Science.gov

Sample records for reciprocal translocations induced

  1. Reciprocal translocations

    SciTech Connect

    1993-12-31

    Chapter 26, describes reciprocal translocations of chromosomes: their occurrence, breakpoints, and multiple rearrangements. In addition, phenotypes of balanced and unbalanced translocation carriers and fetal death are discussed. Examples of translocation families are given. Meiosis and genetic risk in translocation carriers is presented. Finally, sperm chromosomes in meiotic segregation analysis is mentioned. 39 refs., 3 figs., 1 tab.

  2. Reciprocal translocations in Saccharomyces cerevisiae formed by nonhomologous end joining.

    PubMed

    Yu, Xin; Gabriel, Abram

    2004-02-01

    Reciprocal translocations are common in cancer cells, but their creation is poorly understood. We have developed an assay system in Saccharomyces cerevisiae to study reciprocal translocation formation in the absence of homology. We induce two specific double-strand breaks (DSBs) simultaneously on separate chromosomes with HO endonuclease and analyze the subsequent chromosomal rearrangements among surviving cells. Under these conditions, reciprocal translocations via nonhomologous end joining (NHEJ) occur at frequencies of approximately 2-7 x 10(-5)/cell exposed to the DSBs. Yku80p is a component of the cell's NHEJ machinery. In its absence, reciprocal translocations still occur, but the junctions are associated with deletions and extended overlapping sequences. After induction of a single DSB, translocations and inversions are recovered in wild-type and rad52 strains. In these rearrangements, a nonrandom assortment of sites have fused to the DSB, and their junctions show typical signs of NHEJ. The sites tend to be between open reading frames or within Ty1 LTRs. In some cases the translocation partner is formed by a break at a cryptic HO recognition site. Our results demonstrate that NHEJ-mediated reciprocal translocations can form in S. cerevisiae as a consequence of DSB repair. PMID:15020464

  3. Linkage map construction involving a reciprocal translocation.

    PubMed

    Farré, A; Benito, I Lacasa; Cistué, L; de Jong, J H; Romagosa, I; Jansen, J

    2011-03-01

    This paper is concerned with a novel statistical-genetic approach for the construction of linkage maps in populations obtained from reciprocal translocation heterozygotes of barley (Hordeum vulgare L.). Using standard linkage analysis, translocations usually lead to 'pseudo-linkage': the mixing up of markers from the chromosomes involved in the translocation into a single linkage group. Close to the translocation breakpoints recombination is severely suppressed and, as a consequence, ordering markers in those regions is not feasible. The novel strategy presented in this paper is based on (1) disentangling the "pseudo-linkage" using principal coordinate analysis, (2) separating individuals into translocated types and normal types and (3) separating markers into those close to and those more distant from the translocation breakpoints. The methods make use of a consensus map of the species involved. The final product consists of integrated linkage maps of the distal parts of the chromosomes involved in the translocation. PMID:21153624

  4. Antimutagenic properties of selected radioprotective drug mixtures with regard to X-ray-induced reciprocal translocations in mouse spermatogonia.

    PubMed

    Benova, D K

    1986-01-01

    The radioprotective drugs AET, serotonin, and ATP were tested for antimutagenic activity against induction by 4.0 Gy X-rays of reciprocal translocations in mouse spermatogonia. Single drugs administered in doses of 8, 24 and 360 mg/kg b.wt., respectively, had no effect on translocation yields recorded in diakinesis-metaphase I spermatocytes. Two-drug mixtures afforded insignificant protection. Three-drug mixtures, however, were found to reduce radiation damage considerably, and the extent of protection was dependent in part on the amount of ATP. The best effect was obtained with formulations of serotonin-AET-ATP at the following doses, respectively: 8 + 24 + 360 mg/kg, 16 + 24 + 336 mg/kg, and 16 + 32 + 264 mg/kg. Less effective were the serotonin-AET-ATP formulations: 16 + 32 + 120 mg/kg, and 8 + 24 + 480 mg/kg. Treatment with drugs omitting radiation exposure was observed to raise, though insignificantly, the level of spontaneous translocation frequency. PMID:3941667

  5. Partners with reciprocal translocations: genetic counseling for the 'double translocation'.

    PubMed

    Cook, L; Hartsfield, J K; Vance, G H

    1998-05-01

    SV at age 2 years presented with multiple congenital anomalies including an absent left kidney, anal stenosis, vertebral abnormalities, partial sacral agenesis, microcephaly, dysmorphic facial features, growth deficiency, and developmental delay. She was found to have a complex chromosomal rearrangement derived from balanced translocations in each parent. PMID:9660061

  6. An intergenomic reciprocal translocation associated with oat winterhardiness

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The reciprocal intergenomic translocation between hexaploid oat (Avena sp.) chromosomes 7C and 17 (T7C-17) has been associated with the division of cultivated oat into A. sativa (L.) and A. byzantina (C. Koch) species as well as fall and spring growth habit. The objective of this experiment was to ...

  7. Antimutagenic properties of WR 2721 and of a radioprotective mixture, ATP-AET-serotonin, with regard to X ray induced reciprocal translocations in mouse spermatogonia

    SciTech Connect

    Benova, D.

    1987-01-01

    Pretreatment by intraperitoneal administration of WR 2721 at 400 mg/kg body weight in mice receiving 4.0 Gy X rays was found to have an appreciable antimutagenic effect with regard to reciprocal translocation induction in spermatogonia. The effectiveness of the product tested proved superior to that of a radioprotective mixture of ATP-AET-serotonin given at optimal dose ratio--360, 24, and 8 mg/kg body weight, respectively. The RF (Reduction Factor) was 2.4 for WR 2721 and 1.8 for the mixture. The effect observed indicated WR 2721 to have potential capabilities for reducing the genetic risk of radiation in male individuals.

  8. Antimutagenic properties of WR 2721 and of a radioprotective mixture, ATP-AET-serotonin, with regard to X ray induced reciprocal translocations in mouse spermatogonia.

    PubMed

    Benova, D

    1987-01-01

    Pretreatment by intraperitoneal administration of WR 2721 at 400 mg/kg body weight in mice receiving 4.0 Gy X rays was found to have an appreciable antimutagenic effect with regard to reciprocal translocation induction in spermatogonia. The effectiveness of the product tested proved superior to that of a radioprotective mixture of ATP-AET-serotonin given at optimal dose ratio--360, 24, and 8 mg/kg body weight, respectively. The RF (Reduction Factor) was 2.4 for WR 2721 and 1.8 for the mixture. The effect observed indicated WR 2721 to have potential capabilities for reducing the genetic risk of radiation in male individuals. PMID:3027009

  9. The study of the mechanisms of the different phenotypical manifestations in patients with reciprocal translocations

    NASA Astrophysics Data System (ADS)

    Lozynskyi, Rostyslav; Lozynska, Maria

    2006-04-01

    Cytogenetical study of lymphocytes using the light microscopy could reveal a large amount of chromosomal abnormalities, which determine corresponding hereditary disorders. However, geneticists sometimes observe the cases where the same chromosomal rearrangements seen in light microscope cause quite different phenotype (from normal to abnormal) in relatives. The aim of the study was to explain the mechanisms of the different phenotype appearance in family members carrying the same reciprocal translocations. It was carried out the standard chromosome analysis in 12 families, where some relatives had reciprocal translocations. Chromosomes were differentially stained using G-method. The samples were analysed in optical microscope (x1000). Using OMIM gene map, UCSC Genome Browser, eGenome Release v2.3 and Unigene databases it was revealed transposons and transposon derivates in chromosome regions involved in translocations. We suppose that the variability of clinical manifestations in translocation-bearing patient is caused by the influence of the transposons, such as Hsmar2, Alu-elements or some others. We propose the following mechanisms of transposone action in these patients. The first may lie on recombination between the 2 specific DNA-transposon containing sites on different chromosomes resulting in balanced reciprocal translocation with no significant influence on the most genes' activity in corresponding regions. The weakening of transposase repression, which may follow in gametes, increases the transposase activity, and hereby, the probability of transposon dislocation. Dislocation can change the activity of groups of genes, because transposons often carry the regulatory sequences. This can induce multiply innate disorders in the progeny of the phenotypically healthy parents, carrying the translocation. According to the second mechanism, the reciprocal translocation is caused by recombination between 2 Alu repeats. These repeats can undergo reverse

