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Sample records for cells impairs cardiomyogenesis

  1. Lack of sik1 in mouse embryonic stem cells impairs cardiomyogenesis by down-regulating the cyclin-dependent kinase inhibitor p57kip2.

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    Antonio Romito

    Full Text Available Sik1 (salt inducible kinase 1 is a serine/threonine kinase that belongs to the stress- and energy-sensing AMP-activated protein kinase family. During murine embryogenesis, sik1 marks the monolayer of future myocardial cells that will populate first the primitive ventricle, and later the primitive atrium suggesting its involvement in cardiac cell differentiation and/or heart development. Despite that observation, the involvement of sik1 in cardiac differentiation is still unknown. We examined the sik1 function during cardiomyocyte differentiation using the ES-derived embryoid bodies. We produced a null embryonic stem cell using a gene-trap cell line carrying an insertion in the sik1 locus. In absence of the sik1 protein, the temporal appearance of cardiomyocytes is delayed. Expression profile analysis revealed sik1 as part of a genetic network that controls the cell cycle, where the cyclin-dependent kinase inhibitor p57(Kip2 is directly involved. Collectively, we provided evidence that sik1-mediated effects are specific for cardiomyogenesis regulating cardiomyoblast cell cycle exit toward terminal differentiation.

  2. Science Letters: Brain natriuretic peptide: A potential indicator of cardiomyogenesis after autologous mesenchymal stem cell transplantation?

    Institute of Scientific and Technical Information of China (English)

    LI Nan; WANG Jian-an

    2006-01-01

    We observed in a pilot study that there was a transient elevation of brain natriuretic peptide (BNP) level shortly after the transplantation in the patient with ischemic heart failure, which is unexplainable by the simultaneous increase of the cardiac output and six-minute walk distance. Similar findings were observed in the phase I trial. We postulated on the basis of the finding of Fukuda in vitro that this transient elevation of BNP level against the improvement of cardiac function and exercise capacity might indicate cardiomyogenesis in patients after mesenchymal stem cell transplantation. Further study is warranted to verify the hypothesis.

  3. Gremlin enhances the determined path to cardiomyogenesis.

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    Daisuke Kami

    Full Text Available BACKGROUND: The critical event in heart formation is commitment of mesodermal cells to a cardiomyogenic fate, and cardiac fate determination is regulated by a series of cytokines. Bone morphogenetic proteins (BMPs and fibroblast growth factors have been shown to be involved in this process, however additional factors needs to be identified for the fate determination, especially at the early stage of cardiomyogenic development. METHODOLOGY/PRINCIPAL FINDINGS: Global gene expression analysis using a series of human cells with a cardiomyogenic potential suggested Gremlin (Grem1 is a candidate gene responsible for in vitro cardiomyogenic differentiation. Grem1, a known BMP antagonist, enhanced DMSO-induced cardiomyogenesis of P19CL6 embryonal carcinoma cells (CL6 cells 10-35 fold in an area of beating differentiated cardiomyocytes. The Grem1 action was most effective at the early differentiation stage when CL6 cells were destined to cardiomyogenesis, and was mediated through inhibition of BMP2. Furthermore, BMP2 inhibited Wnt/beta-catenin signaling that promoted CL6 cardiomyogenesis. CONCLUSIONS/SIGNIFICANCE: Grem1 enhances the determined path to cardiomyogenesis in a stage-specific manner, and inhibition of the BMP signaling pathway is involved in initial determination of Grem1-promoted cardiomyogenesis. Our results shed new light on renewal of the cardiovascular system using Grem1 in human.

  4. Enhanced cardiomyogenesis of human embryonic stem cells by a small molecular inhibitor of p38 MAPK.

    NARCIS (Netherlands)

    Graichen, R.; Xu, X.; Braam, S.R.; Balakrishnan, T.; Norfiza, S.; Sieh, S.; Soo, S.Y.; Tham, S.C.; Mummery, C.L.; Colman, A.; Zweigerdt, R.; Davidson, B.P.

    2008-01-01

    Human embryonic stem cells (hESC) can differentiate to cardiomyocytes in vitro but with generally poor efficiency. Here, we describe a novel method for the efficient generation of cardiomyocytes from hESC in a scalable suspension culture process. Differentiation in serum-free medium conditioned by t

  5. mGluR5 stimulating Homer–PIKE formation initiates icariin induced cardiomyogenesis of mouse embryonic stem cells by activating reactive oxygen species

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    Zhou, Limin; Huang, Yujie; Zhang, Yingying [Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, No. 866, Yu Hang Tang Road, Hangzhou 310058 (China); Zhao, Qingwei [The First Affiliated Hospital, College of Medicine, Zhejiang University, No. 79, Qing Chun Road, Hangzhou 310003 (China); Zheng, Bei; Lou, Yijia [Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, No. 866, Yu Hang Tang Road, Hangzhou 310058 (China); Zhu, Danyan, E-mail: zdyzxb@zju.edu.cn [Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, No. 866, Yu Hang Tang Road, Hangzhou 310058 (China)

    2013-06-10

    Icariin (ICA) has been reported to facilitate cardiac differentiation of mouse embryonic stem (ES) cells; however, the mechanism by which ICA induced cardiomyogenesis has not been fully elucidated yet. Here, an underlying signaling network including metabotropic glutamate receptor 5 (mGluR5), Homer, phosphatidylinositol 3-Kinase Enhancer (PIKE), phosphatidylinositol 3-Kinase (PI3K), reactive oxygen species (ROS) and nuclear factor-kappaB (NF-κB) was investigated in ICA induced cardiomyogenesis. Our results showed that the co-expression of mGluR5 together with α-actinin or Troponin T in embryoid bodies (EBs) treated with ICA was elevated to 10.86% and 9.62%, compared with the case in the control (4.04% and 3.45%, respectively). Exposure of EBs to ICA for 2 h remarkably increased the dimeric form of mGluR5, which was inhibited by small interfering RNA targeting mGluR5 (si-mGluR5). Moreover, the extracellular glutamate concentration in ICA treatment medium was elevated to 28.9±3.5 μM. Furthermore, the activation of mGluR5 by ICA triggered the formation of Homer–PIKE complex and activated PI3K, stimulating ROS generation and NF-κB nuclear translocation. Knockdown of mGluR5 or inhibition of PI3K by LY294002 blocked ICA induced cardiomyogenesis via repressing mGluR5 pathway, reducing ROS and NF-κB activation. These results revealed that the inducible mechanisms of ICA were related to activate mGluR5 pathway. -- Highlights: • ICA increased mGluR5 expression in cardiac differentiation of ES cells. • ICA enhanced the glutamate level and the receptor mGluR5 dimerization, stimulating the formation of Homer–PIKE complex. • Knockdown of mGluR5 or inhibition of PI3K by LY294002 inhibited ICA induced ROS generation and NF-κB nuclear translocation.

  6. Parietal endoderm secreted S100A4 promotes early cardiomyogenesis in embryoid bodies

    DEFF Research Database (Denmark)

    Stary, Martina; Schneider, Mikael; Sheikh, Søren P;

    2006-01-01

    Cardiomyogenesis is influenced by factors secreted by anterior-lateral and extra-embryonic endoderm. Differentiation of embryonic stem cells in embryoid bodies allows to study the influence of growth factors on cardiomyogenesis. By these means SPARC was identified as a new factor enhancing...

  7. Cell-specific detection of microRNA expression during cardiomyogenesis by combined in situ hybridization and immunohistochemistry

    DEFF Research Database (Denmark)

    Schneider, Mikael; Andersen, Ditte Caroline; Silahtaroglu, Asli;

    2011-01-01

    in connective tissue cells of the heart. More specifically, by co-staining with a-smooth muscle actin (a-SMA) and collagen-I, we found that miR-125b and -199a localize to perivascular a-SMA(-) stromal cells. Our approach thus proved valid for determining cell-specific localization of miRNAs, and the findings we...

  8. ILK induces cardiomyogenesis in the human heart.

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    Alexandra Traister

    Full Text Available BACKGROUND: Integrin-linked kinase (ILK is a widely conserved serine/threonine kinase that regulates diverse signal transduction pathways implicated in cardiac hypertrophy and contractility. In this study we explored whether experimental overexpression of ILK would up-regulate morphogenesis in the human fetal heart. METHODOLOGY/PRINCIPAL FINDINGS: Primary cultures of human fetal myocardial cells (19-22 weeks gestation yielded scattered aggregates of cardioblasts positive for the early cardiac lineage marker nk × 2.5 and containing nascent sarcomeres. Cardiac cells in colonies uniformly expressed the gap junction protein connexin 43 (C × 43 and displayed a spectrum of differentiation with only a subset of cells exhibiting the late cardiomyogenic marker troponin T (cTnT and evidence of electrical excitability. Adenovirus-mediated overexpression of ILK potently increased the number of new aggregates of primitive cardioblasts (p<0.001. The number of cardioblast colonies was significantly decreased (p<0.05 when ILK expression was knocked down with ILK targeted siRNA. Interestingly, overexpression of the activation resistant ILK mutant (ILK(R211A resulted in much greater increase in the number of new cell aggregates as compared to overexpression of wild-type ILK (ILK(WT. The cardiomyogenic effects of ILK(R211A and ILK(WT were accompanied by concurrent activation of β-catenin (p<0.001 and increase expression of progenitor cell marker islet-1, which was also observed in lysates of transgenic mice with cardiac-specific over-expression of ILK(R211A and ILK(WT. Finally, endogenous ILK expression was shown to increase in concert with those of cardiomyogenic markers during directed cardiomyogenic differentiation in human embryonic stem cells (hESCs. CONCLUSIONS/SIGNIFICANCE: In the human fetal heart ILK activation is instructive to the specification of mesodermal precursor cells towards a cardiomyogenic lineage. Induction of cardiomyogenesis by ILK

  9. Impaired Leydig cell function in infertile men

    DEFF Research Database (Denmark)

    Andersson, A-M; Jørgensen, N; Frydelund-Larsen, L;

    2004-01-01

    of the fertile levels.Thus, the group of infertile men showed significant signs of impaired Leydig cell function in parallel to their impaired spermatogenesis. The association of decreased spermatogenesis and impaired Leydig cell function might reflect a disturbed paracrine communication between the seminiferous...

  10. Cardiac neural crest contributes to cardiomyogenesis in zebrafish.

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    Sato, Mariko; Yost, H Joseph

    2003-05-01

    In birds and mammals, cardiac neural crest is essential for heart development and contributes to conotruncal cushion formation and outflow tract septation. The zebrafish prototypical heart lacks outflow tract septation, raising the question of whether cardiac neural crest exists in zebrafish. Here, results from three distinct lineage-labeling approaches identify zebrafish cardiac neural crest cells and indicate that these cells have the ability to generate MF20-positive muscle cells in the myocardium of the major chambers during development. Fate-mapping demonstrates that cardiac neural crest cells originate both from neural tube regions analogous to those found in birds, as well as from a novel region rostral to the otic vesicle. In contrast to other vertebrates, cardiac neural crest invades the myocardium in all segments of the heart, including outflow tract, atrium, atrioventricular junction, and ventricle in zebrafish. Three distinct groups of premigratory neural crest along the rostrocaudal axis have different propensities to contribute to different segments in the heart and are correspondingly marked by unique combinations of gene expression patterns. Zebrafish will serve as a model for understanding interactions between cardiac neural crest and cardiovascular development.

  11. Impaired regulatory B cells in myasthenia gravis.

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    Sheng, Jian Rong; Rezania, Kourosh; Soliven, Betty

    2016-08-15

    Regulatory B cells (Bregs) attenuate the severity of experimental autoimmune myasthenia gravis (EAMG) in an interleukin-10 (IL-10)-dependent manner. The goal of this study was to investigate the role of human Bregs in MG focusing on CD19(+)CD1d(hi) CD5(+) and CD19(+)CD24(hi)CD38(hi) subsets. We found that MG patients exhibited a decrease in the frequency of both Breg subsets and IL-10 producing B cells within each subset, which correlated with disease severity. In addition, there was impaired suppression of Th1 polarization in MG. These findings, taken together with EAMG data, indicate that Bregs play an important role in regulating the severity of MG. PMID:27397074

  12. Impaired DNA replication within progenitor cell pools promotes leukemogenesis.

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    Ganna Bilousova

    2005-12-01

    Full Text Available Impaired cell cycle progression can be paradoxically associated with increased rates of malignancies. Using retroviral transduction of bone marrow progenitors followed by transplantation into mice, we demonstrate that inhibition of hematopoietic progenitor cell proliferation impairs competition, promoting the expansion of progenitors that acquire oncogenic mutations which restore cell cycle progression. Conditions that impair DNA replication dramatically enhance the proliferative advantage provided by the expression of Bcr-Abl or mutant p53, which provide no apparent competitive advantage under conditions of healthy replication. Furthermore, for the Bcr-Abl oncogene the competitive advantage in contexts of impaired DNA replication dramatically increases leukemogenesis. Impaired replication within hematopoietic progenitor cell pools can select for oncogenic events and thereby promote leukemia, demonstrating the importance of replicative competence in the prevention of tumorigenesis. The demonstration that replication-impaired, poorly competitive progenitor cell pools can promote tumorigenesis provides a new rationale for links between tumorigenesis and common human conditions of impaired DNA replication such as dietary folate deficiency, chemotherapeutics targeting dNTP synthesis, and polymorphisms in genes important for DNA metabolism.

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

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    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...

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

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    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.

  15. Lack of vimentin impairs endothelial differentiation of embryonic stem cells.

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    Boraas, Liana C; Ahsan, Tabassum

    2016-01-01

    The cytoskeletal filament vimentin is inherent to the endothelial phenotype and is critical for the proper function of endothelial cells in adult mice. It is unclear, however, if the presence of vimentin is necessary during differentiation to the endothelial phenotype. Here we evaluated gene and protein expression of differentiating wild type embryonic stem cells (WT ESCs) and vimentin knockout embryonic stem cells (VIM -/- ESCs) using embryoid bodies (EBs) formed from both cell types. Over seven days of differentiation VIM -/- EBs had altered morphology compared to WT EBs, with a rippled outer surface and a smaller size due to decreased proliferation. Gene expression of pluripotency markers decreased similarly for EBs of both cell types; however, VIM -/- EBs had impaired differentiation towards the endothelial phenotype. This was quantified with decreased expression of markers along the specification pathway, specifically the early mesodermal marker Brachy-T, the lateral plate mesodermal marker FLK1, and the endothelial-specific markers TIE2, PECAM, and VE-CADHERIN. Taken together, these results indicate that the absence of vimentin impairs spontaneous differentiation of ESCs to the endothelial phenotype in vitro. PMID:27480130

  16. Hepatitis B virus antigens impair NK cell function.

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    Yang, Yinli; Han, Qiuju; Zhang, Cai; Xiao, Min; Zhang, Jian

    2016-09-01

    An inadequate immune response of the host is thought to be a critical factor causing chronic hepatitis B virus (CHB) infection. Natural killer (NK) cells, as one of the key players in the eradication and control of viral infections, were functionally impaired in CHB patients, which might contribute to viral persistence. Here, we reported that HBV antigens HBsAg and HBeAg directly inhibited NK cell function. HBsAg and/or HBeAg blocked NK cell activation, cytokine production and cytotoxic granule release in human NK cell-line NK-92 cells, which might be related to the downregulation of activating receptors and upregulation of inhibitory receptor. Furthermore, the underlying mechanisms likely involved the suppression of STAT1, NF-κB and p38 MAPK pathways. These findings implicated that HBV antigen-mediated inhibition of NK cells might be an efficient strategy for HBV evasion, targeting the early antiviral responses mediated by NK cells and resulting in the establishment of chronic virus infection. Therefore, this study revealed the relationship between viral antigens and human immune function, especially a potential important interaction between HBV and innate immune responses. PMID:27341035

  17. Impairment of T cell function in parasitic infections.

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    Vasco Rodrigues

    2014-02-01

    Full Text Available In mammals subverted as hosts by protozoan parasites, the latter and/or the agonists they release are detected and processed by sensors displayed by many distinct immune cell lineages, in a tissue(s-dependent context. Focusing on the T lymphocyte lineage, we review our present understanding on its transient or durable functional impairment over the course of the developmental program of the intracellular parasites Leishmania spp., Plasmodium spp., Toxoplasma gondii, and Trypanosoma cruzi in their mammalian hosts. Strategies employed by protozoa to down-regulate T lymphocyte function may act at the initial moment of naïve T cell priming, rendering T cells anergic or unresponsive throughout infection, or later, exhausting T cells due to antigen persistence. Furthermore, by exploiting host feedback mechanisms aimed at maintaining immune homeostasis, parasites can enhance T cell apoptosis. We will discuss how infections with prominent intracellular protozoan parasites lead to a general down-regulation of T cell function through T cell anergy and exhaustion, accompanied by apoptosis, and ultimately allowing pathogen persistence.

  18. Abnormal Cell Responses and Role of TNF-α in Impaired Diabetic Wound Healing

    OpenAIRE

    Fanxing Xu; Chenying Zhang; Graves, Dana T.

    2013-01-01

    Impaired diabetic wound healing constitutes a major health problem. The impaired healing is caused by complex factors such as abnormal keratinocyte and fibroblast migration, proliferation, differentiation, and apoptosis, abnormal macrophage polarization, impaired recruitment of mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs), and decreased vascularization. Diabetes-enhanced and prolonged expression of TNF- α also contributes to impaired healing. In this paper, we discuss...

  19. Glycation of extracellular matrix proteins impairs migration of immune cells.

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    Haucke, Elisa; Navarrete-Santos, Alexander; Simm, Andreas; Silber, Rolf-Edgar; Hofmann, Britt

    2014-01-01

    The immune response during aging and diabetes is disturbed and may be due to the altered migration of immune cells in an aged tissue. Our study should prove the hypothesis that age and diabetes-related advanced glycation end products (AGEs) have an impact on the migration and adhesion of human T-cells. To achieve our purpose, we used in vitro AGE-modified proteins (soluble albumin and fibronectin [FN]), as well as human collagen obtained from bypass graft. A Boyden chamber was used to study cell migration. Migrated Jurkat T-cells were analyzed by flow cytometry and cell adhesion by crystal violet staining. Actin polymerization was determined by phalloidin-Alexa-fluor 488-labeled antibody and fluorescence microscopy. We found that significantly fewer cells (50%, p = 0.003) migrated through methylglyoxal modified FN. The attachment to FN in the presence of AGE-bovine serum albumin (BSA) was also reduced (p < 0.05). In ex vivo experiments, isolated collagen from human vein graft material negatively affected the migration of the cells depending on the grade of AGE modification of the collagen. Collagen with a low AGE level reduced the cell migration by 30%, and collagen with a high AGE level by 60%. Interaction of the cells with an AGE-modified matrix, but not with soluble AGEs like BSA-AGE per se, was responsible for a disturbed migration. The reduced migration was accompanied by an impaired actin polymerization. We conclude that AGEs-modified matrix protein inhibits cell migration and adhesion of Jurkat T-cells.

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

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    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

  1. The endocannabinoid anandamide impairs in vitro decidualization of human cells.

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    Almada, M; Amaral, C; Diniz-da-Costa, M; Correia-da-Silva, G; Teixeira, N A; Fonseca, B M

    2016-10-01

    Endocannabinoids (eCBs) are endogenous mediators that along with the cannabinoid receptors (CB1 and CB2), a membrane transporter and metabolic enzymes form the endocannabinoid system (ECS). Several eCBs have been discovered with emphasis on anandamide (AEA). They are involved in several biological processes such as energy balance, immune response and reproduction. Decidualization occurs during the secretory phase of human menstrual cycle, which involves proliferation and differentiation of endometrial stromal cells into decidual cells and is crucial for the establishment and progression of pregnancy. In this study, a telomerase-immortalized human endometrial stromal cell line (St-T1b) and non-differentiated primary cultures of human decidual fibroblasts from term placenta were used to characterize the ECS using immunoblotting and qRT-PCR techniques. It was shown that St-T1b cells express CB1, but not CB2, and that both receptors are expressed in HdF cells. Furthermore, the expression of fatty acid amide hydrolase (FAAH), the main degrading enzyme of AEA, increased during stromal cell differentiation. AEA inhibited cell proliferation, through deregulation of cell cycle progression and induced polyploidy. Moreover, through CB1 binding receptor, AEA also impaired cell differentiation. Therefore, AEA is proposed as a modulator of human decidualization. Our findings may provide wider implications, as deregulated levels of AEA, due to Cannabis sativa consumption or altered expression of the metabolic enzymes, may negatively regulate human endometrial stromal cell decidualization with an impact on human (in)fertility.Free Portuguese abstract: A Portuguese translation of this abstract is freely available at http://www.reproduction-online.org/content/152/4/351/suppl/DC1. PMID:27568210

  2. Diabetes Impairs Stem Cell and Proangiogenic Cell Mobilization in Humans

    OpenAIRE

    Fadini, Gian Paolo; Albiero, Mattia; Vigili de Kreutzenberg, Saula; Boscaro, Elisa; Cappellari, Roberta; Marescotti, Mariacristina; Poncina, Nicol; Agostini, Carlo; Avogaro, Angelo

    2013-01-01

    OBJECTIVE Diabetes mellitus (DM) increases cardiovascular risk, at least in part, through shortage of vascular regenerative cells derived from the bone marrow (BM). In experimental models, DM causes morphological and functional BM alterations, but information on BM function in human DM is missing. Herein, we sought to assay mobilization of stem and proangiogenic cells in subjects with and without DM. RESEARCH DESIGN AND METHODS In a prospective trial (NCT01102699), we tested BM responsiveness...

  3. Effects of Synthetic Neural Adhesion Molecule Mimetic Peptides and Related Proteins on the Cardiomyogenic Differentiation of Mouse Embryonic Stem Cells

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    Ruodan Xu

    2015-04-01

    Full Text Available Background/Aims: Pluripotent stem cells differentiating into cardiomyocyte-like cells in an appropriate cellular environment have attracted significant attention, given the potential use of such cells for regenerative medicine. However, the precise mechanisms of lineage specification of pluripotent stem cells are still largely to be explored. Identifying the role of various small synthetic peptides involved in cardiomyogenesis may provide new insights into pathways promoting cardiomyogenesis. Methods: In the present study, using a transgenic murine embryonic stem (ES cell lineage expressing enhanced green fluorescent protein (EGFP under the control of α-myosin heavy chain (α-MHC promoter (pαMHC-EGFP, we investigated the cardiomyogenic effects of 7 synthetic peptides (Betrofin3, FGLs, FGLL, hNgf_C2, EnkaminE, Plannexin and C3 on cardiac differentiation. The expression of several cardiac-specific markers was determined by RT-PCR whereas the structural and functional properties of derived cardiomyocytes were examined by immunofluorescence and electrophysiology, respectively. Results: The results revealed that Betrofin3, an agonist of brain derived neurotrophic factor (BDNF peptide exerted the most striking pro-cardiomyogenic effect on ES cells. We found that BDNF receptor, TrkB expression was up-regulated during differentiation. Treatment of differentiating cells with Betrofin3 between days 3 and 5 enhanced the expression of cardiac-specific markers and improved cardiomyocyte differentiation and functionality as revealed by genes regulation, flow cytometry and patch clamp analysis. Thus Betrofin3 may exert its cardiomyogenic effects on ES cells via TrkB receptor. Conclusion: Taken together, the results suggest that Betrofin3 modulates BDNF signaling with positive cardiomyogenic effect in stage and dose-dependent manner providing an effective strategy to increase ES cell-based generation of cardiomyocytes and offer a novel therapeutic approach to

  4. Impairment of mesenchymal stem cells derived from oral leukoplakia.

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    Zhang, Zhihui; Song, Jiangyuan; Han, Ying; Mu, Dongdong; Su, Sha; Ji, Xiaoli; Liu, Hongwei

    2015-01-01

    Oral leukoplakia is one of the common precancerous lesions in oral mucosa. To compare the biological characteristics and regenerative capacities of mesenchymal stem cells (MSCs) from oral leukoplakia (epithelial hyperplasia and dysplasia) and normal oral mucosa, MSCs were isolated by enzyme digestion. Then these cells were identified by the expression of MSC related markers, STRO-1, CD105 and CD90, with the absent for the hematopoietic stem cell marker CD34 by flow cytometric detection. The self-renewal ability of MSCs from oral leukoplakia was enhanced, while the multipotent differentiation was descended, compared with MSCs from normal oral mucosa. Fibrin gel was used as a carrier for MSCs transplanted into immunocompromised mice to detect their regenerative capacity. The regenerative capacities of MSCs from oral leukoplakia became impaired partly. Collagen IV (Col IV) and matrix metalloproteinases-9 (MMP-9) were selected to analyze the potential mechanism for the functional changes of MSCs from oral leukoplakia by immunochemical and western blot analysis. The expression of Col IV was decreased and that of MMP-9 was increased by MSCs with the progression of oral leukoplakia, especially in MSCs from epithelial dysplasia. The imbalance between regenerative and metabolic self-regulatory functions of MSCs from oral leukoplakia may be related to the progression of this premalignant disorder.

  5. Abnormal Cell Responses and Role of TNF-α in Impaired Diabetic Wound Healing

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    Fanxing Xu

    2013-01-01

    Full Text Available Impaired diabetic wound healing constitutes a major health problem. The impaired healing is caused by complex factors such as abnormal keratinocyte and fibroblast migration, proliferation, differentiation, and apoptosis, abnormal macrophage polarization, impaired recruitment of mesenchymal stem cells (MSCs and endothelial progenitor cells (EPCs, and decreased vascularization. Diabetes-enhanced and prolonged expression of TNF-α also contributes to impaired healing. In this paper, we discuss the abnormal cell responses in diabetic wound healing and the contribution of TNF-α.

  6. Myeloid-derived suppressor cells impair the quality of dendritic cell vaccines.

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    Poschke, I; Mao, Y; Adamson, L; Salazar-Onfray, F; Masucci, G; Kiessling, R

    2012-06-01

    Myeloid-derived suppressor cells (MDSC) are important regulators of the immune system and key players in tumor-induced suppression of T-cell responses. CD14+HLA-DR-/low MDSC have been detected in a great number of malignancies, including melanoma. MDSC are known to be impaired in their ability to differentiate along the myeloid lineage, e.g., into dendritic cells (DC). This is a concern for utilization of monocyte-derived DC for vaccination of patients with melanoma or other cancers exhibiting accumulation of CD14+ MDSC. When producing DC according to standard operating procedures of two currently ongoing clinical trials, we found that MDSC co-purified with monocytes isolated by elutriation. MDSC frequencies did not affect yield or viability of the produced DC, but induced a dose-dependent decrease in DC maturation, ability to take up antigen, migrate and induce T-cell IFNγ production. Changes in DC characteristics were most notable when 'pathological' frequencies of >50% CD14+HLA-DR- cells were present in the starting culture. The impaired DC quality could not be explained by altered cytokine production or increased oxidative stress in the cultures. Tracking of HLA-DR- cells throughout the culture period revealed that the observed changes were partially due to the impaired maturation and functionality of the originally HLA-DR- population, but also to their negative effects on HLA-DR+ cells. In conclusion, MDSC could be induced to differentiate into DC but, due to the impairment of overall DC vaccine quality when >50% HLA-DR- cells were present in the starting culture, their removal could be advisable.

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

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    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.

  8. Neural Stem Cell Grafting Counteracts Hippocampal Injury-Mediated Impairments in Mood, Memory, and Neurogenesis

    OpenAIRE

    Hattiangady, Bharathi; Shetty, Ashok K.

    2012-01-01

    Hippocampal injury typically leads to mood and memory impairments associated with reduced and aberrant neurogenesis in the dentate gyrus. This study examined whether subventricular zone-neural stem cell (SVZ-NSC) grafting after hippocampal injury would counteract impairments in mood, memory, and neurogenesis. Analyses through forced swim, water maze, and novel object recognition tests revealed significant impairments in mood and memory function in animals that underwent injury and sham-grafti...

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

    Directory of Open Access Journals (Sweden)

    Hua Shen

    Full Text Available BACKGROUND: 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. PRINCIPAL FINDINGS: 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. CONCLUSION: Aging impairs recipient responses, both T cell intrinsic and extrinsic, in response to organ transplantation.

  10. 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...

  11. 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

  12. Impairment of cell cycle progression by aflatoxin B1 in human cell lines.

    Science.gov (United States)

    Ricordy, R; Gensabella, G; Cacci, E; Augusti-Tocco, G

    2002-05-01

    Aflatoxin B1 is a mycotoxin produced by Aspergillus flavus and Aspergillus parasiticum, which may be present as a food contaminant. It is known to cause acute toxic effects and act as a carcinogenic agent. The carcinogenic action has been related to its ability to form unstable adducts with DNA, which represent possible mutagenic sites. On the other hand, the primary cellular target responsible for its toxic action has not yet been clearly identified. Previous data suggested a possible correlation between cell proliferation and responsiveness to aflatoxin toxicity. These observations led us to investigate the effect of the toxin on cell cycle progression of three human cell lines (HepG2, SK-N-MC and SK-N-SH derived from liver and nervous tissue tumours); they were shown to display different responses to toxin exposure and have different growth kinetics. We performed analysis of the cell cycle, DNA synthesis and expression of p21 and p53 in the presence and absence of the toxin in all cell lines exposed. The results of cell cycle cytofluorometric analysis show significant alterations of cell cycle progression as a result of toxin treatment. In all cell lines exposure to a 24 h toxin treatment causes a dose-dependent accumulation in S phase, however, the ability to recover from impairment to traverse S phase varies in the cell lines under study. SK-N-MC cells appear more prone to resume DNA synthesis when the toxin is removed, while the other two cell lines maintain a significant inhibition of DNA synthesis, as indicated by cytofluorimetry and [(3)H]dTR incorporation. The level of p53 and p21 expression in the three cell lines was examined by western blot analysis and significant differences were detected. The ready resumption of DNA synthesis displayed by SK-N-MC cells could possibly be related to the absence of p53 control of cell cycle progression.

  13. Impaired germ cell development due to compromised cell cycle progression in Skp2-deficient mice

    Directory of Open Access Journals (Sweden)

    Nakayama Keiko

    2006-04-01

    Full Text Available Abstract Background The gonads are responsible for the production of germ cells through both mitosis and meiosis. Skp2 is the receptor subunit of an SCF-type ubiquitin ligase and is a major regulator of the progression of cells into S phase of the cell cycle, which it promotes by mediating the ubiquitin-dependent degradation of p27, an inhibitor of cell proliferation. However, the role of the Skp2-p27 pathway in germ cell development remains elusive. Results We now show that disruption of Skp2 in mice results in a marked impairment in the fertility of males, with the phenotypes resembling Sertoli cell-only syndrome in men. Testes of Skp2-/- mice manifested pronounced germ cell hypoplasia accompanied by massive apoptosis in spermatogenic cells. Flow cytometry revealed an increased prevalence of polyploidy in spermatozoa, suggesting that the aneuploidy of these cells is responsible for the induction of apoptosis. Disruption of the p27 gene of Skp2-/- mice restored germ cell development, indicating that the testicular hypoplasia of Skp2-/- animals is attributable to the antiproliferative effect of p27 accumulation. Conclusion Our results thus suggest that compromised cell cycle progression caused by the accumulation of p27 results in aneuploidy and the induction of apoptosis in gonadal cells of Skp2-/- mice. The consequent reduction in the number of mature gametes accounts for the decreased fertility of these animals. These findings reinforce the importance of the Skp2-p27 pathway in cell cycle regulation and in germ cell development.

  14. Impaired NK Cell Activation and Chemotaxis toward Dendritic Cells Exposed to Complement-Opsonized HIV-1

    Science.gov (United States)

    Ellegård, Rada; Crisci, Elisa; Andersson, Jonas; Shankar, Esaki M.; Nyström, Sofia; Hinkula, Jorma

    2015-01-01

    Mucosa resident dendritic cells (DCs) may represent one of the first immune cells that HIV-1 encounters during sexual transmission. The virions in body fluids can be opsonized with complement factors because of HIV-mediated triggering of the complement cascade, and this appears to influence numerous aspects of the immune defense targeting the virus. One key attribute of host defense is the ability to attract immune cells to the site of infection. In this study, we investigated whether the opsonization of HIV with complement (C-HIV) or a mixture of complement and Abs (CI-HIV) affected the cytokine and chemokine responses generated by DCs, as well as their ability to attract other immune cells. We found that the expression levels of CXCL8, CXCL10, CCL3, and CCL17 were lowered after exposure to either C-HIV or CI-HIV relative to free HIV (F-HIV). DCs exposed to F-HIV induced higher cell migration, consisting mainly of NK cells, compared with opsonized virus, and the chemotaxis of NK cells was dependent on CCL3 and CXCL10. NK cell exposure to supernatants derived from HIV-exposed DCs showed that F-HIV induced phenotypic activation (e.g., increased levels of TIM3, CD69, and CD25) and effector function (e.g., production of IFNγ and killing of target cells) in NK cells, whereas C-HIV and CI-HIV did not. The impairment of NK cell recruitment by DCs exposed to complement-opsonized HIV and the lack of NK activation may contribute to the failure of innate immune responses to control HIV at the site of initial mucosa infection. PMID:26157174

  15. 5-Azacytidine Is Insufficient For Cardiogenesis In Human Adipose-Derived Stem Cells

    OpenAIRE

    Wan Safwani Wan Kamarul Zaman; Makpol Suzana; Sathapan Somasundaram; Chua Kien

    2012-01-01

    Abstract Background Adipose tissue is a source of multipotent adult stem cells and it has the ability to differentiate into several types of cell lineages such as neuron cells, osteogenic cells and adipogenic cells. Several reports have shown adipose-derived stem cells (ASCs) have the ability to undergo cardiomyogenesis. Studies have shown 5-azacytidine can successfully drive stem cells such as bone marrow derived stem cells to differentiate into cardiomyogenic cells. Therefore, in this study...

  16. Visualizing Without Vision at the Microscale: Students With Visual Impairments Explore Cells With Touch

    Science.gov (United States)

    Jones, M. Gail; Minogue, James; Oppewal, Tom; Cook, Michelle P.; Broadwell, Bethany

    2006-12-01

    Science instruction is typically highly dependent on visual representations of scientific concepts that are communicated through textbooks, teacher presentations, and computer-based multimedia materials. Little is known about how students with visual impairments access and interpret these types of visually-dependent instructional materials. This study explored the efficacy of new haptic (simulated tactile feedback and kinesthetics) instructional technology for teaching cell morphology and function to middle and high school students with visual impairments. The study examined students' prior experiences learning about the cell and cell functions in classroom instruction, as well as how haptic feedback technology impacted students' awareness of the 3-D nature of an animal cell, the morphology and function of cell organelles, and students' interest in the haptic technology as an instructional tool. Twenty-one students with visual impairment participated in the study. Students explored a tactile model of the cell with a haptic point probe that allowed them to feel the cell and its organelles. Results showed that students made significant gains in their ability to identify cell organelles and found the technology to be highly interesting as an instructional tool. The need for additional adaptive technology for students with visual impairments is discussed.

  17. 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

    2005-01-01

    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

  18. Impairment of mesenchymal stem cells derived from oral leukoplakia

    OpenAIRE

    Zhang, Zhihui; Song, Jiangyuan; Han, Ying; Mu, Dongdong; Su, Sha; Ji, Xiaoli; Liu, Hongwei

    2015-01-01

    Oral leukoplakia is one of the common precancerous lesions in oral mucosa. To compare the biological characteristics and regenerative capacities of mesenchymal stem cells (MSCs) from oral leukoplakia (epithelial hyperplasia and dysplasia) and normal oral mucosa, MSCs were isolated by enzyme digestion. Then these cells were identified by the expression of MSC related markers, STRO-1, CD105 and CD90, with the absent for the hematopoietic stem cell marker CD34 by flow cytometric detection. The s...

  19. Memory T cell–driven differentiation of naive cells impairs adoptive immunotherapy

    Science.gov (United States)

    Klebanoff, Christopher A.; Scott, Christopher D.; Leonardi, Anthony J.; Yamamoto, Tori N.; Cruz, Anthony C.; Ouyang, Claudia; Ramaswamy, Madhu; Roychoudhuri, Rahul; Ji, Yun; Eil, Robert L.; Sukumar, Madhusudhanan; Crompton, Joseph G.; Palmer, Douglas C.; Borman, Zachary A.; Clever, David; Thomas, Stacy K.; Patel, Shashankkumar; Yu, Zhiya; Muranski, Pawel; Liu, Hui; Wang, Ena; Marincola, Francesco M.; Gros, Alena; Gattinoni, Luca; Rosenberg, Steven A.; Siegel, Richard M.; Restifo, Nicholas P.

    2015-01-01

    Adoptive cell transfer (ACT) of purified naive, stem cell memory, and central memory T cell subsets results in superior persistence and antitumor immunity compared with ACT of populations containing more-differentiated effector memory and effector T cells. Despite a clear advantage of the less-differentiated populations, the majority of ACT trials utilize unfractionated T cell subsets. Here, we have challenged the notion that the mere presence of less-differentiated T cells in starting populations used to generate therapeutic T cells is sufficient to convey their desirable attributes. Using both mouse and human cells, we identified a T cell–T cell interaction whereby antigen-experienced subsets directly promote the phenotypic, functional, and metabolic differentiation of naive T cells. This process led to the loss of less-differentiated T cell subsets and resulted in impaired cellular persistence and tumor regression in mouse models following ACT. The T memory–induced conversion of naive T cells was mediated by a nonapoptotic Fas signal, resulting in Akt-driven cellular differentiation. Thus, induction of Fas signaling enhanced T cell differentiation and impaired antitumor immunity, while Fas signaling blockade preserved the antitumor efficacy of naive cells within mixed populations. These findings reveal that T cell subsets can synchronize their differentiation state in a process similar to quorum sensing in unicellular organisms and suggest that disruption of this quorum-like behavior among T cells has potential to enhance T cell–based immunotherapies. PMID:26657860

  20. NOV/CCN3 impairs muscle cell commitment and differentiation.

    Science.gov (United States)

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

    2006-06-10

    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.

  1. 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

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

    Directory of Open Access Journals (Sweden)

    Sekar Natesampillai

    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.

  3. 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.

  4. Interleukin-8 transcripts in mononuclear cells determine impaired graft function after kidney transplantation

    DEFF Research Database (Denmark)

    Borst, Christoffer; Xia, Shengqiang; Bistrup, Claus;

    2015-01-01

    OBJECTIVE: Interleukin-8 (IL-8) has been associated with ischemia reperfusion injury after renal allograft transplantation. Impaired allograft function may cause major impact on patient morbidity and health care costs. We investigated whether transcript levels in mononuclear cells including IL-8...

  5. Regulatory T cell reprogramming toward a Th2-cell-like lineage impairs oral tolerance and promotes food allergy.

    Science.gov (United States)

    Noval Rivas, Magali; Burton, Oliver T; Wise, Petra; Charbonnier, Louis-Marie; Georgiev, Peter; Oettgen, Hans C; Rachid, Rima; Chatila, Talal A

    2015-03-17

    Oral immunotherapy has had limited success in establishing tolerance in food allergy, reflecting failure to elicit an effective regulatory T (Treg) cell response. We show that disease-susceptible (Il4ra(F709)) mice with enhanced interleukin-4 receptor (IL-4R) signaling exhibited STAT6-dependent impaired generation and function of mucosal allergen-specific Treg cells. This failure was associated with the acquisition by Treg cells of a T helper 2 (Th2)-cell-like phenotype, also found in peripheral-blood allergen-specific Treg cells of food-allergic children. Selective augmentation of IL-4R signaling in Treg cells induced their reprogramming into Th2-like cells and disease susceptibility, whereas Treg-cell-lineage-specific deletion of Il4 and Il13 was protective. IL-4R signaling impaired the capacity of Treg cells to suppress mast cell activation and expansion, which in turn drove Th2 cell reprogramming of Treg cells. Interruption of Th2 cell reprogramming of Treg cells might thus provide candidate therapeutic strategies in food allergy. PMID:25769611

  6. 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

    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 and peri...

  7. Abnormal mitochondrial function impairs calcium influx in diabetic mouse pancreatic beta cells

    Institute of Scientific and Technical Information of China (English)

    LI Fei; D. Marshall Porterfield; ZHENG Xi-yan; WANG Wen-jun; XU Yue; ZHANG Zong-ming

    2012-01-01

    Background Abnormal insulin secretion of pancreatic beta cells is now regarded as the more primary defect than the insulin function in the etiology of type 2 diabetes.Previous studies found impaired mitochondrial function and impaired Ca2+ influx in beta cells in diabetic patients and animal models,suggesting a role for these processes in proper insulin secretion.The aim of this study was to investigate the detailed relationship of mitochondrial function,Ca2+ influx,and defective insulin secretion.Methods We investigated mitochondrial function and morphology in pancreatic beta cell of diabetic KK-Ay mice and C57BL/6J mice.Two types of Ca2+ channel activities,L-type and store-operated Ca2+ (SOC),were evaluated using whole-cell patch-clamp recording.The glucose induced Ca2+ influx was measured by a non-invasive micro-test technique (NMT).Results Mitochondria in KK-Ay mice pancreatic beta cells were swollen with disordered cristae,and mitochondrial function decreased compared with C57BL/6J mice.Ca2+ channel activity was increased and glucose induced Ca2+ influx was impaired,but could be recovered by genipin.Conclusion Defective mitochondrial function in diabetic mice pancreatic beta cells is a key cause of abnormal insulin secretion by altering Ca2+ influx,but not via Ca2+ channel activity.

  8. 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.

  9. Adding Fludarabine to Cyclophophamide-dexamethason induction therapy impair stem cell harvest in MM

    DEFF Research Database (Denmark)

    Johnsen, Hans Erik; Meldgaard Knudsen, Lene; Mylin, Anne Kærsgaard;

    of 34 of planned 80 patients due to a reduced number of patients (4/17) actually harvested in the experimental arm compared to the control arm (11/17; ptherapy impairs stem cell mobilization and standard therapy...... the bone marrow. The pathophysiological significance of these cells is unknown, but hypothetically they may serve as "sleeping" myeloma stem cells responsible for and "feeding" post-treatment relapse and disease progression. The impact of chemotherapy resistant B cells in MM needs to be evaluated......BACKGROUND AND OBJECTIVES Recent data have indicated that the myeloma cell hierarchy includes resistant Recent data have indicated that the myeloma cell hierarchy includes resistant circulating clonal memory B cells, which differ considerably from the classical end stage plasma cells infiltrating...

  10. 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 BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

  11. Yeast cells with impaired drug resistance accumulate glycerol and glucose.

    Science.gov (United States)

    Dikicioglu, Duygu; Oc, Sebnem; Rash, Bharat M; Dunn, Warwick B; Pir, Pınar; Kell, Douglas B; Kirdar, Betul; Oliver, Stephen G

    2014-01-01

    Multiple drug resistance (MDR) in yeast is effected by two major superfamilies of membrane transporters: the major facilitator superfamily (MFS) and the ATP-binding cassette (ABC) superfamily. In the present work, we investigated the cellular responses to disruptions in both MFS (by deleting the transporter gene, QDR3) and ABC (by deleting the gene for the Pdr3 transcription factor) transporter systems by growing diploid homozygous deletion yeast strains in glucose- or ammonium-limited continuous cultures. The transcriptome and the metabolome profiles of these strains, as well as the flux distributions in the optimal solution space, reveal novel insights into the underlying mechanisms of action of QDR3 and PDR3. Our results show how cells rearrange their metabolism to cope with the problems that arise from the loss of these drug-resistance genes, which likely evolved to combat chemical attack from bacterial or fungal competitors. This is achieved through the accumulation of intracellular glucose, glycerol, and inorganic phosphate, as well as by repurposing genes that are known to function in other parts of metabolism in order to minimise the effects of toxic compounds. PMID:24157722

  12. Reduced hippocampal dentate cell proliferation and impaired spatial memory performance in aged epileptic rats

    Directory of Open Access Journals (Sweden)

    Clarissa F Cavarsan

    2013-07-01

    Full Text Available Increased adult neurogenesis is observed after training in hippocampal-dependent tasks and also after acutely induced status epilepticus (SE although the specific roles of these cells are still a matter of debate. In this study, we investigated hippocampal cell proliferation and differentiation and the spatial learning performance in young or aged chronically epileptic rats. Status was induced by pilocarpine in 3 or 20-month old rats. Either two or twenty months later, rats were treated with bromodeoxyuridine (BrdU and subsequently underwent to 8-day schedule of water maze tests. As expected, learning curves were faster in young than in aged animals (P<0.001. Chronically epileptic animals exhibited impaired learning curves compared to age-matched controls. Interestingly, the duration of epilepsy (2 or 20 months did not correlate with the memory impairment of aged epileptic animals. The number of BrdU-positive cells was greater in young epileptic subjects than in age-matched controls. In contrast, cell proliferation was not increased in aged epileptic animals, irrespective of the time of SE induction. Finally, dentate cell proliferation was not related to performance in the water maze. Based on the present results we conclude that even though aging and epilepsy lead to impairments in spatial learning, their effects are not additive.

  13. Impaired Endothelial Progenitor Cell Mobilization and Dysfunctional Bone Marrow Stroma in Diabetes Mellitus

    Science.gov (United States)

    Rafii, Shahin; Jaspers, Janneke E.; White, Ian A.; Hooper, Andrea T.; Doevendans, Pieter A.; Verhaar, Marianne C.

    2013-01-01

    Background 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. Methods 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. Results 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. Conclusion 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. PMID:23555959

  14. 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.

  15. Impaired antiviral response of adenovirus-transformed cell lines supports virus replication.

    Science.gov (United States)

    Bachmann, Mandy; Breitwieser, Theresa; Lipps, Christoph; Wirth, Dagmar; Jordan, Ingo; Reichl, Udo; Frensing, Timo

    2016-02-01

    Activation of the innate immune response represents one of the most important cellular mechanisms to limit virus replication and spread in cell culture. Here, we examined the effect of adenoviral gene expression on the antiviral response in adenovirus-transformed cell lines; HEK293, HEK293SF and AGE1.HN. We demonstrate that the expression of the early region protein 1A in these cell lines impairs their ability to activate antiviral genes by the IFN pathway. This property may help in the isolation of newly emerging viruses and the propagation of interferon-sensitive virus strains.

  16. Regulatory T cell reprogramming towards a Th2 cell-like lineage impairs oral tolerance and promotes food allergy

    OpenAIRE

    Rivas, Magali Noval; Burton, Oliver T.; Wise, Petra; Charbonnier, Louis-Marie; Georgiev, Peter; Oettgen, Hans C.; Rachid, Rima; Chatila, Talal

    2015-01-01

    Oral immunotherapy has had limited success in establishing tolerance in food allergy, reflecting failure to elicit an effective regulatory T (Treg) cell response. We show that disease-susceptible mice (Il4raF709) with enhanced IL-4 receptor (IL-4R) signaling exhibited STAT6-dependent impaired generation and function of mucosal allergen-specific Treg cells. This failure was associated with the acquisition by Treg cells of T helper 2 (Th2) cell-like phenotype, also found in peripheral blood all...

  17. 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.

  18. Aneuploidy impairs hematopoietic stem cell fitness and is selected against in regenerating tissues in vivo.

    Science.gov (United States)

    Pfau, Sarah J; Silberman, Rebecca E; Knouse, Kristin A; Amon, Angelika

    2016-06-15

    Aneuploidy, an imbalanced karyotype, is a widely observed feature of cancer cells that has long been hypothesized to promote tumorigenesis. Here we evaluate the fitness of cells with constitutional trisomy or chromosomal instability (CIN) in vivo using hematopoietic reconstitution experiments. We did not observe cancer but instead found that aneuploid hematopoietic stem cells (HSCs) exhibit decreased fitness. This reduced fitness is due at least in part to the decreased proliferative potential of aneuploid hematopoietic cells. Analyses of mice with CIN caused by a hypomorphic mutation in the gene Bub1b further support the finding that aneuploidy impairs cell proliferation in vivo. Whereas nonregenerating adult tissues are highly aneuploid in these mice, HSCs and other regenerative adult tissues are largely euploid. These findings indicate that, in vivo, mechanisms exist to select against aneuploid cells.

  19. Aneuploidy impairs hematopoietic stem cell fitness and is selected against in regenerating tissues in vivo.

    Science.gov (United States)

    Pfau, Sarah J; Silberman, Rebecca E; Knouse, Kristin A; Amon, Angelika

    2016-06-15

    Aneuploidy, an imbalanced karyotype, is a widely observed feature of cancer cells that has long been hypothesized to promote tumorigenesis. Here we evaluate the fitness of cells with constitutional trisomy or chromosomal instability (CIN) in vivo using hematopoietic reconstitution experiments. We did not observe cancer but instead found that aneuploid hematopoietic stem cells (HSCs) exhibit decreased fitness. This reduced fitness is due at least in part to the decreased proliferative potential of aneuploid hematopoietic cells. Analyses of mice with CIN caused by a hypomorphic mutation in the gene Bub1b further support the finding that aneuploidy impairs cell proliferation in vivo. Whereas nonregenerating adult tissues are highly aneuploid in these mice, HSCs and other regenerative adult tissues are largely euploid. These findings indicate that, in vivo, mechanisms exist to select against aneuploid cells. PMID:27313317

  20. Impaired clearance of apoptotic cells in chronic inflammatory diseases: therapeutic implications

    Directory of Open Access Journals (Sweden)

    Zsuzsa eSzondy

    2014-08-01

    Full Text Available In healthy individuals billions of cells die by apoptosis every day. Removal of the dead cells by phagocytosis (a process called efferocytosis must be efficient to prevent secondary necrosis and the consequent release of proinflammatory cell contents that damages the tissue environment and provokes autoimmunity. In addition, detection and removal of apoptotic cells generally induces an anti-inflammatory response. As a consequence improper clearance of apoptotic cells, being the result of either genetic anomalies and /or a persistent disease state, contributes to the establishment and progression of a number of human chronic inflammatory diseases such as autoimmune and neurological disorders, inflammatory lung diseases, obesity, type 2 diabetes or atherosclerosis. During the past decade our knowledge about the mechanism of efferocytosis has significantly increased, providing therapeutic targets through which impaired phagocytosis of apoptotic cells and the consequent inflammation could be influenced in these diseases.

  1. Diminished Schwann cell repair responses underlie age-associated impaired axonal regeneration.

    Science.gov (United States)

    Painter, Michio W; Brosius Lutz, Amanda; Cheng, Yung-Chih; Latremoliere, Alban; Duong, Kelly; Miller, Christine M; Posada, Sean; Cobos, Enrique J; Zhang, Alice X; Wagers, Amy J; Havton, Leif A; Barres, Ben; Omura, Takao; Woolf, Clifford J

    2014-07-16

    The regenerative capacity of the peripheral nervous system declines with age. Why this occurs, however, is unknown. We demonstrate that 24-month-old mice exhibit an impairment of functional recovery after nerve injury compared to 2-month-old animals. We find no difference in the intrinsic growth capacity between aged and young sensory neurons in vitro or in their ability to activate growth-associated transcriptional programs after injury. Instead, using age-mismatched nerve transplants in vivo, we show that the extent of functional recovery depends on the age of the nerve graft, and not the age of the host. Molecular interrogation of the sciatic nerve reveals that aged Schwann cells (SCs) fail to rapidly activate a transcriptional repair program after injury. Functionally, aged SCs exhibit impaired dedifferentiation, myelin clearance, and macrophage recruitment. These results suggest that the age-associated decline in axonal regeneration results from diminished Schwann cell plasticity, leading to slower myelin clearance. PMID:25033179

  2. Berberine Attenuates Axonal Transport Impairment and Axonopathy Induced by Calyculin A in N2a Cells

    OpenAIRE

    Xiaofeng Liu; Jie Zhou; Morad Dirhem Naji Abid; Huanhuan Yan; Hao Huang; Limin Wan; Zuohua Feng; Juan Chen

    2014-01-01

    Berberine is a primary component of the most functional extracts of Coptidis rhizome used in traditional Chinese medicine for centuries. Recent reports indicate that Berberine has the potential to prevent and treat Alzheimer's disease (AD). The previous studies reported that Calyculin A (CA) impaired the axonal transport in neuroblastoma-2a (N2a) cells. Berberine attenuated tau hyperphosphorylation and cytotoxicity induced by CA. Our study aimed at investigating the effects of Berberine on th...

  3. Renal transplant immunosuppression impairs natural killer cell function in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Olivier Morteau

    Full Text Available Despite an increasing awareness of the importance of innate immunity, the roles of natural killer (NK cells in transplant rejection and antiviral and cancer immunity during immunosuppression have not been clearly defined.To address this issue we have developed a quantitative assay of NK cell function that can be used on clinical samples and have studied the influence of immunosuppression on NK cell function. NK cell degranulation and intracellular interferon (IFN-γ production were determined by flow cytometry of peripheral blood samples.Overnight ex vivo treatment of peripheral blood cells from healthy controls with ciclosporin or tacrolimus inhibited NK cell degranulation and IFN-γ production in a dose-dependent manner. A similar impairment of function was seen in NK cells from patients treated in vivo with calcineurin inhibitors. In the early post-transplant period, there was a variable reduction of NK cell counts after treatment with alemtuzumab and basiliximab.The functional inhibition of NK cells in early transplant patients coincides with the period of maximum susceptibility to viral infections. The ability to assay NK cell function in clinical samples allows assessment of the impact of immunosuppression on these effector cells. This information may be helpful in guiding the titration of immunosuppression in the clinical setting.

  4. Impairment of dendritic cell functions in patients with adaptor protein-3 complex deficiency.

    Science.gov (United States)

    Prandini, Alberto; Salvi, Valentina; Colombo, Francesca; Moratto, Daniele; Lorenzi, Luisa; Vermi, William; De Francesco, Maria Antonia; Notarangelo, Lucia Dora; Porta, Fulvio; Plebani, Alessandro; Facchetti, Fabio; Sozzani, Silvano; Badolato, Raffaele

    2016-06-30

    Hermansky-Pudlak syndrome type 2 (HPS2) is a primary immunodeficiency due to adaptor protein-3 (AP-3) complex deficiency. HPS2 patients present neutropenia, partial albinism, and impaired lysosomal vesicles formation in hematopoietic cells. Given the role of dendritic cells (DCs) in the immune response, we studied monocyte-derived DCs (moDCs) and plasmacytoid DCs (pDCs) in two HPS2 siblings. Mature HPS2 moDCs showed impaired expression of CD83 and DC-lysosome-associated membrane protein (LAMP), low levels of MIP1-β/CCL4, MIG/CXCL9, and severe defect of interleukin-12 (IL-12) secretion. DCs in lymph-node biopsies from the same patients showed a diffuse cytoplasm reactivity in a large fraction of DC-LAMP(+) cells, instead of the classical dot-like stain. In addition, analysis of pDC-related functions of blood-circulating mononuclear cells revealed reduced interferon-α secretion in response to herpes simplex virus-1 (HSV-1), whereas granzyme-B induction upon IL-3/IL-10 stimulation was normal. Finally, T-cell costimulatory activity, as measured by mixed lymphocyte reaction assay, was lower in patients, suggesting that function and maturation of DCs is abnormal in patients with HPS2.

  5. Diabetes impairs adipose tissue-derived stem cell function and efficiency in promoting wound healing.

    Science.gov (United States)

    Cianfarani, Francesca; Toietta, Gabriele; Di Rocco, Giuliana; Cesareo, Eleonora; Zambruno, Giovanna; Odorisio, Teresa

    2013-01-01

    Adipose tissue-derived stem cells (ASCs) are gaining increasing consideration in tissue repair therapeutic application. Recent evidence indicates that ASCs enhance skin repair in animal models of impaired wound healing. To assess the therapeutic activity of autologous vs. allogeneic ASCs in the treatment of diabetic ulcers, we functionally characterized diabetic ASCs and investigated their potential to promote wound healing with respect to nondiabetic ones. Adipose tissue-derived cells from streptozotocin-induced type 1 diabetic mice were analyzed either freshly isolated as stromal vascular fraction (SVF), or following a single passage of culture (ASCs). Diabetic ASCs showed decreased proliferative potential and migration. Expression of surface markers was altered in diabetic SVF and cultured ASCs, with a reduction in stem cell marker-positive cells. ASCs from diabetic mice released lower amounts of hepatocyte growth factor, vascular endothelial growth factor (VEGF)-A, and insulin-like growth factor-1, growth factors playing important roles in skin repair. Accordingly, the supernatant of diabetic ASCs manifested reduced capability to promote keratinocyte and fibroblast proliferation and migration. Therapeutic potential of diabetic SVF administered to wounds of diabetic mice was blunted as compared with cells isolated from nondiabetic mice. Our data indicate that diabetes alters ASC intrinsic properties and impairs their function, thus affecting therapeutic potential in the autologous treatment for diabetic ulcers. PMID:23627689

  6. Orientia tsutsugamushi subverts dendritic cell functions by escaping from autophagy and impairing their migration.

    Directory of Open Access Journals (Sweden)

    Ji-Hye Choi

    Full Text Available BACKGROUND: Dendritic cells (DCs are the most potent antigen-presenting cells that link innate and adaptive immune responses, playing a pivotal role in triggering antigen-specific immunity. Antigen uptake by DCs induces maturational changes that include increased surface expression of major histocompatibility complex (MHC and costimulatory molecules. In addition, DCs actively migrate to regional lymph nodes and activate antigen-specific naive T cells after capturing antigens. We characterize the functional changes of DCs infected with Orientia tsutsugamushi, the causative agent of scrub typhus, since there is limited knowledge of the role played by DCs in O. tsutsugamushi infection. METHODOLOGY/PRINCIPAL FINDING: O. tsutsugamushi efficiently infected bone marrow-derived DCs and induced surface expression of MHC II and costimulatory molecules. In addition, O. tsutsugamushi induced autophagy activation, but actively escaped from this innate defense system. Infected DCs also secreted cytokines and chemokines such as IL-6, IL-12, MCP5, MIP-1α, and RANTES. Furthermore, in vitro migration of DCs in the presence of a CCL19 gradient within a 3D collagen matrix was drastically impaired when infected with O. tsutsugamushi. The infected cells migrated much less efficiently into lymphatic vessels of ear dermis ex vivo when compared to LPS-stimulated DCs. In vivo migration of O. tsutsugamushi-infected DCs to regional lymph nodes was significantly impaired and similar to that of immature DCs. Finally, we found that MAP kinases involved in chemotactic signaling were differentially activated in O. tsutsugamushi-infected DCs. CONCLUSION/SIGNIFICANCE: These results suggest that O. tsutsugamushi can target DCs to exploit these sentinel cells as replication reservoirs and delay or impair the functional maturation of DCs during the bacterial infection in mammals.

  7. Inhibition of HIF-prolyl-4-hydroxylases prevents mitochondrial impairment and cell death in a model of neuronal oxytosis

    NARCIS (Netherlands)

    Neitemeier, S; Dolga, A M; Honrath, B; Karuppagounder, S S; Alim, I; Ratan, R R; Culmsee, C

    2016-01-01

    Mitochondrial impairment induced by oxidative stress is a main characteristic of intrinsic cell death pathways in neurons underlying the pathology of neurodegenerative diseases. Therefore, protection of mitochondrial integrity and function is emerging as a promising strategy to prevent neuronal dama

  8. 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.

  9. Synaptic transmission from horizontal cells to cones is impaired by loss of connexin hemichannels.

    Directory of Open Access Journals (Sweden)

    Lauw J Klaassen

    2011-07-01

    Full Text Available In the vertebrate retina, horizontal cells generate the inhibitory surround of bipolar cells, an essential step in contrast enhancement. For the last decades, the mechanism involved in this inhibitory synaptic pathway has been a major controversy in retinal research. One hypothesis suggests that connexin hemichannels mediate this negative feedback signal; another suggests that feedback is mediated by protons. Mutant zebrafish were generated that lack connexin 55.5 hemichannels in horizontal cells. Whole cell voltage clamp recordings were made from isolated horizontal cells and cones in flat mount retinas. Light-induced feedback from horizontal cells to cones was reduced in mutants. A reduction of feedback was also found when horizontal cells were pharmacologically hyperpolarized but was absent when they were pharmacologically depolarized. Hemichannel currents in isolated horizontal cells showed a similar behavior. The hyperpolarization-induced hemichannel current was strongly reduced in the mutants while the depolarization-induced hemichannel current was not. Intracellular recordings were made from horizontal cells. Consistent with impaired feedback in the mutant, spectral opponent responses in horizontal cells were diminished in these animals. A behavioral assay revealed a lower contrast-sensitivity, illustrating the role of the horizontal cell to cone feedback pathway in contrast enhancement. Model simulations showed that the observed modifications of feedback can be accounted for by an ephaptic mechanism. A model for feedback, in which the number of connexin hemichannels is reduced to about 40%, fully predicts the specific asymmetric modification of feedback. To our knowledge, this is the first successful genetic interference in the feedback pathway from horizontal cells to cones. It provides direct evidence for an unconventional role of connexin hemichannels in the inhibitory synapse between horizontal cells and cones. This is an important

  10. Monocytes from HIV+ individuals show impaired cholesterol efflux and increased foam cell formation after transendothelial migration

    Science.gov (United States)

    MAISA, Anna; HEARPS, Anna C.; ANGELOVICH, Thomas A.; PEREIRA, Candida F.; ZHOU, Jingling; SHI, Margaret D.Y.; PALMER, Clovis S.; MULLER, William A.; CROWE, Suzanne M.; JAWOROWSKI, Anthony

    2016-01-01

    Design HIV+ individuals have an increased risk of atherosclerosis and cardiovascular disease which is independent of antiretroviral therapy and traditional risk factors. Monocytes play a central role in the development of atherosclerosis, and HIV-related chronic inflammation and monocyte activation may contribute to increased atherosclerosis, but the mechanisms are unknown. Methods Using an in vitro model of atherosclerotic plaque formation, we measured the transendothelial migration of purified monocytes from age-matched HIV+ and uninfected donors and examined their differentiation into foam cells. Cholesterol efflux and the expression of cholesterol metabolism genes were also assessed. Results Monocytes from HIV+ individuals showed increased foam cell formation compared to controls (18.9% vs 0% respectively, p=0.004) and serum from virologically suppressed HIV+ individuals potentiated foam cell formation by monocytes from both uninfected and HIV+ donors. Plasma TNF levels were increased in HIV+ vs control donors (5.9 vs 3.5 pg/ml, p=0.02) and foam cell formation was inhibited by blocking antibodies to TNF receptors, suggesting a direct effect on monocyte differentiation to foam cells. Monocytes from virologically suppressed HIV+ donors showed impaired cholesterol efflux and decreased expression of key genes regulating cholesterol metabolism, including the cholesterol transporter ABCA1 (p=0.02). Conclusions Monocytes from HIV+ individuals show impaired cholesterol efflux and are primed for foam cell formation following trans-endothelial migration. Factors present in HIV+ serum, including elevated TNF levels, further enhance foam cell formation. The pro-atherogenic phenotype of monocytes persists in virologically suppressed HIV+ individuals and may contribute mechanistically to increased atherosclerosis in this population. PMID:26244384

  11. 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.

  12. 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.

  13. 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; Morita, Yohei; Rudolph, Karl Lenhard

    2016-04-01

    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.

  14. Reduced Numbers and Impaired Function of Regulatory T Cells in Peripheral Blood of Ischemic Stroke Patients

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    Johanna Ruhnau

    2016-01-01

    Full Text Available Background and Purpose. Regulatory T cells (Tregs have been suggested to modulate stroke-induced immune responses. However, analyses of Tregs in patients and in experimental stroke have yielded contradictory findings. We performed the current study to assess the regulation and function of Tregs in peripheral blood of stroke patients. Age dependent expression of CD39 on Tregs was quantified in mice and men. Methods. Total FoxP3+ Tregs and CD39+FoxP3+ Tregs were quantified by flow cytometry in controls and stroke patients on admission and on days 1, 3, 5, and 7 thereafter. Treg function was assessed by quantifying the inhibition of activation-induced expression of CD69 and CD154 on T effector cells (Teffs. Results. Total Tregs accounted for 5.0% of CD4+ T cells in controls and <2.8% in stroke patients on admission. They remained below control values until day 7. CD39+ Tregs were most strongly reduced in stroke patients. On day 3 the Treg-mediated inhibition of CD154 upregulation on CD4+ Teff was impaired in stroke patients. CD39 expression on Treg increased with age in peripheral blood of mice and men. Conclusion. We demonstrate a loss of active FoxP3+CD39+ Tregs from stroke patient’s peripheral blood. The suppressive Treg function of remaining Tregs is impaired after stroke.

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

    International Nuclear Information System (INIS)

    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 Mg2+ and Mn2+. 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

  16. Impairment of reward-related learning by cholinergic cell ablation in the striatum.

    Science.gov (United States)

    Kitabatake, Yasuji; Hikida, Takatoshi; Watanabe, Dai; Pastan, Ira; Nakanishi, Shigetada

    2003-06-24

    The striatum in the basal ganglia-thalamocortical circuitry is a key neural substrate that is implicated in motor balance and procedural learning. The projection neurons in the striatum are dynamically modulated by nigrostriatal dopaminergic input and intrastriatal cholinergic input. The role of intrastriatal acetylcholine (ACh) in learning behaviors, however, remains to be fully clarified. In this investigation, we examine the involvement of intrastriatal ACh in different categories of learning by selectively ablating the striatal cholinergic neurons with use of immunotoxin-mediated cell targeting. We show that selective ablation of cholinergic neurons in the striatum impairs procedural learning in the tone-cued T-maze memory task. Spatial delayed alternation in the T-maze learning test is also impaired by cholinergic cell elimination. In contrast, the deficit in striatal ACh transmission has no effect on motor learning in the rota-rod test or spatial learning in the Morris water-maze test or on contextual- and tone-cued conditioning fear responses. We also report that cholinergic cell elimination adaptively up-regulates nicotinic ACh receptors not only within the striatum but also in the cerebral cortex and substantia nigra. The present investigation indicates that cholinergic modulation in the local striatal circuit plays a pivotal role in regulation of neural circuitry involving reward-related procedural learning and working memory. PMID:12802017

  17. Puerarin Facilitates T-Tubule Development of Murine Embryonic Stem Cell-Derived Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Lu Wang

    2014-07-01

    Full Text Available Aims: The embryonic stem cell-derived cardiomyocytes (ES-CM is one of the promising cell sources for repopulation of damaged myocardium. However, ES-CMs present immature structure, which impairs their integration with host tissue and functional regeneration. This study used murine ES-CMs as an in vitro model of cardiomyogenesis to elucidate the effect of puerarin, the main compound found in the traditional Chinese medicine the herb Radix puerariae, on t-tubule development of murine ES-CMs. Methods: Electron microscope was employed to examine the ultrastructure. The investigation of transverse-tubules (t-tubules was performed by Di-8-ANEPPS staining. Quantitative real-time PCR was utilized to study the transcript level of genes related to t-tubule development. Results: We found that long-term application of puerarin throughout cardiac differentiation improved myofibril array and sarcomeres formation, and significantly facilitated t-tubules development of ES-CMs. The transcript levels of caveolin-3, amphiphysin-2 and junctophinlin-2, which are crucial for the formation and development of t-tubules, were significantly upregulated by puerarin treatment. Furthermore, puerarin repressed the expression of miR-22, which targets to caveolin-3. Conclusion: Our data showed that puerarin facilitates t-tubule development of murine ES-CMs. This might be related to the repression of miR-22 by puerarin and upregulation of Cav3, Bin1 and JP2 transcripts.

  18. N-Docosahexaenoylethanolamine ameliorates ethanol-induced impairment of neural stem cell neurogenic differentiation.

    Science.gov (United States)

    Rashid, Mohammad Abdur; Kim, Hee-Yong

    2016-03-01

    Previous studies demonstrated that prenatal exposure to ethanol interferes with embryonic and fetal development, and causes abnormal neurodevelopment. Docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid highly enriched in the brain, was shown to be essential for proper brain development and function. Recently, we found that N-docosahexenoyethanolamine (synaptamide), an endogenous metabolite of DHA, is a potent PKA-dependent neurogenic factor for neural stem cell (NSC) differentiation. In this study, we demonstrate that ethanol at pharmacologically relevant concentrations downregulates cAMP signaling in NSC and impairs neurogenic differentiation. In contrast, synaptamide reverses ethanol-impaired NSC neurogenic differentiation through counter-acting on the cAMP production system. NSC exposure to ethanol (25-50 mM) for 4 days dose-dependently decreased the number of Tuj-1 positive neurons and PKA/CREB phosphorylation with a concomitant reduction of cellular cAMP. Ethanol-induced cAMP reduction was accompanied by the inhibition of G-protein activation and expression of adenylyl cyclase (AC) 7 and AC8, as well as PDE4 upregulation. In contrast to ethanol, synaptamide increased cAMP production, GTPγS binding, and expression of AC7 and AC8 isoforms in a cAMP-dependent manner, offsetting the ethanol-induced impairment in neurogenic differentiation. These results indicate that synaptamide can reduce ethanol-induced impairment of neuronal differentiation by counter-affecting shared targets in G-protein coupled receptor (GPCR)/cAMP signaling. The synaptamide-mediated mechanism observed in this study may offer a possible avenue for ameliorating the adverse impact of fetal alcohol exposure on neurodevelopment.

  19. N-acetylcysteine impairs survival of luteal cells through mitochondrial dysfunction.

    Science.gov (United States)

    Löhrke, Berthold; Xu, Jinxian; Weitzel, Joachim M; Krüger, Burkhard; Goldammer, Tom; Viergutz, Torsten

    2010-04-01

    N-acetylcysteine (NAC) is known as an antioxidant and used for mucus viscosity reduction. However, this drug prevents or induces cell death depending on the cell type. The response of steroidogenic luteal cells to NAC is unknown. Our data shows that NAC can behave as an antioxidant or prooxidant in dependency on the concentration and mitochondrial energization. NAC elevated the flowcytometric-measured portion of hypodiploid (dying) cells. This rise was completely abolished by aurintricarboxylic acid, an inhibitor of topoisomerase II. NAC increased the secretion of nitric oxide and cellular nitrotyrosine. An image analysis indicated that cells pretreated with NAC and loaded with DHR showed a fluorescent structure probably elicited by the oxidative product of DHR, rhodamine 123 that sequesters mitochondrially. Pretreating luteal cells with NAC or adding NAC directly to mitochondrial fractions followed by assessing the mitochondrial transmembrane potential difference (Deltapsi) by the JC-1 technique demonstrated a marked decrease in Deltapsi. A protonophore restored Deltapsi and rotenone (an inhibitor of respiratory chain complex I) inhibited mitochondrial recovering. Thus, in steroidogenic luteal cells from healthy mature corpus luteum, NAC impairs cellular survival by interfering with mitochondrial metabolism. The protonophore-induced recovering of NAC-provoked decrease in Deltapsi indicates that an ATP synthase-favored route of H(+) re-entry to the matrix is essentially switched off by NAC while other respiratory chain complexes remain intact. These data may be important for therapeutic timing of treatments with NAC. (c) 2010 International Society for Advancement of Cytometry.

