyl-CoA for fatty acid synthesis. Analyses of RNAi lines revealed that DLA2 is involved in the synthesis of both D1 and acetyl-CoA. Gel filtration analyses demonstrated an RNP complex containing DLA2 and the chloroplast psbA mRNA specifically in cells metabolizing acetate. An intrinsic RNA binding activity of DLA2 was confirmed by in vitro RNA binding assays. Results of fluorescence microscopy and subcellular fractionation experiments support a role of DLA2 in acetate-dependent localization of the psbA mRNA to a translation zone within the chloroplast. Reciprocally, the activity of the cpPDC was specifically affected by binding of psbA mRNA. Beyond that, in silico analysis and in vitro RNA binding studies using recombinant proteins support the possibility that RNA binding is an ancient feature of dihydrolipoamide acetyltransferases. Our results suggest a regulatory function of DLA2 in response to growth on reduced carbon energy sources. This raises the intriguing possibility that this regulation functions to coordinate the synthesis of lipids and proteins for the biogenesis of photosynthetic membranes.

  4. Growth hormone action in rat insulinoma cells expressing truncated growth hormone receptors

    DEFF Research Database (Denmark)

    Møldrup, Annette; Allevato, G; Dyrberg, Thomas;

    1991-01-01

    Transfection of the insulin-producing rat islet tumor cell line RIN-5AH with a full length cDNA of the rat hepatic growth hormone (GH) receptor (GH-R1-638) augments the GH-responsive insulin synthesis in these cells. Using this functional system we analyzed the effect of COOH-terminal truncation...... a markedly reduced capability of GH internalization. In contrast to cells transfected with GH-R1-638, none of the cell lines expressing truncated GH receptors exhibited any increase of the GH-stimulated insulin production. We conclude that domains within the COOH-terminal half of the cytoplasmic part...... of the GH receptor are required for transduction of the signal for GH-stimulated insulin synthesis, whereas cytoplasmic domains proximal to the transmembrane region are involved in receptor-mediated GH internalization....

  5. Sphingosine kinase-1 mediates androgen-induced osteoblast cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Claire [CNRS, Institut de Pharmacologie et de Biologie Structurale, Toulouse F-31000 (France); Universite de Toulouse, UPS, IPBS, Toulouse F-31000 (France); Lafosse, Jean-Michel [CHU Toulouse, Hopital Rangueil, Service d' orthopedie et Traumatologie, Toulouse F-31000 (France); Malavaud, Bernard [CNRS, Institut de Pharmacologie et de Biologie Structurale, Toulouse F-31000 (France); Universite de Toulouse, UPS, IPBS, Toulouse F-31000 (France); CHU Toulouse, Hopital Rangueil, Service d' Urologie et de Transplantation Renale, Toulouse F-31000 (France); Cuvillier, Olivier, E-mail: olivier.cuvillier@ipbs.fr [CNRS, Institut de Pharmacologie et de Biologie Structurale, Toulouse F-31000 (France); Universite de Toulouse, UPS, IPBS, Toulouse F-31000 (France)

    2010-01-01

    Herein we report that the lipid kinase sphingosine kinase-1 (SphK1) is instrumental in mediating androgen-induced cell proliferation in osteoblasts. Dihydrotestosterone (DHT) triggered cell growth in steroid-deprived MC3T3 cells, which was associated with a rapid stimulation of SphK1 and activation of both Akt and ERK signaling pathways. This mechanism relied on functional androgen receptor/PI3K/Akt nongenotropic signaling as pharmacological antagonists could block SphK1 stimulation by DHT and its consequences. Finally, SphK1 inhibition not only abrogated DHT-induced ERK activation but also blocked cell proliferation, while ERK inhibition had no impact, suggesting that SphK1 was critical for DHT signaling yet independently of the ERK.

  6. Cell transfection as a tool to study growth hormone action

    DEFF Research Database (Denmark)

    Norstedt, G; Enberg, B; Francis, S;

    1994-01-01

    The isolation of growth hormone receptor (GHR) cDNA clones has made possible the transfection of GHRs into cultured cells. Our aim in this minireview is to show how the application of such approaches have benefited GHR research. GH stimulation of cells expressing GHR cDNAs can cause an alteration...... of cellular function that mimic those of the endogenous GHR. GHR cDNA transfected cells also offer a system where the mechanism of GH action can be studied. Such a system has been used to demonstrate that the GHR itself becomes tyrosine phosphorylated and that further phosphorylation of downstream proteins...... is important in GH action. The GH signals are transmitted to the nucleus and GH regulated genes have now begun to be characterized. The ability to use cell transfection for mechanistic studies of GH action will be instrumental to define domains within the receptor that are of functional importance...

  7. Fluctuation of Parameters in Tumor Cell Growth Model

    Institute of Scientific and Technical Information of China (English)

    AI Bao-Quan; WANG Xian-Ju; LIU Guo-Tao; LIU Liang-Gang

    2003-01-01

    We study the steady state properties of a logistic growth model in the presence of Gaussian white noise.Based on the corresponding Fokker-Planck equation the steady state solution of the probability distribution functionand its extrema have been investigated. It is found that the fluctuation of the tumor birth rate reduces the populationof the cells while the fluctuation of predation rate can prevent the population of tumor cells from going into extinction.Noise in the system can induce the phase transition.

  8. Disrupting the oncogenic synergism between nucleolin and Ras results in cell growth inhibition and cell death.

    Directory of Open Access Journals (Sweden)

    Sari Schokoroy

    Full Text Available BACKGROUND: The ErbB receptors, Ras proteins and nucleolin are major contributors to malignant transformation. The pleiotropic protein nucleolin can bind to both Ras protein and ErbB receptors. Previously, we have demonstrated a crosstalk between Ras, nucleolin and the ErbB1 receptor. Activated Ras facilitates nucleolin interaction with ErbB1 and stabilizes ErbB1 levels. The three oncogenes synergistically facilitate anchorage independent growth and tumor growth in nude mice. METHODOLOGY/PRINCIPAL FINDINGS: In the present study we used several cancer cell lines. The effect of Ras and nucleolin inhibition was determined using cell growth, cell death and cell motility assays. Protein expression was determined by immunohistochemistry. We found that inhibition of Ras and nucleolin reduces tumor cell growth, enhances cell death and inhibits anchorage independent growth. Our results reveal that the combined treatment affects Ras and nucleolin levels and localization. Our study also indicates that Salirasib (FTS, Ras inhibitor reduces cell motility, which is not affected by the nucleolin inhibitor. CONCLUSIONS/SIGNIFICANCE: These results suggest that targeting both nucleolin and Ras may represent an additional avenue for inhibiting cancers driven by these oncogenes.

  9. Photoresist Derived Carbon for Growth and Differentiation of Neuronal Cells

    Directory of Open Access Journals (Sweden)

    Tie Zou

    2007-08-01

    Full Text Available Apoptosis or necrosis of neurons in the central nervous system (CNS is thehallmark of many neurodegenerative diseases and Traumatic Brain Injury (TBI. Theinability to regenerate in CNS offers little hope for naturally repairing the damagedneurons. However, with the rapid development of new technologies, regenerative medicineoffers great promises to patients with these disorders. Among many events for furtheradvancement of regenerative medicine, extracellular matrix (ECM plays a critical role forcellular migration and differentiation. To develop a biocompatible and electricallyconductive substrate that can be potentially used to promote growth and regeneration ofneurons and to record intracellular and multisite signals from brain as a probe, a polymericprecursor – SPR 220.7 was fabricated by pyrolysis at temperatures higher than 700 oC.Human Neuroblastoma cells - SK-N-MC, SY5Y, mouse teratocarcinoma cells P-19 and ratPC12 cells were found to attach and proliferate on photoresist derived carbon film.Significantly, neuronal differentiation of PC12 cells induced by NGF was demonstrated byobserving cell shape and size, and measuring the length of neurites under SEM. Our resultsindicated that fabricated carbon could potentially be explored in regenerative medicine forpromoting neuronal growth and differentiation in CNS with neurodegeneration.

  10. Polyamines in relation to growth in carrot cell cultures.

    Science.gov (United States)

    Fallon, K M; Phillips, R

    1988-09-01

    Changes in polyamine metabolism were investigated in relation to growth of cell suspension cultures of carrot (Daucus carota, cv Chantenay). Changes in levels of the major amines putrescine and spermidine throughout the culture period correlated poorly with changes in fresh weight, but a closer correlation with the minor component spermine was observed. The arginine decarboxylase (ADC) inhibitor difluoromethylarginine (DFMA) strongly and specifically inhibited ADC activity in the supernatant, reduced the major amine (putrescine) by 95% and the total amine content by 80%. It had no effect on cell number and stimulated fresh weight by over 25% through increased cell expansion. Spermine content, in contrast, increased with DFMA concentration in parallel with fresh weight increases. Difluoromethylornithine strongly inhibited ornithine decarboxylase activity in the pellet, but had little effect on either polyamine levels or culture growth. It was concluded that little evidence for a correlation between free polyamines and cell number in carrot cultures could be detected, but that a possible correlation between spermine content and cell expansion was observed.

  11. Polyamines in Relation to Growth in Carrot Cell Cultures 1

    Science.gov (United States)

    Fallon, Kevin M.; Phillips, Richard

    1988-01-01

    Changes in polyamine metabolism were investigated in relation to growth of cell suspension cultures of carrot (Daucus carota, cv Chantenay). Changes in levels of the major amines putrescine and spermidine throughout the culture period correlated poorly with changes in fresh weight, but a closer correlation with the minor component spermine was observed. The arginine decarboxylase (ADC) inhibitor difluoromethylarginine (DFMA) strongly and specifically inhibited ADC activity in the supernatant, reduced the major amine (putrescine) by 95% and the total amine content by 80%. It had no effect on cell number and stimulated fresh weight by over 25% through increased cell expansion. Spermine content, in contrast, increased with DFMA concentration in parallel with fresh weight increases. Difluoromethylornithine strongly inhibited ornithine decarboxylase activity in the pellet, but had little effect on either polyamine levels or culture growth. It was concluded that little evidence for a correlation between free polyamines and cell number in carrot cultures could be detected, but that a possible correlation between spermine content and cell expansion was observed. PMID:16666271

  12. Growth inhibition by tyrosine kinase inhibitors in mesothelioma cell lines.

    Science.gov (United States)

    Nutt, Joyce E; O'Toole, Kieran; Gonzalez, David; Lunec, John

    2009-06-01

    Clinical outcome following chemotherapy for malignant pleural mesothelioma is poor and improvements are needed. This preclinical study investigates the effect of five tyrosine kinase inhibitors (PTK787, ZD6474, ZD1839, SU6668 and SU11248) on the growth of three mesothelioma cell lines (NCI H226, NCI H28 and MSTO 211H), the presence of growth factor receptors and inhibition of their downstream signalling pathways. GI50 values were determined: ZD6474 and SU11248, mainly VEGFR2 inhibitors, gave the lowest GI50 across all cell lines (3.5-6.9 microM) whereas ZD1839 gave a GI50 in this range only in H28 cells. All cell lines were positive for EGFR, but only H226 cells were positive for VEGFR2 by Western blotting. ZD6474 and ZD1839 inhibited EGF-induced phosphorylation of EGFR, AKT and ERK, whereas VEGF-induced phosphorylation of VEGFR2 was completely inhibited with 0.1 microM SU11248. VEGFR2 was detected in tumour samples by immunohistochemistry. VEGFR2 tyrosine kinase inhibitors warrant further investigation in mesothelioma. PMID:19318229

  13. Systems-biology dissection of eukaryotic cell growth

    Directory of Open Access Journals (Sweden)

    Andrews Justen

    2010-05-01

    Full Text Available Abstract A recent article in BMC Biology illustrates the use of a systems-biology approach to integrate data across the transcriptome, proteome and metabolome of budding yeast in order to dissect the relationship between nutrient conditions and cell growth. See research article http://jbiol.com/content/6/2/4 and http://www.biomedcentral.com/1741-7007/8/68

  14. Imatinib alters cell viability but not growth factors levels in TM4 Sertoli cells

    Science.gov (United States)

    Hashemnia, Seyyed Mohammad Reza; Atari-Hajipirloo, Somayeh; Roshan-Milani, Shiva; Valizadeh, Nasim; Mahabadi, Sonya; Kheradmand, Fatemeh

    2016-01-01

    Background: The anticancer agent imatinib (IM) is a small molecular analog of ATP that inhibits tyrosine kinase activity of platelet derived growth factors (PDGFs) and stem cell factor (SCF) receptor in cancer cells. However these factors have a key role in regulating growth and development of normal Sertoli, Leydig and germ cells. Objective: The aim of this study was to determine cell viability, PDGF and SCF levels in mouse normal Sertoli cells exposed to IM. Materials and Methods: In this experimental study, the mouse TM4 Sertoli cells were treated with 0, 2.5, 5, 10 and 20 μM IM for 2, 4 or 6 days. The cell viability and growth factors levels were assessed by MTT and ELISA methods, respectively. For statistical analysis, One-Way ANOVA was performed. Results: IM showed significant decrease in Sertoli cell viability compared to control group (p=0.001). However, IM increased PDGF and SCF level insignificantly (p>0.05). Conclusion: Results suggested that IM treatment induced a dose dependent reduction of cell viability in Sertoli cells. It seems that treatment with this anticancer drug is involved in the fertility process. Further studies are needed to evaluate the role of PDGF and SCF in this cell. PMID:27738659

  15. Stochastic modeling of cell growth with symmetric or asymmetric division

    Science.gov (United States)

    Marantan, Andrew; Amir, Ariel

    2016-07-01

    We consider a class of biologically motivated stochastic processes in which a unicellular organism divides its resources (volume or damaged proteins, in particular) symmetrically or asymmetrically between its progeny. Assuming the final amount of the resource is controlled by a growth policy and subject to additive and multiplicative noise, we derive the recursive integral equation describing the evolution of the resource distribution over subsequent generations and use it to study the properties of stable resource distributions. We find conditions under which a unique stable resource distribution exists and calculate its moments for the class of affine linear growth policies. Moreover, we apply an asymptotic analysis to elucidate the conditions under which the stable distribution (when it exists) has a power-law tail. Finally, we use the results of this asymptotic analysis along with the moment equations to draw a stability phase diagram for the system that reveals the counterintuitive result that asymmetry serves to increase stability while at the same time widening the stable distribution. We also briefly discuss how cells can divide damaged proteins asymmetrically between their progeny as a form of damage control. In the appendixes, motivated by the asymmetric division of cell volume in Saccharomyces cerevisiae, we extend our results to the case wherein mother and daughter cells follow different growth policies.

  16. Stochastic modeling of cell growth with symmetric or asymmetric division.

    Science.gov (United States)

    Marantan, Andrew; Amir, Ariel

    2016-07-01

    We consider a class of biologically motivated stochastic processes in which a unicellular organism divides its resources (volume or damaged proteins, in particular) symmetrically or asymmetrically between its progeny. Assuming the final amount of the resource is controlled by a growth policy and subject to additive and multiplicative noise, we derive the recursive integral equation describing the evolution of the resource distribution over subsequent generations and use it to study the properties of stable resource distributions. We find conditions under which a unique stable resource distribution exists and calculate its moments for the class of affine linear growth policies. Moreover, we apply an asymptotic analysis to elucidate the conditions under which the stable distribution (when it exists) has a power-law tail. Finally, we use the results of this asymptotic analysis along with the moment equations to draw a stability phase diagram for the system that reveals the counterintuitive result that asymmetry serves to increase stability while at the same time widening the stable distribution. We also briefly discuss how cells can divide damaged proteins asymmetrically between their progeny as a form of damage control. In the appendixes, motivated by the asymmetric division of cell volume in Saccharomyces cerevisiae, we extend our results to the case wherein mother and daughter cells follow different growth policies. PMID:27575162

  17. Effect of arginase II on L-arginine depletion and cell growth in murine cell lines of renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Patterson John R

    2008-09-01

    Full Text Available Abstract Background L-arginine is the common substrate for the two isoforms of arginase. Arginase I, highly expressed in the liver and arginase II mainly expressed in the kidney. Arginase I-producing myeloid derived suppressor cells have been shown to inhibit T-cell function by the depletion of L-arginine. On the other hand, arginase II has been detected in patients with cancer and is thought to metabolize L-arginine to L-ornithine needed to sustain rapid tumor growth; however its role in L-arginine depletion is unclear. Thus, in tumor biology, L-arginine metabolism may play a dual role in tumor growth and in the induction of T cell dysfunction. Therefore, we studied in murine renal cell carcinoma (RCC cell lines, the effect of arginase II on tumor cell proliferation and L-arginine depletion. The effect of arginase inhibitors on cell proliferation was also tested. Methods Three murine renal cell carcinoma (mRCC cell lines were tested for the presence of arginase. nor-NOHA, an arginase inhibitor was used to substantiate the effect of arginase on cell growth and L-arginine depletion. Amino acid levels were tested by HPLC. Results Our results show that mRCC cell lines express only arginase II and were able to deplete L-arginine from the medium. Cell growth was independent of the amount of arginase activity expressed by the cells. nor-NOHA significantly (P = 0.01 reduced arginase II activity and suppressed cell growth in cells exhibiting high arginase activity. The depletion of L-arginine by mRCC induced the decrease expression of CD3ζ a key element for T-cell function. Conclusion The results of this study show for the first time that arginase II produced by RCC cell lines depletes L-arginine resulting in decreased expression of CD3ζ. These results indicate that RCC cell lines expressing arginase II can modulate the L-arginine metabolic pathway to regulate both cell growth and T-cell function. Blocking arginase may lead to a decrease in RCC cell

  18. Ginger inhibits cell growth and modulates angiogenic factors in ovarian cancer cells

    Directory of Open Access Journals (Sweden)

    Huang Jennifer

    2007-12-01

    Full Text Available Abstract Background Ginger (Zingiber officinale Rosc is a natural dietary component with antioxidant and anticarcinogenic properties. The ginger component [6]-gingerol has been shown to exert anti-inflammatory effects through mediation of NF-κB. NF-κB can be constitutively activated in epithelial ovarian cancer cells and may contribute towards increased transcription and translation of angiogenic factors. In the present study, we investigated the effect of ginger on tumor cell growth and modulation of angiogenic factors in ovarian cancer cells in vitro. Methods The effect of ginger and the major ginger components on cell growth was determined in a panel of epithelial ovarian cancer cell lines. Activation of NF-κB and and production of VEGF and IL-8 was determined in the presence or absence of ginger. Results Ginger treatment of cultured ovarian cancer cells induced profound growth inhibition in all cell lines tested. We found that in vitro, 6-shogaol is the most active of the individual ginger components tested. Ginger treatment resulted in inhibition of NF-kB activation as well as diminished secretion of VEGF and IL-8. Conclusion Ginger inhibits growth and modulates secretion of angiogenic factors in ovarian cancer cells. The use of dietary agents such as ginger may have potential in the treatment and prevention of ovarian cancer.

  19. Intracellular Angiotensin II and cell growth of vascular smooth muscle cells

    NARCIS (Netherlands)

    Filipeanu, CM; Henning, RH; de Zeeuw, D; Nelemans, A

    2001-01-01

    1 We recently demonstrated that intracellular application of Angiotensin II (Angiotensin IIintr) induces rat aorta contraction independent of plasma membrane Angiotensin II receptors. In this study we investigated the effects of Angiotensin IIintr on cell growth in A7r5 smooth muscle cells. 2 DNA-sy

  20. Growth control in colon epithelial cells: gadolinium enhances calcium-mediated growth regulation.

    Science.gov (United States)

    Attili, Durga; Jenkins, Brian; Aslam, Muhammad Nadeem; Dame, Michael K; Varani, James

    2012-12-01

    Gadolinium, a member of the lanthanoid family of transition metals, interacts with calcium-binding sites on proteins and other biological molecules. The overall goal of the present investigation was to determine if gadolinium could enhance calcium-induced epithelial cell growth inhibition in the colon. Gadolinium at concentrations as low as 1-5 μM combined with calcium inhibits proliferation of human colonic epithelial cells more effectively than calcium alone. Gadolinium had no detectable effect on calcium-induced differentiation in the same cells based on change in cell morphology, induction of E-cadherin synthesis, and translocation of E-cadherin from the cytosol to the cell surface. When the colon epithelial cells were treated with gadolinium and then exposed to increased calcium concentrations, movement of extracellular calcium into the cell was suppressed. In contrast, gadolinium treatment had no effect on ionomycin-induced release of stored intracellular calcium into the cytoplasm. Whether these in vitro observations can be translated into an approach for reducing abnormal proliferation in the colonic mucosa (including polyp formation) is not known. These results do, however, provide an explanation for our recent findings that a multi-mineral supplement containing all of the naturally occurring lanthanoid metals including gadolinium are more effective than calcium alone in preventing colon polyp formation in mice on a high-fat diet.

  1. Models of lipid droplets growth and fission in adipocyte cells

    International Nuclear Information System (INIS)

    Lipid droplets (LD) are spherical cellular inclusion devoted to lipids storage. It is well known that excessive accumulation of lipids leads to several human worldwide diseases like obesity, type 2 diabetes, hepatic steatosis and atherosclerosis. LDs' size range from fraction to one hundred of micrometers in adipocytes and is related to the lipid content, but their growth is still a puzzling question. It has been suggested that LDs can grow in size due to the fusion process by which a larger LD is obtained by the merging of two smaller LDs, but these events seems to be rare and difficult to be observed. Many other processes are thought to be involved in the number and growth of LDs, like the de novo formation and the growth through additional neutral lipid deposition in pre-existing droplets. Moreover the number and size of LDs are influenced by the catabolism and the absorption or interaction with other organelles. The comprehension of these processes could help in the confinement of the pathologies related to lipid accumulation. In this study the LDs' size distribution, number and the total volume of immature (n=12), mature (n=12, 10-days differentiated) and lipolytic (n=12) 3T3-L1 adipocytes were considered. More than 11,000 LDs were measured in the 36 cells after Oil Red O staining. In a previous work Monte Carlo simulations were used to mimic the fusion process alone between LDs. We found that, considering the fusion as the only process acting on the LDs, the size distribution in mature adipocytes can be obtained with numerical simulation starting from the size distribution in immature cells provided a very high rate of fusion events. In this paper Monte Carlo simulations were developed to mimic the interaction between LDs taking into account many other processes in addition to fusion (de novo formation and the growth through additional neutral lipid deposition in pre-existing droplets) in order to reproduce the LDs growth and we also simulated the

  2. Models of lipid droplets growth and fission in adipocyte cells

    Energy Technology Data Exchange (ETDEWEB)

    Boschi, Federico, E-mail: federico.boschi@univr.it [Department of Computer Science, University of Verona, Strada Le Grazie 15, 37134 Verona (Italy); Rizzatti, Vanni; Zamboni, Mauro [Department of Medicine, Geriatric Section, University of Verona, Piazzale Stefani 1, 37126 Verona (Italy); Sbarbati, Andrea [Department of Neurological and Movement Sciences, University of Verona, Strada Le Grazie 8, 37134 Verona (Italy)

    2015-08-15

    Lipid droplets (LD) are spherical cellular inclusion devoted to lipids storage. It is well known that excessive accumulation of lipids leads to several human worldwide diseases like obesity, type 2 diabetes, hepatic steatosis and atherosclerosis. LDs' size range from fraction to one hundred of micrometers in adipocytes and is related to the lipid content, but their growth is still a puzzling question. It has been suggested that LDs can grow in size due to the fusion process by which a larger LD is obtained by the merging of two smaller LDs, but these events seems to be rare and difficult to be observed. Many other processes are thought to be involved in the number and growth of LDs, like the de novo formation and the growth through additional neutral lipid deposition in pre-existing droplets. Moreover the number and size of LDs are influenced by the catabolism and the absorption or interaction with other organelles. The comprehension of these processes could help in the confinement of the pathologies related to lipid accumulation. In this study the LDs' size distribution, number and the total volume of immature (n=12), mature (n=12, 10-days differentiated) and lipolytic (n=12) 3T3-L1 adipocytes were considered. More than 11,000 LDs were measured in the 36 cells after Oil Red O staining. In a previous work Monte Carlo simulations were used to mimic the fusion process alone between LDs. We found that, considering the fusion as the only process acting on the LDs, the size distribution in mature adipocytes can be obtained with numerical simulation starting from the size distribution in immature cells provided a very high rate of fusion events. In this paper Monte Carlo simulations were developed to mimic the interaction between LDs taking into account many other processes in addition to fusion (de novo formation and the growth through additional neutral lipid deposition in pre-existing droplets) in order to reproduce the LDs growth and we also simulated the

  3. Regulation of IGFBP secretion and modulation of cell growth in MDBK cells.

    Science.gov (United States)

    Cohick, W S; Clemmons, D R

    1993-03-01

    The ability of IGF binding proteins (IGFBP) to modulate cell growth and IGF-I responsiveness of epithelial cells was examined using the Madin-Darby bovine kidney (MDBK) cell line. The predominant IGFBP present in conditioned media (CM) of untreated cells was found to be IGFBP-2. Following exposure to forskolin, the abundance of IGFBP-2 in CM was decreased, while IGFBP-3 and -4 were induced. These changes corresponded with alterations in mRNA abundance. Growth of MDBK cells in serum-free media was stimulated by addition of 2.5 to 50 ng/ml of IGF-I in a dose responsive manner. Coincubation with equimolar amounts of IGF-I and exogenous bovine IGFBP-3 potentiated the growth response observed with IGF-I alone. In order to alter endogenous IGFBP-3 secretion, cells were exposed to transfection with an expression vector containing sense IGFBP-3 cDNA. Following selection and amplification with methotrexate, cells underwent a permanent alteration in cell morphology, exhibiting characteristics of transporting epithelia. This was associated with secretion of IGFBP-3 under basal conditions. Secretion of IGFBP-3 was due to expression of endogenous IGFBP-3 and not to expression of the transgene. Cells expressing IGFBP-3 under basal conditions grew slower in serum, but were more responsive to 100 ng/ml of IGF-1 in serum-free media compared to wild-type MDBK cells. The role of IGFBP-3 in mediating these responses requires further study.

  4. Tomato waste: Carotenoids content, antioxidant and cell growth activities.

    Science.gov (United States)

    Stajčić, Sladjana; Ćetković, Gordana; Čanadanović-Brunet, Jasna; Djilas, Sonja; Mandić, Anamarija; Četojević-Simin, Dragana

    2015-04-01

    The carotenoid content, antioxidant and cell growth activities of tomato waste extracts, obtained from five different tomato genotypes, was investigated. High performance liquid chromatography was used to identify and quantify the main carotenoids present in tomato waste extracts. The antioxidant activity of tomato waste extracts was tested using spectrophotometric methods, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and reducing power assay. The highest DPPH scavenging activity (IC50 = 0.057 mg/ml) was obtained for Bačka extract. The Knjaz extract showed the best reducing power (IC50 = 2.12 mg/ml). Cell growth effects were determined in HeLa, MCF7 and MRC-5 cell lines by sulforhodamine B test. Anti-proliferative effects were observed in all cell lines at higher concentrations (⩾ 0.125 mg/ml). The carotenoid contents exhibited a strong correlation with antioxidant and anti-proliferation activity. The results obtained indicated that tomato waste should be regarded as potential nutraceutic resource and may be used as a functional food ingredient. PMID:25442547

  5. Role of CaECM25 in cell morphogenesis, cell growth and virulence in Candida albicans

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Candida albicans is the most prominent opportunistic fungal pathogen in humans. Multiple factors are associated with the virulence of C. albicans, including morphogenesis, cell wall organization and growth rate. Here, we describe the identification and functional characterization of CaECM25, a gene that has not been reported before. We constructed Caecm25?/? mutants and investigated the role of the gene in morphogenesis, cell wall organization and virulence. CaECM25 deletion resulted in defects in cell separation, a slower growth rate, reduced filamentous growth and attenuated adherence to plastic surfaces. The Caecm25?/? mutant was also significantly less virulent than wild type when tested for systemic infection in mice. Therefore, CaECM25 plays important roles in morphogenesis, cell wall organization and virulence.

  6. Role of CaECM25 in cell morphogenesis, cell growth and virulence in Candida albicans

    Institute of Scientific and Technical Information of China (English)

    ZHANG TingTing; LI WanJie; LI Di; WANG Yue; SANG JianLi

    2008-01-01

    Candida albicans is the most prominent opportunistic fungal pathogen in humans. Multiple factors are associated with the virulence of C. albicans, including morphogenesis, cell wall organization and growth rate. Here, we describe the identification and functional characterization of CaECM25, a gene that has not been reported before. We constructed Caecm25△/△ mutants and investigated the role of the gene In morphogenesis, cell wall organization and virulence. CaECM25 deletion resulted in defects in cell separation, a slower growth rate, reduced filamentous growth and attenuated adherence to plastic surfaces. The Caecm25△/△ mutant was also significantly less virulent than wild type when tested for systemic infection in mice. Therefore, CaECM25 plays important roles in morphogenesis, cell wall organization and virulence.

  7. Versatile roles of plastids in plant growth and development.

    Science.gov (United States)

    Inaba, Takehito; Ito-Inaba, Yasuko

    2010-11-01

    Plastids, found in plants and some parasites, are of endosymbiotic origin. The best-characterized plastid is the plant cell chloroplast. Plastids provide essential metabolic and signaling functions, such as the photosynthetic process in chloroplasts. However, the role of plastids is not limited to production of metabolites. Plastids affect numerous aspects of plant growth and development through biogenesis, varying functional states and metabolic activities. Examples include, but are not limited to, embryogenesis, leaf development, gravitropism, temperature response and plant-microbe interactions. In this review, we summarize the versatile roles of plastids in plant growth and development.

  8. Endothelial cells stimulate growth of normal and cancerous breast epithelial cells in 3D culture

    Directory of Open Access Journals (Sweden)

    Magnusson Magnus K

    2010-07-01

    Full Text Available Abstract Background Epithelial-stromal interaction provides regulatory signals that maintain correct histoarchitecture and homeostasis in the normal breast and facilitates tumor progression in breast cancer. However, research on the regulatory role of the endothelial component in the normal and malignant breast gland has largely been neglected. The aim of the study was to investigate the effects of endothelial cells on growth and differentiation of human breast epithelial cells in a three-dimensional (3D co-culture assay. Methods Breast luminal and myoepithelial cells and endothelial cells were isolated from reduction mammoplasties. Primary cells and established normal and malignant breast cell lines were embedded in reconstituted basement membrane in direct co-culture with endothelial cells and by separation of Transwell filters. Morphogenic and phenotypic profiles of co-cultures was evaluated by phase contrast microscopy, immunostaining and confocal microscopy. Results In co-culture, endothelial cells stimulate proliferation of both luminal- and myoepithelial cells. Furthermore, endothelial cells induce a subpopulation of luminal epithelial cells to form large acini/ducts with a large and clear lumen. Endothelial cells also stimulate growth and cloning efficiency of normal and malignant breast epithelial cell lines. Transwell and gradient co-culture studies show that endothelial derived effects are mediated - at least partially - by soluble factors. Conclusion Breast endothelial cells - beside their role in transporting nutrients and oxygen to tissues - are vital component of the epithelial microenvironment in the breast and provide proliferative signals to the normal and malignant breast epithelium. These growth promoting effects of endothelial cells should be taken into consideration in breast cancer biology.

  9. Adrenomedullin as a Growth and Cell Fate Regulatory Factor for Adult Neural Stem Cells

    OpenAIRE

    Sonia Martínez-Herrero; Ignacio M Larráyoz; Laura Ochoa-Callejero; Josune García-Sanmartín; Alfredo Martínez

    2012-01-01

    The use of stem cells as a strategy for tissue repair and regeneration is one of the biomedical research areas that has attracted more interest in the past few years. Despite the classic belief that the central nervous system (CNS) was immutable, now it is well known that cell turnover occurs in the mature CNS. Postnatal neurogenesis is subjected to tight regulation by many growth factors, cell signals, and transcription factors. An emerging molecule involved in this process is adrenomedullin...

  10. Nonlinear Growth Kinetics of Breast Cancer Stem Cells: Implications for Cancer Stem Cell Targeted Therapy

    OpenAIRE

    Liu, Xinfeng; Johnson, Sara; Liu, Shou; Kanojia, Deepak; Yue, Wei; Singn, Udai; Wang, Qian; Wang, Qi; Nie, Qing; Chen, Hexin

    2013-01-01

    Cancer stem cells (CSCs) have been identified in primary breast cancer tissues and cell lines. The CSC population varies widely among cancerous tissues and cell lines, and is often associated with aggressive breast cancers. Despite of intensive research, how the CSC population is regulated within a tumor is still not well understood so far. In this paper, we present a mathematical model to explore the growth kinetics of CSC population both in vitro and in vivo. Our mathematical models and sup...

  11. Metformin inhibits cell growth by upregulating microRNA-26a in renal cancer cells

    OpenAIRE

    Yang, Feng-Qiang; Wang, Ji-Jiao; Yan, Jia-Sheng; Huang, Jian-Hua; Li, Wei; Che, Jian-Ping; Wang, Guang-Chun; Liu, Min; Zheng, Jun-Hua

    2014-01-01

    Accumulating evidence suggests that metformin, a biguanide class of anti-diabetic drugs, possesses anti-cancer properties and may reduce cancer risk and improve prognosis. However, the mechanism by which metformin affects various cancers, including renal cancer still unknown. MiR-26a induces cell growth, cell cycle and cell apoptosis progression via direct targeting of Bcl-2, clyclin D1 and PTEN in cancer cells. In the present study, we used 786-O human renal cancer cell lines to study the ef...

  12. Cheiradone: a vascular endothelial cell growth factor receptor antagonist

    Directory of Open Access Journals (Sweden)

    Ahmed Nessar

    2008-01-01

    Full Text Available Abstract Background Angiogenesis, the growth of new blood vessels from the pre-existing vasculature is associated with physiological (for example wound healing and pathological conditions (tumour development. Vascular endothelial growth factor (VEGF, fibroblast growth factor-2 (FGF-2 and epidermal growth factor (EGF are the major angiogenic regulators. We have identified a natural product (cheiradone isolated from a Euphorbia species which inhibited in vivo and in vitro VEGF- stimulated angiogenesis but had no effect on FGF-2 or EGF activity. Two primary cultures, bovine aortic and human dermal endothelial cells were used in in vitro (proliferation, wound healing, invasion in Matrigel and tube formation and in vivo (the chick chorioallantoic membrane models of angiogenesis in the presence of growth factors and cheiradone. In all cases, the concentration of cheiradone which caused 50% inhibition (IC50 was determined. The effect of cheiradone on the binding of growth factors to their receptors was also investigated. Results Cheiradone inhibited all stages of VEGF-induced angiogenesis with IC50 values in the range 5.20–7.50 μM but did not inhibit FGF-2 or EGF-induced angiogenesis. It also inhibited VEGF binding to VEGF receptor-1 and 2 with IC50 values of 2.9 and 0.61 μM respectively. Conclusion Cheiradone inhibited VEGF-induced angiogenesis by binding to VEGF receptors -1 and -2 and may be a useful investigative tool to study the specific contribution of VEGF to angiogenesis and may have therapeutic potential.

  13. Entrainability of cell cycle oscillator models with exponential growth of cell mass.

    Science.gov (United States)

    Nakao, Mitsuyuki; Enkhkhudulmur, Tsog-Erdene; Katayama, Norihiro; Karashima, Akihiro

    2014-01-01

    Among various aspects of cell cycle, understanding synchronization mechanism of cell cycle is important because of the following reasons. (1)Cycles of cell assembly should synchronize to form an organ. (2) Synchronizing cell cycles are required to experimental analysis of regulatory mechanisms of cell cycles. (3) Cell cycle has a distinct phase relationship with the other biological rhythms such as circadian rhythm. However, forced as well as mutual entrainment mechanisms are not clearly known. In this study, we investigated entrainability of cell cycle models of yeast cell under the periodic forcing to both of the cell mass and molecular dynamics. Dynamics of models under study involve the cell mass growing exponentially. In our result, they are shown to allow only a limited frequency range for being entrained by the periodic forcing. In contrast, models with linear growth are shown to be entrained in a wider frequency range. It is concluded that if the cell mass is included in the cell cycle regulation, its entrainability is sensitive to a shape of growth curve assumed in the model. PMID:25571564

  14. High-throughput quantitative analysis with cell growth kinetic curves for low copy number mutant cells.

    Science.gov (United States)

    Xing, James Z; Gabos, Stephan; Huang, Biao; Pan, Tianhong; Huang, Min; Chen, Jie

    2012-10-01

    The mutation rate in cells induced by environmental genotoxic hazards is very low and difficult to detect using traditional cell counting assays. The established genetic toxicity tests currently recognized by regulatory authorities, such as conventional Ames and hypoxanthine guanine phosphoribosyl-transferase (HPRT) assays, are not well suited for higher-throughput screening as they require large amounts of test compounds and are very time consuming. In this study, we developed a novel cell-based assay for quantitative analysis of low numbers of cell copies with HPRT mutation induced by an environmental mutagen. The HPRT gene mutant cells induced by the mutagen were selected by 6-thioguanine (6-TG) and the cell's kinetic growth curve monitored by a real-time cell electronic sensor (RT-CES) system. When a threshold is set at a certain cell index (CI) level, samples with different initial mutant cell copies take different amounts of time in order for their growth (or CI accumulation) to cross this threshold. The more cells that are initially seeded in the test well, the faster the cell accumulation and therefore the shorter the time required to cross this threshold. Therefore, the culture time period required to cross the threshold of each sample corresponds to the original number of cells in the sample. A mutant cell growth time threshold (MT) value of each sample can be calculated to predict the number of original mutant cells. For mutagenesis determination, the RT-CES assay displayed an equal sensitivity (p > 0.05) and coefficients of variation values with good correlation to conventional HPRT mutagenic assays. Most importantly, the RT-CES mutation assay has a higher throughput than conventional cellular assays.

  15. Exercise induces mitochondrial biogenesis after brain ischemia in rats.

    Science.gov (United States)

    Zhang, Q; Wu, Y; Zhang, P; Sha, H; Jia, J; Hu, Y; Zhu, J

    2012-03-15

    Stroke is a major cause of death worldwide. Previous studies have suggested both exercise and mitochondrial biogenesis contribute to improved post-ischemic recovery of brain function. However, the exact mechanism underlying this effect is unclear. On the other hand, the benefit of exercise-induced mitochondrial biogenesis in brain has been confirmed. In this study, we attempted to determine whether treadmill exercise induces functional improvement through regulation of mitochondrial biogenesis after brain ischemia. We subjected adult male rats to ischemia, followed by either treadmill exercise or non-exercise and analyzed the effect of exercise on the amount of mitochondrial DNA (mtDNA), expression of mitochondrial biogenesis factors, and mitochondrial protein. In the ischemia-exercise group, only peroxisome proliferator activated receptor coactivator-1 (PGC-1) expression was increased significantly after 3 days of treadmill training. However, after 7 days of training, the levels of mtDNA, nuclear respiratory factor 1, NRF-1, mitochondrial transcription factor A, TFAM, and the mitochondrial protein cytochrome C oxidase subunit IV (COXIV) and heat shock protein-60 (HSP60) also increased above levels observed in non-exercised ischemic animals. These changes followed with significant changes in behavioral scores and cerebral infarct volume. The results indicate that exercise can promote mitochondrial biogenesis after ischemic injury, which may serve as a novel component of exercise-induced repair mechanisms of the brain. Understanding the molecular basis for exercise-induced neuroprotection may be beneficial in the development of therapeutic approaches for brain recovery from the ischemic injury. Based upon our findings, stimulation or enhancement of mitochondrial biogenesis may prove a novel neuroprotective strategy in the future. PMID:22266265

  16. Cytokines and growth factors which regulate bone cell function

    Science.gov (United States)

    Seino, Yoshiki

    Everybody knows that growth factors are most important in making bone. Hormones enhance bone formation from a long distance. Growth factors promote bone formation as an autocrine or paracrine factor in nearby bone. BMP-2 through BMP-8 are in the TGF-β family. BMP makes bone by enchondral ossification. In bone, IGF-II is most abundant, second, TGF-β, and third IGF-I. TGF-β enhances bone formation mainly by intramembranous ossification in vivo. TGF-β affects both cell proliferation and differentiation, however, TGF-β mainly enhances bone formation by intramembranous ossification. Interestingly, TGF-β is increased by estrogen(E 2), androgen, vitamin D, TGF-β and FGF. IGF-I and IGF-II also enhance bone formation. At present it remains unclear why IGF-I is more active in bone formation than IGF-II, although IGF-II is more abundant in bone compared to IGF-I. However, if only type I receptor signal transduction promotes bone formation, the strong activity of IGF-I in bone formation is understandable. GH, PTH and E 2 promotes IGF-I production. Recent data suggest that hormones containing vitamin D or E 2 enhance bone formation through growth factors. Therefore, growth factors are the key to clarifying the mechanism of bone formation.