  10. Reciprocal translocations in man. 3:1 Meiotic disjunction resulting in 47- or 45-chromosome offspring.

    PubMed Central

    Lindenbaum, R H; Bobrow, M

    1975-01-01

    Five cases of chromosome imbalance resulting from 3:1 disjunction of reciprocal translocations are described. A review of the literature suggests this phenomenon is more common than has previously been recognized. Images PMID:123589

  11. Fertility of male and female mice heterozygous for the reciprocal translocation T(7;17)3BKM.

    PubMed

    Koleva, M; Benova, D

    1992-01-01

    The present paper describes the fertility of male and female mice heterozygous for the reciprocal translocation T(7;17)3BKM. This translocation was induced by gamma rays in the spermatozoa of an irradiated parent. It is characterized by "asymmetrical" localization of the breakpoints, distally in Chromosome 7 (7F5) and proximally in Chromosome 17 (17B1). The data presented here relate only those matings in which, for both partners, heterozygosity or normality could be confirmed cytogenetically. The results indicate that both male and female translocation heterozygotes are fertile, their mean litter size being reduced to about 50% of that of normal littermates. This leads to the conclusion that the multivalents mainly undergo either alternate or adjacent-1 2:2 segregation. No viable tertiary trisomics were observed among the progeny of the translocation carriers. Analysis of the frequency of the different types of multivalents in diakinesis-metaphase I spermatocytes showed a significant predominance of chain-type figures (CIV and CIII+I), with chains of four elements (CIV) being more frequent than other configurations. This demonstrates that the small marker chromosome remains attached by one of its segments to the tetravalent. PMID:1486808

  12. [Partial trisomy 18q due to maternal reciprocal translocation 4;18].

    PubMed

    Sáenz Hurtado, J; Galán Gómez, E; Carbonell Pérez, J; Villa Milla, A; Rodríguez Martínez, L; Agulla Rodiño, E; Cardesa García, J

    2001-07-01

    We report a new case of partial trisomy 18q due to a balanced reciprocal translocation 4;18 in the mother. The female infant had a partial trisomy of the long arm of chromosome 18 associated with a partial monosomy of distal 4q. The infant showed many of the main clinical features of trisomy 18, such as dysmorphic face, congenital heart defect, crossing of the second and fifth fingers over the third and fourth with flexion contractures, and abnormal genitalia. We believe that the trisomy 18 phenotype requires a large region of 18q and that the greater the trisomic fragment, the more severe the expression. We stress the importance of genetic counseling to carriers of balanced translocations. The risk for each case should be evaluated and information should be given on the possibility of prenatal diagnosis. PMID:11412471

  13. Genetic counselling in carriers of reciprocal chromosomal translocations involving short arm of chromosome X.

    PubMed

    Panasiuk, Barbara; Usinskiené, Ruta; Kostyk, Ewa; Rybałko, Alicja; Stasiewicz-Jarocka, Beata; Krzykwa, Bogustawa; Pieńkowska-Grela, Barbara; Kucinskas, Vaidutis; Michalova, Kyra; Midro, Alina T

    2004-01-01

    the studied group the values of occurrence probability for unbalanced offspring at birth ranged from 2.1% to 17%. Information on the magnitude of the individual figures may be important for women carrying a reciprocal X;A translocation when deciding upon further family planning. PMID:15050871

  14. Acampomelic campomelic dysplasia with de novo 5q;17q reciprocal translocation and severe phenotype.

    PubMed Central

    Savarirayan, R; Bankier, A

    1998-01-01

    Campomelic dysplasia (CD) is a rare skeletal malformation syndrome caused by mutations in the SRY related gene SOX9, mapped to 17q24.3-q25.1. A small proportion of cases are associated with structural rearrangements involving 17q and it has been proposed that this subgroup have a milder phenotype and better prognosis compared to those with mutations in the SOX9 gene. We report a severely affected infant with the acampomelic form of campomelic dysplasia, who died at 11 days and was found to have a de novo reciprocal translocation, 46,XX,t(5;17)(q15;q25.1). This is the second reported case of severe campomelic dysplasia associated with a structural rearrangement involving 17q and suggests that this subgroup of patients may not significantly differ from those without chromosomal rearrangements with regards to phenotype or prognosis. Images PMID:9678706

  15. Cytogenetic and molecular characterization of eight new reciprocal translocations in the pig species. Estimation of their incidence in French populations

    PubMed Central

    Ducos, Alain; Pinton, Alain; Yerle, Martine; Séguéla, Anne; Berland, Hélène-Marie; Brun-Baronnat, Corinne; Bonnet, Nathalie; Darré, Roland

    2002-01-01

    Eight new cases of reciprocal translocation in the domestic pig are described. All the rearrangements were highlighted using GTG banding techniques. Chromosome painting experiments were also carried out to confirm the proposed hypotheses and to accurately locate the breakpoints. Three translocations, rcp(4;6)(q21;p14), rcp(2;6)(p17;q27) and rcp(5;17)(p12;q13) were found in boars siring small litters (8.3 and 7.4 piglets born alive per litter, on average, for translocations 2/6 and 5/17, respectively). The remaining five, rcp(5;8)(p12;q21), rcp(15;17)(q24;q21), rcp(7;8)(q24;p21), rcp(5;8)(p11;p23) and rcp(3;15)(q27;q13) were identified in young boars controlled before entering reproduction. A decrease in prolificacy of 22% was estimated for the 3/15 translocation after reproduction of the boar carrier. A parental origin by inheritance of the translocation was established for the (5;8)(p11;p23) translocation. The overall incidence of reciprocal translocations in the French pig populations over the 2000/2001 period was estimated (0.34%). PMID:12081804

  16. {open_quotes}Balanced{close_quotes} karyotypes in six abnormal offspring of balanced reciprocal translocation normal carrier parents

    SciTech Connect

    Wenger, S.L.; Steele, M.W.; Boone, L.Y.

    1995-01-02

    Among 6800 consecutive blood samples studies for clinical cytogenetic diagnosis, we identified 30 families in which one parent of the proband had a balanced reciprocal autosomal translocation (excluding Robertsonian rearrangements). Twenty-eight of the 30 families had a malformed and/or mentally retarded proband: 19 with an unbalanced derived chromosome, 3 with abnormalities involving chromosomes other than those in the translocation, 5 with a {open_quotes}balanced{close_quotes} reciprocal translocation, and 1 with a normal karyotype. We hypothesize that a latter 6 affected probands with {open_quotes}balanced{close_quotes} karyotypes could be abnormal due to submicroscopic deletions and duplications as was originally suggested by Jacobs. Particularly in these 6 families, 83% of translocation breakpoints were associated with fragile sites, more than expected by chance (P < 0.025). This supports the report of an association between fragile sites and constitutional chromosome breakpoints by Hecht and Hecht. To explain these findings, we propose that autosomal fragile sites are unstable areas which predispose to breaks and unequal crossing over near the fragile site breakpoints creating minute duplications and deletions. Consequently, newborn infants inheriting a seemingly {open_quotes}balanced{close_quotes} karyotype from a normal parent with a balanced reciprocal translocation may still be at an increased risk of being malformed and/or developmentally delayed because of submicroscopic chromosomal imbalances. 19 refs., 6 figs., 2 tabs.