  20. N-acetylcysteine impairs survival of luteal cells through mitochondrial dysfunction.

    Science.gov (United States)

    Löhrke, Berthold; Xu, Jinxian; Weitzel, Joachim M; Krüger, Burkhard; Goldammer, Tom; Viergutz, Torsten

    2010-04-01

    N-acetylcysteine (NAC) is known as an antioxidant and used for mucus viscosity reduction. However, this drug prevents or induces cell death depending on the cell type. The response of steroidogenic luteal cells to NAC is unknown. Our data shows that NAC can behave as an antioxidant or prooxidant in dependency on the concentration and mitochondrial energization. NAC elevated the flowcytometric-measured portion of hypodiploid (dying) cells. This rise was completely abolished by aurintricarboxylic acid, an inhibitor of topoisomerase II. NAC increased the secretion of nitric oxide and cellular nitrotyrosine. An image analysis indicated that cells pretreated with NAC and loaded with DHR showed a fluorescent structure probably elicited by the oxidative product of DHR, rhodamine 123 that sequesters mitochondrially. Pretreating luteal cells with NAC or adding NAC directly to mitochondrial fractions followed by assessing the mitochondrial transmembrane potential difference (Deltapsi) by the JC-1 technique demonstrated a marked decrease in Deltapsi. A protonophore restored Deltapsi and rotenone (an inhibitor of respiratory chain complex I) inhibited mitochondrial recovering. Thus, in steroidogenic luteal cells from healthy mature corpus luteum, NAC impairs cellular survival by interfering with mitochondrial metabolism. The protonophore-induced recovering of NAC-provoked decrease in Deltapsi indicates that an ATP synthase-favored route of H(+) re-entry to the matrix is essentially switched off by NAC while other respiratory chain complexes remain intact. These data may be important for therapeutic timing of treatments with NAC. (c) 2010 International Society for Advancement of Cytometry. PMID:20151456

  1. Altered FGF Signaling Pathways Impair Cell Proliferation and Elevation of Palate Shelves.

    Directory of Open Access Journals (Sweden)

    Weijie Wu

    Full Text Available In palatogenesis, palatal shelves are patterned along the mediolateral axis as well as the anteroposterior axis before the onset of palatal fusion. Fgf10 specifically expressed in lateral mesenchyme of palate maintains Shh transcription in lateral epithelium, while Fgf7 activated in medial mesenchyme by Dlx5, suppressed the expansion of Shh expression to medial epithelium. How FGF signaling pathways regulate the cell behaviors of developing palate remains elusive. In our study, we found that when Fgf8 is ectopically expressed in the embryonic palatal mesenchyme, the elevation of palatal shelves is impaired and the posterior palatal shelves are enlarged, especially in the medial side. The palatal deformity results from the drastic increase of cell proliferation in posterior mesenchyme and decrease of cell proliferation in epithelium. The expression of mesenchymal Fgf10 and epithelial Shh in the lateral palate, as well as the Dlx5 and Fgf7 transcription in the medial mesenchyme are all interrupted, indicating that the epithelial-mesenchymal interactions during palatogenesis are disrupted by the ectopic activation of mesenchymal Fgf8. Besides the altered Fgf7, Fgf10, Dlx5 and Shh expression pattern, the reduced Osr2 expression domain in the lateral mesenchyme also suggests an impaired mediolateral patterning of posterior palate. Moreover, the ectopic Fgf8 expression up-regulates pJak1 throughout the palatal mesenchyme and pErk in the medial mesenchyme, but down-regulates pJak2 in the epithelium, suggesting that during normal palatogenesis, the medial mesenchymal cell proliferation is stimulated by FGF/Erk pathway, while the epithelial cell proliferation is maintained through FGF/Jak2 pathway.

  2. 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.

  3. ARSENIC INDUCES SUSTAINED IMPAIRMENT OF SKELETAL MUSCLE AND MUSCLE PROGENITOR CELL ULTRASTRUCTURE AND BIOENERGETICS

    Science.gov (United States)

    Fabrisia, Ambrosio; Elke, Brown; Donna, Stolz; Ricardo, Ferrari; Bret, Goodpaster; Bridget, Deasy; Giovanna, Distefano; Alexandra, Roperti; Amin, Cheikhi; Yesica, Garciafigueroa; Aaron, Barchowsky

    2014-01-01

    Over 4 million individuals in the US, and over 140 million individuals worldwide, are exposed daily to arsenic-contaminated drinking water. Human exposures can range from below the current limit of 10 µg/L to over 1 mg/L, with 100 µg/L promoting disease in a large portion of those exposed. Although increased attention has recently been paid to myopathy following arsenic exposure, the pathogenic mechanisms underlying clinical symptoms remain poorly understood. This study tested the hypothesis that arsenic induces lasting muscle mitochondrial dysfunction and impairs metabolism. When compared to non-exposed controls, mice exposed to drinking water containing 100µg/L arsenite for 5 weeks demonstrated impaired muscle function, mitochondrial myopathy, and altered oxygen consumption that were concomitant with increased mitochondrial fusion gene transcription. There was no difference in levels of inorganic arsenic or its mononomethyl- and dimethyl- metabolites between controls and exposed muscles, confirming that arsenic does not accumulate in muscle. Nevertheless, muscle progenitor cells isolated from exposed mice recapitulated the aberrant myofiber phenotype and were more resistant to oxidative stress, generated more reactive oxygen species, and displayed autophagic mitochondrial morphology, as compared to cells isolated from non-exposed mice. These pathological changes from a possible maladaptive oxidative stress response provide insight into declines in muscle functioning caused by exposure to this common environmental contaminant. PMID:24960579

  4. New fava bean guard cell signaling mutant impaired in ABA-induced stomatal closure.

    Science.gov (United States)

    Iwai, Sumio; Shimomura, Naoki; Nakashima, Atsushi; Etoh, Takeomi

    2003-09-01

    We isolated a mutant from Vicia faba L. cv. House Ryousai. It wilts easily under strong light and high temperature conditions, suggesting that its stomatal movement may be disturbed. We determined responses of mutant guard cells to some environmental stimuli. Mutant guard cells demonstrated an impaired ability to respond to ABA in 0.1 mM CaCl(2) and stomata did not close in the presence of up to 1 mM ABA, whereas wild-type stomata closed when exposed to 10 micro M ABA. Elevating external Ca(2+) caused a similar degree of stomatal closure in the wild type and the mutant. A high concentration of CO(2) (700 micro l liter(-1)) induced stomatal closure in the wild type, but not in the mutant. On the basis of these results, we propose the working hypothesis that the mutation occurs in the region downstream of CO(2) and ABA sensing and in the region upstream of Ca(2+) elevation. The mutant is named fia (fava bean impaired in ABA-induced stomatal closure). PMID:14519772

  5. Impaired metabolism of senescent muscle satellite cells is associated with oxidative modifications of glycolytic enzymes

    DEFF Research Database (Denmark)

    Baraibar, Martin; Hyzewicz, Janek; Rogowska-Wrzesinska, Adelina;

    2014-01-01

    Accumulation of damaged macromolecules, including irreversibly oxidized proteins, is a hallmark of cellular and organismal ageing. Failure of protein homesotasis is a major contributor to the age-related accumulation of damaged proteins. In skeletal muscle, tissue maintenance and regeneration....... Inactivation of the proteasome in aged cells appeared as a key contributor to the accumulation of such damaged proteins. Untargeted metabolomic profiling and functional analyses indicated glucose metabolism impairment in senescent cells, although mitochondrial respiration remained unaffected. A metabolic shift...... lipids for energy production. Such changes reflect alterations in membrane composition and dysregulation of sphingolipids signaling during senescence. This study establishes a new concept connecting oxidative protein modifications with the altered cellular metabolism associated with the senescent...

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

    OpenAIRE

    Marta ePardo; King, Margaret K.; EMMA ePEREZ-COSTAS; Miguel eMelendez-Ferro; Ana eMartinez; Eleonore eBeurel; Richard Scott Jope

    2015-01-01

    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 ta...

  7. Glial cell-expressed mechanosensitive channel TRPV4 mediates infrasound-induced neuronal impairment.

    Science.gov (United States)

    Shi, Ming; Du, Fang; Liu, Yang; Li, Li; Cai, Jing; Zhang, Guo-Feng; Xu, Xiao-Fei; Lin, Tian; Cheng, Hao-Ran; Liu, Xue-Dong; Xiong, Li-Ze; Zhao, Gang

    2013-11-01

    Vibroacoustic disease, a progressive and systemic disease, mainly involving the central nervous system, is caused by excessive exposure to low-frequency but high-intensity noise generated by various heavy transportations and machineries. Infrasound is a type of low-frequency noise. Our previous studies demonstrated that infrasound at a certain intensity caused neuronal injury in rats but the underlying mechanism(s) is still largely unknown. Here, we showed that glial cell-expressed TRPV4, a Ca(2+)-permeable mechanosensitive channel, mediated infrasound-induced neuronal injury. Among different frequencies and intensities, infrasound at 16 Hz and 130 dB impaired rat learning and memory abilities most severely after 7-14 days exposure, a time during which a prominent loss of hippocampal CA1 neurons was evident. Infrasound also induced significant astrocytic and microglial activation in hippocampal regions following 1- to 7-day exposure, prior to neuronal apoptosis. Moreover, pharmacological inhibition of glial activation in vivo protected against neuronal apoptosis. In vitro, activated glial cell-released proinflammatory cytokines IL-1β and TNF-α were found to be key factors for this neuronal apoptosis. Importantly, infrasound induced an increase in the expression level of TRPV4 both in vivo and in vitro. Knockdown of TRPV4 expression by siRNA or pharmacological inhibition of TRPV4 in cultured glial cells decreased the levels of IL-1β and TNF-α, attenuated neuronal apoptosis, and reduced TRPV4-mediated Ca(2+) influx and NF-κB nuclear translocation. Finally, using various antagonists we revealed that calmodulin and protein kinase C signaling pathways were involved in TRPV4-triggered NF-κB activation. Thus, our results provide the first evidence that glial cell-expressed TRPV4 is a potential key factor responsible for infrasound-induced neuronal impairment. PMID:24002225

  8. 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…

  9. Th1/Th17 Plasticity Is a Marker of Advanced β Cell Autoimmunity and Impaired Glucose Tolerance in Humans

    Science.gov (United States)

    Reinert-Hartwall, Linnea; Honkanen, Jarno; Salo, Harri M.; Nieminen, Janne K.; Luopajärvi, Kristiina; Härkönen, Taina; Veijola, Riitta; Simell, Olli; Ilonen, Jorma; Peet, Aleksandr; Tillmann, Vallo; Knip, Mikael; Knip, Mikael; Koski, Katriina; Koski, Matti; Härkönen, Taina; Ryhänen, Samppa; Hämäläinen, Anu-Maaria; Ormisson, Anne; Peet, Aleksandr; Tillmann, Vallo; Ulich, Valentina; Kuzmicheva, Elena; Mokurov, Sergei; Markova, Svetlana; Pylova, Svetlana; Isakova, Marina; Shakurova, Elena; Petrov, Vladimir; Dorshakova, Natalya V.; Karapetyan, Tatyana; Varlamova, Tatyana; Ilonen, Jorma; Kiviniemi, Minna; Alnek, Kristi; Janson, Helis; Uibo, Raivo; Salum, Tiit; von Mutius, Erika; Weber, Juliane; Ahlfors, Helena; Kallionpää, Henna; Laajala, Essi; Lahesmaa, Riitta; Lähdesmäki, Harri; Moulder, Robert; Nieminen, Janne; Ruohtula, Terhi; Vaarala, Outi; Honkanen, Hanna; Hyöty, Heikki; Kondrashova, Anita; Oikarinen, Sami; Harmsen, Hermie J. M.; De Goffau, Marcus C.; Welling, Gjalt; Alahuhta, Kirsi; Virtanen, Suvi M.

    2015-01-01

    Upregulation of IL-17 immunity and detrimental effects of IL-17 on human islets have been implicated in human type 1 diabetes. In animal models, the plasticity of Th1/Th17 cells contributes to the development of autoimmune diabetes. In this study, we demonstrate that the upregulation of the IL-17 pathway and Th1/Th17 plasticity in peripheral blood are markers of advanced β cell autoimmunity and impaired β cell function in human type 1 diabetes. Activated Th17 immunity was observed in the late stage of preclinical diabetes in children with β cell autoimmunity and impaired glucose tolerance, but not in children with early β cell autoimmunity. We found an increased ratio of IFN-γ/IL-17 expression in Th17 cells in children with advanced β cell autoimmunity, which correlated with HbA1c and plasma glucose concentrations in an oral glucose tolerance test, and thus impaired β cell function. Low expression of Helios was seen in Th17 cells, suggesting that Th1/Th17 cells are not converted thymus-derived regulatory T cells. Our results suggest that the development of Th1/Th17 plasticity may serve as a biomarker of disease progression from β cell autoantibody positivity to type 1 diabetes. These data in human type 1 diabetes emphasize the role of Th1/Th17 plasticity as a potential contributor to tissue destruction in autoimmune conditions. PMID:25480564

  10. Slow Turning Lateral Vessel Bioreactor Improves Embryoid Body Formation and Cardiogenic Differentiation of Mouse Embryonic Stem Cells

    OpenAIRE

    2013-01-01

    Embryonic stem cells (ESCs) have the ability to form aggregates, which are called embryoid bodies (EBs). EBs mimic early embryonic development and are commonly produced for cardiomyogenesis. Here, we describe a method of EB formation in hydrodynamic conditions using a slow-turning lateral vessel (STLV) bioreactor and the subsequent differentiation of EBs into cardiomyocytes. EBs formed in the STLV were compared with conventional techniques, such as hanging drop (HD) or static suspension cell ...

  11. From surface to intracellular non-invasive nanoscale study of living cells impairments

    Energy Technology Data Exchange (ETDEWEB)

    Ewald, Dr. Maxime [University of Bourgogne, 21078 Dijon, France.; Tetard, Laurene [ORNL; Elie-Caille, Dr. Cecile [Institut FEMTO-ST UMR CNRS 6174, University Franche-Comté, 25044 Besancon, France; Nicod, Laurence [University of Franche-Comte, Laboratoire de Biologie Cellulaire; Passian, Ali [ORNL; Bourillot, Dr. Eric [University of Bourgogne, 21078 Dijon, France.; Lesniewska, Prof. Eric [University of Bourgogne, 21078 Dijon, France.

    2014-01-01

    Among the enduring challenges in nanoscience, subsurface characterization of live cells holds major stakes. Developments in nanometrology for soft matter thriving on the sensitivity and high resolution benefits of atomic force microscopy have enabled detection of subsurface structures at the nanoscale (1,2,3). However, measurements in liquid environments remain complex (4,5,6,7), in particular in the subsurface domain. Here we introduce liquid-Mode Synthesizing Atomic Force Microscopy (l-MSAFM) to study both the inner structures and the chemically induced intracellular impairments of living cells. Specifically, we visualize the intracellular stress effects of glyphosate on living keratinocytes skin cells. This new approach for living cell nanoscale imaging, l-MSAFM, in their physiological environment or in presence of a chemical stress agent confirmed the loss of inner structures induced by glyphosate. The ability to monitor the cell's inner response to external stimuli, non-destructively and in real time, has the potential to unveil critical nanoscale mechanisms of life science.

  12. Cadmium Impairs p53 Activity in HepG2 Cells.

    Science.gov (United States)

    Urani, C; Melchioretto, P; Fabbri, M; Bowe, G; Maserati, E; Gribaldo, L

    2014-01-01

    Cadmium and cadmium compounds are contaminants of the environment, food, and drinking water and are important constituents of cigarette smoke. Cd exposure has also been associated with airborne particulate CdO and with Cd-containing quantum dots in medical therapy. Adverse cadmium effects reported in the literature have stimulated during recent years an ongoing discussion to better elucidate cadmium outcomes at cell and molecular level. The present work is designed to gain an insight into the mechanism of p53 impairment at gene and protein level to understand Cd-induced resistance to apoptosis. We used a hepatoma cell line (HepG2) derived from liver, known to be metal responsive. At genotoxic cadmium concentrations no cell cycle arrest was observed. The p53 at gene and protein level was not regulated. Fluorescence images showed that p53 was correctly translocated into the nucleus but that the p21(Cip1/WAF-1), a downstream protein of p53 network involved in cell cycle regulation, was not activated at the highest cadmium concentrations used. The miRNAs analysis revealed an upregulation of mir-372, an miRNA able to affect p21(Cip1/WAF-1) expression and promote cell cycle progression and proliferation. The role of metallothioneins and possible conformational changes of p53 are discussed. PMID:25101185

  13. Alteration of cardiac progenitor cell potency in GRMD dogs.

    Science.gov (United States)

    Cassano, M; Berardi, E; Crippa, S; Toelen, J; Barthelemy, I; Micheletti, R; Chuah, M; Vandendriessche, T; Debyser, Z; Blot, S; Sampaolesi, M

    2012-01-01

    Among the animal models of Duchenne muscular dystrophy (DMD), the Golden Retriever muscular dystrophy (GRMD) dog is considered the best model in terms of size and pathological onset of the disease. As in human patients presenting with DMD or Becker muscular dystrophies (BMD), the GRMD is related to a spontaneous X-linked mutation of dystrophin and is characterized by myocardial lesions. In this respect, GRMD is a useful model to explore cardiac pathogenesis and for the development of therapeutic protocols. To investigate whether cardiac progenitor cells (CPCs) isolated from healthy and GRMD dogs may differentiate into myocardial cell types and to test the feasibility of cell therapy for cardiomyopathies in a preclinical model of DMD, CPCs were isolated from cardiac biopsies of healthy and GRMD dogs. Gene profile analysis revealed an active cardiac transcription network in both healthy and GRMD CPCs. However, GRMD CPCs showed impaired self-renewal and cardiac differentiation. Population doubling and telomerase analyses highlighted earlier senescence and proliferation impairment in progenitors isolated from GRMD cardiac biopsies. Immunofluorescence analysis revealed that only wt CPCs showed efficient although not terminal cardiac differentiation, consistent with the upregulation of cardiac-specific proteins and microRNAs. Thus, the pathological condition adversely influences the cardiomyogenic differentiation potential of cardiac progenitors. Using PiggyBac transposon technology we marked CPCs for nuclear dsRed expression, providing a stable nonviral gene marking method for in vivo tracing of CPCs. Xenotransplantation experiments in neonatal immunodeficient mice revealed a valuable contribution of CPCs to cardiomyogenesis with homing differences between wt and dystrophic progenitors. These results suggest that cardiac degeneration in dystrophinopathies may account for the progressive exhaustion of local cardiac progenitors and shed light on cardiac stemness in

  14. Analytical cell adhesion chromatography reveals impaired persistence of metastatic cell rolling adhesion to P-selectin.

    Science.gov (United States)

    Oh, Jaeho; Edwards, Erin E; McClatchey, P Mason; Thomas, Susan N

    2015-10-15

    Selectins facilitate the recruitment of circulating cells from the bloodstream by mediating rolling adhesion, which initiates the cell-cell signaling that directs extravasation into surrounding tissues. To measure the relative efficiency of cell adhesion in shear flow for in vitro drug screening, we designed and implemented a microfluidic-based analytical cell adhesion chromatography system. The juxtaposition of instantaneous rolling velocities with elution times revealed that human metastatic cancer cells, but not human leukocytes, had a reduced capacity to sustain rolling adhesion with P-selectin. We define a new parameter, termed adhesion persistence, which is conceptually similar to migration persistence in the context of chemotaxis, but instead describes the capacity of cells to resist the influence of shear flow and sustain rolling interactions with an adhesive substrate that might modulate the probability of extravasation. Among cell types assayed, adhesion persistence to P-selectin was specifically reduced in metastatic but not leukocyte-like cells in response to a low dose of heparin. In conclusion, we demonstrate this as an effective methodology to identify selectin adhesion antagonist doses that modulate homing cell adhesion and engraftment in a cell-subtype-selective manner.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ferda, Jiri [Department of Radiology, Charles University Hospital Plzen, Alej Svobody 80, CZ-306 40 Plzen (Czech Republic)], E-mail: ferda@fnplzen.cz; Hora, Milan [Department of Urology, Charles University Hospital Plzen, Dr. Edvarda Benese 13, CZ-306 40 Plzen (Czech Republic); Hes, Ondrej [Institut of Pathology, Charles University Hospital Plzen, Alej Svobody 80, CZ-306 40 Plzen (Czech Republic); Reischig, Tomas [Department of Internal Medicine, Nephrology Unit, Charles University Hospital Plzen, Alej Svobody 80, CZ-306 40 Plzen (Czech Republic); Kreuzberg, Boris; Mirka, Hynek; Ferdova, Eva; Ohlidalova, Kristyna; Baxa, Jan [Department of Radiology, Charles University Hospital Plzen, Alej Svobody 80, CZ-306 40 Plzen (Czech Republic); Urge, Tomas [Department of Urology, Charles University Hospital Plzen, Dr. Edvarda Benese 13, CZ-306 40 Plzen (Czech Republic)

    2007-08-15

    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

  16. From surface to intracellular non-invasive nanoscale study of living cells impairments

    International Nuclear Information System (INIS)

    Among the enduring challenges in nanoscience, subsurface characterization of living cells holds major stakes. Developments in nanometrology for soft matter thriving on the sensitivity and high resolution benefits of atomic force microscopy have enabled detection of subsurface structures at the nanoscale. However, measurements in liquid environments remain complex, in particular in the subsurface domain. Here we introduce liquid-mode synthesizing atomic force microscopy (l-MSAFM) to study both the inner structures and the chemically induced intracellular impairments of living cells. Specifically, we visualize the intracellular stress effects of glyphosate on living keratinocytes skin cells. This new approach, l-MSAFM, for nanoscale imaging of living cell in their physiological environment or in presence of a chemical stress agent could resolve the loss of inner structures induced by glyphosate, the main component of a well-known pesticide (RoundUp™). This firsthand ability to monitor the cell’s inner response to external stimuli non-destructively and in liquid, has the potential to unveil critical nanoscale mechanisms of life science. (paper)

  17. Chronic exposure of juvenile rats to environmental noise impairs hippocampal cell proliferation in adulthood

    Directory of Open Access Journals (Sweden)

    Fernando Jáuregui-Huerta

    2011-01-01

    Full Text Available Increasing evidence indicates that chronic exposure to environmental noise may permanently affect the central nervous system. The aim of this study was to evaluate the long-term effects of early exposure to environmental noise on the hippocampal cell proliferation of the adult male rat. Early-weaned Wistar rats were exposed for 15 days to a rats′ audiogram-fitted adaptation to a noisy environment. Two months later, the rats were injected with the cellular proliferation marker 5΄bromodeoxiuridine (BrdU, and their brains were processed for immunohistochemical analysis. Coronal sections were immunolabeled with anti-BrdU antibodies to identify new-born cells in dentate gyrus (DG, cornu amonis areas CA1 and CA3. In addition, blood samples were obtained to evaluate corticosterone serum levels after noise exposure. All data are expressed as mean΁standard deviation. For mean comparisons between groups, we used the Student t test. We found an increase in corticosterone serum levels after environmental noise exposure. Interestingly, noise-exposed rats showed a long-term reduction of proliferating cells in the hippocampal formation, as compared to controls. These findings indicate that chronic environmental noise exposure at young ages produces persistent non-auditory impairment that modifies cell proliferation in the hippocampal formation.

  18. Ammonia impairs glutamatergic communication in astroglial cells: protective role of resveratrol.

    Science.gov (United States)

    Bobermin, Larissa Daniele; Hansel, Gisele; Scherer, Emilene B S; Wyse, Angela T S; Souza, Diogo Onofre; Quincozes-Santos, André; Gonçalves, Carlos-Alberto

    2015-12-01

    Ammonia is a key toxin in the precipitation of hepatic encephalopathy (HE), a neuropsychiatric disorder associated with liver failure. In response to ammonia, various toxic events are triggered in astroglial cells, and alterations in brain glutamate communication are common. Resveratrol is a polyphenolic compound that has been extensively studied in pathological events because it presents several beneficial effects, including some in the central nervous system (CNS). We previously described that resveratrol is able to significantly modulate glial functioning and has a protective effect during ammonia challenge in vitro. In this study, we addressed the mechanisms by which resveratrol can protect C6 astroglial cells from glutamatergic alterations induced by ammonia. Resveratrol was able to prevent all the effects triggered by ammonia: (i) decrease in glutamate uptake activity and expression of the EAAC1 glutamate transporter, the main glutamate transporter present in C6 cells; (ii) increase of glutamate release, which was also dependent on the activation of the Na(+)-K(+)-Cl(-) co-transporter NKCC1; (iii) reduction in GS activity and intracellular GSH content; and (iv) impairment of Na(+)K(+)-ATPase activity. Interestingly, resveratrol, per se, also positively modulated the astroglial functions evaluated. Moreover, we demonstrated that heme oxygenase 1 (HO1), an enzyme that is part of the cellular defense system, mediated some of the effects of resveratrol. In conclusion, the mechanisms of the putative protective role of resveratrol against ammonia toxicity involve the modulation of pathways and molecules related to glutamate communication in astroglial cells.

  19. Acetylesterase-Mediated Deacetylation of Pectin Impairs Cell Elongation, Pollen Germination, and Plant Reproduction

    Energy Technology Data Exchange (ETDEWEB)

    Gou J. Y.; Liu C.; Miller, L. M.; Hou, G.; Yu, X.-H.; Chen, X.-Y.

    2012-01-01

    Pectin is a major component of the primary cell wall of higher plants. Some galacturonyl residues in the backbone of pectinaceous polysaccharides are often O-acetylated at the C-2 or C-3 position, and the resulting acetylesters change dynamically during the growth and development of plants. The processes involve both enzymatic acetylation and deacetylation. Through genomic sequence analysis, we identified a pectin acetylesterase (PAE1) from black cottonwood (Populus trichocarpa). Recombinant Pt PAE1 exhibited preferential activity in releasing the acetate moiety from sugar beet (Beta vulgaris) and potato (Solanum tuberosum) pectin in vitro. Overexpressing Pt PAE1 in tobacco (Nicotiana tabacum) decreased the level of acetyl esters of pectin but not of xylan. Deacetylation engendered differential changes in the composition and/or structure of cell wall polysaccharides that subsequently impaired the cellular elongation of floral styles and filaments, the germination of pollen grains, and the growth of pollen tubes. Consequently, plants overexpressing PAE1 exhibited severe male sterility. Furthermore, in contrast to the conventional view, PAE1-mediated deacetylation substantially lowered the digestibility of pectin. Our data suggest that pectin acetylesterase functions as an important structural regulator in planta by modulating the precise status of pectin acetylation to affect the remodeling and physiochemical properties of the cell wall's polysaccharides, thereby affecting cell extensibility.

  20. Impaired maturation of large dense-core vesicles in muted-deficient adrenal chromaffin cells.

    Science.gov (United States)

    Hao, Zhenhua; Wei, Lisi; Feng, Yaqin; Chen, Xiaowei; Du, Wen; Ma, Jing; Zhou, Zhuan; Chen, Liangyi; Li, Wei

    2015-04-01

    The large dense-core vesicle (LDCV), a type of lysosome-related organelle, is involved in the secretion of hormones and neuropeptides in specialized secretory cells. The granin family is a driving force in LDCV biogenesis, but the machinery for granin sorting to this biogenesis pathway is largely unknown. The mu mutant mouse, which carries a spontaneous null mutation on the Muted gene (also known as Bloc1s5), which encodes a subunit of the biogenesis of lysosome-related organelles complex-1 (BLOC-1), is a mouse model of Hermansky-Pudlak syndrome. Here, we found that LDCVs were enlarged in mu adrenal chromaffin cells. Chromogranin A (CgA, also known as CHGA) was increased in mu adrenals and muted-knockdown cells. The increased CgA in mu mice was likely due a failure to export this molecule out of immature LDCVs, which impairs LDCV maturation and docking. In mu chromaffin cells, the size of readily releasable pool and the vesicle release frequency were reduced. Our studies suggest that the muted protein is involved in the selective export of CgA during the biogenesis of LDCVs.

  1. Impairment of natural killer cell activity in Indian kala-azar: restoration of activity by interleukin 2 but not by alpha or gamma interferon.

    OpenAIRE

    Manna, P P; Bharadwaj, D.; Bhattacharya, S.; Chakrabarti, G; Basu, D; Mallik, K K; Bandyopadhyay, S.

    1993-01-01

    Indian kala-azar patients have normal numbers of peripheral blood NK cells but impaired functional activity due to decreased binding and lysis of target cells. This impairment of NK activity could not be corrected by exogenous recombinant human alpha or gamma interferon. However, recombinant human interleukin 2 was able to restore this activity by augmenting conjugate formation and lysis of target cells.

  2. Cytokine-induced impairment of short-chain fatty acid oxidation and viability in human colonic epithelial cells

    DEFF Research Database (Denmark)

    Pedersen, G; Saermark, T; Horn, T;

    2000-01-01

    Pro-inflammatory cytokines may directly influence the viability and metabolic function of colonic epithelial cells (CEC) as an early event in the development of inflammatory bowel disease. We report here that TNF-alpha+IFN-gamma induced a synergistic, concentration-dependent decline in butyrate...... oxidation, an essential energy supply, in HT-29 and DLD-1 cells. TNF-alpha+IFN-gamma induced a parallel profound decline in cell viability in HT-29 cells, but not in DLD-1 cells, where impairment of butyrate oxidation seemed to precede later occurrence of cell damage. TNF-alpha+INF-gamma induced CEC damage...

  3. Renal impairment and late toxicity in germ-cell cancer survivors

    DEFF Research Database (Denmark)

    Lauritsen, J.; Mortensen, M. S.; Kier, M. G. G.;

    2015-01-01

    Background Treatment with bleomycin–etoposide–cisplatin (BEP) impairs renal function and increases the risk of late cardiovascular disease (CVD) and death. We investigated the influence of BEP on glomerular filtration rate (GFR) and assessed the importance of GFR changes on CVD and death in a large...... cohort of germ-cell cancer survivors. Patients and methods BEP-treated patients (N = 1206) were identified in the Danish DaTeCa database, and merged with national registers to identify late toxicity. GFR were measured (51Cr-EDTA clearance) before and after treatment and at 1, 3 and 5-year follow......-up. The influence of BEP on GFR was evaluated with a linear mixed model. Risk factors for late toxicity were identified by a landmark analysis adjusting for covariates. The cohort was compared with the background population with standardized hospitalization/mortality rates. Results GFR changed (ΔGFR) −11.3%, −15...

  4. Impaired function of bone marrow-derived endothelial progenitor cells in murine liver fibrosis.

    Science.gov (United States)

    Shirakura, Katsuya; Masuda, Haruchika; Kwon, Sang-Mo; Obi, Syotaro; Ito, Rie; Shizuno, Tomoko; Kurihara, Yusuke; Mine, Tetsuya; Asahara, Takayuki

    2011-01-01

    Liver fibrosis (LF) caused by chronic liver damage has been considered as an irreversible disease. As alternative therapy for liver transplantation, there are high expectations for regenerative medicine of the liver. Bone marrow (BM)- or peripheral blood-derived stem cells, including endothelial progenitor cells (EPCs), have recently been used to treat liver cirrhosis. We investigated the biology of BM-derived EPC in a mouse model of LF. C57BL/6J mice were subcutaneously injected with carbon tetrachloride (CCl(4)) every 3 days for 90 days. Sacrificed 2 days after final injection, whole blood (WB) was collected for isolation of mononuclear cells (MNCs) and biochemical examination. Assessments of EPC in the peripheral blood and BM were performed by flow cytometry and EPC colony-forming assay, respectively, using purified MNCs and BM c-KIT(+), Sca-1(+), and Lin(-) (KSL) cells. Liver tissues underwent histological analysis with hematoxylin/eosin/Azan staining, and spleens were excised and weighed. CCl(4)-treated mice exhibited histologically bridging fibrosis, pseudolobular formation, and splenomegaly, indicating successful induction of LF. The frequency of definitive EPC-colony-forming-units (CFU) as well as total EPC-CFU at the equivalent cell number of 500 BM-KSL cells decreased significantly (p changes in primitive EPC-CFU occurred in LF mice. The frequency of WB-MNCs of definitive EPC-CFU decreased significantly (p < 0.01) in LF mice compared with control mice. Together, these findings indicated the existence of impaired EPC function and differentiation in BM-derived EPCs in LF mice and might be related to clinical LF.

  5. 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.

  6. Multiple Inhibitory Pathways Contribute to Lung CD8+ T Cell Impairment and Protect against Immunopathology during Acute Viral Respiratory Infection.

    Science.gov (United States)

    Erickson, John J; Rogers, Meredith C; Tollefson, Sharon J; Boyd, Kelli L; Williams, John V

    2016-07-01

    Viruses are frequent causes of lower respiratory infection (LRI). Programmed cell death-1 (PD-1) signaling contributes to pulmonary CD8(+) T cell (TCD8) functional impairment during acute viral LRI, but the role of TCD8 impairment in viral clearance and immunopathology is unclear. We now find that human metapneumovirus infection induces virus-specific lung TCD8 that fail to produce effector cytokines or degranulate late postinfection, with minimally increased function even in the absence of PD-1 signaling. Impaired lung TCD8 upregulated multiple inhibitory receptors, including PD-1, lymphocyte activation gene 3 (LAG-3), T cell Ig mucin 3, and 2B4. Moreover, coexpression of these receptors continued to increase even after viral clearance, with most virus-specific lung TCD8 expressing three or more inhibitory receptors on day 14 postinfection. Viral infection also increased expression of inhibitory ligands by both airway epithelial cells and APCs, further establishing an inhibitory environment. In vitro Ab blockade revealed that multiple inhibitory receptors contribute to TCD8 impairment induced by either human metapneumovirus or influenza virus infection. In vivo blockade of T cell Ig mucin 3 signaling failed to enhance TCD8 function or reduce viral titers. However, blockade of LAG-3 in PD-1-deficient mice restored TCD8 effector functions but increased lung pathology, indicating that LAG-3 mediates lung TCD8 impairment in vivo and contributes to protection from immunopathology during viral clearance. These results demonstrate that an orchestrated network of pathways modifies lung TCD8 functionality during viral LRI, with PD-1 and LAG-3 serving prominent roles. Lung TCD8 impairment may prevent immunopathology but also contributes to recurrent lung infections. PMID:27259857

  7. 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.

  8. Cervical cancer cell-derived interleukin-6 impairs CCR7-dependent migration of MMP-9-expressing dendritic cells.

    Science.gov (United States)

    Pahne-Zeppenfeld, Jennifer; Schröer, Nadine; Walch-Rückheim, Barbara; Oldak, Monika; Gorter, Arko; Hegde, Subramanya; Smola, Sigrun

    2014-05-01

    Cervical carcinogenesis is a consequence of persistent infection with high-risk human papillomaviruses (HPVs). Recent studies indicate that HPV-transformed cells actively instruct their microenvironment to promote carcinogenesis. Here, we demonstrate that cervical cancer cells activate monocytes to produce their own CCL2 for further monocyte recruitment and reprogram their function during differentiation and maturation to dendritic cells (DCs). Our data show that cervical cancer cells suppress the induction of the chemokine receptor CCR7 in phenotypically mature DCs and impair their migration toward a lymph node homing chemokine, required to initiate adaptive immune responses. We confirmed the presence of CD83(+)CCR7(low) DCs in cancer biopsies. The second factor essential for DC migration, matrix-metalloproteinase MMP-9, which also has vasculogenic and protumorigenic properties, is not suppressed but upregulated in immature as well as mature DCs. We identified interleukin-6 (IL-6) as a crucial cervical cancer cell-derived mediator and nuclear factor kappaB (NF-jB) as the central signaling pathway targeted in DCs. Anti-IL-6 antibodies reverted not only NF-jB inhibition and restored CCR7-dependent migration but also blocked MMP-9 induction. This is the first report demonstrating the dissociation of CCR7 and MMP-9 expression in phenotypically mature CD83(+) DCs by cancer cells. Our results show that cervical cancer cells actively shape the local microenvironment. They induce the accumulation of myeloid cells and skew their function from immune activation to local production of protumorigenic MMP-9. Neutralizing anti-IL-6 antibodies can counteract this functional dysbalance and should therefore be considered for adjuvant cervical cancer therapy.

  9. Lipid Droplet Accumulation and Impaired Fat Efflux in Polarized Hepatic Cells: Consequences of Ethanol Metabolism

    Directory of Open Access Journals (Sweden)

    Benita L. McVicker

    2012-01-01

    Full Text Available Steatosis, an early manifestation in alcoholic liver disease, is associated with the accumulation of hepatocellular lipid droplets (LDs. However, the role ethanol metabolism has in LD formation and turnover remains undefined. Here, we assessed LD dynamics following ethanol and oleic acid treatment to ethanol-metabolizing WIF-B cells (a hybrid of human fibroblasts (WI 38 and Fao rat hepatoma cells. An OA dose-dependent increase in triglyceride and stained lipids was identified which doubled (P<0.05 in the presence of ethanol. This effect was blunted with the inclusion of an alcohol metabolism inhibitor. The ethanol/ OA combination also induced adipophilin, LD coat protein involved in the attenuation of lipolysis. Additionally, ethanol treatment resulted in a significant reduction in lipid efflux. These data demonstrate that the metabolism of ethanol in hepatic cells is related to LD accumulation, impaired fat efflux, and enhancements in LD-associated proteins. These alterations in LD dynamics may contribute to ethanol-mediated defects in hepatocellular LD regulation and the formation of steatosis.

  10. 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. PMID:25190051

  11. Lipid Droplet Accumulation and Impaired Fat Efflux in Polarized Hepatic Cells: Consequences of Ethanol Metabolism

    Science.gov (United States)

    McVicker, Benita L.; Rasineni, Karuna; Tuma, Dean J.; McNiven, Mark A.; Casey, Carol A.

    2012-01-01

    Steatosis, an early manifestation in alcoholic liver disease, is associated with the accumulation of hepatocellular lipid droplets (LDs). However, the role ethanol metabolism has in LD formation and turnover remains undefined. Here, we assessed LD dynamics following ethanol and oleic acid treatment to ethanol-metabolizing WIF-B cells (a hybrid of human fibroblasts (WI 38) and Fao rat hepatoma cells). An OA dose-dependent increase in triglyceride and stained lipids was identified which doubled (P < 0.05) in the presence of ethanol. This effect was blunted with the inclusion of an alcohol metabolism inhibitor. The ethanol/ OA combination also induced adipophilin, LD coat protein involved in the attenuation of lipolysis. Additionally, ethanol treatment resulted in a significant reduction in lipid efflux. These data demonstrate that the metabolism of ethanol in hepatic cells is related to LD accumulation, impaired fat efflux, and enhancements in LD-associated proteins. These alterations in LD dynamics may contribute to ethanol-mediated defects in hepatocellular LD regulation and the formation of steatosis. PMID:22506128

  12. MUC5B silencing reduces chemo-resistance of MCF-7 breast tumor cells and impairs maturation of dendritic cells.

    Science.gov (United States)

    García, Enrique P; Tiscornia, Inés; Libisch, Gabriela; Trajtenberg, Felipe; Bollati-Fogolín, Mariela; Rodríguez, Ernesto; Noya, Verónica; Chiale, Carolina; Brossard, Natalie; Robello, Carlos; Santiñaque, Federico; Folle, Gustavo; Osinaga, Eduardo; Freire, Teresa

    2016-05-01

    Mucins participate in cancer progression by regulating cell growth, adhesion, signaling, apoptosis or chemo-resistance to drugs. The secreted mucin MUC5B, the major component of the respiratory tract mucus, is aberrantly expressed in breast cancer, where it could constitute a cancer biomarker. In this study we evaluated the role of MUC5B in breast cancer by gene silencing the MUC5B expression with short hairpin RNA on MCF-7 cells. We found that MUC5B-silenced MCF-7 cells have a reduced capacity to grow, adhere and form cell colonies. Interestingly, MUC5B knock-down increased the sensitivity to death induced by chemotherapeutic drugs. We also show that MUC5B silencing impaired LPS-maturation of DCs, and production of cytokines. Furthermore, MUC5B knock-down also influenced DC-differentiation and activation since it resulted in an upregulation of IL-1β, IL-6 and IL-10, cytokines that might be involved in cancer progression. Thus, MUC5B could enhance the production of LPS-induced cytokines, suggesting that the use of MUC5B-based cancer vaccines combined with DC-maturation stimuli, could favor the induction of an antitumor immune response.

  13. The dipeptidyl peptidase-4 inhibitor vildagliptin improves beta-cell function and insulin sensitivity in subjects with impaired fasting glucose

    DEFF Research Database (Denmark)

    Utzschneider, Kristina M; Tong, Jenny; Montgomery, Brenda;

    2007-01-01

    OBJECTIVE: To evaluate the effect of treatment with the dipeptidyl peptidase (DPP)-4 inhibitor vildagliptin on insulin sensitivity and beta-cell function in subjects with impaired fasting glucose (IFG). RESEARCH DESIGN AND METHODS: A total of 22 subjects with IFG (11 female and 11 male, mean +/- ...

  14. Potential role of mesenchymal stem cells in alleviating intestinal ischemia/reperfusion impairment.

    Directory of Open Access Journals (Sweden)

    Haitao Jiang

    Full Text Available BACKGROUND: Transplantation of bone marrow mesenchymal stem cells (MSCs provides a promising therapeutic efficiency for a variety of disorders caused by ischemia or reperfusion impairment. We have previously demonstrated the efficacy of MSCs in mitigating intestinal ischemia/reperfusion (I/R injuries in rats, but the mechanism by which MSCs engraft ameliorates I/R injuries has largely been unknown. The present study aimed at investigating probable mechanisms by which MSCs exert their function. METHODS: Male donor derived rat MSCs were implanted into intestine of female recipient rat by direct submucosal injection after superior mesenteric artery clamping and unclamping. The homed MSCs were detected by Y chromosome in situ hybridization probe, and the tumor necrosis factor-α (TNF-α content in intestinal mucosa was determined by ELISA. Expression of proliferative cell nuclear antigen (PCNA in bowel mucosa was assayed by real-time PCR and intestinal mucosa expression of phosphorylation extracellular signal-regulated kinase (pERK1/2 and nuclear factor-κB (NF-κB were evaluated by western blot. RESULTS: Four and seven days after MSCs transplantation, the TNF-α content of bowel mucosa in MSCs group was significantly lower than that in saline group. The PCNA in bowel mucosa showed higher expression in MSCs treated group than the saline group, both at 4 and 7 days after cell transplantation. The expression of intestinal mucosal pERK1/2 in MSCs treated group was markedly higher than that in saline group, and the expression of NF-κB in MSCs treated group was noticeably decreased than that in saline group at 4 and 7 days post MSCs transplantation. CONCLUSION: The present investigation provides novel evidence that MSCs have the potential to reduce intestinal I/R injuries probably due to their ability to accelerate cell proliferation and decrease the inflammatory response within intestinal mucosa after ischemia and reperfusion.

  15. 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.'

  16. Impaired Cell Volume Regulation in Intestinal Crypt Epithelia of Cystic Fibrosis Mice

    Science.gov (United States)

    Valverde, M. A.; O'Brien, J. A.; Sepulveda, F. V.; Ratcliff, R. A.; Evans, M. J.; Colledge, W. H.

    1995-09-01

    Cystic fibrosis is a disease characterized by abnormalities in the epithelia of the lungs, intestine, salivary and sweat glands, liver, and reproductive systems, often as a result of inadequate hydration of their secretions. The primary defect in cystic fibrosis is the altered activity of a cAMP-activated Cl^- channel, the cystic fibrosis transmembrane conductance regulator (CFTR) channel. However, it is not clear how a defect in the CFTR Cl^- channel function leads to the observed pathological changes. Although much is known about the structural properties and regulation of the CFTR, little is known of its relationship to cellular functions other than the cAMP-dependent Cl^- secretion. Here we report that cell volume regulation after hypotonic challenge is also defective in intestinal crypt epithelial cells isolated from CFTR -/- mutant mice. Moreover, the impairment of the regulatory volume decrease in CFTR -/- crypts appears to be related to the inability of a K^+ conductance to provide a pathway for the exit of this cation during the volume adjustments. This provides evidence that the lack of CFTR protein may have additional consequences for the cellular function other than the abnormal cAMP-mediated Cl^- secretion.

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

    Science.gov (United States)

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

    2016-08-01

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

  18. 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

    2016-05-01

    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. PMID:27133169

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

    Energy Technology Data Exchange (ETDEWEB)

    Horton, J.W.

    1987-06-01

    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 (/sup 14/C)inulin, values (ml H/sub 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.

  20. MiR-492 impairs the angiogenic potential of endothelial cells

    DEFF Research Database (Denmark)

    Patella, Francesca; Leucci, Eleonora; Evangelista, Monica;

    2013-01-01

    . To identify the microRNAs and their targeted genes involved in the glucose responses, we performed the miRNA signature of Human Umbelical Vein Endothelial Cells (HUVECs) exposed and unexposed to high glucose. Among differentially expressed microRNAs, we analysed miR-492 and showed that its overexpression...... was able to reduce proliferation, migration and tube formation of HUVEC. These effects were accompanied by the down-regulation of eNOS, a key regulator of the endothelial cell function. We showed that eNOS was indirectly down-regulated by miR-492 and we discovered that miR-492 was able to bind m......RNAs involved in proliferation, migration, tube formation and regulation of eNOS activity and expression. Moreover, we found that miR-492 decreased VEGF expression in HUVEC and impaired in vivo angiogenesis in a tumour xenograft model, suggesting a role also in modulating the secretion of pro-angiogenic factors...

  1. Development of B cells and erythrocytes is specifically impaired by the drug celastrol in mice.

    Directory of Open Access Journals (Sweden)

    Sophie Kusy

    Full Text Available BACKGROUND: Celastrol, an active compound extracted from the root of the Chinese medicine "Thunder of God Vine" (Tripterygium wilfordii, exhibits anticancer, antioxidant and anti-inflammatory activities, and interest in the therapeutic potential of celastrol is increasing. However, described side effects following treatment are significant and require investigation prior to initiating clinical trials. Here, we investigated the effects of celastrol on the adult murine hematopoietic system. METHODOLOGY/PRINCIPAL FINDINGS: Animals were treated daily with celastrol over a four-day period and peripheral blood, bone marrow, spleen, and peritoneal cavity were harvested for cell phenotyping. Treated mice showed specific impairment of the development of B cells and erythrocytes in all tested organs. In bone marrow, these alterations were accompanied by decreases in populations of common lymphoid progenitors (CLP, common myeloid progenitors (CMP and megakaryocyte-erythrocyte progenitors (MEP. CONCLUSIONS/SIGNIFICANCE: These results indicate that celastrol acts through regulators of adult hematopoiesis and could be used as a modulator of the hematopoietic system. These observations provide valuable information for further assessment prior to clinical trials.

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

    Science.gov (United States)

    Guo, Jian; Li, Yang; Ren, Yi-Hong; Sun, Zhijun; Dong, Jie; Yan, Han; Xu, Yujun; Wang, Dao Wen; Zheng, Gu-Yan; Du, Jie; Tian, Xiao-Li

    2016-01-01

    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. PMID:27455246

  3. Age-Dependent Cell Trafficking Defects in Draining Lymph Nodes Impair Adaptive Immunity and Control of West Nile Virus Infection.

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    Justin M Richner

    2015-07-01

    Full Text Available Impaired immune responses in the elderly lead to reduced vaccine efficacy and increased susceptibility to viral infections. Although several groups have documented age-dependent defects in adaptive immune priming, the deficits that occur prior to antigen encounter remain largely unexplored. Herein, we identify novel mechanisms for compromised adaptive immunity that occurs with aging in the context of infection with West Nile virus (WNV, an encephalitic flavivirus that preferentially causes disease in the elderly. An impaired IgM and IgG response and enhanced vulnerability to WNV infection during aging was linked to delayed germinal center formation in the draining lymph node (DLN. Adoptive transfer studies and two-photon intravital microscopy revealed a decreased trafficking capacity of donor naïve CD4+ T cells from old mice, which manifested as impaired T cell diapedesis at high endothelial venules and reduced cell motility within DLN prior to antigen encounter. Furthermore, leukocyte accumulation in the DLN within the first few days of WNV infection or antigen-adjuvant administration was diminished more generally in old mice and associated with a second aging-related defect in local cytokine and chemokine production. Thus, age-dependent cell-intrinsic and environmental defects in the DLN result in delayed immune cell recruitment and antigen recognition. These deficits compromise priming of early adaptive immune responses and likely contribute to the susceptibility of old animals to acute WNV infection.

  4. Impairment of pneumococcal antigen specific isotype-switched Igg memory B-cell immunity in HIV infected Malawian adults.

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    Oluwadamilola H Iwajomo

    Full Text Available Pneumococcal disease is associated with a particularly high morbidity and mortality amongst adults in HIV endemic countries. Our previous findings implicating a B-cell defect in HIV-infected children from the same population led us to comprehensively characterize B-cell subsets in minimally symptomatic HIV-infected Malawian adults and investigate the isotype-switched IgG memory B-cell immune response to the pneumococcus. We show that similar to vertically acquired HIV-infected Malawian children, horizontally acquired HIV infection in these adults is associated with IgM memory B-cell (CD19(+ CD27(+ IgM(+ IgD(+ depletion, B-cell activation and impairment of specific IgG B-cell memory to a range of pneumococcal proteins. Our data suggest that HIV infection affects both T-cell independent and T-cell dependent B-cell maturation, potentially leading to impairment of humoral responses to extracellular pathogens such as the pneumococcus, and thus leaving this population susceptible to invasive disease.

  5. High antigen levels induce an exhausted phenotype in a chronic infection without impairing T cell expansion and survival.

    Science.gov (United States)

    Utzschneider, Daniel T; Alfei, Francesca; Roelli, Patrick; Barras, David; Chennupati, Vijaykumar; Darbre, Stephanie; Delorenzi, Mauro; Pinschewer, Daniel D; Zehn, Dietmar

    2016-08-22

    Chronic infections induce T cells showing impaired cytokine secretion and up-regulated expression of inhibitory receptors such as PD-1. What determines the acquisition of this chronic phenotype and how it impacts T cell function remain vaguely understood. Using newly generated recombinant antigen variant-expressing chronic lymphocytic choriomeningitis virus (LCMV) strains, we uncovered that T cell differentiation and acquisition of a chronic or exhausted phenotype depend critically on the frequency of T cell receptor (TCR) engagement and less significantly on the strength of TCR stimulation. In fact, we noted that low-level antigen exposure promotes the formation of T cells with an acute phenotype in chronic infections. Unexpectedly, we found that T cell populations with an acute or chronic phenotype are maintained equally well in chronic infections and undergo comparable primary and secondary expansion. Thus, our observations contrast with the view that T cells with a typical chronic infection phenotype are severely functionally impaired and rapidly transition into a terminal stage of differentiation. Instead, our data unravel that T cells primarily undergo a form of phenotypic and functional differentiation in the early phase of a chronic LCMV infection without inheriting a net survival or expansion deficit, and we demonstrate that the acquired chronic phenotype transitions into the memory T cell compartment.

  6. Prion infection impairs lysosomal degradation capacity by interfering with rab7 membrane attachment in neuronal cells.

    Science.gov (United States)

    Shim, Su Yeon; Karri, Srinivasarao; Law, Sampson; Schatzl, Hermann M; Gilch, Sabine

    2016-01-01

    Prions are proteinaceous infectious particles which cause fatal neurodegenerative disorders in humans and animals. They consist of a mostly β-sheeted aggregated isoform (PrP(Sc)) of the cellular prion protein (PrP(c)). Prions replicate autocatalytically in neurons and other cell types by inducing conformational conversion of PrP(c) into PrP(Sc). Within neurons, PrP(Sc) accumulates at the plasma membrane and in vesicles of the endocytic pathway. To better understand the mechanisms underlying neuronal dysfunction and death it is critical to know the impact of PrP(Sc) accumulation on cellular pathways. We have investigated the effects of prion infection on endo-lysosomal transport. Our study demonstrates that prion infection interferes with rab7 membrane association. Consequently, lysosomal maturation and degradation are impaired. Our findings indicate a mechanism induced by prion infection that supports stable prion replication. We suggest modulation of endo-lysosomal vesicle trafficking and enhancement of lysosomal maturation as novel targets for the treatment of prion diseases. PMID:26865414

  7. Neuropsychological impairment in children with sickle cell anemia and cerebrovascular accidents.

    Science.gov (United States)

    Cohen, M J; Branch, W B; McKie, V C; Adams, R J

    1994-09-01

    Neuropsychological functioning of children with sickle cell anemia (HbSS) who have experienced a single stroke has not been extensively investigated. In this study, the neuropsychological functioning of 10 children with HbSS who were receiving transfusion therapy following stroke with no identifiable recurrence was examined. The patients were subgrouped into children with only left hemisphere stroke (LCI), N = 4, and those with only right hemisphere stroke (RCI), N = 6. Results indicated that these youngsters experienced significant impairments of cognitive functioning following stroke. It was found that the LCI and RCI children tended to perform more like adult stroke patients than what has been typically reported in children with infantile hemiplegia. These findings support the need for periodic neuropsychological evaluation following stroke in order to identify patterns of higher cortical dysfunction and assist in the development of appropriate rehabilitation and special education programs. Further, pediatricians, child neurologists, and psychologists who care for these children must act as strong advocates on their behalf in order to ensure that they receive appropriate rehabilitation and the special education services necessary for maximal recovery and future educational success.

  8. Eicosapentaenoic acid enhances heat stress-impaired intestinal epithelial barrier function in Caco-2 cells.

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    Guizhen Xiao

    Full Text Available OBJECTIVE: Dysfunction of the intestinal epithelial tight junction (TJ barrier is known to have an important etiologic role in the pathophysiology of heat stroke. N-3 polyunsaturated fatty acids (PUFAs, including eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA, play a role in maintaining and protecting the TJ structure and function. This study is aimed at investigating whether n-3 PUFAs could alleviate heat stress-induced dysfunction of intestinal tight junction. METHODS: Human intestinal epithelial Caco-2 cells were pre-incubated with EPA, DHA or arachidonic acid (AA and then exposed to heat stress. Transepithelial electrical resistance (TEER and Horseradish Peroxidase (HRP permeability were measured to analyze barrier integrity. Levels of TJ proteins, including occludin, ZO-1 and claudin-2, were analyzed by Western blot and localized by immunofluorescence microscopy. Messenger RNA levels were determined by quantitative real time polymerase chain reaction (Q-PCR. TJ morphology was observed by transmission electron microscopy. RESULTS: EPA effectively attenuated the decrease in TEER and impairment of intestinal permeability in HRP flux induced by heat exposure. EPA significantly elevated the expression of occludin and ZO-1, while DHA was less effective and AA was not at all effective. The distortion and redistribution of TJ proteins, and disruption of morphology were also effectively prevented by pretreatment with EPA. CONCLUSION: This study indicates for the first time that EPA is more potent than DHA in protecting against heat-induced permeability dysfunction and epithelial barrier damage of tight junction.

  9. Hypoxia impairs primordial germ cell migration in zebrafish (Danio rerio embryos.

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    Kwok Hong Lo

    Full Text Available BACKGROUND: As a global environmental concern, hypoxia is known to be associated with many biological and physiological impairments in aquatic ecosystems. Previous studies have mainly focused on the effect of hypoxia in adult animals. However, the effect of hypoxia and the underlying mechanism of how hypoxia affects embryonic development of aquatic animals remain unclear. METHODOLOGY/PRINCIPAL FINDINGS: In the current study, the effect of hypoxia on primordial germ cell (PGC migration in zebrafish embryos was investigated. Hypoxic embryos showed PGC migration defect as indicated by the presence of mis-migrated ectopic PGCs. Insulin-like growth factor (IGF signaling is required for embryonic germ line development. Using real-time PCR, we found that the mRNA expression levels of insulin-like growth factor binding protein (IGFBP-1, an inhibitor of IGF bioactivity, were significantly increased in hypoxic embryos. Morpholino knockdown of IGFBP-1 rescued the PGC migration defect phenotype in hypoxic embryos, suggesting the role of IGFBP-1 in inducing PGC mis-migration. CONCLUSIONS/SIGNIFICANCE: This study provides novel evidence that hypoxia disrupts PGC migration during embryonic development in fish. IGF signaling is shown to be one of the possible mechanisms for the causal link between hypoxia and PGC migration. We propose that hypoxia causes PGC migration defect by inhibiting IGF signaling through the induction of IGFBP-1.

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

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    Matthew P Krause

    Full Text Available BACKGROUND: 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. PRINCIPAL FINDINGS: 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. CONCLUSIONS: Our findings suggest the mechanism underlying how impaired collagen remodelling in type-1 diabetes results in delayed

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

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    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.

  12. Impaired T cell function in malignant pleural effusion is caused by TGF-β derived predominantly from macrophages.

    Science.gov (United States)

    Li, Lifeng; Yang, Li; Wang, Liping; Wang, Fei; Zhang, Zhen; Li, Jieyao; Yue, Dongli; Chen, Xinfeng; Ping, Yu; Huang, Lan; Zhang, Bin; Zhang, Yi

    2016-11-15

    Malignant pleural effusion (MPE) is an indication of advanced cancer. Immune dysfunction often occurs in MPE. We aimed to identify the reason for impaired T cell activity in MPE from lung cancer patients and to provide clues toward potential immune therapies for MPE. The surface inhibitory molecules and cytotoxic activity of T cells in MPE and peripheral blood (PB) were analyzed using flow cytometry. Levels of inflammatory cytokines in MPE and PB were tested using ELISA. TGF-β expression in tumor-associated macrophages (TAMs) was also analyzed. The effect of TAMs on T cells was verified in vitro. Lastly, changes in T cells were evaluated following treatment with anti-TGF-β antibody. We found that expression levels of Tim-3, PD-1 and CTLA-4 in T cells from MPE were upregulated compared with those from PB, but levels of IFN-γ and Granzyme B were downregulated (p TGF-β was significantly higher in MPE than in PB (p TGF-β was mainly produced by TAMs in MPE. When T cells were co-cultured with TAMs, expression levels of Tim-3, PD-1 and CTLA-4 were significantly higher than controls, whereas levels of IFN-γ and Granzyme B were significantly decreased, in a dose-dependent manner (p TGF-β antibody restored the impaired T cell cytotoxic activity in MPE. Our results indicate that macrophage-derived TGF-β plays an important role in impaired T cell cytotoxicity. It will therefore be valuable to develop therapeutic strategies against TGF-β pathway for MPE therapy of lung cancer.

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

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    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. The NRF2 Activation and Antioxidative Response Are Not Impaired Overall during Hyperoxia-Induced Lung Epithelial Cell Death

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    Haranatha R. Potteti

    2013-01-01

    Full Text Available Lung epithelial and endothelial cell death caused by pro-oxidant insults is a cardinal feature of acute lung injury/acute respiratory distress syndrome (ALI/ARDS patients. The NF-E2-related factor 2 (NRF2 activation in response to oxidant exposure is crucial to the induction of several antioxidative and cytoprotective enzymes that mitigate cellular stress. Since prolonged exposure to hyperoxia causes cell death, we hypothesized that chronic hyperoxia impairs NRF2 activation, resulting in cell death. To test this hypothesis, we exposed nonmalignant small airway epithelial cells (AECs to acute (1–12 h and chronic (36–48 h hyperoxia and evaluated cell death, NRF2 nuclear accumulation and target gene expression, and NRF2 recruitment to the endogenous HMOX1 and NQO1 promoters. As expected, hyperoxia gradually induced death in AECs, noticeably and significantly by 36 h; ~60% of cells were dead by 48 h. However, we unexpectedly found increased expression levels of NRF2-regulated antioxidative genes and nuclear NRF2 in AECs exposed to chronic hyperoxia as compared to acute hyperoxia. Chromatin Immunoprecipitation (ChIP assays revealed an increased recruitment of NRF2 to the endogenous HMOX1 and NQO1 promoters in AECs exposed to acute or chronic hyperoxia. Thus, our findings demonstrate that NRF2 activation and antioxidant gene expression are functional during hyperoxia-induced lung epithelial cell death and that chronic hyperoxia does not impair NRF2 signaling overall.

  15. GNA13 loss in germinal center B cells leads to impaired apoptosis and promotes lymphoma in vivo.

    Science.gov (United States)

    Healy, Jane A; Nugent, Adrienne; Rempel, Rachel E; Moffitt, Andrea B; Davis, Nicholas S; Jiang, Xiaoyu; Shingleton, Jennifer R; Zhang, Jenny; Love, Cassandra; Datta, Jyotishka; McKinney, Matthew E; Tzeng, Tiffany J; Wettschureck, Nina; Offermanns, Stefan; Walzer, Katelyn A; Chi, Jen-Tsan; Rasheed, Suhail A K; Casey, Patrick J; Lossos, Izidore S; Dave, Sandeep S

    2016-06-01

    GNA13 is the most frequently mutated gene in germinal center (GC)-derived B-cell lymphomas, including nearly a quarter of Burkitt lymphoma and GC-derived diffuse large B-cell lymphoma. These mutations occur in a pattern consistent with loss of function. We have modeled the GNA13-deficient state exclusively in GC B cells by crossing the Gna13 conditional knockout mouse strain with the GC-specific AID-Cre transgenic strain. AID-Cre(+) GNA13-deficient mice demonstrate disordered GC architecture and dark zone/light zone distribution in vivo, and demonstrate altered migration behavior, decreased levels of filamentous actin, and attenuated RhoA activity in vitro. We also found that GNA13-deficient mice have increased numbers of GC B cells that display impaired caspase-mediated cell death and increased frequency of somatic hypermutation in the immunoglobulin VH locus. Lastly, GNA13 deficiency, combined with conditional MYC transgene expression in mouse GC B cells, promotes lymphomagenesis. Thus, GNA13 loss is associated with GC B-cell persistence, in which impaired apoptosis and ongoing somatic hypermutation may lead to an increased risk of lymphoma development. PMID:26989201

  16. 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...

  17. Effects of Impaired ATP Production and Glucose Sensitivity on Human B-Cell Function: A Simulation Study

    OpenAIRE

    G. J. Félix-Martínez; J. Azpiroz-Leehan; R. Ávila-Pozos; J. R. Godínez Fernández

    2014-01-01

    In this paper we used a mathematical model to explore the effects of impaired ATP production and glucose sensitivity on the electrical response and insulin secretion of human B-cells. The model was extended by the addition of explicit empirical equations that describe recent experimental observations, namely, the increase of ATP as a function of glucose concentration and the oscillations in ATP at high glucose levels. Simulations were performed at selected glucose concentrations from an oral ...

  18. Parallel fiber to Purkinje cell synaptic impairment in a mouse model of spinocerebellar ataxia type 27

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    Filippo eTempia

    2015-06-01

    Full Text Available Genetically inherited mutations in the fibroblast growth factor 14 (FGF14 gene lead to spinocerebellar ataxia type 27 (SCA27, an autosomal dominant disorder characterized by severe heterogeneous motor and cognitive impairments. Consistently, genetic deletion of Fgf14 in Fgf14-/- mice recapitulates salient features of the SCA27 human disease. In vitro molecular studies in cultured neurons indicate that the FGF14F145S SCA27 allele acts as a dominant negative mutant suppressing the FGF14 wild type function and resulting in inhibition of voltage-gated Na+ and Ca2+ channels. To gain insights in the cerebellar deficits in the animal model of the human disease, we applied whole-cell voltage-clamp in the acute cerebellar slice preparation to examine the properties of parallel fibers (PF to Purkinje neuron synapses in Fgf14-/- mice and wild type littermates. We found that the AMPA receptor-mediated excitatory postsynaptic currents evoked by PF stimulation (PF-EPSCs were significantly reduced in Fgf14-/- animals, while short-term plasticity, measured as paired-pulse facilitation (PPF, was enhanced. Measuring Sr2+-induced release of quanta from stimulated synapses, we found that the size of the PF-EPSCs was unchanged, ruling out a postsynaptic deficit. This phenotype was corroborated by decreased expression of VGLUT1, a specific presynaptic marker at PF-Purkinje neuron synapses. We next examined the mGluR1 receptor-induced response (mGluR1-EPSC that under normal conditions requires a gradual build-up of glutamate concentration in the synaptic cleft, and found no changes in these responses in Fgf14-/- mice. These results provide evidence of a critical role of FGF14 in maintaining presynaptic function at PF-Purkinje neuron synapses highlighting critical target mechanisms to recapitulate the complexity of the SCA27 disease.

  19. Impaired adipogenesis and insulin resistance in epicardial fat-mesenchymal cells from patients with cardiovascular disease.

    Science.gov (United States)

    Fernández-Trasancos, Angel; Fandiño-Vaquero, Rubén; Agra, Rosa María; Fernández, Angel Luis; Viñuela, Juan E; González-Juanatey, José Ramón; Eiras, Sonia

    2014-11-01

    The thickness of epicardial adipose tissue (EAT), which is an inflammatory source for coronary artery disease (CAD), correlates with insulin resistance. One trigger factor is impaired adipogenesis. Here, our aim was to clarify the underlying mechanisms of insulin resistance on EAT-mesenchymal cells (MC). EAT and subcutaneous adipose tissue (SAT) were collected from 19 patients who were undergoing heart surgery. Their dedifferentiated adipocytes (DAs) and/or MCs were cultured. After the induction of adipogenesis or stimulation with insulin, the expression of adipokines was analyzed using real-time polymerase chain reaction (PCR). Colorimetric assays were performed to measure glucose levels and proliferation rate. Proteins modifications were detected via the proteomic approach and Western blot. Our results showed lower adipogenic ability in EAT-MCs than in SAT-MCs. Maximum adiponectin levels were reached within 28-35 days of exposure to adipogenic inducers. Moreover, the adipogenesis profile in EAT-MCs was dependent on the patients' clinical characteristics. The low adipogenic ability of EAT-MCs might be associated with an insulin-resistant state because chronic insulin treatment reduced the inflammatory cytokine expression levels, improved the glucose consumption, and increased the post-translational modifications (PTMs) of the glycolytic enzyme phosphoglycerate mutase 1 (PGAM1). We found lower adipogenic ability in EAT-MCs than in SAT-MCs. This lower ability level was dependent on gender and the presence of diabetes, obesity, and CAD. Low adipogenesis ability and insulin resistance in EAT-MCs might shed light on the association between EAT dysfunction and cardiovascular disease. PMID:24648294

  20. 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. PMID:26348137

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

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    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.

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

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    Adiba Isa

    Full Text Available 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 a 9-42 fold increase of all six HLA-A,-B,-C gene transcripts. Interestingly, prior to stimulation, gene transcripts for all but two alleles were present in similar amounts suggesting that post-transcriptional mechanisms regulate the constitutive expression of HLA-A,-B, and -C. Locus-restricted expression of HLA-A, -B and -C challenges our current understanding of the function of these molecules as regulators of CD8(+ T-cell and NK-cell function and should lead to further inquiries into their expression on other cell types.

  3. Impaired Ca(2+ signaling in β-cells lacking leptin receptors by Cre-loxP recombination.

    Directory of Open Access Journals (Sweden)

    Eva Tudurí

    Full Text Available Obesity is a major risk factor for diabetes and is typically associated with hyperleptinemia and a state of leptin resistance. The impact of chronically elevated leptin levels on the function of insulin-secreting β-cells has not been elucidated. We previously generated mice lacking leptin signaling in β-cells by using the Cre-loxP strategy and showed that these animals develop increased body weight and adiposity, hyperinsulinemia, impaired glucose-stimulated insulin secretion and insulin resistance. Here, we performed several in vitro studies and observed that β-cells lacking leptin signaling in this model are capable of properly metabolizing glucose, but show impaired intracellular Ca(2+ oscillations and lack of synchrony within the islets in response to glucose, display reduced response to tolbutamide and exhibit morphological abnormalities including increased autophagy. Defects in intracellular Ca(2+ signaling were observed even in neonatal islets, ruling out the possible contribution of obesity to the β-cell irregularities observed in adults. In parallel, we also detected a disrupted intracellular Ca(2+ pattern in response to glucose and tolbutamide in control islets from adult transgenic mice expressing Cre recombinase under the rat insulin promoter, despite these animals being glucose tolerant and secreting normal levels of insulin in response to glucose. This unexpected observation impeded us from discerning the consequences of impaired leptin signaling as opposed to long-term Cre expression in the function of insulin-secreting cells. These findings highlight the need to generate improved Cre-driver mouse models or new tools to induce Cre recombination in β-cells.

  4. Nitric oxide-induced oxidative stress impairs pacemaker function of murine interstitial cells of Cajal during inflammation.

    Science.gov (United States)

    Kaji, Noriyuki; Horiguchi, Kazuhide; Iino, Satoshi; Nakayama, Shinsuke; Ohwada, Tomohiko; Otani, Yuko; Firman; Murata, Takahisa; Sanders, Kenton M; Ozaki, Hiroshi; Hori, Masatoshi

    2016-09-01

    The pacemaker function of interstitial cells of Cajal (ICC) is impaired during intestinal inflammation. The aim of this study is to clarify the pathophysiological mechanisms of ICC dysfunction during inflammatory condition by using intestinal cell clusters. Cell clusters were prepared from smooth muscle layer of murine jejunum and treated with interferon-gamma and lipopolysaccharide (IFN-γ+LPS) for 24h to induce inflammation. Pacemaker function of ICC was monitored by measuring cytosolic Ca(2+) oscillation in the presence of nifedipine. Treatment with IFN-γ+LPS impaired the pacemaker activity of ICC with increasing mRNA level of interleukin-1 beta, tumor necrosis factor-alpha and interleukin-6 in cell clusters; however, treatment with these cytokines individually had little effect on pacemaker activity of ICC. Treatment with IFN-γ+LPS also induced the expression of inducible nitric oxide synthase (iNOS) in smooth muscle cells and resident macrophages, but not in ICC. Pretreatment with NOS inhibitor, L-NAME or iNOS inhibitor, 1400W ameliorated IFN-γ+LPS-induced pacemaker dysfunction of ICC. Pretreatment with guanylate cyclase inhibitor, ODQ did not, but antioxidant, apocynin, to suppress NO-induced oxidative stress, significantly suppressed the impairment of ICC function induced by IFN-γ+LPS. Treatment with IFN-γ+LPS also decreased c-Kit-positive ICC, which was prevented by pretreatment with L-NAME. However, apoptotic ICC were not detected in IFN-γ+LPS-treated clusters, suggesting IFN-γ+LPS stimulation just changed the phenotype of ICC but not induced cell death. Moreover, ultrastructure of ICC was not disturbed by IFN-γ+LPS. In conclusion, ICC dysfunction during inflammation is induced by NO-induced oxidative stress rather than NO/cGMP signaling. NO-induced oxidative stress might be the main factor to induce phenotypic changes of ICC.

  5. Fatty acid-binding protein 4 impairs the insulin-dependent nitric oxide pathway in vascular endothelial cells

    OpenAIRE

    Aragonès Gemma; Saavedra Paula; Heras Mercedes; Cabré Anna; Girona Josefa; Masana Lluís

    2012-01-01

    Abstract Background Recent studies have shown that fatty acid-binding protein 4 (FABP4) plasma levels are associated with impaired endothelial function in type 2 diabetes (T2D). In this work, we analysed the effect of FABP4 on the insulin-mediated nitric oxide (NO) production by endothelial cells in vitro. Methods In human umbilical vascular endothelial cells (HUVECs), we measured the effects of FABP4 on the insulin-mediated endothelial nitric oxide synthase (eNOS) expression and activation a...

