WorldWideScience

Sample records for interaction impairs cell

  1. Fibronectin-cell interactions

    DEFF Research Database (Denmark)

    Couchman, J R; Austria, M R; Woods, A

    1990-01-01

    Fibronectins are widespread extracellular matrix and body fluid glycoproteins, capable of multiple interactions with cell surfaces and other matrix components. Their structure at a molecular level has been resolved, yet there are still many unanswered questions regarding their biologic activity...... in vivo. Much data suggests that fibronectins may promote extracellular matrix assembly, and cell adhesion to those matrices. However, one outstanding enigma is that fibronectins may, under different circumstances, promote both cell migration and anchorage. An analysis of the interaction of fibroblasts...... with proteolytically derived and purified domains of plasma fibronectin revealed that the type of adhesion and the correlated cytoskeletal organization depended on multiple interactions of fibronectin domains with the cell surface. Human dermal fibroblasts were capable of interacting with the integrin-binding domain...

  2. Interacting with women can impair men's cognitive functioning

    NARCIS (Netherlands)

    Karremans, J.C.T.M.; Verwijmeren, T.; Pronk, T.M.; Reitsma, M.

    2009-01-01

    The present research tested the prediction that mixed-sex interactions may temporarily impair cognitive functioning. Two studies, in which participants interacted either with a same-sex or opposite-sex other, demonstrated that men's (but not women's) cognitive performance declined following a

  3. T cell-B cell interactions in primary immunodeficiencies.

    Science.gov (United States)

    Tangye, Stuart G; Deenick, Elissa K; Palendira, Umaimainthan; Ma, Cindy S

    2012-02-01

    Regulated interactions between cells of the immune system facilitate the generation of successful immune responses, thereby enabling efficient neutralization and clearance of pathogens and the establishment of both cell- and humoral-mediated immunological memory. The corollary of this is that impediments to efficient cell-cell interactions, normally necessary for differentiation and effector functions of immune cells, underly the clinical features and disease pathogenesis of primary immunodeficiencies. In affected individuals, these defects manifest as impaired long-term humoral immunity and susceptibility to infection by specific pathogens. In this review, we discuss the importance of, and requirements for, effective interactions between B cells and T cells during the formation of CD4(+) T follicular helper cells and the elicitation of cytotoxic function of virus-specific CD8(+) T cells, as well as how these processes are abrogated in primary immunodeficiencies due to loss-of-function mutations in defined genes. © 2012 New York Academy of Sciences.

  4. ALCOHOL AND DISTRACTION INTERACT TO IMPAIR DRIVING PERFORMANCE

    Science.gov (United States)

    Harrison, Emily L. R.; Fillmore, Mark T.

    2011-01-01

    Background Recognition of the risks associated with alcohol intoxication and driver distraction has led to a wealth of simulated driving research aimed at studying the adverse effects of each of these factors. Research on driving has moved beyond the individual, separate examination of these factors to the examination of potential interactions between alcohol intoxication and driver distraction. In many driving situations, distractions are commonplace and might have little or no disruptive influence on primary driving functions. Yet, such distractions might become disruptive to a driver who is intoxicated. Methods The present study examined the interactive impairing effects of alcohol intoxication and driver distraction on simulated driving performance in 40 young adult drivers using a divided attention task as a distracter activity. The interactive influence of alcohol and distraction was tested by having drivers perform the driving task under four different conditions: 0.65 g/kg alcohol; 0.65 g/kg alcohol + divided attention; placebo; and placebo + divided attention. Results As hypothesized, divided attention had no impairing effect on driving performance in sober drivers. However, under alcohol, divided attention exacerbated the impairing effects of alcohol on driving precision. Conclusions Alcohol and distraction continue to be appropriate targets for research into ways to reduce the rates of driving-related fatalities and injuries. Greater consideration of how alcohol and distraction interact to impair aspects of driving performance can further efforts to create prevention and intervention measures to protect drivers, particularly young adults. PMID:21277119

  5. Alcohol and distraction interact to impair driving performance.

    Science.gov (United States)

    Harrison, Emily L R; Fillmore, Mark T

    2011-08-01

    Recognition of the risks associated with alcohol intoxication and driver distraction has led to a wealth of simulated driving research aimed at studying the adverse effects of each of these factors. Research on driving has moved beyond the individual, separate examination of these factors to the examination of potential interactions between alcohol intoxication and driver distraction. In many driving situations, distractions are commonplace and might have little or no disruptive influence on primary driving functions. Yet, such distractions might become disruptive to a driver who is intoxicated. The present study examined the interactive impairing effects of alcohol intoxication and driver distraction on simulated driving performance in 40 young adult drivers using a divided attention task as a distracter activity. The interactive influence of alcohol and distraction was tested by having drivers perform the driving task under four different conditions: 0.65 g/kg alcohol; 0.65 g/kg alcohol+divided attention; placebo; and placebo+divided attention. As hypothesized, divided attention had no impairing effect on driving performance in sober drivers. However, under alcohol, divided attention exacerbated the impairing effects of alcohol on driving precision. Alcohol and distraction continue to be appropriate targets for research into ways to reduce the rates of driving-related fatalities and injuries. Greater consideration of how alcohol and distraction interact to impair aspects of driving performance can further efforts to create prevention and intervention measures to protect drivers, particularly young adults. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  6. High passage MIN6 cells have impaired insulin secretion with impaired glucose and lipid oxidation.

    Directory of Open Access Journals (Sweden)

    Kim Cheng

    Full Text Available Type 2 diabetes is a metabolic disorder characterized by the inability of beta-cells to secrete enough insulin to maintain glucose homeostasis. MIN6 cells secrete insulin in response to glucose and other secretagogues, but high passage (HP MIN6 cells lose their ability to secrete insulin in response to glucose. We hypothesized that metabolism of glucose and lipids were defective in HP MIN6 cells causing impaired glucose stimulated insulin secretion (GSIS. HP MIN6 cells had no first phase and impaired second phase GSIS indicative of global functional impairment. This was coupled with a markedly reduced ATP content at basal and glucose stimulated states. Glucose uptake and oxidation were higher at basal glucose but ATP content failed to increase with glucose. HP MIN6 cells had decreased basal lipid oxidation. This was accompanied by reduced expressions of Glut1, Gck, Pfk, Srebp1c, Ucp2, Sirt3, Nampt. MIN6 cells represent an important model of beta cells which, as passage numbers increased lost first phase but retained partial second phase GSIS, similar to patients early in type 2 diabetes onset. We believe a number of gene expression changes occurred to produce this defect, with emphasis on Sirt3 and Nampt, two genes that have been implicated in maintenance of glucose homeostasis.

  7. Interaction between memory impairment and depressive symptoms can exacerbate anosognosia: a comparison of Alzheimer's disease with mild cognitive impairment.

    Science.gov (United States)

    Oba, Hikaru; Matsuoka, Teruyuki; Imai, Ayu; Fujimoto, Hiroshi; Kato, Yuka; Shibata, Keisuke; Nakamura, Kaeko; Narumoto, Jin

    2018-03-12

    To investigate the effects of interactions between memory impairment, depressive symptoms, and anosognosia. Anosognosia for memory impairment was assessed in 118 patients with Alzheimer's disease (AD), 47 patients with mild cognitive impairment (MCI), and 17 non-diagnosed controls (NC) using a questionnaire and evaluation of the anosognosia score as the discrepancy between ratings of the patient and a relative. Demographic characteristics, such as the relationship of the patient with the relative and the activities of daily living (ADL) were evaluated. Memory impairment was evaluated with the Rivermead Behavioral Memory Test (RBMT), depressive symptoms were evaluated using the Geriatric Depression Scale (GDS) 15 items version. In the MCI group, a stepwise multiple regression analysis showed an interaction between RBMT and GDS scores, and simple slope analysis indicated that scores for RBMT at low GDS (-1 standard deviation) were positively correlated with self-rated memory impairment. In the AD group, the relationship of the patient with the relative, ADL, and GDS and RBMT scores were associated with the anosognosia score. Patients with MCI who have no depressive symptoms may be able to more accurately evaluate their memory impairment than those who have depressive symptoms and patients with AD. The evaluation by relatives, depressive symptoms or ADL of patients may distort evaluation of anosognosia for memory impairment in patients with AD or MCI. It seems necessary to include not only depression scale scores but also results of objective memory tests in the patients' medical information for the correct assessment of anosognosia.

  8. Tumor cytotoxicity by endothelial cells. Impairment of the mitochondrial system for glutathione uptake in mouse B16 melanoma cells that survive after in vitro interaction with the hepatic sinusoidal endothelium.

    Science.gov (United States)

    Ortega, Angel L; Carretero, Julian; Obrador, Elena; Gambini, Juan; Asensi, Miguel; Rodilla, Vicente; Estrela, José M

    2003-04-18

    High GSH content associates with high metastatic activity in B16-F10 melanoma cells cultured to low density (LD B16M). GSH homeostasis was investigated in LD B16M cells that survive after adhesion to the hepatic sinusoidal endothelium (HSE). Invasive B16M (iB16M) cells were isolated using anti-Met-72 monoclonal antibodies and flow cytometry-coupled cell sorting. HSE-derived NO and H(2)O(2) caused GSH depletion and a decrease in gamma-glutamylcysteine synthetase activity in iB16M cells. Overexpression of gamma-glutamylcysteine synthetase heavy and light subunits led to a rapid recovery of cytosolic GSH, whereas mitochondrial GSH (mtGSH) further decreased during the first 18 h of culture. NO and H(2)O(2) damaged the mitochondrial system for GSH uptake (rates in iB16M were approximately 75% lower than in LD B16M cells). iB16M cells also showed a decreased activity of mitochondrial complexes II, III, and IV, less O(2) consumption, lower ATP levels, higher O(2) and H(2)O(2) production, and lower mitochondrial membrane potential. In vitro growing iB16M cells maintained high viability (>98%) and repaired HSE-induced mitochondrial damages within 48 h. However, iB16M cells with low mtGSH levels were highly susceptible to TNF-alpha-induced oxidative stress and death. Therefore depletion of mtGSH levels may represent a critical target to challenge survival of invasive cancer cells.

  9. Impairment of lymphocyte adhesion to cultured fibroblasts and endothelial cells by γ-irradiation

    International Nuclear Information System (INIS)

    Piela-Smith, T.H.; Aneiro, L.; Nuveen, E.; Korn, J.H.; Aune, T.

    1992-01-01

    A critical component of immune responsiveness is the localization of effector cells at sites of inflammatory lesions. Adhesive molecules that may play a role in this process have been described on the surfaces of both lymphocytes and connective tissue cells. Adhesive interactions of T lymphocytes with fibroblasts or endothelial cells can be inhibited by preincubation of the fibroblasts or endothelial cells with antibody to intercellular adhesion molecule 1 (CD54) or by preincubation of the T cells with antibody to lymphocyte function-associated Ag 1 (CD11a/CD18), molecules shown to be important in several other cell-cell adhesion interactions. Here the authors show that γ-irradiation of human T lymphocytes impaired their ability to adhere to both fibroblasts and endothelial cells. This impairment was not associated with a loss of cell viability or of cell surface lymphocyte function-associated Ag 1 expression. γ-Irradiation of T cells is known to result in the activation of ADP-ribosyltransferase, an enzyme involved in DNA strand-break repair, causing subsequent depletion of cellular nicotinamide adenine dinucleotide (NAD) pools by increasing NAD consumption for poly(ADP-ribose) formation. Preincubation of T cells with either nicotinamide or 3-aminobenzamide, both known inhibitors of ADP-ribosyltransferase, completely reversed the suppressive effects of γ-irradiation on T cell adhesion. The maintenance of adhesion was accompanied by inhibition of irradiation-induced depletion of cellular NAD. These experiments suggest that the impairment of cellular immune function after irradiation in vivo may be caused, in part, by defective T cell emigration and localization at inflammatory sites. 44 refs., 5 figs., 3 tabs

  10. Nanoparticle-Cell Interaction: A Cell Mechanics Perspective.

    Science.gov (United States)

    Septiadi, Dedy; Crippa, Federica; Moore, Thomas Lee; Rothen-Rutishauser, Barbara; Petri-Fink, Alke

    2018-05-01

    Progress in the field of nanoparticles has enabled the rapid development of multiple products and technologies; however, some nanoparticles can pose both a threat to the environment and human health. To enable their safe implementation, a comprehensive knowledge of nanoparticles and their biological interactions is needed. In vitro and in vivo toxicity tests have been considered the gold standard to evaluate nanoparticle safety, but it is becoming necessary to understand the impact of nanosystems on cell mechanics. Here, the interaction between particles and cells, from the point of view of cell mechanics (i.e., bionanomechanics), is highlighted and put in perspective. Specifically, the ability of intracellular and extracellular nanoparticles to impair cell adhesion, cytoskeletal organization, stiffness, and migration are discussed. Furthermore, the development of cutting-edge, nanotechnology-driven tools based on the use of particles allowing the determination of cell mechanics is emphasized. These include traction force microscopy, colloidal probe atomic force microscopy, optical tweezers, magnetic manipulation, and particle tracking microrheology. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. HAMLET interacts with histones and chromatin in tumor cell nuclei.

    Science.gov (United States)

    Düringer, Caroline; Hamiche, Ali; Gustafsson, Lotta; Kimura, Hiroshi; Svanborg, Catharina

    2003-10-24

    HAMLET is a folding variant of human alpha-lactalbumin in an active complex with oleic acid. HAMLET selectively enters tumor cells, accumulates in their nuclei and induces apoptosis-like cell death. This study examined the interactions of HAMLET with nuclear constituents and identified histones as targets. HAMLET was found to bind histone H3 strongly and to lesser extent histones H4 and H2B. The specificity of these interactions was confirmed using BIAcore technology and chromatin assembly assays. In vivo in tumor cells, HAMLET co-localized with histones and perturbed the chromatin structure; HAMLET was found associated with chromatin in an insoluble nuclear fraction resistant to salt extraction. In vitro, HAMLET bound strongly to histones and impaired their deposition on DNA. We conclude that HAMLET interacts with histones and chromatin in tumor cell nuclei and propose that this interaction locks the cells into the death pathway by irreversibly disrupting chromatin organization.

  12. PREFACE: Cell-substrate interactions Cell-substrate interactions

    Science.gov (United States)

    Gardel, Margaret; Schwarz, Ulrich

    2010-05-01

    One of the most striking achievements of evolution is the ability to build cellular systems that are both robust and dynamic. Taken by themselves, both properties are obvious requirements: robustness reflects the fact that cells are there to survive, and dynamics is required to adapt to changing environments. However, it is by no means trivial to understand how these two requirements can be implemented simultaneously in a physical system. The long and difficult quest to build adaptive materials is testimony to the inherent difficulty of this goal. Here materials science can learn a lot from nature, because cellular systems show that robustness and dynamics can be achieved in a synergetic fashion. For example, the capabilities of tissues to repair and regenerate are still unsurpassed in the world of synthetic materials. One of the most important aspects of the way biological cells adapt to their environment is their adhesive interaction with the substrate. Numerous aspects of the physiology of metazoan cells, including survival, proliferation, differentiation and migration, require the formation of adhesions to the cell substrate, typically an extracellular matrix protein. Adhesions guide these diverse processes both by mediating force transmission from the cell to the substrate and by controlling biochemical signaling pathways. While the study of cell-substrate adhesions is a mature field in cell biology, a quantitative biophysical understanding of how the interactions of the individual molecular components give rise to the rich dynamics and mechanical behaviors observed for cell-substrate adhesions has started to emerge only over the last decade or so. The recent growth of research activities on cell-substrate interactions was strongly driven by the introduction of new physical techniques for surface engineering into traditional cell biological work with cell culture. For example, microcontact printing of adhesive patterns was used to show that cell fate depends

  13. Severe Impairments of Social Interaction and Associated Abnormalities in Children: Epidemiology and Classification.

    Science.gov (United States)

    Wing, Lorna; Gould, Judith

    1979-01-01

    The prevalence of severe impairments of social interaction, language abnormalities, and repetitive stereotyped behaviors was investigated in a group of 132 children under 15 years old, consisting of a socially impaired group (more than half of whom were severely retarded) and a comparison group of sociable severely mentally retarded. Author/DLS)

  14. Impaired endothelial progenitor cell mobilization and dysfunctional bone marrow stroma in diabetes mellitus.

    Science.gov (United States)

    Westerweel, Peter E; Teraa, Martin; Rafii, Shahin; Jaspers, Janneke E; White, Ian A; Hooper, Andrea T; Doevendans, Pieter A; Verhaar, Marianne C

    2013-01-01

    Circulating Endothelial Progenitor Cell (EPC) levels are reduced in diabetes mellitus. This may be a consequence of impaired mobilization of EPC from the bone marrow. We hypothesized that under diabetic conditions, mobilization of EPC from the bone marrow to the circulation is impaired -at least partly- due to dysfunction of the bone marrow stromal compartment. Diabetes was induced in mice by streptozotocin injection. Circulating Sca-1(+)Flk-1(+) EPC were characterized and quantified by flow cytometry at baseline and after mobilization with G-CSF/SCF injections. In vivo hemangiogenic recovery was tested by 5-FU challenge. Interaction within the bone marrow environment between CD34(+) hematopoietic progenitor cells (HPC) and supporting stroma was assessed by co-cultures. To study progenitor cell-endothelial cell interaction under normoglycemic and hyperglycemic conditions, a co-culture model using E4Orf1-transfected human endothelial cells was employed. In diabetic mice, bone marrow EPC levels were unaffected. However, circulating EPC levels in blood were lower at baseline and mobilization was attenuated. Diabetic mice failed to recover and repopulate from 5-FU injection. In vitro, primary cultured bone marrow stroma from diabetic mice was impaired in its capacity to support human CFU-forming HPC. Finally, hyperglycemia hampered the HPC supportive function of endothelial cells in vitro. EPC mobilization is impaired under experimental diabetic conditions and our data suggest that diabetes induces alterations in the progenitor cell supportive capacity of the bone marrow stroma, which could be partially responsible for the attenuated EPC mobilization and reduced EPC levels observed in diabetic patients.

  15. Impaired endothelial progenitor cell mobilization and dysfunctional bone marrow stroma in diabetes mellitus.

    Directory of Open Access Journals (Sweden)

    Peter E Westerweel

    Full Text Available Circulating Endothelial Progenitor Cell (EPC levels are reduced in diabetes mellitus. This may be a consequence of impaired mobilization of EPC from the bone marrow. We hypothesized that under diabetic conditions, mobilization of EPC from the bone marrow to the circulation is impaired -at least partly- due to dysfunction of the bone marrow stromal compartment.Diabetes was induced in mice by streptozotocin injection. Circulating Sca-1(+Flk-1(+ EPC were characterized and quantified by flow cytometry at baseline and after mobilization with G-CSF/SCF injections. In vivo hemangiogenic recovery was tested by 5-FU challenge. Interaction within the bone marrow environment between CD34(+ hematopoietic progenitor cells (HPC and supporting stroma was assessed by co-cultures. To study progenitor cell-endothelial cell interaction under normoglycemic and hyperglycemic conditions, a co-culture model using E4Orf1-transfected human endothelial cells was employed.In diabetic mice, bone marrow EPC levels were unaffected. However, circulating EPC levels in blood were lower at baseline and mobilization was attenuated. Diabetic mice failed to recover and repopulate from 5-FU injection. In vitro, primary cultured bone marrow stroma from diabetic mice was impaired in its capacity to support human CFU-forming HPC. Finally, hyperglycemia hampered the HPC supportive function of endothelial cells in vitro.EPC mobilization is impaired under experimental diabetic conditions and our data suggest that diabetes induces alterations in the progenitor cell supportive capacity of the bone marrow stroma, which could be partially responsible for the attenuated EPC mobilization and reduced EPC levels observed in diabetic patients.

  16. High glucose-mediated oxidative stress impairs cell migration.

    Directory of Open Access Journals (Sweden)

    Marcelo L Lamers

    Full Text Available Deficient wound healing in diabetic patients is very frequent, but the cellular and molecular causes are poorly defined. In this study, we evaluate the hypothesis that high glucose concentrations inhibit cell migration. Using CHO.K1 cells, NIH-3T3 fibroblasts, mouse embryonic fibroblasts and primary skin fibroblasts from control and diabetic rats cultured in 5 mM D-glucose (low glucose, LG, 25 mM D-glucose (high glucose, HG or 25 mM L-glucose medium (osmotic control--OC, we analyzed the migration speed, protrusion stability, cell polarity, adhesion maturation and the activity of the small Rho GTPase Rac1. We also analyzed the effects of reactive oxygen species by incubating cells with the antioxidant N-Acetyl-Cysteine (NAC. We observed that HG conditions inhibited cell migration when compared to LG or OC. This inhibition resulted from impaired cell polarity, protrusion destabilization and inhibition of adhesion maturation. Conversely, Rac1 activity, which promotes protrusion and blocks adhesion maturation, was increased in HG conditions, thus providing a mechanistic basis for the HG phenotype. Most of the HG effects were partially or completely rescued by treatment with NAC. These findings demonstrate that HG impairs cell migration due to an increase in oxidative stress that causes polarity loss, deficient adhesion and protrusion. These alterations arise, in large part, from increased Rac1 activity and may contribute to the poor wound healing observed in diabetic patients.

  17. Workshop on programming beta cell development, impairment and regeneration

    DEFF Research Database (Denmark)

    Heller, Scott; Nielsen, Jens Høiriis

    2012-01-01

    Helsingør, the city of Hamlet in Denmark, provided the site for the workshop "Programming Beta Cell Development, Impairment and Regeneration" on October 23-26th, 2011. The same location has held two EASD Islet study group meetings, while the previous three workshops were held in Helsinki, Finland...... (2003), El Perello, Spain (2006) and Peebles, Scotland (2009). The meeting drew 190 attendees from 12 different countries. There were 37 main oral presentations, and 68 posters covered virtually all aspects of the pancreas and provided a dynamic snapshot of the most interesting areas of current...

  18. Impairment of myocardial perfusion in children with sickle cell disease

    International Nuclear Information System (INIS)

    Maunoury, C.; Acar, P.; Montalembert, M. de

    2003-01-01

    While brain, bone and spleen strokes are well documented in children with sickle cell disease (SCD), impairment of myocardial perfusion is an unknown complication. Non invasive techniques such as exercise testing and echocardiography have a low sensitivity to detect myocardial ischemia in patients with SCD. We have prospectively assessed myocardial perfusion with Tl-201 SPECT in 23 patients with SCD (10 female, 13 male, mean age 12 ± 5 years). Myocardial SPECT was performed after stress and 3 hours later after reinjection on a single head gamma camera equipped with a LEAP collimator (64 x 64 matrix size format, 30 projections over 180 deg C, 30 seconds per step). Left ventricular ejection fraction (LVEF) was assessed by equilibrium radionuclide angiography at rest on the same day. Myocardial perfusion was impaired in 14/23 patients: 9 reversible defects and 5 fixed defects. The left ventricular cavity was dilated in 14/23 patients. The mean LVEF was 63 ± 9%. There was no relationship between myocardial perfusion and left ventricular dilation or function. The frequent impairment of myocardial perfusion in children with SCD could lead to suggest a treatment with hydroxyurea, an improvement of perfusion can be noted with hydroxyurea. (author)

  19. Inorganic arsenic impairs differentiation and functions of human dendritic cells

    Energy Technology Data Exchange (ETDEWEB)

    Macoch, Mélinda; Morzadec, Claudie [UMR INSERM U1085, Institut de Recherche sur la Santé, l' Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France); Fardel, Olivier [UMR INSERM U1085, Institut de Recherche sur la Santé, l' Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France); Pôle Biologie, Centre Hospitalier Universitaire (CHU) Rennes, 2 rue Henri Le Guilloux, 35033 Rennes (France); Vernhet, Laurent, E-mail: laurent.vernhet@univ-rennes1.fr [UMR INSERM U1085, Institut de Recherche sur la Santé, l' Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France)

    2013-01-15

    Experimental studies have demonstrated that the antileukemic trivalent inorganic arsenic prevents the development of severe pro-inflammatory diseases mediated by excessive Th1 and Th17 cell responses. Differentiation of Th1 and Th17 subsets is mainly regulated by interleukins (ILs) secreted from dendritic cells (DCs) and the ability of inorganic arsenic to impair interferon-γ and IL-17 secretion by interfering with the physiology of DCs is unknown. In the present study, we demonstrate that high concentrations of sodium arsenite (As(III), 1–2 μM) clinically achievable in plasma of arsenic-treated patients, block differentiation of human peripheral blood monocytes into immature DCs (iDCs) by inducing their necrosis. Differentiation of monocytes in the presence of non-cytotoxic concentrations of As(III) (0.1 to 0.5 μM) only slightly impacts endocytotic activity of iDCs or expression of co-stimulatory molecules in cells activated with lipopolysaccharide. However, this differentiation in the presence of As(III) strongly represses secretion of IL-12p70 and IL-23, two major regulators of Th1 and Th17 activities, from iDCs stimulated with different toll-like receptor (TLR) agonists in metalloid-free medium. Such As(III)-exposed DCs also exhibit reduced mRNA levels of IL12A and/or IL12B genes when activated with TLR agonists. Finally, differentiation of monocytes with non-cytotoxic concentrations of As(III) subsequently reduces the ability of activated DCs to stimulate the release of interferon-γ and IL-17 from Th cells. In conclusion, our results demonstrate that clinically relevant concentrations of inorganic arsenic markedly impair in vitro differentiation and functions of DCs, which may contribute to the putative beneficial effects of the metalloid towards inflammatory autoimmune diseases. Highlights: ► Inorganic arsenic impairs differentiation and functions of human dendritic cells (DCs) ► Arsenite (> 1 μM) blocks differentiation of dendritic cells by

  20. Inorganic arsenic impairs differentiation and functions of human dendritic cells

    International Nuclear Information System (INIS)

    Macoch, Mélinda; Morzadec, Claudie; Fardel, Olivier; Vernhet, Laurent

    2013-01-01

    Experimental studies have demonstrated that the antileukemic trivalent inorganic arsenic prevents the development of severe pro-inflammatory diseases mediated by excessive Th1 and Th17 cell responses. Differentiation of Th1 and Th17 subsets is mainly regulated by interleukins (ILs) secreted from dendritic cells (DCs) and the ability of inorganic arsenic to impair interferon-γ and IL-17 secretion by interfering with the physiology of DCs is unknown. In the present study, we demonstrate that high concentrations of sodium arsenite (As(III), 1–2 μM) clinically achievable in plasma of arsenic-treated patients, block differentiation of human peripheral blood monocytes into immature DCs (iDCs) by inducing their necrosis. Differentiation of monocytes in the presence of non-cytotoxic concentrations of As(III) (0.1 to 0.5 μM) only slightly impacts endocytotic activity of iDCs or expression of co-stimulatory molecules in cells activated with lipopolysaccharide. However, this differentiation in the presence of As(III) strongly represses secretion of IL-12p70 and IL-23, two major regulators of Th1 and Th17 activities, from iDCs stimulated with different toll-like receptor (TLR) agonists in metalloid-free medium. Such As(III)-exposed DCs also exhibit reduced mRNA levels of IL12A and/or IL12B genes when activated with TLR agonists. Finally, differentiation of monocytes with non-cytotoxic concentrations of As(III) subsequently reduces the ability of activated DCs to stimulate the release of interferon-γ and IL-17 from Th cells. In conclusion, our results demonstrate that clinically relevant concentrations of inorganic arsenic markedly impair in vitro differentiation and functions of DCs, which may contribute to the putative beneficial effects of the metalloid towards inflammatory autoimmune diseases. Highlights: ► Inorganic arsenic impairs differentiation and functions of human dendritic cells (DCs) ► Arsenite (> 1 μM) blocks differentiation of dendritic cells by

  1. Glucocorticoids interact with the hippocampal endocannabinoid system in impairing retrieval of contextual fear memory

    Science.gov (United States)

    Atsak, Piray; Hauer, Daniela; Campolongo, Patrizia; Schelling, Gustav; McGaugh, James L.; Roozendaal, Benno

    2012-01-01

    There is extensive evidence that glucocorticoid hormones impair the retrieval of memory of emotionally arousing experiences. Although it is known that glucocorticoid effects on memory retrieval impairment depend on rapid interactions with arousal-induced noradrenergic activity, the exact mechanism underlying this presumably nongenomically mediated glucocorticoid action remains to be elucidated. Here, we show that the hippocampal endocannabinoid system, a rapidly activated retrograde messenger system, is involved in mediating glucocorticoid effects on retrieval of contextual fear memory. Systemic administration of corticosterone (0.3–3 mg/kg) to male Sprague–Dawley rats 1 h before retention testing impaired the retrieval of contextual fear memory without impairing the retrieval of auditory fear memory or directly affecting the expression of freezing behavior. Importantly, a blockade of hippocampal CB1 receptors with AM251 prevented the impairing effect of corticosterone on retrieval of contextual fear memory, whereas the same impairing dose of corticosterone increased hippocampal levels of the endocannabinoid 2-arachidonoylglycerol. We also found that antagonism of hippocampal β-adrenoceptor activity with local infusions of propranolol blocked the memory retrieval impairment induced by the CB receptor agonist WIN55,212–2. Thus, these findings strongly suggest that the endocannabinoid system plays an intermediary role in regulating rapid glucocorticoid effects on noradrenergic activity in impairing memory retrieval of emotionally arousing experiences. PMID:22331883

  2. Advanced and natural interaction system for motion-impaired users

    OpenAIRE

    Manresa Yee, Cristina Suemay

    2009-01-01

    Human-computer interaction is an important area that searches for better and more comfortable systems to promote communication between humans and machines. Vision-based interfaces can offer a more natural and appealing way of communication. Moreover, it can help in the e-accessibility component of the e-inclusion. The aim is to develop a usable system, that is, the end-user must consider the use of this device effective, efficient and satisfactory. The research's main contribution is SINA, a ...

  3. Caregivers' experiences of interaction with families expecting a fetally impaired child.

    Science.gov (United States)

    Maijala, Hanna; Paavilainen, Eija; Väisänen, Leena; Astedt-Kurki, Päivi

    2004-03-01

    On the basis of earlier research, caregivers' actions when interacting with clients should be developed. However, nursing research has focused little attention on the interaction between caregivers and families expecting a fetally impaired child. The study aimed at generating a practical family nursing theory of caregivers' interaction with families expecting a malformed child. A grounded theory study was undertaken at Tampere University Hospital in Finland in 1999-2000. Data consisted of semi-structured interviews with 22 (n=22) nurses and doctors. The data were analysed using the constant comparative method. The interaction process starts when a caregiver informs the parents of the fetal impairment. The process is influenced by caregivers' attitude towards issues related to the family's life situation. Caregivers' views of their job, and of human coping and cultural attitudes towards these issues are also of importance. These factors account for their goals in the interaction, which, in turn, underlie their actions. When the caregiver's interpretation is that the family accepted the help provided, the outcome of the interaction is satisfaction with having been able to help. Correspondingly, in the case of an opposite interpretation, the caregiver experiences strain caused by inadequacy of the help he/she is providing. The core of interaction consists of two dimensions: gaining strength and losing strength in relation to impairment issues. Caregivers' views of helpful interaction were consistent with earlier research on the subject, but the findings of this study showed that more attention should be focused on the family as a whole. Furthermore, caregivers rarely criticized their own actions, thus their interaction skills should be upgraded by focusing on systematic self-assessment through training. Nursing research deepening our understanding of why interaction fails is warranted. The study results can be used in the family nursing practice as tools in

  4. Interactive Auroral Science for Hearing-Impaired Students

    Science.gov (United States)

    Samara, M.; Michell, R. G.; Jahn, J.; Pfeifer, M.; Ibarra, S.; Hampton, D. L.; Powell, D.

    2012-12-01

    Under a NASA E/PO grant, we have partnered with San Antonio's Sunshine Cottage School for Deaf Children to develop a science class experience where students directly interact with scientists and participate in a research-grade space science measurement campaign. The unique aspect of partnering with Sunshine Cottage lies in Sunshine's approach of auditory-verbal communication. Aided by technology (hearing aids, cochlear implants), a diverse student body with students of all levels of hearing loss (moderate through profound) is taught in an entirely auditory-verbal environment at Sunshine Cottage. Bringing these students into early contact with research work can lay the foundation for future careers in the STEM field that normally they might not consider as indicated by the first year of this collaboration where the student response was distinctly positive. Here we report on the first year of those activities, as they related to a ground based imaging approach to exploring the northern lights and from the point of view of the scientists that participated. The major components of that activity included a site visit to SwRI by the students and their teachers, a semester long lab at school utilizing current research tools and a real-time campaign night. The students used a number of diagnostics to first predict and then verify auroral activity. One of the tools used was the MOOSE observatory which is a community resource state of the art observatory comprised of 5 EMCCD imagers in Alaska, established through an NSF MRI grant. We will discuss the approach and lessons learned during the first year of the project and the directions that we will likely take in the second year. Lessons learned from teaching these students space science related topic can be flowed right back into mainstream classroom settings. One other significant and unexpected aspect of this first year was that we were able to connect two groups of students through skype (in the 4th to 5th grades) that

  5. Why do interracial interactions impair executive function? A resource depletion account.

    Science.gov (United States)

    Richeson, Jennifer A; Trawalter, Sophie

    2005-06-01

    Three studies investigated the veracity of a resource depletion account of the impairment of inhibitory task performance after interracial contact. White individuals engaged in either an interracial or same-race interaction, then completed an ostensibly unrelated Stroop color-naming test. In each study, the self-regulatory demands of the interaction were either increased (Study 1) or decreased (Studies 2 and 3). Results revealed that increasing the self-regulatory demands of an interracial interaction led to greater Stroop interference compared with control, whereas reducing self-regulatory demands led to less Stroop interference. Manipulating self-regulatory demands did not affect Stroop performance after same-race interactions. Taken together, the present studies point to resource depletion as the likely mechanism underlying the impairment of cognitive functioning after interracial dyadic interactions.

  6. Focal adhesions and cell-matrix interactions

    DEFF Research Database (Denmark)

    Woods, A; Couchman, J R

    1988-01-01

    Focal adhesions are areas of cell surfaces where specializations of cytoskeletal, membrane and extracellular components combine to produce stable cell-matrix interactions. The morphology of these adhesions and the components identified in them are discussed together with possible mechanisms...

  7. Interactions between semiconductor nanowires and living cells.

    Science.gov (United States)

    Prinz, Christelle N

    2015-06-17

    Semiconductor nanowires are increasingly used for biological applications and their small dimensions make them a promising tool for sensing and manipulating cells with minimal perturbation. In order to interface cells with nanowires in a controlled fashion, it is essential to understand the interactions between nanowires and living cells. The present paper reviews current progress in the understanding of these interactions, with knowledge gathered from studies where living cells were interfaced with vertical nanowire arrays. The effect of nanowires on cells is reported in terms of viability, cell-nanowire interface morphology, cell behavior, changes in gene expression as well as cellular stress markers. Unexplored issues and unanswered questions are discussed.

  8. Histone h1 depletion impairs embryonic stem cell differentiation.

    Science.gov (United States)

    Zhang, Yunzhe; Cooke, Marissa; Panjwani, Shiraj; Cao, Kaixiang; Krauth, Beth; Ho, Po-Yi; Medrzycki, Magdalena; Berhe, Dawit T; Pan, Chenyi; McDevitt, Todd C; Fan, Yuhong

    2012-01-01

    Pluripotent embryonic stem cells (ESCs) are known to possess a relatively open chromatin structure; yet, despite efforts to characterize the chromatin signatures of ESCs, the role of chromatin compaction in stem cell fate and function remains elusive. Linker histone H1 is important for higher-order chromatin folding and is essential for mammalian embryogenesis. To investigate the role of H1 and chromatin compaction in stem cell pluripotency and differentiation, we examine the differentiation of embryonic stem cells that are depleted of multiple H1 subtypes. H1c/H1d/H1e triple null ESCs are more resistant to spontaneous differentiation in adherent monolayer culture upon removal of leukemia inhibitory factor. Similarly, the majority of the triple-H1 null embryoid bodies (EBs) lack morphological structures representing the three germ layers and retain gene expression signatures characteristic of undifferentiated ESCs. Furthermore, upon neural differentiation of EBs, triple-H1 null cell cultures are deficient in neurite outgrowth and lack efficient activation of neural markers. Finally, we discover that triple-H1 null embryos and EBs fail to fully repress the expression of the pluripotency genes in comparison with wild-type controls and that H1 depletion impairs DNA methylation and changes of histone marks at promoter regions necessary for efficiently silencing pluripotency gene Oct4 during stem cell differentiation and embryogenesis. In summary, we demonstrate that H1 plays a critical role in pluripotent stem cell differentiation, and our results suggest that H1 and chromatin compaction may mediate pluripotent stem cell differentiation through epigenetic repression of the pluripotency genes.

  9. Diet-induced obesity impairs endometrial stromal cell decidualization: a potential role for impaired autophagy.

    Science.gov (United States)

    Rhee, Julie S; Saben, Jessica L; Mayer, Allyson L; Schulte, Maureen B; Asghar, Zeenat; Stephens, Claire; Chi, Maggie M-Y; Moley, Kelle H

    2016-06-01

    What effect does diet-induced obesity have on endometrial stromal cell (ESC) decidualization? Diet-induced obesity impairs ESC decidualization. Decidualization is important for successful implantation and subsequent health of the pregnancy. Compared with normal-weight women, obese women have lower pregnancy rates (both spontaneous and by assisted reproductive technology), higher rates of early pregnancy loss and poorer oocyte quality. Beginning at 6 weeks of age, female C57Bl/6J mice were fed either a high-fat/high-sugar diet (HF/HS; 58% Fat Energy/Sucrose) or a diet of standard mouse chow (CON; 13% Fat) for 12 weeks. At this point, metabolic parameters were measured. Some of the mice (n = 9 HF/HS and 9 CON) were mated with reproductively competent males, and implantation sites were assessed. Other mice (n = 11 HF/HS and 10 CON) were mated with vasectomized males, and artificial decidualization was induced. For in vitro human studies of primary ESCs, endometrial tissue was obtained via biopsy from normo-ovulatory patients without history of infertility (obese = BMI > 30 kg/m(2), n = 11 and lean = BMI treatment with cAMP and medroxyprogesterone. The level of expression of decidualization markers was assessed by RT-qPCR (mRNA) and western blotting (protein). ATP content of ESCs was measured, and levels of autophagy were assessed by western blotting of the autophagy regulators acetyl coa carboxylase (ACC) and ULK1 (Ser 317). Autophagic flux was measured by western blot of the marker LC3b-II. Mice exposed to an HF/HS diet became obese and metabolically impaired. HF/HS-exposed mice mated to reproductively competent males had smaller implantation sites in early pregnancy (P obese women than in those of normal-weight women (Ptreatment abrogated this increase. Many aspects of obesity and metabolic impairment could contribute to the decidualization defects observed in the HF/HS-exposed mice. Although our findings suggest that both autophagy and decidualization are impaired

  10. Reading Intervention Using Interactive Metronome in Children with Language and Reading Impairment: A Preliminary Investigation

    Science.gov (United States)

    Ritter, Michaela; Colson, Karen A.; Park, Jungjun

    2013-01-01

    This exploratory study examined the effects of Interactive Metronome (IM) when integrated with a traditional language and reading intervention on reading achievement. Forty-nine school-age children with language and reading impairments were assigned randomly to either an experimental group who received the IM treatment or to a control group who…

  11. Computer-Assisted Learning for the Hearing Impaired: An Interactive Written Language Enviroment.

    Science.gov (United States)

    Ward, R. D.; Rostron, A. B.

    1983-01-01

    To help hearing-impaired children develop their linguistic competence, a computer system that can process sentences and give feedback about their acceptability was developed. Suggestions are made of ways to use the system as an environment for interactive written communication. (Author/CL)

  12. Teaching Play Skills to Visually Impaired Preschool Children: Its Effect on Social Interaction

    Science.gov (United States)

    Ozaydin, Latife

    2015-01-01

    The aim of this study is to assess the effects that teaching visually impaired (VI) preschool children play skills has on their abilities to initialize and respond to social interactions with their typically developing (TD) peers in a reverse mainstreaming preschool class. The subjects of the study were three female VI students regularly attending…

  13. Interaction of Language Processing and Motor Skill in Children with Specific Language Impairment

    Science.gov (United States)

    DiDonato Brumbach, Andrea C.; Goffman, Lisa

    2014-01-01

    Purpose: To examine how language production interacts with speech motor and gross and fine motor skill in children with specific language impairment (SLI). Method: Eleven children with SLI and 12 age-matched peers (4-6 years) produced structurally primed sentences containing particles and prepositions. Utterances were analyzed for errors and for…

  14. Using a Three-Dimensional Interactive Model To Teach Environmental Concepts to Visually Impaired Children.

    Science.gov (United States)

    Budd, Julia M.; LaGrow, Steven J.

    2000-01-01

    A study investigated the efficacy of using the Buddy Road Kit, an interactive, wooden model, to teach environmental concepts to 4 children with visual impairments ages 7 to 11 years old. Results indicate the model was effective in teaching environmental concepts and traffic safety to the children involved. (Contains references.) (CR)

  15. Impairment of endothelial-myocardial interaction increases the susceptibility of cardiomyocytes to ischemia/reperfusion injury.

    Directory of Open Access Journals (Sweden)

    Thorsten M Leucker

    Full Text Available Endothelial-myocardial interactions may be critically important for ischemia/reperfusion injury. Tetrahydrobiopterin (BH4 is a required cofactor for nitric oxide (NO production by endothelial NO synthase (eNOS. Hyperglycemia (HG leads to significant increases in oxidative stress, oxidizing BH4 to enzymatically incompetent dihydrobiopterin. How alterations in endothelial BH4 content impact myocardial ischemia/reperfusion injury remains elusive. The aim of this study was to examine the effect of endothelial-myocardial interaction on ischemia/reperfusion injury, with an emphasis on the role of endothelial BH4 content. Langendorff-perfused mouse hearts were treated by triton X-100 to produce endothelial dysfunction and subsequently subjected to 30 min of ischemia followed by 2 h of reperfusion. The recovery of left ventricular systolic and diastolic function during reperfusion was impaired in triton X-100 treated hearts compared with vehicle-treated hearts. Cardiomyocytes (CMs were co-cultured with endothelial cells (ECs and subsequently subjected to 2 h of hypoxia followed by 2 h of reoxygenation. Addition of ECs to CMs at a ratio of 1∶3 significantly increased NO production and decreased lactate dehydrogenase activity compared with CMs alone. This EC-derived protection was abolished by HG. The addition of 100 µM sepiapterin (a BH4 precursor or overexpression of GTP cyclohydrolase 1 (the rate-limiting enzyme for BH4 biosynthesis in ECs by gene trasfer enhanced endothelial BH4 levels, the ratio of eNOS dimer/monomer, eNOS phosphorylation, and NO production and decreased lactate dehydrogenase activity in the presence of HG. These results demonstrate that increased BH4 content in ECs by either pharmacological or genetic approaches reduces myocardial damage during hypoxia/reoxygenation in the presence of HG. Maintaining sufficient endothelial BH4 is crucial for cardioprotection against hypoxia/reoxygenation injury.

  16. iPads Enhance Social Interaction Skills among Hearing-Impaired Children of Low Income Families in Saudi Arabia

    Science.gov (United States)

    Bahatheg, Raja Omar

    2015-01-01

    This research tries to investigate the technical contribution on improving the social interaction of hearing-impaired children from low income families in Saudi Arabia. It compares the social interaction skills of hearing-impaired children who do and do not have access to iPads. To achieve the goals of the study; seventeen children aged five years…

  17. Mesenchymal Stem Cells from Patients with Rheumatoid Arthritis Display Impaired Function in Inhibiting Th17 Cells

    Directory of Open Access Journals (Sweden)

    Yue Sun

    2015-01-01

    Full Text Available Mesenchymal stem cells (MSCs possess multipotent and immunomodulatory properties and are suggested to be involved in the pathogenesis of immune-related diseases. This study explored the function of bone marrow MSCs from rheumatoid arthritis (RA patients, focusing on immunomodulatory effects. RA MSCs showed decreased proliferative activity and aberrant migration capacity. No significant differences were observed in cytokine profiles between RA and control MSCs. The effects of RA MSCs on proliferation of peripheral blood mononuclear cells (PBMCs and distribution of specific CD4+ T cell subtypes (Th17, Treg, and Tfh cells were investigated. RA MSCs appeared to be indistinguishable from controls in suppressing PBMC proliferation, decreasing the proportion of Tfh cells, and inducing the polarization of Treg cells. However, the capacity to inhibit Th17 cell polarization was impaired in RA MSCs, which was related to the low expression of CCL2 in RA MSCs after coculture with CD4+ T cells. These findings indicated that RA MSCs display defects in several important biological activities, especially the capacity to inhibit Th17 cell polarization. These functionally impaired MSCs may contribute to the development of RA disease.

  18. Helicobacter pylori impairs murine dendritic cell responses to infection.

    Directory of Open Access Journals (Sweden)

    Ya-Hui Wang

    Full Text Available BACKGROUND: Helicobacter pylori, a human pathogen associated with chronic gastritis, peptic ulcer and gastric malignancies, is generally viewed as an extracellular microorganism. Here, we show that H. pylori replicates in murine bone marrow derived-dendritic cells (BMDCs within autophagosomes. METHODOLOGY/PRINCIPAL FINDINGS: A 10-fold increase of CFU is found between 2 h and 6 h p.i. in H. pylori-infected BMDCs. Autophagy is induced around the bacterium and participates at late time points of infection for the clearance of intracellular H. pylori. As a consequence of infection, LC3, LAMP1 and MHC class II molecules are retained within the H. pylori-containing vacuoles and export of MHC class II molecules to cell surface is blocked. However, formalin-fixed H. pylori still maintain this inhibitory activity in BMDC derived from wild type mice, but not in from either TLR4 or TLR2-deficient mice, suggesting the involvement of H. pylori-LPS in this process. TNF-alpha, IL-6 and IL-10 expression was also modulated upon infection showing a TLR2-specific dependent IL-10 secretion. No IL-12 was detected favoring the hypothesis of a down modulation of DC functions during H. pylori infection. Furthermore, antigen-specific T cells proliferation was also impaired upon infection. CONCLUSIONS/SIGNIFICANCE: H. pylori can infect and replicate in BMDCs and thereby affects DC-mediated immune responses. The implication of this new finding is discussed for the biological life cycle of H. pylori in the host.

  19. Impaired conditional reasoning in alcoholics: a negative impact on social interactions and risky behaviors?

    Science.gov (United States)

    Kornreich, Charles; Delle-Vigne, Dyna; Knittel, Julian; Nerincx, Aurore; Campanella, Salvatore; Noel, Xavier; Hanak, Catherine; Verbanck, Paul; Ermer, Elsa

    2011-05-01

    To study the 'social brain' in alcoholics by investigating social contract reasoning, theory of mind and emotional intelligence. A behavioral study comparing recently detoxified alcoholics with normal, healthy controls. Emotional intelligence and decoding of emotional non-verbal cues have been shown to be impaired in alcoholics. This study explores whether these deficits extend to conditional reasoning about social contracts. Twenty-five recently detoxified alcoholics (17 men and eight women) were compared with 25 normal controls (17 men and eight women) matched for sex, age and education level. Wason selection task investigating conditional reasoning on three different rule types (social contract, precautionary and descriptive), revised Reading the Mind in the Eyes Test, Trait Emotional Intelligence Questionnaire (modified version) and additional control measures. Conditional reasoning was impaired in alcoholics. Performance on descriptive rules was not above chance. Reasoning performance was markedly better on social contract and precautionary rules, but this performance was still significantly lower than in controls. Several emotional intelligence measures were lower in alcoholics compared to controls, but these were not correlated with reasoning performance. Conditional reasoning, including reasoning about social contracts and emotional intelligence appear to be impaired in alcoholics. Impairment seems to be particularly severe on descriptive rules. Impairment in social contract reasoning might lead to misunderstandings and frustration in social interactions, and reasoning difficulties about precautionary rules might contribute to risky behaviors in this population. © 2011 The Authors, Addiction © 2011 Society for the Study of Addiction.

  20. Programmed death-1 (PD-1)-dependent functional impairment of CD4(+) T cells in recurrent genital papilloma.

    Science.gov (United States)

    Chang, Dong-Yeop; Song, Sang Hoon; You, Sooseong; Lee, Jino; Kim, Jihye; Racanelli, Vito; Son, Hwancheol; Shin, Eui-Cheol

    2014-08-01

    Genital papilloma is caused by human papilloma virus (HPV) infection and recurs frequently. Although T cells are known to play a critical role in the control of HPV infection and papilloma development, the function and phenotype of these cells in the lesion remain to be elucidated. In the present study, we examined the function and phenotype of CD4(+) T cells isolated from the lesions of primary (n = 9) and recurrent (n = 11) genital papillomas. In recurrent papillomas, the frequency of proliferating (Ki-67(+)) CD4(+) T cells was significantly reduced compared with primary papillomas. Cytokine production was evaluated by intracellular cytokine staining in anti-CD3/anti-CD28-stimulated CD4(+) T cells. CD4(+) T cells from recurrent lesions showed impaired production of IL-2, IFN-γ, and TNF-α. Of interest, the frequency of cytokine-producing CD4(+) T cells significantly correlated with the frequency of Ki-67(+)CD4(+) T cells. We also studied expression of programmed death-1 (PD-1), a T-cell exhaustion marker. The frequency of PD-1(+)CD4(+) T cells was significantly increased in recurrent lesions and inversely correlated with the frequency of cytokine-producing CD4(+) T cells. The functional significance of PD-1 expression was determined in blocking assays with anti-PD-L1, which restored cytokine production of CD4(+) T cells from recurrent lesions. Taken together, in recurrent genital papilloma lesions, proliferation, and cytokine production by CD4(+) T cells are impaired and the PD-1/PD-L1 interaction is responsible for the functional impairment of CD4(+) T cells.

  1. Interaction of tumor cells with the microenvironment

    Directory of Open Access Journals (Sweden)

    Lehnert Hendrik

    2011-09-01

    Full Text Available Abstract Recent advances in tumor biology have revealed that a detailed analysis of the complex interactions of tumor cells with their adjacent microenvironment (tumor stroma is mandatory in order to understand the various mechanisms involved in tumor growth and the development of metastasis. The mutual interactions between tumor cells and cellular and non-cellular components (extracellular matrix = ECM of the tumor microenvironment will eventually lead to a loss of tissue homeostasis and promote tumor development and progression. Thus, interactions of genetically altered tumor cells and the ECM on the one hand and reactive non-neoplastic cells on the other hand essentially control most aspects of tumorigenesis such as epithelial-mesenchymal-transition (EMT, migration, invasion (i.e. migration through connective tissue, metastasis formation, neovascularisation, apoptosis and chemotherapeutic drug resistance. In this mini-review we will focus on these issues that were recently raised by two review articles in CCS.

  2. In silico characterization of cell-cell interactions using a cellular automata model of cell culture.

    Science.gov (United States)

    Kihara, Takanori; Kashitani, Kosuke; Miyake, Jun

    2017-07-14

    Cell proliferation is a key characteristic of eukaryotic cells. During cell proliferation, cells interact with each other. In this study, we developed a cellular automata model to estimate cell-cell interactions using experimentally obtained images of cultured cells. We used four types of cells; HeLa cells, human osteosarcoma (HOS) cells, rat mesenchymal stem cells (MSCs), and rat smooth muscle A7r5 cells. These cells were cultured and stained daily. The obtained cell images were binarized and clipped into squares containing about 10 4 cells. These cells showed characteristic cell proliferation patterns. The growth curves of these cells were generated from the cell proliferation images and we determined the doubling time of these cells from the growth curves. We developed a simple cellular automata system with an easily accessible graphical user interface. This system has five variable parameters, namely, initial cell number, doubling time, motility, cell-cell adhesion, and cell-cell contact inhibition (of proliferation). Within these parameters, we obtained initial cell numbers and doubling times experimentally. We set the motility at a constant value because the effect of the parameter for our simulation was restricted. Therefore, we simulated cell proliferation behavior with cell-cell adhesion and cell-cell contact inhibition as variables. By comparing growth curves and proliferation cell images, we succeeded in determining the cell-cell interaction properties of each cell. Simulated HeLa and HOS cells exhibited low cell-cell adhesion and weak cell-cell contact inhibition. Simulated MSCs exhibited high cell-cell adhesion and positive cell-cell contact inhibition. Simulated A7r5 cells exhibited low cell-cell adhesion and strong cell-cell contact inhibition. These simulated results correlated with the experimental growth curves and proliferation images. Our simulation approach is an easy method for evaluating the cell-cell interaction properties of cells.

  3. Fibroblasts Cultured on Nanowires Exhibit Low Motility, Impaired Cell Division, and DNA Damage

    DEFF Research Database (Denmark)

    Persson, H.; Købler, Carsten; Mølhave, Kristian

    2013-01-01

    Mouse fibroblasts cultured on 7-μm-long vertical nanowires are reported on page 4006 by C. N. Prinz and co-workers. Culturing cells on this kind of substrate interferes greatly with cell function, causing the cells to develop into widely different morphologies. The cells' division is impaired...

  4. Research on the Design of Visually Impaired Interactive Accessibility in Large Urban Public Transport System

    Science.gov (United States)

    Zhang, Weiru

    2017-12-01

    In medieval times, due to people’s reliance on belief, public space of Christianity came into being. With the rise of secularization, religion gradually turned into private belief, and accordingly public space returned to private space. In the 21st century, due to people’s reliance on intelligent devices, information-interactive public space emerges, and as information interaction is constantly constraining the visually impaired, public space regressed to the exclusive space of limited people[1]. Modernity is marked by technical rationality, but an ensuing basic problem lies in the separation between human action, ethics and public space. When technology fails to overcome obstacles for a particular group, the gap between the burgeoning intelligent phenomena and the increasing ratio of visually impaired is also expanding, ultimately resulting in a growing number of “blind spots” in information-interactive space. Technological innovation not only promotes the development of the information industry, but also promotes the rapid development of the transportation industry. Traffic patterns are diversifying and diverging nowadays, but it’s a fatal blow for people with visually disabilities, Because they still can only experience the most traditional mode of transportation, sometimes even not go out. How to guarantee their interactive accessibility in large urban public transport system right, currently, is a very important research direction.

  5. Bilateral amygdala damage impairs the acquisition and use of common ground in social interaction.

    Science.gov (United States)

    Gupta, Rupa; Duff, Melissa C; Tranel, Daniel

    2011-03-01

    The development of "common ground," or mutual knowledge of shared information, is believed to require the ability to update a mental representation of another person's thoughts and knowledge based on verbal information and nonverbal social and emotional signals, to facilitate economical communication. As in other forms of everyday social communication, the development of common ground likely requires the orchestration of multiple cognitive processes supported by various neural systems. Here, we investigate the contribution of the amygdala to these processes. SM, a patient with complete, focal, bilateral amygdala damage, and deficits in social and emotional processing, and five healthy comparison participants, each interacted with a familiar partner. We investigated the participants' ability to develop and use referential labels across 24 dynamic, collaborative interactions. Participants verbally directed their partner how to arrange a set of 12 abstract tangrams while separated by a low barrier, allowing them to see each other but hiding their tangrams. In contrast to comparison participants, SM exhibited an impaired rate of learning across trials and did not show the typical simplification in the labels generated during the interactions. Detailed analyses of SM's interactional discourse and social behavior suggested that she has impaired perspective-taking or what can be interpreted as deficient "theory of mind," manifested in abnormal "language-in-use." These results support the conclusion that the amygdala, a structure critical for social and emotional processing, plays an important role in the acquisition and use of common ground and in social communication more broadly.

  6. Psychomotor Impairment Detection via Finger Interactions with a Computer Keyboard During Natural Typing

    Science.gov (United States)

    Giancardo, L.; Sánchez-Ferro, A.; Butterworth, I.; Mendoza, C. S.; Hooker, J. M.

    2015-04-01

    Modern digital devices and appliances are capable of monitoring the timing of button presses, or finger interactions in general, with a sub-millisecond accuracy. However, the massive amount of high resolution temporal information that these devices could collect is currently being discarded. Multiple studies have shown that the act of pressing a button triggers well defined brain areas which are known to be affected by motor-compromised conditions. In this study, we demonstrate that the daily interaction with a computer keyboard can be employed as means to observe and potentially quantify psychomotor impairment. We induced a psychomotor impairment via a sleep inertia paradigm in 14 healthy subjects, which is detected by our classifier with an Area Under the ROC Curve (AUC) of 0.93/0.91. The detection relies on novel features derived from key-hold times acquired on standard computer keyboards during an uncontrolled typing task. These features correlate with the progression to psychomotor impairment (p < 0.001) regardless of the content and language of the text typed, and perform consistently with different keyboards. The ability to acquire longitudinal measurements of subtle motor changes from a digital device without altering its functionality may allow for early screening and follow-up of motor-compromised neurodegenerative conditions, psychological disorders or intoxication at a negligible cost in the general population.

  7. Interaction between dendritic cells and natural killer cells during pregnancy in mice.

    Science.gov (United States)

    Blois, Sandra M; Barrientos, Gabriela; Garcia, Mariana G; Orsal, Arif S; Tometten, Mareike; Cordo-Russo, Rosalia I; Klapp, Burghard F; Santoni, Angela; Fernández, Nelson; Terness, Peter; Arck, Petra C

    2008-07-01

    A complex regulation of innate and adaptive immune responses at the maternal fetal interface promotes tolerance of trophoblast cells carrying paternally derived antigens. Such regulatory functions involve uterine dendritic cells (uDC) and natural killer (uNK) cells. The existence of a NK and DC "cross talk" has been revealed in various experimental settings; its biological significance ranging from cooperative stimulation to cell lysis. Little is known about the presence or role of NK and DC cross talk at the maternal fetal interface. The present study shows that mouse NK and DC interactions are subject to modulation by trophoblast cells in vitro. This interaction promotes a tolerogenic microenvironment characterized by downregulation of the expression of activation markers on uNK cells and uDC and dominance of Th2 cytokines. NK and DC interactions would also influence uterine cell proliferation and this process would be strongly modulated by trophoblast-derived signals. Indeed; while low proliferation rates were observed upon regular coculture allowing direct contact between uterine cells and trophoblasts, incubation in a transwell culture system markedly increased uterine cell proliferation suggesting that soluble factors are key mediators in the molecular "dialog" between the mother and the conceptus during the establishment of mouse pregnancy. Our data further reveal that the regulatory functions of trophoblast cells associated with tolerance induction are impaired in high abortion murine matings. Interestingly, we observed that secretion of interleukin-12p70 by uDC is dramatically abrogated in the presence of uNK cells. Taken together, our results provide the first evidence that a delicate balance of interactions involving NK cells, DC, and trophoblasts at the mouse maternal fetal interface supports a successful pregnancy outcome.

  8. Aging impairs recipient T cell intrinsic and extrinsic factors in response to transplantation.

    Directory of Open Access Journals (Sweden)

    Hua Shen

    Full Text Available As increasing numbers of older people are listed for solid organ transplantation, there is an urgent need to better understand how aging modifies alloimmune responses. Here, we investigated whether aging impairs the ability of donor dendritic cells or recipient immunity to prime alloimmune responses to organ transplantation.Using murine experimental models, we found that aging impaired the host environment to expand and activate antigen specific CD8(+ T cells. Additionally, aging impaired the ability of polyclonal T cells to induce acute allograft rejection. However, the alloimmune priming capability of donor dendritic cells was preserved with aging.Aging impairs recipient responses, both T cell intrinsic and extrinsic, in response to organ transplantation.

  9. Impaired conditional reasoning in alcoholics: A negative impact on social interactions and risky behaviors?

    Science.gov (United States)

    Kornreich, C; Delle-Vigne, D; Knittel, J; Nerincx, A; Campanella, S; Noel, X; Hanak, C; Verbanck, P; Ermer, E

    2011-01-01

    Aims To study the “social brain” in alcoholics by investigating social contract reasoning, theory of mind, and emotional intelligence. Design A behavioral study comparing recently detoxified alcoholics with normal, healthy controls. Setting Emotional intelligence and decoding of emotional non-verbal cues have been shown to be impaired in alcoholics. This study explores whether these deficits extend to conditional reasoning about social contracts. Participants 25 recently detoxified alcoholics (17 men and 8 women) were compared with 25 normal controls (17 men and 8 women) matched for sex, age, and education level. Measurements Wason Selection Task investigating conditional reasoning on three different rule types (social contract, precautionary, and descriptive), Revised Reading the Mind in the Eyes Test, Trait Emotional Intelligence Questionnaire (modified version), and additional control measures. Findings Conditional reasoning was impaired in alcoholics. Performance on descriptive rules was not above chance. Reasoning performance was markedly better on social contract and precautionary rules, but this performance was still significantly lower than in controls. Several emotional intelligence measures were lower in alcoholics compared to controls, but these were not correlated with reasoning performance. Conclusions Conditional reasoning and emotional intelligence appear impaired in alcoholics. Impairment was particularly severe on descriptive rules. Though alcoholics' performance was better on social contract and precautionary rules, overall reasoning performance was still low. Differential performance is consistent with distinct neurocognitive reasoning mechanisms and partial resilience of evolutionarily-relevant functions. Impairment in social contract reasoning might lead to misunderstandings and frustration in social interactions, and reasoning difficulties about precautionary rules might contribute to risky behaviors in this population. PMID:21205056

  10. Disruption of a -35kb enhancer impairs CTCF binding and MLH1 expression in colorectal cells.

    Science.gov (United States)

    Liu, Qing; Thoms, Julie A; Nunez, Andrea C; Huang, Yizhou; Knezevic, Kathy; Packham, Deborah; Poulos, Rebecca C; Williams, Rachel; Beck, Dominik; Hawkins, Nicholas J; Ward, Robyn L; Wong, Jason W H; Hesson, Luke B; Sloane, Mathew A; Pimanda, John

    2018-06-13

    MLH1 is a major tumour suppressor gene involved in the pathogenesis of Lynch syndrome and various sporadic cancers. Despite their potential pathogenic importance, genomic regions capable of regulating MLH1 expression over long distances have yet to be identified. Here we use chromosome conformation capture (3C) to screen a 650-kb region flanking the MLH1 locus to identify interactions between the MLH1 promoter and distal regions in MLH1 expressing and non-expressing cells. Putative enhancers were functionally validated using luciferase reporter assays, chromatin immunoprecipitation and CRISPR-Cas9 mediated deletion of endogenous regions. To evaluate whether germline variants in the enhancer might contribute to impaired MLH1 expression in patients with suspected Lynch syndrome, we also screened germline DNA from a cohort of 74 patients with no known coding mutations or epimutations at the MLH1 promoter. A 1.8kb DNA fragment, 35kb upstream of the MLH1 transcription start site enhances MLH1 gene expression in colorectal cells. The enhancer was bound by CTCF and CRISPR-Cas9 mediated deletion of a core binding region impairs endogenous MLH1 expression. 5.4% of suspected Lynch syndrome patients have a rare single nucleotide variant (G>A; rs143969848; 2.5% in gnomAD European, non-Finnish) within a highly conserved CTCF binding motif, which disrupts enhancer activity in SW620 colorectal carcinoma cells. A CTCF bound region within the MLH1 -35 enhancer regulates MLH1 expression in colorectal cells and is worthy of scrutiny in future genetic screening strategies for suspected Lynch syndrome associated with loss of MLH1 expression. Copyright ©2018, American Association for Cancer Research.

  11. Inhibition of Wnt Signaling Pathways Impairs Chlamydia trachomatis Infection in Endometrial Epithelial Cells.

    Science.gov (United States)

    Kintner, Jennifer; Moore, Cheryl G; Whittimore, Judy D; Butler, Megan; Hall, Jennifer V

    2017-01-01

    Chlamydia trachomatis infections represent the predominant cause of bacterial sexually transmitted infections. As an obligate intracellular bacterium, C. trachomatis is dependent on the host cell for survival, propagation, and transmission. Thus, factors that affect the host cell, including nutrition, cell cycle, and environmental signals, have the potential to impact chlamydial development. Previous studies have demonstrated that activation of Wnt/β-catenin signaling benefits C. trachomatis infections in fallopian tube epithelia. In cervical epithelial cells chlamydiae sequester β-catenin within the inclusion. These data indicate that chlamydiae interact with the Wnt signaling pathway in both the upper and lower female genital tract (FGT). However, hormonal activation of canonical and non-canonical Wnt signaling pathways is an essential component of cyclic remodeling in another prominent area of the FGT, the endometrium. Given this information, we hypothesized that Wnt signaling would impact chlamydial infection in endometrial epithelial cells. To investigate this hypothesis, we analyzed the effect of Wnt inhibition on chlamydial inclusion development and elementary body (EB) production in two endometrial cell lines, Ishikawa (IK) and Hec-1B, in nonpolarized cell culture and in a polarized endometrial epithelial (IK)/stromal (SHT-290) cell co-culture model. Inhibition of Wnt by the small molecule inhibitor (IWP2) significantly decreased inclusion size in IK and IK/SHT-290 cultures ( p Wnt inhibition caused chlamydiae to become aberrant in morphology. EB formation was also impaired in IK, Hec-1B and IK/SHT-290 cultures regardless of whether Wnt inhibition occurred throughout, in the middle (24 hpi) or late (36 hpi) during the development cycle. Overall, these data lead us to conclude that Wnt signaling in the endometrium is a key host pathway for the proper development of C. trachomatis .

  12. Interactive effects of diabetes and impaired kidney function on cognitive performance in old age: a population-based study.

    Science.gov (United States)

    Yin, Zhaoxue; Yan, Zhongrui; Liang, Yajun; Jiang, Hui; Cai, Chuanzhu; Song, Aiqin; Feng, Lei; Qiu, Chengxuan

    2016-01-12

    The interactive effect between diabetes and impaired kidney function on cognitive impairment in older adults has not yet been reported. The aim of this study was to investigate the association of diabetes and impaired kidney function with cognitive impairment among Chinese older people living in a rural area. This cross-sectional study included 1,358 participants (age ≥60 years; 60.5% women) in the population-based Confucius Hometown Aging Project in Shandong, China. Data on demographics, lifestyle factors, health history, use of medications, global cognitive function, and kidney function were collected through structured interviews, clinical examinations, and blood tests. We defined diabetes as a fasting plasma glucose level ≥7.0 mmol/l or use of hypoglycemic agents, impaired kidney function as glomerular filtration rate estimated from cystatin C (eGFRcys) Cognitive impairment was defined using the education-based cut-off scores of Mini-Mental State Examination (MMSE). Data were analyzed using multiple general linear and logistic regression models. Cognitive impairment was defined in 197 (14.5%) persons. The multi-adjusted β coefficient of MMSE score associated with diabetes was -0.06 (95% confidence interval [CI], -0.16, 0.03); the corresponding figures associated with eGFRcys function showed an interactive effect on cognitive impairment ( interaction = 0.02). Compared with individuals having neither diabetes nor impaired kidney function, those with both conditions had a multi-adjusted odds ratio of 4.23 (95% CI, 2.10-8.49) for cognitive impairment. The relative excess risk due to interaction was 2.74. This study suggests that concurrent presence of diabetes and impaired kidney function is associated with a substantial likelihood for cognitive impairment in older adults.

  13. A naringenin–tamoxifen combination impairs cell proliferation and survival of MCF-7 breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Hatkevich, Talia; Ramos, Joseph; Santos-Sanchez, Idalys; Patel, Yashomati M., E-mail: ympatel@uncg.edu

    2014-10-01

    Since over 60% of breast cancers are estrogen receptor positive (ER+), many therapies have targeted the ER. The ER is activated by both estrogen binding and phosphorylation. While anti-estrogen therapies, such as tamoxifen (Tam) have been successful they do not target the growth factor promoting phosphorylation of the ER. Other proliferation pathways such as the phosphatidylinositol-3 kinase, (PI3K) and the mitogen-activated protein kinase (MAPK) pathways are activated in breast cancer cells and are associated with poor prognosis. Thus targeting multiple cellular proliferation and survival pathways at the onset of treatment is critical for the development of more effective therapies. The grapefruit flavanone naringenin (Nar) is an inhibitor of both the PI3K and MAPK pathways. Previous studies examining either Nar or Tam used charcoal-stripped serum which removed estrogen as well as other factors. We wanted to use serum containing medium in order to retain all the potential inducers of cell proliferation so as not to exclude any targets of Nar. Here we show that a Nar–Tam combination is more effective than either Tam alone or Nar alone in MCF-7 breast cancer cells. We demonstrate that a Nar–Tam combination impaired cellular proliferation and viability to a greater extent than either component alone in MCF-7 cells. Furthermore, the use of a Nar–Tam combination requires lower concentrations of both compounds to achieve the same effects on proliferation and viability. Nar may function by inhibiting both PI3K and MAPK pathways as well as localizing ERα to the cytoplasm in MCF-7 cells. Our results demonstrate that a Nar–Tam combination induces apoptosis and impairs proliferation signaling to a greater extent than either compound alone. These studies provide critical information for understanding the molecular mechanisms involved in cell proliferation and apoptosis in breast cancer cells. - Highlights: • Nar–Tam impairs cell viability more effectively than

  14. A naringenin–tamoxifen combination impairs cell proliferation and survival of MCF-7 breast cancer cells

    International Nuclear Information System (INIS)

    Hatkevich, Talia; Ramos, Joseph; Santos-Sanchez, Idalys; Patel, Yashomati M.

    2014-01-01

    Since over 60% of breast cancers are estrogen receptor positive (ER+), many therapies have targeted the ER. The ER is activated by both estrogen binding and phosphorylation. While anti-estrogen therapies, such as tamoxifen (Tam) have been successful they do not target the growth factor promoting phosphorylation of the ER. Other proliferation pathways such as the phosphatidylinositol-3 kinase, (PI3K) and the mitogen-activated protein kinase (MAPK) pathways are activated in breast cancer cells and are associated with poor prognosis. Thus targeting multiple cellular proliferation and survival pathways at the onset of treatment is critical for the development of more effective therapies. The grapefruit flavanone naringenin (Nar) is an inhibitor of both the PI3K and MAPK pathways. Previous studies examining either Nar or Tam used charcoal-stripped serum which removed estrogen as well as other factors. We wanted to use serum containing medium in order to retain all the potential inducers of cell proliferation so as not to exclude any targets of Nar. Here we show that a Nar–Tam combination is more effective than either Tam alone or Nar alone in MCF-7 breast cancer cells. We demonstrate that a Nar–Tam combination impaired cellular proliferation and viability to a greater extent than either component alone in MCF-7 cells. Furthermore, the use of a Nar–Tam combination requires lower concentrations of both compounds to achieve the same effects on proliferation and viability. Nar may function by inhibiting both PI3K and MAPK pathways as well as localizing ERα to the cytoplasm in MCF-7 cells. Our results demonstrate that a Nar–Tam combination induces apoptosis and impairs proliferation signaling to a greater extent than either compound alone. These studies provide critical information for understanding the molecular mechanisms involved in cell proliferation and apoptosis in breast cancer cells. - Highlights: • Nar–Tam impairs cell viability more effectively than

  15. Different cell fates from cell-cell interactions: core architectures of two-cell bistable networks.

    Science.gov (United States)

    Rouault, Hervé; Hakim, Vincent

    2012-02-08

    The acquisition of different fates by cells that are initially in the same state is central to development. Here, we investigate the possible structures of bistable genetic networks that can allow two identical cells to acquire different fates through cell-cell interactions. Cell-autonomous bistable networks have been previously sampled using an evolutionary algorithm. We extend this evolutionary procedure to take into account interactions between cells. We obtain a variety of simple bistable networks that we classify into major subtypes. Some have long been proposed in the context of lateral inhibition through the Notch-Delta pathway, some have been more recently considered and others appear to be new and based on mechanisms not previously considered. The results highlight the role of posttranscriptional interactions and particularly of protein complexation and sequestration, which can replace cooperativity in transcriptional interactions. Some bistable networks are entirely based on posttranscriptional interactions and the simplest of these is found to lead, upon a single parameter change, to oscillations in the two cells with opposite phases. We provide qualitative explanations as well as mathematical analyses of the dynamical behaviors of various created networks. The results should help to identify and understand genetic structures implicated in cell-cell interactions and differentiation. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  16. Cell Phones, Tablets, and Other Mobile Technology for Users with Visual Impairments

    Science.gov (United States)

    ... research. Share: Email Print Like (218 Likes) Cell Phones, Tablets, and Other Mobile Technology Touchscreen Smartphone Accessibility for People with Visual Impairments and Blindness The Benefits of Accessible Touchscreen Mobile Devices for People with ...

  17. β-Cell dedifferentiation, reduced duct cell plasticity, and impaired β-cell mass regeneration in middle-aged rats.

    Science.gov (United States)

    Téllez, Noèlia; Vilaseca, Marina; Martí, Yasmina; Pla, Arturo; Montanya, Eduard

    2016-09-01

    Limitations in β-cell regeneration potential in middle-aged animals could contribute to the increased risk to develop diabetes associated with aging. We investigated β-cell regeneration of middle-aged Wistar rats in response to two different regenerative stimuli: partial pancreatectomy (Px + V) and gastrin administration (Px + G). Pancreatic remnants were analyzed 3 and 14 days after surgery. β-Cell mass increased in young animals after Px and was further increased after gastrin treatment. In contrast, β-cell mass did not change after Px or after gastrin treatment in middle-aged rats. β-Cell replication and individual β-cell size were similarly increased after Px in young and middle-aged animals, and β-cell apoptosis was not modified. Nuclear immunolocalization of neurog3 or nkx6.1 in regenerative duct cells, markers of duct cell plasticity, was increased in young but not in middle-aged Px rats. The pancreatic progenitor-associated transcription factors neurog3 and sox9 were upregulated in islet β-cells of middle-aged rats and further increased after Px. The percentage of chromogranin A+/hormone islet cells was significantly increased in the pancreases of middle-aged Px rats. In summary, the potential for compensatory β-cell hyperplasia and hypertrophy was retained in middle-aged rats, but β-cell dedifferentiation and impaired duct cell plasticity limited β-cell regeneration. Copyright © 2016 the American Physiological Society.

  18. Blood cell interactions and segregation in flow.

    Science.gov (United States)

    Munn, Lance L; Dupin, Michael M

    2008-04-01

    For more than a century, pioneering researchers have been using novel experimental and computational approaches to probe the mysteries of blood flow. Thanks to their efforts, we know that blood cells generally prefer to migrate to the axis of flow, that red and white cells segregate in flow, and that cell deformability and their tendency to reversibly aggregate contribute to the non-Newtonian nature of this unique fluid. All of these properties have beneficial physiological consequences, allowing blood to perform a variety of critical functions. Our current understanding of these unusual flow properties of blood have been made possible by the ingenuity and diligence of a number of researchers, including Harry Goldsmith, who developed novel technologies to visualize and quantify the flow of blood at the level of individual cells. Here we summarize efforts in our lab to continue this tradition and to further our understanding of how blood cells interact with each other and with the blood vessel wall.