  17. In vivo roles of BamA, BamB and BamD in the biogenesis of BamA, a core protein of the β-barrel assembly machine of Escherichia coli.

    Science.gov (United States)

    Misra, Rajeev; Stikeleather, Ryan; Gabriele, Rebecca

    2015-03-13

    Assembly of the β-barrel outer membrane proteins (OMPs) is an essential cellular process in Gram-negative bacteria and in the mitochondria and chloroplasts of eukaryotes--two organelles of bacterial origin. Central to this process is the conserved β-barrel OMP that belongs to the Omp85 superfamily. In Escherichia coli, BamA is the core β-barrel OMP and, together with four outer membrane lipoproteins, BamBCDE, constitutes the β-barrel assembly machine (BAM). In this paper, we investigated the roles of BamD, an essential lipoprotein, and BamB in BamA biogenesis. Depletion of BamD caused impairment in BamA biogenesis and cessation of cell growth. These defects of BamD depletion were partly reversed by single-amino-acid substitutions mapping within the β-barrel domain of BamA. However, in the absence of BamB, the positive effects of the β-barrel substitutions on BamA biogenesis under BamD depletion conditions were nullified. By employing a BamA protein bearing one such substitution, F474L, it was demonstrated that the mutant BamA protein could not only assemble without BamD but also facilitate the assembly of wild-type BamA expressed in trans. Based on these data, we propose a model in which the Bam lipoproteins, which are localized to the outer membrane by the BAM-independent Lol pathway, aid in the creation of new BAM complexes by serving as outer membrane receptors and folding factors for nascent BamA molecules. The newly assembled BAM holocomplex then catalyzes the assembly of substrate OMPs and BamA. These in vivo findings are corroborated by recently published in vitro data. PMID:24792419

  18. What can rapid terrestrial biogenesis tell us about life in the universe?

    CERN Document Server

    Lineweaver, C H; Lineweaver, Charles H.; Davis, Tamara M.

    2002-01-01

    It is sometimes asserted that the rapidity of biogenesis on Earth suggests that life is common in the Universe. We critically examine the assumptions inherent in this argument. Using a lottery model for biogenesis in the Universe, we convert the observational constraints on the rapidity of biogenesis on Earth into constraints on the probability of biogenesis on other terrestrial planets. For example, if terrestrial biogenesis took less than 200 Myr (and we assume that it could have taken 1 billion years) then we find the probability of biogenesis on terrestrial planets older than ~ 1 Gyr, is > 36% at the 95% confidence level. However, there are assumptions and selection effects that complicate this result: although we correct the analysis for the fact that biogenesis is a prerequisite for our existence, our result depends on the plausible assumption that rapid biogenesis is not such a prerequisite.

  19. Dickkopf3 overexpression inhibits pancreatic cancer cell growth in vitro

    Institute of Scientific and Technical Information of China (English)

    Yu-Mei Gu; Yi-Hui Ma; Wu-Gan Zhao; Jie Chen

    2011-01-01

    AIM: To elucidate the role of dickkopf3 (Dkk3) in human pancreatic cancer cell growth.METHODS: Dkk3 mRNA and protein expression in human pancreatic cancer cell lines were detected by real-time reverse transcription polymerase chain reaction (real-time RT-PCR), Western blotting and immunofluorescence. Methylation of the Dkk3 promoter sequence was examined by methylation-specific polymerase chain reaction (MSP) and Dkk3 mRNA expression was determined by real-time RT-PCR after 5-aza-2'-deoxycytidine (5-aza-dC) treatment. The effects of Dkk3 on cancer cell proliferation and in vitro sensitivity to gemcitabine were investigated by CellTiter 96. AQueous One Solution Cell Proliferation Assay (MTS) after transfecting the Dkk3 expression plasmid into human pancreatic cancer cells. The expression of β-catenin, phosphorylated extracellular signal-regulated protein kinases (pERK) and extracellular signal-regulated protein kinases (ERK) was also examined by real-time RT-PCR and Western blotting after upregulating Dkk3 expression in human pancreatic cancer cells.RESULTS: The results show that the expression levels of both Dkk3 mRNA and protein were low in all pancreatic cancer cell lines tested. The Dkk3 promoter sequence was methylated in the MIA PaCa-2 and AsPC-1 cell lines, which showed reduced Dkk3 expression. These two cell lines, which initially had a methylated Dkk3 promoter, showed increased Dkk3 mRNA expression that was dependent upon the dosage and timing of the DNA demethylating agent, 5-aza-dC, treatment (P < 0.05 or P < 0.01). When Dkk3 expression was upregulated following the transfection of a Dkk3 expression plasmid into MIA PaCa-2 cells, the ability of cells to proliferate decreased (P < 0.01), and the expression of β-catenin and pERK was downregulated (P < 0.01). Sensitivity to gemcitabine was enhanced in Dkk3 expression plasmid-transfected cells.CONCLUSION: Our findings, for the first time, implicate Dkk3 as a tumor suppressor in human pancreatic cancer

  20. Autoregulation and multiple DNA interactions by a transcriptional regulatory protein in E. coli pili biogenesis.

    OpenAIRE

    Forsman, K; M. Göransson; Uhlin, B E

    1989-01-01

    An operon mediating biogenesis of digalactoside-binding pilus-adhesin of serotype F13 in uropathogenic Escherichia coli includes the regulatory gene papB. The papB gene product was found to act as transcriptional activator of an operon which includes the papB gene and several pap cistrons encoding the proteins of the pilus polymer. Studies of how pap gene expression was affected by increasing amounts of PapB protein in the cells showed that high levels did not stimulate transcription but caus...

  1. IL-35 over-expression increases apoptosis sensitivity and suppresses cell growth in human cancer cells.

    Science.gov (United States)

    Long, Jun; Zhang, Xulong; Wen, Mingjie; Kong, Qingli; Lv, Zhe; An, Yunqing; Wei, Xiao-Qing

    2013-01-01

    Interleukin (IL)-35 is a novel heterodimeric cytokine in the IL-12 family and is composed of two subunits: Epstein-Barr virus-induced gene 3 (EBI3) and IL-12p35. IL-35 is expressed in T regulatory (Treg) cells and contributes to the immune suppression function of these cells. In contrast, we found that both IL-35 subunits were expressed concurrently in most human cancer cell lines compared to normal cell lines. In addition, we found that TNF-α and IFN-γ stimulation led to increased IL-35 expression in human cancer cells. Furthermore, over-expression of IL-35 in human cancer cells suppressed cell growth in vitro, induced cell cycle arrest at the G1 phase, and mediated robust apoptosis induced by serum starvation, TNF-α, and IFN-γ stimulation through the up-regulation of Fas and concurrent down-regulation of cyclinD1, survivin, and Bcl-2 expression. In conclusion, our results reveal a novel functional role for IL-35 in suppressing cancer activity, inhibiting cancer cell growth, and increasing the apoptosis sensitivity of human cancer cells through the regulation of genes related to the cell cycle and apoptosis. Thus, this research provides new insights into IL-35 function and presents a possible target for the development of novel cancer therapies.

  2. Cloning and analysis of genes regulating plant cell growth

    International Nuclear Information System (INIS)

    The aims of this work are to identify, clone and analyze genes involved in the regulation of plant cell growth. To do this, we have induced tumors on Arabidopsis thaliana by exposing seed or germinating seedlings to ionizing radiation. The tumors which developed on the plants derived from these seed were excised and established in culture. Unlike normal tissue explants, the tumors are able to grow on hormone-free medium suggesting changes in growth control (either hormonal or other) induced by the radiation exposure. This progress report describes work aimed at characterizing these tumors at the physiological and cellular levels and at determining the molecular basis of the changes leading to the tumorous phenotype

  3. Nonlinear Growth Kinetics of Breast Cancer Stem Cells: Implications for Cancer Stem Cell Targeted Therapy

    Science.gov (United States)

    Liu, Xinfeng; Johnson, Sara; Liu, Shou; Kanojia, Deepak; Yue, Wei; Singn, Udai; Wang, Qian; Wang, Qi; Nie, Qing; Chen, Hexin

    2013-08-01

    Cancer stem cells (CSCs) have been identified in primary breast cancer tissues and cell lines. The CSC population varies widely among cancerous tissues and cell lines, and is often associated with aggressive breast cancers. Despite of intensive research, how the CSC population is regulated within a tumor is still not well understood so far. In this paper, we present a mathematical model to explore the growth kinetics of CSC population both in vitro and in vivo. Our mathematical models and supporting experiments suggest that there exist non-linear growth kinetics of CSCs and negative feedback mechanisms to control the balance between the population of CSCs and that of non-stem cancer cells. The model predictions can help us explain a few long-standing questions in the field of cancer stem cell research, and can be potentially used to predict the efficicacy of anti-cancer therapy.

  4. Single-cell analysis of growth and cell division of the anaerobe Desulfovibrio vulgaris Hildenborough

    Directory of Open Access Journals (Sweden)

    Anouchka eFievet

    2015-12-01

    Full Text Available Recent years have seen significant progress in understanding basic bacterial cell cycle properties such as cell growth and cell division. While characterization and regulation of bacterial cell cycle is quite well documented in the case of fast growing aerobic model organisms, no data has been so far reported for anaerobic bacteria. This lack of information in anaerobic microorganisms can mainly be explained by the absence of molecular and cellular tools such as single cell microscopy and fluorescent probes usable for anaerobes and essential to study cellular events and/or subcellular localization of the actors involved in cell cycle.In this study, single-cell microscopy has been adapted to study for the first time, in real time, the cell cycle of a bacterial anaerobe, Desulfovibrio vulgaris Hildenborough (DvH. This single-cell analysis provides mechanistic insights into the cell division cycle of DvH, which seems to be governed by the recently discussed so-called incremental model that generates remarkably homogeneous cell sizes. Furthermore, cell division was reversibly blocked during oxygen exposure. This may constitute a strategy for anaerobic cells to cope with transient exposure to oxygen that they may encounter in their natural environment, thereby contributing to their aerotolerance. This study lays the foundation for the first molecular, single-cell assay that will address factors that cannot otherwise be resolved in bulk assays and that will allow visualization of a wide range of molecular mechanisms within living anaerobic cells.

  5. Growth and radiosensitivity of irradiated human glioma cell progeny

    Institute of Scientific and Technical Information of China (English)

    Chao Li; Li Li; Changshao Xu; Juying Zhou

    2008-01-01

    BACKGROUND: Progenitors of the immortalized human glioma cell line, SHG-44, are significantly less sensitive to irradiation. Two hypotheses regarding the mechanism of this effect exist: several studies have suggested that there is a subgroup with different radiosensitivities in identical cell group, and the progenitors of irradiate is a adaptive response subgroup, so its radiosensitivity is descend. A second hypothesis suggests that irradiated glioma progeny have a stronger ability to repair DNA damage. This would suggest that when progeny are continuously irradiated, resistance to irradiation-induced DNA increases, and radiosensitivity decreases.OBJECTIVE: To investigate radiosensitivity and growth features after irradiation to progeny of the human glioma cell line SHG-44.DESIGN, TIME AND SETTING: A randomized, controlled experiment, which was performed at the Department of Radiology Laboratory, the First Hospital Affiliated to Soochow University, between September 2004 and January 2006.MATERIALS: The glioma cell line SHG-44 was provided by the Institute of Neuroscience, First Affiliated Hospital of Suzhou University. Propidium iodide reagent was provided by Coulter Corporation. A linear accelerator, KD-2 type, was provided by Siemens, Germany. The flow cytometer EPICS-XL was provided by Coulter Corporation.METHODS: Brain glioma SHG-44 cells were divided into four groups: SHG-44, SHG-44-2, SHG-44-6, and SHG-44-10. The SHG-44-2, SHG-44-6, and SHG-44-10 cells were vertically irradiated with varying doses of 2,6 and 10 Gy by a linear accelerator (6 MVX). The cells were passaged for 15 generations and cultured in RPMI-1640 culture media.MAIN OUTCOME MEASURES: Community re-double time, mean lethal dose (D0), extrapolation number (N), fraction surviving fraction irradiated by 2 Gy dose (SF2), quasi-threshold dose (Dq), and cell cycle.RESULTS: The Population doubling time (PDT) of SHG-44-2, SHG-44-6, and SHG-44-10 cell groups was not significant (P=0.052). Compared to

  6. Nerve growth factor: role in growth, differentiation and controlling cancer cell development.

    Science.gov (United States)

    Aloe, Luigi; Rocco, Maria Luisa; Balzamino, Bijorn Omar; Micera, Alessandra

    2016-01-01

    Recent progress in the Nerve Growth Factor (NGF) research has shown that this factor acts not only outside its classical domain of the peripheral and central nervous system, but also on non-neuronal and cancer cells. This latter observation has led to divergent hypothesis about the role of NGF, its specific distribution pattern within the tissues and its implication in induction as well as progression of carcinogenesis. Moreover, other recent studies have shown that NGF has direct clinical relevance in certain human brain neuron degeneration and a number of human ocular disorders. These studies, by suggesting that NGF is involved in a plethora of physiological function in health and disease, warrant further investigation regarding the true role of NGF in carcinogenesis. Based on our long-lasting experience in the physiopathology of NGF, we aimed to review previous and recent in vivo and in vitro NGF studies on tumor cell induction, progression and arrest. Overall, these studies indicate that the only presence of NGF is unable to generate cell carcinogenesis, both in normal neuronal and non-neuronal cells/tissues. However, it cannot be excluded the possibility that the co-expression of NGF and pro-carcinogenic molecules might open to different consequence. Whether NGF plays a direct or an indirect role in cell proliferation during carcinogenesis remains to demonstrate. PMID:27439311

  7. Physical growth of children with sickle cell disease

    Directory of Open Access Journals (Sweden)

    Mukherjee Malay

    2004-01-01

    Full Text Available Anthropometric measurements were used to study the physical growth of 58 sickle cell disease(SS children with severe clinical manifestations and compared with 86 normal(AA children from Nagpur district of Maharashtra. Both sickle cell disease male and female children were shown to have statistically significant lower weights, heights, sitting heights, mid arm circumferences, skin fold thickness and body mass indexes but not upper/ lower segment ratio as compared to normal children with comparable sex and ages. No significant differences were observed between the male and female children with sickle cell disease or normal for any of the anthropometric measurements. A significant lower values of all the measurements except U/L ratio was observed in the age group of 11-14 years than the earlier age among the sickle cell disease children as compared to the normal children of the same age and sex groups. Thus, these results indicate that as a group, children with sickle cell disease weigh less, are shorter and undernourished as compared to normal children.

  8. Fluctuation of Parameters in Tumor Cell Growth Model

    Institute of Scientific and Technical Information of China (English)

    AIBao-Quan; WANGXian-Ju; LIUGuo-Tao; LIULiang-Gang

    2003-01-01

    We study the steady state properties of a logistic growth model in the presence of Gaussian white noise.Based on the corresponding Fokker-Planck equation the steady state solution of the probability distribution function and its extrema have been investigated. It is found that the fluctuation of the tumor birth rate reduces the population of the cells while the fluctuation of predation rate can prevent the population of tumor ceils from going into extinction.Noise in the system can induce the phase transition.

  9. Centriole Age Underlies Asynchronous Primary Cilium Growth in Mammalian Cells

    OpenAIRE

    Anderson, Charles T; Stearns, Tim

    2009-01-01

    Primary cilia are microtubule-based sensory organelles that are present in most mammalian tissues and play important roles in development and disease [1]. They are required for the Sonic hedgehog (Shh) [2-4] and PDGF [5] signalling pathways. Primary cilia grow from the older of the two centrioles of the centrosome, referred to as the mother centriole. In cycling cells the cilium typically grows in G1 and is lost before mitosis, but the regulation of its growth is poorly understood. Centriole ...

  10. Efficient mitochondrial biogenesis drives incomplete penetrance in Leber's hereditary optic neuropathy.

    Science.gov (United States)

    Giordano, Carla; Iommarini, Luisa; Giordano, Luca; Maresca, Alessandra; Pisano, Annalinda; Valentino, Maria Lucia; Caporali, Leonardo; Liguori, Rocco; Deceglie, Stefania; Roberti, Marina; Fanelli, Francesca; Fracasso, Flavio; Ross-Cisneros, Fred N; D'Adamo, Pio; Hudson, Gavin; Pyle, Angela; Yu-Wai-Man, Patrick; Chinnery, Patrick F; Zeviani, Massimo; Salomao, Solange R; Berezovsky, Adriana; Belfort, Rubens; Ventura, Dora Fix; Moraes, Milton; Moraes Filho, Milton; Barboni, Piero; Sadun, Federico; De Negri, Annamaria; Sadun, Alfredo A; Tancredi, Andrea; Mancini, Massimiliano; d'Amati, Giulia; Loguercio Polosa, Paola; Cantatore, Palmiro; Carelli, Valerio

    2014-02-01

    Leber's hereditary optic neuropathy is a maternally inherited blinding disease caused as a result of homoplasmic point mutations in complex I subunit genes of mitochondrial DNA. It is characterized by incomplete penetrance, as only some mutation carriers become affected. Thus, the mitochondrial DNA mutation is necessary but not sufficient to cause optic neuropathy. Environmental triggers and genetic modifying factors have been considered to explain its variable penetrance. We measured the mitochondrial DNA copy number and mitochondrial mass indicators in blood cells from affected and carrier individuals, screening three large pedigrees and 39 independently collected smaller families with Leber's hereditary optic neuropathy, as well as muscle biopsies and cells isolated by laser capturing from post-mortem specimens of retina and optic nerves, the latter being the disease targets. We show that unaffected mutation carriers have a significantly higher mitochondrial DNA copy number and mitochondrial mass compared with their affected relatives and control individuals. Comparative studies of fibroblasts from affected, carriers and controls, under different paradigms of metabolic demand, show that carriers display the highest capacity for activating mitochondrial biogenesis. Therefore we postulate that the increased mitochondrial biogenesis in carriers may overcome some of the pathogenic effect of mitochondrial DNA mutations. Screening of a few selected genetic variants in candidate genes involved in mitochondrial biogenesis failed to reveal any significant association. Our study provides a valuable mechanism to explain variability of penetrance in Leber's hereditary optic neuropathy and clues for high throughput genetic screening to identify the nuclear modifying gene(s), opening an avenue to develop predictive genetic tests on disease risk and therapeutic strategies.

  11. Lipid raft involvement in yeast cell growth and death.

    Science.gov (United States)

    Mollinedo, Faustino

    2012-01-01

    The notion that cellular membranes contain distinct microdomains, acting as scaffolds for signal transduction processes, has gained considerable momentum. In particular, a class of such domains that is rich in sphingolipids and cholesterol, termed as lipid rafts, is thought to compartmentalize the plasma membrane, and to have important roles in survival and cell death signaling in mammalian cells. Likewise, yeast lipid rafts are membrane domains enriched in sphingolipids and ergosterol, the yeast counterpart of mammalian cholesterol. Sterol-rich membrane domains have been identified in several fungal species, including the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe as well as the pathogens Candida albicans and Cryptococcus neoformans. Yeast rafts have been mainly involved in membrane trafficking, but increasing evidence implicates rafts in a wide range of additional cellular processes. Yeast lipid rafts house biologically important proteins involved in the proper function of yeast, such as proteins that control Na(+), K(+), and pH homeostasis, which influence many cellular processes, including cell growth and death. Membrane raft constituents affect drug susceptibility, and drugs interacting with sterols alter raft composition and membrane integrity, leading to yeast cell death. Because of the genetic tractability of yeast, analysis of yeast rafts could be an excellent model to approach unanswered questions of mammalian raft biology, and to understand the role of lipid rafts in the regulation of cell death and survival in human cells. A better insight in raft biology might lead to envisage new raft-mediated approaches to the treatment of human diseases where regulation of cell death and survival is critical, such as cancer and neurodegenerative diseases.

  12. Lipid raft involvement in yeast cell growth and death

    Directory of Open Access Journals (Sweden)

    Faustino eMollinedo

    2012-10-01

    Full Text Available The notion that cellular membranes contain distinct microdomains, acting as scaffolds for signal transduction processes, has gained considerable momentum. In particular, a class of such domains that is rich in sphingolipids and cholesterol, termed as lipid rafts, is thought to compartmentalize the plasma membrane, and to have important roles in survival and cell death signaling in mammalian cells. Likewise, yeast lipid rafts are membrane domains enriched in sphingolipids and ergosterol, the yeast counterpart of mammalian cholesterol. Sterol-rich membrane domains have been identified in several fungal species, including the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe as well as the pathogens Candida albicans and Crytococcus neoformans. Yeast rafts have been mainly involved in membrane trafficking, but increasing evidence implicates rafts in a wide range of additional cellular processes. Yeast lipid rafts house biologically important proteins involved in the proper function of yeast, such as proteins that control Na+, K+ and pH homeostasis, which influence many cellular processes, including cell growth and death. Membrane raft constituents affect drug susceptibility, and drugs interacting with sterols alter raft composition and membrane integrity, leading to yeast cell death. Because of the genetic tractability of yeast, analysis of yeast rafts could be an excellent model to approach unanswered questions of mammalian raft biology, and to understand the role of lipid rafts in the regulation of cell death and survival in human cells. A better insight in raft biology might lead to envisage new raft-mediated approaches to the treatment of human diseases where regulation of cell death and survival is critical, such as cancer and neurodegenerative diseases.

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

    International Nuclear Information System (INIS)

    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 μm) 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

  14. 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.

  15. Chicken stem cell factor enhances primordial germ cell proliferation cooperatively with fibroblast growth factor 2.

    Science.gov (United States)

    Miyahara, Daichi; Oishi, Isao; Makino, Ryuichi; Kurumisawa, Nozomi; Nakaya, Ryuma; Ono, Tamao; Kagami, Hiroshi; Tagami, Takahiro

    2016-04-22

    An in vitro culture system of chicken primordial germ cells (PGCs) has been recently developed, but the growth factor involved in the proliferation of PGCs is largely unknown. In the present study, we investigated the growth effects of chicken stem cell factor (chSCF) on the in vitro proliferation of chicken PGCs. We established two feeder cell lines (buffalo rat liver cells; BRL cells) that stably express the putative secreted form of chSCF (chSCF1-BRL) and membrane bound form of chSCF (chSCF2-BRL). Cultured PGC lines were incubated on chSCF1 or chSCF2-BRL feeder cells with fibroblast growth factor 2 (FGF2), and growth effects of each chSCF isoform were investigated. The in vitro proliferation rate of the PGCs cultured on chSCF2-BRL at 20 days of culture was more than threefold higher than those cultured on chSCF1-BRL cells and more than fivefold higher than those cultured on normal BRL cells. Thus, use of chSCF2-BRL feeder layer was effective for in vitro proliferation of chicken PGCs. However, the acceleration of PGC proliferation on chSCF2-BRL was not observed without FGF2, suggesting that chSCF2 would act as a proliferation co-factor of FGF2. We transferred the PGCs cultured on chSCF2-BRL cells to recipient embryos, generated germline chimeric chickens and assessed the germline competency of cultured PGCs by progeny test. Donor-derived progenies were obtained, and the frequency of germline transmission was 3.39%. The results of this study demonstrate that chSCF2 induces hyperproliferation of chicken PGCs retaining germline competency in vitro in cooperation with FGF2. PMID:26727404

  16. Benzimidazoles diminish ERE transcriptional activity and cell growth in breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Payton-Stewart, Florastina [Department of Chemistry, College of Arts and Sciences, Xavier University of Louisiana, New Orleans, LA (United States); Tilghman, Syreeta L. [Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA (United States); Williams, LaKeisha G. [Division of Clinical and Administrative Sciences, College of Pharmacy Xavier University of Louisiana, New Orleans, LA (United States); Winfield, Leyte L., E-mail: lwinfield@spelman.edu [Department of Chemistry, Spelman College, Atlanta, GA (United States)

    2014-08-08

    Highlights: • The methyl-substituted benzimidazole was more effective at inhibiting growth in MDA-MB 231 cells. • The naphthyl-substituted benzimidazole was more effective at inhibiting growth in MCF-7 cells than ICI. • The benzimidazole molecules demonstrated a dose-dependent reduction in ERE transcriptional activity. • The benzimidazole molecules had binding mode in ERα and ERβ comparable to that of the co-crystallized ligand. - Abstract: Estrogen receptors (ERα and ERβ) are members of the nuclear receptor superfamily. They regulate the transcription of estrogen-responsive genes and mediate numerous estrogen related diseases (i.e., fertility, osteoporosis, cancer, etc.). As such, ERs are potentially useful targets for developing therapies and diagnostic tools for hormonally responsive human breast cancers. In this work, two benzimidazole-based sulfonamides originally designed to reduce proliferation in prostate cancer, have been evaluated for their ability to modulate growth in estrogen dependent and independent cell lines (MCF-7 and MDA-MB 231) using cell viability assays. The molecules reduced growth in MCF-7 cells, but differed in their impact on the growth of MDA-MB 231 cells. Although both molecules reduced estrogen response element (ERE) transcriptional activity in a dose dependent manner, the contrasting activity in the MDA-MB-231 cells seems to suggest that the molecules may act through alternate ER-mediated pathways. Further, the methyl analog showed modest selectivity for the ERβ receptor in an ER gene expression array panel, while the naphthyl analog did not significantly alter gene expression. The molecules were docked in the ligand binding domains of the ERα-antagonist and ERβ-agonist crystal structures to evaluate the potential of the molecules to interact with the receptors. The computational analysis complimented the results obtained in the assay of transcriptional activity and gene expression suggesting that the molecules

  17. Three Dimensional Simulation Method in Early Process of Division and Growth for Tumour Cells

    Institute of Scientific and Technical Information of China (English)

    XIA Zhi-qiu; ZHAO Ting-ting

    2014-01-01

    The process of division, growth and death for tumour cell mass in the early is simulated. An integrated GUI is provided for users to set the value of each parameters, which are cell growth rates, cell mass division rates, cell mass death rates, simulate type, maximum running time, polarity and cell colour. It can display the growth process of each cell on result GUI. Also, it can display the values of each parameters for observing and analysing in current life cycle on result GUI, which are cell mass division times, cell mass death rate, cell mass division rate and cell mass growth rate. In the process of simulation, The cell growth rate is described by the approach to combine the exponential model with the linear model. In addition, a linked list data structure to store the tumour cells is used by the cellular automata for a reference to determine the position of each cell. It sets up two linked list to store the cells, one of them save the new small division cells and the other one save the big cell. That can make the painting process of cells on result GUI clearer and more organized. At last, the polarity of tumour growth is described for determining the growth direction of cells.

  18. Nerve Growth Factor Modulate Proliferation of Cultured Rabbit Corneal Endothelial Cells and Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In order to investigate the effect of nerve growth factor (NGF) on the proliferation of rabbit corneal endothelial cells and epithelial cells, the in vitro cultured rabbit corneal endothelial cells and epithelial cells were treated with different concentrations of NGF.MTT assay was used to examine the clonal growth and proliferation of the cells by determining the absorbency values at 570nm. The results showed that NGF with three concentrations ranging from 5 U/mL to 500 U/mL enhanced the proliferation of rabbit corneal endothelial cells in a concentration-dependent manner.50 U/mL and 500 U/mL NGF got more increase of proliferation than that of 5 U/mL NGF did.Meanwhile, 50 U/mL and 500 U/mL NGF could promote the proliferation of the rabbit corneal epithelial cells significantly in a concentration-dependent manner. However, 5 U/mL NGF did not enhance the proliferation of epithelial cells. It was suggested that exogenous NGF can stimulate the proliferation of both rabbit corneal endothelial and epithelial cells, but the extent of modulation is different.

  19. Structural, biophysical and functional characterization of Nop7-Erb1-Ytm1 complex and its implications in eukaryotic ribosome biogenesis

    OpenAIRE

    Wegrecki, Marcin

    2015-01-01

    [EN] Ribosome biogenesis is one of the most important and energy-consuming processes in the cell. However, the vast majority of the events and factors that are involved in the synthesis of ribosomal subunits are not well understood. Ribosome maturation comprises multiple steps of rRNA processing that require sequential association and dissociation of numerous assembly factors. These proteins establish a complex network of interactions that are essential for the pathway to continue. Extensive ...

  20. Peroxisome Biogenesis Disorders: Biological, Clinical and Pathophysiological Perspectives

    Science.gov (United States)

    Braverman, Nancy E.; D'Agostino, Maria Daniela; MacLean, Gillian E.

    2013-01-01

    The peroxisome biogenesis disorders (PBD) are a heterogeneous group of autosomal recessive disorders in which peroxisome assembly is impaired, leading to multiple peroxisome enzyme deficiencies, complex developmental sequelae and progressive disabilities. Mammalian peroxisome assembly involves the protein products of 16 "PEX" genes;…

  1. Identifying anti-growth factors for human cancer cell lines through genome-scale metabolic modeling

    DEFF Research Database (Denmark)

    Ghaffari, Pouyan; Mardinoglu, Adil; Asplund, Anna;

    2015-01-01

    85 antimetabolites that can inhibit growth of, or even kill, any of the cell lines, while at the same time not being toxic for 83 different healthy human cell types. 60 of these antimetabolites were found to inhibit growth in all cell lines. Finally, we experimentally validated one of the predicted...... for inhibition of cell growth may provide leads for the development of efficient cancer treatment strategies.......Human cancer cell lines are used as important model systems to study molecular mechanisms associated with tumor growth, hereunder how genomic and biological heterogeneity found in primary tumors affect cellular phenotypes. We reconstructed Genome scale metabolic models (GEMs) for eleven cell lines...

  2. Pyramidal cell development: postnatal spinogenesis, dendritic growth, axon growth, and electrophysiology.

    Directory of Open Access Journals (Sweden)

    Guy eElston

    2014-08-01

    Full Text Available Here we review recent findings related to postnatal spinogenesis, dendritic and axon growth, pruning and electrophysiology of neocortical pyramidal cells in the developing primate brain. Pyramidal cells in sensory, association and executive cortex grow dendrites, spines and axons at different rates, and vary in the degree of pruning. Of particular note is the fact that pyramidal cells in primary visual area (V1 prune more spines than they grow during postnatal development, whereas those in inferotemporal (TEO and TE and granular prefrontal cortex (gPFC; Brodmann’s area 12 grow more than they prune. Moreover, pyramidal cells in TEO, TE and the gPFC continue to grow larger dendritic territories from birth into adulthood, replete with spines, whereas those in V1 become smaller during this time. The developmental profile of intrinsic axons also varies between cortical areas: those in V1, for example, undergo an early proliferation followed by pruning and local consolidation into adulthood, whereas those in area TE tend to establish their territory and consolidate it into adulthood with little pruning. We correlate the anatomical findings with the electrophysiological properties of cells in the different cortical areas, including membrane time constant, depolarizing sag, duration of individual action potentials, and spike-frequency adaptation. All of the electrophysiological variables ramped up before 7 months of age in V1, but continued to ramp up over a protracted period of time in area TE. These data suggest that the anatomical and electrophysiological profiles of pyramidal cells vary among cortical areas at birth, and continue to diverge into adulthood. Moreover, the data reveal that the use it or lose it notion of synaptic reinforcement may speak to only part of the story, use it but you still might lose it may be just as prevalent in the cerebral cortex.

  3. Why Cells Grow and Divide? General Growth Mechanism and How it Defines Cells’ Growth, Reproduction and Metabolic Properties

    Science.gov (United States)

    Shestopaloff, Yuri K.

    2015-02-01

    We consider a general growth mechanism, which acts at cellular level and above (organs, systems and whole organisms). Using its mathematical representation, the growth equation, we study the growth and division mechanisms of amoeba and fission yeast Schizosaccharomyces pombe. We show how this mechanism, together with biomolecular machinery, governs growth and reproduction of cells, and these organisms in particular. This mechanism provides revealing answers to fundamental questions of biology, like why cells grow and divide, why and when cells’ growth stops. It also sheds light on questions like why and how life originated and developed. Solving the growth equation, we obtain analytical expression for the growth curve of fission yeast as a function of geometrical characteristics and nutrient influxes for RNA and protein synthesis, and compare the computed growth curves with 85 experiments. Statistical evaluation shows that these growth curves correspond to experimental data significantly better than all previous approximations. Also, using the general growth mechanism, we show how metabolic characteristics of cells, their size and evolutionary traits relate, considering fission yeast. In particular, we found that fission yeast S. pombe consumes about 16-18 times more nutrients for maintenance needs than for biomass synthesis.

  4. Effects of different Helicobacter pylori culture filtrates on growth of gastric epithelial cells

    Institute of Scientific and Technical Information of China (English)

    Yan-Guo Yan; Gang Zhao; Jin-Ping Ma; Shi-Rong Cai; Wen-Hua Zhan

    2008-01-01

    AIM: To study the effects of different Helicobacter pylori (H py/orl) culture filtrates on growth of gastric epithelial cells.METHODS: Broth culture filtrates of H pylori were prepared. Gastric epithelial cells were treated with the filtrates, and cell growth was determined by growth curve and flow cytometry. DNA damage of gastric epithelial cells was measured by single-cell microgel electrophoresis.RESULTS: Gastric epithelial cells proliferated actively when treated by CagA-gene-positive broth culture filtrates, and colony formation reached 40%. The number of cells in S phase increased compared to controls. Comet assay showed 41.2% comet cells in GES-1 cells treated with CagA-positive filtrates (P<0.05).CONCLUSION: CagA-positive filtrates enhance the changes in morphology and growth characteristics of human gastric epithelial tumor cells. DNA damage maybe one of the mechanisms involved in the growth changes.

  5. Inhibitory Effect of Melatonin on the Growth of H22 Hepatocarcinoma Cells by Inducing Apoptosis

    Institute of Scientific and Technical Information of China (English)

    泰莉; 王西明; 段秋红; 陈蓓蓓; 何善述

    2004-01-01

    Summary: Whether melatonin not only inhibits the growth of H22 hepatocarcinoma cells but also induces apoptosis in vitro was assessed. The anti-proliferative effects of melatonin on tumor cells was observed by MTT assay and tumor cells growth curve assay. And the apoptosis of the cells was studied by acridine orange fluorescence assay and flow cytometry. The cell cycle of the tumor cells was also observed by flow cytometry. It was found that melatonin could significantly inhibit the growth of H22 hepatocarcinoma cells. Incubated with melatonin, chromatin condensation of the tumor cells was observed by fluorescence microscopy. Compared with control, the percentage of apoptotic cells was increased, and the proportion of G0/S increased but that of G2/M decreased. It was suggested that melatonin could directly inhibit the growth of H22 hepatocarcinoma cells by inducing apoptosis and extending the length of cell cycle of the tumor cells.

  6. Glycogen Synthase Kinase-3 regulates multiple myeloma cell growth and bortezomib-induced cell death

    Directory of Open Access Journals (Sweden)

    Colpo Anna

    2010-10-01

    Full Text Available Abstract Background Glycogen Synthase Kinase-3 (GSK-3 α and β are two serine-threonine kinases controlling insulin, Wnt/β-catenin, NF-κB signaling and other cancer-associated transduction pathways. Recent evidence suggests that GSK-3 could function as growth-promoting kinases, especially in malignant cells. In this study, we have investigated GSK-3α and GSK-3β function in multiple myeloma (MM. Methods GSK-3 α and β expression and cellular localization were investigated by Western blot (WB and immunofluorescence analysis in a panel of MM cell lines and in freshly isolated plasma cells from patients. MM cell growth, viability and sensitivity to bortezomib was assessed upon treatment with GSK-3 specific inhibitors or transfection with siRNAs against GSK-3 α and β isoforms. Survival signaling pathways were studied with WB analysis. Results GSK-3α and GSK-3β were differently expressed and phosphorylated in MM cells. Inhibition of GSK-3 with the ATP-competitive, small chemical compounds SB216763 and SB415286 caused MM cell growth arrest and apoptosis through the activation of the intrinsic pathway. Importantly, the two inhibitors augmented the bortezomib-induced MM cell cytotoxicity. RNA interference experiments showed that the two GSK-3 isoforms have distinct roles: GSK-3β knock down decreased MM cell viability, while GSK-3α knock down was associated with a higher rate of bortezomib-induced cytotoxicity. GSK-3 inhibition caused accumulation of β-catenin and nuclear phospho-ERK1, 2. Moreover, GSK-3 inhibition and GSK-3α knockdown enhanced bortezomib-induced AKT and MCL-1 protein degradation. Interestingly, bortezomib caused a reduction of GSK-3 serine phosphorylation and its nuclear accumulation with a mechanism that resulted partly dependent on GSK-3 itself. Conclusions These data suggest that in MM cells GSK-3α and β i play distinct roles in cell survival and ii modulate the sensitivity to proteasome inhibitors.

  7. 地西他滨对同步化的G0/G1期MDS-L细胞系线粒体功能的影响%Role of decitabine in the mitochondria biogenesis of synchronized G0/G1 phase MDS-L cell line

    Institute of Scientific and Technical Information of China (English)

    邱宗建; 杨娟; 宋强

    2014-01-01

    目的:初步探讨地西他滨( DAC)在不整合入基因组DNA的情况下对线粒体生物学功能的影响。方法采用阿非迪霉素( APC)将MDS-L细胞同步化在G0/G1期。 DCFH-DA检测不同浓度DAC(0、5、10、15μmol/L)处理后的同步化G0/G1期细胞系活性氧( ROS)的产生水平。采用qRT-PCR法检测线粒体DNA拷贝数和线粒体编码基因NADH脱氢酶1、6( ND1、ND6) mRNA改变。结果与对照组相比,DAC在低浓度5μmol/L条件下可以通过不依赖DNA损伤的途径增加细胞ROS的产生(P<0.05),同时细胞内线粒体DNA(MtDNA)的拷贝数较对照组明显增加,差异有统计学意义(P<0.05)。但随着DAC浓度增加,DAC在高浓度(15μmol/L)可降低ROS的产生(P<0.05)。此外,在高浓度DAC作用下,ND1和ND6基因表达较对照组明显升高(P<0.05)。结论 DAC通过影响细胞ROS产生,改变线粒体DNA的拷贝数以及调控线粒体基因的表达,产生对线粒体功能的影响,并呈浓度依赖性。%Objective To investigate the effect of decitabin ( DAC) on the mitochondrial biogenesis of synchronized G0/G1 cells.Methods MDS-L cells were treated with aphidicolin ( APC) to synchronize cell cycle at G0/G1 stage. After treatment of decitabine at different concentrations (0, 5, 10, 15μmol/L), reactive oxygen species (ROS) pro-ductions were detected by DCFH-DA.Changes of mitochondrial DNA copy number and expressions of coded genes, NADH dehydrogenase 1 (ND1) and NADH dehydrogenase 6(ND6), were detected with qRT-PCR.Results In com-parison with the control group, decitabine at low concentration (5μmol/L) could promote the production of ROS ( P<0.05) and increase the copy number of mtDNA ( P<0.05); however, as the concentration increased to 15μmol/L, ROS production started to decline to even lower than that of the control (P<0.05).Besides, DAC could significantly change the expressions of ND1 and ND6 at high

  8. Silencing NOTCH signaling causes growth arrest in both breast cancer stem cells and breast cancer cells

    Science.gov (United States)

    Suman, S; Das, T P; Damodaran, C

    2013-01-01

    Background: Breast cancer stem cells (BCSCs) are characterized by high aldehyde dehydrogenase (ALDH) enzyme activity and are refractory to current treatment modalities, show a higher risk for metastasis, and influence the epithelial to mesenchymal transition (EMT), leading to a shorter time to recurrence and death. In this study, we focused on examination of the mechanism of action of a small herbal molecule, psoralidin (Pso) that has been shown to effectively suppress the growth of BSCSs and breast cancer cells (BCCs), in breast cancer (BC) models. Methods: ALDH− and ALDH+ BCCs were isolated from MDA-MB-231 cells, and the anticancer effects of Pso were measured using cell viability, apoptosis, colony formation, invasion, migration, mammosphere formation, immunofluorescence, and western blot analysis. Results: Psoralidin significantly downregulated NOTCH1 signaling, and this downregulation resulted in growth inhibition and induction of apoptosis in both ALDH− and ALDH+ cells. Molecularly, Pso inhibited NOTCH1 signaling, which facilitated inhibition of EMT markers (β-catenin and vimentin) and upregulated E-cadherin expression, resulting in reduced migration and invasion of both ALDH− and ALDH+ cells. Conclusion: Together, our results suggest that inhibition of NOTCH1 by Pso resulted in growth arrest and inhibition of EMT in BCSCs and BCCs. Psoralidin appears to be a novel agent that targets both BCSCs and BCCs. PMID:24129237

  9. Glucose Signaling-Mediated Coordination of Cell Growth and Cell Cycle in Saccharomyces Cerevisiae

    Directory of Open Access Journals (Sweden)

    Stefano Busti

    2010-06-01

    Full Text Available Besides being the favorite carbon and energy source for the budding yeast Sacchromyces cerevisiae, glucose can act as a signaling molecule to regulate multiple aspects of yeast physiology. Yeast cells have evolved several mechanisms for monitoring the level of glucose in their habitat and respond quickly to frequent changes in the sugar availability in the environment: the cAMP/PKA pathways (with its two branches comprising Ras and the Gpr1/Gpa2 module, the Rgt2/Snf3-Rgt1 pathway and the main repression pathway involving the kinase Snf1. The cAMP/PKA pathway plays the prominent role in responding to changes in glucose availability and initiating the signaling processes that promote cell growth and division. Snf1 (the yeast homologous to mammalian AMP-activated protein kinase is primarily required for the adaptation of yeast cell to glucose limitation and for growth on alternative carbon source, but it is also involved in the cellular response to various environmental stresses. The Rgt2/Snf3-Rgt1 pathway regulates the expression of genes required for glucose uptake. Many interconnections exist between the diverse glucose sensing systems, which enables yeast cells to fine tune cell growth, cell cycle and their coordination in response to nutritional changes.