  17. A Novel de novo Balanced Reciprocal Translocation t(18;22) Associated with Recurrent Miscarriages: A Case Report

    PubMed Central

    Dutta, Usha R.; Ponnala, Rajitha; Dalal, Ashwin

    2014-01-01

    Background Recurrent miscarriage is a major concern in the couples with reproductive problems. The chromosomal abnormalities, mainly balanced rearrangements are reported in variable phenotypes and the prevalence of them is 2-8% in such couples. Case Presentation In this study, the clinical, cytogenetic and molecular cytogenetic evaluations were performed on a couple with RM. The cytogenetic analysis of the husband revealed a balanced reciprocal translocation of t(18;22)(q21.1;q12) whereas wife had a normal karyotype of 46,XX. Further spectral karyotyping was performed to rule out the involvement of any other chromosomal aberrations present in the genome. Additional whole chromosome paint FISH (Fluorescence in situ hybridization) with paint probes 18 and 22 confirmed the translocation. Conclusion To our knowledge, this is the first report of a novel (18;22) translocation with unique breakpoints and their association with RM. The reciprocal translocations provide a good opportunity for the identification of disease associated genes. However, in recurrent miscarriages, most of them do not disrupt any gene at the breakpoint but can lead to unbalanced gametes and hence poor reproductive outcome like RM or birth of a child with malformations and intellectual disability. The translocation breakpoints might be risk factors for RM. Moreover, the impact of the balanced translocations in association with RM is discussed in this report. PMID:24918085

  18. Wnt signaling induces transcription, spatial proximity, and translocation of fusion gene partners in human hematopoietic cells.

    PubMed

    Ugarte, Giorgia D; Vargas, Macarena F; Medina, Matías A; León, Pablo; Necuñir, David; Elorza, Alvaro A; Gutiérrez, Soraya E; Moon, Randall T; Loyola, Alejandra; De Ferrari, Giancarlo V

    2015-10-01

    Chromosomal translocations are frequently associated with a wide variety of cancers, particularly hematologic malignancies. A recurrent chromosomal abnormality in acute myeloid leukemia is the reciprocal translocation t(8;21) that fuses RUNX1 and ETO genes. We report here that Wnt/β-catenin signaling increases the expression of ETO and RUNX1 genes in human hematopoietic progenitors. We found that β-catenin is rapidly recruited into RNA polymerase II transcription factories (RNAPII-Ser5) and that ETO and RUNX1 genes are brought into close spatial proximity upon Wnt3a induction. Notably, long-term treatment of cells with Wnt3a induces the generation a frequent RUNX1-ETO translocation event. Thus, Wnt/β-catenin signaling induces transcription and translocation of RUNX1 and ETO fusion gene partners, opening a novel window to understand the onset/development of leukemia. PMID:26333776

  19. Rieger syndrome with de Novo reciprocal translocation t(1;4) (q23.1;q25)

    SciTech Connect

    Makita, Yoshio; Masuno, Mitsuo; Imaizumi, Kiyoshi

    1995-05-22

    We report on a boy with Rieger syndrome, who had an apparently balanced reciprocal translocation between chromosomes 1 and 4. The clinical manifestations of this patient were characterized by irregular shaped pupils with a prominent Schwalbe line and an umbilical hernia. On cytogenetic studies, he was found to have a de novo reciprocal translocation 46,XY,t(1;4) (q23.1;q25), without visible deletion. His parents had normal chromosomes. A review of both cytogenetic and genetic linkage analyses with Rieger syndrome showed that chromosome 4q was involved. This and other previous reports suggested that the gene for Rieger syndrome is mapped to the 4q25{r_arrow}4q26 segment adjoining the breakpoint. 14 refs., 3 figs., 1 tab.

  20. Induction of reciprocal translocations in rhesus monkey stem-cell spermatogonia: effects of low doses and low dose rates

    SciTech Connect

    van Buul, P.P.; Richardson, J.F. Jr.; Goudzwaard, J.H.

    1986-01-01

    The induction of reciprocal translocation in rhesus monkey spermatogonial stem cells was studied following exposure to low doses of acute X rays (0.25 Gy, 300 mGy/min) or to low-dose-rate X rays (1 Gy, 2 mGy/min) and gamma rays (1 Gy, 0.2 mGy/min). The results obtained at 0.25 Gy of X rays fitted exactly the linear extrapolation down from the 0.5 and 1.0 Gy points obtained earlier. Extension of X-ray exposure reduced the yield of translocations similar to that in the mouse by about 50%. The reduction to 40% of translocation rate after chronic gamma exposure was clearly less than the value of about 80% reported for the mouse over the same range of dose rates. Differential cell killing with ensuing differential elimination of aberration-carrying cells is the most likely explanation for the differences between mouse and monkey.

  1. Sequencing and Analyzing the "t" (1;7) Reciprocal Translocation Breakpoints Associated with a Case of Childhood-Onset Schizophrenia/Autistic Disorder

    ERIC Educational Resources Information Center

    Idol, Jacquelyn R.; Addington, Anjene M.; Long, Robert T.; Rapoport, Judith L.; Green, Eric D.

    2008-01-01

    We characterized a "t"(1;7)(p22;q21) reciprocal translocation in a patient with childhood-onset schizophrenia (COS) and autism using genome mapping and sequencing methods. Based on genomic maps of human chromosome 7 and fluorescence in situ hybridization (FISH) studies, we delimited the region of 7q21 harboring the translocation breakpoint to a…

  2. Genetic counseling in carriers of reciprocal chromosomal translocations involving long arm of chromosome 16.

    PubMed

    Stasiewicz-Jarocka, B; Haus, O; Van Assche, E; Kostyk, E; Constantinou, M; Rybałko, A; Krzykwa, B; Marcinkowska, A; Barisic, I; Kucinskas, V; Katuzewski, B; Schwanitz, G; Midro, A T

    2004-09-01

    Families with balanced chromosomal changes ascertained by unbalanced progeny, miscarriages, or by chance are interested in their probability for unbalanced offspring and other unfavorable pregnancy outcomes. This is usually done based on the original data published by Stengel-Rutkowski et al. several decades ago. That data set has never been updated. It is particularly true for the subgroup with low number of observations, to which belong reciprocal chromosomal translocations (RCTs) with breakpoint in an interstitial segment of 16q. The 11 pedigrees from original data together with the new 18 pedigrees of RCT carriers at risk of single-segment imbalance detected among 100 pedigrees of RCT carriers with breakpoint position at 16q were used for re-evaluation of the probability estimation for unbalanced offspring at birth and at second trimester of prenatal diagnosis, published in 1988. The new probability rate for unbalanced offspring after 2 : 2 disjunction and adjacent-1 segregation for the total group of pedigrees was 4 +/- 3.9% (1/25). In addition, the probability estimate for unbalanced fetuses at second trimester of prenatal diagnosis was calculated as 2/11, i.e. 18.2 +/- 11.6%. The probability rates for miscarriages and stillbirths/early deaths were about 16 +/- 7.3% (4/25) and <2% (0/25), respectively. Considering different segment lengths of 16q, higher probability rate (0/8, i.e. <6.1%) for maternal RCT carriers at risk of distal 16q segment imbalance (shorter segment) was obtained in comparison with the rate (0/10, i.e. <4.8%) for RCT at risk of proximal segment imbalance (longer segment). It supports findings obtained from the original data for RCT with other chromosomes, where the probability for unbalanced offspring generally increased with decreasing length of the segments involved in RCT. Our results were applied for five new families with RCT involving 16q, namely three at risk of single-segment imbalance [t(8;16)(q24.3;q22)GTG, ish(wcp8+,wcp16+;wcp8

  3. Co-Occurence of Reciprocal Translocation and COL2A1 Mutation in a Fetus with Severe Skeletal Dysplasia: Implications for Genetic Counseling.