  19. Secret handshakes: cell-cell interactions and cellular mimics.

    Science.gov (United States)

    Cohen, Daniel J; Nelson, W James

    2018-02-01

    Cell-cell junctions, acting as 'secret handshakes', mediate cell-cell interactions and make multicellularity possible. Work over the previous century illuminated key players comprising these junctions including the cadherin superfamily, nectins, CAMs, connexins, notch/delta, lectins, and eph/Ephrins. Recent work has focused on elucidating how interactions between these complex and often contradictory cues can ultimately give rise to large-scale organization in tissues. This effort, in turn, has enabled bioengineering advances such as cell-mimetic interfaces that allow us to better probe junction biology and to develop new biomaterials. This review details exciting, recent developments in these areas as well as providing both historical context and a discussion of some topical challenges and opportunities for the future. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Cognitive Impairment in Patients with Chronic Neuropathic or Radicular Pain: An Interaction of Pain and Age

    Directory of Open Access Journals (Sweden)

    Orla Moriarty

    2017-06-01

    Full Text Available A growing body of empirical research has confirmed an association between chronic pain and cognitive dysfunction. The aim of the present study was to determine whether cognitive function is affected in patients with a diagnosis of chronic neuropathic or radicular pain relative to healthy control participants matched by age, gender, and years of education. We also examined the interaction of pain with age in terms of cognitive performance. Some limitations of previous clinical research investigating the effects of chronic pain on cognitive function include differences in the pain and cognitive scale materials used, and the heterogeneity of patient participants, both in terms of their demographics and pathological conditions. To address these potential confounds, we have used a relatively homogenous patient group and included both experimental and statistical controls. We have also specifically investigated the interaction effect of pain and age on cognitive performance. Patients (n = 38 and controls (n = 38 were administered a battery of cognitive tests measuring IQ, spatial and verbal memory, attention, and executive function. Educational level, depressive symptoms, and state anxiety were assessed as were medication usage, caffeine, and nicotine consumption to control for possible confounding effects. Both the level of depressive symptoms and the state anxiety score were higher in chronic pain patients than in matched control participants. Chronic pain patients had a lower estimated IQ than controls, and showed impairments on measures of spatial and verbal memory. Attentional responding was altered in the patient group, possibly indicative of impaired inhibitory control. There were significant interactions between chronic pain condition and age on a number of cognitive outcome variables, such that older patients with chronic pain were more impaired than both age-matched controls and younger patients with chronic pain. Chronic pain did not appear

  1. Interactions between human mesenchymal stem cells and natural killer cells.

    Science.gov (United States)

    Sotiropoulou, Panagiota A; Perez, Sonia A; Gritzapis, Angelos D; Baxevanis, Constantin N; Papamichail, Michael

    2006-01-01

    Mesenchymal stem cells (MSCs) are multipotent progenitor cells representing an attractive therapeutic tool for regenerative medicine. They possess unique immunomodulatory properties, being capable of suppressing T-cell responses and modifying dendritic cell differentiation, maturation, and function, whereas they are not inherently immunogenic, failing to induce alloreactivity to T cells and freshly isolated natural killer (NK) cells. To clarify the generation of host immune responses to implanted MSCs in tissue engineering and their potential use as immunosuppressive elements, the effect of MSCs on NK cells was investigated. We demonstrate that at low NK-to-MSC ratios, MSCs alter the phenotype of NK cells and suppress proliferation, cytokine secretion, and cyto-toxicity against HLA-class I- expressing targets. Some of these effects require cell-to-cell contact, whereas others are mediated by soluble factors, including transforming growth factor-beta1 and prostaglandin E2, suggesting the existence of diverse mechanisms for MSC-mediated NK-cell suppression. On the other hand, MSCs are susceptible to lysis by activated NK cells. Overall, these data improve our knowledge of interactions between MSCs and NK cells and consequently of their effect on innate immune responses and their contribution to the regulation of adaptive immunity, graft rejection, and cancer immunotherapy.

  2. Quercetin suppresses insulin receptor signaling through inhibition of the insulin ligand–receptor binding and therefore impairs cancer cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Feng [Department of Gastroenterology, The Tenth People’s Hospital of Shanghai, Tongji University, Shanghai 200072 (China); Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Yang, Yong, E-mail: yyang@houstonmethodist.org [Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Department of Medicine, Weill Cornell Medical College, New York, NY 10065 (United States)

    2014-10-03

    Graphical abstract: - Highlights: • Quercetin inhibits insulin ligand–receptor interactions. • Quercetin reduces downstream insulin receptor signaling. • Quercetin blocks insulin induced glucose uptake. • Quercetin suppresses insulin stimulated cancer cell proliferation and tumor growth. - Abstract: Although the flavonoid quercetin is known to inhibit activation of insulin receptor signaling, the inhibitory mechanism is largely unknown. In this study, we demonstrate that quercetin suppresses insulin induced dimerization of the insulin receptor (IR) through interfering with ligand–receptor interactions, which reduces the phosphorylation of IR and Akt. This inhibitory effect further inhibits insulin stimulated glucose uptake due to decreased cell membrane translocation of glucose transporter 4 (GLUT4), resulting in impaired cancer cell proliferation. The effect of quercetin in inhibiting tumor growth was also evident in an in vivo model, indicating a potential future application for quercetin in the treatment of cancers.

  3. Quercetin suppresses insulin receptor signaling through inhibition of the insulin ligand–receptor binding and therefore impairs cancer cell proliferation

    International Nuclear Information System (INIS)

    Wang, Feng; Yang, Yong

    2014-01-01

    Graphical abstract: - Highlights: • Quercetin inhibits insulin ligand–receptor interactions. • Quercetin reduces downstream insulin receptor signaling. • Quercetin blocks insulin induced glucose uptake. • Quercetin suppresses insulin stimulated cancer cell proliferation and tumor growth. - Abstract: Although the flavonoid quercetin is known to inhibit activation of insulin receptor signaling, the inhibitory mechanism is largely unknown. In this study, we demonstrate that quercetin suppresses insulin induced dimerization of the insulin receptor (IR) through interfering with ligand–receptor interactions, which reduces the phosphorylation of IR and Akt. This inhibitory effect further inhibits insulin stimulated glucose uptake due to decreased cell membrane translocation of glucose transporter 4 (GLUT4), resulting in impaired cancer cell proliferation. The effect of quercetin in inhibiting tumor growth was also evident in an in vivo model, indicating a potential future application for quercetin in the treatment of cancers

  4. T cell motility as modulator of interactions with dendritic cells

    Directory of Open Access Journals (Sweden)

    Jens Volker Stein

    2015-11-01

    Full Text Available It is well established that the balance of costimulatory and inhibitory signals during interactions with dendritic cells (DCs determines T cell transition from a naïve to an activated or tolerant/anergic status. While many of these molecular interactions are well reproduced in reductionist in vitro assays, the highly dynamic motility of naïve T cells in lymphoid tissue acts as an additional lever to fine-tune their activation threshold. T cell detachment from DCs providing suboptimal stimulation allows them to search for DCs with higher levels of stimulatory signals, while storing a transient memory of short encounters. In turn, adhesion of weakly reactive T cells to DCs presenting pMHC with low affinity is prevented by lipid mediators. Finally, controlled recruitment of CD8+ T cells to cognate DC – CD4+ T cell clusters shapes memory T cell formation and the quality of the immune response. Dynamic physiological lymphocyte motility therefore constitutes a mechanism to mitigate low avidity T cell activation and to improve the search for optimal DCs, while contributing to peripheral tolerance induction in the absence of inflammation.

  5. Theory of mind in Alzheimer disease: Evidence of authentic impairment during social interaction.

    Science.gov (United States)

    Moreau, Noémie; Rauzy, Stéphane; Viallet, François; Champagne-Lavau, Maud

    2016-03-01

    The present study aimed to investigate theory of mind (the ability to infer others' mental states) deficit in 20 patients with mild Alzheimer's disease and 20 healthy controls, with 2 theory of mind tasks, 1 of them being a real interactive task. Previous results concerning preserved or altered theory of mind abilities in Alzheimer's disease have been inconsistent and relationships with other cognitive dysfunctions (notably episodic memory and executive functions) are still unclear. The first task we used was a false belief paradigm as frequently used in literature whereas the second task, a referential communication task, assessed theory of mind in a real situation of interaction. Participants also underwent neuropsychological evaluation to investigate potential relationships between theory of mind and memory deficits. The results showed that Alzheimer patients presented a genuine and significant theory of mind deficit compared to control participants characterized notably by difficulties to attribute knowledge to an interlocutor in a real social interaction. These results further confirm that theory of mind is altered in early stages of Alzheimer dementia which is consistent with previous works. More specifically, this study is the first to objectivize this impairment in social interaction. (c) 2016 APA, all rights reserved).

  6. Cell-ECM Interactions During Cancer Invasion

    Science.gov (United States)

    Jiang, Yi

    The extracellular matrix (ECM), a fibrous material that forms a network in a tissue, significantly affects many aspects of cellular behavior, including cell movement and proliferation. Transgenic mouse tumor studies indicate that excess collagen, a major component of ECM, enhances tumor formation and invasiveness. Clinically, tumor associated collagen signatures are strong markers for breast cancer survival. However, the underlying mechanisms are unclear since the properties of ECM are complex, with diverse structural and mechanical properties depending on various biophysical parameters. We have developed a three-dimensional elastic fiber network model, and parameterized it with in vitro collagen mechanics. Using this model, we study ECM remodeling as a result of local deformation and cell migration through the ECM as a network percolation problem. We have also developed a three-dimensional, multiscale model of cell migration and interaction with ECM. Our model reproduces quantitative single cell migration experiments. This model is a first step toward a fully biomechanical cell-matrix interaction model and may shed light on tumor associated collagen signatures in breast cancer. This work was partially supported by NIH-U01CA143069.

  7. Interaction of Stellate Cells with Pancreatic Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Marco Siech

    2010-09-01

    Full Text Available Pancreatic cancer is characterized by its late detection, aggressive growth, intense infiltration into adjacent tissue, early metastasis, resistance to chemo- and radiotherapy and a strong “desmoplastic reaction”. The dense stroma surrounding carcinoma cells is composed of fibroblasts, activated stellate cells (myofibroblast-like cells, various inflammatory cells, proliferating vascular structures, collagens and fibronectin. In particular the cellular components of the stroma produce the tumor microenvironment, which plays a critical role in tumor growth, invasion, spreading, metastasis, angiogenesis, inhibition of anoikis, and chemoresistance. Fibroblasts, myofibroblasts and activated stellate cells produce the extracellular matrix components and are thought to interact actively with tumor cells, thereby promoting cancer progression. In this review, we discuss our current understanding of the role of pancreatic stellate cells (PSC in the desmoplastic response of pancreas cancer and the effects of PSC on tumor progression, metastasis and drug resistance. Finally we present some novel ideas for tumor therapy by interfering with the cancer cell-host interaction.

  8. Well-Controlled Cell-Trapping Systems for Investigating Heterogeneous Cell-Cell Interactions.

    Science.gov (United States)

    Kamiya, Koki; Abe, Yuta; Inoue, Kosuke; Osaki, Toshihisa; Kawano, Ryuji; Miki, Norihisa; Takeuchi, Shoji

    2018-03-01

    Microfluidic systems have been developed for patterning single cells to study cell-cell interactions. However, patterning multiple types of cells to understand heterogeneous cell-cell interactions remains difficult. Here, it is aimed to develop a cell-trapping device to assemble multiple types of cells in the well-controlled order and morphology. This device mainly comprises a parylene sheet for assembling cells and a microcomb for controlling the cell-trapping area. The cell-trapping area is controlled by moving the parylene sheet on an SU-8 microcomb using tweezers. Gentle downward flow is used as a driving force for the cell-trapping. The assembly of cells on a parylene sheet with round and line-shaped apertures is demonstrated. The cell-cell contacts of the trapped cells are then investigated by direct cell-cell transfer of calcein via connexin nanopores. Finally, using the device with a system for controlling the cell-trapping area, three different types of cells in the well-controlled order are assembled. The correct cell order rate obtained using the device is 27.9%, which is higher than that obtained without the sliding parylene system (0.74%). Furthermore, the occurrence of cell-cell contact between the three cell types assembled is verified. This cell-patterning device will be a useful tool for investigating heterogeneous cell-cell interactions. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Cell Biology of Astrocyte-Synapse Interactions.

    Science.gov (United States)

    Allen, Nicola J; Eroglu, Cagla

    2017-11-01

    Astrocytes, the most abundant glial cells in the mammalian brain, are critical regulators of brain development and physiology through dynamic and often bidirectional interactions with neuronal synapses. Despite the clear importance of astrocytes for the establishment and maintenance of proper synaptic connectivity, our understanding of their role in brain function is still in its infancy. We propose that this is at least in part due to large gaps in our knowledge of the cell biology of astrocytes and the mechanisms they use to interact with synapses. In this review, we summarize some of the seminal findings that yield important insight into the cellular and molecular basis of astrocyte-neuron communication, focusing on the role of astrocytes in the development and remodeling of synapses. Furthermore, we pose some pressing questions that need to be addressed to advance our mechanistic understanding of the role of astrocytes in regulating synaptic development. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Parent-Child Interaction Therapy (PCIT) in school-aged children with specific language impairment.

    Science.gov (United States)

    Allen, Jessica; Marshall, Chloë R

    2011-01-01

    Parents play a critical role in their child's language development. Therefore, advising parents of a child with language difficulties on how to facilitate their child's language might benefit the child. Parent-Child Interaction Therapy (PCIT) has been developed specifically for this purpose. In PCIT, the speech-and-language therapist (SLT) works collaboratively with parents, altering interaction styles to make interaction more appropriate to their child's level of communicative needs. This study investigates the effectiveness of PCIT in 8-10-year-old children with specific language impairment (SLI) in the expressive domain. It aimed to identify whether PCIT had any significant impact on the following communication parameters of the child: verbal initiations, verbal and non-verbal responses, mean length of utterance (MLU), and proportion of child-to-parent utterances. Sixteen children with SLI and their parents were randomly assigned to two groups: treated or delayed treatment (control). The treated group took part in PCIT over a 4-week block, and then returned to the clinic for a final session after a 6-week consolidation period with no input from the therapist. The treated and control group were assessed in terms of the different communication parameters at three time points: pre-therapy, post-therapy (after the 4-week block) and at the final session (after the consolidation period), through video analysis. It was hypothesized that all communication parameters would significantly increase in the treated group over time and that no significant differences would be found in the control group. All the children in the treated group made language gains during spontaneous interactions with their parents. In comparison with the control group, PCIT had a positive effect on three of the five communication parameters: verbal initiations, MLU and the proportion of child-to-parent utterances. There was a marginal effect on verbal responses, and a trend towards such an effect

  11. Interactions between working memory and language in young children with specific language impairment (SLI).

    Science.gov (United States)

    Vugs, Brigitte; Knoors, Harry; Cuperus, Juliane; Hendriks, Marc; Verhoeven, Ludo

    2016-01-01

    The underlying structure of working memory (WM) in young children with and without specific language impairment (SLI) was examined. The associations between the components of WM and the language abilities of young children with SLI were then analyzed. The Automated Working Memory Assessment and four linguistic tasks were administered to 58 children with SLI and 58 children without SLI, aged 4-5 years. The WM of the children was best represented by a model with four separate but interacting components of verbal storage, visuospatial storage, verbal central executive (CE), and visuospatial CE. The associations between the four components of WM did not differ significantly for the two groups of children. However, the individual components of WM showed varying associations with the language abilities of the children with SLI. The verbal CE component of WM was moderately to strongly associated with all the language abilities in children with SLI: receptive vocabulary, expressive vocabulary, verbal comprehension, and syntactic development. These results show verbal CE to be involved in a wide range of linguistic skills; the limited ability of young children with SLI to simultaneously store and process verbal information may constrain their acquisition of linguistic skills. Attention should thus be paid to the language problems of children with SLI, but also to the WM impairments that can contribute to their language problems.

  12. Impaired hematopoietic stem cell functioning after serial transplantation and during normal aging

    NARCIS (Netherlands)

    Kamminga, LM; Van Os, R; Ausema, A; Noach, EJK; Weersing, E; Dontje, B; Vellenga, E; De Haan, G

    Adult somatic stem cells possess extensive self-renewal capacity, as their primary role is to replenish aged and functionally impaired tissues. We have previously shown that the stem cell pool in short-lived DBA/2 (D2) mice is reduced during aging, in contrast to long-lived C57BL/6 (136) mice. This

  13. Dysregulation of Dicer1 in Beta Cells Impairs Islet Architecture and Glucose Metabolism

    Directory of Open Access Journals (Sweden)

    Amitai D. Mandelbaum

    2012-01-01

    Full Text Available microRNAs (miRNAs play important roles in pancreas development and in regulation of insulin expression in the adult. Here we show that loss of miRNAs activity in beta-cells during embryonic development results in lower beta-cell mass and in impaired glucose tolerance. Dicer1-null cells initially constitute a significant portion of the total beta-cell population. However, during postnatal development, Dicer1-null cells are depleted. Furthermore, wild-type beta cells are repopulating the islets in complex compensatory dynamics. Because loss of Dicer1 is also associated with changes in the distribution of membranous E-cadherin, we hypothesized that E-cadherin activity may play a role in beta cell survival or islet architecture. However, genetic loss of E-cadherin function does not impair islet architecture, suggesting that miRNAs likely function through other or redundant effectors in the endocrine pancreas.

  14. Interaction of Staphylococci with Human B cells.

    Directory of Open Access Journals (Sweden)

    Tyler K Nygaard

    Full Text Available Staphylococcus aureus is a leading cause of human infections worldwide. The pathogen produces numerous molecules that can interfere with recognition and binding by host innate immune cells, an initial step required for the ingestion and subsequent destruction of microbes by phagocytes. To better understand the interaction of this pathogen with human immune cells, we compared the association of S. aureus and S. epidermidis with leukocytes in human blood. We found that a significantly greater proportion of B cells associated with S. epidermidis relative to S. aureus. Complement components and complement receptors were important for the binding of B cells with S. epidermidis. Experiments using staphylococci inactivated by ultraviolet radiation and S. aureus isogenic deletion mutants indicated that S. aureus secretes molecules regulated by the SaeR/S two-component system that interfere with the ability of human B cells to bind this bacterium. We hypothesize that the relative inability of B cells to bind S. aureus contributes to the microbe's success as a human pathogen.

  15. Designing Multimodal Mobile Interaction for a Text Messaging Application for Visually Impaired Users

    Directory of Open Access Journals (Sweden)

    Carlos Duarte

    2017-12-01

    Full Text Available While mobile devices have experienced important accessibility advances in the past years, people with visual impairments still face important barriers, especially in specific contexts when both their hands are not free to hold the mobile device, like when walking outside. By resorting to a multimodal combination of body based gestures and voice, we aim to achieve full hands and vision free interaction with mobile devices. In this article, we describe this vision and present the design of a prototype, inspired by that vision, of a text messaging application. The article also presents a user study where the suitability of the proposed approach was assessed, and a performance comparison between our prototype and existing SMS applications was conducted. Study participants received positively the prototype, which also supported better performance in tasks that involved text editing.

  16. Cytokines, hepatic cell profiling and cell interactions during bone marrow cell therapy for liver fibrosis in cholestatic mice.

    Directory of Open Access Journals (Sweden)

    Daphne Pinheiro

    Full Text Available Bone marrow cells (BMC migrate to the injured liver after transplantation, contributing to regeneration through multiple pathways, but mechanisms involved are unclear. This work aimed to study BMC migration, characterize cytokine profile, cell populations and proliferation in mice with liver fibrosis transplanted with GFP+ BMC. Confocal microscopy analysis showed GFP+ BMC near regions expressing HGF and SDF-1 in the fibrotic liver. Impaired liver cell proliferation in fibrotic groups was restored after BMC transplantation. Regarding total cell populations, there was a significant reduction in CD68+ cells and increased Ly6G+ cells in transplanted fibrotic group. BMC contributed to the total populations of CD144, CD11b and Ly6G cells in the fibrotic liver, related to an increment of anti-fibrotic cytokines (IL-10, IL-13, IFN-γ and HGF and reduction of pro-inflammatory cytokines (IL-17A and IL-6. Therefore, HGF and SDF-1 may represent important chemoattractants for transplanted BMC in the injured liver, where these cells can give rise to populations of extrahepatic macrophages, neutrophils and endothelial progenitor cells that can interact synergistically with other liver cells towards the modulation of an anti-fibrotic cytokine profile promoting the onset of liver regeneration.

  17. Aging impairs transcriptional regulation of vascular endothelial growth factor in human microvascular endothelial cells: implications for angiogenesis and cell survival.

    Science.gov (United States)

    Ahluwalia, A; Jones, M K; Szabo, S; Tarnawski, A S

    2014-04-01

    In some tissues, aging impairs angiogenesis and reduces expression of vascular endothelial growth factor A (VEGF), a fundamental regulator of angiogenesis. We previously examined angiogenesis in aging and young gastric mucosa in vivo and in vitro and showed that an imbalance between expressions of VEGF (pro-angiogenic factor) and endostatin (anti-angiogenic protein) results in an aging-related impairment of angiogenesis in rats. However, the human relevance of these findings, and whether these mechanisms apply to endothelial cells derived from other tissues, is not clear. Since P-STAT3 and P-CREB are transcription factors that, in association with HIF-1α, can activate VEGF gene expression in some cells (e.g., liver cancer cells, vascular smooth muscle cells), we examined the expression of these two proteins in human dermal microvascular endothelial cells (HMVECs) derived from aging and neonatal individuals. We examined and quantified in vitro angiogenesis, expression of VEGF, P-STAT3, P-CREB and importin-α in HMVECs isolated from neonates (neonatal) and a 66 year old subject (aging). We also examined the effects of treatment with exogenous VEGF and endostatin on in vitro angiogenesis in these cells. Endothelial cells isolated from aging individuals had impaired angiogenesis (vs. neonatal endothelial cells) and reduced expression of VEGF mRNA and protein. Aged HMVECs also had reduced importin-α expression, and reduced expression and nuclear translocation of P-STAT3 and P-CREB. Reduced VEGF gene expression in aged HMVECs strongly correlated with the decreased levels of P-STAT3, P-CREB and importin-α in these cells. Our study clearly demonstrates that endothelial cells from aging individuals have impaired angiogenesis and reduced expression of VEGF likely due to impaired nuclear transport of P-STAT3 and P-CREB transcription factors in these cells.

  18. NOV/CCN3 impairs muscle cell commitment and differentiation

    International Nuclear Information System (INIS)

    Calhabeu, Frederico; Lafont, Jerome; Le Dreau, Gwenvael; Laurent, Maryvonne; Kazazian, Chantal; Schaeffer, Laurent; Martinerie, Cecile; Dubois, Catherine

    2006-01-01

    NOV (nephroblastoma overexpressed) is a member of a family of proteins which encodes secreted matrix-associated proteins. NOV is expressed during development in dermomyotome and limb buds, but its functions are still poorly defined. In order to understand the role of NOV in myogenic differentiation, C2C12 cells overexpressing NOV (C2-NOV) were generated. These cells failed to engage into myogenic differentiation, whereas they retained the ability to differentiate into osteoblasts. In differentiating conditions, C2-NOV cells remained proliferative, failed to express differentiation markers and lost their ability to form myotubes. Inhibition of differentiation by NOV was also observed with human primary muscle cells. Further examination of C2-NOV cells revealed a strong downregulation of the myogenic determination genes MyoD and Myf5 and of IGF-II expression. MyoD forced expression in C2-NOV was sufficient to restore differentiation and IGF-II induction whereas 10 -6 M insulin treatment had no effects. NOV therefore acts upstream of MyoD and does not affect IGF-II induction and signaling. HES1, a target of Notch, previously proposed to mediate NOV action, was not implicated in the inhibition of differentiation. We propose that NOV is a specific cell fate regulator in the myogenic lineage, acting negatively on key myogenic genes thus controlling the transition from progenitor cells to myoblasts

  19. Impairing the radioresistance of cancer cells by hydrogenated nanodiamonds.

    Science.gov (United States)

    Grall, Romain; Girard, Hugues; Saad, Lina; Petit, Tristan; Gesset, Céline; Combis-Schlumberger, Mathilde; Paget, Vincent; Delic, Jozo; Arnault, Jean-Charles; Chevillard, Sylvie

    2015-08-01

    Hydrogenated nanodiamonds (H-NDs) exhibit a negative electron affinity that confers a high reactivity with oxygen species and a positive charge in aqueous solutions. It allows electron emission from H-NDs following irradiation by photons and in consequence may enhance the effects of radiation on cancer cells. By using three human radioresistant cancer cell lines, we showed a potentialization of cytotoxicity after a co-exposure to H-NDs and irradiation; an event occurring through the induction of DNA damage and reactive oxygen species. This occurred together with a decrease in cell impedance, the activation of G1/S, an unlocking of G2 cell cycle check-points and early low cell death rate. At later stage of exposure, persistent increases in heterochromatinization, large γ-H2AX foci and β-galactosidase activity were detected providing evidence of cells' entrance into senescence. Similar potentialization was observed with neocarzinostatin (NCS), a radiomimetic drug. This original finding underlines a wide clinical potential of H-NDs to intensify radiation effects on radio-resistant cancer cells. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Abnormalities in iNKT cells are associated with impaired ability of monocytes to produce IL-10 and suppress T-cell proliferation in sarcoidosis.

    Science.gov (United States)

    Crawshaw, Anjali; Kendrick, Yvonne R; McMichael, Andrew J; Ho, Ling-Pei

    2014-07-01

    Sarcoidosis is a multisystem granulomatous disorder characterized by marked T-cell expansion of T helper 1 (Th1) cells. The cause of T-cell overactivity is unknown. We hypothesized that interleukin-10 (IL-10) production by a yet undefined cell type might be defective, resulting in loss of regulation of T-cell activity. Focusing on IL-10-producing monocytes, we first showed that monocytes isolated from the peripheral blood of corticosteroid-naïve sarcoidosis patients (n = 51) produced less IL-10 compared to controls, and were less able to suppress T-cell proliferation. In addition, monocytic IL-10 production correlated negatively with disease activity score. As invariant natural killer T (iNKT) cells are known to both interact with monocytes and be reduced in sarcoidosis patients, we then asked whether iNKT-specific defects might be responsible for this reduced IL-10 production. We found that greater numbers of circulating iNKT cells was associated with higher IL-10 production. Moreover, iNKT cells enhanced monocytic IL-10 production in vitro. Defective IL-10 production and T-cell suppression by sarcoidosis monocytes could be restored following their coculture with iNKT cells, in a CD1d- and cell contact-dependent process. We suggest that reduced iNKT-cell numbers in sarcoidosis may lead to impaired monocytic IL-10 production and unchecked T-cell expansion in sarcoidosis. These findings provide fresh insight into the mechanism of sarcoidosis disease, and interaction between iNKT cells and monocytes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Sperm Impairment by Sperm Agglutinating Factor Isolated from Escherichia coli: Receptor Specific Interactions

    Directory of Open Access Journals (Sweden)

    Kiranjeet Kaur

    2013-01-01

    Full Text Available In an earlier work done in our laboratory, we have been able to isolate a sperm agglutinating strain of Escherichia coli from the semen sample of a male attending infertility clinic. Further, factor responsible for sperm agglutination (SAF was isolated and purified, and, using SAF as a tool, corresponding SAF binding receptor from human spermatozoa has been purified. Characterization of SAF and SAF binding receptor using MALDI-TOF showed homology to glutamate decarboxylase and MHC class I molecule, respectively. Coincubation of SAF with spermatozoa not only resulted in spermagglutination but could also compromise other sperm parameters, namely, Mg2+ dependent ATPase activity and apoptosis. Intravaginal administration of SAF could lead to infertility in Balb/c mice. SAF induced impairment of sperm parameters, and infertility was observed to be due to interaction of SAF with sperm surface receptor component as, when purified receptor was introduced, receptor completely inhibited all the detrimental effects induced by SAF. From these results, it could be concluded that interaction of SAF with spermatozoa is receptor mediated.

  2. Interaction of Defensins with Model Cell Membranes

    Science.gov (United States)

    Sanders, Lori K.; Schmidt, Nathan W.; Yang, Lihua; Mishra, Abhijit; Gordon, Vernita D.; Selsted, Michael E.; Wong, Gerard C. L.

    2009-03-01

    Antimicrobial peptides (AMPs) comprise a key component of innate immunity for a wide range of multicellular organisms. For many AMPs, activity comes from their ability to selectively disrupt and lyse bacterial cell membranes. There are a number of proposed models for this action, but the detailed molecular mechanism of selective membrane permeation remains unclear. Theta defensins are circularized peptides with a high degree of selectivity. We investigate the interaction of model bacterial and eukaryotic cell membranes with theta defensins RTD-1, BTD-7, and compare them to protegrin PG-1, a prototypical AMP, using synchrotron small angle x-ray scattering (SAXS). The relationship between membrane composition and peptide induced changes in membrane curvature and topology is examined. By comparing the membrane phase behavior induced by these different peptides we will discuss the importance of amino acid composition and placement on membrane rearrangement.

  3. Interactions of Model Cell Membranes with Nanoparticles

    Science.gov (United States)

    D'Angelo, S. M.; Camesano, T. A.; Nagarajan, R.

    2011-12-01

    The same properties that give nanoparticles their enhanced function, such as high surface area, small size, and better conductivity, can also alter the cytotoxicity of nanomaterials. Ultimately, many of these nanomaterials will be released into the environment, and can cause cytotoxic effects to environmental bacteria, aquatic organisms, and humans. Previous results from our laboratory suggest that nanoparticles can have a detrimental effect on cells, depending on nanoparticle size. It is our goal to characterize the properties of nanomaterials that can result in membrane destabilization. We tested the effects of nanoparticle size and chemical functionalization on nanoparticle-membrane interactions. Gold nanoparticles at 2, 5,10, and 80 nm were investigated, with a concentration of 1.1x1010 particles/mL. Model cell membranes were constructed of of L-α-phosphatidylcholine (egg PC), which has negatively charged lipid headgroups. A quartz crystal microbalance with dissipation (QCM-D) was used to measure frequency changes at different overtones, which were related to mass changes corresponding to nanoparticle interaction with the model membrane. In QCM-D, a lipid bilayer is constructed on a silicon dioxide crystal. The crystals, oscillate at different harmonic frequencies depending upon changes in mass or energy dissipation. When mass is added to the crystal surface, such as through addition of a lipid vesicle solution, the frequency change decreases. By monitoring the frequency and dissipation, we could verify that a supported lipid bilayer (SLB) formed on the silica surface. After formation of the SLB, the nanoparticles can be added to the system, and the changes in frequency and dissipation are monitored in order to build a mechanistic understanding of nanoparticle-cell membrane interactions. For all of the smaller nanoparticles (2, 5, and 10 nm), nanoparticle addition caused a loss of mass from the lipid bilayer, which appears to be due to the formation of holes

  4. Renal Impairment with Sublethal Tubular Cell Injury in a Chronic Liver Disease Mouse Model.

    Directory of Open Access Journals (Sweden)

    Tokiko Ishida

    Full Text Available The pathogenesis of renal impairment in chronic liver diseases (CLDs has been primarily studied in the advanced stages of hepatic injury. Meanwhile, the pathology of renal impairment in the early phase of CLDs is poorly understood, and animal models to elucidate its mechanisms are needed. Thus, we investigated whether an existing mouse model of CLD induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC shows renal impairment in the early phase. Renal injury markers, renal histology (including immunohistochemistry for tubular injury markers and transmission electron microscopy, autophagy, and oxidative stress were studied longitudinally in DDC- and standard diet-fed BALB/c mice. Slight but significant renal dysfunction was evident in DDC-fed mice from the early phase. Meanwhile, histological examinations of the kidneys with routine light microscopy did not show definitive morphological findings, and electron microscopic analyses were required to detect limited injuries such as loss of brush border microvilli and mitochondrial deformities. Limited injuries have been recently designated as sublethal tubular cell injury. As humans with renal impairment, either with or without CLD, often show almost normal tubules, sublethal injury has been of particular interest. In this study, the injuries were associated with mitochondrial aberrations and oxidative stress, a possible mechanism for sublethal injury. Intriguingly, two defense mechanisms were associated with this injury that prevent it from progressing to apparent cell death: autophagy and single-cell extrusion with regeneration. Furthermore, the renal impairment of this model progressed to chronic kidney disease with interstitial fibrosis after long-term DDC feeding. These findings indicated that DDC induces renal impairment with sublethal tubular cell injury from the early phase, leading to chronic kidney disease. Importantly, this CLD mouse model could be useful for studying the

  5. Anthocyanins influence tannin-cell wall interactions.

    Science.gov (United States)

    Bautista-Ortín, Ana Belén; Martínez-Hernández, Alejandro; Ruiz-García, Yolanda; Gil-Muñoz, Rocío; Gómez-Plaza, Encarna

    2016-09-01

    The rate of tannin extraction was studied in a vinification of red grapes and the results compared with another vinification made with white grapes fermented as for typical red wine, in the presence of skins and seeds. Even though the grapes presented a quite similar skin and seed tannin content, the differences in tannin concentration between both vinifications was very large, despite the fact that the only apparent difference between the phenolic composition of both wines was the anthocyanin content. This suggests that anthocyanins play an important role in tannin extractability, perhaps because they affect the extent of the tannin-cell wall interaction, a factor that largely controls the resulting quantity of tannins in wines. To confirm this observation, the effect of anthocyanins on the tannin extractability from grape seeds and skin and on the interaction between tannins and grape cell walls suspended in model solutions were studied. The results indicated that anthocyanins favored skin and seed tannin extraction and that there is a competition for the adsorption sites between anthocyanins and tannins that increases the tannin content when anthocyanins are present. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Patients with discordant responses to antiretroviral therapy have impaired killing of HIV-infected T cells.

    Directory of Open Access Journals (Sweden)

    Sekar Natesampillai

    2010-11-01

    Full Text Available In medicine, understanding the pathophysiologic basis of exceptional circumstances has led to an enhanced understanding of biology. We have studied the circumstance of HIV-infected patients in whom antiretroviral therapy results in immunologic benefit, despite virologic failure. In such patients, two protease mutations, I54V and V82A, occur more frequently. Expressing HIV protease containing these mutations resulted in less cell death, caspase activation, and nuclear fragmentation than wild type (WT HIV protease or HIV protease containing other mutations. The impaired induction of cell death was also associated with impaired cleavage of procaspase 8, a requisite event for HIV protease mediated cell death. Primary CD4 T cells expressing I54V or V82A protease underwent less cell death than with WT or other mutant proteases. Human T cells infected with HIV containing these mutations underwent less cell death and less Casp8p41 production than WT or HIV containing other protease mutations, despite similar degrees of viral replication. The reductions in cell death occurred both within infected cells, as well as in uninfected bystander cells. These data indicate that single point mutations within HIV protease which are selected in vivo can significantly impact the ability of HIV to kill CD4 T cells, while not impacting viral replication. Therefore, HIV protease regulates both HIV replication as well as HIV induced T cell depletion, the hallmark of HIV pathogenesis.

  7. Local cell metrics: a novel method for analysis of cell-cell interactions.

    Science.gov (United States)

    Su, Jing; Zapata, Pedro J; Chen, Chien-Chiang; Meredith, J Carson

    2009-10-23

    The regulation of many cell functions is inherently linked to cell-cell contact interactions. However, effects of contact interactions among adherent cells can be difficult to detect with global summary statistics due to the localized nature and noise inherent to cell-cell interactions. The lack of informatics approaches specific for detecting cell-cell interactions is a limitation in the analysis of large sets of cell image data, including traditional and combinatorial or high-throughput studies. Here we introduce a novel histogram-based data analysis strategy, termed local cell metrics (LCMs), which addresses this shortcoming. The new LCM method is demonstrated via a study of contact inhibition of proliferation of MC3T3-E1 osteoblasts. We describe how LCMs can be used to quantify the local environment of cells and how LCMs are decomposed mathematically into metrics specific to each cell type in a culture, e.g., differently-labelled cells in fluorescence imaging. Using this approach, a quantitative, probabilistic description of the contact inhibition effects in MC3T3-E1 cultures has been achieved. We also show how LCMs are related to the naïve Bayes model. Namely, LCMs are Bayes class-conditional probability functions, suggesting their use for data mining and classification. LCMs are successful in robust detection of cell contact inhibition in situations where conventional global statistics fail to do so. The noise due to the random features of cell behavior was suppressed significantly as a result of the focus on local distances, providing sensitive detection of cell-cell contact effects. The methodology can be extended to any quantifiable feature that can be obtained from imaging of cell cultures or tissue samples, including optical, fluorescent, and confocal microscopy. This approach may prove useful in interpreting culture and histological data in fields where cell-cell interactions play a critical role in determining cell fate, e.g., cancer, developmental

  8. A novel paradigm links mitochondrial dysfunction with muscle stem cell impairment in sepsis.

    Science.gov (United States)

    Chatre, Laurent; Verdonk, Franck; Rocheteau, Pierre; Crochemore, Clément; Chrétien, Fabrice; Ricchetti, Miria

    2017-10-01

    Sepsis is an acute systemic inflammatory response of the body to microbial infection and a life threatening condition associated with multiple organ failure. Survivors may display long-term disability with muscle weakness that remains poorly understood. Recent data suggest that long-term myopathy in sepsis survivors is due to failure of skeletal muscle stem cells (satellite cells) to regenerate the muscle. Satellite cells impairment in the acute phase of sepsis is linked to unusual mitochondrial dysfunctions, characterized by a dramatic reduction of the mitochondrial mass and hyperactivity of residual organelles. Survivors maintain the impairment of satellite cells, including alterations of the mitochondrial DNA (mtDNA), in the long-term. This condition can be rescued by treatment with mesenchymal stem cells (MSCs) that restore mtDNA alterations and mitochondrial function in satellite cells, and in fine their regenerative potential. Injection of MSCs in turn increases the force of isolated muscle fibers and of the whole animal, and improves the survival rate. These effects occur in the context of reduced inflammation markers that also raised during sepsis. Targeting muscle stem cells mitochondria, in a context of reduced inflammation, may represent a valuable strategy to reduce morbidity and long-term impairment of the muscle upon sepsis. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Glucose Toxic Effects on Granulation Tissue Productive Cells: The Diabetics’ Impaired Healing

    Directory of Open Access Journals (Sweden)

    Jorge Berlanga-Acosta

    2013-01-01

    Full Text Available Type 2 diabetes mellitus is a metabolic noncommunicable disease with an expanding pandemic magnitude. Diabetes predisposes to lower extremities ulceration and impairs the healing process leading to wound chronification. Diabetes also dismantles innate immunity favoring wound infection. Amputation is therefore acknowledged as one of the disease’s complications. Hyperglycemia is the proximal detonator of systemic and local toxic effectors including proinflammation, acute-phase proteins elevation, and spillover of reactive oxygen and nitrogen species. Insulin axis deficiency weakens wounds’ anabolism and predisposes to inflammation. The systemic accumulation of advanced glycation end-products irreversibly impairs the entire physiology from cells-to-organs. These factors in concert hamper fibroblasts and endothelial cells proliferation, migration, homing, secretion, and organization of a productive granulation tissue. Diabetic wound bed may turn chronically inflammed, procatabolic, and an additional source of circulating pro-inflammatory cytokines, establishing a self-perpetuating loop. Diabetic fibroblasts and endothelial cells may bear mitochondrial damages becoming prone to apoptosis, which impairs granulation tissue cellularity and perfusion. Endothelial progenitor cells recruitment and tubulogenesis are also impaired. Failure of wound reepithelialization remains a clinical challenge while it appears to be biologically multifactorial. Ulcer prevention by primary care surveillance, education, and attention programs is of outmost importance to reduce worldwide amputation figures.

  10. Cerebrovascular reserve capacity is impaired in patients with sickle cell disease

    NARCIS (Netherlands)

    Nur, Erfan; Kim, Yu-Sok; Truijen, Jasper; van Beers, Eduard J.; Davis, Shyrin C. A. T.; Brandjes, Dees P.; Biemond, Bart J.; van Lieshout, Johannes J.

    2009-01-01

    Sickle cell disease (SCD) is associated with a high incidence of ischemic stroke. SCD is characterized by hemolytic anemia, resulting in reduced nitric oxide-bioavailability, and by impaired cerebrovascular hemodynamics. Cerebrovascular CO2 responsiveness is nitric oxide dependent and has been

  11. Adolescent cannabis exposure interacts with mutant DISC1 to produce impaired adult emotional memory.

    Science.gov (United States)

    Ballinger, Michael D; Saito, Atsushi; Abazyan, Bagrat; Taniguchi, Yu; Huang, Ching-Hsun; Ito, Koki; Zhu, Xiaolei; Segal, Hadar; Jaaro-Peled, Hanna; Sawa, Akira; Mackie, Ken; Pletnikov, Mikhail V; Kamiya, Atsushi

    2015-10-01

    Cannabis is an increasingly popular and controversial drug used worldwide. Cannabis use often begins during adolescence, a highly susceptible period for environmental stimuli to alter functional and structural organization of the developing brain. Given that adolescence is a critical time for the emergence of mental illnesses before full-onset in early adulthood, it is particularly important to investigate how genetic insults and adolescent cannabis exposure interact to affect brain development and function. Here we show for the first time that a perturbation in disrupted in schizophrenia 1 (DISC1) exacerbates the response to adolescent exposure to delta-9-tetrahydrocannabinol (Δ(9)-THC), a major psychoactive ingredient of cannabis, consistent with the concept that gene-environment interaction may contribute to the pathophysiology of psychiatric conditions. We found that chronic adolescent treatment with Δ(9)-THC exacerbates deficits in fear-associated memory in adult mice that express a putative dominant-negative mutant of DISC1 (DN-DISC1). Synaptic expression of cannabinoid receptor 1 (CB1R) is down-regulated in the prefrontal cortex, hippocampus, and amygdala, critical brain regions for fear-associated memory, by either expression of DN-DISC1 or adolescent Δ(9)-THC treatment. Notably, elevation of c-Fos expression evoked by context-dependent fear memory retrieval is impaired in these brain regions in DN-DISC1 mice. We also found a synergistic reduction of c-Fos expression induced by cue-dependent fear memory retrieval in DN-DISC1 with adolescent Δ(9)-THC exposure. These results suggest that alteration of CB1R-mediated signaling in DN-DISC1 mice may underlie susceptibility to detrimental effects of adolescent cannabis exposure on adult behaviors. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Interaction of language processing and motor skill in children with specific language impairment.

    Science.gov (United States)

    DiDonato Brumbach, Andrea C; Goffman, Lisa

    2014-02-01

    To examine how language production interacts with speech motor and gross and fine motor skill in children with specific language impairment (SLI). Eleven children with SLI and 12 age-matched peers (4-6 years) produced structurally primed sentences containing particles and prepositions. Utterances were analyzed for errors and for articulatory duration and variability. Standard measures of motor, language, and articulation skill were also obtained. Sentences containing particles, as compared with prepositions, were less likely to be produced in a priming task and were longer in duration, suggesting increased difficulty with this syntactic structure. Children with SLI demonstrated higher articulatory variability and poorer gross and fine motor skills compared with aged-matched controls. Articulatory variability was correlated with generalized gross and fine motor performance. Children with SLI show co-occurring speech motor and generalized motor deficits. Current theories do not fully account for the present findings, though the procedural deficit hypothesis provides a framework for interpreting overlap among language and motor domains.

  13. Impaired B cell development in the absence of Krüppel-like factor 3.

    Science.gov (United States)

    Vu, Thi Thanh; Gatto, Dominique; Turner, Vivian; Funnell, Alister P W; Mak, Ka Sin; Norton, Laura J; Kaplan, Warren; Cowley, Mark J; Agenès, Fabien; Kirberg, Jörg; Brink, Robert; Pearson, Richard C M; Crossley, Merlin

    2011-11-15

    Krüppel-like factor 3 (Klf3) is a member of the Klf family of transcription factors. Klfs are widely expressed and have diverse roles in development and differentiation. In this study, we examine the function of Klf3 in B cell development by studying B lymphopoiesis in a Klf3 knockout mouse model. We show that B cell differentiation is significantly impaired in the bone marrow, spleen, and peritoneal cavity of Klf3 null mice and confirm that the defects are cell autonomous. In the bone marrow, there is a reduction in immature B cells, whereas recirculating mature cells are noticeably increased. Immunohistology of the spleen reveals a poorly structured marginal zone (MZ) that may in part be caused by deregulation of adhesion molecules on MZ B cells. In the peritoneal cavity, there are significant defects in B1 B cell development. We also report that the loss of Klf3 in MZ B cells is associated with reduced BCR signaling strength and an impaired ability to respond to LPS stimulation. Finally, we show increased expression of a number of Klf genes in Klf3 null B cells, suggesting that a Klf regulatory network may exist in B cells.

  14. Hepatitis C virus host cell interactions uncovered

    DEFF Research Database (Denmark)

    Gottwein, Judith; Bukh, Jens

    2007-01-01

      Insights into virus-host cell interactions as uncovered by Randall et al. (1) in a recent issue of PNAS further our understanding of the hepatitis C virus (HCV) life cycle, persistence, and pathogenesis and might lead to the identification of new therapeutic targets. HCV persistently infects 180...... million individuals worldwide, causing chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. The only approved treatment, combination therapy with IFN- and ribavirin, targets cellular pathways (2); however, a sustained virologic response is achieved only in approximately half of the patients...... treated. Therefore, there is a pressing need for the identification of novel drugs against hepatitis C. Although most research focuses on the development of HCV-specific antivirals, such as protease and polymerase inhibitors (3), cellular targets could be pursued and might allow the development of broad...

  15. Impaired heat shock response in cells expressing full-length polyglutamine-expanded huntingtin.

    Directory of Open Access Journals (Sweden)

    Sidhartha M Chafekar

    Full Text Available The molecular mechanisms by which polyglutamine (polyQ-expanded huntingtin (Htt causes neurodegeneration in Huntington's disease (HD remain unclear. The malfunction of cellular proteostasis has been suggested as central in HD pathogenesis and also as a target of therapeutic interventions for the treatment of HD. We present results that offer a previously unexplored perspective regarding impaired proteostasis in HD. We find that, under non-stress conditions, the proteostatic capacity of cells expressing full length polyQ-expanded Htt is adequate. Yet, under stress conditions, the presence of polyQ-expanded Htt impairs the heat shock response, a key component of cellular proteostasis. This impaired heat shock response results in a reduced capacity to withstand the damage caused by cellular stress. We demonstrate that in cells expressing polyQ-expanded Htt the levels of heat shock transcription factor 1 (HSF1 are reduced, and, as a consequence, these cells have an impaired a heat shock response. Also, we found reduced HSF1 and HSP70 levels in the striata of HD knock-in mice when compared to wild-type mice. Our results suggests that full length, non-aggregated polyQ-expanded Htt blocks the effective induction of the heat shock response under stress conditions and may thus trigger the accumulation of cellular damage during the course of HD pathogenesis.

  16. Cutting edge: impairment of dendritic cells and adaptive immunity by Ebola and Lassa viruses.

    Science.gov (United States)

    Mahanty, Siddhartha; Hutchinson, Karen; Agarwal, Sudhanshu; McRae, Michael; Rollin, Pierre E; Pulendran, Bali

    2003-03-15

    Acute infection of humans with Ebola and Lassa viruses, two principal etiologic agents of hemorrhagic fevers, often results in a paradoxical pattern of immune responses: early infection, characterized by an outpouring of inflammatory mediators such as TNF-alpha, IL-1 beta, and IL-6, vs late stage infections, which are associated with poor immune responses. The mechanisms underlying these diverse outcomes are poorly understood. In particular, the role played by cells of the innate immune system, such as dendritic cells (DC), is not known. In this study, we show that Ebola and Lassa viruses infect human monocyte-derived DC and impair their function. Monocyte-derived DC exposed to either virus fail to secrete proinflammatory cytokines, do not up-regulate costimulatory molecules, and are poor stimulators of T cells. These data represent the first evidence for a mechanism by which Ebola and Lassa viruses target DC to impair adaptive immunity.

  17. Free-zone electrophoresis of animal cells. 1: Experiments on cell-cell interactions

    Science.gov (United States)

    Todd, P. W.; Hjerten, S.

    1985-01-01

    The electrophoretically migrating zones wasa monitored. The absence of fluid flows in the direction of migration permits direct measurement of electrophoretic velocities of any material. Sedimentation is orthogonal to electrokinetic motion and the effects of particle-particle interaction on electrophoretic mobility is studied by free zone electrophoresis. Fixed erythrocytes at high concentrations, mixtures of fixed erythrocytes from different animal species, and mixtures of cultured human cells were studied in low ionic strength buffers. The electrophoretic velocity of fixed erythrocytes was not altered by increasing cell concentration or by the mixing of erythrocytes from different species. When zones containing cultured human glial cells and neuroblastoma cells are permitted to interact during electrophoresis, altered migration patterns occur. It is found that cell-cell interactions depends upon cell type.

  18. Cell-cell interactions mediate cytoskeleton organization and collective endothelial cell chemotaxis.

    Science.gov (United States)

    Shamloo, Amir

    2014-09-01

    This study investigates the role of cell-cell and cell-ligand interactions in cytoskeleton organization of endothelial cells (ECs) and their directional migration within a microfluidic device. The migration of ECs in response to a biochemical factor was studied. Mathematical analysis of the cell migration pathways and cellular cytoskeleton revealed that directional migration, migration persistence length, migration speed, and cytoskeletal stress fiber alignment can be mediated by the level of cell contacts as well as the presence or absence of a biochemical polarizing factor. It was shown that in the presence of a biochemical polarizing factor, higher cell density and more frequent cell contacts has a reinforcing effect on collective cell chemotaxis. In contrast, in the absence of a polarizing factor, high cell density can decrease or suppress the ability of the cells to migrate. Also, the correlation of actin stress fiber organization and alignment with directional migration of ECs was investigated. It was shown that in the presence of a biochemical polarizing factor, stress fibers within the cytoskeleton of ECs can be significantly aligned parallel to the gradient direction when the cells have higher level of contacts. The results also show that the organization and alignment of actin stress fibers is mediated by cell adhesion junctions during collective cell migration and introduce cell-cell interactions as a key factor during collective cell chemotaxis. © 2014 Wiley Periodicals, Inc.

  19. Diabetic Hyperglycemia: Link to Impaired Glucose Transport in Pancreatic β Cells

    Science.gov (United States)

    Unger, Roger H.

    1991-03-01

    Glucose uptake into pancreatic β cells by means of the glucose transporter GLUT-2, which has a high Michaelis constant, is essential for the normal insulin secretory response to hyperglycemia. In both autoimmune and nonautoimmune diabetes, this glucose transport is reduced as a consequence of down-regulation of the normal β-cell transporter. In autoimmune diabetes, circulating immunoglobulins can further impair this glucose transport by inhibiting functionally intact transporters. Insights into mechanisms of the unresponsiveness of β cells to hyperglycemia may improve the management and prevention of diabetes.

  20. Targeting of beta 1 integrins impairs DNA repair for radiosensitization of head and neck cancer cells

    NARCIS (Netherlands)

    Dickreuter, E.; Eke, I.; Krause, M.; Borgmann, K.; van Vugt, M. A.; Cordes, N.

    2016-01-01

    beta 1 Integrin-mediated cell-extracellular matrix interactions allow cancer cell survival and confer therapy resistance. It was shown that inhibition of beta 1 integrins sensitizes cells to radiotherapy. Here, we examined the impact of beta 1 integrin targeting on the repair of radiation-induced

  1. Histone deacetylase inhibitors impair the elimination of HIV-infected cells by cytotoxic T-lymphocytes.

    Directory of Open Access Journals (Sweden)

    Richard Brad Jones

    2014-08-01

    Full Text Available Resting memory CD4+ T-cells harboring latent HIV proviruses represent a critical barrier to viral eradication. Histone deacetylase inhibitors (HDACis, such as suberanilohydroxamic acid (SAHA, romidepsin, and panobinostat have been shown to induce HIV expression in these resting cells. Recently, it has been demonstrated that the low levels of viral gene expression induced by a candidate HDACi may be insufficient to cause the death of infected cells by viral cytopathic effects, necessitating their elimination by immune effectors, such as cytotoxic T-lymphocytes (CTL. Here, we study the impact of three HDACis in clinical development on T-cell effector functions. We report two modes of HDACi-induced functional impairment: i the rapid suppression of cytokine production from viable T-cells induced by all three HDACis ii the selective death of activated T-cells occurring at later time-points following transient exposures to romidepsin or, to a lesser extent, panobinostat. As a net result of these factors, HDACis impaired CTL-mediated IFN-γ production, as well as the elimination of HIV-infected or peptide-pulsed target cells, both in liquid culture and in collagen matrices. Romidepsin exerted greater inhibition of antiviral function than SAHA or panobinostat over the dose ranges tested. These data suggest that treatment with HDACis to mobilize the latent reservoir could have unintended negative impacts on the effector functions of CTL. This could influence the effectiveness of HDACi-based eradication strategies, by impairing elimination of infected cells, and is a critical consideration for trials where therapeutic interruptions are being contemplated, given the importance of CTL in containing rebound viremia.

  2. Impaired T-lymphocyte colony formation by cord blood mononuclear cells

    International Nuclear Information System (INIS)

    Herrod, H.G.; Valenski, W.R.

    1982-01-01

    When compared to adult mononuclear cells, cord blood mononuclear cells demonstrated significantly decreased T-lymphocyte colony formation (1351 +/- 643 vs 592 +/- 862, P less than 0.01). This diminished colony-forming activity did not appear to be associated with impaired responsiveness to the stimulant phytohemagglutinin or with excessive suppressor-cell activity. Irradiation reduced the colony-forming capacity of cord blood mononuclear cells more than it did that of adult mononuclear cells. Depletion of adherent cells reduced cord blood mononuclear-cell colony-forming capacity by 40%, while similar treatment reduced adult colony formation by 10%. Lymphocyte proliferation in liquid culture of cord and adult cells was minimally affected by these procedures. The colony-forming capacity of cord blood could be enhanced by the addition of irradiated adult cells (284 +/- 72 vs 752 +/- 78, P less than 0.01). This enhancement was demonstrated to be due to a soluble factor produced by a population of irradiated adult cells depleted of the OKT8+ subpopulation of lymphocytes. These results indicate that the progenitor cells of T-lymphocyte colonies in cord blood have distinct biologic characteristics when compared to colony progenitors present in adult blood. This assay may prove to be useful in our efforts to understand the differentiation of T-cell function in man

  3. p53 functional impairment and high p21waf1/cip1 expression in human T-cell lymphotropic/leukemia virus type I-transformed T cells.

    Science.gov (United States)

    Cereseto, A; Diella, F; Mulloy, J C; Cara, A; Michieli, P; Grassmann, R; Franchini, G; Klotman, M E

    1996-09-01

    Human T-cell lymphotropic/leukemia virus type I (HTLV-I) is associated with T-cell transformation both in vivo and in vitro. Although some of the mechanisms responsible for transformation remain unknown, increasing evidence supports a direct role of viral as well as dysregulated cellular proteins in transformation. We investigated the potential role of the tumor suppressor gene p53 and of the p53-regulated gene, p21waf1/cip1 (wild-type p53 activated fragment 1/cycling dependent kinases [cdks] interacting protein 1), in HTLV-I-infected T cells. We have found that the majority of HTLV-I-infected T cells have the wild-type p53 gene. However, its function in HTLV-I-transformed cells appears to be impaired, as shown by the lack of appropriate p53-mediated responses to ionizing radiation (IR). Interestingly, the expression of the p53 inducible gene, p21waf1/cip1, is elevated at the messenger ribonucleic acid and protein levels in all HTLV-I-infected T-cell lines examined as well as in Taxl-1, a human T-cell line stably expressing Tax. Additionally, Tax induces upregulation of a p21waf1/cip1 promoter-driven luciferase gene in p53 null cells, and increases p21waf1/cip1 expression in Jurkat T cells. These findings suggest that the Tax protein is at least partially responsible for the p53-independent expression of p21waf1/cip1 in HTLV-I-infected cells. Dysregulation of p53 and p21waf1/cip1 proteins regulating cell-cycle progression, may represent an important step in HTLV-I-induced T-cell transformation.

  4. Local cell metrics: a novel method for analysis of cell-cell interactions

    Directory of Open Access Journals (Sweden)

    Chen Chien-Chiang

    2009-10-01

    Full Text Available Abstract Background The regulation of many cell functions is inherently linked to cell-cell contact interactions. However, effects of contact interactions among adherent cells can be difficult to detect with global summary statistics due to the localized nature and noise inherent to cell-cell interactions. The lack of informatics approaches specific for detecting cell-cell interactions is a limitation in the analysis of large sets of cell image data, including traditional and combinatorial or high-throughput studies. Here we introduce a novel histogram-based data analysis strategy, termed local cell metrics (LCMs, which addresses this shortcoming. Results The new LCM method is demonstrated via a study of contact inhibition of proliferation of MC3T3-E1 osteoblasts. We describe how LCMs can be used to quantify the local environment of cells and how LCMs are decomposed mathematically into metrics specific to each cell type in a culture, e.g., differently-labelled cells in fluorescence imaging. Using this approach, a quantitative, probabilistic description of the contact inhibition effects in MC3T3-E1 cultures has been achieved. We also show how LCMs are related to the naïve Bayes model. Namely, LCMs are Bayes class-conditional probability functions, suggesting their use for data mining and classification. Conclusion LCMs are successful in robust detection of cell contact inhibition in situations where conventional global statistics fail to do so. The noise due to the random features of cell behavior was suppressed significantly as a result of the focus on local distances, providing sensitive detection of cell-cell contact effects. The methodology can be extended to any quantifiable feature that can be obtained from imaging of cell cultures or tissue samples, including optical, fluorescent, and confocal microscopy. This approach may prove useful in interpreting culture and histological data in fields where cell-cell interactions play a critical

  5. Liberal red blood cell transfusions impair quality of life after cardiac surgery.

    Science.gov (United States)

    González-Pérez, A; Al-Sibai, J Z; Álvarez-Fernández, P; Martínez-Camblor, P; Argüello-Junquera, M; García-Gala, J M; Martínez-Revuelta, E; Silva, J; Morís, C; Albaiceta, G M

    2018-03-12

    The optimal blood management after cardiac surgery remains controversial. Moreover, blood transfusions may have an impact on long-term outcomes. The aim of this study is to characterize the impact of liberal red blood cell transfusions on Health-Related Quality of life (HRQoL) after cardiac surgery. We studied a cohort of 205 consecutive patients after ICU discharge. Baseline characteristics and clinical data were recorded, and HRQoL was assessed using the EuroQoL-5D instrument, applied 6 months after ICU discharge. A specific question regarding the improvement in the quality of life after the surgical intervention was added to the HRQoL questionnaire. Risk factors related to impaired quality of life were identified using univariate comparisons and multivariate regression techniques. The median (interquartile range, IQR) of transfused red blood cells was 3 (1-4). Among 205 patients, 178 were studied 6 months after discharge. Impairment in at least one dimension of the EuroQoL-5D questionnaire was observed in 120 patients, with an overall score of 0.8 (IQR 0.61-1). The number of red blood cell transfusions was related to an impaired HRQoL (OR 1.17 per additional unit, 95% confidence interval 1.03-1.36, p=0.03), a trend to lower visual analog scale score (coefficient -0.75 per additional unit, 95% confidence interval -1.61 to 0.1, p=0.09) and an absence of improvement in HRQoL after surgery compared to the previous status (OR 1.13, 95% confidence interval 1.03-1.25, p=0.01). Liberal red blood cell transfusions increase the risk of impaired HRQoL after cardiac surgery. Copyright © 2018 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  6. Neurofibromin 1 Impairs Natural Killer T-Cell-Dependent Antitumor Immunity against a T-Cell Lymphoma

    Directory of Open Access Journals (Sweden)

    Jianyun Liu

    2018-01-01

    Full Text Available Neurofibromin 1 (NF1 is a tumor suppressor gene encoding a Ras GTPase that negatively regulates Ras signaling pathways. Mutations in NF1 are linked to neurofibromatosis type 1, juvenile myelomonocytic leukemia and Watson syndrome. In terms of antitumor immunity, CD1d-dependent natural killer T (NKT cells play an important role in the innate antitumor immune response. Generally, Type-I NKT cells protect (and Type-II NKT cells impair host antitumor immunity. We have previously shown that CD1d-mediated antigen presentation to NKT cells is regulated by cell signaling pathways. To study whether a haploinsufficiency in NF1 would affect CD1d-dependent activation of NKT cells, we analyzed the NKT-cell population as well as the functional expression of CD1d in Nf1+/− mice. Nf1+/− mice were found to have similar levels of NKT cells as wildtype (WT littermates. Interestingly, however, reduced CD1d expression was observed in Nf1+/− mice compared with their WT littermates. When inoculated with a T-cell lymphoma in vivo, Nf1+/− mice survived longer than their WT littermates. Furthermore, blocking CD1d in vivo significantly enhanced antitumor activity in WT, but not in Nf1+/− mice. In contrast, a deficiency in Type-I NKT cells increased antitumor activity in Nf1+/− mice, but not in WT littermates. Therefore, these data suggest that normal NF1 expression impairs CD1d-mediated NKT-cell activation and antitumor activity against a T-cell lymphoma.

  7. SHIP-1 Deficiency in AID+ B Cells Leads to the Impaired Function of B10 Cells with Spontaneous Autoimmunity.

    Science.gov (United States)

    Chen, Yingjia; Hu, Fanlei; Dong, Xuejiao; Zhao, Meng; Wang, Jing; Sun, Xiaolin; Kim, Tae Jin; Li, Zhanguo; Liu, Wanli

    2017-11-01

    Unlike conventional B cells, regulatory B cells exhibit immunosuppressive functions to downregulate inflammation via IL-10 production. However, the molecular mechanism regulating the production of IL-10 is not fully understood. In this study, we report the finding that activation-induced cytidine deaminase (AID) is highly upregulated in the IL-10-competent B cell (B10) cell from Innp5d fl/fl Aicda Cre/+ mice, whereas the 5' inositol phosphatase SHIP-1 is downregulated. Notably, SHIP-1 deficiency in AID + B cells leads to a reduction in cell count and impaired IL-10 production by B10 cells. Furthermore, the Innp5d fl/fl Aicda Cre/+ mouse model shows B cell-dependent autoimmune lupus-like phenotypes, such as elevated IgG serum Abs, formation of spontaneous germinal centers, production of anti-dsDNA and anti-nuclear Abs, and the obvious deposition of IgG immune complexes in the kidney with age. We observe that these lupus-like phenotypes can be reversed by the adoptive transfer of B10 cells from control Innp5d fl/fl mice, but not from the Innp5d fl/fl Aicda Cre/+ mice. This finding highlights the importance of defective B10 cells in Innp5d fl/fl Aicda Cre/+ mice. Whereas p-Akt is significantly upregulated, MAPK and AP-1 activation is impaired in B10 cells from Innp5d fl/fl Aicda Cre/+ mice, resulting in the reduced production of IL-10. These results show that SHIP-1 is required for the maintenance of B10 cells and production of IL-10, and collectively suggests that SHIP-1 could be a new potential therapeutic target for the treatment of autoimmune diseases. Copyright © 2017 by The American Association of Immunologists, Inc.

  8. An Interactive Mobile Application for the Visually Impaired to Have Access to Listening Audio Books with Handy Books Portal

    Directory of Open Access Journals (Sweden)

    Avanthika Meenakshi

    2015-01-01

    Full Text Available Mobile phones are used in almost all aspects of life by people. But in the case of visually impaired, they are still a step behind in using smart phones for various purposes. Having interactive android OS, navigation and travel aiding apps using sensors and voice user interfaces (VUI or the voice response systems, we are still a step lagging in giving them an application for educational purposes. This paper proposes a complete new idea of having a portal where they can store audio books aided with interactive system so that they can use them whenever needed.

  9. From single cells to tissues: interactions between the matrix and human breast cells in real time.

    Directory of Open Access Journals (Sweden)

    Clifford Barnes

    Full Text Available Mammary gland morphogenesis involves ductal elongation, branching, and budding. All of these processes are mediated by stroma--epithelium interactions. Biomechanical factors, such as matrix stiffness, have been established as important factors in these interactions. For example, epithelial cells fail to form normal acinar structures in vitro in 3D gels that exceed the stiffness of a normal mammary gland. Additionally, heterogeneity in the spatial distribution of acini and ducts within individual collagen gels suggests that local organization of the matrix may guide morphogenesis. Here, we quantified the effects of both bulk material stiffness and local collagen fiber arrangement on epithelial morphogenesis.The formation of ducts and acini from single cells and the reorganization of the collagen fiber network were quantified using time-lapse confocal microscopy. MCF10A cells organized the surrounding collagen fibers during the first twelve hours after seeding. Collagen fiber density and alignment relative to the epithelial surface significantly increased within the first twelve hours and were a major influence in the shaping of the mammary epithelium. The addition of Matrigel to the collagen fiber network impaired cell-mediated reorganization of the matrix and increased the probability of spheroidal acini rather than branching ducts. The mechanical anisotropy created by regions of highly aligned collagen fibers facilitated elongation and branching, which was significantly correlated with fiber organization. In contrast, changes in bulk stiffness were not a strong predictor of this epithelial morphology.Localized regions of collagen fiber alignment are required for ductal elongation and branching suggesting the importance of local mechanical anisotropy in mammary epithelial morphogenesis. Similar principles may govern the morphology of branching and budding in other tissues and organs.

  10. Impaired angiogenesis during fracture healing in GPCR kinase 2 interacting protein-1 (GIT1 knock out mice.

    Directory of Open Access Journals (Sweden)

    Guoyong Yin

    Full Text Available G protein coupled receptor kinase 2 (GRK2 interacting protein-1 (GIT1, is a scaffold protein that plays an important role in angiogenesis and osteoclast activity. We have previously demonstrated that GIT1 knockout (GIT1 KO mice have impaired angiogenesis and dysregulated osteoclast podosome formation leading to a reduction in the bone resorbing ability of these cells. Since both angiogenesis and osteoclast-mediated bone remodeling are involved in the fracture healing process, we hypothesized that GIT1 participates in the normal progression of repair following bone injury. In the present study, comparison of fracture healing in wild type (WT and GIT1 KO mice revealed altered healing in mice with loss of GIT1 function. Alcian blue staining of fracture callus indicated a persistence of cartilagenous matrix in day 21 callus samples from GIT1 KO mice which was temporally correlated with increased type 2 collagen immunostaining. GIT1 KO mice also showed a decrease in chondrocyte proliferation and apoptosis at days 7 and 14, as determined by PCNA and TUNEL staining. Vascular microcomputed tomography analysis of callus samples at days 7, 14 and 21 revealed decreased blood vessel volume, number, and connection density in GIT1 KO mice compared to WT controls. Correlating with this, VEGF-A, phospho-VEGFR2 and PECAM1 (CD31 were decreased in GIT1 KO mice, indicating reduced angiogenesis with loss of GIT1. Finally, calluses from GIT1 KO mice displayed a reduced number of tartrate resistant acid phosphatase-positive osteoclasts at days 14 and 21. Collectively, these results indicate that GIT1 is an important signaling participant in fracture healing, with gene ablation leading to reduced callus vascularity and reduced osteoclast number in the healing callus.

  11. Impaired Autophagy and Defective T Cell Homeostasis in Mice with T Cell-Specific Deletion of Receptor for Activated C Kinase 1

    Directory of Open Access Journals (Sweden)

    Guihua Qiu

    2017-05-01

    Full Text Available Autophagy plays a central role in maintaining T cell homeostasis. Our previous study has shown that hepatocyte-specific deficiency of receptor for activated C kinase 1 (RACK1 leads to lipid accumulation in the liver, accompanied by impaired autophagy, but its in vivo role in T cells remains unclear. Here, we report that mice with T cell-specific deletion of RACK1 exhibit normal intrathymic development of conventional T cells and regulatory T (Treg cells but reduced numbers of peripheral CD4+ and CD8+ T cells. Such defects are cell intrinsic with impaired mitochondrial clearance, increased sensitivity to cell death, and decreased proliferation that could be explained by impaired autophagy. Furthermore, RACK1 is essential for invariant natural T cell development. In vivo, T cell-specific loss of RACK1 dampens concanavalin A-induced acute liver injury. Our data suggest that RACK1 is a key regulator of T cell homeostasis.

  12. Impairment of T-regulatory cells in cord blood of atopic mothers.

    Science.gov (United States)

    Schaub, Bianca; Liu, Jing; Höppler, Sabine; Haug, Severine; Sattler, Christine; Lluis, Anna; Illi, Sabina; von Mutius, Erika

    2008-06-01

    Maternal atopy is a strong predictor for the development of childhood allergic diseases. The underlying mechanisms are ill defined, yet regulatory T (Treg) and T(H)17 cells may play a key role potentially shaping the early immune system toward a proallergic or antiallergic immune regulation. We examined T(H)1/T(H)2, Treg, and T(H)17 cell responses to innate (lipid A/peptidoglycan) and mitogen/adaptive (phytohemagglutinin/Dermatophagoides pteronyssinus 1) immune stimulation in cord blood from offspring of atopic/nonatopic mothers. Cord blood mononuclear cells from 161 healthy neonates (59% nonatopic, 41% atopic mothers) were investigated regarding Treg and T(H)17 cells (mRNA/surface markers), suppressive function, and proliferation/cytokine secretion. Cord blood from offspring of atopic mothers showed fewer innate-induced Treg cells (CD4(+)CD25(+)high), lower mRNA expression of associated markers (glucocorticoid-induced tumor necrosis factor receptor-related protein/lymphocyte activation gene 3; P cell function was impaired in mitogen-induced suppression of T effector cells in cord blood of offspring from atopic mothers (P = .03). Furthermore, IL-10 and IFN-gamma secretion were decreased in innate-stimulated cord blood of offspring from atopic mothers (P = .04/.05). Innate-induced IL-17 was independent of maternal atopy and highly correlated with IL-13 secretion. In offspring of atopic mothers, Treg cell numbers, expression, and function were impaired at birth. T(H)17 cells were correlated with T(H)2 cells, independently of maternal atopy.

  13. Cell Adhesions: Actin-Based Modules that Mediate Cell-Extracellular Matrix and Cell-Cell Interactions

    Science.gov (United States)

    Bachir, Alexia; Horwitz, Alan Rick; Nelson, W. James; Bianchini, Julie M.

    2018-01-01

    Cell adhesions link cells to the extracellular matrix (ECM) and to each other, and depend on interactions with the actin cytoskeleton. Both cell-ECM and cell-cell adhesion sites contain discrete, yet overlapping functional modules. These modules establish physical association with the actin cytoskeleton, locally modulate actin organization and dynamics, and trigger intracellular signaling pathways. Interplay between these modules generates distinct actin architectures that underlie different stages, types, and functions of cell-ECM and cell-cell adhesions. Actomyosin contractility is required to generate mature, stable adhesions, as well as sense and translate the mechanical properties of the cellular environment to changes in cell organization and behavior. In this chapter we discuss the organization and function of different adhesion modules and how they interact with the actin cytoskeleton. We highlight the molecular mechanisms of mechanotransduction in adhesions, and how adhesion molecules mediate crosstalk between cell-ECM and cell-cell adhesion sites. PMID:28679638

  14. A zinc-resistant human epithelial cell line is impaired in cadmium and manganese import

    International Nuclear Information System (INIS)

    Rousselet, Estelle; Richaud, Pierre; Douki, Thierry; Chantegrel, Jocelyne Garcia; Favier, Alain; Bouron, Alexandre; Moulis, Jean-Marc

    2008-01-01

    A human epithelial cell line (HZR) growing with high zinc concentrations has been analyzed for its ability to sustain high cadmium concentrations. Exposure to up to 200 μM of cadmium acetate for 24 h hardly impacted viability, whereas most of parental HeLa cells were killed by less than 10 μM of cadmium. Upon challenge by 35 fold higher cadmium concentrations than HeLa cells, HZR cells did not display increased DNA damage, increased protein oxidation, or changed intracellular cadmium localization. Rather, the main cause of resistance against cadmium was by avoiding cadmium entry into cells, which differs from that against zinc as the latter accumulates inside cells. The zinc-resistant phenotype of these cells was shown to also impair extracellular manganese uptake. Manganese and cadmium competed for entry into HeLa cells. Probing formerly identified cadmium or manganese transport systems in different animal cells did not evidence any significant change between HeLa and HZR cells. These results reveal zinc adaptation influences manganese and cadmium cellular traffic and they highlight previously unknown connections among homeostasis of divalent metals

  15. Urea impairs β cell glycolysis and insulin secretion in chronic kidney disease

    Science.gov (United States)

    Koppe, Laetitia; Nyam, Elsa; Vivot, Kevin; Manning Fox, Jocelyn E.; Dai, Xiao-Qing; Nguyen, Bich N.; Attané, Camille; Moullé, Valentine S.; MacDonald, Patrick E.; Ghislain, Julien

    2016-01-01

    Disorders of glucose homeostasis are common in chronic kidney disease (CKD) and are associated with increased mortality, but the mechanisms of impaired insulin secretion in this disease remain unclear. Here, we tested the hypothesis that defective insulin secretion in CKD is caused by a direct effect of urea on pancreatic β cells. In a murine model in which CKD is induced by 5/6 nephrectomy (CKD mice), we observed defects in glucose-stimulated insulin secretion in vivo and in isolated islets. Similarly, insulin secretion was impaired in normal mouse and human islets that were cultured with disease-relevant concentrations of urea and in islets from normal mice treated orally with urea for 3 weeks. In CKD mouse islets as well as urea-exposed normal islets, we observed an increase in oxidative stress and protein O-GlcNAcylation. Protein O-GlcNAcylation was also observed in pancreatic sections from CKD patients. Impairment of insulin secretion in both CKD mouse and urea-exposed islets was associated with reduced glucose utilization and activity of phosphofructokinase 1 (PFK-1), which could be reversed by inhibiting O-GlcNAcylation. Inhibition of O-GlcNAcylation also restored insulin secretion in both mouse models. These results suggest that insulin secretory defects associated with CKD arise from elevated circulating levels of urea that increase islet protein O-GlcNAcylation and impair glycolysis. PMID:27525435

  16. 1Protein Energy Malnutrition Impairs Homeostatic Proliferation of Memory CD8 T cells

    Science.gov (United States)

    Iyer, Smita S.; Chatraw, Janel Hart; Tan, Wendy G.; Wherry, E. John; Becker, Todd C.; Ahmed, Rafi; Kapasi, Zoher F.

    2011-01-01

    Nutrition is a critical but poorly understood determinant of immunity. There is abundant epidemiological evidence linking protein malnutrition to impaired vaccine efficacy and increased susceptibility to infections; yet, the role of dietary protein in immune memory homeostasis remains poorly understood. Here we show that protein energy malnutrition (PEM) induced in mice by low-protein (LP) feeding has a detrimental impact on CD8 memory. Relative to adequate-protein (AP) fed controls, LP feeding in lymphocytic choriomeningitis virus (LCMV) immune mice resulted in a 2-fold decrease in LCMV-specific CD8 memory T cells. Adoptive transfer of memory cells, labeled with a division tracking dye, from AP mice into naive LP or AP mice demonstrated that PEM caused profound defects in homeostatic proliferation. Remarkably, this defect occurred despite the lymphopenic environment in LP hosts. While antigen-specific memory cells in LP and AP hosts were phenotypically similar, memory cells in LP hosts were markedly less-responsive to poly(I:C)-induced acute proliferative signals. Furthermore, upon recall, memory cells in LP hosts displayed reduced proliferation and protection from challenge with LCMV-clone 13 resulting in impaired viral clearance in the liver. The findings show a metabolic requirement of dietary protein in sustaining functional CD8 memory and suggest that interventions to optimize dietary protein intake may improve vaccine efficacy in malnourished individuals. PMID:22116826

  17. Protein energy malnutrition impairs homeostatic proliferation of memory CD8 T cells.

    Science.gov (United States)

    Iyer, Smita S; Chatraw, Janel Hart; Tan, Wendy G; Wherry, E John; Becker, Todd C; Ahmed, Rafi; Kapasi, Zoher F

    2012-01-01

    Nutrition is a critical but poorly understood determinant of immunity. There is abundant epidemiological evidence linking protein malnutrition to impaired vaccine efficacy and increased susceptibility to infections; yet, the role of dietary protein in immune memory homeostasis remains poorly understood. In this study, we show that protein-energy malnutrition induced in mice by low-protein (LP) feeding has a detrimental impact on CD8 memory. Relative to adequate protein (AP)-fed controls, LP feeding in lymphocytic choriomeningitis virus (LCMV)-immune mice resulted in a 2-fold decrease in LCMV-specific CD8 memory T cells. Adoptive transfer of memory cells, labeled with a division tracking dye, from AP mice into naive LP or AP mice demonstrated that protein-energy malnutrition caused profound defects in homeostatic proliferation. Remarkably, this defect occurred despite the lymphopenic environment in LP hosts. Whereas Ag-specific memory cells in LP and AP hosts were phenotypically similar, memory cells in LP hosts were markedly less responsive to polyinosinic-polycytidylic acid-induced acute proliferative signals. Furthermore, upon recall, memory cells in LP hosts displayed reduced proliferation and protection from challenge with LCMV-clone 13, resulting in impaired viral clearance in the liver. The findings show a metabolic requirement of dietary protein in sustaining functional CD8 memory and suggest that interventions to optimize dietary protein intake may improve vaccine efficacy in malnourished individuals.

  18. The seleno-organic compound ebselen impairs mitochondrial physiology and induces cell death in AR42J cells.

    Science.gov (United States)

    Santofimia-Castaño, Patricia; Garcia-Sanchez, Lourdes; Ruy, Deborah Clea; Fernandez-Bermejo, Miguel; Salido, Gines M; Gonzalez, Antonio

    2014-09-17

    Ebselen is a seleno-organic compound that causes cell death in several cancer cell types. The mechanisms underlying its deleterious effects have not been fully elucidated. In this study, the effects of ebselen (1 μM-40 μM) on AR42J tumor cells have been examined. Cell viability was studied using AlamarBlue(®) test. Cell cycle phase determination was carried out by flow cytometry. Changes in intracellular free Ca(2+) concentration were followed by fluorimetry analysis of fura-2-loaded cells. Distribution of mitochondria, mitochondrial Ca(2+) concentration and mitochondrial membrane potential were monitored by confocal microscopy of cells loaded with Mitotracker Green™ FM, rhod-2 or TMRM respectively. Caspase-3 activity was calculated following the luorogenic substrate ACDEVD-AMC signal with a spectrofluorimeter. Results show that cell viability decreased in the presence of ebselen. An increase in the number of cells in the S-phase of the cell cycle was observed. Ebselen induced a concentration-dependent mobilization of Ca(2+) from agonist- and thapsigargin-sensitive Ca(2+) pools. Ebselen induced also a transient increase in mitochondrial Ca(2+) concentration, a progressive decrease of the mitochondrial membrane potential and a disruption of the mitochondrial network. Finally, a concentration-dependent increase in caspase-3 activity was detected. We conclude that ebselen exerts deleterious actions on the cells that involve the impairment of mitochondrial physiology and the activation of caspase-3-mediated apoptotic pathway. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  19. Casticin impairs cell growth and induces cell apoptosis via cell cycle arrest in human oral cancer SCC-4 cells.