  6. Inhibition of N-linked glycosylation impairs ALK phosphorylation and disrupts pro-survival signaling in neuroblastoma cell lines

    Directory of Open Access Journals (Sweden)

    Del Grosso Federica

    2011-12-01

    Full Text Available Abstract Background The Anaplastic Lymphoma Kinase (ALK is an orphan receptor tyrosine kinase, which undergoes post-translational N-linked glycosylation. The catalytic domain of ALK was originally identified in the t(2;5 translocation that produces the unglycosylated oncogenic protein NPM-ALK, which occurs in Anaplastic Large Cell Lymphoma (ALCL. Recently, both germline and somatic activating missense mutations of ALK have been identified in neuroblastoma (NB, a pediatric cancer arising from neural crest cells. Moreover, we previously reported that ALK expression is significantly upregulated in advanced/metastatic NB. We hypothesized that ALK function may depend on N-linked glycosylation and that disruption of this post-translational modification would impair ALK activation, regardless the presence of either gene mutations or overexpression. Methods We employed tunicamycin to inhibit N-linked glycosylation. The following ALK-positive NB cell lines were used: SH-SY5Y and KELLY (ALK mutation F1174L, UKF-NB3 (ALK mutation R1275Q and NB1 (ALK amplification. As a control, we used the NB cell lines LA1-5S and NB5 (no ALK expression, and the ALCL cell line SU-DHL1 (NPM-ALK. Results Tunicamycin treatment of ALK-positive NB cells resulted in a hypoglycosylated ALK band and in decreased amounts of mature full size receptor. Concomitantly, we observed a marked reduction of mature ALK phosphorylation. On the contrary, tunicamycin had no effects on NPM-ALK phosphorylation in SU-DHL1 cells. Moreover, phosphorylation levels of ALK downstream effectors (AKT, ERK1/2, STAT3 were clearly impaired only in ALK mutated/amplified NB cell lines, whereas no significant reduction was observed in both ALK-negative and NPM-ALK-positive cell lines. Furthermore, inhibition of N-linked glycosylation considerably impaired cell viability only of ALK mutated/amplified NB cells. Finally, the cleavage of the Poly-ADP-ribose-polymerase (PARP suggested that apoptotic pathways may be

  7. Impact of incretin hormones on beta-cell function in subjects with normal or impaired glucose tolerance

    DEFF Research Database (Denmark)

    Muscelli, Elza; Mari, Andrea; Natali, Andrea;

    2006-01-01

    The mechanisms by which the enteroinsular axis influences beta-cell function have not been investigated in detail. We performed oral and isoglycemic intravenous (IV) glucose administration in subjects with normal (NGT; n = 11) or impaired glucose tolerance (IGT; n = 10), using C-peptide deconvolu......The mechanisms by which the enteroinsular axis influences beta-cell function have not been investigated in detail. We performed oral and isoglycemic intravenous (IV) glucose administration in subjects with normal (NGT; n = 11) or impaired glucose tolerance (IGT; n = 10), using C......-like peptide 1 and glucose-dependent insulinotropic polypeptide responses, total insulin secretion, and enhancement of beta-cell glucose sensitivity (OGTT/IV ratio = 1.73 +/- 0.24, P = NS vs. NGT). However, the time courses of incretin-mediated insulin secretion and potentiation were altered......, with a predominance of glucose-induced vs. incretin-mediated stimulation. We conclude that, under physiological circumstances, incretin-mediated stimulation of insulin secretion results from an enhancement of all dynamic aspects of beta-cell function, particularly beta-cell glucose sensitivity. In IGT, beta...

  8. Dendritic cell-mediated HIV-1 transmission to T cells of LAD-1 patients is impaired due to the defect in LFA-1

    Directory of Open Access Journals (Sweden)

    Kuijpers Taco W

    2006-11-01

    Full Text Available Abstract Background Dendritic cells (DC have been proposed to mediate sexual HIV-1 transmission by capturing the virus in the mucosa and subsequently presenting it to CD4+ T cells. We have demonstrated before that DC subsets expressing higher levels of intercellular adhesion molecule-1 (ICAM-1 are better HIV-1 transmitters. ICAM-1 binds leukocyte function-associated molecule-1 (LFA-1 on T cells, an integrin responsible for adhesion and signaling at the immunological synapse. To corroborate the importance of the ICAM-1— LFA-1 interaction, we performed transmission experiments to LFA-1 negative leukocytes from Leukocyte Adhesion Deficiency type 1 (LAD-1 patients. Results We clearly show that DC-mediated HIV-1 transmission to LAD-1 T cells is impaired in comparison to healthy controls. Furthermore, HIV-1 transmission to T cells from a unique LAD-1 patient with a well characterized LFA-1 activation defect was impaired as well, demonstrating that activation of LFA-1 is crucial for efficient transmission. Decreased cell adhesion between DC and LAD-1 T cells could also be illustrated by significantly smaller DC-T cell clusters after HIV-1 transmission. Conclusion By making use of LFA-1 defect cells from unique patients, this study provides more insight into the mechanism of HIV-1 transmission by DC. This may offer new treatment options to reduce sexual transmission of HIV-1.

  9. Does Sex Influence the Impact That Smoking, Treatment Interruption and Impaired Pulmonary Function Have on Outcomes in Limited Stage Small Cell Lung Cancer Treatment?

    Directory of Open Access Journals (Sweden)

    Gregory MM Videtic

    2005-01-01

    Full Text Available PURPOSE: To look for survival differences between men and women with limited stage small cell lung cancer (LS-SCLC by examining stratified variables that impair treatment efficacy.

  10. Computer and cell phone access for individuals with mobility impairments: an overview and case studies.

    Science.gov (United States)

    Burgstahler, Sheryl; Comden, Dan; Lee, Sang-Mook; Arnold, Anthony; Brown, Kayla

    2011-01-01

    Computers, telephones, and assistive technology hold promise for increasing the independence, productivity, and participation of individuals with disabilities in academic, employment, recreation, and other activities. However, to reach this goal, technology must be accessible to, available to, and usable by everyone. The authors of this article share computer and telephone access challenges faced by individuals with neurological and other impairments, assistive technology solutions, issues that impact product adoption and use, needs for new technologies, and recommendations for practitioners and researchers. They highlight the stories of three individuals with neurological/mobility impairments, the technology they have found useful to them, and their recommendations for future product development. PMID:21558625

  11. Impaired blood dendritic cell numbers and functions after aneurysmal subarachnoid hemorrhage.

    Directory of Open Access Journals (Sweden)

    Antoine Roquilly

    Full Text Available PREVIOUS PRESENTATION: Portions of this study were presented at the Annual Congress of Société Française d'Anesthésie et de Réanimation in Paris, September 2012. BACKGROUND: Toll-like receptor (TLR agonists are promising therapy for the prevention of nosocomial infections in critical ill patients. We aimed to analyze the TLR-reactivity of circulating dendritic cells (DC as assessed by cytokine production after an ex vivo challenge with TLR agonists in aneurysmal subarachnoid hemorrhage (SAH patients. METHODS AND FINDINGS: A single-center prospective observational study took place in one intensive care unit of a teaching hospital. Blood samples were harvested on days 2, 5 and 10 in 21 severe SAH patients requiring mechanical ventilation and 17 healthy controls. DC production of cytokines (Tumour Necrosis Factor, TNF-α; Interleukin, IL-12; and Interferon, IFN-α was assessed by intracellular immunostaining on TLR-3, 4, 7/8 and 9 stimulations. SAH patients had decreased numbers of blood myeloid (mDCs and plasmacytoid DCs (pDCs on days 2, 5 and 10. Compared with the healthy controls, the frequency of mDCs producing TNF-α after TLR-3 stimulation was decreased in the SAH patients. The frequency of myeloid DCs producing IL-12 after TLR-3 and 4 stimulations was also decreased in the SAH patients. In contrast, the mDCs response to TLR-7/8 was not impaired in the SAH patients. The frequency of pDCs producing TNF-α(+ and IFN-α(+ on TLR-7/8 stimulation were reduced at all of the tested times in the SAH patients, whereas reactivity to TLR-9 was preserved. On day 2, the pDCs from non-survivor patients (n=8 had a decreased ability to produce IFN-α on TLR-9 stimulation compared with the survivors. CONCLUSIONS: These data suggest functional abnormalities of circulating pDCs and mDCs that could be important for immunomodulation after SAH.

  12. 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.

  13. Intravenous transplantation of bone marrow-derived mononuclear cells prevents memory impairment in transgenic mouse models of Alzheimer's disease.

    Science.gov (United States)

    Kanamaru, Takuya; Kamimura, Naomi; Yokota, Takashi; Nishimaki, Kiyomi; Iuchi, Katsuya; Lee, Hyunjin; Takami, Shinya; Akashiba, Hiroki; Shitaka, Yoshitsugu; Ueda, Masayuki; Katsura, Ken-Ichiro; Kimura, Kazumi; Ohta, Shigeo

    2015-04-24

    Stem cell transplantation therapy is currently in clinical trials for the treatment of ischemic stroke, and several beneficial aspects have been reported. Similarly, in Alzheimer's disease (AD), stem cell therapy is expected to provide an efficient therapeutic approach. Indeed, the intracerebral transplantation of stem cells reduced amyloid-β (Aβ) deposition and rescued memory deficits in AD model mice. Here, we show that intravenous transplantation of bone marrow-derived mononuclear cells (BMMCs) improves cognitive function in two different AD mouse models, DAL and APP mice, and prevents neurodegeneration. GFP-positive BMMCs were isolated from tibiae and femurs of 4-week-old mice and then transplanted intravenously into DAL and APP mice. Transplantation of BMMCs suppressed neuronal loss and restored memory impairment of DAL mice to almost the same level as in wild-type mice. Transplantation of BMMCs to APP mice reduced Aβ deposition in the brain. APP mice treated with BMMCs performed significantly better on behavioral tests than vehicle-injected mice. Moreover, the effects were observed even with transplantation after the onset of cognitive impairment in DAL mice. Together, our results indicate that intravenous transplantation of BMMCs has preventive effects against the cognitive decline in AD model mice and suggest a potential therapeutic effect of BMMC transplantation therapy.

  14. The DNase of gammaherpesviruses impairs recognition by virus-specific CD8+ T cells through an additional host shutoff function.

    Science.gov (United States)

    Zuo, Jianmin; Thomas, Wendy; van Leeuwen, Daphne; Middeldorp, Jaap M; Wiertz, Emmanuel J H J; Ressing, Maaike E; Rowe, Martin

    2008-03-01

    The DNase/alkaline exonuclease (AE) genes are well conserved in all herpesvirus families, but recent studies have shown that the AE proteins of gammaherpesviruses such as Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) exhibit an additional function which shuts down host protein synthesis. One correlate of this additional shutoff function is that levels of cell surface HLA molecules are downregulated, raising the possibility that shutoff/AE genes of gammaherpesviruses might contribute to viral immune evasion. In this study, we show that both BGLF5 (EBV) and SOX (KSHV) shutoff/AE proteins do indeed impair the ability of virus-specific CD8+ T-cell clones to recognize endogenous antigen via HLA class I. Random mutagenesis of the BGLF5 gene enabled us to genetically separate the shutoff and AE functions and to demonstrate that the shutoff function was the critical factor determining whether BGLF5 mutants can impair T-cell recognition. These data provide further evidence that EBV has multiple mechanisms to modulate HLA class I-restricted T-cell responses, thus enabling the virus to replicate and persist in the immune-competent host.

  15. Peroxisome proliferator-activated receptor gamma B cell-specific deficient mice have an impaired antibody response1

    Science.gov (United States)

    Ramon, Sesquile; Bancos, Simona; Thatcher, Thomas H.; Murant, Thomas I.; Moshkani, Safiehkhatoon; Sahler, Julie M.; Bottaro, Andrea; Sime, Patricia J.; Phipps, Richard P.

    2012-01-01

    Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily. PPARγ, a ligand activated transcription factor, has important anti-inflammatory and anti-proliferative functions and it has been associated with diseases including diabetes, scarring and atherosclerosis among others. PPARγ is expressed in most bone marrow derived cells and influences their function. PPARγ ligands can stimulate human B cell differentiation and promote antibody production. A knowledge gap is that the role of PPARγ in B cells under physiological conditions is not known. We developed a new B cell-specific PPARγ (B-PPARγ) knockout mouse and explored the role of PPARγ during both the primary and secondary immune response. Here, we show that PPARγ deficiency in B cells decreases germinal center B cells and plasma cell development as well as the levels of circulating antigen-specific antibodies during a primary challenge. Inability to generate germinal center B cells and plasma cells is correlated to decreased MHC class II expression and decreased Bcl-6 and Blimp-1 levels. Furthermore, B-PPARγ-deficient mice have an impaired memory response, characterized by low titers of antigen-specific antibodies and low numbers of antigen-experienced antibody-secreting cells. However, B-PPARγ-deficient mice have no differences in B cell population distribution within neither primary nor secondary lymphoid organs during development. This is the first report to show under physiological conditions that PPARγ expression in B cells is required for an efficient B cell-mediated immune response as it regulates B cell differentiation and antibody production. PMID:23041568

  16. Peroxisome proliferator-activated receptor γ B cell-specific-deficient mice have an impaired antibody response.

    Science.gov (United States)

    Ramon, Sesquile; Bancos, Simona; Thatcher, Thomas H; Murant, Thomas I; Moshkani, Safiehkhatoon; Sahler, Julie M; Bottaro, Andrea; Sime, Patricia J; Phipps, Richard P

    2012-11-15

    Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily. PPARγ, a ligand-activated transcription factor, has important anti-inflammatory and antiproliferative functions, and it has been associated with diseases including diabetes, scarring, and atherosclerosis, among others. PPARγ is expressed in most bone marrow-derived cells and influences their function. PPARγ ligands can stimulate human B cell differentiation and promote Ab production. A knowledge gap is that the role of PPARγ in B cells under physiological conditions is not known. We developed a new B cell-specific PPARγ (B-PPARγ) knockout mouse and explored the role of PPARγ during both the primary and secondary immune response. In this article, we show that PPARγ deficiency in B cells decreases germinal center B cells and plasma cell development, as well as the levels of circulating Ag-specific Abs during a primary challenge. Inability to generate germinal center B cells and plasma cells is correlated to decreased MHC class II expression and decreased Bcl-6 and Blimp-1 levels. Furthermore, B-PPARγ-deficient mice have an impaired memory response, characterized by low titers of Ag-specific Abs and low numbers of Ag-experienced, Ab-secreting cells. However, B-PPARγ-deficient mice have no differences in B cell population distribution within primary or secondary lymphoid organs during development. This is the first report, to our knowledge, to show that, under physiological conditions, PPARγ expression in B cells is required for an efficient B cell-mediated immune response as it regulates B cell differentiation and Ab production.

  17. Leydig cell micronodules are a common finding in testicular biopsies from men with impaired spermatogenesis and are associated with decreased testosterone/LH ratio

    DEFF Research Database (Denmark)

    Holm, Mette; Rajpert-De Meyts, Ewa; Andersson, Anna-Maria;

    2003-01-01

    . Leydig cell clusters of more than 15 cells in a cross-section, for which we proposed the name 'micronodules', were frequently seen in testicles exhibiting Sertoli-cell-only syndrome (SCO), a mixed pattern of impaired spermatogenesis, or complete spermatogenesis in combination with elevated FSH. Median...

  18. 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.

  19. N-Acetyl cysteine restores viability and function of rat odontoblast-like cells impaired by polymethylmethacrylate dental resin extract.

    Science.gov (United States)

    Yamada, Masahiro; Kojima, Norinaga; Att, Wael; Hori, Norio; Suzuki, Takeo; Ogawa, Takahiro

    2009-01-01

    There is concern that dental-resin materials directly loaded on a prepared tooth adversely affect dental pulp tissue by releasing the resin chemicals through dentinal tubes. This study determined whether self-curing polymethyl methacrylate (PMMA)-based dental resin extract adversely affected the viability and function of odontoblast-like cells and whether the cytotoxicity of this resin, if any, could be eliminated by N-acetyl cysteine, an antioxidant amino acid derivative. Odontoblast-like cells isolated from rat maxillary incisor dental pulp tissue were exposed to a PMMA resin extract with or without N-acetyl cysteine for 1 h and then cultured in osteoblastic media. The percentage of viable cells 24 h after seeding was 20% in cells exposed to the resin extract without N-acetyl cysteine, whereas 45% of cells were viable after exposure to the N-acetyl cysteine-supplemented extract. The cells that had been exposed to the extract showed a strong tendency for apoptosis associated with the increased reactive oxygen species production and decreased intracellular glutathione level, which was improved by the addition of N-acetyl cysteine. N-Acetyl cysteine supplementation almost completely restored the significantly reduced alkaline phosphatase activity and matrix mineralization by the resin extract. These results conclusively demonstrated that exposure of odontoblast-like cells to the resin extract impaired the cell viability and function and, more intriguingly, N-acetyl cysteine supplementation to the extract significantly prevented these toxic effects.

  20. Deletion of genes encoding PU.1 and Spi-B in B cells impairs differentiation and induces pre-B cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Sokalski, Kristen M; Li, Stephen K H; Welch, Ian; Cadieux-Pitre, Heather-Anne T; Gruca, Marek R; DeKoter, Rodney P

    2011-09-01

    The E26 transformation-specific (Ets) transcription factor PU.1 is required to generate lymphoid progenitor cells from hematopoietic stem cells, but it is not required to generate B cells from committed B-cell lineage progenitors. We hypothesized that PU.1 function in B-cell differentiation is complemented by the related Ets transcription factor Spi-B. To test this hypothesis, mice were generated lacking both PU.1 and Spi-B in the B-cell lineage. Unlike mice lacking PU.1 or Spi-B, mice deficient in both PU.1 and Spi-B in the B-cell lineage had reduced frequencies of B cells as well as impaired B-cell differentiation. Strikingly, all PU.1 and Spi-B-deficient mice developed pre-B cell acute lymphoblastic leukemia before 30 weeks of age. Pre-B cells accumulated in the thymus resulting in massive thymic enlargement and dyspnea. These findings demonstrate that PU.1 and Spi-B are essential transcriptional regulators of B-cell differentiation as well as novel tumor suppressors in the B-cell lineage.

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

    International Nuclear Information System (INIS)

    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

  2. Deletion of the von Hippel-Lindau gene causes sympathoadrenal cell death and impairs chemoreceptor-mediated adaptation to hypoxia.

    Science.gov (United States)

    Macías, David; Fernández-Agüera, Mary Carmen; Bonilla-Henao, Victoria; López-Barneo, José

    2014-12-01

    Mutations of the von Hippel-Lindau (VHL) gene are associated with pheochromocytomas and paragangliomas, but the role of VHL in sympathoadrenal homeostasis is unknown. We generated mice lacking Vhl in catecholaminergic cells. They exhibited atrophy of the carotid body (CB), adrenal medulla, and sympathetic ganglia. Vhl-null animals had an increased number of adult CB stem cells, although the survival of newly generated neuron-like glomus cells was severely compromised. The effects of Vhl deficiency were neither prevented by pharmacological inhibition of prolyl hydroxylases or selective genetic down-regulation of prolyl hydroxylase-3, nor phenocopied by hypoxia inducible factor overexpression. Vhl-deficient animals appeared normal in normoxia but survived for only a few days in hypoxia, presenting with pronounced erythrocytosis, pulmonary edema, and right cardiac hypertrophy. Therefore, in the normal sympathoadrenal setting, Vhl deletion does not give rise to tumors but impairs development and plasticity of the peripheral O₂-sensing system required for survival in hypoxic conditions.

  3. 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.

  4. Kaempferia parviflora extract ameliorates the cognitive impairments and the reduction in cell proliferation induced by valproic acid treatment in rats.

    Science.gov (United States)

    Welbat, Jariya Umka; Chaisawang, Pornthip; Chaijaroonkhanarak, Wunnee; Prachaney, Parichat; Pannangrong, Wanassanun; Sripanidkulchai, Bungorn; Wigmore, Peter

    2016-07-01

    Kaempferia parviflora is a herbal plant whose rhizomes are used in traditional medicine. Investigations of this plant have shown it to have antidepressant activity and to improve learning and memory in animal models. The aim of the present investigation was to determine whether K. parviflora could protect the brain from the impairments in cognition and hippocampal neurogenesis which are caused by valproic acid (VPA). Male Sprague Dawley rats (180-200g) were given once daily K. parviflora extract (100mg/kg) via oral gavage for 21 days. Rats received twice daily intraperitoneal injections of valproic acid (300mg/kg) from days 8 to 21 of the experiment. Spatial memory was tested using the novel object location (NOL) test five days after the end of treatment. Cell proliferation in the sub granular zone (SGZ) of the dentate gyrus was quantified by immunohistochemistry and levels of doublecortin (DCX) were determined by Western blotting. Co-treatment of VPA and K. parviflora prevented the cognitive decline and reduction in proliferating cells caused by VPA. Furthermore, co-treatment significantly increased DCX protein levels within the hippocampus. These findings demonstrate that K. parviflora is able to prevent the brain from VPA-induced the impairments of spatial memory and proliferating cells within the SGZ. PMID:27142346

  5. Immunotoxicity of aflatoxin B1: impairment of the cell-mediated response to vaccine antigen and modulation of cytokine expression.

    Science.gov (United States)

    Meissonnier, Guylaine M; Pinton, Philippe; Laffitte, Joëlle; Cossalter, Anne-Marie; Gong, Yun Yun; Wild, Christopher P; Bertin, Gérard; Galtier, Pierre; Oswald, Isabelle P

    2008-09-01

    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 microg 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-alpha, IL-1beta, IL-6, IFN-gamma) 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-gamma 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.

  6. Immunotoxicity of aflatoxin B1: Impairment of the cell-mediated response to vaccine antigen and modulation of cytokine expression

    International Nuclear Information System (INIS)

    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

  7. Lipodystrophy in human immunodeficiency virus patients impairs insulin action and induces defects in beta-cell function.

    Science.gov (United States)

    Andersen, Ove; Haugaard, Steen B; Andersen, Ulrik B; Friis-Møller, Nina; Storgaard, Heidi; Vølund, Aage; Nielsen, Jens Ole; Iversen, Johan; Madsbad, Sten

    2003-10-01

    The pathophysiology of insulin resistance in human immunodeficiency virus (HIV)-associated lipodystrophy syndrome (HALS) is not fully clarified. We investigated 18 men with HALS and 18 HIV-positive males without lipodystrophy (control subjects). Duration and modality of antiretroviral therapy were similar between study groups. A hyperinsulinemic euglycemic clamp showed an impaired glucose disposal rate (GDR) in HALS patients (5.6 v 8.3 mg glucose/min. kg(FFM), P =.0006). As demonstrated by indirect calorimetry, HALS patients showed an impaired nonoxidative glucose metabolism (NOGM, 2.2 v 4.2, P =.006), whereas levels of basal and insulin-stimulated oxidative glucose metabolism (OGM) (2.4 v 2.3, P =.55, and 3.3 v 4.0, P =.064, respectively) were not significantly different between groups. Despite comparable total fat masses, dual energy x-ray absorptiometry (DEXA) scans showed that the percentage of limb fat (ie, peripheral-fat-mass/[peripheral-fat-mass + trunk-fat-mass]. 100%) was reduced in HALS patients (36% v 46%, P =.0002). Multiple linear regression analysis indicated that percentage of limb fat explained 53% of the variability of GDR and 45% of the variability of NOGM in HALS patients. In HALS patients, leg fat mass correlated positively with NOGM (r =.51, P <.05), whereas abdominal fat mass and NOGM did not correlate (P =.91). Analyzing the relationship between first phase insulin secretion and insulin sensitivity, 6 HALS patients compared with none of the control subjects exhibited impaired insulin secretion (P <.05). Our data suggest that fat redistribution independently of antiretroviral therapy is highly related to insulin resistance in HALS patients. Furthermore, in HALS patients, impaired glucose metabolism most likely relates to decreased NOGM and to defects in beta-cell function.

  8. Studying post-stroke functional impairment after treatment with neural progenitor cells – an analysis of behavioral tests

    Directory of Open Access Journals (Sweden)

    Thorsten R. Doeppner

    2014-10-01

    Full Text Available Systemic transplantation of neural progenitor cells (NPCs in rodents reduces functional impairment after cerebral ischemia. In light of upcoming stroke trials regarding safety and feasibility of NPC transplantation, experimental studies have to successfully analyze the extent of NPC-induced neurorestoration on the functional level. However, appropriate behavioral tests for analysis of post-stroke motor coordination deficits and cognitive impairment after NPC grafting are not fully established. We therefore exposed male C57BL6 mice to either 45 min (mild or 90 min (severe of cerebral ischemia, using the thread occlusion model followed by intravenous injection of PBS or NPCs 6 h post-stroke with an observation period of three months. Post-stroke motor coordination was assessed by means of the rota rod, tight rope, corner turn, inclined plane, grip strength, foot fault, adhesive removal, pole test and balance beam test, whereas cognitive impairment was analyzed using the water maze, the open field and the passive avoidance test. Significant motor coordination differences after both mild and severe cerebral ischemia in favor of NPC-treated mice were observed for each motor coordination test except for the inclined plane and the grip strength test, which only showed significant differences after severe cerebral ischemia. Cognitive impairment after mild cerebral ischemia was successfully assessed using the water maze test, the open field and the passive avoidance test. On the contrary, the water maze test was not suitable in the severe cerebral ischemia paradigm, as it too much depends on motor coordination capabilities of test mice. In terms of both reliability and cost-effectiveness considerations, we thus recommend the corner turn, foot fault, balance beam, and open field test, which do not depend on durations of cerebral ischemia.

  9. Age-related impairment of humoral response to influenza is associated with changes in antigen specific T follicular helper cell responses.

    Science.gov (United States)

    Lefebvre, Julie S; Masters, April R; Hopkins, Jacob W; Haynes, Laura

    2016-01-01

    T follicular helper (TFH) cell responses are essential for generation of protective humoral immunity during influenza infection. Aging has a profound impact on CD4(+) T cell function and humoral immunity, yet the impact of aging on antigen specific TFH responses remains unclear. Influenza specific TFH cells are generated in similar numbers in young and aged animals during infection, but TFH cells from aged mice exhibit significant differences, including reduced expression of ICOS and elevated production of IL-10 and IFNγ, which potentially impairs interaction with cognate B cells. Also, more influenza specific T cells in aged mice have a regulatory phenotype, which could contribute to the impaired TFH function. Adoptive transfer studies with young T cells demonstrated that TGF-β1 in the aged environment can drive increased regulatory T cell accumulation. Aging and the aged environment thus impact antigen specific TFH cell function and formation, which contribute to reduced protective humoral responses. PMID:27109638

  10. Loss-of-function mutations in ATP6V0A2 impair vesicular trafficking, tropoelastin secretion and cell survival.

    Science.gov (United States)

    Hucthagowder, Vishwanathan; Morava, Eva; Kornak, Uwe; Lefeber, Dirk J; Fischer, Björn; Dimopoulou, Aikaterini; Aldinger, Annika; Choi, Jiwon; Davis, Elaine C; Abuelo, Dianne N; Adamowicz, Maciej; Al-Aama, Jumana; Basel-Vanagaite, Lina; Fernandez, Bridget; Greally, Marie T; Gillessen-Kaesbach, Gabriele; Kayserili, Hulya; Lemyre, Emmanuelle; Tekin, Mustafa; Türkmen, Seval; Tuysuz, Beyhan; Yüksel-Konuk, Berrin; Mundlos, Stefan; Van Maldergem, Lionel; Wevers, Ron A; Urban, Zsolt

    2009-06-15

    Autosomal recessive cutis laxa type 2 (ARCL2), a syndrome of growth and developmental delay and redundant, inelastic skin, is caused by mutations in the a2 subunit of the vesicular ATPase H+-pump (ATP6V0A2). The goal of this study was to define the disease mechanisms that lead to connective tissue lesions in ARCL2. In a new cohort of 17 patients, DNA sequencing of ATP6V0A2 detected either homozygous or compound heterozygous mutations. Considerable allelic and phenotypic heterogeneity was observed, with a missense mutation of a moderately conserved residue p.P87L leading to unusually mild disease. Abnormal N- and/or mucin type O-glycosylation was observed in all patients tested. Premature stop codon mutations led to decreased ATP6V0A2 mRNA levels by destabilizing the mutant mRNA via the nonsense-mediated decay pathway. Loss of ATP6V0A2 either by siRNA knockdown or in ARCL2 cells resulted in distended Golgi cisternae, accumulation of abnormal lysosomes and multivesicular bodies. Immunostaining of ARCL2 cells showed the accumulation of tropoelastin (TE) in the Golgi and in large, abnormal intracellular and extracellular aggregates. Pulse-chase studies confirmed impaired secretion and increased intracellular retention of TE, and insoluble elastin assays showed significantly reduced extracellular deposition of mature elastin. Fibrillin-1 microfibril assembly and secreted lysyl oxidase activity were normal in ARCL2 cells. TUNEL staining demonstrated increased rates of apoptosis in ARCL2 cell cultures. We conclude that loss-of-function mutations in ATP6V0A2 lead to TE aggregation in the Golgi, impaired clearance of TE aggregates and increased apoptosis of elastogenic cells.

  11. 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.

  12. 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.

  13. Endoplasmic Reticulum Stress Links Oxidative Stress to Impaired Pancreatic Beta-Cell Function Caused by Human Oxidized LDL

    Science.gov (United States)

    Favre, Dimitri; Ezanno, Hélène; Bonnefond, Amélie; Bonner, Caroline; Gmyr, Valéry; Kerr-Conte, Julie; Gauthier, Benoit R.; Widmann, Christian; Waeber, Gérard; Pattou, François; Froguel, Philippe; Abderrahmani, Amar

    2016-01-01

    Elevated plasma concentration of the pro-atherogenic oxidized low density lipoprotein cholesterol (LDL) triggers adverse effects in pancreatic beta-cells and is associated with type 2 diabetes. Here, we investigated whether the endoplasmic reticulum (ER) stress is a key player coupling oxidative stress to beta-cell dysfunction and death elicited by human oxidized LDL. We found that human oxidized LDL activates ER stress as evidenced by the activation of the inositol requiring 1α, and the elevated expression of both DDIT3 (also called CHOP) and DNAJC3 (also called P58IPK) ER stress markers in isolated human islets and the mouse insulin secreting MIN6 cells. Silencing of Chop and inhibition of ER stress markers by the chemical chaperone phenyl butyric acid (PBA) prevented cell death caused by oxidized LDL. Finally, we found that oxidative stress accounts for activation of ER stress markers induced by oxidized LDL. Induction of Chop/CHOP and p58IPK/P58IPK by oxidized LDL was mimicked by hydrogen peroxide and was blocked by co-treatment with the N-acetylcystein antioxidant. As a conclusion, the harmful effects of oxidized LDL in beta-cells requires ER stress activation in a manner that involves oxidative stress. This mechanism may account for impaired beta-cell function in diabetes and can be reversed by antioxidant treatment. PMID:27636901

  14. Lentivirus-mediated Gene Transfer in Hematopoietic Stem Cells Is Impaired in SHIV-infected, ART-treated Nonhuman Primates.

    Science.gov (United States)

    Younan, Patrick M; Peterson, Christopher W; Polacino, Patricia; Kowalski, John P; Obenza, Willimark; Miller, Hannah W; Milless, Brian P; Gafken, Phil; DeRosa, Stephen C; Hu, Shiu-Lok; Kiem, Hans-Peter

    2015-05-01

    Recent studies have demonstrated that genetically modified hematopoietic stem cells (HSCs) can reduce HIV viremia. We have developed an HIV/AIDS-patient model in Simian/human immunodeficiency virus (SHIV)-infected pigtailed macaques that are stably suppressed on antiretroviral therapy (ART: raltegravir, emtricitabine and tenofovir). Following SHIV infection and ART, animals undergo autologous HSC transplantation (HSCT) with lentivirally transduced cluster of differentiation (CD)34(+) cells expressing the mC46 anti-HIV fusion protein. We show that SHIV(+), ART-treated animals had very low gene marking levels after HSCT. Pretransduction CD34(+) cells contained detectable levels of all three ART drugs, likely contributing to the low gene transfer efficiency. Following HSCT recovery and the cessation of ART, plasma viremia rebounded, indicating that myeloablative total body irradiation cannot completely eliminate viral reservoirs after autologous HSCT. The kinetics of recovery following autologous HSCT in SHIV(+), ART-treated macaques paralleled those observed following transplantation of control animals. However, T-cell subset analyses demonstrated a high percentage of C-C chemokine receptor 5 (CCR5)-expressing CD4(+) T-cells after HSCT. These data suggest that an extended ART interruption time may be required for more efficient lentiviral transduction. To avoid complications associated with ART interruption in the context of high percentages of CD4(+)CCR5(+)T-cells after HSCT, the use of vector systems not impaired by the presence of residual ART may also be beneficial. PMID:25648264

  15. Endoplasmic Reticulum Stress Links Oxidative Stress to Impaired Pancreatic Beta-Cell Function Caused by Human Oxidized LDL.

    Science.gov (United States)

    Plaisance, Valérie; Brajkovic, Saška; Tenenbaum, Mathie; Favre, Dimitri; Ezanno, Hélène; Bonnefond, Amélie; Bonner, Caroline; Gmyr, Valéry; Kerr-Conte, Julie; Gauthier, Benoit R; Widmann, Christian; Waeber, Gérard; Pattou, François; Froguel, Philippe; Abderrahmani, Amar

    2016-01-01

    Elevated plasma concentration of the pro-atherogenic oxidized low density lipoprotein cholesterol (LDL) triggers adverse effects in pancreatic beta-cells and is associated with type 2 diabetes. Here, we investigated whether the endoplasmic reticulum (ER) stress is a key player coupling oxidative stress to beta-cell dysfunction and death elicited by human oxidized LDL. We found that human oxidized LDL activates ER stress as evidenced by the activation of the inositol requiring 1α, and the elevated expression of both DDIT3 (also called CHOP) and DNAJC3 (also called P58IPK) ER stress markers in isolated human islets and the mouse insulin secreting MIN6 cells. Silencing of Chop and inhibition of ER stress markers by the chemical chaperone phenyl butyric acid (PBA) prevented cell death caused by oxidized LDL. Finally, we found that oxidative stress accounts for activation of ER stress markers induced by oxidized LDL. Induction of Chop/CHOP and p58IPK/P58IPK by oxidized LDL was mimicked by hydrogen peroxide and was blocked by co-treatment with the N-acetylcystein antioxidant. As a conclusion, the harmful effects of oxidized LDL in beta-cells requires ER stress activation in a manner that involves oxidative stress. This mechanism may account for impaired beta-cell function in diabetes and can be reversed by antioxidant treatment. PMID:27636901

  16. The ethanol response gene Cab45 can modulate the impairment elicited by ethanol and ultraviolet in PC12 cells

    Institute of Scientific and Technical Information of China (English)

    Yunfeng Zhu; Quanli Wang; Wangru Xu; Sha Li

    2008-01-01

    High consumption of ethanolic beverages facilitates neurodegeneration,but the mechanism of this process still remained elusive.Suppression subtractive hybridization (SSH) is a technique for detection of rare transcripts.With SSH approach,we identified one ethanol response gene Cab45,which was down-regulated by ethanol with time-dependent manner in B104 cells.The full-length sequence of Cab45 gene was obtained by 5'-RACE (5'Rapid Amplification of cDNA Ends) for the first time in rat.Based on the sequence of deduced amino acid of rat Cab45,the alignment was conducted with its counterparts in different species and displayed a high conservation.Using different tissues in rat and cell lines,Cab45 was characterized by a ubiquitous expression and differentiation dependent down-regulation.Given that ethanol facilitates some cell differentiation,we hypothesize that Cab45 is involved in ethanol-mediated differentiation.With transient transfection,the function of Cab45 was investigated by up-regulation and down-regulation in PC12 cells.Ethanol treatment and UV exposure were conducted subsequently and cell proliferations were detected by MTT (Methyl Thiazolyl Tetrazolium) approach.It revealed that the up-regulation of Cab45 modulated the impairment elicited by ethanol and UV in transfected cells.As a member of new calcium binding protein family,the exact role of Cab45 still remains unclear.

  17. A potential role of karyopherin a2 in the impaired maturation of dendritic cells observed in glioblastoma patients

    Directory of Open Access Journals (Sweden)

    Konstantinos Gousias

    2015-03-01

    Full Text Available Aim: Patients with glioblastomas demonstrate well-documented immunological impairments including decreased numbers of mature dendritic cells (DCs. Recent data identified karyopherin a2 (KPNA2, a nucleocytoplasmic shuttling receptor, as diagnostic and prognostic biomarker for gliomas. The aim of this ongoing study is to correlate parameters of immunity and nucleocytoplasmic transport in glioblastoma patients. Methods: We preoperatively collected serum from 17 patients with glioblastomas and determined DC subsets (HLA DR+ Lin-, CD34-, CD45+, CD123+, CD11+ were analyzed using a 6-color flow cytometry panel. Expression levels of KPNA2 and nuclear accumulation of p53 were evaluated semi-quantitatively by immunohistochemistry. O6-methylguanine DNA methyltransferase (MGMT and isocitrate dehydrogenase-1 (IDH-1 status were assessed by pyrosequencing and immunohistochemistry, respectively. Results: Median expression levels for both KPNA2 and p53 were 5-10%. IDH-1-R132H mutation and MGMT promoter hypermethylation was detected in 3/16 and 1/9 patients, respectively. Mean counts of total mature DCs, myeloid DCs and plasmacytoid DCs were 9.6, 2.1, 3.4 cells/μL. A preliminary analysis suggests an association between low KPNA2 nuclear expression and increased numbers of mature DCs. However, this correlation did not reach statistical significance so far (P = 0.077. Conclusion: Our preliminary data may indicate a role of KPNA2 in the impaired maturation of DCs observed in glioblastoma patients.

  18. 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.

  19. PD-L1 expression induced by the 2009 pandemic influenza A(H1N1) virus impairs the human T cell response.

    Science.gov (United States)

    Valero-Pacheco, Nuriban; Arriaga-Pizano, Lourdes; Ferat-Osorio, Eduardo; Mora-Velandia, Luz María; Pastelin-Palacios, Rodolfo; Villasís-Keever, Miguel Ángel; Alpuche-Aranda, Celia; Sánchez-Torres, Luvia Enid; Isibasi, Armando; Bonifaz, Laura; López-Macías, Constantino

    2013-01-01

    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(H1N1)pdm09), and its effects on the T cell response have not been widely explored. We found that A(H1N1)pdm09 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(H1N1)pdm09 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(H1N1)pdm09. Therefore, PD-L1 expression on DCs and T cells could be associated with an impaired T cell response during acute infection with A(H1N1)pdm09 virus.

  20. PD-L1 Expression Induced by the 2009 Pandemic Influenza A(H1N1) Virus Impairs the Human T Cell Response

    Science.gov (United States)

    Arriaga-Pizano, Lourdes; Ferat-Osorio, Eduardo; Mora-Velandia, Luz María; Pastelin-Palacios, Rodolfo; Villasís-Keever, Miguel Ángel; Alpuche-Aranda, Celia; Sánchez-Torres, Luvia Enid; Isibasi, Armando; Bonifaz, Laura; López-Macías, Constantino

    2013-01-01

    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(H1N1)pdm09), and its effects on the T cell response have not been widely explored. We found that A(H1N1)pdm09 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(H1N1)pdm09 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(H1N1)pdm09. Therefore, PD-L1 expression on DCs and T cells could be associated with an impaired T cell response during acute infection with A(H1N1)pdm09 virus. PMID:24187568

  1. Crohn's disease intestinal CD4+ T cells have impaired interleukin-10 productionwhich is not restored by probiotic bacteria

    DEFF Research Database (Denmark)

    Hvas, Christian L; Kelsen, Jens; Agnholt, Jørgen;

    2007-01-01

    /ml+/-standard error of the mean 1.1 ng/ml) but low levels of IL-10 (0.7 ng/ml+/-0.1 ng/ml). In contrast, HV intestinal T cells produced less IFN-gamma (3.9 ng/ml+/-0.8 ng/ml, p=0.06) and more IL-10 (4.6 ng/ml+/-0.9 ng/ml, p=0.0001) than CD intestinal T cells. Co-culture with Lactobacilli failed to revert...... a pro-inflammatory cytokine profile with impaired production of the regulatory cytokine IL-10. Tolerogenic bacteria (Lactobacilli) failed to restore this regulatory defect....

  2. Bone marrow-derived mesenchymal stem cells improve diabetes-induced cognitive impairment by exosome transfer into damaged neurons and astrocytes

    OpenAIRE

    Masako Nakano; Kanna Nagaishi; Naoto Konari; Yuki Saito; Takako Chikenji; Yuka Mizue; Mineko Fujimiya

    2016-01-01

    The incidence of dementia is higher in diabetic patients, but no effective treatment has been developed. This study showed that rat bone marrow mesenchymal stem cells (BM-MSCs) can improve the cognitive impairments of STZ-diabetic mice by repairing damaged neurons and astrocytes. The Morris water maze test demonstrated that cognitive impairments induced by diabetes were significantly improved by intravenous injection of BM-MSCs. In the CA1 region of the hippocampus, degeneration of neurons an...

  3. 5-Azacytidine Promotes an Inhibitory T-Cell Phenotype and Impairs Immune Mediated Antileukemic Activity

    Directory of Open Access Journals (Sweden)

    Thomas Stübig

    2014-01-01

    Full Text Available Demethylating agent, 5-Azacytidine (5-Aza, has been shown to be active in treatment of myeloid malignancies. 5-Aza enhances anticancer immunity, by increasing expression of tumor-associated antigens. However, the impact of 5-Aza immune responses remains poorly understood. Here, T-cell mediated tumor immunity effects of 5-Aza, are investigated in vitro and in vivo. T-cells from healthy donors were treated with 5-Aza and analyzed by qRT-PCR and flow cytometry for changes in gene expression and phenotype. Functionality was assessed by a tumor lysis assay. Peripheral blood from patients treated with 5-Aza after alloSCT was monitored for changes in T-cell subpopulations. 5-Aza treatment resulted in a decrease in CD8+ T-cells, whereas CD4+ T-cells increased. Furthermore, numbers of IFN-γ+ T-helper 1 cells (Th1 were reduced, while Treg-cells showed substantial increase. Additionally, CD8+ T-cells exhibited limited killing capacity against leukemic target cells. In vivo data confirm the increase of Treg compartment, while CD8+ T-effector cell numbers were reduced. 5-Aza treatment results in a shift from cytotoxic to regulatory T-cells with a functional phenotype and a major reduction in proinflammatory Th1-cells, indicating a strong inhibition of tumor-specific T-cell immunity by 5-Aza.

  4. 5-Azacytidine Promotes an Inhibitory T-Cell Phenotype and Impairs Immune Mediated Antileukemic Activity

    Science.gov (United States)

    Stübig, Thomas; Luetkens, Tim; Hildebrandt, York; Atanackovic, Djordje; Binder, Thomas M. C.; Fehse, Boris; Kröger, Nicolaus

    2014-01-01

    Demethylating agent, 5-Azacytidine (5-Aza), has been shown to be active in treatment of myeloid malignancies. 5-Aza enhances anticancer immunity, by increasing expression of tumor-associated antigens. However, the impact of 5-Aza immune responses remains poorly understood. Here, T-cell mediated tumor immunity effects of 5-Aza, are investigated in vitro and in vivo. T-cells from healthy donors were treated with 5-Aza and analyzed by qRT-PCR and flow cytometry for changes in gene expression and phenotype. Functionality was assessed by a tumor lysis assay. Peripheral blood from patients treated with 5-Aza after alloSCT was monitored for changes in T-cell subpopulations. 5-Aza treatment resulted in a decrease in CD8+ T-cells, whereas CD4+ T-cells increased. Furthermore, numbers of IFN-γ+ T-helper 1 cells (Th1) were reduced, while Treg-cells showed substantial increase. Additionally, CD8+ T-cells exhibited limited killing capacity against leukemic target cells. In vivo data confirm the increase of Treg compartment, while CD8+ T-effector cell numbers were reduced. 5-Aza treatment results in a shift from cytotoxic to regulatory T-cells with a functional phenotype and a major reduction in proinflammatory Th1-cells, indicating a strong inhibition of tumor-specific T-cell immunity by 5-Aza. PMID:24757283

  5. 5-azacytidine promotes an inhibitory T-cell phenotype and impairs immune mediated antileukemic activity.

    Science.gov (United States)

    Stübig, Thomas; Badbaran, Anita; Luetkens, Tim; Hildebrandt, York; Atanackovic, Djordje; Binder, Thomas M C; Fehse, Boris; Kröger, Nicolaus

    2014-01-01

    Demethylating agent, 5-Azacytidine (5-Aza), has been shown to be active in treatment of myeloid malignancies. 5-Aza enhances anticancer immunity, by increasing expression of tumor-associated antigens. However, the impact of 5-Aza immune responses remains poorly understood. Here, T-cell mediated tumor immunity effects of 5-Aza, are investigated in vitro and in vivo. T-cells from healthy donors were treated with 5-Aza and analyzed by qRT-PCR and flow cytometry for changes in gene expression and phenotype. Functionality was assessed by a tumor lysis assay. Peripheral blood from patients treated with 5-Aza after alloSCT was monitored for changes in T-cell subpopulations. 5-Aza treatment resulted in a decrease in CD8+ T-cells, whereas CD4+ T-cells increased. Furthermore, numbers of IFN-γ + T-helper 1 cells (Th1) were reduced, while Treg-cells showed substantial increase. Additionally, CD8+ T-cells exhibited limited killing capacity against leukemic target cells. In vivo data confirm the increase of Treg compartment, while CD8+ T-effector cell numbers were reduced. 5-Aza treatment results in a shift from cytotoxic to regulatory T-cells with a functional phenotype and a major reduction in proinflammatory Th1-cells, indicating a strong inhibition of tumor-specific T-cell immunity by 5-Aza. PMID:24757283

  6. Aldosterone increases oxidant stress to impair guanylyl cyclase activity by cysteinyl thiol oxidation in vascular smooth muscle cells.

    Science.gov (United States)

    Maron, Bradley A; Zhang, Ying-Yi; Handy, Diane E; Beuve, Annie; Tang, Shiow-Shih; Loscalzo, Joseph; Leopold, Jane A

    2009-03-20

    Hyperaldosteronism is associated with impaired endothelium-dependent vascular reactivity owing to increased reactive oxygen species and decreased bioavailable nitric oxide (NO(.)); however, the effects of aldosterone on vasodilatory signaling pathways in vascular smooth muscle cells (VSMC) remain unknown. Soluble guanylyl cyclase (GC) is a heterodimer that is activated by NO(.) to convert cytosolic GTP to cGMP, a second messenger required for normal VSMC relaxation. Here, we show that aldosterone (10(-9)-10(-7) mol/liter) diminishes GC activity by activating NADPH oxidase in bovine aortic VSMC to increase reactive oxygen species levels and induce oxidative posttranslational modification(s) of Cys-122, a beta(1)-subunit cysteinyl residue demonstrated previously to modulate NO(.) sensing by GC. In VSMC treated with aldosterone, Western immunoblotting detected evidence of GC beta(1)-subunit disulfide bonding, whereas mass spectrometry analysis of a homologous peptide containing the Cys-122-bearing sequence exposed to conditions of increased oxidant stress confirmed cysteinyl sulfinic acid (m/z 435), sulfonic acid (m/z 443), and disulfide (m/z 836) bond formation. The functional effect of these modifications was examined by transfecting COS-7 cells with wild-type GC or mutant GC containing an alanine substitution at Cys-122 (C122A). Exposure to aldosterone or hydrogen peroxide (H(2)O(2)) significantly decreased cGMP levels in cells expressing wild-type GC. In contrast, aldosterone or H(2)O(2) did not influence cGMP levels in cells expressing the mutant C122A GC, confirming that oxidative modification of Cys-122 specifically impairs GC activity. These findings demonstrate that pathophysiologically relevant concentrations of aldosterone increase oxidant stress to convert GC to an NO(.)-insensitive state, resulting in disruption of normal vasodilatory signaling pathways in VSMC.

  7. Salmonella impairs CD8 T cell response through PD-1: PD-L axis.

    Science.gov (United States)

    López-Medina, Marcela; Carrillo-Martín, Ismael; Leyva-Rangel, Jessica; Alpuche-Aranda, Celia; Ortiz-Navarrete, Vianney

    2015-12-01

    We have shown that Salmonella remains for a long period of time within B cells, plasma cells, and bone marrow B cell precursors, which might allow persistence and dissemination of infection. Nonetheless, how infected cells evade CD8 T cell response has not been characterized. Evidence indicates that some pathogens exploit the PD-1: PD-L (PD-L1 and PD-L2) interaction to inhibit CD8 T cells response to contribute the chronicity of the infection. To determine whether the PD-1: PD-L axis plays a role during Salmonella infection; we evaluated PD-1 expression in antigen-specific CD8 T cells and PD-1 ligands in Salmonella-infected cells. Our results show that infected B cells and macrophages express continuously co-stimulatory (CD40, CD80, and CD86) and inhibitory molecules (PD-L1 and PD-L2) in early and late stages of chronic Salmonella infection, while antigen-specific CD8 T cells express in a sustained manner PD-1 in the late stages of infection. Blocking this axis restores the ability of the CD8 T cells to proliferate and eliminate primary infected APCs. Therefore, a continuous PD-1: PDL interaction might be a mechanism employed by Salmonella to negatively regulate Salmonella-specific CD8 T cell cytotoxic response in order to remain within the host for a long period of time.

  8. DOCK8 deficiency impairs CD8 T cell survival and function in humans and mice

    Science.gov (United States)

    Randall, Katrina L.; Chan, Stephanie S.-Y.; Ma, Cindy S.; Fung, Ivan; Mei, Yan; Yabas, Mehmet; Tan, Andy; Arkwright, Peter D.; Al Suwairi, Wafaa; Lugo Reyes, Saul Oswaldo; Yamazaki-Nakashimada, Marco A.; de la Luz Garcia-Cruz, Maria; Smart, Joanne M.; Picard, Capucine; Okada, Satoshi; Jouanguy, Emmanuelle; Casanova, Jean-Laurent; Lambe, Teresa; Cornall, Richard J.; Russell, Sarah; Oliaro, Jane; Tangye, Stuart G.; Bertram, Edward M.

    2011-01-01

    In humans, DOCK8 immunodeficiency syndrome is characterized by severe cutaneous viral infections. Thus, CD8 T cell function may be compromised in the absence of DOCK8. In this study, by analyzing mutant mice and humans, we demonstrate a critical, intrinsic role for DOCK8 in peripheral CD8 T cell survival and function. DOCK8 mutation selectively diminished the abundance of circulating naive CD8 T cells in both species, and in DOCK8-deficient humans, most CD8 T cells displayed an exhausted CD45RA+CCR7− phenotype. Analyses in mice revealed the CD8 T cell abnormalities to be cell autonomous and primarily postthymic. DOCK8 mutant naive CD8 T cells had a shorter lifespan and, upon encounter with antigen on dendritic cells, exhibited poor LFA-1 synaptic polarization and a delay in the first cell division. Although DOCK8 mutant T cells underwent near-normal primary clonal expansion after primary infection with recombinant influenza virus in vivo, they showed greatly reduced memory cell persistence and recall. These findings highlight a key role for DOCK8 in the survival and function of human and mouse CD8 T cells. PMID:22006977

  9. 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.

  10. Aberrant mural cell recruitment to lymphatic vessels and impaired lymphatic drainage in a murine model of pulmonary fibrosis.

    Science.gov (United States)

    Meinecke, Anna-Katharina; Nagy, Nadine; Lago, Gabriela D'Amico; Kirmse, Santina; Klose, Ralph; Schrödter, Katrin; Zimmermann, Annika; Helfrich, Iris; Rundqvist, Helene; Theegarten, Dirk; Anhenn, Olaf; Orian-Rousseau, Véronique; Johnson, Randall S; Alitalo, Kari; Fischer, Jens W; Fandrey, Joachim; Stockmann, Christian

    2012-06-14

    Pulmonary fibrosis is a progressive disease with unknown etiology that is characterized by extensive remodeling of the lung parenchyma, ultimately resulting in respiratory failure. Lymphatic vessels have been implicated with the development of pulmonary fibrosis, but the role of the lymphatic vasculature in the pathogenesis of pulmonary fibrosis remains enigmatic. Here we show in a murine model of pulmonary fibrosis that lymphatic vessels exhibit ectopic mural coverage and that this occurs early during the disease. The abnormal lymphatic vascular patterning in fibrotic lungs was driven by expression of platelet-derived growth factor B (PDGF-B) in lymphatic endothelial cells and signaling through platelet-derived growth factor receptor (PDGFR)-β in associated mural cells. Because of impaired lymphatic drainage, aberrant mural cell coverage fostered the accumulation of fibrogenic molecules and the attraction of fibroblasts to the perilymphatic space. Pharmacologic inhibition of the PDGF-B/PDGFR-β signaling axis disrupted the association of mural cells and lymphatic vessels, improved lymphatic drainage of the lung, and prevented the attraction of fibroblasts to the perilymphatic space. Our results implicate aberrant mural cell recruitment to lymphatic vessels in the pathogenesis of pulmonary fibrosis and that the drainage capacity of pulmonary lymphatics is a critical mediator of fibroproliferative changes.

  11. Prolonged Treatment with Propofol Transiently Impairs Proliferation but Not Survival of Rat Neural Progenitor Cells In Vitro.

    Science.gov (United States)

    Palanisamy, Arvind; Friese, Matthew B; Cotran, Emily; Moller, Ludde; Boyd, Justin D; Crosby, Gregory; Culley, Deborah J

    2016-01-01

    Neurocognitive dysfunction is common in survivors of intensive care. Prolonged sedation has been implicated but the mechanisms are unclear. Neurogenesis continues into adulthood and is implicated in learning. The neural progenitor cells (NPC) that drive neurogenesis have receptors for the major classes of sedatives used clinically, suggesting that interruption of neurogenesis may partly contribute to cognitive decline in ICU survivors. Using an in vitro system, we tested the hypothesis that prolonged exposure to propofol concentration- and duration-dependently kills or markedly decreases the proliferation of NPCs. NPCs isolated from embryonic day 14 Sprague-Dawley rat pups were exposed to 0, 2.5, or 5.0 μg/mL of propofol, concentrations consistent with deep clinical anesthesia, for either 4 or 24 hours. Cells were assayed for cell death and proliferation either immediately following propofol exposure or 24 hours later. NPC death and apoptosis were measured by propidium iodine staining and cleaved caspase-3 immunocytochemistry, respectively, while proliferation was measured by EdU incorporation. Staurosporine (1μM for 6h) was used as a positive control for cell death. Cells were analyzed with unbiased high-throughput immunocytochemistry. There was no cell death at either concentration of propofol or duration of exposure. Neither concentration of propofol impaired NPC proliferation when exposure lasted 4 h, but when exposure lasted 24 h, propofol had an anti-proliferative effect at both concentrations (P < 0.0001, propofol vs. control). However, this effect was transient; proliferation returned to baseline 24 h after discontinuation of propofol (P = 0.37, propofol vs. control). The transient but reversible suppression of NPC proliferation, absence of cytotoxicity, and negligible effect on the neural stem cell pool pool suggest that propofol, even in concentrations used for clinical anesthesia, has limited impact on neural progenitor cell biology. PMID:27379684

  12. 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.

  13. Impaired selective cytokine production by CD4(+) T cells in Common Variable Immunodeficiency associated with the absence of memory B cells.

    Science.gov (United States)

    Berrón-Ruiz, Laura; López-Herrera, Gabriela; Vargas-Hernández, Alexander; Santos-Argumedo, Leopoldo; López-Macías, Constantino; Isibasi, Armando; Segura-Méndez, Nora Hilda; Bonifaz, Laura

    2016-05-01

    Common Variable Immunodeficiency (CVID) is a primary immunodeficiency characterized by B cell dysfunction and decreased serum immunoglobulin. CVID patients are classified by the absence or presence of memory B cells. In addition, T cell defects have been demonstrated in only a proportion of CVID patients. The aim of this study was to evaluate the function of CD4(+) T cells from CVID patients and its association with memory B cells. Patients were classified according to their Freiburg groups: group Ia and Ib, with decreased switched memory B cells (<0.4 of PBL), and group II, with normal B cell subsets. Their T cell function was evaluated after stimulation. We observed normal and even increased CD4(+) T cell proliferation in group Ia (p=0.0277). The proliferation positively correlated with the clinical severity score (r=0.4796). We observed lower levels of IL-17A and IL-10 in group Ia (p=0.0177, 0.0109) and Ib (p=0.0009, 0.0084) patients. Group Ib patients also had low levels of IL-13 and IL-9 (p=0.0169, 0.010). Group II patients had similar cytokine production to that of the controls. BAFFR expression was reduced in groups Ia (p=0.0001) and Ib (p=0.0002) and showed an inverse correlation with the severity score (p=0.0262; r=0.5371). ICOS expression was reduced in group Ia (p=0.0364), and PD-1 was increased in group Ib (p=0.0432) patients. This study shows a selective impairment in cytokine production in group Ia patients, which was more extensive than in group Ib patients. The impairment was associated with BAFFR expression in B cells, with ICOS and PD-1 in T cells and, remarkably, with the absence of memory B cells and with the disease severity. Our results suggest that the evaluation of cytokine expression by T cells in combination with the study of B cell memory could be important for understand the pathogenesis of CVID patients.

  14. 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.

  15. Rapamycin Impairs Antitumor CD8+ T-cell Responses and Vaccine-Induced Tumor Eradication.

    Science.gov (United States)

    Chaoul, Nada; Fayolle, Catherine; Desrues, Belinda; Oberkampf, Marine; Tang, Alexandre; Ladant, Daniel; Leclerc, Claude

    2015-08-15

    The metabolic sensor mTOR broadly regulates cell growth and division in cancer cells, leading to a significant focus on studies of rapamycin and its analogues as candidate anticancer drugs. However, mTOR inhibitors have failed to produce useful clinical efficacy, potentially because mTOR is also critical in T cells implicated in immunosurveillance. Indeed, recent studies using rapamycin have demonstrated the important role of mTOR in differentiation and induction of the CD8+ memory in T-cell responses associated with antitumor properties. In this study, we demonstrate that rapamycin harms antitumor immune responses mediated by T cells in the setting of cancer vaccine therapy. Specifically, we analyzed how rapamycin affects the antitumor efficacy of a human papilloma virus E7 peptide vaccine (CyaA-E7) capable of eradicating tumors in the TC-1 mouse model of cervical cancer. In animals vaccinated with CyaA-E7, rapamycin administration completely abolished recruitment of CD8+ T cells into TC-1 tumors along with the ability of the vaccine to reduce infiltration of T regulatory cells and myeloid-derived suppressor cells. Moreover, rapamycin completely abolished vaccine-induced cytotoxic T-cell responses and therapeutic activity. Taken together, our results demonstrate the powerful effects of mTOR inhibition in abolishing T-cell-mediated antitumor immune responses essential for the therapeutic efficacy of cancer vaccines.

  16. Loss of quiescence and impaired function of CD34+/CD38low cells one year following autologous stem cell transplantation

    OpenAIRE

    Woolthuis, Carolien M.; Brouwers-Vos, Annet Z.; Huls, Gerwin; de Wolf, Joost Th. M.; Schuringa, Jan Jacob; Vellenga, Edo

    2013-01-01

    Patients who have undergone autologous stem cell transplantation are subsequently more susceptible to chemotherapy-induced bone marrow toxicity. In the present study, bone marrow primitive progenitor cells were examined one year after autologous stem cell transplantation and compared with normal bone marrow and mobilized peripheral blood stem cells. Post-transplantation bone marrow contained a significantly lower percentage of quiescent cells in the CD34+/CD38low fraction compared to normal b...

  17. A Fluidic Cell Embedded Electromagnetic Wave Sensor for Online Indication of Neurological Impairment during Surgical Procedures

    International Nuclear Information System (INIS)

    Lactate is known to be an indicator of neurological impairment during aortic aneurysm surgery. It is suggested that cerebrospinal fluid removed during such surgery could provide useful information in this regard. Medical professionals find the prospect of online detection of such analytes exciting, as current practice is time consuming and leads to multiple invasive procedures. Advancing from the current laboratory based analysis techniques to online methods could provide the basis for improved treatment regimes, better quality of care, and enhanced resource efficiency within hospitals. Accordingly, this article considers the use of a low power fluidic system with embedded electromagnetic wave sensor to detect varying lactate concentrations. Results are promising over the physiological range of 0 − 20 mmol/L with a calibration curve demonstrating an R2 value > 0.98.

  18. Impaired expression of the mitochondrial calcium uniporter suppresses mast cell degranulation.

    Science.gov (United States)

    Furuno, Tadahide; Shinkai, Narumi; Inoh, Yoshikazu; Nakanishi, Mamoru

    2015-12-01

    Calcium ion (Ca(2+)) uptake into the mitochondrial matrix influences ATP production, Ca(2+) homeostasis, and apoptosis regulation. Ca(2+) uptake across the ion-impermeable inner mitochondrial membrane is mediated by the mitochondrial Ca(2+) uniporter (MCU) complex. The MCU complex forms a pore structure composed of several proteins. MCU is a Ca(2+)-selective channel in the inner-mitochondrial membrane that allows electrophoretic Ca(2+) entry into the matrix. Mitochondrial Ca(2+) uptake 1 (MICU1) functions as a Ca(2+)-sensing regulator of the MCU complex. Previously, by microscopic analysis at the single-cell level, we found that during mast cell activation, mitochondria capture cytosolic Ca(2+) in two steps. Consequently, mitochondrial Ca(2+) uptake likely plays a role in cellular function through cytosolic Ca(2+) buffering. Here, we investigate the role of MCU and MICU1 in mitochondrial Ca(2+) uptake and mast cell degranulation using MCU- and MICU1-knockdown (KD) mast cells. Whereas MCU- and MICU1-KD mast cells show normal proliferation rates and mitochondrial membrane potential, they exhibit slow and reduced cytosolic and mitochondrial Ca(2+) elevation after antigen stimulation. Moreover, β-hexosaminidase release induced by antigen was significantly suppressed in MCU-KD cells but not MICU1-KD cells. This suggests that both MCU and MICU1 are involved in mitochondrial Ca(2+) uptake in mast cells, while MCU plays a role in mast cell degranulation.

  19. Individual with subclinical atherosclerosis have impaired proliferation of blood outgrowth endothelial cells, which can be restored by statin therapy.

    Directory of Open Access Journals (Sweden)

    Javier Martin-Ramirez

    Full Text Available BACKGROUND: To study the regenerative capacity of the endothelium in patients with coronary artery disease (CAD, we cultured blood outgrowth endothelial cells (BOECs of patients with premature CAD and their first degree relatives (FDR. Additionally we evaluated the influence of statin treatment on circulating BOEC precursors in subjects with subclinical atherosclerosis. METHODS AND RESULTS: Patients with premature CAD (men 0. We did not observe differences in the number of BOEC colonies and proliferation between premature CAD patients and FDRs. FDRs with subclinical atherosclerosis had lower colony numbers compared with healthy FDRs, however this was not statistically significant, and BOEC proliferation was significantly impaired (OR = 0.45, 95% CI 0.21-0.96. Unexpectedly, the number of BOEC colonies and BOEC proliferation were similar for premature CAD patients and healthy FDRs. Since a considerable number of premature CAD patients used statins, we studied the number of BOEC precursors as well as their proliferative capacity in ten individuals with subclinical atherosclerosis, before and after statin therapy. Interestingly, FDRs with subclinical atherosclerosis showed a significant increase in the number of BOEC colonies after statin therapy. CONCLUSION: BOEC proliferation of subjects with subclinical atherosclerosis is impaired compared with healthy controls. In these subjects, statin therapy significantly increased the number of circulating BOEC precursors as well as their proliferative capacity, revealing a beneficial effect of statins on endothelial regeneration.

  20. Impaired LRP6-TCF7L2 Activity Enhances Smooth Muscle Cell Plasticity and Causes Coronary Artery Disease

    Directory of Open Access Journals (Sweden)

    Roshni Srivastava

    2015-10-01

    Full Text Available Mutations in Wnt-signaling coreceptor LRP6 have been linked to coronary artery disease (CAD by unknown mechanisms. Here, we show that reduced LRP6 activity in LRP6R611C mice promotes loss of vascular smooth muscle cell (VSMC differentiation, leading to aortic medial hyperplasia. Carotid injury augmented these effects and led to partial to total vascular obstruction. LRP6R611C mice on high-fat diet displayed dramatic obstructive CAD and exhibited an accelerated atherosclerotic burden on LDLR knockout background. Mechanistically, impaired LRP6 activity leads to enhanced non-canonical Wnt signaling, culminating in diminished TCF7L2 and increased Sp1-dependent activation of PDGF signaling. Wnt3a administration to LRP6R611C mice improved LRP6 activity, led to TCF7L2-dependent VSMC differentiation, and rescued post-carotid-injury neointima formation. These findings demonstrate the critical role of intact Wnt signaling in the vessel wall, establish a causal link between impaired LRP6/TCF7L2 activities and arterial disease, and identify Wnt signaling as a therapeutic target against CAD.

  1. Acute and chronic wound fluids inversely influence adipose-derived stem cell function: molecular insights into impaired wound healing.

    Science.gov (United States)

    Koenen, Paola; Spanholtz, Timo A; Maegele, Marc; Stürmer, Ewa; Brockamp, Thomas; Neugebauer, Edmund; Thamm, Oliver C

    2015-02-01

    Wound healing is a complex biological process that requires a well-orchestrated interaction of mediators as well as resident and infiltrating cells. In this context, mesenchymal stem cells play a crucial role as they are attracted to the wound site and influence tissue regeneration by various mechanisms. In chronic wounds, these processes are disturbed. In a comparative approach, adipose-derived stem cells (ASC) were treated with acute and chronic wound fluids (AWF and CWF, respectively). Proliferation and migration were investigated using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test and transwell migration assay. Gene expression changes were analysed using quantitative real time-polymerase chain reaction. AWF had a significantly stronger chemotactic impact on ASC than CWF (77·5% versus 59·8% migrated cells). While proliferation was stimulated by AWF up to 136·3%, CWF had a negative effect on proliferation over time (80·3%). Expression of b-FGF, vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 was strongly induced by CWF compared with a mild induction by AWF. These results give an insight into impaired ASC function in chronic wounds. The detected effect of CWF on proliferation and migration of ASC might be one reason for an insufficient healing process in chronic wounds.

  2. Bordetella pertussis attachment to respiratory epithelial cells can be impaired by fimbriae-specific antibodies

    NARCIS (Netherlands)

    Rodriguez, ME; Hellwig, SMM; Vidakovics, MLAP; Berbers, GAM; van de Winkel, JGJ

    2006-01-01

    Bordetella pertussis attachment to host cells is a crucial step in colonization. In this study, we investigated the specificity of antibodies, induced either by vaccination or infection, capable of reducing bacterial adherence to respiratory epithelial cells. Both sera and purified anti-B. pertussis

  3. Nuclear lipid microdomain as resting place of dexamethasone to impair cell proliferation.

    Science.gov (United States)

    Cataldi, Samuela; Codini, Michela; Cascianelli, Giacomo; Tringali, Sabina; Tringali, Anna Rita; Lazzarini, Andrea; Floridi, Alessandro; Bartoccini, Elisa; Garcia-Gil, Mercedes; Lazzarini, Remo; Ambesi-Impiombato, Francesco Saverio; Curcio, Francesco; Beccari, Tommaso; Albi, Elisabetta

    2014-01-01

    The action of dexamethasone is initiated by, and strictly dependent upon, the interaction of the drug with its receptor followed by its translocation into the nucleus where modulates gene expression. Where the drug localizes at the intranuclear level is not yet known. We aimed to study the localization of the drug in nuclear lipid microdomains rich in sphingomyelin content that anchor active chromatin and act as platform for transcription modulation. The study was performed in non-Hodgkin's T cell human lymphoblastic lymphoma (SUP-T1 cell line). We found that when dexamethasone enters into the nucleus it localizes in nuclear lipid microdomains where influences sphingomyelin metabolism. This is followed after 24 h by a cell cycle block accompanied by the up-regulation of cyclin-dependent kinase inhibitor 1A (CDKN1A), cyclin-dependent kinase inhibitor 1B (CDKN1B), growth arrest and DNA-damage 45A (GADD45A), and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) genes and by the reduction of signal transducer and activator of transcription 3 (STAT3) and phospho signal transducer and activator of transcription 3 (phoshoSTAT3) proteins. After 48 h some cells show morphological changes characteristic of apoptosis while the number of the cells that undergo cell division and express B-cell lymphoma-2 (Bcl-2) is very low. We suggest that the integrity of nuclear lipid microdomains is important for the response to glucocorticoids of cancer cells.

  4. Nuclear Lipid Microdomain as Resting Place of Dexamethasone to Impair Cell Proliferation

    Directory of Open Access Journals (Sweden)

    Samuela Cataldi

    2014-10-01

    Full Text Available The action of dexamethasone is initiated by, and strictly dependent upon, the interaction of the drug with its receptor followed by its translocation into the nucleus where modulates gene expression. Where the drug localizes at the intranuclear level is not yet known. We aimed to study the localization of the drug in nuclear lipid microdomains rich in sphingomyelin content that anchor active chromatin and act as platform for transcription modulation. The study was performed in non-Hodgkin’s T cell human lymphoblastic lymphoma (SUP-T1 cell line. We found that when dexamethasone enters into the nucleus it localizes in nuclear lipid microdomains where influences sphingomyelin metabolism. This is followed after 24 h by a cell cycle block accompanied by the up-regulation of cyclin-dependent kinase inhibitor 1A (CDKN1A, cyclin-dependent kinase inhibitor 1B (CDKN1B, growth arrest and DNA-damage 45A (GADD45A, and glyceraldehyde 3-phosphate dehydrogenase (GAPDH genes and by the reduction of signal transducer and activator of transcription 3 (STAT3 and phospho signal transducer and activator of transcription 3 (phoshoSTAT3 proteins. After 48 h some cells show morphological changes characteristic of apoptosis while the number of the cells that undergo cell division and express B-cell lymphoma-2 (Bcl-2 is very low. We suggest that the integrity of nuclear lipid microdomains is important for the response to glucocorticoids of cancer cells.

  5. The mitochondrial function was impaired in APP knockout mouse embryo fibroblast cells

    Institute of Scientific and Technical Information of China (English)

    SHENG BaiYang; NIU Ying; ZHOU Hui; YAN JiaXin; ZHAO NanMing; ZHANG XiuFang; GONG YanDao

    2009-01-01

    The amyloid precursor protein (APP) is recognized as the source of Aβ, which plays an important role in Alzheimer's disease. However, the biological function of APP is obscure. Previous studies showed that mitochondria could be a target of APP. In this work, APP knockout mouse embryo fibroblast (MEF) cells were used to test if APP plays any role in maintaining the mitochondrial function. As the result, APP knockout MEF cells (APP-/- cells) showed the abnormal mitochondrial function, including slower cell proliferation, lower mitochondrial membrane potential, lower intracellular ROS, higher mitochon-drial membrane fluidity and lower cytochrome c oxidase activity than their wild-type counterparts. However, no change was found in the amount of mitochondria in MEF APP-/- cells.

  6. 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).

  7. Oleuropein-Enriched Olive Leaf Extract Affects Calcium Dynamics and Impairs Viability of Malignant Mesothelioma Cells

    Directory of Open Access Journals (Sweden)

    Carla Marchetti

    2015-01-01

    Full Text Available Malignant mesothelioma is a poor prognosis cancer in urgent need of alternative therapies. Oleuropein, the major phenolic of olive tree (Olea europaea L., is believed to have therapeutic potentials for various diseases, including tumors. We obtained an oleuropein-enriched fraction, consisting of 60% w/w oleuropein, from olive leaves, and assessed its effects on intracellular Ca2+ and cell viability in mesothelioma cells. Effects of the oleuropein-enriched fraction on Ca2+ dynamics and cell viability were studied in the REN mesothelioma cell line, using fura-2 microspectrofluorimetry and MTT assay, respectively. Fura-2-loaded cells, transiently exposed to the oleuropein-enriched fraction, showed dose-dependent transient elevations of cytosolic Ca2+ concentration (Ca2+i. Application of standard oleuropein and hydroxytyrosol, and of the inhibitor of low-voltage T-type Ca2+ channels NNC-55-0396, suggested that the effect is mainly due to oleuropein acting through its hydroxytyrosol moiety on T-type Ca2+ channels. The oleuropein-enriched fraction and standard oleuropein displayed a significant antiproliferative effect, as measured on REN cells by MTT cell viability assay, with IC50 of 22 μg/mL oleuropein. Data suggest that our oleuropein-enriched fraction from olive leaf extract could have pharmacological application in malignant mesothelioma anticancer therapy, possibly by targeting T-type Ca2+ channels and thereby dysregulating intracellular Ca2+ dynamics.