  10. RASSF1A expression inhibits cell growth and enhances cell chemosensitivity to mitomycin in BEL-7402 hepatocellular carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    GUAN Hong-geng; XUE Wan-jiang; QIAN Hai-xin; ZHOU Xiao-jun; QIN Lei; LAN Jing

    2009-01-01

    Background The antitumor role of Ras association domain family 1A (RASSFIA) gene and its potential molecular mechanisms are not well understood. The objective of this study was to observe the antitumor ability of RASSFIA in hepatoceliular carcinoma, and study the mechanisms of cell apoptosis induced by RASSFIA.Methods After stably transfecting a RASSF1A (wild-type or mutant) expression vector into the BEL-7402 hepatocellular carcinoma cell line, RT-PCR and Westem blotting was used to detect the RASSF1A expression levels in recombinant cells. The effects of wild-type RASSF1A on cell growth were observed in vitro by analyzing cell proliferation rate, cell colony formation, and in vivo by analyzing tumorigenesis in nude mice. In addition, the effect of RASSF1A gene expression on the chemosensitivity of human hepatocellular carcinoma cells to antitumor drugs was examined by inhibition of cell proliferation and the percentage of apoptotic cells.Results Wild-type RASSF1A, not the mutant, suppressed cell growth in vitro and in vivo. Re-expression of wild-type RASSF1A could enhance the inhibition of cell proliferation and the percentage of apoptotic cells following cell treatment with mitomycin, but had no significant effect when combined with adriamycin, etoposide, 5-fluorouracil and cisplatJn treatment.Conclusion Wild-type RASSF1A inhibits cell growth and enhances cell chemosensitivity to mitomycin in hepatocellular carcinoma, suggesting that RASSF1A may serve as a new target for gene therapy in hepatocellular carcinoma patients.

  11. Regulation of Transcription from Two ssrS Promoters in 6S RNA Biogenesis

    Science.gov (United States)

    Lee, Ji Young; Park, Hongmarn; Bak, Geunu; Kim, Kwang-sun; Lee, Younghoon

    2013-01-01

    ssrS-encoded 6S RNA is an abundant noncoding RNA that binds σ70-RNA polymerase and regulates expression at a subset of promoters in Escherichia coli. It is transcribed from two tandem promoters, ssrS P1 and ssrS P2. Regulation of transcription from two ssrS promoters in 6S RNA biogenesis was examined. Both P1 and P2 were growth phase-dependently regulated. Depletion of 6S RNA had no effect on growth-phase-dependent transcription from either promoter, whereas overexpression of 6S RNA increased P1 transcription and decreased P2 transcription, suggesting that transcription from P1 and P2 is subject to feedback activation and feedback inhibition, respectively. This feedback regulation disappeared in Δfis strains, supporting involvement of Fis in this process. The differential feedback regulation may provide a means for maintaining appropriate cellular concentrations of 6S RNA. PMID:23864284

  12. Mesenchymal stem cells with rhBMP-2 inhibits the growth of canine osteosarcoma cells

    Directory of Open Access Journals (Sweden)

    Grassi Rici Rose

    2012-02-01

    Full Text Available Abstract Background The bone morphogenetic proteins (BMPs belong to a unique group of proteins that includes the growth factor TGF-β. BMPs play important roles in cell differentiation, cell proliferation, and inhibition of cell growth. They also participate in the maturation of several cell types, depending on the microenvironment and interactions with other regulatory factors. Depending on their concentration gradient, the BMPs can attract various types of cells and act as chemotactic, mitogenic, or differentiation agents. BMPs can interfere with cell proliferation and the formation of cartilage and bone. In addition, BMPs can induce the differentiation of mesenchymal progenitor cells into various cell types, including chondroblasts and osteoblasts. The aim of this study was to analyze the effects of treatment with rhBMP-2 on the proliferation of canine mesenchymal stem cells (cMSCs and the tumor suppression properties of rhBMP-2 in canine osteocarcoma (OST cells. Osteosarcoma cell lines were isolated from biopsies and excisions of animals with osteosarcoma and were characterized by the Laboratory of Biochemistry and Biophysics, Butantan Institute. The mesenchymal stem cells were derived from the bone marrow of canine fetuses (cMSCs and belong to the University of São Paulo, College of Veterinary Medicine (FMVZ-USP stem cell bank. After expansion, the cells were cultured in a 12-well Transwell system; cells were treated with bone marrow mesenchymal stem cells associated with rhBMP2. Expression of the intracytoplasmic and nuclear markers such as Caspase-3, Bax, Bad, Bcl-2, Ki-67, p53, Oct3/4, Nanog, Stro-1 were performed by flow citometry. Results We evaluated the regenerative potential of in vitro treatment with rhBMP-2 and found that both osteogenic induction and tumor regression occur in stem cells from canine bone marrow. rhBMP-2 inhibits the proliferation capacity of OST cells by mechanisms of apoptosis and tumor suppression mediated by p

  13. NK4, an antagonist of hepatocyte growth factor (HGF), inhibits growth of multiple myeloma cells: molecular targeting of angiogenic growth factor.

    Science.gov (United States)

    Du, Wenlin; Hattori, Yutaka; Yamada, Taketo; Matsumoto, Kunio; Nakamura, Toshikazu; Sagawa, Morihiko; Otsuki, Takemi; Niikura, Takako; Nukiwa, Toshihiro; Ikeda, Yasuo

    2007-04-01

    Hepatocyte growth factor (HGF) promotes cell growth and motility and also increases neovascularization. Multiple myeloma (MM) cells produce HGF, and the plasma concentration of HGF is significantly elevated in patients with clinically active MM, suggesting that HGF might play a role in the pathogenesis of MM. NK4, an antagonist of HGF, is structurally homologous to angiostatin, and our previous report showed that NK4 inhibited the proliferation of vascular endothelial cells induced by HGF stimulation. The purposes of this study were to elucidate the contribution of HGF to the growth of MM cells as well as to investigate the possibility of the therapeutic use of NK4. In vitro study showed that NK4 protein stabilized the growth of MM cell lines and regulated the activation of c-MET, ERK1/2, STAT3, and AKT-1. Recombinant adenovirus containing NK4 cDNA (AdCMV.NK4) was injected intramuscularly into Icr/scid mice bearing tumors derived from HGF-producing MM cells. AdCMV.NK4 significantly inhibited the growth of these tumors in vivo. Histologic examination revealed that AdCMV.NK4 induced apoptosis of MM cells, accompanied by a reduction in neovascularization in the tumors. Thus, NK4 inhibited the growth of MM cells via antiangiogenic as well as direct antitumor mechanisms. The molecular targeting of HGF by NK4 could be applied as a novel therapeutic approach to MM. PMID:17179234

  14. Influence of different ammonium, lactate and glutamine concentrations on CCO cell growth

    OpenAIRE

    Slivac, Igor; Blajić, Višnja; Radošević, Kristina; Kniewald, Zlatko; Gaurina Srček, Višnja

    2010-01-01

    In this study the effects of ammonium and lactate on a culture of channel catfish ovary (CCO) cells were examined. We also made investigation on the influence of glutamine, since our previous research revealed that this amino acid stimulated CCO cell growth more than glucose in a concentration-dependent manner. The effect of ammonium in cell culture included the considerable decrease in cell growth rate with eventual growth arrest as well as the retardation of glucose consumption. At ammonium...

  15. Nebivolol stimulates mitochondrial biogenesis in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Highlights: •Nebivolol may act as a partial agonist of β3-adrenergic receptor (AR). •Nebivolol stimulates mitochondrial DNA replication and protein expression. •Nebivolol promotes mitochondrial synthesis via activation of eNOS by β3-AR. -- Abstract: Nebivolol is a third-generation β-adrenergic receptor (β-AR) blocker with additional beneficial effects, including the improvement of lipid and glucose metabolism in obese individuals. However, the underlying mechanism of nebivolol’s role in regulating the lipid profile remains largely unknown. In this study, we investigated the role of nebivolol in mitochondrial biogenesis in 3T3-L1 adipocytes. Exposure of 3T3-L1 cells to nebivolol for 24 h increased mitochondrial DNA copy number, mitochondrial protein levels and the expression of transcription factors involved in mitochondrial biogenesis, including PPAR-γ coactivator-1α (PGC-1α), Sirtuin 3 (Sirt3), mitochondrial transcription factor A (Tfam) and nuclear related factor 1 (Nrf1). These changes were accompanied by an increase in oxygen consumption and in the expression of genes involved in fatty acid oxidation and antioxidant enzymes in 3T3-L1 adipocytes, including nebivolol-induced endothelial nitric oxide synthase (eNOS), as well as an increase in the formation of cyclic guanosine monophosphate (cGMP). Pretreatment with NG-nitro-L-arginine methyl ester (l-NAME) attenuated nebivolol-induced mitochondrial biogenesis, as did the soluble guanylate cyclase inhibitor, ODQ. Treatment with nebivolol and β3-AR blocker SR59230A markedly attenuated PGC-1α, Sirt3 and manganese superoxide dismutase (MnSOD) protein levels in comparison to treatment with nebivolol alone. These data indicate that the mitochondrial synthesis and metabolism in adipocytes that is promoted by nebivolol is primarily mediated through the eNOS/cGMP-dependent pathway and is initiated by the activation of β3-AR receptors

  16. Nebivolol stimulates mitochondrial biogenesis in 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chenglin; Chen, Dongrui; Xie, Qihai [State Key Laboratory of Medical Genomics, Shanghai Key Laboratory of Vascular Biology, Department of Hypertension, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200025 (China); Yang, Ying, E-mail: yangying_sh@yahoo.com [Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200025 (China); Shen, Weili, E-mail: weili_shen@hotmail.com [State Key Laboratory of Medical Genomics, Shanghai Key Laboratory of Vascular Biology, Department of Hypertension, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200025 (China)

    2013-08-16

    Highlights: •Nebivolol may act as a partial agonist of β3-adrenergic receptor (AR). •Nebivolol stimulates mitochondrial DNA replication and protein expression. •Nebivolol promotes mitochondrial synthesis via activation of eNOS by β3-AR. -- Abstract: Nebivolol is a third-generation β-adrenergic receptor (β-AR) blocker with additional beneficial effects, including the improvement of lipid and glucose metabolism in obese individuals. However, the underlying mechanism of nebivolol’s role in regulating the lipid profile remains largely unknown. In this study, we investigated the role of nebivolol in mitochondrial biogenesis in 3T3-L1 adipocytes. Exposure of 3T3-L1 cells to nebivolol for 24 h increased mitochondrial DNA copy number, mitochondrial protein levels and the expression of transcription factors involved in mitochondrial biogenesis, including PPAR-γ coactivator-1α (PGC-1α), Sirtuin 3 (Sirt3), mitochondrial transcription factor A (Tfam) and nuclear related factor 1 (Nrf1). These changes were accompanied by an increase in oxygen consumption and in the expression of genes involved in fatty acid oxidation and antioxidant enzymes in 3T3-L1 adipocytes, including nebivolol-induced endothelial nitric oxide synthase (eNOS), as well as an increase in the formation of cyclic guanosine monophosphate (cGMP). Pretreatment with NG-nitro-L-arginine methyl ester (l-NAME) attenuated nebivolol-induced mitochondrial biogenesis, as did the soluble guanylate cyclase inhibitor, ODQ. Treatment with nebivolol and β3-AR blocker SR59230A markedly attenuated PGC-1α, Sirt3 and manganese superoxide dismutase (MnSOD) protein levels in comparison to treatment with nebivolol alone. These data indicate that the mitochondrial synthesis and metabolism in adipocytes that is promoted by nebivolol is primarily mediated through the eNOS/cGMP-dependent pathway and is initiated by the activation of β3-AR receptors.

  17. The DraC usher in Dr fimbriae biogenesis of uropathogenic E. coli Dr(+) strains.

    Science.gov (United States)

    Zalewska-Piatek, Beata; Kur, Marta; Wilkanowicz, Sabina; Piatek, Rafał; Kur, Józef

    2010-05-01

    Biogenesis of Dr fimbriae encoded by the dra gene cluster of uropathogenic Escherichia coli strains requires the chaperone-usher pathway. This secretion system is based on two non-structural assembly components, the DraB periplasmic chaperone and DraC outer-membrane usher. The DraB controls the folding of DraE subunits, and DraC forms the assembly and secretion platform for polymerization of subunits in linear fibers. In this study, mutagenesis of the DraC N-terminus was undertaken to select residues critical for Dr fimbriae bioassembly. The DraC-F4A, DraC-C64, DraC-C100A and DraC-W142A significantly reduced the adhesive ability of E. coli strains. The biological activity of the DraC mutants as a assembly platform for Dr fimbriae polymerization was verified by agglutination of human erythrocytes and adhesion to DAF localized at the surface of CHO-DAF(+) and HeLa cells. The residue F4 of the DraC usher conserved among FGL and FGS chaperone-assembled adhesive organelles can be used to design pillicides blocking the biogenesis of Dr fimbriae. Because the draC and afaC-III genes share 100% identity the range of the virulence determinant inhibitors could also be extended to E. coli strains encoding afa-3 gene cluster. The investigations performed showed that the usher N-terminus plays an important role in biogenesis of complete fiber.

  18. The role of tumor cell-derived connective tissue growth factor (CTGF/CCN2) in pancreatic tumor growth

    DEFF Research Database (Denmark)

    Bennewith, Kevin L; Huang, Xin; Ham, Christine M;

    2009-01-01

    RNA-expressing clones showed dramatically reduced growth in soft agar and when implanted s.c. We also observed a role for CCN2 in the growth of pancreatic tumors implanted orthotopically, with tumor volume measurements obtained by positron emission tomography imaging. Mechanistically, CCN2 protects cells from hypoxia...

  19. Analysis of Vero cell growth behavior on microcarrier by means of environmental scanning electron microscopy

    Institute of Scientific and Technical Information of China (English)

    邵曼君; 姜蕾; 丛威; 欧阳藩

    2002-01-01

    By using environmental scanning electron microscopy, the morphological changes of Vero cells attached to and grown on the microcarrier Cytodex-3 were observed, and their behavior of adhesion, spreading and proliferation was analyzed. The effect of exogenous fibronectin/ laminin on adhesion and spreading of MCC/Vero cell was studied. The images of ESEM showed that expansion of cell growth was directed toward vacancy space. The growth curve and cell concentration change during the whole culture process were obtained from the statistical counting method based on ESEM images and the crystal violet method. The growth rate of Vero cells increases with increasing the concentration of cell inoculation, that is, the specific growth rate increases quickly with increasing the concentration of cell inoculation. When serum concentration in medium #199 ranged from 5% to 10%, experimental results indicated that serum concentration is one of the important factors influencing cell growth, particularly in the cell adhesion and spreading stage.

  20. Analysis of Vero cell growth behavior on microcarrier by means of environmental scanning electron microscopy.

    Science.gov (United States)

    Shao, Manjun; Jiang, Lei; Cong, Wei; Ouyang, Fan

    2002-04-01

    By using environmental scanning electron microscopy, the morphological changes of Vero cells attached to and grown on the microcarrier Cytodex-3 were observed, and their behavior of adhesion, spreading and proliferation was analyzed. The effect of exogenous fibronectin/ laminin on adhesion and spreading of MCC/Vero cell was studied. The images of ESEM showed that expansion of cell growth was directed toward vacancy space. The growth curve and cell concentration change during the whole culture process were obtained from the statistical counting method based on ESEM images and the crystal violet method. The growth rate of Vero cells increases with increasing the concentration of cell inoculation, that is, the specific growth rate increases quickly with increasing the concentration of cell inoculation. When serum concentration in medium #199 ranged from 5% to 10%, experimental results indicated that serum concentration is one of the important factors influencing cell growth, particularly in the cell adhesion and spreading stage. PMID:18763074

  1. Ratite oils promote keratinocyte cell growth and inhibit leukocyte activation

    Science.gov (United States)

    Bennett, Darin C.; Leung, Gigi; Wang, Eddy; Ma, Sam; Lo, Blanche K. K.; McElwee, Kevin J.; Cheng, Kimberly M.

    2015-01-01

    Traditionally, native Australian aborigines have used emu oil for the treatment of inflammation and to accelerate wound healing. Studies on mice suggest that topically applied emu oil may have anti-inflammatory properties and may promote wound healing. We investigated the effects of ratite oils (6 emu, 3 ostrich, 1 rhea) on immortalized human keratinocytes (HaCaT cells) in vitro by culturing the cells in media with oil concentrations of 0%, 0.5%, and 1.0%. Peking duck, tea tree, and olive oils were used as comparative controls. The same oils at 0.5% concentration were evaluated for their influence on peripheral blood mononuclear cell (PBMC) survival over 48 hr and their ability to inhibit IFNγ production in PBMCs activated by phytohemagglutinin (PHA) in ELISpot assays. Compared to no oil control, significantly shorter population doubling time durations were observed for HaCaT cells cultured in emu oil (1.51 × faster), ostrich oil (1.46 × faster), and rhea oil (1.64 × faster). Tea tree oil demonstrated significant antiproliferative activity and olive oil significantly prolonged (1.35 × slower) cell population doubling time. In contrast, almost all oils, particularly tea tree oil, significantly reduced PBMC viability. Different oils had different levels of inhibitory effect on IFNγ production with individual emu, ostrich, rhea, and duck oil samples conferring full inhibition. This preliminary investigation suggests that emu oil might promote wound healing by accelerating the growth rate of keratinocytes. Combined with anti-inflammatory properties, ratite oil may serve as a useful component in bandages and ointments for the treatment of wounds and inflammatory skin conditions. PMID:26217022

  2. A millifluidic study of cell-to-cell heterogeneity in growth-rate and cell-division capability in populations of isogenic cells of Chlamydomonas reinhardtii.

    Science.gov (United States)

    Damodaran, Shima P; Eberhard, Stephan; Boitard, Laurent; Rodriguez, Jairo Garnica; Wang, Yuxing; Bremond, Nicolas; Baudry, Jean; Bibette, Jérôme; Wollman, Francis-André

    2015-01-01

    To address possible cell-to-cell heterogeneity in growth dynamics of isogenic cell populations of Chlamydomonas reinhardtii, we developed a millifluidic drop-based device that not only allows the analysis of populations grown from single cells over periods of a week, but is also able to sort and collect drops of interest, containing viable and healthy cells, which can be used for further experimentation. In this study, we used isogenic algal cells that were first synchronized in mixotrophic growth conditions. We show that these synchronized cells, when placed in droplets and kept in mixotrophic growth conditions, exhibit mostly homogeneous growth statistics, but with two distinct subpopulations: a major population with a short doubling-time (fast-growers) and a significant subpopulation of slowly dividing cells (slow-growers). These observations suggest that algal cells from an isogenic population may be present in either of two states, a state of restricted division and a state of active division. When isogenic cells were allowed to propagate for about 1000 generations on solid agar plates, they displayed an increased heterogeneity in their growth dynamics. Although we could still identify the original populations of slow- and fast-growers, drops inoculated with a single progenitor cell now displayed a wider diversity of doubling-times. Moreover, populations dividing with the same growth-rate often reached different cell numbers in stationary phase, suggesting that the progenitor cells differed in the number of cell divisions they could undertake. We discuss possible explanations for these cell-to-cell heterogeneities in growth dynamics, such as mutations, differential aging or stochastic variations in metabolites and macromolecules yielding molecular switches, in the light of single-cell heterogeneities that have been reported among isogenic populations of other eu- and prokaryotes. PMID:25760649

  3. A millifluidic study of cell-to-cell heterogeneity in growth-rate and cell-division capability in populations of isogenic cells of Chlamydomonas reinhardtii.

    Directory of Open Access Journals (Sweden)

    Shima P Damodaran

    Full Text Available To address possible cell-to-cell heterogeneity in growth dynamics of isogenic cell populations of Chlamydomonas reinhardtii, we developed a millifluidic drop-based device that not only allows the analysis of populations grown from single cells over periods of a week, but is also able to sort and collect drops of interest, containing viable and healthy cells, which can be used for further experimentation. In this study, we used isogenic algal cells that were first synchronized in mixotrophic growth conditions. We show that these synchronized cells, when placed in droplets and kept in mixotrophic growth conditions, exhibit mostly homogeneous growth statistics, but with two distinct subpopulations: a major population with a short doubling-time (fast-growers and a significant subpopulation of slowly dividing cells (slow-growers. These observations suggest that algal cells from an isogenic population may be present in either of two states, a state of restricted division and a state of active division. When isogenic cells were allowed to propagate for about 1000 generations on solid agar plates, they displayed an increased heterogeneity in their growth dynamics. Although we could still identify the original populations of slow- and fast-growers, drops inoculated with a single progenitor cell now displayed a wider diversity of doubling-times. Moreover, populations dividing with the same growth-rate often reached different cell numbers in stationary phase, suggesting that the progenitor cells differed in the number of cell divisions they could undertake. We discuss possible explanations for these cell-to-cell heterogeneities in growth dynamics, such as mutations, differential aging or stochastic variations in metabolites and macromolecules yielding molecular switches, in the light of single-cell heterogeneities that have been reported among isogenic populations of other eu- and prokaryotes.

  4. Growth hormone promotes skeletal muscle cell fusion independent of insulin-like growth factor 1 up-regulation

    OpenAIRE

    Sotiropoulos, Athanassia; Ohanna, Mickaël; Kedzia, Cécile; Menon, Ram K.; Kopchick, John J.; Kelly, Paul A; Pende, Mario

    2006-01-01

    Growth hormone (GH) participates in the postnatal regulation of skeletal muscle growth, although the mechanism of action is unclear. Here we show that the mass of skeletal muscles lacking GH receptors is reduced because of a decrease in myofiber size with normal myofiber number. GH signaling controls the size of the differentiated myotubes in a cell-autonomous manner while having no effect on size, proliferation, and differentiation of the myoblast precursor cells. The GH hypertrophic action ...

  5. NFkB signaling is important for growth of antiestrogen resistant breast cancer cells

    DEFF Research Database (Denmark)

    Yde, Christina Westmose; Emdal, Kristina Bennet; Guerra, Barbara;

    2012-01-01

    resistant cell growth and a potential target for re-sensitizing resistant cells to endocrine therapy. We used an MCF-7-derived cell model for antiestrogen resistant breast cancer to investigate dependence on NF¿B signaling for antiestrogen resistant cell growth. We found that targeting NF¿B preferentially...... inhibited resistant cell growth. Antiestrogen resistant cells expressed increased p50 and RelB, and displayed increased phosphorylation of p65 at Ser529 and Ser536. Moreover, transcriptional activity of NF¿B after stimulation with tumor necrosis factor a was enhanced in antiestrogen resistant cell lines...... resistant cells increased sensitivity to tamoxifen treatment. Our data provide evidence that NF¿B signaling is enhanced in antiestrogen resistant breast cancer cells and plays an important role for antiestrogen resistant cell growth and for sensitivity to tamoxifen treatment in resistant cells. Our results...

  6. Berberine slows cell growth in autosomal dominant polycystic kidney disease cells

    Energy Technology Data Exchange (ETDEWEB)

    Bonon, Anna; Mangolini, Alessandra [Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, 44121 Ferrara (Italy); Pinton, Paolo [Department of Morphology, Surgery and Experimental Medicine, Section of General Pathology, University of Ferrara, 44121 Ferrara (Italy); Senno, Laura del [Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, 44121 Ferrara (Italy); Aguiari, Gianluca, E-mail: dsn@unife.it [Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, 44121 Ferrara (Italy)

    2013-11-22

    Highlights: •Berberine at appropriate doses slows cell proliferation in ADPKD cystic cells. •Reduction of cell growth by berberine occurs by inhibition of ERK and p70-S6 kinase. •Higher doses of berberine cause an overall cytotoxic effect. •Berberine overdose induces apoptotic bodies formation and DNA fragmentation. •Antiproliferative properties of this drug make it a new candidate for ADPKD therapy. -- Abstract: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary monogenic disorder characterized by development and enlargement of kidney cysts that lead to loss of renal function. It is caused by mutations in two genes (PKD1 and PKD2) encoding for polycystin-1 and polycystin-2 proteins which regulate different signals including cAMP, mTOR and EGFR pathways. Abnormal activation of these signals following PC1 or PC2 loss of function causes an increased cell proliferation which is a typical hallmark of this disease. Despite the promising findings obtained in animal models with targeted inhibitors able to reduce cystic cell growth, currently, no specific approved therapy for ADPKD is available. Therefore, the research of new more effective molecules could be crucial for the treatment of this severe pathology. In this regard, we have studied the effect of berberine, an isoquinoline quaternary alkaloid, on cell proliferation and apoptosis in human and mouse ADPKD cystic cell lines. Berberine treatment slows cell proliferation of ADPKD cystic cells in a dose-dependent manner and at high doses (100 μg/mL) it induces cell death in cystic cells as well as in normal kidney tubule cells. However, at 10 μg/mL, berberine reduces cell growth in ADPKD cystic cells only enhancing G{sub 0}/G{sub 1} phase of cell cycle and inhibiting ERK and p70-S6 kinases. Our results indicate that berberine shows a selected antiproliferative activity in cellular models for ADPKD, suggesting that this molecule and similar natural compounds could open new

  7. Contribution of chloroplast biogenesis to carbon-nitrogen balance during early leaf development in rice.

    Science.gov (United States)

    Kusumi, Kensuke; Hirotsuka, Shoko; Shimada, Hiroshi; Chono, Yoko; Matsuda, Osamu; Iba, Koh

    2010-07-01

    Chloroplast biogenesis is most significant during the changes in cellular organization associated with leaf development in higher plants. To examine the physiological relationship between developing chloroplasts and host leaf cells during early leaf development, we investigated changes in the carbon and nitrogen contents in leaves at the P4 developmental stage of rice, during which leaf blade structure is established and early events of chloroplast differentiation occur. During the P4 stage, carbon content on a dry mass basis remained constant, whereas the nitrogen content decreased by 30%. Among carbohydrates, sucrose and starch accumulated to high levels early in the P4 stage, and glucose, fructose and cellulose degradation increased during the mid-to-late P4 stage. In the chloroplast-deficient leaves of the virescent-1 mutant of rice, however, the carbon and nitrogen contents, as well as the C/N ratio during the P4 stage, were largely unaffected. These observations suggest that developing rice leaves function as sink organs at the P4 stage, and that chloroplast biogenesis and carbon and nitrogen metabolism in the leaf cell is regulated independently at this stage.

  8. Lipids implicated in the journey of a secretory granule: from biogenesis to fusion.

    Science.gov (United States)

    Tanguy, Emeline; Carmon, Ophélie; Wang, Qili; Jeandel, Lydie; Chasserot-Golaz, Sylvette; Montero-Hadjadje, Maité; Vitale, Nicolas

    2016-06-01

    The regulated secretory pathway begins with the formation of secretory granules by budding from the Golgi apparatus and ends by their fusion with the plasma membrane leading to the release of their content into the extracellular space, generally following a rise in cytosolic calcium. Generation of these membrane-bound transport carriers can be classified into three steps: (i) cargo sorting that segregates the cargo from resident proteins of the Golgi apparatus, (ii) membrane budding that encloses the cargo and depends on the creation of appropriate membrane curvature, and (iii) membrane fission events allowing the nascent carrier to separate from the donor membrane. These secretory vesicles then mature as they are actively transported along microtubules toward the cortical actin network at the cell periphery. The final stage known as regulated exocytosis involves the docking and the priming of the mature granules, necessary for merging of vesicular and plasma membranes, and the subsequent partial or total release of the secretory vesicle content. Here, we review the latest evidence detailing the functional roles played by lipids during secretory granule biogenesis, recruitment, and exocytosis steps. In this review, we highlight evidence supporting the notion that lipids play important functions in secretory vesicle biogenesis, maturation, recruitment, and membrane fusion steps. These effects include regulating various protein distribution and activity, but also directly modulating membrane topology. The challenges ahead to understand the pleiotropic functions of lipids in a secretory granule's journey are also discussed. This article is part of a mini review series on Chromaffin cells (ISCCB Meeting, 2015).

  9. Mutants of Chlamydomonas: tools to study thylakoid membrane structure, function and biogenesis.

    Science.gov (United States)

    de Vitry, C; Vallon, O

    1999-06-01

    The unicellular green alga Chlamydomonas reinhardtii is a model system for the study of photosynthesis and chloroplast biogenesis. C. reinhardtii has a photosynthesis apparatus similar to that of higher plants and it grows at rapid rate (generation time about 8 h). It is a facultative phototroph, which allows the isolation of mutants unable to perform photosynthesis and its sexual cycle allows a variety of genetic studies. Transformation of the nucleus and chloroplast genomes is easily performed. Gene transformation occurs mainly by homologous recombination in the chloroplast and heterologous recombination in the nucleus. Mutants are precious tools for studies of thylakoid membrane structure, photosynthetic function and assembly. Photosynthesis mutants affected in the biogenesis of a subunit of a protein complex usually lack the entire complex; this pleiotropic effect has been used in the identification of the other subunits, in the attribution of spectroscopic signals and also as a 'genetic cleaning' process which facilitates both protein complex purification, absorption spectroscopy studies or freeze-fracture analysis. The cytochrome b6f complex is not required for the growth of C. reinhardtii, unlike the case of photosynthetic prokaryotes in which the cytochrome complex is also part of the respiratory chain, and can be uniquely studied in Chlamydomonas by genetic approaches. We describe in greater detail the use of Chlamydomonas mutants in the study of this complex. PMID:10433117

  10. Downregulation of Akt1 Inhibits Anchorage-Independent Cell Growth and Induces Apoptosis in Cancer Cells

    Directory of Open Access Journals (Sweden)

    Xuesong Liu

    2001-01-01

    Full Text Available The serine/threonine kinases, Akti/PKBα, Akt2/PKBβ, and Akt3/PKBγ, play a critical role in preventing cancer cells from undergoing apoptosis. However, the function of individual Akt isoforms in the tumorigenicity of cancer cells is still not well defined. In the current study, we used an AM antisense oligonucleotide (AS to specifically downregulate Akti protein in both cancer and normal cells. Our data indicate that AM AS treatment inhibits the ability of MiaPaCa-2, H460, HCT-15, and HT1080 cells to grow in soft agar. The treatment also induces apoptosis in these cancer cells as demonstrated by FRCS analysis and a caspase activity assay. Conversely, Akti AS treatment has little effect on the cell growth and survival of normal human cells including normal human fibroblast (NHF, fibroblast from muscle (FBM, and mammary gland epithelial 184135 cells. In addition, AM AS specifically sensitizes cancer cells to typical chemotherapeutic agents. Thus, Akti is indispensable for maintaining the tumorigenicity of cancer cells. Inhibition of AM may provide a powerful sensitization agent for chemotherapy specifically in cancer cells.

  11. Mesenchymal stem cells directly interact with breast cancer cells and promote tumor cell growth in vitro and in vivo.

    Science.gov (United States)

    Mandel, Katharina; Yang, Yuanyuan; Schambach, Axel; Glage, Silke; Otte, Anna; Hass, Ralf

    2013-12-01

    Cellular interactions were investigated between human mesenchymal stem cells (MSC) and human breast cancer cells. Co-culture of the two cell populations was associated with an MSC-mediated growth stimulation of MDA-MB-231 breast cancer cells. A continuous expansion of tumor cell colonies was progressively surrounded by MSC(GFP) displaying elongated cell bodies. Moreover, some MSC(GFP) and MDA-MB-231(cherry) cells spontaneously generated hybrid/chimeric cell populations, demonstrating a dual (green fluorescent protein+cherry) fluorescence. During a co-culture of 5-6 days, MSC also induced expression of the GPI-anchored CD90 molecule in breast cancer cells, which could not be observed in a transwell assay, suggesting the requirement of direct cellular interactions. Indeed, MSC-mediated CD90 induction in the breast cancer cells could be partially blocked by a gap junction inhibitor and by inhibition of the notch signaling pathway, respectively. Similar findings were observed in vivo by which a subcutaneous injection of a co-culture of primary MSC with MDA-MB-231(GFP) cells into NOD/scid mice exhibited an about 10-fold increased tumor size and enhanced metastatic capacity as compared with the MDA-MB-231(GFP) mono-culture. Flow cytometric evaluation of the co-culture tumors revealed more than 90% of breast cancer cells with about 3% of CD90-positive cells, also suggesting an MSC-mediated in vivo induction of CD90 in MDA-MB-231 cells. Furthermore, immunohistochemical analysis demonstrated an elevated neovascularization and viability in the MSC/MDA-MB-231(GFP)-derived tumors. Together, these data suggested an MSC-mediated growth stimulation of breast cancer cells in vitro and in vivo by which the altered MSC morphology and the appearance of hybrid/chimeric cells and breast cancer-expressing CD90(+) cells indicate mutual cellular alterations.

  12. CTRP9 induces mitochondrial biogenesis and protects high glucose-induced endothelial oxidative damage via AdipoR1 -SIRT1- PGC-1α activation.

    Science.gov (United States)

    Cheng, Liang; Li, Bin; Chen, Xu; Su, Jie; Wang, Hongbing; Yu, Shiqiang; Zheng, Qijun

    2016-09-01

    Vascular lesions caused by endothelial dysfunction are the most common and serious complication of diabetes. The vasoactive potency of CTRP9 has been reported in our previous study via nitric oxide (NO) production. However, the effect of CTRP9 on vascular endothelial cells remains unknown. This study aimed to investigate the protection role of CTRP9 in the primary aortic vascular endothelial cells and HAECs under high-glucose condition. We found that the aortic vascular endothelial cells isolated from mice fed with a high fat diet generated more ROS production than normal cells, along with decreased mitochondrial biogenesis, which was also found in HAECs treated with high glucose. However, the treatment of CTPR9 significantly reduced ROS production and increased the activities of endogenous antioxidant enzymes, the expression of PGC-1α, NRF1, TFAM, ATP5A1 and SIRT1, and the activity of cytochrome c oxidase, indicating an induction of mitochondrial biogenesis. Furthermore, silencing the expression of SIRT1 in HAECs impeded the effect of CTRP9 on mitochondrial biogenesis, while silencing the expression of AdipoR1 in HAECs reversed the expression of SIRT1 and PGC-1α. Based on these findings, this study showed that CTRP9 might induce mitochondrial biogenesis and protect high glucose-induced endothelial oxidative damage via AdipoR1-SIRT1-PGC-1α signaling pathway. PMID:27349872

  13. Growth hormone and retinal ganglion cell function: QNR/D cells as an experimental model.

    Science.gov (United States)

    Martínez-Moreno, Carlos; Andres, Alexis; Giterman, Daniel; Karpinski, Edward; Harvey, Steve

    2014-01-01

    Retinal ganglion cells (RGCs) have been shown to be sites of growth hormone (GH) production and GH action in the embryonic (embryo day 7, ED7) chick neural retina. Primary RGC cell cultures were previously used to determine autocrine or paracrine actions of GH in the retina, but the antibody used in their immunopanning (anti-Thy-1) is no longer available. We have therefore characterized an immortalized neural retina (QNR/D) cell line derived from ED7 embryonic quail as a replacement experimental model. These cells express the GH gene and have GH receptor (GHR)-immunoreactivity. They are also immunoreactive for RGC markers (islet-1, calretinin, RA4) and neural fibers (neurofilament, GAP 43, vimentin) and they express the genes for Thy-1, neurotrophin 3 (NTF3), neuritin 1 (NRN1) and brn3 (POU4F). These cells are also electrically active and therefore resemble the RGCs in the neural retina. They are also similarly responsive to exogenous GH, which induces overexpression of the neurotrophin 3 and insulin-like growth factor (IGF) 1 genes and stimulates cell survival, as in the chick embryo neural retina. QNR/D cells are therefore a useful experimental model to assess the actions of GH in retinal function. PMID:24239556

  14. Nerve growth factor promotes in vitro proliferation of neural stem cells from tree shrews

    Institute of Scientific and Technical Information of China (English)

    Liu-lin Xiong; Zhi-wei Chen; Ting-hua Wang

    2016-01-01

    Neural stem cells promote neuronal regeneration and repair of brain tissue after injury, but have limited resources and proliferative ability in vivo. We hypothesized that nerve growth factor would promotein vitro proliferation of neural stem cells derived from the tree shrews, a primate-like mammal that has been proposed as an alternative to primates in biomedical translational research. We cultured neural stem cells from the hippocampus of tree shrews at embryonic day 38, and added nerve growth factor (100 μg/L) to the culture medium. Neural stem cells from the hippocampus of tree shrews cultured without nerve growth factor were used as controls. After 3 days, lfuorescence mi-croscopy after DAPI and nestin staining revealed that the number of neurospheres and DAPI/nestin-positive cells was markedly greater in the nerve growth factor-treated cells than in control cells. These ifndings demonstrate that nerve growth factor promotes the proliferation of neural stem cells derived from tree shrews.

  15. The Extracellular Vesicles of the Helminth Pathogen, Fasciola hepatica: Biogenesis Pathways and Cargo Molecules Involved in Parasite Pathogenesis.

    Science.gov (United States)

    Cwiklinski, Krystyna; de la Torre-Escudero, Eduardo; Trelis, Maria; Bernal, Dolores; Dufresne, Philippe J; Brennan, Gerard P; O'Neill, Sandra; Tort, Jose; Paterson, Steve; Marcilla, Antonio; Dalton, John P; Robinson, Mark W

    2015-12-01

    Extracellular vesicles (EVs) released by parasites have important roles in establishing and maintaining infection. Analysis of the soluble and vesicular secretions of adult Fasciola hepatica has established a definitive characterization of the total secretome of this zoonotic parasite. Fasciola secretes at least two subpopulations of EVs that differ according to size, cargo molecules and site of release from the parasite. The larger EVs are released from the specialized cells that line the parasite gastrodermus and contain the zymogen of the 37 kDa cathepsin L peptidase that performs a digestive function. The smaller exosome-like vesicle population originate from multivesicular bodies within the tegumental syncytium and carry many previously described immunomodulatory molecules that could be delivered into host cells. By integrating our proteomics data with recently available transcriptomic data sets we have detailed the pathways involved with EV biogenesis in F. hepatica and propose that the small exosome biogenesis occurs via ESCRT-dependent MVB formation in the tegumental syncytium before being shed from the apical plasma membrane. Furthermore, we found that the molecular "machinery" required for EV biogenesis is constitutively expressed across the intramammalian development stages of the parasite. By contrast, the cargo molecules packaged within the EVs are developmentally regulated, most likely to facilitate the parasites migration through host tissue and to counteract host immune attack.

  16. Aspects of plant cell growth and the actin cytoskeleton: lessons from root hairs

    NARCIS (Netherlands)

    Ruijter, de N.C.A.

    1999-01-01

    The main topic the thesis addresses is the role of the actin cytoskeleton in the growth process of plant cells. Plant growth implies a combination of cell division and cell expansion. The cytoskeleton, which exists of microtubules and actin filaments, plays a major role in both processes. Before cel

  17. Cell growth characteristics, differentiation frequency, and immunophenotype of adult ear mesenchymal stem cells.

    Science.gov (United States)

    Staszkiewicz, Jaroslaw; Frazier, Trivia P; Rowan, Brian G; Bunnell, Bruce A; Chiu, Ernest S; Gimble, Jeffrey M; Gawronska-Kozak, Barbara

    2010-01-01

    Ear mesenchymal stem cells (EMSCs) represent a readily accessible population of stem-like cells that are adherent, clonogenic, and have the ability to self-renew. Previously, we have demonstrated that they can be induced to differentiate into adipocyte, osteocyte, chondrocyte, and myocyte lineages. The purpose of the current study was to characterize the growth kinetics of the cells and to determine their ability to form colonies of fibroblasts, adipocytes, osteocytes, and chondrocytes. In addition, the immunophenotypes of freshly isolated and culture-expanded cells were evaluated. From 1 g of tissue, we were able to isolate an average of 7.8 x 10(6) cells exhibiting a cell cycle length of approximately 2-3 days. Colony-forming unit (CFU) assays indicated high proliferation potential, and confirmed previously observed multipotentiality of the cells. Fluorescence-activated cell sorting (FACS) showed that EMSCs were negative for hematopoietic markers (CD4, CD45), proving that they did not derive from circulating hematopoietic cells. The FACS analyses also showed high expression of stem cell antigen-1 (Sca-1) with only a minor population of cells expressing CD117, thus identifying Sca-1 as the more robust stem cell biomarker. Additionally, flow cytometry data revealed that the expression patterns of hematopoietic, stromal, and stem cell markers were maintained in the passaged EMSCs, consistent with the persistence of an undifferentiated state. This study indicates that EMSCs provide an alternative model for in vitro analyses of adult mesenchymal stem cells (MSCs). Further studies will be necessary to determine their utility for tissue engineering and regenerative medical applications. PMID:19400629

  18. Constitutive SOCS-3 expression protects T-cell lymphoma against growth inhibition by IFNalpha

    DEFF Research Database (Denmark)

    Brender, C; Lovato, P; Sommer, V H;

    2005-01-01

    expression in tumour cells is equal to or higher than in cytokine-stimulated nonmalignant T cells, (ii) SOCS-3 is not mutated in CTCL, (iii) overexpression of SOCS-3 blocks IFNalpha-mediated growth inhibition without affecting Stat3 activation, growth, and apoptosis, and (iv) inhibition of SOCS-3...... by a dominant negative Stat3 (Stat3D) increases the IFNalpha-mediated growth inhibition. Taken together, these data show that SOCS-3 does not inhibit Stat3 activation, growth, and survival in CTCL. In contrast, SOCS3 protects tumour cells against growth inhibition by IFNalpha. Unlike SOCS-1, SOCS-3 is therefore...