    Science.gov (United States)

    Chou, Guan-Ling; Peng, Shu-Fen; Liao, Ching-Lung; Ho, Heng-Chien; Lu, Kung-Wen; Lien, Jin-Cherng; Fan, Ming-Jen; La, Kuang-Chi; Chung, Jing-Gung

    2018-02-01

    Casticin, a polymethoxyflavone, present in natural plants, has been shown to have biological activities including anti-cancer activities. Herein, we investigated the anti-oral cancer activity of casticin on SCC-4 cells in vitro. Viable cells, cell cycle distribution, apoptotic cell death, reactive oxygen species (ROS) production, and Ca 2+ production, levels of ΔΨ m and caspase activity were measured by flow cytometric assay. Cell apoptosis associated protein expressions were examined by Western blotting and confocal laser microscopy. Results indicated that casticin induced cell morphological changes, DNA condensation and damage, decreased the total viable cells, induced G 2 /M phase arrest in SCC-4 cells. Casticin promoted ROS and Ca 2+ productions, decreases the levels of ΔΨ m , promoted caspase-3, -8, and -9 activities in SCC-4 cells. Western blotting assay demonstrated that casticin affect protein level associated with G2/M phase arrest and apoptosis. Confocal laser microscopy also confirmed that casticin increased the translocation of AIF and cytochrome c in SCC-4 cells. In conclusion, casticin decreased cell number through G 2 /M phase arrest and the induction of cell apoptosis through caspase- and mitochondria-dependent pathways in SCC-4 cells. © 2017 Wiley Periodicals, Inc.

  20. A map of directional genetic interactions in a metazoan cell.

    Science.gov (United States)

    Fischer, Bernd; Sandmann, Thomas; Horn, Thomas; Billmann, Maximilian; Chaudhary, Varun; Huber, Wolfgang; Boutros, Michael

    2015-03-06

    Gene-gene interactions shape complex phenotypes and modify the effects of mutations during development and disease. The effects of statistical gene-gene interactions on phenotypes have been used to assign genes to functional modules. However, directional, epistatic interactions, which reflect regulatory relationships between genes, have been challenging to map at large-scale. Here, we used combinatorial RNA interference and automated single-cell phenotyping to generate a large genetic interaction map for 21 phenotypic features of Drosophila cells. We devised a method that combines genetic interactions on multiple phenotypes to reveal directional relationships. This network reconstructed the sequence of protein activities in mitosis. Moreover, it revealed that the Ras pathway interacts with the SWI/SNF chromatin-remodelling complex, an interaction that we show is conserved in human cancer cells. Our study presents a powerful approach for reconstructing directional regulatory networks and provides a resource for the interpretation of functional consequences of genetic alterations.

  1. Elevated HLA-A expression impairs HIV control through inhibition of NKG2A-expressing cells.

    Science.gov (United States)

    Ramsuran, Veron; Naranbhai, Vivek; Horowitz, Amir; Qi, Ying; Martin, Maureen P; Yuki, Yuko; Gao, Xiaojiang; Walker-Sperling, Victoria; Del Prete, Gregory Q; Schneider, Douglas K; Lifson, Jeffrey D; Fellay, Jacques; Deeks, Steven G; Martin, Jeffrey N; Goedert, James J; Wolinsky, Steven M; Michael, Nelson L; Kirk, Gregory D; Buchbinder, Susan; Haas, David; Ndung'u, Thumbi; Goulder, Philip; Parham, Peter; Walker, Bruce D; Carlson, Jonathan M; Carrington, Mary

    2018-01-05

    The highly polymorphic human leukocyte antigen ( HLA ) locus encodes cell surface proteins that are critical for immunity. HLA-A expression levels vary in an allele-dependent manner, diversifying allele-specific effects beyond peptide-binding preference. Analysis of 9763 HIV-infected individuals from 21 cohorts shows that higher HLA-A levels confer poorer control of HIV. Elevated HLA-A expression provides enhanced levels of an HLA-A-derived signal peptide that specifically binds and determines expression levels of HLA-E, the ligand for the inhibitory NKG2A natural killer (NK) cell receptor. HLA-B haplotypes that favor NKG2A-mediated NK cell licensing (i.e., education) exacerbate the deleterious effect of high HLA-A on HIV control, consistent with NKG2A-mediated inhibition impairing NK cell clearance of HIV-infected targets. Therapeutic blockade of HLA-E:NKG2A interaction may yield benefit in HIV disease. Copyright © 2017, American Association for the Advancement of Science.

  2. The depletion of nuclear glutathione impairs cell proliferation in 3t3 fibroblasts.

    Directory of Open Access Journals (Sweden)

    Jelena Markovic

    2009-07-01

    Full Text Available Glutathione is considered essential for survival in mammalian cells and yeast but not in prokaryotic cells. The presence of a nuclear pool of glutathione has been demonstrated but its role in cellular proliferation and differentiation is still a matter of debate.We have studied proliferation of 3T3 fibroblasts for a period of 5 days. Cells were treated with two well known depleting agents, diethyl maleate (DEM and buthionine sulfoximine (BSO, and the cellular and nuclear glutathione levels were assessed by analytical and confocal microscopic techniques, respectively. Both agents decreased total cellular glutathione although depletion by BSO was more sustained. However, the nuclear glutathione pool resisted depletion by BSO but not with DEM. Interestingly, cell proliferation was impaired by DEM, but not by BSO. Treating the cells simultaneously with DEM and with glutathione ethyl ester to restore intracellular GSH levels completely prevented the effects of DEM on cell proliferation.Our results demonstrate the importance of nuclear glutathione in the control of cell proliferation in 3T3 fibroblasts and suggest that a reduced nuclear environment is necessary for cells to progress in the cell cycle.

  3. Interactive video gaming compared with health education in older adults with mild cognitive impairment: a feasibility study.

    Science.gov (United States)

    Hughes, Tiffany F; Flatt, Jason D; Fu, Bo; Butters, Meryl A; Chang, Chung-Chou H; Ganguli, Mary

    2014-09-01

    We evaluated the feasibility of a trial of Wii interactive video gaming, and its potential efficacy at improving cognitive functioning compared with health education, in a community sample of older adults with neuropsychologically defined mild cognitive impairment. Twenty older adults were equally randomized to either group-based interactive video gaming or health education for 90 min each week for 24 weeks. Although the primary outcomes were related to study feasibility, we also explored the effect of the intervention on neuropsychological performance and other secondary outcomes. All 20 participants completed the intervention, and 18 attended at least 80% of the sessions. The majority (80%) of participants were "very much" satisfied with the intervention. Bowling was enjoyed by the most participants and was also rated the highest among the games for mental, social, and physical stimulation. We observed medium effect sizes for cognitive and physical functioning in favor of the interactive video gaming condition, but these effects were not statistically significant in this small sample. Interactive video gaming is feasible for older adults with mild cognitive impairment, and medium effect sizes in favor of the Wii group warrant a larger efficacy trial. Copyright © 2014 John Wiley & Sons, Ltd.

  4. Sodium arsenite impairs insulin secretion and transcription in pancreatic β-cells

    International Nuclear Information System (INIS)

    Diaz-Villasenor, Andrea; Sanchez-Soto, M. Carmen; Cebrian, Mariano E.; Ostrosky-Wegman, Patricia; Hiriart, Marcia

    2006-01-01

    Human studies have shown that chronic inorganic arsenic (iAs) exposure is associated with a high prevalence and incidence of type 2 diabetes. However, the mechanism(s) underlying this effect are not well understood, and practically, there is no information available on the effects of arsenic on pancreatic β-cells functions. Thus, since insulin secreted by the pancreas plays a crucial role in maintaining glucose homeostasis, our aim was to determine if sodium arsenite impairs insulin secretion and mRNA expression in single adult rat pancreatic β-cells. Cells were treated with 0.5, 1, 2, 5 and 10 μM sodium arsenite and incubated for 72 and 144 h. The highest dose tested (10 μM) decreased β-cell viability, by 33% and 83%, respectively. Insulin secretion and mRNA expression were evaluated in the presence of 1 and 5 μM sodium arsenite. Basal insulin secretion, in 5.6 mM glucose, was not significantly affected by 1 or 5 μM treatment for 72 h, but basal secretion was reduced when cells were exposed to 5 μM sodium arsenite for 144 h. On the other hand, insulin secretion in response to 15.6 mM glucose decreased with sodium arsenite in a dose-dependent manner in such a way that cells were no longer able to distinguish between different glucose concentrations. We also showed a significant decrease in insulin mRNA expression of cells exposed to 5 μM sodium arsenite during 72 h. Our data suggest that arsenic may contribute to the development of diabetes mellitus by impairing pancreatic β-cell functions, particularly insulin synthesis and secretion

  5. Cognitive Impairment in Temporal Lobe Epilepsy: Role of Online and Offline Processing of Single Cell Information

    Science.gov (United States)

    Titiz, A. S.; Mahoney, J. M.; Testorf, M. E.; Holmes, G. L.; Scott, R. C.

    2014-01-01

    Cognitive impairment is a common comorbidity in temporal lobe epilepsy (TLE) and is often considered more detrimental to quality of life than seizures. While it has been previously shown that the encoding of memory during behavior is impaired in the pilocarpine model of TLE in rats, how this information is consolidated during the subsequent sleep period remains unknown. In this study, we first report marked deficits in spatial memory performance and severe cell loss in the CA1 layer of the hippocampus lower spatial coherence of firing in TLE rats. We then present the first evidence that the reactivation of behavior-driven patterns of activity of CA1 place cells in the hippocampus is intact in TLE rats. Using a template-matching method, we discovered that real-time (3–5 s) reactivation structure was intact in TLE rats. Furthermore, we estimated the entropy rate of short time scale (~250 ms) bursting activity using block entropies and found that significant, extended temporal correlations exist in both TLE and Control rats. Fitting a first order Markov Chain model to these bursting time series, we found that long sequences derived from behavior were significantly enriched in the Markov model over corresponding models fit on randomized data confirming the presence of replay in shorter time scales. We propose that the persistent consolidation of poor spatial information in both real-time and during bursting activity may contribute to memory impairments in TLE rats. PMID:24799359

  6. Platelet-tumor cell interaction with the subendothelial extracellular matrix: relationship to cancer metastasis

    Energy Technology Data Exchange (ETDEWEB)

    Yahalom, J; Biran, S; Fuks, Z; Vlodavsky, I [Hadassah University Hospital, Jerusalem (Israel). Dept. of Radiation and Clinical Oncology; Eldor, A [Hadassah University Hospital, Jerusalem (Israel). Dept. of Hematology

    1985-04-01

    Dissemination of neoplastic cells within the body involves invasion of blood vessels by tumor cells. This requires adhesion of blood-borne cells to the luminal surface of the vascular endothelium, invasion through the endothelial cell layer and local dissolution of the subendothelial basement membrane. The authors studied the interaction of platelets and tumor cells with cultured vascular endothelial cells and their secreted basement membrane-like extracellular matrix (ECM). Interaction of platelets with this ECM was associated with platelet activation, aggregation and degradation of heparan sulfate in the ECM by means of the platelet heparitinase. Biochemical and scanning electron microscopy (SEM) studies have demonstrated that platelets may detect even minor gaps between adjacent endothelial cells and degrade the ECM heparan sulfate. Platelets were also shown to recruit lymphoma cells into minor gaps in the vascular endothelium. It is suggested that the platelet heparitinase is involved in the impairment of the integrity of the vessel wall and thus play a role in tumor cell metastasis.

  7. The interaction of dendritic cells and γδ T cells promotes the activation of γδ T cells in experimental autoimmune uveitis

    Directory of Open Access Journals (Sweden)

    Beibei Wang

    2017-03-01

    Full Text Available Uveitis is a severe inflammatory disease that can cause visual impairment. Recently, activated γδ T cells were proved to play a central role in the development of experimental autoimmune uveitis (EAU. However, the mechanism underlying γδ T-cell activation in EAU is incompletely known. In this study, we determined the percentage changes in and the phenotypes of γδ T cells and dendritic cells (DCs obtained from the spleens of immunized C57BL/6 (B6 mice, an animal model of EAU. We found that the number of γδ T cells and DCs obviously increased during the inflammation phase of EAU (days 16–20 of our experiment, and that during this time, γδ T cells expressed high levels of CD69 and the integrin lymphocyte function–associated antigen-1 (LFA-1 and secreted high levels of interleukin (IL-17A. Moreover, DCs obtained during this phase expressed high levels of CD80, CD83, CD86, and intracellular cell adhesion molecule-1 (ICAM-1. Furthermore, we studied the interaction between DCs and γδ T cells by using flow cytometry and confocal microscopy in order to determine whether DCs affected γδ T-cell activation in vitro. Co-cultures of the two types of cells showed that DCs induced high levels of CD69, LFA-1, and IL-17A in γδ T cells. Imaging studies revealed contact between the DCs and γδ T cells. This interaction was mediated by the accumulation of ICAM-1 and LFA-1 at the interface of DCs-γδ T cells. Thus, the activation of γδ T cells in EAU was promoted by DCs interacting with γδ T cells.

  8. Natural killer cells in obesity: impaired function and increased susceptibility to the effects of cigarette smoke.

    LENUS (Irish Health Repository)

    O'Shea, Donal

    2012-02-01

    BACKGROUND: Obese individuals who smoke have a 14 year reduction in life expectancy. Both obesity and smoking are independently associated with increased risk of malignancy. Natural killer cells (NK) are critical mediators of anti-tumour immunity and are compromised in obese patients and smokers. We examined whether NK cell function was differentially affected by cigarette smoke in obese and lean subjects. METHODOLOGY AND PRINCIPAL FINDINGS: Clinical data and blood were collected from 40 severely obese subjects (BMI>40 kg\\/m(2)) and 20 lean healthy subjects. NK cell levels and function were assessed using flow cytometry and cytotoxicity assays. The effect of cigarette smoke on NK cell ability to kill K562 tumour cells was assessed in the presence or absence of the adipokines leptin and adiponectin. NK cell levels were significantly decreased in obese subjects compared to lean controls (7.6 vs 16.6%, p = 0.0008). NK function was also significantly compromised in obese patients (30% +\\/- 13% vs 42% +\\/-12%, p = 0.04). Cigarette smoke inhibited NK cell ability to kill tumour cell lines (p<0.0001). NK cells from obese subjects were even more susceptible to the inhibitory effects of smoke compared to lean subjects (33% vs 28%, p = 0.01). Cigarette smoke prevented NK cell activation, as well as perforin and interferon-gamma secretion upon tumour challenge. Adiponectin but not leptin partially reversed the effects of smoke on NK cell function in both obese (p = 0.002) and lean controls (p = 0.01). CONCLUSIONS\\/SIGNIFICANCE: Obese subjects have impaired NK cell activity that is more susceptible to the detrimental effects of cigarette smoke compared to lean subjects. This may play a role in the increase of cancer and infection seen in this population. Adiponectin is capable of restoring NK cell activity and may have therapeutic potential for immunity in obese subjects and smokers.

  9. Natural killer cells in obesity: impaired function and increased susceptibility to the effects of cigarette smoke.

    LENUS (Irish Health Repository)

    O'Shea, Donal

    2010-01-01

    BACKGROUND: Obese individuals who smoke have a 14 year reduction in life expectancy. Both obesity and smoking are independently associated with increased risk of malignancy. Natural killer cells (NK) are critical mediators of anti-tumour immunity and are compromised in obese patients and smokers. We examined whether NK cell function was differentially affected by cigarette smoke in obese and lean subjects. METHODOLOGY AND PRINCIPAL FINDINGS: Clinical data and blood were collected from 40 severely obese subjects (BMI>40 kg\\/m(2)) and 20 lean healthy subjects. NK cell levels and function were assessed using flow cytometry and cytotoxicity assays. The effect of cigarette smoke on NK cell ability to kill K562 tumour cells was assessed in the presence or absence of the adipokines leptin and adiponectin. NK cell levels were significantly decreased in obese subjects compared to lean controls (7.6 vs 16.6%, p = 0.0008). NK function was also significantly compromised in obese patients (30% +\\/- 13% vs 42% +\\/-12%, p = 0.04). Cigarette smoke inhibited NK cell ability to kill tumour cell lines (p<0.0001). NK cells from obese subjects were even more susceptible to the inhibitory effects of smoke compared to lean subjects (33% vs 28%, p = 0.01). Cigarette smoke prevented NK cell activation, as well as perforin and interferon-gamma secretion upon tumour challenge. Adiponectin but not leptin partially reversed the effects of smoke on NK cell function in both obese (p = 0.002) and lean controls (p = 0.01). CONCLUSIONS\\/SIGNIFICANCE: Obese subjects have impaired NK cell activity that is more susceptible to the detrimental effects of cigarette smoke compared to lean subjects. This may play a role in the increase of cancer and infection seen in this population. Adiponectin is capable of restoring NK cell activity and may have therapeutic potential for immunity in obese subjects and smokers.

  10. Natural killer cells in obesity: impaired function and increased susceptibility to the effects of cigarette smoke.

    Directory of Open Access Journals (Sweden)

    Donal O'Shea

    Full Text Available BACKGROUND: Obese individuals who smoke have a 14 year reduction in life expectancy. Both obesity and smoking are independently associated with increased risk of malignancy. Natural killer cells (NK are critical mediators of anti-tumour immunity and are compromised in obese patients and smokers. We examined whether NK cell function was differentially affected by cigarette smoke in obese and lean subjects. METHODOLOGY AND PRINCIPAL FINDINGS: Clinical data and blood were collected from 40 severely obese subjects (BMI>40 kg/m(2 and 20 lean healthy subjects. NK cell levels and function were assessed using flow cytometry and cytotoxicity assays. The effect of cigarette smoke on NK cell ability to kill K562 tumour cells was assessed in the presence or absence of the adipokines leptin and adiponectin. NK cell levels were significantly decreased in obese subjects compared to lean controls (7.6 vs 16.6%, p = 0.0008. NK function was also significantly compromised in obese patients (30% +/- 13% vs 42% +/-12%, p = 0.04. Cigarette smoke inhibited NK cell ability to kill tumour cell lines (p<0.0001. NK cells from obese subjects were even more susceptible to the inhibitory effects of smoke compared to lean subjects (33% vs 28%, p = 0.01. Cigarette smoke prevented NK cell activation, as well as perforin and interferon-gamma secretion upon tumour challenge. Adiponectin but not leptin partially reversed the effects of smoke on NK cell function in both obese (p = 0.002 and lean controls (p = 0.01. CONCLUSIONS/SIGNIFICANCE: Obese subjects have impaired NK cell activity that is more susceptible to the detrimental effects of cigarette smoke compared to lean subjects. This may play a role in the increase of cancer and infection seen in this population. Adiponectin is capable of restoring NK cell activity and may have therapeutic potential for immunity in obese subjects and smokers.

  11. Hydrogen peroxide impairs autophagic flux in a cell model of nonalcoholic fatty liver disease

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Pengtao [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101 (China); University of Chinese Academy of Sciences, 19 Yuquan Road, Shijingshan District, Beijing 100049 (China); Huang, Zhen [Department of Abdominal Surgical Oncology, Cancer Hospital, Chinese Academy of Medical Sciences, 17 Panjiayuan Nanli, Chaoyang District, Beijing 100021 (China); Zhao, Hong, E-mail: zhaohong9@sina.com [Department of Abdominal Surgical Oncology, Cancer Hospital, Chinese Academy of Medical Sciences, 17 Panjiayuan Nanli, Chaoyang District, Beijing 100021 (China); Wei, Taotao, E-mail: weitt@moon.ibp.ac.cn [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101 (China)

    2013-04-19

    Highlights: •Free fatty acids exposure induces elevated autophagy. •H{sub 2}O{sub 2} inhibits autophagic flux through impairing the fusion between autophagosomes and lysosomes. •Inhibition of autophagy potentiates H{sub 2}O{sub 2}-induced cell death. -- Abstract: Nonalcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver disease, but the pathogenesis of NAFLD is not fully clear. The aim of this study was to determine whether autophagy plays a role in the pathogenesis of NAFLD. We found that the levels of autophagy were elevated in hepatoma cells upon exposure to free fatty acids, as confirmed by the increase in the number of autophagosomes. However, exposure of hepatoma cells to H{sub 2}O{sub 2} and TNF-α, two typical “second hit” factors, increased the initiation of autophagy but inhibited the autophagic flux. The inhibition of autophagy sensitized cells to pro-apoptotic stimuli. Taken together, our results suggest that autophagy acts as a protective mechanism in the pathogenesis of NAFLD and that impairment of autophagy might induce more severe lesions of the liver. These findings will be a benefit to the understanding of the pathogenesis of NAFLD and might suggest a strategy for the prevention and cure of NAFLD.

  12. Nuclear SREBP-1a causes loss of pancreatic β-cells and impaired insulin secretion

    International Nuclear Information System (INIS)

    Iwasaki, Yuko; Iwasaki, Hitoshi; Yatoh, Shigeru; Ishikawa, Mayumi; Kato, Toyonori; Matsuzaka, Takashi; Nakagawa, Yoshimi; Yahagi, Naoya; Kobayashi, Kazuto; Takahashi, Akimitsu; Suzuki, Hiroaki; Yamada, Nobuhiro; Shimano, Hitoshi

    2009-01-01

    Transgenic mice expressing nuclear sterol regulatory element-binding protein-1a under the control of the insulin promoter were generated to determine the role of SREBP-1a in pancreatic β-cells. Only low expressors could be established, which exhibited mild hyperglycemia, impaired glucose tolerance, and reduced plasma insulin levels compared to C57BL/6 controls. The islets isolated from the transgenic mice were fewer and smaller, and had decreased insulin content and unaltered glucagon staining. Both glucose- and potassium-stimulated insulin secretions were decreased. The transgenic islets consistently expressed genes for fatty acids and cholesterol synthesis, resulting in accumulation of triglycerides but not cholesterol. PDX-1, ΒΕΤΑ2, MafA, and IRS-2 were suppressed, partially explaining the loss and dysfunction of β-cell mass. The transgenic mice on a high fat/high sucrose diet still exhibited impaired insulin secretion and continuous β-cell growth defect. Therefore, nuclear SREBP-1a, even at a low level, strongly disrupts β-cell mass and function.

  13. Lithium Impairs Kidney Development and Inhibits Glycogen Synthase Kinase-3β in Collecting Duct Principal Cells

    DEFF Research Database (Denmark)

    Kjærsgaard, Gitte; Madsen, Kirsten; Marcussen, Niels

    level significantly whereas total GSK-3β abundance was unaltered. Li+ treatment increased α-Smooth Muscle Actin (α-SMA) protein level significantly whereas E-cadherin expression was unaltered. In summary, Li+ treatment impairs postnatal development of the kidney cortex and outer medulla and increases pGSK......The postnatal rat kidney is highly susceptible to Lithium (Li+), which leads to significant tissue injury. We hypothesized that Li+ impairs development of the kidney through entry into epithelial cells of the distal nephron, inhibition of Glycogen Synthase Kinase-3β (GSK-3β) through phosphorylation...... on serine9 (pGSK-3β)and subsequent epithelial to mesenchymal dedifferentiation (EMT). GSK-3β immunoreactive protein was associated with collecting ducts in developing and adult human and rat kidney. Total GSK-3β protein abundance was stable in medulla while it decreased in cortex in the postnatal period...

  14. Impaired fasting glycaemia vs impaired glucose tolerance: similar impairment of pancreatic alpha and beta cell function but differential roles of incretin hormones and insulin action

    DEFF Research Database (Denmark)

    Faerch, K; Vaag, A; Holst, Jens Juul

    2008-01-01

    .892) compared with NGT. Hepatic insulin sensitivity was normal in i-IFG and i-IGT individuals (p > or = 0.179). Individuals with i-IGT had peripheral insulin resistance (p = 0.003 vs NGT), and consequently the disposition index (DI; insulin secretion x insulin sensitivity) during IVGTT (DI(IVGTT))) was reduced......AIMS/HYPOTHESIS: The impact of strategies for prevention of type 2 diabetes in isolated impaired fasting glycaemia (i-IFG) vs isolated impaired glucose tolerance (i-IGT) may differ depending on the underlying pathophysiology. We examined insulin secretion during OGTTs and IVGTTs, hepatic...

  15. Neuronal chemokines : Versatile messengers in central nervous system cell interaction

    NARCIS (Netherlands)

    de Haas, A. H.; van Weering, H. R. J.; de Jong, E. K.; Boddeke, H. W. G. M.; Biber, K. P. H.

    2007-01-01

    Whereas chemokines are well known for their ability to induce cell migration, only recently it became evident that chemokines also control a variety of other cell functions and are versatile messengers in the interaction between a diversity of cell types. In the central nervous system (CNS),

  16. Blood Cell Interactions and Segregation in Flow

    OpenAIRE

    Munn, Lance L.; Dupin, Michael M.

    2008-01-01

    For more than a century, pioneering researchers have been using novel experimental and computational approaches to probe the mysteries of blood flow. Thanks to their efforts, we know that blood cells generally prefer to migrate to the axis of flow, that red and white cells segregate in flow, and that cell deformability and their tendency to reversibly aggregate contribute to the non-Newtonian nature of this unique fluid. All of these properties have beneficial physiological consequences, allo...

  17. Valsartan Improves β-Cell Function and Insulin Sensitivity in Subjects With Impaired Glucose Metabolism

    Science.gov (United States)

    van der Zijl, Nynke J.; Moors, Chantalle C.M.; Goossens, Gijs H.; Hermans, Marc M.H.; Blaak, Ellen E.; Diamant, Michaela

    2011-01-01

    OBJECTIVE Recently, the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research Trial demonstrated that treatment with the angiotensin receptor blocker (ARB) valsartan for 5 years resulted in a relative reduction of 14% in the incidence of type 2 diabetes in subjects with impaired glucose metabolism (IGM). We investigated whether improvements in β-cell function and/or insulin sensitivity underlie these preventive effects of the ARB valsartan in the onset of type 2 diabetes. RESEARCH DESIGN AND METHODS In this randomized controlled, double-blind, two-center study, the effects of 26 weeks of valsartan (320 mg daily; n = 40) or placebo (n = 39) on β-cell function and insulin sensitivity were assessed in subjects with impaired fasting glucose and/or impaired glucose tolerance, using a combined hyperinsulinemic-euglycemic and hyperglycemic clamp with subsequent arginine stimulation and a 2-h 75-g oral glucose tolerance test (OGTT). Treatment effects were analyzed using ANCOVA, adjusting for center, glucometabolic status, and sex. RESULTS Valsartan increased first-phase (P = 0.028) and second-phase (P = 0.002) glucose-stimulated insulin secretion compared with placebo, whereas the enhanced arginine-stimulated insulin secretion was comparable between groups (P = 0.25). In addition, valsartan increased the OGTT-derived insulinogenic index (representing first-phase insulin secretion after an oral glucose load; P = 0.027). Clamp-derived insulin sensitivity was significantly increased with valsartan compared with placebo (P = 0.049). Valsartan treatment significantly decreased systolic and diastolic blood pressure compared with placebo (P valsartan treatment increased glucose-stimulated insulin release and insulin sensitivity in normotensive subjects with IGM. These findings may partly explain the beneficial effects of valsartan in the reduced incidence of type 2 diabetes. PMID:21330640

  18. Repetitive Supra-Physiological Shear Stress Impairs Red Blood Cell Deformability and Induces Hemolysis.

    Science.gov (United States)

    Horobin, Jarod T; Sabapathy, Surendran; Simmonds, Michael J

    2017-11-01

    The supra-physiological shear stress that blood is exposed to while traversing mechanical circulatory assist devices affects the physical properties of red blood cells (RBCs), impairs RBC deformability, and may induce hemolysis. Previous studies exploring RBC damage following exposure to supra-physiological shear stress have employed durations exceeding clinical instrumentation, thus we explored changes in RBC deformability following exposure to shear stress below the reported "hemolytic threshold" using shear exposure durations per minute (i.e., duty-cycles) reflective of that employed by circulatory assist devices. Blood collected from 20 male donors, aged 18-38 years, was suspended in a viscous medium and exposed to an intermittent shear stress protocol of 1 s at 100 Pa, every 60 s for 60 duty-cycles. During the remaining 59 s/min, the cells were left at stasis until the subsequent duty-cycle commenced. At discrete time points (15/30/45/60 duty-cycles), an ektacytometer measured RBC deformability immediately after shear exposure at 100 Pa. Plasma-free hemoglobin, a measurement of hemolysis, was quantified via spectrophotometry. Supra-physiological shear stress impaired RBC properties, as indicated by: (1) decreased maximal elongation of RBCs at infinite shear stress following 15 duty-cycles (P supra-physiological shear stress protocol (100 Pa) following exposure to 1 duty-cycle (F (1.891, 32.15) = 12.21, P = 0.0001); and (3) increased plasma-free hemoglobin following 60 duty-cycles (P supra-physiological shear stress, impairs RBC deformability, with the extent of impairment exacerbated with each duty-cycle, and ultimately precipitates hemolysis. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  19. Interactive cervical motion kinematics: sensitivity, specificity and clinically significant values for identifying kinematic impairments in patients with chronic neck pain.

    Science.gov (United States)

    Sarig Bahat, Hilla; Chen, Xiaoqi; Reznik, David; Kodesh, Einat; Treleaven, Julia

    2015-04-01

    Chronic neck pain has been consistently shown to be associated with impaired kinematic control including reduced range, velocity and smoothness of cervical motion, that seem relevant to daily function as in quick neck motion in response to surrounding stimuli. The objectives of this study were: to compare interactive cervical kinematics in patients with neck pain and controls; to explore the new measures of cervical motion accuracy; and to find the sensitivity, specificity, and optimal cutoff values for defining impaired kinematics in those with neck pain. In this cross-section study, 33 patients with chronic neck pain and 22 asymptomatic controls were assessed for their cervical kinematic control using interactive virtual reality hardware and customized software utilizing a head mounted display with built-in head tracking. Outcome measures included peak and mean velocity, smoothness (represented by number of velocity peaks (NVP)), symmetry (represented by time to peak velocity percentage (TTPP)), and accuracy of cervical motion. Results demonstrated significant and strong effect-size differences in peak and mean velocities, NVP and TTPP in all directions excluding TTPP in left rotation, and good effect-size group differences in 5/8 accuracy measures. Regression results emphasized the high clinical value of neck motion velocity, with very high sensitivity and specificity (85%-100%), followed by motion smoothness, symmetry and accuracy. These finding suggest cervical kinematics should be evaluated clinically, and screened by the provided cut off values for identification of relevant impairments in those with neck pain. Such identification of presence or absence of kinematic impairments may direct treatment strategies and additional evaluation when needed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. R-Ras regulates migration through an interaction with filamin A in melanoma cells.

    Directory of Open Access Journals (Sweden)

    Joanna E Gawecka

    2010-06-01

    Full Text Available Changes in cell adhesion and migration in the tumor microenvironment are key in the initiation and progression of metastasis. R-Ras is one of several small GTPases that regulate cell adhesion and migration on the extracellular matrix, however the mechanism has not been completely elucidated. Using a yeast two-hybrid approach we sought to identify novel R-Ras binding proteins that might mediate its effects on integrins.We identified Filamin A (FLNa as a candidate interacting protein. FLNa is an actin-binding scaffold protein that also binds to integrin beta1, beta2 and beta7 tails and is associated with diverse cell processes including cell migration. Indeed, M2 melanoma cells require FLNa for motility. We further show that R-Ras and FLNa interact in co-immunoprecipitations and pull-down assays. Deletion of FLNa repeat 3 (FLNaDelta3 abrogated this interaction. In M2 melanoma cells active R-Ras co-localized with FLNa but did not co-localize with FLNa lacking repeat 3. Thus, activated R-Ras binds repeat 3 of FLNa. The functional consequence of this interaction was that active R-Ras and FLNa coordinately increased cell migration. In contrast, co-expression of R-Ras and FLNaDelta3 had a significantly reduced effect on migration. While there was enhancement of integrin activation and fibronectin matrix assembly, cell adhesion was not altered. Finally, siRNA knockdown of endogenous R-Ras impaired FLNa-dependent fibronectin matrix assembly.These data support a model in which R-Ras functionally associates with FLNa and thereby regulates integrin-dependent migration. Thus in melanoma cells R-Ras and FLNa may cooperatively promote metastasis by enhancing cell migration.

  1. Cell Phone Roulette and "Consumer Interactive" Quality

    Science.gov (United States)

    Navarro, Peter

    2005-01-01

    Under current policies, cell phone consumers face a lower probability of finding the best carrier for their usage patterns than winning at roulette. Corroborating survey data consistently show significant dissatisfaction among cell phone users, network performance is a major issue, and customer "churn" is high. This problem may be traced to a new…

  2. Comparison of cell homogenization methods considering interaction effect between fuel cells and control rod cells

    International Nuclear Information System (INIS)

    Takeda, T.; Uto, N.

    1988-01-01

    Several methods to determine cell-averaged group cross sections and anisotropic diffusion coefficients which consider the interaction effect between core fuel cells and control rods or control rod followers have been compared to discuss the physical meaning included in cell homogenization. As the cell homogenization methods considered are the commonly used flux-weighting method, the reaction rate preservation method and the reactivity preservation method. These homogenization methods have been applied to control rod worth calculations in 1-D slab cores to investigate their applicability. (author). 6 refs, 2 figs, 9 tabs

  3. Interaction of obstructive sleep apnoea and cognitive impairment with slow gait speed in middle-aged and older adults.

    Science.gov (United States)

    Lee, Sunghee; Shin, Chol

    2017-07-01

    to investigate whether slow gait speed is associated with cognitive impairment and further whether the association is modified by obstructive sleep apnoea (OSA). in total, 2,222 adults aged 49-80 years, free from dementia, stroke and head injury were asked to walk a 4-m course at fast and usual gait speeds. The time taken to walk was measured. All participants completed the Korean Mini-Mental State Examination, which was validated in the Korean language, to assess cognitive function. Additionally, the participants completed a polysomnography test to ascertain OSA (defined as an apnoea-hypopnoea index ≥15). Multivariable linear regression models were utilised to test the associations. time taken to walk 4 m showed significant inverse associations with cognitive scores (P value = 0.001 at fast gait speed and P = 0.002 at usual gait speed). Furthermore, a significant interaction according to OSA on the association between time to walk and cognitive impairment was found (P value for interaction = 0.003 at fast gait speed and P value for interaction = 0.007 at usual gait speed). we found that the inverse association between the time taken to walk 4 m and a cognitive score became significantly stronger, if an individual had OSA. © The Author 2017. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  4. Hilar Mossy Cell Degeneration Causes Transient Dentate Granule Cell Hyperexcitability and Impaired Pattern Separation

    Science.gov (United States)

    Jinde, Seiichiro; Zsiros, Veronika; Jiang, Zhihong; Nakao, Kazuhito; Pickel, James; Kohno, Kenji; Belforte, Juan E.; Nakazawa, Kazu

    2012-01-01

    Summary Although excitatory mossy cells of the hippocampal hilar region are known to project both to dentate granule cells and to interneurons, it is as yet unclear whether mossy cell activity’s net effect on granule cells is excitatory or inhibitory. To explore their influence on dentate excitability and hippocampal function, we generated a conditional transgenic mouse line, using the Cre/loxP system, in which diphtheria toxin receptor was selectively expressed in mossy cells. One week after injecting toxin into this line, mossy cells throughout the longitudinal axis were degenerated extensively, theta wave power of dentate local field potentials increased during exploration, and deficits occurred in contextual discrimination. By contrast, we detected no epileptiform activity, spontaneous behavioral seizures, or mossy-fiber sprouting 5–6 weeks after mossy cell degeneration. These results indicate that the net effect of mossy cell excitation is to inhibit granule cell activity and enable dentate pattern separation. PMID:23259953

  5. Impaired methylation as a novel mechanism for proteasome suppression in liver cells

    Energy Technology Data Exchange (ETDEWEB)

    Osna, Natalia A., E-mail: nosna@UNMC.edu [Liver Study Unit, The Omaha Veterans Affairs VA Medical Center, Omaha, NE 68105 (United States); Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68105 (United States); White, Ronda L.; Donohue, Terrence M. [Liver Study Unit, The Omaha Veterans Affairs VA Medical Center, Omaha, NE 68105 (United States); Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68105 (United States); Beard, Michael R. [Department of Molecular Biosciences, University of Adelaide (Australia); Tuma, Dean J.; Kharbanda, Kusum K. [Liver Study Unit, The Omaha Veterans Affairs VA Medical Center, Omaha, NE 68105 (United States); Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68105 (United States)

    2010-01-08

    The proteasome is a multi-catalytic protein degradation enzyme that is regulated by ethanol-induced oxidative stress; such suppression is attributed to CYP2E1-generated metabolites. However, under certain conditions, it appears that in addition to oxidative stress, other mechanisms are also involved in proteasome regulation. This study investigated whether impaired protein methylation that occurs during exposure of liver cells to ethanol, may contribute to suppression of proteasome activity. We measured the chymotrypsin-like proteasome activity in Huh7CYP cells, hepatocytes, liver cytosols and nuclear extracts or purified 20S proteasome under conditions that maintain or prevent protein methylation. Reduction of proteasome activity of hepatoma cell and hepatocytes by ethanol or tubercidin was prevented by simultaneous treatment with S-adenosylmethionine (SAM). Moreover, the tubercidin-induced decline in proteasome activity occurred in both nuclear and cytosolic fractions. In vitro exposure of cell cytosolic fractions or highly purified 20S proteasome to low SAM:S-adenosylhomocysteine (SAH) ratios in the buffer also suppressed proteasome function, indicating that one or more methyltransferase(s) may be associated with proteasomal subunits. Immunoblotting a purified 20S rabbit red cell proteasome preparation using methyl lysine-specific antibodies revealed a 25 kDa proteasome subunit that showed positive reactivity with anti-methyl lysine. This reactivity was modified when 20S proteasome was exposed to differential SAM:SAH ratios. We conclude that impaired methylation of proteasome subunits suppressed proteasome activity in liver cells indicating an additional, yet novel mechanism of proteasome activity regulation by ethanol.

  6. Impaired replication stress response in cells from immunodeficiency patients carrying Cernunnos/XLF mutations.

    Directory of Open Access Journals (Sweden)

    Michal Schwartz

    Full Text Available Non-Homologous End Joining (NHEJ is one of the two major pathways of DNA Double Strand Breaks (DSBs repair. Mutations in human NHEJ genes can lead to immunodeficiency due to its role in V(DJ recombination in the immune system. In addition, most patients carrying mutations in NHEJ genes display developmental anomalies which are likely the result of a general defect in repair of endogenously induced DSBs such as those arising during normal DNA replication. Cernunnos/XLF is a recently identified NHEJ gene which is mutated in immunodeficiency with microcephaly patients. Here we aimed to investigate whether Cernunnos/XLF mutations disrupt the ability of patient cells to respond to replication stress conditions. Our results demonstrate that Cernunnos/XLF mutated cells and cells downregulated for Cernunnos/XLF have increased sensitivity to conditions which perturb DNA replication. In addition, under replication stress, these cells exhibit impaired DSB repair and increased accumulation of cells in G2/M. Moreover Cernunnos/XLF mutated and down regulated cells display greater chromosomal instability, particularly at fragile sites, under replication stress conditions. These results provide evidence for the role of Cernunnos/XLF in repair of DSBs and maintenance of genomic stability under replication stress conditions. This is the first study of a NHEJ syndrome showing association with impaired cellular response to replication stress conditions. These findings may be related to the clinical features in these patients which are not due to the V(DJ recombination defect. Additionally, in light of the emerging important role of replication stress in the early stages of cancer development, our findings may provide a mechanism for the role of NHEJ in preventing tumorigenesis.

  7. Knockdown of E2f1 by RNA interference impairs proliferation of rat cells in vitro

    Directory of Open Access Journals (Sweden)

    Luciana dos Reis Vasques

    2010-01-01

    Full Text Available E2F1 plays a key role in cell-cycle regulation in mammals, since its transcription factor activity controls genes required for DNA synthesis and apoptosis. E2F1 deregulation is a common feature among different tumor types and can be a major cause of cell proliferation. Thus, blocking E2F1 expression by RNA interference represents a promising therapeutic approach. In this study, the introduction of specific short hairpin RNAs (shRNAs reduced E2f1 expression by up to 77%, and impaired rat glioma cell proliferation by approximately 70%, as compared to control cells. Furthermore, we investigated the expression of E2f1 target genes, Cyclin A and Cyclin E. Cyclin A was found to be down-regulated, whereas Cyclin E had similar expression to control cells, indicating that gene(s other than E2f1 control its transcription. Other E2f family members, E2f2 and E2f3, which have been classified in the same subgroup of transcriptional activators, were also analyzed. Expression of both E2f2 and E2f3 was similar to control cells, showing no cross-inactivation or up-regulation to compensate for the absence of E2f1. Nevertheless, their expression was insufficient to maintain the initial proliferation potential. Taken together, our results suggest that shE2f1 is a promising therapy to control tumor cell proliferation.

  8. Inhibition of Cell Division and DNA Replication Impair Mouse-Naïve Pluripotency Exit.

    Science.gov (United States)

    Waisman, Ariel; Vazquez Echegaray, Camila; Solari, Claudia; Cosentino, María Soledad; Martyn, Iain; Deglincerti, Alessia; Ozair, Mohammad Zeeshan; Ruzo, Albert; Barañao, Lino; Miriuka, Santiago; Brivanlou, Ali; Guberman, Alejandra

    2017-09-01

    The cell cycle has gained attention as a key determinant for cell fate decisions, but the contribution of DNA replication and mitosis in stem cell differentiation has not been extensively studied. To understand if these processes act as "windows of opportunity" for changes in cell identity, we established synchronized cultures of mouse embryonic stem cells as they exit the ground state of pluripotency. We show that initial transcriptional changes in this transition do not require passage through mitosis and that conversion to primed pluripotency is linked to lineage priming in the G1 phase. Importantly, we demonstrate that impairment of DNA replication severely blocks transcriptional switch to primed pluripotency, even in the absence of p53 activity induced by the DNA damage response. Our data suggest an important role for DNA replication during mouse embryonic stem cell differentiation, which could shed light on why pluripotent cells are only receptive to differentiation signals during G1, that is, before the S phase. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Augmented internalisation of ferroportin to late endosomes impairs iron uptake by enterocyte-like IEC-6 cells.

    Science.gov (United States)

    Oates, Phillip S; Thomas, Carla

    2005-08-01

    Absorption of iron occurs by duodenal enterocytes, involving uptake by the divalent metal transporter-1 (DMT1) and release by ferroportin. Ferroportin responds to the hepatocyte-produced 25-amino-acid-peptide hepcidin-25 by undergoing internalisation to late endosomes that impair iron release. Ferroportin is also expressed on the apical membrane of polarised Caco-2 cells, rat intestinal cells and in IEC-6 cells (an intestinal epithelial cell line). A blocking antibody to ferroportin also impairs the uptake, but not the release, of iron. In this study IEC-6 cells were used to study the mechanism of impairment or recovery from impairment produced by the blocking antibody and the fate of DMT1 and ferroportin. Uptake of 1 muM Fe(II) was studied by adding the antibody from time 0 and after adding or removing the antibody once a steady state had been reached. Surface binding, maximum iron transport rate V(max) and transporter affinity (K(m)) were measured after impairment of iron uptake. Ferroportin and DMT1 distribution were assessed by immunofluorescence microscopy. Antibody-mediated impairment, or recovery from impairment, of Fe(II) uptake occurred within minutes. Impairment was lost when the antibody was combined with the immunizing peptide. DMT1 and ferroportin undergo internalisation to late endosomes and, in the presence of the antibody, augmented internalisation of DMT1 and ferroportin caused swelling of late endosomes. Surface binding of Fe(II) and iron transport V(max) were reduced by 50%, indicating that the antibody removed membrane-bound DMT1. The ferroportin antibody induced rapid turnover of membrane ferroportin and DMT1 and its internalisation to late endosomes, resulting in impaired Fe(II) uptake.

  10. Matrix remodeling between cells and cellular interactions with collagen bundle

    Science.gov (United States)

    Kim, Jihan; Sun, Bo

    When cells are surrounded by complex environment, they continuously probe and interact with it by applying cellular traction forces. As cells apply traction forces, they can sense rigidity of their local environment and remodel the matrix microstructure simultaneously. Previous study shows that single human carcinoma cell (MDA-MB-231) remodeled its surrounding extracellular matrix (ECM) and the matrix remodeling was reversible. In this study we examined the matrix microstructure between cells and cellular interaction between them using quantitative confocal microscopy. The result shows that the matrix microstructure is the most significantly remodeled between cells consisting of aligned, and densified collagen fibers (collagen bundle)., the result shows that collagen bundle is irreversible and significantly change micromechanics of ECM around the bundle. We further examined cellular interaction with collagen bundle by analyzing dynamics of actin and talin formation along with the direction of bundle. Lastly, we analyzed dynamics of cellular protrusion and migrating direction of cells along the bundle.

  11. Regulation of Laminin γ2 Expression by CDX2 in Colonic Epithelial Cells Is Impaired During Active Inflammation

    DEFF Research Database (Denmark)

    Coskun, Mehmet; Soendergaard, Christoffer; Jørgensen, Steffen

    2017-01-01

    and to assess the influence of inflammation. Transcriptional regulation of LAMC2 was examined by reporter gene assays, overexpression, and shRNA-mediated knock-down of CDX2. CDX2-DNA interactions were assessed by chromatin immunoprecipitation on Caco-2 cells without or with TNF-α, as well as in purified colonic......The expression of Caudal-related homeobox transcription factor 2 (CDX2) is impaired by tumor necrosis factor-α (TNF-α)-mediated activation of nuclear factor-κB (NF-κB) in ulcerative colitis (UC). Laminin subunit γ2 (LAMC2) is an epithelial basement membrane protein implicated in cell migration......, proliferation, differentiation, as well as tumor invasion and intestinal inflammation, and its expression is enhanced by TNF-α in a NF-κB-dependent regulation of the recently identified LAMC2 enhancer. The aim was to determine whether CDX2 is involved in the basal regulation of LAMC2 in epithelial cells...

  12. High Fat Diet Inhibits Dendritic Cell and T Cell Response to Allergens but Does Not Impair Inhalational Respiratory Tolerance.

    Directory of Open Access Journals (Sweden)

    Angela Pizzolla

    Full Text Available The incidence of obesity has risen to epidemic proportions in recent decades, most commonly attributed to an increasingly sedentary lifestyle, and a 'western' diet high in fat and low in fibre. Although non-allergic asthma is a well-established co-morbidity of obesity, the influence of obesity on allergic asthma is still under debate. Allergic asthma is thought to result from impaired tolerance to airborne antigens, so-called respiratory tolerance. We sought to investigate whether a diet high in fats affects the development of respiratory tolerance. Mice fed a high fat diet (HFD for 8 weeks showed weight gain, metabolic disease, and alteration in gut microbiota, metabolites and glucose metabolism compared to age-matched mice fed normal chow diet (ND. Respiratory tolerance was induced by repeated intranasal (i.n. administration of ovalbumin (OVA, prior to induction of allergic airway inflammation (AAI by sensitization with OVA in alum i.p. and subsequent i.n. OVA challenge. Surprisingly, respiratory tolerance was induced equally well in HFD and ND mice, as evidenced by decreased lung eosinophilia and serum OVA-specific IgE production. However, in a pilot study, HFD mice showed a tendency for impaired activation of airway dendritic cells and regulatory T cells compared with ND mice after induction of respiratory tolerance. Moreover, the capacity of lymph node cells to produce IL-5 and IL-13 after AAI was drastically diminished in HFD mice compared to ND mice. These results indicate that HFD does not affect the inflammatory or B cell response to an allergen, but inhibits priming of Th2 cells and possibly dendritic cell and regulatory T cell activation.

  13. Characterization of substances that restore impaired cell division of UV-irradiated E. coli B

    International Nuclear Information System (INIS)

    Yoshiyama, Y.; Shimoii, H.; Tamura, G.

    1981-01-01

    Substances which restore impaired cell division in UV-irradiated E. coli B were surveyed among various bacteria. The active substance was found only in several genera of Gram-negative bacteria, i.e., Escherichia, Enterobacter, Salmonella and some species of Pseudomonas. The activity in the dialyzed cell extract of E. coli B/r was observed in the presence of β-NAD and was enhanced by Mg 2+ and Mn 2+ . The active substance was very labile, but the activity was protected by 1 mM dithiothreitol in the process of purification. The activity of a fraction recovered through DEAE-cellulose column chromatography was stimulated by the presence of membrane fraction. Upon treatment with lipid-degrading enzymes and proteases, the division-stimulating activity was lost or reduced. It appears that the inactivation by lipase and phospholipase A2 was due to the formation of lysophospholipids and that a proteinous substance participated in the recovery of impaired cell division of UV-irradiated E. coli B

  14. SPATIAL MEMORY IMPAIRMENT AND HIPPOCAMPAL CELL LOSS INDUCED BY OKADAIC ACID (EXPERIMENTAL STUDY).

    Science.gov (United States)

    Chighladze, M; Dashniani, M; Beselia, G; Kruashvili, L; Naneishvili, T

    2016-01-01

    In the present study, we evaluated and compared effect of intracerebroventricular (ICV) and intrahippocampal bilateral microinjection of okadaic acid (OA) on spatial memory function assessed in one day water maze paradigm and hippocampal structure in rats. Rats were divided in following groups: Control(icv) - rats injected with ICV and aCSF; Control(hipp) - rats injected intrahippocampally with aCSF; OAicv - rats injected with ICV and OA; OAhipp - rats injected intrahippocampally with OA. Nissl staining of hippocampal sections showed that the pyramidal cell loss in OAhipp group is significantly higher than that in the OAicv. The results of behavioral experiments showed that ICV or intrahippocampal bilateral microinjection of OA did not affect learning process and short-term spatial memory but induced impairment in spatial long-term memory assessed in probe test performance 24 h after training. OA-induced spatial memory impairment may be attributed to the hippocampal cell death. Based on these results OA induced memory deficit and hippocampal cell loss in rat may be considered as a potential animal model for preclinical evaluation of antidementic drug activity.

  15. NF-κB activation impairs somatic cell reprogramming in ageing.

    Science.gov (United States)

    Soria-Valles, Clara; Osorio, Fernando G; Gutiérrez-Fernández, Ana; De Los Angeles, Alejandro; Bueno, Clara; Menéndez, Pablo; Martín-Subero, José I; Daley, George Q; Freije, José M P; López-Otín, Carlos

    2015-08-01

    Ageing constitutes a critical impediment to somatic cell reprogramming. We have explored the regulatory mechanisms that constitute age-associated barriers, through derivation of induced pluripotent stem cells (iPSCs) from individuals with premature or physiological ageing. We demonstrate that NF-κB activation blocks the generation of iPSCs in ageing. We also show that NF-κB repression occurs during cell reprogramming towards a pluripotent state. Conversely, ageing-associated NF-κB hyperactivation impairs the generation of iPSCs by eliciting the reprogramming repressor DOT1L, which reinforces senescence signals and downregulates pluripotency genes. Genetic and pharmacological NF-κB inhibitory strategies significantly increase the reprogramming efficiency of fibroblasts from Néstor-Guillermo progeria syndrome and Hutchinson-Gilford progeria syndrome patients, as well as from normal aged donors. Finally, we demonstrate that DOT1L inhibition in vivo extends lifespan and ameliorates the accelerated ageing phenotype of progeroid mice, supporting the interest of studying age-associated molecular impairments to identify targets of rejuvenation strategies.

  16. Cigarette smoke induced autophagy-impairment regulates AMD pathogenesis mechanisms in ARPE-19 cells.

    Directory of Open Access Journals (Sweden)

    Viren Kumar Govindaraju

    Full Text Available Age related macular degeneration (AMD is one of the leading causes of blindness. Genetics, environmental insult, and age-related factors all play a key role in altering proteostasis, the homeostatic process regulating protein synthesis, degradation and processing. These factors also play a role in the pathogenesis of AMD and it has been well established that cigarette smoking (CS initiates AMD pathogenic mechanisms. The primary goal of this study is to elucidate whether CS can induce proteostasis/autophagy-impairment in retinal pigment epithelial (RPE cells. In our preliminary analysis, it was found that cigarette smoke extract (CSE induces accumulation of ubiquitinated proteins in the insoluble protein fraction (p < 0.01, which was subsequently mitigated through cysteamine (p < 0.01 or fisetin (p < 0.05 treatment. Further, it was verified that these CSE induced ubiquitinated proteins accumulated in the peri-nuclear spaces (p<0.05 that were cleared- off with cysteamine (p < 0.05 or fisetin (p < 0.05. Moreover, CSE-induced aggresome-formation (LC3B-GFP and Ub-RFP co-localization and autophagy-flux impairment was significantly (p<0.01 mitigated by cysteamine (p<0.05 or fisetin (p<0.05 treatment, indicating the restoration of CSE-mediated autophagy-impairment. CSE treatment was also found to induce intracellular reactive oxygen species (ROS, p < 0.001 while impacting cell viability (p < 0.001, which was quantified using CMH2DCFDA-dye (ROS and MTS (proliferation or propodium iodide staining (cell viability assays, respectively. Moreover, cysteamine and fisetin treatment ameliorated CS-mediated ROS production (p < 0.05 and diminished cell viability (p < 0.05. Lastly, CSE was found to induce cellular senescence (p < 0.001, which was significantly ameliorated by cysteamine (p < 0.001 or fisetin (p < 0.001. In conclusion, our study indicates that CS induced proteostasis/autophagy-impairment regulates mechanisms associated with AMD pathogenesis. Moreover

  17. Interactive relations of type 2 diabetes and abdominal obesity to cognitive impairment: A cross-sectional study in rural area of Xi'an in China.

    Science.gov (United States)

    Li, Yanbo; Shang, Suhang; Fei, Yulang; Chen, Chen; Jiang, Yu; Dang, Liangjun; Liu, Jie; Ma, Louyan; Wei, Meng; Qu, Qiumin

    2018-01-01

    Type 2 diabetes and obesity, which are frequently comorbid, have been associated with cognitive impairment. We aim to examine the potential modulating effect between obesity and diabetes on cognitive impairment. We recruited 865 adults (aged ≥55years) lived in a village of Xi'an in China from October 2014 to March 2015. All participants underwent biomedical and neuropsychological assessment. Relations of diabetes and abdominal obesity to cognitive impairment were examined in multiple regression models. A total of 155 participants (17.9%) presented with the diagnosis of cognitive impairment. Diabetes or obesity alone wasn't significantly associated with cognitive impairment. Interaction analysis showed a significant interaction between abdominal obesity and diabetes on cognitive impairment. Stratified multivariate analysis revealed that the association between diabetes and cognitive impairment was positive in participants with abdominal obesity (OR 2.436, 95% CI 1.345-4.411, p=0.003, in diabetics with high WC, and OR 2.348, 95% CI 1.373-4.014, p=0.002, in diabetics with high WHR), but negative in those without abdominal obesity. Type 2 diabetes interacts with abdominal obesity to be associated with an increased risk of cognitive impairment by more than two times. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Dietary restriction improves repopulation but impairs lymphoid differentiation capacity of hematopoietic stem cells in early aging

    Science.gov (United States)

    Tang, Duozhuang; Tao, Si; Chen, Zhiyang; Koliesnik, Ievgen Oleksandrovich; Calmes, Philip Gerald; Hoerr, Verena; Han, Bing; Gebert, Nadja; Zörnig, Martin; Löffler, Bettina

    2016-01-01

    Dietary restriction (DR) improves health, delays tissue aging, and elongates survival in flies and worms. However, studies on laboratory mice and nonhuman primates revealed ambiguous effects of DR on lifespan despite improvements in health parameters. In this study, we analyzed consequences of adult-onset DR (24 h to 1 yr) on hematopoietic stem cell (HSC) function. DR ameliorated HSC aging phenotypes, such as the increase in number of HSCs and the skewing toward myeloid-biased HSCs during aging. Furthermore, DR increased HSC quiescence and improved the maintenance of the repopulation capacity of HSCs during aging. In contrast to these beneficial effects, DR strongly impaired HSC differentiation into lymphoid lineages and particularly inhibited the proliferation of lymphoid progenitors, resulting in decreased production of peripheral B lymphocytes and impaired immune function. The study shows that DR-dependent suppression of growth factors and interleukins mediates these divergent effects caused by DR. Supplementation of insulin-like growth factor 1 partially reverted the DR-induced quiescence of HSCs, whereas IL-6/IL-7 substitutions rescued the impairment of B lymphopoiesis exposed to DR. Together, these findings delineate positive and negative effects of long-term DR on HSC functionality involving distinct stress and growth signaling pathways. PMID:26951333

  19. MiADMSA reverses impaired mitochondrial energy metabolism and neuronal apoptotic cell death after arsenic exposure in rats

    Energy Technology Data Exchange (ETDEWEB)

    Dwivedi, Nidhi; Mehta, Ashish; Yadav, Abhishek [Division of Pharmacology and Toxicology, Defence Research and Development Establishment, Gwalior-474 002 (India); Binukumar, B.K.; Gill, Kiran Dip [Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh-160 012 (India); Flora, Swaran J.S., E-mail: sjsflora@hotmail.com [Division of Pharmacology and Toxicology, Defence Research and Development Establishment, Gwalior-474 002 (India)

    2011-11-15

    Arsenicosis, due to contaminated drinking water, is a serious health hazard in terms of morbidity and mortality. Arsenic induced free radicals generated are known to cause cellular apoptosis through mitochondrial driven pathway. In the present study, we investigated the effect of arsenic interactions with various complexes of the electron transport chain and attempted to evaluate if there was any complex preference of arsenic that could trigger apoptosis. We also evaluated if chelation with monoisoamyl dimercaptosuccinic acid (MiADMSA) could reverse these detrimental effects. Our results indicate that arsenic exposure induced free radical generation in rat neuronal cells, which diminished mitochondrial potential and enzyme activities of all the complexes of the electron transport chain. Moreover, these complexes showed differential responses towards arsenic. These early events along with diminished ATP levels could be co-related with the later events of cytosolic migration of cytochrome c, altered bax/bcl{sub 2} ratio, and increased caspase 3 activity. Although MiADMSA could reverse most of these arsenic-induced altered variables to various extents, DNA damage remained unaffected. Our study for the first time demonstrates the differential effect of arsenic on the complexes leading to deficits in bioenergetics leading to apoptosis in rat brain. However, more in depth studies are warranted for better understanding of arsenic interactions with the mitochondria. -- Research highlights: Black-Right-Pointing-Pointer Arsenic impairs mitochondrial energy metabolism leading to neuronal apoptosis. Black-Right-Pointing-Pointer Arsenic differentially affects mitochondrial complexes, I - III and IV being more sensitive than complex II. Black-Right-Pointing-Pointer Arsenic-induced apoptosis initiates through ROS generation or impaired [Ca{sup 2+}]i homeostasis. Black-Right-Pointing-Pointer MiADMSA reverses arsenic toxicity via intracellular arsenic- chelation, antioxidant

  20. Signs of impaired immunoregulation and enhanced effector T-cell responses in the primary antiphospholipid syndrome.

    Science.gov (United States)

    Jakiela, B; Iwaniec, T; Plutecka, H; Celinska-Lowenhoff, M; Dziedzina, S; Musial, J

    2016-04-01

    We investigated whether primary antiphospholipid syndrome (PAPS) is characterized by a deficiency in immunoregulatory pathways, a phenomenon recently implicated in the pathogenesis of autoimmune diseases. Serum levels of immunoregulatory (e.g., IL-10 and TGF-β1) and proinflammatory (e.g., IL-17A) cytokines were measured in PAPS, systemic lupus erythematosus (SLE) with secondary APS (SAPS), or without APS, and in healthy controls (n = 40 in each group). In a subgroup of PAPS patients we also compared phenotype and function (flow cytometry) of regulatory T-cells (Treg) and cytokine production by effector T-cells. Our major finding was decreased levels of TGF-β1 in PAPS and SAPS as compared to SLE without APS and controls. TGF-β1 was the lowest in PAPS patients showing high levels of aPL IgG with significant negative correlation with the titer. SLE patients were characterized by lower serum levels of IL-2 and increased IL-17A, as compared to the other groups. The numbers of circulating Treg cells and their phenotype (e.g., FoxP3 isoforms) were not disturbed in PAPS. However, surface expression of latency associated peptide (binds TGF-β) in activated FoxP3 + cells and in vitro production of TGF-β1 were decreased in PAPS patients with high titers of aPL IgG. Moreover, frequencies of cytokine producing effector T-helper cells (including Th17) were significantly elevated in this group. PAPS patients with high titers of aPL IgG antibodies were characterized by decreased systemic levels of TGF-β1 and its impaired production in vitro, suggesting impaired immunoregulation and enhanced adaptive autoimmune responses leading to the production of aPL antibodies. © The Author(s) 2015.

  1. The Knockout of Secretin in Cerebellar Purkinje Cells Impairs Mouse Motor Coordination and Motor Learning

    Science.gov (United States)

    Zhang, Li; Chung, Sookja Kim; Chow, Billy Kwok Chong

    2014-01-01

    Secretin (SCT) was first considered to be a gut hormone regulating gastrointestinal functions when discovered. Recently, however, central actions of SCT have drawn intense research interest and are supported by the broad distribution of SCT in specific neuronal populations and by in vivo physiological studies regarding its role in water homeostasis and food intake. The direct action of SCT on a central neuron was first discovered in cerebellar Purkinje cells in which SCT from cerebellar Purkinje cells was found to potentiate GABAergic inhibitory transmission from presynaptic basket cells. Because Purkinje neurons have a major role in motor coordination and learning functions, we hypothesize a behavioral modulatory function for SCT. In this study, we successfully generated a mouse model in which the SCT gene was deleted specifically in Purkinje cells. This mouse line was tested together with SCT knockout and SCT receptor knockout mice in a full battery of behavioral tasks. We found that the knockout of SCT in Purkinje neurons did not affect general motor ability or the anxiety level in open field tests. However, knockout mice did exhibit impairments in neuromuscular strength, motor coordination, and motor learning abilities, as shown by wire hanging, vertical climbing, and rotarod tests. In addition, SCT knockout in Purkinje cells possibly led to the delayed development of motor neurons, as supported by the later occurrence of key neural reflexes. In summary, our data suggest a role in motor coordination and motor learning for SCT expressed in cerebellar Purkinje cells. PMID:24356714

  2. CTC-Endothelial Cell Interactions during Metastasis

    Science.gov (United States)

    2014-06-01

    equipped with a Zeiss AxioCam MRm camera . A syringe pump (KDS 230, IITC Life Science, Woodland Hills, CA) was used to control the shear stress of the...HUVECs in 2 ml growth medium at 180 x g for 5 min. Measure the cell concentration using a neubauer hemocytometer and prepare 107 HUVEC cells/100 µl...selectin (R&D Systems, Minneapolis, MN). Coated microtubes were mounted on an inverted microscope equipped with a Zeiss AxioCam MRm camera . A syringe pump

  3. Blocking CD147 induces cell death in cancer cells through impairment of glycolytic energy metabolism

    International Nuclear Information System (INIS)

    Baba, Miyako; Inoue, Masahiro; Itoh, Kazuyuki; Nishizawa, Yasuko

    2008-01-01

    CD147 is a multifunctional transmembrane protein and promotes cancer progression. We found that the anti-human CD147 mouse monoclonal antibody MEM-M6/1 strongly induces necrosis-like cell death in LoVo, HT-29, WiDr, and SW620 colon cancer cells and A2058 melanoma cells, but not in WI-38 and TIG-113 normal fibroblasts. Silencing or overexpression of CD147 in LoVo cells enhanced or decreased the MEM-M6/1 induced cell death, respectively. CD147 is known to form complex with proton-linked monocarboxylate transporters (MCTs), which is critical for lactate transport and intracellular pH (pHi) homeostasis. In LoVo cells, CD147 and MCT-1 co-localized on the cell surface, and MEM-M6/1 inhibited the association of these molecules. MEM-M6/1 inhibited lactate uptake, lactate release, and reduced pHi. Further, the induction of acidification was parallel to the decrease of the glycolytic flux and intracellular ATP levels. These effects were not found in the normal fibroblasts. As cancer cells depend on glycolysis for their energy production, CD147 inhibition might induce cell death specific to cancer cells

  4. Interaction of Proteins Identified in Human Thyroid Cells

    Science.gov (United States)

    Pietsch, Jessica; Riwaldt, Stefan; Bauer, Johann; Sickmann, Albert; Weber, Gerhard; Grosse, Jirka; Infanger, Manfred; Eilles, Christoph; Grimm, Daniela

    2013-01-01

    Influence of gravity forces on the regulation of protein expression by healthy and malignant thyroid cells was studied with the aim to identify protein interactions. Western blot analyses of a limited number of proteins suggested a time-dependent regulation of protein expression by simulated microgravity. After applying free flow isoelectric focusing and mass spectrometry to search for differently expressed proteins by thyroid cells exposed to simulated microgravity for three days, a considerable number of candidates for gravi-sensitive proteins were detected. In order to show how proteins sensitive to microgravity could directly influence other proteins, we investigated all polypeptide chains identified with Mascot scores above 100, looking for groups of interacting proteins. Hence, UniProtKB entry numbers of all detected proteins were entered into the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and processed. The program indicated that we had detected various groups of interacting proteins in each of the three cell lines studied. The major groups of interacting proteins play a role in pathways of carbohydrate and protein metabolism, regulation of cell growth and cell membrane structuring. Analyzing these groups, networks of interaction could be established which show how a punctual influence of simulated microgravity may propagate via various members of interaction chains. PMID:23303277

  5. Interaction of Proteins Identified in Human Thyroid Cells

    Directory of Open Access Journals (Sweden)

    Jessica Pietsch

    2013-01-01

    Full Text Available Influence of gravity forces on the regulation of protein expression by healthy and malignant thyroid cells was studied with the aim to identify protein interactions. Western blot analyses of a limited number of proteins suggested a time-dependent regulation of protein expression by simulated microgravity. After applying free flow isoelectric focusing and mass spectrometry to search for differently expressed proteins by thyroid cells exposed to simulated microgravity for three days, a considerable number of candidates for gravi-sensitive proteins were detected. In order to show how proteins sensitive to microgravity could directly influence other proteins, we investigated all polypeptide chains identified with Mascot scores above 100, looking for groups of interacting proteins. Hence, UniProtKB entry numbers of all detected proteins were entered into the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING and processed. The program indicated that we had detected various groups of interacting proteins in each of the three cell lines studied. The major groups of interacting proteins play a role in pathways of carbohydrate and protein metabolism, regulation of cell growth and cell membrane structuring. Analyzing these groups, networks of interaction could be established which show how a punctual influence of simulated microgravity may propagate via various members of interaction chains.

  6. Dual inhibition of mTORC1 and mTORC2 perturbs cytoskeletal organization and impairs endothelial cell elongation.

    Science.gov (United States)

    Tsuji-Tamura, Kiyomi; Ogawa, Minetaro

    2018-02-26

    Elongation of endothelial cells is an important process in vascular formation and is expected to be a therapeutic target for inhibiting tumor angiogenesis. We have previously demonstrated that inhibition of mTORC1 and mTORC2 impaired endothelial cell elongation, although the mechanism has not been well defined. In this study, we analyzed the effects of the mTORC1-specific inhibitor everolimus and the mTORC1/mTORC2 dual inhibitor KU0063794 on the cytoskeletal organization and morphology of endothelial cell lines. While both inhibitors equally inhibited cell proliferation, KU0063794 specifically caused abnormal accumulation of F-actin and disordered distribution of microtubules, thereby markedly impairing endothelial cell elongation and tube formation. The effects of KU0063794 were phenocopied by paclitaxel treatment, suggesting that KU0063794 might impair endothelial cell morphology through over-stabilization of microtubules. Although mTORC1 is a key signaling molecule in cell proliferation and has been considered a target for preventing angiogenesis, mTORC1 inhibitors have not been sufficient to suppress angiogenesis. Our results suggest that mTORC1/mTORC2 dual inhibition is more effective for anti-angiogenic therapy, as it impairs not only endothelial cell proliferation, but also endothelial cell elongation. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Targeted inhibition of the phosphoinositide 3-kinase impairs cell proliferation, survival, and invasion in colon cancer.

    Science.gov (United States)

    Yang, Fei; Gao, Jun-Yi; Chen, Hua; Du, Zhen-Hua; Zhang, Xue-Qun; Gao, Wei

    2017-01-01

    Colon cancer is the third most common cancer in the world, and its metastasis and drug resistance are challenging for its effective treatment. The PI3K/Akt/mTOR pathway plays a crucial role in the pathogenesis of colon cancer. The aim of this study was to investigate the targeting of PI3K in colon cancer cells HT-29 and HCT-116 in vitro. In HT-29 and HCT-116 cells, BEZ235, a dual inhibitor of PI3K/mTOR, and shRNAtarget to PI3KCA were used to inhibit PI3K/Akt/mTOR pathway. The inhibition efficiency of PI3K/Akt/mTOR pathway was detected by RT-PCR and Western blot. Cell proliferation, migration, invasion, and apoptosis were evaluated by Cell Counting Kit-8, Transwell, and flow cytometry assays. The expression of apoptosis-related proteins (cleavage caspase 3, Bcl-2, Bax, and Bim) were also detected. We found that in HT-29 and HCT-116 cells, the treatment of BEZ235 (1 μM) and PI3KCA knockdown inhibited the activation of PI3K/Akt/mTOR pathway and significantly suppressed cell proliferation, migration, and invasion of HT-29 and HCT-116 cells. In addition, we confirmed that knockdown of BEZ235 and PI3KCA induced cell apoptosis through the upregulated levels of cleavage caspase 3 and Bax and downregulated expression of Bcl-2 and Bim. Our results indicated that targeted inhibition of the PI3K/Akt/mTOR pathway impaired cell proliferation, survival, and invasion in human colon cancer.

  8. Neonatal erythropoietin mitigates impaired gait, social interaction and diffusion tensor imaging abnormalities in a rat model of prenatal brain injury.

    Science.gov (United States)

    Robinson, Shenandoah; Corbett, Christopher J; Winer, Jesse L; Chan, Lindsay A S; Maxwell, Jessie R; Anstine, Christopher V; Yellowhair, Tracylyn R; Andrews, Nicholas A; Yang, Yirong; Sillerud, Laurel O; Jantzie, Lauren L

    2018-04-01

    Children who are born preterm are at risk for encephalopathy of prematurity, a leading cause of cerebral palsy, cognitive delay and behavioral disorders. Current interventions are limited and none have been shown to reverse cognitive and behavioral impairments, a primary determinant of poor quality of life for these children. Moreover, the mechanisms of perinatal brain injury that result in functional deficits and imaging abnormalities in the mature brain are poorly defined, limiting the potential to target interventions to those who may benefit most. To determine whether impairments are reversible after a prenatal insult, we investigated a spectrum of functional deficits and diffusion tensor imaging (DTI) abnormalities in young adult animals. We hypothesized that prenatal transient systemic hypoxia-ischemia (TSHI) would induce multiple functional deficits concomitant with reduced microstructural white and gray matter integrity, and tested whether these abnormalities could be ameliorated using postnatal erythropoietin (EPO), an emerging neurorestorative intervention. On embryonic day 18 uterine arteries were transiently occluded for 60min via laparotomy. Shams underwent anesthesia and laparotomy for 60min. Pups were born and TSHI pups were randomized to receive EPO or vehicle via intraperitoneal injection on postnatal days 1 to 5. Gait, social interaction, olfaction and open field testing was performed from postnatal day 25-35 before brains underwent ex vivo DTI to measure fractional anisotropy, axial diffusivity and radial diffusivity. Prenatal TSHI injury causes hyperactivity, impaired gait and poor social interaction in young adult rats that mimic the spectrum of deficits observed in children born preterm. Collectively, these data show for the first time in a model of encephalopathy of prematurity that postnatal EPO treatment mitigates impairments in social interaction, in addition to gait deficits. EPO also normalizes TSHI-induced microstructural abnormalities

  9. Palmitate-induced inflammatory pathways in human adipose microvascular endothelial cells promote monocyte adhesion and impair insulin transcytosis.

    Science.gov (United States)

    Pillon, Nicolas J; Azizi, Paymon M; Li, Yujin E; Liu, Jun; Wang, Changsen; Chan, Kenny L; Hopperton, Kathryn E; Bazinet, Richard P; Heit, Bryan; Bilan, Philip J; Lee, Warren L; Klip, Amira

    2015-07-01

    Obesity is associated with inflammation and immune cell recruitment to adipose tissue, muscle and intima of atherosclerotic blood vessels. Obesity and hyperlipidemia are also associated with tissue insulin resistance and can compromise insulin delivery to muscle. The muscle/fat microvascular endothelium mediates insulin delivery and facilitates monocyte transmigration, yet its contribution to the consequences of hyperlipidemia is poorly understood. Using primary endothelial cells from human adipose tissue microvasculature (HAMEC), we investigated the effects of physiological levels of fatty acids on endothelial inflammation and function. Expression of cytokines and adhesion molecules was measured by RT-qPCR. Signaling pathways were evaluated by pharmacological manipulation and immunoblotting. Surface expression of adhesion molecules was determined by immunohistochemistry. THP1 monocyte interaction with HAMEC was measured by cell adhesion and migration across transwells. Insulin transcytosis was measured by total internal reflection fluorescence microscopy. Palmitate, but not palmitoleate, elevated the expression of IL-6, IL-8, TLR2 (Toll-like receptor 2), and intercellular adhesion molecule 1 (ICAM-1). HAMEC had markedly low fatty acid uptake and oxidation, and CD36 inhibition did not reverse the palmitate-induced expression of adhesion molecules, suggesting that inflammation did not arise from palmitate uptake/metabolism. Instead, inhibition of TLR4 to NF-κB signaling blunted palmitate-induced ICAM-1 expression. Importantly, palmitate-induced surface expression of ICAM-1 promoted monocyte binding and transmigration. Conversely, palmitate reduced insulin transcytosis, an effect reversed by TLR4 inhibition. In summary, palmitate activates inflammatory pathways in primary microvascular endothelial cells, impairing insulin transport and increasing monocyte transmigration. This behavior may contribute in vivo to reduced tissue insulin action and enhanced tissue

  10. Depletion of NAD pool contributes to impairment of endothelial progenitor cell mobilization in diabetes.

    Science.gov (United States)

    Wang, Pei; Yang, Xi; Zhang, Zheng; Song, Jie; Guan, Yun-Feng; Zou, Da-Jin; Miao, Chao-Yu

    2016-06-01

    The impaired mobilization of endothelial progenitor cells (EPCs) from bone marrow (BM) critically contributes to the diabetes-associated vascular complications. Here, we investigated the relationship between the nicotinamide phosphoribosyltransferase (NAMPT)-controlled nicotinamide adenine dinucleotide (NAD) metabolism and the impaired mobilization of BM-derived EPCs in diabetic condition. The NAMPT-NAD pool in BM and BM-derived EPCs in wild-type (WT) and diabetic db/db mice was determined. Nicotinamide, a natural substrate for NAD biosynthesis, was administrated for 2weeks in db/db mice to examine the influence of enhancing NAD pool on BM and blood EPCs number. The modulations of stromal cell-derived factor-1α (SDF-1α) and endothelial nitric oxide synthase (eNOS) protein in BM were measured using immunoblotting. The EPCs intracellular NAMPT level and NAD concentration, as well as the blood EPCs number, were compared between 9 healthy people and 16 patients with type 2 diabetes mellitus (T2DM). The T2DM patients were treated with nicotinamide for two weeks and then the blood EPCs number was determined. Moreover, the association between blood EPCs numbers and EPCs intracellular NAD(+)/NAMPT protein levels in 21 healthy individuals was determined. We found that NAD concentration and NAMPT expression in BM and BM-derived EPCs of db/db mice were significantly lower than those in WT mice BM. Enhancing NAD pool not only increased the EPCs intracellular NAD concentration and blood EPCs number, but also improved post-ischemic wound healing and blood reperfusion in db/db mice with hind-limb ischemia model. Enhancing NAD pool rescued the impaired modulations of stromal cell-derived factor-1α (SDF-1α) and endothelial nitric oxide synthase (eNOS) protein levels in db/db mice BM upon hind-limb ischemia. In addition, enhancing NAD pool significantly inhibited PARP and caspase-3 activates in db/db mice BM. The intracellular NAMPT-NAD pool was positively associated with blood

  11. Visualization and targeted disruption of protein interactions in living cells

    Science.gov (United States)

    Herce, Henry D.; Deng, Wen; Helma, Jonas; Leonhardt, Heinrich; Cardoso, M. Cristina

    2013-01-01

    Protein–protein interactions are the basis of all processes in living cells, but most studies of these interactions rely on biochemical in vitro assays. Here we present a simple and versatile fluorescent-three-hybrid (F3H) strategy to visualize and target protein–protein interactions. A high-affinity nanobody anchors a GFP-fusion protein of interest at a defined cellular structure and the enrichment of red-labelled interacting proteins is measured at these sites. With this approach, we visualize the p53–HDM2 interaction in living cells and directly monitor the disruption of this interaction by Nutlin 3, a drug developed to boost p53 activity in cancer therapy. We further use this approach to develop a cell-permeable vector that releases a highly specific peptide disrupting the p53 and HDM2 interaction. The availability of multiple anchor sites and the simple optical readout of this nanobody-based capture assay enable systematic and versatile analyses of protein–protein interactions in practically any cell type and species. PMID:24154492

  12. Oxidative stress induces caveolin 1 degradation and impairs caveolae functions in skeletal muscle cells.

    Directory of Open Access Journals (Sweden)

    Alexis Mougeolle

    Full Text Available Increased level of oxidative stress, a major actor of cellular aging, impairs the regenerative capacity of skeletal muscle and leads to the reduction in the number and size of muscle fibers causing sarcopenia. Caveolin 1 is the major component of caveolae, small membrane invaginations involved in signaling and endocytic trafficking. Their role has recently expanded to mechanosensing and to the regulation of oxidative stress-induced pathways. Here, we increased the amount of reactive oxidative species in myoblasts by addition of hydrogen peroxide (H2O2 at non-toxic concentrations. The expression level of caveolin 1 was significantly decreased as early as 10 min after 500 μM H2O2 treatment. This reduction was not observed in the presence of a proteasome inhibitor, suggesting that caveolin 1 was rapidly degraded by the proteasome. In spite of caveolin 1 decrease, caveolae were still able to assemble at the plasma membrane. Their functions however were significantly perturbed by oxidative stress. Endocytosis of a ceramide analog monitored by flow cytometry was significantly diminished after H2O2 treatment, indicating that oxidative stress impaired its selective internalization via caveolae. The contribution of caveolae to the plasma membrane reservoir has been monitored after osmotic cell swelling. H2O2 treatment increased membrane fragility revealing that treated cells were more sensitive to an acute mechanical stress. Altogether, our results indicate that H2O2 decreased caveolin 1 expression and impaired caveolae functions. These data give new insights on age-related deficiencies in skeletal muscle.