    PubMed

    Heinrich, Tilman; Nanda, Indrajit; Rehn, Monika; Zollner, Ursula; Ernestus, Karen; Wirth, Clemens; Schlüter, Gregor; Schmid, Michael; Kunstmann, Erdmute

    2015-01-01

    Achondrogenesis type II is an autosomal-dominant disease leading to severe micromelic dwarfism. Here, we report on the postmortem identification of a de novo heterozygous mutation in the COL2A1 gene (c.1529G>A, p.Gly510Asp) in a fetus who presented with generalized hydrops fetalis and severe micromelia during prenatal sonographic examinations. Initially, a reciprocal translocation t(4;17)(q31;p13) was detected in this fetus by chorionic villus sampling. Subsequent chromosomal analysis of maternal and paternal blood showed that the patient's mother was carrier of the same reciprocal translocation. SNP array analysis of the fetus did not provide evidence for chromosomal imbalances or CNVs that could be associated with the fetal phenotype. The coexistence of a cytogenetic (reciprocal translocation) and a molecular genetic (COL2A1 mutation) abnormality in the fetus carries important implications for genetic counseling. PMID:25823796

  4. Normal birth following PGD for reciprocal translocation after serial vitrification of oocytes from a poor responder: a case report.

    PubMed

    Chung, Jin Tae; Son, Weon-Young; Zhang, Xiao Yun; Ao, Asangla; Tan, Seang Lin; Holzer, Hananel

    2012-11-01

    This case study reports the first successful birth outcome following preimplantation genetic diagnosis (PGD) for a chromosome translocation in embryos generated by serial vitrification of oocytes. A couple presented to the fertility clinic with 2 years of primary infertility. The woman was diagnosed with poor ovarian reserve and her partner was diagnosed with severe oligoteratozoospermia and the reciprocal translocation 46,XY,t(1;7)(p36.1;q11.23). Following counselling, the couple opted for serial vitrification of oocytes followed by PGD. A total of 31 oocytes were obtained in five egg collection cycles over a period of 12 months and 27 metaphase-II oocytes were vitrified. Nineteen of the 27 vitrified oocytes survived warming: 14 oocytes from the vitrified group and three oocytes from the fresh cycle were fertilized by intracytoplasmic sperm injection. Eleven embryos, including three from the fresh cycle, were biopsied on day 3 post insemination. Fluorescence in-situ hybridization was performed for the specific chromosomes involved in translocation. Only two embryos from the cryopreservation cycles were diagnosed as normal/balanced, one of which was transferred on day 5 post insemination. A normal healthy female infant was born at week 42 of gestation. PMID:22995749

  5. De novo apparently balanced reciprocal translocation between 5q11.2 and 17q23 associated with Klippel-Feil anomaly and type A1 brachydactyly

    SciTech Connect

    Fukushima, Yoshimitsu; Ohashi, Hirofumi; Wakui, Keiko

    1995-07-03

    We report on a girl with Klippel-Feil anomaly, type A1 brachydactyly, and minor facial anomalies. She has an apparently balanced de novo reciprocal translocation between 5q11.2 and 17q23. The possible significance of this chromosomal abnormality is discussed. 7 refs., 3 figs.

  6. Meiotic segregation of five different reciprocal translocations in the onion fly, Hylemya antiqua (Meigen).

    PubMed

    Vosselman, L

    1981-01-01

    For one translocation (T14) with short interstitial segments in Hylemya antiqua significant differences in segregation behaviour between males and females were observed. In males the ratio of alternate:adjacent 1:adjacent 2 was approximately 7:3:0 and in females about 8:1:3. This difference is attributed to the difference in type of chromosome association. Female meiosis is chiasmate and male meiosis is achiasmate. It is suggested that meiotic pairing in males results in relative short "Coorientation Determining Distances" (CDDs) between homologous centromeres which favours alternate and adjacent 1 segregation. In females because of non-localized chiasmata on the average no differences in CDD between homologous and nonhomologous centromeres are expected. This might explain the occurrence of coorientation between non-homologous centromeres resulting in adjacent 2 segregations. Four other translocations with longer interstitial segments than T14 showed in males as well as females predominantly an alternate and adjacent 1 segregation, adjacent 2 was hardly found (0-3.6%). The longer distance between non-homologous centromeres is probably the reason. PMID:7472022

  7. Mechanism of the t(14; 18) chromosomal translocation: structural analysis of both derivative 14 and 18 reciprocal partners

    SciTech Connect

    Bakhshi, A.; Wright, J.J.; Graninger, W.; Seto, M.; Owens, J.; Cossman, J.; Jensen, J.P.; Goldman, P.; Korsmeyer, S.J.

    1987-04-01

    To elucidate the mechanism of the t(14;18)(q32;q21) chromosomal translocation found in follicular lymphoma, the authors examined the structure of both derivative (der) chromosomal breakpoints as well as their germ-line predecessors. They noted that chromosome segment 18q21 was juxtaposed with immunoglobulin heavy (H) chain gene diversity (D/sub H/) regions on all five der(18) chromosomes they examined, and they confirmed the juncture with immunoglobulin H-chain gene joining (J/sub H/) regions on the der(14) chromosome. However, the t(14;18) was not fully reciprocal in that chromosome 14 DNA between the D/sub H/ and J/sub H/ regions was deleted. Furthermore, extra nucleotides, reminiscent of N segments, were present at the der(14) and possibly der(18) junctions. This indicates that despite the mature B-cell phenotype of follicular lymphoma, the t(14;18) occurs during attempted D/sub H/-J/sub H/ joining, the earliest event in immunoglobulin rearrangement in a pre-B-cell. The detailed analysis of the germ-line 18q21 region indicated that most breakpoints clustered within a 150-base-pair major breakpoint region. A direct repeat duplication of chromosome 18 sequences was discovered at both chromosomal junctures, typical of the repair of a naturally occurring staggered double-stranded DNA break. These results prompt a translocation model with illegitimate pairing of a staggered double-stranded DNA break at 18q21 and an immunoglobulin endonuclease-mediated break at 14q32 and with N-segment addition, repair, and ligation to generate der(14) and der(18) chromosomes.

  8. Testing for Local Adaptation to Spawning Habitat in Sympatric Subpopulations of Pike by Reciprocal Translocation of Embryos

    PubMed Central

    Berggren, Hanna; Nordahl, Oscar; Tibblin, Petter; Larsson, Per

    2016-01-01

    We tested for local adaption in early life-history traits by performing a reciprocal translocation experiment with approximately 2,500 embryos of pike (Esox lucius) divided in paired split-family batches. The experiment indicated local adaptation in one of the two subpopulations manifested as enhanced hatching success of eggs in the native habitat, both when compared to siblings transferred to a non-native habitat, and when compared to immigrant genotypes from the other subpopulation. Gene-by-environment effects on viability of eggs and larvae were evident in both subpopulations, showing that there existed genetic variation allowing for evolutionary responses to divergent selection, and indicating a capacity for plastic responses to environmental change. Next, we tested for differences in female life-history traits. Results uncovered that females from one population invested more resources into reproduction and also produced more (but smaller) eggs in relation to their body size compared to females from the other population. We suggest that these females have adjusted their reproductive strategies as a counter-adaptation because a high amount of sedimentation on the eggs in that subpopulations spawning habitat might benefit smaller eggs. Collectively, our findings point to adaptive divergence among sympatric subpopulations that are physically separated only for a short period during reproduction and early development—which is rare. These results illustrate how combinations of translocation experiments and field studies of life-history traits might infer about local adaptation and evolutionary divergence among populations. Local adaptations in subdivided populations are important to consider in management and conservation of biodiversity, because they may otherwise be negatively affected by harvesting, supplementation, and reintroduction efforts targeted at endangered populations. PMID:27139695

  9. A Non-Reciprocal Autosomal Translocation 64,XX, t(4;10)(q21;p15) in an Arabian Mare with Repeated Early Embryonic Loss.