  8. Impaired telomerase activity hinders proliferation and in vitro transformation of Penaeus monodon lymphoid cells.

    Science.gov (United States)

    Jayesh, P; Vrinda, S; Priyaja, P; Philip, Rosamma; Singh, I S Bright

    2016-08-01

    Retaining terminal transferase activity of telomerase, the ribonucleoprotein enzyme which add telomeric repeats on chromosome end is thought to be required to prevent cellular ageing. Additionally, telomerase considered as a marker for cell proliferation and immortalization in eukaryotes. We examined telomerase activity in tissues and lymphoid cell culture of Penaeus monodon. Along with telomerase activity, telomere repeats and an attempt on identification of telomerase reverse transcriptase (PmTERT) were made. Telomeric repeat amplification protocol revealed that telomerase-dependent telomeric lengthening has been taking place in P. monodon and the adult tissues were retaining this capacity throughout their lifespan with the highest activity in ovary, testis and lymphoid organ. However, telomerase activity could not be detected in lymphoid cells in culture. The canonical telomeric repeats added by telomerase of lymphoid tissue extract were identified as TTAGG, but pentameric repeats GGTTA and AGGTT were also added by the telomerase. PmTERT protein sequence (partial) shared 100 % identity with the TERT sequence of Daphnia pulex, 27 % sequence identity with Purple sea urchin and 24-25 % with Zebra fish. Undetectable telomerase activity in lymphoid cell culture supports the hypothesis that the inadequate telomerase activity or gene expression may be a reason that prevents neoplastic transformation and spontaneous immortalization of the cells in vitro. Thus, it is envisaged that telomerase activation in lymphoid cells may surmount cellular ageing for in vitro transformation and cell line establishment. PMID:26084784

  9. The anthelmintic drug niclosamide induces apoptosis, impairs metastasis and reduces immunosuppressive cells in breast cancer model.

    Directory of Open Access Journals (Sweden)

    Tinghong Ye

    Full Text Available Breast carcinoma is the most common female cancer with considerable metastatic potential. Discovery of new therapeutic approaches for treatment of metastatic breast cancer is still needed. Here, we reported our finding with niclosamide, an FDA approved anthelmintic drug. The potency of niclosamide on breast cancer was assessed in vitro and in vivo. In this investigation, we found that niclosamide showed a dramatic growth inhibition against breast cancer cell lines and induced apoptosis of 4T1 cells in a dose-dependent manner. Further, Western blot analysis demonstrated the occurrence of its apoptosis was associated with activation of Cleaved caspases-3, down-regulation of Bcl-2, Mcl-1 and Survivin. Moreover, niclosamide blocked breast cancer cells migration and invasion, and the reduction of phosphorylated STAT3(Tyr705, phosphorylated FAK(Tyr925 and phosphorylated Src(Tyr416 were also observed. Furthermore, in our animal experiments, intraperitoneal administration of 20 mg/kg/d niclosamide suppressed 4T1 tumor growth without detectable toxicity. Histological and immunohistochemical analyses revealed a decrease in Ki67-positive cells, VEGF-positive cells and microvessel density (MVD and an increase in Cleaved caspase-3-positive cells upon niclosamide. Notably, niclosamide reduced the number of myeloid-derived suppressor cells (MDSCs in tumor tissues and blocked formation of pulmonary metastases. Taken together, these results demonstrated that niclosamide may be a promising candidate for breast cancer.

  10. Reprint of "Vitamin D deficiency in pregnant women impairs regulatory T cell function".

    Science.gov (United States)

    Vijayendra Chary, A; Hemalatha, R; Seshacharyulu, M; Vasudeva Murali, M; Jayaprakash, D; Dinesh Kumar, B

    2015-04-01

    Regulatory T cells and IgE receptors (CD23 and CD21) on B cells were assessed in vitamin D deficient pregnant women. For this, 153 pregnant women were recruited from a government hospital and were categorized into three groups based on 25-hydroxyvitamin D3 (25(OH)D3) status. Regulatory T cell population (Treg cells) and CD23/CD21 expression on B cells were quantified by FACS ARIA II in maternal blood at third trimester; and the same parameters were evaluated in cord blood soon after delivery. In addition, TGF β and IL-10 were quantified in maternal and cord blood by using Milliplex kits. In a representative sample of eight women from each group (vitamin D sufficient, insufficient and deficient), placental tissues were processed for mRNA expressions of vitamin D receptor (VDR), retinoic acid receptor (RXR), vitamin D binding protein (VDBP) and vitamin D regulating enzymes. Of the 153 pregnant women, 18 were sufficient (≥30ng/mL), 55 were insufficient (20-29ng/mL) and 80 were deficient (≤19ng/mL) for 25(OH)D3 status. The maternal blood Treg cell population (mean (%)±SE) was lower (pTreg cell population (mean (%)±SE) was also lower (pasthma in neonates. PMID:25644204

  11. Vitamin D deficiency in pregnant women impairs regulatory T cell function.

    Science.gov (United States)

    Vijayendra Chary, A; Hemalatha, R; Seshacharyulu, M; Vasudeva Murali, M; Jayaprakash, D; Dinesh Kumar, B

    2015-03-01

    Regulatory T cells and IgE receptors (CD23 and CD21) on B cells were assessed in vitamin D deficient pregnant women. For this, 153 pregnant women were recruited from a government hospital and were categorized into three groups based on 25-hydroxyvitamin D3 (25(OH)D3) status. Regulatory T cell population (Treg cells) and CD23/CD21 expression on B cells were quantified by FACS ARIA II in maternal blood at third trimester; and the same parameters were evaluated in cord blood soon after delivery. In addition, TGF β and IL-10 were quantified in maternal and cord blood by using Milliplex kits. In a representative sample of eight women from each group (vitamin D sufficient, insufficient and deficient), placental tissues were processed for mRNA expressions of vitamin D receptor (VDR), retinoic acid receptor (RXR), vitamin D binding protein (VDBP) and vitamin D regulating enzymes. Of the 153 pregnant women, 18 were sufficient (≥30 ng/mL), 55 were insufficient (20-29 ng/mL) and 80 were deficient (≤19 ng/mL) for 25(OH)D3 status. The maternal blood Treg cell population (mean (%)± SE) was lower (pTreg cell population (mean (%)± SE) was also lower (pasthma in neonates. PMID:25448751

  12. Impaired telomerase activity hinders proliferation and in vitro transformation of Penaeus monodon lymphoid cells.

    Science.gov (United States)

    Jayesh, P; Vrinda, S; Priyaja, P; Philip, Rosamma; Singh, I S Bright

    2016-08-01

    Retaining terminal transferase activity of telomerase, the ribonucleoprotein enzyme which add telomeric repeats on chromosome end is thought to be required to prevent cellular ageing. Additionally, telomerase considered as a marker for cell proliferation and immortalization in eukaryotes. We examined telomerase activity in tissues and lymphoid cell culture of Penaeus monodon. Along with telomerase activity, telomere repeats and an attempt on identification of telomerase reverse transcriptase (PmTERT) were made. Telomeric repeat amplification protocol revealed that telomerase-dependent telomeric lengthening has been taking place in P. monodon and the adult tissues were retaining this capacity throughout their lifespan with the highest activity in ovary, testis and lymphoid organ. However, telomerase activity could not be detected in lymphoid cells in culture. The canonical telomeric repeats added by telomerase of lymphoid tissue extract were identified as TTAGG, but pentameric repeats GGTTA and AGGTT were also added by the telomerase. PmTERT protein sequence (partial) shared 100 % identity with the TERT sequence of Daphnia pulex, 27 % sequence identity with Purple sea urchin and 24-25 % with Zebra fish. Undetectable telomerase activity in lymphoid cell culture supports the hypothesis that the inadequate telomerase activity or gene expression may be a reason that prevents neoplastic transformation and spontaneous immortalization of the cells in vitro. Thus, it is envisaged that telomerase activation in lymphoid cells may surmount cellular ageing for in vitro transformation and cell line establishment.

  13. Gain of Cellular Adaptation Due to Prolonged p53 Impairment Leads to Functional Switchover from p53 to p73 during DNA Damage in Acute Myeloid Leukemia Cells*

    OpenAIRE

    Chakraborty, Juni; Banerjee, Shuvomoy; Ray, Pallab; Hossain, Dewan Md Sakib; Bhattacharyya, Sankar; Adhikary, Arghya; Chattopadhyay, Sreya; Das, Tanya; Sa, Gaurisankar

    2010-01-01

    Tumor suppressor p53 plays the central role in regulating apoptosis in response to genotoxic stress. From an evolutionary perspective, the activity of p53 has to be backed up by other protein(s) in case of any functional impairment of this protein, to trigger DNA damage-induced apoptosis in cancer cells. We adopted multiple experimental approaches to demonstrate that in p53-impaired cancer cells, DNA damage caused accumulation of p53 paralogue p73 via Chk-1 that strongly impacted Bax expressi...

  14. 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.

  15. Impaired growth and elevated Fas receptor expression in PIGA+ stem cells in primary paroxysmal nocturnal hemoglobinuria

    OpenAIRE

    Chen, Rui; Nagarajan, Shanmugam; Prince, Gregory M.; Maheshwari, Uma; Terstappen, Leon W. M. M.; Kaplan, David R.; Stanton L Gerson; Albert, Jeffrey M.; Dunn, Daniel E.; Lazarus, Hillard M.; Medof, M. Edward

    2000-01-01

    The genetic defect underlying paroxysmal nocturnal hemoglobinuria (PNH) has been shown to reside in PIGA, a gene that encodes an element required for the first step in glycophosphatidylinositol anchor assembly. Why PIGA-mutated cells are able to expand in PNH marrow, however, is as yet unclear. To address this question, we compared the growth of affected CD59–CD34+ and unaffected CD59+CD34+ cells from patients with that of normal CD59+CD34+ cells in liquid culture. One hundred FACS-sorted cel...

  16. Impairment and Differential Expression of PR3 and MPO on Peripheral Myelomonocytic Cells with Endothelial Properties in Granulomatosis with Polyangiitis

    Science.gov (United States)

    Patschan, Susann; Patschan, Daniel; Henze, Elvira; Blaschke, Sabine; Wessels, Johannes T.; Müller, Gerhard Anton

    2012-01-01

    Background. Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) are autoimmune-mediated diseases characterized by vasculitic inflammation of respiratory tract and kidneys. Clinical observations indicated a strong association between disease activity and serum levels of certain types of autoantibodies (antineutrophil cytoplasm antibodies with cytoplasmic [cANCA in GPA] or perinuclear [pAN CA in MPA] immunofluorescence). Pathologically, both diseases are characterized by severe microvascular endothelial cell damage. Early endothelial outgrowth cells (eEOCs) have been shown to be critically involved in neovascularization under both physiological and pathological condition. Objectives. The principal aims of our study were (i) to analyze the regenerative activity of the eEOC system and (ii) to determine mPR3 and MPO expression in myelo monocytic cells with endothelial characteristics in GPA and MPA patients. Methods. In 27 GPA and 10 MPA patients, regenerative activity blood-derived eEOCs were analyzed using a culture-forming assay. Flk-1+, CD133+/Flk-1+, mPR3+, and Flk-1+/mPR3+ myelomonocytic cells were quantified by FACS analysis. Serum levels of Angiopoietin-1 and TNF-α were measured by ELISA. Results. We found reduced eEOC regeneration, accompanied by lower serum levels of Angiopoietin-1 in GPA patients as compared to healthy controls. In addition, the total numbers of Flk-1+ myelomonocytic cells in the peripheral circulation were decreased. Membrane PR3 expression was significantly higher in total as well as in Flk-1+ myelomonocytic cells. Expression of MPO was not different between the groups. Conclusions. These data suggest impairment of the eEOC system and a possible role for PR3 in this process in patients suffering from GPA. PMID:22792461

  17. Impairment and Differential Expression of PR3 and MPO on Peripheral Myelomonocytic Cells with Endothelial Properties in Granulomatosis with Polyangiitis

    Directory of Open Access Journals (Sweden)

    Susann Patschan

    2012-01-01

    Full Text Available Background. Granulomatosis with polyangiitis (GPA and microscopic polyangiitis (MPA are autoimmune-mediated diseases characterized by vasculitic inflammation of respiratory tract and kidneys. Clinical observations indicated a strong association between disease activity and serum levels of certain types of autoantibodies (antineutrophil cytoplasm antibodies with cytoplasmic [cANCA in GPA] or perinuclear [pAN CA in MPA] immunofluorescence. Pathologically, both diseases are characterized by severe microvascular endothelial cell damage. Early endothelial outgrowth cells (eEOCs have been shown to be critically involved in neovascularization under both physiological and pathological condition. Objectives. The principal aims of our study were (i to analyze the regenerative activity of the eEOC system and (ii to determine mPR3 and MPO expression in myelo monocytic cells with endothelial characteristics in GPA and MPA patients. Methods. In 27 GPA and 10 MPA patients, regenerative activity blood-derived eEOCs were analyzed using a culture-forming assay. Flk-1+, CD133+/Flk-1+, mPR3+, and Flk-1+/mPR3+ myelomonocytic cells were quantified by FACS analysis. Serum levels of Angiopoietin-1 and TNF-α were measured by ELISA. Results. We found reduced eEOC regeneration, accompanied by lower serum levels of Angiopoietin-1 in GPA patients as compared to healthy controls. In addition, the total numbers of Flk-1+ myelomonocytic cells in the peripheral circulation were decreased. Membrane PR3 expression was significantly higher in total as well as in Flk-1+ myelomonocytic cells. Expression of MPO was not different between the groups. Conclusions. These data suggest impairment of the eEOC system and a possible role for PR3 in this process in patients suffering from GPA.

  18. Frequently Increased but Functionally Impaired CD4+CD25+ Regulatory T Cells in Patients with Oral Lichen Planus.

    Science.gov (United States)

    Zhou, Leilei; Cao, Tianyi; Wang, Yufeng; Yao, Hui; Du, Guanhuan; Chen, Guangjie; Niu, Xiaoyin; Tang, Guoyao

    2016-06-01

    Oral lichen planus (OLP) is a T cell-mediated chronic inflammatory mucosal disease, and CD4(+)CD25(+) regulatory T cells (Tregs) are considered involved in the pathogenesis of OLP. In this study, to investigate whether there are intrinsic factors that might cause functional changes in Tregs in this disease, we evaluated the frequency of Tregs in peripheral blood and oral lesions and the expression levels of function-related transcription factors, forkhead/winged-helix transcription factor box P3 (FOXP3), transforming growth factor β (TGF-β), interleukin 10 (IL-10), and TGF-β receptors (TβRI and TβRII) mRNAs in Tregs of patients with oral lichen planus (OLP). We also investigated the frequency of pro-inflammatory cytokines (IFN-γ and IL-17A) producing Foxp3(+) regulatory cells. Increased proportions of Tregs were found in OLP patients. The expression of FOXP3 on mRNA and protein level was elevated in the Tregs of OLP. The expression of TGF-β was lower both on the mRNA and serum level, whereas the expression of IL-10 showed no significant difference between the OLP patients and normal controls. The percentages of CD4(+)FOXP3(+)IL-17(+) T cells were significantly higher than that of normal controls, whereas the percentages of CD4(+)FOXP3(+)IFN-γ(+) T cells did not differ significantly. Furthermore, impaired suppressive function of CD4(+)CD25(+) T cells was demonstrated in OLP patients by in vitro proliferation assay. These data indicate that Tregs in OLP are frequently expanded but functionally deficient. This could explain, at least in part, why the increased Tregs in OLP fail to control the pathogenesis and development of this autoimmune disease. PMID:27106476

  19. Suppression by Δ9-tetrahydrocannabinol of the primary immunoglobulin M response by human peripheral blood B cells is associated with impaired STAT3 activation

    International Nuclear Information System (INIS)

    This study was undertaken to gain insights into the mechanism for Δ9-tetrahydrocannabinol (Δ9-THC)-mediated suppression of primary immunoglobulin M (IgM) responses in humans. An in vitro activation model, which employs cell surface-expressed CD40 ligand (CD40L) and recombinant cytokines (interleukin (IL)-2, -6, and -10), was used to differentiate human peripheral blood (HPB) naïve B cells into IgM secreting cells. Pretreatment with Δ9-THC significantly decreased the number of IgM secreting cells as determined by ELISPOT. The attenuation of IgM secretion by Δ9-THC involved, at least in part, the impairment of plasma cell differentiation as evidenced by suppression of immunoglobulin joining chain (IgJ) mRNA expression. The analysis at each of two different stages critically involved in plasma cell differentiation indicates that Δ9-THC impaired both the primary activation stage and proliferation of B cells. Interestingly, Δ9-THC selectively suppressed the surface expression of CD80, but not other measured B-cell activation markers (CD69, CD86, and ICAM1). Furthermore, pretreatment with Δ9-THC was accompanied by a robust decrease of STAT3 phosphorylation, whereas the phosphorylation of the p65 NFκB subunit was not affected. Collectively, these data provide new insights into the mechanisms for impaired B cell function by Δ9-THC

  20. Impaired growth of pancreatic exocrine cells in transgenic mice expressing human activin βE subunit

    International Nuclear Information System (INIS)

    Activins, TGF-β superfamily members, have multiple functions in a variety of cells and tissues. Recently, additional activin β subunit genes, βC and βE, have been identified. To explore the role of activin E, we created transgenic mice overexpressing human activin βE subunit. There were pronounced differences in the pancreata of the transgenic animals as compared with their wild-type counterparts. Pancreatic weight, expressed relative to total body weight, was significantly reduced. Histologically, adipose replacement of acini in the exocrine pancreas was observed. There was a significant decrease in the number of PCNA-positive cells in the acinar cells, indicating reduced proliferation in the exocrine pancreas of the transgenic mice. However, quantitative pancreatic morphometry showed that the total number and mass of the islets of the transgenic mice were comparable with those of the nontransgenic control mice. Our findings suggest a role for activin E in regulating the proliferation of pancreatic exocrine cells

  1. Cell-phone use diminishes self-awareness of impaired driving.

    Science.gov (United States)

    Sanbonmatsu, David M; Strayer, David L; Biondi, Francesco; Behrends, Arwen A; Moore, Shannon M

    2016-04-01

    Multitasking diminishes the self-awareness of performance that is often essential for self-regulation and self-knowledge. Participants drove in a simulator while either talking or not talking on a hands-free cell phone. Following previous research, participants who talked on a cell phone made more serious driving errors than control participants who did not use a phone while driving. Control participants' assessments of the safeness of their driving and general ability to drive safely while distracted were negatively correlated with the actual number of errors made when they were driving. By contrast, cell-phone participants' assessments of the safeness of their driving and confidence in their driving abilities were uncorrelated with their actual errors. Thus, talking on a cell phone not only diminished the safeness of participants' driving, it diminished their awareness of the safeness of their driving. PMID:26282831

  2. 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

    beam milling and scanning electron microscopy, highly curved but intact nuclear membranes are observed, showing no direct contact between the nanowires and the DNA. The nanowires possibly induce cellular stress and high respiration rates, which trigger the formation of ROS, which in turn results in DNA......Nanowires are commonly used as tools for interfacing living cells, acting as biomolecule-delivery vectors or electrodes. It is generally assumed that the small size of the nanowires ensures a minimal cellular perturbation, yet the effects of nanowires on cell migration and proliferation remain...... largely unknown. Fibroblast behaviour on vertical nanowire arrays is investigated, and it is shown that cell motility and proliferation rate are reduced on nanowires. Fibroblasts cultured on long nanowires exhibit failed cell division, DNA damage, increased ROS content and respiration. Using focused ion...

  3. Free fatty acid palmitate impairs the vitality and function of cultured human bladder smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    Andreas Oberbach

    Full Text Available BACKGROUND: Incidence of urinary tract infections is elevated in patients with diabetes mellitus. Those patients show increased levels of the saturated free fatty acid palmitate. As recently shown metabolic alterations induced by palmitate include production and secretion of the pro-inflammatory cytokine interleukine-6 (IL-6 in cultured human bladder smooth muscle cells (hBSMC. Here we studied the influence of palmitate on vital cell properties, for example, regulation of cell proliferation, mitochondrial enzyme activity and antioxidant capacity in hBSMC, and analyzed the involvement of major cytokine signaling pathways. METHODOLOGY/PRINCIPAL FINDINGS: HBSMC cultures were set up from bladder tissue of patients undergoing cystectomy and stimulated with palmitate. We analyzed cell proliferation, mitochondrial enzyme activity, and antioxidant capacity by ELISA and confocal immunofluorescence. In signal transduction inhibition experiments we evaluated the involvement of NF-κB, JAK/STAT, MEK1, PI3K, and JNK in major cytokine signaling pathway regulation. We found: (i palmitate decreased cell proliferation, increased mitochondrial enzyme activity and antioxidant capacity; (ii direct inhibition of cytokine receptor by AG490 even more strongly suppressed cell proliferation in palmitate-stimulated cells, while counteracting palmitate-induced increase of antioxidant capacity; (iii in contrast knockdown of the STAT3 inhibitor SOCS3 increased cell proliferation and antioxidant capacity; (iv further downstream JAK/STAT3 signaling cascade the inhibition of PI3K or JNK enhanced palmitate induced suppression of cell proliferation; (v increase of mitochondrial enzyme activity by palmitate was enhanced by inhibition of PI3K but counteracted by inhibition of MEK1. CONCLUSIONS/SIGNIFICANCE: Saturated free fatty acids (e.g., palmitate cause massive alterations in vital cell functions of cultured hBSMC involving distinct major cytokine signaling pathways. Thereby

  4. Reduced Hippocampal Dentate Cell Proliferation and Impaired Spatial Memory Performance in Aged-Epileptic Rats

    OpenAIRE

    LucieneCovolan; ClaudioM TQueiroz; JairGuilhermeSantos; GilbertoFXavier

    2013-01-01

    Increased adult neurogenesis is observed after training in hippocampal-dependent tasks and also after acutely induced status epilepticus (SE) although the specific roles of these cells are still a matter of debate. In this study, we investigated hippocampal cell proliferation and differentiation and the spatial learning performance in young or aged chronically epileptic rats. Status was induced by pilocarpine in 3 or 20-month old rats. Either two or twenty months later, rats were treated with...

  5. PARD3 Inactivation in Lung Squamous Cell Carcinomas Impairs STAT3 and Promotes Malignant Invasion

    OpenAIRE

    Bonastre, Ester; Verdura, Sara; Zondervan, Ilse; Facchinetti, Federica; Lantuejoul, Sylvie; Chiara, Maria Dolores; Rodrigo, Juan Pablo; Carretero, Julian; Condom, Enric; Vidal, Agustin; Sidransky, David; Villanueva, Alberto; Roz, Luca; Brambilla, Elisabeth; Savola, Suvi

    2015-01-01

    Correct apicobasal polarization and intercellular adhesions are essential for the appropriate development of normal epithelia. Here, we investigated the contribution of the cell polarity regulator PARD3 to the development of lung squamous cell carcinomas (LSCC). Tumor-specific PARD3 alterations were found in 8% of LSCCs examined, placing PARD3 among the most common tumor suppressor genes in this malignancy. Most PAR3-mutant proteins exhibited a relative reduction in the ability to mediate for...

  6. Galvanic vestibular stimulation impairs cell proliferation and neurogenesis in the rat hippocampus but not spatial memory.

    Science.gov (United States)

    Zheng, Yiwen; Geddes, Lisa; Sato, Go; Stiles, Lucy; Darlington, Cynthia L; Smith, Paul F

    2014-05-01

    Galvanic vestibular stimulation (GVS) is a method of activating the peripheral vestibular system using direct current that is widely employed in clinical neurological testing. Since movement is recognized to stimulate hippocampal neurogenesis and movement is impossible without activation of the vestibular system, we speculated that activating the vestibular system in rats while minimizing movement, by delivering GVS under anesthesia, would affect hippocampal cell proliferation and neurogenesis, and spatial memory. Compared with the sham control group, the number of cells incorporating the DNA replication marker, bromodeoxyuridine (BrdU), was significantly reduced in the bilateral hippocampi in both the cathode left-anode right and cathode right-anode left stimulation groups (P ≤ 0.0001). The majority of the BrdU(+ve) cells co-expressed Ki-67, a marker for the S phase of the cell cycle, suggesting that these BrdU(+ve) cells were still in the cell cycle; however, there was no significant difference in the degree of co-labeling between the two stimulation groups. Single labeling for doublecortin (DCX), a marker of immature neurons, showed that while there was no significant difference between the different groups in the number of DCX(+ve) cells in the right dentate gryus, in the left dentate gyrus there was a significant decrease in the cathode left-anode right group compared with the sham controls (P ≤ 0.03). Nonetheless, when animals were tested in place recognition, object exploration and Morris water maze tasks, there were no significant differences between the GVS groups and the sham controls. These results suggest that GVS can have striking effects on cell proliferation and possibly neurogenesis in the hippocampus, without affecting spatial memory. PMID:24449222

  7. Galvanic vestibular stimulation impairs cell proliferation and neurogenesis in the rat hippocampus but not spatial memory.

    Science.gov (United States)

    Zheng, Yiwen; Geddes, Lisa; Sato, Go; Stiles, Lucy; Darlington, Cynthia L; Smith, Paul F

    2014-05-01

    Galvanic vestibular stimulation (GVS) is a method of activating the peripheral vestibular system using direct current that is widely employed in clinical neurological testing. Since movement is recognized to stimulate hippocampal neurogenesis and movement is impossible without activation of the vestibular system, we speculated that activating the vestibular system in rats while minimizing movement, by delivering GVS under anesthesia, would affect hippocampal cell proliferation and neurogenesis, and spatial memory. Compared with the sham control group, the number of cells incorporating the DNA replication marker, bromodeoxyuridine (BrdU), was significantly reduced in the bilateral hippocampi in both the cathode left-anode right and cathode right-anode left stimulation groups (P ≤ 0.0001). The majority of the BrdU(+ve) cells co-expressed Ki-67, a marker for the S phase of the cell cycle, suggesting that these BrdU(+ve) cells were still in the cell cycle; however, there was no significant difference in the degree of co-labeling between the two stimulation groups. Single labeling for doublecortin (DCX), a marker of immature neurons, showed that while there was no significant difference between the different groups in the number of DCX(+ve) cells in the right dentate gryus, in the left dentate gyrus there was a significant decrease in the cathode left-anode right group compared with the sham controls (P ≤ 0.03). Nonetheless, when animals were tested in place recognition, object exploration and Morris water maze tasks, there were no significant differences between the GVS groups and the sham controls. These results suggest that GVS can have striking effects on cell proliferation and possibly neurogenesis in the hippocampus, without affecting spatial memory.

  8. Suction assisted liposuction does not impair the regenerative potential of adipose derived stem cells

    OpenAIRE

    Duscher, Dominik; Luan, Anna; Rennert, Robert C; Atashroo, David; Maan, Zeshaan N; Brett, Elizabeth A.; Whittam, Alexander J.; Ho, Natalie; Lin, Michelle; Hu, Michael S.; Graham G Walmsley; Wenny, Raphael; Schmidt, Manfred; Schilling, Arndt F.; Machens, Hans-Günther

    2016-01-01

    Background Adipose-derived stem cells (ASCs) have been identified as a population of multipotent cells with promising applications in tissue engineering and regenerative medicine. ASCs are abundant in fat tissue, which can be safely harvested through the minimally invasive procedure of liposuction. However, there exist a variety of different harvesting methods, with unclear impact on ASC regenerative potential. The aim of this study was thus to compare the functionality of ASCs derived from t...

  9. Dystroglycan Depletion Impairs Actin-Dependent Functions of Differentiated Kasumi-1 Cells

    Science.gov (United States)

    Escárcega-Tame, Marco Antonio; Martínez-Vieyra, Ivette; Alonso-Rangel, Lea; Cisneros, Bulmaro; Winder, Steve J.; Cerecedo, Doris

    2015-01-01

    Background Dystroglycan has recently been characterised in blood tissue cells, as part of the dystrophin glycoprotein complex involved in the differentiation process of neutrophils. Purpose In the present study we have investigated the role of dystroglycan in the human promyelocytic leukemic cell line Kasumi-1 differentiated to macrophage-like cells. Methods We characterised the pattern expression and subcellular distribution of dystroglycans in non-differentiated and differentiated Kasumi-1 cells. Results Our results demonstrated by WB and flow cytometer assays that during the differentiation process to macrophages, dystroglycans were down-regulated; these results were confirmed with qRT-PCR assays. Additionally, depletion of dystroglycan by RNAi resulted in altered morphology and reduced properties of differentiated Kasumi-1 cells, including morphology, migration and phagocytic activities although secretion of IL-1β and expression of markers of differentiation are not altered. Conclusion Our findings strongly implicate dystroglycan as a key membrane adhesion protein involved in actin-based structures during the differentiation process in Kasumi-1 cells. PMID:26630171

  10. Expression of frog virus 3 genes is impaired in mammalian cell lines

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    Metcalf Julie

    2008-07-01

    Full Text Available Abstract Frog virus 3 (FV3 is a large DNA virus that is the prototypic member of the family Iridoviridae. To examine levels of FV3 gene expression we generated a polyclonal antibody against the FV3 protein 75L. Following a FV3 infection in fathead minnow (FHM cells 75L was found in vesicles throughout the cytoplasm as early as 3 hours post-infection. While 75L expressed strongly in FHM cells, our findings revealed no 75L expression in mammalian cells lines despite evidence of a FV3 infection. One explanation for the lack of gene expression in mammalian cell lines may be inefficient codon usage. As a result, 75L was codon optimized and transfection of the codon optimized construct resulted in detectable expression in mammalian cells. Therefore, although FV3 can infect and replicate in mammalian cell lines, the virus may not express its full complement of genes due to inefficient codon usage in mammalian species.

  11. Dystroglycan Depletion Impairs Actin-Dependent Functions of Differentiated Kasumi-1 Cells.

    Directory of Open Access Journals (Sweden)

    Marco Antonio Escárcega-Tame

    Full Text Available Dystroglycan has recently been characterised in blood tissue cells, as part of the dystrophin glycoprotein complex involved in the differentiation process of neutrophils.In the present study we have investigated the role of dystroglycan in the human promyelocytic leukemic cell line Kasumi-1 differentiated to macrophage-like cells.We characterised the pattern expression and subcellular distribution of dystroglycans in non-differentiated and differentiated Kasumi-1 cells.Our results demonstrated by WB and flow cytometer assays that during the differentiation process to macrophages, dystroglycans were down-regulated; these results were confirmed with qRT-PCR assays. Additionally, depletion of dystroglycan by RNAi resulted in altered morphology and reduced properties of differentiated Kasumi-1 cells, including morphology, migration and phagocytic activities although secretion of IL-1β and expression of markers of differentiation are not altered.Our findings strongly implicate dystroglycan as a key membrane adhesion protein involved in actin-based structures during the differentiation process in Kasumi-1 cells.

  12. APOBEC3G impairs the multimerization of the HIV-1 Vif protein in living cells.

    Science.gov (United States)

    Batisse, Julien; Guerrero, Santiago Xavier; Bernacchi, Serena; Richert, Ludovic; Godet, Julien; Goldschmidt, Valérie; Mély, Yves; Marquet, Roland; de Rocquigny, Hugues; Paillart, Jean-Christophe

    2013-06-01

    The HIV-1 viral infectivity factor (Vif) is a small basic protein essential for viral fitness and pathogenicity. Vif allows productive infection in nonpermissive cells, including most natural HIV-1 target cells, by counteracting the cellular cytosine deaminases APOBEC3G (apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G [A3G]) and A3F. Vif is also associated with the viral assembly complex and packaged into viral particles through interactions with the viral genomic RNA and the nucleocapsid domain of Pr55(Gag). Recently, we showed that oligomerization of Vif into high-molecular-mass complexes induces Vif folding and influences its binding to high-affinity RNA binding sites present in the HIV genomic RNA. To get further insight into the role of Vif multimerization in viral assembly and A3G repression, we used fluorescence lifetime imaging microscopy (FLIM)- and fluorescence resonance energy transfer (FRET)-based assays to investigate Vif-Vif interactions in living cells. By using two N-terminally tagged Vif proteins, we show that Vif-Vif interactions occur in living cells. This oligomerization is strongly reduced when the putative Vif multimerization domain ((161)PPLP(164)) is mutated, indicating that this domain is crucial, but that regions outside this motif also participate in Vif oligomerization. When coexpressed together with Pr55(Gag), Vif is largely relocated to the cell membrane, where Vif oligomerization also occurs. Interestingly, wild-type A3G strongly interferes with Vif multimerization, contrary to an A3G mutant that does not bind to Vif. These findings confirm that Vif oligomerization occurs in living cells partly through its C-terminal motif and suggest that A3G may target and perturb the Vif oligomerization state to limit its functions in the cell. PMID:23576497

  13. Impairment of the accumulation of decidual T cells, NK cells, and monocytes, and the poor vascular remodeling of spiral arteries, were observed in oocyte donation cases, regardless of the presence or absence of preeclampsia.

    Science.gov (United States)

    Nakabayashi, Yasushi; Nakashima, Akitoshi; Yoshino, Osamu; Shima, Tomoko; Shiozaki, Arihiro; Adachi, Tomoko; Nakabayashi, Masao; Okai, Takashi; Kushima, Miki; Saito, Shigeru

    2016-04-01

    In oocyte donation (OD) pregnancies, a fetus is a complete allograft to the maternal host and OD pregnancies are an independent risk factor for preeclampsia. Immunocompetent cells contribute to spiral artery remodeling and the failure of this process could contribute to the pathophysiology of preeclampsia. Recent data have shown that impaired autophagy of extravillous trophoblasts (EVT) may induce poor vascular remodeling in preeclampsia. We have studied the distribution of T cells, NK cells and macrophages in the decidua basalis of 14 normotensive OD pregnancies, 5 preeclamptic OD cases, 16 normotensive pregnancy cases, and 13 preeclamptic cases in natural pregnancy or autologous oocyte IVF-ET (NP/IVF). The populations of decidual CD3(+)T cells, CD8(+)T cells, CD4(+)T cells, Foxp3(+)Treg cells, CD56(+)NK cells, and CD68(+) macrophages in preeclampsia were significantly smaller than those in normal pregnancy in NP/IVF. Those frequencies in normotensive OD pregnancies or preeclamptic cases in OD pregnancies were similar to those in preeclamptic cases in NP/IVF. Impaired vascular remodeling was observed in OD pregnancies, regardless of the presence or absence of preeclampsia. The expression of p62, an impaired autophagy marker in EVT of normotensive or preeclamptic OD pregnancies, was significantly higher than that in normal pregnancies in NP/IVF. Immunological change in the decidua basalis and impairment of autophagy in EVT may induce impairment of spiral artery remodeling in OD pregnancies. PMID:26282090

  14. Influenza A virus infection of human primary dendritic cells impairs their ability to cross-present antigen to CD8 T cells.

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    Anna Smed-Sörensen

    Full Text Available Influenza A virus (IAV infection is normally controlled by adaptive immune responses initiated by dendritic cells (DCs. We investigated the consequences of IAV infection of human primary DCs on their ability to function as antigen-presenting cells. IAV was internalized by both myeloid DCs (mDCs and plasmacytoid DCs but only mDCs supported viral replication. Although infected mDCs efficiently presented endogenous IAV antigens on MHC class II, this was not the case for presentation on MHC class I. Indeed, cross-presentation by uninfected cells of minute amounts of endocytosed, exogenous IAV was -300-fold more efficient than presentation of IAV antigens synthesized by infected cells and resulted in a statistically significant increase in expansion of IAV-specific CD8 T cells. Furthermore, IAV infection also impaired cross-presentation of other exogenous antigens, indicating that IAV infection broadly attenuates presentation on MHC class I molecules. Our results suggest that cross-presentation by uninfected mDCs is a preferred mechanism of antigen-presentation for the activation and expansion of CD8 T cells during IAV infection.

  15. Influenza A virus infection of human primary dendritic cells impairs their ability to cross-present antigen to CD8 T cells.

    Science.gov (United States)

    Smed-Sörensen, Anna; Chalouni, Cécile; Chatterjee, Bithi; Cohn, Lillian; Blattmann, Peter; Nakamura, Norihiro; Delamarre, Lélia; Mellman, Ira

    2012-01-01

    Influenza A virus (IAV) infection is normally controlled by adaptive immune responses initiated by dendritic cells (DCs). We investigated the consequences of IAV infection of human primary DCs on their ability to function as antigen-presenting cells. IAV was internalized by both myeloid DCs (mDCs) and plasmacytoid DCs but only mDCs supported viral replication. Although infected mDCs efficiently presented endogenous IAV antigens on MHC class II, this was not the case for presentation on MHC class I. Indeed, cross-presentation by uninfected cells of minute amounts of endocytosed, exogenous IAV was -300-fold more efficient than presentation of IAV antigens synthesized by infected cells and resulted in a statistically significant increase in expansion of IAV-specific CD8 T cells. Furthermore, IAV infection also impaired cross-presentation of other exogenous antigens, indicating that IAV infection broadly attenuates presentation on MHC class I molecules. Our results suggest that cross-presentation by uninfected mDCs is a preferred mechanism of antigen-presentation for the activation and expansion of CD8 T cells during IAV infection. PMID:22412374

  16. Gestational marginal zinc deficiency impaired fetal neural progenitor cell proliferation by disrupting the ERK1/2 signaling pathway.

    Science.gov (United States)

    Nuttall, Johnathan R; Supasai, Suangsuda; Kha, Jennifer; Vaeth, Brandon M; Mackenzie, Gerardo G; Adamo, Ana M; Oteiza, Patricia I

    2015-11-01

    This study investigated if a marginal zinc deficiency during gestation in rats could affect fetal neural progenitor cell (NPC) proliferation through a down-regulation of the extracellular signal-regulated kinase (ERK1/2) signaling pathway. Rats were fed a marginally zinc-deficient or adequate diet from the beginning of gestation until embryonic day (E)19. The proportion of proliferating cells in the E19 fetal ventricular zone was decreased by marginal zinc deficiency. Immunostaining for phosphorylated ERK1/2 in the cerebral cortex was decreased in the marginal zinc fetuses, and this effect was strongest in the ventricular zone. Furthermore, phosphorylation of the upstream mitogen-activated ERK kinases (MEK1/2) was not affected, suggesting that marginal zinc deficiency could have increased ERK-directed phosphatase activity. Similar findings were observed in cultured rat embryonic cortical neurons and in IMR-32 neuroblastoma cells, in which zinc-deficiency decreased ERK1/2 phosphorylation without affecting MEK1/2 phosphorylation. Indeed, zinc deficiency increased the activity of the ERK-directed phosphatase protein phosphatase 2A (PP2A) in the fetal cortex and IMR-32 cells. Inhibition of PP2A with okadaic acid prevented the decrease in ERK phosphorylation and proliferation of zinc-deficient IMR-32 cells. Together these results demonstrated that decreased zinc availability reduces ERK1/2 signaling and decreased NPC proliferation as a consequence of PP2A activation. Disruption of fetal neurogenesis could underlie irreversible neurobehavioral impairments observed after even marginal zinc nutrition during a critical period of early brain development.

  17. Production of infectious genotype 1b virus particles in cell culture and impairment by replication enhancing mutations.

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    Thomas Pietschmann

    2009-06-01

    Full Text Available With the advent of subgenomic hepatitis C virus (HCV replicons, studies of the intracellular steps of the viral replication cycle became possible. These RNAs are capable of self-amplification in cultured human hepatoma cells, but save for the genotype 2a isolate JFH-1, efficient replication of these HCV RNAs requires replication enhancing mutations (REMs, previously also called cell culture adaptive mutations. These mutations cluster primarily in the central region of non-structural protein 5A (NS5A, but may also reside in the NS3 helicase domain or at a distinct position in NS4B. Most efficient replication has been achieved by combining REMs residing in NS3 with distinct REMs located in NS4B or NS5A. However, in spite of efficient replication of HCV genomes containing such mutations, they do not support production of infectious virus particles. By using the genotype 1b isolate Con1, in this study we show that REMs interfere with HCV assembly. Strongest impairment of virus formation was found with REMs located in the NS3 helicase (E1202G and T1280I as well as NS5A (S2204R, whereas a highly adaptive REM in NS4B still allowed virus production although relative levels of core release were also reduced. We also show that cells transfected with the Con1 wild type genome or the genome containing the REM in NS4B release HCV particles that are infectious both in cell culture and in vivo. Our data provide an explanation for the in vitro and in vivo attenuation of cell culture adapted HCV genomes and may open new avenues for the development of fully competent culture systems covering the therapeutically most relevant HCV genotypes.

  18. 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

  19. Cell killing by simian virus 40: impairment of membrane formation and function.

    Science.gov (United States)

    Norkin, L C

    1977-03-01

    Simian virus 40 infection of the CV-1 line of green monkey kidney cells results in the release of mitochondrial malic dehydrogenase as early as 24 h. Released malic dehydrogenase is detected in the cytoplasm prior to its appearance in the overlay medium. Infected cells lose the ability to consume oxygen between 48 and 56 h, and damage to the elctron transport system is indicated. Nevertheless, cellular ATP levels remain high as late as 72 h. Infection leads to a stimulation of membrane phospholipid synthesis, which reaches a peak at about 32 h. This is followed by a severe decline in new membrane synthesis, which correlates in time with the release of cytoplasmic lactic dehydrogenase into the overlay media. Lactic dehydrogenase release precedes the accumulation of trypan blue-stainable cells by about 6 h. Infection had no effect on the turnover of prelabeled membrane phospholipids. An early simian virus 40 mutant, tsA58, and a late mutant, tsB11, are both less effective than wild-type virus at causing reduced levels of phospholipid synthesis, enzyme release, and the accumulation of trypan blue-stainable cells. Another late mutant, tsB8, is similar to wild-type virus in these respects. At 64 h, there is no detectable cell-associated lactic dehydrogenase and nearly all the cells are trypan blue stainable. Nevertheless, at concentrations of deoxyglucose in the medium below the transport Km, deoxyglucose uptake was similar in infected and control cultures. With higher concentrations of deoxyglucose in the medium, uptake by the infected cultures exceeded that by the control cultures.

  20. APOBEC3G Impairs the Multimerization of the HIV-1 Vif Protein in Living Cells

    OpenAIRE

    Batisse, Julien; Guerrero, Santiago Xavier; Bernacchi, Serena; Richert, Ludovic; Godet, Julien; Goldschmidt, Valérie; Mély, Yves; Marquet, Roland; de Rocquigny, Hugues; Paillart, Jean-Christophe

    2013-01-01

    The HIV-1 viral infectivity factor (Vif) is a small basic protein essential for viral fitness and pathogenicity. Vif allows productive infection in nonpermissive cells, including most natural HIV-1 target cells, by counteracting the cellular cytosine deaminases APOBEC3G (apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G [A3G]) and A3F. Vif is also associated with the viral assembly complex and packaged into viral particles through interactions with the viral genomic RNA and t...

  1. 5-Azacytidine Promotes an Inhibitory T-Cell Phenotype and Impairs Immune Mediated Antileukemic Activity

    OpenAIRE

    Thomas Stübig; Anita Badbaran; Tim Luetkens; York Hildebrandt; Djordje Atanackovic; Binder, Thomas M. C.; Boris Fehse; Nicolaus Kröger

    2014-01-01

    Demethylating agent, 5-Azacytidine (5-Aza), has been shown to be active in treatment of myeloid malignancies. 5-Aza enhances anticancer immunity, by increasing expression of tumor-associated antigens. However, the impact of 5-Aza immune responses remains poorly understood. Here, T-cell mediated tumor immunity effects of 5-Aza, are investigated in vitro and in vivo. T-cells from healthy donors were treated with 5-Aza and analyzed by qRT-PCR and flow cytometry for changes in gene expression and...

  2. Impaired osteoblast differentiation in Annexin A2- and -A5-deficient cells

    Energy Technology Data Exchange (ETDEWEB)

    Genetos, Damian C.; Wong, Alice; Weber, Thomas J.; Karin, Norman J.; Yellowley, Clare E.

    2014-09-15

    Annexins are a class of calcium-binding proteins with diverse functions in the regulation of lipid rafts inflammation,fibrinolysis, transcriptional programming and ion transport. Within bone, they are well-characterized as components of mineralizing matrix vesicles, although little else is known as to their function during osteogenesis. We generated annexin A2 (AnxA2)- or annexin A5 (AnxA5)-knockdown pre-osteoblasts, and asked whether proliferation or osteogenic differentiation was altered in knockdown cells, compared to vector controls. We report that DNA content, a marker of proliferation, was significantly reduced in both AnxA2 and AnxA5 knockdown cells. Alkaline phosphatase expression and staining activity were also suppressed in AnxA2- or AnxA5-knockdown after 14 days of culture. The pattern of osteogenic gene expression was altered in knockdown cells, with Col1a1 expressed more rapidly in knock-down cells, compared to controls. In contrast, Runx2, Ibsp, and Bglap all revealed decreased expression after 14 days of culture. Using a murine fracture model, we demonstrate that AnxA2 and AnxA5 are rapidly expressed within the fracture callus. These data demonstrate that AnxA2 and AnxA5 can influence bone formation via regulation of osteoprogenitor proliferation and differentiation in addition to their well-studied function in matrix vesicles.

  3. Hyperglycemic Stress Impairs the Stemness Capacity of Kidney Stem Cells in Rats.

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    Guang Yang

    Full Text Available The incidence of acute kidney injury in patients with diabetes is significantly higher than that of patients without diabetes, and may be associated with the poor stemness capacity of kidney stem cells (KSCs and limited recovery of injured renal tubules. To investigate the effects of hyperglycemic stress on KSC stemness, KSCs were isolated from the rat renal papilla and analyzed for their self-renewal and differentiation abilities. Our results showed that isolated KSCs expressed the mesenchymal stem cell markers N-cadherin, Nestin, CD133, CD29, CD90, and CD73. Moreover, KSCs co-cultured with hypoxia-injured renal tubular epithelial cell (RTECs induced the expression of the mature epithelial cell marker CK18, suggesting that the KSCs could differentiate into RTECs in vitro. However, KSC proliferation, differentiation ability and tolerance to hypoxia were decreased in high-glucose cultures. Taken together, these results suggest the high-glucose microenvironment can damage the reparative ability of KSCs. It may result in a decreased of recovery capability of renal tubules from injury.

  4. Intracellular overexpression of HIV-1 Nef impairs differentiation and maturation of monocytic precursors towards dendritic cells.

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    Yan Guo

    Full Text Available Nef functions as an immunosuppressive factor critical for HIV-1 replication, survival and development of AIDS following HIV-1 infection. What effects Nef exerts on differentiation and maturation of monocytes towards dendritic cells (DCs remains greatly controversial. In this study, we used THP-1 (human monocytic leukemia cell line as monocytic DC precursors to investigate how overexpression of HIV-1 Nef influences the processes of differentiation and maturation of dendritic cells. In striking contrast to negative controls, our results showed that morphological and phenotypical changes (CD11c, CD14, CD40, CD80, CD83, CD86, and HLA-DR occurred on recombinant THP-1 expressing HIV-1 Nef (short for Nef upon co-stimulation of GM-CSF/IL-4 or GM-CSF/IL-4/TNF-α/ionomycin. Moreover, CD4, CCR5, and CXCR4 were also down-regulated on Nef. It might be hypothesized that Nef prevents superinfection and signal transduction in HIV-1 infected monocytes. Collectively, our study demonstrates that long-lasting expression of Nef at high levels indeed retards differentiation and maturation of dendritic cells in terms of phenotype and morphology. We are hopeful that potentially, stable expression of intracellular Nef in vivo may function as a subtle mode to support long-lasting HIV-1 existence.

  5. Impaired Cell Cycle Regulation in a Natural Equine Model of Asthma.

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    Alicja Pacholewska

    Full Text Available Recurrent airway obstruction (RAO is a common and potentially debilitating lower airway disease in horses, which shares many similarities with human asthma. In susceptible horses RAO exacerbation is caused by environmental allergens and irritants present in hay dust. The objective of this study was the identification of genes and pathways involved in the pathology of RAO by global transcriptome analyses in stimulated peripheral blood mononuclear cells (PBMCs. We performed RNA-seq on PBMCs derived from 40 RAO affected and 45 control horses belonging to three cohorts of Warmblood horses: two half-sib families and one group of unrelated horses. PBMCs were stimulated with hay dust extract, lipopolysaccharides, a recombinant parasite antigen, or left unstimulated. The total dataset consisted of 561 individual samples. We detected significant differences in the expression profiles between RAO and control horses. Differential expression (DE was most marked upon stimulation with hay dust extract. An important novel finding was a strong upregulation of CXCL13 together with many genes involved in cell cycle regulation in stimulated samples from RAO affected horses, in addition to changes in the expression of several HIF-1 transcription factor target genes. The RAO condition alters systemic changes observed as differential expression profiles of PBMCs. Those changes also depended on the cohort and stimulation of the samples and were dominated by genes involved in immune cell trafficking, development, and cell cycle regulation. Our findings indicate an important role of CXCL13, likely macrophage or Th17 derived, and the cell cycle regulator CDC20 in the immune response in RAO.

  6. Sodium Arsenite Caused Mineralization Impairment in Rat Bone Marrow Mesenchymal Stem Cells Differentiating to Osteoblasts

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    Mohammad Hossein Abnosi

    2012-05-01

    Full Text Available Background: Sodium arsenite (SA recently has been recommended to be used in malignancy therapy. Our studies showed, SA in short and long period of treatment caused reduction of rats Bone Marrow Mesenchymal Stem Cells (MSCs viability and induced caspase dependent apoptosis. The aim of this study was to investigate the effect of SA on osteogenic differentiation of MSCs. Methods: MSCs were extracted and expanded to third passage, then cultured in DMEM supplemented with osteogenic media in presence of 1 and 25nM of SA for 21 days. The viability and the level of mineralization were determined using MTT assay and alizarin red respectively. In addition morphology and nuclear diameter of the cells were studied with the help of fluorescent dye. Furthermore, calcium content and alkalinphosphatase activity also were estimated using commercial kit. Data was statistically analyzed and the P<0.05 was taken as the level of significant. Results: The viability and mineralization of the cells treated with SA reduced significantly (P<0.05 after tenth day in compare with control. Also, chromatin condensation, reduction of nuclei diameter and cytoplasm shrinkage were observed in the cell treated with 1 and 25 nM concentrations. The calcium and alkalinphosphatase activity of the cells decreased significantly with 1 and 25 nM concentrations of SA when compared with control. Conclusion: Adverse effect of SA was observed on osteogenic differentiation of MSCs at 1 and 25 nM due to disruption of mineralization. We strongly suggest more investigation to be run on this chemical with respect to the therapy of the malignant patients.

  7. Crosstalk between Helicobacter pylori and gastric epithelial cells is impaired by docosahexaenoic acid.

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    Marta Correia

    Full Text Available H. pylori colonizes half of the world's population leading to gastritis, ulcers and gastric cancer. H. pylori strains resistant to antibiotics are increasing which raises the need for alternative therapeutic approaches. Docosahexaenoic acid (DHA has been shown to decrease H. pylori growth and its associated-inflammation through mechanisms poorly characterized. We aimed to explore DHA action on H. pylori-mediated inflammation and adhesion to gastric epithelial cells (AGS and also to identify bacterial structures affected by DHA. H. pylori growth and metabolism was assessed in liquid cultures. Bacterial adhesion to AGS cells was visualized by transmission electron microscopy and quantified by an Enzyme Linked Immunosorbent Assay. Inflammatory proteins were assessed by immunoblotting in infected AGS cells, previously treated with DHA. Bacterial total and outer membrane protein composition was analyzed by 2-dimensional gel electrophoresis. Concentrations of 100 µM of DHA decreased H. pylori growth, whereas concentrations higher than 250 µM irreversibly inhibited bacteria survival. DHA reduced ATP production and adhesion to AGS cells. AGS cells infected with DHA pre-treated H. pylori showed a 3-fold reduction in Interleukin-8 (IL-8 production and a decrease of COX2 and iNOS. 2D electrophoresis analysis revealed that DHA changed the expression of H. pylori outer membrane proteins associated with stress response and metabolism and modified bacterial lipopolysaccharide phenotype. As conclusions our results show that DHA anti-H. pylori effects are associated with changes of bacteria morphology and metabolism, and with alteration of outer membrane proteins composition, that ultimately reduce the adhesion of bacteria and the burden of H. pylori-related inflammation.

  8. 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

  9. Impaired Peroxisome Proliferator-activated Receptor-γ Contributes to Phenotypic Modulation of Vascular Smooth Muscle Cells during Hypertension*

    Science.gov (United States)

    Zhang, Lili; Xie, Peng; Wang, Jingzhou; Yang, Qingwu; Fang, Chuanqin; Zhou, Shuang; Li, Jingcheng

    2010-01-01

    The phenotypic modulation of vascular smooth muscle cells (VSMCs) plays a pivotal role in hypertension-induced vascular changes including vascular remodeling. The precise mechanisms underlying VSMC phenotypic modulation remain elusive. Here we test the role of peroxisome proliferator-activated receptor (PPAR)-γ in the VSMC phenotypic modulation during hypertension. Both spontaneously hypertensive rat (SHR) aortas and SHR-derived VSMCs exhibited reduced PPAR-γ expression and excessive VSMC phenotypic modulation identified by reduced contractile proteins, α-smooth muscle actin (α-SMA) and smooth muscle 22α (SM22α), and enhanced proliferation and migration. PPAR-γ overexpression rescued the expression of α-SMA and SM22α, and inhibited the proliferation and migration in SHR-derived VSMCs. In contrast, PPAR-γ silencing exerted the opposite effect. Activating PPAR-γ using rosiglitazone in vivo up-regulated aortic α-SMA and SM22α expression and attenuated aortic remodeling in SHRs. Increased activation of phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling was observed in SHR-derived VSMCs. PI3K inhibitor LY294002 rescued the impaired expression of contractile proteins, and inhibited proliferation and migration in VSMCs from SHRs, whereas constitutively active PI3K mutant had the opposite effect. Overexpression or silencing of PPAR-γ inhibited or excited PI3K/Akt activity, respectively. LY294002 counteracted the PPAR-γ silencing induced proliferation and migration in SHR-derived VSMCs, whereas active PI3K mutant had the opposite effect. In contrast, reduced proliferation and migration by PPAR-γ overexpression were reversed by the active PI3K mutant, and further inhibited by LY294002. We conclude that PPAR-γ inhibits VSMC phenotypic modulation through inhibiting PI3K/Akt signaling. Impaired PPAR-γ expression is responsible for VSMC phenotypic modulation during hypertension. These findings highlight an attractive therapeutic target for

  10. Heterogeneous abnormalities of CCND1 and RB1 in primary cutaneous T-Cell lymphomas suggesting impaired cell cycle control in disease pathogenesis.

    Science.gov (United States)

    Mao, Xin; Orchard, Guy; Vonderheid, Eric C; Nowell, Peter C; Bagot, Martine; Bensussan, Armand; Russell-Jones, Robin; Young, Bryan D; Whittaker, Sean J

    2006-06-01

    Upregulation of cyclin D1/B-cell leukemia/lymphoma 1 (CCND1/BCL1) is present in most mantle cell lymphomas with the t(11;14)(q13;q32) translocation. However, little is known about the abnormalities of CCND1 and its regulator RB1 in primary cutaneous T-cell lymphomas (CTCL). We analyzed CCND and RB status in CTCL using fluorescent in situ hybridization (FISH), immunohistochemistry (IHC), and Affymetrix expression microarray. FISH revealed loss of CCND1/BCL1 in five of nine Sézary syndrome (SS) cases but gain in two cases, and RB1 loss in four of seven SS cases. IHC showed absent CCND1/BCL1 expression in 18 of 30 SS, 10 of 23 mycosis fungoides (MF), and three of 10 primary cutaneous CD30+ anaplastic large-cell lymphoma (C-ALCL). Increased CCND1/BCL1 expression was seen in nine MF, seven C-ALCL, and six SS cases. Absent RB1 expression was detected in 8 of 12 MF and 7 of 9 SS cases, and raised RB1 expression in 7 of 8 C-ALCL. Affymetrix revealed increased gene expression of CCND2 in four of eight CTCL cases, CCND3 in three cases, and CDKN2C in two cases with a normal expression of CCND1 and RB1. These findings suggest heterogeneous abnormalities of CCND and RB in CTCL, in which dysregulated CCND and RB1 may lead to impaired cell cycle control.

  11. Impaired inhibitory Fcγ receptor IIB expression on B cells in chronic inflammatory demyelinating polyneuropathy

    OpenAIRE

    Tackenberg, Björn; Jelčić, Ilijas; Baerenwaldt, Anne; Wolfgang H Oertel; Sommer, Norbert; Nimmerjahn, Falk; Lünemann, Jan D.

    2009-01-01

    The inhibitory Fc-γ receptor FcγRIIB, expressed on myeloid and B cells, has a critical role in the balance of tolerance and autoimmunity, and is required for the antiinflammatory activity of intravenous Ig (IVIG) in various murine disease models. However, the function of FcγRIIB and its regulation by IVIG in human autoimmune diseases are less well understood. Chronic inflammatory demyelinating polyneuropathy (CIDP) is the most common treatable acquired chronic polyneuropathy, and IVIG is wide...

  12. Cadmium Impairs p53 Activity in HepG2 Cells

    OpenAIRE

    Urani, C.; Melchioretto, P.; M. Fabbri; Bowe, G.; Maserati, E.; Gribaldo, L.

    2014-01-01

    Cadmium and cadmium compounds are contaminants of the environment, food, and drinking water and are important constituents of cigarette smoke. Cd exposure has also been associated with airborne particulate CdO and with Cd-containing quantum dots in medical therapy. Adverse cadmium effects reported in the literature have stimulated during recent years an ongoing discussion to better elucidate cadmium outcomes at cell and molecular level. The present work is designed to gain an insight into the...

  13. Impaired regeneration of dystrophin-deficient muscle fibers is caused by exhaustion of myogenic cells

    Directory of Open Access Journals (Sweden)

    Luz M.A.M.

    2002-01-01

    Full Text Available Duchenne muscular dystrophy is one of the most devastating myopathies. Muscle fibers undergo necrosis and lose their ability to regenerate, and this may be related to increased interstitial fibrosis or the exhaustion of satellite cells. In this study, we used mdx mice, an animal model of Duchenne muscular dystrophy, to assess whether muscle fibers lose their ability to regenerate after repeated cycles of degeneration-regeneration and to establish the role of interstitial fibrosis or exhaustion of satellite cells in this process. Repeated degenerative-regenerative cycles were induced by the injection of bupivacaine (33 mg/kg, a myotoxic agent. Bupivacaine was injected weekly into the right tibialis anterior muscle of male, 8-week-old mdx (N = 20 and C57Bl/10 (control, N = 10 mice for 20 and 50 weeks. Three weeks after the last injection, the mice were killed and the proportion of regenerated fibers was counted and reported as a fibrosis index. Twenty weekly bupivacaine injections did not change the ability of mdx muscle to regenerate. However, after 50 weekly bupivacaine injections, there was a significant decrease in the regenerative response. There was no correlation between the inability to regenerate and the increase in interstitial fibrosis. These results show that after prolonged repeated cycles of degeneration-regeneration, mdx muscle loses its ability to regenerate because of the exhaustion of satellite cells, rather than because of an increase in interstitial fibrosis. This finding may be relevant to cell and gene therapy in the treatment of Duchenne muscular dystrophy.

  14. Weight Cycling Increases T-Cell Accumulation in Adipose Tissue and Impairs Systemic Glucose Tolerance

    OpenAIRE

    Anderson, Emily K.; Gutierrez, Dario A.; Kennedy, Arion; Hasty, Alyssa H.

    2013-01-01

    Obesity is one of the leading causes of morbidity in the U.S. Accumulation of proinflammatory immune cells in adipose tissue (AT) contributes to the development of obesity-associated disorders. Weight loss is the ideal method to counteract the negative consequences of obesity; however, losses are rarely maintained, leading to bouts of weight cycling. Fluctuations in weight have been associated with worsened metabolic and cardiovascular outcomes; yet, the mechanisms explaining this potential c...

  15. Alcohol impairs long-term depression at the cerebellar parallel fiber-Purkinje cell synapse

    OpenAIRE

    Belmeguenai, A.; Botta, Paolo; Weber, John; Carta, Mario; De Ruiter, Martijn; De Zeeuw, Chris; Valenzuela, Fernando; Hansel, Christian

    2008-01-01

    textabstractAcute alcohol consumption causes deficits in motor coordination and gait, suggesting an involvement of cerebellar circuits, which play a role in the fine adjustment of movements and in motor learning. It has previously been shown that ethanol modulates inhibitory transmission in the cerebellum and affects synaptic transmission and plasticity at excitatory climbing fiber (CF) to Purkinje cell synapses. However, it has not been examined thus far how acute ethanol application affects...

  16. Oxidative Stress Impairs Cell Death by Repressing the Nuclease Activity of Mitochondrial Endonuclease G

    Directory of Open Access Journals (Sweden)

    Jason L.J. Lin

    2016-07-01

    Full Text Available Endonuclease G (EndoG is a mitochondrial protein that is released from mitochondria and relocated into the nucleus to promote chromosomal DNA fragmentation during apoptosis. Here, we show that oxidative stress causes cell-death defects in C. elegans through an EndoG-mediated cell-death pathway. In response to high reactive oxygen species (ROS levels, homodimeric CPS-6—the C. elegans homolog of EndoG—is dissociated into monomers with diminished nuclease activity. Conversely, the nuclease activity of CPS-6 is enhanced, and its dimeric structure is stabilized by its interaction with the worm AIF homolog, WAH-1, which shifts to disulfide cross-linked dimers under high ROS levels. CPS-6 thus acts as a ROS sensor to regulate the life and death of cells. Modulation of the EndoG dimer conformation could present an avenue for prevention and treatment of diseases resulting from oxidative stress.

  17. Impairments of cells and genomic DNA by environmentally transformed engineered nanomaterials

    Science.gov (United States)

    Jones, Philip; Sugino, Sakiko; Yamamura, Shohei; Lacy, Fred; Biju, Vasudevanpillai

    2013-09-01

    Enormous increase in the production of nanomaterials and their growing applications in the device technology, biotechnology and biomedical areas suggest the need for developing models for predicting the environmental health and safety (EHS) risks posed by such nanomaterials. We hypothesize that CdSe quantum dots (QDs) and ZnO nanoparticles (NPs) encompassed in liposomes or not and transformed by simulated solar UV light can be model systems for studying the environmental toxicity of engineered nanomaterials. In this study, human lung epithelial adenocarcinoma cells (H1650) are exposed to photoirradiated CdSe QDs or ZnO nanopowder included or not in liposomes. The release of cadmium and zinc ions from the nanomaterials exposed to solar simulated UV radiation is detected and quantified by measuring the steady-state and time resolved fluorescence of the metal ion sensor tetracarboxyphenylporphyrin (TCPP) or the commercial Measure iT Pd/Cd sensor. Viability of cells treated with nanomaterials exposed to solar simulated UV radiation for different durations is measured by MTT assay. Enhanced etching of the nanoparticles exposed to solar simulated UV radiation results in the release of toxic levels of heavy metal ions, which considerably lower the viability of H1650 cells is due to the deactivation of DNA repair enzymes as evidenced by the pinching off of nuclear DNA in comet assays and DNA samples in electrophoresis. Results from this study highlight the need to obtain not only quantitative information about the environmental risks posed by engineered nanomaterials but also environment friendly nanomaterials for practical applications.Enormous increase in the production of nanomaterials and their growing applications in the device technology, biotechnology and biomedical areas suggest the need for developing models for predicting the environmental health and safety (EHS) risks posed by such nanomaterials. We hypothesize that CdSe quantum dots (QDs) and ZnO nanoparticles

  18. DNA methylation analysis using CpG microarrays is impaired in benzopyrene exposed cells

    International Nuclear Information System (INIS)

    Epigenetic alterations have emerged as a key mechanism involved in tumorigenesis. These disruptions are partly due to environmental factors that change normal DNA methylation patterns necessary for transcriptional regulation and chromatin compaction. Microarray technologies are allowing environmentally susceptible epigenetic patterns to be mapped and the precise targets of environmentally induced alterations to be identified. Previously, we observed BaP-induced epigenetic events and cell cycle disruptions in breast cancer cell lines that included time- and concentration-dependent loss of proliferation as well as sequence-specific hypo- and hypermethylation events. In this present report, we further characterized epigenetic changes in BaP-exposed MCF-7 cells. We analyzed DNA methylation on a CpG island microarray platform with over 5400 unique genomic regions. Depleted and enriched microarray targets, representative of putative DNA methylation changes, were identified across the genome; however, subsequent sodium bisulfite analyses revealed no changes in DNA methylation at a number of these loci. Instead, we found that the identification of DNA methylation changes using this restriction enzyme-based microarray approach corresponded with the regions of DNA bound by the BaP derived DNA adducts. This DNA adduct formation occurs at both methylated and unmethylated CpG dinucleotides and affects PCR amplification during sample preparation. Our data suggest that caution should be exercised when interpreting data from comparative microarray experiments that rely on enzymatic reactions. These results are relevant to genome screening approaches involving environmental exposures in which DNA adduct formation at specific nucleotide sites may bias target acquisition and compromise the correct identification of epigenetically responsive genes

  19. Aging impairs osteoblast differentiation of mesenchymal stem cells grown on titanium by favoring adipogenesis

    Science.gov (United States)

    ABUNA, Rodrigo Paolo Flores; STRINGHETTA-GARCIA, Camila Tami; FIORI, Leonardo Pimentel; DORNELLES, Rita Cassia Menegati; ROSA, Adalberto Luiz; BELOTI, Marcio Mateus

    2016-01-01

    ABSTRACT Aging negatively affects bone/titanium implant interactions. Our hypothesis is that the unbalance between osteogenesis and adipogenesis induced by aging may be involved in this phenomenon. Objective We investigated the osteoblast and adipocyte differentiation of mesenchymal stem cells (MSCs) from young and aged rats cultured on Ti. Material and Methods Bone marrow MSCs derived from 1-month and 21-month rats were cultured on Ti discs under osteogenic conditions for periods of up to 21 days and osteoblast and adipocyte markers were evaluated. Results Cell proliferation, alkaline phosphatase (ALP) activity, extracellular matrix mineralization and gene expression of RUNX2, osterix, ALP, bone sialoprotein, osteopontin, and osteocalcin were reduced in cultures of 21-month rats compared with 1-month rats grown on Ti. Gene expression of PPAR-γ , adipocyte protein 2, and resistin and lipid accumulation were increased in cultures of 21-month rats compared with 1-month rats grown on the same conditions. Conclusions These results indicate that the lower osteogenic potential of MSCs derived from aged rats compared with young rats goes along with the higher adipogenic potential in cultures grown on Ti surface. This unbalance between osteoblast and adipocyte differentiation should be considered in dental implant therapy to the elderly population. PMID:27556209

  20. Thymosin beta4 targeting impairs tumorigenic activity of colon cancer stem cells.

    Science.gov (United States)

    Ricci-Vitiani, Lucia; Mollinari, Cristiana; di Martino, Simona; Biffoni, Mauro; Pilozzi, Emanuela; Pagliuca, Alfredo; de Stefano, Maria Chiara; Circo, Rita; Merlo, Daniela; De Maria, Ruggero; Garaci, Enrico

    2010-11-01

    Thymosin β4 (Tβ4) is an actin-binding peptide overexpressed in several tumors, including colon carcinomas. The aim of this study was to investigate the role of Tβ4 in promoting the tumorigenic properties of colorectal cancer stem cells (CR-CSCs), which are responsible for tumor initiation and growth. We first found that CR-CSCs from different patients have higher Tβ4 levels than normal epithelial cells. Then, we used a lentiviral strategy to down-regulate Tβ4 expression in CR-CSCs and analyzed the effects of such modulation on proliferation, survival, and tumorigenic activity of CR-CSCs. Empty vector-transduced CR-CSCs were used as a control. Targeting of the Tβ4 produced CR-CSCs with a lower capacity to grow and migrate in culture and, interestingly, reduced tumor size and aggressiveness of CR-CSC-based xenografts in mice. Moreover, such loss in tumorigenic activity was accompanied by a significant increase of phosphatase and tensin homologue (PTEN) and a concomitant reduction of the integrin-linked kinase (ILK) expression, which resulted in a decreased activation of protein kinase B (Akt). Accordingly, exogenous expression of an active form of Akt rescued all the protumoral features lost after Tβ4 targeting in CR-CSCs. In conclusion, Tβ4 may have important implications for therapeutic intervention for treatment of human colon carcinoma. PMID:20566622

  1. CD38 Ligation in Peripheral Blood Mononuclear Cells of Myeloma Patients Induces Release of Protumorigenic IL-6 and Impaired Secretion of IFNγ Cytokines and Proliferation

    Directory of Open Access Journals (Sweden)

    Giorgio Fedele

    2013-01-01

    Full Text Available CD38, a surface receptor that controls signals in immunocompetent cells, is densely expressed by cells of multiple myeloma (MM. The immune system of MM patients appears as functionally impaired, with qualitative and quantitative defects in T cell immune responses. This work answers the issue whether CD38 plays a role in the impairment of T lymphocyte response. To this aim, we analyzed the signals implemented by monoclonal antibodies (mAb ligation in peripheral blood mononuclear cells (PBMC obtained from MM patients and compared to benign monoclonal gammopathy of undetermined significance (MGUS. PBMC from MM both failed to proliferate and secrete IFNγ induced by CD38 ligation while it retained the ability to respond to TCR/CD3. The impaired CD38-dependent proliferative response likely reflects an arrest in the progression of cell cycle, as indicated by the reduced expression of PCNA. CD38 signaling showed an enhanced ability to induce IL-6 secretion. PBMC from MM patients displays a deregulated response possibly due to defects of CD38 activation pathways and CD38 may be functionally involved in the progression of this pathology via the secretion of high levels of IL-6 that protects neoplastic cells from apoptosis.

  2. Methylglyoxal Impairs Insulin Secretion of Pancreatic β-Cells through Increased Production of ROS and Mitochondrial Dysfunction Mediated by Upregulation of UCP2 and MAPKs.

    Science.gov (United States)

    Bo, Jinshuang; Xie, Shiya; Guo, Yi; Zhang, Chunli; Guan, Yanming; Li, Chunmei; Lu, Jianxin; Meng, Qing H

    2016-01-01

    Methylglyoxal (MG) is a highly reactive glucose metabolic intermediate and a major precursor of advanced glycation end products. MG level is elevated in hyperglycemic disorders such as diabetes mellitus. Substantial evidence has shown that MG is involved in the pathogenesis of diabetes and diabetic complications. We investigated the impact of MG on insulin secretion by MIN6 and INS-1 cells and the potential mechanisms of this effect. Our study demonstrates that MG impaired insulin secretion by MIN6 or ISN-1 cells in a dose-dependent manner. It increased reactive oxygen species (ROS) production and apoptosis rate in MIN6 or ISN-1 cells and inhibited mitochondrial membrane potential (MMP) and ATP production. Furthermore, the expression of UCP2, JNK, and P38 as well as the phosphorylation JNK and P38 was increased by MG. These effects of MG were attenuated by MG scavenger N-acetyl cysteine. Collectively, these data indicate that MG impairs insulin secretion of pancreatic β-cells through increasing ROS production. High levels of ROS can damage β-cells directly via JNK/P38 upregulation and through activation of UCP2 resulting in reduced MMP and ATP production, leading to β-cell dysfunction and impairment of insulin production.

  3. MicroRNA-497 impairs the growth of chemoresistant neuroblastoma cells by targeting cell cycle, survival and vascular permeability genes

    Science.gov (United States)

    Soriano, Aroa; París-Coderch, Laia; Jubierre, Luz; Martínez, Alba; Zhou, Xiangyu; Piskareva, Olga; Bray, Isabella; Vidal, Isaac; Almazán-Moga, Ana; Molist, Carla; Roma, Josep; Bayascas, José R.; Casanovas, Oriol; Stallings, Raymond L.; de Toledo, José Sánchez; Gallego, Soledad; Segura, Miguel F.