  13. Apoptosis of Endothelial Cells by 13-HPODE Contributes to Impairment of Endothelial Barrier Integrity

    Directory of Open Access Journals (Sweden)

    Valerie E. Ryman

    2016-01-01

    Full Text Available Inflammation is an essential host response during bacterial infections such as bovine mastitis. Endothelial cells are critical for an appropriate inflammatory response and loss of vascular barrier integrity is implicated in the pathogenesis of Streptococcus uberis-induced mastitis. Previous studies suggested that accumulation of linoleic acid (LA oxygenation products derived from 15-lipoxygenase-1 (15-LOX-1 metabolism could regulate vascular functions. The initial LA derivative from the 15-LOX-1 pathway, 13-hydroperoxyoctadecadienoic acid (HPODE, can induce endothelial death, whereas the reduced hydroxyl product, 13-hydroxyoctadecadienoic acid (HODE, is abundantly produced during vascular activation. However, the relative contribution of specific LA-derived metabolites on impairment of mammary endothelial integrity is unknown. Our hypothesis was that S. uberis-induced LA-derived 15-LOX-1 oxygenation products impair mammary endothelial barrier integrity by apoptosis. Exposure of bovine mammary endothelial cells (BMEC to S. uberis did not increase 15-LOX-1 LA metabolism. However, S. uberis challenge of bovine monocytes demonstrated that monocytes may be a significant source of both 13-HPODE and 13-HODE during mastitis. Exposure of BMEC to 13-HPODE, but not 13-HODE, significantly reduced endothelial barrier integrity and increased apoptosis. Changing oxidant status by coexposure to an antioxidant during 13-HPODE treatment prevented adverse effects of 13-HPODE, including amelioration of apoptosis. A better understanding of how the oxidant status of the vascular microenvironment impacts endothelial barrier properties could lead to more efficacious treatments for S. uberis mastitis.

  14. Increased antigen presentation but impaired T cells priming after upregulation of interferon-beta induced by lipopolysaccharides is mediated by upregulation of B7H1 and GITRL.

    Directory of Open Access Journals (Sweden)

    Fang Wang

    Full Text Available Dendritic cells are able to present Ag-derived peptides on MHC class I and II molecules and induce T cells priming. Lipopolysaccharides (LPS, an activator of Toll-like 4 receptor (TLR4 signaling, has been demonstrated to facilitate Ag-presentation, up-regulate surface molecules expression but impair T cells priming. In this study, we investigated the effect of LPS on nicotine-enhanced DCs-dependent T cells priming and the mechanisms of LPS orchestrating the immunosuppressive program. We could demonstrate that the treatment with LPS resulted in increased surface molecules expression, enhanced Ag-presentation, up-regulated release of TGF-beta, TNF-alpha, IL-6, and IFN-beta. Concomititantly, the upregulation of IFN-beta in DCs induces the up-regulation of coinhibitory molecules B7H1 and GITRL, which cause an impaired activation of naïve Ag-specific T cells and the induction of T cell tolerance by enhancing B7H1-PD-1 interactions and promoting GITRL-GITL facilitated Treg generation, respectively. These data provide a mechanistic basis for the immunomodulatory action of IFN-beta which might open new possibilities in the development of therapeutic approaches aimed at the control of excessive immune response and persistent infection.

  15. Nanomaterials modulate stem cell differentiation: biological interaction and underlying mechanisms.

    Science.gov (United States)

    Wei, Min; Li, Song; Le, Weidong

    2017-10-25

    Stem cells are unspecialized cells that have the potential for self-renewal and differentiation into more specialized cell types. The chemical and physical properties of surrounding microenvironment contribute to the growth and differentiation of stem cells and consequently play crucial roles in the regulation of stem cells' fate. Nanomaterials hold great promise in biological and biomedical fields owing to their unique properties, such as controllable particle size, facile synthesis, large surface-to-volume ratio, tunable surface chemistry, and biocompatibility. Over the recent years, accumulating evidence has shown that nanomaterials can facilitate stem cell proliferation and differentiation, and great effort is undertaken to explore their possible modulating manners and mechanisms on stem cell differentiation. In present review, we summarize recent progress in the regulating potential of various nanomaterials on stem cell differentiation and discuss the possible cell uptake, biological interaction and underlying mechanisms.

  16. Suppression of Glut1 and Glucose Metabolism by Decreased Akt/mTORC1 Signaling Drives T Cell Impairment in B Cell Leukemia

    NARCIS (Netherlands)

    Siska, Peter J.; van der Windt, Gerritje J. W.; Kishton, Rigel J.; Cohen, Sivan; Eisner, William; MacIver, Nancie J.; Kater, Arnon P.; Weinberg, J. Brice; Rathmell, Jeffrey C.

    2016-01-01

    Leukemia can promote T cell dysfunction and exhaustion that contributes to increased susceptibility to infection and mortality. The treatment-independent mechanisms that mediate leukemia-associated T cell impairments are poorly understood, but metabolism tightly regulates T cell function and may

  17. Cerebral organoids derived from Sandhoff disease-induced pluripotent stem cells exhibit impaired neurodifferentiation.

    Science.gov (United States)

    Allende, Maria L; Cook, Emily K; Larman, Bridget C; Nugent, Adrienne; Brady, Jacqueline M; Golebiowski, Diane; Sena-Esteves, Miguel; Tifft, Cynthia J; Proia, Richard L

    2018-03-01

    Sandhoff disease, one of the GM2 gangliosidoses, is a lysosomal storage disorder characterized by the absence of β-hexosaminidase A and B activity and the concomitant lysosomal accumulation of its substrate, GM2 ganglioside. It features catastrophic neurodegeneration and death in early childhood. How the lysosomal accumulation of ganglioside might affect the early development of the nervous system is not understood. Recently, cerebral organoids derived from induced pluripotent stem (iPS) cells have illuminated early developmental events altered by disease processes. To develop an early neurodevelopmental model of Sandhoff disease, we first generated iPS cells from the fibroblasts of an infantile Sandhoff disease patient, then corrected one of the mutant HEXB alleles in those iPS cells using CRISPR/Cas9 genome-editing technology, thereby creating isogenic controls. Next, we used the parental Sandhoff disease iPS cells and isogenic HEXB -corrected iPS cell clones to generate cerebral organoids that modeled the first trimester of neurodevelopment. The Sandhoff disease organoids, but not the HEXB -corrected organoids, accumulated GM2 ganglioside and exhibited increased size and cellular proliferation compared with the HEXB -corrected organoids. Whole-transcriptome analysis demonstrated that development was impaired in the Sandhoff disease organoids, suggesting that alterations in neuronal differentiation may occur during early development in the GM2 gangliosidoses.

  18. Severe Malaria Infections Impair Germinal Center Responses by Inhibiting T Follicular Helper Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Victoria Ryg-Cornejo

    2016-01-01

    Full Text Available Naturally acquired immunity to malaria develops only after years of repeated exposure to Plasmodium parasites. Despite the key role antibodies play in protection, the cellular processes underlying the slow acquisition of immunity remain unknown. Using mouse models, we show that severe malaria infection inhibits the establishment of germinal centers (GCs in the spleen. We demonstrate that infection induces high frequencies of T follicular helper (Tfh cell precursors but results in impaired Tfh cell differentiation. Despite high expression of Bcl-6 and IL-21, precursor Tfh cells induced during infection displayed low levels of PD-1 and CXCR5 and co-expressed Th1-associated molecules such as T-bet and CXCR3. Blockade of the inflammatory cytokines TNF and IFN-γ or T-bet deletion restored Tfh cell differentiation and GC responses to infection. Thus, this study demonstrates that the same pro-inflammatory mediators that drive severe malaria pathology have detrimental effects on the induction of protective B cell responses.

  19. Transplantation of mesenchymal stem cells overexpressing IL10 attenuates cardiac impairments in rats with myocardial infarction.

    Science.gov (United States)

    Meng, Xin; Li, Jianping; Yu, Ming; Yang, Jian; Zheng, Minjuan; Zhang, Jinzhou; Sun, Chao; Liang, Hongliang; Liu, Liwen

    2018-01-01

    Mesenchymal stem cell (MSC) has been well known to exert therapeutic potential for patients with myocardial infarction (MI). In addition, interleukin-10 (IL10) could attenuate MI through suppressing inflammation. Thus, the combination of MSC implantation with IL10 delivery may extend health benefits to ameliorate cardiac injury after MI. Here we established overexpression of IL10 in bone marrow-derived MSC through adenoviral transduction. Cell viability, apoptosis, and IL10 secretion under ischemic challenge in vitro were examined. In addition, MSC was transplanted into the injured hearts in a rat model of MI. Four weeks after the MI induction, MI, cardiac functions, apoptotic cells, and inflammation cytokines were assessed. In response to in vitro oxygen-glucose deprivation (OGD), IL10 overexpression in MSC (Ad.IL10-MSC) enhanced cell viability, decreased apoptosis, and increased IL10 secretion. Consistently, the implantation of Ad.IL10-MSCs into MI animals resulted in more reductions in myocardial infarct size, cardiac impairment, and cell apoptosis, compared to the individual treatments of either MSC or IL10 administration. Moreover, the attenuation of both systemic and local inflammations was most prominent for Ad.IL10-MSC treatment. IL10 overexpression and MSC may exert a synergistic anti-inflammatory effect to alleviate cardiac injury after MI. © 2017 Wiley Periodicals, Inc.

  20. Impaired neuronal maturation of hippocampal neural progenitor cells in mice lacking CRAF.

    Science.gov (United States)

    Pfeiffer, Verena; Götz, Rudolf; Camarero, Guadelupe; Heinsen, Helmut; Blum, Robert; Rapp, Ulf Rüdiger

    2018-01-01

    RAF kinases are major constituents of the mitogen activated signaling pathway, regulating cell proliferation, differentiation and cell survival of many cell types, including neurons. In mammals, the family of RAF proteins consists of three members, ARAF, BRAF, and CRAF. Ablation of CRAF kinase in inbred mouse strains causes major developmental defects during fetal growth and embryonic or perinatal lethality. Heterozygous germline mutations in CRAF result in Noonan syndrome, which is characterized by neurocognitive impairment that may involve hippocampal physiology. The role of CRAF signaling during hippocampal development and generation of new postnatal hippocampal granule neurons has not been examined and may provide novel insight into the cause of hippocampal dysfunction in Noonan syndrome. In this study, by crossing CRAF-deficiency to CD-1 outbred mice, a CRAF mouse model was established which enabled us to investigate the interplay of neural progenitor proliferation and postmitotic differentiation during adult neurogenesis in the hippocampus. Albeit the general morphology of the hippocampus was unchanged, CRAF-deficient mice displayed smaller granule cell layer (GCL) volume at postnatal day 30 (P30). In CRAF-deficient mice a substantial number of abnormal, chromophilic, fast dividing cells were found in the subgranular zone (SGZ) and hilus of the dentate gyrus (DG), indicating that CRAF signaling contributes to hippocampal neural progenitor proliferation. CRAF-deficient neural progenitor cells showed an increased cell death rate and reduced neuronal maturation. These results indicate that CRAF function affects postmitotic neural cell differentiation and points to a critical role of CRAF-dependent growth factor signaling pathway in the postmitotic development of adult-born neurons.

  1. Stem cells rejuvenate radiation-impaired vasculogenesis in murine distraction osteogenesis.

    Science.gov (United States)

    Deshpande, Sagar S; Gallagher, Kathleen K; Donneys, Alexis; Nelson, Noah S; Guys, Nicholas P; Felice, Peter A; Page, Erin E; Sun, Hongli; Krebsbach, Paul H; Buchman, Steven R

    2015-03-01

    Radiotherapy is known to be detrimental to bone and soft-tissue repair. Bone marrow stromal cells have been shown to enhance bone regeneration during distraction osteogenesis following radiation therapy. The authors posit that transplanted bone marrow stromal cells will significantly augment the mandibular vascularity devastated by radiation therapy. Nineteen male Lewis rats were split randomly into three groups: distraction osteogenesis only (n = 5), radiation therapy plus distraction osteogenesis (n = 7), and radiation therapy plus distraction osteogenesis with intraoperative placement of 2 million bone marrow stromal cells (n = 7). A mandibular osteotomy was performed, and an external fixator device was installed. From postoperative days 4 through 12, rats underwent a gradual 5.1-mm distraction followed by a 28-day consolidation period. On postoperative day 40, Microfil was perfused into the vasculature and imaging commenced. Vascular radiomorphometric values were calculated for regions of interest. An analysis of variance with post hoc Tukey or Games-Howell tests was used, dependent on data homogeneity. Stereologic analysis indicated significant remediation in vasculature in the bone marrow stromal cell group compared with the radiation therapy/distraction osteogenesis group. Each of five metrics idicated significant improvements from radiation therapy/distraction osteogenesis to the bone marrow stromal cell group, with no difference between the bone marrow stromal cell group and the distraction osteogenesis group. Bone marrow stromal cells used together with distraction osteogenesis can rejuvenate radiation-impaired vasculogenesis in the mandible, reversing radiation therapy-induced isotropy and creating a robust vascular network. Bone marrow stromal cells may offer clinicians an alternative reconstructive modality that could improve the lifestyle of patients with hypovascular bone.

  2. Language and Social Factors in the Use of Cell Phone Technology by Adolescents with and without Specific Language Impairment (SLI)

    Science.gov (United States)

    Conti-Ramsden, Gina; Durkin, Kevin; Simkin, Zoe

    2010-01-01

    Purpose: This study aimed to compare cell phone use (both oral and text-based) by adolescents with and without specific language impairment (SLI) and examine the extent to which language and social factors affect frequency of use. Method: Both interview and diary methods were used to compare oral and text-based communication using cell phones by…

  3. Human immunodeficiencies related to APC/T cell interaction

    Directory of Open Access Journals (Sweden)

    Marinos eKallikourdis

    2015-08-01

    Full Text Available The primary event for initiating adaptive immune responses is the encounter between T lymphocytes and antigen presenting cells (APC in the T cell area of secondary lymphoid organs and the formation of highly organized inter-cellular junctions referred to as the immune synapses. In vivo live-cell imaging of APC-T cell interactions combined to functional studies unveiled that T cell fate is dictated, in large part, by the stability of the initial contact. Immune cell interaction is equally important during delivery of T cell help to B cells and for the killing of target cells by cytotoxic T cells and NK cells. The critical role of contact dynamics and synapse stability on the immune response is well illustrated by human immune deficiencies in which disease pathogenesis is linked to altered adhesion or defective cross-talk between the synaptic partners. Here we will discuss in details the mechanisms of defective APC-T cell communications in Wiskott-Aldrich syndrome (WAS and in warts, hypogammaglobulinemia, infections, myelokathexis syndrome (WHIM. In addition, we will summarize the evidences pointing to a compromised conjugate formation in WIP deficiency, DOCK8 deficiency and X-linked lymphoproliferative syndrome.

  4. Computed tomography of renal cell carcinoma in patients with terminal renal impairment

    International Nuclear Information System (INIS)

    Ferda, Jiri; Hora, Milan; Hes, Ondrej; Reischig, Tomas; Kreuzberg, Boris; Mirka, Hynek; Ferdova, Eva; Ohlidalova, Kristyna; Baxa, Jan; Urge, Tomas

    2007-01-01

    Purpose: An increased incidence of renal tumors has been observed in patients with end-stage-renal-disease (ESRD). The very strong association with acquired renal cystic disease (ACRD) and increased incidence of the renal tumors (conventional renal cell carcinoma (CRCC), papillary renal cell carcinoma (PRCC) or papillary renal cell adenoma (PRCA)) was reported. This study discusses the role of computed tomography (CT) in detecting renal tumors in patients with renal impairment: pre-dialysis, those receiving dialysis or with renal allograft transplants. Materials and methods: Ten patients (nine male, one female) with renal cell tumors were enrolled into a retrospective study; two were new dialysis patients, three on long-term dialysis, and five were renal transplant recipients with history of dialysis. All patients underwent helical CT, a total of 11 procedures were performed. Sixteen-row detector system was used five times, and a 64-row detector system for the six examinations. All patients underwent nephrectomy of kidney with suspected tumor, 15 nephrectomies were performed, and 1 kidney was assessed during autopsy. CT findings were compared with macroscopic and microscopic assessments of the kidney specimen in 16 cases. Results: Very advanced renal parenchyma atrophy with small cysts corresponding to ESRD was found in nine patients, chronic pyelonephritis in remained one. A spontaneously ruptured tumor was detected incidentally in one case, patient died 2 years later. In the present study, 6.25% (1/16) were multiple PRCA, 12.5% (2/16) were solitary PRCC, 12.5% tumors (2/16) were solitary conventional renal cell carcinomas (CRCC's), 12.5% tumors (2/16) were multiple conventional renal cell carcinomas (CRCC's), 25% (4/16) were CRCC's combined with multiple papillary renal cell carcinomas with adenomas (PRCC's and PRCA's), and 25% (4/16) of the tumors were multiple PRCC's combined with PRCA's without coexisting CRCC's. Bilateral renal tumors were found in our study

  5. A novel CD44-binding peptide from the pro-matrix metalloproteinase-9 hemopexin domain impairs adhesion and migration of chronic lymphocytic leukemia (CLL) cells.

    Science.gov (United States)

    Ugarte-Berzal, Estefanía; Bailón, Elvira; Amigo-Jiménez, Irene; Albar, Juan Pablo; García-Marco, José A; García-Pardo, Angeles

    2014-05-30

    (pro)MMP-9 binds to CLL cells through the PEX9 domain and contributes to CLL progression. To biochemically characterize this interaction and identify potential therapeutic targets, we prepared GST-PEX9 forms containing structural blades B1B2 or B3B4. We recently described a sequence in blade B4 (P3 sequence) that bound α4β1 integrin and partially impaired cell adhesion and migration. We have now studied the possible contribution of the B1B2 region to cell interaction with PEX9. CLL cells bound to GST-B1B2 and CD44 was the primary receptor. GST-B1B2 inhibited CLL cell migration as effectively as GST-B3B4. Overlapping synthetic peptides spanning the B1B2 region identified the sequence FDAIAEIGNQLYLFKDGKYW, present in B1 and contained in peptide P6, as the most effective site. P6 inhibited cell adhesion to PEX9 in a dose-dependent manner and with an IC50 value of 90 μM. P6 also inhibited cell adhesion to hyaluronan but had no effect on adhesion to VCAM-1 (α4β1 integrin ligand), confirming its specific interaction with CD44. Spatial localization analyses mapped P6 to the central cavity of PEX9, in close proximity to the previously identified P3 sequence. Both P6 and P3 equally impaired cell adhesion to (pro)MMP-9. Moreover, P6 synergistically cooperated with P3, resulting in complete inhibition of CLL cell binding to PEX9, chemotaxis, and transendothelial migration. Thus, P6 is a novel sequence in PEX9 involved in cell-PEX9/(pro)MMP-9 binding by interacting with CD44. Targeting both sites, P6 and P3, should efficiently prevent (pro)MMP-9 binding to CLL cells and its pathological consequences. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. CHLORPYRIFOS DEVELOPMENTAL NEUROTOXICITY: INTERACTION WITH GLUCOCORTICOIDS IN PC12 CELLS

    Science.gov (United States)

    Slotkin, Theodore A.; Card, Jennifer; Seidler, Frederic J.

    2012-01-01

    Prenatal coexposures to glucocorticoids and organophosphate pesticides are widespread. Glucocorticoids are elevated by maternal stress and are commonly given in preterm labor; organophosphate exposures are virtually ubiquitous. We used PC12 cells undergoing neurodifferentiation in order to assess whether dexamethasone enhances the developmental neurotoxicity of chlorpyrifos, focusing on concentrations relevant to human exposures. By themselves, each agent reduced the number of cells and the combined exposure elicited a correspondingly greater effect than with either agent alone. There was no general cytotoxicity, as cell growth was actually enhanced, and again, the combined treatment evoked greater cellular hypertrophy than with the individual compounds. The effects on neurodifferentiation were more complex. Chlorpyrifos alone had a promotional effect on neuri to genesis whereas dexamethasone impaired it; combined treatment showed an overall impairment greater than that seen with dexamethasone alone. The effect of chlorpyrifos on differentiation into specific neurotransmitter phenotypes was shifted by dexamethasone. Either agent alone promoted differentiation into the dopaminergic phenotype at the expense of the cholinergic phenotype. However, in dexamethasone-primed cells, chlorpyrifos actually enhanced cholinergic neurodifferentiation instead of suppressing this phenotype. Our results indicate that developmental exposure to glucocorticoids, either in the context of stress or the therapy of preterm labor, could enhance the developmental neurotoxicity of organophosphates and potentially of other neurotoxicants, as well as producing neurobehavioral outcomes distinct from those seen with either individual agent. PMID:22796634

  7. [Interactive dynamic scalp acupuncture combined with occupational therapy for upper limb motor impairment in stroke: a randomized controlled trial].

    Science.gov (United States)

    Wang, Jun; Pei, Jian; Cui, Xiao; Sun, Kexing; Ni, Huanhuan; Zhou, Cuixia; Wu, Ji; Huang, Mei; Ji, Li

    2015-10-01

    To compare the clinical efficacy on upper limb motor impairment in stroke between the interactive dynamic scalp acupuncture therapy and the traditional scalp acupuncture therapy. The randomized controlled trial and MINIMIZE layering randomization software were adopted. Seventy patients of upper limb with III to V grade in Brunnstrom scale after stroke were randomized into an interactive dynamic scalp acupuncture group and a traditional scalp acupuncture group, 35 cases in each one. In the interactive dynamic scalp acupuncture group, the middle 2/5 of Dingnieqianxiexian (anterior oblique line of vertex-temporal), the middle 2/5 of Dingniehouxiexian (posterior oblique line of vertex-temporal) and Dingpangerxian (lateral line 2 of vertex) on the affected side were selected as the stimulation areas. Additionally, the rehabilitation training was applied during scalp acupuncture treatment. In the traditional scalp acupuncture group, the scalp stimulation areas were same as the interactive dynamic scalp acupuncture group. But the rehabilitation training was applied separately. The rehabilitation training was applied in the morning and the scalp acupuncture was done in the afternoon. The results in Fugl-Meyer for the upper limb motor function (U-FMA), the Wolf motor function measure scale (WM- FT) and the modified Barthel index in the two groups were compared between the two groups before treatment and in 1 and 2 months of treatment, respectively. After treatment, the U-FMA score, WMFT score and the score of the modified Barthel index were all apparently improved as compared with those before treatment (all P acupuncture group was better than that in the traditional scalp acupuncture group (P acupuncture group were improved apparently as compared with those in the traditional scalp acupuncture group (P acupuncture group were not different significantly as compared with those in the traditional scalp acupuncture group (both P > 0.05). For the patients of IV to V grade in

  8. Knockdown of SVCT2 impairs in-vitro cell attachment, migration and wound healing in bone marrow stromal cells

    Directory of Open Access Journals (Sweden)

    Rajnikumar Sangani

    2014-03-01

    Full Text Available Bone marrow stromal cell (BMSC adhesion and migration are fundamental to a number of pathophysiologic processes, including fracture and wound healing. Vitamin C is beneficial for bone formation, fracture repair and wound healing. However, the role of the vitamin C transporter in BMSC adhesion, migration and wound healing is not known. In this study, we knocked-down the sodium-dependent vitamin C transporter, SVCT2, the only known transporter of vitamin C in BMSCs, and performed cell adhesion, migration, in-vitro scratch wound healing and F-actin re-arrangement studies. We also investigated the role of oxidative stress on the above processes. Our results demonstrate that both oxidative stress and down-regulation of SVCT2 decreased cell attachment and spreading. A trans-well cell migration assay showed that vitamin C helped in BMSC migration and that knockdown of SVCT2 decreased cell migration. In the in-vitro scratch wound healing studies, we established that oxidative stress dose-dependently impairs wound healing. Furthermore, the supplementation of vitamin C significantly rescued the BMSCs from oxidative stress and increased wound closing. The knockdown of SVCT2 in BMSCs strikingly decreased wound healing, and supplementing with vitamin C failed to rescue cells efficiently. The knockdown of SVCT2 and induction of oxidative stress in cells produced an alteration in cytoskeletal dynamics. Signaling studies showed that oxidative stress phosphorylated members of the MAP kinase family (p38 and that vitamin C inhibited their phosphorylation. Taken together, these results indicate that both the SVCT2 transporter and oxidative stress play a vital role in BMSC attachment, migration and cytoskeletal re-arrangement. BMSC-based cell therapy and modulation of SVCT2 could lead to a novel therapeutic approach that enhances bone remodeling, fracture repair and wound healing in chronic disease conditions.

  9. BTG interacts with retinoblastoma to control cell fate in Dictyostelium.

    Directory of Open Access Journals (Sweden)

    Daniele Conte

    Full Text Available BACKGROUND: In the genesis of many tissues, a phase of cell proliferation is followed by cell cycle exit and terminal differentiation. The latter two processes overlap: genes involved in the cessation of growth may also be important in triggering differentiation. Though conceptually distinct, they are often causally related and functional interactions between the cell cycle machinery and cell fate control networks are fundamental to coordinate growth and differentiation. A switch from proliferation to differentiation may also be important in the life cycle of single-celled organisms, and genes which arose as regulators of microbial differentiation may be conserved in higher organisms. Studies in microorganisms may thus contribute to understanding the molecular links between cell cycle machinery and the determination of cell fate choice networks. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that in the amoebozoan D. discoideum, an ortholog of the metazoan antiproliferative gene btg controls cell fate, and that this function is dependent on the presence of a second tumor suppressor ortholog, the retinoblastoma-like gene product. Specifically, we find that btg-overexpressing cells preferentially adopt a stalk cell (and, more particularly, an Anterior-Like Cell fate. No btg-dependent preference for ALC fate is observed in cells in which the retinoblastoma-like gene has been genetically inactivated. Dictyostelium btg is the only example of non-metazoan member of the BTG family characterized so far, suggesting that a genetic interaction between btg and Rb predated the divergence between dictyostelids and metazoa. CONCLUSIONS/SIGNIFICANCE: While the requirement for retinoblastoma function for BTG antiproliferative activity in metazoans is known, an interaction of these genes in the control of cell fate has not been previously documented. Involvement of a single pathway in the control of mutually exclusive processes may have relevant implication in the

  10. Can mesenchymal stem cells reverse chronic stress-induced impairment of lung healing following traumatic injury?

    Science.gov (United States)

    Gore, Amy V; Bible, Letitia E; Livingston, David H; Mohr, Alicia M; Sifri, Ziad C

    2015-04-01

    One week following unilateral lung contusion (LC), rat lungs demonstrate full histologic recovery. When animals undergo LC plus the addition of chronic restraint stress (CS), wound healing is significantly delayed. Mesenchymal stem cells (MSCs) are pluripotent cells capable of immunomodulation, which have been the focus of much research in wound healing and tissue regeneration. We hypothesize that the addition of MSCs will improve wound healing in the setting of CS. Male Sprague-Dawley rats (n = 6-7 per group) were subjected to LC/CS with or without the injection of MSCs. MSCs were given as a single intravenous dose of 5 × 10 cells in 1 mL Iscove's Modified Dulbecco's Medium at the time of LC. Rats were subjected to 2 hours of restraint stress on Days 1 to 6 following LC. Seven days following injury, rats were sacrificed, and the lungs were examined for histologic evidence of wound healing using a well-established histologic lung injury score (LIS) to grade injury. LIS examines inflammatory cells/high-power field (HPF) averaged over 30 fields, interstitial edema, pulmonary edema, and alveolar integrity, with scores ranging from 0 (normal) to 11 (highly damaged). Peripheral blood was analyzed by flow cytometry for the presence of T-regulatory (C4CD25FoxP3) cells. Data were analyzed by analysis of variance followed by Tukey's multiple comparison test, expressed as mean (SD). As previously shown, 7 days following isolated LC, LIS has returned to 0.83 (0.41), with a subscore of zero for inflammatory cells/HPF. The addition of CS results in an LIS of 4.4 (2.2), with a subscore of 1.9 (0.7) for inflammatory cells/HPF. Addition of MSC to LC/CS decreased LIS to 1.7 (0.8), with a subscore of zero for inflammatory cells/HPF. Furthermore, treatment of animals undergoing LC/CS with MSCs increased the %T-regulatory cells by 70% in animals undergoing LC/CS alone (12.9% [2.4]% vs. 6.2% [1.3%]). Stress-induced impairment of wound healing is reversed by the addition of MSCs given

  11. Specific Language Impairment - Evidence for the division of labor and the interaction between grammar and pragmatics

    NARCIS (Netherlands)

    Schaeffer, J.

    2012-01-01

    This study analyzes grammatical and pragmatic data of English and Dutch acquiring children with SLI, and compares them to the language of typically developing children, in order to gain more insight in the organization of language, in particular, the dissociation and interaction of grammar and

  12. Interactions between chitosan and cells measured by AFM

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, Sheng-Wen; Thien, Doan Van Hong; Ho, Ming-Hua [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10617, Taiwan (China); Hsieh, Hsyue-Jen [Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Li, Chung-Hsing [Division of Orthodontics and Pediatric Dentistry, Department of Dentistry, Tri-Service General Hospital, Taipei, Taiwan (China); Hung, Chang-Hsiang [Department of Dentistry, Kinmen Hospital Department of Health, Taiwan (China); Li, Hsi-Hsin, E-mail: mhho@mail.ntust.edu.t [Deputy Superintendent, Kinmen Hospital Department of Health, Taiwan (China)

    2010-10-01

    Chitosan, a biocompatible material that has been widely used in bone tissue engineering, is believed to have a high affinity to osteoblastic cells. This research is the first to prove this hypothesis. By using atomic force microscopy (AFM) with a chitosan-modified cantilever, quantitative evaluation of the interforce between chitosan and cells was carried out. A chitosan tip functionalized with Arg-Gly-Asp (RGD) was also used to measure the interforce between RGD-chitosan and osteoblastic cells. This research concluded by examining cell adhesion and spreading of chitosan substrates as further characterization of the interactions between cells and chitosan. The force measured by AFM showed that the interforce between chitosan and osteoblasts was the highest (209 nN). The smallest adhesion force (61.8 nN) appeared between chitosan and muscle fibroblasts, which did not demonstrate any osteoblastic properties. This result proved that there was a significant interaction between chitosan and bone cells, and correlated with the observations of cell attachment and spreading. The technique developed in this research directly quantified the adhesion between chitosan and cells. This is the first study to demonstrate that specific interaction exists between chitosan and osteoblasts.

  13. Interactions between chitosan and cells measured by AFM

    International Nuclear Information System (INIS)

    Hsiao, Sheng-Wen; Thien, Doan Van Hong; Ho, Ming-Hua; Hsieh, Hsyue-Jen; Li, Chung-Hsing; Hung, Chang-Hsiang; Li, Hsi-Hsin

    2010-01-01

    Chitosan, a biocompatible material that has been widely used in bone tissue engineering, is believed to have a high affinity to osteoblastic cells. This research is the first to prove this hypothesis. By using atomic force microscopy (AFM) with a chitosan-modified cantilever, quantitative evaluation of the interforce between chitosan and cells was carried out. A chitosan tip functionalized with Arg-Gly-Asp (RGD) was also used to measure the interforce between RGD-chitosan and osteoblastic cells. This research concluded by examining cell adhesion and spreading of chitosan substrates as further characterization of the interactions between cells and chitosan. The force measured by AFM showed that the interforce between chitosan and osteoblasts was the highest (209 nN). The smallest adhesion force (61.8 nN) appeared between chitosan and muscle fibroblasts, which did not demonstrate any osteoblastic properties. This result proved that there was a significant interaction between chitosan and bone cells, and correlated with the observations of cell attachment and spreading. The technique developed in this research directly quantified the adhesion between chitosan and cells. This is the first study to demonstrate that specific interaction exists between chitosan and osteoblasts.

  14. Bone impairment in phenylketonuria is characterized by circulating osteoclast precursors and activated T cell increase.

    Directory of Open Access Journals (Sweden)

    Ilaria Roato

    Full Text Available BACKGROUND: Phenylketonuria (PKU is a rare inborn error of metabolism often complicated by a progressive bone impairment of uncertain etiology, as documented by both ionizing and non- ionizing techniques. METHODOLOGY: Peripheral blood mononuclear cell (PBMC cultures were performed to study osteoclastogenesis, in the presence or absence of recombinant human monocyte-colony stimulating factor (M-CSF and receptor activator of NFκB ligand (RANKL. Flow cytometry was utilized to analyze osteoclast precursors (OCPs and T cell phenotype. Tumour necrosis factor α (TNF-α, RANKL and osteoprotegerin (OPG were quantified in cell culture supernatants by ELISA. The effects of RANKFc and anti-TNF-α antibodies were also investigated to determine their ability to inhibit osteoclastogenesis. In addition, bone conditions and phenylalanine levels in PKU patients were clinically evaluated. PRINCIPAL FINDINGS: Several in vitro studies in PKU patients' cells identified a potential mechanism of bone formation inhibition commonly associated with this disorder. First, PKU patients disclosed an increased osteoclastogenesis compared to healthy controls, both in unstimulated and M-CSF/RANKL stimulated PBMC cultures. OCPs and the measured RANKL/OPG ratio were higher in PKU patients compared to healthy controls. The addition of specific antagonist RANKFc caused osteoclastogenesis inhibition, whereas anti-TNF-α failed to have this effect. Among PBMCs isolated from PKU patients, activated T cells, expressing CD69, CD25 and RANKL were identified. Confirmatory in vivo studies support this proposed model. These in vivo studies included the analysis of osteoclastogenesis in PKU patients, which demonstrated an inverse relation to bone condition assessed by phalangeal Quantitative Ultrasound (QUS. This was also directly related to non-compliance to therapeutic diet reflected by hyperphenylalaninemia. CONCLUSIONS: Our results indicate that PKU spontaneous osteoclastogenesis

  15. The hydroxyflavone, fisetin, suppresses mast cell activation induced by interaction with activated T cell membranes

    Science.gov (United States)

    Nagai, K; Takahashi, Y; Mikami, I; Fukusima, T; Oike, H; Kobori, M

    2009-01-01

    Background and purpose: Cell-to-cell interactions between mast cells and activated T cells are increasingly recognized as a possible mechanism in the aetiology of allergic or non-allergic inflammatory disorders. To determine the anti-allergic effect of fisetin, we examined the ability of fisetin to suppress activation of the human mast cell line, HMC-1, induced by activated Jurkat T cell membranes. Experimental approach: HMC-1 cells were incubated with or without fisetin for 15 min and then co-cultured with Jurkat T cell membranes activated by phorbol-12-myristate 13-acetate for 16 h. We determined gene expression in activated HMC-1 cells by DNA microarray and quantitative reverse transcription (RT)-PCR analysis. We also examined activation of the transcription factor NF-κB and MAP kinases (MAPKs) in activated HMC-1 cells. Key results: Fisetin suppresses cell spreading and gene expression in HMC-1 cells stimulated by activated T cell membranes. Additionally, we show that these stimulated HMC-1 cells expressed granzyme B. The stimulatory interaction also induced activation of NF-κB and MAPKs; these activations were suppressed by fisetin. Fisetin also reduced the amount of cell surface antigen CD40 and intercellular adhesion molecule-1 (ICAM-1) on activated HMC-1 cells. Conclusions and implications: Fisetin suppressed activation of HMC-1 cells by activated T cell membranes by interfering with cell-to-cell interaction and inhibiting the activity of NF-κB and MAPKs and thereby suppressing gene expression. Fisetin may protect against the progression of inflammatory diseases by limiting interactions between mast cells and activated T cells. PMID:19702784

  16. Child-Parent Interactions in Families Raising Children with Hearing Impairment

    Directory of Open Access Journals (Sweden)

    Nikitina Yu.V.

    2015-06-01

    Full Text Available Article reveals communication (information exchange between parents and their deaf children. The effectiveness of information exchange in different communication means between parents and children having hearing loss was investigated. Effectiveness here is an opportunity of fast understanding of the information given by one participant to another. Special experimental situation was constructed to measure the effectiveness. This situation was divided in two parts: at first parent was giving instructions to the child, then – child was giving instructions to the parent. The time that was needed to follow the instructions was measured, and communication means were registered. 17 deaf children and their mothers participated in the study. 5 of those mothers also have hearing impairment and do know sign language. Control group was represented by 10 regular developing children and their parents. Experimental results allows us to make the conclusion that there are significant difficulties in information exchange between parent and child in families raising deaf children. These difficulties are more shown in situations when children have to understand parents’ instructions and are the result of not very efficient communication means that parents use in several cases. The most efficient communication means that allow receiving information faster, accurately and fully is Russian sign language. That is shown by the best results of information exchange in pairs of mother and child both having hearing loss.

  17. Bioinsecticide-predator interactions: azadirachtin behavioral and reproductive impairment of the coconut mite predator Neoseiulus baraki.

    Directory of Open Access Journals (Sweden)

    Debora B Lima

    Full Text Available Synthetic pesticide use has been the dominant form of pest control since the 1940s. However, biopesticides are emerging as sustainable pest control alternatives, with prevailing use in organic agricultural production systems. Foremost among botanical biopesticides is the limonoid azadirachtin, whose perceived environmental safety has come under debate and scrutiny in recent years. Coconut production, particularly organic coconut production, is one of the agricultural systems in which azadirachtin is used as a primary method of pest control for the management of the invasive coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae. The management of this mite species also greatly benefits from predation by Neoseiulus baraki (Athias-Henriot (Acari: Phytoseiidae. Here, we assessed the potential behavioral impacts of azadirachtin on the coconut mite predator, N. baraki. We explored the effects of this biopesticide on overall predator activity, female searching time, and mating behavior and fecundity. Azadirachtin impairs the overall activity of the predator, reducing it to nearly half; however, female searching was not affected. In contrast, mating behavior was compromised by azadirachtin exposure particularly when male predators were exposed to the biopesticide. Consequently, predator fecundity was also compromised by azadirachtin, furthering doubts about its environmental safety and selectivity towards biological control agents.

  18. Bioinsecticide-predator interactions: azadirachtin behavioral and reproductive impairment of the coconut mite predator Neoseiulus baraki.

    Science.gov (United States)

    Lima, Debora B; Melo, José Wagner S; Guedes, Nelsa Maria P; Gontijo, Lessando M; Guedes, Raul Narciso C; Gondim, Manoel Guedes C

    2015-01-01

    Synthetic pesticide use has been the dominant form of pest control since the 1940s. However, biopesticides are emerging as sustainable pest control alternatives, with prevailing use in organic agricultural production systems. Foremost among botanical biopesticides is the limonoid azadirachtin, whose perceived environmental safety has come under debate and scrutiny in recent years. Coconut production, particularly organic coconut production, is one of the agricultural systems in which azadirachtin is used as a primary method of pest control for the management of the invasive coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae). The management of this mite species also greatly benefits from predation by Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae). Here, we assessed the potential behavioral impacts of azadirachtin on the coconut mite predator, N. baraki. We explored the effects of this biopesticide on overall predator activity, female searching time, and mating behavior and fecundity. Azadirachtin impairs the overall activity of the predator, reducing it to nearly half; however, female searching was not affected. In contrast, mating behavior was compromised by azadirachtin exposure particularly when male predators were exposed to the biopesticide. Consequently, predator fecundity was also compromised by azadirachtin, furthering doubts about its environmental safety and selectivity towards biological control agents.

  19. Processing complex pseudo-words in mild cognitive impairment: The interaction of preserved morphological rule knowledge with compromised cognitive ability.

    Science.gov (United States)

    Manouilidou, Christina; Dolenc, Barbara; Marvin, Tatjana; Pirtošek, Zvezdan

    2016-01-01

    Mild cognitive impairment (MCI) affects the cognitive performance of elderly adults. However, the level of severity is not high enough to be diagnosed with dementia. Previous research reports subtle language impairments in individuals with MCI specifically in domains related to lexical meaning. The present study used both off-line (grammaticality judgment) and on-line (lexical decision) tasks to examine aspects of lexical processing and how they are affected by MCI. 21 healthy older adults and 23 individuals with MCI saw complex pseudo-words that violated various principles of word formation in Slovenian and decided if each letter string was an actual word of their language. The pseudo-words ranged in their degree of violability. A task effect was found, with MCI performance to be similar to that of healthy controls in the off-line task but different in the on-line task. Overall, the MCI group responded slower than the elderly controls. No significant differences were observed in the off-line task, while the on-line task revealed a main effect of Violation type, a main effect of Group and a significant Violation × Group interaction reflecting a difficulty for the MCI group to process pseudo-words in real time. That is, while individuals with MCI seem to preserve morphological rule knowledge, they experience additional difficulties while processing complex pseudo-words. This was attributed to an executive dysfunction associated with MCI that delays the recognition of ungrammatical formations.

  20. Synergistic interaction of fatty acids and oxysterols impairs mitochondrial function and limits liver adaptation during nafld progression

    Directory of Open Access Journals (Sweden)

    Francesco Bellanti

    2018-05-01

    Full Text Available The complete mechanism accounting for the progression from simple steatosis to steatohepatitis in nonalcoholic fatty liver disease (NAFLD has not been elucidated. Lipotoxicity refers to cellular injury caused by hepatic free fatty acids (FFAs and cholesterol accumulation. Excess cholesterol autoxidizes to oxysterols during oxidative stress conditions. We hypothesize that interaction of FAs and cholesterol derivatives may primarily impair mitochondrial function and affect biogenesis adaptation during NAFLD progression. We demonstrated that the accumulation of specific non-enzymatic oxysterols in the liver of animals fed high-fat+high-cholesterol diet induces mitochondrial damage and depletion of proteins of the respiratory chain complexes. When tested in vitro, 5α-cholestane-3β,5,6β-triol (triol combined to FFAs was able to reduce respiration in isolated liver mitochondria, induced apoptosis in primary hepatocytes, and down-regulated transcription factors involved in mitochondrial biogenesis. Finally, a lower protein content in the mitochondrial respiratory chain complexes was observed in human non-alcoholic steatohepatitis. In conclusion, hepatic accumulation of FFAs and non-enzymatic oxysterols synergistically facilitates development and progression of NAFLD by impairing mitochondrial function, energy balance and biogenesis adaptation to chronic injury.

  1. Neoantigen landscape dynamics during human melanoma-T cell interactions

    DEFF Research Database (Denmark)

    Verdegaal, Els M. E.; De Miranda, Noel F. C. C.; Visser, Marten

    2016-01-01

    Recognition of neoantigens that are formed as a consequence of DNA damage is likely to form a major driving force behind the clinical activity of cancer immunotherapies such as T-cell checkpoint blockade and adoptive T-cell therapy. Therefore, strategies to selectively enhance T-cell reactivity...... against genetically defined neoantigens are currently under development. In mouse models, T-cell pressure can sculpt the antigenicity of tumours, resulting in the emergence of tumours that lack defined mutant antigens. However, whether the T-cell-recognized neoantigen repertoire in human cancers...... by overall reduced expression of the genes or loss of the mutant alleles. Notably, loss of expression of T-cell-recognized neoantigens was accompanied by development of neoantigen-specific T-cell reactivity in tumour-infiltrating lymphocytes. These data demonstrate the dynamic interactions between cancer...

  2. Human computer interaction and communication aids for hearing-impaired, deaf and deaf-blind people: Introduction to the special thematic session

    DEFF Research Database (Denmark)

    Bothe, Hans-Heinrich

    2008-01-01

    This paper gives ail overview and extends the Special Thematic Session (STS) oil research and development of technologies for hearing-impaired, deaf, and deaf-blind people. The topics of the session focus oil special equipment or services to improve communication and human computer interaction....... The papers are related to visual communication using captions, sign language, speech-reading, to vibro-tactile stimulation, or to general services for hearing-impaired persons....

  3. Cancer exosomes and NKG2D receptor-ligand interactions: impairing NKG2D-mediated cytotoxicity and anti-tumour immune surveillance.

    Science.gov (United States)

    Mincheva-Nilsson, Lucia; Baranov, Vladimir

    2014-10-01

    Human cancers constitutively produce and release endosome-derived nanometer-sized vesicles called exosomes that carry biologically active proteins, messenger and micro RNAs and serve as vehicles of intercellular communication. The tumour exosomes are present in the blood, urine and various malignant effusions such as peritoneal and pleural fluid of cancer patients and can modulate immune cells and responses thus deranging the immune system of cancer patients and giving advantage to the cancer to establish and spread itself. Here, the role of exosomes in the NKG2D receptor-ligand system's interactions is discussed. The activating NK cell receptor NKG2D and its multiple ligands, the MHC class I-related chain (MIC) A/B and the retinoic acid transcript-1/UL-16 binding proteins (RAET1/ULBP) 1-6 comprise a powerful stress-inducible danger detector system that targets infected, inflamed and malignantly transformed cells and plays a decisive role in anti-tumour immune surveillance. Mounting evidence reveals that the MIC- and RAET1/ULBP ligand family members are enriched in the endosomal compartment of various tumour cells and expressed and released into the intercellular space and bodily fluids on exosomes thus preserving their entire molecule, three-dimensional protein structure and biologic activity. The NKG2D ligand-expressing exosomes serve as decoys with a powerful ability to down regulate the cognate receptor and impair the cytotoxic function of NK-, NKT-, gamma/delta- and cytotoxic T cells. This review summarizes recent findings concerning the role of NKG2D receptor-ligand system in cancer with emphasis on regulation of NKG2D ligand expression and the immunosuppressive role of exosomally expressed NKG2D ligands. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Interactions of Condensed Tannins with Saccharomyces cerevisiae Yeast Cells and Cell Walls: Tannin Location by Microscopy.

    Science.gov (United States)

    Mekoue Nguela, Julie; Vernhet, Aude; Sieczkowski, Nathalie; Brillouet, Jean-Marc

    2015-09-02

    Interactions between grape tannins/red wine polyphenols and yeast cells/cell walls was previously studied within the framework of red wine aging and the use of yeast-derived products as an alternative to aging on lees. Results evidenced a quite different behavior between whole cells (biomass grown to elaborate yeast-derived products, inactivated yeast, and yeast inactivated after autolysis) and yeast cell walls (obtained from mechanical disruption of the biomass). Briefly, whole cells exhibited a high capacity to irreversibly adsorb grape and wine tannins, whereas only weak interactions were observed for cell walls. This last point was quite unexpected considering the literature and called into question the real role of cell walls in yeasts' ability to fix tannins. In the present work, tannin location after interactions between grape and wine tannins and yeast cells and cell walls was studied by means of transmission electron microscopy, light epifluorescence, and confocal microscopy. Microscopy observations evidenced that if tannins interact with cell walls, and especially cell wall mannoproteins, they also diffuse freely through the walls of dead cells to interact with their plasma membrane and cytoplasmic components.

  5. Endothelial progenitor cells dysfunction and impaired tissue reparation: The missed link in diabetes mellitus development.

    Science.gov (United States)

    Berezin, Alexander E

    Diabetes mellitus (DM) is considered a leading cause of premature cardiovascular (CV) mortality and morbidity in general population and in individuals with known CV disease. Recent animal and clinical studies have shown that reduced number and weak function of endothelial progenitor cells (EPCs) may not only indicate to higher CV risk, but contribute to the impaired heart and vessels reparation in patients with DM. Moreover, EPCs having a protective impact on the vasculature may mediate the functioning of other organs and systems. Therefore, EPCs dysfunction is probably promising target for DM treatment strategy, while the role of restoring of EPCs number and functionality in CV risk diminish and reduce of DM-related complications is not fully clear. The aim of the review is summary of knowledge regarding EPCs dysfunction in DM patients. Copyright © 2016 Diabetes India. Published by Elsevier Ltd. All rights reserved.

  6. Working memory and referential communication – multimodal aspects of interaction between children with sensorineural hearing impairment and normal hearing peers

    Directory of Open Access Journals (Sweden)

    Olof eSandgren

    2015-03-01

    Full Text Available Whereas the language development of children with sensorineural hearing impairment (SNHI has repeatedly been shown to differ from that of peers with normal hearing (NH, few studies have used an experimental approach to investigate the consequences on everyday communicative interaction. This mini review gives an overview of a range of studies on children with SNHI and NH exploring intra- and inter-individual cognitive and linguistic systems during communication.Over the last decade, our research group has studied the conversational strategies of Swedish speaking children and adolescents with SNHI and NH using referential communication, an experimental analogue to problem-solving in the classroom. We have established verbal and nonverbal control and validation mechanisms, related to working memory capacity (WMC and phonological short term memory (PSTM. We present main findings and future directions relevant for the field of cognitive hearing science and for the clinical and school-based management of children and adolescents with SNHI.

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

    Directory of Open Access Journals (Sweden)

    Grégory Lacraz

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

  8. Muscle satellite cells are functionally impaired in myasthenia gravis: consequences on muscle regeneration.

    Science.gov (United States)

    Attia, Mohamed; Maurer, Marie; Robinet, Marieke; Le Grand, Fabien; Fadel, Elie; Le Panse, Rozen; Butler-Browne, Gillian; Berrih-Aknin, Sonia

    2017-12-01

    Myasthenia gravis (MG) is a neuromuscular disease caused in most cases by anti-acetyl-choline receptor (AChR) autoantibodies that impair neuromuscular signal transmission and affect skeletal muscle homeostasis. Myogenesis is carried out by muscle stem cells called satellite cells (SCs). However, myogenesis in MG had never been explored. The aim of this study was to characterise the functional properties of myasthenic SCs as well as their abilities in muscle regeneration. SCs were isolated from muscle biopsies of MG patients and age-matched controls. We first showed that the number of Pax7+ SCs was increased in muscle sections from MG and its experimental autoimmune myasthenia gravis (EAMG) mouse model. Myoblasts isolated from MG muscles proliferate and differentiate more actively than myoblasts from control muscles. MyoD and MyoG were expressed at a higher level in MG myoblasts as well as in MG muscle biopsies compared to controls. We found that treatment of control myoblasts with MG sera or monoclonal anti-AChR antibodies increased the differentiation and MyoG mRNA expression compared to control sera. To investigate the functional ability of SCs from MG muscle to regenerate, we induced muscle regeneration using acute cardiotoxin injury in the EAMG mouse model. We observed a delay in maturation evidenced by a decrease in fibre size and MyoG mRNA expression as well as an increase in fibre number and embryonic myosin heavy-chain mRNA expression. These findings demonstrate for the first time the altered function of SCs from MG compared to control muscles. These alterations could be due to the anti-AChR antibodies via the modulation of myogenic markers resulting in muscle regeneration impairment. In conclusion, the autoimmune attack in MG appears to have unsuspected pathogenic effects on SCs and muscle regeneration, with potential consequences on myogenic signalling pathways, and subsequently on clinical outcome, especially in the case of muscle stress.

  9. hiPSC-derived neural stem cells from patients with schizophrenia induce an impaired angiogenesis.

    Science.gov (United States)

    Casas, Bárbara S; Vitória, Gabriela; do Costa, Marcelo N; Madeiro da Costa, Rodrigo; Trindade, Pablo; Maciel, Renata; Navarrete, Nelson; Rehen, Stevens K; Palma, Verónica

    2018-02-22

    Schizophrenia is a neurodevelopmental disease characterized by cerebral connectivity impairment and loss of gray matter. It was described in adult schizophrenia patients (SZP) that concentration of VEGFA, a master angiogenic factor, is decreased. Recent evidence suggests cerebral hypoperfusion related to a dysfunctional Blood Brain Barrier (BBB) in SZP. Since neurogenesis and blood-vessel formation occur in a coincident and coordinated fashion, a defect in neurovascular development could result in increased vascular permeability and, therefore, in poor functionality of the SZP's neurons. Here, we characterized the conditioned media (CM) of human induced Pluripotent Stem Cells (hiPSC)-derived Neural Stem Cells of SZP (SZP NSC) versus healthy subjects (Ctrl NSC), and its impact on angiogenesis. Our results reveal that SZP NSC have an imbalance in the secretion and expression of several angiogenic factors, among them non-canonical neuro-angiogenic guidance factors. SZP NSC migrated less and their CM was less effective in inducing migration and angiogenesis both in vitro and in vivo. Since SZP originates during embryonic brain development, our findings suggest a defective crosstalk between NSC and endothelial cells (EC) during the formation of the neuro-angiogenic niche.

  10. Impaired respiration elicits SrrAB-dependent programmed cell lysis and biofilm formation in Staphylococcus aureus

    Science.gov (United States)

    Mashruwala, Ameya A; van de Guchte, Adriana; Boyd, Jeffrey M

    2017-01-01

    Biofilms are communities of microorganisms attached to a surface or each other. Biofilm-associated cells are the etiologic agents of recurrent Staphylococcus aureus infections. Infected human tissues are hypoxic or anoxic. S. aureus increases biofilm formation in response to hypoxia, but how this occurs is unknown. In the current study we report that oxygen influences biofilm formation in its capacity as a terminal electron acceptor for cellular respiration. Genetic, physiological, or chemical inhibition of respiratory processes elicited increased biofilm formation. Impaired respiration led to increased cell lysis via divergent regulation of two processes: increased expression of the AtlA murein hydrolase and decreased expression of wall-teichoic acids. The AltA-dependent release of cytosolic DNA contributed to increased biofilm formation. Further, cell lysis and biofilm formation were governed by the SrrAB two-component regulatory system. Data presented support a model wherein SrrAB-dependent biofilm formation occurs in response to the accumulation of reduced menaquinone. DOI: http://dx.doi.org/10.7554/eLife.23845.001 PMID:28221135

  11. Impaired IFN-α-mediated signal in dendritic cells differentiates active from latent tuberculosis.

    Directory of Open Access Journals (Sweden)

    Stefania Parlato

    Full Text Available Individuals exposed to Mycobacterium tuberculosis (Mtb may be infected and remain for the entire life in this condition defined as latent tuberculosis infection (LTBI or develop active tuberculosis (TB. Among the multiple factors governing the outcome of the infection, dendritic cells (DCs play a major role in dictating antibacterial immunity. However, current knowledge on the role of the diverse components of human DCs in shaping specific T-cell response during Mtb infection is limited. In this study, we performed a comparative evaluation of peripheral blood circulating DC subsets as well as of monocyte-derived Interferon-α DCs (IFN-DCs from patients with active TB, subjects with LTBI and healthy donors (HD. The proportion of circulating myeloid BDCA3+ DCs (mDC2 and plasmacytoid CD123+ DCs (pDCs declined significantly in active TB patients compared to HD, whereas the same subsets displayed a remarkable activation in LTBI subjects. Simultaneously, the differentiation of IFN-DCs from active TB patients resulted profoundly impaired compared to those from LTBI and HD individuals. Importantly, the altered developmental trait of IFN-DCs from active TB patients was associated with down-modulation of IFN-linked genes, marked changes in molecular signaling conveying antigen (Ag presentation and full inability to induce Ag-specific T cell response. Thus, these data reveal an important role of IFN-α in determining the induction of Mtb-specific immunity.

  12. Impaired pubertal development and testicular hormone function in males with sickle cell anemia.

    Science.gov (United States)

    Martins, Paulo Roberto Juliano; Kerbauy, José; Moraes-Souza, Helio; Pereira, Gilberto de Araújo; Figueiredo, Maria Stella; Verreschi, Ieda Therezinha

    2015-01-01

    Changes in weight/height ratio, delayed sexual maturation, hypogonadism and impaired fertility have been demonstrated in sickle cell disease (SCD). This study aimed to evaluate the clinical and laboratory views of the Leydig cells function after stimulation with hCG in adults with sickle cell disease. We studied 15 patients with SCD (18 to 40 years; median=27 years old), fourteen homozygous S, and one with SC disease. The control group, composed by adult males, was divided into two groups: I - 10 relatives (18-39 years, median=26 years) with the same socioeconomic level of the patients, and II - 9 normal individuals (23-28, median=31 years) randomly chosen. Clinically it was observed a slight degree of malnutrition, important puberty delay, rarefaction of chest, underarm and pubic hair, and important reduction of the testis and penis size, featuring a mild hypogonadism in patients with SCD. The hormonal level assessment of testosterone at baseline and at 24, 48 and 72 h after hCG stimulation showed no significant differences between the groups studied. We can presume that adult men with SCD showed clinical hypoandrogenism with normal testicular hormonal function, a fact inconsistent with the hypothesis of primary hypogonadism. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Impaired succinic dehydrogenase activity of rat Purkinje cell mitochondria during aging.

    Science.gov (United States)

    Fattoretti, P; Bertoni-Freddari, C; Caselli, U; Paoloni, R; Meier-Ruge, W

    1998-03-16

    The perikaryal Purkinje cell mitochondria positive to the copper ferrocyanide histochemical reaction for succinic dehydrogenase (SDH) have been investigated by means of semiautomatic morphometric methods in rats of 3, 12 and 24 months of age. The number of organelles/microm3 of Purkinje cell cytoplasm (Numeric density: Nv), the average mitochondrial volume (V) and the mitochondrial volume fraction (Volume density: Vv) were the ultrastructural parameters taken into account. Nv was significantly higher at 12 than at 3 and 24 months of age. V was significantly decreased at 12 and 24 months of age, but no difference was envisaged between adult and old rats. Vv was significantly decreased in old animals vs. the other age groups. In young and old rats, the percentage of organelles larger than 0.32 microm3 was 13.5 and 11%, respectively, while these enlarged mitochondria accounted for less than 1% in the adult group. Since SDH activity is of critical importance when energy demand is high, the marked decrease of Vv supports an impaired capacity of the old Purkinje cells to match actual energy supply at sustained transmission of the nervous impulse. However, the high percentage of enlarged organelles found in old rats may witness a morphofunctional compensatory response.

  14. Resignifying the sickle cell gene: Narratives of genetic risk, impairment and repair.

    Science.gov (United States)

    Berghs, Maria; Dyson, Simon M; Atkin, Karl

    2017-03-01

    Connecting theoretical discussion with empirical qualitative work, this article examines how sickle cell became a site of public health intervention in terms of 'racialised' risks. Historically, sickle cell became socio-politically allied to ideas of repair, in terms of the state improving the health of a neglected ethnic minority population. Yet, we elucidate how partial improvements in care and education arose alongside preventative public health screening efforts. Using qualitative research based in the United Kingdom, we show how a focus on collective efforts of repair can lie in tension with how services and individuals understand and negotiate antenatal screening. We illustrate how screening for sickle cell disorder calls into question narrative identity, undoing paradigms in which ethnicity, disablement and genetic impairment become framed. Research participants noted that rather than 'choices', it is 'risks' and their negotiation that are a part of discourses of modernity and the new genetics. Furthermore, while biomedical paradigms are rationally and ethically (de)constructed by participants, this was never fully engaged with by professionals, contributing to overall perception of antenatal screening as disempowering and leading to disengagement.

  15. Targeted inhibition of the phosphoinositide 3-kinase impairs cell proliferation, survival, and invasion in colon cancer

    Directory of Open Access Journals (Sweden)

    Yang F

    2017-09-01

    Full Text Available Fei Yang,1,* Jun-Yi Gao,2,* Hua Chen,1 Zhen-Hua Du,1 Xue-Qun Zhang,3 Wei Gao4 1Department of Pathology, Jinan Central Hospital Affiliated to Shandong University, Jinan, 2Department of Clinical Medicine, Weifang Medical College, Weifang, 3Graduate School, Taishan Medical University, Xintai, 4Department of Oncology, Jinan Central Hospital Affiliated to Shandong University, Jinan, People’s Republic of China *These authors contributed equally to this work Background: Colon cancer is the third most common cancer in the world, and its metastasis and drug resistance are challenging for its effective treatment. The PI3K/Akt/mTOR pathway plays a crucial role in the pathogenesis of colon cancer. The aim of this study was to investigate the targeting of PI3K in colon cancer cells HT-29 and HCT-116 in vitro. Methods: In HT-29 and HCT-116 cells, BEZ235, a dual inhibitor of PI3K/mTOR, and shRNAtarget to PI3KCA were used to inhibit PI3K/Akt/mTOR pathway. The inhibition efficiency of PI3K/Akt/mTOR pathway was detected by RT-PCR and Western blot. Cell proliferation, migration, invasion, and apoptosis were evaluated by Cell Counting Kit-8, Transwell, and flow cytometry assays. The expression of apoptosis-related proteins (cleavage caspase 3, Bcl-2, Bax, and Bim were also detected. Results: We found that in HT-29 and HCT-116 cells, the treatment of BEZ235 (1 µM and PI3KCA knockdown inhibited the activation of PI3K/Akt/mTOR pathway and significantly suppressed cell proliferation, migration, and invasion of HT-29 and HCT-116 cells. In addition, we confirmed that knockdown of BEZ235 and PI3KCA induced cell apoptosis through the upregulated levels of cleavage caspase 3 and Bax and downregulated expression of Bcl-2 and Bim. Conclusion: Our results indicated that targeted inhibition of the PI3K/Akt/mTOR pathway impaired cell proliferation, survival, and invasion in human colon cancer. Keywords: human colon cancer, PI3K/Akt/mTOR pathway, BEZ235, PI3KCA knockdown

  16. Hepatitis B virus surface antigen impairs myeloid dendritic cell function: a possible immune escape mechanism of hepatitis B virus

    Science.gov (United States)

    Op den Brouw, Marjoleine L; Binda, Rekha S; van Roosmalen, Mark H; Protzer, Ulrike; Janssen, Harry L A; van der Molen, Renate G; Woltman, Andrea M

    2009-01-01

    Chronic hepatitis B virus (HBV) infection is the result of an inadequate immune response towards the virus. Myeloid dendritic cells (mDC) of patients with chronic HBV are impaired in their maturation and function, resulting in more tolerogenic rather than immunogenic responses, which may contribute to viral persistence. The mechanism responsible for altered mDC function remains unclear. The HBV-infected patients display large amounts of HBV particles and viral proteins in their circulation, especially the surface antigen HBsAg, which allows multiple interactions between the virus, its viral proteins and DC. To assess whether HBV directly influences mDC function, the effects of HBV and HBsAg on human mDC maturation and function were investigated in vitro. As already described for internalization of HBV by DC, the present study shows that peripheral blood-derived mDC of healthy controls also actively take up HBsAg in a time-dependent manner. Cytokine-induced maturation in the presence of HBV or HBsAg resulted in a significantly more tolerogenic mDC phenotype as demonstrated by a diminished up-regulation of costimulatory molecules and a decreased T-cell stimulatory capacity, as assessed by T-cell proliferation and interferon-γ production. In addition, the presence of HBV significantly reduced interleukin-12 production by mDC. These results show that both HBV particles and purified HBsAg have an immune modulatory capacity and may directly contribute to the dysfunction of mDC in patients with chronic HBV. The direct immune regulatory effect of HBV and circulating HBsAg particles on the function of DC can be considered as part of the mechanism by which HBV escapes immunity. PMID:18624732

  17. A SMYD3 Small-Molecule Inhibitor Impairing Cancer Cell Growth

    Science.gov (United States)

    Barbosa, Armenio Jorge; Di Virgilio, Valeria; Fittipaldi, Raffaella; Fabini, Edoardo; Bertucci, Carlo; Varchi, Greta; Moyer, Mary Pat; Caretti, Giuseppina; Del Rio, Alberto; Simone, Cristiano

    2016-01-01

    SMYD3 is a histone lysine methyltransferase that plays an important role in transcriptional activation as a member of an RNA polymerase complex, and its oncogenic role has been described in different cancer types. We studied the expression and activity of SMYD3 in a preclinical model of colorectal cancer (CRC) and found that it is strongly upregulated throughout tumorigenesis both at the mRNA and protein level. Our results also showed that RNAi-mediated SMYD3 ablation impairs CRC cell proliferation indicating that SMYD3 is required for proper cancer cell growth. These data, together with the importance of lysine methyltransferases as a target for drug discovery, prompted us to carry out a virtual screening to identify new SMYD3 inhibitors by testing several candidate small molecules. Here we report that one of these compounds (BCI-121) induces a significant reduction in SMYD3 activity both in vitro and in CRC cells, as suggested by the analysis of global H3K4me2/3 and H4K5me levels. Of note, the extent of cell growth inhibition by BCI-121 was similar to that observed upon SMYD3 genetic ablation. Most of the results described above were obtained in CRC; however, when we extended our observations to tumor cell lines of different origin, we found that SMYD3 inhibitors are also effective in other cancer types, such as lung, pancreatic, prostate, and ovarian. These results represent the proof of principle that SMYD3 is a druggable target and suggest that new compounds capable of inhibiting its activity may prove useful as novel therapeutic agents in cancer treatment. PMID:25728514

  18. Epigenetically induced ectopic expression of UNCX impairs the proliferation and differentiation of myeloid cells.

    Science.gov (United States)

    Daniele, Giulia; Simonetti, Giorgia; Fusilli, Caterina; Iacobucci, Ilaria; Lonoce, Angelo; Palazzo, Antonio; Lomiento, Mariana; Mammoli, Fabiana; Marsano, Renè Massimiliano; Marasco, Elena; Mantovani, Vilma; Quentmeier, Hilmar; Drexler, Hans G; Ding, Jie; Palumbo, Orazio; Carella, Massimo; Nadarajah, Niroshan; Perricone, Margherita; Ottaviani, Emanuela; Baldazzi, Carmen; Testoni, Nicoletta; Papayannidis, Cristina; Ferrari, Sergio; Mazza, Tommaso; Martinelli, Giovanni; Storlazzi, Clelia Tiziana

    2017-07-01

    We here describe a leukemogenic role of the homeobox gene UNCX , activated by epigenetic modifications in acute myeloid leukemia (AML). We found the ectopic activation of UNCX in a leukemia patient harboring a t(7;10)(p22;p14) translocation, in 22 of 61 of additional cases [a total of 23 positive patients out of 62 (37.1%)], and in 6 of 75 (8%) of AML cell lines. UNCX is embedded within a low-methylation region (canyon) and encodes for a transcription factor involved in somitogenesis and neurogenesis, with specific expression in the eye, brain, and kidney. UNCX expression turned out to be associated, and significantly correlated, with DNA methylation increase at its canyon borders based on data in our patients and in archived data of patients from The Cancer Genome Atlas. UNCX -positive and -negative patients displayed significant differences in their gene expression profiles. An enrichment of genes involved in cell proliferation and differentiation, such as MAP2K1 and CCNA1 , was revealed. Similar results were obtained in UNCX -transduced CD34 + cells, associated with low proliferation and differentiation arrest. Accordingly, we showed that UNCX expression characterizes leukemia cells at their early stage of differentiation, mainly M2 and M3 subtypes carrying wild-type NPM1 We also observed that UNCX expression significantly associates with an increased frequency of acute promyelocytic leukemia with PML-RARA and AML with t(8;21)(q22;q22.1); RUNX1-RUNX1T1 classes, according to the World Health Organization disease classification. In summary, our findings suggest a novel leukemogenic role of UNCX , associated with epigenetic modifications and with impaired cell proliferation and differentiation in AML. Copyright© 2017 Ferrata Storti Foundation.

  19. Hippocampal gene expression patterns in oxytocin male knockout mice are related to impaired social interaction.

    Science.gov (United States)

    Lazzari, Virginia Meneghini; Zimmermann-Peruzatto, Josi Maria; Agnes, Grasiela; Becker, Roberta Oriques; de Moura, Ana Carolina; Almeida, Silvana; Guedes, Renata Padilha; Giovenardi, Marcia

    2017-11-02

    Social interaction between animals is crucial for the survival and life in groups. It is well demonstrated that oxytocin (OT) and vasopressin (AVP) play critical roles in the regulation of social behaviors in mammals, however, other neurotransmitters and hormones are involved in the brain circuitry related to these behaviors. The present study aimed to investigate the gene expression of neurotransmitter receptors in the brain of OT knockout (OTKO) male mice. In this study, we evaluated the expression levels of the OT receptor (Oxtr), AVP receptors 1a and 1b (Avpr1a; Avpr1b), dopamine receptor 2 (Drd2), and the estrogen receptors alpha and beta (Esr1; Esr2) genes in the hippocampus (HPC), olfactory bulb (OB), hypothalamus (HPT) and prefrontal cortex (PFC). AVP gene (Avp) expression was analyzed in the HPT. Gene expression results were discussed regarding to social interaction and sexual behavior findings. Additionally, we analyzed the influence of OT absence on the Avp mRNA expression levels in the HPT. RNA extraction and cDNAs synthesis followed by quantitative polymerase chain reaction were performed for gene expression determination. Results were calculated with the 2 -ΔΔCt method. Our main finding was that HPC is more susceptible to gene expression changes due to the lack of OT. OTKOs exhibited decreased expression of Drd2 and Avpr1b, but increased expression of Oxtr in the HPC. In the PFC, Esr2 was increased. In the HPT, there was a reduced Avp expression in the OTKO group. No differences were detected in the OB and HPT. Despite these changes in gene expression, sexual behavior was not affected. However, OTKO showed higher social investigation and lower aggressive performance than wild-type mice. Our data highlight the importance of OT for proper gene expression of neurotransmitter receptors related to the regulation of social interaction in male mice. Copyright © 2017. Published by Elsevier B.V.

  20. Childhood tuberculosis is associated with decreased abundance of T cell gene transcripts and impaired T cell function.

    Directory of Open Access Journals (Sweden)

    Cheryl Hemingway

    Full Text Available The WHO estimates around a million children contract tuberculosis (TB annually with over 80 000 deaths from dissemination of infection outside of the lungs. The insidious onset and association with skin test anergy suggests failure of the immune system to both recognise and respond to infection. To understand the immune mechanisms, we studied genome-wide whole blood RNA expression in children with TB meningitis (TBM. Findings were validated in a second cohort of children with TBM and pulmonary TB (PTB, and functional T-cell responses studied in a third cohort of children with TBM, other extrapulmonary TB (EPTB and PTB. The predominant RNA transcriptional response in children with TBM was decreased abundance of multiple genes, with 140/204 (68% of all differentially regulated genes showing reduced abundance compared to healthy controls. Findings were validated in a second cohort with concordance of the direction of differential expression in both TBM (r2 = 0.78 p = 2x10-16 and PTB patients (r2 = 0.71 p = 2x10-16 when compared to a second group of healthy controls. Although the direction of expression of these significant genes was similar in the PTB patients, the magnitude of differential transcript abundance was less in PTB than in TBM. The majority of genes were involved in activation of leucocytes (p = 2.67E-11 and T-cell receptor signalling (p = 6.56E-07. Less abundant gene expression in immune cells was associated with a functional defect in T-cell proliferation that recovered after full TB treatment (p<0.0003. Multiple genes involved in T-cell activation show decreased abundance in children with acute TB, who also have impaired functional T-cell responses. Our data suggest that childhood TB is associated with an acquired immune defect, potentially resulting in failure to contain the pathogen. Elucidation of the mechanism causing the immune paresis may identify new treatment and prevention strategies.

  1. Prion protein-deficient mice exhibit decreased CD4 T and LTi cell numbers and impaired spleen structure.

    Science.gov (United States)

    Kim, Soochan; Han, Sinsuk; Lee, Ye Eun; Jung, Woong-Jae; Lee, Hyung Soo; Kim, Yong-Sun; Choi, Eun-Kyoung; Kim, Mi-Yeon

    2016-01-01

    The cellular prion protein is expressed in almost all tissues, including the central nervous system and lymphoid tissues. To investigate the effects of the prion protein in lymphoid cells and spleen structure formation, we used prion protein-deficient (Prnp(0/0)) Zürich I mice generated by inactivation of the Prnp gene. Prnp(0/0) mice had decreased lymphocytes, in particular, CD4 T cells and lymphoid tissue inducer (LTi) cells. Decreased CD4 T cells resulted from impaired expression of CCL19 and CCL21 in the spleen rather than altered chemokine receptor CCR7 expression. Importantly, some of the white pulp regions in spleens from Prnp(0/0) mice displayed impaired T zone structure as a result of decreased LTi cell numbers and altered expression of the lymphoid tissue-organizing genes lymphotoxin-α and CXCR5, although expression of the lymphatic marker podoplanin and CXCL13 by stromal cells was not affected. In addition, CD3(-)CD4(+)IL-7Rα(+) LTi cells were rarely detected in impaired white pulp in spleens of these mice. These data suggest that the prion protein is required to form the splenic white pulp structure and for development of normal levels of CD4 T and LTi cells. Copyright © 2015. Published by Elsevier GmbH.

  2. Short-lived, transitory cell-cell interactions foster migration-dependent aggregation.

    Directory of Open Access Journals (Sweden)

    Melissa D Pope

    Full Text Available During embryonic development, motile cells aggregate into cohesive groups, which give rise to tissues and organs. The role of cell migration in regulating aggregation is unclear. The current paradigm for aggregation is based on an equilibrium model of differential cell adhesivity to neighboring cells versus the underlying substratum. In many biological contexts, however, dynamics is critical. Here, we provide evidence that multicellular aggregation dynamics involves both local adhesive interactions and transport by cell migration. Using time-lapse video microscopy, we quantified the duration of cell-cell contacts among migrating cells that collided and adhered to another cell. This lifetime of cell-cell interactions exhibited a monotonic decreasing dependence on substratum adhesivity. Parallel quantitative measurements of cell migration speed revealed that across the tested range of adhesive substrata, the mean time needed for cells to migrate and encounter another cell was greater than the mean adhesion lifetime, suggesting that aggregation dynamics may depend on cell motility instead of the local differential adhesivity of cells. Consistent with this hypothesis, aggregate size exhibited a biphasic dependence on substratum adhesivity, matching the trend we observed for cell migration speed. Our findings suggest a new role for cell motility, alongside differential adhesion, in regulating developmental aggregation events and motivate new design principles for tuning aggregation dynamics in tissue engineering applications.

  3. Complications impaired endothelial progenitor cell function in Type 2 diabetic patients with or without critical leg ischaemia: implication for impaired neovascularization in diabetes.