    PubMed

    Ghosh, S; Das, P J; Avila, F; Thwaits, B K; Chowdhary, B P; Raudsepp, T

    2016-02-01

    Balanced autosomal translocations are a known cause for repeated early embryonic loss (REEL) in horses. In most cases, carriers of such translocations are phenotypically normal, but the chromosomal aberration negatively affects gametogenesis giving rise to both genetically balanced and unbalanced gametes. The latter, if involved in fertilization, result in REEL, whereas gametes with the balanced form of translocation will pass the defect into next generation. Therefore, in order to reduce the incidence of REEL, identification of translocation carriers is critical. Here, we report about a phenotypically normal 3-year-old Arabian mare that had repeated resorption of conceptuses prior to day 45 of gestation and was diagnosed with REEL. Conventional and molecular cytogenetic analyses revealed that the mare had normal chromosome number 64,XX but carried a non-mosaic and non-reciprocal autosomal translocation t(4;10)(q21;p15). This is a novel translocation described in horses with REEL and the first such report in Arabians. Previous cases of REEL due to autosomal translocations have exclusively involved Thoroughbreds. The findings underscore the importance of routine cytogenetic screening of breeding animals. PMID:26547799

  10. Turner Syndrome with Isochromosome Xq and Familial Reciprocal Translocation t(4;16)(p15.2;p13.1)

    PubMed Central

    Cetin, Z; Mendilcioglu, I; Yakut, S; Berker-Karauzum, S; Karaman, B; Luleci, G

    2011-01-01

    We present here a 16-year-old Turner syndrome patient with a complex karyotype that includes a maternally-inherited balanced translocation between chromosomes 4 and 16 and mosaicism of the isochromosome Xq10. Her karyotype was 45,X,t(4;16) (p15.2;p13.1)[9]/46,X,i(X) (q10),t(4;16)(p15.2;p13.1) [91]. The karyotype of her father was normal, whereas that of her mother had the same balanced translocation and numerical abnormalities of chromosome X and was designated as 45,X,t(4;16)(p15.2;p13.1) [2]/46,XX,t(4;16)(p15.2;p13.1)[93]/47,XXX,t(4;16) (p15.2; p13.1)[5]. The two siblings of the patient also had the same reciprocal translocation. We consider this to be the first such patient with an inherited reciprocal translocation and structural abnormality of the X chromosome (isochromosome Xq). PMID:24052704

  11. Warburg effect and translocation-induced genomic instability: two yeast models for cancer cells

    PubMed Central

    Tosato, Valentina; Grüning, Nana-Maria; Breitenbach, Michael; Arnak, Remigiusz; Ralser, Markus; Bruschi, Carlo V.

    2013-01-01

    Yeast has been established as an efficient model system to study biological principles underpinning human health. In this review we focus on yeast models covering two aspects of cancer formation and progression (i) the activity of pyruvate kinase (PK), which recapitulates metabolic features of cancer cells, including the Warburg effect, and (ii) chromosome bridge-induced translocation (BIT) mimiking genome instability in cancer. Saccharomyces cerevisiae is an excellent model to study cancer cell metabolism, as exponentially growing yeast cells exhibit many metabolic similarities with rapidly proliferating cancer cells. The metabolic reconfiguration includes an increase in glucose uptake and fermentation, at the expense of respiration and oxidative phosphorylation (the Warburg effect), and involves a broad reconfiguration of nucleotide and amino acid metabolism. Both in yeast and humans, the regulation of this process seems to have a central player, PK, which is up-regulated in cancer, and to occur mostly on a post-transcriptional and post-translational basis. Furthermore, BIT allows to generate selectable translocation-derived recombinants (“translocants”), between any two desired chromosomal locations, in wild-type yeast strains transformed with a linear DNA cassette carrying a selectable marker flanked by two DNA sequences homologous to different chromosomes. Using the BIT system, targeted non-reciprocal translocations in mitosis are easily inducible. An extensive collection of different yeast translocants exhibiting genome instability and aberrant phenotypes similar to cancer cells has been produced and subjected to analysis. In this review, we hence provide an overview upon two yeast cancer models, and extrapolate general principles for mimicking human disease mechanisms in yeast. PMID:23346549

  12. Bacterial translocation in the rat model of lectin induced diarrhoea.

    PubMed

    Shoda, R; Mahalanabis, D; Wahed, M A; Albert, M J

    1995-03-01

    Red kidney beans were fed to weanling Long-Evans rats to cause diarrhoea (mean (SD) faecal wet weight: 2.66 (0.73) g/day in six rats fed beans v 1.12 (0.47) g/day in six control rats, p < 0.01) and increased faecal energy loss (4.87 (0.41) v 2.14 (0.23) kcal/day, p < 0.01). In addition, the rats fed beans had heavier small intestines (80.6 (4.6) v 51.9 (8.4) g/kg body weight, p < 0.01), heavier mesenteric lymph nodes (0.72 (0.27) v 0.08 (0.08) g/kg body weight, p < 0.05), and translocation of indigenous intestinal bacteria, Citrobacter Spp and Escherichia coli, to the mesenteric lymph nodes. (Translocation positive, that is, > 100 colonies per g of nodal tissue: 75% v 0%, p < 0.005.) These data suggest that diarrhoea induced by red kidney beans is a suitable model for studies of an important cause of persistent diarrhoea--that is, systemic complications. This rat model of lectin induced diarrhoea with translocation of intraluminal enteric bacteria into mesenteric lymph nodes should be useful in understanding the well known septicaemic complications associated with prolonged diarrhoea in infants and small children and in studies on factors that may modify or prevent bacterial translocation. PMID:7698696

  13. Monosomy 1p36.31-33{yields}pter due to a paternal reciprocal translocation: Prognostic significance of FISH analysis

    SciTech Connect

    Blennow, E.; Bui, The-Hung; Wallin, A.

    1996-10-02

    A rare monosomy 1p36.31-33{r_arrow}pter was found in a child with physical anomalies, psycho-motor retardation, and seizures. Cytogenetic investigation suggested an unbalanced translocation between 1p and an acrocentric chromosome, but the rearrangement was difficult to assess accurately using conventional chromosome banding techniques. The half-cryptic translocation was further characterized using fluorescence in situ hybridization, and the aberrant chromosome 1 was shown to be a derivate of a paternal reciprocal translocation t(1;15)(p36.31-33;p11.2-12). The breakpoints on chromosome 1 and 15 were defined in detail using locus specific probes. The rearrangement did not include the region on chromosome 1p which previously has been suggested to predispose to the development of neuroblastoma in a case with a constitutional translocation. At 3 6/12 years, the patient has no clinical signs of this disease, which illustrates the prognostic significance of this investigation. 30 refs., 4 figs., 1 tab.

  14. Flow-induced translocation of star polymers through a nanopore.

    PubMed

    Ding, Mingming; Duan, Xiaozheng; Shi, Tongfei

    2016-03-01

    We study the flow-induced translocation of the star polymers through a nanopore using a hybrid simulation method that incorporates a lattice-Boltzmann approach for the fluid into a molecular dynamics model for the polymer. Our simulation demonstrates the existence of an optimal forward arm number of the star polymers captured by the nanopore, and illustrates its significance in determining the critical velocity flux of the star polymer translocation through the nanopore. Importantly, we find that the critical velocity flux of the star polymers is independent of the arm polymerization degree, but exhibits a linear dependence on the arm number. Based on previous scaling arguments and our simulation results, we conclude a linear dependence of the critical velocity flux on the arm number of the star polymers, which can successfully describe the dynamics of the star polymer translocation. Our simulation results rationalize the experimental results for the dependence of the critical velocity flux on the arm polymerization degree and the arm number of the star polymers, which provide new insights for the characterization and the purification of the star polymers. PMID:26879130

  15. A homozygous balanced reciprocal translocation suggests LINC00237 as a candidate gene for MOMO (macrosomia, obesity, macrocephaly, and ocular abnormalities) syndrome.