  19. Eugenol and its synthetic analogues inhibit cell growth of human cancer cells (Part I)

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco A, H.; Cardona, W. [Universidad Andres Bello, Vina del Mar (Chile). Dept. de Ciencias Quimicas]. E-mail: hcarrasco@unab.cl; Espinoza C, L.; Gallardo, C.; Catalan M, K. [Universidad Tecnica Federico Santa Maria, Valparaiso (Chile). Dept. de Quimica; Cardile, V.; Lombardo, L. [University of Catania (Italy). Dept. of Physiological Sciences; Cuellar F, M. [Universidad de Valparaiso (Chile). Facultad de Farmacia; Russo, A. [University of Catania (Italy). Dept. of Biological Chemistry, Medical Chemistry and Molecular Biology

    2008-07-01

    Eugenol (4-allyl-2-methoxyphenol) (1) has been reported to possess antioxidant and anticancer properties. In an attempt to enhance intrinsic activity of this natural compound, some derivatives were synthesized. Eugenol was extracted from cloves oil and further, the eugenol analogues (2-6) were obtained through acetylation and nitration reactions. Eugenol (1) and its analogues (2-6) were examined by in vitro model of cancer using two human cancer cell lines: DU-145 (androgeninsensitive prostate cancer cells) and KB (oral squamous carcinoma cells). Cell viability, by tetrazolium salts assay, was measured. Lactic dehydrogenase (LDH) release was also investigated to evaluate the presence of cell toxicity as a result of cell disruption, subsequent to membrane rupture. In the examined cancer cells, all compounds showed cell-growth inhibition activity. The obtained results demonstrate that the compounds 5-allyl-3-nitrobenzene-1,2-diol (3) and 4-allyl- 2-methoxy-5-nitrophenyl acetate (5) were significantly (p < 0,001) more active than eugenol, with IC{sub 50} values in DU-145 cells of 19.02 x 10{sup -6} and 21.5 x 10{sup -6} mol L{sup -1}, respectively, and in KB cells of 18.11 x 10{sup -6} and 21.26 x 10{sup -6} mol L{sup -1}, respectively, suggesting that the presence of nitro and hydroxyl groups could be important in the activity of these compounds. In addition, our results seem to indicate that apoptotic cell demise appears to be induced in KB and DU-145 cells. In fact, in our experimental conditions, no statistically significant increase in LDH release was observed in cancer cells treated with eugenol and its analogues. (author)

  20. Knockdown of asparagine synthetase by RNAi suppresses cell growth in human melanoma cells and epidermoid carcinoma cells.

    Science.gov (United States)

    Li, Hui; Zhou, Fusheng; Du, Wenhui; Dou, Jinfa; Xu, Yu; Gao, Wanwan; Chen, Gang; Zuo, Xianbo; Sun, Liangdan; Zhang, Xuejun; Yang, Sen

    2016-05-01

    Melanoma, the most aggressive form of skin cancer, causes more than 40,000 deaths each year worldwide. And epidermoid carcinoma is another major form of skin cancer, which could be studied together with melanoma in several aspects. Asparagine synthetase (ASNS) gene encodes an enzyme that catalyzes the glutamine- and ATP-dependent conversion of aspartic acid to asparagine, and its expression is associated with the chemotherapy resistance and prognosis in several human cancers. The present study aims to explore the potential role of ASNS in melanoma cells A375 and human epidermoid carcinoma cell line A431. We applied a lentivirus-mediated RNA interference (RNAi) system to study its function in cell growth of both cells. The results revealed that inhibition of ASNS expression by RNAi significantly suppressed the growth of melanoma cells and epidermoid carcinoma cells, and induced a G0/G1 cell cycle arrest in melanoma cells. Knockdown of ASNS in A375 cells remarkably downregulated the expression levels of CDK4, CDK6, and Cyclin D1, and upregulated the expression of p21. Therefore, our study provides evidence that ASNS may represent a potential therapeutic target for the treatment of melanoma. PMID:25858017

  1. Cyclovirobuxine D Attenuates Doxorubicin-Induced Cardiomyopathy by Suppression of Oxidative Damage and Mitochondrial Biogenesis Impairment

    Directory of Open Access Journals (Sweden)

    Qian Guo

    2015-01-01

    Full Text Available The clinical application of doxorubicin (DOX is compromised by its cardiac toxic effect. Cyclovirobuxine D (CVB-D is a steroid alkaloid extracted from a traditional Chinese medicine, Buxus microphylla. Our results showed that CVB-D pretreatment markedly attenuated DOX-induced cardiac contractile dysfunction and histological alterations. By using TUNEL assay and western blot analysis, we found that CVB-D pretreatment reduced DOX-induced apoptosis of myocardial cells and mitochondrial cytochrome c release to cytosol. CVB-D pretreatment ameliorated DOX-induced cardiac oxidative damage including lipid peroxidation and protein carbonylation and a decrease in the ratio of reduced glutathione (GSH to oxidized glutathione (GSSG. Moreover, CVB-D was found to prevent DOX-induced mitochondrial biogenesis impairment as evidenced by preservation of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α and nuclear respiratory factor 1 (NRF1, as well as mitochondrial DNA copy number. These findings demonstrate that CVB-D protects against DOX-induced cardiomyopathy, at least in part, by suppression of oxidative damage and mitochondrial biogenesis impairment.

  2. Rev-erb-α modulates skeletal muscle oxidative capacity by regulating mitochondrial biogenesis and autophagy

    Science.gov (United States)

    Woldt, Estelle; Sebti, Yasmine; Solt, Laura A.; Duhem, Christian; Lancel, Steve; Eeckhoute, Jérôme; Hesselink, Matthijs K.C.; Paquet, Charlotte; Delhaye, Stéphane; Shin, Youseung; Kamenecka, Theodore M.; Schaart, Gert; Lefebvre, Philippe; Nevière, Rémi; Burris, Thomas P.; Schrauwen, Patrick; Staels, Bart; Duez, Hélène

    2013-01-01

    The nuclear receptor Rev-erb-α modulates hepatic lipid and glucose metabolism, adipogenesis and the inflammatory response in macrophages. We show here that Rev-erb-α is highly expressed in oxidative skeletal muscle and plays a role in mitochondrial biogenesis and oxidative function, in gain- and loss-of function studies. Rev-erb-α-deficiency in skeletal muscle leads to reduced mitochondrial content and oxidative function, resulting in compromised exercise capacity. This phenotype was recapitulated in isolated fibers and in muscle cells upon Rev-erbα knock-down, while Rev-erb-α over-expression increased the number of mitochondria with improved respiratory capacity. Rev-erb-α-deficiency resulted in deactivation of the Stk11–Ampk–Sirt1–Ppargc1-α signaling pathway, whereas autophagy was up-regulated, resulting in both impaired mitochondrial biogenesis and increased clearance. Muscle over-expression or pharmacological activation of Rev-erb-α increased respiration and exercise capacity. This study identifies Rev-erb-α as a pharmacological target which improves muscle oxidative function by modulating gene networks controlling mitochondrial number and function. PMID:23852339

  3. A Biogenesis Step Upstream of Microprocessor Controls miR-17∼92 Expression.

    Science.gov (United States)

    Du, Peng; Wang, Longfei; Sliz, Piotr; Gregory, Richard I

    2015-08-13

    The precise control of miR-17∼92 microRNA (miRNA) is essential for normal development, and overexpression of certain miRNAs from this cluster is oncogenic. Here, we find that the relative expression of the six miRNAs processed from the primary (pri-miR-17∼92) transcript is dynamically regulated during embryonic stem cell (ESC) differentiation. Pri-miR-17∼92 is processed to a biogenesis intermediate, termed "progenitor-miRNA" (pro-miRNA). Pro-miRNA is an efficient substrate for Microprocessor and is required to selectively license production of pre-miR-17, pre-miR-18a, pre-miR-19a, pre-miR-20a, and pre-miR-19b from this cluster. Two complementary cis-regulatory repression domains within pri-miR-17∼92 are required for the blockade of miRNA processing through the formation of an autoinhibitory RNA conformation. The endonuclease CPSF3 (CPSF73) and the spliceosome-associated ISY1 are responsible for pro-miRNA biogenesis and expression of all miRNAs within the cluster except miR-92. Thus, developmentally regulated pro-miRNA processing is a key step controlling miRNA expression and explains the posttranscriptional control of miR-17∼92 expression in development.

  4. Mutant p53 inhibits miRNA biogenesis by interfering with the microprocessor complex.

    Science.gov (United States)

    Garibaldi, F; Falcone, E; Trisciuoglio, D; Colombo, T; Lisek, K; Walerych, D; Del Sal, G; Paci, P; Bossi, G; Piaggio, G; Gurtner, A

    2016-07-21

    Downregulation of microRNAs (miRNAs) is commonly observed in cancers and promotes tumorigenesis suggesting that miRNAs may function as tumor suppressors. However, the mechanism through which miRNAs are regulated in cancer, and the connection between oncogenes and miRNA biogenesis remain poorly understood. The TP53 tumor-suppressor gene is mutated in half of human cancers resulting in an oncogene with gain-of-function activities. Here we demonstrate that mutant p53 (mutp53) oncoproteins modulate the biogenesis of a subset of miRNAs in cancer cells inhibiting their post-transcriptional maturation. Interestingly, among these miRNAs several are also downregulated in human tumors. By confocal, co-immunoprecipitation and RNA-chromatin immunoprecipitation experiments, we show that endogenous mutp53 binds and sequesters RNA helicases p72/82 from the microprocessor complex, interfering with Drosha-pri-miRNAs association. In agreement with this, the overexpression of p72 leads to an increase of mature miRNAs levels. Moreover, functional experiments demonstrate the oncosuppressive role of mutp53-dependent miRNAs (miR-517a, -519a, -218, -105). Our study highlights a previously undescribed mechanism by which mutp53 interferes with Drosha-p72/82 association leading, at least in part, to miRNA deregulation observed in cancer.

  5. Structure of BamA, an essential factor in outer membrane protein biogenesis.

    Science.gov (United States)

    Albrecht, Reinhard; Schütz, Monika; Oberhettinger, Philipp; Faulstich, Michaela; Bermejo, Ivan; Rudel, Thomas; Diederichs, Kay; Zeth, Kornelius

    2014-06-01

    Outer membrane protein (OMP) biogenesis is an essential process for maintaining the bacterial cell envelope and involves the β-barrel assembly machinery (BAM) for OMP recognition, folding and assembly. In Escherichia coli this function is orchestrated by five proteins: the integral outer membrane protein BamA of the Omp85 superfamily and four associated lipoproteins. To unravel the mechanism underlying OMP folding and insertion, the structure of the E. coli BamA β-barrel and P5 domain was determined at 3 Å resolution. These data add information beyond that provided in the recently published crystal structures of BamA from Haemophilus ducreyi and Neisseria gonorrhoeae and are a valuable basis for the interpretation of pertinent functional studies. In an `open' conformation, E. coli BamA displays a significant degree of flexibility between P5 and the barrel domain, which is indicative of a multi-state function in substrate transfer. E. coli BamA is characterized by a discontinuous β-barrel with impaired β1-β16 strand interactions denoted by only two connecting hydrogen bonds and a disordered C-terminus. The 16-stranded barrel surrounds a large cavity which implies a function in OMP substrate binding and partial folding. These findings strongly support a mechanism of OMP biogenesis in which substrates are partially folded inside the barrel cavity and are subsequently released laterally into the lipid bilayer. PMID:24914988

  6. Membrane trafficking and organelle biogenesis in Giardia lamblia: use it or lose it.

    Science.gov (United States)

    Faso, Carmen; Hehl, Adrian B

    2011-04-01

    The secretory transport capacity of Giardia trophozoites is perfectly adapted to the changing environment in the small intestine of the host and is able to deploy essential protective surface coats as well as molecules which act on epithelia. These lumen-dwelling parasites take up nutrients by bulk endocytosis through peripheral vesicles or by receptor-mediated transport. The environmentally-resistant cyst form is quiescent but poised for activation following stomach passage. Its versatility and fidelity notwithstanding, the giardial trafficking systems appear to be the product of a general secondary reduction process geared towards minimization of all components and machineries identified to date. Since membrane transport is directly linked to organelle biogenesis and maintenance, less complexity also means loss of organelle structures and functions. A case in point is the Golgi apparatus which is missing as a steady-state organelle system. Only a few basic Golgi functions have been experimentally demonstrated in trophozoites undergoing encystation. Similarly, mitochondrial remnants have reached a terminally minimized state and appear to be functionally restricted to essential iron-sulfur protein maturation processes. Giardia's minimized organization combined with its genetic tractability provides unique opportunities to study basic principles of secretory transport in an uncluttered cellular environment. Not surprisingly, Giardia is gaining increasing attention as a model for the investigation of gene regulation, organelle biogenesis, and export of simple but highly protective cell wall biopolymers, a hallmark of all perorally transmitted protozoan and metazoan parasites. PMID:21296082

  7. Role of membrane glycerolipids in photosynthesis, thylakoid biogenesis and chloroplast development.

    Science.gov (United States)

    Kobayashi, Koichi

    2016-07-01

    The lipid bilayer of the thylakoid membrane in plant chloroplasts and cyanobacterial cells is predominantly composed of four unique lipid classes; monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), sulfoquinovosyldiacylglycerol (SQDG) and phosphatidylglycerol (PG). MGDG and DGDG are uncharged galactolipids that constitute the bulk of thylakoid membrane lipids and provide a lipid bilayer matrix for photosynthetic complexes as the main constituents. The glycolipid SQDG and phospholipid PG are anionic lipids with a negative charge on their head groups. SQDG and PG substitute for each other to maintain the amount of total anionic lipids in the thylakoid membrane, with PG having indispensable functions in photosynthesis. In addition to biochemical studies, extensive analyses of mutants deficient in thylakoid lipids have revealed important roles of these lipids in photosynthesis and thylakoid membrane biogenesis. Moreover, recent studies of Arabidopsis thaliana suggest that thylakoid lipid biosynthesis triggers the expression of photosynthesis-associated genes in both the nucleus and plastids and activates the formation of photosynthetic machineries and chloroplast development. Meanwhile, galactolipid biosynthesis is regulated in response to chloroplast functionality and lipid metabolism at transcriptional and post-translational levels. This review summarizes the roles of thylakoid lipids with their biosynthetic pathways in plants and discusses the coordinated regulation of thylakoid lipid biosynthesis with the development of photosynthetic machinery during chloroplast biogenesis. PMID:27114097

  8. MIWI2 and MILI Have Differential Effects on piRNA Biogenesis and DNA Methylation

    Directory of Open Access Journals (Sweden)

    Sergei A. Manakov

    2015-08-01

    Full Text Available In developing male germ cells, prospermatogonia, two Piwi proteins, MILI and MIWI2, use Piwi-interacting RNA (piRNA guides to repress transposable element (TE expression and ensure genome stability and proper gametogenesis. In addition to their roles in post-transcriptional TE repression, both proteins are required for DNA methylation of TE sequences. Here, we analyzed the effect of Miwi2 deficiency on piRNA biogenesis and transposon repression. Miwi2 deficiency had only a minor impact on piRNA biogenesis; however, the piRNA profile of Miwi2-knockout mice indicated overexpression of several LINE1 TE families that led to activation of the ping-pong piRNA cycle. Furthermore, we found that MILI and MIWI2 have distinct functions in TE repression in the nucleus. MILI is responsible for DNA methylation of a larger subset of TE families than MIWI2 is, suggesting that the proteins have independent roles in establishing DNA methylation patterns.

  9. Introduction of exogenous growth hormone receptors augments growth hormone-responsive insulin biosynthesis in rat insulinoma cells.

    OpenAIRE

    Billestrup, N; Møldrup, A; Serup, P.; Mathews, L S; Norstedt, G; Nielsen, J H

    1990-01-01

    The stimulation of insulin biosynthesis in the pancreatic insulinoma cell line RIN5-AH by growth hormone (GH) is initiated by GH binding to specific receptors. To determine whether the recently cloned rat hepatic GH receptor is able to mediate the insulinotropic effect of GH, we have transfected a GH receptor cDNA under the transcriptional control of the human metallothionein promoter into RIN5-AH cells. The transfected cells were found to exhibit an increased expression of GH receptors and t...

  10. Study of wavy laminar growth of human urinary bladder cancer cell line in vitro

    Institute of Scientific and Technical Information of China (English)

    DENG Guo-hong; CONG Yan-guang; LIU Jun-kang; XU Qi-wang; YUAN Ze-tao

    2001-01-01

    To observe the ordered growth behavior of human urinary bladder cancer cell line (BIU) under culture in vitro. Methods: The suspension of BIU cells was spread locally in a culture container. When the cells grew along the wall to form a cellular colony, macroscopic and microscopic observations complemented with measurements of the parameters including expanding diameter, expanding rate, cell shape, average cell density, average cell size, dehydrogenase activity and sensitivity to pH were conducted dynamically. Results: During cell culture, obvious laminar characteristics appeared in localized growing BIU cell colonies and there was difference between the cells of different zones in shape, size, density, dehydrogenase activity and sensitivity to pH. Conclusion: Space closing and bio-dissipation result in self-organization of BIU cells with ordered growth behavior. The present experiment offers a simple, controllable model for the study of wavy growth of human cells.

  11. Mitochondria biogenesis and the development of diabetic retinopathy

    OpenAIRE

    dos Santos, Julia M.; Tewari, Shikha; Goldberg, Andrew F. X.; Kowluru, Renu A.

    2011-01-01

    Retinal mitochondria become dysfunctional and their DNA (mtDNA) is damaged in diabetes. Biogenesis of mitochondria DNA is tightly controlled by nuclear-mitochondrial transcriptional factors, and translocation of transcription factor A (TFAM) to the mitochondria is essential for transcription and replication. Our aim is to investigate the effect of diabetes on nuclear-mitochondrial communication in the retina, and its role in the development of retinopathy. Damage of mtDNA, copy number and bio...

  12. Regulation of chloroplast biogenesis: the immutans mutant of Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Rodermel, Steven

    2015-11-16

    The immutans (im) variegation mutant of Arabidopsis is an ideal model to gain insight into factors that control chloroplast biogenesis. im defines the gene for PTOX, a plastoquinol terminal oxidase that participates in control of thylakoid redox. Here, we report that the im defect can be suppressed during the late stages of plant development by gigantea (gi2), which defines the gene for GIGANTEA (GI), a central component of the circadian clock that plays a poorly-understood role in diverse plant developmental processes. imgi2 mutants are late-flowering and display other well-known phenotypes associated with gi2, such as starch accumulation and resistance to oxidative stress. We show that the restoration of chloroplast biogenesis in imgi2 is caused by a developmental-specific de-repression of cytokinin signaling that involves crosstalk with signaling pathways mediated by gibberellin (GA) and SPINDLY (SPY), a GA response inhibitor. Suppression of the plastid defect in imgi2 is likely caused by a relaxation of excitation pressures in developing plastids by factors contributed by gi2, including enhanced rates of photosynthesis and increased resistance to oxidative stress. Interestingly, the suppression phenotype of imgi can be mimicked by crossing im with the starch accumulation mutant, sex1, perhaps because sex1 utilizes pathways similar to gi. We conclude that our studies provide a direct genetic linkage between GIGANTEA and chloroplast biogenesis, and we construct a model of interactions between signaling pathways mediated by gi, GA, SPY, cytokinins, and sex1 that are required for chloroplast biogenesis.

  13. Coupling between the circadian clock and cell cycle oscillators: implication for healthy cells and malignant growth

    Directory of Open Access Journals (Sweden)

    Celine eFeillet

    2015-05-01

    Full Text Available Uncontrolled cell proliferation is one of the key features leading to cancer. Seminal works in chronobiology have revealed that disruption of the circadian timing system in mice, either by surgical, genetic or environmental manipulation, increased tumor development. In humans, shift work is a risk factor for cancer. Based on these observations, the link between the circadian clock and cell cycle has become intuitive. But despite identification of molecular connections between the two processes, the influence of the clock on the dynamics of the cell cycle has never been formally observed. Recently, two studies combining single live cell imaging with computational methods have shed light on robust coupling between clock and cell cycle oscillators. We recapitulate here these novel findings and integrate them with earlier results in both healthy and cancerous cells. Moreover, we propose that the cell cycle may be synchronized or slowed down through coupling with the circadian clock, which results in reduced tumour growth. More than ever, systems biology has become instrumental to understand the dynamic interaction between the circadian clock and cell cycle, which is critical in cellular coordination and for diseases such as cancer.

  14. Inhibitory effect of maple syrup on the cell growth and invasion of human colorectal cancer cells.

    Science.gov (United States)

    Yamamoto, Tetsushi; Uemura, Kentaro; Moriyama, Kaho; Mitamura, Kuniko; Taga, Atsushi

    2015-04-01

    Maple syrup is a natural sweetener consumed by individuals of all ages throughout the world. Maple syrup contains not only carbohydrates such as sucrose but also various components such as organic acids, amino acids, vitamins and phenolic compounds. Recent studies have shown that these phenolic compounds in maple syrup may possess various activities such as decreasing the blood glucose level and an anticancer effect. In this study, we examined the effect of three types of maple syrup, classified by color, on the cell proliferation, migration and invasion of colorectal cancer (CRC) cells in order to investigate whether the maple syrup is suitable as a phytomedicine for cancer treatment. CRC cells that were administered maple syrup showed significantly lower growth rates than cells that were administered sucrose. In addition, administration of maple syrup to CRC cells caused inhibition of cell invasion, while there was no effect on cell migration. Administration of maple syrup clearly inhibited AKT phosphorylation, while there was no effect on ERK phosphorylation. These data suggest that maple syrup might inhibit cell proliferation and invasion through suppression of AKT activation and be suitable as a phytomedicine for CRC treatment, with fewer adverse effects than traditional chemotherapy.

  15. Coupling between the Circadian Clock and Cell Cycle Oscillators: Implication for Healthy Cells and Malignant Growth

    Science.gov (United States)

    Feillet, Celine; van der Horst, Gijsbertus T. J.; Levi, Francis; Rand, David A.; Delaunay, Franck

    2015-01-01

    Uncontrolled cell proliferation is one of the key features leading to cancer. Seminal works in chronobiology have revealed that disruption of the circadian timing system in mice, either by surgical, genetic, or environmental manipulation, increased tumor development. In humans, shift work is a risk factor for cancer. Based on these observations, the link between the circadian clock and cell cycle has become intuitive. But despite identification of molecular connections between the two processes, the influence of the clock on the dynamics of the cell cycle has never been formally observed. Recently, two studies combining single live cell imaging with computational methods have shed light on robust coupling between clock and cell cycle oscillators. We recapitulate here these novel findings and integrate them with earlier results in both healthy and cancerous cells. Moreover, we propose that the cell cycle may be synchronized or slowed down through coupling with the circadian clock, which results in reduced tumor growth. More than ever, systems biology has become instrumental to understand the dynamic interaction between the circadian clock and cell cycle, which is critical in cellular coordination and for diseases such as cancer. PMID:26029155

  16. Metformin inhibits cell growth by upregulating microRNA-26a in renal cancer cells.

    Science.gov (United States)

    Yang, Feng-Qiang; Wang, Ji-Jiao; Yan, Jia-Sheng; Huang, Jian-Hua; Li, Wei; Che, Jian-Ping; Wang, Guang-Chun; Liu, Min; Zheng, Jun-Hua

    2014-01-01

    Accumulating evidence suggests that metformin, a biguanide class of anti-diabetic drugs, possesses anti-cancer properties and may reduce cancer risk and improve prognosis. However, the mechanism by which metformin affects various cancers, including renal cancer still unknown. MiR-26a induces cell growth, cell cycle and cell apoptosis progression via direct targeting of Bcl-2, clyclin D1 and PTEN in cancer cells. In the present study, we used 786-O human renal cancer cell lines to study the effects and mechanisms of metformin. Metformin treatment inhibited RCC cells proliferation by increasing expression of miR-26a in 786-O cells (P metformin. Also over-expression of miR-26a can inhibited cell proliferation by down-regulating Bcl-2, cyclin D1 and up-regulating PTEN expression. Therefore, these data for the first time provide novel evidence for a mechanism that the anticancer activities of metformin are due to upregulation of miR-26a and affect its downstream target gene. PMID:25419360

  17. Effects of medium nutrition on cell growth and isocamptothecin A and B production by suspension cell culture of Camptotheca acuminata

    Institute of Scientific and Technical Information of China (English)

    Zhang Dongyan; Yu Fang; Bai Fengwu; An Lijia

    2006-01-01

    The effects of initial sucrose concentration, nitrate to ammonium ratio, total N concentration and phosphate concentration in medium on cell growth and isocamptothecin A and B synthesis by suspension cell culture of Camptotheca acuminata were investigated in 250 mL shake flasks. 30 g L-1 sucrose concentration was beneficial to secondary metabolites synthesis. The cell growth and metabolites synthesis were also affected by the ratio of NO-3/NH+4, and nitrate was favourable for cell growth. The maximum dry weight was achieved when nitrate was used as the sole N source. The effect of total initial N on the cell cultures was also investigated with NO-3/NH+4 ratio of 1∶2. The final dry cell weight was similar throughout culture period and 50 mM initial N was favourable for secondary metabolite synthesis. 50 mM initial phosphate concentration facilitated both cell growth and secondary metabolites synthesis.

  18. Growth suppression by transforming growth factor beta 1 of human small-cell lung cancer cell lines is associated with expression of the type II receptor

    DEFF Research Database (Denmark)

    Nørgaard, P; Damstrup, L; Rygaard, K;

    1994-01-01

    was observed in two cell lines expressing only type III receptor and in TGF-beta-r negative cell lines. In two cell lines expressing all three receptor types, growth suppression was accompanied by morphological changes. To evaluate the possible involvement of the retinoblastoma protein (pRb) in mediating...... the growth-suppressive effect of TGF-beta 1, the expression of functional pRb, as characterised by nuclear localisation, was examined by immunocytochemistry. Nuclear association of pRb was only seen in two of the five TGF-beta 1-responsive cell lines. These results indicate that in SCLC pRb is not required...

  19. Insulin and insulin-like growth factor I exert different effects on plasminogen activator production or cell growth in the ovine thyroid cell line OVNIS.

    Science.gov (United States)

    Degryse, B; Maisonobe, F; Hovsépian, S; Fayet, G

    1991-11-01

    Insulin and Insulin-like Growth Factor I (IGF-I) are evaluated for their capacity to affect cell proliferation and plasminogen activator (PA) activity production in an ovine thyroid cell line OVNIS. Insulin at physiological and supraphysiological doses induces cell proliferation and increases PA activity. IGF-I, which is also clearly mitogenic for these cells, surprisingly does not modulate PA activity. The results indicate that the growth promoting effect is mediated through the insulin and IGF-I receptors whereas PA activity is solely regulated via the insulin receptors. PMID:1802921

  20. An experimental platform for studying growth and invasiveness of tumor cells within teratomas derived from human embryonic stem cells

    OpenAIRE

    Tzukerman, Maty; Rosenberg, Tzur; Ravel, Yael; Reiter, Irena; Coleman, Raymond; Skorecki, Karl

    2003-01-01

    There is currently no available experimental system wherein human cancer cells can be grown in the context of a mixed population of normal differentiated human cells for testing biological aspects of cancer cell growth (e.g., tumor cell invasion and angiogenesis) or response to anti-cancer therapies. When implanted into immunocompromised mice, human embryonic stem cells develop teratomas containing complex structures comprising differentiated cell types representing the major germ line-derive...

  1. The effects of antisense PTEN gene transfection on the growth and invasion of glioma cells

    Institute of Scientific and Technical Information of China (English)

    CHEN Hong-jie; ZHENG Zhao-cong; WANG Ru-mi; WANG Shou-sen; YANG Wei-zhong

    2006-01-01

    Objective:To study the effects of antisense PTEN gene on the growth and invasion of glioma cells. Methods:A pcDNA3. 1/Hygro (-) recombinant plasmid containing antisense PTEN gene fragment was constructed. Glioma cells of primary culture were transfected with antisense PTEN gene vector and stably transfected clones were selected. Then, the different growth and invasion abilities and the different MMP9 mRNA expressions of three kinds of cells were observed, including the transfected cells, untransfected cells and the cells transfected with empty vector. Results :The abilities of growth and invasion of the transfected cells and the expressions of MMP9 mRNA were obviously enhanced. Conclusion: Antisense PTEN gene could have a negative impact on the growth and invasion of primary culture glioma cells.

  2. Assembly of the Biogenesis of Lysosome-related Organelles Complex-3 (BLOC-3) and Its Interaction with Rab9*

    Science.gov (United States)

    Kloer, Daniel P.; Rojas, Raul; Ivan, Viorica; Moriyama, Kengo; van Vlijmen, Thijs; Murthy, Namita; Ghirlando, Rodolfo; van der Sluijs, Peter; Hurley, James H.; Bonifacino, Juan S.

    2010-01-01

    The Hermansky-Pudlak syndrome (HPS) is a genetic hypopigmentation and bleeding disorder caused by defective biogenesis of lysosome-related organelles (LROs) such as melanosomes and platelet dense bodies. HPS arises from mutations in any of 8 genes in humans and 16 genes in mice. Two of these genes, HPS1 and HPS4, encode components of the biogenesis of lysosome-related organelles complex-3 (BLOC-3). Herein we show that recombinant HPS1-HPS4 produced in insect cells can be efficiently isolated as a 1:1 heterodimer. Analytical ultracentrifugation reveals that this complex has a molecular mass of 146 kDa, equivalent to that of the native complex and to the sum of the predicted molecular masses of HPS1 and HPS4. This indicates that HPS1 and HPS4 interact directly in the absence of any other protein as part of BLOC-3. Limited proteolysis and deletion analyses show that both subunits interact with one another throughout most of their lengths with the sole exception of a long, unstructured loop in the central part of HPS4. An interaction screen reveals a specific and strong interaction of BLOC-3 with the GTP-bound form of the endosomal GTPase, Rab9. This interaction is mediated by HPS4 and the switch I and II regions of Rab9. These characteristics indicate that BLOC-3 might function as a Rab9 effector in the biogenesis of LROs. PMID:20048159

  3. DNA damage triggers SAF-A and RNA biogenesis factors exclusion from chromatin coupled to R-loops removal.

    Science.gov (United States)

    Britton, Sébastien; Dernoncourt, Emma; Delteil, Christine; Froment, Carine; Schiltz, Odile; Salles, Bernard; Frit, Philippe; Calsou, Patrick

    2014-08-01

    We previously identified the heterogeneous ribonucleoprotein SAF-A/hnRNP U as a substrate for DNA-PK, a protein kinase involved in DNA damage response (DDR). Using laser micro-irradiation in human cells, we report here that SAF-A exhibits a two-phase dynamics at sites of DNA damage, with a rapid and transient recruitment followed by a prolonged exclusion. SAF-A recruitment corresponds to its binding to Poly(ADP-ribose) while its exclusion is dependent on the activity of ATM, ATR and DNA-PK and reflects the dissociation from chromatin of SAF-A associated with ongoing transcription. Having established that SAF-A RNA-binding domain recapitulates SAF-A dynamics, we show that this domain is part of a complex comprising several mRNA biogenesis proteins of which at least two, FUS/TLS and TAFII68/TAF15, exhibit similar biphasic dynamics at sites of damage. Using an original reporter for live imaging of DNA:RNA hybrids (R-loops), we show a transient transcription-dependent accumulation of R-loops at sites of DNA damage that is prolonged upon inhibition of RNA biogenesis factors exclusion. We propose that a new component of the DDR is an active anti-R-loop mechanism operating at damaged transcribed sites which includes the exclusion of mRNA biogenesis factors such as SAF-A, FUS and TAF15. PMID:25030905

  4. AKT3 controls mitochondrial biogenesis and autophagy via regulation of the major nuclear export protein CRM-1.

    Science.gov (United States)

    Corum, Daniel G; Tsichlis, Philip N; Muise-Helmericks, Robin C

    2014-01-01

    Our previous work has shown that Akt3 is required for mitochondrial biogenesis in primary human endothelial cells (ECs) and in Akt3-null mice; Akt3 affects subcellular localization of peroxisome proliferator-activated receptor γ coactivator-1 (PGC-1α), the master regulator of mitochondrial biogenesis. The purpose of this study is to determine the mechanism by which Akt3 controls the subcellular distribution of PGC-1α and to explore the effect on mitochondrial biogenesis and turnover during angiogenesis. Here we use standard biochemical analyses and Akt3-knockdown strategies to show that Akt3 controls the stabilization of chromosome maintenance region-1 (CRM-1), the major nuclear export receptor. Site-directed mutagenesis and association analyses show that PGC-1α nuclear export is CRM-1 dependent. Akt3 knockdown and CRM-1 overexpression cause 3-fold reductions in PGC-1α target gene expression, compared to control levels. Akt3 inhibition causes autophagy, as measured by autophagosome formation, in a CRM-1-dependent, Akt1/mTOR-independent pathway. In vivo, Akt3-null and heterozygous mice show dose-dependent decreases in angiogenesis compared to wild-type littermates (~5- and 2.5-fold decreases, respectively), as assessed by Matrigel plug assays. This correlates with an ~1.5-fold decrease in mitochondrial Cox IV expression. Our studies suggest that Akt3 is a regulator of mitochondrial dynamics in the vasculature via regulation of CRM-1-dependent nuclear export.

  5. Control of Vascular Smooth Muscle Cell Growth by Connexin 43

    Directory of Open Access Journals (Sweden)

    Chintamani eJoshi

    2012-06-01

    Full Text Available Connexin 43 (Cx43, the principal gap junction protein in vascular smooth muscle cells (VSMCs, regulates movement of ions and other signaling molecules through gap junction intercellular communication (GJIC and plays important roles in maintaining normal vessel function; however, many of the signaling mechanisms controlling Cx43 in VSMCs are not clearly described. The goal of this study was to investigate mechanisms of Cx43 regulation with respect to VSMC proliferation. Treatment of rat primary VSMCs with the cAMP analog 8Br-cAMP, the soluble guanylate cyclase (sGC stimulator BAY 41-2272 (BAY, or the Cx inducer diallyl disulfide (DADS significantly reduced proliferation after 72 h compared to vehicle controls. Bromodeoxyuridine uptake revealed reduction (p<.001 in DNA synthesis after 6 h and flow cytometry showed reduced (40% S phase cell numbers after 16 h in DADS-treated cells compared to controls. Cx43 expression significantly increased after 270 min treatment with 8Br-cAMP, 8Br-cGMP, BAY or DADS. Inhibition of PKA, PKG or PKC reversed 8Br-cAMP-stimulated increases in Cx43 expression, whereas only PKG or PKC inhibition reversed 8Br-cGMP- and BAY-stimulated increases in total Cx43. Interestingly, stimulation of Cx43 expression by DADS was not dependent on PKA, PKG or PKC. Using fluorescence recovery after photobleaching, only 8Br-cAMP or DADS increased GJIC with 8Br-cAMP mediated by PKC and DADS mediated by PKG. Further, DADS significantly increased phosphorylation at the MAPK-sensitive serine (Ser255 and Ser279, the cell cycle regulatory kinase-sensitive Ser262 and the PKC-sensitive Ser368 after 30 min while 8Br-cAMP significantly increased phosphorylation only at Ser279 compared to controls. This study demonstrates that 8Br-cAMP- and DADS-enhanced GJIC rather than Cx43 expression and/or phosphorylation plays an important role in regulation of VSMC proliferation and provides new insights into the growth-regulatory capacities of Cx43 in VSMCs.

  6. Spatial Patterning of Newly-Inserted Material during Bacterial Cell Growth

    Science.gov (United States)

    Ursell, Tristan

    2012-02-01

    In the life cycle of a bacterium, rudimentary microscopy demonstrates that cell growth and elongation are essential characteristics of cellular reproduction. The peptidoglycan cell wall is the main load-bearing structure that determines both cell shape and overall size. However, simple imaging of cellular growth gives no indication of the spatial patterning nor mechanism by which material is being incorporated into the pre-existing cell wall. We employ a combination of high-resolution pulse-chase fluorescence microscopy, 3D computational microscopy, and detailed mechanistic simulations to explore how spatial patterning results in uniform growth and maintenance of cell shape. We show that growth is happening in discrete bursts randomly distributed over the cell surface, with a well-defined mean size and average rate. We further use these techniques to explore the effects of division and cell wall disrupting antibiotics, like cephalexin and A22, respectively, on the patterning of cell wall growth in E. coli. Finally, we explore the spatial correlation between presence of the bacterial actin-like cytoskeletal protein, MreB, and local cell wall growth. Together these techniques form a powerful method for exploring the detailed dynamics and involvement of antibiotics and cell wall-associated proteins in bacterial cell growth.[4pt] In collaboration with Kerwyn Huang, Stanford University.

  7. Mesenchymal stem cell 1 (MSC1-based therapy attenuates tumor growth whereas MSC2-treatment promotes tumor growth and metastasis.

    Directory of Open Access Journals (Sweden)

    Ruth S Waterman

    Full Text Available BACKGROUND: Currently, there are many promising clinical trials using mesenchymal stem cells (MSCs in cell-based therapies of numerous diseases. Increasingly, however, there is a concern over the use of MSCs because they home to tumors and can support tumor growth and metastasis. For instance, we established that MSCs in the ovarian tumor microenvironment promoted tumor growth and favored angiogenesis. In parallel studies, we also developed a new approach to induce the conventional mixed pool of MSCs into two uniform but distinct phenotypes we termed MSC1 and MSC2. METHODOLOGY/PRINCIPAL FINDINGS: Here we tested the in vitro and in vivo stability of MSC1 and MSC2 phenotypes as well as their effects on tumor growth and spread. In vitro co-culture of MSC1 with various cancer cells diminished growth in colony forming units and tumor spheroid assays, while conventional MSCs or MSC2 co-culture had the opposite effect in these assays. Co-culture of MSC1 and cancer cells also distinctly affected their migration and invasion potential when compared to MSCs or MSC2 treated samples. The expression of bioactive molecules also differed dramatically among these samples. MSC1-based treatment of established tumors in an immune competent model attenuated tumor growth and metastasis in contrast to MSCs- and MSC2-treated animals in which tumor growth and spread was increased. Also, in contrast to these groups, MSC1-therapy led to less ascites accumulation, increased CD45+leukocytes, decreased collagen deposition, and mast cell degranulation. CONCLUSION/SIGNIFICANCE: These observations indicate that the MSC1 and MSC2 phenotypes may be convenient tools for the discovery of critical components of the tumor stroma. The continued investigation of these cells may help ensure that cell based-therapy is used safely and effectively in human disease.

  8. Cells from the adult corneal stroma can be reprogrammed to a neuron-like cell using exogenous growth factors

    Energy Technology Data Exchange (ETDEWEB)

    Greene, Carol Ann, E-mail: carol.greene@auckland.ac.nz; Chang, Chuan-Yuan; Fraser, Cameron J.; Nelidova, Dasha E.; Chen, Jing A.; Lim, Angela; Brebner, Alex; McGhee, Jennifer; Sherwin, Trevor; Green, Colin R.

    2014-03-10

    Cells thought to be stem cells isolated from the cornea of the eye have been shown to exhibit neurogenic potential. We set out to uncover the identity and location of these cells within the cornea and to elucidate their neuronal protein and gene expression profile during the process of switching to a neuron-like cell. Here we report that every cell of the adult human and rat corneal stroma is capable of differentiating into a neuron-like cell when treated with neurogenic differentiation specifying growth factors. Furthermore, the expression of genes regulating neurogenesis and mature neuronal structure and function was increased. The switch from a corneal stromal cell to a neuron-like cell was also shown to occur in vivo in intact corneas of living rats. Our results clearly indicate that lineage specifying growth factors can affect changes in the protein and gene expression profiles of adult cells, suggesting that possibly many adult cell populations can be made to switch into another type of mature cell by simply modifying the growth factor environment. - Highlights: • Adult corneal stromal cells can differentiated into neuron-like cells. • Neuronal specification of the adult stromal cell population is stochastic. • Neuronal specification in an adult cell population can be brought about by growth factors.