    Science.gov (United States)

    Chen, M-C; Sheu, J-J; Wang, P-W; Chen, C-Y; Kuo, M-C; Hsieh, C-J; Chen, J-F; Chang, H-W

    2009-02-01

    This study tested the hypothesis that migratory function of endothelial progenitor cells (EPCs) is impaired in Type 2 diabetic patients with or without critical leg ischaemia. Seventy-four patients were classified into four groups: Type 2 diabetic (n = 21) and non-diabetic patients (n = 10) with critical leg ischaemia and Type 2 diabetic patients without lower extremity vascular disease (n = 30) and healthy subjects (n = 13). The number and functional activity of circulating and cultured EPCs were determined. The migratory function of cultured EPCs was significantly impaired in diabetic patients without (median, 48, interquartile range, 46, 49 count/view/well) and with (median, 51, interquartile range, 46, 60 count/view/well) critical leg ischaemia and non-diabetic patients with critical leg ischaemia (median, 49, interquartile range, 47, 55 count/view/well) compared with healthy subjects (median, 63, interquartile range, 57, 65 count/view/well) (P interquartile range, 1600, 6600/10(6) cytometric events) than Type 2 diabetic patients with critical leg ischaemia (median, 5300, interquartile range, 2400, 11,100/10(6) cytometric events), non-diabetic patients with critical leg ischaemia (median, 5550, interquartile range, 2000, 32,100/10(6) cytometric events) and healthy subjects (median, 5400, interquartile range, 2700, 8700/10(6) cytometric events) (P = 0.413). The migratory function of EPCs is impaired in patients with Type 2 diabetes, even in those without critical leg ischaemia. These findings present an important new insight into the pathogenesis of impaired neovascularization and critical limb ischaemia in diabetic patients and provide avenues of future clinical study.

  4. Low concentrations of antimony impair DNA damage signaling and the repair of radiation-induced DSB in HeLa S3 cells.

    Science.gov (United States)

    Koch, Barbara; Maser, Elena; Hartwig, Andrea

    2017-12-01

    Antimony is utilized in a large variety of industrial applications, leading to significant environmental and occupational exposure. Mainly based on animal experiments, the IARC and MAK Commission have classified antimony and its inorganic compounds as Group 2B or 2 carcinogens, respectively. However, the underlying mode(s) of action are still largely unknown. In the present study, we investigated the impact of non-cytotoxic up to cytotoxic concentrations of SbCl 3 on DNA DSB repair and cell cycle control in HeLa S3 cells. We induced DSB by γ-irradiation and analyzed inhibitory actions of antimony on potential molecular targets of the DSB repair machinery. Antimony disturbed cell cycle control, affecting phosphorylation of Chk1. Furthermore, the repair of DSB was impaired in the presence of antimony, as monitored by pulsed-field gel electrophoresis and γH2AX foci formation of cells in G1 and G2 phase. Specifically, BRCA1 and RAD51 were identified as molecular targets. Our results point towards an interference with both non-homologous end-joining (NHEJ) and homologous recombination (HR), and inhibitory effects may be explained by interactions with critical cysteine groups; this needs to be further investigated. Altogether, the results provide further evidence for the impairment of DNA repair processes as one underlying mechanism in antimony-induced carcinogenicity.

  5. Identification of the Interaction between P-Glycoprotein and Anxa2 in Multidrug-resistant Human Breast Cancer Cells

    International Nuclear Information System (INIS)

    Zhang, Hai-chang; Zhang, Fei; Wu, Bing; Han, Jing-hua; Ji, Wei; Zhou, Yan; Niu, Rui-fang

    2012-01-01

    To explore the interaction of Anxa2 with P-Glycoprotein (P-gp) in the migration and invasion of the multidrug-resistant (MDR) human breast cancer cell line MCF-7/ADR. A pair of short hairpin RNA (shRNA) targeting P-gp was transfected into MCF-7/ADR cells, and monoclonal cell strains were screened. The expression of P-gp was detected by Western blot. Transwell chambers were used to observe the cell migration capacity and invasion ability. The interaction between P-gp and Anxa2 was examined by immunoprecipitation and immunofluorescence confocal microscopy analyses. P-gp expression was significantly knocked down, and there were notable decreasing trends in the migration and invasion capability of MDR breast cancer cells (P<0.05). There was a close interaction between Anxa2 and P-gp. MCF-7/ADR is an MDR human breast cancer cell line with high migration and invasion abilities. The knockdown of P-gp notably impaired the migration and invasion abilities of the tumor cells. The interaction of Anxa2 with P-pg may play an important role in the enhanced invasiveness of MDR human breast cancer cells

  6. Functional living biointerfaces to direct cell-material interaction

    OpenAIRE

    Rodrigo Navarro, Aleixandre

    2016-01-01

    [EN] This thesis deals with the development of a living biointerface between synthetic substrates and living cells to engineer cell-material interactions for tissue engineering purposes. This living biointerface is made of Lactococcus lactis, a non-pathogenic lactic bacteria widely used as starter in the dairy industry and, recently, in the expression of heterologous proteins in applications such as oral vaccine delivery or membrane-bound expression of proteins. L. lactis has been engine...

  7. Stem cell autotomy and niche interaction in different systems.

    Science.gov (United States)

    Dorn, David C; Dorn, August

    2015-07-26

    The best known cases of cell autotomy are the formation of erythrocytes and thrombocytes (platelets) from progenitor cells that reside in special niches. Recently, autotomy of stem cells and its enigmatic interaction with the niche has been reported from male germline stem cells (GSCs) in several insect species. First described in lepidopterans, the silkmoth, followed by the gipsy moth and consecutively in hemipterans, foremost the milkweed bug. In both, moths and the milkweed bug, GSCs form finger-like projections toward the niche, the apical cells (homologs of the hub cells in Drosophila). Whereas in the milkweed bug the projection terminals remain at the surface of the niche cells, in the gipsy moth they protrude deeply into the singular niche cell. In both cases, the projections undergo serial retrograde fragmentation with progressing signs of autophagy. In the gipsy moth, the autotomized vesicles are phagocytized and digested by the niche cell. In the milkweed bug the autotomized vesicles accumulate at the niche surface and disintegrate. Autotomy and sprouting of new projections appears to occur continuously. The significance of the GSC-niche interactions, however, remains enigmatic. Our concept on the signaling relationship between stem cell-niche in general and GSC and niche (hub cells and cyst stem cells) in particular has been greatly shaped by Drosophila melanogaster. In comparing the interactions of GSCs with their niche in Drosophila with those in species exhibiting GSC autotomy it is obvious that additional or alternative modes of stem cell-niche communication exist. Thus, essential signaling pathways, including niche-stem cell adhesion (E-cadherin) and the direction of asymmetrical GSC division - as they were found in Drosophila - can hardly be translated into the systems where GSC autotomy was reported. It is shown here that the serial autotomy of GSC projections shows remarkable similarities with Wallerian axonal destruction, developmental axon

  8. Stem cell autotomy and niche interaction in different systems

    Science.gov (United States)

    Dorn, David C; Dorn, August

    2015-01-01

    The best known cases of cell autotomy are the formation of erythrocytes and thrombocytes (platelets) from progenitor cells that reside in special niches. Recently, autotomy of stem cells and its enigmatic interaction with the niche has been reported from male germline stem cells (GSCs) in several insect species. First described in lepidopterans, the silkmoth, followed by the gipsy moth and consecutively in hemipterans, foremost the milkweed bug. In both, moths and the milkweed bug, GSCs form finger-like projections toward the niche, the apical cells (homologs of the hub cells in Drosophila). Whereas in the milkweed bug the projection terminals remain at the surface of the niche cells, in the gipsy moth they protrude deeply into the singular niche cell. In both cases, the projections undergo serial retrograde fragmentation with progressing signs of autophagy. In the gipsy moth, the autotomized vesicles are phagocytized and digested by the niche cell. In the milkweed bug the autotomized vesicles accumulate at the niche surface and disintegrate. Autotomy and sprouting of new projections appears to occur continuously. The significance of the GSC-niche interactions, however, remains enigmatic. Our concept on the signaling relationship between stem cell-niche in general and GSC and niche (hub cells and cyst stem cells) in particular has been greatly shaped by Drosophila melanogaster. In comparing the interactions of GSCs with their niche in Drosophila with those in species exhibiting GSC autotomy it is obvious that additional or alternative modes of stem cell-niche communication exist. Thus, essential signaling pathways, including niche-stem cell adhesion (E-cadherin) and the direction of asymmetrical GSC division - as they were found in Drosophila - can hardly be translated into the systems where GSC autotomy was reported. It is shown here that the serial autotomy of GSC projections shows remarkable similarities with Wallerian axonal destruction, developmental axon

  9. Aging-induced dysregulation of dicer1-dependent microRNA expression impairs angiogenic capacity of rat cerebromicrovascular endothelial cells.

    Science.gov (United States)

    Ungvari, Zoltan; Tucsek, Zsuzsanna; Sosnowska, Danuta; Toth, Peter; Gautam, Tripti; Podlutsky, Andrej; Csiszar, Agnes; Losonczy, Gyorgy; Valcarcel-Ares, M Noa; Sonntag, William E; Csiszar, Anna

    2013-08-01

    Age-related impairment of angiogenesis is likely to play a central role in cerebromicrovascular rarefaction and development of vascular cognitive impairment, but the underlying mechanisms remain elusive. To test the hypothesis that dysregulation of Dicer1 (ribonuclease III, a key enzyme of the microRNA [miRNA] machinery) impairs endothelial angiogenic capacity in aging, primary cerebromicrovascular endothelial cells (CMVECs) were isolated from young (3 months old) and aged (24 months old) Fischer 344 × Brown Norway rats. We found an age-related downregulation of Dicer1 expression both in CMVECs and in small cerebral vessels isolated from aged rats. In aged CMVECs, Dicer1 expression was increased by treatment with polyethylene glycol-catalase. Compared with young cells, aged CMVECs exhibited altered miRNA expression profile, which was associated with impaired proliferation, adhesion to vitronectin, collagen and fibronectin, cellular migration (measured by a wound-healing assay using electric cell-substrate impedance sensing technology), and impaired ability to form capillary-like structures. Overexpression of Dicer1 in aged CMVECs partially restored miRNA expression profile and significantly improved angiogenic processes. In young CMVECs, downregulation of Dicer1 (siRNA) resulted in altered miRNA expression profile associated with impaired proliferation, adhesion, migration, and tube formation, mimicking the aging phenotype. Collectively, we found that Dicer1 is essential for normal endothelial angiogenic processes, suggesting that age-related dysregulation of Dicer1-dependent miRNA expression may be a potential mechanism underlying impaired angiogenesis and cerebromicrovascular rarefaction in aging.

  10. Multicellular tumor spheroid interactions with bone cells and bone

    International Nuclear Information System (INIS)

    Wezeman, F.H.; Guzzino, K.M.; Waxler, B.

    1985-01-01

    In vitro coculture techniques were used to study HSDM1C1 murine fibrosarcoma multicellular tumor spheroid (HSDM1C1-MTS) interactions with mouse calvarial bone cells having osteoblastic characteristics and mouse bone explants. HSDM1C1-MTS attached to confluent bone cell monolayers and their attachment rate was quantified. HSDM1C1-MTS interaction with bone cells was further demonstrated by the release of 3 H-deoxyuridine from prelabeled bone cells during coculture with multicellular tumor spheroids. HSDM1C1-MTS-induced cytotoxicity was mimicked by the addition of 10(-5) M prostaglandin E2 (PGE2) to 3 H-deoxyuridine-labeled bone cells. The effects of low (10(-9) M) and high (10(-5) M) concentrations of PGE2 on bone cell proliferation were also studied. Higher concentrations of PGE2 inhibited bone cell proliferation. HSDM1C1-MTS resorbed living explants in the presence of indomethacin, suggesting that other tumor cell products may also participate in bone resorption. HSDM1C1-MTS caused direct bone resorption as measured by the significantly elevated release of 45 Ca from prelabeled, devitalized calvaria. However, the growth of a confluent bone cell layer on devitalized, 45 Ca-prelabeled calvaria resulted in a significant reduction in the amount of 45 Ca released subsequent to the seeding of HSDM1C1-MTS onto the explants. Bone cells at the bone surface may act as a barrier against invasion and tumor cell-mediated bone resorption. Violation of this cellular barrier is achieved, in part, by tumor cell products

  11. Why does interactional justice promote organizational loyalty, job performance, and prevent mental impairment? The role of social support and social stressors.

    Science.gov (United States)

    Otto, Kathleen; Mamatoglu, Nihal

    2015-01-01

    Using social exchange theory as a conceptual framework, we investigated the relationship between interactional justice and the outcomes organizational loyalty (affective commitment, turnover intentions), perceived job performance (self-rated performance, personal accomplishment), and mental impairment (cognitive irritation, emotional exhaustion) in an online survey of 218 employees working in the field of computer technology. Specifically, we predicted that interactional justice would heighten the quality of social exchange relationships and therefore expected perceived social support (POS) and bullying to mediate the proposed relationships. We tested our hypotheses applying a latent structural equation model. Our findings revealed that POS mediated the relationship between interactional justice and organizational loyalty, whereas bullying mediated the relationship between interactional justice and mental impairment. Practical implications are discussed concerning how to foster interactional justice and POS and how to weaken bullying behavior.

  12. Inactivation of STAT3 Signaling Impairs Hair Cell Differentiation in the Developing Mouse Cochlea

    Directory of Open Access Journals (Sweden)

    Qianqian Chen

    2017-07-01

    Full Text Available Although STAT3 signaling is demonstrated to regulate sensory cell differentiation and regeneration in the zebrafish, its exact role is still unclear in mammalian cochleae. Here, we report that STAT3 and its activated form are specifically expressed in hair cells during mouse cochlear development. Importantly, conditional cochlear deletion of Stat3 leads to an inhibition on hair cell differentiation in mice in vivo and in vitro. By cell fate analysis, inactivation of STAT3 signaling shifts the cell division modes from asymmetric to symmetric divisions from supporting cells. Moreover, inhibition of Notch signaling stimulates STAT3 phosphorylation, and inactivation of STAT3 signaling attenuates production of supernumerary hair cells induced by a Notch pathway inhibitor. Our findings highlight an important role of the STAT3 signaling during mouse cochlear hair cell differentiation and may have clinical implications for the recovery of hair cell loss-induced hearing impairment.

  13. Selective Inner Hair Cell Dysfunction in Chinchillas Impairs Hearing-in-Noise in the Absence of Outer Hair Cell Loss.

    Science.gov (United States)

    Lobarinas, Edward; Salvi, Richard; Ding, Dalian

    2016-04-01

    Poorer hearing in the presence of background noise is a significant problem for the hearing impaired. Ototoxic drugs, ageing, and noise exposure can damage the sensory hair cells of the inner ear that are essential for normal hearing sensitivity. The relationship between outer hair cell (OHC) loss and progressively poorer hearing sensitivity in quiet or in competing background noise is supported by a number of human and animal studies. In contrast, the effect of moderate inner hair cell (IHC) loss or dysfunction shows almost no impact on behavioral measures of hearing sensitivity in quiet, when OHCs remain intact, but the relationship between selective IHC loss and hearing in noise remains relatively unknown. Here, a moderately high dose of carboplatin (75 mg/kg) that produced IHC loss in chinchillas ranging from 40 to 80 % had little effect on thresholds in quiet. However, when tested in the presence of competing broadband (BBN) or narrowband noise (NBN), thresholds increased significantly. IHC loss >60 % increased signal-to-noise ratios (SNRs) for tones (500-11,300 Hz) in competing BBN by 5-10 dB and broadened the masking function under NBN. These data suggest that IHC loss or dysfunction may play a significant role in listening in noise independent of OHC integrity and that these deficits may be present even when thresholds in quiet are within normal limits.

  14. Ca2+ signalling in endothelial progenitor cells: a novel means to improve cell-based therapy and impair tumour vascularisation.

    Science.gov (United States)

    Moccia, Francesco; Lodola, Francesco; Dragoni, Silvia; Bonetti, Elisa; Bottino, Cinzia; Guerra, Germano; Laforenza, Umberto; Rosti, Vittorio; Tanzi, Franco

    2014-01-01

    Endothelial progenitor cells (EPCs) have recently been employed in cell-based therapy (CBT) to promote regeneration of ischemic organs, such as heart and limbs. Furthermore, EPCs may sustain tumour vascularisation and provide an additional target for anticancer therapies. CBT is limited by the paucity of cells harvested from peripheral blood and suffers from several pitfalls, including the low rate of engrafted EPCs, whereas classic antiangiogenic treatments manifest a number of side effects and may induce resistance into the patients. CBT will benefit of a better understanding of the signal transduction pathway(s) which drive(s) EPC proliferation, trafficking, and incorporation into injured tissues. At the same time, this information might outline alternative molecular targets to impair tumor neovascularisation and improve the therapeutic outcome of antiangiogenic strategies. An increase in intracellular Ca(2+) concentration is the key signal in the regulation of cellular replication, migration, and differentiation. In particular, Ca(2+) signalling may regulate cellcycle progression, due to the Ca(2+)-sensitivity of a number of cycline-dependent kinases, and gene expression, owing to the Ca(2+)-dependence of several transcription factors. Recent work has outlined the role of the so-called store-operated Ca(2+) entry in driving EPC proliferation and migration. Unravelling the mechanisms guiding EPC engraftment into neovessels might supply the biological bases required to improve CBT and anticancer treatments. For example, genetic manipulation of the Ca(2+) signalling machinery could provide a novel approach to increase the extent of limb regeneration or preventing tumour vascularisation by EPCs.

  15. Engineering systems for the generation of patterned co-cultures for controlling cell-cell interactions.

    Science.gov (United States)

    Kaji, Hirokazu; Camci-Unal, Gulden; Langer, Robert; Khademhosseini, Ali

    2011-03-01

    Inside the body, cells lie in direct contact or in close proximity to other cell types in a tightly controlled architecture that often regulates the resulting tissue function. Therefore, tissue engineering constructs that aim to reproduce the architecture and the geometry of tissues will benefit from methods of controlling cell-cell interactions with microscale resolution. We discuss the use of microfabrication technologies for generating patterned co-cultures. In addition, we categorize patterned co-culture systems by cell type and discuss the implications of regulating cell-cell interactions in the resulting biological function of the tissues. Patterned co-cultures are a useful tool for fabricating tissue engineered constructs and for studying cell-cell interactions in vitro, because they can be used to control the degree of homotypic and heterotypic cell-cell contact. In addition, this approach can be manipulated to elucidate important factors involved in cell-matrix interactions. Patterned co-culture strategies hold significant potential to develop biomimetic structures for tissue engineering. It is expected that they would create opportunities to develop artificial tissues in the future. This article is part of a Special Issue entitled Nanotechnologies - Emerging Applications in Biomedicine. 2010 Elsevier B.V. All rights reserved.

  16. Interaction between BDNF Polymorphism and Physical Activity on Inhibitory Performance in the Elderly without Cognitive Impairment

    Directory of Open Access Journals (Sweden)

    Anne Canivet

    2017-11-01

    Full Text Available Background: In the elderly, physical activity (PA enhances cognitive performances, increases brain plasticity and improves brain health. The neurotrophic hypothesis is that the release of brain-derived neurotrophic factor (BDNF, which is implicated in brain plasticity and cognition, is triggered by PA because motoneurons secrete BDNF into the bloodstream during exercise. Individual differences in cognitive performance may be explained by individual differences in genetic predisposition. A single nucleotide polymorphism on the BDNF gene, BDNFVal66Met, affects activity-dependent BDNF secretion. This study investigated the influence of the BDNFVal66Met polymorphism on the relationship between PA and controlled inhibition performance in older adults.Methods: A total of 114 healthy elderly volunteers (mean age = 71.53 years old were evaluated. Participants were genotyped for the BDNFVal66Met polymorphism. We evaluated inhibitory performance using choice reaction times (RT and error rates from a Simon-like task and estimated their PA using two self-reported questionnaires. We established four groups according to PA level (active vs. inactive and BDNFVal66Met genotype (Met carriers vs. Val-homozygous. The results were analyzed using ANOVA and ANCOVA, including age, gender and body mass index as covariates.Results: The BDNFVal66Met polymorphism interacted with PA on controlled inhibition performance. More specifically, inactive Val-homozygous participants exhibited a lower inhibition performance than active Val homozygotes and inactive Met carriers; the former had a higher error rate without differences in RT.Conclusion: Differences between individuals on inhibitory performance may be partially understood by the interaction between genetic influence in BDNF secretion and PA level. The results of this study clearly support the neurotrophic hypothesis that BDNF synthesis is an important mechanism underlying the influence of physical activity on brain

  17. MILD CHOLESTEROL DEPLETION REDUCES AMYLOID-β PRODUCTION BY IMPAIRING APP TRAFFICKING TO THE CELL SURFACE

    Science.gov (United States)

    Guardia-Laguarta, Cristina; Coma, Mireia; Pera, Marta; Clarimón, Jordi; Sereno, Lidia; Agulló, José M.; Molina-Porcel, Laura; Gallardo, Eduard; Deng, Amy; Berezovska, Oksana; Hyman, Bradley T.; Blesa, Rafael; Gómez-Isla, Teresa; Lleó, Alberto

    2009-01-01

    It has been suggested that cellular cholesterol levels can modulate the metabolism of the amyloid precursor protein (APP) but the underlying mechanism remains controversial. In the current study, we investigate in detail the relationship between cholesterol reduction, APP processing and γ-secretase function in cell culture studies. We found that mild membrane cholesterol reduction led to a decrease in Aβ40 and Aβ42 in different cell types. We did not detect changes in APP intracellular domain or Notch intracellular domain generation. Western blot analyses showed a cholesterol-dependent decrease in the APP C-terminal fragments and cell surface APP. Finally, we applied a fluorescence resonance energy transfer (FRET)-based technique to study APP-Presenilin 1 (PS1) interactions and lipid rafts in intact cells. Our data indicate that cholesterol depletion reduces association of APP into lipid rafts and disrupts APP-PS1 interaction. Taken together, our results suggest that mild membrane cholesterol reduction impacts the cleavage of APP upstream of γ-secretase and appears to be mediated by changes in APP trafficking and partitioning into lipid rafts. PMID:19457132

  18. Inverting adherent cells for visualizing ECM interactions at the basal cell side

    Energy Technology Data Exchange (ETDEWEB)

    Gudzenko, Tetyana [DFG-Center for Functional Nanostructures, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1a, 76131 Karlsruhe (Germany); Franz, Clemens M., E-mail: clemens.franz@kit.edu [DFG-Center for Functional Nanostructures, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1a, 76131 Karlsruhe (Germany)

    2013-05-15

    Interactions with the extracellular matrix (ECM) govern a wide range of cellular functions, including survival, migration and invasion. However, in adherent cells these interactions occur primarily on the basal cell side, making them inaccessible to high-resolution, surface-scanning imaging techniques such as atomic force microscopy (AFM) or scanning electron microscopy (SEM). Here we describe a fast and reliable method for inverting adherent cells, exposing the basal cell membrane for direct analysis by AFM or SEM in combination with fluorescence microscopy. Cells including their matrix adhesion sites remain intact during the inversion process and are transferred together with the complete array of basally associated ECM proteins. Molecular features of ECM proteins, such as the characteristic 67 nm collagen D-periodicity, are well preserved after inversion. To demonstrate the versatility of the method, we compared basal interactions of fibroblasts with fibrillar collagen I and fibronectin matrices. While fibroblasts remodel the fibronectin layer exclusively from above, they actively invade even thin collagen layers by contacting individual collagen nanofibrils both basally and apically through a network of cellular extensions. Cell–matrix entanglement coincides with enhanced cell spreading and flattening, indicating that nanoscale ECM interactions govern macroscopic changes in cell morphology. The presented cell inversion technique can thus provide novel insight into nanoscale cell–matrix interactions at the basal cell side. - Highlights: ► We present a novel method for inverting adherent cells to expose the basal cell side. ► Basal cell sides can be imaged at high resolution by AFM and SEM. ► Cells can be inverted together with the underlying extracellular matrix. ► AFM images of inverted cells provide a nanoscale look at basal cell–ECM interactions.

  19. Impaired development of cortico-striatal synaptic connectivity in a cell culture model of Huntington's disease.

    Science.gov (United States)

    Buren, Caodu; Parsons, Matthew P; Smith-Dijak, Amy; Raymond, Lynn A

    2016-03-01

    Huntington's disease (HD) is a genetically inherited neurodegenerative disease caused by a mutation in the gene encoding the huntingtin protein. This mutation results in progressive cell death that is particularly striking in the striatum. Recent evidence indicates that early HD is initially a disease of the synapse, in which subtle alterations in synaptic neurotransmission, particularly at the cortico-striatal (C-S) synapse, can be detected well in advance of cell death. Here, we used a cell culture model in which striatal neurons are co-cultured with cortical neurons, and monitored the development of C-S connectivity up to 21days in vitro (DIV) in cells cultured from either the YAC128 mouse model of HD or the background strain, FVB/N (wild-type; WT) mice. Our data demonstrate that while C-S connectivity in WT co-cultures develops rapidly and continuously from DIV 7 to 21, YAC128 C-S connectivity shows no significant growth from DIV 14 onward. Morphological and electrophysiological data suggest that a combination of pre- and postsynaptic mechanisms contribute to this effect, including a reduction in both the postsynaptic dendritic arborization and the size and replenishment rate of the presynaptic readily releasable pool of excitatory vesicles. Moreover, a chimeric culture strategy confirmed that the most robust impairment in C-S connectivity was only observed when mutant huntingtin was expressed both pre- and postsynaptically. In all, our data demonstrate a progressive HD synaptic phenotype in this co-culture system that may be exploited as a platform for identifying promising therapeutic strategies to prevent early HD-associated synaptopathy. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Chemotherapy-induced cognitive impairment is associated with decreases in cell proliferation and histone modifications

    Directory of Open Access Journals (Sweden)

    Briones Teresita L

    2011-12-01

    Full Text Available Abstract Background In this study, we examined the effects of cyclophosphamide, methothrexate, and 5-Fluorouracil (CMF drug combination on various aspects of learning and memory. We also examined the effects of CMF on cell proliferation and chromatin remodeling as possible underlying mechanisms to explain chemotherapy-associated cognitive dysfunction. Twenty-four adult female Wistar rats were included in the study and had minimitter implantation for continuous activity monitoring two weeks before the chemotherapy regimen was started. Once baseline activity data were collected, rats were randomly assigned to receive either CMF or saline injections given intraperitoneally. Treatments were given once a week for a total of 4 weeks. Two weeks after the last injection, rats were tested in the water maze for spatial learning and memory ability as well as discrimination learning. Bromodeoxyuridine (BrdU injection was given at 100 mg/Kg intraperitoneally 4 hours prior to euthanasia to determine hippocampal cell proliferation while histone acetylation and histone deacetylase activity was measured to determine CMF effects on chromatin remodeling. Results Our data showed learning and memory impairment following CMF administration independent of the drug effects on physical activity. In addition, CMF-treated rats showed decreased hippocampal cell proliferation, associated with increased histone acetylation and decreased histone deacetylase activity. Conclusions These results suggest the negative consequences of chemotherapy on brain function and that anti-cancer drugs can adversely affect the self-renewal potential of neural progenitor cells and also chromatin remodeling in the hippocampus. The significance of our findings lie on the possible usefulness of animal models in addressing the clinical phenomenon of 'chemobrain.'

  1. Influence of Cell-Cell Interactions on the Population Growth Rate in a Tumor

    Science.gov (United States)

    Chen, Yong

    2017-12-01

    The understanding of the macroscopic phenomenological models of the population growth at a microscopic level is important to predict the population behaviors emerged from the interactions between the individuals. In this work, we consider the influence of the population growth rate R on the cell-cell interaction in a tumor system and show that, in most cases especially small proliferative probabilities, the regulative role of the interaction will be strengthened with the decline of the intrinsic proliferative probabilities. For the high replication rates of an individual and the cooperative interactions, the proliferative probability almost has no effect. We compute the dependences of R on the interactions between the cells under the approximation of the nearest neighbor in the rim of an avascular tumor. Our results are helpful to qualitatively understand the influence of the interactions between the individuals on the growth rate in population systems. Supported by the National Natural Science Foundation of China under Grant Nos. 11675008 and 21434001

  2. Myeloid-Cell-Derived VEGF Maintains Brain Glucose Uptake and Limits Cognitive Impairment in Obesity.

    Science.gov (United States)

    Jais, Alexander; Solas, Maite; Backes, Heiko; Chaurasia, Bhagirath; Kleinridders, André; Theurich, Sebastian; Mauer, Jan; Steculorum, Sophie M; Hampel, Brigitte; Goldau, Julia; Alber, Jens; Förster, Carola Y; Eming, Sabine A; Schwaninger, Markus; Ferrara, Napoleone; Karsenty, Gerard; Brüning, Jens C

    2016-05-05

    High-fat diet (HFD) feeding induces rapid reprogramming of systemic metabolism. Here, we demonstrate that HFD feeding of mice downregulates glucose transporter (GLUT)-1 expression in blood-brain barrier (BBB) vascular endothelial cells (BECs) and reduces brain glucose uptake. Upon prolonged HFD feeding, GLUT1 expression is restored, which is paralleled by increased expression of vascular endothelial growth factor (VEGF) in macrophages at the BBB. In turn, inducible reduction of GLUT1 expression specifically in BECs reduces brain glucose uptake and increases VEGF serum concentrations in lean mice. Conversely, myeloid-cell-specific deletion of VEGF in VEGF(Δmyel) mice impairs BBB-GLUT1 expression, brain glucose uptake, and memory formation in obese, but not in lean mice. Moreover, obese VEGF(Δmyel) mice exhibit exaggerated progression of cognitive decline and neuroinflammation on an Alzheimer's disease background. These experiments reveal that transient, HFD-elicited reduction of brain glucose uptake initiates a compensatory increase of VEGF production and assign obesity-associated macrophage activation a homeostatic role to restore cerebral glucose metabolism, preserve cognitive function, and limit neurodegeneration in obesity. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Hemorrhagic shock impairs myocardial cell volume regulation and membrane integrity in dogs

    International Nuclear Information System (INIS)

    Horton, J.W.

    1987-01-01

    An in vitro myocardial slice technique was used to quantitate alterations in cell volume regulation and membrane integrity after 2 h or hemorrhagic shock. After in vitro incubation in Krebs-Ringer-phosphate medium containing trace [ 14 C]inulin, values (ml H 2 O/g dry wt) for control nonshocked myocardial slices were 4.03 /plus minus/ 0.11 (SE) for total water, 2.16 /plus minus/ 0.07 for inulin impermeable space, and 1.76 /plus minus/ 0.15 for inulin diffusible space. Shocked myocardial slices showed impaired response to cold incubation. After 2 h of in vivo shock, total tissue water, inulin diffusible space, and inulin impermeable space increased significantly for subendocardium, whereas changes in subepicardium parameters were minimal. Shock-induced cellular swelling was accompanied by an increased total tissue sodium, but no change in tissue potassium. Calcium entry blockade in vivo significantly reduced subendocardial total tissue water as compared with shock-untreated dogs. In addition, calcium entry blockade reduced shock-induced increases in inulin diffusible space. In vitro myocardial slice studies confirm alterations in subendocardial membrane integrity after 2 h of in vivo hemorrhagic shock. Shock-induced abnormalities in myocardial cell volume regulation are reduced by calcium entry blockade in vivo

  4. MicroRNA-22 impairs anti-tumor ability of dendritic cells by targeting p38.

    Directory of Open Access Journals (Sweden)

    Xue Liang

    Full Text Available Dendritic cells (DCs play a critical role in triggering anti-tumor immune responses. Their intracellular p38 signaling is of great importance in controlling DC activity. In this study, we identified microRNA-22 (miR-22 as a microRNA inhibiting p38 protein expression by directly binding to the 3' untranslated region (3'UTR of its mRNA. The p38 down-regulation further interfered with the synthesis of DC-derived IL-6 and the differentiation of DC-driven Th17 cells. Moreover, overexpression of miR-22 in DCs impaired their tumor-suppressing ability while miR-22 inhibitor could reverse this phenomenon and improve the curative effect of DC-based immunotherapy. Thus, our results highlight a suppressive role for miR-22 in the process of DC-invoked anti-tumor immunity and that blocking this microRNA provides a new strategy for generating potent DC vaccines for patients with cancer.

  5. Mutant LRP6 Impairs Endothelial Cell Functions Associated with Familial Normolipidemic Coronary Artery Disease

    Directory of Open Access Journals (Sweden)

    Jian Guo

    2016-07-01

    Full Text Available Mutations in the genes low-density lipoprotein (LDL receptor-related protein-6 (LRP6 and myocyte enhancer factor 2A (MEF2A were reported in families with coronary artery disease (CAD. We intend to determine the mutational spectrum of these genes among hyperlipidemic and normolipidemic CAD families. Forty probands with early-onset CAD were recruited from 19 hyperlipidemic and 21 normolipidemic Chinese families. We sequenced all exons and intron-exon boundaries of LRP6 and MEF2A, and found a novel heterozygous variant in LRP6 from a proband with normolipidemic CAD. This variant led to a substitution of histidine to tyrosine (Y418H in an evolutionarily conserved domain YWTD in exon 6 and was not found in 1025 unrelated healthy individuals. Co-segregated with CAD in the affected family, LRP6Y418H significantly debilitated the Wnt3a-associated signaling pathway, suppressed endothelial cell proliferation and migration, and decreased anti-apoptotic ability. However, it exhibited no influences on low-density lipoprotein cholesterol uptake. Thus, mutation Y418H in LRP6 likely contributes to normolipidemic familial CAD via impairing endothelial cell functions and weakening the Wnt3a signaling pathway.

  6. Cell In Situ Zymography: Imaging Enzyme-Substrate Interactions.

    Science.gov (United States)

    Chhabra, Aastha; Rani, Vibha

    2017-01-01

    Zymography has long been used for the detection of substrate-specific enzyme activity. In situ zymography (ISZ), an adaptation from the conventional substrate zymography, is a widely employed technique useful for the detection, localization, and estimation of enzyme-substrate interactions in tissues. Here, we describe a protocol to detect 'in position' matrix metalloproteinase (MMP) activity in cells utilizing H9c2 cardiomyoblasts as a model. This technique is primarily adopted from the method used for histological sections and is termed as 'Cell in situ Zymography'. It is a simple, sensitive, and quantifiable methodology to assess the functional activity of an enzyme 'on site/in position' in cell culture.

  7. Dysregulation of type 2 innate lymphoid cells and TH2 cells impairs pollutant-induced allergic airway responses.

    Science.gov (United States)

    De Grove, Katrien C; Provoost, Sharen; Hendriks, Rudi W; McKenzie, Andrew N J; Seys, Leen J M; Kumar, Smitha; Maes, Tania; Brusselle, Guy G; Joos, Guy F

    2017-01-01

    Although the prominent role of T H 2 cells in type 2 immune responses is well established, the newly identified type 2 innate lymphoid cells (ILC2s) can also contribute to orchestration of allergic responses. Several experimental and epidemiologic studies have provided evidence that allergen-induced airway responses can be further enhanced on exposure to environmental pollutants, such as diesel exhaust particles (DEPs). However, the components and pathways responsible remain incompletely known. We sought to investigate the relative contribution of ILC2 and adaptive T H 2 cell responses in a murine model of DEP-enhanced allergic airway inflammation. Wild-type, Gata-3 +/nlslacZ (Gata-3-haploinsufficient), RAR-related orphan receptor α (RORα) fl/fl IL7R Cre (ILC2-deficient), and recombination-activating gene (Rag) 2 -/- mice were challenged with saline, DEPs, or house dust mite (HDM) or DEP+HDM. Airway hyperresponsiveness, as well as inflammation, and intracellular cytokine expression in ILC2s and T H 2 cells in the bronchoalveolar lavage fluid and lung tissue were assessed. Concomitant DEP+HDM exposure significantly enhanced allergic airway inflammation, as characterized by increased airway eosinophilia, goblet cell metaplasia, accumulation of ILC2s and T H 2 cells, type 2 cytokine production, and airway hyperresponsiveness compared with sole DEPs or HDM. Reduced Gata-3 expression decreased the number of functional ILC2s and T H 2 cells in DEP+HDM-exposed mice, resulting in an impaired DEP-enhanced allergic airway inflammation. Interestingly, although the DEP-enhanced allergic inflammation was marginally reduced in ILC2-deficient mice that received combined DEP+HDM, it was abolished in DEP+HDM-exposed Rag2 -/- mice. These data indicate that dysregulation of ILC2s and T H 2 cells attenuates DEP-enhanced allergic airway inflammation. In addition, a crucial role for the adaptive immune system was shown on concomitant DEP+HDM exposure. Copyright © 2016 American

  8. Interaction of basal forebrain cholinergic neurons with the glucocorticoid system in stress regulation and cognitive impairment

    Directory of Open Access Journals (Sweden)

    Saswati ePaul

    2015-04-01

    Full Text Available A substantial number of studies on basal forebrain cholinergic neurons (BFCN have provided compelling evidence for their role in the etiology of stress, cognitive aging, Alzheimer’s disease (AD, and other neurodegenerative diseases. BFCN project to a broad range of cortical sites and limbic structures, including the hippocampus, and are involved in stress and cognition. In particular, the hippocampus, the primary target tissue of the glucocorticoid stress hormones, is associated with cognitive function in tandem with hypothalamic-pituitary-adrenal (HPA axis modulation. The present review summarizes glucocorticoid and HPA axis research to date in an effort to establish the manner in which stress affects the release of acetylcholine, glucocorticoids, and their receptor in the context of cognitive processes. We attempt to provide the molecular interactive link between the glucocorticoids and cholinergic system that contributes to BFCN degeneration in stress-induced acceleration of cognitive decline in aging and AD. We also discuss the importance of animal models in facilitating such studies for pharmacological use, which could help decipher disease states and propose leads for pharmacological intervention.

  9. Chronic In Vivo Interaction of Dendritic Cells Expressing the Ligand Rae-1ε with NK Cells Impacts NKG2D Expression and Function.

    Science.gov (United States)

    Morvan, Maelig G; Champsaur, Marine; Reizis, Boris; Lanier, Lewis L

    2017-05-01

    To investigate how dendritic cells (DCs) interact with NK cells in vivo, we developed a novel mouse model in which Rae-1ε, a ligand of the NKG2D receptor, is expressed in cells with high levels of CD11c. In these CD11c-Rae1 mice, expression of Rae-1 was confirmed on all subsets of DCs and a small subset of B and T cells, but not on NK cells. DC numbers and activation status were unchanged, and NK cells in these CD11c-Rae1 mice presented the same Ly49 repertoire and maturation levels as their littermate wildtype controls. Early NK cell activation after mouse CMV infection was slightly lower than in wildtype mice, but NK cell expansion and viral control were comparable. Notably, we demonstrate that chronic interaction of NK cells with NKG2D ligand-expressing DCs leads to a reversible NKG2D down-modulation, as well as impaired NKG2D-dependent NK cell functions, including tumor rejection. In addition to generating a useful mouse model, our studies reveal in vivo the functional importance of the NK cell and DC cross-talk.

  10. Fusobacterium nucleatum-Induced Impairment of Autophagic Flux Enhances the Expression of Proinflammatory Cytokines via ROS in Caco-2 Cells.

    Directory of Open Access Journals (Sweden)

    Bin Tang

    Full Text Available Fusobacterium nucleatum (F. nucleatum plays a critical role in gastrointestinal inflammation. However, the exact mechanism by which F. nucleatum contributes to inflammation is unclear. In the present study, it was revealed that F. nucleatum could induce the production of proinflammatory cytokines (IL-8, IL-1β and TNF-α and reactive oxygen species (ROS in Caco-2 colorectal adenocarcinoma cells. Furthermore, ROS scavengers (NAC or Tiron could decrease the production of proinflammatory cytokines during F. nucleatum infection. In addition, we observed that autophagy is impaired in Caco-2 cells after F. nucleatum infection. The production of proinflammatory cytokines and ROS induced by F. nucleatum was enhanced with either autophagy pharmacologic inhibitors (3-methyladenine, bafilomycin A1 or RNA interference in essential autophagy genes (ATG5 or ATG12 in Caco-2 cells. Taken together, these results indicate that F. nucleatum-induced impairment of autophagic flux enhances the expression of proinflammatory cytokines via ROS in Caco-2 Cells.

  11. Microarrays for the evaluation of cell-biomaterial surface interactions

    Science.gov (United States)

    Thissen, H.; Johnson, G.; McFarland, G.; Verbiest, B. C. H.; Gengenbach, T.; Voelcker, N. H.

    2007-01-01

    The evaluation of cell-material surface interactions is important for the design of novel biomaterials which are used in a variety of biomedical applications. While traditional in vitro test methods have routinely used samples of relatively large size, microarrays representing different biomaterials offer many advantages, including high throughput and reduced sample handling. Here, we describe the simultaneous cell-based testing of matrices of polymeric biomaterials, arrayed on glass slides with a low cell-attachment background coating. Arrays were constructed using a microarray robot at 6 fold redundancy with solid pins having a diameter of 375 μm. Printed solutions contained at least one monomer, an initiator and a bifunctional crosslinker. After subsequent UV polymerisation, the arrays were washed and characterised by X-ray photoelectron spectroscopy. Cell culture experiments were carried out over 24 hours using HeLa cells. After labelling with CellTracker ® Green for the final hour of incubation and subsequent fixation, the arrays were scanned. In addition, individual spots were also viewed by fluorescence microscopy. The evaluation of cell-surface interactions in high-throughput assays as demonstrated here is a key enabling technology for the effective development of future biomaterials.

  12. Nuclear envelope and genome interactions in cell fate

    Science.gov (United States)

    Talamas, Jessica A.; Capelson, Maya

    2015-01-01

    The eukaryotic cell nucleus houses an organism’s genome and is the location within the cell where all signaling induced and development-driven gene expression programs are ultimately specified. The genome is enclosed and separated from the cytoplasm by the nuclear envelope (NE), a double-lipid membrane bilayer, which contains a large variety of trans-membrane and associated protein complexes. In recent years, research regarding multiple aspects of the cell nucleus points to a highly dynamic and coordinated concert of efforts between chromatin and the NE in regulation of gene expression. Details of how this concert is orchestrated and how it directs cell differentiation and disease are coming to light at a rapid pace. Here we review existing and emerging concepts of how interactions between the genome and the NE may contribute to tissue specific gene expression programs to determine cell fate. PMID:25852741

  13. Interaction of dermatologically relevant nanoparticles with skin cells and skin

    Directory of Open Access Journals (Sweden)

    Annika Vogt

    2014-12-01

    Full Text Available The investigation of nanoparticle interactions with tissues is complex. High levels of standardization, ideally testing of different material types in the same biological model, and combinations of sensitive imaging and detection methods are required. Here, we present our studies on nanoparticle interactions with skin, skin cells, and biological media. Silica, titanium dioxide and silver particles were chosen as representative examples for different types of skin exposure to nanomaterials, e.g., unintended environmental exposure (silica versus intended exposure through application of sunscreen (titanium dioxide or antiseptics (silver. Because each particle type exhibits specific physicochemical properties, we were able to apply different combinations of methods to examine skin penetration and cellular uptake, including optical microscopy, electron microscopy, X-ray microscopy on cells and tissue sections, flow cytometry of isolated skin cells as well as Raman microscopy on whole tissue blocks. In order to assess the biological relevance of such findings, cell viability and free radical production were monitored on cells and in whole tissue samples. The combination of technologies and the joint discussion of results enabled us to look at nanoparticle–skin interactions and the biological relevance of our findings from different angles.

  14. C-Reactive Protein Impairs Dendritic Cell Development, Maturation, and Function: Implications for Peripheral Tolerance

    Directory of Open Access Journals (Sweden)

    Rachel V. Jimenez

    2018-03-01

    Full Text Available C-reactive protein (CRP is the prototypical acute phase reactant, increasing in blood concentration rapidly and several-fold in response to inflammation. Recent evidence indicates that CRP has an important physiological role even at low, baseline levels, or in the absence of overt inflammation. For example, we have shown that human CRP inhibits the progression of experimental autoimmune encephalomyelitis (EAE in CRP transgenic mice by shifting CD4+ T cells away from the TH1 and toward the TH2 subset. Notably, this action required the inhibitory Fcγ receptor IIB (FcγRIIB, but did not require high levels of human CRP. Herein, we sought to determine if CRP’s influence in EAE might be explained by CRP acting on dendritic cells (DC; antigen presenting cells known to express FcγRIIB. We found that CRP (50 µg/ml reduced the yield of CD11c+ bone marrow-derived DCs (BMDCs and CRP (≥5 μg/ml prevented their full expression of major histocompatibility complex class II and the co-stimulatory molecules CD86 and CD40. CRP also decreased the ability of BMDCs to stimulate antigen-driven proliferation of T cells in vitro. Importantly, if the BMDCs were genetically deficient in mouse FcγRIIB then (i the ability of CRP to alter BMDC surface phenotype and impair T cell proliferation was ablated and (ii CD11c-driven expression of a human FCGR2B transgene rescued the CRP effect. Lastly, the protective influence of CRP in EAE was fully restored in mice with CD11c-driven human FcγRIIB expression. These findings add to the growing evidence that CRP has important biological effects even in the absence of an acute phase response, i.e., CRP acts as a tonic suppressor of the adaptive immune system. The ability of CRP to suppress development, maturation, and function of DCs implicates CRP in the maintenance of peripheral T cell tolerance.

  15. Interactions of Cells with Magnetic Nanowires and Micro Needles

    KAUST Repository

    Perez, Jose E.

    2017-12-01

    The use of nanowires, nano and micro needles in biomedical applications has markedly increased in the past years, mainly due to attractive properties such as biocompatibility and simple fabrication. Specifically, these structures have shown promise in applications including cell separation, tumor cell capture, intracellular delivery, cell therapy, cancer treatment and as cell growth scaffolds. The work proposed here aims to study two platforms for different applications: a vertical magnetic nanowire array for mesenchymal stem cell differentiation and a micro needle platform for intracellular delivery. First, a thorough evaluation of the cytotoxicity of nanowires was done in order to understand how a biological system interacts with high aspect ratio structures. Nanowires were fabricated through pulsed electrodeposition and characterized by electron microscopy, vibrating sample magnetometry and energy dispersive X-ray spectroscopy. Studies of biocompatibility, cell death, cell membrane integrity, nanowire internalization and intracellular dissolution were all performed in order to characterize the cell response. Results showed a variable biocompatibility depending on nanowire concentration and incubation time, with cell death resulting from an apoptotic pathway arising after internalization. A vertical array of nanowires was then used as a scaffold for the differentiation of human mesenchymal stem cells. Using fluorescence and electron microscopy, the interactions between the dense array of nanowires and the cells were analyzed, as well as the biocompatibility of the array and its effects on cell differentiation. A magnetic field was additionally applied on the substrate to observe a possible differentiation. Stem cells grown on this scaffold showed a cytoskeleton and focal adhesion reorganization, and later expressed the osteogenic marker osteopontin. The application of a magnetic field counteracted this outcome. Lastly, a micro needle platform was fabricated

  16. Manganese induces mitochondrial dynamics impairment and apoptotic cell death: a study in human Gli36 cells.

    Science.gov (United States)

    Alaimo, Agustina; Gorojod, Roxana M; Miglietta, Esteban A; Villarreal, Alejandro; Ramos, Alberto J; Kotler, Mónica L

    2013-10-25

    Manganese (Mn) is an essential trace element due to its participation in many physiological processes. However, overexposure to this metal leads to a neurological disorder known as Manganism whose clinical manifestations and molecular mechanisms resemble Parkinson's disease. Several lines of evidence implicate astrocytes as an early target of Mn neurotoxicity being the mitochondria the most affected organelles. The aim of this study was to investigate the possible mitochondrial dynamics alterations in Mn-exposed human astrocytes. Therefore, we employed Gli36 cells which express the astrocytic markers GFAP and S100B. We demonstrated that Mn triggers the mitochondrial apoptotic pathway revealed by increased Bax/Bcl-2 ratio, by the loss of mitochondrial membrane potential and by caspase-9 activation. This apoptotic program may be in turn responsible of caspase-3/7 activation, PARP-1 cleavage, chromatin condensation and fragmentation. In addition, we determined that Mn induces deregulation in mitochondria-shaping proteins (Opa-1, Mfn-2 and Drp-1) expression levels in parallel with the disruption of the mitochondrial network toward to an exacerbated fragmentation. Since mitochondrial dynamics is altered in several neurodegenerative diseases, these proteins could become future targets to be considered in Manganism treatment. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  17. Treadmill exercise alleviates stress-induced impairment of social interaction through 5-hydroxytryptamine 1A receptor activation in rats.

    Science.gov (United States)

    Kim, Tae-Woon; Lim, Baek-Vin; Kim, Kijeong; Seo, Jin-Hee; Kim, Chang-Ju

    2015-08-01

    Brain-derived neurotrophic factor (BDNF) and its receptors tyrosine kinase B (trkB), and cyclic adenosine monophosphate response element binding protein (CREB) have been suggested as the neurobiological risk factors causing depressive disorder. Serotonin (5-hydroxytryptamine, 5-HT) plays an important role in the pathogenesis of depression. We in-vestigated the effect of treadmill exercise on social interaction in relation with BDNF and 5-HT expressions following stress in rats. Stress was induced by applying inescapable 0.2 mA electric foot shock to the rats for 7 days. The rats in the exercise groups were forced to run on a motorized treadmill for 30 min once a day for 4 weeks. Social interaction test and western blot for BDNF, TrkB, pCREB, and 5-HT1A in the hippocampus were performed. The results indicate that the spend time with unfamiliar partner was decreased by stress, in contrast, treadmill exercise increased the spending time in the stress-induced rats. Expressions of BDNF, TrkB, and pCREB were decreased by stress, in contrast, treadmill exercise enhanced expressions of BDNF, TrkB, and pCREB in the stress-induced rats. In addition, 5-HT1A receptor expression was de-creased by stress, in contrast, treadmill exercise enhanced 5-HT1A expression in the stress-induced rats. In the present study, treadmill exercise alleviated stress-induced social interaction impairment through enhancing hippocampal plasticity and serotonergic function in the hippocampus. These effects of treadmill exercise are achieved through 5-HT1A receptor activation.

  18. Detecting protein-protein interactions in living cells

    DEFF Research Database (Denmark)

    Gottschalk, Marie; Bach, Anders; Hansen, Jakob Lerche

    2009-01-01

    to the endogenous C-terminal peptide of the NMDA receptor, as evaluated by a cell-free protein-protein interaction assay. However, it is important to address both membrane permeability and effect in living cells. Therefore a bioluminescence resonance energy transfer (BRET) assay was established, where the C......-terminal of the NMDA receptor and PDZ2 of PSD-95 were fused to green fluorescent protein (GFP) and Renilla luciferase (Rluc) and expressed in COS7 cells. A robust and specific BRET signal was obtained by expression of the appropriate partner proteins and subsequently, the assay was used to evaluate a Tat......The PDZ domain mediated interaction between the NMDA receptor and its intracellular scaffolding protein, PSD-95, is a potential target for treatment of ischemic brain diseases. We have recently developed a number of peptide analogues with improved affinity for the PDZ domains of PSD-95 compared...

  19. Interaction between adipose tissue-derived mesenchymal stem cells and regulatory T-cells

    OpenAIRE

    Engela, Anja; Baan, Carla; Peeters, Anna; Weimar, Willem; Hoogduijn, Martin

    2013-01-01

    textabstractMesenchymal stem cells (MSCs) exhibit immunosuppressive capabilities, which have evoked interest in their application as cell therapy in transplant patients. So far it has been unclear whether allogeneic MSCs and host regulatory T-cells (Tregs) functionally influence each other. We investigated the interaction between both cell types using perirenal adipose tissue-derived MSCs (ASCs) from kidney donors and Tregs from blood bank donors or kidney recipients 6 months after transplant...

  20. EZH2 Impairs Human Dental Pulp Cell Mineralization via the Wnt/β-Catenin Pathway.

    Science.gov (United States)

    Li, B; Yu, F; Wu, F; Hui, T; A, P; Liao, X; Yin, B; Wang, C; Ye, L

    2018-05-01

    The enhancer of zeste homolog 2 (EZH2) is a catalytic subunit of PRC2 (polycomb repressor complex 2). It mediates gene silencing via methyltransferase activity and is involved in the determination of cell lineage. However, the function of EZH2 and the underlying mechanisms by which it affects the differentiation of human dental pulp cell (hDPC) have remained underexplored. In this research, we found that EZH2 expression decreased during the mineralization of hDPCs, with attenuated H3K27me3 (trimethylation on lysine 27 in histone H3). Overexpression of EZH2 impaired the odontogenic differentiation of hDPCs, while EZH2 without methyltransferase activity mutation (mutation of suppressed variegation of 3 to 9, enhancer of zeste and trithorax domain, EZH2ΔSET) did not display this phenotype. In addition, siRNA knockdown studies showed that EZH2 negatively modulated hDPC differentiation in vitro and inhibited mineralized nodule formation in transplanted β-tricalcium phosphate / hDPC composites. To further investigate the underlying mechanisms, we explored the Wnt/β-catenin signaling pathway in view of the fact that previous research had documented the essential role that it plays during hDPC mineralization, as well as its links to EZH2 in other cells. We demonstrated for the first time that EZH2 depletion activated the Wnt/β-catenin signaling pathway and enhanced the accumulation of β-catenin in hDPCs. Chromatin immunoprecipitation analysis suggested that these effects are attributable to the level of the EZH2-regulated H3K27me3 on the β-catenin promoter. We conclude that EZH2 plays a negative role during the odontogenic differentiation of hDPCs. Suppression of EZH2 could promote hDPC mineralization by epigenetically regulating the expression of β-catenin and activating the Wnt canonical signaling pathway.

  1. Zoledronate inhibits ischemia-induced neovascularization by impairing the mobilization and function of endothelial progenitor cells.

    Directory of Open Access Journals (Sweden)

    Shih-Hung Tsai

    Full Text Available BACKGROUND: Bisphosphonates are a class of pharmacologic compounds that are commonly used to treat postmenopausal osteoporosis and malignant osteolytic processes. Studies have shown that bone marrow-derived endothelial progenitor cells (EPCs play a significant role in postnatal neovascularization. Whether the nitrogen-containing bisphosphonate zoledronate inhibits ischemia-induced neovascularization by modulating EPC functions remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: Unilateral hindlimb ischemia was surgically induced in wild-type mice after 2 weeks of treatment with vehicle or zoledronate (low-dose: 30 μg/kg; high-dose: 100 μg/kg. Doppler perfusion imaging demonstrated that the ischemic limb/normal side blood perfusion ratio was significantly lower in wild-type mice treated with low-dose zoledronate and in mice treated with high-dose zoledronate than in controls 4 weeks after ischemic surgery (control vs. low-dose vs. high-dose: 87±7% vs. *61±18% vs. **49±17%, *p<0.01, **p<0.005 compared to control. Capillary densities were also significantly lower in mice treated with low-dose zoledronate and in mice treated with high-dose zoledronate than in control mice. Flow cytometry analysis showed impaired mobilization of EPC-like cells (Sca-1(+/Flk-1(+ after surgical induction of ischemia in mice treated with zoledronate but normal levels of mobilization in mice treated with vehicle. In addition, ischemic tissue from mice that received zoledronate treatment exhibited significantly lower levels of the active form of MMP-9, lower levels of VEGF, and lower levels of phosphorylated eNOS and phosphorylated Akt than ischemic tissue from mice that received vehicle. Results of the in vitro studies showed that incubation with zoledronate inhibited the viability, migration, and tube-forming capacities of EPC. CONCLUSIONS/SIGNIFICANCE: Zoledronate inhibited ischemia-induced neovascularization by impairing EPC mobilization and angiogenic functions

  2. Impaired cell surface expression of HLA-B antigens on mesenchymal stem cells and muscle cell progenitors

    DEFF Research Database (Denmark)

    Isa, Adiba; Nehlin, Jan; Sabir, Hardee Jawad

    2010-01-01

    HLA class-I expression is weak in embryonic stem cells but increases rapidly during lineage progression. It is unknown whether all three classical HLA class-I antigens follow the same developmental program. In the present study, we investigated allele-specific expression of HLA-A, -B, and -C...... at the mRNA and protein levels on human mesenchymal stem cells from bone marrow and adipose tissue as well as striated muscle satellite cells and lymphocytes. Using multicolour flow cytometry, we found high cell surface expression of HLA-A on all stem cells and PBMC examined. Surprisingly, HLA-B was either...... undetectable or very weakly expressed on all stem cells protecting them from complement-dependent cytotoxicity (CDC) using relevant human anti-B and anti-Cw sera. IFNgamma stimulation for 48-72 h was required to induce full HLA-B protein expression. Quantitative real-time RT-PCR showed that IFNgamma induced...

  3. Ionizing radiation induces heritable disruption of epithelial cell interactions

    Science.gov (United States)

    Park, Catherine C.; Henshall-Powell, Rhonda L.; Erickson, Anna C.; Talhouk, Rabih; Parvin, Bahram; Bissell, Mina J.; Barcellos-Hoff, Mary Helen; Chatterjee, A. (Principal Investigator)

    2003-01-01

    Ionizing radiation (IR) is a known human breast carcinogen. Although the mutagenic capacity of IR is widely acknowledged as the basis for its action as a carcinogen, we and others have shown that IR can also induce growth factors and extracellular matrix remodeling. As a consequence, we have proposed that an additional factor contributing to IR carcinogenesis is the potential disruption of critical constraints that are imposed by normal cell interactions. To test this hypothesis, we asked whether IR affected the ability of nonmalignant human mammary epithelial cells (HMEC) to undergo tissue-specific morphogenesis in culture by using confocal microscopy and imaging bioinformatics. We found that irradiated single HMEC gave rise to colonies exhibiting decreased localization of E-cadherin, beta-catenin, and connexin-43, proteins necessary for the establishment of polarity and communication. Severely compromised acinar organization was manifested by the majority of irradiated HMEC progeny as quantified by image analysis. Disrupted cell-cell communication, aberrant cell-extracellular matrix interactions, and loss of tissue-specific architecture observed in the daughters of irradiated HMEC are characteristic of neoplastic progression. These data point to a heritable, nonmutational mechanism whereby IR compromises cell polarity and multicellular organization.

  4. A population dynamics analysis of the interaction between adaptive regulatory T cells and antigen presenting cells.

    Directory of Open Access Journals (Sweden)

    David Fouchet

    Full Text Available BACKGROUND: Regulatory T cells are central actors in the maintenance of tolerance of self-antigens or allergens and in the regulation of the intensity of the immune response during infections by pathogens. An understanding of the network of the interaction between regulatory T cells, antigen presenting cells and effector T cells is starting to emerge. Dynamical systems analysis can help to understand the dynamical properties of an interaction network and can shed light on the different tasks that can be accomplished by a network. METHODOLOGY AND PRINCIPAL FINDINGS: We used a mathematical model to describe a interaction network of adaptive regulatory T cells, in which mature precursor T cells may differentiate into either adaptive regulatory T cells or effector T cells, depending on the activation state of the cell by which the antigen was presented. Using an equilibrium analysis of the mathematical model we show that, for some parameters, the network has two stable equilibrium states: one in which effector T cells are strongly regulated by regulatory T cells and another in which effector T cells are not regulated because the regulatory T cell population is vanishingly small. We then simulate different types of perturbations, such as the introduction of an antigen into a virgin system, and look at the state into which the system falls. We find that whether or not the interaction network switches from the regulated (tolerant state to the unregulated state depends on the strength of the antigenic stimulus and the state from which the network has been perturbed. CONCLUSION/SIGNIFICANCE: Our findings suggest that the interaction network studied in this paper plays an essential part in generating and maintaining tolerance against allergens and self-antigens.

  5. Diet-Induced Obesity Is Associated with an Impaired NK Cell Function and an Increased Colon Cancer Incidence

    Directory of Open Access Journals (Sweden)

    Ina Bähr

    2017-01-01

    Full Text Available Obesity is associated with an increased colon cancer incidence, but underlying mechanisms remained unclear. Previous studies showed altered Natural killer (NK cell functions in obese individuals. Therefore, we studied the impact of an impaired NK cell functionality on the increased colon cancer risk in obesity. In vitro investigations demonstrated a decreased IFN-γ secretion and cytotoxicity of human NK cells against colon tumor cells after NK cell preincubation with the adipokine leptin. In addition, leptin incubation decreased the expression of activating NK cell receptors. In animal studies, colon cancer growth was induced by injection of azoxymethane (AOM in normal weight and diet-induced obese rats. Body weight and visceral fat mass were increased in obese animals compared to normal weight rats. AOM-treated obese rats showed an increased quantity, size, and weight of colon tumors compared to the normal weight tumor group. Immunohistochemical analyses demonstrated a decreased number of NK cells in spleen and liver in obesity. Additionally, the expression levels of activating NK cell receptors were lower in spleen and liver of obese rats. The results show for the first time that the decreased number and impaired NK cell function may be one cause for the higher colon cancer risk in obesity.

  6. Deletion of the calmodulin-binding domain of Grb7 impairs cell attachment to the extracellular matrix and migration

    Energy Technology Data Exchange (ETDEWEB)

    García-Palmero, Irene; Villalobo, Antonio, E-mail: antonio.villalobo@iib.uam.es

    2013-06-28

    Highlights: •Grb7 is a calmodulin (CaM)-binding protein. •Deleting the CaM-binding site impairs cell attachment and migration. •CaM antagonists inhibit Grb7-mediated cell migration. •We conclude that CaM controls Grb7-mediated cell migration. -- Abstract: The adaptor Grb7 is a calmodulin (CaM)-binding protein that participates in signaling pathways involved in cell migration, proliferation and the control of angiogenesis, and plays a significant role in tumor growth, its metastatic spread and tumor-associated neo-vasculature formation. In this report we show that deletion of the CaM-binding site of Grb7, located in the proximal region of its pleckstrin homology (PH) domain, impairs cell migration, cell attachment to the extracellular matrix, and the reorganization of the actin cytoskeleton occurring during this process. Moreover, we show that the cell-permeable CaM antagonists N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) and N-(4-aminobutyl)-5-chloro-2-naphthalenesulfonamide (W-13) both retard the migration of cells expressing wild type Grb7, but not the migration of cells expressing the mutant protein lacking the CaM-binding site (Grb7Δ), underscoring the proactive role of CaM binding to Grb7 during this process.

  7. Cell-substrate interaction with cell-membrane-stress dependent adhesion.

    Science.gov (United States)

    Jiang, H; Yang, B

    2012-01-10

    Cell-substrate interaction is examined in a two-dimensional mechanics model. The cell and substrate are treated as a shell and an elastic solid, respectively. Their interaction through adhesion is treated using nonlinear springs. Compared to previous cell mechanics models, the present model introduces a cohesive force law that is dependent not only on cell-substrate distance but also on internal cell-membrane stress. It is postulated that a living cell would establish focal adhesion sites with density dependent on the cell-membrane stress. The formulated mechanics problem is numerically solved using coupled finite elements and boundary elements for the cell and the substrate, respectively. The nodes in the adhesion zone from either side are linked by the cohesive springs. The specific cases of a cell adhering to a homogeneous substrate and a heterogeneous bimaterial substrate are examined. The analyses show that the substrate stiffness affects the adhesion behavior significantly and regulates the direction of cell adhesion, in good agreement with the experimental results in the literature. By introducing a reactive parameter (i.e., cell-membrane stress) linking biological responses of a living cell to a mechanical environment, the present model offers a unified mechanistic vehicle for characterization and prediction of living cell responses to various kinds of mechanical stimuli including local extracellular matrix and neighboring cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Gammadelta receptor bearing T cells in scleroderma: enhanced interaction with vascular endothelial cells in vitro.

    Science.gov (United States)

    Kahaleh, M B; Fan, P S; Otsuka, T

    1999-05-01

    In view of the documented perivascular mononuclear cell infiltration in the involved organs in scleroderma (SSc) and the reported accumulation of gammadelta-T cells in SSc skin and lung, we evaluated gammadelta-T cell interaction with endothelial cells (EC) in vitro. gammadelta- and alphabeta-T cells were isolated from BPMN of SSc patients with early diffuse disease and of matched control subjects by an immunomagnetic method after stimulation with mycobacterium lysate and interleukin-2 for 2 weeks. Lymphocyte adhesion, proliferation, and cytotoxicity to EC were investigated. SSc gammadelta-T cells adhered to cultured EC and proliferated at higher rates than control cells. Furthermore, significant EC cytotoxicity by SSc gammadelta was seen. The cytotoxicity was blocked by addition of anti-gammadelta-TCR antibody and by anti-granzyme A antibody but not by anti-MHC class I and II antibodies. Expression of granzyme A mRNA was seen in five/five SSc gammadelta-T cells and in one/five control cells. alphabeta-T cells from both SSc and control subjects were significantly less interactive with EC than gammadelta-T cells. The data demonstrate EC recognition by SSc gammadelta-T cells and propose gammadelta-T cells as a possible effector cell type in the immune pathogenesis of SSc. Copyright 1999 Academic Press.

  9. The Effects of Online Interactions on the Relationship between Learning-Related Anxiety and Intention to Persist among E-Learning Students with Visual Impairment

    Science.gov (United States)

    Oh, Yunjin; Lee, Soon Min

    2016-01-01

    This study explored whether learning-related anxiety would negatively affect intention to persist with e-learning among students with visual impairment, and examined the roles of three online interactions in the relationship between learning-related anxiety and intention to persist with e-learning. For this study, a convenience sample of…

  10. Interactions between Innate Lymphoid Cells and Cells of the Innate and Adaptive Immune System.

    Science.gov (United States)

    Symowski, Cornelia; Voehringer, David

    2017-01-01

    Type 2 innate lymphoid cells (ILC2s) are a major source of cytokines, which are also produced by Th2 cells and several cell types of the innate immune system. Work over the past few years indicates that ILC2s play a central role in regulating type 2 immune responses against allergens and helminths. ILC2s can interact with a variety of cells types of the innate and adaptive immune system by cell-cell contacts or by communication via soluble factors. In this review, we provide an overview about recent advances in our understanding how ILC2s orchestrate type 2 immune responses with focus on direct interactions between ILC2s and other cells of the immune system.

  11. Nanoscale tissue engineering: spatial control over cell-materials interactions

    Science.gov (United States)

    Wheeldon, Ian; Farhadi, Arash; Bick, Alexander G.; Jabbari, Esmaiel; Khademhosseini, Ali

    2011-01-01

    Cells interact with the surrounding environment by making tens to hundreds of thousands of nanoscale interactions with extracellular signals and features. The goal of nanoscale tissue engineering is to harness the interactions through nanoscale biomaterials engineering in order to study and direct cellular behaviors. Here, we review the nanoscale tissue engineering technologies for both two- and three-dimensional studies (2- and 3D), and provide a holistic overview of the field. Techniques that can control the average spacing and clustering of cell adhesion ligands are well established and have been highly successful in describing cell adhesion and migration in 2D. Extension of these engineering tools to 3D biomaterials has created many new hydrogel and nanofiber scaffolds technologies that are being used to design in vitro experiments with more physiologically relevant conditions. Researchers are beginning to study complex cell functions in 3D, however, there is a need for biomaterials systems that provide fine control over the nanoscale presentation of bioactive ligands in 3D. Additionally, there is a need for 2- and 3D techniques that can control the nanoscale presentation of multiple bioactive ligands and the temporal changes in cellular microenvironment. PMID:21451238

  12. Nanoscale tissue engineering: spatial control over cell-materials interactions

    International Nuclear Information System (INIS)

    Wheeldon, Ian; Farhadi, Arash; Bick, Alexander G; Khademhosseini, Ali; Jabbari, Esmaiel

    2011-01-01

    Cells interact with the surrounding environment by making tens to hundreds of thousands of nanoscale interactions with extracellular signals and features. The goal of nanoscale tissue engineering is to harness these interactions through nanoscale biomaterials engineering in order to study and direct cellular behavior. Here, we review two- and three-dimensional (2- and 3D) nanoscale tissue engineering technologies, and provide a holistic overview of the field. Techniques that can control the average spacing and clustering of cell adhesion ligands are well established and have been highly successful in describing cell adhesion and migration in 2D. Extension of these engineering tools to 3D biomaterials has created many new hydrogel and nanofiber scaffold technologies that are being used to design in vitro experiments with more physiologically relevant conditions. Researchers are beginning to study complex cell functions in 3D. However, there is a need for biomaterials systems that provide fine control over the nanoscale presentation of bioactive ligands in 3D. Additionally, there is a need for 2- and 3D techniques that can control the nanoscale presentation of multiple bioactive ligands and that can control the temporal changes in the cellular microenvironment. (topical review)

  13. Mast cell-neural interactions contribute to pain and itch.

    Science.gov (United States)

    Gupta, Kalpna; Harvima, Ilkka T

    2018-03-01

    Mast cells are best recognized for their role in allergy and anaphylaxis, but increasing evidence supports their role in neurogenic inflammation leading to pain and itch. Mast cells act as a "power house" by releasing algogenic and pruritogenic mediators, which initiate a reciprocal communication with specific nociceptors on sensory nerve fibers. Consequently, nerve fibers release inflammatory and vasoactive neuropeptides, which in turn activate mast cells in a feedback mechanism, thus promoting a vicious cycle of mast cell and nociceptor activation leading to neurogenic inflammation and pain/pruritus. Mechanisms underlying mast cell differentiation, activation, and intercellular interactions with inflammatory, vascular, and neural systems are deeply influenced by their microenvironment, imparting enormous heterogeneity and complexity in understanding their contribution to pain and pruritus. Neurogenic inflammation is central to both pain and pruritus, but specific mediators released by mast cells to promote this process may vary depending upon their location, stimuli, underlying pathology, gender, and species. Therefore, in this review, we present the contribution of mast cells in pathological conditions, including distressing pruritus exacerbated by psychologic stress and experienced by the majority of patients with psoriasis and atopic dermatitis and in different pain syndromes due to mastocytosis, sickle cell disease, and cancer. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Perspectives on the Trypanosoma cruzi–host cell receptor interactions

    Science.gov (United States)

    Villalta, Fernando; Scharfstein, Julio; Ashton, Anthony W.; Tyler, Kevin M.; Guan, Fangxia; Mukherjee, Shankar; Lima, Maria F.; Alvarez, Sandra; Weiss, Louis M.; Huang, Huan; Machado, Fabiana S.

    2009-01-01

    Chagas disease is caused by the parasite Trypanosoma cruzi. The critical initial event is the interaction of the trypomastigote form of the parasite with host receptors. This review highlights recent observations concerning these interactions. Some of the key receptors considered are those for thromboxane, bradykinin, and for the nerve growth factor TrKA. Other important receptors such as galectin-3, thrombospondin, and laminin are also discussed. Investigation into the molecular biology and cell biology of host receptors for T. cruzi may provide novel therapeutic targets. PMID:19283409

  15. Interactions between bone cells and biomaterials: An update.

    Science.gov (United States)

    Beauvais, Sabrina; Drevelle, Olivier; Jann, Jessica; Lauzon, Marc-Antoine; Foruzanmehr, Mohammadreza; Grenier, Guillaume; Roux, Sophie; Faucheux, Nathalie

    2016-06-01

    As the populations of the Western world become older, they will suffer more and more from bone defects related to osteoporosis (non-union fractures, vertebral damages), cancers (malignant osteolysis) and infections (osteomyelitis). Autografts are usually used to fill these defects, but they have several drawbacks such as morbidity at the donor site and the amount and quality of bone that can be harvested. Recent scientific milestones made in biomaterials development were shown to be promising to overcome these limitations. Cell interactions with biomaterials can be improved by adding at their surface functional groups such as adhesive peptides and/or growth factors. The development of such biomimetic materials able to control bone cell responses can only proceed if it is based on a sound understanding of bone cell behavior and regulation. This review focuses on bone physiology and the regulation of bone cell differentiation and function, and how the latest advances in biomimetic materials can be translated within promising clinical outcomes.

  16. Quantitative image analysis for investigating cell-matrix interactions

    Science.gov (United States)

    Burkel, Brian; Notbohm, Jacob

    2017-07-01

    The extracellular matrix provides both chemical and physical cues that control cellular processes such as migration, division, differentiation, and cancer progression. Cells can mechanically alter the matrix by applying forces that result in matrix displacements, which in turn may localize to form dense bands along which cells may migrate. To quantify the displacements, we use confocal microscopy and fluorescent labeling to acquire high-contrast images of the fibrous material. Using a technique for quantitative image analysis called digital volume correlation, we then compute the matrix displacements. Our experimental technology offers a means to quantify matrix mechanics and cell-matrix interactions. We are now using these experimental tools to modulate mechanical properties of the matrix to study cell contraction and migration.

  17. Granule cell dispersion is associated with memory impairment in right mesial temporal lobe epilepsy.

    Science.gov (United States)

    Neves, Rafael Scarpa da Costa; de Souza Silva Tudesco, Ivanda; Jardim, Anaclara Prada; Caboclo, Luís Otávio Sales Ferreira; Lancellotti, Carmen; Ferrari-Marinho, Taíssa; Hamad, Ana Paula; Marinho, Murilo; Centeno, Ricardo Silva; Cavalheiro, Esper Abrão; Scorza, Carla Alessandra; Yacubian, Elza Márcia Targas

    2012-11-01

    We analyzed the association of granule cell dispersion (GCD) with memory performance, clinical data and surgical outcome in a series of patients with mesial temporal lobe epilepsy (MTLE) and mesial temporal sclerosis (MTS). Hippocampal specimens from 54 patients with MTLE (27 patients with right MTLE and 27 with left MTLE) and unilateral MTS, who were separated into GCD and no-GCD groups and thirteen controls were studied. Quantitative neuropathological evaluation was performed using hippocampal sections stained with NeuN. Patients' neuropsychological measures, clinical data, type of MTS and surgical outcome were reviewed. GCD occurred in 28 (51.9%) patients. No correlation between GCD and MTS pattern, clinical data or surgical outcome was found. The presence of GCD was correlated with worse visuospatial memory performance in right MTLE, but not with memory performance in left MTLE. GCD may be related to memory impairment in right MTLE-MTS patients. However, the role of GCD in memory function is not precisely defined. Copyright © 2012 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  18. Impaired Circulating Angiogenic Cells Mobilization and Metalloproteinase-9 Activity after Dynamic Exercise in Early Metabolic Syndrome.

    Science.gov (United States)

    Rocha, Natalia G; Sales, Allan R K; Penedo, Leticia A; Pereira, Felipe S; Silva, Mayra S; Miranda, Renan L; Silva, Jemima F R; Silva, Bruno M; Santos, Aline A; Nobrega, Antonio C L

    2015-01-01

    Increased levels of adhesion molecules or metalloproteinases (MMPs) may indicate endothelial dysfunction. Exercise mobilizes circulating angiogenic cells (CACs) from bone marrow in healthy subjects, improving vascular function. However, it is unclear whether this mechanism is preserved in the early stages of metabolic syndrome (early MetS). We aimed to evaluate the acute effects of exercise on adhesion molecules, angiogenic factors, MMPs, and CACs in early MetS. Fifteen subjects with early MetS and nine healthy controls underwent an exercise session and a nonexercise session, randomly. Adhesion molecules, angiogenic factors, CACs, and MMPs were evaluated before and after exercise or nonexercise sessions. At baseline, levels of sE-selectin, sICAM-1, and MMP-9 were higher in early MetS than in controls (P ≤ 0.03). After exercise, sE-selectin, sICAM-1, and MMP-9 levels were still higher in early MetS (P exercise. There was no difference between moments in nonexercise session (P > 0.05). In conclusion, subjects with early MetS already presented impaired endothelial function at rest along with a decrease in CACs and an increase in MMP-9 activity in response to exercise.