    2016-01-01

    Despite multimodal therapies, a high percentage of high-risk neuroblastoma (NB) become refractory to current treatments, most of which interfere with cell cycle and DNA synthesis or function, activating the DNA damage response (DDR). In cancer, this process is frequently altered by deregulated expression or function of several genes which contribute to multidrug resistance (MDR). MicroRNAs are outstanding candidates for therapy since a single microRNA can modulate the expression of multiple genes of the same or different pathways, thus hindering the development of resistance mechanisms by the tumor. We found several genes implicated in the MDR to be overexpressed in high-risk NB which could be targeted by microRNAs simultaneously. Our functional screening identified several of those microRNAs that reduced proliferation of chemoresistant NB cell lines, the best of which was miR-497. Low expression of miR-497 correlated with poor patient outcome. The overexpression of miR-497 reduced the proliferation of multiple chemoresistant NB cell lines and induced apoptosis in MYCN-amplified cell lines. Moreover, the conditional expression of miR-497 in NB xenografts reduced tumor growth and inhibited vascular permeabilization. MiR-497 targets multiple genes related to the DDR, cell cycle, survival and angiogenesis, which renders this molecule a promising candidate for NB therapy. PMID:26824183

  4. Heptachlor induced mitochondria-mediated cell death via impairing electron transport chain complex III

    International Nuclear Information System (INIS)

    Highlights: •Heptachlor inhibited mitochondrial electron transport chain complex III activity. •Heptachlor promoted generation of reactive oxygen species. •Heptachlor induced Bax activation. •Heptachlor induced mitochondria-mediated and caspase-dependent apoptosis. -- Abstract: Environmental toxins like pesticides have been implicated in the pathogenesis of Parkinson’s disease (PD). Epidemiological studies suggested that exposures to organochlorine pesticides have an association with an increased PD risk. In the present study, we examined the mechanism of toxicity induced by an organochlorine pesticide heptachlor. In a human dopaminergic neuroblastoma SH-SY5Y cells, heptachlor induced both morphological and functional damages in mitochondria. Interestingly, the compound inhibited mitochondrial electron transport chain complex III activity. Rapid generation of reactive oxygen species and the activation of Bax were then detected. Subsequently, mitochondria-mediated, caspase-dependent apoptosis followed. Our results raise a possibility that an organochlorine pesticide heptachlor can act as a neurotoxicant associated with PD

  5. STAT5 transcriptional activity is impaired by LIF in a mammary epithelial cell line.

    Science.gov (United States)

    Granillo, Agustina Rodriguez; Boffi, Juan Carlos; Barañao, Lino; Kordon, Edith; Pecci, Adali; Guberman, Alejandra

    2007-05-11

    Gene regulation mediated by STAT factors has been implicated in cellular functions with relevance to a variety of processes. Particularly, STAT5 and STAT3 play a crucial role in mammary epithelium displaying reciprocal activation kinetics during pregnancy, lactation and involution. Here, we show that LIF treatment of mammary epithelial HC11 cells reduces the phosphorylation levels and transcriptional activity of p-STAT5 in correlation with STAT3 phosphorylation. We have also found that STAT5 activity is negatively modulated by this cytokine, both on a gene whose expression is induced, as well as on a promoter repressed by STAT5. Besides, our results show that lactogenic hormones increase LIF effect on gene induction without modifying STAT3 phosphorylation state. Our findings strongly suggest that there is crosstalk between STAT5 and STAT3 pathways that could modulate their ability to regulate gene expression.

  6. Heptachlor induced mitochondria-mediated cell death via impairing electron transport chain complex III

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seokheon; Kim, Joo Yeon; Hwang, Joohyun [Department of Molecular Biology, Sejong University, Seoul 143-747 (Korea, Republic of); Shin, Ki Soon [Department of Biology, Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Kang, Shin Jung, E-mail: sjkang@sejong.ac.kr [Department of Molecular Biology, Sejong University, Seoul 143-747 (Korea, Republic of)

    2013-08-09

    Highlights: •Heptachlor inhibited mitochondrial electron transport chain complex III activity. •Heptachlor promoted generation of reactive oxygen species. •Heptachlor induced Bax activation. •Heptachlor induced mitochondria-mediated and caspase-dependent apoptosis. -- Abstract: Environmental toxins like pesticides have been implicated in the pathogenesis of Parkinson’s disease (PD). Epidemiological studies suggested that exposures to organochlorine pesticides have an association with an increased PD risk. In the present study, we examined the mechanism of toxicity induced by an organochlorine pesticide heptachlor. In a human dopaminergic neuroblastoma SH-SY5Y cells, heptachlor induced both morphological and functional damages in mitochondria. Interestingly, the compound inhibited mitochondrial electron transport chain complex III activity. Rapid generation of reactive oxygen species and the activation of Bax were then detected. Subsequently, mitochondria-mediated, caspase-dependent apoptosis followed. Our results raise a possibility that an organochlorine pesticide heptachlor can act as a neurotoxicant associated with PD.

  7. Impaired T cell responsiveness to interleukin-6 in hematological patients with invasive aspergillosis.

    Directory of Open Access Journals (Sweden)

    Jose F Camargo

    Full Text Available Invasive mold infections (IMI are among the most devastating complications following chemotherapy and hematopoietic stem cell transplantation (HSCT, with high mortality rates. Yet, the molecular basis for human susceptibility to invasive aspergillosis (IA and mucormycosis remain poorly understood. Herein, we aimed to characterize the immune profile of individuals with hematological malignancies (n = 18 who developed IMI during the course of chemotherapy or HSCT, and compared it to that of hematological patients who had no evidence of invasive fungal infection (n = 16. First, we measured the expression of the pattern recognition receptors pentraxin 3, dectin-1, and Toll-like receptors (TLR 2 and 4 in peripheral blood of chemotherapy and HSCT recipients with IMI. Compared to hematological controls, individuals with IA and mucormycosis had defective expression of dectin-1; in addition, patients with mucormycosis had decreased TLR2 and increased TLR4 expression. Since fungal recognition via dectin-1 favors T helper 17 responses and the latter are highly dependent on activation of the signal transducer and activator of transcription (STAT 3, we next used phospho-flow cytometry to measure the phosphorylation of the transcription factors STAT1 and STAT3 in response to interferon-gamma (IFN-γ and interleukin (IL-6, respectively. While IFN-γ/STAT1 signaling was similar between groups, naïve T cells from patients with IA, but not those with mucormycosis, exhibited reduced responsiveness to IL-6 as measured by STAT3 phosphorylation. Furthermore, IL-6 increased Aspergillus-induced IL-17 production in culture supernatants from healthy and hematological controls but not in patients with IA. Altogether, these observations suggest an important role for dectin-1 and the IL-6/STAT3 pathway in protective immunity against Aspergillus.

  8. Impaired Driving

    Science.gov (United States)

    ... help prevent injuries and deaths from alcohol-impaired driving. The Problem Risk Factors BAC Effects Prevention Additional Resources How big is the problem? In 2014, 9,967 people were killed in alcohol-impaired driving crashes, accounting for nearly one-third (31%) of ...

  9. Deletion of ARNT (Aryl hydrocarbon receptor nuclear translocator in β-cells causes islet transplant failure with impaired β-cell function.

    Directory of Open Access Journals (Sweden)

    Amit Lalwani

    Full Text Available BACKGROUND: Replacing β-cells by islet-transplantation can cure type 1 diabetes, but up to 70% of β-cells die within 10 days of transplantation. ARNT (Aryl hydrocarbon Receptor Nuclear Translocator regulates β-cell function, and potentially survival. Lack of ARNT impairs the ability of β-cells to respond to physiological stress and potentiates the onset of diabetes, but the exact role of ARNT in graft outcome is unknown. AIM: To investigate the effect of β-cell deletion of ARNT on graft outcomes. METHODS: Islets were isolated from donor mice which had β-cell specific ARNT-deletion (β-ARNT or littermate floxed controls. The islets were transplanted into diabetic SCID recipients in ratios of (a 3 donors: 1 recipient, (b 1 donor: 1 recipient or (c ½ of the islets from 1 donor: 1 recipient. After 28 days, the kidney containing the graft was removed (nephrectomy to exclude regeneration of the endogenous pancreas. RESULTS: In the supra-physiological-mass model (3:1, both groups achieved reasonable glycaemia, with slightly higher levels in β-ARNT-recipients. In adequate-mass model (1:1, β-ARNT recipients had poor glucose control versus floxed-control recipients and versus the β-ARNT donors. In the low-β-cell-mass model (½:1 β-ARNT transplants completely failed, whereas controls had good outcomes. Unexpectedly, there was no difference in the graft insulin content or β-cell mass between groups indicating that the defect was not due to early altered β-cell survival. CONCLUSION: Outcomes for islet transplants lacking β-cell ARNT were poor, unless markedly supra-physiological masses of islets were transplanted. In the 1:1 transplant model, there was no difference in β-cell volume. This is surprising because transplants of islets lacking one of the ARNT-partners HIF-1α have increased apoptosis and decreased islet volume. ARNT also partners HIF-2α and AhR (aryl hydrocarbon receptor to form active transcriptional complexes, and further work

  10. ENA/VASP downregulation triggers cell death by impairing axonal maintenance in hippocampal neurons.

    Science.gov (United States)

    Franco, D Lorena; Rezával, Carolina; Cáceres, Alfredo; Schinder, Alejandro F; Ceriani, M Fernanda

    2010-06-01

    Neurodegenerative diseases encompass a broad variety of motor and cognitive disorders that are accompanied by death of specific neuronal populations or brain regions. Cellular and molecular mechanisms underlying these complex disorders remain largely unknown. In a previous work we searched for novel Drosophila genes relevant for neurodegeneration and singled out enabled (ena), which encodes a protein involved in cytoskeleton remodeling. To extend our understanding on the mechanisms of ENA-triggered degeneration we now investigated the effect of silencing ena ortholog genes in mouse hippocampal neurons. We found that ENA/VASP downregulation led to neurite retraction and concomitant neuronal cell death through an apoptotic pathway. Remarkably, this retraction initially affected the axonal structure, showing no effect on dendrites. Reduction in ENA/VASP levels blocked the neuritogenic effect of a specific RhoA kinase (ROCK) inhibitor, thus suggesting that these proteins could participate in the Rho-signaling pathway. Altogether these observations demonstrate that ENA/VASP proteins are implicated in the establishment and maintenance of the axonal structure and that a change on their expression levels triggers neuronal degeneration.

  11. Lead exposure impairs NMDA agonist-induced no production in pyramidal hippocampal cells

    Directory of Open Access Journals (Sweden)

    Seyed Nasser Ostad

    2006-03-01

    Full Text Available Chronic exposure to Lead (Pb affects neural functions in central nervous system (CNS particularly the learning and memory. On the other hand, alteration of calcium level in the CNS results in activation of NOS where it is expected to increase nitric oxide level in hippocampus. In this study the role of Lead exposure in NMDA induced NO production in pyramidal hippocampal cells (CA1HP was investigated. The NO level was determined by measurement of concentration of nitrite and nitrate as NO products using the metHb production at 401 nm. The ACBD (NMDA agonist-induced NO level was almost reduced to the control level (2.5 nM in the presence of 10 and 100 nM of Lead acetate. Lead acetate at concentrations which normally results in chronic toxicity did not increase the nitric oxide (NO production by CA1HP. One reason for this finding could be the interaction of Lead with NMDA receptors due to similarity of Pb2+ to Zn2+ ion. Another reason may be related to direct interaction of Lead with NMDA receptors that inhibit the stimulated NO production.

  12. Up-regulation of SOX9 in sertoli cells from testiculopathic patients accounts for increasing anti-mullerian hormone expression via impaired androgen receptor signaling.

    Directory of Open Access Journals (Sweden)

    Kuo-Chung Lan

    Full Text Available BACKGROUND: Testosterone provokes Sertoli cell maturation and represses AMH production. In adult patients with Sertoli-cells-only syndrome (SCOS and androgen insensitivity syndrome (AIS, high level of AMH expression is detected in Sertoli cells due to defect of androgen/AR signaling. OBJECTIVE: We postulated that up-regulation of SOX9 due to impairment of androgen/AR signaling in Sertoli cells might explain why high level of anti-Mullerian hormone (AMH expression occur in these testiculopathic patients. METHODS: Biological research of testicular specimens from men with azoospermia or mouse. The serum hormone levels were studied in 23 men with obstructive azoospermia, 33 men with SCOS azoospermia and 21 volunteers with normal seminograms during a period of 4 years. Immunohistochemical staining and reverse-transcription PCR were used to examine the relationships among AR, SOX9 and AMH expression in adult human and mouse testes. The ability of AR to repress the expression of SOX9 and AMH was evaluated in vitro in TM4 Sertoli cells and C3H10T1/2 cells. RESULTS: SCOS specimens showed up-regulation of SOX9 and AMH proteins but down-regulation of AR proteins in Sertoli cells. The mRNA levels of AR were significantly lower and the SOX9, AMH mRNA levels higher in all SCOS patients compared to controls (P< 0.05. The testosterone levels in the SCOS patients were within the normal range, but most were below the median of the controls. Furthermore, our in vitro cell line experiments demonstrated that androgen/AR signaling suppressed the gene and protein levels of AMH via repression of SOX9. CONCLUSIONS: Our data show that the functional androgen/AR signaling to repress SOX9 and AMH expression is essential for Sertoli cell maturation. Impairment of androgen/AR signaling promotes SOX9-mediated AMH production, accounts for impairments of Sertoli cells in SCOS azoospermic patients.

  13. Adenosine A2A Receptor and IL-10 in Peripheral Blood Mononuclear Cells of Patients with Mild Cognitive Impairment

    Directory of Open Access Journals (Sweden)

    Beatrice Arosio

    2011-01-01

    Full Text Available Adenosine suppresses immune responses through the A2A receptor (A2AR. This study investigated the interleukin 10 (IL-10 genetic profile and the expression of A2AR in peripheral blood mononuclear cells (PBMCs of patients with mild cognitive impairment (MCI, Alzheimer disease (AD, and age-matched controls to verify, if they may help distinguish different forms of cognitive decline. We analyzed the IL-10 genotype and the expression of A2AR in 41 subjects with AD, 10 with amnestic MCI (a-MCI, 49 with multiple cognitive domain MCI (mcd-MCI, and 46 controls. There was a significant linear increase in A2AR mRNA levels and A2AR density from mcd-MCI to a-MCI, with intermediate levels being found in AD. The IL-10 AA genotype frequency was 67% in a-MCI, 46% in AD, 35% in mcd-MCI, and 20% in controls. These data suggest that the assessment of the IL-10 genotype and the expression of A2AR in PBMCs may be a valuable means of differentiating between a-MCI and mcd-MCI.

  14. Epicardial delivery of VEGF and cardiac stem cells guided by 3-dimensional PLLA mat enhancing cardiac regeneration and angiogenesis in acute myocardial infarction.

    Science.gov (United States)

    Chung, Hye-Jin; Kim, Jong-Tae; Kim, Hee-Jung; Kyung, Hei-Won; Katila, Pramila; Lee, Jeong-Han; Yang, Tae-Hyun; Yang, Young-Il; Lee, Seung-Jin

    2015-05-10

    Congestive heart failure is mostly resulted in a consequence of the limited myocardial regeneration capacity after acute myocardial infarction. Targeted delivery of proangiogenic factors and/or stem cells to the ischemic myocardium is a promising strategy for enhancing their local and sustained therapeutic effects. Herein, we designed an epicardial delivery system of vascular endothelial growth factor (VEGF) and cardiac stem cells (CSCs) using poly(l-lactic acid) (PLLA) mat applied to the acutely infarcted myocardium. The fibrous VEGF-loaded PLLA mat was fabricated by an electrospinning method using PLLA solution emulsified VEGF. This mat not only allowed for sustained release of VEGF for 4weeks but boosted migration and proliferation of both endothelial cells and CSCs in vitro. Furthermore, sustained release of VEGF showed a positive effect on in vitro capillary-like network formation of endothelial cells compared with bolus treatment of VEGF. PLLA mat provided a permissive 3-dimensional (3D) substratum that led to spontaneous cardiomyogenic differentiation of CSCs in vitro. Notably, sustained stimulation by VEGF-loaded PLLA mat resulted in a substantial increase in the expression of proangiogenic mRNAs of CSCs in vitro. The epicardially implanted VEGF-loaded PLLA mat showed modest effects on angiogenesis and cardiomyogenesis in the acutely infarcted hearts. However, co-implantation of VEGF and CSCs using the PLLA mat showed meaningful therapeutic effects on angiogenesis and cardiomyogenesis compared with controls, leading to reduced cardiac remodeling and enhanced global cardiac function. Collectively, the PLLA mat allowed a smart cargo that enabled the sustained release of VEGF and the delivery of CSCs, thereby synergistically inducing angiogenesis and cardiomyogenesis in acute myocardial infarction.

  15. Respiratory Impairment after Early Red Cell Transfusion in Pediatric Patients with ALI/ARDS

    Directory of Open Access Journals (Sweden)

    Surender Rajasekaran

    2012-01-01

    Full Text Available Introduction. In the first 48 hours of ventilating patients with acute lung injury (ALI/acute respiratory distress syndrome (ARDS, a multipronged approach including packed red blood cell (PRBC transfusion is undertaken to maintain oxygen delivery. Hypothesis. We hypothesized children with ALI/ARDS transfused within 48 hours of initiating mechanical ventilation would have worse outcome. The course of 34 transfused patients was retrospectively compared to 45 nontransfused control patients admitted to the PICU at Helen DeVos Children’s Hospital between January 1st 2008 and December 31st 2009. Results. Mean hemoglobin (Hb prior to transfusion was 8.2 g/dl compared to 10.1 g/dl in control. P/F ratio decreased from 135.4±7.5 to 116.5±8.8 in transfused but increased from 148.0±8.0 to 190.4±17.8 (P<0.001 in control. OI increased in the transfused from 11.7±0.9 to 18.7±1.6 but not in control. Ventilator days in the transfused were 15.6±1.7 versus 9.5±0.6 days in control (P<0.001. There was a trend towards higher rates of MODS in transfused patients; 29.4% versus 17.7%, odds ratio 1.92, 95% CI; 0.6–5.6 Fisher exact P<0.282. Conclusion. This study suggests that early transfusions of patients with ALI/ARDS were associated with increased ventilatory needs.

  16. CD4+ FOXP3+ Regulatory T Cells Exhibit Impaired Ability to Suppress Effector T Cell Proliferation in Patients with Turner Syndrome.

    Directory of Open Access Journals (Sweden)

    Young Ah Lee

    Full Text Available We investigated whether the frequency, phenotype, and suppressive function of CD4+ FOXP3+ regulatory T cells (Tregs are altered in young TS patients with the 45,X karyotype compared to age-matched controls.Peripheral blood mononuclear cells from young TS patients (n = 24, 17.4-35.9 years and healthy controls (n = 16 were stained with various Treg markers to characterize their phenotypes. Based on the presence of thyroid autoimmunity, patients were categorized into TS (- (n = 7 and TS (+ (n = 17. Tregs sorted for CD4+ CD25bright were co-cultured with autologous CD4+ CD25- target cells in the presence of anti-CD3 and -CD28 antibodies to assess their suppressive function.Despite a lower frequency of CD4+ T cells in the TS (- and TS (+ patients (mean 30.8% and 31.7%, vs. 41.2%; P = 0.003 and P < 0.001, respectively, both groups exhibited a higher frequency of FOXP3+ Tregs among CD4+ T cells compared with controls (means 1.99% and 2.05%, vs. 1.33%; P = 0.029 and P = 0.004, respectively. There were no differences in the expression of CTLA-4 and the frequency of Tregs expressing CXCR3+, and CCR4+ CCR6+ among the three groups. However, the ability of Tregs to suppress the in vitro proliferation of autologous CD4+ CD25- T cells was significantly impaired in the TS (- and TS (+ patients compared to controls (P = 0.003 and P = 0.041. Meanwhile, both the TS (- and TS (+ groups had lower frequencies of naïve cells (P = 0.001 for both but higher frequencies of effector memory cells (P = 0.004 and P = 0.002 than did the healthy control group.The Tregs of the TS patients could not efficiently suppress the proliferation of autologous effector T cells, despite their increased frequency in peripheral CD4+ T cells.

  17. CD4+FOXP3+ Regulatory T Cells Exhibit Impaired Ability to Suppress Effector T Cell Proliferation in Patients with Turner Syndrome

    Science.gov (United States)

    Lee, Young Ah; Kim, Hang-Rae; Lee, Jeong Seon; Jung, Hae Woon; Kim, Hwa Young; Lee, Gyung Min; Lee, Jieun; Sim, Ji Hyun; Oh, Sae Jin; Chung, Doo Hyun; Shin, Choong Ho; Yang, Sei Won

    2015-01-01

    Objective We investigated whether the frequency, phenotype, and suppressive function of CD4+FOXP3+ regulatory T cells (Tregs) are altered in young TS patients with the 45,X karyotype compared to age-matched controls. Design and Methods Peripheral blood mononuclear cells from young TS patients (n = 24, 17.4–35.9 years) and healthy controls (n = 16) were stained with various Treg markers to characterize their phenotypes. Based on the presence of thyroid autoimmunity, patients were categorized into TS (–) (n = 7) and TS (+) (n = 17). Tregs sorted for CD4+CD25bright were co-cultured with autologous CD4+CD25− target cells in the presence of anti-CD3 and -CD28 antibodies to assess their suppressive function. Results Despite a lower frequency of CD4+ T cells in the TS (-) and TS (+) patients (mean 30.8% and 31.7%, vs. 41.2%; P = 0.003 and P < 0.001, respectively), both groups exhibited a higher frequency of FOXP3+ Tregs among CD4+ T cells compared with controls (means 1.99% and 2.05%, vs. 1.33%; P = 0.029 and P = 0.004, respectively). There were no differences in the expression of CTLA-4 and the frequency of Tregs expressing CXCR3+, and CCR4+CCR6+ among the three groups. However, the ability of Tregs to suppress the in vitro proliferation of autologous CD4+CD25− T cells was significantly impaired in the TS (–) and TS (+) patients compared to controls (P = 0.003 and P = 0.041). Meanwhile, both the TS (–) and TS (+) groups had lower frequencies of naïve cells (P = 0.001 for both) but higher frequencies of effector memory cells (P = 0.004 and P = 0.002) than did the healthy control group. Conclusions The Tregs of the TS patients could not efficiently suppress the proliferation of autologous effector T cells, despite their increased frequency in peripheral CD4+ T cells. PMID:26709833

  18. Abdominal γ-Radiation Induces an Accumulation of Function-Impaired Regulatory T Cells in the Small Intestine

    International Nuclear Information System (INIS)

    Purpose: To assess the frequency and the functional characteristics of one major component of immune tolerance, the CD4+FoxP3+ regulatory T cells (Tregs) in a mouse model of abdominal irradiation. Methods and Materials: Mice were exposed to a single abdominal dose of γ-radiation (10 Gy). We evaluated small intestine Treg infiltration by Foxp3 immunostaining and the functional suppressive activity of Tregs isolated from mesenteric lymph nodes. Results: Foxp3 immunostaining showed that radiation induced a long-term infiltration of the intestine by Tregs (levels 5.5 times greater than in controls). Co-culture of Tregs from mesenteric lymph nodes with CD4+ effector cells showed that the Tregs had lost their suppressive function. This loss was associated with a significant decrease in the levels of Foxp3, TGF-β, and CTLA-4 mRNA, all required for optimal Treg function. At Day 90 after irradiation, Tregs regained their suppressive activity as forkhead box P3 (Foxp3), transforming growth factor beta (TGF-β), and cytotoxic T-lymphocyte antigen 4 (CTLA-4) expression returned to normal. Analysis of the secretory function of mesenteric lymph node Tregs, activated in vitro with anti-CD3/anti-CD28 Abs, showed that this dysfunction was independent of a defect in interleukin-10 secretion. Conclusion: Radiation caused a long-term accumulation of function-impaired Foxp3+CD4+ Tregs in the intestine. Our study provides new insights into how radiation affects the immune tolerance in peripheral tissues.

  19. Adipose-derived stem cells from diabetic mice show impaired vascular stabilization in a murine model of diabetic retinopathy.

    Science.gov (United States)

    Cronk, Stephen M; Kelly-Goss, Molly R; Ray, H Clifton; Mendel, Thomas A; Hoehn, Kyle L; Bruce, Anthony C; Dey, Bijan K; Guendel, Alexander M; Tavakol, Daniel N; Herman, Ira M; Peirce, Shayn M; Yates, Paul A

    2015-05-01

    Diabetic retinopathy is characterized by progressive vascular dropout with subsequent vision loss. We have recently shown that an intravitreal injection of adipose-derived stem cells (ASCs) can stabilize the retinal microvasculature, enabling repair and regeneration of damaged capillary beds in vivo. Because an understanding of ASC status from healthy versus diseased donors will be important as autologous cellular therapies are developed for unmet clinical needs, we took advantage of the hyperglycemic Akimba mouse as a preclinical in vivo model of diabetic retinopathy in an effort aimed at evaluating therapeutic efficacy of adipose-derived stem cells (mASCs) derived either from healthy, nondiabetic or from diabetic mice. To these ends, Akimba mice received intravitreal injections of media conditioned by mASCs or mASCs themselves, subsequent to development of substantial retinal capillary dropout. mASCs from healthy mice were more effective than diabetic mASCs in protecting the diabetic retina from further vascular dropout. Engrafted ASCs were found to preferentially associate with the retinal vasculature. Conditioned medium was unable to recapitulate the vasoprotection seen with injected ASCs. In vitro diabetic ASCs showed decreased proliferation and increased apoptosis compared with healthy mASCs. Diabetic ASCs also secreted less vasoprotective factors than healthy mASCs, as determined by high-throughput enzyme-linked immunosorbent assay. Our findings suggest that diabetic ASCs are functionally impaired compared with healthy ASCs and support the utility of an allogeneic injection of ASCs versus autologous or conditioned media approaches in the treatment of diabetic retinopathy.

  20. mir-30d Regulates multiple genes in the autophagy pathway and impairs autophagy process in human cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaojun [Ovarian Cancer Research Center and Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Department of General Surgery, Gansu Provincial Hospital, Lanzhou, Gansu 710000 (China); Zhong, Xiaomin [Ovarian Cancer Research Center and Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200011 (China); Tanyi, Janos L.; Shen, Jianfeng [Ovarian Cancer Research Center and Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Xu, Congjian [Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200011 (China); Gao, Peng [Department of General Surgery, Gansu Provincial Hospital, Lanzhou, Gansu 710000 (China); Zheng, Tim M. [Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104 (United States); DeMichele, Angela [Division of Hematology and Oncology, Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104 (United States); Zhang, Lin, E-mail: linzhang@mail.med.upenn.edu [Ovarian Cancer Research Center and Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, PA 19104 (United States)

    2013-02-15

    Highlights: ► Gene set enrichment analysis indicated mir-30d might regulate the autophagy pathway. ► mir-30d represses the expression of BECN1, BNIP3L, ATG12, ATG5 and ATG2. ► BECN1, BNIP3L, ATG12, ATG5 and ATG2 are direct targets of mir-30d. ► mir-30d inhibits autophagosome formation and LC3B-I conversion to LC3B-II. ► mir-30d regulates the autophagy process. -- Abstract: In human epithelial cancers, the microRNA (miRNA) mir-30d is amplified with high frequency and serves as a critical oncomir by regulating metastasis, apoptosis, proliferation, and differentiation. Autophagy, a degradation pathway for long-lived protein and organelles, regulates the survival and death of many cell types. Increasing evidence suggests that autophagy plays an important function in epithelial tumor initiation and progression. Using a combined bioinformatics approach, gene set enrichment analysis, and miRNA target prediction, we found that mir-30d might regulate multiple genes in the autophagy pathway including BECN1, BNIP3L, ATG12, ATG5, and ATG2. Our further functional experiments demonstrated that the expression of these core proteins in the autophagy pathway was directly suppressed by mir-30d in cancer cells. Finally, we showed that mir-30d regulated the autophagy process by inhibiting autophagosome formation and LC3B-I conversion to LC3B-II. Taken together, our results provide evidence that the oncomir mir-30d impairs the autophagy process by targeting multiple genes in the autophagy pathway. This result will contribute to understanding the molecular mechanism of mir-30d in tumorigenesis and developing novel cancer therapy strategy.

  1. Glycated albumin suppresses glucose-induced insulin secretion by impairing glucose metabolism in rat pancreatic β-cells

    Directory of Open Access Journals (Sweden)

    Muto Takashi

    2011-04-01

    Full Text Available Abstract Background Glycated albumin (GA is an Amadori product used as a marker of hyperglycemia. In this study, we investigated the effect of GA on insulin secretion from pancreatic β cells. Methods Islets were collected from male Wistar rats by collagenase digestion. Insulin secretion in the presence of non-glycated human albumin (HA and GA was measured under three different glucose concentrations, 3 mM (G3, 7 mM (G7, and 15 mM (G15, with various stimulators. Insulin secretion was measured with antagonists of inducible nitric oxide synthetase (iNOS, and the expression of iNOS-mRNA was investigated by real-time PCR. Results Insulin secretion in the presence of HA and GA was 20.9 ± 3.9 and 21.6 ± 5.5 μU/3 islets/h for G3 (P = 0.920, and 154 ± 9.3 and 126.1 ± 7.3 μU/3 islets/h (P = 0.046, for G15, respectively. High extracellular potassium and 10 mM tolbutamide abrogated the inhibition of insulin secretion by GA. Glyceraldehyde, dihydroxyacetone, methylpyruvate, GLP-1, and forskolin, an activator of adenylate cyclase, did not abrogate the inhibition. Real-time PCR showed that GA did not induce iNOS-mRNA expression. Furthermore, an inhibitor of nitric oxide synthetase, aminoguanidine, and NG-nitro-L-arginine methyl ester did not abrogate the inhibition of insulin secretion. Conclusion GA suppresses glucose-induced insulin secretion from rat pancreatic β-cells through impairment of intracellular glucose metabolism.

  2. Type 2 diabetes impairs venous, but not arterial smooth muscle cell function: Possible role of differential RhoA activity

    International Nuclear Information System (INIS)

    Background/purpose: Coronary heart disease is the leading cause of morbidity in patients with type 2 diabetes mellitus (T2DM), frequently resulting in a requirement for coronary revascularization using the internal mammary artery (IMA) or saphenous vein (SV). Patency rates of SV grafts are inferior to IMA and further impaired by T2DM whilst IMA patencies appear similar in both populations. Smooth muscle cells (SMC) play a pivotal role in graft integration; we therefore examined the phenotype and proliferative function of IMA- and SV-SMC isolated from non-diabetic (ND) patients or those diagnosed with T2DM. Methods/materials: SMC were cultured from fragments of SV or IMA. Morphology was analyzed under light microscopy (spread cell area measurements) and confocal microscopy (F-actin staining). Proliferation was analyzed by cell counting. Levels of RhoA mRNA, protein and activity were measured by real-time RT-PCR, western blotting and G-LISA respectively. Results: IMA-SMC from T2DM and ND patients were indistinguishable in both morphology and function. By comparison, SV-SMC from T2DM patients exhibited significantly larger spread cell areas (1.5-fold increase, P < 0.05), truncated F-actin fibers and reduced proliferation (33% reduction, P < 0.05). Furthermore, lower expression and activity of RhoA were observed in SV-SMC of T2DM patients (37% reduction in expression, P < 0.05 and 43% reduction in activity, P < 0.01). Conclusions: IMA-SMC appear impervious to phenotypic modulation by T2DM. In contrast, SV-SMC from T2DM patients exhibit phenotypic and functional changes accompanied by reduced RhoA activity. These aberrancies may be epigenetic in nature, compromising SMC plasticity and SV graft adaptation in T2DM patients. Summary: The internal mammary artery (IMA) is the conduit of choice for bypass grafting and is generally successful in all patients, including those with type 2 diabetes (T2DM). By contrast, saphenous vein (SV) is inferior to IMA and furthermore

  3. Type 2 diabetes impairs venous, but not arterial smooth muscle cell function: Possible role of differential RhoA activity

    Energy Technology Data Exchange (ETDEWEB)

    Riches, Kirsten [Division of Cardiovascular and Diabetes Research, Leeds Institute of Genetics, Health and Therapeutics (LIGHT), University of Leeds, Leeds (United Kingdom); Multidisciplinary Cardiovascular Research Centre (MCRC), University of Leeds, Leeds (United Kingdom); Warburton, Philip [Division of Cardiovascular and Diabetes Research, Leeds Institute of Genetics, Health and Therapeutics (LIGHT), University of Leeds, Leeds (United Kingdom); O’Regan, David J. [Multidisciplinary Cardiovascular Research Centre (MCRC), University of Leeds, Leeds (United Kingdom); Department of Cardiac Surgery, The Yorkshire Heart Centre, Leeds General Infirmary, Leeds (United Kingdom); Turner, Neil A. [Division of Cardiovascular and Diabetes Research, Leeds Institute of Genetics, Health and Therapeutics (LIGHT), University of Leeds, Leeds (United Kingdom); Multidisciplinary Cardiovascular Research Centre (MCRC), University of Leeds, Leeds (United Kingdom); Porter, Karen E., E-mail: medkep@leeds.ac.uk [Division of Cardiovascular and Diabetes Research, Leeds Institute of Genetics, Health and Therapeutics (LIGHT), University of Leeds, Leeds (United Kingdom); Multidisciplinary Cardiovascular Research Centre (MCRC), University of Leeds, Leeds (United Kingdom)

    2014-04-15

    Background/purpose: Coronary heart disease is the leading cause of morbidity in patients with type 2 diabetes mellitus (T2DM), frequently resulting in a requirement for coronary revascularization using the internal mammary artery (IMA) or saphenous vein (SV). Patency rates of SV grafts are inferior to IMA and further impaired by T2DM whilst IMA patencies appear similar in both populations. Smooth muscle cells (SMC) play a pivotal role in graft integration; we therefore examined the phenotype and proliferative function of IMA- and SV-SMC isolated from non-diabetic (ND) patients or those diagnosed with T2DM. Methods/materials: SMC were cultured from fragments of SV or IMA. Morphology was analyzed under light microscopy (spread cell area measurements) and confocal microscopy (F-actin staining). Proliferation was analyzed by cell counting. Levels of RhoA mRNA, protein and activity were measured by real-time RT-PCR, western blotting and G-LISA respectively. Results: IMA-SMC from T2DM and ND patients were indistinguishable in both morphology and function. By comparison, SV-SMC from T2DM patients exhibited significantly larger spread cell areas (1.5-fold increase, P < 0.05), truncated F-actin fibers and reduced proliferation (33% reduction, P < 0.05). Furthermore, lower expression and activity of RhoA were observed in SV-SMC of T2DM patients (37% reduction in expression, P < 0.05 and 43% reduction in activity, P < 0.01). Conclusions: IMA-SMC appear impervious to phenotypic modulation by T2DM. In contrast, SV-SMC from T2DM patients exhibit phenotypic and functional changes accompanied by reduced RhoA activity. These aberrancies may be epigenetic in nature, compromising SMC plasticity and SV graft adaptation in T2DM patients. Summary: The internal mammary artery (IMA) is the conduit of choice for bypass grafting and is generally successful in all patients, including those with type 2 diabetes (T2DM). By contrast, saphenous vein (SV) is inferior to IMA and furthermore

  4. The Coumarin Derivative Osthole Stimulates Adult Neural Stem Cells, Promotes Neurogenesis in the Hippocampus, and Ameliorates Cognitive Impairment in APP/PS1 Transgenic Mice.

    Science.gov (United States)

    Kong, Liang; Hu, Yu; Yao, Yingjia; Jiao, Yanan; Li, Shaoheng; Yang, Jingxian

    2015-01-01

    It is believed that neuronal death caused by abnormal deposition of amyloid-beta peptide is the major cause of the cognitive decline in Alzheimer's disease. Adult neurogenesis plays a key role in the rescue of impaired neurons and amelioration of cognitive impairment. In the present study, we demonstrated that osthole, a natural coumarin derivative, was capable of promoting neuronal stem cell (NSC) survival and inducing NSC proliferation in vitro. In osthole-treated APP/PS1 transgenic mice, a significant improvement in learning and memory function was seen, which was associated with a significant increase in the number of new neurons (Ki67(+)/NF-M(+)) and a decrease in apoptotic cells in the hippocampal region of the brain. These observations suggested that osthole promoted NSC proliferation, supported neurogenesis, and thus efficiently rescued impaired neurons in the hippocampus and ameliorated cognitive impairment. We also found that osthole treatment activated the Notch pathway and upregulated the expression of self-renewal genes Notch 1 and Hes 1 mRNA in NSCs. However, when Notch activity was blocked by the γ-secretase inhibitor DAPT, the augmentation of Notch 1 and Hes 1 protein was ameliorated, and the proliferation-inducing effect of osthole was abolished, suggesting that the effects of osthole are at least in part mediated by activation of the Notch pathway. PMID:26328484

  5. MEK/ERK pathway mediates UVB-induced AQP1 downregulation and water permeability impairment in human retinal pigment epithelial cells.

    Science.gov (United States)

    Jiang, Qin; Cao, Cong; Lu, Shan; Kivlin, Rebecca; Wallin, Brittany; Chu, Wenming; Bi, Zhigang; Wang, Xinru; Wan, Yinsheng

    2009-06-01

    Aquaporins (AQPs) are a family of 13 small ( approximately 30 kDa/monomer), hydrophobic, integral membrane proteins. AQPs are expressed in various epithelial and endothelial cells involved in fluid transport. Here, we demonstrated for the first time that AQP1 is expressed in cultured human retinal pigment epithelial (RPE) cells (ARPE-19 cell line). Ultraviolet radiation (UVB) and H2O2, two major factors causing RPE cell damage, induced AQP1 downregulation which was mediated by MEK/ERK activation. UV and H2O2 as well as AQP1-specific siRNA knockdown impaired water permeability of ARPE-19 cells. Notably, pretreatment with all-trans retinoic acid attenuated UV- and H2O2-induced AQP1 downregulation and water permeability impairment. Considering that water permeability is involved in multiple functions of RPE cells such as cellular junction formation, fluid or protein exchange and barrier formation, our data elucidated a novel mechanism through which UV radiation and oxidative stress induce eye cell damage. Our results further support the notion that all-trans retinoic acid might be useful for protection against UV or oxidative stress-induced eye cell damage. PMID:19424603

  6. Reduced Plasmodium Parasite Burden Associates with CD38+ CD4+ T Cells Displaying Cytolytic Potential and Impaired IFN-γ Production

    Science.gov (United States)

    Burel, Julie G.; Apte, Simon H.; Groves, Penny L.; Klein, Kerenaftali; McCarthy, James S.; Doolan, Denise L.

    2016-01-01

    Using a unique resource of samples from a controlled human malaria infection (CHMI) study, we identified a novel population of CD4+ T cells whose frequency in the peripheral blood was inversely correlated with parasite burden following P. falciparum infection. These CD4+ T cells expressed the multifunctional ectoenzyme CD38 and had unique features that distinguished them from other CD4+ T cells. Specifically, their phenotype was associated with proliferation, activation and cytotoxic potential as well as significantly impaired production of IFN-γ and other cytokines and reduced basal levels of activated STAT1. A CD38+ CD4+ T cell population with similar features was identified in healthy uninfected individuals, at lower frequency. CD38+ CD4+ T cells could be generated in vitro from CD38- CD4+ T cells after antigenic or mitogenic stimulation. This is the first report of a population of CD38+ CD4+ T cells with a cytotoxic phenotype and markedly impaired IFN-γ capacity in humans. The expansion of this CD38+ CD4+ T population following infection and its significant association with reduced blood-stage parasite burden is consistent with an important functional role for these cells in protective immunity to malaria in humans. Their ubiquitous presence in humans suggests that they may have a broad role in host-pathogen defense. Trial Registration ClinicalTrials.gov clinical trial numbers ACTRN12612000814875, ACTRN12613000565741 and ACTRN12613001040752 PMID:27662621

  7. 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

    Hematologic and immunologic functions were examined in 19 HIV-negative infants of HIV-positive mothers and 19 control infants of HIV-negative mothers. Control infants were selected to match for gestational age, weight, and mode of delivery. Cord blood was obtained from all infants and used for flow...... cytometric determination of lymphocyte subsets, including the naive CD4 count. Furthermore, to determine thymic output, cord blood mononuclear cells were used for determination of T-cell receptor excision circles (TRECs). Evaluation of progenitor cell function was done by means of colony-forming cell assay......). 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...

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

    OpenAIRE

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

    2016-01-01

    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 p...

  9. Protection from Palmitate-Induced Mitochondrial DNA Damage Prevents from Mitochondrial Oxidative Stress, Mitochondrial Dysfunction, Apoptosis, and Impaired Insulin Signaling in Rat L6 Skeletal Muscle Cells

    OpenAIRE

    Yuzefovych, Larysa V.; Solodushko, Viktoriya A.; Wilson, Glenn L.; Rachek, Lyudmila I.

    2011-01-01

    Saturated free fatty acids have been implicated in the increase of oxidative stress, mitochondrial dysfunction, apoptosis, and insulin resistance seen in type 2 diabetes. The purpose of this study was to determine whether palmitate-induced mitochondrial DNA (mtDNA) damage contributed to increased oxidative stress, mitochondrial dysfunction, apoptosis, impaired insulin signaling, and reduced glucose uptake in skeletal muscle cells. Adenoviral vectors were used to deliver the DNA repair enzyme ...

  10. Growth retardation, reduced invasiveness, and impaired colistin-mediated cell death associated with colistin resistance development in Acinetobacter baumannii.

    Science.gov (United States)

    Pournaras, Spyros; Poulou, Aggeliki; Dafopoulou, Konstantina; Chabane, Yassine Nait; Kristo, Ioulia; Makris, Demosthenes; Hardouin, Julie; Cosette, Pascal; Tsakris, Athanassios; Dé, Emmanuelle

    2014-01-01

    Two colistin-susceptible/colistin-resistant (Col(s)/Col(r)) pairs of Acinetobacter baumannii strains assigned to international clone 2, which is prevalent worldwide, were sequentially recovered from two patients after prolonged colistin administration. Compared with the respective Col(s) isolates (Ab248 and Ab299, both having a colistin MIC of 0.5 μg/ml), both Col(r) isolates (Ab249 and Ab347, with colistin MICs of 128 and 32 μg/ml, respectively) significantly overexpressed pmrCAB genes, had single-amino-acid shifts in the PmrB protein, and exhibited significantly slower growth. The Col(r) isolate Ab347, tested by proteomic analysis in comparison with its Col(s) counterpart Ab299, underexpressed the proteins CsuA/B and C from the csu operon (which is necessary for biofilm formation). This isolate also underexpressed aconitase B and different enzymes involved in the oxidative stress response (KatE catalase, superoxide dismutase, and alkyl hydroperoxide reductase), suggesting a reduced response to reactive oxygen species (ROS) and, consequently, impaired colistin-mediated cell death through hydroxyl radical production. Col(s) isolates that were indistinguishable by macrorestriction analysis from Ab299 caused six sequential bloodstream infections, and isolates indistinguishable from Ab248 caused severe soft tissue infection, while Col(r) isolates indistinguishable from Ab347 and Ab249 were mainly colonizers. In particular, a Col(s) isolate identical to Ab299 was still invading the bloodstream 90 days after the colonization of this patient by Col(r) isolates. These observations indicate considerably lower invasiveness of A. baumannii clinical isolates following the development of colistin resistance. PMID:24247145

  11. Leptin impairs myogenesis in C2C12 cells through JAK/STAT and MEK signaling pathways.

    Science.gov (United States)

    Pijet, Maja; Pijet, Barbara; Litwiniuk, Anna; Pajak, Beata; Gajkowska, Barbara; Orzechowski, Arkadiusz

    2013-02-01

    Reduced lean body mass in genetically obese (ob/ob) or anorectic/cachectic subjects prompted us to verify the hypothesis whether leptin, white adipose tissue cytokine, might be a negative organizer of myogenesis. Recombinant leptin (100 ng/mL) stimulated mitogenesis together with the raise in T(202/)Y(204)P-ERK1/2 protein expression. Concomitantly, it impaired cell viability and muscle fiber formation from C2C12 mouse myoblasts. Detailed acute and chronic studies with the use of metabolic inhibitors revealed that both JAK/STAT3 and MEK/MAPK but not PI3-K/AKT/GSK-3β signaling pathways were activated by leptin, and that STAT3 (Y(705)P-STAT3) and MEK (T(202/)Y(204)P-ERK1/2) mediate these effects. In contrary, insulin evoked PI3-K-dependent phosphorylation of AKT (S(473)) and GSK-3β (S(9)) and insulin surpassed leptin-dependent inhibition of myogenic differentiation in PI3-K-dependent manner. GSK-3β seems to play dual role in muscle development. Insulin-dependent effect on GSK-3β (S(9)P-GSK-3β) led to accelerated myotube construction. In contrary, leptin through MEK-dependent manner caused GSK-3β phosphorylation (Y(216)P-GSK-3β) with resultant drop in myoblast fusion. Summing up, partially opposite effects of insulin and leptin on skeletal muscle growth emphasize the importance of interplay between these cytokines. They determine how muscle mass is gained or lost.

  12. Leptin impairs myogenesis in C2C12 cells through JAK/STAT and MEK signaling pathways.

    Science.gov (United States)

    Pijet, Maja; Pijet, Barbara; Litwiniuk, Anna; Pajak, Beata; Gajkowska, Barbara; Orzechowski, Arkadiusz

    2013-02-01

    Reduced lean body mass in genetically obese (ob/ob) or anorectic/cachectic subjects prompted us to verify the hypothesis whether leptin, white adipose tissue cytokine, might be a negative organizer of myogenesis. Recombinant leptin (100 ng/mL) stimulated mitogenesis together with the raise in T(202/)Y(204)P-ERK1/2 protein expression. Concomitantly, it impaired cell viability and muscle fiber formation from C2C12 mouse myoblasts. Detailed acute and chronic studies with the use of metabolic inhibitors revealed that both JAK/STAT3 and MEK/MAPK but not PI3-K/AKT/GSK-3β signaling pathways were activated by leptin, and that STAT3 (Y(705)P-STAT3) and MEK (T(202/)Y(204)P-ERK1/2) mediate these effects. In contrary, insulin evoked PI3-K-dependent phosphorylation of AKT (S(473)) and GSK-3β (S(9)) and insulin surpassed leptin-dependent inhibition of myogenic differentiation in PI3-K-dependent manner. GSK-3β seems to play dual role in muscle development. Insulin-dependent effect on GSK-3β (S(9)P-GSK-3β) led to accelerated myotube construction. In contrary, leptin through MEK-dependent manner caused GSK-3β phosphorylation (Y(216)P-GSK-3β) with resultant drop in myoblast fusion. Summing up, partially opposite effects of insulin and leptin on skeletal muscle growth emphasize the importance of interplay between these cytokines. They determine how muscle mass is gained or lost. PMID:23201486

  13. Bisphenol-A impairs insulin action and up-regulates inflammatory pathways in human subcutaneous adipocytes and 3T3-L1 cells.

    Directory of Open Access Journals (Sweden)

    Rossella Valentino

    Full Text Available Current evidence indicates that chemical pollutants may interfere with the homeostatic control of nutrient metabolism, thereby contributing to the increased prevalence of metabolic disorders. Bisphenol-A (BPA is a lipophilic compound contained in plastic which is considered a candidate for impairing energy and glucose metabolism. We have investigated the impact of low doses of BPA on adipocyte metabolic functions. Human adipocytes derived from subcutaneous adipose tissue and differentiated 3T3-L1 cells were incubated with BPA, in order to evaluate the effect on glucose utilization, insulin sensitivity and cytokine secretion. Treatment with 1 nM BPA significantly inhibited insulin-stimulated glucose utilization, without grossly interfering with adipocyte differentiation. Accordingly, mRNA levels of the adipogenic markers PPARγ and GLUT4 were unchanged upon BPA exposure. BPA treatment also impaired insulin-activated receptor phosphorylation and signaling. Moreover, adipocyte incubation with BPA was accompanied by increased release of IL-6 and IFN-γ, as assessed by multiplex ELISA assays, and by activation of JNK, STAT3 and NFkB pathways. Treatment of the cells with the JNK inhibitor SP600125 almost fully reverted BPA effect on insulin signaling and glucose utilization. In conclusion, low doses of BPA interfere with inflammatory/insulin signaling pathways, leading to impairment of adipose cell function.

  14. Use antibodies to DNA for detection of X-ray impairments of DNA in nuclei of brain stem cells of irradiated animals

    International Nuclear Information System (INIS)

    Using antibodies to DNA, impairments of DNA in nuclei of brain stem cells were studied in white male-rats at early stages after X-ray irradiation. Irradiation doses were 25.8, 103.2, 154.8, 206.4 and 258 m Coul/kg. Only at 258 m Coul/kg dose the complete repair of immunofluorescent cells percentage up to the level of intact animals was observed 1h after irradiation. The complete repair at 103.2 m Coul/kg dose occured 3h after the irradiation. The lethal doses (206.4 - 258 m Coul/kg) caused such DNA impairments which were not reduced even 3h after the irradiation of the animals. Thus, it is shown that the immunological method can be useful for studying DNA structural impairments in the range of 25.8-258 m Coul/kg doses. The method permits to test DNA radiation damages without its extraction from the cell

  15. Cholesterol efflux via ATP-binding cassette transporter A1 (ABCA1) and cholesterol uptake via the LDL receptor influences cholesterol-induced impairment of beta cell function in mice

    NARCIS (Netherlands)

    Kruit, J. K.; Kremer, P. H. C.; Dai, L.; Tang, R.; Ruddle, P.; de Haan, W.; Brunham, L. R.; Verchere, C. B.; Hayden, M. R.

    2010-01-01

    Cellular cholesterol accumulation is an emerging mechanism for beta cell dysfunction in type 2 diabetes. Absence of the cholesterol transporter ATP-binding cassette transporter A1 (ABCA1) results in increased islet cholesterol and impaired insulin secretion, indicating that impaired cholesterol effl

  16. Impaired desensitization of a human polymorphic α2B-adrenergic receptor variant enhances its sympatho-inhibitory activity in chromaffin cells

    Directory of Open Access Journals (Sweden)

    Lymperopoulos Anastasios

    2011-02-01

    Full Text Available Abstract Background α2-adrenergic receptors (ARs mediate many cellular actions of epinephrine and norepinephrine and inhibit their secretion from adrenal chromaffin cells. Like many other G-protein coupled receptors (GPCRs, they undergo agonist-dependent phopshorylation and desensitization by GPCR Kinases (GRKs, a phenomenon recently shown to play a major role in the sympathetic overdrive that accompanies and aggravates chronic heart failure. A deletion polymorphism in the human α2B-AR gene (Glu301-303 causes impaired agonist-promoted receptor phosphorylation and desensitization in heterologous cell lines. Given the importance of α2-ARs in regulation of catecholamine secretion from chromaffin cells, we sought to investigate, in the present study, the desensitization properties and the sympatho-inhibitory activity of this variant in a chromaffin cell line. For this purpose, we expressed this variant and its wild type counterpart in the well-established chromaffin cell line PC12, and performed receptor phosphorylation and desensitization studies, as well as in vitro catecholamine secretion assays. Results Both the agonist-induced phosphorylation and agonist-dependent desensitization of the human Glu301-303 deletion polymorphic α2B-AR are significantly impaired in PC12 cells, resulting in enhanced signaling to inhibition of cholinergic-induced catecholamine secretion in vitro. Conclusion This α2B-AR gene polymorphism (Glu301-303 deletion might confer better protection against conditions characterized and aggravated by sympathetic/catecholaminergic overstimulation in vivo.

  17. The role of microRNA-146a in the pathogenesis of the diabetic wound-healing impairment: correction with mesenchymal stem cell treatment.

    Science.gov (United States)

    Xu, Junwang; Wu, Wenjie; Zhang, Liping; Dorset-Martin, Wanda; Morris, Michael W; Mitchell, Marc E; Liechty, Kenneth W

    2012-11-01

    The impairment in diabetic wound healing represents a significant clinical problem. Chronic inflammation is thought to play a central role in the pathogenesis of this impairment. We have previously shown that treatment of diabetic murine wounds with mesenchymal stem cells (MSCs) can improve healing, but the mechanisms are not completely defined. MicroRNA-146a (miR-146a) has been implicated in regulation of the immune and inflammatory responses. We hypothesized that abnormal miRNA-146a expression may contribute to the chronic inflammation. To test this hypothesis, we examined the expression of miRNA-146a and its target genes in diabetic and nondiabetic mice at baseline and after injury. MiR-146a expression was significantly downregulated in diabetic mouse wounds. Decreased miR-146a levels also closely correlated with increased gene expression of its proinflammatory target genes. Furthermore, the correction of the diabetic wound-healing impairment with MSC treatment was associated with a significant increase in the miR-146a expression level and decreased gene expression of its proinflammatory target genes. These results provide the first evidence that decreased expression of miR-146a in diabetic wounds in response to injury may, in part, be responsible for the abnormal inflammatory response seen in diabetic wounds and may contribute to wound-healing impairment. PMID:22851573

  18. Molecular Interplay between microRNA-34a and Sirtuin1 in Hyperglycemia-Mediated Impaired Angiogenesis in Endothelial Cells: Effects of Metformin.

    Science.gov (United States)

    Arunachalam, Gnanapragasam; Lakshmanan, Arun Prasath; Samuel, Samson Mathews; Triggle, Chris R; Ding, Hong

    2016-02-01

    Impaired angiogenesis is a prominent risk factor that contributes to the development of diabetes-associated cardiovascular disease. MicroRNAs (miRNAs), small noncoding RNAs, are implicated as important regulators of vascular function, including endothelial cell differentiation, proliferation, and angiogenesis. In silico analysis and in vitro studies indicate that silent information regulator 1 (SIRT1) is a potential target for endothelial cell-specific miRNAs. In this study, we investigated the molecular crosstalk between miR-34a, the protein product of SIRT1 (sirtuin1), and the antidiabetic drug, metformin, in hyperglycemia-mediated impaired angiogenesis in mouse microvascular endothelial cells (MMECs). MMECs were cultured, transfected with either a miR-34a inhibitor or mimic in normal glucose (11 mM) or high glucose (HG, 40 mM) in the presence or absence of metformin. The expression of miR-34a, sirtuin1, and their signaling targets was evaluated. miR-34a expression is upregulated in a hyperglycemic milieu and parallels changes in the expression of sirtuin1, post-translational modification of endothelial nitric oxide synthase (phospho/acetylation), as well as an impairment in angiogenesis. The presence of metformin, or the inhibition of miR-34a using an anti-miR-34a inhibitor, increases the expression of sirtuin1 and attenuates the impairment in angiogenesis in HG-exposed MMECs. In contrast, overexpression of a miR-34a mimic prevents metformin-mediated protection. These data indicate that miR-34a, via the regulation of sirtuin1 expression, has an anti-angiogenic action in MMECs, which can be modulated by metformin. In summary, miR-34a represents both a target whereby metformin mediates its vasculoprotective actions and also a potential therapeutic target for the prevention/treatment of diabetic vascular disease. PMID:26582729

  19. Molecular Interplay between microRNA-34a and Sirtuin1 in Hyperglycemia-Mediated Impaired Angiogenesis in Endothelial Cells: Effects of Metformin.

    Science.gov (United States)

    Arunachalam, Gnanapragasam; Lakshmanan, Arun Prasath; Samuel, Samson Mathews; Triggle, Chris R; Ding, Hong

    2016-02-01

    Impaired angiogenesis is a prominent risk factor that contributes to the development of diabetes-associated cardiovascular disease. MicroRNAs (miRNAs), small noncoding RNAs, are implicated as important regulators of vascular function, including endothelial cell differentiation, proliferation, and angiogenesis. In silico analysis and in vitro studies indicate that silent information regulator 1 (SIRT1) is a potential target for endothelial cell-specific miRNAs. In this study, we investigated the molecular crosstalk between miR-34a, the protein product of SIRT1 (sirtuin1), and the antidiabetic drug, metformin, in hyperglycemia-mediated impaired angiogenesis in mouse microvascular endothelial cells (MMECs). MMECs were cultured, transfected with either a miR-34a inhibitor or mimic in normal glucose (11 mM) or high glucose (HG, 40 mM) in the presence or absence of metformin. The expression of miR-34a, sirtuin1, and their signaling targets was evaluated. miR-34a expression is upregulated in a hyperglycemic milieu and parallels changes in the expression of sirtuin1, post-translational modification of endothelial nitric oxide synthase (phospho/acetylation), as well as an impairment in angiogenesis. The presence of metformin, or the inhibition of miR-34a using an anti-miR-34a inhibitor, increases the expression of sirtuin1 and attenuates the impairment in angiogenesis in HG-exposed MMECs. In contrast, overexpression of a miR-34a mimic prevents metformin-mediated protection. These data indicate that miR-34a, via the regulation of sirtuin1 expression, has an anti-angiogenic action in MMECs, which can be modulated by metformin. In summary, miR-34a represents both a target whereby metformin mediates its vasculoprotective actions and also a potential therapeutic target for the prevention/treatment of diabetic vascular disease.

  20. Omentum-derived stromal cells improve myocardial regeneration in pig post-infarcted heart through a potent paracrine mechanism

    International Nuclear Information System (INIS)

    Cell-based therapy could be a valid option to treat myocardial infarct (MI). Adipose-derived stromal cells (ADStCs) have demonstrated tissue regenerative potential including cardiomyogenesis. Omentum is an extremely rich source of visceral fat and its accumulation seems to correlate with cardiovascular diseases. We investigated the capacity of human fat Omentum-derived StCs (FOStCs) to affect heart function upon acute infarct in pigs induced by permanent ligation of the anterior interventricular artery (IVA). We demonstrated for the first time that the local injection of 50 x 106 of FOStCs ameliorates the functional parameters of post-infarct heart. Most importantly, histology of FOStCs treated hearts demonstrated a substantial improvement of cardiomyogenesis. In culture, FOStCs produced an impressive number and amount of angiogenic factors and cytokines. Moreover, the conditioned medium of FOStCs (FOStCs-CM) stimulates in vitro cardiac endothelial cells (ECs) proliferation and vascular morphogenesis and inhibits monocytes, EC activation and cardiomyocyte apoptosis. Since FOStCs in vivo did not trans-differentiate into cardiomyocyte-like cells, we conclude that FOStCs efficacy was presumably mediated by a potent paracrine mechanism involving molecules that concomitantly improved angiogenesis, reduced inflammation and prevented cardiomyocytes death. Our results highlight for the first time the important role that human FOStCs may have in cardiac regeneration.

  1. Calpastatin overexpression reduces oxidative stress-induced mitochondrial impairment and cell death in human neuroblastoma SH-SY5Y cells by decreasing calpain and calcineurin activation, induction of mitochondrial fission and destruction of mitochondrial fusion.

    Science.gov (United States)

    Tangmansakulchai, Kulvadee; Abubakar, Zuroida; Kitiyanant, Narisorn; Suwanjang, Wilasinee; Leepiyasakulchai, Chaniya; Govitrapong, Piyarat; Chetsawang, Banthit

    2016-09-01

    Calpain is an intracellular Ca(2+)-dependent protease, and the activation of calpain has been implicated in neurodegenerative diseases. Calpain activity can be regulated by calpastatin, an endogenous specific calpain inhibitor. Several lines of evidence have demonstrated a potential role of calpastatin in preventing calpain-mediated pathogenesis. Additionally, several studies have revealed that calpain activation and mitochondrial damage are involved in the cell death process; however, recent evidence has not clearly indicated a neuroprotective mechanism of calpastatin against calpain-dependent mitochondrial impairment in the process of neuronal cell death. Therefore, the purpose of this study was to investigate the potential ability of calpastatin to inhibit calpain activation and mitochondrial impairment in oxidative stress-induced neuron degeneration. Calpastatin was stably overexpressed in human neuroblastoma SH-SY5Y cells. In non-calpastatin overexpressing SH-SY5Y cells, hydrogen peroxide significantly decreased cell viability, superoxide dismutase activity, mitochondrial membrane potential, ATP production and mitochondrial fusion protein (Opa1) levels in the mitochondrial fraction but increased reactive oxygen species formation, calpain and calcineurin activation, mitochondrial fission protein (Fis1 and Drp1) levels in the mitochondrial fraction and apoptotic cells. Nevertheless, these toxic effects were abolished in hydrogen peroxide-treated calpastatin-overexpressing SH-SY5Y cells. The results of the present study demonstrate the potential ability of calpastatin to diminish calpain and calcineurin activation and mitochondrial impairment in neurons that are affected by oxidative damage. PMID:27453331

  2. Seipin knockout in mice impairs stem cell proliferation and progenitor cell differentiation in the adult hippocampal dentate gyrus via reduced levels of PPARγ

    Directory of Open Access Journals (Sweden)

    Guoxi Li

    2015-12-01

    Full Text Available The seipin gene (BSCL2 was originally identified in humans as a loss-of-function gene associated with congenital generalized lipodystrophy type 2 (CGL2. Neuronal seipin-knockout (seipin-nKO mice display a depression-like phenotype with a reduced level of hippocampal peroxisome proliferator-activated receptor gamma (PPARγ. The present study investigated the influence of seipin deficiency on adult neurogenesis in the hippocampal dentate gyrus (DG and the underlying mechanisms of the effects. We show that the proliferative capability of stem cells in seipin-nKO mice was substantially reduced compared to in wild-type (WT mice, and that this could be rescued by the PPARγ agonist rosiglitazone (rosi. In seipin-nKO mice, neuronal differentiation of progenitor cells was inhibited, with the enhancement of astrogliogenesis; both of these effects were recovered by rosi treatment during early stages of progenitor cell differentiation. In addition, rosi treatment could correct the decline in hippocampal ERK2 phosphorylation and cyclin A mRNA level in seipin-nKO mice. The MEK inhibitor U0126 abolished the rosi-rescued cell proliferation and cyclin A expression in seipin-nKO mice. In seipin-nKO mice, the hippocampal Wnt3 protein level was less than that in WT mice, and there was a reduction of neurogenin 1 (Neurog1 and neurogenic differentiation 1 (NeuroD1 mRNA, levels of which were corrected by rosi treatment. STAT3 phosphorylation (Tyr705 was enhanced in seipin-nKO mice, and was further elevated by rosi treatment. Finally, rosi treatment for 10 days could alleviate the depression-like phenotype in seipin-nKO mice, and this alleviation was blocked by the MEK inhibitor U0126. The results indicate that, by reducing PPARγ, seipin deficiency impairs proliferation and differentiation of neural stem and progenitor cells, respectively, in the adult DG, which might be responsible for the production of the depression-like phenotype in seipin-nKO mice.

  3. Effects of intravenous administration of bone marrow stromal stem cells on cognitive impairment of the whole-brain irradiated rat models

    International Nuclear Information System (INIS)

    Objective: To explore the effect of intravenous infusion of bone marrow stromal stem cells(MSCs) on cognitive function of rats after whole brain irradiation. Methods: MSCs were isolated and cultured from adult rats. After Sprague-Dawly female rats were anaesthetized with chloral hydrate, their whole cerebrum was irradiated with a single dose of 20 Gy by 6 MV X-ray. Seven days after irradiation, 4 x 106 Hoechst33342-1abelled MSCs were intravenously injected into the tail vein of these rats. Four and 8 weeks after transplantation, the learning and memorizing ability was measured with the Y maze test. Immunohistochemical method was used to identify MSCs or ceils derived from MSCs in the brain. Results: The learning and memorizing ability of irradiation groups were significantly different from that of normal control group (P < 0.01). Significant improvement of cognitive impairment was observed in rats treated with MSCs at 4 and 8 weeks after transplantation as compared with the controll groups (P<0.05). This showed that the MSCs survived and were localized to the brain tissue. The number of Hoechst33342 immunohistofluorescence positive cells and double-immunostaining cells significantly decreased in 8 weeks group as compared with the 4 weeks group. Conclusion: Marrow stromal stem cells delivered to the irradiation brain tissue through intravenous route improve the cognitive impairment after whole brain irradiation. These cells may survive and differentiate in the brain tissue of irradiated rats. (authors)

  4. Targeted impairment of thymidine kinase 2 expression in cells induces mitochondrial DNA depletion and reveals molecular mechanisms of compensation of mitochondrial respiratory activity

    International Nuclear Information System (INIS)

    Highlights: → We impaired TK2 expression in Ost TK1- cells via siRNA-mediated interference (TK2-). → TK2 impairment caused severe mitochondrial DNA (mtDNA) depletion in quiescent cells. → Despite mtDNA depletion, TK2- cells show high cytochrome oxidase activity. → Depletion of mtDNA occurs without imbalance in the mitochondrial dNTP pool. → Nuclear-encoded ENT1, DNA-pol γ, TFAM and TP gene expression is lowered in TK2- cells. -- Abstract: The mitochondrial DNA (mtDNA) depletion syndrome comprises a clinically heterogeneous group of diseases characterized by reductions of the mtDNA abundance, without associated point mutations or rearrangements. We have developed the first in vitro model to study of mtDNA depletion due to reduced mitochondrial thymidine kinase 2 gene (TK2) expression in order to understand the molecular mechanisms involved in mtDNA depletion syndrome due to TK2 mutations. Small interfering RNA targeting TK2 mRNA was used to decrease TK2 expression in Ost TK1- cells, a cell line devoid of endogenous thymidine kinase 1 (TK1). Stable TK2-deficient cell lines showed a reduction of TK2 levels close to 80%. In quiescent conditions, TK2-deficient cells showed severe mtDNA depletion, also close to 80% the control levels. However, TK2-deficient clones showed increased cytochrome c oxidase activity, higher cytochrome c oxidase subunit I transcript levels and higher subunit II protein expression respect to control cells. No alterations of the deoxynucleotide pools were found, whereas a reduction in the expression of genes involved in nucleoside/nucleotide homeostasis (human equilibrative nucleoside transporter 1, thymidine phosphorylase) and mtDNA maintenance (DNA-polymerase γ, mitochondrial transcription factor A) was observed. Our findings highlight the importance of cellular compensatory mechanisms that enhance the expression of respiratory components to ensure respiratory activity despite profound depletion in mtDNA levels.

  5. Enhanced expression of VEGF-A in β cells increases endothelial cell number but impairs islet morphogenesis and β cell proliferation

    OpenAIRE

    Cai, Qing; Brissova, Marcela; Reinert, Rachel B.; Pan, Fong Cheng; Brahmachary, Priyanka; Jeansson, Marie; Shostak, Alena; Radhika, Aramandla; Poffenberger, Greg; Quaggin, Susan E; Jerome, W. Gray; Daniel J Dumont; Alvin C Powers

    2012-01-01

    There is a reciprocal interaction between pancreatic islet cells and vascular endothelial cells (EC) in which EC-derived signals promote islet cell differentiation and islet development while islet cell-derived angiogenic factors promote EC recruitment and extensive islet vascularization. To examine the role of angiogenic factors in the coordinated development of islets and their associated vessels, we used a “tet-on” inducible system (mice expressing rat insulin promoter-reverse tetracycline...

  6. Mesenchymal stem cells ameliorate inflammatory cytokine-induced impairment of AT-II cells through a keratinocyte growth factor-dependent PI3K/Akt/mTOR signaling pathway

    Science.gov (United States)

    LI, JIWEI; HUANG, SHA; ZHANG, JUNHUA; FENG, CHANGJIANG; GAO, DONGYUN; YAO, BIN; WU, XU; FU, XIAOBING

    2016-01-01

    Lung epithelium restoration subsequent to injury is of concern in association with the outcomes of diverse inflammatory lung diseases. Previous studies have demonstrated that mesenchymal stem cells (MSCs) may promote epithelial repair subsequent to inflammatory injury, however the mechanism that mediates this effect remains unclear. The current study examined the role of MSCs in alveolar type II epithelial cell (AT-II cell) restoration subsequent to an inflammatory insult. AT-II cells were firstly exposed to inflammatory cytokines including tumor necrosis factor-α, interleukin (IL)-6 and IL-1β, then were co-cultured with MSCs in Transwell for 72 h. Cell proliferation, expression of surfactant protein A (SP-A) and expression of the α1 subunit were evaluated respectively by the Cell Counting Kit-8 assay, western blotting and semiquantitative reverse transcription-polymerase chain reaction. Keratinocyte growth factor (KGF) small interfering RNA (siRNA) was applied to knockdown the main cytoprotective factors in the MSCs. Subsequent to an inflammatory insult, AT-II cells were observed to be impaired, exhibiting the characteristics of injured cell morphology, reduced cell proliferation and reduced expression of SP-A and the α1 subunit. Co-culture with MSCs significantly ameliorated these cell impairments, while these benefits were weakened by the application of KGF siRNA. Simultaneously, expression levels of phosphorylated (p-) protein kinase B (AKT) and p-mammalian target of rapamycin (mTOR) in AT-II cells were upregulated by MSCs, suggesting activation of the phosphoinositide 3-kinase (PI3K) pathway. These data demonstrate that administration of MSCs to the inflammation-insulted AT-II cells may ameliorate the impairments through a KGF-dependent PI3K/AKT/mTOR signaling pathway. PMID:27035760

  7. Hyperoxia-mediated LC3B activation contributes to the impaired transdifferentiation of type II alveolar epithelial cells (AECIIs) to type I cells (AECIs).

    Science.gov (United States)

    Zhang, Liang; Zhao, Shuang; Yuan, Lijie; Wu, Hongmin; Jiang, Hong; Luo, Gang

    2016-09-01

    Life-saving mechanical ventilation can also cause lung injury through the overproduction of reactive oxygen species (ROS), leading to bronchopulmonary dysplasia (BPD)-like symptoms in preterm infants. It is reported that the autophagic protein microtubule-associated protein-1 light chain (LC)-3B can confer protection against hyperoxia-induced DNA damage in lung alveolar epithelium. However, its role in the transdifferentiation of type II alveolar epithelial cells (AECIIs) to type I cells (AECIs) is unclear and requires further investigation. In this study, newborn Sprague-Dawley rats were exposed to 90% oxygen for up to 14 days to mimic BPD in human infants, with neonatal pups exposed to room air (21% oxygen) as controls. Primary rat AECIIs were cultured under hyperoxic conditions for up to 24 hours to further investigate the underlying mechanisms. This study found that hyperoxia promoted a significant and time-dependent increase of AECII marker surfactant protein (SP)-C in the lung. The increase of AECI marker T1α was repressed by hyperoxia during lung development. These results indicated an impaired AECII transdifferentiation. Pulmonary ROS concentration and expression of autophagic protein LC-3B were increased gradually in response to hyperoxia exposure. Furthermore, AECIIs produced more ROS when cultured under hyperoxic conditions in vitro. Both the LC3B expression and the conversion from LC3BI to LC3BII were enhanced in hyperoxic AECs. Interestingly, inhibition of LC3B either by ROS inhibitor N-acetyl-l-cysteine (NAC) or adenovirus-mediated LC3B shRNA could partly restore AECII transdifferentiation under hyperoxia condition. In summary, the current study reveals a novel role of activated LC3B induced by hyperoxia in AECII transdifferentiation. PMID:27187184

  8. Gene Related to Anergy in Lymphocytes (GRAIL) Expression in CD4+ T Cells Impairs Actin Cytoskeletal Organization during T Cell/Antigen-presenting Cell Interactions*

    OpenAIRE

    Schartner, Jill M.; Simonson, William T; Wernimont, Sarah A.; Nettenstrom, Lauren M.; Huttenlocher, Anna; Seroogy, Christine M.

    2009-01-01

    GRAIL (gene related to anergy in lymphocytes), is an E3 ubiquitin ligase with increased expression in anergic CD4+ T cells. The expression of GRAIL has been shown to be both necessary and sufficient for the induction of T cell (T) anergy. To date, several subsets of anergic T cells have demonstrated altered interactions with antigen-presenting cells (APC) and perturbed TCR-mediated signaling. The role of GRAIL in mediating these aspects of T cell anergy remains unclear. We used flow cytometry...

  9. Hearing Impairment

    Science.gov (United States)

    ... hearing loss is present at birth. Acquired hearing loss happens later in life — during childhood, the teen years, or in adulthood — ... for your ears to avoid a permanent hearing loss. See your doctor right away ... basis. What's Life Like for People Who Are Hearing Impaired? For ...