  9. Mitochondrial DNA (mtDNA) biogenesis: visualization and duel incorporation of BrdU and EdU into newly synthesized mtDNA in vitro.

    Science.gov (United States)

    Lentz, Stephen I; Edwards, James L; Backus, Carey; McLean, Lisa L; Haines, Kristine M; Feldman, Eva L

    2010-02-01

    Mitochondria are key regulators of cellular energy and are the focus of a large number of studies examining the regulation of mitochondrial dynamics and biogenesis in healthy and diseased conditions. One approach to monitoring mitochondrial biogenesis is to measure the rate of mitochondrial DNA (mtDNA) replication. We developed a sensitive technique to visualize newly synthesized mtDNA in individual cells to study mtDNA replication within subcellular compartments of neurons. The technique combines the incorporation of 5-bromo-2-deoxyuridine (BrdU) and/or 5-ethynyl-2'-deoxyuridine (EdU) into mtDNA, together with a tyramide signal amplification protocol. Employing this technique, we visualized and measured mtDNA biogenesis in individual cells. The labeling procedure for EdU allows for more comprehensive results by allowing the comparison of its incorporation with other intracellular markers, because it does not require the harsh acid or enzyme digests necessary to recover the BrdU epitope. In addition, the utilization of both BrdU and EdU permits sequential pulse-chase experiments to follow the intracellular localization of mtDNA replication. The ability to quantify mitochondrial biogenesis provides an essential tool for investigating the alterations in mitochondrial dynamics involved in the pathogenesis of multiple cellular disorders, including neuropathies and neurodegenerative diseases. PMID:19875847

  10. Small GTPase Rab40c associates with lipid droplets and modulates the biogenesis of lipid droplets.

    Directory of Open Access Journals (Sweden)

    Ran Tan

    Full Text Available The subcellular location and cell biological function of small GTPase Rab40c in mammalian cells have not been investigated in detail. In this study, we demonstrated that the exogenously expressed GFP-Rab40c associates with lipid droplets marked by neutral lipid specific dye Oil red or Nile red, but not with the Golgi or endosomal markers. Further examination demonstrated that Rab40c is also associated with ERGIC-53 containing structures, especially under the serum starvation condition. Rab40c is increasingly recruited to the surface of lipid droplets during lipid droplets formation and maturation in HepG2 cells. Rab40c knockdown moderately decreases the size of lipid droplets, suggesting that Rab40c is involved in the biogenesis of lipid droplets. Stimulation for adipocyte differentiation increases the expression of Rab40c in 3T3-L1 cells. Rab40c interacts with TIP47, and is appositionally associated with TIP47-labeled lipid droplets. In addition, over-expression of Rab40c causes the clustering of lipid droplets independent of its GTPase activity, but completely dependent of the intact SOCS box domain of Rab40c. In addition, Rab40c displayed self-interaction as well as interaction with TIP47 and the SOCS box is essential for its ability to induce clustering of lipid droplets. Our results suggest that Rab40c is a novel Rab protein associated with lipid droplets, and is likely involved in modulating the biogenesis of lipid droplets.

  11. Phosphorylation-dependent 14-3-3 protein interactions regulate CFTR biogenesis.

    Science.gov (United States)

    Liang, Xiubin; Da Paula, Ana Carina; Bozóky, Zoltán; Zhang, Hui; Bertrand, Carol A; Peters, Kathryn W; Forman-Kay, Julie D; Frizzell, Raymond A

    2012-03-01

    Cystic fibrosis transmembrane conductance regulator (CFTR) is a cAMP/protein kinase A (PKA)-regulated chloride channel whose phosphorylation controls anion secretion across epithelial cell apical membranes. We examined the hypothesis that cAMP/PKA stimulation regulates CFTR biogenesis posttranslationally, based on predicted 14-3-3 binding motifs within CFTR and forskolin-induced CFTR expression. The 14-3-3β, γ, and ε isoforms were expressed in airway cells and interacted with CFTR in coimmunoprecipitation assays. Forskolin stimulation (15 min) increased 14-3-3β and ε binding to immature and mature CFTR (bands B and C), and 14-3-3 overexpression increased CFTR bands B and C and cell surface band C. In pulse-chase experiments, 14-3-3β increased the synthesis of immature CFTR, reduced its degradation rate, and increased conversion of immature to mature CFTR. Conversely, 14-3-3β knockdown decreased CFTR B and C bands (70 and 55%) and elicited parallel reductions in cell surface CFTR and forskolin-stimulated anion efflux. In vitro, 14-3-3β interacted with the CFTR regulatory region, and by nuclear magnetic resonance analysis, this interaction occurred at known PKA phosphorylated sites. In coimmunoprecipitation assays, forskolin stimulated the CFTR/14-3-3β interaction while reducing CFTR's interaction with coat protein complex 1 (COP1). Thus 14-3-3 binding to phosphorylated CFTR augments its biogenesis by reducing retrograde retrieval of CFTR to the endoplasmic reticulum. This mechanism permits cAMP/PKA stimulation to make more CFTR available for anion secretion.

  12. An Atypical Acidophil Cell Line Tumor Showing Focal Differentiation Toward Both Growth Hormone and Prolactin Cells.

    Science.gov (United States)

    Naritaka, Heiji; Kameya, Toru; Sato, Yuichi; Furuhata, Shigeru; Okui, Junichi; Kamiguchi, Yuji; Otani, Mitsuhiro; Toya, Shigeo

    1995-01-01

    We report a case of giant pituitary adenoma in a child. Computerized tomography (CT) scan revealed a suprasellar extension tumor mass with hydrocephalus. There was no clinical evidence of acromegaly, gigantism, and other hormonal symptoms. Endocrinologic studies showed within normal value of serum growth hormone (GH: 4.2 ng/mL) and slightly increased levels of prolactin (PRL: 78 ng/mL) and other pituitary hormone values were within normal range. On suppression test by bromocryptin, both GH and PRL levels were reduced. Histopathological findings revealed that the tumor consisted of predominantly chromophobic and partly eosinophilic adenoma cells. Immunohistochemical staining detected GH and PRL in a small number of distinctly different adenoma cells, respectively. Nonradioactive in situ hybridization (ISH) also showed GH and PRL mRNA expression in identical immunopositive cells. Electron microscopy (EM) demonstrated adenoma cells with moderate or small numbers of two types of dense granules and without fibrous body which are characteristic of sparsely granulated GH-cell adenomas. The adenoma does not fit into any classification but may be an atypical acidophil cell line tumor showing focal differentiation toward both GH and PRL cells. PMID:12114745

  13. Inducing effects of hepatocyte growth factor on the expression of vascular endothelial growth factor in human colorectal carcinoma cells through MEK and PI3K signaling pathways

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu-hua; WEI Wei; XU Hao; WANG Yan-yan; WU Wen-xi

    2007-01-01

    Background Vascular endothelial growth factor plays a key role in human colorectal carcinoma invasion and metastasis. However, the regulation mechanism remains unknown. Recent studies have shown that several cytokines can regulate the expression of vascular endothelial growth factor in tumor cells. In this study, we investigated whether hepatocyte growth factor can regulate the expression of vascular endothelial growth factor in colorectal carcinoma cells.Methods Hepatocyte growth factor and vascular endothelial growth factor in human serum were measured by ELISA.The mRNA level of vascular endothelial growth factor was analyzed by reverse transcription-PCR. Western blot assay was performed to evaluate levels of c-Met and several other proteins involved in the MAPK and PI3K signaling pathways in colorectal carcinoma cells.Results Serum hepatocyte growth factor and vascular endothelial growth factor were significantly increased in colorectal carcinoma subjects. In vitro extraneous hepatocyte growth factor markedly increased protein and mRNA levels of vascular endothelial growth factor in colorectal carcinoma cells. Hepatocyte growth factor induced phosphorylation of c-Met, ERK1/2 and AKT in a dose-dependent manner. Specific inhibitors on MEK and PI3K inhibited the hepatocyte growth factor-induced expression of vascular endothelial growth factor in colorectal carcinoma cells.Conclusion This present study indicates that hepatocyte growth factor upregulates the expression of vascular endothelial growth factor in colorectal carcinoma cells via the MEK/ERK and PI3K/AKT signaling pathways.

  14. Mitochondrial biogenesis of astrocytes is increased under experimental septic conditions

    Institute of Scientific and Technical Information of China (English)

    Wang Yang; Chen Zhijiang; Zhang Yu; Fang Suzhen; Zeng Qiyi

    2014-01-01

    Background Mitochondrial dysfunction has been reported to be one of the contributing factors of sepsis-associated encephalopathy (SAE).Mitochondrial biogenesis controls mitochondrial homeostasis and responds to changes in cellular energy demand.In addition,it is enhanced or decreased due to mitochondrial dysfunction during SAE.The aim of this study was to explore the changes of mitochondrial biogenesis of astrocytes under septic conditions.Methods Lipopolysaccharide (LPS; 50 ng/ml) and interferon-γ (IFN-γ; 200 U/ml) were incubated with astrocytes to model the effects of a septic insult on astrocytes in vitro.The mitochondrial ultrastructure and volume density were evaluated by transmission electron microscopy.Intracellular adenosine triphosphate (ATP) levels were detected by the firefly luciferase system.The expression of protein markers of mitochondrial biogenesis and the binding ability of mitochondrial transcription factor A (TFAM) were determined by western blot and electrophoretic mobility shift assays,respectively.The mitochondrial DNA (mtDNA) content was detected by real-time polymerase chain reaction.Results The number of mildly damaged mitochondria was found to be significantly greater after treatment for 6 hours,as compared with at 0 hour (P<0.05).The mitochondrial volume density was significantly elevated at 24 hours,as compared with at 0 hour (P<0.05).The ATP levels at 6 hours,12 hours,and 24 hours were significantly greater than those at 0 hour (P<0.05).The protein markers of mitochondrial biogenesis were significantly increased at 6 hours and 12 hours,as compared with at 0 hour (P<0.05).The TFAM binding activity was not significantly changed among the four time points analyzed.The mtDNA contents were significantly increased at 12 hours and 24 hours,as compared with at 0 hour (P<0.05).Conclusions Under septic conditions,mitochonddal biogenesis of astrocytes increased to meet the high-energy demand and to promote mitochondrial recovery

  15. Identification and Characterization of the Nickel Uptake System for Urease Biogenesis in Streptococcus salivarius 57.I

    Science.gov (United States)

    Chen, Yi-Ywan M.; Burne, Robert A.

    2003-01-01

    Ureases are multisubunit enzymes requiring Ni2+ for activity. The low pH-inducible urease gene cluster in Streptococcus salivarius 57.I is organized as an operon, beginning with ureI, followed by ureABC (structural genes), and ureEFGD (accessory genes). Urease biogenesis also requires a high-affinity Ni2+ uptake system. By searching the partial genome sequence of a closely related organism, Streptococcus thermophilus LMG18311, three open reading frame (ORFs) homologous to those encoding proteins involved in cobalamin biosynthesis and cobalt transport (cbiMQO) were identified immediately 3′ to the ure operon. To determine whether these genes were involved in urease biogenesis by catalyzing Ni2+ uptake in S. salivarius, regions 3′ to ureD were amplified by PCRs from S. salivarius by using primers identical to the S. thermophilus sequences. Sequence analysis of the products revealed three ORFs. Reverse transcriptase PCR was used to demonstrate that the ORFs are transcribed as part of the ure operon. Insertional inactivation of ORF1 with a polar kanamycin marker completely abolished urease activity and the ability to accumulate 63Ni2+ during growth. Supplementation of the growth medium with NiCl2 at concentrations as low as 2.5 μM partially restored urease activity in the mutant. Both wild-type and mutant strains showed enhanced urease activity when exogenous Ni2+ was provided at neutral pH. Enhancement of urease activity by adding nickel was regulated at the posttranslational level. Thus, ORF1, ORF2, and ORF3 are part of the ure operon, and these genes, designated ureM, ureQ, and ureO, respectively, likely encode a Ni2+-specific ATP-binding cassette transporter. PMID:14617641

  16. Effects of Basic Fibroblast Growth Factor and Insulin-like Growth Factor on Cultured Cartilage Cells from Skate Raja porasa

    Institute of Scientific and Technical Information of China (English)

    樊廷俊; 晋凌云; 汪小锋

    2003-01-01

    Effects of basic fibroblast growth factor (bFGF) and insulin-like growth factor II (IGF-II) on cartilage cells from proboscis of skate, Raja porasa Günther, were investigated in this study. The cartilage cells were cultured in 20% FBS-supplemented MEM medium at 24℃. Twelve hours after culture initiation, the cartilage cells were treated with bFGF and IGF-II at different concentration combinations. It was found that 20 ng/ml of bFGF or 80 ng/ml of IGF-II was enough to have obvious stimulating effect on the growth and division of skate cartilage cells. Test of bFGF and IGF-II together, revealed that 20 ng/ml of bFGF and 80 ng/ml of IGF-II together had the best stimulating effect on the growth and division of skate cartilage cells. The cartilage cells cultured could form a monolayer at day 7.

  17. MicroRNAs in neural cell development and brain diseases.

    Science.gov (United States)

    Feng, Wei; Feng, Yue

    2011-12-01

    MicroRNAs play important roles in post-transcriptional regulation of gene expression by inhibiting protein translation and/or promoting mRNA degradation. Importantly, biogenesis of microRNAs displays specific temporal and spatial profiles in distinct cell and tissue types and hence affects a broad spectrum of biological functions in normal cell growth and tumor development. Recent discoveries have revealed sophisticated mechanisms that control microRNA production and homeostasis in response to developmental and extracellular signals. Moreover, a link between dysregulation of microRNAs and human brain disorders has become increasingly evident. In this review, we focus on recent advances in understanding the regulation of microRNA biogenesis and function in neuronal and glial development in the mammalian brain, and dysregulation of the microRNA pathway in neurodevelopmental and neurodegenerative diseases.

  18. Transfection of gene Livin α/β into A549 cells and separate effect on the cell growth

    Institute of Scientific and Technical Information of China (English)

    SUN Jian-guo; LIAO Rong-xia; CHEN Zheng-tang; WANG Zhi-xin; ZHANG Qing; HU Yi-de; WANG Dong-lin

    2005-01-01

    Objective:To express two Livin isoforms (Livin α & β genes) with transfection techniques in A549 cell line respectively in order to observe their effect on growth of cell line. Methods:Two eukaryotic expression vectors of Livin, pcDNA3.1-Livin α & β, were transfected into A549 cell line by electroporation. Then G418-resistant clones were screened. RT-PCR, Northern blot and immunofluorescence cytochemistry were used to detect Livin α & β expression level in the transfected cells. Finally, observation of cell morphology, growth curve assay and colony formation analysis were performed to explore the effect of Livin on growth of the cells. Results:Livin α & β were expressed in transfected A549 cells, and induced a faster cell growth, shorter doubling time and stronger cell colony forming ability, yet had no morphology change.Conclusion:Both isoforms can accelerate the growth of A549 cells, indicating a close relationship between Livin expression and the genesis and development of lung cancer. The expression of Livin α & β in A549 cells provides basis for further study of their different biological functions of anti-apoptosis and of their role in lung cancer cell resistance to radiotherapy and chemotherapy.

  19. Increasing cell culture population doublings for long-term growth of finite life span human cell cultures

    Energy Technology Data Exchange (ETDEWEB)

    Stampfer, Martha R.; Garbe, James C.

    2016-06-28

    Cell culture media formulations for culturing human epithelial cells are herein described. Also described are methods of increasing population doublings in a cell culture of finite life span human epithelial cells and prolonging the life span of human cell cultures. Using the cell culture media disclosed alone and in combination with addition to the cell culture of a compound associated with anti-stress activity achieves extended growth of pre-stasis cells and increased population doublings and life span in human epithelial cell cultures.

  20. Increasing cell culture population doublings for long-term growth of finite life span human cell cultures

    Energy Technology Data Exchange (ETDEWEB)

    Stampfer, Martha R; Garbe, James C

    2015-02-24

    Cell culture media formulations for culturing human epithelial cells are herein described. Also described are methods of increasing population doublings in a cell culture of finite life span human epithelial cells and prolonging the life span of human cell cultures. Using the cell culture media disclosed alone and in combination with addition to the cell culture of a compound associated with anti-stress activity achieves extended growth of pre-stasis cells and increased population doublings and life span in human epithelial cell cultures.

  1. Expression of growth factor receptors and targeting of EGFR in cholangiocarcinoma cell lines

    International Nuclear Information System (INIS)

    Cholangiocarcinoma (CC) is a malignant neoplasm of the bile ducts or the gallbladder. Targeting of growth factor receptors showed therapeutic potential in palliative settings for many solid tumors. The aim of this study was to determine the expression of seven growth factor receptors in CC cell lines and to assess the effect of blocking the EGFR receptor in vitro. Expression of EGFR (epithelial growth factor receptor), HGFR (hepatocyte growth factor receptor) IGF1R (insulin-like growth factor 1 receptor), IGF2R (insulin-like growth factor 2 receptor) and VEGFR1-3 (vascular endothelial growth factor receptor 1-3) were examined in four human CC cell lines (EGI-1, HuH28, OZ and TFK-1). The effect of the anti-EGFR-antibody cetuximab on cell growth and apoptosis was studied and cell lines were examined for KRAS mutations. EGFR, HGFR and IGFR1 were present in all four cell lines tested. IGFR2 expression was confirmed in EGI-1 and TFK-1. No growth-inhibitory effect was found in EGI-1 cells after incubation with cetuximab. Cetuximab dose-dependently inhibited growth in TFK-1. Increased apoptosis was only seen in TFK-1 cells at the highest cetuximab dose tested (1 mg/ml), with no dose-response-relationship at lower concentrations. In EGI-1 a heterozygous KRAS mutation was found in codon 12 (c.35G>A; p.G12D). HuH28, OZ and TFK-1 lacked KRAS mutation. CC cell lines express a pattern of different growth receptors in vitro. Growth factor inhibitor treatment could be affected from the KRAS genotype in CC. The expression of EGFR itself does not allow prognoses on growth inhibition by cetuximab

  2. Evidence for osmoregulation of cell growth and buoyant density in Escherichia coli.

    OpenAIRE

    Baldwin, W W; Kubitschek, H. E.

    1984-01-01

    The buoyant density of cells of Escherichia coli B/r NC32 increased with the osmolarity of the growth medium. Growth rate and its variability were also dependent upon the osmolarity of the medium. Maximum growth rates and minimum variability of these rates were obtained in Luria broth by addition of NaCl to a concentration of about 0.23 M.

  3. Growth factors have a protective effect on neomycin-induced hair cell loss.

    Science.gov (United States)

    Lou, Xiangxin; Yuan, Huihua; Xie, Jing; Wang, Xianliu; Yang, Liangliang; Zhang, Yanzhong

    2015-01-01

    We have demonstrated that selected growth factors are involved in regulating survival and proliferation of progenitor cells derived from the neonatal rat organ of Corti (OC). The protective and regenerative effects of these defined growth factors on the injured organ of Corti were therefore investigated. The organ of Corti dissected from the Wistar rat pups (P3-P5) was split into apical, middle, and basal parts, explanted and cultured with or without neomycin and growth factors. Insulin-like growth factor-1 (IGF-1), fibroblast growth factor-2 (FGF-2), and epidermal growth factor (EGF) protected the inner hair cells (IHCs) and outer hair cells (OHCs) from neomycin ototoxicity. Using EGF, IGF-1, and FGF-2 alone induced no protective effect on the survival of auditory hair cells. Combining 2 growth factors (EGF + IGF-1, EGF + FGF-2, or IGF-1 + FGF-2) gave statistically protective effects. Similarly, combining all three growth factors effectively protected auditory hair cells from the ototoxic insult. None of the growth factors induced regeneration of hair cells in the explants injured with neomycin. Thus various combinations of the three defined factors (IGF-1, FGF-2, and EGF) can protect the auditory hair cells from the neomycin-induced ototoxic damage, but no regeneration was seen. This offers a possible novel approach to the treatment of hearing loss.

  4. Rice Coleoptile Growth under Water and in Air-Possible Effect of Buoyancy on Growth and Cell Walls

    OpenAIRE

    Kah-Siew, Tan; Takayuki, Hoson; Seiichiro, Kamisaka; Yoshio, Masuda

    1992-01-01

    Maximum growth was achieved in rice coleoptiles (Oryza sativa L. cv. Sasanishiki) grown under water; they reached maximum length of 81.2 mm on day 5. The maximum length of coleoptiles grown in air or under water with air bubbling was 12.4 mm and 23.5 mm in day 5,respectively. Differences in coleoptile growth between air bubbling and air conditions, namely approximately 11 mm at day 5,could be due to buoyancy effect under water. Promoted growth under water was due to a decrease in cell wall ex...

  5. GROWTH AND METABOLISM OF INDIVIDUAL BACTERIAL CELLS UTILIZING NANOSIMS

    Energy Technology Data Exchange (ETDEWEB)

    NEALSON, H. K.

    2007-08-03

    This work involved the use of the Nano-SIMS Instrument at Lawrence Livermore Laboratory, in an effort to utilize this unique tool for experiments in Biology. The work consisted primarily of experiments to measure in real time, C and N fixation in cyanobacteria. The work revealed a number of the difficulties in using the nano-SIMS approach with biological material, but with collaboration from a number of individuals at USC and LLNL, major progress was made. The collaborators from LLNL were from the Chemistry Group (Dr. Peter Weber), and the Biology Group (Dr. Jennifer Pett-Ridge). In addition, there were a number of other scientists involved from LLNL. The USC group consisted of Dr. K.H. Nealson, the PI on the grant, Dr. R. Popa, a postdoctoral fellow and research associate at USC, Professor Douglas Capone, and Juliet Finze, a graduate student in biology. Two major experiments were done, both of which yielded new and exciting data. (1) We studied nitrogen and carbon fixation in Anabaena, demonstrating that fixation ofN occurred rapidly in the heterocysts, and that the fixed N was transported rapidly and completely to the vegetative cells. C fixation occurred in the vegetative cells, with labeled C remaining in these cells in support of their growth and metabolism. This work was accepted in the ISME Journal (Nature Publication), and published last month. (2) We studied nitrogen and carbon fixation in Trichodesmium, a non-heterocystous cyanobacterium that also fixes nitrogen. Interestingly, the nitrogen fixation was confined to regions within the filaments that seem to be identical to the so-called cyanophycaen granules. The fixed N is then transported to other parts of the cyanobacterium, as judged by movement of the heavy N throughout the filaments. On the basis of these very exciting results, we have applied for funding from the NSF to continue the collaboration with LLNL. The results of both studies were presented in the summer of 2007 at the Gordon Research

  6. Role of CBCA in RNA biogenesis

    DEFF Research Database (Denmark)

    Iasillo, Claudia

    2016-01-01

    the nuclear Cap Binding Complex (CBC). This thesis focuses on the protein ARS2, which binds the CBC to form the CBCA complex. CBCA can further associate with different proteins playing different roles in RNA metabolism. For example, CBCA binds the Nuclear Exosome Targeting Complex (NEXT), which...... is an interactor of the RNA exosome, the main nuclear RNA degradation machinery. Through this binding, CBCA is involved in the degradation of some non-functional RNAs which are exosome targets. In addition, CBCA also promotes the transcription termination at some gene 3’ ends. Therefore, the study of the CBCA......- and exosome-depleted cells, to assess the specific role of those factors in RNAPII transcription. The results confirm a specific genome-wide role of ARS2 in transcription termination of specific gene classes. Interestingly, the results indicate a new role for ARS2 in the early stages of protein coding gene...

  7. A single dividing cell population with imbalanced fate drives oesophageal tumour growth.

    Science.gov (United States)

    Frede, Julia; Greulich, Philip; Nagy, Tibor; Simons, Benjamin D; Jones, Philip H

    2016-09-01

    Understanding the cellular mechanisms of tumour growth is key for designing rational anticancer treatment. Here we used genetic lineage tracing to quantify cell behaviour during neoplastic transformation in a model of oesophageal carcinogenesis. We found that cell behaviour was convergent across premalignant tumours, which contained a single proliferating cell population. The rate of cell division was not significantly different in the lesions and the surrounding epithelium. However, dividing tumour cells had a uniform, small bias in cell fate so that, on average, slightly more dividing than non-dividing daughter cells were generated at each round of cell division. In invasive cancers induced by Kras(G12D) expression, dividing cell fate became more strongly biased towards producing dividing over non-dividing cells in a subset of clones. These observations argue that agents that restore the balance of cell fate may prove effective in checking tumour growth, whereas those targeting cycling cells may show little selectivity. PMID:27548914

  8. Pharmacological targeting of the KIT growth factor receptor: a therapeutic consideration for mast cell disorders

    DEFF Research Database (Denmark)

    Jensen, Bettina Margrethe; Akin, C; Gilfillan, A M

    2008-01-01

    KIT is a member of the tyrosine kinase family of growth factor receptors which is expressed on a variety of haematopoietic cells including mast cells. Stem cell factor (SCF)-dependent activation of KIT is critical for mast cell homeostasis and function. However, when KIT is inappropriately activa...

  9. FEM simulations and experimental studies of the temperature field in a large diamond crystal growth cell

    Institute of Scientific and Technical Information of China (English)

    Li Zhan-Chang; Jia Xiao-Peng; Huang Guo-Feng; Hu Mei-Hua; Li Yong; Yan Bing-Min; Ma Hong-An

    2013-01-01

    We investigate the temperature field variation in the growth region of a diamond crystal in a sealed cell during the whole process of crystal growth by using the temperature gradient method (TGM) at high pressure and high temperature (HPHT).We employ both the finite element method (FEM) and in situ experiments.Simulation results show that the temperature in the center area of the growth cell continues to decrease during the process of large diamond crystal growth.These results are in good agreement with our experimental data,which demonstrates that the finite element model can successfully predict the temperature field variations in the growth cell.The FEM simulation will be useful to grow larger high-quality diamond crystal by using the TGM.Furthermore,this method will be helpful in designing better cells and improving the growth process of gem-quality diamond crystal.

  10. FEM simulations and experimental studies of the temperature field in a large diamond crystal growth cell

    International Nuclear Information System (INIS)

    We investigate the temperature field variation in the growth region of a diamond crystal in a sealed cell during the whole process of crystal growth by using the temperature gradient method (TGM) at high pressure and high temperature (HPHT). We employ both the finite element method (FEM) and in situ experiments. Simulation results show that the temperature in the center area of the growth cell continues to decrease during the process of large diamond crystal growth. These results are in good agreement with our experimental data, which demonstrates that the finite element model can successfully predict the temperature field variations in the growth cell. The FEM simulation will be useful to grow larger high-quality diamond crystal by using the TGM. Furthermore, this method will be helpful in designing better cells and improving the growth process of gem-quality diamond crystal. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  11. The FGFR/MEK/ERK/brachyury pathway is critical for chordoma cell growth and survival

    Science.gov (United States)

    Hu, Yunping; Mintz, Akiva; Shah, Sagar R.; Quinones-Hinojosa, Alfredo; Hsu, Wesley

    2014-01-01

    Recent evidence suggests that the expression of brachyury is necessary for chordoma growth. However, the mechanism associated with brachyury-regulated cell growth is poorly understood. Fibroblast growth factor (FGF), a regulator of brachyury expression in normal tissue, may also play an important role in chordoma pathophysiology. Using a panel of chordoma cell lines, we explored the role of FGF signaling and brachyury in cell growth and survival. Western blots showed that all chordoma cell lines expressed fibroblast growth factor receptor 2 (FGFR2), FGFR3, mitogen-activated protein kinase kinase (MEK) and extracellular signal-regulated kinase (ERK), whereas no cell lines expressed FGFR1 and FGFR4. Results of enzyme-linked immunosorbent assay indicated that chordoma cells produced FGF2. Neutralization of FGF2 inhibited MEK/ERK phosphorylation, decreased brachyury expression and induced apoptosis while reducing cell growth. Activation of the FGFR/MEK/ERK/brachyury pathway by FGF2-initiated phosphorylation of FGFR substrate 2 (FRS2)-α (Tyr196) prevented apoptosis while promoting cell growth and epithelial-mesenchymal transition (EMT). Immunofluorescence staining showed that FGF2 promoted the translocation of phosphorylated ERK to the nucleus and increased brachyury expression. The selective inhibition of FGFR, MEK and ERK phosphorylation by PD173074, PD0325901 and PD184352, respectively, decreased brachyury expression, induced apoptosis, and inhibited cell growth and EMT. Moreover, knockdown of brachyury by small hairpin RNA reduced FGF2 secretion, inhibited FGFR/MEK/ERK phosphorylation and blocked the effects of FGF2 on cell growth, apoptosis and EMT. Those findings highlight that FGFR/MEK/ERK/brachyury pathway coordinately regulates chordoma cell growth and survival and may represent a novel chemotherapeutic target for chordoma. PMID:24445144

  12. Inhibition of connective tissue growth factor overexpression decreases growth of hepatocellular carcinoma cells in vitro and in vivo

    Institute of Scientific and Technical Information of China (English)

    JIA Xiao-qin; CHENG Hai-qing; LI Hong; ZHU Yan; LI Yu-hua; FENG Zhen-qing; ZHANG Jian-ping

    2011-01-01

    Background We have previously found that connective tissue growth factor (CTGF) is highly expressed in a rat model of liver cancer.Here,we examined expression of CTGFin human hepatocellular carcinoma (HCC) cells and its effect on cell growth.Methods Real-time PCR was used to observe expression of CTGF in human HCC cell lines HepG2,SMMC-7721,MHCC-97H and LO2.siRNA for the CTGFgene was designed,synthesized and cloned into a Plk0.1-GFP-SP6 vector to construct a lentivirus-mediated shRNA/CTGF.CTGF mRNA and protein expression in HepG2 cells treated by CTGF-specific shRNA was evaluated by real-time PCR and Western blotting.3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was utilized to evaluate the growth effect,and a colony formation assay was used for observing clonogenic growth.In vivo,tumor cell proliferation was evaluated in a nude mouse model of xenotransplantation.Statistical significance was determined by t test for comparison between two groups,or analysis of variance (ANOVA) for multiple groups.Results Immunohistochemical staining of CTGF was seen in 35 of 40 HCC samples (87.5%).CTGF was overexpressed 5-fold in 20 HCC tissues,compared with surrounding non-tumor liver tissue.CTGF mRNA level was 5-8-fold higher in HepG2,SMMC-7721 and MHCC-97H than in LO2 cells.This indicated that the inhibition rate of cell growth was 43% after knockdown of CTGF expression (P <0.05).Soft agar colony formation assay showed that siRNA mediated knockdown of CTGF inhibited colony formation in soft agar of HepG2 cells (P <0.05).The volume of tumors from CTGF-shRNA-expressing cells only accounted for 35% of the tumors from the scrambled control-infected HepG2 cells (P <0.05).Conclusions CTGF was overexpressed in human HCC cells and downregulation of CTGF inhibited HCC growth in vitro and in vivo.Knockdown of CTGF may be a potential therapeutic strategy for treatment of HCC.

  13. Inhibition of human gastric carcinoma cell growth by atofluding derivative N3-o-toluyl-fluorouracil

    Institute of Scientific and Technical Information of China (English)

    Jian Liu; Wei Tang; Xian-Jun Qu; Wen-Fang Xu; Shu-Xiang Cui; Yong Zhou; Yun-Xia Yuan; Ming-Hui Chen; Ruo-Han Wang; Ruo-Yan Gai; Masatoshi Makuuchi

    2006-01-01

    AIM:To evaluate the growth inhibition efficacy of atofluding derivative N3-o-toluyl-fluorouracil (TFU)on human gastric carcinoma cell lines SGC-7901 and MKN-45.METHODS:Cell growth inhibition by TFU was measured by MTT and clonogenic assays without or with liver microsomal enzymes. Xenografts of cancer cells in nude mice were employed to study the anti-proliferative effects of TFU in vivo,RESULTS:TFU inhibited the growth of SGC-7901 and MKN-45 cells. However, the inhibitory effects of TFU on cell growth were not significant. The inhibition rates were enhanced in the presence of liver microsomal enzymes, ranging 4.73%-48.57% in SGC-7901 cells and 9.0%-62.02% in MKN-45 cells. In vivo, TFU delayed the growth of SGC-7901 and MKN-45 cells in nude mice. The inhibition rates were 40.49%, 63.24%, and 75.98% in SGC-7901 cells and 40.76%, 61.41%, and 82.07% in MKN-45 cells when the oral doses were 25, 50, and 100 mg/kg, respectively. TFU treatment was generally well tolerated by mice with less than 20% reduction in body weight.CONCLUSION:TFU inhibits the growth of human gastric carcinoma cells. The inhibition rates are increased in the presence of liver microsomal enzymes. The efficacy of TFU may be associated with the sustaining release of 5-fluorouracil (5-FU) mediated by the enzymes.

  14. Correlation between dielectric property by dielectrophoretic levitation and growth activity of cells exposed to electric field.

    Science.gov (United States)

    Hakoda, Masaru; Hirota, Yusuke

    2013-09-01

    The purpose of this study is to develop a system analyzing cell activity by the dielectrophoresis method. Our previous studies revealed a correlation between the growth activity and dielectric property (Re[K(ω)]) of mouse hybridoma 3-2H3 cells using dielectrophoretic levitation. Furthermore, it was clarified that the differentiation activity of many stem cells could be evaluated by the Re[K(ω)] without differentiation induction. In this paper, 3-2H3 cells exposed to an alternating current (AC) electric field or a direct current (DC) electric field were cultivated, and the influence of damage by the electric field on the growth activity of the cells was examined. To evaluate the activity of the cells by measuring the Re[K(ω)], the correlation between the growth activity and the Re[K(ω)] of the cells exposed to the electric field was examined. The relations between the cell viability, growth activity, and Re[K(ω)] in the cells exposed to the AC electric field were obtained. The growth activity of the cells exposed to the AC electric field could be evaluated by the Re[K(ω)]. Furthermore, it was found that the adverse effects of the electric field on the cell viability and the growth activity were smaller in the AC electric field than the DC electric field.

  15. c-myb stimulates cell growth by regulation of insulin-like growth factor (IGF) and IGF-binding protein-3 in K562 leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min-Sun; Kim, Sun-Young; Arunachalam, Sankarganesh [Department of Pediatrics, School of Medicine, Chonbuk National University, Jeonju 561-712 (Korea, Republic of); Hwang, Pyoung-Han [Department of Pediatrics, School of Medicine, Chonbuk National University, Jeonju 561-712 (Korea, Republic of); Research Institute of Clinical Medicine, School of Medicine, Chonbuk National University, Jeonju 561-712 (Korea, Republic of); Yi, Ho-Keun [Department of Biochemistry, School of Dentistry, Chonbuk National University, Jeonju 561-712 (Korea, Republic of); Nam, Sang-Yun [Department of Alternative Therapy, School of Alternative Medicine and Health Science, Jeonju University, Jeonju 561-712 (Korea, Republic of); Lee, Dae-Yeol, E-mail: leedy@chonbuk.ac.kr [Department of Pediatrics, School of Medicine, Chonbuk National University, Jeonju 561-712 (Korea, Republic of); Research Institute of Clinical Medicine, School of Medicine, Chonbuk National University, Jeonju 561-712 (Korea, Republic of)

    2009-07-17

    c-myb plays an important role in the regulation of cell growth and differentiation, and is highly expressed in immature hematopoietic cells. The human chronic myelogenous leukemia cell K562, highly expresses IGF-I, IGF-II, IGF-IR, and IGF-induced cellular proliferation is mediated by IGF-IR. To characterize the impact of c-myb on the IGF-IGFBP-3 axis in leukemia cells, we overexpressed c-myb using an adenovirus gene transfer system in K562 cells. The overexpression of c-myb induced cell proliferation, compared to control, and c-myb induced cell growth was inhibited by anti-IGF-IR antibodies. c-myb overexpression resulted in a significant increase in the expression of IGF-I, IGF-II, and IGF-IR, and a decrease in IGFBP-3 expression. By contrast, disruption of c-myb function by DN-myb overexpression resulted in significant reduction of IGF-I, IGF-II, IGF-IR, and elevation of IGFBP-3 expression. In addition, exogenous IGFBP-3 inhibited the proliferation of K562 cells, and c-myb induced cell growth was blocked by IGFBP-3 overexpression in a dose-dependent manner. The growth-promoting effects of c-myb were mediated through two major intracellular signaling pathways, Akt and Erk. Activation of Akt and Erk by c-myb was completely blocked by IGF-IR and IGFBP-3 antibodies. These findings suggest that c-myb stimulates cell growth, in part, by regulating expression of the components of IGF-IGFBP axis in K562 cells. In addition, disruption of c-myb function by DN-myb may provide a useful strategy for treatment of leukemia.

  16. Transactivation of the TIEG1 confers growth inhibition of transforming growth factor-β-susceptible hepatocellular carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Lei Jiang; Yiu-Kay Lai; Jin-Fang Zhang; Chu-Yan Chan; Gang Lu; Marie CM Lin; Ming-Liang He; Ji-Cheng Li; Hsiang-Fu Kung

    2012-01-01

    AIM:To investigate the role of transforming growth factor (TGF)-β-inducible early gene 1 (TIEG1) in TGF-β-induced growth inhibition in hepatocellular carcinoma (HCC) cells.METHODS:Human hepatocyte and HCC cell lines with varied susceptibilities to TGF-β1 were tested by methylthiazoletetrazolium (MTT) assay.The expression changes of Smad2,Smad3,Smad4,Smad7,TIEG1 and TIEG2 gene following treatment with TGF-β1 in a TGF-β-sensitive hepatocyte cell line (MIHA),a TGF-β-sensitive hepatoma cell line (Hep3B) and two TGF-β-insensitive hepatoma cell lines (HepG2 and Bel7404)were examined.SiRNA targeting TIEG1 was transfected into Hep3B cells and the sensitivity of cells to TGF-β1 was examined.Overexpression of TIEG1 was induced by lentiviral-mediated transduction in TGF-β1-resistant hepatoma cell lines (Bel7404 and HepG2).MTT assay and 4',6-Diamidino-2-phenylindole staining were used to identify cell viability and apoptosis,respectively.The expression level of stathmin was measured by reverse transcriptase polymerase chain reaction and Western-blotting analysis,and stathmin promoter activity by TIEG1 was monitored by a luciferase reporter gene system.RESULTS:TIEG1 was significantly upregulated by TGF-β1 in the TGF-β1-sensitive HCC cell line,Hep3B,but not in the resistant cell lines.The suppression of TIEG1 by siRNAs decreased the sensitivity of Hep3B cells to TGF-β1,whereas the overexpression of TIEG1 mediated growth inhibition and apoptosis in TGF-β1-resistant HCC cell lines,which resembled those of TGF-β1-sensitive HCC cells treated with TGF-β1.Our data further suggested that stathmin was a direct target of TIEG1,as stathmin was significantly downregulated by TIEG1 overexpression,and stathmin promoter activity was inhibited by TIEG1 in a dose-dependent manner.CONCLUSION:Our data suggest that transactivation of TIEG1 conferred growth inhibition of TGF-β-susceptible human HCC cells.

  17. Protein translocation and thylakoid biogenesis in cyanobacteria.

    Science.gov (United States)

    Frain, Kelly M; Gangl, Doris; Jones, Alexander; Zedler, Julie A Z; Robinson, Colin

    2016-03-01

    Cyanobacteria exhibit a complex form of membrane differentiation that sets them apart from most bacteria. Many processes take place in the plasma membrane, but photosynthetic light capture, electron transport and ATP synthesis take place in an abundant internal thylakoid membrane. This review considers how this system of subcellular compartmentalisation is maintained, and how proteins are directed towards the various subcompartments--specifically the plasma membrane, periplasm, thylakoid membrane and thylakoid lumen. The involvement of Sec-, Tat- and signal recognition particle- (SRP)-dependent protein targeting pathways is discussed, together with the possible involvement of a so-called 'spontaneous' pathway for the insertion of membrane proteins, previously characterised for chloroplast thylakoid membrane proteins. An intriguing aspect of cyanobacterial cell biology is that most contain only a single set of genes encoding Sec, Tat and SRP components, yet the proteomes of the plasma and thylakoid membranes are very different. The implications for protein sorting mechanisms are considered. This article is part of a Special Issue entitled Organization and dynamics of bioenergetic systems in bacteria, edited by Prof Conrad Mullineaux.