  19. Interaction of radon Exposure and cigarette smoking on cells

    International Nuclear Information System (INIS)

    Zhu, Maoxiang; Wei, Han; Yang, Zhihua; Pan, Xiujie; Cao, Zhenshan

    2008-01-01

    Full text: Environmental radon and its progenies is important lung carcinogen both in occupational underground miners and in the general population. Exposure to radon often occurs combined with smoking, another most important lung carcinogen. The join biological effects of alpha- particle radiation and cigarette smoke condense (CSC) were investigated here in order to provide experimental base for medical protection from lung cancer inducing by joint exposure of radon and smoking. Immortalized human bronchial epithelial cells (BEP2D) were divided into 5 groups, namely normal control group (NC), alpha particles irradiation group (0.25 Gy,α), CSC administration group (1μg/ml, CSC), CSC administration (1μg/ml) before (CSC + α) and after (α + CSC) alpha particles irradiation (0.25 Gy) group. On the 35 th passage after treated by alpha particles irradiation and CSC singly or jointly, only α + CSC cells showed malignant transformation characteristics, representing anchor growing independently, losing contact inhibition, and cell cycle disordering, whereas, there were no distinct difference between cells of other groups and normal cells. Moreover, comparison to the groups treated alone with alpha particles radiation or CSC administration, in the groups of joint exposure to alpha particles radiation and CSC treatment, cell survival fractions markedly decreased, intracellular ROS levels, frequencies of comet cell generation significantly increase, and could found that cell survival fractions of group CSC administration after α particle radiation was significantly higher than that of group CSC administration before alpha particles irradiation, suggesting that interaction of radon and smoking associated with their exposure sequence. In summary, interaction of radon and smoking was synergistic effect, and which was impacted by the order of exposure. (author)

  20. Mast Cells and MCPT4 Chymase Promote Renal Impairment after Partial Ureteral Obstruction

    Directory of Open Access Journals (Sweden)

    Maguelonne Pons

    2017-05-01

    Full Text Available Obstructive nephropathy constitutes a major cause of pediatric renal progressive disease. The mechanisms leading to disease progression are still poorly understood. Kidney fibrotic lesions are reproduced using a model of partial unilateral ureteral obstruction (pUUO in newborn mice. Based on data showing significant mast cell (MC infiltration in patients, we investigated the role of MC and murine MCPT4, a MC-released chymase, in pUUO using MC- (Wsh/sh, MCPT4-deficient (Mcpt4−/−, and wild-type (WT mice. Measurement of kidney length and volume by magnetic resonance imaging (MRI as well as postmortem kidney weight revealed hypotrophy of operated right kidneys (RKs and compensatory hypertrophy of left kidneys. Differences between kidneys were major for WT, minimal for Wsh/sh, and intermediate for Mcpt4−/− mice. Fibrosis development was focal and increased only in WT-obstructed kidneys. No differences were noticed for local inflammatory responses, but serum CCL2 was significantly higher in WT versus Mcpt4−/− and Wsh/sh mice. Alpha-smooth muscle actin (αSMA expression, a marker of epithelial–mesenchymal transition (EMT, was high in WT, minimal for Wsh/sh, and intermediate for Mcpt4−/− RK. Supernatants of activated MC induced αSMA in co-culture experiments with proximal tubular epithelial cells. Our results support a role of MC in EMT and parenchyma lesions after pUUO involving, at least partly, MCPT4 chymase. They confirm the importance of morphologic impairment evaluation by MRI in pUUO.

  1. MYBPH inhibits NM IIA assembly via direct interaction with NMHC IIA and reduces cell motility

    International Nuclear Information System (INIS)

    Hosono, Yasuyuki; Usukura, Jiro; Yamaguchi, Tomoya; Yanagisawa, Kiyoshi; Suzuki, Motoshi; Takahashi, Takashi

    2012-01-01

    Highlights: ► MYBPH inhibits NMHC IIA assembly and cell motility. ► MYBPH interacts to assembly-competent NM IIA. ► MYBPH inhibits RLC and NMHC IIA, independent components of NM IIA. -- Abstract: Actomyosin filament assembly is a critical step in tumor cell migration. We previously found that myosin binding protein H (MYBPH) is directly transactivated by the TTF-1 lineage-survival oncogene in lung adenocarcinomas and inhibits phosphorylation of the myosin regulatory light chain (RLC) of non-muscle myosin IIA (NM IIA) via direct interaction with Rho kinase 1 (ROCK1). Here, we report that MYBPH also directly interacts with an additional molecule, non-muscle myosin heavy chain IIA (NMHC IIA), which was found to occur between MYBPH and the rod portion of NMHC IIA. MYBPH inhibited NMHC IIA assembly and reduced cell motility. Conversely, siMYBPH-induced increased motility was partially, yet significantly, suppressed by blebbistatin, a non-muscle myosin II inhibitor, while more profound effects were attained by combined treatment with siROCK1 and blebbistatin. Electron microscopy observations showed well-ordered paracrystals of NMHC IIA reflecting an assembled state, which were significantly less frequently observed in the presence of MYBPH. Furthermore, an in vitro sedimentation assay showed that a greater amount of NMHC IIA was in an unassembled state in the presence of MYBPH. Interestingly, treatment with a ROCK inhibitor that impairs transition of NM IIA from an assembly-incompetent to assembly-competent state reduced the interaction between MYBPH and NMHC IIA, suggesting that MYBPH has higher affinity to assembly-competent NM IIA. These results suggest that MYBPH inhibits RLC and NMHC IIA, independent components of NM IIA, and negatively regulates actomyosin organization at 2 distinct steps, resulting in firm inhibition of NM IIA assembly.

  2. Crotamine and crotoxin interact with tumor cells and trigger cell death

    International Nuclear Information System (INIS)

    Soares, Marcella Araugio; Pujatti, Priscilla Brunelli; Santos, Raquel Gouvea dos; Dias, Consuelo Latorre Fortes; Chavez Olortegui, Carlos Delfin; Santos, Wagner Gouvea dos

    2007-01-01

    Crotoxin (Crtx) and Crotamine (Crota) are polypeptides isolated from Crotalus durissus terrificus snake venom (CV). Previous reports have been shown therapeutic effects of Crotalus durissus terrificus venom and Crtx on skin, breast and lung tumours, although, the mechanisms of this antitumoral effect are still unknown. The aim of this work was to investigate the antitumoral effect of Crtx and Crota on brain tumours cells (GH3 and RT2) in vitro and their capacity of interaction with these tumour cells membranes. Cell survival after Crtx and Crota treatment was evaluated by MTT assay in different times post-treatment and apoptosis was evaluated by DAPI staining. In order to evaluate the specific interaction of Crtx and Crota, these polypeptides were radiolabelled, using 125 I as radiotracer and binding assays were performed. The results were compared with the binding in nontumoral brain tissue. Crtx and Crota induced apoptosis on both tumour cells lineages but, Crota was more powerful than Crtx 90% and 20% cell death for RT2 cells; 80% and 20% cell death for GH3 cells, respectively). Both 125 I-Crtx and 125 I-Crota bound specifically in glioblastoma membranes. Nonetheless, CV polypeptides recognised glioblastoma cells with higher specificity than normal brain tissue. These results suggest that the Crtx and Crota interactions with the plasmatic membrane of tumour cells may be the first step of the cascade of signalling that trigger their antitumoral effect. (author)

  3. Biomaterials that promote cell-cell interactions enhance the paracrine function of MSCs.

    Science.gov (United States)

    Qazi, Taimoor H; Mooney, David J; Duda, Georg N; Geissler, Sven

    2017-09-01

    Mesenchymal stromal cells (MSCs) secrete paracrine factors that play crucial roles during tissue regeneration. Whether this paracrine function is influenced by the properties of biomaterials in general, and those used for cell delivery in particular, largely remains unexplored. Here, we investigated if three-dimensional culture in distinct microenvironments - nanoporous hydrogels (mean pore size ∼5 nm) and macroporous scaffolds (mean pore size ∼120 μm) - affects the secretion pattern of MSCs, and consequently leads to differential paracrine effects on target progenitor cells such as myoblasts. We report that compared to MSCs encapsulated in hydrogels, scaffold seeded MSCs show an enhanced secretion profile and exert beneficial paracrine effects on various myoblast functions including migration and proliferation. Additionally, we show that the heightened paracrine effects of scaffold seeded cells can in part be attributed to N-cadherin mediated cell-cell interactions during culture. In hydrogels, this physical interaction between cells is prevented by the encapsulating matrix. Functionally blocking N-cadherin negatively affected the secretion profile and paracrine effects of MSCs on myoblasts, with stronger effects observed for scaffold seeded compared to hydrogel encapsulated cells. Together, these findings demonstrate that the therapeutic potency of MSCs can be enhanced by biomaterials that promote cell-cell interactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Spatial evolutionary games of interaction among generic cancer cells

    DEFF Research Database (Denmark)

    Bach, L.A.; Sumpter, D.J.T.; Alsner, J.

    2003-01-01

    Evolutionary game models of cellular interactions have shown that heterogeneity in the cellular genotypic composition is maintained through evolution to stable coexistence of growth-promoting and non-promoting cell types. We generalise these mean-field models and relax the assumption of perfect m...... at a cellular level. This study thus points a new direction towards more plausible spatial tumour modelling and the understanding of cancerous growth....

  5. Interactions Between Epidermal Keratinocytes, Dendritic Epidermal T-Cells, and Hair Follicle Stem Cells.

    Science.gov (United States)

    Badarinath, Krithika; Dutta, Abhik; Hegde, Akshay; Pincha, Neha; Gund, Rupali; Jamora, Colin

    2018-06-13

    The interplay of immune cells and stem cells in maintaining skin homeostasis and repair is an exciting new frontier in cutaneous biology. With the growing appreciation of the importance of this new crosstalk comes the requirement of methods to interrogate the molecular underpinnings of these leukocyte-stem cell interactions. Here we describe how a combination of FACS, cellular coculture assays, and conditioned media treatments can be utilized to advance our understanding of this emerging area of intercellular communication between immune cells and stem cells.

  6. Map Learning with a 3D Printed Interactive Small-Scale Model: Improvement of Space and Text Memorization in Visually Impaired Students

    Directory of Open Access Journals (Sweden)

    Stéphanie Giraud

    2017-06-01

    Full Text Available Special education teachers for visually impaired students rely on tools such as raised-line maps (RLMs to teach spatial knowledge. These tools do not fully and adequately meet the needs of the teachers because they are long to produce, expensive, and not versatile enough to provide rapid updating of the content. For instance, the same RLM can barely be used during different lessons. In addition, those maps do not provide any interactivity, which reduces students’ autonomy. With the emergence of 3D printing and low-cost microcontrollers, it is now easy to design affordable interactive small-scale models (SSMs which are adapted to the needs of special education teachers. However, no study has previously been conducted to evaluate non-visual learning using interactive SSMs. In collaboration with a specialized teacher, we designed a SSM and a RLM representing the evolution of the geography and history of a fictitious kingdom. The two conditions were compared in a study with 24 visually impaired students regarding the memorization of the spatial layout and historical contents. The study showed that the interactive SSM improved both space and text memorization as compared to the RLM with braille legend. In conclusion, we argue that affordable home-made interactive small scale models can improve learning for visually impaired students. Interestingly, they are adaptable to any teaching situation including students with specific needs.

  7. Map Learning with a 3D Printed Interactive Small-Scale Model: Improvement of Space and Text Memorization in Visually Impaired Students.

    Science.gov (United States)

    Giraud, Stéphanie; Brock, Anke M; Macé, Marc J-M; Jouffrais, Christophe

    2017-01-01

    Special education teachers for visually impaired students rely on tools such as raised-line maps (RLMs) to teach spatial knowledge. These tools do not fully and adequately meet the needs of the teachers because they are long to produce, expensive, and not versatile enough to provide rapid updating of the content. For instance, the same RLM can barely be used during different lessons. In addition, those maps do not provide any interactivity, which reduces students' autonomy. With the emergence of 3D printing and low-cost microcontrollers, it is now easy to design affordable interactive small-scale models (SSMs) which are adapted to the needs of special education teachers. However, no study has previously been conducted to evaluate non-visual learning using interactive SSMs. In collaboration with a specialized teacher, we designed a SSM and a RLM representing the evolution of the geography and history of a fictitious kingdom. The two conditions were compared in a study with 24 visually impaired students regarding the memorization of the spatial layout and historical contents. The study showed that the interactive SSM improved both space and text memorization as compared to the RLM with braille legend. In conclusion, we argue that affordable home-made interactive small scale models can improve learning for visually impaired students. Interestingly, they are adaptable to any teaching situation including students with specific needs.

  8. Β-amyloid 1-42 oligomers impair function of human embryonic stem cell-derived forebrain cholinergic neurons.

    Directory of Open Access Journals (Sweden)

    Linn Wicklund

    Full Text Available Cognitive impairment in Alzheimer's disease (AD patients is associated with a decline in the levels of growth factors, impairment of axonal transport and marked degeneration of basal forebrain cholinergic neurons (BFCNs. Neurogenesis persists in the adult human brain, and the stimulation of regenerative processes in the CNS is an attractive prospect for neuroreplacement therapy in neurodegenerative diseases such as AD. Currently, it is still not clear how the pathophysiological environment in the AD brain affects stem cell biology. Previous studies investigating the effects of the β-amyloid (Aβ peptide on neurogenesis have been inconclusive, since both neurogenic and neurotoxic effects on progenitor cell populations have been reported. In this study, we treated pluripotent human embryonic stem (hES cells with nerve growth factor (NGF as well as with fibrillar and oligomeric Aβ1-40 and Aβ1-42 (nM-µM concentrations and thereafter studied the differentiation in vitro during 28-35 days. The process applied real time quantitative PCR, immunocytochemistry as well as functional studies of intracellular calcium signaling. Treatment with NGF promoted the differentiation into functionally mature BFCNs. In comparison to untreated cells, oligomeric Aβ1-40 increased the number of functional neurons, whereas oligomeric Aβ1-42 suppressed the number of functional neurons. Interestingly, oligomeric Aβ exposure did not influence the number of hES cell-derived neurons compared with untreated cells, while in contrast fibrillar Aβ1-40 and Aβ1-42 induced gliogenesis. These findings indicate that Aβ1-42 oligomers may impair the function of stem cell-derived neurons. We propose that it may be possible for future AD therapies to promote the maturation of functional stem cell-derived neurons by altering the brain microenvironment with trophic support and by targeting different aggregation forms of Aβ.

  9. Cytolytic T lymphocyte responses to metabolically inactivated stimulator cells. I. Metabolic inactivation impairs both CD and LD antigen signals

    International Nuclear Information System (INIS)

    Kelso, A.; Boyle, W.

    1982-01-01

    The effects of metabolic inactivation of spleen cells on antigen presentation to precursors of alloreactive cytolytic T lymphocytes (T/sub c/) were examined. By serological methods, populations inactivated by ultraviolet irradiation, glutaraldehyde fixation or plasma membrane isolation were found to retain normal levels of H-2K/D and Ia antigens. However, comparison of the antigen doses required to stimulate secondary T/sub c/ responses in mixed leukocyte culture showed that the inactivated preparations were approximately 10-fold less immunogenic than X-irradiated spleen cells. Their total inability to stimulate primary cytolytic responses pointed to at least a 100-fold impairment of immunogenicity for unprimed T/sub c/ precursors in the case of uv-irradiated and glutaraldehyde-treated stimulator cells, and at least a 10-fold impairment for membrane fragments. Experiments showing that the capacity of cell monolayers to absorb precursor T/sub c/ from unprimed spleen populations was reduced following uv-irradiation or glutaraldehyde treatment provided direct evidence that this loss of immunogenicity was due in part to suboptimal antigen presentation to precursor T/sub c/. It is concluded that, in addition to the traditional view that these treatments damage the ''LD'' signal to helper T lymphocytes, metabolic inactivation also impairs recognition of ''CD'' determinants by precursor T/sub c/

  10. Use of scanning electron microscopy to monitor nanofibre/cell interaction in digestive epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Millaku, Agron, E-mail: agron.mi@hotmail.com [Limnos-Company for Applied Ecology Ltd, Podlimbarskega 31, 1000 Ljubljana (Slovenia); Drobne, Damjana [University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, 1000 Ljubljana (Slovenia); Centre of Excellence, Advanced Materials and Technologies for the Future (CO NAMASTE), Jamova cesta 39, 1000 Ljubljana (Slovenia); Centre of Excellence, Nanoscience and Nanotechnology (Nanocentre), Jamova cesta 39, 1000 Ljubljana (Slovenia); Torkar, Matjaz [Institute of Metals and Technology IMT, Lepi pot 11, 1000 Ljubljana (Slovenia); Jožef Stefan Institute, Condensed Matter Physics Department, Jamova cesta 39, 1000 Ljubljana (Slovenia); Novak, Sara [University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, 1000 Ljubljana (Slovenia); Remškar, Maja [Jožef Stefan Institute, Condensed Matter Physics Department, Jamova cesta 39, 1000 Ljubljana (Slovenia); Pipan-Tkalec, Živa [University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, 1000 Ljubljana (Slovenia)

    2013-09-15

    Graphical abstract: Scanning electron microscopy is particularly well suited to the observation of nanofibre/cell interaction in the endothelial cells lining the hepatopancreas. (a) Tungsten oxide nanofibres, (b) test organism Porcellio scaber and schematic appearance of digestive tubes, (c) digestive tube (hepatopancreas) prepared for SEM investigation, (d) digestive gland cells (C) with nanofibres (NF) embedded in the cell membrane and (e) nanofibres inserted deeply in the cells and damaged nanofibres due to peristalsis. -- Highlights: • Tungsten oxide nanofibres react physically with digestive gland epithelial cells in Porcellio scaber. • Physical peristaltic forces of lead to insertion of nanofibres into the cells. • No toxic responses as measured by conventional toxicity biomarkers were detected. • Physical interactions were observed in a majority of the investigated animals. -- Abstract: We provide data obtained by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) on the interaction of ingested tungsten nanofibers with epithelial cells of the digestive tubes of a test organism Porcellio scaber. Conventional toxicity endpoints including feeding behaviour, weight loss and mortality were also measured in each investigated animal. No toxicity was detected in any of exposed animals after 14 days of feeding on tungsten nanofiber dosed food, but when nanofibers enter the digestive system they can react with epithelial cells of the digestive tubes, becoming physically inserted into the cells. In this way, nanofibers can injure the epithelial cells of digestive gland tubes when they are ingested with food. Our SEM data suggest that peristaltic forces may have an important role, not predicted by in vitro experiments, in the interactions of nanomaterials with digestive intestinal cells.

  11. Use of scanning electron microscopy to monitor nanofibre/cell interaction in digestive epithelial cells

    International Nuclear Information System (INIS)

    Millaku, Agron; Drobne, Damjana; Torkar, Matjaz; Novak, Sara; Remškar, Maja; Pipan-Tkalec, Živa

    2013-01-01

    Graphical abstract: Scanning electron microscopy is particularly well suited to the observation of nanofibre/cell interaction in the endothelial cells lining the hepatopancreas. (a) Tungsten oxide nanofibres, (b) test organism Porcellio scaber and schematic appearance of digestive tubes, (c) digestive tube (hepatopancreas) prepared for SEM investigation, (d) digestive gland cells (C) with nanofibres (NF) embedded in the cell membrane and (e) nanofibres inserted deeply in the cells and damaged nanofibres due to peristalsis. -- Highlights: • Tungsten oxide nanofibres react physically with digestive gland epithelial cells in Porcellio scaber. • Physical peristaltic forces of lead to insertion of nanofibres into the cells. • No toxic responses as measured by conventional toxicity biomarkers were detected. • Physical interactions were observed in a majority of the investigated animals. -- Abstract: We provide data obtained by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) on the interaction of ingested tungsten nanofibers with epithelial cells of the digestive tubes of a test organism Porcellio scaber. Conventional toxicity endpoints including feeding behaviour, weight loss and mortality were also measured in each investigated animal. No toxicity was detected in any of exposed animals after 14 days of feeding on tungsten nanofiber dosed food, but when nanofibers enter the digestive system they can react with epithelial cells of the digestive tubes, becoming physically inserted into the cells. In this way, nanofibers can injure the epithelial cells of digestive gland tubes when they are ingested with food. Our SEM data suggest that peristaltic forces may have an important role, not predicted by in vitro experiments, in the interactions of nanomaterials with digestive intestinal cells

  12. Impaired macrophage and satellite cell infiltration occurs in a muscle-specific fashion following injury in diabetic skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Matthew P Krause

    Full Text Available Systemic elevations in PAI-1 suppress the fibrinolytic pathway leading to poor collagen remodelling and delayed regeneration of tibialis anterior (TA muscles in type-1 diabetic Akita mice. However, how impaired collagen remodelling was specifically attenuating regeneration in Akita mice remained unknown. Furthermore, given intrinsic differences between muscle groups, it was unclear if the reparative responses between muscle groups were different.Here we reveal that diabetic Akita muscles display differential regenerative responses with the TA and gastrocnemius muscles exhibiting reduced regenerating myofiber area compared to wild-type mice, while soleus muscles displayed no difference between animal groups following injury. Collagen levels in TA and gastrocnemius, but not soleus, were significantly increased post-injury versus controls. At 5 days post-injury, when degenerating/necrotic regions were present in both animal groups, Akita TA and gastrocnemius muscles displayed reduced macrophage and satellite cell infiltration and poor myofiber formation. By 10 days post-injury, necrotic regions were absent in wild-type TA but persisted in Akita TA. In contrast, Akita soleus exhibited no impairment in any of these measures compared to wild-type soleus. In an effort to define how impaired collagen turnover was attenuating regeneration in Akita TA, a PAI-1 inhibitor (PAI-039 was orally administered to Akita mice following cardiotoxin injury. PAI-039 administration promoted macrophage and satellite cell infiltration into necrotic areas of the TA and gastrocnemius. Importantly, soleus muscles exhibit the highest inducible expression of MMP-9 following injury, providing a mechanism for normative collagen degradation and injury recovery in this muscle despite systemically elevated PAI-1.Our findings suggest the mechanism underlying how impaired collagen remodelling in type-1 diabetes results in delayed regeneration is an impairment in macrophage

  13. Secondary structure of cell-penetrating peptides during interaction with fungal cells.

    Science.gov (United States)

    Gong, Zifan; Ikonomova, Svetlana P; Karlsson, Amy J

    2018-03-01

    Cell-penetrating peptides (CPPs) are peptides that cross cell membranes, either alone or while carrying molecular cargo. Although their interactions with mammalian cells have been widely studied, much less is known about their interactions with fungal cells, particularly at the biophysical level. We analyzed the interactions of seven CPPs (penetratin, Pep-1, MPG, pVEC, TP-10, MAP, and cecropin B) with the fungal pathogen Candida albicans using experiments and molecular simulations. Circular dichroism (CD) of the peptides revealed a structural transition from a random coil or weak helix to an α-helix occurs for all peptides when the solvent is changed from aqueous to hydrophobic. However, CD performed in the presence of C. albicans cells showed that proximity to the cell membrane is not necessarily sufficient to induce this structural transition, as penetratin, Pep-1, and MPG did not display a structural shift in the presence of cells. Monte Carlo simulations were performed to further probe the molecular-level interaction with the cell membrane, and these simulations suggested that pVEC, TP-10, MAP, and cecropin B strongly penetrate into the hydrophobic domain of the membrane lipid bilayer, inducing a transition to an α-helical conformation. In contrast, penetratin, Pep-1 and MPG remained in the hydrophilic region without a shift in conformation. The experimental data and MC simulations combine to explain how peptide structure affects their interaction with cells and their mechanism of translocation into cells (direct translocation vs. endocytosis). Our work also highlights the utility of combining biophysical experiments, biological experiments, and molecular modeling to understand biological phenomena. © 2017 The Protein Society.

  14. Galectin-3 impairment of MYCN-dependent apoptosis-sensitive phenotype is antagonized by nutlin-3 in neuroblastoma cells.

    Directory of Open Access Journals (Sweden)

    Veronica Veschi

    Full Text Available MYCN amplification occurs in about 20-25% of human neuroblastomas and characterizes the majority of the high-risk cases, which display less than 50% prolonged survival rate despite intense multimodal treatment. Somehow paradoxically, MYCN also sensitizes neuroblastoma cells to apoptosis, understanding the molecular mechanisms of which might be relevant for the therapy of MYCN amplified neuroblastoma. We recently reported that the apoptosis-sensitive phenotype induced by MYCN is linked to stabilization of p53 and its proapoptotic kinase HIPK2. In MYCN primed neuroblastoma cells, further activation of both HIPK2 and p53 by Nutlin-3 leads to massive apoptosis in vitro and to tumor shrinkage and impairment of metastasis in xenograft models. Here we report that Galectin-3 impairs MYCN-primed and HIPK2-p53-dependent apoptosis in neuroblastoma cells. Galectin-3 is broadly expressed in human neuroblastoma cell lines and tumors and is repressed by MYCN to induce the apoptosis-sensitive phenotype. Despite its reduced levels, Galectin-3 can still exert residual antiapoptotic effects in MYCN amplified neuroblastoma cells, possibly due to its specific subcellular localization. Importantly, Nutlin-3 represses Galectin-3 expression, and this is required for its potent cell killing effect on MYCN amplified cell lines. Our data further characterize the apoptosis-sensitive phenotype induced by MYCN, expand our understanding of the activity of MDM2-p53 antagonists and highlight Galectin-3 as a potential biomarker for the tailored p53 reactivation therapy in patients with high-risk neuroblastomas.

  15. Aging-related impairments of hippocampal mossy fibers synapses on CA3 pyramidal cells.

    Science.gov (United States)

    Villanueva-Castillo, Cindy; Tecuatl, Carolina; Herrera-López, Gabriel; Galván, Emilio J

    2017-01-01

    The network interaction between the dentate gyrus and area CA3 of the hippocampus is responsible for pattern separation, a process that underlies the formation of new memories, and which is naturally diminished in the aged brain. At the cellular level, aging is accompanied by a progression of biochemical modifications that ultimately affects its ability to generate and consolidate long-term potentiation. Although the synapse between dentate gyrus via the mossy fibers (MFs) onto CA3 neurons has been subject of extensive studies, the question of how aging affects the MF-CA3 synapse is still unsolved. Extracellular and whole-cell recordings from acute hippocampal slices of aged Wistar rats (34 ± 2 months old) show that aging is accompanied by a reduction in the interneuron-mediated inhibitory mechanisms of area CA3. Several MF-mediated forms of short-term plasticity, MF long-term potentiation and at least one of the critical signaling cascades necessary for potentiation are also compromised in the aged brain. An analysis of the spontaneous glutamatergic and gamma-aminobutyric acid-mediated currents on CA3 cells reveal a dramatic alteration in amplitude and frequency of the nonevoked events. CA3 cells also exhibited increased intrinsic excitability. Together, these results demonstrate that aging is accompanied by a decrease in the GABAergic inhibition, reduced expression of short- and long-term forms of synaptic plasticity, and increased intrinsic excitability. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Curcumin targets fibroblast–tumor cell interactions in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Dudás, József; Fullár, Alexandra; Romani, Angela; Pritz, Christian; Kovalszky, Ilona; Hans Schartinger, Volker; Mathias Sprinzl, Georg; Riechelmann, Herbert

    2013-01-01

    Co-culture of periodontal ligament fibroblasts (PDLs) and SCC-25 oral squamous carcinoma cells (OSCC) results in conversion of PDLs into carcinoma-associated fibroblasts (CAFs) and induces epithelial-to mesenchymal transition (EMT) of OSCC tumor cells. We hypothesized that Curcumin targets this dynamic mutual interaction between CAFs and tumor cells. Normal and 2 μM Curcumin-treated co-culture were performed for 4 days, followed by analysis of tumor cell invasivity, mRNA/protein expression of EMT-markers and mediators, activity measure of matrix metalloproteinase 9 (MMP-9), and western blot analysis of signal transduction in tumor cells and fibroblasts. In Curcumin-treated co-culture, in tumor cells, the levels of nuclear factor κB (NFκBα) and early response kinase (ERK)—decreased, in fibroblasts, integrin αv protein synthesis decreased compared to corresponding cells in normal co-culture. The signal modulatory changes induced by Curcumin caused decreased release of EMT-mediators in CAFs and reversal of EMT in tumor cells, which was associated with decreased invasion. These data confirm the palliative potential of Curcumin in clinical application. - Graphical abstract: Co-culture of periodontal ligament fibroblasts (PDLs) and SCC-25 oral squamous carcinoma cells (OSCC) results in conversion of PDLs into carcinoma-associated fibroblasts (CAFs) and induces epithelial-to mesenchymal transition (EMT) of tumor cells. Curcumin targets this dynamic mutual interaction between CAFs and tumor cells by inhibiting the production of EMT mediators in CAFs and by modification of intracellular signaling in tumor cells. This causes less invasivity and reversal of EMT in tumor cells. Highlights: ► Curcumin targets tumor–fibroblast interaction in head and neck cancer. ► Curcumin suppresses mediators of epithelial–mesenchymal transition. ► Curcumin decreases the invasivity of tumor cells

  17. Curcumin targets fibroblast–tumor cell interactions in oral squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Dudás, József, E-mail: jozsef.dudas@i-med.ac.at [Department of Otorhinolaryngology and Head and Neck Surgery, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Fullár, Alexandra, E-mail: fullarsz@gmail.com [Department of Otorhinolaryngology and Head and Neck Surgery, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); 1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Üllői út 26, 1085 Budapest (Hungary); Romani, Angela, E-mail: angela.romani@i-med.ac.at [Department of Otorhinolaryngology and Head and Neck Surgery, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Pritz, Christian, E-mail: christian.pritz@i-med.ac.at [Department of Otorhinolaryngology and Head and Neck Surgery, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Kovalszky, Ilona, E-mail: koval@korb1.sote.hu [1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Üllői út 26, 1085 Budapest (Hungary); Hans Schartinger, Volker, E-mail: volker.schartinger@i-med.ac.at [Department of Otorhinolaryngology and Head and Neck Surgery, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Mathias Sprinzl, Georg, E-mail: georg.sprinzl@i-med.ac.at [Department of Otorhinolaryngology and Head and Neck Surgery, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Riechelmann, Herbert, E-mail: herbert.riechelmann@i-med.ac.at [Department of Otorhinolaryngology and Head and Neck Surgery, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria)

    2013-04-01

    Co-culture of periodontal ligament fibroblasts (PDLs) and SCC-25 oral squamous carcinoma cells (OSCC) results in conversion of PDLs into carcinoma-associated fibroblasts (CAFs) and induces epithelial-to mesenchymal transition (EMT) of OSCC tumor cells. We hypothesized that Curcumin targets this dynamic mutual interaction between CAFs and tumor cells. Normal and 2 μM Curcumin-treated co-culture were performed for 4 days, followed by analysis of tumor cell invasivity, mRNA/protein expression of EMT-markers and mediators, activity measure of matrix metalloproteinase 9 (MMP-9), and western blot analysis of signal transduction in tumor cells and fibroblasts. In Curcumin-treated co-culture, in tumor cells, the levels of nuclear factor κB (NFκBα) and early response kinase (ERK)—decreased, in fibroblasts, integrin αv protein synthesis decreased compared to corresponding cells in normal co-culture. The signal modulatory changes induced by Curcumin caused decreased release of EMT-mediators in CAFs and reversal of EMT in tumor cells, which was associated with decreased invasion. These data confirm the palliative potential of Curcumin in clinical application. - Graphical abstract: Co-culture of periodontal ligament fibroblasts (PDLs) and SCC-25 oral squamous carcinoma cells (OSCC) results in conversion of PDLs into carcinoma-associated fibroblasts (CAFs) and induces epithelial-to mesenchymal transition (EMT) of tumor cells. Curcumin targets this dynamic mutual interaction between CAFs and tumor cells by inhibiting the production of EMT mediators in CAFs and by modification of intracellular signaling in tumor cells. This causes less invasivity and reversal of EMT in tumor cells. Highlights: ► Curcumin targets tumor–fibroblast interaction in head and neck cancer. ► Curcumin suppresses mediators of epithelial–mesenchymal transition. ► Curcumin decreases the invasivity of tumor cells.

  18. Aryl- and alkyl-phosphorus-containing flame retardants induced mitochondrial impairment and cell death in Chinese hamster ovary (CHO-k1) cells

    International Nuclear Information System (INIS)

    Huang, Chao; Li, Na; Yuan, Shengwu; Ji, Xiaoya; Ma, Mei; Rao, Kaifeng; Wang, Zijian

    2017-01-01

    Phosphorus-containing flame retardants (PFRs) are increasingly in demand worldwide as replacements for brominated flame retardants (BFRs), but insufficient available toxicological information on PFRs makes assessing their health risks challenging. Mitochondria are important targets of various environmental pollutants, and mitochondrial dysfunction may lead to many common diseases. In the present study, mitochondria impairment-related endpoints were measured by a high content screening (HCS) assay for 11 selected non-halogen PFRs in Chinese hamster ovary (CHO-k1) cells. A cluster analysis was used to categorize these PFRs into three groups according to their structural characteristics and results from the HCS assay. Two groups, containing long-chain alkyl-PFRs and all aryl-PFRs, were found to cause mitochondrial impairment but showed different mechanisms of toxicity. Due to the high correlation between cell death and mitochondrial impairment, two PFRs with different structures, trihexyl phosphate (THP) and cresyl diphenyl phosphate (CDP), were selected and compared with chlorpyrifos (CPF) to elucidate their mechanism of inducing cell death. THP (an alkyl-PFR) was found to utilize a similar pathway as CPF to induce apoptosis. However, cell death induced by CDP (an aryl-PFR) was different from classical necrosis based on experiments to discriminate among the different modes of cell death. These results confirm that mitochondria might be important targets for some PFRs and that differently structured PFRs could function via distinct mechanisms of toxicity. - Highlights: • Mitochondrial impairment induced by PFRs was observed in CHO-k1 cells. • THP (an alkyl-PFR) induced a caspase-mediated apoptosis in CHO-k1 cells. • The cell death induced by CDP (an aryl-PFR) was not traditional apoptosis or necrosis.

  19. Involvement of dendritic cells in allograft rejection new implications of dendritic cell-endothelial cell interactions.

    Science.gov (United States)

    Schlichting, C L; Schareck, W D; Kofler, S; Weis, M

    2007-04-01

    For almost half a century immunologists have tried to tear down the MHC barrier, which separates two unrelated individuals during transplantation. Latest experimental data suggest that a breakthrough in vitro is imminent. Dendritic cells (DCs), which activate naïve allo-reactive T-cells (TCs), play a central role in the establishment of allo-antigen-specific immunity. Allograft solid organ rejection is initiated at the foreign endothelial cell (EC) layer, which forms an immunogenic barrier for migrating DCs. Thus, DC/EC interactions might play a crucial role in antigen-specific allograft rejection. Organ rejection is mediated by host allo-reactive TCs, which are activated by donor DCs (direct activation) or host DCs (indirect activation). Direct allo-antigen presentation by regulatory dendritic cells (DCreg) can play an instructive role towards tolerance induction. Several groups established that, DCregs, if transplanted beforehand, enter host thymus, spleen, or bone marrow where they might eventually establish allo-antigen-specific tolerance. A fundamental aspect of DC function is migration throughout the entire organism. After solid organ transplantation, host DCs bind to ECs, invade allograft tissues, and finally transmigrate into lymphoid vessels and secondary lymphoid organs, where they present allo-antigens to naïve host TCs. Recent data suggest that in vitro manipulated DCregs may mediate allo-transplantation tolerance induction. However, the fundamental mechanisms on how such DCregs cause host TCs in the periphery towards tolerance remain unclear. One very promising experimental concept is the simultaneous manipulation of DC direct and indirect TC activation/suppression, towards donor antigen-specific allo-transplantation tolerance. The allo-antigen-specific long-term tolerance induction mediated by DCreg pre-transplantation (with simultaneous short-term immunosuppression) has become reproducible in the laboratory animal setting. Despite the shortcomings

  20. Sensitive Detection of the Natural Killer Cell-Mediated Cytotoxicity of Anti-CD20 Antibodies and Its Impairment by B-Cell Receptor Pathway Inhibitors

    Directory of Open Access Journals (Sweden)

    Floyd Hassenrück

    2018-01-01

    Full Text Available The antibody-dependent cell-mediated cytotoxicity (ADCC of the anti-CD20 monoclonal antibodies (mAbs rituximab and obinutuzumab against the cell line Raji and isolated CLL cells and its potential impairment by kinase inhibitors (KI was determined via lactate dehydrogenase release or calcein retention, respectively, using genetically modified NK92 cells expressing CD16-176V as effector cells. Compared to peripheral blood mononuclear cells, recombinant effector cell lines showed substantial alloreactivity-related cytotoxicity without addition of mAbs but afforded determination of ADCC with reduced interassay variability. The cytotoxicity owing to alloreactivity was less susceptible to interference by KI than the ADCC of anti-CD20 mAbs, which was markedly diminished by ibrutinib, but not by idelalisib. Compared to rituximab, the ADCC of obinutuzumab against primary CLL cells showed approximately 30% higher efficacy and less interference with KI. Irreversible BTK inhibitors at a clinically relevant concentration of 1 μM only weakly impaired the ADCC of anti-CD20 mAbs, with less influence in combinations with obinutuzumab than with rituximab and by acalabrutinib than by ibrutinib or tirabrutinib. In summary, NK cell line-based assays permitted the sensitive detection of ADCC of therapeutic anti-CD20 mAbs against CLL cells and of the interference of KI with this important killing mechanism.

  1. Defective IL-10 signaling in hyper-IgE syndrome results in impaired generation of tolerogenic dendritic cells and induced regulatory T cells

    Science.gov (United States)

    Saito, Masako; Nagasawa, Masayuki; Takada, Hidetoshi; Hara, Toshiro; Tsuchiya, Shigeru; Agematsu, Kazunaga; Yamada, Masafumi; Kawamura, Nobuaki; Ariga, Tadashi; Tsuge, Ikuya; Nonoyama, Shigeaki; Karasuyama, Hajime

    2011-01-01

    Hyper-IgE syndrome (HIES) is a primary immunodeficiency characterized by recurrent staphylococcal infections and atopic dermatitis associated with elevated serum IgE levels. Although defective differentiation of IL-17–producing CD4+ T cells (Th17) partly accounts for the susceptibility to staphylococcal skin abscesses and pneumonia, the pathogenesis of atopic manifestations in HIES still remains an enigma. In this study, we examined the differentiation and function of Th1, Th2, regulatory T cells (Treg cells), and dendritic cells (DCs) in HIES patients carrying either STAT3 or TYK2 mutations. Although the in vitro differentiation of Th1 and Th2 cells and the number and function of Treg cells in the peripheral blood were normal in HIES patients with STAT3 mutations, primary and monocyte-derived DCs showed defective responses to IL-10 and thus failed to become tolerogenic. When treated with IL-10, patient DCs showed impaired up-regulation of inhibitory molecules on their surface, including PD-L1 and ILT-4, compared with control DCs. Moreover, IL-10–treated DCs from patients displayed impaired ability to induce the differentiation of naive CD4+ T cells to FOXP3+ induced Treg cells (iTreg cells). These results suggest that the defective generation of IL-10–induced tolerogenic DCs and iTreg cells may contribute to inflammatory changes in HIES. PMID:21300911

  2. Interaction and uptake of exosomes by ovarian cancer cells

    Directory of Open Access Journals (Sweden)

    Altevogt Peter

    2011-03-01

    Full Text Available Abstract Background Exosomes consist of membrane vesicles that are secreted by several cell types, including tumors and have been found in biological fluids. Exosomes interact with other cells and may serve as vehicles for the transfer of protein and RNA among cells. Methods SKOV3 exosomes were labelled with carboxyfluoresceine diacetate succinimidyl-ester and collected by ultracentrifugation. Uptake of these vesicles, under different conditions, by the same cells from where they originated was monitored by immunofluorescence microscopy and flow cytometry analysis. Lectin analysis was performed to investigate the glycosylation properties of proteins from exosomes and cellular extracts. Results In this work, the ovarian carcinoma SKOV3 cell line has been shown to internalize exosomes from the same cells via several endocytic pathways that were strongly inhibited at 4°C, indicating their energy dependence. Partial colocalization with the endosome marker EEA1 and inhibition by chlorpromazine suggested the involvement of clathrin-dependent endocytosis. Furthermore, uptake inhibition in the presence of 5-ethyl-N-isopropyl amiloride, cytochalasin D and methyl-beta-cyclodextrin suggested the involvement of additional endocytic pathways. The uptake required proteins from the exosomes and from the cells since it was inhibited after proteinase K treatments. The exosomes were found to be enriched in specific mannose- and sialic acid-containing glycoproteins. Sialic acid removal caused a small but non-significant increase in uptake. Furthermore, the monosaccharides D-galactose, α-L-fucose, α-D-mannose, D-N-acetylglucosamine and the disaccharide β-lactose reduced exosomes uptake to a comparable extent as the control D-glucose. Conclusions In conclusion, exosomes are internalized by ovarian tumor cells via various endocytic pathways and proteins from exosomes and cells are required for uptake. On the other hand, exosomes are enriched in specific

  3. Interaction and uptake of exosomes by ovarian cancer cells

    International Nuclear Information System (INIS)

    Escrevente, Cristina; Keller, Sascha; Altevogt, Peter; Costa, Júlia

    2011-01-01

    Exosomes consist of membrane vesicles that are secreted by several cell types, including tumors and have been found in biological fluids. Exosomes interact with other cells and may serve as vehicles for the transfer of protein and RNA among cells. SKOV3 exosomes were labelled with carboxyfluoresceine diacetate succinimidyl-ester and collected by ultracentrifugation. Uptake of these vesicles, under different conditions, by the same cells from where they originated was monitored by immunofluorescence microscopy and flow cytometry analysis. Lectin analysis was performed to investigate the glycosylation properties of proteins from exosomes and cellular extracts. In this work, the ovarian carcinoma SKOV3 cell line has been shown to internalize exosomes from the same cells via several endocytic pathways that were strongly inhibited at 4°C, indicating their energy dependence. Partial colocalization with the endosome marker EEA1 and inhibition by chlorpromazine suggested the involvement of clathrin-dependent endocytosis. Furthermore, uptake inhibition in the presence of 5-ethyl-N-isopropyl amiloride, cytochalasin D and methyl-beta-cyclodextrin suggested the involvement of additional endocytic pathways. The uptake required proteins from the exosomes and from the cells since it was inhibited after proteinase K treatments. The exosomes were found to be enriched in specific mannose- and sialic acid-containing glycoproteins. Sialic acid removal caused a small but non-significant increase in uptake. Furthermore, the monosaccharides D-galactose, α-L-fucose, α-D-mannose, D-N-acetylglucosamine and the disaccharide β-lactose reduced exosomes uptake to a comparable extent as the control D-glucose. In conclusion, exosomes are internalized by ovarian tumor cells via various endocytic pathways and proteins from exosomes and cells are required for uptake. On the other hand, exosomes are enriched in specific glycoproteins that may constitute exosome markers. This work contributes to

  4. Interaction of Dendritic Polymers with Synthetic Lipid and Cell Membranes

    Science.gov (United States)

    Mecke, Almut; Hong, Seungpyo; Bielinska, Anna U.; Banaszak Holl, Mark M.; Orr, Bradford G.; Baker, James R., Jr.

    2004-03-01

    Polyamidoamine (PAMAM) dendrimers are promising candidates for the development of nanoscale therapeutic transport agents. Here we present studies on dendrimer-membrane interactions leading to a better understanding of possible uptake mechanisms into cells. Using synthetic lipid and natural cell membranes as model systems it is shown that the effect of PAMAM dendrimers on a membrane strongly depends on the dendrimer generation, architecture and chemical properties of the branch end groups. Atomic force microscopy data indicates that generation 7 dendrimers have the ability to form small ( 10-100 nm) holes in a lipid bilayer. When dendrimers with otherwise identical chemical properties are arranged in a covalently linked cluster, no hole formation occurs. Dendrimer-lipid micelle formation is proposed and investigated as a possible mechanism for this behavior. Smaller dendrimers (generation 5) have a greatly reduced ability to remove lipid molecules from a bilayer. In addition to the size of the dendrimer, the charge of the branch end groups plays a significant role for dendrimer-membrane interactions. These results agree well with biological studies using cultured cells and point to a new mechanism of specific targeting and uptake into cells.

  5. Impact of Salinomycin on human cholangiocarcinoma: induction of apoptosis and impairment of tumor cell proliferation in vitro

    Directory of Open Access Journals (Sweden)

    Lieke Thorsten

    2012-10-01

    Full Text Available Abstract Background Cholangiocarcinoma (CC is a primary liver cancer with increasing incidence worldwide. Despite all efforts made in past years, prognosis remains to be poor. At least in part, this might be explained by a pronounced resistance of CC cells to undergo apoptosis. Thus, new therapeutic strategies are imperatively required. In this study we investigated the effect of Salinomycin, a polyether ionophore antibiotic, on CC cells as an appropriate agent to treat CC. Salinomycin was quite recently identified to induce apoptosis in cancer stem cells and to overcome apoptosis-resistance in several leukemia-cells and other cancer cell lines of different origin. Methods To delineate the effects of Salinomycin on CC, we established an in vitro cell culture model using three different human CC cell lines. After treatment apoptosis as well as migration and proliferation behavior was assessed and additional cell cycle analyses were performed by flowcytometry. Results By demonstrating Annexin V and TUNEL positivity of human CC cells, we provide evidence that Salinomycin reveals the capacity to break apoptosis-resistance in CC cells. Furthermore, we are able to demonstrate that the non-apoptotic cell fraction is characterized by sustainable impaired migration and proliferation. Cell cycle analyses revealed G2-phase accumulation of human CC cells after treatment with Salinomycin. Even though apoptosis is induced in two of three cell lines of CC cells, one cell line remained unaffected in regard of apoptosis but revealed as the other CC cells decreased proliferation and migration. Conclusion In this study, we are able to demonstrate that Salinomycin is an effective agent against previously resistant CC cells and might be a potential candidate for the treatment of CC in the future.

  6. Direct observation of nanoparticle-cancer cell nucleus interactions.

    Science.gov (United States)

    Dam, Duncan Hieu M; Lee, Jung Heon; Sisco, Patrick N; Co, Dick T; Zhang, Ming; Wasielewski, Michael R; Odom, Teri W

    2012-04-24

    We report the direct visualization of interactions between drug-loaded nanoparticles and the cancer cell nucleus. Nanoconstructs composed of nucleolin-specific aptamers and gold nanostars were actively transported to the nucleus and induced major changes to the nuclear phenotype via nuclear envelope invaginations near the site of the construct. The number of local deformations could be increased by ultrafast, light-triggered release of the aptamers from the surface of the gold nanostars. Cancer cells with more nuclear envelope folding showed increased caspase 3 and 7 activity (apoptosis) as well as decreased cell viability. This newly revealed correlation between drug-induced changes in nuclear phenotype and increased therapeutic efficacy could provide new insight for nuclear-targeted cancer therapy.

  7. Spatial Evolutionary Games of Interaction among Generic Cancer Cells

    DEFF Research Database (Denmark)

    Bach, Lars Arve; Sumpter, David J.T.; Alsner, Jan

    2003-01-01

    Evolutionary game models of cellular interactions have shown that heterogeneity in the cellular genotypic composition is maintained through evolution to stable coexistence of growth-promoting and non-promoting cell types. We generalise these mean-field models and relax the assumption of perfect...... mixing of cells by instead implementing an individual-based model that includes the stochastic and spatial effects likely to occur in tumours. The scope for coexistence of genotypic strategies changed with the inclusion of explicit space and stochasticity. The spatial models show some interesting...... deviations from their mean-field counterparts, for example the possibility of altruistic (paracrine) cell strategies to thrive. Such effects can however, be highly sensitive to model implementation and the more realistic models with semi-synchronous and stochastic updating do not show evolution of altruism...

  8. Dendritic Cells in the Gut: Interaction with Intestinal Helminths

    Directory of Open Access Journals (Sweden)

    Fela Mendlovic

    2010-01-01

    Full Text Available The mucosal environment in mammals is highly tolerogenic; however, after exposure to pathogens or danger signals, it is able to shift towards an inflammatory response. Dendritic cells (DCs orchestrate immune responses and are highly responsible, through the secretion of cytokines and expression of surface markers, for the outcome of such immune response. In particular, the DC subsets found in the intestine have specialized functions and interact with different immune as well as nonimmune cells. Intestinal helminths primarily induce Th2 responses where DCs have an important yet not completely understood role. In addition, this cross-talk results in the induction of regulatory T cells (T regs as a result of the homeostatic mucosal environment. This review highlights the importance of studying the particular relation “helminth-DC-milieu” in view of the significance that each of these factors plays. Elucidating the mechanisms that trigger Th2 responses may provide the understanding of how we might modulate inflammatory processes.

  9. A multidirectional non-cell autonomous control and a genetic interaction restricting tobacco etch virus susceptibility in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Suresh Gopalan

    2007-10-01

    Full Text Available Viruses constitute a major class of pathogens that infect a variety of hosts. Understanding the intricacies of signaling during host-virus interactions should aid in designing disease prevention strategies and in understanding mechanistic aspects of host and pathogen signaling machinery.An Arabidopsis mutant, B149, impaired in susceptibility to Tobacco etch virus (TEV, a positive strand RNA virus of picoRNA family, was identified using a high-throughput genetic screen and a counterselection scheme. The defects include initiation of infection foci, rate of cell-to-cell movement and long distance movement.The defect in infectivity is conferred by a recessive locus. Molecular genetic analysis and complementation analysis with three alleles of a previously published mutant lsp1 (loss of susceptibility to potyviruses indicate a genetic interaction conferring haploinsufficiency between the B149 locus and certain alleles of lsp1 resulting in impaired host susceptibility. The pattern of restriction of TEV foci on leaves at or near the boundaries of certain cell types and leaf boundaries suggest dysregulation of a multidirectional non-cell autonomous regulatory mechanism. Understanding the nature of this multidirectional signal and the molecular genetic mechanism conferring it should potentially reveal a novel arsenal in the cellular machinery.

  10. Use of scanning electron microscopy to monitor nanofibre/cell interaction in digestive epithelial cells.

    Science.gov (United States)

    Millaku, Agron; Drobne, Damjana; Torkar, Matjaz; Novak, Sara; Remškar, Maja; Pipan-Tkalec, Živa

    2013-09-15

    We provide data obtained by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) on the interaction of ingested tungsten nanofibers with epithelial cells of the digestive tubes of a test organism Porcellio scaber. Conventional toxicity endpoints including feeding behaviour, weight loss and mortality were also measured in each investigated animal. No toxicity was detected in any of exposed animals after 14 days of feeding on tungsten nanofiber dosed food, but when nanofibers enter the digestive system they can react with epithelial cells of the digestive tubes, becoming physically inserted into the cells. In this way, nanofibers can injure the epithelial cells of digestive gland tubes when they are ingested with food. Our SEM data suggest that peristaltic forces may have an important role, not predicted by in vitro experiments, in the interactions of nanomaterials with digestive intestinal cells. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Increased androgen levels in rats impair glucose-stimulated insulin secretion through disruption of pancreatic beta cell mitochondrial function.

    Science.gov (United States)

    Wang, Hongdong; Wang, Xiaping; Zhu, Yunxia; Chen, Fang; Sun, Yujie; Han, Xiao

    2015-11-01

    Although insulin resistance is recognized to contribute to the reproductive and metabolic phenotypes of polycystic ovary syndrome (PCOS), pancreatic beta cell dysfunction plays an essential role in the progression from PCOS to the development of type 2 diabetes. However, the role of insulin secretory abnormalities in PCOS has received little attention. In addition, the precise changes in beta cells and the underlying mechanisms remain unclear. In this study, we therefore attempted to elucidate potential mechanisms involved in beta cell alterations in a rat model of PCOS. Glucose-induced insulin secretion was measured in islets isolated from DHT-treated and control rats. Oxygen consumption rate (OCR), ATP production, and mitochondrial copy number were assayed to evaluate mitochondrial function. Glucose-stimulated insulin secretion is significantly decreased in islets from DHT-treated rats. On the other hand, significant reductions are observed in the expression levels of several key genes involved in mitochondrial biogenesis and in mitochondrial OCR and ATP production in DHT-treated rat islets. Meanwhile, we found that androgens can directly impair beta cell function by inducing mitochondrial dysfunction in vitro in an androgen receptor dependent manner. For the first time, our study demonstrates that increased androgens in female rats can impair glucose-stimulated insulin secretion partly through disruption of pancreatic beta cell mitochondrial function. This work has significance for hyperandrogenic women with PCOS: excess activation of the androgen receptor by androgens may provoke beta cell dysfunction via mitochondrial dysfunction. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Amastin Knockdown in Leishmania braziliensis Affects Parasite-Macrophage Interaction and Results in Impaired Viability of Intracellular Amastigotes.

    Directory of Open Access Journals (Sweden)

    Rita Marcia Cardoso de Paiva

    2015-12-01

    Full Text Available Leishmaniasis, a human parasitic disease with manifestations ranging from cutaneous ulcerations to fatal visceral infection, is caused by several Leishmania species. These protozoan parasites replicate as extracellular, flagellated promastigotes in the gut of a sandfly vector and as amastigotes inside the parasitophorous vacuole of vertebrate host macrophages. Amastins are surface glycoproteins encoded by large gene families present in the genomes of several trypanosomatids and highly expressed in the intracellular amastigote stages of Trypanosoma cruzi and Leishmania spp. Here, we showed that the genome of L. braziliensis contains 52 amastin genes belonging to all four previously described amastin subfamilies and that the expression of members of all subfamilies is upregulated in L. braziliensis amastigotes. Although primary sequence alignments showed no homology to any known protein sequence, homology searches based on secondary structure predictions indicate that amastins are related to claudins, a group of proteins that are components of eukaryotic tight junction complexes. By knocking-down the expression of δ-amastins in L. braziliensis, their essential role during infection became evident. δ-amastin knockdown parasites showed impaired growth after in vitro infection of mouse macrophages and completely failed to produce infection when inoculated in BALB/c mice, an attenuated phenotype that was reverted by the re-expression of an RNAi-resistant amastin gene. Further highlighting their essential role in host-parasite interactions, electron microscopy analyses of macrophages infected with amastin knockdown parasites showed significant alterations in the tight contact that is normally observed between the surface of wild type amastigotes and the membrane of the parasitophorous vacuole.

  13. Impairments in cognition and neural precursor cell proliferation in mice expressing constitutively active glycogen synthase kinase-3

    Directory of Open Access Journals (Sweden)

    Marta ePardo

    2015-03-01

    Full Text Available ABSTRACTBrain glycogen synthase kinase-3 (GSK3 is hyperactive in several neurological conditions that involve impairments in both cognition and neurogenesis. This raises the hypotheses that hyperactive GSK3 may directly contribute to impaired cognition, and that this may be related to deficiencies in neural precursor cells (NPC. To study the effects of hyperactive GSK3 in the absence of disease influences, we compared adult hippocampal NPC proliferation and performance in three cognitive tasks in male and female wild-type mice and GSK3 knockin mice, which express constitutively active GSK3. NPC proliferation was ~40% deficient in both male and female GSK3 knockin mice compared with wild-type mice. Environmental enrichment (EE increased NPC proliferation in male, but not female, GSK3 knockin mice and wild-type mice. Male and female GSK3 knockin mice exhibited impairments in novel object recognition, temporal order memory, and coordinate spatial processing compared with gender-matched wild-type mice. EE restored impaired novel object recognition and temporal ordering in both sexes of GSK3 knockin mice, indicating that this repair was not dependent on NPC proliferation, which was not increased by EE in female GSK3 knockin mice. Acute 1 hr pretreatment with the GSK3 inhibitor TDZD-8 also improved novel object recognition and temporal ordering in male and female GSK3 knockin mice. These findings demonstrate that hyperactive GSK3 is sufficient to impair adult hippocampal NPC proliferation and to impair performance in three cognitive tasks in both male and female mice, but these changes in NPC proliferation do not directly regulate novel object recognition and temporal ordering tasks.

  14. An Interactive Exercise To Learn Eukaryotic Cell Structure and Organelle Function.

    Science.gov (United States)

    Klionsky, Daniel J.; Tomashek, John J.

    1999-01-01

    Describes a cooperative, interactive problem-solving exercise for studying eukaryotic cell structure and function. Highlights the dynamic aspects of movement through the cell. Contains 15 references. (WRM)

  15. Advanced glycation end-products (AGEs acutely impair Ca2+ signalling in bovine aortic endothelial cells

    Directory of Open Access Journals (Sweden)

    Nadim eNaser

    2013-03-01

    Full Text Available Post-translational modification of proteins in diabetes, including formation of advanced glycation end products (AGEs are believed to contribute to vascular dysfunction and disease. Impaired function of the endothelium is an early indicator of vascular dysfunction in diabetes and as many endothelial cell processes are dependent upon intracellular [Ca2+] and Ca2+ signalling, the aim of this study was to examine the acute effects of AGEs on Ca2+ signalling in bovine aortic endothelial cells (BAEC. Ca2+ signalling was studied using the fluorescent indicator dye Fura2-AM. AGEs were generated by incubating bovine serum albumin with 0 - 250 mM glucose or glucose-6-phosphate for 0 to 120 days at 37ºC. Under all conditions, the main AGE species generated was carboxymethyl lysine (CML as assayed using both GC-MS and HPLC. In Ca2+-replete solution, exposure of BAEC to AGEs for 5 min caused an elevation in basal [Ca2+] and attenuated the increase in intracellular [Ca2+] caused by ATP (100 µM. In the absence of extracellular Ca2+, exposure of BAEC to AGEs for 5 min caused an elevation in basal [Ca2+] and attenuated subsequent intracellular Ca2+ release caused by ATP, thapsigargin (0.1 µM and ionomycin (3 µM, but AGEs did not affect extracellular Ca2+ entry induced by the re-addition of Ca2+ to the bathing solution in the presence of any of these agents. The anti-oxidant α-lipoic acid (2 µM and NAD(PH oxidase inhibitors apocynin (500 µM and diphenyleneiodonium (DPI, 1 µM abolished these effects of AGEs on BAECs, as did the IP3 receptor antagonist xestospongin C (1 µM. In summary, AGEs caused an acute depletion of Ca2+ from the intracellular store in BAECs, such that the Ca2+ signal stimulated by the subsequent application other agents acting upon this store is reduced. The mechanism may involve generation of ROS from NAD(PH oxidase and possible activation of the IP3 receptor.

  16. Food-allergic infants have impaired regulatory T-cell responses following in vivo allergen exposure.

    Science.gov (United States)

    Dang, Thanh D; Allen, Katrina J; J Martino, David; Koplin, Jennifer J; Licciardi, Paul V; Tang, Mimi L K

    2016-02-01

    Regulatory T cells (Tregs) are critical for development of oral tolerance, and studies suggest that dysfunction of Tregs may lead to food allergy. However, to date, no study has investigated Treg responses following in vivo exposure to peanut or egg allergens in humans. To examine changes in peripheral blood CD4(+) CD25(+) Foxp3(+) Treg populations (total, activated and naive) in food-allergic, food-sensitized but tolerant, and healthy (non-sensitized non-allergic) patients over time following in vivo allergen exposure. A subset of infants from the HealthNuts study with egg or peanut allergy (n = 37), egg or peanut sensitization (n = 35), or who were non-sensitized non-allergic (n = 15) were studied. All subjects underwent oral food challenge (OFC) to egg or peanut. PBMCs were obtained within 1 h of OFC (in vivo allergen exposure), and Treg populations enumerated ex vivo on day 0, and after 2 and 6 days rest in vitro. Non-allergic infants showed stable total Treg frequencies over time; food-sensitized infants had a transient fall in Treg percentage with recovery to baseline by day 6 (6.87% day 0, 5.27% day 2, 6.5% day 6); and food-allergic infants showed persistent reduction in Treg (6.85% day 0, 5.4% day 2, 6.2% day 6) following in vivo allergen exposure. Furthermore, food-allergic infants had a significantly lower ratio of activated Treg:activated T cells (10.5 ± 0.77) at day 0 compared to food-sensitized (14.6 ± 1.24) and non-allergic subjects (16.2 ± 1.23). Our data suggest that the state of allergen sensitization is associated with depletion of Treg following allergen exposure. Impaired capacity to regenerate the Treg pool following allergen exposure may be an important factor that determines clinical allergy vs. sensitization without allergic reaction. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Advanced glycation end products impair function of late endothelial progenitor cells through effects on protein kinase Akt and cyclooxygenase-2

    International Nuclear Information System (INIS)

    Chen Qin; Dong Li; Wang Lian; Kang Lina; Xu Biao

    2009-01-01

    Endothelial progenitor cells (EPCs) exhibit impaired function in the context of diabetes, and advanced glycation end products (AGEs), which accumulate in diabetes, may contribute to this. In the present study, we investigated the mechanism by which AGEs impair late EPC function. EPCs from human umbilical cord blood were isolated, and incubated with AGE-modified albumin (AGE-albumin) at different concentrations found physiologically in plasma. Apoptosis, migration, and tube formation assays were used to evaluate EPC function including capacity for vasculogenesis, and expression of the receptor for AGEs (RAGE), Akt, endothelial nitric oxide synthase (eNOS), and cycloxygenase-2 (COX-2) were determined. Anti-RAGE antibody was used to block RAGE function. AGE-albumin concentration-dependently enhanced apoptosis and depressed migration and tube formation, but did not affect proliferation, of late EPCs. High AGE-albumin increased RAGE mRNA and protein expression, and decreased Akt and COX-2 protein expression, whilst having no effect on eNOS mRNA or protein in these cells. These effects were inhibited by co-incubation with anti-RAGE antibody. These results suggest that RAGE mediates the AGE-induced impairment of late EPC function, through down-regulation of Akt and COX-2 in these cells.

  18. Taurine Protected Against the Impairments of Neural Stem Cell Differentiated Neurons Induced by Oxygen-Glucose Deprivation.

    Science.gov (United States)

    Xiao, Bo; Liu, Huazhen; Gu, Zeyun; Liu, Sining; Ji, Cheng

    2015-11-01

    Cell transplantation of neural stem cells (NSCs) is a promising approach for neurological recovery both structurally and functionally. However, one big obstacle is to promote differentiation of NSCs into neurons and the followed maturation. In the present study, we aimed to investigate the protective effect of taurine on the differentiation of NSCs and subsequent maturation of their neuronal lineage, when exposed to oxygen-glucose deprivation (OGD). The results suggested that taurine (5-20 mM) promoted the viability and proliferation of NSCs, and it protected against 8 h of OGD induced impairments. Furthermore, 20 mM taurine promoted NSCs to differentiate into neurons after 7 days of culture, and it also protected against the suppressive impairments of 8 h of OGD. Consistently, taurine (20 mM) promoted the neurite sprouting and outgrowth of the NSC differentiated neurons after 14 days of differentiation, which were significantly inhibited by OGD (8 h). At D21, the mushroom spines and spine density were promoted or restored by 20 mM taurine. Taken together, the enhanced viability and proliferation of NSCs, more differentiated neurons and the promoted maturation of neurons by 20 mM taurine support its therapeutic application during stem cell therapy to enhance neurological recovery. Moreover, it protected against the impairments induced by OGD, which may highlight its role for a more direct therapeutic application especially in an ischemic stroke environment.

  19. Real-time sensing of epithelial cell-cell and cell-substrate interactions by impedance spectroscopy on porous substrates

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, D.; RoyChaudhuri, C., E-mail: chirosreepram@yahoo.com [Department of Electronics and Telecommunication Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103 (India); Pal, D. [Department of Aerospace Engineering and Applied Mechanics, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103 (India)

    2015-07-28

    Oxidized porous silicon (PS) is a common topographical biocompatible substrate that potentially provides a distinct in vitro environment for better understanding of in vivo behavior. But in the reported studies on oxidized PS, cell-cell and cell-substrate interactions have been detected only by fluorescent labeling. This paper is the first attempt to investigate real-time sensing of these interactions on HaCaT cells by label-free impedance spectroscopy on oxidized PS of two pore diameters (50 and 500 nm). One of the major requirements for successful impedance spectroscopy measurement is to restrict the channeling of electric field lines through the pores. To satisfy this criterion, we have designed the pore depths after analyzing the penetration of the medium by using computational fluid dynamics simulation. A distributed electrical model was also developed for estimating the various cellular attributes by considering a pseudorandom distribution of pores. It is observed from the impedance measurements and from the model that the proliferation rate increases for 50 nm pores but decreases for 500 nm pores compared to that for planar substrates. The rate of decrease in cell substrate separation (h) in the initial stage is more than the rate of increase in cell-cell junction resistance (R{sub b}) corresponding to the initial adhesion phase of cells. It is observed that R{sub b} and h are higher for 50 nm pores than those for planar substrates, corresponding to the fact that substrates more conducive toward cell adhesion encourage cell-cell interactions than direct cell-substrate interactions. Thus, the impedance spectroscopy coupled with the proposed theoretical framework for PS substrates can sense and quantify the cellular interactions.

  20. Real-time sensing of epithelial cell-cell and cell-substrate interactions by impedance spectroscopy on porous substrates

    International Nuclear Information System (INIS)

    Mondal, D.; RoyChaudhuri, C.; Pal, D.

    2015-01-01

    Oxidized porous silicon (PS) is a common topographical biocompatible substrate that potentially provides a distinct in vitro environment for better understanding of in vivo behavior. But in the reported studies on oxidized PS, cell-cell and cell-substrate interactions have been detected only by fluorescent labeling. This paper is the first attempt to investigate real-time sensing of these interactions on HaCaT cells by label-free impedance spectroscopy on oxidized PS of two pore diameters (50 and 500 nm). One of the major requirements for successful impedance spectroscopy measurement is to restrict the channeling of electric field lines through the pores. To satisfy this criterion, we have designed the pore depths after analyzing the penetration of the medium by using computational fluid dynamics simulation. A distributed electrical model was also developed for estimating the various cellular attributes by considering a pseudorandom distribution of pores. It is observed from the impedance measurements and from the model that the proliferation rate increases for 50 nm pores but decreases for 500 nm pores compared to that for planar substrates. The rate of decrease in cell substrate separation (h) in the initial stage is more than the rate of increase in cell-cell junction resistance (R b ) corresponding to the initial adhesion phase of cells. It is observed that R b and h are higher for 50 nm pores than those for planar substrates, corresponding to the fact that substrates more conducive toward cell adhesion encourage cell-cell interactions than direct cell-substrate interactions. Thus, the impedance spectroscopy coupled with the proposed theoretical framework for PS substrates can sense and quantify the cellular interactions

  1. Involvement of leucocyte/endothelial cell interactions in anorexia nervosa.

    Science.gov (United States)

    Víctor, Víctor M; Rovira-Llopis, Susana; Saiz-Alarcón, Vanessa; Sangüesa, Maria C; Rojo-Bofill, Luis; Bañuls, Celia; de Pablo, Carmen; Álvarez, Ángeles; Rojo, Luis; Rocha, Milagros; Hernández-Mijares, Antonio

    2015-07-01

    Anorexia nervosa is a common psychiatric disorder in adolescence and is related to cardiovascular complications. Our aim was to study the effect of anorexia nervosa on metabolic parameters, leucocyte-endothelium interactions, adhesion molecules and proinflammatory cytokines. This multicentre, cross-sectional, case-control study employed a population of 24 anorexic female patients and 36 controls. We evaluated anthropometric and metabolic parameters, interactions between leucocytes polymorphonuclear neutrophils (PMN) and human umbilical vein endothelial cells (HUVEC), proinflammatory cytokines such as tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) and soluble cellular adhesion molecules (CAMs) including E-selectin, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Anorexia nervosa was related to a decrease in weight, body mass index, waist circumference, systolic blood pressure, glucose, insulin and HOMA-IR, and an increase in HDL cholesterol. These effects disappeared after adjusting for BMI. Anorexia nervosa induced a decrease in PMN rolling velocity and an increase in PMN rolling flux and PMN adhesion. Increases in IL-6 and TNF-α and adhesion molecule VCAM-1 were also observed. This study supports the hypothesis of an association between anorexia nervosa, inflammation and the induction of leucocyte-endothelium interactions. These findings may explain, in part at least, the increased risk of vascular disease among patients with anorexia nervosa. © 2015 Stichting European Society for Clinical Investigation Journal Foundation.

  2. Electron microscopy study of antioxidant interaction with bacterial cells

    Science.gov (United States)

    Plotnikov, Oleg P.; Novikova, Olga V.; Konnov, Nikolai P.; Korsukov, Vladimir N.; Gunkin, Ivan F.; Volkov, Uryi P.

    2000-10-01

    To maintain native microorganisms genotype and phenotype features a lyophylization technique is widely used. However in this case cells are affected by influences of vacuum and low temperature that cause a part of the cells population to be destruction. Another factor reduced microorganisms vitality is formation of reactive oxygen forms that damage certain biological targets (such as DNA, membranes etc.) Recently to raise microorganism's resistance against adverse condition natural and synthetic antioxidants are used. Antioxidant- are antagonists of free radicals. Introduction of antioxidants in protective medium for lyophylization increase bacteria storage life about 2,0-4,8 fold in comparison with reference samples. In the article the main results of our investigation of antioxidants interaction with microorganism cells is described. As bacteria cells we use vaccine strain yersinia pestis EV, that were grown for 48 h at 28 degree(s)C on the Hottinger agar (pH 7,2). Antioxidants are inserted on the agar surface in specimen under test. To investigate a localization of antioxidants for electron microscopy investigation, thallium organic antioxidants were used. The thallium organic compounds have an antioxidant features if thallium is in low concentration (about 1(mu) g/ml). The localization of the thallium organic antioxidants on bacteria Y. pestis EV is visible in electron microscopy images, thallium being heavy metal with high electron density. The negatively stained bacteria and bacteria thin sections with thallium organic compounds were investigated by means of transmission electron microscopy. The localization of the thallium organic compounds is clearly visible in electron micrographs as small dark spots with size about 10-80nm. Probably mechanisms of interaction of antioxidants with bacteria cells are discussed.

  3. Cell penetrating peptides to dissect host-pathogen protein-protein interactions in Theileria -transformed leukocytes

    KAUST Repository

    Haidar, Malak; de Laté , Perle Latré ; Kennedy, Eileen J.; Langsley, Gordon

    2017-01-01

    One powerful application of cell penetrating peptides is the delivery into cells of molecules that function as specific competitors or inhibitors of protein-protein interactions. Ablating defined protein-protein interactions is a refined way

  4. Music application alleviates short-term memory impairments through increasing cell proliferation in the hippocampus of valproic acid-induced autistic rat pups.

    Science.gov (United States)

    Lee, Sung-Min; Kim, Bo-Kyun; Kim, Tae-Woon; Ji, Eun-Sang; Choi, Hyun-Hee

    2016-06-01

    Autism is a neurodevelopmental disorder and this disorder shows impairment in reciprocal social interactions, deficits in communication, and restrictive and repetitive patterns of behaviors and interests. The effect of music on short-term memory in the view of cell proliferation in the hippocampus was evaluated using valproic acid-induced autistic rat pups. Animal model of autism was made by subcutaneous injection of 400-mg/kg valproic acid into the rat pups on the postnatal day 14. The rat pups in the music-applied groups were exposed to the 65-dB comfortable classic music for 1 hr once a day, starting postnatal day 15 and continued until postnatal day 28. In the present results, short-term memory was deteriorated by autism induction. The numbers of 5-bromo-2'-deoxyridine (BrdU)-positive, Ki-67-positive, and doublecortin (DCX)-positive cells in the hippocampal dentate gyrus were decreased by autism induction. Brain-derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB) expressions in the hippocampus were also suppressed in the autistic rat pups. Music application alleviated short-term memory deficits with enhancing the numbers of BrdU-positive, Ki-67-positive, and DCX-positive cells in the autistic rat pups. Music application also enhanced BDNF and TrkB expressions in the autistic rat pups. The present study show that application of music enhanced hippocampal cell proliferation and alleviated short-term memory impairment through stimulating BDNF-TrkB signaling in the autistic rat pups. Music can be suggested as the therapeutic strategy to overcome the autism-induced memory deficits.

  5. Interactions between endothelial progenitor cells (EPC) and titanium implant surfaces.

    Science.gov (United States)

    Ziebart, Thomas; Schnell, Anne; Walter, Christian; Kämmerer, Peer W; Pabst, Andreas; Lehmann, Karl M; Ziebart, Johanna; Klein, Marc O; Al-Nawas, Bilal

    2013-01-01

    Endothelial cells play an important role in peri-implant angiogenesis during early bone formation. Therefore, interactions between endothelial progenitor cells (EPCs) and titanium dental implant surfaces are of crucial interest. The aim of our in vitro study was to investigate the reactions of EPCs in contact with different commercially available implant surfaces. EPCs from buffy coats were isolated by Ficoll density gradient separation. After cell differentiation, EPC were cultured for a period of 7 days on different titanium surfaces. The test surfaces varied in roughness and hydrophilicity: acid-etched (A), sand-blasted-blasted and acid-etched (SLA), hydrophilic A (modA), and hydrophilic SLA (modSLA). Plastic and fibronectin-coated plastic surfaces served as controls. Cell numbers and morphology were analyzed by confocal laser scanning microscopy. Secretion of vascular endothelial growth factor (VEGF)-A was measured by enzyme-linked immunosorbent assay and expressions of iNOS and eNOS were investigated by real-time polymerase chain reaction. Cell numbers were higher in the control groups compared to the cells of titanium surfaces. Initially, hydrophilic titanium surfaces (modA and modSLA) showed lower cell numbers than hydrophobic surfaces (A and SLA). After 7 days smoother surfaces (A and modA) showed increased cell numbers compared to rougher surfaces (SLA and modSLA). Cell morphology of A, modA, and control surfaces was characterized by a multitude of pseudopodia and planar cell soma architecture. SLA and modSLA promoted small and plump cell soma with little quantity of pseudopodia. The lowest VEGF level was measured on A, the highest on modSLA. The highest eNOS and iNOS expressions were found on modA surfaces. The results of this study demonstrate that biological behaviors of EPCs can be influenced by different surfaces. The modSLA surface promotes an undifferentiated phenotype of EPCs that has the ability to secrete growth factors in great quantities. In

  6. T cells in chronic lymphocytic leukaemia display an exhausted phenotype and impaired functionality that can be restored by chemotherapy

    International Nuclear Information System (INIS)

    Gassner, F.

    2012-01-01

    In chronic lymphocytic leukaemia (CLL), beside a massive accumulation of neoplastic B cells, tumour-induced deficiencies in autologous T cells have been reported that impede efficient tumour control and might even support survival of the malignant clone. Here, we investigated our hypothesis that T cells in CLL, due to the persistent availability of tumour antigen, are exhausted, and that reduction of tumour load by chemotherapy might restore T cell functions. We could show that T cells in CLL patients and in a CLL mouse model display an exhausted phenotype, with high expression of the inhibitory surface receptor PD-1, that is clearly induced by the presence of tumour cells. Although the PD-1 ligand PD-L1 is not expressed on peripheral CLL cells, abundant expression could be shown in lymph node sections. Intriguingly, blocking the PD-1/PD-L1 pathway increased short term tumour lysis in a murine in vivo cytotoxicity assay. Furthermore, we present data that after cytoreduction by fludarabine, a standard chemotherapy agent for CLL, the surviving T cell pool consists mainly of fully functional memory T cells with high proliferative potential and increased secretion of pro-inflammatory Th1 cytokines. Taken together, we conclude that the impaired tumour surveillance observed in CLL might be rooted in the exhaustion of tumour-specific effector T cells. A combination of cytodepletion by chemotherapy and blockade of PD-1 might hence represent a novel therapeutic approach for CLL. (author) [de

  7. Inactivation of STAT3 Signaling Impairs Hair Cell Differentiation in the Developing Mouse Cochlea.

    Science.gov (United States)

    Chen, Qianqian; Quan, Yizhou; Wang, Naitao; Xie, Chengying; Ji, Zhongzhong; He, Hao; Chai, Renjie; Li, Huawei; Yin, Shankai; Chin, Y Eugene; Wei, Xunbin; Gao, Wei-Qiang

    2017-07-11

    Although STAT3 signaling is demonstrated to regulate sensory cell differentiation and regeneration in the zebrafish, its exact role is still unclear in mammalian cochleae. Here, we report that STAT3 and its activated form are specifically expressed in hair cells during mouse cochlear development. Importantly, conditional cochlear deletion of Stat3 leads to an inhibition on hair cell differentiation in mice in vivo and in vitro. By cell fate analysis, inactivation of STAT3 signaling shifts the cell division modes from asymmetric to symmetric divisions from supporting cells. Moreover, inhibition of Notch signaling stimulates STAT3 phosphorylation, and inactivation of STAT3 signaling attenuates production of supernumerary hair cells induced by a Notch pathway inhibitor. Our findings highlight an important role of the STAT3 signaling during mouse cochlear hair cell differentiation and may have clinical implications for the recovery of hair cell loss-induced hearing impairment. Copyright © 2017 International Society for Stem Cell Research. Published by Elsevier Inc. All rights reserved.

  8. Impaired liver regeneration is associated with reduced cyclin B1 in natural killer T cell-deficient mice.

    Science.gov (United States)

    Ben Ya'acov, Ami; Meir, Hadar; Zolotaryova, Lydia; Ilan, Yaron; Shteyer, Eyal

    2017-03-23

    It has been shown that the proportion of natural killer T cells is markedly elevated during liver regeneration and their activation under different conditions can modulate this process. As natural killer T cells and liver injury are central in liver regeneration, elucidating their role is important. The aim of the current study is to explore the role of natural killer T cells in impaired liver regeneration. Concanvalin A was injected 4 days before partial hepatectomy to natural killer T cells- deficient mice or to anti CD1d1-treated mice. Ki-67 and proliferating cell nuclear antigen were used to measure hepatocytes proliferation. Expression of hepatic cyclin B1 and proliferating cell nuclear antigen were evaluated by Western Blot and liver injury was assessed by ALT and histology. Natural killer T cells- deficient or mice injected with anti CD1d antibodies exhibited reduced liver regeneration. These mice were considerably resistant to ConA-induced liver injury. In the absence of NKT cells hepatic proliferating cell nuclear antigen and cyclin B1 decreased in mice injected with Concanvalin A before partial hepatectomy. This was accompanied with reduced serum interleukin-6 levels. Natural killer T cells play an important role in liver regeneration, which is associated with cyclin B1 and interleukin-6.