  10. A Research into Cell Protection and Mechanism of Zengyetang on Acute Impairment of Yin Amimal Models%增液汤对急性伤阴动物模型的细胞保护作用及其机理探讨

    Institute of Scientific and Technical Information of China (English)

    仝小林; 王君; 李宁; 王红; 曹丽英; 叶智文

    2003-01-01

    Acute Yin impairment is a frequently occurring clinic syndrome. We suggest the process of acute Yin impairment be divided into two stages, namely early impairment of lung and stomach fluid and later Yin impairment of liver and kidney. This work aims to research into the cell-protecting mechanism of Zengyetang, from the angle of protecting cells, change of inner and outer fluid ion of cells, change of enzyme of cell membrane, free radical impairment, appoptosis and gene expression. The study, taking inner and outer fluid ion of cells as objective indicators,also researches into dynamic change of inner and outer fluid of cells in the different stages of Yin impairment development on the animal models of yin impairment by fever and poison. Zengyetang is one of the typical Yin-nourishing prescriptions, gengyetang is made into injection in accordance with the rate of the original prescription. This work researches into the affects of Zengyetang on the four types of acute Yin impairment animal models, including Yin impairment model by pathogenic heat, Yin impairment model by summer heat and sweat, Yin impairment model by high-infiltration Yin impairment and Yin impairment by drugs and toxin. Main experiment results show: 1. in early stage,pathogenic heat Yin impairment impairs outer liquid of cells; 2. Zengyetang has the function of adjusting disorder of inner and outer fluid of red cells; 3. Zengyetang has the function of protecting enzyme activity of cell membrane and maintaining normal operation of red cell ion; 4. Zengyetang can protect liver cells of rabbits through resisting free radical impairment and lessen thymocyte apoptosis of young rat resulted from glucocorticoid.

  11. NK cells infiltrating a MHC class I-deficient lung adenocarcinoma display impaired cytotoxic activity toward autologous tumor cells associated with altered NK cell-triggering receptors.

    Science.gov (United States)

    Le Maux Chansac, Béatrice; Moretta, Alessandro; Vergnon, Isabelle; Opolon, Paule; Lécluse, Yann; Grunenwald, Dominique; Kubin, Marek; Soria, Jean-Charles; Chouaib, Salem; Mami-Chouaib, Fathia

    2005-11-01

    NK cells are able to discriminate between normal cells and cells that have lost MHC class I (MHC-I) molecule expression as a result of tumor transformation. This function is the outcome of the capacity of inhibitory NK receptors to block cytotoxicity upon interaction with their MHC-I ligands expressed on target cells. To investigate the role of human NK cells and their various receptors in the control of MHC-I-deficient tumors, we have isolated several NK cell clones from lymphocytes infiltrating an adenocarcinoma lacking beta2-microglobulin expression. Unexpectedly, although these clones expressed NKG2D and mediated a strong cytolytic activity toward K562, Daudi and allogeneic MHC-class I+ carcinoma cells, they were unable to lyse the autologous MHC-I- tumor cell line. This defect was associated with alterations in the expression of natural cytotoxicity receptor (NCR) by NK cells and the NKG2D ligands, MHC-I-related chain A, MHC-I-related chain B, and UL16 binding protein 1, and the ICAM-1 by tumor cells. In contrast, the carcinoma cell line was partially sensitive to allogeneic healthy donor NK cells expressing high levels of NCR. Indeed, this lysis was inhibited by anti-NCR and anti-NKG2D mAbs, suggesting that both receptors are required for the induced killing. The present study indicates that the MHC-I-deficient lung adenocarcinoma had developed mechanisms of escape from the innate immune response based on down-regulation of NCR and ligands required for target cell recognition.

  12. TiO2 nanoparticles cause cell damage independent of apoptosis and autophagy by impairing the ROS-scavenging system in Pichia pastoris.

    Science.gov (United States)

    Liu, Zhe; Zhang, Meng; Han, Xueying; Xu, Haiming; Zhang, Biao; Yu, Qilin; Li, Mingchun

    2016-05-25

    The wide applications of titanium dioxide nanoparticles (TiO2 NPs) increase the possibility of their exposure to ecosystems, and therefore an improved understanding of their effects to organisms is required. However, their potential toxicity on eukaryotes, especially fungi, needs further detailed investigation. Here, we investigated the effects of anatase TiO2 NPs on the reactive oxygen species (ROS)-scavenging system in the model fungal organism, Pichia pastoris. Results showed that the NPs entered cells and had toxicity to this fungus, and their toxicity was attributed to cell wall damage, cell membrane damage, and ROS accumulation, but not apoptosis or autophagy. Interestingly, the synthesized TiO2 NPs impaired but not activated the ROS-scavenging system, which contributes to the cytotoxicity. Moreover, this impairment was associated with down-regulation of antioxidant-related genes, especially those genes involved in GSH regulation. Hence, GSH may play a key role in the interaction between TiO2 NPs and yeast cells. PMID:27041071

  13. Fenofibrate Reverses Palmitate Induced Impairment in Glucose Uptake in Skeletal Muscle Cells by Preventing Cytosolic Ceramide Accumulation

    Directory of Open Access Journals (Sweden)

    Sudarshan Bhattacharjee

    2015-10-01

    Full Text Available Backgrounds/Aims: The lipid induced insulin resistance is a major pathophysiologic mechanism underlying glucose intolerance of varying severity. PPARα-agonists are proven as effective hypolipidemic agents. The aim of this study was to see if impaired glucose uptake in palmitate treated myotubes is reversed by fenofibrate. Methods: Palmitate-treated myotubes were used as a model for insulin resistance, impaired glucose uptake, fatty acid oxidation and ceramide synthesis. mRNA levels of CPT1 and CPT2 were determined by PCR array and Q-PCR. Results: The incubation of myotubes with 750 uM palmitate not only reduced glucose uptake but also impaired fatty acid oxidation and cytosolic ceramide accumulation. Palmitate upregulated CPT1b expression in L6 myotubes, while CPT2 expression level remained unchanged. The altered stoichiometric ratio between the two CPT isoforms led to reduced fatty acid oxidation (FAO, ceramide accumulation and impaired glucose uptake, whereas administration of 200 µM fenofibrate signifcantly reversed the above abnormalities by increasing CPT2 mRNA levels and restoring CPT1b to CPT2 ratio. Conclusion: Palmitate-induced alteration in the stoichiometric ratio of mitochondrial CPT isoforms leads to incomplete FAO and enhanced cytosolic ceramide accumulation that lead to insulin resistance. Fenofibrate ameliorated insulin resistance by restoring the altered stoichiometry by upregulating CPT2 and preventing, cytoplasmic ceramide accumulation.

  14. Long-lasting suppression of hippocampal cell proliferation and impaired cognitive performance by methotrexate in the rat

    NARCIS (Netherlands)

    Seigers, Riejanne; Schagen, Sanne B.; Beerling, Wieteke; Boogerd, Willem; Van Tellingen, Olaf; Van Dam, Frits S. A. M.; Koolhaas, Jaap M.; Buwalda, Bauke

    2008-01-01

    Methotrexate (MTX) is a cytostatic agent widely used in combination with other agents as adjuvant chemotherapy for breast cancer and is associated with cognitive impairment as a long-term side effect in some cancer patients. This paper aimed to identify a neurobiological mechanism possibly responsib

  15. Mouse hepatic oval cells require Met-dependent PI3K to impair TGF-β-induced oxidative stress and apoptosis.

    Directory of Open Access Journals (Sweden)

    Adoración Martínez-Palacián

    Full Text Available We have previously shown that oval cells harboring a genetically inactivated Met tyrosine kinase (Met(-/- oval cells are more sensitive to TGF-β-induced apoptosis than cells expressing a functional Met (Met(flx/flx, demonstrating that the HGF/Met axis plays a pivotal role in oval cell survival. Here, we have examined the mechanism behind this effect and have found that TGF-β induced a mitochondria-dependent apoptotic cell death in Met(flx/flx and Met(-/- oval cells, associated with a marked increase in levels of the BH3-only proteins Bim and Bmf. Bmf plays a key role during TGF-β-mediated apoptosis since knocking down of BMF significantly diminished the apoptotic response in Met(-/- oval cells. TGF-β also induced oxidative stress accompanied by NADPH oxidase 4 (Nox4 mRNA up-regulation and decreased protein levels of antioxidant enzymes. Antioxidants inhibit both TGF-β-induced caspase 3 activity and Bmf up-regulation, revealing an oxidative stress-dependent Bmf regulation by TGF-β. Notably, oxidative stress-related events were strongly amplified in Met(-/- oval cells, emphasizing the critical role of Met in promoting survival. Pharmacological inhibition of PI3K did impair HGF-driven protection from TGF-β-induced apoptosis and increased sensitivity of Met(flx/flx oval cells to TGF-ß by enhancing oxidative stress, reaching apoptotic indices similar to those obtained in Met(-/- oval cells. Interestingly, both PI3K inhibition and/or knockdown itself resulted in caspase-3 activation and loss of viability in Met(flx/flx oval cells, whereas no effect was observed in Met(-/- oval cells. Altogether, results presented here provide solid evidences that both paracrine and autocrine HGF/Met signaling requires PI3K to promote mouse hepatic oval cell survival against TGF-β-induced oxidative stress and apoptosis.

  16. Impairment of myocardial perfusion in children with sickle cell disease; Alteration de la perfusion myocardique chez l'enfant drepanocytaire

    Energy Technology Data Exchange (ETDEWEB)

    Maunoury, C. [Hopital Necker-Enfants-Malades, Service de Medecine Nucleaire, 75 - Paris (France); Acar, P. [Centre Hospitalier Universitaire, Hopital des Enfants, Service de Cardiologie Pediatrique, 31 - Toulouse (France); Montalembert, M. de [Hopital Necker-Enfants-Malades, Service de Pediatrie Generale, 75 - Paris (France)

    2003-10-01

    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)

  17. Oleic Acid Increases Synthesis and Secretion of VEGF in Rat Vascular Smooth Muscle Cells: Role of Oxidative Stress and Impairment in Obesity

    Directory of Open Access Journals (Sweden)

    Mariella Trovati

    2013-09-01

    Full Text Available Obesity is characterized by poor collateral vessel formation, a process involving vascular endothelial growth factor (VEGF action on vascular smooth muscle cells (VSMC. Free fatty acids are involved in the pathogenesis of obesity vascular complications, and we have aimed to clarify whether oleic acid (OA enhances VEGF synthesis/secretion in VSMC, and whether this effect is impaired in obesity. In cultured aortic VSMC from lean and obese Zucker rats (LZR and OZR, respectively we measured the influence of OA on VEGF-A synthesis/secretion, signaling molecules and reactive oxygen species (ROS. In VSMC from LZR we found the following: (a OA increases VEGF-A synthesis/secretion by a mechanism blunted by inhibitors of Akt, mTOR, ERK-1/2, PKC-beta, NADPH-oxidase and mitochondrial electron transport chain complex; (b OA activates the above mentioned signaling pathways and increases ROS; (c OA-induced activation of PKC-beta enhances oxidative stress, which activates signaling pathways responsible for the increased VEGF synthesis/secretion. In VSMC from OZR, which present enhanced baseline oxidative stress, the above mentioned actions of OA on VEGF-A, signaling pathways and ROS are impaired: this impairment is reproduced in VSMC from LZR by incubation with hydrogen peroxide. Thus, in OZR chronically elevated oxidative stress causes a resistance to the action on VEGF that OA exerts in LZR by increasing ROS.

  18. Dexamethasone impairs the differentiation and maturation of murine dendritic cells by Toll-like receptor 4-nuclear factor-κB pathway

    Institute of Scientific and Technical Information of China (English)

    HE Xiao-kui; WU Xiang-ling; HE Xiu-juan; LI Bo; HU Yong-xiu

    2010-01-01

    Background Recent studies have demonstrated that dexamethasone (DEX) interferes with immune responses by targeting key functions of dendritic cells (DCs) at the earliest stage. However, the cellular and molecular mechanisms are still incompletely understood. This study aimed to explore the possible mechanisms by investigating the roles of DEX on differentiation, maturation & function of murine DCs and the effects of DEX on DCs via Toll-like receptor 4 (TLR4)-nuclear factor (NF)-κB mediated signal pathway.Methods Immature DCs (imDCs) were cultured from murine bone marrow (BM) cells. We added DEX into culture medium at different time. The expression of CD11c, CD86 and I-A~b (mouse MHC class Ⅱ molecule) was determined by flow cytometry. We determined the expression of NF-κB and its inhibitory protein I-κBα by electrophoretic mobility shift assay (EMSA) and Western blotting, respectively. The productions of interleukin (IL)-12p70 and IL-10 in cell culture supernatants were determined by enzyme-linked immunosorbent assay (ELISA).Results DEX impaired differentiation of DCs from murine bone marrow progenitors, and inhibited lipopolysaccharide (LPS) induced maturation of DCs. DEX significantly inhibited NF-κB expression of normal DCs, the higher the DEX concentration or the longer the DEX treatment time, the more obvious the effect. However, DEX had little effect on LPS-induced NF-κB activation, and partially impaired LPS-induced I-κBα degradation. DEX significantly decreased LPS induced IL-12p70 production by DCs. Interestingly, our results showed a synergistic effect between DEX and LPS on the production of IL-10 by DCs.Conclusions DEX inhibits the differentiation and maturation of murine DCs involved in TLR4-I-κB-NF-κB pathway, and also indirectly impairs Th1 development and interferes with the Th1-Th2 balance through IL-12 and/or IL-10 secretion by DCs.

  19. Retinal nerve fiber layer and ganglion cell complex thickness assessment in patients with Alzheimer disease and mild cognitive impairment. Preliminary results

    Directory of Open Access Journals (Sweden)

    A. S. Tiganov

    2014-07-01

    Full Text Available Purpose: to investigate the retinal nerve fiber layer (RNFL and the macular ganglion cell complex (GCC in patients with Alzheimer`s disease and mild cognitive impairment.Methods: this study included 10 patients (20 eyes with Alzheimer`s disease, 10 patients with mild cognitive impairment and 10 age- and sex-matched healthy controls that had no history of dementia. All the subjects underwent psychiatric examination, including the Mini-Mental State Examination (MMSE, and complete ophthalmological examination, comprising optical coherence tomography and scanning laser polarimetry.Results: there was a significant decrease in GCC thickness in patients with Alzheimer`s disease compared to the control group, global loss volume of ganglion cells was higher than in control group. there was no significant difference among the groups in terms of RNFL thickness. Weak positive correlation of GCC thickness and MMSE results was observed.Conclusion: Our data confirm the retinal involvement in Alzheimer`s disease, as reflected by loss of ganglion cells. Further studies will clear up the role and contribution of dementia in pathogenesis of optic neuropathy.

  20. Microwave Exposure Impairs Synaptic Plasticity in the Rat Hippocampus and PC12 Cells through Over-activation of the NMDA Receptor Signaling Pathway

    Institute of Scientific and Technical Information of China (English)

    XIONG Lu; DONG Ji; YAO Bin Wei; ZHAO Li; PENG Rui Yun; SUN Cheng Feng; ZHANG Jing; GAO Ya Bing; WANG Li Feng; ZUO Hong Yan; WANG Shui Ming; ZHOU Hong Mei; XU Xin Ping

    2015-01-01

    Objective The aim of this study is to investigate whether microwave exposure would affect the N-methyl-D-aspartate receptor (NMDAR) signaling pathway to establish whether this plays a role in synaptic plasticity impairment. Methods 48 male Wistar rats were exposed to 30 mW/cm² microwave for 10 min every other day for three times. Hippocampal structure was observed through H&E staining and transmission electron microscope. PC12 cells were exposed to 30 mW/cm² microwave for 5 min and the synapse morphology was visualized with scanning electron microscope and atomic force microscope. The release of amino acid neurotransmitters and calcium influx were detected. The expressions of several key NMDAR signaling molecules were evaluated. Results Microwave exposure caused injury in rat hippocampal structure and PC12 cells, especially the structure and quantity of synapses. The ratio of glutamic acid and gamma-aminobutyric acid neurotransmitters was increased and the intracellular calcium level was elevated in PC12 cells. A significant change in NMDAR subunits (NR1, NR2A, and NR2B) and related signaling molecules (Ca2+/calmodulin-dependent kinase II gamma and phosphorylated cAMP-response element binding protein) were examined. Conclusion 30 mW/cm² microwave exposure resulted in alterations of synaptic structure, amino acid neurotransmitter release and calcium influx. NMDAR signaling molecules were closely associated with impaired synaptic plasticity.

  1. The effect of acetaminophen on the expression of BCRP in trophoblast cells impairs the placental barrier to bile acids during maternal cholestasis

    International Nuclear Information System (INIS)

    Acetaminophen is used as first-choice drug for pain relief during pregnancy. Here we have investigated the effect of acetaminophen at subtoxic doses on the expression of ABC export pumps in trophoblast cells and its functional repercussion on the placental barrier during maternal cholestasis. The incubation of human choriocarcinoma cells (JAr, JEG-3 and BeWo) with acetaminophen for 48 h resulted in no significant changes in the expression and/or activity of MDR1 and MRPs. In contrast, in JEG-3 cells, BCRP mRNA, protein, and transport activity were reduced. In rat placenta, collected at term, acetaminophen administration for the last three days of pregnancy resulted in enhanced mRNA, but not protein, levels of Mrp1 and Bcrp. In fact, a decrease in Bcrp protein was found. Using in situ perfused rat placenta, a reduction in the Bcrp-dependent fetal-to-maternal bile acid transport after treating the dams with acetaminophen was found. Complete biliary obstruction in pregnant rats induced a significant bile acid accumulation in fetal serum and tissues, which was further enhanced when the mothers were treated with acetaminophen. This drug induced increased ROS production in JEG-3 cells and decreased the total glutathione content in rat placenta. Moreover, the NRF2 pathway was activated in JEG-3 cells as shown by an increase in nuclear NRF2 levels and an up-regulation of NRF2 target genes, NQO1 and HMOX-1, which was not observed in rat placenta. In conclusion, acetaminophen induces in placenta oxidative stress and a down-regulation of BCRP/Bcrp, which may impair the placental barrier to bile acids during maternal cholestasis. - Highlights: • Acetaminophen induces changes in placental BCRP expression in vitro. • This drug reduces the ability of placental cells to export BCRP substrates. • Acetaminophen induces changes in Bcrp expression in rat placenta. • Placental barrier to bile acids is impaired in rats treated with this drug

  2. Impaired NFAT and NFκB activation are involved in suppression of CD40 ligand expression by Δ9-tetrahydrocannabinol in human CD4+ T cells

    International Nuclear Information System (INIS)

    We have previously reported that Δ9-tetrahydrocannabinol (Δ9-THC), the main psychoactive cannabinoid in marijuana, suppresses CD40 ligand (CD40L) expression by activated mouse CD4+ T cells. CD40L is involved in pathogenesis of many autoimmune and inflammatory diseases. In the present study, we investigated the molecular mechanism of Δ9-THC-mediated suppression of CD40L expression using peripheral blood human T cells. Pretreatment with Δ9-THC attenuated CD40L expression in human CD4+ T cells activated by anti-CD3/CD28 at both the protein and mRNA level, as determined by flow cytometry and quantitative real-time PCR, respectively. Electrophoretic mobility shift assays revealed that Δ9-THC suppressed the DNA-binding activity of both NFAT and NFκB to their respective response elements within the CD40L promoter. An assessment of the effect of Δ9-THC on proximal T cell-receptor (TCR) signaling induced by anti-CD3/CD28 showed significant impairment in the rise of intracellular calcium, but no significant effect on the phosphorylation of ZAP70, PLCγ1/2, Akt, and GSK3β. Collectively, these findings identify perturbation of the calcium-NFAT and NFκB signaling cascade as a key mechanistic event by which Δ9-THC suppresses human T cell function. - Highlights: • Δ9-THC attenuated CD40L expression in activated human CD4+ T cells. • Δ9-THC suppressed DNA-binding activity of NFAT and NFκB. • Δ9-THC impaired elevation of intracellular Ca2+. • Δ9-THC did not affect phosphorylation of ZAP70, PLCγ1/2, Akt, and GSK3β

  3. The effect of acetaminophen on the expression of BCRP in trophoblast cells impairs the placental barrier to bile acids during maternal cholestasis

    Energy Technology Data Exchange (ETDEWEB)

    Blazquez, Alba G., E-mail: albamgb@usal.es [Laboratory of Experimental Hepatology and Drug Targeting (HEVEFARM), IBSAL, University of Salamanca, Salamanca (Spain); CIBERehd, Instituto de Salud Carlos III, Madrid (Spain); Briz, Oscar, E-mail: obriz@usal.es [Laboratory of Experimental Hepatology and Drug Targeting (HEVEFARM), IBSAL, University of Salamanca, Salamanca (Spain); CIBERehd, Instituto de Salud Carlos III, Madrid (Spain); Gonzalez-Sanchez, Ester, E-mail: u60343@usal.es [Laboratory of Experimental Hepatology and Drug Targeting (HEVEFARM), IBSAL, University of Salamanca, Salamanca (Spain); Perez, Maria J., E-mail: mjperez@usal.es [Laboratory of Experimental Hepatology and Drug Targeting (HEVEFARM), IBSAL, University of Salamanca, Salamanca (Spain); University Hospital of Salamanca, IECSCYL-IBSAL, Salamanca (Spain); CIBERehd, Instituto de Salud Carlos III, Madrid (Spain); Ghanem, Carolina I., E-mail: cghanem@ffyb.uba.ar [Instituto de Investigaciones Farmacologicas, Facultad de Farmacia y Bioquimica, CONICET, Universidad de Buenos Aires, Buenos Aires (Argentina); Marin, Jose J.G., E-mail: jjgmarin@usal.es [Laboratory of Experimental Hepatology and Drug Targeting (HEVEFARM), IBSAL, University of Salamanca, Salamanca (Spain); CIBERehd, Instituto de Salud Carlos III, Madrid (Spain)

    2014-05-15

    Acetaminophen is used as first-choice drug for pain relief during pregnancy. Here we have investigated the effect of acetaminophen at subtoxic doses on the expression of ABC export pumps in trophoblast cells and its functional repercussion on the placental barrier during maternal cholestasis. The incubation of human choriocarcinoma cells (JAr, JEG-3 and BeWo) with acetaminophen for 48 h resulted in no significant changes in the expression and/or activity of MDR1 and MRPs. In contrast, in JEG-3 cells, BCRP mRNA, protein, and transport activity were reduced. In rat placenta, collected at term, acetaminophen administration for the last three days of pregnancy resulted in enhanced mRNA, but not protein, levels of Mrp1 and Bcrp. In fact, a decrease in Bcrp protein was found. Using in situ perfused rat placenta, a reduction in the Bcrp-dependent fetal-to-maternal bile acid transport after treating the dams with acetaminophen was found. Complete biliary obstruction in pregnant rats induced a significant bile acid accumulation in fetal serum and tissues, which was further enhanced when the mothers were treated with acetaminophen. This drug induced increased ROS production in JEG-3 cells and decreased the total glutathione content in rat placenta. Moreover, the NRF2 pathway was activated in JEG-3 cells as shown by an increase in nuclear NRF2 levels and an up-regulation of NRF2 target genes, NQO1 and HMOX-1, which was not observed in rat placenta. In conclusion, acetaminophen induces in placenta oxidative stress and a down-regulation of BCRP/Bcrp, which may impair the placental barrier to bile acids during maternal cholestasis. - Highlights: • Acetaminophen induces changes in placental BCRP expression in vitro. • This drug reduces the ability of placental cells to export BCRP substrates. • Acetaminophen induces changes in Bcrp expression in rat placenta. • Placental barrier to bile acids is impaired in rats treated with this drug.

  4. P2X7 Cell Death Receptor Activation and Mitochondrial Impairment in Oxaliplatin-Induced Apoptosis and Neuronal Injury: Cellular Mechanisms and In Vivo Approach.

    Directory of Open Access Journals (Sweden)

    France Massicot

    Full Text Available Limited information is available regarding the cellular mechanisms of oxaliplatin-induced painful neuropathy during exposure of patients to this drug. We therefore determined oxidative stress in cultured cells and evaluated its occurrence in C57BL/6 mice. Using both cultured neuroblastoma (SH-SY5Y and macrophage (RAW 264.7 cell lines and also brain tissues of oxaliplatin-treated mice, we investigated whether oxaliplatin (OXA induces oxidative stress and apoptosis. Cultured cells were treated with 2-200 µM OXA for 24 h. The effects of pharmacological inhibitors of oxidative stress or inflammation (N-acetyl cysteine, ibuprofen, acetaminophen were also tested. Inhibitors were added 30 min before OXA treatment and then in combination with OXA for 24 h. In SH-SY5Y cells, OXA caused a significant dose-dependent decrease in viability, a large increase in ROS and NO production, lipid peroxidation and mitochondrial impairment as assessed by a drop in mitochondrial membrane potential, which are deleterious for the cell. An increase in levels of negatively charged phospholipids such as cardiolipin but also phosphatidylserine and phosphatidylinositol, was also observed. Additionally, OXA caused concentration-dependent P2X7 receptor activation, increased chromatin condensation and caspase-3 activation associated with TNF-α and IL-6 release. The majority of these toxic effects were equally observed in Raw 264.7 which also presented high levels of PGE2. Pretreatment of SH-SY5Y cells with pharmacological inhibitors significantly reduced or blocked all the neurotoxic OXA effects. In OXA-treated mice (28 mg/kg cumulated dose significant cold hyperalgesia and oxidative stress in the tested brain areas were shown. Our study suggests that targeting P2X7 receptor activation and mitochondrial impairment might be a potential therapeutic strategy against OXA-induced neuropathic pain.

  5. Impaired Macrophage and Satellite Cell Infiltration Occurs in a Muscle-Specific Fashion Following Injury in Diabetic Skeletal Muscle

    OpenAIRE

    Krause, Matthew P.; Dhuha Al-Sajee; Donna M D'Souza; Rebalka, Irena A.; Jasmin Moradi; Michael C Riddell; Hawke, Thomas J.

    2013-01-01

    BACKGROUND: 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. PRINCIPAL FINDINGS: Here we revea...

  6. HTLV-1 bZIP Factor Impairs Anti-viral Immunity by Inducing Co-inhibitory Molecule, T Cell Immunoglobulin and ITIM Domain (TIGIT.

    Directory of Open Access Journals (Sweden)

    Keiko Yasuma

    2016-01-01

    Full Text Available Human T-cell leukemia virus type 1 (HTLV-1 infects CD4+ T cells and induces proliferation of infected cells in vivo, which leads to the onset of adult T-cell leukemia (ATL in some infected individuals. The HTLV-1 bZIP factor (HBZ gene, which is encoded in the minus strand of HTLV-1, plays critical roles in pathogenesis. In this study, RNA-seq and ChIP-seq analyses using HBZ transduced T cells revealed that HBZ upregulates the expression and promoter acetylation levels of a co-inhibitory molecule, T cell immunoglobulin and ITIM domain (TIGIT, in addition to those of regulatory T cells related genes, Foxp3 and Ccr4. TIGIT was expressed on CD4+ T cells from HBZ-transgenic (HBZ-Tg mice, and on ATL cells and HTLV-1 infected CD4+ T cells of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP in vivo. Expression of Blimp1 and IL-10 was upregulated in TIGIT+CD4+ cells of HBZ-Tg mice compared with TIGIT-CD4+ T cells, suggesting the correlation between TIGIT expression and IL-10 production. When CD4+ T cells from HBZ-Tg mice were stimulated with TIGIT's ligand, CD155, their production of the inhibitory cytokine IL-10 was enhanced. Furthermore, dendritic cells from HBZ-Tg mice produced high levels of IL-10 after stimulation. These data suggest that HBZ alters immune system to suppressive state via TIGIT and IL-10. Importantly, TIGIT suppressed T-cell responses to another HTLV-1 virus protein, Tax, in vitro. Blocking of TIGIT and PD-1 slightly increased anti-Tax T-cell activity in some HAM/TSP patients. These results suggest that HBZ-induced TIGIT on HTLV-1 infected cells impairs T-cell responses to viral antigens. This study shows that HBZ-induced TIGIT plays a pivotal role in attenuating host immune responses and shaping a microenvironment favorable to HTLV-1.

  7. Defect of CARD9 leads to impaired accumulation of gamma interferon-producing memory phenotype T cells in lungs and increased susceptibility to pulmonary infection with Cryptococcus neoformans.

    Science.gov (United States)

    Yamamoto, Hideki; Nakamura, Yuri; Sato, Ko; Takahashi, Yurie; Nomura, Toshiki; Miyasaka, Tomomitsu; Ishii, Keiko; Hara, Hiromitsu; Yamamoto, Natsuo; Kanno, Emi; Iwakura, Yoichiro; Kawakami, Kazuyoshi

    2014-04-01

    Caspase recruitment domain-containing protein 9 (CARD9) is an adaptor molecule signal that is critical for NF-κB activation and is triggered through C-type lectin receptors (CLRs), which are pattern recognition receptors that recognize carbohydrate structures. Previous studies have reported that Cryptococcus neoformans, a fungal pathogen that causes meningoencephalitis in AIDS patients, is recognized through some CLRs, such as mannose receptors or DC-SIGN. However, the role of CARD9 in the host defense against cryptococcal infection remains to be elucidated. In the present study, we analyzed the role of CARD9 in the host defense against pulmonary infection with C. neoformans. CARD9 gene-disrupted (knockout [KO]) mice were highly susceptible to this infection, as shown by the reduced fungal clearance in the infected lungs of CARD9 KO mice, compared to that in wild-type (WT) mice. Gamma interferon (IFN-γ) production was strongly reduced in CARD9 KO mice during the innate-immunity phase of infection. Reduced IFN-γ synthesis was due to impaired accumulation of NK and memory phenotype T cells, which are major sources of IFN-γ innate-immunity-phase production; a reduction in the accumulation of these cells was correlated with reduced CCL4, CCL5, CXCL9, and CXCL10 synthesis. However, differentiation of Th17 cells, but not of Th1 cells, was impaired at the adaptive-immunity phase in CARD9 KO mice compared to WT mice, although there was no significant difference in the infection susceptibility between interleukin 17A (IL-17A) KO and WT mice. These results suggest that CARD9 KO mice are susceptible to C. neoformans infection probably due to the reduced accumulation of IFN-γ-expressing NK and memory phenotype T cells at the early stage of infection. PMID:24470469

  8. Primary T-cells from human CD4/CCR5-transgenic rats support all early steps of HIV-1 replication including integration, but display impaired viral gene expression

    Directory of Open Access Journals (Sweden)

    Hermann Volker

    2007-07-01

    Full Text Available Abstract Background In vivo studies on HIV-1 pathogenesis and testing of antiviral strategies have been hampered by the lack of an immunocompetent small animal model that is highly susceptible to HIV-1 infection. Since native rodents are non-permissive, we developed transgenic rats that selectively express the HIV-1 receptor complex, hCD4 and hCCR5, on relevant target cells. These animals display a transient low-level plasma viremia after HIV-1YU-2 infection, demonstrating HIV-1 susceptibility in vivo. However, unlike macrophages, primary CD4 T-cells from double-transgenic animals fail to support viral spread ex vivo. To identify quantitative limitations or absolute blocks in this rodent species, we quantitatively assessed the efficiency of key steps in the early phase of the viral replication cycle in a side-by-side comparison in infected cell lines and primary T-cells from hCD4/hCCR5-transgenic rats and human donors. Results Levels of virus entry, HIV-1 cDNA synthesis, nuclear import, and integration into the host genome were shown to be remarkably similar in cell lines and, where technically accessible, in primary T-cells from both species. In contrast, a profound impairment at the level of early HIV gene expression was disclosed at the single-cell level in primary rat T-cells and most other rat-derived cells. Macrophages were a notable exception, possibly reflecting the unique transcriptional milieu in this evolutionarily conserved target cell of all lentiviruses. Importantly, transient trans-complementation by ex vivo nucleofection with the Tat-interacting protein Cyclin T1 of human origin markedly elevated HIV gene expression in primary rat T-cells. Conclusion This is the first study that has quantitatively determined the efficiency of consecutive steps in the HIV-1 replication cycle in infected primary HIV target cells from a candidate transgenic small animal and compared it to human cells. Unlike cells derived from mice or rabbits, rat

  9. Methyl-β-Cyclodextrin Impairs the Monocyte-Adhering Ability of Endothelial Cells by Down-Regulating Adhesion Molecules and Caveolae and Reorganizing the Actin Cytoskeleton.

    Science.gov (United States)

    Ao, Meiying; Wu, Li; Zhou, Xing; Chen, Yong

    2016-01-01

    Due to its powerful ability to deplete cholesterol from the plasma membrane of cells, methyl-β-cyclodextrin (MβCD) has been widely used as a putative research tool in cell biology. Recently, recruiting MβCD as an effective drug (e.g., antitumor drugs) has been developed. However, it remains unclear whether MβCD, when it enters the blood circulation as a drug, influences the functions of the endothelium, e.g., the adhesion of leukocytes to the endothelium. In this study, we found that MβCD can impair the adhesion of monocytes to the monolayer of endothelial cells by lowering the cell-surface adhesive force and expression of adhesion molecules and caveolae-related molecules on/in endothelial cells, and reorganizing the actin cytoskeleton of endothelial cells. The data imply that MβCD, when recruited as a drug, potentially helps to inhibit inflammation or initiation/progression of atherosclerosis since its important early step is the adhesion of circulating leukocytes (e.g., monocytes) to the endothelium. PMID:27251506

  10. Caspase-independent apoptosis in Friend's erythroleukemia cells: role of mitochondrial ATP synthesis impairment in relocation of apoptosis-inducing factor and endonuclease G.

    Science.gov (United States)

    Comelli, Marina; Genero, Nadia; Mavelli, Irene

    2009-02-01

    Mitochondria have emerged as the central components of both caspase-dependent and independent apoptosis signalling pathways through release of different apoptogenic proteins. We previously documented that parental and differentiated Friend's erythroleukemia cells were induced to apoptosis by oligomycin and H(2)O(2) exposure, showing that the energy impairment occurring in both cases as a consequence of a severe mitochondrial F(0)F(1)ATPsynthase inactivation was a common early feature. Here we provide evidence for AIF and Endo G mitochondrio-nuclear relocation in both cases, as a component of caspase-independent apoptosis pathways. No detectable change in mitochondrial transmembrane potential and no variation in mitochondrial levels of Bcl-2 and Bax are observed. These results point to the osmotic rupture of the mitochondrial outer membrane as occurring in response to cell exposure to the two energy-impairing treatments under conditions preserving the mitochondrial inner membrane. A critical role of the mitochondrial F(0)F(1)ATP synthase inhibition in this process is also suggested.

  11. Exposure to runoff from coal-tar-sealed pavement induces genotoxicity and impairment of DNA repair capacity in the RTL-W1 fish liver cell line

    Energy Technology Data Exchange (ETDEWEB)

    Kienzler, Aude, E-mail: aude.kienzler@entpe.fr [Université de Lyon, UMR LEHNA 5023, USC INRA, ENTPE, rue Maurice Audin, Vaulx-en-Velin F-69518 (France); Mahler, Barbara J., E-mail: bjmahler@usgs.gov [U.S. Geological Survey, 1505 Ferguson Lane, Austin, TX 78754 (United States); Van Metre, Peter C., E-mail: pcvanmet@usgs.gov [U.S. Geological Survey, 1505 Ferguson Lane, Austin, TX 78754 (United States); Schweigert, Nathalie [Université de Lyon, UMR LEHNA 5023, USC INRA, ENTPE, rue Maurice Audin, Vaulx-en-Velin F-69518 (France); Devaux, Alain, E-mail: alain.devaux@entpe.fr [Université de Lyon, UMR LEHNA 5023, USC INRA, ENTPE, rue Maurice Audin, Vaulx-en-Velin F-69518 (France); Bony, Sylvie, E-mail: bony@entpe.fr [Université de Lyon, UMR LEHNA 5023, USC INRA, ENTPE, rue Maurice Audin, Vaulx-en-Velin F-69518 (France)

    2015-07-01

    Coal-tar-based (CTB) sealcoat, frequently applied to parking lots and driveways in North America, contains elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and related compounds. The RTL-W1 fish liver cell line was used to investigate two endpoints (genotoxicity and DNA-repair-capacity impairment) associated with exposure to runoff from asphalt pavement with CTB sealcoat or with an asphalt-based sealcoat hypothesized to contain about 7% CTB sealcoat (AS-blend). Genotoxic potential was assessed by the Formamido pyrimidine glycosylase (Fpg)-modified comet assay for 1:10 and 1:100 dilutions of runoff samples collected from 5 h to 36 d following sealcoat application. DNA-repair capacity was assessed by the base excision repair comet assay for 1:10 dilution of samples collected 26 h and 36 d following application. Both assays were run with and without co-exposure to ultraviolet-A radiation (UVA). With co-exposure to UVA, genotoxic effects were significant for both dilutions of CTB runoff for three of four sample times, and for some samples of AS-blend runoff. Base excision repair was significantly impaired for CTB runoff both with and without UVA exposure, and for AS-blend runoff only in the absence of UVA. This study is the first to investigate the effects of exposure to the complex mixture of chemicals in coal tar on DNA repair capacity. The results indicate that co-exposure to runoff from CT-sealcoated pavement and UVA as much as a month after sealcoat application has the potential to cause genotoxicity and impair DNA repair capacity. - Highlights: • Co-exposure to runoff from coal-tar-sealcoated pavement and UVA caused DNA damage. • Significant genotoxicity occurred with a 1:100 dilution of runoff. • Runoff collected up to 36 d following coal-tar-sealcoat application was genotoxic. • Exposure to runoff from sealed pavement impaired an important DNA repair pathway. • Repair capacity was impaired with a 1:10 dilution of runoff (1:100 not

  12. Exposure to runoff from coal-tar-sealed pavement induces genotoxicity and impairment of DNA repair capacity in the RTL-W1 fish liver cell line

    International Nuclear Information System (INIS)

    Coal-tar-based (CTB) sealcoat, frequently applied to parking lots and driveways in North America, contains elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and related compounds. The RTL-W1 fish liver cell line was used to investigate two endpoints (genotoxicity and DNA-repair-capacity impairment) associated with exposure to runoff from asphalt pavement with CTB sealcoat or with an asphalt-based sealcoat hypothesized to contain about 7% CTB sealcoat (AS-blend). Genotoxic potential was assessed by the Formamido pyrimidine glycosylase (Fpg)-modified comet assay for 1:10 and 1:100 dilutions of runoff samples collected from 5 h to 36 d following sealcoat application. DNA-repair capacity was assessed by the base excision repair comet assay for 1:10 dilution of samples collected 26 h and 36 d following application. Both assays were run with and without co-exposure to ultraviolet-A radiation (UVA). With co-exposure to UVA, genotoxic effects were significant for both dilutions of CTB runoff for three of four sample times, and for some samples of AS-blend runoff. Base excision repair was significantly impaired for CTB runoff both with and without UVA exposure, and for AS-blend runoff only in the absence of UVA. This study is the first to investigate the effects of exposure to the complex mixture of chemicals in coal tar on DNA repair capacity. The results indicate that co-exposure to runoff from CT-sealcoated pavement and UVA as much as a month after sealcoat application has the potential to cause genotoxicity and impair DNA repair capacity. - Highlights: • Co-exposure to runoff from coal-tar-sealcoated pavement and UVA caused DNA damage. • Significant genotoxicity occurred with a 1:100 dilution of runoff. • Runoff collected up to 36 d following coal-tar-sealcoat application was genotoxic. • Exposure to runoff from sealed pavement impaired an important DNA repair pathway. • Repair capacity was impaired with a 1:10 dilution of runoff (1:100 not

  13. Targeted impairment of thymidine kinase 2 expression in cells induces mitochondrial DNA depletion and reveals molecular mechanisms of compensation of mitochondrial respiratory activity

    Energy Technology Data Exchange (ETDEWEB)

    Villarroya, Joan, E-mail: joanvillarroya@gmail.com [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Institut de Recerca l' Hospital de la Santa Creu i Sant Pau, Barcelona (Spain); Lara, Mari-Carmen [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Department of Neurology, Columbia University Medical Center, New York, NY (United States); Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), ISCIII (Spain); Dorado, Beatriz [Department of Neurology, Columbia University Medical Center, New York, NY (United States); Garrido, Marta [Unitat de Biologia Cel.lular i Molecular, IMIM-Hospital del Mar, Barcelona (Spain); Garcia-Arumi, Elena [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), ISCIII (Spain); Meseguer, Anna [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Hirano, Michio [Department of Neurology, Columbia University Medical Center, New York, NY (United States); Vila, Maya R. [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain)

    2011-04-08

    Highlights: {yields} We impaired TK2 expression in Ost TK1{sup -} cells via siRNA-mediated interference (TK2{sup -}). {yields} TK2 impairment caused severe mitochondrial DNA (mtDNA) depletion in quiescent cells. {yields} Despite mtDNA depletion, TK2{sup -} cells show high cytochrome oxidase activity. {yields} Depletion of mtDNA occurs without imbalance in the mitochondrial dNTP pool. {yields} Nuclear-encoded ENT1, DNA-pol {gamma}, TFAM and TP gene expression is lowered in TK2{sup -} cells. -- Abstract: The mitochondrial DNA (mtDNA) depletion syndrome comprises a clinically heterogeneous group of diseases characterized by reductions of the mtDNA abundance, without associated point mutations or rearrangements. We have developed the first in vitro model to study of mtDNA depletion due to reduced mitochondrial thymidine kinase 2 gene (TK2) expression in order to understand the molecular mechanisms involved in mtDNA depletion syndrome due to TK2 mutations. Small interfering RNA targeting TK2 mRNA was used to decrease TK2 expression in Ost TK1{sup -} cells, a cell line devoid of endogenous thymidine kinase 1 (TK1). Stable TK2-deficient cell lines showed a reduction of TK2 levels close to 80%. In quiescent conditions, TK2-deficient cells showed severe mtDNA depletion, also close to 80% the control levels. However, TK2-deficient clones showed increased cytochrome c oxidase activity, higher cytochrome c oxidase subunit I transcript levels and higher subunit II protein expression respect to control cells. No alterations of the deoxynucleotide pools were found, whereas a reduction in the expression of genes involved in nucleoside/nucleotide homeostasis (human equilibrative nucleoside transporter 1, thymidine phosphorylase) and mtDNA maintenance (DNA-polymerase {gamma}, mitochondrial transcription factor A) was observed. Our findings highlight the importance of cellular compensatory mechanisms that enhance the expression of respiratory components to ensure respiratory activity

  14. Increased CD45RA+ FoxP3(low regulatory T cells with impaired suppressive function in patients with systemic lupus erythematosus.

    Directory of Open Access Journals (Sweden)

    Xiujun Pan

    Full Text Available BACKGROUND: The role of naturally occurring regulatory T cells (Treg in the control of the development of systemic lupus erythematosus (SLE has not been well defined. Therefore, we dissect the phenotypically heterogeneous CD4(+FoxP3(+ T cells into subpopulations during the dynamic SLE development. METHODLOGY/PRINCIPAL FINDINGS: To evaluate the proliferative and suppressive capacities of different CD4(+ T cell subgroups between active SLE patients and healthy donors, we employed CD45RA and CD25 as surface markers and carboxyfluorescein diacetatesuccinimidyl ester (CFSE dilution assay. In addition, multiplex cytokines expression in active SLE patients was assessed using Luminex assay. Here, we showed a significant increase in the frequency of CD45RA(+FoxP3(low naive Treg cells (nTreg cells and CD45RA(-FoxP3(low (non-Treg cells in patients with active SLE. In active SLE patients, the increased proportions of CD45RA(+FoxP3(low nTreg cells were positively correlated with the disease based on SLE disease activity index (SLEDAI and the status of serum anti-dsDNA antibodies. We found that the surface marker combination of CD25(+CD45RA(+ can be used to defined CD45RA(+FoxP3(low nTreg cells for functional assays, wherein nTreg cells from active SLE patients demonstrated defective suppression function. A significant correlation was observed between inflammatory cytokines, such as IL-6, IL-12 and TNFα, and the frequency of nTreg cells. Furthermore, the CD45RA(+FoxP3(low nTreg cell subset increased when cultured with SLE serum compared to healthy donor serum, suggesting that the elevated inflammatory cytokines of SLE serum may promote nTreg cell proliferation/expansion. CONCLUSIONS/SIGNIFICANCE: Our results indicate that impaired numbers of functional CD45RA(+FoxP3(low naive Treg cell and CD45RA(-FoxP3(low non-suppressive T cell subsets in inflammatory conditions may contribute to SLE development. Therefore, analysis of subsets of FoxP3(+ T cells, using a

  15. Gene delivery of the elastase inhibitor elafin protects macrophages from neutrophil elastase-mediated impairment of apoptotic cell recognition.

    Science.gov (United States)

    Henriksen, Peter A; Devitt, Andrew; Kotelevtsev, Yuri; Sallenave, Jean-Michel

    2004-09-10

    The resolution of inflammation is dependent on recognition and phagocytic removal of apoptotic cells by macrophages. Receptors for apoptotic cells are sensitive to degradation by human neutrophil elastase (HNE). We show in the present study that HNE cleaves macrophage cell surface CD14 and in so doing, reduces phagocytic recognition of apoptotic lymphocytic cells (Mutu 1). Using an improved method of adenovirus-mediated transfection of macrophages with the HNE inhibitor elafin, we demonstrate that elafin overexpression prevents CD14 cleavage and restores apoptotic cell recognition by macrophages. This approach of genetic modification of macrophages could be used to restore apoptotic cell recognition in inflammatory conditions. PMID:15358543

  16. 14S,21R-Dihydroxydocosahexaenoic Acid Remedies Impaired Healing and Mesenchymal Stem Cell Functions in Diabetic Wounds*

    OpenAIRE

    Tian, Haibin; Lu, Yan; Shah, Shraddha P.; Hong, Song

    2010-01-01

    Treatment of diabetes-impaired wound healing remains a major unresolved medical challenge. Here, we identified suppressed formation of a novel reparative lipid mediator 14S,21R-dihydroxydocosa-4Z,7Z,10Z,12E,16Z,19Z-hexaenoic acid (14S,21R-diHDHA) in cutaneous wounds of diabetic db/db mice. These results indicate that diabetes impedes the biosynthetic pathways of 14S,21R-diHDHA in skin wounds. Administration of exogenous 14S,21R-diHDHA to wounds in diabetic animals rescued healing and angiogen...

  17. 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.

  18. 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

    2016-01-01

    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. PMID:27419108

  19. 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. PMID:27419108

  20. Production of Reactive Oxygen Species, Alteration of Cytosolic Ascorbate Peroxidase, and Impairment of Mitochondrial Metabolism Are Early Events in Heat Shock-Induced Programmed Cell Death in Tobacco Bright-Yellow 2 Cells1

    Science.gov (United States)

    Vacca, Rosa Anna; de Pinto, Maria Concetta; Valenti, Daniela; Passarella, Salvatore; Marra, Ersilia; De Gara, Laura

    2004-01-01

    To gain some insight into the mechanisms by which plant cells die as a result of abiotic stress, we exposed tobacco (Nicotiana tabacum) Bright-Yellow 2 cells to heat shock and investigated cell survival as a function of time after heat shock induction. Heat treatment at 55°C triggered processes leading to programmed cell death (PCD) that was complete after 72 h. In the early phase, cells undergoing PCD showed an immediate burst in hydrogen peroxide (H2O2) and superoxide (O2·-) anion production. Consistently, death was prevented by the antioxidants ascorbate (ASC) and superoxide dismutase (SOD). Actinomycin D and cycloheximide, inhibitors of transcription and translation, respectively, also prevented cell death, but with a lower efficiency. Induction of PCD resulted in gradual oxidation of endogenous ASC; this was accompanied by a decrease in both the amount and the specific activity of the cytosolic ASC peroxidase (cAPX). A reduction in cAPX gene expression was also found in the late PCD phase. Moreover, changes of cAPX kinetic properties were found in PCD cells. Production of ROS in PCD cells was accompanied by early inhibition of glucose (Glc) oxidation, with a strong impairment of mitochondrial function as shown by an increase in cellular NAD(P)H fluorescence, and by failure of mitochondria isolated from cells undergoing PCD to generate membrane potential and to oxidize succinate in a manner controlled by ADP. Thus, we propose that in the early phase of tobacco Bright-Yellow 2 cell PCD, ROS production occurs, perhaps because of damage of the cell antioxidant system, with impairment of the mitochondrial oxidative phosphorylation. PMID:15020761

  1. Impaired degradation followed by enhanced recycling of epidermal growth factor receptor caused by hypo-phosphorylation of tyrosine 1045 in RBE cells

    Directory of Open Access Journals (Sweden)

    Gui Anping

    2012-05-01

    Full Text Available Abstract Background Since cholangiocarcinoma has a poor prognosis, several epidermal growth factor receptor (EGFR-targeted therapies with antibody or small molecule inhibitor treatment have been proposed. However, their effect remains limited. The present study sought to understand the molecular genetic characteristics of cholangiocarcinoma related to EGFR, with emphasis on its degradation and recycling. Methods We evaluated EGFR expression and colocalization by immunoblotting and immunofluorescence, cell surface EGFR expression by fluorescence-activated cell sorting (FACS, and EGFR ubiquitination and protein binding by immunoprecipitation in the human cholangiocarcinoma RBE and immortalized cholangiocyte MMNK-1 cell lines. Monensin treatment and Rab11a depletion by siRNA were adopted for inhibition of EGFR recycling. Results Upon stimulation with EGF, ligand-induced EGFR degradation was impaired and the expression of phospho-tyrosine 1068 and phospho-p44/42 MAPK was sustained in RBE cells as compared with MMNK-1 cells. In RBE cells, the process of EGFR sorting for lysosomal degradation was blocked at the early endosome stage, and non-degradated EGFR was recycled to the cell surface. A disrupted association between EGFR and the E3 ubiquitin ligase c-Cbl, as well as hypo-phosphorylation of EGFR at tyrosine 1045 (Tyr1045, were also observed in RBE cells. Conclusion In RBE cells, up-regulation of EGFR Tyr1045 phosphorylation is a potentially useful molecular alteration in EGFR-targeted therapy. The combination of molecular-targeted therapy determined by the characteristics of individual EGFR phosphorylation events and EGFR recycling inhibition show promise in future treatments of cholangiocarcinoma.

  2. Impaired degradation followed by enhanced recycling of epidermal growth factor receptor caused by hypo-phosphorylation of tyrosine 1045 in RBE cells

    International Nuclear Information System (INIS)

    Since cholangiocarcinoma has a poor prognosis, several epidermal growth factor receptor (EGFR)-targeted therapies with antibody or small molecule inhibitor treatment have been proposed. However, their effect remains limited. The present study sought to understand the molecular genetic characteristics of cholangiocarcinoma related to EGFR, with emphasis on its degradation and recycling. We evaluated EGFR expression and colocalization by immunoblotting and immunofluorescence, cell surface EGFR expression by fluorescence-activated cell sorting (FACS), and EGFR ubiquitination and protein binding by immunoprecipitation in the human cholangiocarcinoma RBE and immortalized cholangiocyte MMNK-1 cell lines. Monensin treatment and Rab11a depletion by siRNA were adopted for inhibition of EGFR recycling. Upon stimulation with EGF, ligand-induced EGFR degradation was impaired and the expression of phospho-tyrosine 1068 and phospho-p44/42 MAPK was sustained in RBE cells as compared with MMNK-1 cells. In RBE cells, the process of EGFR sorting for lysosomal degradation was blocked at the early endosome stage, and non-degradated EGFR was recycled to the cell surface. A disrupted association between EGFR and the E3 ubiquitin ligase c-Cbl, as well as hypo-phosphorylation of EGFR at tyrosine 1045 (Tyr1045), were also observed in RBE cells. In RBE cells, up-regulation of EGFR Tyr1045 phosphorylation is a potentially useful molecular alteration in EGFR-targeted therapy. The combination of molecular-targeted therapy determined by the characteristics of individual EGFR phosphorylation events and EGFR recycling inhibition show promise in future treatments of cholangiocarcinoma

  3. Metformin synergizes 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) combination therapy through impairing intracellular ATP production and DNA repair in breast cancer stem cells.

    Science.gov (United States)

    Soo, Jaslyn Sian-Siu; Ng, Char-Hong; Tan, Si Hoey; Malik, Rozita Abdul; Teh, Yew-Ching; Tan, Boon-Shing; Ho, Gwo-Fuang; See, Mee-Hoong; Taib, Nur Aishah Mohd; Yip, Cheng-Har; Chung, Felicia Fei-Lei; Hii, Ling-Wei; Teo, Soo-Hwang; Leong, Chee-Onn

    2015-10-01

    Metformin, an AMPK activator, has been reported to improve pathological response to chemotherapy in diabetic breast cancer patients. To date, its mechanism of action in cancer, especially in cancer stem cells (CSCs) have not been fully elucidated. In this study, we demonstrated that metformin, but not other AMPK activators (e.g. AICAR and A-769662), synergizes 5-fluouracil, epirubicin, and cyclophosphamide (FEC) combination chemotherapy in non-stem breast cancer cells and breast cancer stem cells. We show that this occurs through an AMPK-dependent mechanism in parental breast cancer cell lines. In contrast, the synergistic effects of metformin and FEC occurred in an AMPK-independent mechanism in breast CSCs. Further analyses revealed that metformin accelerated glucose consumption and lactate production more severely in the breast CSCs but the production of intracellular ATP was severely hampered, leading to a severe energy crisis and impairs the ability of CSCs to repair FEC-induced DNA damage. Indeed, addition of extracellular ATP completely abrogated the synergistic effects of metformin on FEC sensitivity in breast CSCs. In conclusion, our results suggest that metformin synergizes FEC sensitivity through distinct mechanism in parental breast cancer cell lines and CSCs, thus providing further evidence for the clinical relevance of metformin for the treatment of cancers. PMID:26276035

  4. Solitary Bone Plasmacytoma Progressing into Retroperitoneal Plasma Cell Myeloma with No Related End Organ or Tissue Impairment: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Gargi Tikku

    2014-09-01

    Full Text Available Solitary bone plasmacytomas and plasma cell myeloma are clonal proliferations of plasma cells. Many patients with solitary bone plasmacytomas develop plasma cell myeloma on follow-up. We present a case of a 70-year-old man who presented with fracture and a lytic lesion in the subtrochanteric region of the left femur and was assigned a diagnosis of solitary bone plasmacytoma. He received local curative radiotherapy. However, 4 months later his serum M protein and β2-microglobulin levels increased to 2.31 g/dL and 5.965 mg/L, respectively. He complained of abdominal fullness and constipation. Ultrasound and non-contrast CT imaging revealed multiple retroperitoneal masses. Colonoscopic examination was normal. Biopsy of the a retroperitoneal mass confirmed it to be a plasmacytoma. Repeat hemogram, blood urea, serum creatinine, skeletal survey, and bone marrow examination revealed no abnormalities. This is an unusual presentation of plasma cell myeloma, which manifested as multiple huge extramedullary retroperitoneal masses and arose from a solitary bone plasmacytoma, without related end organ or tissue impairment and bone marrow plasmacytosis. The patient succumbed to his disease 8 months after the appearance of the retroperitoneal masses. This case highlights the importance of close monitoring of patients diagnosed with solitary bone plasmacytoma with increased serum M protein and serum β2-microglobulin levels, so that early therapy can be instituted to prevent conversion to plasma cell myeloma.

  5. Elevated Apoptosis and Impaired Proliferation Contribute to Downregulated Peripheral γδ T Cells in Patients with Systemic Lupus Erythematosus

    Directory of Open Access Journals (Sweden)

    Zhimin Lu

    2013-01-01

    Full Text Available Objective. To investigate the frequency of peripheral γδ T cells in patients with systemic lupus erythematosus (SLE and its correlation with disease activity and to analyze the apoptotic status, proliferation ability, and intracellular cytokine profile of these cells. Methods. Flow cytometry was performed to detect the percentage and intracellular cytokine expression of peripheral γδ T cells from SLE patients. Annexin-V/PI double staining was applied to determine the proportion of apoptotic γδ and CD3+ T cells. γδ T cell proliferation was analyzed by CFSE labeling technique. Results. The percentage and absolute number of γδ T cells were remarkably decreased in active SLE patients compared to those in inactive patients and healthy controls, with γδ T cell count negatively correlated with disease activity. Compared with healthy controls, peripheral γδ T cells from active SLE patients exhibited higher apoptotic rate and lower proliferation ability, as well as elevated expression of intracellular IFN-γ, IL-4, IL-10, and TGF-β, but not IL-17 or Foxp3. Conclusion. Decreased γδ T cells in the peripheral blood of SLE patients might be caused by upregulated apoptosis and downregulated cell proliferation. These γδ T cells may secret both pro- and anti-inflammatory cytokines to perform their functions in SLE.

  6. Impaired APP activity and altered Tau splicing in embryonic stem cell-derived astrocytes obtained from an APPsw transgenic minipig

    DEFF Research Database (Denmark)

    Hall, Vanessa Jane; Lindblad, Maiken Marie; Jakobsen, Jannik E.;

    2015-01-01

    analyze in vitro-produced stem cells and their derivatives from a large mammalian model of the disease created by overexpression of a single mutant human gene (APPsw). We produced hemizygous and homozygous radial glial-like cells following culture and differentiation of embryonic stem cells (ESCs......) isolated from embryos obtained from mated hemizygous minipigs. These cells were confirmed to co-express varying neural markers, including NES, GFAP and BLBP, typical of type one radial glial cells (RGs) from the subgranular zone. These cells had altered expression of CCND1 and NOTCH1 and decreased...... expression of several ribosomal RNA genes. We found that these cells were able to differentiate into astrocytes upon directed differentiation. The astrocytes produced had decreased α- and β-secretase activity, increased γ-secretase activity and altered splicing of tau. This indicates novel aspects of early...

  7. Dennexin peptides modeled after the homophilic binding sites of the neural cell adhesion molecule (NCAM) promote neuronal survival, modify cell adhesion and impair spatial learning

    DEFF Research Database (Denmark)

    Køhler, Lene B; Christensen, Claus; Rossetti, Clara;

    2010-01-01

    , and the effect of dennexinA was independent of polysialic acid expression. Consistent with the effect of dennexinA on NCAM-mediated adhesion in vitro, the peptide impaired long-term memory retention in rats in the Morris water maze test. Thus, dennexins are novel site-specific pharmacological tools...

  8. Exposure to runoff from coal-tar-sealed pavement induces genotoxicity and impairment of DNA repair capacity in the RTL-W1 fish liver cell line

    Science.gov (United States)

    Kienzler, Aude; Mahler, Barbara J.; Van Metre, Peter C.; Schweigert, Nathalie; Devaux, Alain; Bony, Sylvie

    2015-01-01

    Coal-tar-based (CTB) sealcoat, frequently applied to parking lots and driveways in North America, contains elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and related compounds. The RTL-W1 fish liver cell line was used to investigate two endpoints (genotoxicity and DNA-repair-capacity impairment) associated with exposure to runoff from asphalt pavement with CTB sealcoat or with an asphalt-based sealcoat hypothesized to contain about 7% CTB sealcoat (AS-blend). Genotoxic potential was assessed by the Formamido pyrimidine glycosylase (Fpg)-modified comet assay for 1:10 and 1:100 dilutions of runoff samples collected from 5 h to 36 d following sealcoat application. DNA-repair capacity was assessed by the base excision repair comet assay for 1:10 dilution of samples collected 26 h and 36 d following application. Both assays were run with and without co-exposure to ultraviolet-A radiation (UVA). With co-exposure to UVA, genotoxic effects were significant for both dilutions of CTB runoff for three of four sample times, and for some samples of AS-blend runoff. Base excision repair was significantly impaired for CTB runoff both with and without UVA exposure, and for AS-blend runoff only in the absence of UVA. This study is the first to investigate the effects of exposure to the complex mixture of chemicals in coal tar on DNA repair capacity. The results indicate that co-exposure to runoff from CT-sealcoated pavement and UVA as much as a month after sealcoat application has the potential to cause genotoxicity and impair DNA repair capacity.

  9. Mucosal-Associated Invariant T (MAIT Cells Are Impaired in Th17 Associated Primary and Secondary Immunodeficiencies.

    Directory of Open Access Journals (Sweden)

    Yifang Gao

    Full Text Available The recently described Mucosal Associated Invariant T (MAIT cells mediate specific recognition of bacterial and fungal vitamin B2 metabolites. As innate T cells, they possess broad effector responses, including IFN- including Iproduction, that are comparable to conventional T cell responses. Immunodeficiencies associated with systemic Th17 deficiency may also be compounded by defects in MAIT immunity. We evaluated Th17 immunity in this innate T cell compartment in primary (AD-HIES and secondary immunodeficiency (thymoma patients with conventional Th17 deficiency and susceptibility to fungal and bacterial disease. Our results suggest that MAIT cells are both reduced and functional deficient in STAT3 deficiency and thymoma patients with IL-12/23 autoantibodies. In contrast, thymoma patients without autoantibodies preserved the normal number and functional MAIT cells.

  10. Ethanol affects NMDA receptor signaling at climbing fiber-Purkinje cell synapses in mice and impairs cerebellar LTD

    OpenAIRE

    He, Qionger; Titley, Heather; Grasselli, Giorgio; Piochon, Claire; Hansel, Christian

    2012-01-01

    Ethanol profoundly influences cerebellar circuit function and motor control. It has recently been demonstrated that functional N-methyl-d-aspartate (NMDA) receptors are postsynaptically expressed at climbing fiber (CF) to Purkinje cell synapses in the adult cerebellum. Using whole cell patch-clamp recordings from mouse cerebellar slices, we examined whether ethanol can affect NMDA receptor signaling in mature Purkinje cells. NMDA receptor-mediated currents were isolated by bath application of...

  11. The mitochondrial complex I activity is reduced in cells with impaired cystic fibrosis transmembrane conductance regulator (CFTR function.

    Directory of Open Access Journals (Sweden)

    Angel G Valdivieso

    Full Text Available Cystic fibrosis (CF is a frequent and lethal autosomal recessive disease. It results from different possible mutations in the CFTR gene, which encodes the CFTR chloride channel. We have previously studied the differential expression of genes in CF and CF corrected cell lines, and found a reduced expression of MTND4 in CF cells. MTND4 is a mitochondrial gene encoding the MTND4 subunit of the mitochondrial Complex I (mCx-I. Since this subunit is essential for the assembly and activity of mCx-I, we have now studied whether the activity of this complex was also affected in CF cells. By using Blue Native-PAGE, the in-gel activity (IGA of the mCx-I was found reduced in CFDE and IB3-1 cells (CF cell lines compared with CFDE/6RepCFTR and S9 cells, respectively (CFDE and IB3-1 cells ectopically expressing wild-type CFTR. Moreover, colon carcinoma T84 and Caco-2 cells, which express wt-CFTR, either treated with CFTR inhibitors (glibenclamide, CFTR(inh-172 or GlyH101 or transfected with a CFTR-specific shRNAi, showed a significant reduction on the IGA of mCx-I. The reduction of the mCx-I activity caused by CFTR inhibition under physiological or pathological conditions may have a profound impact on mitochondrial functions of CF and non-CF cells.

  12. Upregulation of SOCS-3 and PIAS-3 impairs IL-12-mediated interferon-gamma response in CD56 T cells in HCV-infected heroin users.

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    Li Ye

    Full Text Available BACKGROUND: CD56(+ T cells are abundant in liver and play an important role in host innate immunity against viral infections, including hepatitis C virus (HCV infection, a common infection among heroin abusers. We thus investigated the in vivo impact of heroin use or heroin use plus HCV infection on the CD56(+ T cell frequency and function. METHODOLOGY/PRINCIPAL FINDINGS: A total of 37 heroin users with (17 or without (20 HCV infection and 17 healthy subjects were included in the study. Although there was no significant difference in CD56(+ T cell frequency in PBMCs among three study groups, CD56(+ T cells isolated from the heroin users had significantly lower levels of constitutive interferon-gamma (IFN-gamma expression than those from the normal subjects. In addition, when stimulated by interleukin (IL-12, CD56(+ natural T cells from HCV-infected heroin users produced significantly lower levels of IFN-gamma than those from the normal subjects. This diminished ability to produce IFN-gamma by CD56(+ T cells was associated with the increased plasma HCV viral loads in the HCV-infected heroin users. Investigation of the mechanisms showed that although heroin use or heroin use plus HCV infection had little impact on the expression of the key positive regulators (IL-12 receptors, STAT-1, 3, 4, 5, JAK-2, and TYK-2 in IL-12 pathway, heroin use or heroin use plus HCV infection induced the expression of suppressor of cytokine signaling protein-3 (SOCS-3 and protein inhibitors of activated STAT-3 (PIAS-3, two key inhibitors of IL-12 pathway. CONCLUSION/SIGNIFICANCE: These findings provide compelling in vivo evidence that heroin use or heroin use plus HCV infection impairs CD56(+ T cell-mediated innate immune function, which may account for HCV infection and persistence in liver.

  13. Ornithine and Homocitrulline Impair Mitochondrial Function, Decrease Antioxidant Defenses and Induce Cell Death in Menadione-Stressed Rat Cortical Astrocytes: Potential Mechanisms of Neurological Dysfunction in HHH Syndrome.

    Science.gov (United States)

    Zanatta, Ângela; Rodrigues, Marília Danyelle Nunes; Amaral, Alexandre Umpierrez; Souza, Débora Guerini; Quincozes-Santos, André; Wajner, Moacir

    2016-09-01

    Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome is caused by deficiency of ornithine translocase leading to predominant tissue accumulation and high urinary excretion of ornithine (Orn), homocitrulline (Hcit) and ammonia. Although affected patients commonly present neurological dysfunction manifested by cognitive deficit, spastic paraplegia, pyramidal and extrapyramidal signs, stroke-like episodes, hypotonia and ataxia, its pathogenesis is still poorly known. Although astrocytes are necessary for neuronal protection. Therefore, in the present study we investigated the effects of Orn and Hcit on cell viability (propidium iodide incorporation), mitochondrial function (thiazolyl blue tetrazolium bromide-MTT-reduction and mitochondrial membrane potential-ΔΨm), antioxidant defenses (GSH) and pro-inflammatory response (NFkB, IL-1β, IL-6 and TNF-α) in unstimulated and menadione-stressed cortical astrocytes that were previously shown to be susceptible to damage by neurotoxins. We first observed that Orn decreased MTT reduction, whereas both amino acids decreased GSH levels, without altering cell viability and the pro-inflammatory factors in unstimulated astrocytes. Furthermore, Orn and Hcit decreased cell viability and ΔΨm in menadione-treated astrocytes. The present data indicate that the major compounds accumulating in HHH syndrome impair mitochondrial function and reduce cell viability and the antioxidant defenses in cultured astrocytes especially when stressed by menadione. It is presumed that these mechanisms may be involved in the neuropathology of this disease. PMID:27161368

  14. Higher Viral Load and Prolonged Viral Shedding Period is Associated with Impaired Th17 Cell Response in Patients with H1N1 Influenza A

    Institute of Scientific and Technical Information of China (English)

    Gui-lin; Yang; Ying-xia; Liu; Mu-tong; Fang; Wei-long; Liu; Xin-chun; Chen; John; Nunnari; Jing-jing; Xie; Ming-feng; Liao; Ming-xia; Zhang; Guo-bao; Li; Pei-ze; Zhang; Yi; Guan; Bo-ping; Zhou

    2012-01-01

    Objective To explore whether age,disease severity,cytokines and lymphocytes in H1N1 influenza A patients correlate with viral load and clearance.Methods Total of 70 mild and 16 severe patients infected with H1N1 influenza A virus were enrolled in this study.Results It was found that the patients under 14 years old and severe patients displayed significantly higher viral loads and prolonged viral shedding periods compared with the patients over 14 years old and mild patients,respectively(P < 0.05).Moreover,the patients under 14 years old and severe patients displayed significantly lower Th17 cell frequency than the patients over 14 years old and mild patients(P < 0.01).The viral shedding period inversely correlated with the frequency of IL-17+IFN-γ-CD4+ T cells.Additionally,the decreased concentration of serum TGF-β correlated with the decreased frequency of IL-17+IFN-γ-CD4+ T cells.Conclusions Both younger and severe patients are associated with higher viral loads and longer viral shedding periods,which may partially be attributed to the impaired Th17 cell response.

  15. Ornithine and Homocitrulline Impair Mitochondrial Function, Decrease Antioxidant Defenses and Induce Cell Death in Menadione-Stressed Rat Cortical Astrocytes: Potential Mechanisms of Neurological Dysfunction in HHH Syndrome.

    Science.gov (United States)

    Zanatta, Ângela; Rodrigues, Marília Danyelle Nunes; Amaral, Alexandre Umpierrez; Souza, Débora Guerini; Quincozes-Santos, André; Wajner, Moacir

    2016-09-01

    Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome is caused by deficiency of ornithine translocase leading to predominant tissue accumulation and high urinary excretion of ornithine (Orn), homocitrulline (Hcit) and ammonia. Although affected patients commonly present neurological dysfunction manifested by cognitive deficit, spastic paraplegia, pyramidal and extrapyramidal signs, stroke-like episodes, hypotonia and ataxia, its pathogenesis is still poorly known. Although astrocytes are necessary for neuronal protection. Therefore, in the present study we investigated the effects of Orn and Hcit on cell viability (propidium iodide incorporation), mitochondrial function (thiazolyl blue tetrazolium bromide-MTT-reduction and mitochondrial membrane potential-ΔΨm), antioxidant defenses (GSH) and pro-inflammatory response (NFkB, IL-1β, IL-6 and TNF-α) in unstimulated and menadione-stressed cortical astrocytes that were previously shown to be susceptible to damage by neurotoxins. We first observed that Orn decreased MTT reduction, whereas both amino acids decreased GSH levels, without altering cell viability and the pro-inflammatory factors in unstimulated astrocytes. Furthermore, Orn and Hcit decreased cell viability and ΔΨm in menadione-treated astrocytes. The present data indicate that the major compounds accumulating in HHH syndrome impair mitochondrial function and reduce cell viability and the antioxidant defenses in cultured astrocytes especially when stressed by menadione. It is presumed that these mechanisms may be involved in the neuropathology of this disease.

  16. HIV-1 infection leads to increased HLA-E expression resulting in impaired function of natural killer cells.

    Science.gov (United States)

    Nattermann, Jacob; Nischalke, Hans Dieter; Hofmeister, Valesko; Kupfer, Bernd; Ahlenstiel, Golo; Feldmann, Georg; Rockstroh, Jiirgen; Weiss, Elisabeth H; Sauerbruch, Tilman; Spengler, Ulrich

    2005-01-01

    HIV has evolved several strategies to evade recognition by the host immune system including down-regulation of major histocompatibility complex (MHC) class I molecules. However, reduced expression of MHC class I molecules may stimulate natural killer (NK) cell lysis in cells of haematopoietic lineage. Here, we describe how HIV counteracts stimulation of NK cells by stabilizing surface expression of the non-classical MHC class I molecule, HLA-E. We demonstrate enhanced expression of HLA-E on lymphocytes from HIV-infected patients and show that in vitro infection of lymphocytes with HIV results in up-regulation of HLA-E expression and reduced susceptibility to NK cell cytotoxicity. Using HLA-E transfected K-562 cells, we identified the well-known HIV T-cell epitope p24 aa14-22a as a ligand for HLA-E that stabilizes surface expression of HLA-E, favouring inhibition of NK cell cytotoxicity. These results propose HIV-mediated up-regulation of HLA-E expression as an additional evasion strategy targeting the antiviral activities of NK cells, which may contribute to the capability of the virus in establishing chronic infection. PMID:15751767

  17. Accumulation of 3-hydroxytetradecenoic acid: Cause or corollary of glucolipotoxic impairment of pancreatic β-cell bioenergetics?

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    Nicolai M. Doliba

    2015-12-01

    Conclusions: As long chain 3-hydroxylated FA metabolites are known to uncouple heart and brain mitochondria [53–55], we propose that under glucolipotoxic condition, unsaturated hydroxylated long-chain FAs accumulate, uncouple and ultimately inhibit β-cell respiration. This leads to the slow deterioration of mitochondrial function progressing to bioenergetics β-cell failure.