  18. Identification of nucleolus-localized PTEN and its function in regulating ribosome biogenesis.

    Science.gov (United States)

    Li, Pingdong; Wang, Danni; Li, Haiyang; Yu, Zhenkun; Chen, Xiaohong; Fang, Jugao

    2014-10-01

    The tumor suppressor PTEN is a lipid phosphatase that is found mutated in different types of human cancers. PTEN suppresses cell proliferation by inhibiting the PI3K-Akt signaling pathway at the cell membrane. However, PTEN is also demonstrated to localize in the cell nucleus where it exhibits tumor suppressive activity via a different, unknown mechanism. In this study we report that PTEN also localizes to the nucleolus and that nucleolar PTEN plays an important role in regulating nucleolar homeostasis and maintaining nucleolar morphology. Overexpression of nuclear PTEN in PTEN null cells inhibits Akt phosphorylation and reduces cell size. Knockdown of PTEN in PTEN positive cells leads to nucleolar morphologic changes and an increase in the proportion of cells with a greater number of nucleoli. In addition, knockdown of PTEN in PTEN positive cells increased ribosome biogenesis. These findings expand current understanding of function and relevance of nuclear localized PTEN and provide a foundation for the development of novel therapies targeting PTEN.

  19. Hormone activities and the cell cycle machinery in immunity-triggered growth inhibition.

    Science.gov (United States)

    Reitz, M U; Gifford, M L; Schäfer, P

    2015-04-01

    Biotic stress and diseases caused by pathogen attack pose threats in crop production and significantly reduce crop yields. Enhancing immunity against pathogens is therefore of outstanding importance in crop breeding. However, this must be balanced, as immune activation inhibits plant growth. This immunity-coupled growth trade-off does not support resistance but is postulated to reflect the reallocation of resources to drive immunity. There is, however, increasing evidence that growth-immunity trade-offs are based on the reconfiguration of hormone pathways, shared by growth and immunity signalling. Studies in roots revealed the role of hormones in orchestrating growth across different cell types, with some hormones showing a defined cell type-specific activity. This is apparently highly relevant for the regulation of the cell cycle machinery and might be part of the growth-immunity cross-talk. Since plants are constantly exposed to Immuno-activating microbes under agricultural conditions, the transition from a growth to an immunity operating mode can significantly reduce crop yield and can conflict our efforts to generate next-generation crops with improved yield under climate change conditions. By focusing on roots, we outline the current knowledge of hormone signalling on the cell cycle machinery to explain growth trade-offs induced by immunity. By referring to abiotic stress studies, we further introduce how root cell type-specific hormone activities might contribute to growth under immunity and discuss the feasibility of uncoupling the growth-immunity cross-talk.

  20. Growth

    Science.gov (United States)

    Waag, Andreas

    , molecular beam epitaxy (MBE) delivers high quality ZnMgO-ZnO quantum well structures. Other thin film techniques such as PLD or MOCVD are also widely used. The main problem at present is to consistently achieve reliable p-type doping. For this topic, see also Chap. 5. In the past years, there have been numerous publications on p-type doping of ZnO, as well as ZnO p-n junctions and light emitting diodes (LEDs). However, a lot of these reports are in one way or the other inconsistent or at least incomplete. It is quite clear from optical data that once a reliable hole injection can be achieved, high brightness ZnO LEDs should be possible. In contrast to that expectation, none of the LEDs reported so far shows efficient light emission, as would be expected from a reasonable quality ZnO-based LED. See also Chap. 13. As a matter of fact, there seems to be no generally accepted and reliable technique for p-type doping available at present. The reason for this is the unfavorable position of the band structure of ZnO relative to the vacuum level, with a very low lying valence band. See also Fig. 5.1. This makes the incorporation of electrically active acceptors difficult. Another difficulty is the huge defect density in ZnO. There are many indications that defects play a major role in transport and doping. In order to solve the doping problem, it is generally accepted that the quality of the ZnO material grown by the various techniques needs to be improved. Therefore, the optimization of ZnO epitaxy is thought to play a key role in the further development of this material system. Besides being used as an active material in optoelectronic devices, ZnO plays a major role as transparent contact material in thin film solar cells. Polycrystalline, heavily n-type doped ZnO is used for this, combining a high electrical conductivity with a good optical transparency. In this case, ZnO thin films are fabricated by large area growth techniques such as sputtering. For this and other

  1. Research on the Structure of Fish Collagen Nanofibers Influenced Cell Growth

    Directory of Open Access Journals (Sweden)

    Gang Zhou

    2013-01-01

    Full Text Available Electrospinning is highlighted in biomaterials field. The structures of nanofibers depend on various parameters, which are related closely to the bioactivity of biomaterials. The aim of this research is to analyze the structure of fish collagen nanofibers and to propose the new criterion for cell growth. This paper focused on the flow rate of solvent during the electrospinning. Through the cell culture, the relationship of the structure and cell growth is investigated. The results obtained in this study provide an understanding of the behaviors of cell growth under different structure of fish collagen nanofibers scaffold.

  2. Retinoic acid. Inhibition of the clonal growth of human myeloid leukemia cells.

    OpenAIRE

    Douer, D; Koeffler, H P

    1982-01-01

    Vitamin A and its analogues (retinoids) affect normal and malignant hematopoietic cells. We examined the effect of retinoids on the clonal growth in vitro of myeloid leukemia cells. Retinoic acid inhibited the clonal growth of the KG-1, acute myeloblastic leukemia, and the HL-60, acute promyelocytic leukemia, human cell lines. The KG-1 cells were extremely sensitive to retinoic acid, with 50% of the colonies inhibited by 2.4-nM concentrations of the drug. A 50% growth inhibition of HL-60 was ...

  3. Prolyl oligopeptidase inhibition-induced growth arrest of human gastric cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Kanayo [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Sakaguchi, Minoru, E-mail: sakaguti@gly.oups.ac.jp [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Tanaka, Satoshi [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Yoshimoto, Tadashi [Department of Life Science, Setsunan University, 17-8 Ikeda-Nakamachi, Neyagawa, Osaka 572-8508 (Japan); Takaoka, Masanori [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan)

    2014-01-03

    Highlights: •We examined the effects of prolyl oligopeptidase (POP) inhibition on p53 null gastric cancer cell growth. •POP inhibition-induced cell growth suppression was associated with an increase in a quiescent G{sub 0} state. •POP might regulate the exit from and/or reentry into the cell cycle. -- Abstract: Prolyl oligopeptidase (POP) is a serine endopeptidase that hydrolyzes post-proline peptide bonds in peptides that are <30 amino acids in length. We recently reported that POP inhibition suppressed the growth of human neuroblastoma cells. The growth suppression was associated with pronounced G{sub 0}/G{sub 1} cell cycle arrest and increased levels of the CDK inhibitor p27{sup kip1} and the tumor suppressor p53. In this study, we investigated the mechanism of POP inhibition-induced cell growth arrest using a human gastric cancer cell line, KATO III cells, which had a p53 gene deletion. POP specific inhibitors, 3-((4-[2-(E)-styrylphenoxy]butanoyl)-L-4-hydroxyprolyl)-thiazolidine (SUAM-14746) and benzyloxycarbonyl-thioprolyl-thioprolinal, or RNAi-mediated POP knockdown inhibited the growth of KATO III cells irrespective of their p53 status. SUAM-14746-induced growth inhibition was associated with G{sub 0}/G{sub 1} cell cycle phase arrest and increased levels of p27{sup kip1} in the nuclei and the pRb2/p130 protein expression. Moreover, SUAM-14746-mediated cell cycle arrest of KATO III cells was associated with an increase in the quiescent G{sub 0} state, defined by low level staining for the proliferation marker, Ki-67. These results indicate that POP may be a positive regulator of cell cycle progression by regulating the exit from and/or reentry into the cell cycle by KATO III cells.

  4. Biogenesis and Membrane Targeting of Lipoproteins.

    Science.gov (United States)

    Narita, Shin-Ichiro; Tokuda, Hajime

    2010-09-01

    Bacterial lipoproteins represent a unique class of membrane proteins, which are anchored to membranes through triacyl chains attached to the amino-terminal cysteine. They are involved in various functions localized in cell envelope. Escherichia coli possesses more than 90 species of lipoproteins, most of which are localized in the outer membrane, with others being in the inner membrane. All lipoproteins are synthesized in the cytoplasm with an N-terminal signal peptide, translocated across the inner membrane by the Sec translocon to the periplasmic surface of the inner membrane, and converted to mature lipoproteins through sequential reactions catalyzed by three lipoprotein-processing enzymes: Lgt, LspA, and Lnt. The sorting of lipoproteins to the outer membrane requires a system comprising five Lol proteins. An ATP-binding cassette transporter, LolCDE, initiates the sorting by mediating the detachment of lipoproteins from the inner membrane. Formation of the LolA-lipoprotein complex is coupled to this LolCDE-dependent release reaction. LolA accommodates the amino-terminal acyl chain of lipoproteins in its hydrophobic cavity, thereby generating a hydrophilic complex that can traverse the periplasmic space by diffusion. Lipoproteins are then transferred to LolB on the outer membrane and anchored to the inner leaflet of the outer membrane by the action of LolB. In contrast, since LolCDE does not recognize lipoproteins possessing Asp at position +2, these lipoproteins remain anchored to the inner membrane. Genes for Lol proteins are widely conserved among gram-negative bacteria, and Lol-mediated outer membrane targeting of lipoproteins is considered to be the general lipoprotein localization mechanism. PMID:26443779

  5. Cell growth stimulating effect of Ganoderma lucidum spores and their potential application for Chinese hamster ovary K1 cell cultivation.

    Science.gov (United States)

    Li, Ding; Zhong, Qi; Liu, Tingting; Wang, Jufang

    2016-06-01

    In this work, water-soluble extracts of Ganoderma lucidum spores (Gls), a Chinese medicinal herb that possesses cell growth stimulating function, were found to be an effective growth factor for Chinese hamster ovary (CHO) cell cultivation. The Gls extract was prepared and supplemented to CHO K1 cell culture media with various serum levels. Our results obtained from both the static culture and the spinner-flask suspension culture showed that use of small-amount Gls extract effectively promoted cell growth and suppressed cell apoptosis induced by serum deprivation with normal cell cycle maintained in a low-serum medium. The low-serum medium containing 1 % (v/v) fetal bovine serum (FBS) and 0.01 % (w/v) Gls extract showed a comparable performance on both cell growth and fusion protein productivity with the conventional CHO culture medium containing 10 % (v/v) FBS and a commercial serum-free medium. This is the first study of the potential of Gls extracts for use as an alternative cell growth factor and nutrient for CHO cells. The findings have presented a new approach to economic cultivation of CHO cells for therapeutic protein production.

  6. Cell growth stimulating effect of Ganoderma lucidum spores and their potential application for Chinese hamster ovary K1 cell cultivation.

    Science.gov (United States)

    Li, Ding; Zhong, Qi; Liu, Tingting; Wang, Jufang

    2016-06-01

    In this work, water-soluble extracts of Ganoderma lucidum spores (Gls), a Chinese medicinal herb that possesses cell growth stimulating function, were found to be an effective growth factor for Chinese hamster ovary (CHO) cell cultivation. The Gls extract was prepared and supplemented to CHO K1 cell culture media with various serum levels. Our results obtained from both the static culture and the spinner-flask suspension culture showed that use of small-amount Gls extract effectively promoted cell growth and suppressed cell apoptosis induced by serum deprivation with normal cell cycle maintained in a low-serum medium. The low-serum medium containing 1 % (v/v) fetal bovine serum (FBS) and 0.01 % (w/v) Gls extract showed a comparable performance on both cell growth and fusion protein productivity with the conventional CHO culture medium containing 10 % (v/v) FBS and a commercial serum-free medium. This is the first study of the potential of Gls extracts for use as an alternative cell growth factor and nutrient for CHO cells. The findings have presented a new approach to economic cultivation of CHO cells for therapeutic protein production. PMID:26921102

  7. Growth activity of epidermal cells from different parts of human body

    Institute of Scientific and Technical Information of China (English)

    CHAI Jia-ke; SHENG Zhi-yong; MA Zhong-feng; YANG Hong-ming; LIU Qiang; Liang Li-ming

    2007-01-01

    Background Most epidermal cells used in skin tissue engineering are obtained from the skins of fetuses or prepuces,which can not be widely used in culturing and transplanting autologous epidermis for patients with extensive burn wounds. To solve the problem, in this study, we cultured epidermal cells from different parts of human body in vitro, and detected their growth activity.Methods Normal epidermal cells obtained from the prepuce, scalp, and axilla of male patients, were cultured and passaged. Their growth characteristics including adherent rate and growth activity were compared. Data were analyzed by homogeneity test of variance.Results In primary culture, the growth of epidermal cells from the prepuce was significantly faster than that of the epidermal cells from the scalp and axilla. In the cells obtained from the prepuce, 80% confluence was achieved on day 12, while on day 16 and day 20 in the cells from the scalp and axilla, respectively. However, no significant difference was detected in their growth and proliferation in the second passage.Conclusions Although the growth of epidermal cells obtained from the scalp and axilla is slower than that from the prepuce in primary culture, stable cell line can be established and used in preparation of auto-epidermal grafts for patients with extensive burn wounds. Therefore, the scalp and axillary skin should be considered as important sources of epidermal cells other than the prepuce.

  8. Altered growth, differentiation, and responsiveness to epidermal growth factor of human embryonic mesenchymal cells of palate by persistent rubella virus infection

    Energy Technology Data Exchange (ETDEWEB)

    Yoneda, T.; Urade, M.; Sakuda, M.; Miyazaki, T.

    1986-05-01

    We previously demonstrated that human embryonic mesenchymal cells derived from the palate (HEMP cells) retain alkaline phosphatase (ALP) content and capacity for collagen synthesis after long-term culture, and their growth is markedly stimulated by epidermal growth factor (EGF). There was a dramatic decrease in ALP content and capacity to synthesize collagen in HEMP cells (HEMP-RV cells) persistently infected with rubella virus (RV). EGF increased ALP activity and decreased collagen synthesis in HEMP cells, whereas EGF showed no effect on these activities in HEMP-RV cells. Growth of HEMP-RV cells was slightly reduced compared with that of HEMP cells. EGF stimulated growth of HEMP cells and to a lesser extent of HEMP-RV cells. Binding of /sup 125/I-EGF to cell-surface receptors in HEMP-RV cells was, to our surprise, twice as much as that in HEMP cells. However, internalization of bound /sup 125/I-EGF in HEMP-RV cells was profoundly diminished. Thus, persistent RV infection causes not only changes in HEMP cell growth and differentiation but a decrease in or loss of HEMP cell responsiveness to EGF. The effects of persistent RV infection on palatal cell differentiation as well as growth may be responsible for the pathogenesis of congenital rubella. Furthermore, since HEMP cells appear to be closely related to osteoblasts, these results suggest a mechanism for RV-induced osseous abnormalities manifested in congenital rubella patients.

  9. Gremlin is overexpressed in lung adenocarcinoma and increases cell growth and proliferation in normal lung cells.

    Directory of Open Access Journals (Sweden)

    Michael S Mulvihill

    Full Text Available BACKGROUND: Gremlin, a member of the Dan family of BMP antagonists, is a glycosylated extracellular protein. Previously Gremlin has been shown to play a role in dorsal-ventral patterning, in tissue remodeling, and recently in angiogenesis. Evidence has previously been presented showing both over- and under-expression of Gremlin in different tumor tissues. Here, we sought to quantify expression of Gremlin in cancers of the lung and performed in vitro experiments to check whether Gremlin promotes cell growth and proliferation. METHODOLOGY/PRINCIPAL FINDINGS: Expression of Gremlin in 161 matched tumor and normal lung cancer specimens is quantified by quantitative real-time PCR and protein level is measured by immunohistochemistry. GREM1 was transfected into lung fibroblast and epithelial cell lines to assess the impact of overexpression of Gremlin in vitro. RESULTS: Lung adenocarcinoma but not squamous cell carcinoma shows a significant increase in Gremlin expression by mRNA and protein level. Lung fibroblast and epithelial cell lines transfected with GREM1 show significantly increased cell proliferation. CONCLUSIONS/SIGNIFICANCE: Our data suggest that Gremlin acts in an oncogenic manner in lung adenocarcinoma and could hold promise as a new diagnostic marker or potential therapeutic target in lung AD or general thoracic malignancies.

  10. Shot and Patronin polarise microtubules to direct membrane traffic and biogenesis of microvilli in epithelia.

    Science.gov (United States)

    Khanal, Ichha; Elbediwy, Ahmed; Diaz de la Loza, Maria Del Carmen; Fletcher, Georgina C; Thompson, Barry J

    2016-07-01

    In epithelial tissues, polarisation of microtubules and actin microvilli occurs along the apical-basal axis of each cell, yet how these cytoskeletal polarisation events are coordinated remains unclear. Here, we examine the hierarchy of events during cytoskeletal polarisation in Drosophila melanogaster epithelia. Core apical-basal polarity determinants polarise the spectrin cytoskeleton to recruit the microtubule-binding proteins Patronin (CAMSAP1, CAMSAP2 and CAMPSAP3 in humans) and Shortstop [Shot; MACF1 and BPAG1 (also known as DST) in humans] to the apical membrane domain. Patronin and Shot then act to polarise microtubules along the apical-basal axis to enable apical transport of Rab11 endosomes by the Nuf-Dynein microtubule motor complex. Finally, Rab11 endosomes are transferred to the MyoV (also known as Didum in Drosophila) actin motor to deliver the key microvillar determinant Cadherin 99C to the apical membrane to organise the biogenesis of actin microvilli. PMID:27231092

  11. Forced Expression of ZNF143 Restrains Cancer Cell Growth

    Directory of Open Access Journals (Sweden)

    Kimitoshi Kohno

    2011-10-01

    Full Text Available We previously reported that the transcription factor Zinc Finger Protein 143 (ZNF143 regulates the expression of genes associated with cell cycle and cell division, and that downregulation of ZNF143 induces cell cycle arrest at G2/M. To assess the function of ZNF143 expression in the cell cycle, we established two cells with forced expression of ZNF143 derived from PC3 prostate cancer cell lines. These cell lines overexpress genes associated with cell cycle and cell division, such as polo-like kinase 1 (PLK1, aurora kinase B (AURKB and some minichromosome maintenance complex components (MCM. However, the doubling time of cells with forced expression of ZNF143 was approximately twice as long as its control counterpart cell line. Analysis following serum starvation and re-seeding showed that PC3 cells were synchronized at G1 in the cell cycle. Also, ZNF143 expression fluctuated, and was at its lowest level in G2/M. However, PC3 cells with forced expression of ZNF143 synchronized at G2/M, and showed lack of cell cycle-dependent fluctuation of nuclear expression of MCM proteins. Furthermore, G2/M population of both cisplatin-resistant PCDP6 cells over-expressing ZNF143 (derived from PC3 cells and cells with forced expression of ZNF143 was significantly higher than that of each counterpart, and the doubling time of PCDP6 cells is about 2.5 times longer than that of PC3 cells. These data suggested that fluctuations in ZNF143 expression are required both for gene expression associated with cell cycle and for cell division.

  12. Forced Expression of ZNF143 Restrains Cancer Cell Growth

    Energy Technology Data Exchange (ETDEWEB)

    Izumi, Hiroto, E-mail: h-izumi@med.uoeh-u.ac.jp; Yasuniwa, Yoshihiro; Akiyama, Masaki; Yamaguchi, Takahiro; Kuma, Akihiro; Kitamura, Noriaki; Kohno, Kimitoshi [Department of Molecular Biology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555 (Japan)

    2011-10-19

    We previously reported that the transcription factor Zinc Finger Protein 143 (ZNF143) regulates the expression of genes associated with cell cycle and cell division, and that downregulation of ZNF143 induces cell cycle arrest at G2/M. To assess the function of ZNF143 expression in the cell cycle, we established two cells with forced expression of ZNF143 derived from PC3 prostate cancer cell lines. These cell lines overexpress genes associated with cell cycle and cell division, such as polo-like kinase 1 (PLK1), aurora kinase B (AURKB) and some minichromosome maintenance complex components (MCM). However, the doubling time of cells with forced expression of ZNF143 was approximately twice as long as its control counterpart cell line. Analysis following serum starvation and re-seeding showed that PC3 cells were synchronized at G1 in the cell cycle. Also, ZNF143 expression fluctuated, and was at its lowest level in G2/M. However, PC3 cells with forced expression of ZNF143 synchronized at G2/M, and showed lack of cell cycle-dependent fluctuation of nuclear expression of MCM proteins. Furthermore, G2/M population of both cisplatin-resistant PCDP6 cells over-expressing ZNF143 (derived from PC3 cells) and cells with forced expression of ZNF143 was significantly higher than that of each counterpart, and the doubling time of PCDP6 cells is about 2.5 times longer than that of PC3 cells. These data suggested that fluctuations in ZNF143 expression are required both for gene expression associated with cell cycle and for cell division.

  13. Calcium influences sensitivity to growth inhibition induced by a cell surface sialoglycopeptide

    Science.gov (United States)

    Betz, N. A.; Fattaey, H. K.; Johnson, T. C.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    While studies concerning mitogenic factors have been an important area of research for many years, much less is understood about the mechanisms of action of cell surface growth inhibitors. We have purified an 18 kDa cell surface sialoglycopeptide growth inhibitor (CeReS-18) which can reversibly inhibit the proliferation of diverse cell types. The studies discussed in this article show that three mouse keratinocyte cell lines exhibit sixty-fold greater sensitivity than other fibroblasts and epithelial-like cells to CeReS-18-induced growth inhibition. Growth inhibition induced by CeReS-18 treatment is a reversible process, and the three mouse keratinocyte cell lines exhibited either single or multiple cell cycle arrest points, although a predominantly G0/G1 cell cycle arrest point was exhibited in Swiss 3T3 fibroblasts. The sensitivity of the mouse keratinocyte cell lines to CeReS-18-induced growth inhibition was not affected by the degree of tumorigenic progression in the cell lines and was not due to differences in CeReS-18 binding affinity or number of cell surface receptors per cell. However, the sensitivity of both murine fibroblasts and keratinocytes could be altered by changing the extracellular calcium concentration, such that increased extracellular calcium concentrations resulted in decreased sensitivity to CeReS-18-induced proliferation inhibition. Thus the increased sensitivity of the murine keratinocyte cell lines to CeReS-18 could be ascribed to the low calcium concentration used in their propagation. Studies are currently under way investigating the role of calcium in CeReS-18-induced growth arrest. The CeReS-18 may serve as a very useful tool to study negative growth control and the signal transduction events associated with cell cycling.

  14. Fatty acid control of growth of human cervical and endometrial cancer cells.

    OpenAIRE

    Gleeson, R P; Ayub, M.; Wright, J T; Wood, C B; Habib, N.A.; Soutter, W P; Sullivan, M. H.; White, J. O.

    1990-01-01

    Stearic acid and iodo-stearic and inhibited cell growth in a cervical cancer cell line (HOG-1) in a dose-related manner, with a half maximal effect at 50 microM stearic acid. Addition of oleic acid abrogated the effect of stearic acid. EGF-stimulated DNA synthesis and growth of HOG-1 cells was inhibited in the presence of stearic acid without any apparent effect on EGF receptor number or affinity.

  15. Amphiregulin enhances regulatory T cell suppressive function via the epidermal growth factor receptor

    OpenAIRE

    Zaiss, Dietmar M.W.; van Loosdregt, Jorg; Gorlani, Andrea; Bekker, Cornelis P.J.; Gröne, Andrea; Sibilia, Maria; van Bergen en Henegouwen, Paul M. P.; Roovers, Rob C.; Coffer, Paul J.; Sijts, Alice J.A.M.

    2013-01-01

    Epidermal growth factor receptor (EGFR) is known to be critically involved in tissue development and homeostasis as well as in the pathogenesis of cancer. Here we showed that Foxp3+ regulatory T (Treg) cells express EGFR under inflammatory conditions. Stimulation with the EGF-like growth factor Amphiregulin (AREG) markedly enhanced Treg cell function in vitro, and in a colitis and tumor vaccination model we showed that AREG was critical for efficient Treg cell function in vivo. In addition, m...

  16. In vivo cell wall loosening by hydroxyl radicals during cress seed germination and elongation growth

    OpenAIRE

    Müller, Kerstin; Linkies, Ada; Vreeburg, Robert A. M.; Fry, Stephen C; Krieger-Liszkay, Anja; Leubner-Metzger, Gerhard

    2009-01-01

    Loosening of cell walls is an important developmental process in key stages of plant life cycles, including seed germination, elongation growth and fruit ripening. Here we report direct in vivo evidence for hydroxyl radical (•OH)-mediated cell wall loosening during plant seed germination and seedling growth. We used electron paramagnetic resonance (EPR)-spectroscopy to show that •OH is generated in the cell wall during radicle elongation and weakening of the endosperm of cress (Lepidium sativ...

  17. Expression of a hyperactive androgen receptor leads to androgen-independent growth of prostate cancer cells.

    Science.gov (United States)

    Hsieh, Chen-Lin; Cai, Changmeng; Giwa, Ahmed; Bivins, Aaronica; Chen, Shao-Yong; Sabry, Dina; Govardhan, Kumara; Shemshedini, Lirim

    2008-07-01

    Cellular changes that affect the androgen receptor (AR) can cause prostate cancer to transition from androgen dependent to androgen independent, which is usually lethal. One common change in prostate tumors is overexpression of the AR, which has been shown to lead to androgen-independent growth of prostate cancer cells. This led us to hypothesize that expression of a hyperactive AR would be sufficient for androgen-independent growth of prostate cancer cells. To test this hypothesis, stable lune cancer prostate (LNCaP) cell lines were generated, which express a virion phosphoprotein (VP)16-AR hybrid protein that contains full-length AR fused to the strong viral transcriptional activation domain VP16. This fusion protein elicited as much as a 20-fold stronger transcriptional activity than the natural AR. Stable expression of VP16-AR in LNCaP cells yielded androgen-independent cell proliferation, while under the same growth conditions the parental LNCaP cells exhibited only androgen-dependent growth. These results show that expression of a hyperactive AR is sufficient for androgen-independent growth of prostate cancer cells. To study the molecular basis of this enhanced growth, we measured the expression of soluble guanylyl cyclase-alpha1 (sGCalpha1), a subunit of the sGC, an androgen-regulated gene that has been shown to be involved in prostate cancer cell growth. Interestingly, the expression of sGCalpha1 is androgen independent in VP16-AR-expressing cells, in contrast to its androgen-induced expression in control LNCaP cells. RNA(I)-dependent inhibition of sGCalpha1 expression resulted in significantly reduced proliferation of VP16-AR cells, implicating an important role for sGCalpha1 in the androgen-independent growth of these cells. PMID:18469090

  18. Growth inhibition of thyroid follicular cell-derived cancers by the opioid growth factor (OGF - opioid growth factor receptor (OGFr axis

    Directory of Open Access Journals (Sweden)

    Donahue Renee N

    2009-10-01

    Full Text Available Abstract Background Carcinoma of the thyroid gland is an uncommon cancer, but the most frequent malignancy of the endocrine system. Most thyroid cancers are derived from the follicular cell. Follicular carcinoma (FTC is considered more malignant than papillary thyroid carcinoma (PTC, and anaplastic thyroid cancer (ATC is one of the most lethal human cancers. Opioid Growth Factor (OGF; chemical term - [Met5]-enkephalin and its receptor, OGFr, form an inhibitory axis regulating cell proliferation. Both the peptide and receptor have been detected in a wide variety of cancers, and OGF is currently used clinically as a biotherapy for some non-thyroid neoplasias. This study addressed the question of whether the OGF-OGFr axis is present and functional in human thyroid follicular cell - derived cancer. Methods Utilizing human ATC (KAT-18, PTC (KTC-1, and FTC (WRO 82-1 cell lines, immunohistochemistry was employed to ascertain the presence and location of OGF and OGFr. The growth characteristics in the presence of OGF or the opioid antagonist naltrexone (NTX, and the specificity of opioid peptides for proliferation of ATC, were established in KAT-18 cells. Dependence on peptide and receptor were investigated using neutralization studies with antibodies and siRNA experiments, respectively. The mechanism of peptide action on DNA synthesis and cell survival was ascertained. The ubiquity of the OGF-OGFr axis in thyroid follicular cell-derived cancer was assessed in KTC-1 (PTC and WRO 82-1 (FTC tumor cells. Results OGF and OGFr were present in KAT-18 cells. Concentrations of 10-6 M OGF inhibited cell replication up to 30%, whereas NTX increased cell growth up to 35% relative to cultures treated with sterile water. OGF treatment reduced cell number by as much as 38% in KAT-18 ATC in a dose-dependent and receptor-mediated manner. OGF antibodies neutralized the inhibitory effects of OGF, and siRNA knockdown of OGFr negated growth inhibition by OGF. Cell survival

  19. Growth of cultured porcine retinal pigment epithelial cells

    DEFF Research Database (Denmark)

    Wiencke, A.K.; Kiilgaard, Jens Folke; Nicolini, Jair;

    2003-01-01

    To establish and characterize cultures of porcine retinal pigment epithelial (pRPE) cells in order to produce confluent monolayers of cells for transplantation.......To establish and characterize cultures of porcine retinal pigment epithelial (pRPE) cells in order to produce confluent monolayers of cells for transplantation....

  20. Influence of Carbon Monoxide on Growth and Apoptosis of Human Umbilical Artery Smooth Muscle Cells and Vein Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Yajuan Li, Hai Wang, Bin Yang, Jichen Yang, Xiuyan Ruan, Yadong Yang, Edward K. Wakeland, Quanzhen Li, Xiangdong Fang

    2012-01-01

    Full Text Available Carbon monoxide (CO is a vasoactive molecule that is generated by vascular cells as a byproduct of heme catabolism and it plays an important physiological role in circulation system. In order to investigate whether exogenous CO can mediate the growth and proliferation of vascular cells, in this study, we used 250 parts per million (ppm of CO to treat human umbilical artery smooth muscle cell (hUASMC and human umbilical vein endothelial cell (HuVEC and further evaluated the growth and apoptosis status of SMC and HuVEC. After SMC and HuVEC were exposed to CO for 7-day, the growth of SMC and HuVEC was significantly inhibited by CO in vitro on day 5 of CO exposure. And CO blocked cell cycle progress of SMC and HuVEC, more SMC and HuVEC stagnated at G0/G1 phase by flow cytometric analysis. Moreover, CO treatment inhibited SMC and HuVEC apoptosis caused by hydrogen peroxide through decreasing caspase 3 and 9 activities. To confirm the molecular mechanism of CO effect on SMC and HuVEC growth, we compared the gene expression profile in SMC and CO-treated SMC, HuVEC and CO-treated HuVEC. By microarray analysis, we found the expression level of some genes which are related to cell cycle regulation, cell growth and proliferation, and apoptosis were changed during CO exposure. We further identified that the down-regulated CDK2 contributed to arresting cell growth and the down-regulated Caspase 3 (CASP3 and Caspase 9 (CASP9 were associated with the inhibition of cell apoptosis. Therefore, CO exerts a certain growth arrest on SMC and HuVEC by inhibiting cell cycle transition from G0/G1 phase to S phase and has regulatory effect on cell apoptosis by regulating the expression of apoptosis-associated genes.

  1. Biogenesis and Functions of Exosomes and Extracellular Vesicles.

    Science.gov (United States)

    Dreyer, Florian; Baur, Andreas

    2016-01-01

    Research on extracellular vesicles (EVs) is a new and emerging field that is rapidly growing. Many features of these structures still need to be described and discovered. This concerns their biogenesis, their release and cellular entrance mechanisms, as well as their functions, particularly in vivo. Hence our knowledge on EV is constantly evolving and sometimes changing. In our review we summarize the most important facts of our current knowledge about extracellular vesicles and described some of the assumed functions in the context of cancer and HIV infection. PMID:27317183

  2. Insights into mRNP biogenesis provided by new genetic interactions among export and transcription factors

    Directory of Open Access Journals (Sweden)

    Estruch Francisco

    2012-09-01

    Full Text Available Abstract Background The various steps of mRNP biogenesis (transcription, processing and export are interconnected. It has been shown that the transcription machinery plays a pivotal role in mRNP assembly, since several mRNA export factors are recruited during transcription and physically interact with components of the transcription machinery. Although the shuttling DEAD-box protein Dbp5p is concentrated on the cytoplasmic fibrils of the NPC, previous studies demonstrated that it interacts physically and genetically with factors involved in transcription initiation. Results We investigated the effect of mutations affecting various components of the transcription initiation apparatus on the phenotypes of mRNA export mutant strains. Our results show that growth and mRNA export defects of dbp5 and mex67 mutant strains can be suppressed by mutation of specific transcription initiation components, but suppression was not observed for mutants acting in the very first steps of the pre-initiation complex (PIC formation. Conclusions Our results indicate that mere reduction in the amount of mRNP produced is not sufficient to suppress the defects caused by a defective mRNA export factor. Suppression occurs only with mutants affecting events within a narrow window of the mRNP biogenesis process. We propose that reducing the speed with which transcription converts from initiation and promoter clearance to elongation may have a positive effect on mRNP formation by permitting more effective recruitment of partially-functional mRNP proteins to the nascent mRNP.

  3. Effects of EPO Gene on Growth and Apoptosis of Lung Adenocarcinoma Cell Line A549

    Directory of Open Access Journals (Sweden)

    Jianqing WU

    2009-09-01

    Full Text Available Background and objective Published data on the association between erythropoietin (EPO and cancer cell are inconclusive. The aim of this study is to investigate the effect of erythropoietin (EPO on the growth and survival of lung adenocarcinoma cell line A549. Methods The recombinant plasmid pcDNA3.1(--hEPO was constructed and transfected into A549 cells by liposome protoco1. The Levels of EPO in culture supernatant were detected by ELISA. Effects of EPO gene on growth and survival of the transfected cells were evaluated by MTT assay and flow cytometry (FCM . Levels of vascular endothelial growth factor (VEGF were also evaluated by ELISA. Results The recombinant eukaryotic expression vector pcDNA3.1(--hEPO was successfully constructed. The growth of cells in hEPO transfected cells was significantly inhibited after transfection (P < 0.01. More cells were blocked in S phase in hEPO transfected group compared with control group (P < 0.05, and the apoptotic rate were also significantly higher than those of their controls (P < 0.01. Levels of VEGF in hEPO transfected cells were significantly lower than controls (P < 0.01. Conclusion Exogenous EPO gene expression in A549 cells can induce cell growth inhibition and apoptosis of A549 cells, and expression of VEGF can also be inhibited.

  4. Effects of transforming growth interacting factor on biological behaviors of gastric carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Zhong-Liang Hu; Ji-Fang Wen; De-Sheng Xiao; Hui Zhen; Chun-Yan Fu

    2005-01-01

    AIM:Transforming growth interacting factor (TGIF) is an inhibitor of both transforming growth factor β (TGF-β) and retinoid signaling pathways. Moreover, the activation of MAPK pathway can prolong its half-life. However, its role in carcinogenesis is still unknown. Thus we attempted to investigate the effect of TGIF on biologic behaviors of gastric carcinoma cells.METHODS: Gastric carcinoma cell line, SGC-7901, was stably transfected with plasmid PcDNA3.1-TGIF. Western blotting and cell immunohistochemistry screening for the highly expressing clone of TGIF were employed. The growth of transfected cells was investigated by MTT and colonyformation assays, and apoptosis was measured by flow cytometry (FCM) and transmission electron microscopy.Tumorigenicity of the transfectant cells was also analyzed.RESULTS: TGIF had no effect on the proliferation, cell cycle and apoptosis of SGC-7901 cells, but cellular organelles of cells transfected with TGIF were richer than those of vector control or parental cells. Its clones were smaller than the control ones in plate efficiency, and its tumor tissues also had no obvious necrosis compared with the vector control or parental cells. Moreover, TGIF could resist TGF-β mediated growth inhibition.CONCLUSION: TGIF may induce differentiation of stomach neoplastic cells. In addition, TGIF can counteract the growth inhibition induced by TGF-β.

  5. Effect of tumor suppressor in lung cancer-1 on growth inhibition of MG63 cell line

    Institute of Scientific and Technical Information of China (English)

    Li Qin; Yang Lin; Wenjian Chen; Wentao Zhu

    2013-01-01

    Objective: The aim of this study was to establish the osteosarcoma cell sublines which stably expressing tumor suppressor in lung cancer-1 (TSLC1) gene and evaluate its effect on growth inhibition of human osteosarcoma cell line MG63. Methods: The recombinant plasmid pCI-TSLC1 was stably transfected into MG63 cells with Lipofectamine 2000. The positive clones were developed by selection by G418. Biological characteristics of one of the 6 cell lines which highly expressing TSLC1, namely, the M8T were studied. Cell growth was analyzed with MTT assay. 2 × 107 cells suspended in 0.2 mL phosphate buffered saline (PBS) were injected into the two flanks of 5-6-week-old female BALB/C nu/nu athymic nude mice. The volumes of subcutaneous of tumor growth were evaluated and calculated by the formula V= Length × Width × Height × 0.5 once a week. Results: The M8T cell subline which stably expressing TSLC1 was characterized by Western blot. The genetic stability and purity of M8T cells were stable. TSLC1 significantly suppressed the growth of M8T cells in vitro. Moreover, the tumorigenicity of M8T cells was suppressed in vivo. Conclusion: The osteosarcoma cell sublines M8T which stably expressing TSLC1 had been successfully established. The ability of growth and metastasis of M8T was significantly suppressed both in vitro and in vivo.

  6. Curcumin inhibits cell growth and invasion and induces apoptosis through down-regulation of Skp2 in pancreatic cancer cells

    Science.gov (United States)

    Su, Jingna; Zhou, Xiuxia; Wang, Lixia; Yin, Xuyuan; Wang, Zhiwei

    2016-01-01

    Natural polyphenol compound curcumin has been found to exhibit its anticancer activity in a variety of human malignancies including pancreatic cancer (PC). However, the underlying mechanism has not been fully understood. Accumulating evidence has demonstrated that Skp2 (S-phase kinase associated protein 2) plays an oncogenic role in the development and progression of human cancers. In this study, we aim to explore the molecular basis of curcumin-induced cell growth inhibition in PC cells.Multiple methods such as CTG assay, Flow cytometry, clonogenic assay, wound healing assay, Transwell invasion assay, Western blotting, and transfection were performed to validate the oncogenic role of curcumin in PC cells. We found that curcumin suppressed cell growth, clonogenic potential, migration and invasion, and induced cell apoptosis and cell cycle arrest. Moreover, we observed thatover-expression of Skp2 significantly promoted cell growth, whereas down-regulation of Skp2 with siRNAs inhibited cell growth. The molecular basis of curcumin-mediated cell growth inhibition we identified is that curcumin significantly suppressed Skp2 expression and subsequently induced p21 expression. These findings suggested thattargeting Skp2 by curcumin could be a promising therapeutic strategy for the treatment of PC patients.

  7. Analysis of a stochastic model for bacterial growth and the lognormality in the cell-size distribution

    CERN Document Server

    Yamamoto, Ken

    2016-01-01

    This paper theoretically analyzes a phenomenological stochastic model for bacterial growth. This model comprises cell divisions and linear growth of cells, where growth rates and cell cycles are drawn from lognormal distributions. We derive that the cell size is expressed as a sum of independent lognormal variables. We show numerically that the quality of the lognormal approximation greatly depends on the distributions of the growth rate and cell cycle. Furthermore, we show that actual parameters of the growth rate and cell cycle take values which give good lognormal approximation, so the experimental cell-size distribution is in good agreement with a lognormal distribution.

  8. Analysis of a Stochastic Model for Bacterial Growth and the Lognormality of the Cell-Size Distribution

    Science.gov (United States)

    Yamamoto, Ken; Wakita, Jun-ichi

    2016-07-01

    This paper theoretically analyzes a phenomenological stochastic model for bacterial growth. This model comprises cell division and the linear growth of cells, where growth rates and cell cycles are drawn from lognormal distributions. We find that the cell size is expressed as a sum of independent lognormal variables. We show numerically that the quality of the lognormal approximation greatly depends on the distributions of the growth rate and cell cycle. Furthermore, we show that actual parameters of the growth rate and cell cycle take values that give a good lognormal approximation; thus, the experimental cell-size distribution is in good agreement with a lognormal distribution.

  9. Optimization of the cell seeding density and modeling of cell growth and metabolism using the modified Gompertz model for microencapsulated animal cell culture.

    Science.gov (United States)

    Wen-tao, Qi; Ying, Zhang; Juan, Ma; Xin, Guo; Yu-bing, Xie; Wei, Wang; Xiaojun, Ma

    2006-04-01

    Cell microencapsulation is one of the promising strategies for the in vitro production of proteins or in vivo delivery of therapeutic products. In order to design and fabricate the optimized microencapsulated cell system, the Gompertz model was applied and modified to describe the growth and metabolism of microencapsulated cell, including substrate consumption and product formation. The Gompertz model successfully described the cell growth kinetics and the modified Gompertz models fitted the substrate consumption and product formation well. It was demonstrated that the optimal initial cell seeding density was about 4-5 x 10(6) cells/mL of microcapsule, in terms of the maximum specific growth rate, the glucose consumption potential and the product formation potential calculated by the Gompertz and modified Gompertz models. Modeling of cell growth and metabolism in microcapsules provides a guideline for optimizing the culture of microencapsulated cells.