    PubMed

    Vu, Phi Yen; Toutain, Jérôme; Cappellen, David; Delrue, Marie-Ange; Daoud, Hussein; El Moneim, Azza Abd; Barat, Pascal; Montaubin, Orianne; Bonnet, Françoise; Dai, Zong Qi; Philippe, Christophe; Tran, Cong Toai; Rooryck, Caroline; Arveiler, Benoît; Saura, Robert; Briault, Sylvain; Lacombe, Didier; Taine, Laurence

    2012-11-01

    Macrosomia, obesity, macrocephaly, and ocular abnormalities syndrome (MOMO syndrome) has been reported in only four patients to date. In these sporadic cases, no chromosomal or molecular abnormality has been identified thus far. Here, we report on the clinical, cytogenetic, and molecular findings in a child of healthy consanguineous parents suffering from MOMO syndrome. Conventional karyotyping revealed an inherited homozygous balanced reciprocal translocation (16;20)(q21;p11.2). Uniparental disomy testing showed bi-parental inheritance for both derivative chromosomes 16 and 20. The patient's oligonucleotide array-comparative genomic hybridization profile revealed no abnormality. From the homozygous balanced reciprocal translocation (16;20)(q21;p11.2), a positional cloning strategy, designed to narrow 16q21 and 20p11.2 breakpoints, revealed the disruption of a novel gene located at 20p11.23. This gene is now named LINC00237, according to the HUGO (Human Genome Organization) nomenclature. The gene apparently leads to the production of a non-coding RNA. We established that LINC00237 was expressed in lymphocytes of control individuals while normal transcripts were absent in lymphocytes of our MOMO patient. LINC00237 was not ubiquitously expressed in control tissues, but it was notably highly expressed in the brain. Our results suggested autosomal recessive inheritance of MOMO syndrome. LINC00237 could play a role in the pathogenesis of this syndrome and could provide new insights into hyperphagia-related obesity and intellectual disability. PMID:23034868

  16. Three new cases with a mosaicism involving a normal cell line and a cryptic unbalanced autosomal reciprocal translocation.

    PubMed

    Gijsbers, Antoinet C J; Dauwerse, Johannes G; Bosch, Cathy A J; Boon, Elles M J; van den Ende, Wilco; Kant, Sarina G; Hansson, Kerstin M B; Breuning, Martijn H; Bakker, Egbert; Ruivenkamp, Claudia A L

    2011-01-01

    Mosaicism involving a normal cell line and an unbalanced autosomal translocation are rare. In this study we present three new cases with such a mosaicism, which were detected by Single Nucleotide Polymorphism (SNP) array analysis in our routine diagnostic setting. These cases were further characterized using Fluorescence in situ Hybridisation (FISH) analysis and conventional karyotyping. The first case is a mentally retarded male who carries an unbalanced translocation in 87% of his cells. The phenotypically normal mother carries the balanced form of the translocation in all her cells. The second case is a phenotypically normal female who has an unbalanced translocation in 52% of her cells. The inheritance could not be determined. The third case is a female referred for Rubinstein-Taybi syndrome who carries an unbalanced translocation in 60% of her cells. Both parents of this case showed a normal karyotype. The mechanisms that might be responsible for these mosaic karyotypes are discussed. Furthermore, we demonstrate that high-resolution whole-genome SNP array is a powerful tool to reveal cryptic unbalanced translocations and mosaicisms, including the more rare cases. PMID:21664500

  17. A cohort of balanced reciprocal translocations associated with dyslexia: identification of two putative candidate genes at DYX1.

    PubMed

    Buonincontri, Roberta; Bache, Iben; Silahtaroglu, Asli; Elbro, Carsten; Nielsen, Anne-Mette Veber; Ullmann, Reinhard; Arkesteijn, Ger; Tommerup, Niels

    2011-01-01

    Dyslexia is one of the most common neurodevelopmental disorders where likely many genes are involved in the pathogenesis. So far six candidate dyslexia genes have been proposed, and two of these were identified by rare chromosomal translocations in affected individuals. By systematic re-examination of all translocation carriers in Denmark, we have identified 16 different translocations associated with dyslexia. In four families, where the translocation co-segregated with the phenotype, one of the breakpoints concurred (at the cytogenetic level) with either a known dyslexia linkage region--at 15q21 (DYX1), 2p13 (DYX3) and 1p36 (DYX8)--or an unpublished linkage region at 19q13. As a first exploitation of this unique cohort, we identify three novel candidate dyslexia genes, ZNF280D and TCF12 at 15q21, and PDE7B at 6q23.3, by molecular mapping of the familial translocation with the 15q21 breakpoint. PMID:20798984

  18. Hyperthermia increases gamma-ray and fission neutron-induced translocations in Drosophila

    SciTech Connect

    Mittler, S.

    1984-01-01

    Hyperthermia has been reported in Drosophila melanogaster to increase radiation-induced chromosome rearrangements, chromosome loss, recessive and dominant lethals. To determine whether hyperthermia would also affect high linear energy transfer (LET)-induced genetic damage such as translocations, which involve breakage and reunion of chromosomes, a genetic system was employed not only allowing detection of ordinary 2;3 translocations, but also permitting a more accurate measure of Y-autosome translocations.

  19. Unbalanced interchromosomal insertion diagnosed prenatally by FISH, with carrier mother, previously misdiagnosed as having a balanced reciprocal translocation

    SciTech Connect

    Yu, M.T.; Leiber, E.; Qazi, Q.

    1994-09-01

    Insertion translocations are rare. A carrier with a balanced insertion translocation is most likely to be detected through offspring with an unbalanced translocation. We with to report a case where a correct diagnosis, made prenatally with FISH, corrected the initial misdiagnosis of the mother in another institute. PDL received an amniotic fluid sample from a 28 y.o. woman (G5P2Sab1TOP1) at 19 wks gestation. The indications were a reported balanced translocation, t(6;13), in the mother and a previous daughter with an unbalanced translocation. Chromosome analysis of the amniocytes showed a female karyotype with an abnormal chr. 13. Since the mother was diagnosed as having t(6;13)(q21;q34), the der(13) in the amniocytes was initially assumed to result from an adjacent segregation of the t(6;13). However, the banding patterns of this abnormal chr. 13 did not fit into the above defined translocation. With FISH and a chr. 13 painting probe, this der(13) was painted in the proximal and the distal thirds, but NOT in the middle region. This indicates that the middle section of the der(13) must have originated from 6q. The banding pattern is compatible with a direct insertion of 6q15 to 6q23.3 into 13q21.2. Thus, the fetus has partial trisomy 6q. After counseling, the mother elected to terminate the pregnancy but later changed her mind. An 8 lb 12 oz baby girl was born at 36 wks. (mother diabetic). Chromosome analysis of the newborn blood confirmed the dx. The mother was studied, using multicolor painting probes for chromosomes 13 and 6, a balanced direct insertion of 6q15 to 6q23.3 into chr. 13q21.2 was clearly shown. The previous affected daughter with a 13q+ is now 4 y.o. (a restudy is planned). She has microcephaly, severe developmental delay and other dysmorphic features. This case illustrates the advantage of using FISH to arrive at a definitive diagnosis of an insertion translocation.

  20. Temporal and spatial characteristics of bid and bax translocation during UV-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Wu, Yinyuan; Xing, Da; Liu, Lei; Chen, Tongsheng

    2007-05-01

    UV irradiation is a DNA-damage agent that triggers apoptosis through both the membrane death receptor and the mitochondrial apoptotic signaling pathways. Bid and Bax are two important proapoptotic members of the Bcl-2 family, localize largely in the cytoplasm and redistribute to mitochondria in response to most apoptotic stimuli. Cells deficient in Bax are resistant to UV-induced apoptosis, cells deficient in Bid are less susceptible than normal cells in response to DNA damage. Thus, studying characteristics of Bid and Bax translocation by UV irradiation is very important for us to understand the cellular signaling mechanisms mediating UV-induced apoptosis. In this study, to investigate Bid and Bax translocation in real time in a single cell by UV irradiation, we transfected Bid-CFP, YFP-Bax and DsRed-Mit into human lung adenocarcinoma cells (ASTC-a-1), then observed temporal and spatial characteristics of Bid and Bax translocation by laser confocal scanning microscope imaging technique. Our results showed that Bax translocation was earlier than Bid translocation and the average duration of Bax translocation was about 20-30 min during UV-induced apoptosis.