  18. Cadmium affects viability of bone marrow mesenchymal stem cells through membrane impairment, intracellular calcium elevation and DNA breakage

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    Abnosi Mohammad Hussein

    2010-01-01

    Full Text Available Background: Cadmium is an important heavy metal with occupational and environmental hazard. Cadmium toxicity results mainly in bone-related complication such as itai-itai disease. Mesenchymal stem cells of the bone marrow have the ability to differentiate to osteoblasts which ensure the well-being of the bone tissue. Thus the aim was to investigate the effect of cadmium on viability of rat bone marrow mesenchymal stem cells. Materials and Methods: The rat bone marrow mesenchymal stem cells were grown to confluency in DMEM medium supplemented with 15% fetal bovine serum and penicillin-streptomycin up to third passage. Then the cells were treated with 0, 5, 15, 25, 35, and 45 of CdCl 2 at 12, 24, 36, and 48 h, and their viability was investigated using trypan blue staining. In addition, after treatment with selected dose (15 and 45 μM and time (24 and 48 h the cell morphology, DNA damage and calcium content of the cells were evaluated. Data was analyzed using one and two-way ANOVA (Tukey test and the P2+ was observed. Conclusion: Cadmium chloride is a toxic compound which might affect the well-being of bone tissue through affecting the mesenchymal stem cells.

  19. Rad51C deficiency destabilizes XRCC3, impairs recombination and radiosensitizes S/G2-phase cells

    Energy Technology Data Exchange (ETDEWEB)

    Lio, Yi-Ching; Schild, David; Brenneman, Mark A.; Redpath, J. Leslie; Chen, David J.

    2004-05-01

    The highly conserved Rad51 protein plays an essential role in repairing DNA damage through homologous recombination. In vertebrates, five Rad51 paralogs (Rad51B, Rad51C, Rad51D, XRCC2, XRCC3) are expressed in mitotically growing cells, and are thought to play mediating roles in homologous recombination, though their precise functions remain unclear. Here we report the use of RNA interference to deplete expression of Rad51C protein in human HT1080 and HeLa cells. In HT1080 cells, depletion of Rad51C by small interfering RNA caused a significant reduction of frequency in homologous recombination. The level of XRCC3 protein was also sharply reduced in Rad51C-depleted HeLa cells, suggesting that XRCC3 is dependent for its stability upon heterodimerization with Rad51C. In addition, Rad51C-depleted HeLa cells showed hypersensitivity to the DNA cross-linking agent mitomycin C, and moderately increased sensitivity to ionizing radiation. Importantly, the radiosensitivity of Rad51C-deficient HeLa cells was evident in S and G{sub 2}/M phases of the cell cycle but not in G{sub 1} phase. Together, these results provide direct cellular evidence for the importance of human Rad51C in homologous recombinational repair.

  20. Impaired APP activity and altered Tau splicing in embryonic stem cell-derived astrocytes obtained from an APPsw transgenic minipig

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    Vanessa J. Hall

    2015-10-01

    Full Text Available Animal models of familial juvenile onset of Alzheimer's disease (AD often fail to produce diverse pathological features of the disease by modification of single gene mutations that are responsible for the disease. They can hence be poor models for testing and development of novel drugs. Here, we analyze in vitro-produced stem cells and their derivatives from a large mammalian model of the disease created by overexpression of a single mutant human gene (APPsw. We produced hemizygous and homozygous radial glial-like cells following culture and differentiation of embryonic stem cells (ESCs isolated from embryos obtained from mated hemizygous minipigs. These cells were confirmed to co-express varying neural markers, including NES, GFAP and BLBP, typical of type one radial glial cells (RGs from the subgranular zone. These cells had altered expression of CCND1 and NOTCH1 and decreased expression of several ribosomal RNA genes. We found that these cells were able to differentiate into astrocytes upon directed differentiation. The astrocytes produced had decreased α- and β-secretase activity, increased γ-secretase activity and altered splicing of tau. This indicates novel aspects of early onset mechanisms related to cell renewal and function in familial AD astrocytes. These outcomes also highlight that radial glia could be a potentially useful population of cells for drug discovery, and that altered APP expression and altered tau phosphorylation can be detected in an in vitro model of the disease. Finally, it might be possible to use large mammal models to model familial AD by insertion of only a single mutation.

  1. Impaired circulating CD4+ LAP+ regulatory T cells in patients with acute coronary syndrome and its mechanistic study.

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    Zheng-Feng Zhu

    Full Text Available OBJECTIVE: CD4(+ latency-associated peptide (LAP(+ regulatory T cells (Tregs are a newly discovered T cell subset in humans and the role of these cells in patients with acute coronary syndrome (ACS has not been explored. We designed to investigate whether circulating frequency and function of CD4(+LAP(+ Tregs are defective in ACS. METHODS: One hundred eleven ACS patients (acute myocardial infarction and unstable angina and 117 control patients were enrolled in the study. The control patients consisted of chronic stable angina (CSA and chest pain syndrome (CPS. The frequencies of circulating CD4(+LAP(+ Tregs and the expression of the transmembrane protein glycoprotein-A repetitions predominant (GARP on CD4(+ T cells were determined by flow cytometry. The function of CD4(+LAP(+ Tregs was detected using thymidine uptake. Serum interleukin-10 (IL-10 and transforming growth factor-β protein (TGF-β levels were detected using ELISA and expression of GARP mRNA in peripheral blood mononuclear cells (PBMCs was measured by real time-polymerase chain reaction. RESULTS: We found ACS patients had a significantly lower frequency of circulating CD4(+LAP(+ Tregs, and the function of these cells was reduced compared to controls. The expression of GARP in CD4(+ T cells and the serum levels of TGF-β in ACS patients were lower than those of control patients. The serum levels of IL-10 were similar between the two cohorts. CONCLUSIONS: A novel regulatory T cell subset, defined as CD4(+LAP(+ T cells is defective in ACS patients.

  2. Altered Expression of Connexin-43 and Impaired Capacity of Gap Junctional Intercellular Communication in Prostate Cancer Cells

    Institute of Scientific and Technical Information of China (English)

    XING Yifei; XIAO Yajun; ZENG FuQing; ZHAO Jun; XIAO Chuanguo; XIONG Ping; FENG Wei

    2007-01-01

    Connexin-43 (Cx43) expression in prostate cancer (PCa) cells and the potency of gap junctional intercellular communication (GJIC) in the cells were investigated, with an attempt to elucidate the reason why the so-called "bystander effect" mediated by thymidine kinase (TK) suicide gene therapy on PCa cells is not of significance and to explore the role of GJIC in PCa carcinogenesis.mRNA and protein expression of Cx43 in a PCa cell line PC-3m was detected by reverse-transcription polymerase chain reaction (RT-PCR) and strapt-avidin-biotin-enzyme complex (SABC) immunohistochemical staining, and inherent GJIC of PC-3m cells was assayed by scrape-loading and dye transfer (SLDT) assay. The expression of Cx43 in human normal and malignant prostate tissues was determined by SABC immunohistochemistry as well. It was found that Cx43 mRNA and protein expression in PC-3m cells was slightly reduced as compared with positive controls and the location of Cx43 protein was aberrant in cytoplasm rather than on membrane. Assessment of paraffin sections demonstrated that the expression of Cx43 protein in PCa cells was abnormally located and markedly diminished as compared with normal prostatic epithelial ones, displaying a negative correlation to the pathological grade (χ2=4.025, P<0.05). Additionally, capacity of inherent GJIC in PC-3m cells was disrupted, which was semi-quantified as (+) or (-). It was indicated that both down-regulated expression of Cx43 mRNA and aberrant location of Cx43 protein participated in the mechanisms leading to deficient GJIC in PC-3m cells. Lack of efficient GJIC is a molecular event, which may contribute not only to limited extent of "bystander effect", but also to initiation and progression of prostatic neoplasm.

  3. Ribavirin Does Not Impair the Suppressive Activity of Foxp3+CD4+CD25+ Regulatory T Cells

    OpenAIRE

    Lee, Jeewon; CHOI, YOON SEOK; Shin, Eui-Cheol

    2013-01-01

    Ribavirin is an antiviral drug used in combination with pegylated interferon-α (IFN-α) for the treatment of hepatitis C virus (HCV) infection. Recently, ribavirin was reported to inhibit the suppressive activity of regulatory T (Treg) cells. In the present study, we re-evaluated the effect of ribavirin on Foxp3+CD4+CD25+ Treg cells from normal donors. First, we examined the expression of CTLA-4 and CD39, which are known to play a role in the suppressive function of Treg cells. We found that r...

  4. Selective Aryl Hydrocarbon Receptor Modulator 3,3'-Diindolylmethane Impairs AhR and ARNT Signaling and Protects Mouse Neuronal Cells Against Hypoxia.

    Science.gov (United States)

    Rzemieniec, J; Litwa, E; Wnuk, A; Lason, W; Krzeptowski, W; Kajta, M

    2016-10-01

    The neuroprotective potential of 3,3'-diindolylmethane (DIM), which is a selective aryl hydrocarbon receptor modulator, has recently been shown in cellular and animal models of Parkinson's disease and lipopolysaccharide-induced inflammation. However, there are no data concerning the protective capacity and mechanisms of DIM action in neuronal cells exposed to hypoxia. The aim of the present study was to investigate the neuroprotective potential of DIM against the hypoxia-induced damage in mouse hippocampal cells in primary cultures, with a particular focus on DIM interactions with the aryl hydrocarbon receptor (AhR), its nuclear translocator ARNT, and estrogen receptor β (ERβ). In the present study, 18 h of hypoxia induced apoptotic processes, in terms of the mitochondrial membrane potential, activation of caspase-3, and fragmentation of cell nuclei. These effects were accompanied by substantial lactate dehydrogenase release and neuronal cell death. The results of the present study demonstrated strong neuroprotective and anti-apoptotic actions of DIM in hippocampal cells exposed to hypoxia. In addition, DIM decreased the Ahr and Arnt mRNA expression and stimulated Erβ mRNA expression level. DIM-induced mRNA alterations were mirrored by changes in protein levels, except for ERβ, as detected by ELISA, Western blotting, and immunofluorescence labeling. We also demonstrated that DIM decreased the expression of AhR-regulated CYP1A1. Using specific siRNAs, we provided evidence that impairment of AhR and ARNT, but not ERβ plays a key role in the neuroprotective action of DIM against hypoxia-induced cell damage. This study may have implication for identifying new agents that could protect neurons against hypoxia by targeting AhR/ARNT signaling. PMID:26476840

  5. Angiotensin I-converting enzyme Gln1069Arg mutation impairs trafficking to the cell surface resulting in selective denaturation of the C-domain.

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    Sergei M Danilov

    Full Text Available BACKGROUND: Angiotensin-converting enzyme (ACE; Kininase II; CD143 hydrolyzes small peptides such as angiotensin I, bradykinin, substance P, LH-RH and several others and thus plays a key role in blood pressure regulation and vascular remodeling. Complete absence of ACE in humans leads to renal tubular dysgenesis (RTD, a severe disorder of renal tubule development characterized by persistent fetal anuria and perinatal death. METHODOLOGY/PRINCIPAL FINDINGS: Patient with RTD in Lisbon, Portugal, maintained by peritoneal dialysis since birth, was found to have a homozygous substitution of Arg for Glu at position 1069 in the C-terminal domain of ACE (Q1069R resulting in absence of plasma ACE activity; both parents and a brother who are heterozygous carriers of this mutation had exactly half-normal plasma ACE activity compared to healthy individuals. We hypothesized that the Q1069R substitution impaired ACE trafficking to the cell surface and led to accumulation of catalytically inactive ACE in the cell cytoplasm. CHO cells expressing wild-type (WT vs. Q1069R-ACE demonstrated the mutant accumulates intracellularly and also that it is significantly degraded by intracellular proteases. Q1069R-ACE retained catalytic and immunological characteristics of WT-ACE N domain whereas it had 10-20% of the nativity of the WT-ACE C domain. A combination of chemical (sodium butyrate or pharmacological (ACE inhibitor chaperones with proteasome inhibitors (MG 132 or bortezomib significantly restored trafficking of Q1069R-ACE to the cell surface and increased ACE activity in the cell culture media 4-fold. CONCLUSIONS/SIGNIFICANCE: Homozygous Q1069R substitution results in an ACE trafficking and processing defect which can be rescued, at least in cell culture, by a combination of chaperones and proteasome inhibitors. Further studies are required to determine whether similar treatment of individuals with this ACE mutation would provide therapeutic benefits such as

  6. Loss of the Drosophila cell polarity regulator Scribbled promotes epithelial tissue overgrowth and cooperation with oncogenic Ras-Raf through impaired Hippo pathway signaling

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    Grusche Felix A

    2011-09-01

    Full Text Available Abstract Background Epithelial neoplasias are associated with alterations in cell polarity and excessive cell proliferation, yet how these neoplastic properties are related to one another is still poorly understood. The study of Drosophila genes that function as neoplastic tumor suppressors by regulating both of these properties has significant potential to clarify this relationship. Results Here we show in Drosophila that loss of Scribbled (Scrib, a cell polarity regulator and neoplastic tumor suppressor, results in impaired Hippo pathway signaling in the epithelial tissues of both the eye and wing imaginal disc. scrib mutant tissue overgrowth, but not the loss of cell polarity, is dependent upon defective Hippo signaling and can be rescued by knockdown of either the TEAD/TEF family transcription factor Scalloped or the transcriptional coactivator Yorkie in the eye disc, or reducing levels of Yorkie in the wing disc. Furthermore, loss of Scrib sensitizes tissue to transformation by oncogenic Ras-Raf signaling, and Yorkie-Scalloped activity is required to promote this cooperative tumor overgrowth. The inhibition of Hippo signaling in scrib mutant eye disc clones is not dependent upon JNK activity, but can be significantly rescued by reducing aPKC kinase activity, and ectopic aPKC activity is sufficient to impair Hippo signaling in the eye disc, even when JNK signaling is blocked. In contrast, warts mutant overgrowth does not require aPKC activity. Moreover, reducing endogenous levels of aPKC or increasing Scrib or Lethal giant larvae levels does not promote increased Hippo signaling, suggesting that aPKC activity is not normally rate limiting for Hippo pathway activity. Epistasis experiments suggest that Hippo pathway inhibition in scrib mutants occurs, at least in part, downstream or in parallel to both the Expanded and Fat arms of Hippo pathway regulation. Conclusions Loss of Scrib promotes Yorkie/Scalloped-dependent epithelial tissue

  7. Lessons from Hepatocyte-Specific Cyp51 Knockout Mice: Impaired Cholesterol Synthesis Leads to Oval Cell-Driven Liver Injury

    Science.gov (United States)

    Lorbek, Gregor; Perše, Martina; Jeruc, Jera; Juvan, Peter; Gutierrez-Mariscal, Francisco M.; Lewinska, Monika; Gebhardt, Rolf; Keber, Rok; Horvat, Simon; Björkhem, Ingemar; Rozman, Damjana

    2015-03-01

    We demonstrate unequivocally that defective cholesterol synthesis is an independent determinant of liver inflammation and fibrosis. We prepared a mouse hepatocyte-specific knockout (LKO) of lanosterol 14α-demethylase (CYP51) from the part of cholesterol synthesis that is already committed to cholesterol. LKO mice developed hepatomegaly with oval cell proliferation, fibrosis and inflammation, but without steatosis. The key trigger was reduced cholesterol esters that provoked cell cycle arrest, senescence-associated secretory phenotype and ultimately the oval cell response, while elevated CYP51 substrates promoted the integrated stress response. In spite of the oval cell-driven fibrosis being histologically similar in both sexes, data indicates a female-biased down-regulation of primary metabolism pathways and a stronger immune response in males. Liver injury was ameliorated by dietary fats predominantly in females, whereas dietary cholesterol rectified fibrosis in both sexes. Our data place defective cholesterol synthesis as a focus of sex-dependent liver pathologies.

  8. Nitric oxide from inflammatory origin impairs neural stem cell proliferation by inhibiting epidermal growth factor receptor signaling

    OpenAIRE

    Bruno Pereira Carreira; Maria Inês Morte; Ana Isabel Santos; Ana Sofia Lourenço; António Francisco Ambrósio; Carvalho, Caetana M.; Araújo, Inês M.

    2014-01-01

    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 (NSCs), and explored possible mechanisms underlying this effect. We investigated which mechanisms are involved in the regulation of NSC proliferation following treatment with an...

  9. Mesenchymal phenotype predisposes lung cancer cells to impaired proliferation and redox stress in response to glutaminase inhibition.

    Directory of Open Access Journals (Sweden)

    Danielle B Ulanet

    Full Text Available Recent work has highlighted glutaminase (GLS as a key player in cancer cell metabolism, providing glutamine-derived carbon and nitrogen to pathways that support proliferation. There is significant interest in targeting GLS for cancer therapy, although the gene is not known to be mutated or amplified in tumors. As a result, identification of tractable markers that predict GLS dependence is needed for translation of GLS inhibitors to the clinic. Herein we validate a small molecule inhibitor of GLS and show that non-small cell lung cancer cells marked by low E-cadherin and high vimentin expression, hallmarks of a mesenchymal phenotype, are particularly sensitive to inhibition of the enzyme. Furthermore, lung cancer cells induced to undergo epithelial to mesenchymal transition (EMT acquire sensitivity to the GLS inhibitor. Metabolic studies suggest that the mesenchymal cells have a reduced capacity for oxidative phosphorylation and increased susceptibility to oxidative stress, rendering them unable to cope with the perturbations induced by GLS inhibition. These findings elucidate selective metabolic dependencies of mesenchymal lung cancer cells and suggest novel pathways as potential targets in this aggressive cancer type.

  10. Impaired Coenzyme A metabolism affects histone and tubulin acetylation in Drosophila and human cell models of pantothenate kinase associated neurodegeneration.

    Science.gov (United States)

    Siudeja, Katarzyna; Srinivasan, Balaji; Xu, Lanjun; Rana, Anil; de Jong, Jannie; Nollen, Ellen A A; Jackowski, Suzanne; Sanford, Lynn; Hayflick, Susan; Sibon, Ody C M

    2011-12-01

    Pantothenate kinase-associated neurodegeneration (PKAN is a neurodegenerative disease with unresolved pathophysiology. Previously, we observed reduced Coenzyme A levels in a Drosophila model for PKAN. Coenzyme A is required for acetyl-Coenzyme A synthesis and acyl groups from the latter are transferred to lysine residues of proteins, in a reaction regulated by acetyltransferases. The tight balance between acetyltransferases and their antagonistic counterparts histone deacetylases is a well-known determining factor for the acetylation status of proteins. However, the influence of Coenzyme A levels on protein acetylation is unknown. Here we investigate whether decreased levels of the central metabolite Coenzyme A induce alterations in protein acetylation and whether this correlates with specific phenotypes of PKAN models. We show that in various organisms proper Coenzyme A metabolism is required for maintenance of histone- and tubulin acetylation, and decreased acetylation of these proteins is associated with an impaired DNA damage response, decreased locomotor function and decreased survival. Decreased protein acetylation and the concurrent phenotypes are partly rescued by pantethine and HDAC inhibitors, suggesting possible directions for future PKAN therapy development. PMID:21998097

  11. Multiple low-dose infusions of human umbilical cord blood cells improve cognitive impairments and reduce amyloid-β-associated neuropathology in Alzheimer mice.

    Science.gov (United States)

    Darlington, Donna; Deng, Juan; Giunta, Brian; Hou, Huayan; Sanberg, Cyndy D; Kuzmin-Nichols, Nicole; Zhou, Hua-Dong; Mori, Takashi; Ehrhart, Jared; Sanberg, Paul R; Tan, Jun

    2013-02-01

    Alzheimer's disease (AD) is the most common progressive age-related dementia in the elderly and the fourth major cause of disability and mortality in that population. The disease is pathologically characterized by deposition of β-amyloid plaques neurofibrillary tangles in the brain. Current strategies for the treatment of AD are symptomatic only. As such, they are less than efficacious in terms of significantly slowing or halting the underlying pathophysiological progression of the disease. Modulation by cell therapy may be new promising disease-modifying therapy. Recently, we showed reduction in amyloid-β (Aβ) levels/β-amyloid plaques and associated astrocytosis following low-dose infusions of mononuclear human umbilical cord blood cells (HUCBCs). Our current study extended our previous findings by examining cognition via (1) the rotarod test, (2) a 2-day version of the radial-arm water maze test, and (3) a subsequent observation in an open pool platform test to characterize the effects of monthly peripheral HUCBC infusion (1×10(6) cells/μL) into the transgenic PSAPP mouse model of cerebral amyloidosis (bearing mutant human APP and presenilin-1 transgenes) from 6 to 12 months of age. We show that HUCBC therapy correlates with decreased (1) cognitive impairment, (2) Aβ levels/β-amyloid plaques, (3) amyloidogenic APP processing, and (4) reactive microgliosis after a treatment of 6 or 10 months. As such, this report lays the groundwork for an HUCBC therapy as potentially novel alternative to oppose AD at the disease-modifying level.

  12. In vivo inhibition of c-MYC in myeloid cells impairs tumor-associated macrophage maturation and pro-tumoral activities.

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    Oscar M Pello

    Full Text Available Although tumor-associated macrophages (TAMs are involved in tumor growth and metastasis, the mechanisms controlling their pro-tumoral activities remain largely unknown. The transcription factor c-MYC has been recently shown to regulate in vitro human macrophage polarization and be expressed in macrophages infiltrating human tumors. In this study, we exploited the predominant expression of LysM in myeloid cells to generate c-Myc(fl/fl LysM(cre/+ mice, which lack c-Myc in macrophages, to investigate the role of macrophage c-MYC expression in cancer. Under steady-state conditions, immune system parameters in c-Myc(fl/fl LysM(cre/+ mice appeared normal, including the abundance of different subsets of bone marrow hematopoietic stem cells, precursors and circulating cells, macrophage density, and immune organ structure. In a model of melanoma, however, TAMs lacking c-Myc displayed a delay in maturation and showed an attenuation of pro-tumoral functions (e.g., reduced expression of VEGF, MMP9, and HIF1α that was associated with impaired tissue remodeling and angiogenesis and limited tumor growth in c-Myc(fl/fl LysM(cre/+ mice. Macrophage c-Myc deletion also diminished fibrosarcoma growth. These data identify c-Myc as a positive regulator of the pro-tumoral program of TAMs and suggest c-Myc inactivation as an attractive target for anti-cancer therapy.

  13. Immature dendritic cells generated from cryopreserved human monocytes show impaired ability to respond to LPS and to induce allogeneic lymphocyte proliferation.

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    Guilherme Ferreira Silveira

    Full Text Available Dendritic cells play a key role in the immune system, in the sensing of foreign antigens and triggering of an adaptive immune response. Cryopreservation of human monocytes was investigated to understand its effect on differentiation into immature monocyte-derived dendritic cells (imdDCs, the response to inflammatory stimuli and the ability to induce allogeneic lymphocyte proliferation. Cryopreserved (crp-monocytes were able to differentiate into imdDCs, albeit to a lesser extent than freshly (frh-obtained monocytes. Furthermore, crp-imdDCs had lower rates of maturation and cytokine/chemokine secretion in response to LPS than frh-imdDCs. Lower expression of Toll-like receptor 4 (at 24 and 48 h and higher susceptibility to apoptosis in crp-imdDCs than in fresh cells would account for the impaired maturation and cytokine/chemokine secretion observed. A mixed leukocyte reaction showed that lymphocyte proliferation was lower with crp-imdDCs than with frh-imdDCs. These findings suggested that the source of monocytes used to generate human imdDCs could influence the accuracy of results observed in studies of the immune response to pathogens, lymphocyte activation, vaccination and antigen sensing. It is not always possible to work with freshly isolated monocytes but the possible effects of freezing/thawing on the biology and responsiveness of imdDCs should be taken into account.

  14. Inhibition of miR-21 restores RANKL/OPG ratio in multiple myeloma-derived bone marrow stromal cells and impairs the resorbing activity of mature osteoclasts.

    Science.gov (United States)

    Pitari, Maria Rita; Rossi, Marco; Amodio, Nicola; Botta, Cirino; Morelli, Eugenio; Federico, Cinzia; Gullà, Annamaria; Caracciolo, Daniele; Di Martino, Maria Teresa; Arbitrio, Mariamena; Giordano, Antonio; Tagliaferri, Pierosandro; Tassone, Pierfrancesco

    2015-09-29

    miR-21 is an oncogenic microRNA (miRNA) with an emerging role as therapeutic target in human malignancies, including multiple myeloma (MM). Here we investigated whether miR-21 is involved in MM-related bone disease (BD). We found that miR-21 expression is dramatically enhanced, while osteoprotegerin (OPG) is strongly reduced, in bone marrow stromal cells (BMSCs) adherent to MM cells. On this basis, we validated the 3'UTR of OPG mRNA as miR-21 target. Constitutive miR-21 inhibition in lentiviral-transduced BMSCs adherent to MM cells restored OPG expression and secretion. Interestingly, miR-21 inhibition reduced RANKL production by BMSCs. Overexpression of protein inhibitor of activated STAT3 (PIAS3), which is a direct and validated target of miR-21, antagonized STAT3-mediated RANKL gene activation. Finally, we demonstrate that constitutive expression of miR-21 inhibitors in BMSCs restores RANKL/OPG balance and dramatically impairs the resorbing activity of mature osteoclasts. Taken together, our data provide proof-of-concept that miR-21 overexpression within MM-microenviroment plays a crucial role in bone resorption/apposition balance, supporting the design of innovative miR-21 inhibition-based strategies for MM-related BD. PMID:26160841

  15. Cross-talk between macrophages and smooth muscle cells impairs collagen and metalloprotease synthesis and promotes angiogenesis.

    Science.gov (United States)

    Butoi, E; Gan, A M; Tucureanu, M M; Stan, D; Macarie, R D; Constantinescu, C; Calin, M; Simionescu, M; Manduteanu, I

    2016-07-01

    Coronary atherosclerosis complicated by plaque disruption and thrombosis is a critical event in myocardial infarction and stroke, the major causes of cardiovascular death. In atherogenesis, macrophages (MAC) and smooth muscle cells (SMC) are key actors; they synthesize matrix components and numerous factors involved in the process. Here, we design experiments to investigate whether SMC-MAC communication induces changes in ECM protein composition and/or neo-angiogenesis. Cell to cell communication was achieved using trans-well chambers, where SMCs were grown in the upper chamber and differentiated MAC in the bottom chamber for 24 or 72h. We found that cross-talk between MAC and SMC during co-culture: (i) significantly decreased the expression of ECM proteins (collagen I, III, elastin) in SMC; (ii) increased the expression and activity of metalloprotease MMP-9 and expression of collagenase MMP-1, in both MAC and SMC; (iii) augmented the secretion of soluble VEGF in the conditioned media of cell co-culture and VEGF gene expression in both cell types, compared with control cells. Moreover, the conditioned media collected from MAC-SMC co-culture promoted endothelial cell tube formation in Matrigel, signifying an increased angiogenic effect. In addition, the MAC-SMC communication led to an increase in inflammatory IL-1β and TLR-2, which could be responsible for cellular signaling. In conclusion, MAC-SMC communication affects factors and molecules that could alter ECM composition and neo-angiogenesis, features that could directly dictate the progression of atheroma towards the vulnerable plaque. Targeting the MAC-SMC cross-talk may represent a novel therapeutic strategy to slow-down or retard the plaque progression. PMID:27060293

  16. Cleavage of SNAP-25 and VAMP-2 impairs store-operated Ca2+ entry in mouse pancreatic acinar cells.

    Science.gov (United States)

    Rosado, Juan A; Redondo, Pedro C; Salido, Ginés M; Sage, Stewart O; Pariente, Jose A

    2005-01-01

    We recently reported that store-operated Ca(2+) entry (SOCE) in nonexcitable cells is likely to be mediated by a reversible interaction between Ca(2+) channels in the plasma membrane and the endoplasmic reticulum, a mechanism known as "secretion-like coupling." As for secretion, in this model the actin cytoskeleton plays a key regulatory role. In the present study we have explored the involvement of the secretory proteins synaptosome-associated protein (SNAP-25) and vesicle-associated membrane protein (VAMP) in SOCE in pancreatic acinar cells. Cleavage of SNAP-25 and VAMPs by treatment with botulinum toxin A (BoNT A) and tetanus toxin (TeTx), respectively, effectively inhibited amylase secretion stimulated by the physiological agonist CCK-8. BoNT A significantly reduced Ca(2+) entry induced by store depletion using thapsigargin or CCK-8. In addition, treatment with BoNT A once SOCE had been activated reduced Ca(2+) influx, indicating that SNAP-25 is needed for both the activation and maintenance of SOCE in pancreatic acinar cells. VAMP-2 and VAMP-3 are expressed in mouse pancreatic acinar cells. Both proteins associate with the cytoskeleton upon Ca(2+) store depletion, although only VAMP-2 seems to be sensitive to TeTx. Treatment of pancreatic acinar cells with TeTx reduced the activation of SOCE without affecting its maintenance. These findings support a role for SNAP-25 and VAMP-2 in the activation of SOCE in pancreatic acinar cells and show parallels between this process and secretion in a specialized secretory cell type.

  17. A novel angiogenesis inhibitor impairs lovo cell survival via targeting against human VEGFR and its signaling pathway of phosphorylation.

    Science.gov (United States)

    Zhang, Y M; Dai, B L; Zheng, L; Zhan, Y Z; Zhang, J; Smith, W W; Wang, X L; Chen, Y N; He, L C

    2012-10-11

    Colorectal cancer represents the fourth commonest malignancy, and constitutes a major cause of significant morbidity and mortality among other diseases. However, the chemical therapy is still under development. Angiogenesis plays an important role in colon cancer development. We developed HMQ18-22 (a novel analog of taspine) with the aim to target angiogenesis. We found that HMQ18-22 significantly reduced angiogenesis of chicken chorioallantoic membrane (CAM) and mouse colon tissue, and inhibited cell migration and tube formation as well. Then, we verified the interaction between HMQ18-22 and VEGFR2 by AlphaScreen P-VEGFR assay, screened the targets on angiogenesis by VEGF Phospho Antibody Array, validated the target by western blot and RNAi in lovo cells. We found HMQ18-22 could decrease phosphorylation of VEGFR2(Tyr(1214)), VEGFR1(Tyr(1333)), Akt(Tyr(326)), protein kinase Cα (PKCα) (Tyr(657)) and phospholipase-Cγ-1 (PLCγ-1) (Tyr(771)). Most importantly, HMQ18-22 inhibited proliferation of lovo cell and tumor growth in a human colon tumor xenografted model of athymic mice. Compared with normal lovo cells proliferation, the inhibition on proliferation of knockdown cells (VEGFR2, VEGFR1, Akt, PKCα and PLCγ-1) by HMQ18-22 decreased. These results suggested that HMQ18-22 is a novel angiogenesis inhibitor and can be a useful therapeutic candidate for colon cancer intervention.

  18. Tumour necrosis factor-alpha impairs neuronal differentiation but not proliferation of hippocampal neural precursor cells: Role of Hes1.

    Science.gov (United States)

    Keohane, Aoife; Ryan, Sinead; Maloney, Eimer; Sullivan, Aideen M; Nolan, Yvonne M

    2010-01-01

    Tumour necrosis factor-alpha (TNFalpha) is a pro-inflammatory cytokine, which influences neuronal survival and function yet there is limited information available on its effects on hippocampal neural precursor cells (NPCs). We show that TNFalpha treatment during proliferation had no effect on the percentage of proliferating cells prepared from embryonic rat hippocampal neurosphere cultures, nor did it affect cell fate towards either an astrocytic or neuronal lineage when cells were then allowed to differentiate. However, when cells were differentiated in the presence of TNFalpha, significantly reduced percentages of newly born and post-mitotic neurons, significantly increased percentages of astrocytes and increased expression of TNFalpha receptors, TNF-R1 and TNF-R2, as well as expression of the anti-neurogenic Hes1 gene, were observed. These data indicate that exposure of hippocampal NPCs to TNFalpha when they are undergoing differentiation but not proliferation has a detrimental effect on their neuronal lineage fate, which may be mediated through increased expression of Hes1.

  19. Modulation of H2O2-Induced Neurite Outgrowth Impairment and Apoptosis in PC12 Cells by a 1,2,4-Triazine Derivative

    Directory of Open Access Journals (Sweden)

    Solaleh Khoramian Tusi

    2012-12-01

    Full Text Available Increased oxidative stress is widely accepted to be a factor in the development and progression of Alzheimer’s disease. Triazine derivatives possess a wide range of pharmacological activities including anti-oxidative and anti-inflammatory actions. In this study, we aimed to investigate the possible protective effect of 3-thioethyl-5,6-dimethoxyphenyl-1,2,4-triazine (TEDMT on H2O2-induced neurite outgrowth impairment and apoptosis in neuron-like PC12 cells. We pretreated PC12 cells with 5, 7, and 10 µM of TEDMT followed by adding H2O2 as an oxidative stress agent. We found that TEDMT contributed to up-regulation of Bcl-2, down regulation of Bax protein and reduction of cleaved Caspase-3 and PARP proteins. Moreover, TEDMT could inhibit the phosphorylation of different mitogen activated protein kinases (extracellular signal-regulated kinase, c-Jun N-terminal kinase and P38 mitogen-activated protein kinase. TEDMT induced heat shock protein 70 while decreased heat shock protein 90 level. Besides we measured six different parameters of neurite outgrowth and complexity. We showed that H2O2 increased cell body area, average neurite width and the proportion of bipolar cells, while decreased average neurite length, the numbers of primary neurites and the ratio of the total neurite branching nodes to the total number of primary neurites. Interestingly, we found that TEDMT not only protects PC12 cell against H2O2-induced apoptosis, but also defends against the destructive effect of oxidative stress on the criteria of neural differentiation. Protective effect of this compound could represent a promising approach for treatment of neurodegenerative diseases.

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

    DEFF Research Database (Denmark)

    Coskun, Mehmet; Soendergaard, Christoffer; Joergensen, Steffen;

    2016-01-01

    , 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...... human epithelial cells. Immunohistochemical staining and quantitative reverse-transcription polymerase chain reaction analyses were used to measure the expression of CDX2 and LAMC2 in colonic biopsies from healthy controls and patients with UC. These data indicate that CDX2 directly regulates LAMC2 gene...... expression through interaction with elements in the LAMC2 promoter region. We further revealed an inverse effect of inflammation on CDX2 and LAMC2. The data presented provide a novel insight into how CDX2 is implicated in the transcriptional regulation of LAMC2 in intestinal epithelial cells, a function...

  1. Testosterone deficiency induced by progressive stages of diabetes mellitus impairs glucose metabolism and favors glycogenesis in mature rat Sertoli cells.

    Science.gov (United States)

    Rato, Luís; Alves, Marco G; Duarte, Ana I; Santos, Maria S; Moreira, Paula I; Cavaco, José E; Oliveira, Pedro F

    2015-09-01

    The incidence of type 2 diabetes mellitus and its prodromal stage, pre-diabetes, is rapidly increasing among young men, leading to disturbances in testosterone synthesis. However, the impact of testosterone deficiency induced by these progressive stages of diabetes on the metabolic behavior of Sertoli cells remains unknown. We evaluated the effects of testosterone deficiency associated with pre-diabetes and type 2 diabetes on Sertoli cells metabolism, by measuring (1) the expression and/or activities of glycolysis and glycogen metabolism-related proteins and (2) the metabolite secretion/consumption in Sertoli cells obtained from rat models of different development stages of the disease, to unveil the mechanisms by which testosterone deregulation may affect spermatogenesis. Glucose and pyruvate uptake were decreased in cells exposed to the testosterone concentration found in pre-diabetic rats (600nM), whereas the decreased testosterone concentrations found in type 2 diabetic rats (7nM) reversed this profile. Lactate production was not altered, although the expression and/or activity of lactate dehydrogenase and monocarboxylate transporter 4 were affected by progressive testosterone-deficiency. Sertoli cells exposed to type 2 diabetic conditions exhibited intracellular glycogen accumulation. These results illustrate that gradually reduced levels of testosterone, induced by progressive stages of diabetes mellitus, favor a metabolic reprogramming toward glycogen synthesis. Our data highlights a pivotal role for testosterone in the regulation of spermatogenesis metabolic support by Sertoli cells, particularly in individuals suffering from metabolic diseases. Such alterations may be in the basis of male subfertility/infertility associated with the progression of diabetes mellitus. PMID:26148570

  2. Vitamin B-6 restriction impairs fatty acid synthesis in cultured human hepatoma (HepG2) cells

    OpenAIRE

    Zhao, Mei; Ralat, Maria A.; Da Silva, Vanessa; Garrett, Timothy J; Melnyk, Stephan; James, S. Jill; Gregory, Jesse F.

    2012-01-01

    Vitamin B-6 deficiency has been reported to alter n-6 and n-3 fatty acid profiles in plasma and tissue lipids; however, the mechanisms underlying such metabolic changes remain unclear. The objective of this study was to determine the effects of vitamin B-6 restriction on fatty acid profiles and fatty acid synthesis in HepG2 cells. Cells were cultured for 6 wk in media with four different vitamin B-6 concentrations (10, 20, 50, and 2,000 nM added pyridoxal, representing deficient, marginal, ad...

  3. Age-Related Cognitive Impairments in Mice with a Conditional Ablation of the Neural Cell Adhesion Molecule

    Science.gov (United States)

    Bisaz, Reto; Boadas-Vaello, Pere; Genoux, David; Sandi, Carmen

    2013-01-01

    Most of the mechanisms involved in neural plasticity support cognition, and aging has a considerable effect on some of these processes. The neural cell adhesion molecule (NCAM) of the immunoglobulin superfamily plays a pivotal role in structural and functional plasticity and is required to modulate cognitive and emotional behaviors. However,…

  4. Albumin-bound fatty acids induce mitochondrial oxidant stress and impair antioxidant responses in proximal tubular cells

    NARCIS (Netherlands)

    Ishola, D. A.; Post, J. A.; van Timmeren, M. M.; Bakker, S. J. L.; Goldschmeding, R.; Koomans, H. A.; Braam, B.; Joles, J. A.

    2006-01-01

    Albumin induces oxidative stress and cytokine production in proximal tubular cells (PTECs). Albumin-bound fatty acids (FAs) enhance tubulopathic effects of albumin in vivo. We proposed that FA aggravation of albumin-induced oxidative stress in PTECs might be involved. We hypothesized that mitochondr

  5. Th1/Th17 plasticity is a marker of advanced β cell autoimmunity and impaired glucose tolerance in humans

    NARCIS (Netherlands)

    Reinert-Hartwall, Linnea; Honkanen, Jarno; Salo, Harri M; Nieminen, Janne K; Luopajärvi, Kristiina; Härkönen, Taina; Veijola, Riitta; Simell, Olli; Ilonen, Jorma; Peet, Aleksandr; Tillmann, Vallo; Knip, Mikael; Vaarala, Outi; Harmsen, Hermanus

    2015-01-01

    Upregulation of IL-17 immunity and detrimental effects of IL-17 on human islets have been implicated in human type 1 diabetes. In animal models, the plasticity of Th1/Th17 cells contributes to the development of autoimmune diabetes. In this study, we demonstrate that the upregulation of the IL-17 pa

  6. Viral suppressors of RNA interference impair RNA silencing induced by a Semliki Forest virus replicon in tick cells

    NARCIS (Netherlands)

    Garcia, S.; Billecocq, A.; Crance, J.M.; Prins, M.W.; Garin, D.; Bouloy, M.

    2006-01-01

    It was recently shown that infection of ISE6 tick cells by a recombinant Semliki Forest virus (SFV) expressing a heterologous gene induced small interfering RNAs (siRNAs) and silencing of the gene. To gain information on RNA interference (RNAi) in ticks, three known viral inhibitors that act in diff

  7. Purkinje cell-specific knockout of the protein phosphatase PP2B impairs potentiation and cerebellar motor learning

    NARCIS (Netherlands)

    M. Schonewille (Martijn); A. Belmeguenai; S.K.E. Koekkoek (Bas); S.H. Houtman (Simone Hendrika); H.J. Boele (Henk-Jan); B.J. van Beugen (Boeke); Z. Gao (Zhenyu); A.M. Badura (Aleksandra); G. Ohtsuki (Gen); W.E. Amerika; E. Hosy; F.E. Hoebeek (Freek); Y. Elgersma (Ype); C.R.W. Hansel (Christian); C.I. de Zeeuw (Chris)

    2010-01-01

    textabstractCerebellar motor learning is required to obtain procedural skills. Studies have provided supportive evidence for a potential role of kinase-mediated long-term depression (LTD) at the parallel fiber to Purkinje cell synapse in cerebellar learning. Recently, phosphatases have been implicat

  8. AM404 inhibits NFAT and NF-κB signaling pathways and impairs migration and invasiveness of neuroblastoma cells.

    Science.gov (United States)

    Caballero, Francisco J; Soler-Torronteras, Rafael; Lara-Chica, Maribel; García, Victor; Fiebich, Bernd L; Muñoz, Eduardo; Calzado, Marco A

    2015-01-01

    N-Arachidonoylphenolamine (AM404), a paracetamol lipid metabolite, is a modulator of the endocannabinoid system endowed with pleiotropic activities. AM404 is a dual agonist of the Transient Receptor Potential Vanilloid type 1 (TRPV1) and the Cannabinoid Receptor type 1 (CB₁) and inhibits anandamide (AEA) transport and degradation. In addition, it has been shown that AM404 also exerts biological activities through TRPV1- and CB₁ -independent pathways. In the present study we have investigated the effect of AM404 in the NFAT and NF-κB signaling pathways in SK-N-SH neuroblastoma cells. AM404 inhibited NFAT transcriptional activity through a CB₁- and TRPV1-independent mechanism. Moreover, AM404 inhibited both the expression of COX-2 at transcriptional and post-transcriptional levels and the synthesis of PGE₂. AM404 also inhibited NF-κB activation induced by PMA/Ionomycin in SK-N-SH cells by targeting IKKβ phosphorylation and activation. We found that Cot/Tlp-2 induced NFAT and COX-2 transcriptional activities were inhibited by AM404. NFAT inhibition paralleled with the ability of AM404 to inhibit MMP-1, -3 and -7 expression, cell migration and invasion in a cell-type specific dependent manner. Taken together, these data reveal that paracetamol, the precursor of AM404, can be explored not only as an antipyretic and painkiller drug but also as a co-adjuvant therapy in inflammatory and cancer diseases.

  9. p53 deletion impairs clearance of chromosomal-instable stem cells in aging telomere-dysfunctional mice

    NARCIS (Netherlands)

    Begus-Nahrmann, Y.; Lechel, A.; Obenauf, A.C.; Nalapareddy, K.; Peit, E.; Hoffmann, E.; Schlaudraff, F.; Liss, B.; Schirmacher, P.; Kestler, H.; Danenberg, E.M.; Barker, N.; Clevers, H.; Speicher, M.R.; Rudolph, K.L.

    2009-01-01

    Telomere dysfunction limits the proliferative capacity of human cells and induces organismal aging by activation of p53 and p21. Although deletion of p21 elongates the lifespan of telomere-dysfunctional mice, a direct analysis of p53 in telomere-related aging has been hampered by early tumor formati

  10. A novel coumarin-quinone derivative SV37 inhibits CDC25 phosphatases, impairs proliferation, and induces cell death.

    Science.gov (United States)

    Bana, Emilie; Sibille, Estelle; Valente, Sergio; Cerella, Claudia; Chaimbault, Patrick; Kirsch, Gilbert; Dicato, Mario; Diederich, Marc; Bagrel, Denyse

    2015-03-01

    Cell division cycle (CDC) 25 proteins are key phosphatases regulating cell cycle transition and proliferation by regulating CDK/cyclin complexes. Overexpression of these enzymes is frequently observed in cancer and is related to aggressiveness, high-grade tumors and poor prognosis. Thus, targeting CDC25 by compounds, able to inhibit their activity, appears a good therapeutic approach. Here, we describe the synthesis of a new inhibitor (SV37) whose structure is based on both coumarin and quinone moieties. An analytical in vitro approach shows that this compound efficiently inhibits all three purified human CDC25 isoforms (IC50 1-9 µM) in a mixed-type mode. Moreover, SV37 inhibits growth of breast cancer cell lines. In MDA-MB-231 cells, reactive oxygen species generation is followed by pCDK accumulation, a mark of CDC25 dysfunction. Eventually, SV37 treatment leads to activation of apoptosis and DNA cleavage, underlining the potential of this new type of coumarin-quinone structure.

  11. Osmotic stress confers enhanced cell integrity to hydrostatic pressure but impairs growth in Alcanivorax borkumensis SK2

    Directory of Open Access Journals (Sweden)

    Alberto eScoma

    2016-05-01

    Full Text Available Alcanivorax is a hydrocarbonoclastic genus dominating oil spills worldwide. While its presence has been detected in oil-polluted seawaters, marine sediment and salt marshes under ambient pressure, its presence in deep-sea contaminated environments is negligible. Recent laboratory evidences highlighted the piezosensitive nature of some Alcanivorax species, whose growth yields are highly impacted by mild hydrostatic pressures (HPs. In the present study, osmotic stress was used as a tool to increase HP resistance in the type strain A. borkumensis SK2. Control cultures grown under standard conditions of salinity and osmotic pressure with respect to seawater (35.6 ppt or 1136 mOsm kg-1, respectively were compared with cultures subjected to hypo- and hyperosmosis (330 and 1720 mOsm kg-1, or 18 and 62 ppt in salinity, equivalent to brackish and brine waters, respectively, under atmospheric or increased HP (0.1 and 10MPa. Osmotic stress had a remarkably positive impact on cell metabolic activity in terms of CO2 production (thus, oil bioremediation and O2 respiration under hyperosmosis, as acclimation to high salinity enhanced cell activity under 10MPa by a factor of 10. Both osmotic shocks significantly enhanced cell protection by reducing membrane damage under HP, with cell integrities close to 100% under hyposmosis. The latter was likely due to intracellular water-reclamation as no trace of the piezolyte ectoine was found, contrary to hyperosmosis. Notably, ectoine production was equivalent at 0.1MPa in hyperosmosis-acclimated cells and at 10MPa under isosmotic conditions, supporting the hypothesis that ectoine synthesis may be primarily triggered by HP rather than osmotic stress. While stimulating cell metabolism and enhancing cell integrity, osmotic stress had always a negative impact on culture growth and performance. No net growth was observed during 4-day incubation tests, and CO2:O2 ratios and pH values indicated that culture performance in

  12. Osmotic Stress Confers Enhanced Cell Integrity to Hydrostatic Pressure but Impairs Growth in Alcanivorax borkumensis SK2

    Science.gov (United States)

    Scoma, Alberto; Boon, Nico

    2016-01-01

    Alcanivorax is a hydrocarbonoclastic genus dominating oil spills worldwide. While its presence has been detected in oil-polluted seawaters, marine sediment and salt marshes under ambient pressure, its presence in deep-sea oil-contaminated environments is negligible. Recent laboratory studies highlighted the piezosensitive nature of some Alcanivorax species, whose growth yields are highly impacted by mild hydrostatic pressures (HPs). In the present study, osmotic stress was used as a tool to increase HP resistance in the type strain Alcanivorax borkumensis SK2. Control cultures grown under standard conditions of salinity and osmotic pressure with respect to seawater (35.6 ppt or 1136 mOsm kg-1, respectively) were compared with cultures subjected to hypo- and hyperosmosis (330 and 1720 mOsm kg-1, or 18 and 62 ppt in salinity, equivalent to brackish and brine waters, respectively), under atmospheric or increased HP (0.1 and 10 MPa). Osmotic stress had a remarkably positive impact on cell metabolic activity in terms of CO2 production (thus, oil bioremediation) and O2 respiration under hyperosmosis, as acclimation to high salinity enhanced cell activity under 10 MPa by a factor of 10. Both osmotic shocks significantly enhanced cell protection by reducing membrane damage under HP, with cell integrities close to 100% under hyposmosis. The latter was likely due to intracellular water-reclamation as no trace of the piezolyte ectoine was found, contrary to hyperosmosis. Notably, ectoine production was equivalent at 0.1 MPa in hyperosmosis-acclimated cells and at 10 MPa under isosmotic conditions. While stimulating cell metabolism and enhancing cell integrity, osmotic stress had always a negative impact on culture growth and performance. No net growth was observed during 4-days incubation tests, and CO2:O2 ratios and pH values indicated that culture performance in terms of hydrocarbon degradation was lowered by the effects of osmotic stress alone or combined with increased HP

  13. Novel avian influenza A (H7N9 virus induces impaired interferon responses in human dendritic cells.

    Directory of Open Access Journals (Sweden)

    Veera Arilahti

    Full Text Available In March 2013 a new avian influenza A(H7N9 virus emerged in China and infected humans with a case fatality rate of over 30%. Like the highly pathogenic H5N1 virus, H7N9 virus is causing severe respiratory distress syndrome in most patients. Based on genetic analysis this avian influenza A virus shows to some extent adaptation to mammalian host. In the present study, we analyzed the activation of innate immune responses by this novel H7N9 influenza A virus and compared these responses to those induced by the avian H5N1 and seasonal H3N2 viruses in human monocyte-derived dendritic cells (moDCs. We observed that in H7N9 virus-infected cells, interferon (IFN responses were weak although the virus replicated as well as the H5N1 and H3N2 viruses in moDCs. H7N9 virus-induced expression of pro-inflammatory cytokines remained at a significantly lower level as compared to H5N1 virus-induced "cytokine storm" seen in human moDCs. However, the H7N9 virus was extremely sensitive to the antiviral effects of IFN-α and IFN-β in pretreated cells. Our data indicates that different highly pathogenic avian viruses may show considerable differences in their ability to induce host antiviral responses in human primary cell models such as moDCs. The unexpected appearance of the novel H7N9 virus clearly emphasizes the importance of the global influenza surveillance system. It is, however, equally important to systematically characterize in normal human cells the replication capacity of the new viruses and their ability to induce and respond to natural antiviral substances such as IFNs.

  14. Aryl hydrocarbon receptor activation leads to impairment of estrogen-driven chicken vitellogenin promoter activity in LMH cells.

    Science.gov (United States)

    Bussmann, Ursula A; Pérez Sáez, Juan M; Bussmann, Leonardo E; Barañao, J Lino

    2013-03-01

    The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that mediates most of the toxic effects of environmental contaminants. Among the multiple pleiotropic responses elicited by AHR agonists, the antiestrogenic and endocrine-disrupting action of the receptor activation is one of the most studied. It has been demonstrated that some AHR agonists disrupt estradiol-induced vitellogenin synthesis in the fish liver via a mechanism that involves crosstalk between the AHR and the estrogen receptor (ER). Chicken hepatocytes have become a model for the study of AHR action in birds and the induction of the signal and its effect in these cells are well established. However, the impact of AHR activation on estradiol-regulated responses in the chicken liver remains to be demonstrated. The aim of the present study was, therefore, to determine the effect of AHR action on ER-driven transcription in a convenient model of chicken liver cells. For this purpose, we designed a reporter construct bearing the 5' regulatory region of the chicken vitellogenin II gene and used it to transfect chicken hepatoma LMH cells. We found that β-naphthoflavone represses ER-driven vitellogenin promoter activity and that this action is mediated by the AHR. This inhibitory crosstalk between both pathways appears to be unidirectional, since estradiol did not alter the transcript levels of an AHR target gene. Besides, and highly relevant, we show that LMH cell line transfected with a reporter construct bearing the chicken vitellogenin promoter sequence is a useful and convenient model for the study of AHR-ER interaction in chicken liver-derived cells. PMID:23103859

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

    Science.gov (United States)

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

    2016-01-01

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

  16. MiR-34a targeting of Notch ligand delta-like 1 impairs CD15+/CD133+ tumor-propagating cells and supports neural differentiation in medulloblastoma.

    Directory of Open Access Journals (Sweden)

    Pasqualino de Antonellis

    Full Text Available BACKGROUND: Through negative regulation of gene expression, microRNAs (miRNAs can function as oncosuppressors in cancers, and can themselves show altered expression in various tumor types. Here, we have investigated medulloblastoma tumors (MBs, which arise from an early impairment of developmental processes in the cerebellum, where Notch signaling is involved in many of the cell-fate-determining stages. Notch regulates a subset of MB cells that have stem-cell-like properties and can promote tumor growth. On the basis of this evidence, we hypothesized that miRNAs targeting the Notch pathway can regulate these phenomena, and can be used in anti-cancer therapies. METHODOLOGY/PRINCIPAL FINDINGS: In a screening of potential targets within Notch signaling, miR-34a was seen to be a regulator of the Notch pathway through its targeting of Notch ligand Delta-like 1 (Dll1. Down-regulation of Dll1 expression by miR-34a negatively regulates cell proliferation, and induces apoptosis and neural differentiation in MB cells. Using an inducible tetracycline on-off model of miR-34a expression, we show that in Daoy MB cells, Dll1 is the first target that is regulated in MB, as compared to the other targets analyzed here: Cyclin D1, cMyc and CDK4. MiR-34a expression negatively affects CD133(+/CD15(+ tumor-propagating cells, then we assay through reverse-phase proteomic arrays, Akt and Stat3 signaling hypo-phosphorylation. Adenoviruses carrying the precursor miR-34a induce neurogenesis of tumor spheres derived from a genetic animal model of MB (Patch1(+/- p53(-/-, thus providing further evidence that the miR-34a/Dll1 axis controls both autonomous and non autonomous signaling of Notch. In vivo, miR-34a overexpression carried by adenoviruses reduces tumor burden in cerebellum xenografts of athymic mice, thus demonstrating an anti-tumorigenic role of miR-34a in vivo. CONCLUSIONS/SIGNIFICANCE: Despite advances in our understanding of the pathogenesis of MB, one-third of

  17. Glucose restriction can extend normal cell lifespan and impair precancerous cell growth through epigenetic control of hTERT and p16 expression

    OpenAIRE

    Li, Yuanyuan; Liang LIU; Tollefsbol, Trygve O.

    2010-01-01

    Cancer cells metabolize glucose at elevated rates and have a higher sensitivity to glucose reduction. However, the precise molecular mechanisms leading to different responses to glucose restriction between normal and cancer cells are not fully understood. We analyzed normal WI-38 and immortalized WI-38/S fetal lung fibroblasts and found that glucose restriction resulted in growth inhibition and apoptosis in WI-38/S cells, whereas it induced lifespan extension in WI-38 cells. Moreover, in WI-3...

  18. Up-regulation of Ras/Raf/ERK1/2 signaling in the spinal cord impairs neural cell migration, neurogenesis, synapse formation, and dendritic spine development

    Institute of Scientific and Technical Information of China (English)

    CAO Fu-jiang; ZHANG Xu; LIU Tao; LI Xia-wen; Mazar Malik; FENG Shi-qing

    2013-01-01

    Background The Ras/Raf/ERK1/2 signaling pathway controls many cellular responses such as cell proliferation,migration,differentiation,and death.In the nervous system,emerging evidence also points to a death-promoting role for ERK1/2 in both in vitro and in vivo models of neuronal death.To further investigate how Ras/Raf/ERK1/2 up-regulation may lead to the development of spinal cord injury,we developed a cellular model of Raf/ERK up-regulation by overexpressing c-Raf in cultured spinal cord neurons (SCNs) and dorsal root ganglions (DRGs).Methods DRGs and SCNs were prepared from C57BL/6J mouse pups.DRGs or SCNs were infected with Ad-Raf-1 or Ad-Null adenovirus alone.Cell adhesion assay and cell migration assay were investigated,Dil labeling was employed to examine the effect of the up-regulation of Ras/Raf/ERK1/2 signaling on the dendritic formation of spinal neurons.We used the TO-PRO-3 staining to examine the apoptotic effect of c-Raf on DRGs or SCNs.The effect on the synapse formation of neurons was measured by using immunofluorescence.Results We found that Raf/ERK up-regulation stimulates the migration of both SCNs and DRGs,and impairs the formation of excitatory synapses in SCNs.In addition,we found that Raf/ERK up-regulation inhibits the development of mature dendritic spines in SCNs.Investigating the possible mechanisms through which Raf/ERK up-regulation affects the excitatory synapse formation and dendritic spine development,we discovered that Raf/ERK up-regulation suppresses the development and maturation of SCNs.Conclusion The up-regulation of the Raf/ERK signaling pathway may contribute to the pathogenesis of spinal cord injury through both its impairment of the SCN development and causing neural circuit imbalances.

  19. Transcriptomic Analysis of Persistent Infection with Foot-and-Mouth Disease Virus in Cattle Suggests Impairment of Apoptosis and Cell-Mediated Immunity in the Nasopharynx.

    Science.gov (United States)

    Eschbaumer, Michael; Stenfeldt, Carolina; Smoliga, George R; Pacheco, Juan M; Rodriguez, Luis L; Li, Robert W; Zhu, James; Arzt, Jonathan

    2016-01-01

    In order to investigate the mechanisms of persistent foot-and-mouth disease virus (FMDV) infection in cattle, transcriptome alterations associated with the FMDV carrier state were characterized using a bovine whole-transcriptome microarray. Eighteen cattle (8 vaccinated with a recombinant FMDV A vaccine, 10 non-vaccinated) were challenged with FMDV A24 Cruzeiro, and the gene expression profiles of nasopharyngeal tissues collected between 21 and 35 days after challenge were compared between 11 persistently infected carriers and 7 non-carriers. Carriers and non-carriers were further compared to 2 naïve animals that had been neither vaccinated nor challenged. At a controlled false-discovery rate of 10% and a minimum difference in expression of 50%, 648 genes were differentially expressed between FMDV carriers and non-carriers, and most (467) had higher expression in carriers. Among these, genes associated with cellular proliferation and the immune response-such as chemokines, cytokines and genes regulating T and B cells-were significantly overrepresented. Differential gene expression was significantly correlated between non-vaccinated and vaccinated animals (biological correlation +0.97), indicating a similar transcriptome profile across these groups. Genes related to prostaglandin E2 production and the induction of regulatory T cells were overexpressed in carriers. In contrast, tissues from non-carrier animals expressed higher levels of complement regulators and pro-apoptotic genes that could promote virus clearance. Based on these findings, we propose a working hypothesis for FMDV persistence in nasopharyngeal tissues of cattle, in which the virus may be maintained by an impairment of apoptosis and the local suppression of cell-mediated antiviral immunity by inducible regulatory T cells. PMID:27643611

  20. Modeling of autosomal-dominant retinitis pigmentosa in Caenorhabditis elegans uncovers a nexus between global impaired functioning of certain splicing factors and cell type-specific apoptosis.

    Science.gov (United States)

    Rubio-Peña, Karinna; Fontrodona, Laura; Aristizábal-Corrales, David; Torres, Silvia; Cornes, Eric; García-Rodríguez, Francisco J; Serrat, Xènia; González-Knowles, David; Foissac, Sylvain; Porta-De-La-Riva, Montserrat; Cerón, Julián

    2015-12-01

    Retinitis pigmentosa (RP) is a rare genetic disease that causes gradual blindness through retinal degeneration. Intriguingly, seven of the 24 genes identified as responsible for the autosomal-dominant form (adRP) are ubiquitous spliceosome components whose impairment causes disease only in the retina. The fact that these proteins are essential in all organisms hampers genetic, genomic, and physiological studies, but we addressed these difficulties by using RNAi in Caenorhabditis elegans. Our study of worm phenotypes produced by RNAi of splicing-related adRP (s-adRP) genes functionally distinguishes between components of U4 and U5 snRNP complexes, because knockdown of U5 proteins produces a stronger phenotype. RNA-seq analyses of worms where s-adRP genes were partially inactivated by RNAi, revealed mild intron retention in developing animals but not in adults, suggesting a positive correlation between intron retention and transcriptional activity. Interestingly, RNAi of s-adRP genes produces an increase in the expression of atl-1 (homolog of human ATR), which is normally activated in response to replicative stress and certain DNA-damaging agents. The up-regulation of atl-1 correlates with the ectopic expression of the pro-apoptotic gene egl-1 and apoptosis in hypodermal cells, which produce the cuticle, but not in other cell types. Our model in C. elegans resembles s-adRP in two aspects: The phenotype caused by global knockdown of s-adRP genes is cell type-specific and associated with high transcriptional activity. Finally, along with a reduced production of mature transcripts, we propose a model in which the retina-specific cell death in s-adRP patients can be induced through genomic instability.

  1. CD40L deficiency attenuates diet-induced adipose tissue inflammation by impairing immune cell accumulation and production of pathogenic IgG-antibodies.

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    Dennis Wolf

    Full Text Available BACKGROUND: Adipose tissue inflammation fuels the metabolic syndrome. We recently reported that CD40L--an established marker and mediator of cardiovascular disease--induces inflammatory cytokine production in adipose cells in vitro. Here, we tested the hypothesis that CD40L deficiency modulates adipose tissue inflammation in vivo. METHODOLOGY/PRINCIPAL FINDINGS: WT or CD40L(-/- mice consumed a high fat diet (HFD for 20 weeks. Inflammatory cell recruitment was impaired in mice lacking CD40L as shown by a decrease of adipose tissue macrophages, B-cells, and an increase in protective T-regulatory cells. Mechanistically, CD40L-deficient mice expressed significantly lower levels of the pro-inflammatory chemokine MCP-1 both, locally in adipose tissue and systemically in plasma. Moreover, levels of pro-inflammatory IgG-antibodies against oxidized lipids were reduced in CD40L(-/- mice. Also, circulating low-density lipoproteins and insulin levels were lower in CD40L(-/- mice. However, CD40L(-/- mice consuming HFD were not protected from the onset of diet-induced obesity (DIO, insulin resistance, and hepatic steatosis, suggesting that CD40L selectively limits the inflammatory features of diet-induced obesity rather than its metabolic phenotype. Interestingly, CD40L(-/- mice consuming a low fat diet (LFD showed both, a favorable inflammatory and metabolic phenotype characterized by diminished weight gain, improved insulin tolerance, and attenuated plasma adipokine levels. CONCLUSION: We present the novel finding that CD40L deficiency limits adipose tissue inflammation in vivo. These findings identify CD40L as a potential mediator at the interface of cardiovascular and metabolic disease.

  2. 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

    By means of i.c.v. administration of preaggregated oligomeric beta-amyloid (Abeta)25-35 peptide it was possible in rats to generate neuropathological signs related to those of early stages of Alzheimer's disease (AD). Abeta25-35-administration induced the deposition of endogenously produced amyloid...... protein. Furthermore, quantitative immunohistochemistry demonstrated time-related statistically significant increases in amyloid immunoreactivity, tau phosphorylation, microglial activation, and astrocytosis, and stereological investigations demonstrated statistically significant increased neuronal cell...... by intranasal and s.c. administration of the peptide. Furthermore, FGL-treatment was shown to inhibit the activity of GSK3beta, a kinase implicated in signaling regulating cell survival, tau phosphorylation and the processing of the amyloid precursor protein (APP). Thus, the peptide induced a statistically...

  3. Early infection with respiratory syncytial virus impairs regulatory T cell function and increases susceptibility to allergic asthma

    OpenAIRE

    Krishnamoorthy, Nandini; Khare, Anupriya; Oriss, Timothy B.; Raundhal, Mahesh; Morse, Christina; Yarlagadda, Manohar; Wenzel, Sally E.; Moore, Martin L.; Peebles, R. Stokes; Ray, Anuradha; Ray, Prabir

    2012-01-01

    Immune tolerance is instituted early in life, during which time regulatory T (Treg) cells have an important role. Recurrent infections with respiratory syncytial virus (RSV) in early life increase the risk for asthma in adult life. Repeated infection of infant mice tolerized to ovalbumin (OVA) through their mother’s milk with RSV induced allergic airway disease in response to OVA sensitization and challenge, including airway inflammation, hyper-reactivity and higher OVA-specific IgE, as compa...

  4. Storage of factor VIII variants with impaired von Willebrand factor binding in Weibel-Palade bodies in endothelial cells.

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    Maartje van den Biggelaar

    Full Text Available BACKGROUND: Point mutations resulting in reduced factor VIII (FVIII binding to von Willebrand factor (VWF are an important cause of mild/moderate hemophilia A. Treatment includes desmopressin infusion, which concomitantly increases VWF and FVIII plasma levels, apparently from storage pools containing both proteins. The source of these VWF/FVIII co-storage pools and the mechanism of granule biogenesis are not fully understood. METHODOLOGY/PRINCIPAL FINDINGS: We studied intracellular trafficking of FVIII variants implicated in mild/moderate hemophilia A together with VWF in HEK293 cells and primary endothelial cells. The role of VWF binding was addressed using FVIII variants displaying reduced VWF interaction. Binding studies using purified FVIII proteins revealed moderate (Arg2150His, Del2201, Pro2300Ser to severe (Tyr1680Phe, Ser2119Tyr VWF binding defects. Expression studies in HEK293 cells and primary endothelial cells revealed that all FVIII variants were present within VWF-containing organelles. Quantitative studies showed that the relative amount of FVIII storage was independent of various mutations. Substantial amounts of FVIII variants are co-stored in VWF-containing storage organelles, presumably by virtue of their ability to interact with VWF at low pH. CONCLUSIONS: Our data suggest that the potential of FVIII co-storage with VWF is not affected in mild/moderate hemophilia A caused by reduced FVIII/VWF interaction in the circulation. These data support the hypothesis that Weibel-Palade bodies comprise the desmopressin-releasable FVIII storage pool in vivo.

  5. Impaired Peroxisome Proliferator-activated Receptor-γ Contributes to Phenotypic Modulation of Vascular Smooth Muscle Cells during Hypertension*

    OpenAIRE

    Zhang, Lili; Xie, Peng; Wang, Jingzhou; Yang, Qingwu; Fang, Chuanqin; Zhou, Shuang; Li, Jingcheng

    2010-01-01

    The phenotypic modulation of vascular smooth muscle cells (VSMCs) plays a pivotal role in hypertension-induced vascular changes including vascular remodeling. The precise mechanisms underlying VSMC phenotypic modulation remain elusive. Here we test the role of peroxisome proliferator-activated receptor (PPAR)-γ in the VSMC phenotypic modulation during hypertension. Both spontaneously hypertensive rat (SHR) aortas and SHR-derived VSMCs exhibited reduced PPAR-γ expression and excessive VSMC phe...

  6. Impaired functions of neural stem cells by abnormal nitric oxide-mediated signaling in an in vitro model of Niemann-Pick type C disease

    Institute of Scientific and Technical Information of China (English)

    Sun-Jung Kim; Myung-Sin Lim; Soo-Kyung Kang; Yong-Soon Lee; Kyung-Sun Kang

    2008-01-01

    Nitric oxide (NO) has been implicated in the promotion of neurodegeneration.However,little is known about the relationship between NO and the self-renewal or differentiation capacity of neural stem cells (NSCs) in neurodegenerative disease.In this study,we investigated the effect of NO on self-renewal of NSCs in an animal model for Niemann-Pick type C (NPC) disease.We found that NO production was significantly increased in NSCs from NPC1-deficient mice (NPC1-/-),which showed reduced NSC self-renewal.The number of nestin-positive cells and the size of neurospheres were both significantly decreased.The expression of NO synthase (NOS) was increased in neurospheres derived from the brain of NPC1-/- mice in comparison to wild-type neurospheres.NO-mediated activation of glycogen synthase kinase-3β(GSK3β) and caspase-3 was also observed in NSCs from NPC1-/- mice.The self-renewal ability of NSCs from NPC1-/- mice was restored by an NOS inhibitor,L-NAME,which resulted in the inhibition of GSK3β and caspase-3.In addition,the differentiation ability of NSCs was partially restored and the number of Fluoro-Jade C-positive degenerating neurons was reduced.These data suggest that overproduction of NO in NPC disease impaired the self-renewal of NSCs.Control of NO production may be key for the treatment of NPC disease.

  7. The dynamin chemical inhibitor dynasore impairs cholesterol trafficking and sterol-sensitive genes transcription in human HeLa cells and macrophages.

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    Emmanuelle Girard

    Full Text Available Intracellular transport of cholesterol contributes to the regulation of cellular cholesterol homeostasis by mechanisms that are yet poorly defined. In this study, we characterized the impact of dynasore, a recently described drug that specifically inhibits the enzymatic activity of dynamin, a GTPase regulating receptor endocytosis and cholesterol trafficking. Dynasore strongly inhibited the uptake of low-density lipoprotein (LDL in HeLa cells, and to a lower extent in human macrophages. In both cell types, dynasore treatment led to the abnormal accumulation of LDL and free cholesterol (FC within the endolysosomal network. The measure of cholesterol esters (CE further showed that the delivery of regulatory cholesterol to the endoplasmic reticulum (ER was deficient. This resulted in the inhibition of the transcriptional control of the three major sterol-sensitive genes, sterol-regulatory element binding protein 2 (SREBP-2, 3-hydroxy-3-methyl-coenzymeA reductase (HMGCoAR, and low-density lipoprotein receptor (LDLR. The sequestration of cholesterol in the endolysosomal compartment impaired both the active and passive cholesterol efflux in HMDM. Our data further illustrate the importance of membrane trafficking in cholesterol homeostasis and validate dynasore as a new pharmacological tool to study the intracellular transport of cholesterol.

  8. Impairment of circulating CD4+CD25+ regulatory T cells in patients with chronic inflammatory demyelinating polyradiculoneuropathy.

    Science.gov (United States)

    Chi, Li-Jun; Wang, Hua-Bing; Wang, Wei-Zhi

    2008-03-01

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated peripheral nervous system disease. CD4+CD25+ T regulatory cells (Tregs) have been unequivocally shown to be critical in maintaining immune tolerance and preventing auto-immune diseases by suppressing self-reactive T cells. Thus, we hypothesized that the numbers and/or the function of Tregs would be deranged during the progressive or relapse phases of CIDP. The number of Tregs was determined by flow cytometry according to their characteristic CD4+CD25(high) membrane phenotype. Functional characterization of Tregs was analyzed by suppression of proliferation and secretion of cytokines by co-cultured effector CD4+CD25- T cells. FOXP3 message expression level was assessed by quantitative real-time polymerase chain reaction. The results showed significant reduction in both the number and the suppressive function of Tregs in the patients with CIDP compared with healthy controls. Also, Tregs isolated from CIDP patients expressed lower levels of FoxP3 mRNA. During the progressive or the relapsing phases of CIDP, the number of Tregs was reduced, and the suppressive function of them decreased. These findings may be helpful to our understanding of the possible role of Tregs in the pathogenesis of CIDP.

  9. IFN-gamma Impairs Release of IL-8 by IL-1beta-stimulated A549 Lung Carcinoma Cells

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    Pfeilschifter Josef

    2008-09-01

    Full Text Available Abstract Background Production of interferon (IFN-γ is key to efficient anti-tumor immunity. The present study was set out to investigate effects of IFNγ on the release of the potent pro-angiogenic mediator IL-8 by human A549 lung carcinoma cells. Methods A549 cells were cultured and stimulated with interleukin (IL-1β alone or in combination with IFNγ. IL-8 production by these cells was analyzed with enzyme linked immuno sorbent assay (ELISA. mRNA-expression was analyzed by real-time PCR and RNase protection assay (RPA, respectively. Expression of inhibitor-κ Bα, cellular IL-8, and cyclooxygenase-2 was analyzed by Western blot analysis. Results Here we demonstrate that IFNγ efficiently reduced IL-8 secretion under the influence of IL-1β. Surprisingly, real-time PCR analysis and RPA revealed that the inhibitory effect of IFNγ on IL-8 was not associated with significant changes in mRNA levels. These observations concurred with lack of a modulatory activity of IFNγ on IL-1β-induced NF-κB activation as assessed by cellular IκB levels. Moreover, analysis of intracellular IL-8 suggests that IFNγ modulated IL-8 secretion by action on the posttranslational level. In contrast to IL-8, IL-1β-induced cyclooxygenase-2 expression and release of IL-6 were not affected by IFNγ indicating that modulation of IL-1β action by this cytokine displays specificity. Conclusion Data presented herein agree with an angiostatic role of IFNγ as seen in rodent models of solid tumors and suggest that increasing T helper type 1 (Th1-like functions in lung cancer patients e.g. by local delivery of IFNγ may mediate therapeutic benefit via mechanisms that potentially include modulation of pro-angiogenic IL-8.