  10. The Kinetic of Growth Cell of Neurospora Sitophila at Phythohormone Production Medium

    International Nuclear Information System (INIS)

    The study of growth cell kinetic of Neurospora Sitophila at Phythohormone production medium has been done. The growth of this mould at Mendel broth medium is affected by pH and glucose concentration. In the enriched medium by 2 % glucose content and pH 4.5 shows the optimal growth of cell with specific growth rate by 0.0785 per hour. The changing of pH connected with the growth cell curve, so this moment as an indicator of cell harvest time. At the stationary phase to dead phase is explained by pH changed between 2.80-2.85. This phase may be estimated as a time of Phythohormone synthesize by mold. (author)

  11. L-Methionine inhibits growth of human pancreatic cancer cells.

    Science.gov (United States)

    Benavides, Maximo A; Bosland, Maarten C; da Silva, Cássio P; Gomes Sares, Claudia T; de Oliveira, Alana M Cerqueira; Kemp, Rafael; dos Reis, Rodolfo B; Martins, Vilma R; Sampaio, Suely V; Bland, Kirby I; Grizzle, William E; dos Santos, José S

    2014-02-01

    We have previously shown that L-methionine inhibits proliferation of breast, prostate, and colon cancer cells. This study extends these findings to BXPC-3 (mutated p53) and HPAC (wild-type p53) pancreatic cancer cells and explores the reversibility of these effects. Cells were exposed to L-methionine (5 mg/ml) for 7 days or for 3 days, followed by 4 days of culture without L-methionine (recovery). Cell proliferation, apoptosis, and cell cycle effects were assessed by flow cytometry after staining for Ki-67 or annexin V/propidium iodide. Cell proliferation was reduced by 31-35% after 7 days of methionine exposure; the effect persisted in BXPC-3 and HPAC cells after 4 days of recovery. Methionine increased apoptosis by 40-75% in HPAC cells, but not in BXPC-3 cells. Continuous exposure to methionine caused accumulation of BXPC-3 cells in the S phase and HPAC cells in both the G0/G1 and S phases; however, after 4 days of recovery, these effects disappeared. In conclusion, L-methionine inhibits proliferation and interferes with the cell cycle of BXPC-3 and HPAC pancreatic cancer cells; the effects on apoptosis remarkably persisted after methionine withdrawal. Apoptosis was induced only in BXPC-3 cells. Some of the differences in the effects of methionine between cell lines may be related to disparate p53 status. These findings warrant further studies on the potential therapeutic benefit of L-methionine against pancreatic cancer.

  12. Sexual dimorphism in epigenomicresponses of stem cells to extreme fetal growth

    Science.gov (United States)

    Delahaye, Fabien; Wijetunga, N. Ari; Heo, Hye J.; Tozour, Jessica N.; Zhao, Yong Mei; Greally, John M.; Einstein, Francine H.

    2014-01-01

    Extreme fetal growth is associated with increased susceptibility to a range of adult diseases through an unknown mechanism of cellular memory. We tested whether heritable epigenetic processes in long-lived CD34+ hematopoietic stem/progenitor cells (HSPCs) showed evidence for re-programming associated with the extremes of fetal growth. Here we show that both fetal growth restriction and over-growth are associated with global shifts towards DNA hypermethylation, targeting cis-regulatory elements in proximity to genes involved in glucose homeostasis and stem cell function. We find a sexually dimorphic response; intrauterine growth restriction (IUGR) is associated with substantially greater epigenetic dysregulation in males, whereas large for gestational age (LGA) growth predominantly affects females. The findings are consistent with extreme fetal growth interacting with variable fetal susceptibility to influence cellular aging and metabolic characteristics through epigenetic mechanisms, potentially generating biomarkers that could identify infants at higher risk for chronic disease later in life. PMID:25300954

  13. Sexual dimorphism in epigenomic responses of stem cells to extreme fetal growth.

    Science.gov (United States)

    Delahaye, Fabien; Wijetunga, N Ari; Heo, Hye J; Tozour, Jessica N; Zhao, Yong Mei; Greally, John M; Einstein, Francine H

    2014-10-10

    Extreme fetal growth is associated with increased susceptibility to a range of adult diseases through an unknown mechanism of cellular memory. We tested whether heritable epigenetic processes in long-lived CD34(+) haematopoietic stem/progenitor cells showed evidence for re-programming associated with the extremes of fetal growth. Here we show that both fetal growth restriction and over-growth are associated with global shifts towards DNA hypermethylation, targeting cis-regulatory elements in proximity to genes involved in glucose homeostasis and stem cell function. We find a sexually dimorphic response; intrauterine growth restriction is associated with substantially greater epigenetic dysregulation in males, whereas large for gestational age growth predominantly affects females. The findings are consistent with extreme fetal growth interacting with variable fetal susceptibility to influence cellular ageing and metabolic characteristics through epigenetic mechanisms, potentially generating biomarkers that could identify infants at higher risk for chronic disease later in life.

  14. Direct Image-Based Enumeration of Clostridium phytofermentans Cells on Insoluble Plant Biomass Growth Substrates.

    Science.gov (United States)

    Alvelo-Maurosa, Jesús G; Lee, Scott J; Hazen, Samuel P; Leschine, Susan B

    2016-02-01

    A dual-fluorescent-dye protocol to visualize and quantify Clostridium phytofermentans ISDg (ATCC 700394) cells growing on insoluble cellulosic substrates was developed by combining calcofluor white staining of the growth substrate with cell staining using the nucleic acid dye Syto 9. Cell growth, cell substrate attachment, and fermentation product formation were investigated in cultures containing either Whatman no. 1 filter paper, wild-type Sorghum bicolor, or a reduced-lignin S. bicolor double mutant (bmr-6 bmr-12 double mutant) as the growth substrate. After 3 days of growth, cell numbers in cultures grown on filter paper as the substrate were 6.0- and 2.2-fold higher than cell numbers in cultures with wild-type sorghum and double mutant sorghum, respectively. However, cells produced more ethanol per cell when grown with either sorghum substrate than with filter paper as the substrate. Ethanol yields of cultures were significantly higher with double mutant sorghum than with wild-type sorghum or filter paper as the substrate. Moreover, ethanol production correlated with cell attachment in sorghum cultures: 90% of cells were directly attached to the double mutant sorghum substrate, while only 76% of cells were attached to wild-type sorghum substrate. With filter paper as the growth substrate, ethanol production was correlated with cell number; however, with either wild-type or mutant sorghum, ethanol production did not correlate with cell number, suggesting that only a portion of the microbial cell population was active during growth on sorghum. The dual-staining procedure described here may be used to visualize and enumerate cells directly on insoluble cellulosic substrates, enabling in-depth studies of interactions of microbes with plant biomass. PMID:26637592

  15. miR-134 inhibits non-small cell lung cancer growth by targeting the epidermal growth factor receptor.

    Science.gov (United States)

    Qin, Qin; Wei, Furong; Zhang, Jianbo; Wang, Xingwu; Li, Baosheng

    2016-10-01

    The epidermal growth factor receptor (EGFR) is frequently activated in a wide range of solid tumours and represents an important therapeutic target. MicroRNAs (miRNAs) have recently been recognized as a rational and potential modality for anti-EGFR therapies. However, more EGFR-targeting miRNAs need to be explored. In this study, we identified a novel EGFR-targeting miRNA, miRNA-134 (miR-134), in non-small-cell lung cancer (NSCLC) cell lines. Luciferase assays confirmed that EGFR is a direct target of miR-134. In addition, the overexpression of miR-134 inhibited EGFR-related signaling and suppressed NSCLC cells proliferation by inducing cell cycle arrest and/or apoptosis, suggesting that miR-134 functions as a tumour suppressor in NSCLC. Further mechanistic investigation including RNAi and rescue experiments suggested that the down-regulation of EGFR by miR-134 partially contributes to the antiproliferative role of miR-134. Last, in vivo experiments demonstrated that miR-134 suppressed tumour growth of A549 xenograft in nude mice. Taken together, our findings suggest that miR-134 inhibits non-small cell lung cancer growth by targeting the EGFR.

  16. Research progress of mitochondrial biogenesis and cerebral ischemia/reperfusion injury%线粒体生成与脑缺血再灌注损伤的研究进展

    Institute of Scientific and Technical Information of China (English)

    王来; 祝世功

    2016-01-01

    Mitochondria are important intracellular energy supply organelles .As semi-autonomous organelles , the mitochondrial biogenesis , damage and clearance were the dynamic processes , which are dual-regulated by mitochondrial genes and nuclear genes , and maintain mitochondrial homeostasis according to the needs of the cells for energy .Recent studies provide evidence that the disorder of mitochondrial biogenesis in the neurons participates in the pathological process after cerebral ischemia/reperfusion, resulting in metabolic disturbance and cell apoptosis .This paper reviews the research progress of mitochondrion and cerebral ischemia/reperfusion injury .

  17. Growth Inhibition Effect of DL-Lysine Acetylalicylate on sw480 Colon Carcinoma Cells

    Institute of Scientific and Technical Information of China (English)

    WANG Shu; TIAN Xiao-feng; WANG Li-ming

    2007-01-01

    Objective: To investigate the effect of DL-lysine acetylsalicylate on proliferation of colon carcinoma cells line sw480. Methods: After treatment of DL-lysine acetylsalicylate, the study was performed by observing sw480 colorectal cancer cells with phase contrast microscope, making growth curve, and examining the inhibition rate of sw480 cells with MTT assay. Results: The morphology of sw480 cells showed characteristics of apoptosis, the cell growth curve showed inhibited proliferation of sw480 cells when treated with DL-lysine acetylsalicylate (P<0.05). The rate of inhibition was upward when the drug concentration increased. Conclusion: DL-lysine acetylsalicylate for injection can inhibit the growth of sw480 colorectal cancer cells obviously in a dose dependent manner.

  18. Angiogenin mediates androgen-stimulated growth of prostate cancer cells and correlates with castration resistance

    OpenAIRE

    Li, Shuping; Hu, Miaofen G.; Sun, Yeqing; YOSHIOKA, NORIE; IBARAGI, SOICHIRO; Sheng, Jinghao; Sun, Guangjie; Kishimoto, Koji; Hu, Guo-fu

    2013-01-01

    Androgen receptor (AR) is a critical effector of prostate cancer (PCa) development and progression. Androgen-dependent PCa rely on the function of AR for growth and progression. Many castration-resistant PCa continue to depend on AR signaling for survival and growth. Ribosomal RNA (rRNA) is essential for both androgen-dependent and castration-resistant growth of PCa cells. During androgen-dependent growth of prostate cells, androgen-AR signaling leads to the accumulation of rRNA. However, the...

  19. FACTORS LIMITING BACTERIAL GROWTH : III. CELL SIZE AND "PHYSIOLOGIC YOUTH" IN BACTERIUM COLI CULTURES.

    Science.gov (United States)

    Hershey, A D; Bronfenbrenner, J

    1938-07-20

    1. Measurements of the rate of oxygen uptake per cell in transplants of Bacterium coli from cultures of this organism in different phases of growth have given results in essential agreement with the observations of others. 2. Correlations of viable count, centrifugable nitrogen, and turbidity, with oxygen consumption, indicate that the increased metabolism during the early portion of the growth period is quantitatively referable to increased average size of cells. 3. Indirect evidence has suggested that the initial rate of growth of transplants is not related to the phase of growth of the parent culture.

  20. Direct and in vitro observation of growth hormone receptor molecules in A549 human lung epithelial cells by nanodiamond labeling

    Science.gov (United States)

    Cheng, C.-Y.; Perevedentseva, E.; Tu, J.-S.; Chung, P.-H.; Cheng, C.-L.; Liu, K.-K.; Chao, J.-I.; Chen, P.-H.; Chang, C.-C.

    2007-04-01

    This letter presents direct observation of growth hormone receptor in one single cancer cell using nanodiamond-growth hormone complex as a specific probe. The interaction of surface growth hormone receptor of A549 human lung epithelial cells with growth hormone was observed using nanodiamond's unique spectroscopic signal via confocal Raman mapping. The growth hormone molecules were covalent conjugated to 100nm diameter carboxylated nanodiamonds, which can be recognized specifically by the growth hormone receptors of A549 cell. The Raman spectroscopic signal of diamond provides direct and in vitro observation of growth hormone receptors in physiology condition in a single cell level.

  1. Effect of soy saponin on the growth of human colon cancer cells

    Institute of Scientific and Technical Information of China (English)

    Cheng-Yu; Tsai; Yue-Hwa; Chen; Yi-Wen; Chien; Wen-Hsuan; Huang; Shyh-Hsiang; Lin

    2010-01-01

    AIM:To investigate the effect of extracted soybean saponins on the growth of human colon cancer cells.METHODS:WiDr human colon cancer cells were treated with 150,300,600 or 1200 ppm of soy saponin to determine the effect on cell growth,cell morphology,alkaline phosphatase(AP) and protein kinase C(PKC) activities,and P53 protein,c-Fos and c-Jun gene expression.RESULTS:Soy saponin decreased the number of viable cells in a dose-dependent manner and suppressed 12-Otetradecanol-phorbol-13-acetate-stimulated PKC ...

  2. Electrospun silk fibroin nanofibers promote Schwann cell adhesion, growth and proliferation

    Institute of Scientific and Technical Information of China (English)

    Aijun Hu; Baoqi Zuo; Feng Zhang; Qing Lan; Huanxiang Zhang

    2012-01-01

    In this study, Schwann cells, at a density of 1 × 105 cells/well, were cultured on regenerated silk fibroin nanofibers (305 ± 84 nm) prepared using the electrospinning method. Schwann cells cultured on the silk fibroin nanofibers appeared more ordered, their processes extended further, and they formed more extensive and complex interconnections. In addition, the silk fibroin nanofibers had no impact on the proliferation of Schwann cells or on the secretion of ciliary neurotrophic factor, brain-derived neurotrophic factor or nerve growth factor. These findings indicate that regenerated electrospun silk fibroin nanofibers can promote Schwann cell adhesion, growth and proliferation, and have excellent biocompatibility.

  3. Insulin-like growth factors act synergistically with basic fibroblast growth factor and nerve growth factor to promote chromaffin cell proliferation

    DEFF Research Database (Denmark)

    Frödin, M; Gammeltoft, S

    1994-01-01

    and immunocytochemical staining of cell nuclei. After 6 days in culture in the absence of growth factors, nuclear BrdUrd incorporation was detected in 30% of fetal chromaffin cells, 1.5% of neonatal cells, and 0.1% of adult cells. Addition of 10 nM IGF-I or IGF-II increased the fraction of BrdUrd-labeled nuclei to 50......% of fetal, 20% of neonatal, and 2% of adult chromaffin cells. The ED50 value of IGF-I- and IGF-II-stimulated BrdUrd labeling in neonatal chromaffin cells was 0.3 nM and 0.8 nM, respectively. In neonatal and adult chromaffin cells, addition of 1 nM bFGF or 2 nM NGF stimulated nuclear BrdUrd incorporation...... was further improved when bFGF or NGF was added together with IGF-II. In conclusion, we propose that IGF-I and IGF-II act in synergy with bFGF and NGF to stimulate proliferation and survival of chromaffin cells during neonatal growth and adult maintenance of the adrenal medulla. Our findings may have...

  4. Specific immunotherapy generates CD8(+) CD196(+) T cells to suppress lung cancer growth in mice.

    Science.gov (United States)

    Zhang, Jian; Liu, Jing; Chen, Huiguo; Wu, Weibin; Li, Xiaojun; Wu, Yonghui; Wang, Zhigang; Zhang, Kai; Li, Yun; Weng, Yimin; Liao, Hongying; Gu, Lijia

    2016-08-01

    That specific immunotherapy can inhibit cancer growth has been recognized; its efficiency is to be improved. This study aimed to inhibit lung cancer (LC) growth in a mouse model by using an LC-specific vaccination. In this study, a LC mouse model was created by adoptive transplantation with LC cells. The tumor-bearing mice were vaccinated with LC cell extracts plus adjuvant TNBS or adoptive transplantation with specific CD8(+) CD196(+) T cells. The results showed that the vaccination with LC extracts (LCE)/TNBS markedly inhibited the LC growth and induced CD8(+) CD196(+) T cells in LC tissue and the spleen. These CD8(+) CD196(+) T cells proliferated and produce high levels of perforin upon exposure to LCE and specifically induced LC cell apoptosis. Exposure to TNBS induced RAW264.7 cells to produce macrophage inflammatory protein-3α; the latter activated signal transducer and activator of transcription 3 and further induced perforin expression in the CD8(+) CD196(+) T cells. Adoptive transfer with specific CD8(+) CD196(+) T cells suppressed LC growth in mice. In conclusion, immunization with LC extracts and TNBS can induce LC-specific CD8(+) CD196(+) T cells in LC-bearing mice and inhibit LC growth. PMID:26910585

  5. The intrusive growth of initial cells in re-arangement of cells in cambium of Tilia cordata Mill.

    Directory of Open Access Journals (Sweden)

    Wiesław Włoch

    2014-02-01

    Full Text Available In the cambium of linden producing wood with short period of grain inclination change (2-4 years, the intensive reorientation of cells takes place. This is possible mainly through an intrusive growth of cell ends from one radial file entering space between tangential walls of neighboring file and through unequal periclinal divisions that occur in the "initial surface". The intrusive growth is located on the longitudinal edge of a fusiform cell close to the end, and causes deviation of cell ends in a neighbouring file from the initial surface. Unequal periclinal division divides a cell with a deviated end into two derivatives, unequal in size. The one of them, which inherits the deviated end, leaves the initial surface becoming a xylem or phloem mother cell. This means that the old end is eliminated. The intensity of intrusive growth and unequal periclinal divisions is decisive for the velocity of cambial cell reorientation. The oriented intrusive growth occurs only in the initial cells. For that reason, changes in cell-ends position do not occur within one packet of cells but are distinct between neighbouring packets.

  6. Angiostatin inhibits pancreatic cancer cell proliferation and growth in nude mice

    Institute of Scientific and Technical Information of China (English)

    Ding-Zhong Yang; Jing He; Ji-Cheng Zhang; Zhuo-Ren Wang

    2005-01-01

    AIM: To observe the biologic behavior of pancreatic cancer cells in vitro and in vivo, and to explore the potential value of angiostatin gene therapy for pancreatic cancer.METHODS: The recombinant vector pcDNA3.1(+)-angiostatin was transfected into human pancreatic cancer cells PC-3 with Lipofectamine 2000, and paralleled with the vector and mock control. Angiostatin transcription and protein expression were determined by immunofluorescence and Western blot. The stable cell line was selected by G418. The supernatant was collected to treat endothelial cells. Cell proliferation and growth in vitro were observed under microscope. Cell growth curves were plotted.The troms-fected or untroms-fected cells overexpressing angiostatin vector were implanted subcutaneously into nude mice. The size of tumors was measured, and microvessel density count (MVD) in tumor tissues was assessed by immunohistochemistry with primary anti-CD34antibody.RESULTS: After transfected into PC-3 with Lipofectamine 2000 and selected by G418, macroscopic resistant cell clones were formed in the experimental group transfected with pcDNA 3.1(+)-angiostatin and vector control. But untreated cells died in the mock control. Angiostatin protein expression was detected in the experimental group by immunofluorescence and Western-blot. Cell proliferation and growth in vitro in the three groups were observed respectively under microscope. After treatment with supernatant, significant differences were observed in endothelial cell (ECV-304) growth in vitro. The cell proliferation and growth were inhibited. In nude mice model, markedly inhibited tumorigenesis and slowed tumor expansion were observed in the experimental group as compared to controls, which was parallel to the decreased microvessel density in and around tumor tissue.CONCLUSION: Angiostatin does not directly inhibit human pancreatic cancer cell proliferation and growth in vitro,but it inhibits endothelial cell growthin vitro. It exerts the anti

  7. Amygdalin Blocks Bladder Cancer Cell Growth In Vitro by Diminishing Cyclin A and cdk2

    OpenAIRE

    Jasmina Makarević; Jochen Rutz; Eva Juengel; Silke Kaulfuss; Michael Reiter; Igor Tsaur; Georg Bartsch; Axel Haferkamp; Blaheta, Roman A.

    2014-01-01

    Amygdalin, a natural compound, has been used by many cancer patients as an alternative approach to treat their illness. However, whether or not this substance truly exerts an anti-tumor effect has never been settled. An in vitro study was initiated to investigate the influence of amygdalin (1.25-10 mg/ml) on the growth of a panel of bladder cancer cell lines (UMUC-3, RT112 and TCCSUP). Tumor growth, proliferation, clonal growth and cell cycle progression were investigated. The cell cycle regu...

  8. Growth inhibition and apoptosis induction of Sulindac on Human gastric cancer cells

    Institute of Scientific and Technical Information of China (English)

    Yun-Lin Wu; Bo Sun; Xue-Jun Zhang; Sheng-Nian Wang; Heng-Yi He; Min-Min Qiao; Jie Zhong; Jia-Yu Xu

    2001-01-01

    AIM: To evaluate the effects of sulindac in inducing growth inhibition and apoptosis of human gastric cancer cells in comparison with human hepatocellular carcinoma (HCC)cells. METHODS: The human gastric cancer cell lines MKN45 and MKN28 and human hepatocellular carcinoma cell lines HepG2and SMMC7721 were used for the study. Anti-proliferative effect was measured by MTT assay, and apoptosis was determined by Hoechst-33258 staining, electronography and DNA fragmentation. The protein of cyclooxygenase-2 (COX(2) and Bcl-2 were detected by Westem dot blotting. RESULTS: Sulindac could initiate growth inhibition and apoptosis of MKN45, MKN28, HepG2 and SMMC7721 cells in a dose-and time-dependent manner. Growth inhibitory activity and apoptosis were more sensitive in HepG2 cells than in SMMC7721 cells, MKN45 and MKN28 cells. After 24hours incubation with sulindac at 2mmol. L-1 and 4mmol.L-1, the level of COX-2 and Bcl-2 protein were lowered in MKN45, SMMC7721 and HepG2 cells but not in MKN28 cells. CONCLUSION: Sulindac could inhibit the growth of gastric cancer cells and HCC cells effectively in vitro by apoptosis induction, which was associated with regression of COX-2and Bcl-2 expression. The growth inhibition and apoptosis of HCC cells were greater then that of human gastric cancer cells. The different effects of apoptosis in gastric cancer cells may be related to the differentiation of the cells.

  9. The Neurospora crassa dfg5 and dcw1 Genes Encode α-1,6-Mannanases That Function in the Incorporation of Glycoproteins into the Cell Wall

    OpenAIRE

    Abhiram Maddi; Ci Fu; Free, Stephen J.

    2012-01-01

    The covalent cross-linking of cell wall proteins into the cell wall glucan/chitin matrix is an important step in the biogenesis of the fungal cell wall. We demonstrate that the Neurospora crassa DFG5 (NCU03770) and DCW1 (NCU08127) enzymes function in vivo to cross-link glycoproteins into the cell wall. Mutants lacking DFG5 or DCW1 release slightly elevated levels of cell wall proteins into their growth medium. Mutants lacking both DFG5 and DCW1 have substantially reduced levels of cell wall p...

  10. Exposure to nerve growth factor worsens nephrotoxic effect induced by Cyclosporine A in HK-2 cells.

    Directory of Open Access Journals (Sweden)

    Donatella Vizza

    Full Text Available Nerve growth factor is a neurotrophin that promotes cell growth, differentiation, survival and death through two different receptors: TrkA(NTR and p75(NTR. Nerve growth factor serum concentrations increase during many inflammatory and autoimmune diseases, glomerulonephritis, chronic kidney disease, end-stage renal disease and, particularly, in renal transplant. Considering that nerve growth factor exerts beneficial effects in the treatment of major central and peripheral neurodegenerative diseases, skin and corneal ulcers, we asked whether nerve growth factor could also exert a role in Cyclosporine A-induced graft nephrotoxicity. Our hypothesis was raised from basic evidence indicating that Cyclosporine A-inhibition of calcineurin-NFAT pathway increases nerve growth factor expression levels. Therefore, we investigated the involvement of nerve growth factor and its receptors in the damage exerted by Cyclosporine A in tubular renal cells, HK-2. Our results showed that in HK-2 cells combined treatment with Cyclosporine A + nerve growth factor induced a significant reduction in cell vitality concomitant with a down-regulation of Cyclin D1 and up-regulation of p21 levels respect to cells treated with Cyclosporine A alone. Moreover functional experiments showed that the co-treatment significantly up-regulated human p21promoter activity by involvement of the Sp1 transcription factor, whose nuclear content was negatively regulated by activated NFATc1. In addition we observed that the combined exposure to Cyclosporine A + nerve growth factor promoted an up-regulation of p75 (NTR and its target genes, p53 and BAD leading to the activation of intrinsic apoptosis. Finally, the chemical inhibition of p75(NTR down-regulated the intrinsic apoptotic signal. We describe two new mechanisms by which nerve growth factor promotes growth arrest and apoptosis in tubular renal cells exposed to Cyclosporine A.

  11. Vulnerability of microRNA biogenesis in FTD-ALS.

    Science.gov (United States)

    Eitan, Chen; Hornstein, Eran

    2016-09-15

    The genetics of the neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) turn our attention to RNA metabolism, primarily because many of the identified diseases-associated genes encode for RNA-binding proteins. microRNAs (miRNAs) are endogenous noncoding RNAs that play critical roles in maintaining brain integrity. The current review sheds light on miRNA dysregulation in neurodegenerative diseases, focusing on FTD-ALS. We propose that miRNAs are susceptible to fail when protein factors that are critical for miRNA biogenesis malfunction. Accordingly, potential insufficiencies of the 'microprocessor' complex, the nucleo-cytoplasmic export of miRNA precursors or their processing by Dicer were recently reported. Furthermore, specific miRNAs are involved in the regulation of pathways that are essential for neuronal survival or function. Any change in the expression of these specific miRNAs or in their ability to recognize their target sequences will have negative consequences. Taken together, recent reports strengthens the hypothesis that dysregulation of miRNAs might play an important role in the pathogenesis of neurodegenerative diseases, and highlights the miRNA biogenesis machinery as an interesting target for therapeutic interventions for ALS as well as FTD. This article is part of a Special Issue entitled SI:RNA Metabolism in Disease. PMID:26778173

  12. Organotypic Cultures of Intervertebral Disc Cells: Responses to Growth Factors and Signaling Pathways Involved

    Directory of Open Access Journals (Sweden)

    Harris Pratsinis

    2015-01-01

    Full Text Available Intervertebral disc (IVD degeneration is strongly associated with low back pain, a major cause of disability worldwide. An in-depth understanding of IVD cell physiology is required for the design of novel regenerative therapies. Accordingly, aim of this work was the study of IVD cell responses to mitogenic growth factors in a three-dimensional (3D organotypic milieu, comprising characteristic molecules of IVD’s extracellular matrix. In particular, annulus fibrosus (AF cells were cultured inside collagen type-I gels, while nucleus pulposus (NP cells in chondroitin sulfate A (CSA supplemented collagen gels, and the effects of Platelet-Derived Growth Factor (PDGF, basic Fibroblast Growth Factor (bFGF, and Insulin-Like Growth Factor-I (IGF-I were assessed. All three growth factors stimulated DNA synthesis in both AF and NP 3D cell cultures, with potencies similar to those observed previously in monolayers. CSA supplementation inhibited basal DNA synthesis rates, without affecting the response to growth factors. ERK and Akt were found to be phosphorylated following growth factor stimulation. Blockade of these two signaling pathways using pharmacologic inhibitors significantly, though not completely, inhibited growth factor-induced DNA synthesis. The proposed culture systems may prove useful for further in vitro studies aiming at future interventions for IVD regeneration.

  13. Growth inhibitory effect of 4-phenyl butyric acid on human gastric cancer cells is associated with cell cycle arrest

    Institute of Scientific and Technical Information of China (English)

    Long-Zhu Li; Hong-Xia Deng; Wen-Zhu Lou; Xue-Yan Sun; Meng-Wan Song; Jing Tao; Bing-Xiu Xiao; Jun-Ming Guo

    2012-01-01

    AIM: To investigate the growth effects of 4-phenyl butyric acid (PBA) on human gastric carcinoma cells and their mechanisms. METHODS: Moderately-differentiated human gastric carcinoma SGC-7901 and lowly-differentiated MGC-803 cells were treated with 5, 10, 20, 40, and 60 μmol/L PBA for 1-4 d. Cell proliferation was detected using the MTT colorimetric assay. Cell cycle distributions were examined using flow cytometry. RESULTS: The proliferation of gastric carcinoma cells was inhibited by PBA in a dose- and time-dependent fashion. Flow cytometry showed that SGC-7901 cells treated with low concentrations of PBA were arrested at the G0/G1 phase, whereas cells treated with high concentrations of PBA were arrested at the G2/M phase. Although MGC-803 cells treated with low concentrations of PBA were also arrested at the G0/G1 phase, cells treated with high concentrations of PBA were arrested at the S phase. CONCLUSION: The growth inhibitory effect of PBA on gastric cancer cells is associated with alteration of the cell cycle. For moderately-differentiated gastric cancer cells, the cell cycle was arrested at the G0/G1 and G2/M phases. For lowly-differentiated gastric cancer cells, the cell cycle was arrested at the G0/G1 and S phases.

  14. Role of calcium in growth inhibition induced by a novel cell surface sialoglycopeptide

    Science.gov (United States)

    Betz, N. A.; Westhoff, B. A.; Johnson, T. C.; Spooner, B. S. (Principal Investigator)

    1995-01-01

    Our laboratory has purified an 18 kDa cell surface sialoglycopeptide growth inhibitor (CeReS-18) from intact bovine cerebral cortex cells. Evidence presented here demonstrates that sensitivity to CeReS-18-induced growth inhibition in BALB-c 3T3 cells is influenced by calcium, such that a decrease in the calcium concentration in the growth medium results in an increase in sensitivity to CeReS-18. Calcium did not alter CeReS-18 binding to its cell surface receptor and CeReS-18 does not bind calcium directly. Addition of calcium, but not magnesium, to CeReS-18-inhibited 3T3 cells results in reentry into the cell cycle. A greater than 3-hour exposure to increased calcium is required for escape from CeReS-18-induced growth inhibition. The calcium ionophore ionomycin could partially mimic the effect of increasing extracellular calcium, but thapsigargin was ineffective in inducing escape from growth inhibition. Increasing extracellular calcium 10-fold resulted in an approximately 7-fold increase in total cell-associated 45Ca+2, while free intracellular calcium only increased approximately 30%. However, addition of CeReS-18 did not affect total cell-associated calcium or the increase in total cell-associated calcium observed with an increase in extracellular calcium. Serum addition induced mobilization of intracellular calcium and influx across the plasma membrane in 3T3 cells, and pretreatment of 3T3 cells with CeReS-18 appeared to inhibit these calcium mobilization events. These results suggest that a calcium-sensitive step exists in the recovery from CeReS-18-induced growth inhibition. CeReS-18 may inhibit cell proliferation through a novel mechanism involving altering the intracellular calcium mobilization/regulation necessary for cell cycle progression.

  15. l-Methionine inhibits growth of human pancreatic cancer cells

    OpenAIRE

    Benavides, Maximo A.; Bosland, Maarten C.; da Silva, Cássio P.; Sares, Claudia T. Gomes; de Oliveira, Alana M. Cerqueira; Kemp, Rafael; dos Reis, Rodolfo B.; VILMA R. MARTINS; Sampaio, Suely V; Bland, Kirby I; Grizzle, William E.; dos Santos, José S.

    2014-01-01

    We have previously shown that l-methionine inhibits proliferation of breast, prostate, and colon cancer cells. This study extends these findings to BXPC-3 (mutated p53) and HPAC (wild-type p53) pancreatic cancer cells and explores the reversibility of these effects. Cells were exposed to l-methionine (5 mg/ml) for 7 days or for 3 days, followed by 4 days of culture without l-methionine (recovery). Cell proliferation, apoptosis, and cell cycle effects were assessed by flow cytometry after stai...

  16. Phosphorus deficiency inhibits cell division but not growth in the dinoflagellate Amphidinium carterae

    Directory of Open Access Journals (Sweden)

    Meizhen eLi

    2016-06-01

    Full Text Available Phosphorus (P is an essential nutrient element for the growth of phytoplankton. How P deficiency affects population growth and the cell division cycle in dinoflagellates has only been studied in some species, and how it affects photosynthesis and cell growth remains poorly understood. In the present study, we investigated the impact of P deficiency on the cell division cycle, the abundance of the carbon-fixing enzyme Rubisco, and other cellular characteristics in the Gymnodiniales peridinin-plastid species Amphidinium carterae. We found that under P-replete condition, the cell cycle actively progressed in the culture in a 24-hour diel cycle with daily growth rates markedly higher than the P-deficient cultures, in which cells were arrested in the G1 phase and cell size significantly enlarged. The results suggest that, as in previously studied dinoflagellates, P deficiency likely disenables A. carterae to complete DNA duplication or check-point protein phosphorylation. We further found that under P-deficient condition, overall photosystem II quantum efficiency (Fv/Fm ratio and Rubisco abundance decreased but not significantly, while cellular contents of carbon, nitrogen, and proteins increased significantly. These observations indicated that under P-deficiency, this dinoflagellate was able to continue photosynthesis and carbon fixation, such that proteins and photosynthetically fixed carbon could accumulate resulting in continued cell growth in the absence of division. This is likely an adaptive strategy thereby P-limited cells can be ready to resume the cell division cycle upon resupply of phosphorus.

  17. Microcarrier culture of lepidopteran cell lines: implications for growth and recombinant protein production.

    Science.gov (United States)

    Ikonomou, Laertis; Drugmand, Jean-Christophe; Bastin, Georges; Schneider, Yves-Jacques; Agathos, Spiros N

    2002-01-01

    Several microcarrier systems were screened with Sf-9 and High-Five cell lines as to their ability to support cell growth and recombinant (beta-galactosidase) protein production. Growth of both cell lines on compact microcarriers, such as Cytodex-1 and glass beads, was minimal, as cells detached easily from the microcarrier surface and grew as single cells in the medium. Cell growth was also problematic on Cytopore-1 and -2 porous microcarriers. Cells remained attached for several days inside the microcarrier pores, but no cell division and proliferation were observed. On the contrary, insect cells grew well in the interior of Fibra-Cel disks mainly as aggregates at points of fiber intersection, reaching final (plateau) densities of about 4 x 10(6) (Sf-9) and 2.7 x 10(6) (High-Five) cells mL(-1) (8 x 10(6) and 5.5 x 10(6) cells per cm(2) of projected disk area, respectively). Their growth was described well by the logistic equation, which takes into account possible inhibition effects. Beta-Galactosidase (beta-gal) production of Sf-9 cells on Fibra-Cel disks (infected at 3.3 x 10(6) cells mL(-1)) was prolonged (192 h), and specific protein production was similar to that of high-density free cell infection. Cultispher-S microcarriers were found to be a very efficient system for the growth of High-Five cells, whereas no growth of Sf-9 cells took place for the same system. Concentrations of about 9 x 10(6) cells mL(-1) were reached within 120 h, with cell growth in both microcarriers and aggregates, appearance of cellular bridges between microcarriers and aggregates, and eventual formation of macroaggregates incorporating several microcarriers. Specific protein productions after beta-gal baculovirus infection at increasing cell concentrations were almost constant, thus leading to elevated volumetric protein production: final beta-gal titers of 946, 1728, and 1484 U mL(-1) were obtained for infection densities of 3.4, 7.2, and 8.9 x 10(6) cells mL(-1), respectively

  18. Microcarrier culture of lepidopteran cell lines: implications for growth and recombinant protein production.

    Science.gov (United States)

    Ikonomou, Laertis; Drugmand, Jean-Christophe; Bastin, Georges; Schneider, Yves-Jacques; Agathos, Spiros N

    2002-01-01

    Several microcarrier systems were screened with Sf-9 and High-Five cell lines as to their ability to support cell growth and recombinant (beta-galactosidase) protein production. Growth of both cell lines on compact microcarriers, such as Cytodex-1 and glass beads, was minimal, as cells detached easily from the microcarrier surface and grew as single cells in the medium. Cell growth was also problematic on Cytopore-1 and -2 porous microcarriers. Cells remained attached for several days inside the microcarrier pores, but no cell division and proliferation were observed. On the contrary, insect cells grew well in the interior of Fibra-Cel disks mainly as aggregates at points of fiber intersection, reaching final (plateau) densities of about 4 x 10(6) (Sf-9) and 2.7 x 10(6) (High-Five) cells mL(-1) (8 x 10(6) and 5.5 x 10(6) cells per cm(2) of projected disk area, respectively). Their growth was described well by the logistic equation, which takes into account possible inhibition effects. Beta-Galactosidase (beta-gal) production of Sf-9 cells on Fibra-Cel disks (infected at 3.3 x 10(6) cells mL(-1)) was prolonged (192 h), and specific protein production was similar to that of high-density free cell infection. Cultispher-S microcarriers were found to be a very efficient system for the growth of High-Five cells, whereas no growth of Sf-9 cells took place for the same system. Concentrations of about 9 x 10(6) cells mL(-1) were reached within 120 h, with cell growth in both microcarriers and aggregates, appearance of cellular bridges between microcarriers and aggregates, and eventual formation of macroaggregates incorporating several microcarriers. Specific protein productions after beta-gal baculovirus infection at increasing cell concentrations were almost constant, thus leading to elevated volumetric protein production: final beta-gal titers of 946, 1728, and 1484 U mL(-1) were obtained for infection densities of 3.4, 7.2, and 8.9 x 10(6) cells mL(-1), respectively.

  19. Intratracheal Administration of Recombinant Human Keratinocyte Growth Factor Promotes Alveolar Epithelial Cell Proliferation during Compensatory Lung Growth in Rat

    International Nuclear Information System (INIS)

    Keratinocyte growth factor (KGF) is considered to be one of the most important mitogens for lung epithelial cells. The objectives of this study were to confirm the effectiveness of intratracheal injection of recombinant human KGF (rhKGF) during compensatory lung growth and to optimize the instillation protocol. Here, trilobectomy in adult rat was performed, followed by intratracheal rhKGF instillation with low (0.4 mg/kg) and high (4 mg/kg) doses at various time-points. The proliferation of alveolar cells was assessed by the immunostaining for proliferating cell nuclear antigen (PCNA) in the residual lung. We also investigated other immunohistochemical parameters such as KGF, KGF receptor and surfactant protein A as well as terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling. Consequently, intratracheal single injection of rhKGF in high dose group significantly increased PCNA labeling index (LI) of alveolar cells in the remaining lung. Surprisingly, there was no difference in PCNA LI between low and high doses of rhKGF with daily injection, and PCNA LI reached a plateau level with 2 days-consecutive administration (about 60%). Our results indicate that even at low dose, daily intratracheal injection is effective to maintain high proliferative states during the early phase of compensatory lung growth

  20. Intercellular redistribution of cAMP underlies selective suppression of cancer cell growth by connexin26.

    Directory of Open Access Journals (Sweden)

    Anjana Chandrasekhar

    Full Text Available Connexins (Cx, which constitute gap junction intercellular channels in vertebrates, have been shown to suppress transformed cell growth and tumorigenesis, but the mechanism(s still remain largely speculative. Here, we define the molecular basis by which Cx26, but less frequently Cx43 or Cx32, selectively confer growth suppression on cancer cells. Functional intercellular coupling is shown to be required, producing partial blocks of the cell cycle due to prolonged activation of several mitogenic kinases. PKA is both necessary and sufficient for the Cx26 induced growth inhibition in low serum and the absence of anchorage. Activation of PKA was not associated with elevated cAMP levels, but appeared to result from a redistribution of cAMP throughout the cell population, eliminating the cell cycle oscillations in cAMP required for efficient cell cycle progression. Cx43 and Cx32 fail to mediate this redistribution as, unlike Cx26, these channels are closed during the G2/M phase of the cell cycle when cAMP levels peak. Comparisons of tumor cell lines indicate that this is a general pattern, with growth suppression by connexins occurring whenever cAMP oscillates with the cell cycle, and the gap junction remain open throughout the cell cycle. Thus, gap junctional coupling, in the absence of any external signals, provides a general means to limit the mitotic rate of cell populations.