  9. Impaired STING Pathway in Human Osteosarcoma U2OS Cells Contributes to the Growth of ICP0-Null Mutant Herpes Simplex Virus.

    Science.gov (United States)

    Deschamps, Thibaut; Kalamvoki, Maria

    2017-05-01

    Human herpes simplex virus 1 (HSV-1) is a widespread pathogen, with 80% of the population being latently infected. To successfully evade the host, the virus has evolved strategies to counteract antiviral responses, including the gene-silencing and innate immunity machineries. The immediately early protein of the virus, infected cell protein 0 (ICP0), plays a central role in these processes. ICP0 blocks innate immunity, and one mechanism is by degrading hostile factors with its intrinsic E3 ligase activity. ICP0 also functions as a promiscuous transactivator, and it blocks repressor complexes to enable viral gene transcription. For these reasons, the growth of a ΔICP0 virus is impaired in most cells, except cells of the human osteosarcoma cell line U2OS, and it is only partially impaired in cells of the human osteosarcoma cell line Saos-2. We found that the two human osteosarcoma cell lines that supported the growth of the ΔICP0 virus failed to activate innate immune responses upon treatment with 2'3'-cyclic GAMP (2'3'-cGAMP), the natural agonist of STING (i.e., stimulator of interferon genes) or after infection with the ΔICP0 mutant virus. Innate immune responses were restored in these cells by transient expression of the STING protein but not after overexpression of interferon-inducible protein 16 (IFI16). Restoration of STING expression resulted in suppression of ΔICP0 virus gene expression and a decrease in viral yields. Overexpression of IFI16 also suppressed ΔICP0 virus gene expression, albeit to a lesser extent than STING. These data suggest that the susceptibility of U2OS and Saos-2 cells to the ΔICP0 HSV-1 is in part due to an impaired STING pathway. IMPORTANCE The DNA sensor STING plays pivotal role in controlling HSV-1 infection both in cell culture and in mice. The HSV-1 genome encodes numerous proteins that are dedicated to combat host antiviral responses. The immediate early protein of the virus ICP0 plays major role in this process as it targets

  10. Enforced expression of the transcriptional coactivator OBF1 impairs B cell differentiation at the earliest stage of development.

    Directory of Open Access Journals (Sweden)

    Alain Bordon

    Full Text Available OBF1, also known as Bob.1 or OCA-B, is a B lymphocyte-specific transcription factor which coactivates Oct1 and Oct2 on B cell specific promoters. So far, the function of OBF1 has been mainly identified in late stage B cell populations. The central defect of OBF1 deficient mice is a severely reduced immune response to T cell-dependent antigens and a lack of germinal center formation in the spleen. Relatively little is known about a potential function of OBF1 in developing B cells. Here we have generated transgenic mice overexpressing OBF1 in B cells under the control of the immunoglobulin heavy chain promoter and enhancer. Surprisingly, these mice have greatly reduced numbers of follicular B cells in the periphery and have a compromised immune response. Furthermore, B cell differentiation is impaired at an early stage in the bone marrow: a first block is observed during B cell commitment and a second differentiation block is seen at the large preB2 cell stage. The cells that succeed to escape the block and to differentiate into mature B cells have post-translationally downregulated the expression of transgene, indicating that expression of OBF1 beyond the normal level early in B cell development is deleterious. Transcriptome analysis identified genes deregulated in these mice and Id2 and Id3, two known negative regulators of B cell differentiation, were found to be upregulated in the EPLM and preB cells of the transgenic mice. Furthermore, the Id2 and Id3 promoters contain octamer-like sites, to which OBF1 can bind. These results provide evidence that tight regulation of OBF1 expression in early B cells is essential to allow efficient B lymphocyte differentiation.

  11. Human eosinophil–airway smooth muscle cell interactions

    Directory of Open Access Journals (Sweden)

    J. Margaret Hughes

    2000-01-01

    Full Text Available Eosinophils are present throughout the airway wall of asthmatics. The nature of the interaction between human airway smooth muscle cells (ASMC and eosinophils was investigated in this study. We demonstrated, using light microscopy, that freshly isolated eosinophils from healthy donors rapidly attach to ASMC in vitro. Numbers of attached eosinophils were highest at 2 h, falling to 50% of maximum by 20 h. Eosinophil attachment at 2 h was reduced to 72% of control by anti-VCAM-1, and to 74% at 20 h by anti-ICAM-1. Pre-treatment of ASMC for 24 h with TNF-α, 10 nM, significantly increased eosinophil adhesion to 149 and 157% of control after 2 and 20 h. These results provide evidence that eosinophil interactions with ASMC involve VCAM-1 and ICAM-1 and are modulated by TNF-α.

  12. Activating mitochondrial function and haemoglobin expression with EH-201, an inducer of erythropoietin in neuronal cells, reverses memory impairment.

    Science.gov (United States)

    Horng, Lin-Yea; Hsu, Pei-Lun; Chen, Li-Wen; Tseng, Wang-Zou; Hsu, Kai-Tin; Wu, Chia-Ling; Wu, Rong-Tsun

    2015-10-01

    Memory impairment can be progressive in neurodegenerative diseases, and physiological ageing or brain injury, mitochondrial dysfunction and oxidative stress are critical components of these issues. An early clinical study has demonstrated cognitive improvement during erythropoietin treatment in patients with chronic renal failure. As erythropoietin cannot freely cross the blood-brain barrier, we tested EH-201 (2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucoside, also known as TSG), a low MW inducer of erythropoietin, for its therapeutic effects on memory impairment in models of neurodegenerative diseases, physiological ageing or brain injury. The effects of EH-201 were investigated in astrocytes and PC12 neuronal-like cells. In vivo, we used sleep-deprived (SD) mice as a stress model, amyloid-β (Aβ)-injected mice as a physiological ageing model and kainic acid (KA)-injected mice as a brain damage model to assess the therapeutic effects of EH-201. EH-201 induced expression of erythropoietin, PPAR-γ coactivator 1α (PGC-1α) and haemoglobin in astrocytes and PC12 neuronal-like cells. In vivo, EH-201 treatment restored memory impairment, as assessed by the passive avoidance test, in SD, Aβ and KA mouse models. In the hippocampus of mice given EH-201 in their diet, levels of erythropoietin, PGC-1α and haemoglobin were increased The induction of endogenous erythropoietin in neuronal cells by inducers such as EH-201 might be a therapeutic strategy for memory impairment in neurodegenerative disease, physiological ageing or traumatic brain injury. © 2015 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of The British Pharmacological Society.

  13. Hypoxia-elicited impairment of cell wall integrity, glycosylation precursor synthesis, and growth in scaled-up high-cell density fed-batch cultures of Saccharomyces cerevisiae.

    Science.gov (United States)

    Aon, Juan C; Sun, Jianxin; Leighton, Julie M; Appelbaum, Edward R

    2016-08-15

    In this study we examine the integrity of the cell wall during scale up of a yeast fermentation process from laboratory scale (10 L) to industrial scale (10,000 L). In a previous study we observed a clear difference in the volume fraction occupied by yeast cells as revealed by wet cell weight (WCW) measurements between these scales. That study also included metabolite analysis which suggested hypoxia during scale up. Here we hypothesize that hypoxia weakens the yeast cell wall during the scale up, leading to changes in cell permeability, and/or cell mechanical resistance, which in turn may lead to the observed difference in WCW. We tested the cell wall integrity by probing the cell wall sensitivity to Zymolyase. Also exometabolomics data showed changes in supply of precursors for the glycosylation pathway. The results show a more sensitive cell wall later in the production process at industrial scale, while the sensitivity at early time points was similar at both scales. We also report exometabolomics data, in particular a link with the protein glycosylation pathway. Significantly lower levels of Man6P and progressively higher GDP-mannose indicated partially impaired incorporation of this sugar nucleotide during co- or post-translational protein glycosylation pathways at the 10,000 L compared to the 10 L scale. This impairment in glycosylation would be expected to affect cell wall integrity. Although cell viability from samples obtained at both scales were similar, cells harvested from 10 L bioreactors were able to re-initiate growth faster in fresh shake flask media than those harvested from the industrial scale. The results obtained help explain the WCW differences observed at both scales by hypoxia-triggered weakening of the yeast cell wall during the scale up.

  14. Pyramidal cell-interneuron interactions underlie hippocampal ripple oscillations.

    Science.gov (United States)

    Stark, Eran; Roux, Lisa; Eichler, Ronny; Senzai, Yuta; Royer, Sebastien; Buzsáki, György

    2014-07-16

    High-frequency ripple oscillations, observed most prominently in the hippocampal CA1 pyramidal layer, are associated with memory consolidation. The cellular and network mechanisms underlying the generation, frequency control, and spatial coherence of the rhythm are poorly understood. Using multisite optogenetic manipulations in freely behaving rodents, we found that depolarization of a small group of nearby pyramidal cells was sufficient to induce high-frequency oscillations, whereas closed-loop silencing of pyramidal cells or activation of parvalbumin- (PV) or somatostatin-immunoreactive interneurons aborted spontaneously occurring ripples. Focal pharmacological blockade of GABAA receptors abolished ripples. Localized PV interneuron activation paced ensemble spiking, and simultaneous induction of high-frequency oscillations at multiple locations resulted in a temporally coherent pattern mediated by phase-locked interneuron spiking. These results constrain competing models of ripple generation and indicate that temporally precise local interactions between excitatory and inhibitory neurons support ripple generation in the intact hippocampus. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Efficient internalization of mesoporous silica particles of different sizes by primary human macrophages without impairment of macrophage clearance of apoptotic or antibody-opsonized target cells

    International Nuclear Information System (INIS)

    Witasp, Erika; Kupferschmidt, Natalia; Bengtsson, Linnea; Hultenby, Kjell; Smedman, Christian; Paulie, Staffan; Garcia-Bennett, Alfonso E.; Fadeel, Bengt

    2009-01-01

    Macrophage recognition and ingestion of apoptotic cell corpses, a process referred to as programmed cell clearance, is of considerable importance for the maintenance of tissue homeostasis and in the resolution of inflammation. Moreover, macrophages are the first line of defense against microorganisms and other foreign materials including particles. However, there is sparse information on the mode of uptake of engineered nanomaterials by primary macrophages. In this study, mesoporous silica particles with cubic pore geometries and covalently fluorescein-grafted particles were synthesized through a novel route, and their interactions with primary human monocyte-derived macrophages were assessed. Efficient and active internalization of mesoporous silica particles of different sizes was observed by transmission electron microscopic and flow cytometric analysis and studies using pharmacological inhibitors suggested that uptake occurred through a process of endocytosis. Moreover, uptake of silica particles was independent of serum factors. The silica particles with very high surface areas due to their porous structure did not impair cell viability or function of macrophages, including the ingestion of different classes of apoptotic or opsonized target cells. The current findings are relevant to the development of mesoporous materials for drug delivery and other biomedical applications.

  16. Progesterone impairs antigen-non-specific immune protection by CD8 T memory cells via interferon-γ gene hypermethylation.

    Science.gov (United States)

    Yao, Yushi; Li, Hui; Ding, Jie; Xia, Yixin; Wang, Lei

    2017-11-01

    Pregnant women and animals have increased susceptibility to a variety of intracellular pathogens including Listeria monocytogenes (LM), which has been associated with significantly increased level of sex hormones such as progesterone. CD8 T memory(Tm) cell-mediated antigen-non-specific IFN-γ responses are critically required in the host defense against LM. However, whether and how increased progesterone during pregnancy modulates CD8 Tm cell-mediated antigen-non-specific IFN-γ production and immune protection against LM remain poorly understood. Here we show in pregnant women that increased serum progesterone levels are associated with DNA hypermethylation of IFN-γ gene promoter region and decreased IFN-γ production in CD8 Tm cells upon antigen-non-specific stimulation ex vivo. Moreover, IFN-γ gene hypermethylation and significantly reduced IFN-γ production post LM infection in antigen-non-specific CD8 Tm cells are also observed in pregnant mice or progesterone treated non-pregnant female mice, which is a reversible phenotype following demethylation treatment. Importantly, antigen-non-specific CD8 Tm cells from progesterone treated mice have impaired anti-LM protection when adoptive transferred in either pregnant wild type mice or IFN-γ-deficient mice, and demethylation treatment rescues the adoptive protection of such CD8 Tm cells. These data demonstrate that increased progesterone impairs immune protective functions of antigen-non-specific CD8 Tm cells via inducing IFN-γ gene hypermethylation. Our findings thus provide insights into a new mechanism through which increased female sex hormone regulate CD8 Tm cell functions during pregnancy.

  17. Progesterone impairs antigen-non-specific immune protection by CD8 T memory cells via interferon-γ gene hypermethylation.

    Directory of Open Access Journals (Sweden)

    Yushi Yao

    2017-11-01

    Full Text Available Pregnant women and animals have increased susceptibility to a variety of intracellular pathogens including Listeria monocytogenes (LM, which has been associated with significantly increased level of sex hormones such as progesterone. CD8 T memory(Tm cell-mediated antigen-non-specific IFN-γ responses are critically required in the host defense against LM. However, whether and how increased progesterone during pregnancy modulates CD8 Tm cell-mediated antigen-non-specific IFN-γ production and immune protection against LM remain poorly understood. Here we show in pregnant women that increased serum progesterone levels are associated with DNA hypermethylation of IFN-γ gene promoter region and decreased IFN-γ production in CD8 Tm cells upon antigen-non-specific stimulation ex vivo. Moreover, IFN-γ gene hypermethylation and significantly reduced IFN-γ production post LM infection in antigen-non-specific CD8 Tm cells are also observed in pregnant mice or progesterone treated non-pregnant female mice, which is a reversible phenotype following demethylation treatment. Importantly, antigen-non-specific CD8 Tm cells from progesterone treated mice have impaired anti-LM protection when adoptive transferred in either pregnant wild type mice or IFN-γ-deficient mice, and demethylation treatment rescues the adoptive protection of such CD8 Tm cells. These data demonstrate that increased progesterone impairs immune protective functions of antigen-non-specific CD8 Tm cells via inducing IFN-γ gene hypermethylation. Our findings thus provide insights into a new mechanism through which increased female sex hormone regulate CD8 Tm cell functions during pregnancy.

  18. Enterolactone: A novel radiosensitizer for human breast cancer cell lines through impaired DNA repair and increased apoptosis

    International Nuclear Information System (INIS)

    Bigdeli, Bahareh; Goliaei, Bahram; Masoudi-Khoram, Nastaran; Jooyan, Najmeh; Nikoofar, Alireza; Rouhani, Maryam; Haghparast, Abbas; Mamashli, Fatemeh

    2016-01-01

    Introduction: Radiotherapy is a potent treatment against breast cancer, which is the most commonly diagnosed cancer among women. However, the emergence of radioresistance due to increased DNA repair leads to radiotherapeutic failure. Applying polyphenols combined with radiation is a more promising method leading to better survival. Enterolactone, a phytoestrogenic polyphenol, has been reported to inhibit an important radioresistance signaling pathway, therefore we conjectured that enterolactone could enhance radiosensitivity in breast cancer. To assess this hypothesis, radiation response of enterolactone treated MDA-MB-231 and T47D cell lines and corresponding cellular mechanisms were investigated. Methods: Cytotoxicity of enterolactone was measured via MTT assay. Cells were treated with enterolactone before X-irradiation, and clonogenic assay was used to evaluate radiosensitivity. Cell cycle distribution and apoptosis were measured by flow cytometric analysis. In addition, DNA damages and corresponding repair, chromosomal damages, and aberrations were assessed by comet, micronucleus, and cytogenetic assays, respectively. Results: Enterolactone decreased the viability of cells in a concentration- and time dependent manner. Enterolactone significantly enhanced radiosensitivity of cells by abrogating G2/M arrest, impairing DNA repair, and increasing radiation-induced apoptosis. Furthermore, increased chromosomal damages and aberrations were detected in cells treated with enterolactone combined with X-rays than X-ray alone. These effects were more prominent in T47D than MDA-MB-231 cells. Discussion: To our knowledge, this is the first report that enterolactone is a novel radiosensitizer for breast cancer irrespective of estrogen receptor status. Authors propose enterolactone as a candidate for combined therapy to decrease the radiation dose delivered to patients and subsequent side effects. - Highlights: • Enterolactone is proposed to be a novel radiosensitizer for

  19. Enterolactone: A novel radiosensitizer for human breast cancer cell lines through impaired DNA repair and increased apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Bigdeli, Bahareh, E-mail: bhr.bigdeli@ut.ac.ir [Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, 16th Azar St., Enghelab Sq., Tehran (Iran, Islamic Republic of); Goliaei, Bahram, E-mail: goliaei@ut.ac.ir [Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, 16th Azar St., Enghelab Sq., Tehran (Iran, Islamic Republic of); Masoudi-Khoram, Nastaran, E-mail: n.masoudi@alumni.ut.ac.ir [Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, 16th Azar St., Enghelab Sq., Tehran (Iran, Islamic Republic of); Jooyan, Najmeh, E-mail: n.jooyan@ut.ac.ir [Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, 16th Azar St., Enghelab Sq., Tehran (Iran, Islamic Republic of); Nikoofar, Alireza, E-mail: nikoofar@iums.ac.ir [Department of Radiotherapy, Iran University of Medical Sciences (IUMS), Shahid Hemmat Highway, Tehran (Iran, Islamic Republic of); Rouhani, Maryam, E-mail: rouhani@iasbs.ac.ir [Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Prof. Yousef Sobouti Blvd., Gava Zang, Zanjan (Iran, Islamic Republic of); Haghparast, Abbas, E-mail: Haghparast@sbmu.ac.ir [Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Daneshjo St., Evin, Tehran (Iran, Islamic Republic of); Mamashli, Fatemeh, E-mail: mamashli@ut.ac.ir [Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, 16th Azar St., Enghelab Sq., Tehran (Iran, Islamic Republic of)

    2016-12-15

    Introduction: Radiotherapy is a potent treatment against breast cancer, which is the most commonly diagnosed cancer among women. However, the emergence of radioresistance due to increased DNA repair leads to radiotherapeutic failure. Applying polyphenols combined with radiation is a more promising method leading to better survival. Enterolactone, a phytoestrogenic polyphenol, has been reported to inhibit an important radioresistance signaling pathway, therefore we conjectured that enterolactone could enhance radiosensitivity in breast cancer. To assess this hypothesis, radiation response of enterolactone treated MDA-MB-231 and T47D cell lines and corresponding cellular mechanisms were investigated. Methods: Cytotoxicity of enterolactone was measured via MTT assay. Cells were treated with enterolactone before X-irradiation, and clonogenic assay was used to evaluate radiosensitivity. Cell cycle distribution and apoptosis were measured by flow cytometric analysis. In addition, DNA damages and corresponding repair, chromosomal damages, and aberrations were assessed by comet, micronucleus, and cytogenetic assays, respectively. Results: Enterolactone decreased the viability of cells in a concentration- and time dependent manner. Enterolactone significantly enhanced radiosensitivity of cells by abrogating G2/M arrest, impairing DNA repair, and increasing radiation-induced apoptosis. Furthermore, increased chromosomal damages and aberrations were detected in cells treated with enterolactone combined with X-rays than X-ray alone. These effects were more prominent in T47D than MDA-MB-231 cells. Discussion: To our knowledge, this is the first report that enterolactone is a novel radiosensitizer for breast cancer irrespective of estrogen receptor status. Authors propose enterolactone as a candidate for combined therapy to decrease the radiation dose delivered to patients and subsequent side effects. - Highlights: • Enterolactone is proposed to be a novel radiosensitizer for

  20. Hypertonic saline impedes tumor cell-endothelial cell interaction by reducing adhesion molecule and laminin expression.

    LENUS (Irish Health Repository)

    Shields, Conor J

    2012-02-03

    BACKGROUND: Hypertonic saline infusion dampens inflammatory responses and suppresses neutrophil-endothelial interaction by reducing adhesion molecule expression. This study tested the hypothesis that hypertonic saline attenuates tumor cell adhesion to the endothelium through a similar mechanism. METHODS: Human colon cancer cells (LS174T) were transfected with green fluorescent protein and exposed to lipopolysaccharide, tumor necrosis factor-alpha, and interleukin-6 under hypertonic and isotonic conditions for 1 and 4 hours. Confluent human umbilical vein endothelial cells were similarly exposed. Cellular apoptosis and expression of adhesion molecules and laminin were measured by flow cytometry. Tumor cell adhesion to endothelium and laminin was assessed with fluorescence microscopy. Data are represented as mean +\\/- standard error of mean, and an ANOVA test was performed to gauge statistical significance, with P <.05 considered significant. RESULTS: Hypertonic exposure significantly reduced tumor cell adhesion despite the presence of the perioperative cell stressors (42 +\\/- 2.9 vs 172.5 +\\/- 12.4, P <.05), attenuated tumor cell beta-1 integrin (14.43 vs 23.84, P <.05), and endothelial cell laminin expression (22.78 +\\/- 2.2 vs 33.74 +\\/- 2.4, P <.05), but did not significantly alter cell viability. CONCLUSION: Hypertonic saline significantly attenuates tumor cell adhesion to endothelium by inhibiting adhesion molecule and laminin expression. This may halt the metastatic behavior of tumor cells shed at surgery.

  1. CD70-deficiency impairs effector CD8 T cell generation and viral clearance but is dispensable for the recall response to LCMV

    Science.gov (United States)

    Munitic, Ivana; Kuka, Mirela; Allam, Atef; Scoville, Jonathan P.; Ashwell, Jonathan D.

    2012-01-01

    CD27 interactions with its ligand, CD70, are thought to be necessary for optimal primary and memory adaptive immune responses to a variety of pathogens. Thus far all studies addressing the function of the CD27-CD70 axis have been performed either in mice lacking CD27, overexpressing CD70, or in which these receptors were blocked or mimicked by antibodies or recombinant soluble CD70. Because these methods have in some cases led to divergent results, we generated CD70-deficient mice to directly assess its role in vivo. We find that lack of CD70-mediated stimulation during primary responses to LCMV lowered the magnitude of CD8 antigen-specific T cell response, resulting in impaired viral clearance, without affecting CD4 T cell responses. Unexpectedly, CD70-CD27 costimulation was not needed for memory CD8 T cell generation or the ability to mount a recall response to LCMV. Adoptive transfers of wild type (WT) memory T cells into CD70−/− or WT hosts also showed no need for CD70-mediated stimulation during the course of the recall response. Moreover, CD70-expression by CD8 T cells could not rescue endogenous CD70−/− cells from defective expansion, arguing against a role for CD70-mediated T:T help in this model. Therefore, CD70 appears to be an important factor in the initiation of a robust and effective primary response but dispensable for CD8 T cell memory responses. PMID:23269247

  2. Interferon-gamma improves impaired dentinogenic and immunosuppressive functions of irreversible pulpitis-derived human dental pulp stem cells

    Science.gov (United States)

    Sonoda, Soichiro; Yamaza, Haruyoshi; Ma, Lan; Tanaka, Yosuke; Tomoda, Erika; Aijima, Reona; Nonaka, Kazuaki; Kukita, Toshio; Shi, Songtao; Nishimura, Fusanori; Yamaza, Takayoshi

    2016-01-01

    Clinically, irreversible pulpitis is treated by the complete removal of pulp tissue followed by replacement with artificial materials. There is considered to be a high potential for autologous transplantation of human dental pulp stem cells (DPSCs) in endodontic treatment. The usefulness of DPSCs isolated from healthy teeth is limited. However, DPSCs isolated from diseased teeth with irreversible pulpitis (IP-DPSCs) are considered to be suitable for dentin/pulp regeneration. In this study, we examined the stem cell potency of IP-DPSCs. In comparison with healthy DPSCs, IP-DPSCs expressed lower colony-forming capacity, population-doubling rate, cell proliferation, multipotency, in vivo dentin regeneration, and immunosuppressive activity, suggesting that intact IP-DPSCs may be inadequate for dentin/pulp regeneration. Therefore, we attempted to improve the impaired in vivo dentin regeneration and in vitro immunosuppressive functions of IP-DPSCs to enable dentin/pulp regeneration. Interferon gamma (IFN-γ) treatment enhanced in vivo dentin regeneration and in vitro T cell suppression of IP-DPSCs, whereas treatment with tumor necrosis factor alpha did not. Therefore, these findings suggest that IFN-γ may be a feasible modulator to improve the functions of impaired IP-DPSCs, suggesting that autologous transplantation of IFN-γ-accelerated IP-DPSCs might be a promising new therapeutic strategy for dentin/pulp tissue engineering in future endodontic treatment. PMID:26775677

  3. Interferon-gamma improves impaired dentinogenic and immunosuppressive functions of irreversible pulpitis-derived human dental pulp stem cells.

    Science.gov (United States)

    Sonoda, Soichiro; Yamaza, Haruyoshi; Ma, Lan; Tanaka, Yosuke; Tomoda, Erika; Aijima, Reona; Nonaka, Kazuaki; Kukita, Toshio; Shi, Songtao; Nishimura, Fusanori; Yamaza, Takayoshi

    2016-01-18

    Clinically, irreversible pulpitis is treated by the complete removal of pulp tissue followed by replacement with artificial materials. There is considered to be a high potential for autologous transplantation of human dental pulp stem cells (DPSCs) in endodontic treatment. The usefulness of DPSCs isolated from healthy teeth is limited. However, DPSCs isolated from diseased teeth with irreversible pulpitis (IP-DPSCs) are considered to be suitable for dentin/pulp regeneration. In this study, we examined the stem cell potency of IP-DPSCs. In comparison with healthy DPSCs, IP-DPSCs expressed lower colony-forming capacity, population-doubling rate, cell proliferation, multipotency, in vivo dentin regeneration, and immunosuppressive activity, suggesting that intact IP-DPSCs may be inadequate for dentin/pulp regeneration. Therefore, we attempted to improve the impaired in vivo dentin regeneration and in vitro immunosuppressive functions of IP-DPSCs to enable dentin/pulp regeneration. Interferon gamma (IFN-γ) treatment enhanced in vivo dentin regeneration and in vitro T cell suppression of IP-DPSCs, whereas treatment with tumor necrosis factor alpha did not. Therefore, these findings suggest that IFN-γ may be a feasible modulator to improve the functions of impaired IP-DPSCs, suggesting that autologous transplantation of IFN-γ-accelerated IP-DPSCs might be a promising new therapeutic strategy for dentin/pulp tissue engineering in future endodontic treatment.

  4. Mitochondrial Alterations in Peripheral Mononuclear Blood Cells from Alzheimer’s Disease and Mild Cognitive Impairment Patients

    Directory of Open Access Journals (Sweden)

    A. Delbarba

    2016-01-01

    Full Text Available It is well recognized that mitochondrial dysfunction contributes to neurodegeneration occurring in Alzheimer’s disease (AD. However, evidences of mitochondrial defects in AD peripheral cells are still inconclusive. Here, some mitochondrial-encoded and nuclear-encoded proteins, involved in maintaining the correct mitochondria machine, were investigated in terms of protein expression and enzymatic activity in peripheral blood mononuclear cells (PBMCs isolated from AD and Mild Cognitive Impairment (MCI patients and healthy subjects. In addition mitochondrial DNA copy number was measured by real time PCR. We found some differences and some similarities between AD and MCI patients when compared with healthy subjects. For example, cytochrome C and cytochrome B were decreased in AD, while MCI showed only a statistical reduction of cytochrome C. On the other hand, both AD and MCI blood cells exhibited highly nitrated MnSOD, index of a prooxidant environment inside the mitochondria. TFAM, a regulator of mitochondrial genome replication and transcription, was decreased in both AD and MCI patients’ blood cells. Moreover also the mitochondrial DNA amount was reduced in PBMCs from both patient groups. In conclusion these data confirmed peripheral mitochondria impairment in AD and demonstrated that TFAM and mtDNA amount reduction could be two features of early events occurring in AD pathogenesis.

  5. A neural cell adhesion molecule-derived peptide reduces neuropathological signs and cognitive impairment induced by Abeta25-35

    DEFF Research Database (Denmark)

    Klementiev, B; Novikova, T; Novitskaya, V

    2007-01-01

    death and brain atrophy in response to Abeta25-35. Finally, the Abeta25-35-administration led to a reduced short-term memory as determined by the social recognition test. A synthetic peptide termed FGL derived from the neural cell adhesion molecule (NCAM) was able to prevent or, if already manifest......, strongly reduce all investigated signs of Abeta25-35-induced neuropathology and cognitive impairment. The FGL peptide was recently demonstrated to be able to cross the blood-brain-barrier. Accordingly, we found that the beneficial effects of FGL were achieved not only by intracisternal, but also...... and cognitive impairment involves the modulation of intracellular signal-transduction mediated through GSK3beta....

  6. Impaired mitochondrial function in HepG2 cells treated with hydroxy-cobalamin[c-lactam]: A cell model for idiosyncratic toxicity

    International Nuclear Information System (INIS)

    Haegler, Patrizia; Grünig, David; Berger, Benjamin; Krähenbühl, Stephan; Bouitbir, Jamal

    2015-01-01

    The vitamin B12 analog hydroxy-cobalamin[c-lactam] (HCCL) impairs mitochondrial protein synthesis and the function of the electron transport chain. Our goal was to establish an in vitro model for mitochondrial dysfunction in human hepatoma cells (HepG2), which can be used to investigate hepatotoxicity of idiosyncratic mitochondrial toxicants. For that, HepG2 cells were treated with HCCL, which inhibits the function of methylmalonyl-CoA mutase and impairs mitochondrial protein synthesis. Secondary, cells were incubated with propionate that served as source of propionyl-CoA, a percursor of methylmalonyl-CoA. Dose-finding experiments were conducted to evaluate the optimal dose and treatment time of HCCL and propionate for experiments on mitochondrial function. 50 μM HCCL was cytotoxic after exposure of HepG2 cells for 2 d and 10 and 50 μM HCCL enhanced the cytotoxicity of 100 or 1000 μM propionate. Co-treatment with HCCL (10 μM) and propionate (1000 μM) dissipated the mitochondrial membrane potential and impaired the activity of enzyme complex IV of the electron transport chain. Treatment with HCCL decreased the mRNA content of mitochondrially encoded proteins, whereas the mtDNA content remained unchanged. We observed mitochondrial ROS accumulation and decreased mitochondrial SOD2 expression. Moreover, electron microscopy showed mitochondrial swelling. Finally, HepG2 cells pretreated with a non-cytotoxic combination of HCCL (10 μM) and propionate (100 μM) were more sensitive to the mitochondrial toxicants dronedarone, benzbromarone, and ketoconazole than untreated cells. In conclusion, we established and characterized a cell model, which could be used for testing drugs with idiosyncratic mitochondrial toxicity

  7. Tumor necrosis factor-alpha expression in peripheral blood mononuclear cells correlates with early childhood social interaction in autism spectrum disorder.

    Science.gov (United States)

    Makinodan, Manabu; Iwata, Keiko; Ikawa, Daisuke; Yamashita, Yasunori; Yamamuro, Kazuhiko; Toritsuka, Michihiro; Kimoto, Sohei; Okumura, Kazuki; Yamauchi, Takahira; Yoshino, Hiroki; Tsujii, Masatsugu; Sugiyama, Toshiro; Tsuchiya, Kenji; Mori, Norio; Matsuzaki, Hideo; Kishimoto, Toshifumi

    2017-03-01

    Autism spectrum disorder is a neurodevelopmental disorder characterized by impaired social interaction, poor communication skills, and repetitive/restrictive behaviors. Elevated blood levels of pro-inflammatory cytokines have been reported in subjects with autism spectrum disorder. On the other hand, early childhood adverse experience also increases blood levels of these cytokines. Since social experience of children with autism spectrum disorder is generally unlike to typically developing children, we hypothesized that social interaction during childhood contribute to pro-inflammatory cytokine expression in subjects with autism spectrum disorder. We compared revised Autism Diagnostic Interview scores and expression levels of pro-inflammatory cytokines in peripheral blood mononuclear cells of subjects with autism spectrum disorder (n = 30). The score of domain A on the revised Autism Diagnostic Interview, indicating social interaction impairment in early childhood, was negatively correlated with tumor necrosis factor-α mRNA expression level in peripheral blood mononuclear cells but not interleukin-1β or -6. Consistently, tumor necrosis factor-α mRNA expression was markedly low in subjects with autism spectrum disorder compared to typically developing children who presumably experienced the regular levels of social interaction. These findings suggest that the low blood levels of tumor necrosis factor-α mRNA in subjects with autism spectrum disorder might be due to impaired social interaction in early childhood. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Anti-IL-2 treatment impairs the expansion of T(reg cell population during acute malaria and enhances the Th1 cell response at the chronic disease.

    Directory of Open Access Journals (Sweden)

    Cláudia A Zago

    Full Text Available Plasmodium chabaudi infection induces a rapid and intense splenic CD4(+ T cell response that contributes to both disease pathogenesis and the control of acute parasitemia. The subsequent development of clinical immunity to disease occurs concomitantly with the persistence of low levels of chronic parasitemia. The suppressive activity of regulatory T (T(reg cells has been implicated in both development of clinical immunity and parasite persistence. To evaluate whether IL-2 is required to induce and to sustain the suppressive activity of T(reg cells in malaria, we examined in detail the effects of anti-IL-2 treatment with JES6-1 monoclonal antibody (mAb on the splenic CD4(+ T cell response during acute and chronic P. chabaudi AS infection in C57BL/6 mice. JES6-1 treatment on days 0, 2 and 4 of infection partially inhibits the expansion of the CD4(+CD25(+Foxp3(+ cell population during acute malaria. Despite the concomitant secretion of IL-2 and expression of high affinity IL-2 receptor by large CD4(+ T cells, JES6-1 treatment does not impair effector CD4(+ T cell activation and IFN-γ production. However, at the chronic phase of the disease, an enhancement of cellular and humoral responses occurs in JES6-1-treated mice, with increased production of TNF-α and parasite-specific IgG2a antibodies. Furthermore, JES6-1 mAb completely blocked the in vitro proliferation of CD4(+ T cells from non-treated chronic mice, while it further increased the response of CD4(+ T cells from JES6-1-treated chronic mice. We conclude that JES6-1 treatment impairs the expansion of T(reg cell population during early P. chabaudi malaria and enhances the Th1 cell response in the late phase of the disease.

  9. A Synthetic Thiourea-Based Tripodal Receptor that Impairs the Function of Human First Trimester Cytotrophoblast Cells

    Directory of Open Access Journals (Sweden)

    Darijana Horvat

    2014-07-01

    Full Text Available A synthetic tripodal-based thiourea receptor (PNTTU was used to explore the receptor/ligand binding affinity using CTB cells. The human extravillous CTB cells (Sw.71 used in this study were derived from first trimester chorionic villus tissue. The cell proliferation, migration and angiogenic factors were evaluated in PNTTU-treated CTB cells. The PNTTU inhibited the CTBs proliferation and migration. The soluble fms-like tyrosine kinase-1 (sFlt-1 secretion was increased while vascular endothelial growth factor (VEGF was decreased in the culture media of CTB cells treated with ≥1 nM PNTTU. The angiotensin II receptor type 2 (AT2 expression was significantly upregulated in ≥1 nM PNTTU-treated CTB cells in compared to basal; however, the angiotensin II receptor, type 1 (AT1 and vascular endothelial growth factor receptor 1 (VEGFR-1 expression was downregulated. The anti-proliferative and anti-angiogenic effect of this compound on CTB cells are similar to the effect of CTSs. The receptor/ligand affinity of PNTTU on CTBs provides us the clue to design a potent inhibitor to prevent the CTS-induced impairment of CTB cells.

  10. The inhibition of migration and invasion of cancer cells by graphene via the impairment of mitochondrial respiration.

    Science.gov (United States)

    Zhou, Hejiang; Zhang, Bo; Zheng, Jiajia; Yu, Meifang; Zhou, Teng; Zhao, Kai; Jia, Yanxia; Gao, Xingfa; Chen, Chunying; Wei, Taotao

    2014-02-01

    Graphene and its derivatives have become important nanomaterials worldwide and have potential medical applications including in vivo diagnosis, drug delivery, and photothermal therapy of cancer. However, little is known about their effect on the metastasis of cancer cells, which is the cause of over 90% of patient deaths. In the present investigation, we provide direct evidence that low concentrations of pristine graphene and graphene oxide show no apparent influence on the viability of MDA-MB-231 human breast cancer cells, PC3 human prostate cancer cells, as well as B16F10 mouse melanoma cells. However, both pristine graphene and graphene oxide can effectively inhibit the migration and invasion of these cancer cells. Further studies indicate that exposure of cells to graphene led to the direct inhibition of the electron transfer chain complexes I, II, III and IV, most likely by disrupting electron transfer between iron-sulfur centers, which is due to its stronger ability to accept electrons compared to iron-sulfur clusters through theoretical calculations. The decreased electron transfer chain activity caused a reduction in the production of ATP and subsequent impairment of F-actin cytoskeleton assembly, which is crucial for the migration and invasion of metastatic cancer cells. The inhibition of cancer cell metastasis by graphene and graphene oxide might provide new insights into specific cancer treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Impaired intrinsic immunity to HSV-1 in human iPSC-derived TLR3-deficient CNS cells

    Science.gov (United States)

    Lafaille, Fabien G; Pessach, Itai M.; Zhang, Shen-Ying; Ciancanelli, Michael J.; Herman, Melina; Abhyankar, Avinash; Ying, Shui-Wang; Keros, Sotirios; Goldstein, Peter A.; Mostoslavsky, Gustavo; Ordovas-Montanes, Jose; Jouanguy, Emmanuelle; Plancoulaine, Sabine; Tu, Edmund; Elkabetz, Yechiel; Al-Muhsen, Saleh; Tardieu, Marc; Schlaeger, Thorsten M.; Daley, George Q.; Abel, Laurent; Casanova, Jean-Laurent; Studer, Lorenz; Notarangelo, Luigi D.

    2012-01-01

    In the course of primary infection with herpes simplex virus 1 (HSV-1), children with inborn errors of TLR3 immunity are prone to HSV-1 encephalitis (HSE) 1–3. We tested the hypothesis that the pathogenesis of HSE involves non hematopoietic central nervous system (CNS)-resident cells. We derived induced pluripotent stem cells (iPSCs) from the dermal fibroblasts of TLR3- and UNC-93B-deficient patients and from controls. These iPSCs were differentiated into highly purified populations of neural stem cells (NSCs), neurons, astrocytes and oligodendrocytes. The induction of IFN-β and/or IFN-γ1 in response to poly(I:C) stimulation was dependent on TLR3 and UNC-93B in all cells tested. However, the induction of IFN-β and IFN-γ1 in response to HSV-1 infection was impaired selectively in UNC-93B-deficient neurons and oligodendrocytes. These cells were also much more susceptible to HSV-1 infection than control cells, whereas UNC-93B-deficient NSCs and astrocytes were not. TLR3-deficient neurons were also found to be susceptible to HSV-1 infection. The rescue of UNC-93B- and TLR3-deficient cells with the corresponding wild-type allele demonstrated that the genetic defect was the cause of the poly(I:C) and HSV-1 phenotypes. The viral infection phenotype was further rescued by treatment with exogenous IFN-α/β, but not IFN-γ1.Thus, impaired TLR3- and UNC-93B-dependent IFN-α/β intrinsic immunity to HSV-1 in the CNS, in neurons and oligodendrocytes in particular, may underlie the pathogenesis of HSE in children with TLR3 pathway deficiencies. PMID:23103873

  12. Interaction of KSHV with Host Cell Surface Receptors and Cell Entry

    Directory of Open Access Journals (Sweden)

    Mohanan Valiya Veettil

    2014-10-01

    Full Text Available Virus entry is a complex process characterized by a sequence of events. Since the discovery of KSHV in 1994, tremendous progress has been made in our understanding of KSHV entry into its in vitro target cells. KSHV entry is a complex multistep process involving viral envelope glycoproteins and several cell surface molecules that is utilized by KSHV for its attachment and entry. KSHV has a broad cell tropism and the attachment and receptor engagement on target cells have an important role in determining the cell type-specific mode of entry. KSHV utilizes heparan sulfate, integrins and EphrinA2 molecules as receptors which results in the activation of host cell pre-existing signal pathways that facilitate the subsequent cascade of events resulting in the rapid entry of virus particles, trafficking towards the nucleus followed by viral and host gene expression. KSHV enters human fibroblast cells by dynamin dependant clathrin mediated endocytosis and by dynamin independent macropinocytosis in dermal endothelial cells. Once internalized into endosomes, fusion of the viral envelope with the endosomal membranes in an acidification dependent manner results in the release of capsids which subsequently reaches the nuclear pore vicinity leading to the delivery of viral DNA into the nucleus. In this review, we discuss the principal mechanisms that enable KSHV to interact with the host cell surface receptors as well as the mechanisms that are required to modulate cell signaling machinery for a successful entry.

  13. Osteoblast-Prostate Cancer Cell Interaction in Prostate Cancer Bone Metastases

    National Research Council Canada - National Science Library

    Navone, Nora

    2001-01-01

    .... This suggests that prostate cancer cells interact with cells from the osteoblastic lineage. To understand the molecular bases of prostatic bone metastases, we established two prostate cancer cell lines, MDA PCa 2a and MDA PCa 2b (1...

  14. A glimpse into the interactions of cells in a microenvironment: the modulation of T cells by mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Choi J

    2014-05-01

    Full Text Available Jonghoon Choi,1,2 Mintai P Hwang,3 Jong-Wook Lee,3 Kwan Hyi Lee3,41Institute of Research Strategy and Development (IRSD, Seoul, Republic of Korea; 2Department of Bionano Engineering, Hanyang University, Ansan, Republic of Korea; 3Center for Biomaterials, Biomedical Research Institute, Korea Institute of Science and Technology, Seoul, Republic of Korea; 4Department of Biomedical Engineering, University of Science and Technology, Seoul, Republic of KoreaAbstract: Mesenchymal stem cells (MSCs have been thought to hold potential as a mode of therapy for immuno-related pathologies, particularly for autoimmune diseases. Despite their potential, the interaction between MSCs and T cells, key players in the pathophysiology of autoimmune diseases, is not yet well understood, thereby preventing further clinical progress. A major obstacle is the highly heterogeneous nature of MSCs in vitro. Unfortunately, bulk assays do not provide information with regard to cell–cell contributions that may play a critical role in the overall cellular response. To address these issues, we investigated the interaction between smaller subsets of MSCs and CD4 T cells in a microwell array. We demonstrate that MSCs appear capable of modulating the T cell proliferation rate in response to persistent cell–cell interactions, and we anticipate the use of our microwell array in the classification of subpopulations within MSCs, ultimately leading to specific therapeutic interventions.Keywords: mesenchymal stem cell, T cell, microwell array

  15. Circulating gluten-specific FOXP3+CD39+ regulatory T cells have impaired suppressive function in patients with celiac disease.

    Science.gov (United States)

    Cook, Laura; Munier, C Mee Ling; Seddiki, Nabila; van Bockel, David; Ontiveros, Noé; Hardy, Melinda Y; Gillies, Jana K; Levings, Megan K; Reid, Hugh H; Petersen, Jan; Rossjohn, Jamie; Anderson, Robert P; Zaunders, John J; Tye-Din, Jason A; Kelleher, Anthony D

    2017-12-01

    Celiac disease is a chronic immune-mediated inflammatory disorder of the gut triggered by dietary gluten. Although the effector T-cell response in patients with celiac disease has been well characterized, the role of regulatory T (Treg) cells in the loss of tolerance to gluten remains poorly understood. We sought to define whether patients with celiac disease have a dysfunction or lack of gluten-specific forkhead box protein 3 (FOXP3) + Treg cells. Treated patients with celiac disease underwent oral wheat challenge to stimulate recirculation of gluten-specific T cells. Peripheral blood was collected before and after challenge. To comprehensively measure the gluten-specific CD4 + T-cell response, we paired traditional IFN-γ ELISpot with an assay to detect antigen-specific CD4 + T cells that does not rely on tetramers, antigen-stimulated cytokine production, or proliferation but rather on antigen-induced coexpression of CD25 and OX40 (CD134). Numbers of circulating gluten-specific Treg cells and effector T cells both increased significantly after oral wheat challenge, peaking at day 6. Surprisingly, we found that approximately 80% of the ex vivo circulating gluten-specific CD4 + T cells were FOXP3 + CD39 + Treg cells, which reside within the pool of memory CD4 + CD25 + CD127 low CD45RO + Treg cells. Although we observed normal suppressive function in peripheral polyclonal Treg cells from patients with celiac disease, after a short in vitro expansion, the gluten-specific FOXP3 + CD39 + Treg cells exhibited significantly reduced suppressive function compared with polyclonal Treg cells. This study provides the first estimation of FOXP3 + CD39 + Treg cell frequency within circulating gluten-specific CD4 + T cells after oral gluten challenge of patients with celiac disease. FOXP3 + CD39 + Treg cells comprised a major proportion of all circulating gluten-specific CD4 + T cells but had impaired suppressive function, indicating that Treg cell dysfunction might be a key

  16. Generalized Liver- and Blood-Derived CD8+ T-Cell Impairment in Response to Cytokines in Chronic Hepatitis C Virus Infection.

    Directory of Open Access Journals (Sweden)

    Stephanie C Burke Schinkel

    Full Text Available Generalized CD8+ T-cell impairment in chronic hepatitis C virus (HCV infection and the contribution of liver-infiltrating CD8+ T-cells to the immunopathogenesis of this infection remain poorly understood. It is hypothesized that this impairment is partially due to reduced CD8+ T-cell activity in response to cytokines such as IL-7, particularly within the liver. To investigate this, the phenotype and cytokine responsiveness of blood- and liver-derived CD8+ T-cells from healthy controls and individuals with HCV infection were compared. In blood, IL-7 receptor α (CD127 expression on bulk CD8+ T-cells in HCV infection was no different than controls yet was lower on central memory T-cells, and there were fewer naïve cells. IL-7-induced signalling through phosphorylated STAT5 was lower in HCV infection than in controls, and differed between CD8+ T-cell subsets. Production of Bcl-2 following IL-7 stimulation was also lower in HCV infection and inversely related to the degree of liver fibrosis. In liver-derived CD8+ T-cells, STAT5 activation could not be increased with cytokine stimulation and basal Bcl-2 levels of liver-derived CD8+ T-cells were lower than blood-derived counterparts in HCV infection. Therefore, generalized CD8+ T-cell impairment in HCV infection is characterized, in part, by impaired IL-7-mediated signalling and survival, independent of CD127 expression. This impairment is more pronounced in the liver and may be associated with an increased potential for apoptosis. This generalized CD8+ T-cell impairment represents an important immune dysfunction in chronic HCV infection that may alter patient health.

  17. KLRG1 impairs regulatory T-cell competitive fitness in the gut.

    Science.gov (United States)

    Meinicke, Holger; Bremser, Anna; Brack, Maria; Schrenk, Klaudia; Pircher, Hanspeter; Izcue, Ana

    2017-09-01

    Immune homeostasis requires the tight, tissue-specific control of the different CD4 + Foxp3 + regulatory T (Treg) cell populations. The cadherin-binding inhibitory receptor killer cell lectin-like receptor G1 (KLRG1) is expressed by a subpopulation of Treg cells with GATA3 + effector phenotype. Although such Treg cells are important for the immune balance, especially in the gut, the role of KLRG1 in Treg cells has not been assessed. Using KLRG1 knockout mice, we found that KLRG1 deficiency does not affect Treg cell frequencies in spleen, mesenteric lymph nodes or intestine, or frequencies of GATA3 + Treg cells in the gut. KLRG1-deficient Treg cells were also protective in a T-cell transfer model of colitis. Hence, KLRG1 is not essential for the development or activity of the general Treg cell population. We then checked the effects of KLRG1 on Treg cell activation. In line with KLRG1's reported inhibitory activity, in vitro KLRG1 cross-linking dampened the Treg cell T-cell receptor response. Consistently, lack of KLRG1 on Treg cells conferred on them a competitive advantage in the gut, but not in lymphoid organs. Hence, although absence of KLRG1 is not enough to increase intestinal Treg cells in KLRG1 knockout mice, KLRG1 ligation reduces T-cell receptor signals and the competitive fitness of individual Treg cells in the intestine. © 2017 John Wiley & Sons Ltd.

  18. Up-regulation of microRNA-1290 impairs cytokinesis and affects the reprogramming of colon cancer cells.

    Science.gov (United States)

    Wu, Jia; Ji, Xiaowei; Zhu, Linlin; Jiang, Qiaoli; Wen, Zhenzhen; Xu, Song; Shao, Wei; Cai, Jianting; Du, Qin; Zhu, Yongliang; Mao, Jianshan

    2013-02-28

    Abnormal cytokinesis increases the possibility of nuclear fusion in tumor cells. However, the role of microRNAs (miRNAs) in abnormal cytokinesis is unclear. Here, we found that miR-1290 was significantly up-regulated in clinical colon cancer tissues. Up-regulation of miR-1290 postponed cytokinesis and led to the formation of multinucleated cells. KIF13B was a target of miR-1290 that was involved in aberrant cytokinesis. Furthermore, enforced expression of miR-1290 activated the Wnt pathway and increased the reprogramming-related transcript factors c-Myc and Nanog. Our results suggest that up-regulation of miR-1290 in colon cancer cells impaired cytokinesis and affected reprogramming. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  19. Nitric oxide from inflammatory origin impairs neural stem cell proliferation by inhibiting epidermal growth factor receptor signaling

    Directory of Open Access Journals (Sweden)

    Bruno Pereira Carreira

    2014-10-01

    Full Text Available Neuroinflammation is characterized by activation of microglial cells, followed by production of nitric oxide (NO, which may have different outcomes on neurogenesis, favoring or inhibiting this process. In the present study, we investigated how the inflammatory mediator NO can affect proliferation of neural stem cells (NSC, and explored possible mechanisms underlying this effect. We investigated which mechanisms are involved in the regulation of NSC proliferation following treatment with an inflammatory stimulus (LPS plus IFN-γ, using a culture system of subventricular zone (SVZ-derived NSC mixed with microglia cells obtained from wild-type mice (iNOS+/+ or from iNOS knockout mice (iNOS-/-. We found an impairment of NSC cell proliferation in iNOS+/+ mixed cultures, which was not observed in iNOS-/- mixed cultures. Furthermore, the increased release of NO by activated iNOS+/+ microglial cells decreased the activation of the ERK/MAPK signaling pathway, which was concomitant with an enhanced nitration of the EGF receptor. Preventing nitrogen reactive species formation with MnTBAP, a scavenger of peroxynitrite, or using the peroxynitrite degradation catalyst FeTMPyP, cell proliferation and ERK signaling were restored to basal levels in iNOS+/+ mixed cultures. Moreover, exposure to the NO donor NOC-18 (100 µM, for 48 h, inhibited SVZ-derived NSC proliferation. Regarding the antiproliferative effect of NO, we found that NOC-18 caused the impairment of signaling through the ERK/MAPK pathway, which may be related to increased nitration of the EGF receptor in NSC. Using MnTBAP nitration was prevented, maintaining ERK signaling, rescuing NSC proliferation. We show that NO from inflammatory origin leads to a decreased function of the EGF receptor, which compromised proliferation of NSC. We also demonstrated that NO-mediated nitration of the EGF receptor caused a decrease in its phosphorylation, thus preventing regular proliferation signaling through the

  20. Heparan sulfate proteoglycans: structure, protein interactions and cell signaling

    Directory of Open Access Journals (Sweden)

    Juliana L. Dreyfuss

    2009-09-01

    Full Text Available Heparan sulfate proteoglycans are ubiquitously found at the cell surface and extracellular matrix in all the animal species. This review will focus on the structural characteristics of the heparan sulfate proteoglycans related to protein interactions leading to cell signaling. The heparan sulfate chains due to their vast structural diversity are able to bind and interact with a wide variety of proteins, such as growth factors, chemokines, morphogens, extracellular matrix components, enzymes, among others. There is a specificity directing the interactions of heparan sulfates and target proteins, regarding both the fine structure of the polysaccharide chain as well precise protein motifs. Heparan sulfates play a role in cellular signaling either as receptor or co-receptor for different ligands, and the activation of downstream pathways is related to phosphorylation of different cytosolic proteins either directly or involving cytoskeleton interactions leading to gene regulation. The role of the heparan sulfate proteoglycans in cellular signaling and endocytic uptake pathways is also discussed.Proteoglicanos de heparam sulfato são encontrados tanto superfície celular quanto na matriz extracelular em todas as espécies animais. Esta revisão tem enfoque nas características estruturais dos proteoglicanos de heparam sulfato e nas interações destes proteoglicanos com proteínas que levam à sinalização celular. As cadeias de heparam sulfato, devido a sua variedade estrutural, são capazes de se ligar e interagir com ampla gama de proteínas, como fatores de crescimento, quimiocinas, morfógenos, componentes da matriz extracelular, enzimas, entreoutros. Existe uma especificidade estrutural que direciona as interações dos heparam sulfatos e proteínas alvo. Esta especificidade está relacionada com a estrutura da cadeia do polissacarídeo e os motivos conservados da cadeia polipeptídica das proteínas envolvidas nesta interação. Os heparam

  1. Interactions of the Salience Network and Its Subsystems with the Default-Mode and the Central-Executive Networks in Normal Aging and Mild Cognitive Impairment.

    Science.gov (United States)

    Chand, Ganesh B; Wu, Junjie; Hajjar, Ihab; Qiu, Deqiang

    2017-09-01

    Previous functional magnetic resonance imaging (fMRI) investigations suggest that the intrinsically organized large-scale networks and the interaction between them might be crucial for cognitive activities. A triple network model, which consists of the default-mode network, salience network, and central-executive network, has been recently used to understand the connectivity patterns of the cognitively normal brains versus the brains with disorders. This model suggests that the salience network dynamically controls the default-mode and central-executive networks in healthy young individuals. However, the patterns of interactions have remained largely unknown in healthy aging or those with cognitive decline. In this study, we assess the patterns of interactions between the three networks using dynamical causal modeling in resting state fMRI data and compare them between subjects with normal cognition and mild cognitive impairment (MCI). In healthy elderly subjects, our analysis showed that the salience network, especially its dorsal subnetwork, modulates the interaction between the default-mode network and the central-executive network (Mann-Whitney U test; p control correlated significantly with lower overall cognitive performance measured by Montreal Cognitive Assessment (r = 0.295; p control, especially the dorsal salience network, over other networks provides a neuronal basis for cognitive decline and may be a candidate neuroimaging biomarker of cognitive impairment.

  2. NFAT regulation of cystathionine γ-lyase expression in endothelial cells is impaired in rats exposed to intermittent hypoxia.

    Science.gov (United States)

    Gonzalez Bosc, Laura V; Osmond, Jessica M; Giermakowska, Wieslawa K; Pace, Carolyn E; Riggs, Jennifer L; Jackson-Weaver, Olan; Kanagy, Nancy L

    2017-04-01

    Sleep apnea is a risk factor for cardiovascular disease, and intermittent hypoxia (IH, 20 episodes/h of 5% O 2 -5% CO 2 for 7 h/day) to mimic sleep apnea increases blood pressure and impairs hydrogen sulfide (H 2 S)-induced vasodilation in rats. The enzyme that produces H 2 S, cystathionine γ-lyase (CSE), is decreased in rat mesenteric artery endothelial cells (EC) following in vivo IH exposure. In silico analysis identified putative nuclear factor of activated T cell (NFAT) binding sites in the CSE promoter. Therefore, we hypothesized that IH exposure reduces Ca 2+ concentration ([Ca 2+ ]) activation of calcineurin/NFAT to lower CSE expression and impair vasodilation. In cultured rat aortic EC, inhibiting calcineurin with cyclosporine A reduced CSE mRNA, CSE protein, and luciferase activity driven by a full-length but not a truncated CSE promoter. In male rats exposed to sham or IH conditions for 2 wk, [Ca 2+ ] in EC in small mesenteric arteries from IH rats was lower than in EC from sham rat arteries (Δfura 2 ratio of fluorescence at 340 to 380 nm from Ca 2+ free: IH = 0.05 ± 0.02, sham = 0.17 ± 0.03, P intermittent hypoxia to mimic sleep apnea, nuclear factor of activated T cells c3 nuclear translocation and CSE expression are decreased, concomitant with decreased CSE-dependent vasodilation. Copyright © 2017 the American Physiological Society.

  3. An ultrastructural study of cell-cell interactions in capture organs of the nematophagous fungus Arthrobotrys oligospora

    NARCIS (Netherlands)

    Veenhuis, Marten; Nordbring-Hertz, Birgit; Harder, Willem

    1985-01-01

    A detailed ultrastructural analysis was made of interactions between individual cells within the same adhesive network (trap) of the nematophagous fungus Arthrobotrys oligospora. These interactions were confined to traps which had captured nematodes, and occurred concurrently with the

  4. Salmonella serovar-specific interaction with jejunal epithelial cells.

    Science.gov (United States)

    Razzuoli, Elisabetta; Amadori, Massimo; Lazzara, Fabrizio; Bilato, Dania; Ferraris, Monica; Vito, Guendalina; Ferrari, Angelo

    2017-08-01

    Gut is often a receptacle for many different pathogens in feed and/or the environment, such as Salmonella spp. The current knowledge about pathogenicity of Salmonella is restricted to few serotypes, whereas other important ones like S. Coeln, S. Thompson, S. Veneziana, have not been investigated yet in human and animal models. Therefore, the aim of our work was to verify the ability of widespread environmental Salmonella strains to penetrate and modulate innate immunity in pig intestinal IPEC-J2 cells. Our results outline the different ability of Salmonella strains to modulate innate immunity; the expression of the IFN-β gene was increased by S. Typhimurium, S. Ablogame and S. Diarizonae 2, that also caused an inflammatory response in terms of Interleukin (IL)-1β and/or IL-8 gene espression. In particular, IL-8 gene expression and protein release were significantly modulated by 5 Salmonella strains out of 7. Interestingly, S. Typhimurium, S. Coeln and S. Thompson strains, characterized by a peculiar ability to penetrate into IPEC-J2 cells, up-regulated both IL-8 and TNF-α gene expression. Accordingly, blocking IL-8 was shown to decrease the penetration of S. Typhimurium. On the contrary, S. Diarizonae strain 1, showing lesser invasion of IPEC-J2 cells, down-regulated the p38-MAPK pathway, and it did not induce an inflammatory response. Our results confirm that IPEC-J2 cells are a useful model to evaluate host-gut pathogen interaction and indicate IL-8 and TNF-α as possible predictive markers of invasiveness of Salmonella strains in enterocytes. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Interaction of Munc18c and syntaxin4 facilitates invadopodium formation and extracellular matrix invasion of tumor cells.

    Science.gov (United States)

    Brasher, Megan I; Martynowicz, David M; Grafinger, Olivia R; Hucik, Andrea; Shanks-Skinner, Emma; Uniacke, James; Coppolino, Marc G

    2017-09-29

    Tumor cell invasion involves targeted localization of proteins required for interactions with the extracellular matrix and for proteolysis. The localization of many proteins during these cell-extracellular matrix interactions relies on membrane trafficking mediated in part by SNAREs. The SNARE protein syntaxin4 (Stx4) is involved in the formation of invasive structures called invadopodia; however, it is unclear how Stx4 function is regulated during tumor cell invasion. Munc18c is known to regulate Stx4 activity, and here we show that Munc18c is required for Stx4-mediated invadopodium formation and cell invasion. Biochemical and microscopic analyses revealed a physical association between Munc18c and Stx4, which was enhanced during invadopodium formation, and that a reduction in Munc18c expression decreases invadopodium formation. We also found that an N-terminal Stx4-derived peptide associates with Munc18c and inhibits endogenous interactions of Stx4 with synaptosome-associated protein 23 (SNAP23) and vesicle-associated membrane protein 2 (VAMP2). Furthermore, expression of the Stx4 N-terminal peptide decreased invadopodium formation and cell invasion in vitro Of note, cells expressing the Stx4 N-terminal peptide exhibited impaired trafficking of membrane type 1 matrix metalloproteinase (MT1-MMP) and EGF receptor (EGFR) to the cell surface during invadopodium formation. Our findings implicate Munc18c as a regulator of Stx4-mediated trafficking of MT1-MMP and EGFR, advancing our understanding of the role of SNARE function in the localization of proteins that drive tumor cell invasion. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Indoleamine 2,3-dioxygenase-expressing leukemic dendritic cells impair a leukemia-specific immune response by inducing potent T regulatory cells.

    Science.gov (United States)

    Curti, Antonio; Trabanelli, Sara; Onofri, Chiara; Aluigi, Michela; Salvestrini, Valentina; Ocadlikova, Darina; Evangelisti, Cecilia; Rutella, Sergio; De Cristofaro, Raimondo; Ottaviani, Emanuela; Baccarani, Michele; Lemoli, Roberto M

    2010-12-01

    The immunoregulatory enzyme indoleamine 2,3-dioxygenase, which catalyzes the conversion of tryptophan into kynurenine, is expressed in a significant subset of patients with acute myeloid leukemia, resulting in the inhibition of T-cell proliferation and the induction of regulatory T cells. Acute myeloid leukemia cells can be differentiated into dendritic cells, which have increased immunogenicity and have been proposed as vaccines against leukemia. Leukemic dendritic cells were generated from acute myeloid leukemia cells and used as stimulators in functional assays, including the induction of regulatory T cells. Indoleamine 2,3-dioxygenase expression in leukemic dendritic cells was evaluated at molecular, protein and enzymatic levels. We demonstrate that, after differentiation into dendritic cells, both indoleamine 2,3-dioxygenase-negative and indoleamine 2,3-dioxygenase-positive acute myeloid leukemia samples show induction and up-regulation of indoleamine 2,3-dioxygenase gene and protein, respectively. Indoleamine 2,3-dioxygenase-positive acute myeloid leukemia dendritic cells catabolize tryptophan into kynurenine metabolite and inhibit T-cell proliferation through an indoleamine 2,3-dioxygenase-dependent mechanism. Moreover, indoleamine 2,3-dioxygenase-positive leukemic dendritic cells increase the number of allogeneic and autologous CD4(+)CD25(+) Foxp3(+) T cells and this effect is completely abrogated by the indoleamine 2,3-dioxygenase-inhibitor, 1-methyl tryptophan. Purified CD4(+)CD25(+) T cells obtained from co-culture with indoleamine 2,3-dioxygenase-positive leukemic dendritic cells act as regulatory T cells as they inhibit naive T-cell proliferation and impair the complete maturation of normal dendritic cells. Importantly, leukemic dendritic cell-induced regulatory T cells are capable of in vitro suppression of a leukemia-specific T cell-mediated immune response, directed against the leukemia-associated antigen, Wilms' tumor protein. These data identify

  7. Immunotoxicity of aflatoxin B1: Impairment of the cell-mediated response to vaccine antigen and modulation of cytokine expression

    International Nuclear Information System (INIS)

    Meissonnier, Guylaine M.; Pinton, Philippe; Laffitte, Joelle; Cossalter, Anne-Marie; Gong, Yun Yun; Wild, Christopher P.; Bertin, Gerard; Galtier, Pierre; Oswald, Isabelle P.

    2008-01-01

    Aflatoxin B1 (AFB1), a mycotoxin produced by Aspergillus flavus or A. parasiticus, is a frequent contaminant of food and feed. This toxin is hepatotoxic and immunotoxic. The present study analyzed in pigs the influence of AFB1 on humoral and cellular responses, and investigated whether the immunomodulation observed is produced through interference with cytokine expression. For 28 days, pigs were fed a control diet or a diet contaminated with 385, 867 or 1807 μg pure AFB1/kg feed. At days 4 and 15, pigs were vaccinated with ovalbumin. AFB1 exposure, confirmed by an observed dose-response in blood aflatoxin-albumin adduct, had no major effect on humoral immunity as measured by plasma concentrations of total IgA, IgG and IgM and of anti-ovalbumin IgG. Toxin exposure did not impair the mitogenic response of lymphocytes but delayed and decreased their specific proliferation in response to the vaccine antigen, suggesting impaired lymphocyte activation in pigs exposed to AFB1. The expression level of pro-inflammatory (TNF-α, IL-1β, IL-6, IFN-γ) and regulatory (IL-10) cytokines was assessed by real-time PCR in spleen. A significant up-regulation of all 5 cytokines was observed in spleen from pigs exposed to the highest dose of AFB1. In pigs exposed to the medium dose, IL-6 expression was increased and a trend towards increased IFN-γ and IL-10 was observed. In addition we demonstrate that IL-6 impaired in vitro the antigenic- but not the mitogenic-induced proliferation of lymphocytes from control pigs vaccinated with ovalbumin. These results indicate that AFB1 dietary exposure decreases cell-mediated immunity while inducing an inflammatory response. These impairments in the immune response could participate in failure of vaccination protocols and increased susceptibility to infections described in pigs exposed to AFB1

  8. Frontline Science: Functionally impaired geriatric CAR-T cells rescued by increased α5β1 integrin expression.

    Science.gov (United States)

    Guha, Prajna; Cunetta, Marissa; Somasundar, Ponnandai; Espat, N Joseph; Junghans, Richard P; Katz, Steven C

    2017-08-01

    Chimeric antigen receptor expressing T cells (CAR-T) are a promising form of immunotherapy, but the influence of age-related immune changes on CAR-T production remains poorly understood. We showed that CAR-T cells from geriatric donors (gCAR-T) are functionally impaired relative to CAR-T from younger donors (yCAR-T). Higher transduction efficiencies and improved cell expansion were observed in yCAR-T cells compared with gCAR-T. yCAR-T demonstrated significantly increased levels of proliferation and signaling activation of phosphorylated (p)Erk, pAkt, pStat3, and pStat5. Furthermore, yCAR-T contained higher proportions of CD4 and CD8 effector memory (EM) cells, which are known to have enhanced cytolytic capabilities. Accordingly, yCAR-T demonstrated higher levels of tumor antigen-specific cytotoxicity compared with gCAR-T. Enhanced tumor killing by yCAR-T correlated with increased levels of perforin and granzyme B. yCAR-T had increased α5β1 integrin expression, a known mediator of retroviral transduction. We found that treatment with M-CSF or TGF-β1 rescued the impaired transduction efficiency of the gCAR-T by increasing the α5β1 integrin expression. Neutralization of α5β1 confirmed that this integrin was indispensable for CAR expression. Our study suggests that the increase of α5β1 integrin expression levels enhances CAR expression and thereby improves tumor killing by gCAR-T. © Society for Leukocyte Biology.

  9. Exposure to lipopolysaccharide and/or unconjugated bilirubin impair the integrity and function of brain microvascular endothelial cells.

    Directory of Open Access Journals (Sweden)

    Filipa L Cardoso

    Full Text Available BACKGROUND: Sepsis and jaundice are common conditions in newborns that can lead to brain damage. Though lipopolysaccharide (LPS is known to alter the integrity of the blood-brain barrier (BBB, little is known on the effects of unconjugated bilirubin (UCB and even less on the joint effects of UCB and LPS on brain microvascular endothelial cells (BMEC. METHODOLOGY/PRINCIPAL FINDINGS: Monolayers of primary rat BMEC were treated with 1 µg/ml LPS and/or 50 µM UCB, in the presence of 100 µM human serum albumin, for 4 or 24 h. Co-cultures of BMEC with astroglial cells, a more complex BBB model, were used in selected experiments. LPS led to apoptosis and UCB induced both apoptotic and necrotic-like cell death. LPS and UCB led to inhibition of P-glycoprotein and activation of matrix metalloproteinases-2 and -9 in mono-cultures. Transmission electron microscopy evidenced apoptotic bodies, as well as damaged mitochondria and rough endoplasmic reticulum in BMEC by either insult. Shorter cell contacts and increased caveolae-like invaginations were noticeable in LPS-treated cells and loss of intercellular junctions was observed upon treatment with UCB. Both compounds triggered impairment of endothelial permeability and transendothelial electrical resistance both in mono- and co-cultures. The functional changes were confirmed by alterations in immunostaining for junctional proteins β-catenin, ZO-1 and claudin-5. Enlargement of intercellular spaces, and redistribution of junctional proteins were found in BMEC after exposure to LPS and UCB. CONCLUSIONS: LPS and/or UCB exert direct toxic effects on BMEC, with distinct temporal profiles and mechanisms of action. Therefore, the impairment of brain endothelial integrity upon exposure to these neurotoxins may favor their access to the brain, thus increasing the risk of injury and requiring adequate clinical management of sepsis and jaundice in the neonatal period.

  10. Characterization of Endothelial Progenitor Cell Interactions with Human Tropoelastin.

    Directory of Open Access Journals (Sweden)

    Young Yu

    Full Text Available The deployment of endovascular implants such as stents in the treatment of cardiovascular disease damages the vascular endothelium, increasing the risk of thrombosis and promoting neointimal hyperplasia. The rapid restoration of a functional endothelium is known to reduce these complications. Circulating endothelial progenitor cells (EPCs are increasingly recognized as important contributors to device re-endothelialization. Extracellular matrix proteins prominent in the vessel wall may enhance EPC-directed re-endothelialization. We examined attachment, spreading and proliferation on recombinant human tropoelastin (rhTE and investigated the mechanism and site of interaction. EPCs attached and spread on rhTE in a dose dependent manner, reaching a maximal level of 56±3% and 54±3%, respectively. EPC proliferation on rhTE was comparable to vitronectin, fibronectin and collagen. EDTA, but not heparan sulfate or lactose, reduced EPC attachment by 81±3%, while full attachment was recovered after add-back of manganese, inferring a classical integrin-mediated interaction. Integrin αVβ3 blocking antibodies decreased EPC adhesion and spreading on rhTE by 39±3% and 56±10% respectively, demonstrating a large contribution from this specific integrin. Attachment of EPCs on N-terminal rhTE constructs N25 and N18 accounted for most of this interaction, accompanied by comparable spreading. In contrast, attachment and spreading on N10 was negligible. αVβ3 blocking antibodies reduced EPC spreading on both N25 and N18 by 45±4% and 42±14%, respectively. In conclusion, rhTE supports EPC binding via an integrin mechanism involving αVβ3. N25 and N18, but not N10 constructs of rhTE contribute to EPC binding. The regulation of EPC activity by rhTE may have implications for modulation of the vascular biocompatibility of endovascular implants.

  11. Galactomannan from Schizolobium amazonicum seed and its sulfated derivatives impair metabolism in HepG2 cells.

    Science.gov (United States)

    Cunha de Padua, Monique Meyenberg; Suter Correia Cadena, Silvia Maria; de Oliveira Petkowicz, Carmen Lucia; Martinez, Glaucia Regina; Rodrigues Noleto, Guilhermina

    2017-08-01

    This study evaluated the effects of native galactomannan from Schizolobium amazonicum seeds and its sulfated forms on certain metabolic parameters of HepG2 cells. Aqueous extraction from S. amazonicum seeds furnished galactomannan with 3.2:1 Man:Gal ratio (SAGM) and molar mass of 4.34×10 5 g/mol. The SAGM fraction was subjected to sulfation using chlorosulfonic acid to obtain SAGMS1 and SAGMS2 with DS of 0.4 and 0.6, respectively. Cytotoxicity of SAGM, SAGMS1, and SAGMS2 was evaluated in human hepatocellular carcinoma cells (HepG2). After 72h, SAGM decreased the viability of HepG2 cells by 50% at 250μg/mL, while SAGMS1 reduced it by 30% at the same concentration. SAGM, SAGMS1, and SAGMS2 promoted a reduction in oxygen consumption and an increase in lactate production in non-permeabilized HepG2 cells after 72h of treatment. These results suggest that SAGM, SAGMS1, and SAGMS2 could be recognized by HepG2 cells and might trigger alterations that impair its survival. These effects could be implicated in the modification of the oxidative phosphorylation process in HepG2 cells and activation of the glycolytic pathway. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. PD-L1 Expression Induced by the 2009 Pandemic Influenza A(H1N1 Virus Impairs the Human T Cell Response

    Directory of Open Access Journals (Sweden)

    Nuriban Valero-Pacheco

    2013-01-01

    Full Text Available PD-L1 expression plays a critical role in the impairment of T cell responses during chronic infections; however, the expression of PD-L1 on T cells during acute viral infections, particularly during the pandemic influenza virus (A(H1N1pdm09, and its effects on the T cell response have not been widely explored. We found that A(H1N1pdm09 virus induced PD-L1 expression on human dendritic cells (DCs and T cells, as well as PD-1 expression on T cells. PD-L1 expression impaired the T cell response against A(H1N1pdm09 by promoting CD8+ T cell death and reducing cytokine production. Furthermore, we found increased PD-L1 expression on DCs and T cells from influenza-infected patients from the first and second 2009 pandemic waves in Mexico City. PD-L1 expression on CD8+ T cells correlated inversely with T cell proportions in patients infected with A(H1N1pdm09. Therefore, PD-L1 expression on DCs and T cells could be associated with an impaired T cell response during acute infection with A(H1N1pdm09 virus.

  13. Physical View on the Interactions Between Cancer Cells and the Endothelial Cell Lining During Cancer Cell Transmigration and Invasion

    Science.gov (United States)

    Mierke, Claudia T.

    There exist many reviews on the biological and biochemical interactions of cancer cells and endothelial cells during the transmigration and tissue invasion of cancer cells. For the malignant progression of cancer, the ability to metastasize is a prerequisite. In particular, this means that certain cancer cells possess the property to migrate through the endothelial lining into blood or lymph vessels, and are possibly able to transmigrate through the endothelial lining into the connective tissue and follow up their invasion path in the targeted tissue. On the molecular and biochemical level the transmigration and invasion steps are well-defined, but these signal transduction pathways are not yet clear and less understood in regards to the biophysical aspects of these processes. To functionally characterize the malignant transformation of neoplasms and subsequently reveal the underlying pathway(s) and cellular properties, which help cancer cells to facilitate cancer progression, the biomechanical properties of cancer cells and their microenvironment come into focus in the physics-of-cancer driven view on the metastasis process of cancers. Hallmarks for cancer progression have been proposed, but they still lack the inclusion of specific biomechanical properties of cancer cells and interacting surrounding endothelial cells of blood or lymph vessels. As a cancer cell is embedded in a special environment, the mechanical properties of the extracellular matrix also cannot be neglected. Therefore, in this review it is proposed that a novel hallmark of cancer that is still elusive in classical tumor biological reviews should be included, dealing with the aspect of physics in cancer disease such as the natural selection of an aggressive (highly invasive) subtype of cancer cells displaying a certain adhesion or chemokine receptor on their cell surface. Today, the physical aspects can be analyzed by using state-of-the-art biophysical methods. Thus, this review will present

  14. Impaired energy metabolism of senescent muscle satellite cells is associated with oxidative modifications of glycolytic enzymes

    DEFF Research Database (Denmark)

    Baraibar, Martín A; Hyzewicz, Janek; Rogowska-Wrzesinska, Adelina

    2016-01-01

    Accumulation of oxidized proteins is a hallmark of cellular and organismal aging. Adult muscle stem cell (or satellite cell) replication and differentiation is compromised with age contributing to sarcopenia. However, the molecular events related to satellite cell dysfunction during aging are not...

  15. Interferon-gamma impairs proliferation of hematopoietic stem cells in mice

    NARCIS (Netherlands)

    de Bruin, Alexander M.; Demirel, Özlem; Hooibrink, Berend; Brandts, Christian H.; Nolte, Martijn A.