  10. Targeted genetic inactivation of N-acetylglucosaminyltransferase-IVa impairs insulin secretion from pancreatic beta cells and evokes type 2 diabetes.

    Science.gov (United States)

    Ohtsubo, Kazuaki

    2010-01-01

    The biological significance of protein N-glycosylation has been elucidated using a mouse model bearing a genetic mutation of N-acetylglucosaminyltransferases (GnTs), which initiate the formation of specific branch structures on the mannose core of N-glycans. These glycosylation defects evoked a variety of abnormalities and disorders in specific cell types, tissues, and the whole body, reflecting functional requirements. N-Acetylglucosaminyltransferase-IVa (GnT-IVa) initiates the GlcNAcbeta1-4 branch synthesis on the Manalpha1-3 arm of the N-glycan core thereby increasing N-glycan branch complexity. To investigate the physiological function of GnT-IVa, we engineered and characterized GnT-IVa-deficient mice. GnT-IVa-deficient mice showed a metabolic disorder subsequently diagnosed as type 2 diabetes. In this chapter, methods for characterizing GnT-IVa-deficient mice by physiological analyses to detect metabolic alterations and biochemical analyses using primary isolated pancreatic beta cells are summarized and discussed.

  11. Titanium Implant Impairment and Surrounding Muscle Cell Death Following High-Salt Diet: An In Vivo Study.

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    Mathieu Lecocq

    Full Text Available High-salt consumption has been widely described as a risk factor for cardiovascular, renal and bone functions. In the present study, the extent to which high-salt diet could influence Ti6Al4V implant surface characteristic, its adhesion to rat tibial crest, and could modify muscle cell viability of two surrounding muscles, was investigated in vivo. These parameters have also been assessed following a NMES (neuro-myoelectrostimulation program similar to that currently used in human care following arthroplasty.After a three-week diet, a harmful effect on titanium implant surface and muscle cell viability was noted. This is probably due to salt corrosive effect on metal and then release of toxic substance around biologic tissue. Moreover, if the use of NMES with high-salt diet induced muscles damages, the latter were higher when implant was added. Unexpectedly, higher implant-to-bone adhesion was found for implanted animals receiving salt supplementation.Our in vivo study highlights the potential dangerous effect of high-salt diet in arthroplasty based on titanium prosthesis. This effect appears to be more important when high-salt diet is combined with NMES.

  12. Ectopic expression of anti-HIV-1 shRNAs protects CD8{sup +} T cells modified with CD4ζ CAR from HIV-1 infection and alleviates impairment of cell proliferation

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    Kamata, Masakazu, E-mail: masa3k@ucla.edu [Division of Hematology-Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Kim, Patrick Y. [Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Ng, Hwee L. [Division of Infectious Diseases, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Ringpis, Gene-Errol E.; Kranz, Emiko; Chan, Joshua; O' Connor, Sean [Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Yang, Otto O. [Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Division of Infectious Diseases, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); UCLA AIDS Institute, Los Angeles, CA (United States); AIDS Healthcare Foundation, Los Angeles, CA (United States); Chen, Irvin S.Y. [Division of Hematology-Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); UCLA AIDS Institute, Los Angeles, CA (United States)

    2015-07-31

    Chimeric antigen receptors (CARs) are artificially engineered receptors that confer a desired specificity to immune effector T cells. As an HIV-1-specific CAR, CD4ζ CAR has been extensively tested in vitro as well as in clinical trials. T cells modified with this CAR mediated highly potent anti-HIV-1 activities in vitro and were well-tolerated in vivo, but exerted limited effects on viral load and reservoir size due to poor survival and/or functionality of the transduced cells in patients. We hypothesize that ectopic expression of CD4ζ on CD8{sup +} T cells renders them susceptible to HIV-1 infection, resulting in poor survival of those cells. To test this possibility, highly purified CD8{sup +} T cells were genetically modified with a CD4ζ-encoding lentiviral vector and infected with HIV-1. CD8{sup +} T cells were vulnerable to HIV-1 infection upon expression of CD4ζ as evidenced by elevated levels of p24{sup Gag} in cells and culture supernatants. Concurrently, the number of CD4ζ-modified CD8{sup +} T cells was reduced relative to control cells upon HIV-1 infection. To protect these cells from HIV-1 infection, we co-expressed two anti-HIV-1 shRNAs previously developed by our group together with CD4ζ. This combination vector was able to suppress HIV-1 infection without impairing HIV-1-dependent effector activities of CD4ζ. In addition, the number of CD4ζ-modified CD8{sup +} T cells maintained similar levels to that of the control even under HIV-1 infection. These results suggest that protecting CD4ζ-modified CD8{sup +} T cells from HIV-1 infection is required for prolonged HIV-1-specific immune surveillance. - Highlights: • Ectopic expression of CD4ζ CAR in CD8{sup +} T cells renders them susceptible to HIV-1 infection. • Co-expression of two anti-HIV-1 shRNAs protects CD4ζ CAR-modified CD8{sup +} T cells from HIV-1 infection. • Protecting CD4ζ CAR-modified CD8{sup +} T cells from HIV-1 infection suppresses its cytopathic effect.

  13. Ectopic expression of anti-HIV-1 shRNAs protects CD8+ T cells modified with CD4ζ CAR from HIV-1 infection and alleviates impairment of cell proliferation

    International Nuclear Information System (INIS)

    Chimeric antigen receptors (CARs) are artificially engineered receptors that confer a desired specificity to immune effector T cells. As an HIV-1-specific CAR, CD4ζ CAR has been extensively tested in vitro as well as in clinical trials. T cells modified with this CAR mediated highly potent anti-HIV-1 activities in vitro and were well-tolerated in vivo, but exerted limited effects on viral load and reservoir size due to poor survival and/or functionality of the transduced cells in patients. We hypothesize that ectopic expression of CD4ζ on CD8+ T cells renders them susceptible to HIV-1 infection, resulting in poor survival of those cells. To test this possibility, highly purified CD8+ T cells were genetically modified with a CD4ζ-encoding lentiviral vector and infected with HIV-1. CD8+ T cells were vulnerable to HIV-1 infection upon expression of CD4ζ as evidenced by elevated levels of p24Gag in cells and culture supernatants. Concurrently, the number of CD4ζ-modified CD8+ T cells was reduced relative to control cells upon HIV-1 infection. To protect these cells from HIV-1 infection, we co-expressed two anti-HIV-1 shRNAs previously developed by our group together with CD4ζ. This combination vector was able to suppress HIV-1 infection without impairing HIV-1-dependent effector activities of CD4ζ. In addition, the number of CD4ζ-modified CD8+ T cells maintained similar levels to that of the control even under HIV-1 infection. These results suggest that protecting CD4ζ-modified CD8+ T cells from HIV-1 infection is required for prolonged HIV-1-specific immune surveillance. - Highlights: • Ectopic expression of CD4ζ CAR in CD8+ T cells renders them susceptible to HIV-1 infection. • Co-expression of two anti-HIV-1 shRNAs protects CD4ζ CAR-modified CD8+ T cells from HIV-1 infection. • Protecting CD4ζ CAR-modified CD8+ T cells from HIV-1 infection suppresses its cytopathic effect

  14. T-cell populations and cytokine expression are impaired in thymus and spleen of protein malnourished BALB/c mice infected with Leishmania infantum.

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    Sergio Cuervo-Escobar

    Full Text Available Visceral leishmaniasis (VL is a parasitic infectious disease that causes significant morbidity and mortality in the tropical and subtropical regions of the world. Although infections with visceralizing Leishmania may be asymptomatic, factors such as undernutrition increase the likelihood of progressing to clinical disease. Protein malnutrition, the most deleterious cause of malnutrition in developing countries, has been considered as a primary risk factor for the development of clinical VL. However, data regarding the immunological basis of this association are scarce. With the aim to analyze the effects of protein malnutrition on Leishmania infantum infection, we used BALB/c mice subjected to control or low protein isocaloric diets. Each animal group was divided into two subgroups and one was infected with L. infantum resulting in four study groups: animals fed 14% protein diet (CP, animals fed 4% protein diet (LP, animals fed 14% protein diet and infected (CPi, and animals fed 4% protein diet and infected (LPi.The susceptibility to L. infantum infection and immune responses were assessed in terms of body and lymphoid organ weight, parasite load, lymphocyte subpopulations, and cytokine expression. LPi mice had a significant reduction of body and lymphoid organ weight and exhibited a severe decrease of lymphoid follicles in the spleen. Moreover, LPi animals showed a significant decrease in CD4+CD8+ T cells in the thymus, whereas there was an increase of CD4+ and CD8+ T cells percentages in the spleen. Notably, the cytokine mRNA levels in the thymus and spleen of protein malnourished-infected animals were altered compared to the CP mice. Protein malnutrition results in a drastic dysregulation of T cells and cytokine expression in the thymus and spleen of L. infantum-infected BALB/c mice, which may lead to defective regulation of the thymocyte population and an impaired splenic immune response, accelerating the events of a normal course of

  15. Carriers of loss-of-function mutations in EXT display impaired pancreatic beta-cell reserve due to smaller pancreas volume.

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    Sophie J Bernelot Moens

    Full Text Available Exotosin (EXT proteins are involved in the chain elongation step of heparan sulfate (HS biosynthesis, which is intricately involved in organ development. Loss of function mutations (LOF in EXT1 and EXT2 result in hereditary exostoses (HME. Interestingly, HS plays a role in pancreas development and beta-cell function, and genetic variations in EXT2 are associated with an increased risk for type 2 diabetes mellitus. We hypothesized that loss of function of EXT1 or EXT2 in subjects with hereditary multiple exostoses (HME affects pancreatic insulin secretion capacity and development. We performed an oral glucose tolerance test (OGTT followed by hyperglycemic clamps to investigate first-phase glucose-stimulated insulin secretion (GSIS in HME patients and age and gender matched non-affected relatives. Pancreas volume was assessed with magnetic resonance imaging (MRI. OGTT did not reveal significant differences in glucose disposal, but there was a markedly lower GSIS in HME subjects during hyperglycemic clamp (iAUC HME: 0.72 [0.46-1.16] vs. controls 1.53 [0.69-3.36] nmol·l-1·min-1, p<0.05. Maximal insulin response following arginine challenge was also significantly attenuated (iAUC HME: 7.14 [4.22-10.5] vs. controls 10.2 [7.91-12.70] nmol·l-1·min-1 p<0.05, indicative of an impaired beta-cell reserve. MRI revealed a significantly smaller pancreatic volume in HME subjects (HME: 72.0±15.8 vs. controls 96.5±26.0 cm3 p = 0.04. In conclusion, loss of function of EXT proteins may affect beta-cell mass and insulin secretion capacity in humans, and render subjects at a higher risk of developing type 2 diabetes when exposed to environmental risk factors.

  16. Knockdown of dystrophin Dp71 impairs PC12 cells cycle: localization in the spindle and cytokinesis structures implies a role for Dp71 in cell division.

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    Marcela Villarreal-Silva

    Full Text Available The function of dystrophin Dp71 in neuronal cells remains to be established. Previously, we revealed the involvement of this protein in both nerve growth factor (NGF-induced neuronal differentiation and cell adhesion by isolation and characterization of PC12 neuronal cells with depleted levels of Dp71. In this work, a novel phenotype of Dp71-knockdown cells was characterized, which is their delayed growth rate. Cell cycle analyses revealed an altered behavior of Dp71-depleted cells, which consists of a delay in G0/G1 transition and an increase in apoptosis during nocodazole-induced mitotic arrest. Dp71 associates with lamin B1 and β-dystroglycan, proteins involved in aspects of the cell division cycle; therefore, we compared the distribution of Dp71 with that of lamin B1 and β-dystroglycan in PC12 cells at mitosis and cytokinesis by means of immunofluorescence and confocal microscopy analysis. All of these three proteins exhibited a similar immunostaining pattern, localized at mitotic spindle, cleavage furrow, and midbody. It is noteworthy that a drastic decreased staining in mitotic spindle, cleavage furrow, and midbody was observed for both lamin B1 and β-dystroglycan in Dp71-depleted cells. Furthermore, we demonstrated the interaction of Dp71 with lamin B1 in PC12 cells by immunoprecipitation and pull-down assays, and importantly, we revealed that knockdown of Dp71 expression caused a marked reduction in lamin B1 levels and altered localization of the nuclear envelope protein emerin. Our data indicate that Dp71 is a component of the mitotic spindle and cytokinesis multi-protein apparatuses that might modulate the cell division cycle by affecting lamin B1 and β-dystroglycan levels.

  17. Antioxidant activity of inulin and its role in the prevention of human colonic muscle cell impairment induced by lipopolysaccharide mucosal exposure.

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    Valentina Pasqualetti

    Full Text Available BACKGROUND: Fructans, such as inulin, are dietary fibers which stimulate gastro-intestinal (GI function acting as prebiotics. Lipopolysaccharide (LPS impairs GI motility, through production of reactive oxygen species. The antioxidant activity of various fructans was tested and the protective effect of inulin on colonic smooth muscle cell (SMC impairment, induced by exposure of human mucosa to LPS, was assessed in an ex vivo experimental model. METHODS: The antioxidant capacity of fructans was measured in an in vitro system that simulates cooking and digestion processes. Human colonic mucosa and submucosa, obtained from disease-free margins of resected segments for cancer, were sealed between two chambers, with the mucosal side facing upwards with Krebs solution with or without purified LPS from a pathogenic strain of Escherichia coli (O111:B4 and inulin (Frutafit IQ, and the submucosal side facing downwards into Krebs solution. The solutions on the submucosal side were collected following mucosal exposure to Krebs in the absence (N-undernatant or presence of LPS (LPS-undernatant or LPS+inulin (LPS+INU-undernatant. Undernatants were tested for their antioxidant activity and the effects on SMCs contractility. Inulin protective effects on mucosa and submucosa layers were assessed measuring the protein oxidation level in the experimental conditions analyzed. RESULTS: Antioxidant activity of inulin, which was significantly higher compared to simple sugars, remained unaltered despite cooking and digestion processes. Inulin protected the mucosal and submucosal layers against protein oxidation. Following exposure to LPS-undernatant, a significant decrease in maximal acetylcholine (Ach-induced contraction was observed when compared to the contraction induced in cells incubated with the N-undernatant (4±1% vs 25±5% respectively, P<0.005 and this effect was completely prevented by pre-incubation of LPS with Inulin (35±5%. CONCLUSIONS: Inulin protects

  18. T-cell dysfunction in HIV-1-infected patients with impaired recovery of CD4 cells despite suppression of viral replication

    DEFF Research Database (Denmark)

    Erikstrup, Christian; Kronborg, Gitte; Lohse, Nicolai;

    2010-01-01

    INTRODUCTION: CD4 T-cell recovery is impeded in some HIVinfected patients despite successful combination antiretroviral therapy (cART) with suppressed HIV RNA. We hypothesized that T-cell dysfunction would be increased in these patients. METHODS: In the Danish HIV Cohort Study, we identified HIV-...

  19. Impaired virus control and severe CD8+ T-cell-mediated immunopathology in chimeric mice deficient in gamma interferon receptor expression on both parenchymal and hematopoietic cells

    DEFF Research Database (Denmark)

    Henrichsen, Pernille; Bartholdy, Christina; Christensen, Jan Pravsgaard;

    2005-01-01

    Bone marrow chimeras were used to determine the cellular target(s) for the antiviral activity of gamma interferon (IFN-gamma). By transfusing such mice with high numbers of naive virus-specific CD8(+) T cells, a system was created in which the majority of virus-specific CD8(+) T cells would be...

  20. Vitamin E reverses impaired linker for activation of T cells activation in T cells from aged C57BL/6 mice

    Science.gov (United States)

    Supplemental vitamin E restores age-related defects in IL-2 production, T cell proliferation, and immune synapse formation. Here, we evaluated the effect of vitamin E on TCR-proximal signaling events. In aged murine CD4+ T cells stimulated via CD3 and CD28, tyrosine 191 of the adaptor protein LAT wa...

  1. TNF Regulates Essential Alternative Complement Pathway Components and Impairs Activation of Protein C in Human Glomerular Endothelial Cells.

    Science.gov (United States)

    Sartain, Sarah E; Turner, Nancy A; Moake, Joel L

    2016-01-15

    Atypical hemolytic uremic syndrome (aHUS) is a thrombotic microangiopathy with severe renal injury secondary to an overactive alternative complement pathway (AP). aHUS episodes are often initiated or recur during inflammation. We investigated gene expression of the surface complement regulatory proteins (CD55, CD59, CD46, and CD141 [thrombomodulin]) and AP components in human glomerular microvascular endothelial cells (GMVECs) and in HUVECs, a frequently used investigational model of endothelial cells. Surface complement regulatory proteins were also quantified by flow cytometry. All experiments were done with and without exposure to IL-1β or TNF. Without cytokine stimulation, we found that GMVECs had greater AP activation than did HUVECs. With TNF stimulation, THBD gene expression and corresponding CD141 surface presence in HUVECs and GMVECs were reduced, and gene expression of complement components C3 (C3) and factor B (CFB) was increased. Consequently, AP activation, measured by Ba production, was increased, and conversion of protein C (PC) to activated PC by CD141-bound thrombin was decreased, in GMVECs and HUVECs exposed to TNF. IL-1β had similar, albeit lesser, effects on HUVEC gene expression, and it only slightly affected GMVEC gene expression. To our knowledge, this is the first detailed study of the expression/display of AP components and surface regulatory proteins in GMVECs with and without cytokine stimulation. In aHUS patients with an underlying overactive AP, additional stimulation of the AP and inhibition of activated PC-mediated anticoagulation in GMVECs by the inflammatory cytokine TNF are likely to provoke episodes of renal failure. PMID:26673143

  2. Numerical impairment of nestin(+) bone marrow niches in acute GvHD after allogeneic hematopoietic stem cell transplantation for AML.

    Science.gov (United States)

    Medinger, M; Krenger, W; Jakab, A; Halter, J; Buser, A; Bucher, C; Passweg, J; Tzankov, A

    2015-11-01

    The nestin(+) perivascular bone marrow (BM) stem cell niche (N(+)SCN) may be involved in GvHD. To investigate whether acute GvHD (aGvHD) reduces the number of N(+)SCN, we examined patients with AML who had undergone allogeneic hematopoietic stem cell transplantation. In the test cohort (n=8), the number of N(+)SCN per mm(2) in BM biopsies was significantly reduced in aGvHD patients at the time of aGvHD compared with patients who did not have aGvHD (1.2±0.78 versus 2.6±0.93, P=0.04). In the validation cohort (n=40), the number of N(+)SCN was reduced (1.9±0.99 versus 2.6±0.90 N(+)SCN/mm(2), P=0.05) in aGvHD patients. Receiver operating curves suggested that the cutoff score that best discriminated between patients with and without aGvHD was 2.29 N(+)SCN/mm(2). Applying this cutoff score, 9/11 patients with clinically relevant aGvHD (⩾grade 2) and 13/20 with any type of GvHD had decreased N(+)SCN numbers compared with only 10/29 patients without clinically relevant aGvHD (P=0.007) and 6/20 patients without any type of GvHD (P=0.028). In patients tracked over time, N(+)SCN density returned to normal after aGvHD resolved or remained stable in patients who did not have aGvHD. Our results show a decrease in the number of N(+)SCN in aGvHD.

  3. Target disruption of ribosomal protein pNO40 accelerates aging and impairs osteogenic differentiation of mesenchymal stem cells.

    Science.gov (United States)

    Lin, Yen-Ming; Wu, Chih-Ching; Chang, Yu-Chen; Wu, Chu-Han; Ho, Hsien Li; Hu, Ji Wei; Chang, Ren-Chi; Wang, Chung-Ta; Ouyang, Pin

    2016-01-22

    pNO40/PS1D, a novel nucleolar protein, has been characterized as a core protein of eukaryotic 60S ribosome and at least two splicing forms of pNO40 mRNAs with alternative starting sites have been identified. Through production of knockout (ko) mice with either exon 2 (△E2), exon 4 (△E4) or △E2+E4 targeted disruption we identified a cryptic splicing product occurring in the ko tissues examined which in general cannot be observed in regular RT-PCR detection of wild-type (wt) animals. Among ko animals, △E4 null embryos exhibited prominent senescence-associated β-galactosidase (SA-β-gal) staining, a marker for senescent cells, in notochord, forelimbs and heart while bone marrow-derived mesenchymal stem cells (MSCs) from △E4 null mice developed accelerated aging and osteogenic differentiation defects compared to those from wt and other isoform mutant mice. Examination of the causal relationship between pNO40 deficiency and MSC-accelerated aging revealed △E4 null disruption in MSCs elicits high levels of ROS and elevated expression levels of p16 and Rb but not p53. Further analysis with iTraq identified CYP1B1, a component of the cytochrome p450 system, as a potential molecule mediating ROS generation in pNO40 deficient MSCs. We herein established a mouse model of MSC aging through pNO40-targeted depletion and demonstrated the effects of loss of pNO40 on bone homeostasis.

  4. Impaired NK cells' activity and increased numbers of CD4 + CD25+ regulatory T cells in multidrug-resistant Mycobacterium tuberculosis patients.

    Science.gov (United States)

    Fan, Renhua; Xiang, Yangen; Yang, Li; Liu, Yanke; Chen, Pingsheng; Wang, Lei; Feng, Wenjun; Yin, Ke; Fu, Manjiao; Xu, Yixin; Wu, Jialin

    2016-05-01

    Multidrug-resistant tuberculosis (MDR-TB) often causes persistent infection and chemotherapy failure, which brings heavy burden of society and family. Many immune cell subsets and regulatory mechanisms may operate throughout the various stages of infection. The presence of regulatory T cells (Tregs) is thought to be an important mechanism that TB successfully evades the immune system. Tregs play a central role in the prevention of autoimmunity and in the control of immune responses. The role of Tregs in MDR-TB infection and persistence is inadequately documented. The current study was designed to determine whether CD4 + CD25+ regulatory T cells may modulate innate immunity (such as NK cells) against human tuberculosis. Our results indicated that the numbers of CD4 + CD25+ Treg cells increased in MDR-TB patients' blood, and the cytokine production of IL-10 increased from MDR-patients compared with healthy subjects, along with the lower activity and low CD69 expression of NK cells in patients. These results suggested that immunity to MDR-TB patients induced circulating CD4 + CD25+ T regulatory cells expansion, which may be related to the persistence of Mycobacterium tuberculosis (M. tb) infection, and to the balance between effectors immune responses and suppression immune responses. PMID:27156613

  5. Defining the optimal window for cranial transplantation of human induced pluripotent stem cell-derived cells to ameliorate radiation-induced cognitive impairment.

    Science.gov (United States)

    Acharya, Munjal M; Martirosian, Vahan; Christie, Lori-Ann; Riparip, Lara; Strnadel, Jan; Parihar, Vipan K; Limoli, Charles L

    2015-01-01

    Past preclinical studies have demonstrated the capability of using human stem cell transplantation in the irradiated brain to ameliorate radiation-induced cognitive dysfunction. Intrahippocampal transplantation of human embryonic stem cells and human neural stem cells (hNSCs) was found to functionally restore cognition in rats 1 and 4 months after cranial irradiation. To optimize the potential therapeutic benefits of human stem cell transplantation, we have further defined optimal transplantation windows for maximizing cognitive benefits after irradiation and used induced pluripotent stem cell-derived hNSCs (iPSC-hNSCs) that may eventually help minimize graft rejection in the host brain. For these studies, animals given an acute head-only dose of 10 Gy were grafted with iPSC-hNSCs at 2 days, 2 weeks, or 4 weeks following irradiation. Animals receiving stem cell grafts showed improved hippocampal spatial memory and contextual fear-conditioning performance compared with irradiated sham-surgery controls when analyzed 1 month after transplantation surgery. Importantly, superior performance was evident when stem cell grafting was delayed by 4 weeks following irradiation compared with animals grafted at earlier times. Analysis of the 4-week cohort showed that the surviving grafted cells migrated throughout the CA1 and CA3 subfields of the host hippocampus and differentiated into neuronal (∼39%) and astroglial (∼14%) subtypes. Furthermore, radiation-induced inflammation was significantly attenuated across multiple hippocampal subfields in animals receiving iPSC-hNSCs at 4 weeks after irradiation. These studies expand our prior findings to demonstrate that protracted stem cell grafting provides improved cognitive benefits following irradiation that are associated with reduced neuroinflammation.

  6. Impaired reelin processing and secretion by Cajal-Retzius cells contributes to granule cell dispersion in a mouse model of temporal lobe epilepsy.

    Science.gov (United States)

    Duveau, Venceslas; Madhusudan, Amrita; Caleo, Matteo; Knuesel, Irene; Fritschy, Jean-Marc

    2011-09-01

    Cajal-Retzius cells play a crucial role during ontogeny in regulating cortical lamination via release of reelin. In adult brain, they comprise small calretinin-positive interneurons located in the marginal zone of the cerebral cortex and in the hippocampal fissure. Alterations of reelin signaling or expression have been involved in major neurological disorders, and they underlie granule cell dispersion (GCD) in mesial temporal lobe epilepsy (TLE). Here, we investigated in a mouse model of TLE the contribution of Cajal-Retzius cells to reelin production in epileptic hippocampus and the molecular mechanisms underlying GCD. Following unilateral intrahippocampal Kainic acid injection in adult mice to induce an epileptic focus, we observed that Cajal-Retzius cells gradually became strongly immunopositive for reelin, due to intracellular accumulation. This phenotype resembled the morphology of Cajal-Retzius cells in reeler Orleans (reln (orl/orl) ) mice, which express a secretion-deficient 310-kDa reelin fragment. The possibility that GCD might result from abnormal reelin processing in Cajal-Retzius cells, leading to a lack of reelin secretion, was confirmed by KA injection in reln (orl/+) mice, which induced severe GCD. Furthermore, Western blot analysis in KA-treated wildtype mice revealed increased production of ∼300-kDa reelin fragments, confirming abnormal proteolytic processing. This effect was not seen upon treatment with Botulinum neurotoxin E (BoNT/E), which prevents GCD in KA-lesioned hippocampus by chronic blockade of synaptic transmission. Furthermore, BoNT/E blocked upregulation of TrkB in Cajal-Retzius cells, suggesting that production of truncated reelin in KA-treated hippocampus is activity-dependent and regulated by BDNF. Altogether, these data reveal that GCD results from abnormal reelin processing in Cajal-Retzius cells under the control of BDNF. Our findings highlight the critical role played by Cajal-Retzius cells for hippocampal neuronal

  7. Reduced expression of DNA repair and redox signaling protein APE1/Ref-1 impairs human pancreatic cancer cell survival, proliferation, and cell cycle progression.

    Science.gov (United States)

    Jiang, Yanlin; Zhou, Shaoyu; Sandusky, George E; Kelley, Mark R; Fishel, Melissa L

    2010-11-01

    Pancreatic cancer is a deadly disease that is virtually never cured. Understanding the chemoresistance intrinsic to this cancer will aid in developing new regimens. High expression of APE1/Ref-1, a DNA repair and redox signaling protein, is associated with resistance, poor outcome, and angiogenesis; little is known in pancreatic cancer. Immunostaining of adenocarcinoma shows greater APE1/Ref-1 expression than in normal pancreas tissue. A decrease in APE1/Ref-1 protein levels results in pancreatic cancer cell growth inhibition, increased apoptosis, and altered cell cycle progression. Endogenous cell cycle inhibitors increase when APE1/ Ref-1 is reduced, demonstrating its importance to proliferation and growth of pancreatic cancer.

  8. Short communication: Altered expression of specificity protein 1 impairs milk fat synthesis in goat mammary epithelial cells.

    Science.gov (United States)

    Zhu, J J; Luo, J; Xu, H F; Wang, H; Loor, J J

    2016-06-01

    Specificity protein 1 (encoded by SP1) is a novel transcription factor important for the regulation of lipid metabolism and the normal function of various hormones in model organisms. Its potential role, if any, on ruminant milk fat is unknown. Despite the lower expression of the lipolysis-related gene ATGL (by 44 and 37% respectively), both the adenoviral overexpression and the silencing of SP1 [via short interfering (si)RNA] markedly reduced cellular triacylglycerol (TAG) content (by 28 and 25%, respectively), at least in part by decreasing the expression of DGAT1 (-36% in adenovirus treatment) and DGAT2 (-81 and -87%, respectively) that are involved in TAG synthesis. Consistent with the markedly lower expression of genes related to lipid droplet formation and secretion (TIP47 by 19 and 32%, and ADFP by 25 and 25%, respectively), cellular lipid droplet content was also decreased sharply, by 9 and 8.5%, respectively, after adenoviral overexpression of SP1 or its silencing via siRNA. Overall, the results underscored a potentially important role of SP1 in maintaining milk-fat droplet synthesis in goat mammary epithelial cells.

  9. Dim light at night interferes with the development of the short-day phenotype and impairs cell-mediated immunity in Siberian hamsters (Phodopus sungorus).

    Science.gov (United States)

    Aubrecht, Taryn G; Weil, Zachary M; Nelson, Randy J

    2014-10-01

    Winter is a challenging time to survive and breed outside of the tropics. Animals use day length (photoperiod) to regulate seasonally appropriate adaptations in anticipation of challenging winter conditions. The net result of these photoperiod-mediated adjustments is enhanced immune function and increased survival. Thus, the ability to discriminate day length information is critical for survival and reproduction in small animals. However, during the past century, urban and suburban development has rapidly expanded and filled the night sky with light from various sources, obscuring crucial light-dark signals, which alters physiological interpretation of day lengths. Furthermore, reduced space, increased proximity to people, and the presence of light at night may act as stressors for small animals. Whereas acute stressors typically enhance immune responses, chronic exposure to stressors often impairs immune responses. Therefore, we hypothesized that the combination of dim light at night and chronic stress interferes with enhanced cell-mediated immunity observed during short days. Siberian hamsters (Phodopus sungorus) were assigned to short or long days with dark nights (0 lux) or dim (5 lux) light at night for 10 weeks. Following 2 weeks of chronic restraint (6 hr/day), a model of chronic stress, delayed type hypersensitivity (DTH) responses were assessed. Both dim light at night and restraint reduced the DTH response. Dim light at night during long nights produced an intermediate short day phenotype. These results suggest the constant presence of light at night could negatively affect survival of photoperiodic rodents by disrupting the timing of breeding and immune responses.

  10. Loss of C9ORF72 impairs autophagy and synergizes with polyQ Ataxin-2 to induce motor neuron dysfunction and cell death.

    Science.gov (United States)

    Sellier, Chantal; Campanari, Maria-Letizia; Julie Corbier, Camille; Gaucherot, Angeline; Kolb-Cheynel, Isabelle; Oulad-Abdelghani, Mustapha; Ruffenach, Frank; Page, Adeline; Ciura, Sorana; Kabashi, Edor; Charlet-Berguerand, Nicolas

    2016-06-15

    An intronic expansion of GGGGCC repeats within the C9ORF72 gene is the most common genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia (ALS-FTD). Ataxin-2 with intermediate length of polyglutamine expansions (Ataxin-2 Q30x) is a genetic modifier of the disease. Here, we found that C9ORF72 forms a complex with the WDR41 and SMCR8 proteins to act as a GDP/GTP exchange factor for RAB8a and RAB39b and to thereby control autophagic flux. Depletion of C9orf72 in neurons partly impairs autophagy and leads to accumulation of aggregates of TDP-43 and P62 proteins, which are histopathological hallmarks of ALS-FTD SMCR8 is phosphorylated by TBK1 and depletion of TBK1 can be rescued by phosphomimetic mutants of SMCR8 or by constitutively active RAB39b, suggesting that TBK1, SMCR8, C9ORF72, and RAB39b belong to a common pathway regulating autophagy. While depletion of C9ORF72 only has a partial deleterious effect on neuron survival, it synergizes with Ataxin-2 Q30x toxicity to induce motor neuron dysfunction and neuronal cell death. These results indicate that partial loss of function of C9ORF72 is not deleterious by itself but synergizes with Ataxin-2 toxicity, suggesting a double-hit pathological mechanism in ALS-FTD. PMID:27103069

  11. Diminishing impairments in glucose uptake, mitochondrial content, and ADP-stimulated oxygen flux by mesenchymal stem cell therapy in the infarcted heart.

    Science.gov (United States)

    Hughey, Curtis C; James, Freyja D; Ma, Lianli; Bracy, Deanna P; Wang, Zhizhang; Wasserman, David H; Rottman, Jeffrey N; Shearer, Jane

    2014-01-01

    A constant provision of ATP is of necessity for cardiac contraction. As the heart progresses toward failure following a myocardial infarction (MI), it undergoes metabolic alterations that have the potential to compromise the ability to meet energetic demands. This study evaluated the efficacy of mesenchymal stem cell (MSC) transplantation into the infarcted heart to minimize impairments in the metabolic processes that contribute to energy provision. Seven and twenty-eight days following the MI and MSC transplantation, MSC administration minimized cardiac systolic dysfunction. Hyperinsulinemic-euglycemic clamps, coupled with 2-[(14)C]deoxyglucose administration, were employed to assess systemic insulin sensitivity and tissue-specific, insulin-mediated glucose uptake 36 days following the MI in the conscious, unrestrained, C57BL/6 mouse. The improved systolic performance in MSC-treated mice was associated with a preservation of in vivo insulin-stimulated cardiac glucose uptake. Conserved glucose uptake in the heart was linked to the ability of the MSC treatment to diminish the decline in insulin signaling as assessed by Akt phosphorylation. The MSC treatment also sustained mitochondrial content, ADP-stimulated oxygen flux, and mitochondrial oxidative phosphorylation efficiency in the heart. Maintenance of mitochondrial function and density was accompanied by preserved peroxisome proliferator-activated receptor-γ coactivator-1α, a master regulator of mitochondrial biogenesis. These studies provide insight into mechanisms of action that lead to an enhanced energetic state in the infarcted heart following MSC transplantation that may assist in energy provision and dampen cardiac dysfunction. PMID:24196528

  12. Human embryonic and fetal mesenchymal stem cells differentiate toward three different cardiac lineages in contrast to their adult counterparts.

    Science.gov (United States)

    Ramkisoensing, Arti A; Pijnappels, Daniël A; Askar, Saïd F A; Passier, Robert; Swildens, Jim; Goumans, Marie José; Schutte, Cindy I; de Vries, Antoine A F; Scherjon, Sicco; Mummery, Christine L; Schalij, Martin J; Atsma, Douwe E

    2011-01-01

    Mesenchymal stem cells (MSCs) show unexplained differences in differentiation potential. In this study, differentiation of human (h) MSCs derived from embryonic, fetal and adult sources toward cardiomyocytes, endothelial and smooth muscle cells was investigated. Labeled hMSCs derived from embryonic stem cells (hESC-MSCs), fetal umbilical cord, bone marrow, amniotic membrane and adult bone marrow and adipose tissue were co-cultured with neonatal rat cardiomyocytes (nrCMCs) or cardiac fibroblasts (nrCFBs) for 10 days, and also cultured under angiogenic conditions. Cardiomyogenesis was assessed by human-specific immunocytological analysis, whole-cell current-clamp recordings, human-specific qRT-PCR and optical mapping. After co-culture with nrCMCs, significantly more hESC-MSCs than fetal hMSCs stained positive for α-actinin, whereas adult hMSCs stained negative. Furthermore, functional cardiomyogenic differentiation, based on action potential recordings, was shown to occur, but not in adult hMSCs. Of all sources, hESC-MSCs expressed most cardiac-specific genes. hESC-MSCs and fetal hMSCs contained significantly higher basal levels of connexin43 than adult hMSCs and co-culture with nrCMCs increased expression. After co-culture with nrCFBs, hESC-MSCs and fetal hMSCs did not express α-actinin and connexin43 expression was decreased. Conduction velocity (CV) in co-cultures of nrCMCs and hESC-MSCs was significantly higher than in co-cultures with fetal or adult hMSCs. In angiogenesis bioassays, only hESC-MSCs and fetal hMSCs were able to form capillary-like structures, which stained for smooth muscle and endothelial cell markers.Human embryonic and fetal MSCs differentiate toward three different cardiac lineages, in contrast to adult MSCs. Cardiomyogenesis is determined by stimuli from the cellular microenvironment, where connexin43 may play an important role.

  13. Transcription of the Tollip gene is elevated in intestinal epithelial cells through impaired O-GlcNAcylation-dependent nuclear translocation of the negative regulator Elf-1

    Energy Technology Data Exchange (ETDEWEB)

    Sugi, Yutaka [College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa-shi, Kanagawa 252-0880 (Japan); Takahashi, Kyoko, E-mail: ktaka@brs.nihon-u.ac.jp [College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa-shi, Kanagawa 252-0880 (Japan); Nakano, Kou; Hosono, Akira; Kaminogawa, Shuichi [College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa-shi, Kanagawa 252-0880 (Japan)

    2011-09-09

    Highlights: {yields} Transcriptional activation of the Tollitip gene is higher in IECs than in monocytes. {yields} Nt -194/-186 region acts as a cis-element and is recognized by Elf-1. {yields} Elf-1 suppresses Tollip gene transcription in monocytes but not in IECs. {yields} O-GlcNAc modification is necessary for nuclear translocation of Elf-1. {yields} O-GlcNAcylation-dependent nuclear translocation of Elf-1 is impaired in IECs. -- Abstract: Intestinal epithelial cells (IECs) must be tolerant of the large number of commensal bacteria inhabiting the intestinal tract to avoid excessive inflammatory reactions. Toll-interacting protein (Tollip), a negative regulator of Toll-like receptor signaling, is known to be expressed at high levels in IECs, and to thereby contribute to the hyporesponsiveness of IECs to commensals. In this study, we analyzed the underlying mechanisms for elevated transcription of the Tollip gene in IECs using a human IEC line, Caco-2, and a human monocyte line, THP-1, as a control. Elf-1 was identified as a transcription factor that negatively regulates Tollip gene expression. The transcription factor Elf-1 was localized in the nucleus by O-linked N-acetylglucosamine (O-GlcNAc) modification, whereas the unmodified form was detected only in the cytoplasm. Comparison of Caco-2 and THP-1 cells revealed that O-GlcNAc modification of Elf-1 was significantly lower in IECs than in monocytes. Collectively, the results indicate that insufficient O-GlcNAc modification prevents Elf-1-mediated transcriptional repression and thereby upregulates Tollip gene expression in IECs.

  14. Loss of apical monocilia on collecting duct principal cells impairs ATP secretion across the apical cell surface and ATP-dependent and flow-induced calcium signals.

    Science.gov (United States)

    Hovater, Michael B; Olteanu, Dragos; Hanson, Elizabeth L; Cheng, Nai-Lin; Siroky, Brian; Fintha, Attila; Komlosi, Peter; Liu, Wen; Satlin, Lisa M; Bell, P Darwin; Yoder, Bradley K; Schwiebert, Erik M

    2008-06-01

    Renal epithelial cells release ATP constitutively under basal conditions and release higher quantities of purine nucleotide in response to stimuli. ATP filtered at the glomerulus, secreted by epithelial cells along the nephron, and released serosally by macula densa cells for feedback signaling to afferent arterioles within the glomerulus has important physiological signaling roles within kidneys. In autosomal recessive polycystic kidney disease (ARPKD) mice and humans, collecting duct epithelial cells lack an apical central cilium or express dysfunctional proteins within that monocilium. Collecting duct principal cells derived from an Oak Ridge polycystic kidney (orpk ( Tg737 ) ) mouse model of ARPKD lack a well-formed apical central cilium, thought to be a sensory organelle. We compared these cells grown as polarized cell monolayers on permeable supports to the same cells where the apical monocilium was genetically rescued with the wild-type Tg737 gene that encodes Polaris, a protein essential to cilia formation. Constitutive ATP release under basal conditions was low and not different in mutant versus rescued monolayers. However, genetically rescued principal cell monolayers released ATP three- to fivefold more robustly in response to ionomycin. Principal cell monolayers with fully formed apical monocilia responded three- to fivefold greater to hypotonicity than mutant monolayers lacking monocilia. In support of the idea that monocilia are sensory organelles, intentionally harsh pipetting of medium directly onto the center of the monolayer induced ATP release in genetically rescued monolayers that possessed apical monocilia. Mechanical stimulation was much less effective, however, on mutant orpk collecting duct principal cell monolayers that lacked apical central monocilia. Our data also show that an increase in cytosolic free Ca(2+) primes the ATP pool that is released in response to mechanical stimuli. It also appears that hypotonic cell swelling and

  15. Fertility impairment in radiotherapy.

    Science.gov (United States)

    Biedka, Marta; Kuźba-Kryszak, Tamara; Nowikiewicz, Tomasz; Żyromska, Agnieszka

    2016-01-01

    Infertility as a result of antineoplastic therapy is becoming a very important issue due to the growing incidence of neoplastic diseases. Routinely applied antineoplastic treatments and the illness itself lead to fertility disorders. Therapeutic methods used in antineoplastic treatment may cause fertility impairment or sterilization due to permanent damage to reproductive cells. The risk of sterilization depends on the patient's sex, age during therapy, type of neoplasm, radiation dose and treatment area. It is known that chemotherapy and radiotherapy can lead to fertility impairment and the combination of these two gives an additive effect. The aim of this article is to raise the issue of infertility in these patients. It is of growing importance due to the increase in the number of children and young adults who underwent radiotherapy in the past. The progress in antineoplastic therapy improves treatment results, but at the same time requires a deeper look at existential needs of the patient. Reproductive function is an integral element of self-esteem and should be taken into account during therapy planning. PMID:27647982

  16. Simple non-invasive analysis of embryonic stem cell-derived cardiomyocytes beating in vitro

    Science.gov (United States)

    Radaszkiewicz, Katarzyna Anna; Sýkorová, Dominika; Karas, Pavel; Kudová, Jana; Kohút, Lukáš; Binó, Lucia; Večeřa, Josef; Víteček, Jan; Kubala, Lukáš; Pacherník, Jiří

    2016-02-01

    The analysis of digital video output enables the non-invasive screening of various active biological processes. For the monitoring and computing of the beating parameters of cardiomyocytes in vitro, CB Analyser (cardiomyocyte beating analyser) software was developed. This software is based on image analysis of the video recording of beating cardiomyocytes. CB Analyser was tested using cardiomyocytes derived from mouse embryonic stem cells at different stages of cardiomyogenesis. We observed that during differentiation (from day 18), the beat peak width decreased, which corresponded to the increased speed of an individual pulse. However, the beating frequency did not change. Further, the effects of epinephrine modulating mature cardiomyocyte functions were tested to validate the CB Analyser analysis. In conclusion, data show that CB Analyser is a useful tool for evaluating the functions of both developing and mature cardiomyocytes under various conditions in vitro.

  17. 4-Hydroxybutenolide impairs cell migration, and invasion of human oral cancer SCC-4 cells via the inhibition of NF-κB and MAPK signaling pathways.

    Science.gov (United States)

    Yu, Fu-Shun; Lin, Meng-Liang; Hsu, Shu-Chun; Yu, Chien-Chih; Huang, Yi-Ping; Kuo, Yueh-Hsiung; Chung, Jing-Gung

    2016-08-01

    4-Hydroxybutenolide (K87), a synthetic compound from furfuryl alcohol via photooxidation, was used to investigate whether it can inhibit mobility, migration and invasion of SCC-4 human oral cancer cells in vitro. Cell viability was measured by flow cytometric assay, the enzymatic activities of MMP-2/9 were assayed by gelatin zymography analysis, the protein levels were assayed by western blotting, confocal laser microscopy and EMSA assay, and the gene expression of MMP-2/-7, FAK and ROCK1 mRNA were assayed by PCR. K87 decreased the percentage of viable cells in dose-dependent manner. K87 suppressed cell mobility, migration and invasion of SCC-4 cells dose-dependently. K87 inhibited the enzymatic activities of MMP-2/9 of SCC-4 cells. Western blot analysis revealed that K87 decreased the protein levels in NF-κBp65, COX-2, ROCK1 and Rho A, MMP-1, -2,- 7, -9, VEGF, GRB2, SOS1, PI3K, PKC, PERK, p-PERK, FAK, MEKK3, MKK7, ERK1/2, JNK1/2, p-p38, p38, p-c-Jun, AKT, TIMP2, but increased the protein levels of iNOS, Ras, IRE-1α, p-c-JNK, p-AKT(308), p-AKT(473) and TIMP1. Results from PCR indicated that K87 inhibited the gene expression of MMP-2/-7, FAK and ROCK1 mRNA. Furthermore, confocal laser microscopy was used to confirm that K87 inhibited the translocation of RHOA and ROCK1 in SCC-4 cells. EMSA assay also show that K87 suppressed the nuclear activation of NF-κB and these effects are time-dependent. Western blotting assay indicated that expression of NF-κBp105, NF-κBp50 and NF-κBp65 proteins were decreased and these effects are time-dependent. Based on these observations, we suggest that K87 may be used as a potential agent for anticancer metastasis of human oral cancer in the future. PMID:27221634

  18. Prenylation of a Rab1B mutant with altered GTPase activity is impaired in cell-free systems but not in intact mammalian cells.

    Science.gov (United States)

    Wilson, A L; Sheridan, K M; Erdman, R A; Maltese, W A

    1996-09-15

    Previous studies have reached differing conclusions as to whether or not guanine-nucleotide-dependent conformational changes affect the ability of Rab proteins to undergo post-translational modification by Rab:geranylgeranyltransferase (Rab-GGTase). We now show that the ability of a Rab1B mutant [Q67L (Gln-67-->Leu)] with reduced intrinsic GTPase activity to undergo geranylgeranylation in cell-free assays depends on the guanine nucleotide composition of the system. When GTP is the predominant nucleotide in the assay, Rab1BQ67L is a poor substrate. However, when GDP is present and GTP is omitted, prenylation of the Q67L mutant is comparable with that of the wild-type (WT) protein. These studies, coupled with the poor prenylation of Rab1BWT in the presence of the non-hydrolysable GTP analogue guanosine 5'-[gamma-thio]triphosphate, support the notion that Rab-GGTase prefers substrates in the GDP conformation. When the abilities of Rab1BQ67L and Rab1BWT to undergo prenylation were compared by metabolic labelling of transiently expressed proteins in cultured human 293 cells, we did not observe a decline in prenylation of the mutant protein as predicted on the basis of the cell-free assays. Moreover, the Q67L mutant was comparable with the wild-type Rab1B in its ability to associate with co-expressed Rab GDP dissociation inhibitors in 293 cells. These findings raise the possibility that unidentified proteins present in intact cells may compensate for the reduced intrinsic GTPase activity of the Q67L mutant, allowing a significant proportion of the nascent Rab1BQ67L to assume a GDP conformation. The differential prenylation of Rab1BQ67L in cell-free systems versus intact cells underscores the importance of evaluating the post-translational modification of specific Rab mutants in vivo, where poorly characterized regulatory proteins may have a significant effect on GTPase activity or nucleotide exchange rates.

  19. Functional impairment of Tax-specific but not cytomegalovirus-specific CD8+ T lymphocytes in a minor population of asymptomatic human T-cell leukemia virus type 1-carriers

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    Takamori Ayako

    2011-12-01

    Full Text Available Abstract Background Human T-cell leukemia virus type 1 (HTLV-1 causes adult T-cell leukemia (ATL and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP in a small percentage of infected individuals. ATL is often associated with general immune suppression and an impaired HTLV-1-specific T-cell response, an important host defense system. We previously found that a small fraction of asymptomatic HTLV-1-carriers (AC already showed impaired T-cell responses against the major target antigen, Tax. However, it is unclear whether the impaired HTLV-1 Tax-specific T-cell response in these individuals is an HTLV-1-specific phenomenon, or merely reflects general immune suppression. In this study, in order to characterize the impaired HTLV-1-specific T-cell response, we investigated the function of Tax-specific CD8+ T-cells in various clinical status of HTLV-1 infection. Results By using tetramers consisting of HLA-A*0201, -A*2402, or -A*1101, and corresponding Tax epitope peptides, we detected Tax-specific CD8+ T-cells in the peripheral blood from 87.0% of ACs (n = 20/23 and 100% of HAM/TSP patients (n = 18/18 tested. We also detected Tax-specific CD8+ T-cells in 38.1% of chronic type ATL (cATL patients (n = 8/21, although its frequencies in peripheral blood CD8+ T cells were significantly lower than those of ACs or HAM/TSP patients. Tax-specific CD8+ T-cells detected in HAM/TSP patients proliferated well in culture and produced IFN-γ when stimulated with Tax peptides. However, such functions were severely impaired in the Tax-specific CD8+ T-cells detected in cATL patients. In ACs, the responses of Tax-specific CD8+ T-cells were retained in most cases. However, we found one AC sample whose Tax-specific CD8+ T-cells hardly produced IFN-γ, and failed to proliferate and express activation (CD69 and degranulation (CD107a markers in response to Tax peptide. Importantly, the same AC sample contained cytomegalovirus (CMV pp65-specific CD8+ T-cells

  20. Ionising Radiation Immediately Impairs Synaptic Plasticity-Associated Cytoskeletal Signalling Pathways in HT22 Cells and in Mouse Brain: An In Vitro/In Vivo Comparison Study

    Science.gov (United States)

    Kempf, Stefan J.; Buratovic, Sonja; von Toerne, Christine; Moertl, Simone; Stenerlöw, Bo; Hauck, Stefanie M.; Atkinson, Michael J.; Eriksson, Per; Tapio, Soile

    2014-01-01

    Patients suffering from brain malignancies are treated with high-dose ionising radiation. However, this may lead to severe learning and memory impairment. Preventive treatments to minimise these side effects have not been possible due to the lack of knowledge of the involved signalling pathways and molecular targets. Mouse hippocampal neuronal HT22 cells were irradiated with acute gamma doses of 0.5 Gy, 1.0 Gy and 4.0 Gy. Changes in the cellular proteome were investigated by isotope-coded protein label technology and tandem mass spectrometry after 4 and 24 hours. To compare the findings with the in vivo response, male NMRI mice were irradiated on postnatal day 10 with a gamma dose of 1.0 Gy, followed by evaluation of the cellular proteome of hippocampus and cortex 24 hours post-irradiation. Analysis of the in vitro proteome showed that signalling pathways related to synaptic actin-remodelling were significantly affected at 1.0 Gy and 4.0 Gy but not at 0.5 Gy after 4 and 24 hours. We observed radiation-induced reduction of the miR-132 and Rac1 levels; miR-132 is known to regulate Rac1 activity by blocking the GTPase-activating protein p250GAP. In the irradiated hippocampus and cortex we observed alterations in the signalling pathways similar to those in vitro. The decreased expression of miR-132 and Rac1 was associated with an increase in hippocampal cofilin and phospho-cofilin. The Rac1-Cofilin pathway is involved in the modulation of synaptic actin filament formation that is necessary for correct spine and synapse morphology to enable processes of learning and memory. We suggest that acute radiation exposure leads to rapid dendritic spine and synapse morphology alterations via aberrant cytoskeletal signalling and processing and that this is associated with the immediate neurocognitive side effects observed in patients treated with ionising radiation. PMID:25329592

  1. Ionising radiation immediately impairs synaptic plasticity-associated cytoskeletal signalling pathways in HT22 cells and in mouse brain: an in vitro/in vivo comparison study.

    Directory of Open Access Journals (Sweden)

    Stefan J Kempf

    Full Text Available Patients suffering from brain malignancies are treated with high-dose ionising radiation. However, this may lead to severe learning and memory impairment. Preventive treatments to minimise these side effects have not been possible due to the lack of knowledge of the involved signalling pathways and molecular targets. Mouse hippocampal neuronal HT22 cells were irradiated with acute gamma doses of 0.5 Gy, 1.0 Gy and 4.0 Gy. Changes in the cellular proteome were investigated by isotope-coded protein label technology and tandem mass spectrometry after 4 and 24 hours. To compare the findings with the in vivo response, male NMRI mice were irradiated on postnatal day 10 with a gamma dose of 1.0 Gy, followed by evaluation of the cellular proteome of hippocampus and cortex 24 hours post-irradiation. Analysis of the in vitro proteome showed that signalling pathways related to synaptic actin-remodelling were significantly affected at 1.0 Gy and 4.0 Gy but not at 0.5 Gy after 4 and 24 hours. We observed radiation-induced reduction of the miR-132 and Rac1 levels; miR-132 is known to regulate Rac1 activity by blocking the GTPase-activating protein p250GAP. In the irradiated hippocampus and cortex we observed alterations in the signalling pathways similar to those in vitro. The decreased expression of miR-132 and Rac1 was associated with an increase in hippocampal cofilin and phospho-cofilin. The Rac1-Cofilin pathway is involved in the modulation of synaptic actin filament formation that is necessary for correct spine and synapse morphology to enable processes of learning and memory. We suggest that acute radiation exposure leads to rapid dendritic spine and synapse morphology alterations via aberrant cytoskeletal signalling and processing and that this is associated with the immediate neurocognitive side effects observed in patients treated with ionising radiation.

  2. Are interstitial cells of Cajal involved in mechanical stress-induced gene expression and impairment of smooth muscle contractility in bowel obstruction?

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    Chester C Wu

    Full Text Available BACKGROUND AND AIMS: The network of interstitial cells of Cajal (ICC is altered in obstructive bowel disorders (OBD. However, whether alteration in ICC network is a cause or consequence of OBD remains unknown. This study tested the hypothesis that mechanical dilation in obstruction disrupts the ICC network and that ICC do not mediate mechanotranscription of COX-2 and impairment of smooth muscle contractility in obstruction. METHODS: Medical-grade silicon bands were wrapped around the distal colon to induce partial obstruction in wild-type and ICC deficient (W/W(v mice. RESULTS: In wild-type mice, colon obstruction led to time-dependent alterations of the ICC network in the proximal colon segment. Although unaffected on days 1 and 3, the ICC density decreased markedly and the network was disrupted on day 7 of obstruction. COX-2 expression increased, and circular muscle contractility decreased significantly in the segment proximal to obstruction. In W/W(v control mice, COX-2 mRNA level was 4.0 (±1.1-fold higher (n=4 and circular muscle contractility was lower than in wild-type control mice. Obstruction further increased COX-2 mRNA level in W/W(v mice to 7.2 (±1.0-fold vs. W/W(v controls [28.8 (±4.1-fold vs. wild-type controls] on day 3. Obstruction further suppressed smooth muscle contractility in W/W(v mice. However, daily administration of COX-2 inhibitor NS-398 significantly improved muscle contractility in both W/W(v sham and obstruction mice. CONCLUSIONS: Lumen dilation disrupts the ICC network. ICC deficiency has limited effect on stretch-induced expression of COX-2 and suppression of smooth muscle contractility in obstruction. Rather, stretch-induced COX-2 plays a critical role in motility dysfunction in partial colon obstruction.

  3. Multiple doses of erythropoietin impair liver regeneration by increasing TNF-alpha, the Bax to Bcl-xL ratio and apoptotic cell death.

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    Katja Klemm

    Full Text Available BACKGROUND: Liver resection and the use of small-for-size grafts are restricted by the necessity to provide a sufficient amount of functional liver mass. Only few promising strategies to maximize liver regeneration are available. Apart from its erythropoiesis-stimulating effect, erythropoietin (EPO has meanwhile been recognized as mitogenic, tissue-protective, and anti-apoptotic pleiotropic cytokine. Thus, EPO may support regeneration of hepatic tissue. METHODOLOGY: Rats undergoing 68% hepatectomy received daily either high dose (5000 IU/kg bw i.v. or low dose (500 IU/kg bw i.v. recombinant human EPO or equal amounts of physiologic saline. Parameters of liver regeneration and hepatocellular apoptosis were assessed at 24 h, 48 h and 5 d after resection. In addition, red blood cell count, hematocrit and serum EPO levels as well as plasma concentrations of TNF-alpha and IL-6 were evaluated. Further, hepatic Bcl-x(L and Bax protein expression were analyzed by Western blot. PRINCIPAL FINDINGS: Administration of EPO significantly reduced the expression of PCNA at 24 h followed by a significant decrease in restitution of liver mass at day 5 after partial hepatectomy. EPO increased TNF-alpha levels and shifted the Bcl-x(L to Bax ratio towards the pro-apoptotic Bax resulting in significantly increased hepatocellular apoptosis. CONCLUSIONS: Multiple doses of EPO after partial hepatectomy increase hepatocellular apoptosis and impair liver regeneration in rats. Thus, careful consideration should be made in pre- and post-operative recombinant human EPO administration in the setting of liver resection and transplantation.

  4. Visual impairment in the hearing impaired students

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    Gogate Parikshit

    2009-01-01

    Full Text Available Background : Ocular problems are more common in children with hearing problems than in normal children. Neglected visual impairment could aggravate educational and social disability. Aim : To detect and treat visual impairment, if any, in hearing-impaired children. Setting and Design : Observational, clinical case series of hearing-impaired children in schools providing special education. Materials and Methods : Hearing-impaired children in selected schools underwent detailed visual acuity testing, refraction, external ocular examination and fundoscopy. Ocular motility testing was also performed. Teachers were sensitized and trained to help in the assessment of visual acuity using Snellen′s E charts. Refractive errors and squint were treated as per standard practice. Statistical Analysis : Excel software was used for data entry and SSPS for analysis. Results : The study involved 901 hearing-impaired students between four and 21 years of age, from 14 special education schools. A quarter of them (216/901, 24% had ocular problems. Refractive errors were the most common morbidity 167(18.5%, but only 10 children were using appropriate spectacle correction at presentation. Fifty children had visual acuity less than 20/80 at presentation; after providing refractive correction, this number reduced to three children, all of whom were provided low-vision aids. Other common conditions included strabismus in 12 (1.3% children, and retinal pigmentary dystrophy in five (0.6% children. Conclusion : Ocular problems are common in hearing-impaired children. Screening for ocular problems should be made mandatory in hearing-impaired children, as they use their visual sense to compensate for the poor auditory sense.

  5. Common variable immunodeficiency, impaired neurological development and reduced numbers of T regulatory cells in a 10-year-old boy with a STAT1 gain-of-function mutation.

    Science.gov (United States)

    Kobbe, Robin; Kolster, Manuela; Fuchs, Sebastian; Schulze-Sturm, Ulf; Jenderny, Jutta; Kochhan, Lothar; Staab, Julia; Tolosa, Eva; Grimbacher, Bodo; Meyer, Thomas

    2016-07-25

    Recently, gain-of-function (GOF) mutations in the gene encoding signal transducer and activator of transcription 1 (STAT1) have been associated with chronic mucocutaneous candidiasis (CMC). This case report describes a 10-year-old boy presenting with signs of common variable immunodeficiency (CVID), failure to thrive, impaired neurological development, and a history of recurrent mucocutaneous Candida infections. Sequencing of the STAT1 gene identified a heterozygous missense mutation in exon 7 encoding the STAT1 coiled-coil domain (c.514T>C, p.Phe172Leu). In addition to hypogammaglobulinemia with B-cell deficiency, and a low percentage of Th17 cells, immunological analysis of the patient revealed a marked depletion of forkhead-box P3(+)-expressing regulatory T cells (Tregs). In vitro stimulation of T cells from the patient with interferon-α (IFNα) and/or IFNɣ resulted in a significantly increased expression of STAT1-regulated target genes such as MIG1, IRF1, MX1, MCP1/CCL2, IFI-56K, and CXCL10 as compared to IFN-treated cells from a healthy control, while no IFNα/ɣ-mediated up-regulation of the FOXP3 gene was found. These data demonstrate that the STAT1 GOF mutation F172L, which results in impaired stability of the antiparallel STAT1 dimer conformation, is associated with inhibited Treg cell development and neurological symptoms. PMID:27063510

  6. Depression in Cognitive Impairment

    Science.gov (United States)

    Pellegrino, Laurel D.; Lyketsos, Constantine G.; Marano, Christopher M.

    2014-01-01

    Depression and cognitive disorders, including dementia and mild cognitive impairment, are common in the elderly. Depression is also a common feature of cognitive impairment although the symptoms of depression in cognitive impairment differ from depression without cognitive impairment. Pre-morbid depression approximately doubles the risk of subsequent dementia. There are two predominant, though not mutually exclusive, constructs linking pre-morbid depression to subsequent cognitive impairment: Alzheimer’s pathology and the vascular depression hypothesis. When evaluating a patient with depression and cognitive impairment, it is important to obtain caregiver input and to evaluate for alternative etiologies for depressive symptoms such as delirium. We recommend a sequential approach to the treatment of depression in dementia patients: (1) a period of watchful waiting for milder symptoms, (2) psychosocial treatment program, (3) a medication trial for more severe symptoms or failure of psychosocial interventions, and (4) possible ECT for refractory symptoms. PMID:23933974

  7. Long-term moderate calorie restriction inhibits inflammation without impairing cell-mediated immunity: a randomized controlled trial in non obese humans

    Science.gov (United States)

    Calorie restriction (CR) inhibits inflammation and slows aging in many animal species, but in rodents housed in pathogen-free facilities, CR impairs immunity against certain pathogens. However, little is known about the effects of long-term moderate CR on immune function in humans. In this multi-cen...

  8. Criteria for driver impairment

    NARCIS (Netherlands)

    Brookhuis, K.A.; De Waard, D.; Fairclough, S.H

    2003-01-01

    Most traffic accidents can be attributed to driver impairment, e.g. inattention, fatigue, intoxication, etc. It is now technically feasible to monitor and diagnose driver behaviour with respect to impairment with the aid of a limited number of in-vehicle sensors. However, a valid framework for the e

  9. Advanced Glycation End Products Impair Glucose-Stimulated Insulin Secretion of a Pancreatic β-Cell Line INS-1-3 by Disturbance of Microtubule Cytoskeleton via p38/MAPK Activation

    Directory of Open Access Journals (Sweden)

    Jia You

    2016-01-01

    Full Text Available Advanced glycation end products (AGEs are believed to be involved in diverse complications of diabetes mellitus. Overexposure to AGEs of pancreatic β-cells leads to decreased insulin secretion and cell apoptosis. Here, to understand the cytotoxicity of AGEs to pancreatic β-cells, we used INS-1-3 cells as a β-cell model to address this question, which was a subclone of INS-1 cells and exhibited high level of insulin expression and high sensitivity to glucose stimulation. Exposed to large dose of AGEs, even though more insulin was synthesized, its secretion was significantly reduced from INS-1-3 cells. Further, AGEs treatment led to a time-dependent increase of depolymerized microtubules, which was accompanied by an increase of activated p38/MAPK in INS-1-3 cells. Pharmacological inhibition of p38/MAPK by SB202190 reversed microtubule depolymerization to a stabilized polymerization status but could not rescue the reduction of insulin release caused by AGEs. Taken together, these results suggest a novel role of AGEs-induced impairment of insulin secretion, which is partially due to a disturbance of microtubule dynamics that resulted from an activation of the p38/MAPK pathway.

  10. Advanced Glycation End Products Impair Glucose-Stimulated Insulin Secretion of a Pancreatic β-Cell Line INS-1-3 by Disturbance of Microtubule Cytoskeleton via p38/MAPK Activation

    Science.gov (United States)

    You, Jia; Xu, Shiqing; Zhang, Wenjian; Fang, Qing; Liu, Honglin; Peng, Liang; Deng, Tingting

    2016-01-01

    Advanced glycation end products (AGEs) are believed to be involved in diverse complications of diabetes mellitus. Overexposure to AGEs of pancreatic β-cells leads to decreased insulin secretion and cell apoptosis. Here, to understand the cytotoxicity of AGEs to pancreatic β-cells, we used INS-1-3 cells as a β-cell model to address this question, which was a subclone of INS-1 cells and exhibited high level of insulin expression and high sensitivity to glucose stimulation. Exposed to large dose of AGEs, even though more insulin was synthesized, its secretion was significantly reduced from INS-1-3 cells. Further, AGEs treatment led to a time-dependent increase of depolymerized microtubules, which was accompanied by an increase of activated p38/MAPK in INS-1-3 cells. Pharmacological inhibition of p38/MAPK by SB202190 reversed microtubule depolymerization to a stabilized polymerization status but could not rescue the reduction of insulin release caused by AGEs. Taken together, these results suggest a novel role of AGEs-induced impairment of insulin secretion, which is partially due to a disturbance of microtubule dynamics that resulted from an activation of the p38/MAPK pathway.

  11. Impaired NFAT and NFκB activation are involved in suppression of CD40 ligand expression by Δ{sup 9}-tetrahydrocannabinol in human CD4{sup +} T cells

    Energy Technology Data Exchange (ETDEWEB)

    Ngaotepprutaram, Thitirat [Department of Pharmacology and Toxicology, Michigan State University (United States); Center for Integrative Toxicology, Michigan State University (United States); Kaplan, Barbara L.F. [Department of Pharmacology and Toxicology, Michigan State University (United States); Center for Integrative Toxicology, Michigan State University (United States); Neuroscience Program, Michigan State University (United States); Kaminski, Norbert E., E-mail: kamins11@msu.edu [Department of Pharmacology and Toxicology, Michigan State University (United States); Center for Integrative Toxicology, Michigan State University (United States)

    2013-11-15

    We have previously reported that Δ{sup 9}-tetrahydrocannabinol (Δ{sup 9}-THC), the main psychoactive cannabinoid in marijuana, suppresses CD40 ligand (CD40L) expression by activated mouse CD4{sup +} T cells. CD40L is involved in pathogenesis of many autoimmune and inflammatory diseases. In the present study, we investigated the molecular mechanism of Δ{sup 9}-THC-mediated suppression of CD40L expression using peripheral blood human T cells. Pretreatment with Δ{sup 9}-THC attenuated CD40L expression in human CD4{sup +} T cells activated by anti-CD3/CD28 at both the protein and mRNA level, as determined by flow cytometry and quantitative real-time PCR, respectively. Electrophoretic mobility shift assays revealed that Δ{sup 9}-THC suppressed the DNA-binding activity of both NFAT and NFκB to their respective response elements within the CD40L promoter. An assessment of the effect of Δ{sup 9}-THC on proximal T cell-receptor (TCR) signaling induced by anti-CD3/CD28 showed significant impairment in the rise of intracellular calcium, but no significant effect on the phosphorylation of ZAP70, PLCγ1/2, Akt, and GSK3β. Collectively, these findings identify perturbation of the calcium-NFAT and NFκB signaling cascade as a key mechanistic event by which Δ{sup 9}-THC suppresses human T cell function. - Highlights: • Δ{sup 9}-THC attenuated CD40L expression in activated human CD4+ T cells. • Δ{sup 9}-THC suppressed DNA-binding activity of NFAT and NFκB. • Δ{sup 9}-THC impaired elevation of intracellular Ca2+. • Δ{sup 9}-THC did not affect phosphorylation of ZAP70, PLCγ1/2, Akt, and GSK3β.

  12. Transient and cumulative memory impairments induced by GSM 1.8 GHz cell phone signal in a mouse model.

    Science.gov (United States)

    Ntzouni, Maria P; Skouroliakou, Aikaterini; Kostomitsopoulos, Nikolaos; Margaritis, Lukas H

    2013-03-01

    This study was designed to investigate the transient and cumulative impairments in spatial and non-spatial memory of C57Bl/6J mice exposed to GSM 1.8 GHz signal for 90 min daily by a typical cellular (mobile) phone at a specific absorption rate value of 0.11 W/kg. Free-moving male mice 2 months old were irradiated in two experimental protocols, lasting for 66 and for 148 days respectively. Each protocol used three groups of animals (n = 8 each for exposed, sham exposed and controls) in combination with two behavioural paradigms, the object recognition task and the object location task sequentially applied at different time points. One-way analysis of variance revealed statistically significant impairments of both types of memory gradually accumulating, with more pronounced effects on the spatial memory. The impairments persisted even 2 weeks after interruption of the 8 weeks daily exposure, whereas the memory of mice as detected by both tasks showed a full recovery approximately 1 month later. Intermittent every other day exposure for 1 month had no effect on both types of memory. The data suggest that visual information processing mechanisms in hippocampus, perirhinal and entorhinal cortex are gradually malfunctioning upon long-term daily exposure, a phenotype that persists for at least 2 weeks after interruption of radiation, returning to normal memory performance levels 4 weeks later. It is postulated that cellular repair mechanisms are operating to eliminate the memory affecting molecules. The overall contribution of several possible mechanisms to the observed cumulative and transient impairments in spatial and non-spatial memory is discussed.

  13. Speech impairment (adult)

    Science.gov (United States)

    ... brain tumors or degenerative diseases that affect the language areas of the brain. This term does not apply to children who ... gradually, but anyone can develop a speech and language impairment ... Brain tumor (more common in aphasia than dysarthria) Dementia ...

  14. Impairments to Vision

    Science.gov (United States)

    ... an external Non-Government web site. Impairments to Vision Normal Vision Diabetic Retinopathy Age-related Macular Degeneration In this ... pictures, fixate on the nose to simulate the vision loss. In diabetic retinopathy, the blood vessels in ...

  15. Aids for visual impairment.

    OpenAIRE

    Dudley, N. J.

    1990-01-01

    This article provides only a flavour of the type and range of aids available to the visually impaired person. Many other aids for leisure, learning, and daily living are illustrated in the RNIB equipment and games catalogue.

  16. Kids' Quest: Vision Impairment

    Science.gov (United States)

    ... and neighborhood . Step 8: Now see if your attitudes have changed. Take the Fact Checkup again. ... impairment also have at least one other developmental disability, such as intellectual disabilities, cerebral palsy, hearing loss, ...

  17. 5-Azacytidine Is Insufficient For Cardiogenesis In Human Adipose-Derived Stem Cells

    Science.gov (United States)

    2012-01-01

    Background Adipose tissue is a source of multipotent adult stem cells and it has the ability to differentiate into several types of cell lineages such as neuron cells, osteogenic cells and adipogenic cells. Several reports have shown adipose-derived stem cells (ASCs) have the ability to undergo cardiomyogenesis. Studies have shown 5-azacytidine can successfully drive stem cells such as bone marrow derived stem cells to differentiate into cardiomyogenic cells. Therefore, in this study, we investigated the effect 5-azacytidine on the cardiogenic ability of ASCs. Methods The cardiogenic potential of ASCs was analysed by studying the morphological changes after induction, the changes in the cardiogenic genes expression i.e. GATA4, MLC-2v, MLC-2a, NKX2.5, β-MHC, α-MHC, Atrial natriuretic peptide (ANP), Connexin 43, Cardiac Troponin C, Cardiac Troponin I and myocyte enhancer factor (MEF2C) and the changes of embryonic stem cells genes expression at P5 and P10 using quantitative PCR. Results Our results showed that the induced ASCs did not show significant morphological difference compared to the non-induced ASCs. While quantitative PCR data indicated that most cardiogenic genes and stemness genes expression level decreased after induction at P5 and P10. Conclusion 5-azacytidine is insufficient for the cardiogenic induction of the ASCs. PMID:22221649

  18. 5-Azacytidine Is Insufficient For Cardiogenesis In Human Adipose-Derived Stem Cells

    Directory of Open Access Journals (Sweden)

    Wan Safwani Wan Kamarul Zaman

    2012-01-01

    Full Text Available Abstract Background Adipose tissue is a source of multipotent adult stem cells and it has the ability to differentiate into several types of cell lineages such as neuron cells, osteogenic cells and adipogenic cells. Several reports have shown adipose-derived stem cells (ASCs have the ability to undergo cardiomyogenesis. Studies have shown 5-azacytidine can successfully drive stem cells such as bone marrow derived stem cells to differentiate into cardiomyogenic cells. Therefore, in this study, we investigated the effect 5-azacytidine on the cardiogenic ability of ASCs. Methods The cardiogenic potential of ASCs was analysed by studying the morphological changes after induction, the changes in the cardiogenic genes expression i.e. GATA4, MLC-2v, MLC-2a, NKX2.5, β-MHC, α-MHC, Atrial natriuretic peptide (ANP, Connexin 43, Cardiac Troponin C, Cardiac Troponin I and myocyte enhancer factor (MEF2C and the changes of embryonic stem cells genes expression at P5 and P10 using quantitative PCR. Results Our results showed that the induced ASCs did not show significant morphological difference compare