  1. Bax translocation into mitochondria during dihydroartemisinin(DHA)-induced apoptosis in human lung adenocarcinoma cells

    NASA Astrophysics Data System (ADS)

    Lu, Ying-ying; Chen, Tong-sheng; Qu, Jun-Le

    2009-02-01

    Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, isolated from the traditional Chinese herb Artemisia annua, has been shown to possess promising anticancer activities and induce cancer cell death through apoptotic pathways. However, the molecular mechanisms are not well understood. This study was investigated in human lung adenocarconoma ASTC-a-1 cell line and aimed to determine whether the apoptotic process was mediated by Bax activation and translocation during DHA-induced apoptosis. In this study, DHA induced a time-dependent apoptotic cell death, which was assayed by Cell Counting Kit (CCK-8) and Hoechst 33258 staining. Detection of Bax aggregation and translocation to mitochondria was observed in living cells which were co-transfected with GFP-Bax and Dsred-mito plasmid using confocal fluorescence microscope technique. Overall, these results demonstrated that Bax activation and translocation to mitochondria occurred during DHA-induced apoptosis.

  2. Different Aneuploidies Arise From the Same Bridge-Induced Chromosomal Translocation Event in Saccharomyces cerevisiae

    PubMed Central

    Rossi, Beatrice; Noel, Pawan; Bruschi, Carlo V.

    2010-01-01

    Chromosome translocations are gross chromosomal rearrangements that have often been associated with cancer development in mammalian cells. The feasibility of drastically reshaping the genome with a single translocation event also gives this molecular event a powerful capacity to drive evolution. Despite these implications and their role in genome instability, very little is known about the molecular mechanisms that promote and accompany these events. Here, at the molecular level, we describe 10 morphologically and physiologically different translocants ensuing from the induction of the same bridge-induced translocation (BIT) event in the budding yeast Saccharomyces cerevisiae. We have demonstrated that, despite their common origin from the integration of the same linear DNA construct, all 10 translocation mutant strains have different phenotypes and the ability to sporulate and regulate gene expression and morphology. We also provide insights into how heterogeneous phenotypic variations originate from the same initial genomic event. Here we show eight different ways in which yeast cells have dealt with a single initial event inducing translocation. Our results are in agreement with the formation of complex rearrangements and abnormal karyotypes described in many leukemia patients, thus confirming the modellistic value of the yeast BIT system for mammalian cells. PMID:20805555

  3. pH sensing by intracellular Salmonella induces effector translocation.

    PubMed

    Yu, Xiu-Jun; McGourty, Kieran; Liu, Mei; Unsworth, Kate E; Holden, David W

    2010-05-21

    Salmonella enterica is an important intracellular bacterial pathogen of humans and animals. It replicates within host-cell vacuoles by delivering virulence (effector) proteins through a vacuolar membrane pore made by the Salmonella pathogenicity island 2 (SPI-2) type III secretion system (T3SS). T3SS assembly follows vacuole acidification, but when bacteria are grown at low pH, effector secretion is negligible. We found that effector secretion was activated at low pH from mutant strains lacking a complex of SPI-2-encoded proteins SsaM, SpiC, and SsaL. Exposure of wild-type bacteria to pH 7.2 after growth at pH 5.0 caused dissociation and degradation of SsaM/SpiC/SsaL complexes and effector secretion. In infected cells, loss of the pH 7.2 signal through acidification of host-cell cytosol prevented complex degradation and effector translocation. Thus, intravacuolar Salmonella senses host cytosolic pH, resulting in the degradation of regulatory complex proteins and effector translocation. PMID:20395475

  4. Murine Model of Chemotherapy-Induced Extraintestinal Pathogenic Escherichia coli Translocation

    PubMed Central

    Green, Sabrina I.; Ajami, Nadim J.; Ma, Li; Poole, Nina M.; Price, Roger E.; Petrosino, Joseph F.

    2015-01-01

    Escherichia coli is a major cause of life-threatening infections in patients with neutropenia, particularly those receiving chemotherapy for the treatment of cancer. In most cases, these infections originate from opportunistic strains living within the patient's gastrointestinal tract which then translocate to major organ systems. There are no animal models that faithfully recapitulate these infections, and, as such, the host or bacterial factors that govern this process remain unidentified. We present here a novel model of chemotherapy-induced bacterial translocation of E. coli. Oral gavage of BALB/c mice with a clinical isolate of extraintestinal pathogenic E. coli (ExPEC) leads to stable and long-term colonization of the murine intestine. Following the induction of neutropenia with the chemotherapeutic drug cyclophosphamide, ExPEC translocates from the intestine to the lungs, liver, spleen, and kidneys with concomitant morbidity in infected animals. Translocation can also occur in mice bearing mammary tumors, even in the absence of chemotherapy. Translocation of ExPEC is also associated with an increase of the diversity of bacterial DNA detected in the blood. This is the first report of a chemotherapy-based animal model of ExPEC translocation in cancerous mice, a system that can be readily used to identify important virulence factors for this process. PMID:26034214

  5. PARP-1 Hyperactivation and Reciprocal Elevations in Intracellular Ca2+ During ROS-Induced Nonapoptotic Cell Death

    PubMed Central

    Zhang, Fengjiao; Xie, Ruiye; Munoz, Frances M.; Lau, Serrine S.; Monks, Terrence J.

    2014-01-01

    The generation of reactive oxygen species (ROS) has been implicated in the pathogenesis of renal ischemia/reperfusion injury, and many other pathological conditions. DNA strand breaks caused by ROS lead to the activation of poly(ADP-ribose)polymerase-1 (PARP-1), the excessive activation of which can result in cell death. We have utilized a model in which 2,3,5-tris(glutathion-S-yl)hydroquinone (TGHQ), a nephrotoxic and nephrocarcinogenic metabolite of hydroquinone, causes ROS-dependent cell death in human renal proximal tubule epithelial cells (HK-2), to further elucidate the role of PARP-1 in ROS-dependent cell death. TGHQ-induced ROS generation, DNA strand breaks, hyperactivation of PARP-1, rapid depletion of nicotinamide adenine dinucleotide (NAD), elevations in intracellular Ca2+ concentrations, and subsequent nonapoptotic cell death in both a PARP- and Ca2+-dependent manner. Thus, inhibition of PARP-1 with PJ34 completely blocked TGHQ-mediated accumulation of poly(ADP-ribose) polymers and NAD consumption, and delayed HK-2 cell death. In contrast, chelation of intracellular Ca2+ with BAPTA completely abrogated TGHQ-induced cell death. Ca2+ chelation also attenuated PARP-1 hyperactivation. Conversely, inhibition of PARP-1 modulated TGHQ-mediated changes in Ca2+ homeostasis. Interestingly, PARP-1 hyperactivation was not accompanied by the translocation of apoptosis-inducing factor (AIF) from mitochondria to the nucleus, a process usually associated with PARP-dependent cell death. Thus, pathways coupling PARP-1 hyperactivation to cell death are likely to be context-dependent, and therapeutic strategies designed to target PARP-1 need to recognize such variability. Our studies provide new insights into PARP-1-mediated nonapoptotic cell death, during which PARP-1 hyperactivation and elevations in intracellular Ca2+ are reciprocally coupled to amplify ROS-induced nonapoptotic cell death. PMID:24752504

  6. AIRE-induced apoptosis is associated with nuclear translocation of stress sensor protein GAPDH

    SciTech Connect

    Liiv, Ingrid; Haljasorg, Uku; Kisand, Kai; Maslovskaja, Julia; Laan, Martti; Peterson, Paert