  1. Growth inhibiting effects of antisense eukaryotic expression vector of proliferating cell nuclear antigen gene on human bladder cancer cells

    Institute of Scientific and Technical Information of China (English)

    童强松; 曾甫清; 林晨; 赵军; 鲁功成

    2003-01-01

    Objective To explore the growth inhibiting effects on human bladder cancer by antisense RNA targeting the proliferating cell nuclear antigen (PCNA) gene. Methods The eukaryotic expression vector for antisense PCNA cDNA was constructed and transferred into a bladder cancer EJ cell line. The PCNA expression in the cancer cells was detected by RT-PCR and Western blotting assays. The in vitro proliferation activities of the transferred cells were observed by growth curve, tetrazolium bromide (MTT) colorimetry, tritiated thymidine (3H-TdR)incorporation, flow cytometry and clone formation testing, while its in vivo anti-tumor effects were detected on nude mice allograft models.Results After the antisense vector, pLAPSN, was transferred, cellular PCNA expression was inhibited at both protein and mRNA levels. The growth rates of EJ cells were reduced from 27.91% to 62.07% (P<0.01), with an inhibition of DNA synthesis rate by 52.31% (P<0.01). Transferred cells were blocked at G0/G1 phases in cell-cycle assay, with the clone formation ability decreased by 50.81% (P<0.01). The in vivo carcinogenic abilities of the transferred cancer cells were decreased by 54.23% (P<0.05). Conclusions Antisense PCNA gene transfer could inhibit the growth of bladder cancer cells in vitro and in vivo, which provided an ideal strategy for gene therapy of human cancers.

  2. CAM and cell fate targeting: molecular and energetic insights into cell growth and differentiation.

    Science.gov (United States)

    Ventura, Carlo

    2005-09-01

    Evidence-based medicine is switching from the analysis of single diseases at a time toward an integrated assessment of a diseased person. Complementary and alternative medicine (CAM) offers multiple holistic approaches, including osteopathy, homeopathy, chiropractic, acupuncture, herbal and energy medicine and meditation, all potentially impacting on major human diseases. It is now becoming evident that acupuncture can modify the expression of different endorphin genes and the expression of genes encoding for crucial transcription factors in cellular homeostasis. Extremely low frequency magnetic fields have been found to prime the commitment to a myocardial lineage in mouse embryonic stem cells, suggesting that magnetic energy may direct stem cell differentiation into specific cellular phenotypes without the aid of gene transfer technologies. This finding may pave the way to novel approaches in tissue engineering and regeneration. Different ginseng extracts have been shown to modulate growth and differentiation in pluripotent cells and to exert wound-healing and antitumor effects through opposing activities on the vascular system, prompting the hypothesis that ancient compounds may be the target for new logics in cell therapy. These observations and the subtle entanglement among different CAM systems suggest that CAM modalities may deeply affect both the signaling and transcriptional level of cellular homeostasis. Such a perception holds promises for a new era in CAM, prompting reproducible documentation of biological responses to CAM-related strategies and compounds. To this end, functional genomics and proteomics and the comprehension of the cell signaling networks may substantially contribute to the development of a molecular evidence-based CAM. PMID:16136206

  3. CAM and Cell Fate Targeting: Molecular and Energetic Insights into Cell Growth and Differentiation

    Directory of Open Access Journals (Sweden)

    Carlo Ventura

    2005-01-01

    Full Text Available Evidence-based medicine is switching from the analysis of single diseases at a time toward an integrated assessment of a diseased person. Complementary and alternative medicine (CAM offers multiple holistic approaches, including osteopathy, homeopathy, chiropractic, acupuncture, herbal and energy medicine and meditation, all potentially impacting on major human diseases. It is now becoming evident that acupuncture can modify the expression of different endorphin genes and the expression of genes encoding for crucial transcription factors in cellular homeostasis. Extremely low frequency magnetic fields have been found to prime the commitment to a myocardial lineage in mouse embryonic stem cells, suggesting that magnetic energy may direct stem cell differentiation into specific cellular phenotypes without the aid of gene transfer technologies. This finding may pave the way to novel approaches in tissue engineering and regeneration. Different ginseng extracts have been shown to modulate growth and differentiation in pluripotent cells and to exert wound-healing and antitumor effects through opposing activities on the vascular system, prompting the hypothesis that ancient compounds may be the target for new logics in cell therapy. These observations and the subtle entanglement among different CAM systems suggest that CAM modalities may deeply affect both the signaling and transcriptional level of cellular homeostasis. Such a perception holds promises for a new era in CAM, prompting reproducible documentation of biological responses to CAM-related strategies and compounds. To this end, functional genomics and proteomics and the comprehension of the cell signaling networks may substantially contribute to the development of a molecular evidence–based CAM.

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

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

  5. Growth factor-and cytokine-stimulated endothelial progenitor cells in post-ischemic cerebral neovascularization

    Institute of Scientific and Technical Information of China (English)

    Philip V.Peplow

    2014-01-01

    Endothelial progenitor cells are resident in the bone marrow blood sinusoids and circulate in the peripheral circulation. They mobilize from the bone marrow after vascular injury and home to the site of injury where they differentiate into endothelial cells. Activation and mobilization of endothelial progenitor cells from the bone marrow is induced via the production and release of endothelial progenitor cell-activating factors and includes speciifc growth factors and cytokines in response to peripheral tissue hypoxia such as after acute ischemic stroke or trauma. Endotheli-al progenitor cells migrate and home to speciifc sites following ischemic stroke via growth factor/cytokine gradients. Some growth factors are less stable under acidic conditions of tissue isch-emia, and synthetic analogues that are stable at low pH may provide a more effective therapeutic approach for inducing endothelial progenitor cell mobilization and promoting cerebral neovas-cularization following ischemic stroke.

  6. [Effects of several factors on cell growth and ginsenoside accumulation of Panax ginseng suspension culture].

    Science.gov (United States)

    Li, Tie-Jun; Lian, Mei-Lan; Yu, Dan; Shao, Chun-Hui; Piao, Xuan-Chun

    2013-12-01

    To improve cell suspension culture system of Panax ginseng, the dynamic of cell growth and medium consumption were studied, and the effects of filter on the culture vessel, revolution number, and inoculation density on cell growth and ginsenoside accumulation were also investigated. The maximum cell growth and ginsenoside accumulation was found on the 20th days of suspension culture, therefore, 20 days were confirmed as a suitable culture period for mass production of ginsenoside. Cell growth and ginsenoside content were promoted when the culture vessel had a ventilated filter. Revolution speed during suspension culture affected cell growth, but not ginsenoside content, a peak of ginsenoside productivity was found in the treatment of 120 r x min(-1). Inoculation density also influenced cell growth and ginsenoside accumulation, inoculation density of 6 g was better than other inoculation densities, the ginsenoside content and productivity were up to 12.8 mg x g(-1) DW and 146.6 mg x L(-1), respectively. PMID:24791486

  7. Experimental studies on ultralow frequency pulsed gradient magnetic field inducing apoptosis of cancer cell and inhibiting growth of cancer cell

    Institute of Scientific and Technical Information of China (English)

    曾繁清; 郑从义; 张新晨; 李宗山; 李朝阳; 王川婴; 张新松; 黄晓玲; 张沪生

    2002-01-01

    The morphology characteristics of cell apoptosis of the malignant tumour cells in magnetic field-treated mouse was observed for the first time. The apoptotic cancer cell contracted, became rounder and divorced from adjacent cells; the heterochromatin condensed and coagulated together along the inner side of the nuclear membrane; the endoplasmic reticulums(ER) expanded and fused with the cellular membrane; many apoptotic bodies which were packed by the cellular membrane appeared and were devoured by some lymphocytes and plasma. Apoptosis of cancer cells was detected by terminal deoxynucleotidyl transferase mediated in situ nick end labeling(TUNEL). It was found that the number of apoptosis cancer cells of the sample treated by the magnetic field is more than that of the control sample. The growth of malignant tumour in mice was inhibited and the ability of immune cell to dissolve cancer cells was improved by ultralow frequency(ULF) pulsed gradient magnetic field; the nuclei DNA contents decreased, indicating that magnetic field can block DNA replication and inhibit mitosis of cancer cells. It was suggested that magnetic field could inhibit the metabolism of cancer cell, lower its malignancy, and restrain its rapid and heteromorphic growth. Since ULF pulsed gradient magnetic field can induce apoptosis of cancer cells and inhibit the growth of malignant tumour, it could be used as a new method to treat cancer.

  8. Titanium oxide as substrate for neural cell growth.

    Science.gov (United States)

    Carballo-Vila, Mónica; Moreno-Burriel, Berta; Chinarro, Eva; Jurado, José R; Casañ-Pastor, Nieves; Collazos-Castro, Jorge E

    2009-07-01

    Titanium oxide has antiinflammatory activity and tunable electrochemical behavior that make it an attractive material for the fabrication of implantable devices. The most stable composition is TiO2 and occurs mainly in three polymorphs, namely, anatase, rutile, and brookite, which differ in its crystallochemical properties. Here, we report the preparation of rutile surfaces that permit good adherence and axonal growth of cultured rat cerebral cortex neurons. Rutile disks were obtained by sinterization of TiO2 powders of commercial origin or precipitated from hydrolysis of Ti(IV)-isopropoxide. Commercial powders sintered at 1300-1600 degrees C produced rutile surfaces with abnormal grain growth, probably because of impurities of the powders. Neurons cultured on those surfaces survived in variable numbers and showed fewer neurites than on control materials. On the other hand, rutile sintered from precipitated powders had less contaminants and more homogenous grain growth. By adjusting the thermal treatment it was possible to obtain surfaces performing well as substrate for neuron survival for at least 10 days. Some surfaces permitted normal axonal elongation, whereas dendrite growth was generally impaired. These findings support the potential use of titanium oxide in neuroprostheses and other devices demanding materials with enhanced properties in terms of biocompatibility and axon growth promotion. PMID:18481786

  9. Homeobox A7 increases cell proliferation by up-regulation of epidermal growth factor receptor expression in human granulosa cells

    Directory of Open Access Journals (Sweden)

    Yanase Toshihiko

    2010-06-01

    Full Text Available Abstract Background Homeobox (HOX genes encode transcription factors, which regulate cell proliferation, differentiation, adhesion, and migration. The deregulation of HOX genes is frequently associated with human reproductive system disorders. However, knowledge regarding the role of HOX genes in human granulosa cells is limited. Methods To determine the role of HOXA7 in the regulation and associated mechanisms of cell proliferation in human granulosa cells, HOXA7 and epidermal growth factor receptor (EGFR expressions were examined in primary granulosa cells (hGCs, an immortalized human granulosa cell line, SVOG, and a granulosa tumor cell line, KGN, by real-time PCR and Western blotting. To manipulate the expression of HOXA7, the HOXA7 specific siRNA was used to knockdown HOXA7 in KGN. Conversely, HOXA7 was overexpressed in SVOG by transfection with the pcDNA3.1-HOAX7 vector. Cell proliferation was measured by the MTT assay. Results Our results show that HOXA7 and EGFR were overexpressed in KGN cells compared to hGCs and SVOG cells. Knockdown of HOXA7 in KGN cells significantly decreased cell proliferation and EGFR expression. Overexpression of HOXA7 in SVOG cells significantly promoted cell growth and EGFR expression. Moreover, the EGF-induced KGN proliferation was abrogated, and the activation of downstream signaling was diminished when HOXA7 was knocked down. Overexpression of HOXA7 in SVOG cells had an opposite effect. Conclusions Our present study reveals a novel mechanistic role for HOXA7 in modulating granulosa cell proliferation via the regulation of EGFR. This finding contributes to the knowledge of the pro-proliferation effect of HOXA7 in granulosa cell growth and differentiation.

  10. Human fetal liver stromal cells that overexpress bFGF support growth and maintenance of human embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Jiafei Xi

    Full Text Available In guiding hES cell technology toward the clinic, one key issue to be addressed is to culture and maintain hES cells much more safely and economically in large scale. In order to avoid using mouse embryonic fibroblasts (MEFs we isolated human fetal liver stromal cells (hFLSCs from 14 weeks human fetal liver as new human feeder cells. hFLSCs feeders could maintain hES cells for 15 passages (about 100 days. Basic fibroblast growth factor (bFGF is known to play an important role in promoting self-renewal of human embryonic stem (hES cells. So, we established transgenic hFLSCs that stably express bFGF by lentiviral vectors. These transgenic human feeder cells--bFGF-hFLSCs maintained the properties of H9 hES cells without supplementing with any exogenous growth factors. H9 hES cells culturing under these conditions maintained all hES cell features after prolonged culture, including the developmental potential to differentiate into representative tissues of all three embryonic germ layers, unlimited and undifferentiated proliferative ability, and maintenance of normal karyotype. Our results demonstrated that bFGF-hFLSCs feeder cells were central to establishing the signaling network among bFGF, insulin-like growth factor 2 (IGF-2, and transforming growth factor β (TGF-β, thereby providing the framework in which hES cells were instructed to self-renew or to differentiate. We also found that the conditioned medium of bFGF-hFLSCs could maintain the H9 hES cells under feeder-free conditions without supplementing with bFGF. Taken together, bFGF-hFLSCs had great potential as feeders for maintaining pluripotent hES cell lines more safely and economically.

  11. Regulation of MCF-7 breast cancer cell growth by beta-estradiol sulfation.

    Science.gov (United States)

    Falany, Josie L; Macrina, Nancy; Falany, Charles N

    2002-07-01

    Estrogen stimulation is an important factor in human breast cancer cell growth and development. Metabolism of beta-estradiol (E2), the major endogenous human estrogen, is important in regulating both the level and activity of the hormone in breast tissues. Conjugation of E2 with a sulfonate moiety is an inactivation process since the sulfate ester formed by this reaction can not bind and activate the estrogen receptor. In human tissues including the breast, estrogen sulfotransferase (EST, SULT1E1) is responsible for high affinity E2 sulfation activity. EST is expressed in human mammary epithelial (HME) cells but not in most cultured breast cancer cell lines, including estrogen responsive MCF-7 cells. Stable expression of EST in MCF-7 cells at levels similar to those detected in HME cells significantly inhibits cell growth at physiologically relevant E2 concentrations. The mechanism of cell growth inhibition involves the abrogation of responses observed in growth factor expression in MCF-7 cells following E2 stimulation. MCF-7 cells expressing EST activity did not show a decrease in estrogen receptor-alpha levels, nor a characteristic increase in progesterone receptor or decrease in transforming growth factor-beta expression upon exposure to 100 pM or 1 nM E2. The lack of response in these MCF-7 cells is apparently due to the rapid sulfation and inactivation of free E2 by EST. These results suggest that loss of EST expression in the transformation of normal breast tissues to breast cancer may be an important factor in increasing the growth responsiveness of preneoplastic or tumor cells to estrogen stimulation.

  12. Growth and differentiation of human lens epithelial cells in vitro on matrix

    Science.gov (United States)

    Blakely, E. A.; Bjornstad, K. A.; Chang, P. Y.; McNamara, M. P.; Chang, E.; Aragon, G.; Lin, S. P.; Lui, G.; Polansky, J. R.

    2000-01-01

    PURPOSE: To characterize the growth and maturation of nonimmortalized human lens epithelial (HLE) cells grown in vitro. METHODS: HLE cells, established from 18-week prenatal lenses, were maintained on bovine corneal endothelial (BCE) extracellular matrix (ECM) in medium supplemented with basic fibroblast growth factor (FGF-2). The identity, growth, and differentiation of the cultures were characterized by karyotyping, cell morphology, and growth kinetics studies, reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence, and Western blot analysis. RESULTS: HLE cells had a male, human diploid (2N = 46) karyotype. The population-doubling time of exponentially growing cells was 24 hours. After 15 days in culture, cell morphology changed, and lentoid formation was evident. Reverse transcription-polymerase chain reaction (RT-PCR) indicated expression of alphaA- and betaB2-crystallin, fibroblast growth factor receptor 1 (FGFR1), and major intrinsic protein (MIP26) in exponential growth. Western analyses of protein extracts show positive expression of three immunologically distinct classes of crystallin proteins (alphaA-, alphaB-, and betaB2-crystallin) with time in culture. By Western blot analysis, expression of p57(KIP2), a known marker of terminally differentiated fiber cells, was detectable in exponential cultures, and levels increased after confluence. MIP26 and gamma-crystallin protein expression was detected in confluent cultures, by using immunofluorescence, but not in exponentially growing cells. CONCLUSIONS: HLE cells can be maintained for up to 4 months on ECM derived from BCE cells in medium containing FGF-2. With time in culture, the cells demonstrate morphologic characteristics of, and express protein markers for, lens fiber cell differentiation. This in vitro model will be useful for investigations of radiation-induced cataractogenesis and other studies of lens toxicity.

  13. Autonomous growth potential of leukemia blast cells is associated with poor prognosis in human acute leukemias

    Directory of Open Access Journals (Sweden)

    Jakubowski Ann A

    2009-12-01

    Full Text Available Abstract We have described a severe combined immunodeficiency (SCID mouse model that permits the subcutaneous growth of primary human acute leukemia blast cells into a measurable subcutaneous nodule which may be followed by the development of disseminated disease. Utilizing the SCID mouse model, we examined the growth potential of leukemic blasts from 133 patients with acute leukemia, (67 acute lymphoblastic leukemia (ALL and 66 acute myeloid leukemia (AML in the animals after subcutaneous inoculation without conditioning treatment. The blasts displayed three distinct growth patterns: "aggressive", "indolent", or "no tumor growth". Out of 133 leukemias, 45 (33.8% displayed an aggressive growth pattern, 14 (10.5% displayed an indolent growth pattern and 74 (55.6% did not grow in SCID mice. The growth probability of leukemias from relapsed and/or refractory disease was nearly 3 fold higher than that from patients with newly diagnosed disease. Serial observations found that leukemic blasts from the same individual, which did not initiate tumor growth at initial presentation and/or at early relapse, may engraft and grow in the later stages of disease, suggesting that the ability of leukemia cells for engraftment and proliferation was gradually acquired following the process of leukemia progression. Nine autonomous growing leukemia cell lines were established in vitro. These displayed an aggressive proliferation pattern, suggesting a possible correlation between the capacity of human leukemia cells for autonomous proliferation in vitro and an aggressive growth potential in SCID mice. In addition, we demonstrated that patients whose leukemic blasts displayed an aggressive growth and dissemination pattern in SClD mice had a poor clinical outcome in patients with ALL as well as AML. Patients whose leukemic blasts grew indolently or whose leukemia cells failed to induce growth had a significantly longer DFS and more favorable clinical course.

  14. Growth inhibition and gene induction in human hepatocellular carcinoma cell exposed to sodium 4-phenylbutanoate

    Institute of Scientific and Technical Information of China (English)

    WANG Chun-ting,; MENG Mei; ZHANG Ji-cheng; JIN Chang-jun; JIANG Jin-jiao; REN Hong-sheng; JIANG Jun-mei; QIN Cheng-yong; YU Dong-qing

    2008-01-01

    Background Sodium 4-phenylbutanoate (NaPB) can induce cellular differentiation and cell cycle arrest.However,its potential anticancer properties in hepatocellular carcinoma and influence on normal liver cell are still unclear.We observed the effects of NaPB on growth inhibition,including differentiation and phase growth arrest in normal liver cell line L-02 and hepatocellular carcinoma cell line Bel-7402.Furthermore,we investigated its mechanism in Bel-7402.Methods Hepatocellular carcinoma cells Bel-7402 and normal liver cell line L-02 were treated with NaPB at different concentrations.Light microscopy was used to find morphological change in cells.Cell cycle was detected by flow cytometry.Expression of acetylating histone H4 and of histones deacetylase 4 (HDAC4) were determined by Western blot.The expression of P21WAF1/CIP1 and E-cadherin were observed through immunocytochemistry.Results NaPB treatment led to time dependent growth inhibition in hepatocellular carcinoma cells Bel-7402.NaPB treatment caused a significant decline in the fraction of S phase cells and a significant increase in G0/G1 cells.NaPB increased the expression of P21WAF1/CIP1 and E-cadherin in Bel-7402 and significantly decreased the level of HDAC4 in Bel-7402.NaPB significantly improved the level of acetylating histone H4.The normal liver cell line L-02 showed no distinct changes under treatment with NaPB.Conclusions NaPB inhibited the growth of hepatocellular carcinoma cells Bel-7402 and induced partial differentiation through enhancing the acetylating histones.In Bel-7402,the expressions of P21WAF1/CIP1 and E-cadherin may be related to level of acetylating histones and inhibition of cellular growth.NaPB showed no significant effect on normal liver cells.

  15. Hypoxia is a key regulator of limbal epithelial stem cell growth and differentiation

    DEFF Research Database (Denmark)

    Bath, Chris; Yang, Sufang; Muttuvelu, Danson;

    2013-01-01

    The aim of this study was to determine whether the growth and differentiation of limbal epithelial stem cell cultures could be controlled through manipulation of the oxygen tension. Limbal epithelial cells were isolated from corneoscleral disks, and cultured using either feeder cells in a growth......, progression through cell cycle, colony forming efficiency (CFE), and expression of stem cell (ABCG2 and p63α) and differentiation (CK3) markers was determined throughout the culture period of up to 18 days. Low oxygen levels favored a stem cell phenotype with a lower proliferative rate, high CFE......, and a relatively higher expression of ABCG2 and p63α, while higher levels of oxygen led not only to decreased CFE but also to increased proportion of differentiated cells positive for CK3. Hypoxic cultures may thus potentially improve stem cell grafts for cultured limbal epithelial transplantation (CLET)....

  16. Growth in Agarose of Human Cells Infected with Cytomegalovirus

    Science.gov (United States)

    Lang, David J.; Montagnier, Luc; Latarjet, Raymond

    1974-01-01

    After infection by human cytomegalovirus (CMV), human diploid fibroblasts could grow in agarose medium for several generations. Clones of infected cells grew for weeks, although in every case they ultimately underwent lysis owing to the cytopathic effect of the virus. Virus was inoculated at high dilution and after UV irradiation in an effort to derive cells infected with noninfectious defective particles still capable of inducing cell stimulation. Dilute or irradiated virus occasionally yielded large colonies of replicating cells, although permanent transformation was not observed. One clone derived from UV-CMV-infected cells was passaged four times before undergoing lysis. During these passages the cells exhibited alterations in morphology and orientation. Images PMID:4367907

  17. Growth arrest and apoptosis of human hepatocellular carcinoma cells induced by hexamethylene bisacetamide

    OpenAIRE

    Ouyang, Gao-Liang; Cai, Qiu-Feng; Min LIU; Chen, Rui-Chuan; Huang, Zhi; Jiang, Rui-Sheng; Chen, Fu; Hong, Shui-Gen; Bao, Shi-Deng

    2004-01-01

    AIM: To investigate the cellular effects of hybrid polar compound hexamethylene bisacetamide (HMBA) on the growth and apoptosis of human hepatocellular carcinoma cells and to provide the molecular mechanism for potential application of HMBA in the treatment of liver cancer.

  18. Synthesis of 2-Heterocyclomethyl-5-diphenylmethylenecyclopentanone Hydrochlorides and their Inhibitory Effect on Tumor Cell Growth

    Institute of Scientific and Technical Information of China (English)

    Yun Hai ZHANG; Lin Xiang ZHAO; Zhen Jun BIAN; Rui WANG; Fu Yuan SUN

    2006-01-01

    Sixteen new 2-heterocyclomethyl-5-diphenylmethylenecyclopentanone hydrochlorides were designed and synthesized. The growth inhibitory effect of these compounds in vitro was conducted using a MTT assay in human breast cancer T47D cells.

  19. A GROWTH INHIBITOR SECRETED FROM CULTURED RABBIT SMOOTHMUSCLE CELLS IS DISTINCT FROM TGF-β

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To ascertain whether the growth inhibitor in conditioned medium from cultured rabbit arte rial cells is distinct from TGF-β. Methods Rabbit aortic smooth muscle ceils were grown from explained segments of the aorta. Conditioned medium from cultured rabbit aortic smooth muscle ceils and anti-TGF-β were employed in this study. Smooth muscle cell proliferation was measured by XTT detection (Boehringer Mannheim). Results Acidified conditioned medium from smooth muscle ceils had significantly stronger effects of growth inhibition than controls, and anti-TGF-β did not affect the growth inhibitory effect of conditioned medium from cultured rabbit arterial smooth muscle cells. Conclusion The growth inhibiting substance in conditioned medium from cultured rabbit aortic smooth muscle cells is distinct from TGF-β.

  20. FETAL DEXAMETHASONE EXPOSURE ACCELERATES DEVELOPMENT OF RENAL FUNCTION: RELATIONSHIP TO DOSE, CELL DIFFERENTIATION AND GROWTH INHIBITION

    Science.gov (United States)

    Fetal exposure to high doses of glucocorticoids slows cellular development and impairs organ performance, in association with growth retardation. evertheless, low doses of glucocorticoids may enhance cell differentiation and accelerate specific functions. he current study examine...

  1. Keratinocyte Growth Inhibition through the Modification of Wnt Signaling by Androgen in Balding Dermal Papilla Cells

    OpenAIRE

    Kitagawa, Tomoko; Matsuda, Ken-ichi; Inui, Shigeki; Takenaka, Hideya; Katoh, Norito; Itami, Satoshi; Kishimoto, Saburo; Kawata, Mitsuhiro

    2009-01-01

    Context/Objective: Androgen induces androgenetic alopecia (AGA), which has a regressive effect on hair growth from the frontal region of the scalp. Conversely, Wnt proteins are known to positively affect mammalian hair growth. We hypothesized that androgen reduces hair growth via an interaction with the Wnt signaling system. The objective of this study was to investigate the effect of androgen on Wnt signaling in dermal papilla (DP) cells.

  2. Growth factor treatment enhances vestibular hair cell renewal and results in improved vestibular function

    OpenAIRE

    Kopke, Richard D; Jackson, Ronald L; Li, Geming; Rasmussen, Mark D.; Hoffer, Michael E.; Frenz, Dorothy A.; Costello, Michael; Schultheiss, Peter; Van De Water, Thomas R.

    2001-01-01

    The vestibules of adult guinea pigs were lesioned with gentamicin and then treated with perilymphatic infusion of either of two growth factor mixtures (i.e., GF I or GF II). GF I contained transforming growth factor α (TGFα), insulin-like growth factor type one (IGF-1), and retinoic acid (RA), whereas GF II contained those three factors and brain-derived neurotrophic factor. Treatment with GF I significantly enhanced vestibular hair cell renewal in ototoxin-damaged ...

  3. Severe cell reduction in the future brain cortex in human growth-restricted fetuses and infants

    DEFF Research Database (Denmark)

    Samuelsen, Grethe B; Pakkenberg, Bente; Bogdanović, Nenad;

    2007-01-01

    OBJECTIVE: The objective of the study was to test the hypothesis that the total number of cells in the cortical part of the cerebral wall is the same in intrauterine growth-restricted (IUGR) fetuses, compared with normally grown fetuses. STUDY DESIGN: The total cell number in the cerebral wall...... with controls. The daily increase in brain cells in the future cortex was only half of that of the controls. In the 3 other developmental zones, no significant differences in cell numbers could be demonstrated. CONCLUSIONS: IUGR in humans is associated with a severe reduction in cortical growth...

  4. Induction of growth in kidney epithelial cells in culture by Na+.

    OpenAIRE

    Toback, F G

    1980-01-01

    The role of Na+ in the regulation of cell growth was examined in quiescent, high-density cultures of kidney epithelial cells of the BSC-1 line. The addition of NaCl to the medium increased the number of cells initiating DNA synthesis in a concentration-dependent manner after serum stimulation. In the presence of added NaCl, cells in confluent cultures grew to high density at an increased rate, whereas growth in sparse cultures was retarded. These results suggest that, in the presence of serum...

  5. Human growth hormone binding and stimulation of insulin biosynthesis in cloned rat insulinoma cells

    DEFF Research Database (Denmark)

    Billestrup, Nils

    1985-01-01

    Binding of 125I labelled human growth hormone to cloned insulin producing RIN-5AH cells is described. Binding was specific for somatotropic hormones since both human and rat growth hormone could compete for binding sites, whereas much higher concentrations of lactogenic hormones were needed to in...

  6. MITOGENIC SIGNALS CONTROL TRANSLATION OF THE EARLY GROWTH-RESPONSE GENE-1 IN MYOGENIC CELLS

    NARCIS (Netherlands)

    MAASS, A; GROHE, C; OBERDORF, S; SUKHATME, VP; VETTER, H; NEYSES, L

    1994-01-01

    Muscle is a major site of expression of the early growth reponse gene-1 (Egr-1). To investigate its role in muscle proliferation and/or differentiation we studied the effect of a variety of growth factors on cultured mouse muscle So18 cells. Three groups of responses could be distinguished: 1. AII,

  7. THE INFLUENCE OF MAGNETIC FIELDS ON INHIBITION OF MCF-7 CELL GROWTH BY TAMOXIFEN

    Science.gov (United States)

    THE INFLUENCE OF MAGNETIC FIELDS ON INHIBITION OF MCF-7 CELL GROWTH BY TAMOXIFEN.Harland and Liburdy (1) reported that 1.2-uT, 60-Hz magnetic fields could significantly block the inhibitory action of pharmacological levels of tamoxifen (10-7 M) on the growth of MCF-7 human br...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-07-01

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

  9. Targeting and Regulation of Cell Wall Synthesis During Tip Growth in Plants

    Institute of Scientific and Technical Information of China (English)

    Fangwei Gu; Erik Nielsen

    2013-01-01

    Root hairs and pollen tubes are formed through tip growth, a process requiring synthesis of new cell wall material and the precise targeting and integration of these components to a selected apical plasma membrane domain in the growing tips of these cells. Presence of a tip-focused calcium gradient, control of actin cytoskeleton dynamics, and formation and targeting of secretory vesicles are essential to tip growth. Similar to cells undergoing diffuse growth, cellulose, hemi-celluloses, and pectins are also deposited in the growing apices of tip-growing cells. However, differences in the manner in which these cell wall components are targeted and inserted in the expanding portion of tip-growing cells is reflected by the identification of elements of the plant cell wall synthesis machinery which have been shown to play unique roles in tip-growing cells. In this review, we summarize our current understanding of the tip growth process, with a particular focus on the subcellular targeting of newly synthesized cell wall components, and their roles in this form of plant cell expansion.

  10. Nerve growth factor promotes in vitro proliferation of neural stem cells from tree shrews

    Directory of Open Access Journals (Sweden)

    Liu-lin Xiong

    2016-01-01

    Full Text Available Neural stem cells promote neuronal regeneration and repair of brain tissue after injury, but have limited resources and proliferative ability in vivo. We hypothesized that nerve growth factor would promote in vitro proliferation of neural stem cells derived from the tree shrews, a primate-like mammal that has been proposed as an alternative to primates in biomedical translational research. We cultured neural stem cells from the hippocampus of tree shrews at embryonic day 38, and added nerve growth factor (100 µg/L to the culture medium. Neural stem cells from the hippocampus of tree shrews cultured without nerve growth factor were used as controls. After 3 days, fluorescence microscopy after DAPI and nestin staining revealed that the number of neurospheres and DAPI/nestin-positive cells was markedly greater in the nerve growth factor-treated cells than in control cells. These findings demonstrate that nerve growth factor promotes the proliferation of neural stem cells derived from tree shrews.

  11. In vitro growth inhibition of human cancer cells by novel honokiol analogs

    OpenAIRE

    Lin, Jyh Ming; Prakasha Gowda, A. S.; Sharma, Arun K.; Amin, Shantu

    2012-01-01

    Honokiol possesses many pharmacological activities including anti-cancer properties. Here in, we designed and synthesized honokiol analogs that block major honokiol metabolic pathway which may enhance their effectiveness. We studied their cytotoxicity in human cancer cells and evaluate possible mechanism of cell cycle arrest. Two analogs, namely 2 and 4, showed much higher growth inhibitory activity in A549 human lung cancer cells and significant increase of cell population in the G0-G1 phase...

  12. Inhibition of the growth of transformed and neoplastic cells by the dipeptide carnosine.

    OpenAIRE

    Holliday, R; McFarland, G. A.

    1996-01-01

    Human diploid fibroblasts growth normally in medium containing physiological concentrations of the naturally occurring dipeptide carnosine (beta-alanyl-L-histidine). These concentrations are cytotoxic to transformed and neoplastic cells lines in modified Eagle medium (MEM), whereas these cells grow vigorously in Dulbecco's modified Eagle medium (DMEM) containing carnosine. This difference is due to the presence of 1 mM sodium pyruvate in DMEM. Seven human cell lines and two rodent cell lines ...

  13. Functional maturation of growth hormone cells in the anterior pituitary gland of the fetus

    OpenAIRE

    Nogami, Haruo; Hisano, Setsuji

    2008-01-01

    Recent studies have disclosed the molecular mechanisms responsible for the phenotype determination of the anterior pituitary cell types. However, as far as growth hormone (GH) cells are concerned, particular extra-cellular cues are required for the initiation of GH and GH-releasing hormone (GHRH)-receptor gene production in addition to the expression of the cell type specific transcription factor, pit-1. The glucocorticoids play a principal role in the functional maturation of nascent GH cell...

  14. Epidermal growth factor promotes proliferation of dermal papilla cells via Notch signaling pathway.

    Science.gov (United States)

    Zhang, Haihua; Nan, Weixiao; Wang, Shiyong; Zhang, Tietao; Si, Huazhe; Wang, Datao; Yang, Fuhe; Li, Guangyu

    2016-08-01

    The effect of epidermal growth factor (EGF) on the development and growth of hair follicle is controversial. In the present study, 2-20 ng/ml EGF promoted the growth of mink hair follicles in vitro, whereas 200 ng/ml EGF inhibited follicle growth. Further, dermal papilla (DP) cells, a group of mesenchymal cells that govern hair follicle development and growth, were isolated and cultured in vitro. Treatment with or forced expression of EGF accelerated proliferation and induced G1/S transition in DP cells. Moreover, EGF upregulated the expression of DP mesenchymal genes, such as alkaline phosphatase (ALP) and insulin-like growth factor (IGF-1), as well as the Notch pathway molecules including Notch1, Jagged1, Hes1 and Hes5. In addition, inhibition of Notch signaling pathway by DAPT significantly reduced the basal and EGF-enhanced proliferation rate, and also suppressed cell cycle progression. We also show that the expression of several follicle-regulatory genes, such as Survivin and Msx2, were upregulated by EGF, and was inhibited by DAPT. In summary, our study demonstrates that the concentration of EGF is critical for the switch between hair follicle growth and inhibition, and EGF promotes DP cell proliferation via Notch signaling pathway.

  15. Growth retardation of paramecium and mouse cells by shielding them from background radiation

    International Nuclear Information System (INIS)

    In the 1970s and 1980s, Planel et al. reported that the growth of paramecia was decreased by shielding them from background radiation. In the 1990s, Takizawa et al. found that mouse cells displayed a decreased growth rate under shielded conditions. The purpose of the present study was to confirm that growth is impaired in organisms that have been shielded from background radiation. Radioprotection was produced with a shielding chamber surrounded by a 15 cm thick iron wall and a 10 cm thick paraffin wall that reduced the γ ray and neutron levels in the chamber to 2% and 25% of the background levels, respectively. Although the growth of Paramecium tetraurelia was not impaired by short-term radioprotection (around 10 days), which disagreed with the findings of Planel et al., decreased growth was observed after long-term (40-50 days) radiation shielding. When mouse lymphoma L5178Y cells were incubated inside or outside of the shielding chamber for 7 days, the number of cells present on the 6th and 7th days under the shielding conditions was significantly lower than that present under the non-shielding conditions. These inhibitory effects on cell growth were abrogated by the addition of a 137Cs γ-ray source disk to the chamber. Furthermore, no growth retardation was observed in XRCC4-deficient mouse M10 cells, which display impaired DNA double strand break repair. (author)

  16. De novo peroxisome biogenesis in Penicillium chrysogenum is not dependent on the Pex11 family members or Pex16.

    Directory of Open Access Journals (Sweden)

    Łukasz Opaliński

    Full Text Available We have analyzed the role of the three members of the Pex11 protein family in peroxisome formation in the filamentous fungus Penicillium chrysogenum. Two of these, Pex11 and Pex11C, are components of the peroxisomal membrane, while Pex11B is present at the endoplasmic reticulum. We show that Pex11 is a major factor involved in peroxisome proliferation. We also demonstrate that P. chrysogenum cells deleted for known peroxisome fission factors (all Pex11 family proteins and Vps1 still contain peroxisomes. Interestingly, we find that, unlike in mammals, Pex16 is not essential for peroxisome biogenesis in P. chrysogenum, as partially functional peroxisomes are present in a pex16 deletion strain. We also show that Pex16 is not involved in de novo biogenesis of peroxisomes, as peroxisomes were still present in quadruple Δpex11 Δpex11B Δpex11C Δpex16 mutant cells. By contrast, pex3 deletion in P. chrysogenum led to cells devoid of peroxisomes, suggesting that Pex3 may function independently of Pex16. Finally, we demonstrate that the presence of intact peroxisomes is important for the efficiency of ß-lactam antibiotics production by P. chrysogenum. Remarkably, distinct from earlier results with low penicillin producing laboratory strains, upregulation of peroxisome numbers in a high producing P. chrysogenum strain had no significant effect on penicillin production.

  17. Accommodating the difference in students’ prior knowledge of cell growth kinetics

    OpenAIRE

    Seters, van, J.R.; Ossevoort, M.A.; Goedhart, M.J.; Tramper, J.

    2011-01-01

    This paper describes the development and benefits of an adaptive digital module on cell growth to tackle the problem of educating a heterogeneous group of students at the beginning of an undergraduate course on process engineering. Aim of the digital module is to provide students with the minimal level of knowledge on cell growth kinetics they need to comprehend the content knowledge of the subsequent lectures and pass the exam. The module was organised to offer the subject matter in a differ...

  18. Differential growth rates of Candida utilis mother and daughter cells under phased cultivation.

    OpenAIRE

    Thomas, K C; Dawson, P S; Gamborg, B L

    1980-01-01

    The yeast Candida utilis was continuously synchronized by the phased method of cultivation with the nitrogen source as the growth-limiting nutrient. The doubling time (phasing period) of cells was 6 h. Both cell number and deoxyribonucleic acid synthesis showed a characteristic stepwise increase during the phased growth. The time of bud emergence coincided with the time of initiation of deoxyribonucleic acid synthesis. Size distribution studies combined with microscopic analysis showed that t...

  19. The synthetic inhibitor of Fibroblast Growth Factor Receptor PD166866 controls negatively the growth of tumor cells in culture

    Directory of Open Access Journals (Sweden)

    Castelli Mauro

    2009-12-01

    Full Text Available Abstract Background Many experimental data evidence that over-expression of various growth factors cause disorders in cell proliferation. The role of the Fibroblast Growth Factors (FGF in growth control is indisputable: in particular, FGF1 and its tyrosine kinase receptor (FGFR1 act through a very complex network of mechanisms and pathways. In this work we have evaluated the antiproliferative activity effect of PD166866, a synthetic molecule inhibiting the tyrosin kinase action of FGFR1. Methods Cells were routinely grown in Dulbecco Modified Eagle's medium supplemented with newborn serum and a penicillin-streptomycin mixture. Cell viability was evaluated by Mosmann assay and by trypan blue staining. DNA damage was assessed by in situ fluorescent staining with Terminal Deoxynucleotidyl Transferase dUTP nick end labeling (TUNEL assay. Assessment of oxidative stress at membrane level was measured by quantitative analysis of the intra-cellular formation of malonyl-dialdheyde (MDA deriving from the decomposition of poly-unsaturated fatty acids. The expression of Poly-ADP-Ribose-Polymerase (PARP, consequent to DNA fragmentation, was evidenced by immuno-histochemistry utilizing an antibody directed against an N-terminal fragment of the enzyme. Results The bioactivity of the drug was investigated on Hela cells. Cytoxicity was assessed by the Mosmann assay and by vital staining with trypan blue. The target of the molecule is most likely the cell membrane as shown by the significant increase of the intracellular concentration of malonyl-dihaldheyde. The increase of this compound, as a consequence of the treatment with PD166866, is suggestive of membrane lipoperoxidation. The TUNEL assay gave a qualitative, though clear, indication of DNA damage. Furthermore we demonstrate intracellular accumulation of poly-ADP-ribose polymerase I. This enzyme is a sensor of nicks on the DNA strands and this supports the idea that treatment with the drug induces cell

  20. Combined MET inhibition and topoisomerase I inhibition block cell growth of small cell lung cancer.

    Science.gov (United States)

    Rolle, Cleo E; Kanteti, Rajani; Surati, Mosmi; Nandi, Suvobroto; Dhanasingh, Immanuel; Yala, Soheil; Tretiakova, Maria; Arif, Qudsia; Hembrough, Todd; Brand, Toni M; Wheeler, Deric L; Husain, Aliya N; Vokes, Everett E; Bharti, Ajit; Salgia, Ravi

    2014-03-01

    Small cell lung cancer (SCLC) is a devastating disease, and current therapies have not greatly improved the 5-year survival rates. Topoisomerase (Top) inhibition is a treatment modality for SCLC; however, the response is short lived. Consequently, our research has focused on improving SCLC therapeutics through the identification of novel targets. Previously, we identified MNNG HOS transforming gene (MET) to be overexpressed and functional in SCLC. Herein, we investigated the therapeutic potentia