    2013-01-01

    Balancing the processes of hematopoietic stem cell (HSC) differentiation and self-renewal is critical for maintaining a lifelong supply of blood cells. The bone marrow (BM) produces a stable output of newly generated cells, but immunologic stress conditions inducing leukopenia increase the demand

  16. Blimp-1 impairs T cell function via upregulation of TIGIT and PD-1 in patients with acute myeloid leukemia.

    Science.gov (United States)

    Zhu, Liuluan; Kong, Yaxian; Zhang, Jianhong; Claxton, David F; Ehmann, W Christopher; Rybka, Witold B; Palmisiano, Neil D; Wang, Ming; Jia, Bei; Bayerl, Michael; Schell, Todd D; Hohl, Raymond J; Zeng, Hui; Zheng, Hong

    2017-06-19

    T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT) and programmed cell death protein 1 (PD-1) are important inhibitory receptors that associate with T cell exhaustion in acute myeloid leukemia (AML). In this study, we aimed to determine the underlying transcriptional mechanisms regulating these inhibitory pathways. Specifically, we investigated the role of transcription factor B lymphocyte-induced maturation protein 1 (Blimp-1) in T cell response and transcriptional regulation of TIGIT and PD-1 in AML. Peripheral blood samples collected from patients with AML were used in this study. Blimp-1 expression was examined by flow cytometry. The correlation of Blimp-1 expression to clinical characteristics of AML patients was analyzed. Phenotypic and functional studies of Blimp-1-expressing T cells were performed using flow cytometry-based assays. Luciferase reporter assays and ChIP assays were applied to assess direct binding and transcription activity of Blimp-1. Using siRNA to silence Blimp-1, we further elucidated the regulatory role of Blimp-1 in the TIGIT and PD-1 expression and T cell immune response. Blimp-1 expression is elevated in T cells from AML patients. Consistent with exhaustion, Blimp-1 + T cells upregulate multiple inhibitory receptors including PD-1 and TIGIT. In addition, they are functionally impaired manifested by low cytokine production and decreased cytotoxicity capacity. Importantly, the functional defect is reversed by inhibition of Blimp-1 via siRNA knockdown. Furthermore, Blimp-1 binds to the promoters of PD-1 and TIGIT and positively regulates their expression. Our study demonstrates an important inhibitory effect of Blimp-1 on T cell response in AML; thus, targeting Blimp-1 and its regulated molecules to improve the immune response may provide effective leukemia therapeutics.

  17. Blimp-1 impairs T cell function via upregulation of TIGIT and PD-1 in patients with acute myeloid leukemia

    Directory of Open Access Journals (Sweden)

    Liuluan Zhu

    2017-06-01

    Full Text Available Abstract Background T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM domain (TIGIT and programmed cell death protein 1 (PD-1 are important inhibitory receptors that associate with T cell exhaustion in acute myeloid leukemia (AML. In this study, we aimed to determine the underlying transcriptional mechanisms regulating these inhibitory pathways. Specifically, we investigated the role of transcription factor B lymphocyte-induced maturation protein 1 (Blimp-1 in T cell response and transcriptional regulation of TIGIT and PD-1 in AML. Methods Peripheral blood samples collected from patients with AML were used in this study. Blimp-1 expression was examined by flow cytometry. The correlation of Blimp-1 expression to clinical characteristics of AML patients was analyzed. Phenotypic and functional studies of Blimp-1-expressing T cells were performed using flow cytometry-based assays. Luciferase reporter assays and ChIP assays were applied to assess direct binding and transcription activity of Blimp-1. Using siRNA to silence Blimp-1, we further elucidated the regulatory role of Blimp-1 in the TIGIT and PD-1 expression and T cell immune response. Results Blimp-1 expression is elevated in T cells from AML patients. Consistent with exhaustion, Blimp-1+ T cells upregulate multiple inhibitory receptors including PD-1 and TIGIT. In addition, they are functionally impaired manifested by low cytokine production and decreased cytotoxicity capacity. Importantly, the functional defect is reversed by inhibition of Blimp-1 via siRNA knockdown. Furthermore, Blimp-1 binds to the promoters of PD-1 and TIGIT and positively regulates their expression. Conclusions Our study demonstrates an important inhibitory effect of Blimp-1 on T cell response in AML; thus, targeting Blimp-1 and its regulated molecules to improve the immune response may provide effective leukemia therapeutics.

  18. Repeated Gene Transfection Impairs the Engraftment of Transplanted Porcine Neonatal Pancreatic Cells

    Directory of Open Access Journals (Sweden)

    Min Koo Seo

    2011-02-01

    Full Text Available BackgroundPreviously, we reported that neonatal porcine pancreatic cells transfected with hepatocyte growth factor (HGF gene in an Epstein-Barr virus (EBV-based plasmid (pEBVHGF showed improved proliferation and differentiation compared to those of the control. In this study, we examined if pancreatic cells transfected repeatedly with pEBVHGF can be successfully grafted to control blood glucose in a diabetes mouse model.MethodsNeonatal porcine pancreatic cells were cultured as a monolayer and were transfected with pEBVHGF every other day for a total of three transfections. The transfected pancreatic cells were re-aggregated and transplanted into kidney capsules of diabetic nude mice or normal nude mice. Blood glucose level and body weight were measured every other day after transplantation. The engraftment of the transplanted cells and differentiation into beta cells were assessed using immunohistochemistry.ResultsRe-aggregation of the pancreatic cells before transplantation improved engraftment of the cells and facilitated neovascularization of the graft. Right before transplantation, pancreatic cells that were transfected with pEBVHGF and then re-aggregated showed ductal cell marker expression. However, ductal cells disappeared and the cells underwent fibrosis in a diabetes mouse model two to five weeks after transplantation; these mice also did not show controlled blood glucose levels. Furthermore, pancreatic cells transplanted into nude mice with normal blood glucose showed poor graft survival regardless of the type of transfected plasmid (pCEP4, pHGF, or pEBVHGF.ConclusionFor clinical application of transfected neonatal porcine pancreatic cells, further studies are required to develop methods of overcoming the damage for the cells caused by repeated transfection and to re-aggregate them into islet-like structures.

  19. Andrographolide - A promising therapeutic agent, negatively regulates glial cell derived neurodegeneration of prefrontal cortex, hippocampus and working memory impairment.

    Science.gov (United States)

    Das, Sudeshna; Mishra, K P; Ganju, Lilly; Singh, S B

    2017-12-15

    Over activation of glial cell derived innate immune factors induces neuro-inflammation that results in neurodegenerative disease, like working memory impairment. In this study, we have investigated the role of andrographolide, a major constituent of Andrographis paniculata plant, in reduction of reactive glial cell derived working memory impairment. Real time PCR, Western bloting, flow cytometric and immunofluorescence studies demonstrated that andrographolide inhibited lipopolysaccharide (LPS)-induced overexpression of HMGB1, TLR4, NFκB, COX-2, iNOS, and release of inflammatory mediators in primary mix glial culture, adult mice prefrontal cortex and hippocampus region. Active microglial and reactive astrocytic makers were also downregulated after andrographolide treatment. Andrographolide suppressed overexpression of microglial MIP-1α, P2X7 receptor and its downstream signaling mediators including-inflammasome NLRP3, caspase1 and mature IL-1β. Furthermore, in vivo maze studies suggested that andrographolide treatment reversed LPS-induced behavioural and working memory disturbances including regulation of expression of protein markers like PKC, p-CREB, amyloid beta, APP, p-tau, synapsin and PSD-95. Andrographolide, by lowering expression of pro apoptotic genes and enhancing the expression of anti-apoptotic gene showed its anti-apoptotic nature that in turn reduces neurodegeneration. Morphology studies using Nissl and FJB staining also showed the neuroprotective effect of andrographolide in the prefrontal cortex region. The above studies indicated that andrographolide prevented neuroinflammation-associated neurodegeneration and improved synaptic plasticity markers in cortical as well as hippocampal region which suggests that andrographolide could be a novel pharmacological countermeasure for the treatment of neuroinflammation and neurological disorders related to memory impairment. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Time-resolved functional analysis of acute impairment of frataxin expression in an inducible cell model of Friedreich ataxia

    Directory of Open Access Journals (Sweden)

    Dörte Poburski

    2016-05-01

    Full Text Available Friedreich ataxia is a neurodegenerative disease caused by a GAA triplet repeat expansion in the first intron of the frataxin gene, which results in reduced expression levels of the corresponding protein. Despite numerous animal and cellular models, therapeutic options that mechanistically address impaired frataxin expression are lacking. Here, we have developed a new mammalian cell model employing the Cre/loxP recombination system to induce a homozygous or heterozygous frataxin knockout in mouse embryonic fibroblasts. Induction of Cre-mediated disruption by tamoxifen was successfully tested on RNA and protein levels. After loss of frataxin protein, cell division, aconitase activity and oxygen consumption rates were found to be decreased, while ROS production was increased in the homozygous state. By contrast, in the heterozygous state no such changes were observed. A time-resolved analysis revealed the loss of aconitase activity as an initial event after induction of complete frataxin deficiency, followed by secondarily elevated ROS production and a late increase in iron content. Initial impairments of oxygen consumption and ATP production were found to be compensated in the late state and seemed to play a minor role in Friedreich ataxia pathophysiology. In conclusion and as predicted from its proposed role in iron sulfur cluster (ISC biosynthesis, disruption of frataxin primarily causes impaired function of ISC-containing enzymes, whereas other consequences, including elevated ROS production and iron accumulation, appear secondary. These parameters and the robustness of the newly established system may additionally be used for a time-resolved study of pharmacological candidates in a HTS manner.

  1. Modeling of interactions between nanoparticles and cell membranes

    Science.gov (United States)

    Ban, Young-Min

    containing the nanoparticles exhibit localized perturbation around the nanoparticle. The nanoparticles are not likely to affect membrane protein function by the weak perturbation of the internal stress in the membrane. Due to the short-ranged interactions between the nanoparticles, the nanoparticles would not form aggregates inside membranes. The effect of lipid peroxidation on cell membrane deformation is assessed. The peroxidized lipids introduce a perturbation to the internal structure of the membrane leading to higher amplitude of the membrane fluctuations. Higher concentration of the peroxidized lipids induces more significant perturbation. Cumulative effects of lipid peroxidation caused by nanoparticles are examined for the first time. The considered amphiphilic particle appears to reduce the perturbation of the membrane structure at its equilibrium position inside the peroxidized membrane. This suggests a possibility of antioxidant effect of the nanoparticle.

  2. Molecular Identification of tw5: Vps52 Promotes Pluripotential Cell Differentiation through Cell–Cell Interactions

    Directory of Open Access Journals (Sweden)

    Michihiko Sugimoto

    2012-11-01

    Full Text Available After implantation, pluripotent epiblasts are converted to embryonic ectoderm through cell–cell interactions that significantly change the transcriptional and epigenetic networks. An entrée to understanding this vital developmental transition is the tw5 mutation of the mouse t complex. This mutation produces highly specific defects in the embryonic ectoderm before gastrulation, leading to death of the embryonic ectoderm. Using a positional cloning approach, we have now identified the mutated gene, completing a decades-long search. The gene, vacuolar protein sorting 52 (Vps52, is a mouse homolog of yeast VPS52 that is involved in the retrograde trafficking of endosomes. Our data suggest that Vps52 acts in extraembryonic tissues to support the growth and differentiation of embryonic ectoderm via cell–cell interactions. It is also required in the formation of embryonic structures at a later stage of development, revealing hitherto unknown functions of Vps52 in the development of a multicellular organism.

  3. Impaired beta cell sensitivity to incretins in type 2 diabetes is insufficiently compensated by higher incretin response

    DEFF Research Database (Denmark)

    Tura, A.; Bagger, J. I.; Ferrannini, E.

    2017-01-01

    Background and aims The incretin effect is impaired in type 2 diabetes (T2D), but the underlying mechanisms are only partially understood. We investigated the relationships between the time course of the incretin effect and that of glucose-dependent insulinotropic polypeptide (GIP) and glucagon......-like peptide-1 (GLP-1) during oral glucose tolerance tests (OGTTs), thereby estimating incretin sensitivity of the beta cell, and its associated factors. Methods and results Eight patients with T2D and eight matched subjects with normal glucose tolerance (NGT) received 25, 75, and 125 g OGTTs and corresponding...... was correlated with that of both GIP and GLP-1 in each subject (median r = 0.67 in NGT and 0.45 in T2D). We calculated an individual beta cell sensitivity to incretins (SINCR) using a weighted average of GIP and GLP-1 (pooled incretin concentration, PIC), as the slope of the relationship between PINCR and PIC...

  4. Insulin Resistance and Impaired Pancreatic β-Cell Function in Adult Offspring of Women With Diabetes in Pregnancy

    DEFF Research Database (Denmark)

    Kelstrup, Louise; Damm, Peter; Mathiesen, Elisabeth R

    2013-01-01

    Context:Offspring of women with diabetes during pregnancy have increased risk of glucose intolerance in adulthood, but the underlying mechanisms are unknown.Objective:We aimed to investigate effects of intrauterine hyperglycemia on insulin secretion and - action in adult offspring of mothers...... a standard oral glucose tolerance test (120 minutes, 75 gram glucose). Pancreatic beta-cell function taking the prevailing insulin sensitivity into account was estimated by disposition indices.Results:Both groups of offspring exposed during pregnancy to either maternal gestational diabetes or type 1 diabetes.......005).Conclusion:Reduced insulin sensitivity as well as impaired pancreatic beta cell function may contribute to the increased risk of glucose intolerance among adult offspring born to women with diabetes during pregnancy....

  5. Impaired B cell immunity in acute myeloid leukemia patients after chemotherapy.

    Science.gov (United States)

    Goswami, Meghali; Prince, Gabrielle; Biancotto, Angelique; Moir, Susan; Kardava, Lela; Santich, Brian H; Cheung, Foo; Kotliarov, Yuri; Chen, Jinguo; Shi, Rongye; Zhou, Huizhi; Golding, Hana; Manischewitz, Jody; King, Lisa; Kunz, Lauren M; Noonan, Kimberly; Borrello, Ivan M; Smith, B Douglas; Hourigan, Christopher S

    2017-07-10

    Changes in adaptive immune cells after chemotherapy in adult acute myeloid leukemia (AML) may have implications for the success of immunotherapy. This study was designed to determine the functional capacity of the immune system in adult patients with AML who have completed chemotherapy and are potential candidates for immunotherapy. We used the response to seasonal influenza vaccination as a surrogate for the robustness of the immune system in 10 AML patients in a complete remission post-chemotherapy and performed genetic, phenotypic, and functional characterization of adaptive immune cell subsets. Only 2 patients generated protective titers in response to vaccination, and a majority of patients had abnormal frequencies of transitional and memory B-cells. B-cell receptor sequencing showed a B-cell repertoire with little evidence of somatic hypermutation in most patients. Conversely, frequencies of T-cell populations were similar to those seen in healthy controls, and cytotoxic T-cells demonstrated antigen-specific activity after vaccination. Effector T-cells had increased PD-1 expression in AML patients least removed from chemotherapy. Our results suggest that while some aspects of cellular immunity recover quickly, humoral immunity is incompletely reconstituted in the year following intensive cytotoxic chemotherapy for AML. The observed B-cell abnormalities may explain the poor response to vaccination often seen in AML patients after chemotherapy. Furthermore, the uncoupled recovery of B-cell and T-cell immunity and increased PD-1 expression shortly after chemotherapy might have implications for the success of several modalities of immunotherapy.

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    factors, ECM, and other cells, as well as physical properties of the ECM. To understand regulation of fate decisions, therefore, would require a means of understanding carefully choreographed combinatorial interactions. Here we used microenvironment protein microarrays to functionally identify...... combinations of cell-extrinsic mammary gland proteins and ECM molecules that imposed specific cell fates on bipotent human mammary progenitor cells.Micropatterned cell culture surfaces were fabricated to distinguish between the instructive effects of cell-cell versus cell-ECM interactions, as well...

  7. Impaired low-density lipoprotein receptor activity in chronic B-lymphocytic leukaemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Juliusson, G.; Vitols, S.

    1988-01-01

    Cellular degradation of /sup 125/I-labelled low-density lipoprotein (LDL) was analysed in freshly isolated blood mononuclear cells from 26 patients with chronic B-lymphocytic leukaemia (CLL) and 8 healthy subjects, and in cells following 1,2 and 3 d of culture in medium containing 10% human lipoprotein-deficient serum (LPDS). Fresh CLL cells had lower LDL degradation rates than mononuclear cells from healthy subjects (p < 0.01). The LDL degradation rates increased during culture (p < 0.001), but to a lesser degree in CLL cells than in normal blood mononuclear cells (p < 0.001). The cellular degradation rate of /sup 125/I-LDL was markedly inhibited by an excess of unlabelled LDL, indicating that most of the /sup 125/I-LDL that was degraded had been internalized following binding to the LPDS-induced LDL degradation of CLL cells and the thymidine uptake in CLL cell cultures with (r = 0.70, p < 0.001) and without (r = 0.59, p < 0.01) the B cell mitogen, Epstein-Barr virus. The results indicate that LDL receptors might be involved in the regulation of CLL cell proliferation.

  8. 1,25-dihydroxyvitamin D{sub 3} impairs NF-{kappa}B activation in human naive B cells

    Energy Technology Data Exchange (ETDEWEB)

    Geldmeyer-Hilt, Kerstin, E-mail: kerstin.hilt@charite.de [Allergie-Centrum-Charite, CCM, Klinik fuer Dermatologie und Allergologie, Charite - Universitaetsmedizin Berlin, Chariteplatz 1, 10117 Berlin (Germany); Heine, Guido, E-mail: guido.heine@charite.de [Allergie-Centrum-Charite, CCM, Klinik fuer Dermatologie und Allergologie, Charite - Universitaetsmedizin Berlin, Chariteplatz 1, 10117 Berlin (Germany); Deutsches Rheuma-Forschungszentrum Berlin, Chariteplatz 1, 10117 Berlin (Germany); Hartmann, Bjoern, E-mail: bjoern.hartmann@charite.de [Allergie-Centrum-Charite, CCM, Klinik fuer Dermatologie und Allergologie, Charite - Universitaetsmedizin Berlin, Chariteplatz 1, 10117 Berlin (Germany); Baumgrass, Ria, E-mail: baumgrass@drfz.de [Deutsches Rheuma-Forschungszentrum Berlin, Chariteplatz 1, 10117 Berlin (Germany); Radbruch, Andreas, E-mail: radbruch@drfz.de [Deutsches Rheuma-Forschungszentrum Berlin, Chariteplatz 1, 10117 Berlin (Germany); Worm, Margitta, E-mail: margitta.worm@charite.de [Allergie-Centrum-Charite, CCM, Klinik fuer Dermatologie und Allergologie, Charite - Universitaetsmedizin Berlin, Chariteplatz 1, 10117 Berlin (Germany)

    2011-04-22

    Highlights: {yields} In naive B cells, VDR activation by calcitriol results in reduced NF-{kappa}B p105 and p50 protein expression. {yields} Ligating the VDR with calcitriol causes reduced nuclear translocation of NF-{kappa}B p65. {yields} Reduced nuclear amount of p65 after calcitriol incubation results in reduced binding of p65 on the p105 promoter. {yields} Thus, vitamin D receptor signaling may reduce or prevent activation of B cells and unwanted immune responses, e.g. in IgE dependent diseases such as allergic asthma. -- Abstract: 1{alpha},25-dihydroxyvitamin D{sub 3} (calcitriol), the bioactive metabolite of vitamin D, modulates the activation and inhibits IgE production of anti-CD40 and IL-4 stimulated human peripheral B cells. Engagement of CD40 results in NF-{kappa}B p50 activation, which is essential for the class switch to IgE. Herein, we investigated by which mechanism calcitriol modulates NF-{kappa}B mediated activation of human naive B cells. Naive B cells were predominantly targeted by calcitriol in comparison with memory B cells as shown by pronounced induction of the VDR target gene cyp24a1. Vitamin D receptor activation resulted in a strongly reduced p105/p50 protein and mRNA expression in human naive B cells. This effect is mediated by impaired nuclear translocation of p65 and consequently reduced binding of p65 to its binding site in the p105 promoter. Our data indicate that the vitamin D receptor reduces NF-{kappa}B activation by interference with NF-{kappa}B p65 and p105. Thus, the vitamin D receptor inhibits costimulatory signal transduction in naive B cells, namely by reducing CD40 signaling.

  9. 1,25-dihydroxyvitamin D3 impairs NF-κB activation in human naive B cells

    International Nuclear Information System (INIS)

    Geldmeyer-Hilt, Kerstin; Heine, Guido; Hartmann, Bjoern; Baumgrass, Ria; Radbruch, Andreas; Worm, Margitta

    2011-01-01

    Highlights: → In naive B cells, VDR activation by calcitriol results in reduced NF-κB p105 and p50 protein expression. → Ligating the VDR with calcitriol causes reduced nuclear translocation of NF-κB p65. → Reduced nuclear amount of p65 after calcitriol incubation results in reduced binding of p65 on the p105 promoter. → Thus, vitamin D receptor signaling may reduce or prevent activation of B cells and unwanted immune responses, e.g. in IgE dependent diseases such as allergic asthma. -- Abstract: 1α,25-dihydroxyvitamin D 3 (calcitriol), the bioactive metabolite of vitamin D, modulates the activation and inhibits IgE production of anti-CD40 and IL-4 stimulated human peripheral B cells. Engagement of CD40 results in NF-κB p50 activation, which is essential for the class switch to IgE. Herein, we investigated by which mechanism calcitriol modulates NF-κB mediated activation of human naive B cells. Naive B cells were predominantly targeted by calcitriol in comparison with memory B cells as shown by pronounced induction of the VDR target gene cyp24a1. Vitamin D receptor activation resulted in a strongly reduced p105/p50 protein and mRNA expression in human naive B cells. This effect is mediated by impaired nuclear translocation of p65 and consequently reduced binding of p65 to its binding site in the p105 promoter. Our data indicate that the vitamin D receptor reduces NF-κB activation by interference with NF-κB p65 and p105. Thus, the vitamin D receptor inhibits costimulatory signal transduction in naive B cells, namely by reducing CD40 signaling.

  10. Reduced Dnmt3a increases Gdf5 expression with suppressed satellite cell differentiation and impaired skeletal muscle regeneration.

    Science.gov (United States)

    Hatazawa, Yukino; Ono, Yusuke; Hirose, Yuma; Kanai, Sayaka; Fujii, Nobuharu L; Machida, Shuichi; Nishino, Ichizo; Shimizu, Takahiko; Okano, Masaki; Kamei, Yasutomi; Ogawa, Yoshihiro

    2018-03-01

    DNA methylation is an epigenetic mechanism regulating gene expression. In this study, we observed that DNA methyltransferase 3a (Dnmt3a) expression is decreased after muscle atrophy. We made skeletal muscle-specific Dnmt3a-knockout (Dnmt3a-KO) mice. The regeneration capacity after muscle injury was markedly decreased in Dnmt3a-KO mice. Diminished mRNA and protein expression of Dnmt3a were observed in skeletal muscles as well as in satellite cells, which are important for muscle regeneration, in Dnmt3a-KO mice. Dnmt3a-KO satellite cell showed smaller in size (length/area), suggesting suppressed myotube differentiation. Microarray analysis of satellite cells showed that expression of growth differentiation factor 5 (Gdf5) mRNA was markedly increased in Dnmt3a-KO mice. The DNA methylation level of the Gdf5 promoter was markedly decreased in Dnmt3a-KO satellite cells. In addition, DNA methylation inhibitor azacytidine treatment increased Gdf5 expression in wild-type satellite cells, suggesting Gdf5 expression is regulated by DNA methylation. Also, we observed increased inhibitor of differentiation (a target of Gdf5) mRNA expression in Dnmt3a-KO satellite cells. Thus, Dnmt3a appears to regulate satellite cell differentiation via DNA methylation. This mechanism may play a role in the decreased regeneration capacity during atrophy such as in aged sarcopenia.-Hatazawa, Y., Ono, Y., Hirose, Y., Kanai, S., Fujii, N. L., Machida, S., Nishino, I., Shimizu, T., Okano, M., Kamei, Y., Ogawa, Y. Reduced Dnmt3a increases Gdf5 expression with suppressed satellite cell differentiation and impaired skeletal muscle regeneration.

  11. Study of the adhesion interaction using 51Cr labelling method between the myeloma cell lines and the endothelial cells

    International Nuclear Information System (INIS)

    Zhang Xueguang; Wang Jiangfang; Mao Zijun

    1995-06-01

    Using 51 Cr labelled multiple myeloma (MM) cell lines U266/XG-7, the regulatory effect of cytokines on the adhesive interaction between myeloma-cell lines U266/XG-7 and the endothelial cells, and the effects of these cytokines on expression of adhesion molecules and secretion of other cytokines were studied. The experimental results were as follows: (1) IL-6 and IL-6 Rgp 130-associated growth factors (such as GM-CSF) are not only myeloma cell growth factors, but also can enhance the adhesion between MM cells and endothelial cells and thus facilitated the metastasis of tumor cells. (2) Cytokines could induce increase in the expression of CD54 and CD44 on the endothelial cells and the secretion of IL-6 and TNF by the endothelial cells. On the other hand, the adhesion could also cause the change of CD11a, CD54, CD44 and VLA-4 on surface of myeloma cells XG-7. Finally, the interaction between MM cells and stromal cells from murine bone marrow could rapidly induce autocrine of IL-6 in human IL-6-dependent MM cells. (3) The interaction between stromal cells and tumor cells regulated by the cytokines and adhesion molecules was a key element in the pathogenesis and development of human MM. Among these factors, VLA-4 might be one of the molecules involved in U266/XG-7-EC interaction. (5 tabs., 8 figs.)

  12. Blocking the Interaction between EphB2 and ADDLs by a Small Peptide Rescues Impaired Synaptic Plasticity and Memory Deficits in a Mouse Model of Alzheimer's Disease.

    Science.gov (United States)

    Shi, Xiao-Dong; Sun, Kai; Hu, Rui; Liu, Xiao-Ya; Hu, Qiu-Mei; Sun, Xiao-Yu; Yao, Bin; Sun, Nan; Hao, Jing-Ru; Wei, Pan; Han, Yuan; Gao, Can

    2016-11-23

    Soluble amyloid-β (Aβ) oligomers, also known as Aβ-derived diffusible ligands (ADDLs), are thought to be the key pathogenic factor in Alzheimer's disease (AD), but there is still no effective treatment for preventing or reversing the progression of the disease. Targeting NMDA receptor trafficking and regulation is a new strategy for early treatment of AD. Aβ oligomers have been found to bind to the fibronectin (FN) type III repeat domain of EphB2 to trigger EphB2 degradation, thereby impairing the normal functioning of NMDA receptors and resulting in cognitive deficits. Here, we identified for the first time the interaction sites of the EphB2 FN domain with ADDLs by applying the peptide array method to design and synthesize four candidate peptides (Pep21, Pep25, Pep32, and Pep63) that might be able to block the EphB2-ADDL interaction. Among them, Pep63 was found to be the most effective at inhibiting the binding between EphB2 and ADDLs. We found that Pep63 not only rescued the ADDL-induced depletion of EphB2- and GluN2B-containing NMDA receptors from the neuronal surface in cultured hippocampal neurons, but also improved impaired memory deficits in APPswe/PS1dE9 (APP/PS1) transgenic mice and the phosphorylation and surface expression of GluN2B-containing NMDA receptors in cultures. Together, these results suggest that blocking the EphB2-ADDL interaction by small interfering peptides may be a promising strategy for AD treatment. Alzheimer's disease (AD) is an age-dependent neurodegenerative disorder and amyloid β-derived diffusible ligands (ADDLs) play a key role in triggering the early cognitive deficits that constitute AD. ADDLs may bind EphB2 and alter NMDA receptor trafficking and synaptic plasticity. Here, we identified the interaction sites of the EphB2 FN domain with ADDLs for the first time to develop a small (10 aa) peptide (Pep63) capable of blocking the EphB2-ADDL interaction. We found that Pep63 not only rescued the ADDL-induced depletion of EphB2

  13. Impaired progenitor cell function in HIV-negative infants of HIV-positive mothers results in decreased thymic output and low CD4 counts

    DEFF Research Database (Denmark)

    Nielsen, S. D.; Jeppesen, D. L.; Kolte, L.

    2001-01-01

    and fetal thymic organ cultures (FTOCs). Lower naive CD4 counts (459.3 +/- 68.9 vs 1128.9 +/- 146.8 cells/microL, P mothers were found (frequency of CD4(+) cells with TRECs was 3.6% +/- 0.7% compared with 14.3% +/- 2.2% in controls, P ...). In combination with lower red blood cell counts in infants of HIV-positive mothers, this finding suggested impairment of progenitor cell function. Indeed, progenitors from infants of HIV-positive mothers had decreased cloning efficiency (15.7% +/- 2.6% vs 55.8% +/- 15.9%, P =.009) and seemed to generate fewer T...... cells in FTOCs. In conclusion, lower numbers of naive CD4(+) cells and reduced thymic output in HIV-negative infants of HIV-positive mothers may be due to impaired progenitor cell function....

  14. Indian hedgehog regulates intestinal stem cell fate through epithelial-mesenchymal interactions during development

    NARCIS (Netherlands)

    Kosinski, C.; Stange, D.E.; Xu, C.; Chan, A.S.; Ho, C.; Yuen, S.T.; Mifflin, R.C.; Powell, D.W.; Clevers, H.; Leung, S.Y.; Chen, X.N.

    2010-01-01

    BACKGROUND & AIMS: Intestinal stem cells (ISCs) are regulated by the mesenchymal environment via physical interaction and diffusible factors. We examined the role of Indian hedgehog (Ihh) in mesenchymal organization and the mechanisms by which perturbations in epithelial-mesenchymal interactions

  15. Cell specificity of the cytoplasmic Ca2+ response to tolbutamide is impaired in beta-cells from hyperglycemic mice

    DEFF Research Database (Denmark)

    Gustavsson, Natalia; Larsson-Nyrén, Gerd; Lindström, Per

    2006-01-01

    We recently reported that the timing and magnitude of the nutrient-induced Ca(2+) response are specific and reproducible for each isolated beta-cell. We have now used tolbutamide and arginine to test if the cell specificity exists also for the response to non-nutrient stimulation of beta-cells an...

  16. Extracellular histones disarrange vasoactive mediators release through a COX-NOS interaction in human endothelial cells.

    Science.gov (United States)

    Pérez-Cremades, Daniel; Bueno-Betí, Carlos; García-Giménez, José Luis; Ibañez-Cabellos, José Santiago; Hermenegildo, Carlos; Pallardó, Federico V; Novella, Susana

    2017-08-01

    Extracellular histones are mediators of inflammation, tissue injury and organ dysfunction. Interactions between circulating histones and vascular endothelial cells are key events in histone-mediated pathologies. Our aim was to investigate the implication of extracellular histones in the production of the major vasoactive compounds released by human endothelial cells (HUVECs), prostanoids and nitric oxide (NO). HUVEC exposed to increasing concentrations of histones (0.001 to 100 μg/ml) for 4 hrs induced prostacyclin (PGI2) production in a dose-dependent manner and decreased thromboxane A2 (TXA2) release at 100 μg/ml. Extracellular histones raised cyclooxygenase-2 (COX-2) and prostacyclin synthase (PGIS) mRNA and protein expression, decreased COX-1 mRNA levels and did not change thromboxane A2 synthase (TXAS) expression. Moreover, extracellular histones decreased both, eNOS expression and NO production in HUVEC. The impaired NO production was related to COX-2 activity and superoxide production since was reversed after celecoxib (10 μmol/l) and tempol (100 μmol/l) treatments, respectively. In conclusion, our findings suggest that extracellular histones stimulate the release of endothelial-dependent mediators through an up-regulation in COX-2-PGIS-PGI2 pathway which involves a COX-2-dependent superoxide production that decreases the activity of eNOS and the NO production. These effects may contribute to the endothelial cell dysfunction observed in histone-mediated pathologies. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  17. IDH1R132H in Neural Stem Cells: Differentiation Impaired by Increased Apoptosis.

    Directory of Open Access Journals (Sweden)

    Kamila Rosiak

    Full Text Available The high frequency of mutations in the isocitrate dehydrogenase 1 (IDH1 gene in diffuse gliomas indicates its importance in the process of gliomagenesis. These mutations result in loss of the normal function and acquisition of the neomorphic activity converting α-ketoglutarate to 2-hydroxyglutarate. This potential oncometabolite may induce the epigenetic changes, resulting in the deregulated expression of numerous genes, including those related to the differentiation process or cell survivability.Neural stem cells were derived from human induced pluripotent stem cells following embryoid body formation. Neural stem cells transduced with mutant IDH1R132H, empty vector, non-transduced and overexpressing IDH1WT controls were differentiated into astrocytes and neurons in culture. The neuronal and astrocytic differentiation was determined by morphology and expression of lineage specific markers (MAP2, Synapsin I and GFAP as determined by real-time PCR and immunocytochemical staining. Apoptosis was evaluated by real-time observation of Caspase-3 activation and measurement of PARP cleavage by Western Blot.Compared with control groups, cells expressing IDH1R132H retained an undifferentiated state and lacked morphological changes following stimulated differentiation. The significant inhibitory effect of IDH1R132H on neuronal and astrocytic differentiation was confirmed by immunocytochemical staining for markers of neural stem cells. Additionally, real-time PCR indicated suppressed expression of lineage markers. High percentage of apoptotic cells was detected within IDH1R132H-positive neural stem cells population and their derivatives, if compared to normal neural stem cells and their derivatives. The analysis of PARP and Caspase-3 activity confirmed apoptosis sensitivity in mutant protein-expressing neural cells.Our study demonstrates that expression of IDH1R132H increases apoptosis susceptibility of neural stem cells and their derivatives. Robust

  18. Deletion of psychiatric risk gene Cacna1c impairs hippocampal neurogenesis in cell-autonomous fashion.

    Science.gov (United States)

    Völkening, Bianca; Schönig, Kai; Kronenberg, Golo; Bartsch, Dusan; Weber, Tillmann

    2017-05-01

    Ca 2+ is a universal signal transducer which fulfills essential functions in cell development and differentiation. CACNA1C, the gene encoding the alpha-1C subunit (i.e., Ca v 1.2) of the voltage-dependent l-type calcium channel (LTCC), has been implicated as a risk gene in a variety of neuropsychiatric disorders. To parse the role of Ca v 1.2 channels located on astrocyte-like stem cells and their descendants in the development of new granule neurons, we created Tg GLAST-CreERT2 /Cacna1c fl/fl /RCE:loxP mice, a transgenic tool that allows cell-type-specific inducible deletion of Cacna1c. The EGFP reporter was used to trace the progeny of recombined type-1 cells. FACS-sorted Cacna1c-deficient neural precursor cells from the dentate gyrus showed reduced proliferative activity in neurosphere cultures. Moreover, under differentiation conditions, Cacna1c-deficient NPCs gave rise to fewer neurons and more astroglia. Similarly, under basal conditions in vivo, Cacna1c gene deletion in type-1 cells decreased type-1 cell proliferation and reduced the neuronal fate-choice decision of newly born cells, resulting in reduced net hippocampal neurogenesis. Unexpectedly, electroconvulsive seizures completely compensated for the proliferation deficit of Cacna1c deficient type-1 cells, indicating that there must be Ca v 1.2-independent mechanisms of controlling proliferation related to excitation. In the aggregate, this is the first report demonstrating the presence of functional L-type 1.2 channels on type-1 cells. Ca v 1.2 channels promote type-1 cell proliferation and push the glia-to-neuron ratio in the direction of a neuronal fate choice and subsequent neuronal differentiation. Ca v 1.2 channels expressed on NPCs and their progeny possess the ability to shape neurogenesis in a cell-autonomous fashion. © 2017 Wiley Periodicals, Inc.

  19. The metabolites in peripheral blood mononuclear cells showed greater differences between patients with impaired fasting glucose or type 2 diabetes and healthy controls than those in plasma.

    Science.gov (United States)

    Kim, Minjoo; Kim, Minkyung; Han, Ji Yun; Lee, Sang-Hyun; Jee, Sun Ha; Lee, Jong Ho

    2017-03-01

    To determine differences between peripheral blood mononuclear cells and the plasma metabolites in patients with impaired fasting glucose or type 2 diabetes and healthy controls. In all, 65 nononobese patients (aged 30-70 years) with impaired fasting glucose or type 2 diabetes and 65 nonobese sex-matched healthy controls were included, and fasting peripheral blood mononuclear cell and plasma metabolomes were profiled. The diabetic or impaired fasting glucose patients showed higher circulating and peripheral blood mononuclear cell lipoprotein phospholipase A 2 activities, high-sensitivity C-reactive protein and tumour necrosis factor-α than controls. Compared with controls, impaired fasting glucose or diabetic subjects showed increases in 11 peripheral blood mononuclear cell metabolites: six amino acids (valine, leucine, methionine, phenylalanine, tyrosine and tryptophan), l-pyroglutamic acid, two fatty acid amides containing palmitic amide and oleamide and two lysophosphatidylcholines. In impaired fasting glucose or diabetic patients, peripheral blood mononuclear cell lipoprotein phospholipase A 2 positively associated with peripheral blood mononuclear cell lysophosphatidylcholines and circulating inflammatory markers, including tumour necrosis factor-α, high-sensitivity C-reactive protein and lipoprotein phospholipase A 2 activities. In plasma metabolites between patients and healthy controls, we observed significant increases in only three amino acids (proline, valine and leucine) and decreases in only five lysophosphatidylcholines. This study demonstrates significant differences in the peripheral blood mononuclear cell metabolome in patients with impaired fasting glucose or diabetes compared with healthy controls. These differences were greater than those observed in the plasma metabolome. These data suggest peripheral blood mononuclear cells as a useful tool to better understand the inflammatory pathophysiology of diabetes.

  20. Disruption of endocytic trafficking protein Rab7 impairs invasiveness of cholangiocarcinoma cells.

    Science.gov (United States)

    Suwandittakul, Nantana; Reamtong, Onrapak; Molee, Pattamaporn; Maneewatchararangsri, Santi; Sutherat, Maleerat; Chaisri, Urai; Wongkham, Sopit; Adisakwattana, Poom

    2017-09-07

    Alterations and mutations of endo-lysosomal trafficking proteins have been associated with cancer progression. Identification and characterization of endo-lysosomal trafficking proteins in invasive cholangiocarcinoma (CCA) cells may benefit prognosis and drug design for CCA. To identify and characterize endo-lysosomal trafficking proteins in invasive CCA. A lysosomal-enriched fraction was isolated from a TNF-α induced invasive CCA cell line (KKU-100) and uninduced control cells and protein identification was performed with nano-LC MS/MS. Novel lysosomal proteins that were upregulated in invasive CCA cells were validated by real-time RT-PCR. We selected Rab7 for further studies of protein level using western blotting and subcellular localization using immunofluorescence. The role of Rab7 in CCA invasion was determined by siRNA gene knockdown and matrigel transwell assay. Rab7 mRNA and protein were upregulated in invasive CCA cells compared with non-treated controls. Immunofluorescence studies demonstrated that Rab7 was expressed predominantly in invasive CCA cells and was localized in the cytoplasm and lysosomes. Suppression of Rab7 translation significantly inhibited TNF-α-induced cell invasion compared to non-treated control (p= 0.044). Overexpression of Rab7 in CCA cells was associated with cell invasion, supporting Rab7 as a novel candidate for the development of diagnostic and therapeutic strategies for CCA.

  1. Neuropilin 1 deficiency on CD4+Foxp3+ regulatory T cells impairs mouse melanoma growth

    Science.gov (United States)

    Hutzler, Marina; Abel, Simone; Alter, Christina; Stockmann, Christian; Kliche, Stefanie; Albert, Juliane; Sparwasser, Tim; Sakaguchi, Shimon; Westendorf, Astrid M.; Schadendorf, Dirk; Buer, Jan; Helfrich, Iris

    2012-01-01

    Infiltration of Foxp3+ regulatory T (T reg) cells is considered to be a critical step during tumor development and progression. T reg cells supposedly suppress locally an effective anti-tumor immune response within tumor tissues, although the precise mechanism by which T reg cells infiltrate the tumor is still unclear. We provide evidence that Neuropilin 1 (Nrp-1), highly expressed by Foxp3+ T reg cells, regulates the immunological anti-tumor control by guiding T reg cells into the tumor in response to tumor-derived vascular endothelial growth factor (VEGF). We demonstrate for the first time that T cell–specific ablation of Nrp-1 expression results in a significant breakdown in tumor immune escape in various transplantation models and in a spontaneous, endogenously driven melanoma model associated with strongly reduced tumor growth and prolonged tumor-free survival. Strikingly, numbers of tumor-infiltrating Foxp3+ T reg cells were significantly reduced accompanied by enhanced activation of CD8+ T cells within tumors of T cell–specific Nrp-1–deficient mice. This phenotype can be reversed by adoptive transfer of Nrp-1+ T reg cells from wild-type mice. Thus, our data strongly suggest that Nrp-1 acts as a key mediator of Foxp3+ T reg cell infiltration into the tumor site resulting in a dampened anti-tumor immune response and enhanced tumor progression. PMID:23045606

  2. Functional Impairment of Myeloid Dendritic Cells during Advanced Stage of HIV-1 Infection: Role of Factors Regulating Cytokine Signaling.

    Directory of Open Access Journals (Sweden)

    Meenakshi Sachdeva

    Full Text Available Severely immunocompromised state during advanced stage of HIV-1 infection has been linked to functionally defective antigen presentation by dendritic cells (DCs. The molecular mechanisms behind DC impairment are still obscure. We investigated changes in DC function and association of key regulators of cytokine signaling during different stages of HIV-1 infection and following antiretroviral therapy (ART.Phenotypic and functional characteristics of circulating myeloid DCs (mDCs in 56 ART-naive patients (23 in early and 33 in advanced stage of disease, 36 on ART and 24 healthy controls were evaluated. Sixteen patients were studied longitudinally prior-to and 6 months after the start of ART. For functional studies, monocyte-derived DCs (Mo-DCs were evaluated for endocytosis, allo-stimulation and cytokine secretion. The expression of suppressor of cytokine signaling (SOCS-1 and other regulators of cytokine signaling was evaluated by real-time RT-PCR.The ability to respond to an antigenic stimulation was severely impaired in patients in advanced HIV-1 disease which showed partial recovery in the treated group. Mo-DCs from patients with advanced HIV-disease remained immature with low allo-stimulation and reduced cytokine secretion even after TLR-4 mediated stimulation ex-vivo. The cells had an increased expression of negative regulatory factors like SOCS-1, SOCS-3, SH2-containing phosphatase (SHP-1 and a reduced expression of positive regulators like Janus kinase (JAK2 and Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB1. A functional recovery after siRNA mediated silencing of SOCS-1 in these mo-DCs confirms the role of negative regulatory factors in functional impairment of these cells.Functionally defective DCs in advanced stage of HIV-1 infection seems to be due to imbalanced state of negative and positive regulatory gene expression. Whether this is a cause or effect of increased viral replication at this stage of disease

  3. Structural characteristics of an antigen required for its interaction with Ia and recognition by T cells

    DEFF Research Database (Denmark)

    Sette, A; Buus, S; Colon, S

    1987-01-01

    A detailed analysis of the residues within an immunogenic peptide that endow it with the capacity to interact with Ia and to be recognized by T cells is presented. Ia interacts with only a few of the peptide residues and overall exhibits a very broad specificity. Some residues appear to interact...... both with Ia and with T cells, leading to a model in which a peptide antigen is 'sandwiched' between Ia and the T-cell receptor....

  4. Activation, Impaired Tumor Necrosis Factor-α Production, and Deficiency of Circulating Mucosal-Associated Invariant T Cells in Patients with Scrub Typhus.

    Science.gov (United States)

    Kang, Seung-Ji; Jin, Hye-Mi; Won, Eun Jeong; Cho, Young-Nan; Jung, Hyun-Ju; Kwon, Yong-Soo; Kee, Hae Jin; Ju, Jae Kyun; Kim, Jung-Chul; Kim, Uh Jin; Jang, Hee-Chang; Jung, Sook-In; Kee, Seung-Jung; Park, Yong-Wook

    2016-07-01

    Mucosal-associated invariant T (MAIT) cells contribute to protection against certain microorganism infections. However, little is known about the role of MAIT cells in Orientia tsutsugamushi infection. Hence, the aims of this study were to examine the level and function of MAIT cells in patients with scrub typhus and to evaluate the clinical relevance of MAIT cell levels. Thirty-eight patients with scrub typhus and 53 health control subjects were enrolled in the study. The patients were further divided into subgroups according to disease severity. MAIT cell level and function in the peripheral blood were measured by flow cytometry. Circulating MAIT cell levels were found to be significantly reduced in scrub typhus patients. MAIT cell deficiency reflects a variety of clinical conditions. In particular, MAT cell levels reflect disease severity. MAIT cells in scrub typhus patients displayed impaired tumor necrosis factor (TNF)-α production, which was restored during the remission phase. In addition, the impaired production of TNF-α by MAIT cells was associated with elevated CD69 expression. This study shows that circulating MAIT cells are activated, numerically deficient, and functionally impaired in TNF-α production in patients with scrub typhus. These abnormalities possibly contribute to immune system dysregulation in scrub typhus infection.

  5. Exacerbation of spontaneous autoimmune nephritis following regulatory T cell depletion in B cell lymphoma 2-interacting mediator knock-out mice.

    Science.gov (United States)

    Wang, Y M; Zhang, G Y; Wang, Y; Hu, M; Zhou, J J; Sawyer, A; Cao, Q; Wang, Y; Zheng, G; Lee, V W S; Harris, D C H; Alexander, S I

    2017-05-01

    Regulatory T cells (T regs ) have been recognized as central mediators for maintaining peripheral tolerance and limiting autoimmune diseases. The loss of T regs or their function has been associated with exacerbation of autoimmune disease. However, the temporary loss of T regs in the chronic spontaneous disease model has not been investigated. In this study, we evaluated the role of T regs in a novel chronic spontaneous glomerulonephritis model of B cell lymphoma 2-interacting mediator (Bim) knock-out mice by transient depleting T regs . Bim is a pro-apoptotic member of the B cell lymphoma 2 (Bcl-2) family. Bim knock-out (Bim -/- ) mice fail to delete autoreactive T cells in thymus, leading to chronic spontaneous autoimmune kidney disease. We found that T reg depletion in Bim -/- mice exacerbated the kidney injury with increased proteinuria, impaired kidney function, weight loss and greater histological injury compared with wild-type mice. There was a significant increase in interstitial infiltrate of inflammatory cells, antibody deposition and tubular damage. Furthermore, the serum levels of cytokines interleukin (IL)-2, IL-4, IL-6, IL-10, IL-17α, interferon (IFN)-γ and tumour necrosis factor (TNF)-α were increased significantly after T reg depletion in Bim -/- mice. This study demonstrates that transient depletion of T regs leads to enhanced self-reactive T effector cell function followed by exacerbation of kidney disease in the chronic spontaneous kidney disease model of Bim-deficient mice. © 2017 British Society for Immunology.

  6. Aging Impairs the Ability of Conventional Dendritic Cells to Cross-Prime CD8+ T Cells upon Stimulation with a TLR7 Ligand.

    Directory of Open Access Journals (Sweden)

    Estefanía R Zacca

    Full Text Available The aging process is accompanied by altered immune system functioning and an increased risk of infection. Dendritic cells (DCs are antigen-presenting cells that play a key role in both adaptive and innate immunity, but how aging affects DCs and their influence on immunity has not been thoroughly established. Here we examined the function of conventional DCs (cDCs in old mice after TLR7 stimulation, focusing on their ability to cross-prime CD8+ T cells. Using polyU, a synthetic ssRNA analog, as TLR7 ligand and OVA as an antigen (Ag model, we found that cDCs from old mice have a poor ability to stimulate a CD8+ T cell-mediated cytotoxic response. cDCs from old mice exhibit alterations in Ag-processing machinery and TLR7 activation. Remarkably, CD8α+ cDCs from old mice have an impaired ability to activate naïve CD8+ T cells and, moreover, a lower capacity to mature and to process exogenous Ag. Taken together, our results suggest that immunosenescence impacts cDC function, affecting the activation of naïve CD8+ T cells and the generation of effector cytotoxic T cells.

  7. Interaction with Epithelial Cells Modifies Airway Macrophage Response to Ozone

    Science.gov (United States)

    The initial innate immune response to ozone (03) in the lung is orchestrated by structural cells, such as epithelial cells, and resident immune cells, such as airway macrophages (Macs). We developed an epithelial cell-Mac coculture model to investigate how epithelial cell-derived...

  8. Fungal-induced cell cycle impairment, chromosome instability and apoptosis via differential activation of NF-κB.

    Directory of Open Access Journals (Sweden)

    Mariem Ben-Abdallah

    Full Text Available Microbial pathogens have developed efficient strategies to compromise host immune responses. Cryptococcus neoformans is a facultative intracellular pathogen, recognised as the most common cause of systemic fungal infections leading to severe meningoencephalitis, mainly in immunocompromised patients. This yeast is characterized by a polysaccharide capsule, which inhibits its phagocytosis. Whereas phagocytosis escape and macrophage intracellular survival have been intensively studied, extracellular survival of this yeast and restraint of host innate immune response are still poorly understood. In this study, we have investigated whether C. neoformans affected macrophage cell viability and whether NF-κB (nuclear factor-κB, a key regulator of cell growth, apoptosis and inflammation, was involved. Using wild-type (WT as well as mutant strains of C. neoformans for the pathogen side, and WT and mutant cell lines with altered NF-κB activity or signalling as well as primary macrophages for the host side, we show that C. neoformans manipulated NF-κB-mediated signalling in a unique way to regulate macrophage cell fate and viability. On the one hand, serotype A strains reduced macrophage proliferation in a capsule-independent fashion. This growth decrease, which required a critical dosage of NF-κB activity, was caused by cell cycle disruption and aneuploidy, relying on fungal-induced modification of expression of several cell cycle checkpoint regulators in S and G2/M phases. On the other hand, C. neoformans infection induced macrophage apoptosis in a capsule-dependent manner with a differential requirement of the classical and alternative NF-κB signalling pathways, the latter one being essential. Together, these findings shed new light on fungal strategies to subvert host response through uncoupling of NF-κB activity in pathogen-controlled apoptosis and impairment of cell cycle progression. They also provide the first demonstration of induction of

  9. Aging impairs long-term hematopoietic regeneration after autologous stem cell transplantation

    NARCIS (Netherlands)

    Woolthuis, Carolien M; Mariani, Niccoló; Verkaik-Schakel, Rikst Nynke; Brouwers-Vos, Annet Z.; Schuringa, Jan Jacob; Vellenga, Edo; de Wolf, Joost T M; Huls, Gerwin

    Most of our knowledge of the effects of aging on the hematopoietic system comes from studies in animal models. In this study, to explore potential effects of aging on human hematopoietic stem and progenitor cells (HSPCs), we evaluated CD34(+) cells derived from young (<35 years) and old (>60 years)

  10. Mannose-binding lectin impairs Leptospira activity through the inhibitory effect on the motility of cell.

    Science.gov (United States)

    Xu, Jun; Guo, Yijie; Nakamura, Shuichi; Islam, Md Shafiqul; Tomioka, Rintaro; Yoneyama, Hiroshi; Isogai, Emiko

    2015-02-01

    Mannose-binding lectin (MBL) plays key role in lectin pathway of innate immunity, and shows the ability of triggering opsonization intermediately. Substantial increase in the serum level of MBL has been confirmed during leptospirosis, which caused by a pathogenic spirochete, Leptospira. Leptospira has a fascinating locomotion pattern, which simultaneously gyrating and swimming forward, such motility enables that Leptospira is difficult to be captured by immune cells if without any assistance. In this study, the effect of mannose-binding lectin to Leptospira was quantitatively investigated by measuring some kinematic parameters, to discover the mechanism behind MBL-mediated immune responses during leptospiral infection. The results showed that mannose-binding lectin is capable of inhibiting the motility of Leptospira by transforming free swimming cells to tumbled rotating cells, resulted in the increase number of rotating cells. Otherwise, decrease in rotation rate of rotating cell has been observed. However, the swimming speed of swimming Leptospira cells showed no observable change under the effect of MBL. The inhibitory effect were only valid in a relatively short period, Leptospira cells regained their original motility after 2 h. This raises an interesting topic that Leptospira is somehow able to escape from the inhibitory effect of MBL by dragging such unfavorable molecules toward to the cell end and eventually throwing it out. The inhibitory effect of MBL on the motility of Leptospira is expected to provide a new insight into lectin pathway. Copyright © 2015 Elsevier GmbH. All rights reserved.

  11. Glucose impairs tamoxifen responsiveness modulating connective tissue growth factor in breast cancer cells.

    Science.gov (United States)

    Ambrosio, Maria Rosaria; D'Esposito, Vittoria; Costa, Valerio; Liguoro, Domenico; Collina, Francesca; Cantile, Monica; Prevete, Nella; Passaro, Carmela; Mosca, Giusy; De Laurentiis, Michelino; Di Bonito, Maurizio; Botti, Gerardo; Franco, Renato; Beguinot, Francesco; Ciccodicola, Alfredo; Formisano, Pietro

    2017-12-12

    Type 2 diabetes and obesity are negative prognostic factors in patients with breast cancer (BC). We found that sensitivity to tamoxifen was reduced by 2-fold by 25 mM glucose (High Glucose; HG) compared to 5.5 mM glucose (Low Glucose; LG) in MCF7 BC cells. Shifting from HG to LG ameliorated MCF7 cell responsiveness to tamoxifen. RNA-Sequencing of MCF7 BC cells revealed that cell cycle-related genes were mainly affected by glucose. Connective Tissue Growth Factor (CTGF) was identified as a glucose-induced modulator of cell sensitivity to tamoxifen. Co-culturing MCF7 cells with human adipocytes exposed to HG, enhanced CTGF mRNA levels and reduced tamoxifen responsiveness of BC cells. Inhibition of adipocyte-released IL8 reverted these effects. Interestingly, CTGF immuno-detection in bioptic specimens from women with estrogen receptor positive (ER + ) BC correlated with hormone therapy resistance, distant metastases, reduced overall and disease-free survival. Thus, glucose affects tamoxifen responsiveness directly modulating CTGF in BC cells, and indirectly promoting IL8 release by adipocytes.

  12. Polymicrobial sepsis impairs bystander recruitment of effector cells to infected skin despite optimal sensing and alarming function of skin resident memory CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Derek B Danahy

    2017-09-01

    Full Text Available Sepsis is a systemic infection that enhances host vulnerability to secondary infections normally controlled by T cells. Using CLP sepsis model, we observed that sepsis induces apoptosis of circulating memory CD8 T-cells (TCIRCM and diminishes their effector functions, leading to impaired CD8 T-cell mediated protection to systemic pathogen re-infection. In the context of localized re-infections, tissue resident memory CD8 T-cells (TRM provide robust protection in a variety of infectious models. TRM rapidly 'sense' infection in non-lymphoid tissues and 'alarm' the host by enhancing immune cell recruitment to the site of the infection to accelerate pathogen clearance. Here, we show that compared to pathogen-specific TCIRCM, sepsis does not invoke significant numerical decline of Vaccinia virus induced skin-TRM keeping their effector functions (e.g., Ag-dependent IFN-γ production intact. IFN-γ-mediated recruitment of immune cells to the site of localized infection was, however, reduced in CLP hosts despite TRM maintaining their 'sensing and alarming' functions. The capacity of memory CD8 T-cells in the septic environment to respond to inflammatory cues and arrive to the site of secondary infection/antigen exposure remained normal suggesting T-cell-extrinsic factors contributed to the observed lesion. Mechanistically, we showed that IFN-γ produced rapidly during sepsis-induced cytokine storm leads to reduced IFN-γR1 expression on vascular endothelium. As a consequence, decreased expression of adhesion molecules and/or chemokines (VCAM1 and CXCL9 on skin endothelial cells in response to TRM-derived IFN-γ was observed, leading to sub-optimal bystander-recruitment of effector cells and increased susceptibility to pathogen re-encounter. Importantly, as visualized by intravital 2-photon microscopy, exogenous administration of CXCL9/10 was sufficient to correct sepsis-induced impairments in recruitment of effector cells at the localized site of TRM

  13. Melatonin Attenuates Memory Impairment Induced by Klotho Gene Deficiency Via Interactive Signaling Between MT2 Receptor, ERK, and Nrf2-Related Antioxidant Potential

    Science.gov (United States)

    Shin, Eun-Joo; Chung, Yoon Hee; Le, Hoang-Lan Thi; Jeong, Ji Hoon; Dang, Duy-Khanh; Nam, Yunsung; Wie, Myung Bok; Nah, Seung-Yeol; Nabeshima, Yo-Ichi; Nabeshima, Toshitaka; Kim, Hyoung-Chun

    2015-01-01

    Background: We demonstrated that oxidative stress plays a crucial role in cognitive impairment in klotho mutant mice, a genetic model of aging. Since down-regulation of melatonin due to aging is well documented, we used this genetic model to determine whether the antioxidant property of melatonin affects memory impairment. Methods: First, we examined the effects of melatonin on hippocampal oxidative parameters and the glutathione/oxidized glutathione (GSH/GSSG) ratio and memory dysfunction of klotho mutant mice. Second, we investigated whether a specific melatonin receptor is involved in the melatonin-mediated pharmacological response by application with melatonin receptor antagonists. Third, we examined phospho-extracellular-signal-regulated kinase (ERK) expression, nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation, Nrf2 DNA binding activity, and glutamate-cysteine ligase (GCL) mRNA expression. Finally, we examined effects of the ERK inhibitor SL327 in response to antioxidant efficacy and memory enhancement mediated by melatonin. Results: Treatment with melatonin resulted in significant attenuations of oxidative damage, a decrease in the GSH/GSSG ratio, and a significant amelioration of memory impairment in this aging model. These effects of melatonin were significantly counteracted by the selective MT2 receptor antagonist 4-P-PDOT. Importantly, 4-P-PDOT or SL327 also counteracted melatonin-mediated attenuation in response to the decreases in phospho-ERK expression, Nrf2 nuclear translocation, Nrf2 DNA-binding activity, and GCL mRNA expression in the hippocampi of klotho mutant mice. SL327 also counteracted the up-regulation of the GSH/GSSG ratio and the memory enhancement mediated by melatonin in klotho mutant mice. Conclusions: Melatonin attenuates oxidative stress and the associated memory impairment induced by klotho deficiency via signaling interaction between the MT2 receptor and ERK- and Nrf2-related antioxidant potential. PMID

  14. Interaction of sleep quality and sleep duration on impaired fasting glucose: a population-based cross-sectional survey in China.

    Science.gov (United States)

    Lou, Peian; Chen, Peipei; Zhang, Lei; Zhang, Pan; Chang, Guiqiu; Zhang, Ning; Li, Ting; Qiao, Cheng

    2014-03-13

    To explore the interactions of sleep quality and sleep duration and their effects on impaired fasting glucose (IFG) in Chinese adults. Cross-sectional survey. Community-based investigation in Xuzhou, China. 15 145 Chinese men and women aged 18-75 years old who fulfilled the inclusion criteria. The Pittsburgh Sleep Quality Index was used to produce sleep quality categories of good, common and poor. Fasting blood glucose levels were assessed for IFG. Sleep duration was measured by average hours of sleep per night, with categories of 8 h. The products of sleep and family history of diabetes, obesity and age were added to the logistic regression model to evaluate the addictive interaction and relative excess risk of interaction (RERI) on IFG. The attributable proportion (AP) of the interaction and the synergy index (S) were applied to evaluate the additive interaction of two factors. Bootstrap measures were used to calculate 95% CI of RERI, AP and S. The prevalence of IFG was greatest in those with poor sleep quality and short sleep duration (OR 6.37, 95% CI 4.66 to 8.67; pquality and 6-8 h sleep duration, after adjusting for confounders. After adjusting for potential confounders RERI, AP and S values (and their 95% CI) were 1.69 (0.31 to 3.76), 0.42 (0.15 to 0.61) and 2.85 (2.14 to 3.92), respectively, for the interaction between poor sleep quality and short sleep duration, and 0.78 (0.12 to 1.43), 0.61 (0.26 to 0.87) and -65 (-0.94 to -0.27) for the interaction between good sleep quality and long sleep duration. The results suggest that there are additive interactions between poor sleep quality and short sleep duration.

  15. Silencing Nrf2 impairs glioma cell proliferation via AMPK-activated mTOR inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Yue [Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province (China); Wang, Handong, E-mail: njhdwang@hotmail.com [Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province (China); Wang, Qiang [Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province (China); Ding, Hui [Department of Neurosurgery, Jinling Hospital, School of Medicine, Southern Medical University (Guangzhou), 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province (China); Wu, Heming [Department of Neurosurgery, Nanjing Jingdu Hospital, No. 34, Biao 34, Yanggongjing Road, Nanjing 210002, Jiangsu Province (China); Pan, Hao [Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province (China)

    2016-01-15

    Gliomas are the leading cause of death among adults with primary brain malignancies. Treatment for malignant gliomas remains limited, and targeted therapies have been incompletely explored. Nuclear factor erythroid 2-related factor 2 (Nrf2), a key transcription regulator for antioxidant and detoxification enzymes, is abundantly expressed in cancer cells. In this study, the role and mechanism of Nrf2 in cancer cell proliferation was investigated in multiple glioma cell lines. We first evaluated the expression patterns of Nrf2 in four glioma cell lines and found all four cell lines expressed Nrf2, but the highest level was observed in U251 cells. We further evaluated the biological functions of Nrf2 in U251 glioma cell proliferation by specific inhibition of Nrf2 using short hairpin RNA (shRNA). We found that Nrf2 depletion inhibited glioma cell proliferation. Nrf2 depletion also decreased colony formation in U251 cells stably expressing Nrf2 shRNA compared to scrambled control shRNA. Moreover, suppression of Nrf2 expression could lead to ATP depletion (with concomitant rise in AMP/ATP ratio) and consequently to AMPK-activated mTOR inhibition. Finally, activation of adenosine monophosphate–activated protein kinase (AMPK) by treated with phenformin, an AMPK agonist, can mimic the inhibitory effect of Nrf2 knockdown in U251 cells. In conclusion, our findings will shed light to the role and mechanism of Nrf2 in regulating glioma proliferation via ATP-depletion-induced AMPK activation and consequent mTOR inhibition, a novel insight into our understanding the role and mechanism of Nrf2 in glioma pathoetiology. To our knowledge, this is also the first report to provide a rationale for the implication of cross-linking between Nrf2 and mTOR signaling.

  16. Role of Cytokine-Induced Glycosylation Changes in Regulating Cell Interactions and Cell Signaling in Inflammatory Diseases and Cancer

    Directory of Open Access Journals (Sweden)

    Justine H. Dewald

    2016-11-01

    Full Text Available Glycosylation is one of the most important modifications of proteins and lipids, and cell surface glycoconjugates are thought to play important roles in a variety of biological functions including cell-cell and cell-substrate interactions, bacterial adhesion, cell immunogenicity and cell signaling. Alterations of glycosylation are observed in number of diseases such as cancer and chronic inflammation. In that context, pro-inflammatory cytokines have been shown to modulate cell surface glycosylation by regulating the expression of glycosyltransferases involved in the biosynthesis of carbohydrate chains. These changes in cell surface glycosylation are also known to regulate cell signaling and could contribute to disease pathogenesis. This review summarizes our current knowledge of the glycosylation changes induced by pro-inflammatory cytokines, with a particular focus on cancer and cystic fibrosis, and their consequences on cell interactions and signaling.

  17. Mycobacterium leprae–host-cell interactions and genetic determinants in leprosy: an overview

    Science.gov (United States)

    Pinheiro, Roberta Olmo; de Souza Salles, Jorgenilce; Sarno, Euzenir Nunes; Sampaio, Elizabeth Pereira

    2011-01-01

    Leprosy, also known as Hansen’s disease, is a chronic infectious disease caused by Mycobacterium leprae in which susceptibility to the mycobacteria and its clinical manifestations are attributed to the host immune response. Even though leprosy prevalence has decreased dramatically, the high number of new cases indicates active transmission. Owing to its singular features, M. leprae infection is an attractive model for investigating the regulation of human immune responses to pathogen-induced disease. Leprosy is one of the most common causes of nontraumatic peripheral neuropathy worldwide. The proportion of patients with disabilities is affected by the type of leprosy and delay in diagnosis. This article briefly reviews the clinical features as well as the immunopathological mechanisms related to the establishment of the different polar forms of leprosy, the mechanisms related to M. leprae–host cell interactions and prophylaxis and diagnosis of this complex disease. Host genetic factors are summarized and the impact of the development of interventions that prevent, reverse or limit leprosy-related nerve impairments are discussed. PMID:21366421

  18. Identification of differences in gene expression in primary cell cultures of human endometrial epithelial cells and trophoblast cells following their interaction

    DEFF Research Database (Denmark)

    Høgh, Mette; Islin, Henrik; Møller, Charlotte

    2006-01-01

    The interaction between the cell types was simulated in vitro by growing primary cell cultures of human endometrial epithelial cells and trophoblast cells together (co-culture) and separately (control cultures). Gene expression in the cell cultures was compared using the Differential Display method and confirmed...

  19. Adaptive Regulation of Osteopontin Production by Dendritic Cells Through the Bidirectional Interaction With Mesenchymal Stromal Cells

    Directory of Open Access Journals (Sweden)

    Sara Scutera

    2018-06-01

    Full Text Available Mesenchymal stromal cells (MSCs exert immunosuppressive effects on immune cells including dendritic cells (DCs. However, many details of the bidirectional interaction of MSCs with DCs are still unsolved and information on key molecules by which DCs can modulate MSC functions is limited. Here, we report that osteopontin (OPN, a cytokine involved in homeostatic and pathophysiologic responses, is constitutively expressed by DCs and regulated in the DC/MSC cocultures depending on the activation state of MSCs. Resting MSCs promoted OPN production, whereas the production of OPN was suppressed when MSCs were activated by proinflammatory cytokines (i.e., TNF-α, IL-6, and IL-1β. OPN induction required cell-to-cell contact, mediated at least in part, by β1 integrin (CD29. Conversely, activated MSCs inhibited the release of OPN via the production of soluble factors with a major role played by Prostaglandin E2 (PGE2. Accordingly, pretreatment with indomethacin significantly abrogated the MSC-mediated suppression of OPN while the direct addition of exogenous PGE2 inhibited OPN production by DCs. Furthermore, DC-conditioned medium promoted osteogenic differentiation of MSCs with a concomitant inhibition of adipogenesis. These effects were paralleled by the repression of the adipogenic markers PPARγ, adiponectin, and FABP4, and induction of the osteogenic markers alkaline phosphatase, RUNX2, and of the bone-anabolic chemokine CCL5. Notably, blocking OPN activity with RGD peptides or with an antibody against CD29, one of the OPN receptors, prevented the effects of DC-conditioned medium on MSC differentiation and CCL5 induction. Because MSCs have a key role in maintenance of bone marrow (BM hematopoietic stem cell niche through reciprocal regulation with immune cells, we investigated the possible MSC/DC interaction in human BM by immunohistochemistry. Although DCs (CD1c+ are a small percentage of BM cells, we demonstrated colocalization of CD271+ MSCs with

  20. GroEL1, a heat shock protein 60 of Chlamydia pneumoniae, impairs neovascularization by decreasing endothelial progenitor cell function.

    Directory of Open Access Journals (Sweden)

    Yi-Wen Lin

    Full Text Available The number and function of endothelial progenitor cells (EPCs are sensitive to hyperglycemia, hypertension, and smoking in humans, which are also associated with the development of atherosclerosis. GroEL1 from Chlamydia pneumoniae has been found in atherosclerotic lesions and is related to atherosclerotic pathogenesis. However, the actual effects of GroEL1 on EPC function are unclear. In this study, we investigate the EPC function in GroEL1-administered hind limb-ischemic C57BL/B6 and C57BL/10ScNJ (a toll-like receptor 4 (TLR4 mutation mice and human EPCs. In mice, laser Doppler imaging, flow cytometry, and immunohistochemistry were used to evaluate the degree of neo-vasculogenesis, circulating level of EPCs, and expression of CD34, vWF, and endothelial nitric oxide synthase (eNOS in vessels. Blood flow in the ischemic limb was significantly impaired in C57BL/B6 but not C57BL/10ScNJ mice treated with GroEL1. Circulating EPCs were also decreased after GroEL1 administration in C57BL/B6 mice. Additionally, GroEL1 inhibited the expression of CD34 and eNOS in C57BL/B6 ischemic muscle. In vitro, GroEL1 impaired the capacity of differentiation, mobilization, tube formation, and migration of EPCs. GroEL1 increased senescence, which was mediated by caspases, p38 MAPK, and ERK1/2 signaling in EPCs. Furthermore, GroEL1 decreased integrin and E-selectin expression and induced inflammatory responses in EPCs. In conclusion, these findings suggest that TLR4 and impaired NO-related mechanisms could contribute to the reduced number and functional activity of EPCs in the presence of GroEL1 from C. pneumoniae.

  1. Childhood exposure to ambient polycyclic aromatic hydrocarbons is linked to epigenetic modifications and impaired systemic immunity in T cells

    Science.gov (United States)

    Hew, K. M.; Walker, A. I.; Kohli, A.; Garcia, M.; Syed, A.; McDonald-Hyman, C.; Noth, E. M.; Mann, J. K.; Pratt, B.; Balmes, J.; Hammond, S. Katharine; Eisen, E. A.; Nadeau, K. C.

    2015-01-01

    Summary Background Evidence suggests that exposure to polycyclic aromatic hydrocarbons (PAHs) increases atopy; it is unclear how PAH exposure is linked to increased severity of atopic diseases. Objective We hypothesized that ambient PAH exposure is linked to impairment of immunity in atopic children (defined as children with asthma and/or allergic rhinitis) from Fresno, California, an area with elevated ambient PAHs. Methods We recruited 256 subjects from Fresno, CA. Ambient PAH concentrations (ng/m3) were measured using a spatial-temporal regression model over multiple time periods. Asthma diagnosis was determined by current NHLBI criteria. Phenotyping and functional immune measurements were performed from isolated cells. For epigenetic measurements, DNA was isolated and pyrosequenced. Results We show that higher average PAH exposure was significantly associated with impaired Treg function and increased methylation in the forkhead box protein 3 (FOXP3) locus (P < 0.05), conditional on atopic status. These epigenetic modifications were significantly linked to differential protein expression of FOXP3 (P < 0.001). Methylation was associated with cellular functional changes, specifically Treg dysfunction, and an increase in total plasma IgE levels. Protein expression of IL-10 decreased and IFN-γ increased as the extent of PAH exposure increased. The strength of the associations generally increased as the time window for average PAH exposure increased from 24 hr to 1 year, suggesting more of a chronic response. Significant associations with chronic PAH exposure and immune outcomes were also observed in subjects with allergic rhinitis. Conclusions and Clinical Relevance Collectively, these results demonstrate that increased ambient PAH exposure is associated with impaired systemic immunity and epigenetic modifications in a key locus involved in atopy: FOXP3, with a higher impact on atopic children. The results suggest that increased atopic clinical symptoms in children

  2. Garlic (Allium sativum) feeding impairs Sertoli cell junctional proteins in male Wistar rat testis: microscopy study.

    Science.gov (United States)

    Hammami, I; Nahdi, A; Atig, F; El May, A; El May, M V

    2016-12-01

    Sertoli cell junctions, such as adhesion junction (AJ), gap junction (GJ) and tight junction (TJ), are important for maintaining spermatogenesis. In previous studies, we showed the inhibitory effect of crude garlic (Allium sativum, As) on spermatogenesis and steroidogenesis. The aim of this work was to complete our investigation on the impact of this plant, especially on Sertoli cell junctional proteins (SCJPs). During 1 month, 24 male rats were divided into groups: group control (0% of As) and treated groups fed 5%, 10% and 15% of As. Light and electron microscopy observations were performed to localise junctional proteins: connexin-43, Zona Occluding-1 and N-cadherin (immunohistochemistry) and to describe junctions. We showed that the specific cells involved in the localisation of the SCJP were similar in both control and treated groups, but with different immunoreactivity intensity between them. The electron microscopy observation focused on TJs between Sertoli cells, constituting the blood-testis barrier, showed ultrastructural changes such as fragmentation of TJs between adjacent Sertoli cell membranes and dilatation of rough endoplasmic reticulum saccules giving an aspect of scale to these junctions. We concluded that crude garlic consumption during 1 month induces perturbations on Sertoli cell junctions. These alterations can explain apoptosis in testicular germ cells previously showed. © 2016 Blackwell Verlag GmbH.

  3. Impaired recovery and mutagenic SOS-like responses in ataxia telangiectasia cells

    Energy Technology Data Exchange (ETDEWEB)

    Hilgers, G. (Universite Libre de Bruxelles (Belgium) Rijksuniversiteit Leiden (Netherlands)); Abrahams, P.J. (Rijksuniversiteit Leiden (Netherlands)); Chen, Y.Q. (Universite Libre de Bruxelles (Belgium)); Schouten, R. (Rijksuniversiteit Leiden (Netherlands)); Cornelis, J.J. (Universite Libre de Bruxelles (Belgium) Institut Pasteur, 75 - Paris (France)); Lowe, J.E. (Sussex Univ., Brighton (UK)); Eb, A.J. van der (Rijksuniversiteit Leiden (Netherlands)); Rommelaere, J. (Universite Libre de Bruxelles (Belgium) Institut Pasteur, 75 - Paris (France))

    1989-01-01

    Radiosensitive fibroblasts from patients with ataxia telangiectasia (AT) were studied for their proficiency in two putative eukaryotic SOS-like responses, namely the enhanced reactivation (ER) and enhanced mutagenesis of damaged viruses infecting pre-irradiated versus mock-treated cells. A previous report indicated that, unlike normal human cells, a line of AT fibroblasts (AT5BIVA) could not be induced to express ER of damaged parvovirus H-1, a single-stranded DNA virus, by UV- or X-irradiation. In the present study, AT5BIVA fibroblasts were also distinguished from normal cells by the inability of the former to achieve enhanced mutagenesis of damaged H-1 virus upon cell UV-irradiation. In contrast, dose-response and time-course experiments revealed normal levels of ER of Herpes simplex virus 1, a double-stranded DNA virus, in X- or UV-irradiated AT5BIVA cells. Taken together, these data point to a possible deficiency of AT cells in a conditioned mutagenic process that contributes to a greater extent to the recovery of damaged single-stranded than double-stranded DNA. Such a defect may concern the replication of damaged DNA or the generation of signals promoting the latter process and may be related to the lack of radiation-induced delay that is typical of AT cell DNA synthesis. (author).

  4. Impaired recovery and mutagenic SOS-like responses in ataxia telangiectasia cells

    International Nuclear Information System (INIS)

    Hilgers, G.; Abrahams, P.J.; Chen, Y.Q.; Schouten, R.; Cornelis, J.J.; Lowe, J.E.; Eb, A.J. van der; Rommelaere, J.

    1989-01-01

    Radiosensitive fibroblasts from patients with ataxia telangiectasia (AT) were studied for their proficiency in two putative eukaryotic SOS-like responses, namely the enhanced reactivation (ER) and enhanced mutagenesis of damaged viruses infecting pre-irradiated versus mock-treated cells. A previous report indicated that, unlike normal human cells, a line of AT fibroblasts (AT5BIVA) could not be induced to express ER of damaged parvovirus H-1, a single-stranded DNA virus, by UV- or X-irradiation. In the present study, AT5BIVA fibroblasts were also distinguished from normal cells by the inability of the former to achieve enhanced mutagenesis of damaged H-1 virus upon cell UV-irradiation. In contrast, dose-response and time-course experiments revealed normal levels of ER of Herpes simplex virus 1, a double-stranded DNA virus, in X- or UV-irradiated AT5BIVA cells. Taken together, these data point to a possible deficiency of AT cells in a conditioned mutagenic process that contributes to a greater extent to the recovery of damaged single-stranded than double-stranded DNA. Such a defect may concern the replication of damaged DNA or the generation of signals promoting the latter process and may be related to the lack of radiation-induced delay that is typical of AT cell DNA synthesis. (author)

  5. Diclofenac and triamcinolone acetonide impair tenocytic differentiation and promote adipocytic differentiation of mesenchymal stem cells.

    Science.gov (United States)

    Fredriksson, Maritha; Li, Yan; Stålman, Anders; Haldosén, Lars-Arne; Felländer-Tsai, Li

    2013-09-02

    Tendinopathies are often empirically treated with oral/topical nonsteroidal anti-inflammatory medications and corticosteroid injections despite their unclear effects on tendon regeneration. Recent studies indicate that tendon progenitors exhibit stem cell-like properties, i.e., differentiation to osteoblasts, adipocytes, and chondrocytes, in addition to tenocytes. Our present study aims at understanding the effects of triamcinolone acetonide and diclofenac on tenocytic differentiation of mesenchymal stem cells. The murine fibroblast C3H10T1/2 cell line was induced to tenocytic differentiation by growth differentiation factor-7. Cell proliferation and differentiation with the exposure of different concentrations of triamcinolone acetonide and diclofenac were measured by WST-1 assay and real-time polymerase chain reaction analysis, respectively. Cell proliferation was decreased in a concentration-dependent manner when exposed to triamcinolone acetonide and diclofenac. In addition to tenocytic differentiation, adipocyte formation was observed, both at gene expression and microscopic level, when the cells were exposed to triamcinolone acetonide or high concentrations of diclofenac. Our results indicate that triamcinolone acetonide and diclofenac might alter mesenchymal stem cell differentiation in a nonfavorable way regarding tendon regeneration; therefore, these medicat