    2012-06-22

    Highlights: Black-Right-Pointing-Pointer AIRE induces apoptosis in epithelial cells. Black-Right-Pointing-Pointer CARD domain of AIRE is sufficient for apoptosis induction. Black-Right-Pointing-Pointer AIRE induced apoptosis involves GAPDH translocation to the nuclei. Black-Right-Pointing-Pointer Deprenyl inhibits AIRE induced apoptosis. -- Abstract: AIRE (Autoimmune Regulator) has a central role in the transcriptional regulation of self-antigens in medullary thymic epithelial cells, which is necessary for negative selection of autoreactive T cells. Recent data have shown that AIRE can also induce apoptosis, which may be linked to cross-presentation of these self-antigens. Here we studied AIRE-induced apoptosis using AIRE over-expression in a thymic epithelial cell line as well as doxycycline-inducible HEK293 cells. We show that the HSR/CARD domain in AIRE together with a nuclear localization signal is sufficient to induce apoptosis. In the nuclei of AIRE-positive cells, we also found an increased accumulation of a glycolytic enzyme, glyceraldehyde-3-phosphate (GAPDH) reflecting cellular stress and apoptosis. Additionally, AIRE-induced apoptosis was inhibited with an anti-apoptotic agent deprenyl that blocks GAPDH nitrosylation and nuclear translocation. We propose that the AIRE-induced apoptosis pathway is associated with GAPDH nuclear translocation and induction of NO-induced cellular stress in AIRE-expressing cells.

  7. PUMA promotes Bax translocation by competitive binding to Bcl-Xl during UV-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Zhang, Yingjie; Xing, Da; Wu, Yinyuan; Liu, Lei

    2008-02-01

    Ultraviolet (UV) irradiation can induce apoptosis through both the membrane death receptor and the intrinsic apoptotic signaling pathways as DNA-damaging agents. PUMA, a BH3-only Bcl-2 family protein, plays an essential role in DNA damage-induced apoptosis. Bax, also a Bcl-2 family member, translocates from the cytosol to the mitochondrial membrane during UV-induced apoptosis. However, the regulation of Bax activation induced by UV irradiation remains poorly understood. In this study, the FRET (fluorescence resonance energy transfer) technique was used to study the interactions of Bax, Bcl-Xl, and PUMA in ASTC-a-1 cells. The results show that Bax translocated from the cytosol to the mitochondrial membrane at about 7 h after UV irradiation, and the translocation can not be blocked completely when overexpressed Bcl-xl. Moreover, The interaction of Bax and Bcl-Xl weakened markedly. In addition, Co-immunoprecipitation shows that PUMA released Bax by directly binding to Bcl-XL after UV irradiation in ASTC-a-1 cells. Taken together, these results indicated that PUMA can promote Bax translocation by binding to Bcl-Xl during UV-induced apoptosis.

  8. In a model of immunoglobulin heavy-chain (IGH)/MYC translocation, the Igh 3' regulatory region induces MYC expression at the immature stage of B cell development.

    PubMed

    Yan, Yi; Park, Sung Sup; Janz, Siegfried; Eckhardt, Laurel A

    2007-10-01

    Reciprocal translocations involving the immunoglobulin loci and the cellular oncogene MYC are hallmark mutations of the human postgerminal center B cell neoplasm, Burkitt's lymphoma. They are occasionally found in other B cell lymphomas, as well. Translocations involving the heavy chain locus (IGH) place the MYC gene either in cis with both the intronic enhancer Emu and the IGH 3' regulatory region (3'RR) or in cis with only the 3'RR. The result is deregulated MYC expression. Recent studies have led to some controversy as to when, during B lymphocyte development, IGH/MYC chromosome translocations take place. A related issue, relevant not only to lymphoma development but also to normal controls on IGH gene expression, is the stage, during B lymphocyte development, at which the 3'RR is capable of activating MYC expression. We have developed mice transgenic for a human MYC (hMYC) gene under control of the four core enhancers from the mouse Igh 3'RR. Unlike other transgenic mouse models where premature and inappropriate MYC expression disrupts normal B cell development, the hMYC transgene in these studies carries a mutation that prohibits MYC protein synthesis. As a result, hMYC expression can be analyzed in all of the normal B cell compartments. Our data show that hMYC is expressed almost exclusively in B-lineage cells and is induced to high levels as soon as bone marrow cells reach the immature B cell stage. PMID:17639584

  9. A computational approach to the relationship between radiation induced double strand breaks and translocations

    NASA Technical Reports Server (NTRS)

    Holley, W. R.; Chatterjee, A.

    1994-01-01

    A theoretical framework is presented which provides a quantitative analysis of radiation induced translocations between the ab1 oncogene on CH9q34 and a breakpoint cluster region, bcr, on CH 22q11. Such translocations are associated frequently with chronic myelogenous leukemia. The theory is based on the assumption that incorrect or unfaithful rejoining of initial double strand breaks produced concurrently within the 200 kbp intron region upstream of the second abl exon, and the 16.5 kbp region between bcr exon 2 and exon 6 interact with each other, resulting in a fusion gene. for an x-ray dose of 100 Gy, there is good agreement between the theoretical estimate and the one available experimental result. The theory has been extended to provide dose response curves for these types of translocations. These curves are quadratic at low doses and become linear at high doses.

  10. Flow-induced polymer translocation through a nanopore from a confining nanotube.

    PubMed

    Ding, Mingming; Chen, Qiaoyue; Duan, Xiaozheng; Shi, Tongfei

    2016-05-01

    We study the flow-induced polymer translocation through a nanopore from a confining nanotube, using a hybrid simulation method that couples point particles into a fluctuating lattice-Boltzmann fluid. Our simulation illustrates that the critical velocity flux of the polymer linearly decreases with the decrease in the size of the confining nanotube, which corresponds well with our theoretical analysis based on the blob model of the polymer translocation. Moreover, by decreasing the size of the confining nanotube, we find a significantly favorable capture of the polymer near its ends, as well as a longer translocation time. Our results provide the computational and theoretical support for the development of nanotechnologies based on the ultrafiltration and the single-molecule sequencing. PMID:27155652

  11. Flow-induced polymer translocation through a nanopore from a confining nanotube

    NASA Astrophysics Data System (ADS)

    Ding, Mingming; Chen, Qiaoyue; Duan, Xiaozheng; Shi, Tongfei

    2016-05-01

    We study the flow-induced polymer translocation through a nanopore from a confining nanotube, using a hybrid simulation method that couples point particles into a fluctuating lattice-Boltzmann fluid. Our simulation illustrates that the critical velocity flux of the polymer linearly decreases with the decrease in the size of the confining nanotube, which corresponds well with our theoretical analysis based on the blob model of the polymer translocation. Moreover, by decreasing the size of the confining nanotube, we find a significantly favorable capture of the polymer near its ends, as well as a longer translocation time. Our results provide the computational and theoretical support for the development of nanotechnologies based on the ultrafiltration and the single-molecule sequencing.

  12. A biophysical model for estimating the frequency of radiation-induced mutations resulting from chromosomal translocations

    NASA Astrophysics Data System (ADS)

    Wu, Honglu; Durante, Marco

    Gene mutations can be induced by radiation as a result of chromosomal translocations. A biophysical model is developed to estimate the frequency of this type of mutation induced by low-LET radiation. Mutations resulting from translocations are assumed to be formed by misrejoining of two DNA double strand breaks (DSB), one within the gene and one on a different chromosome. The chromosome containing the gene is assumed to occupy a spherical territory and does not overlap spatially with other chromosomes. Misrejoining between two DSB can occur only if the two DSB are closer than an interaction distance at the time of their induction. Applying the model to mutations of the hprt gene induced in G0 human lymphocyte cells by low-LET radiation, it is calculated that mutations resulting from translocations account for about 14% of the total mutations. The value of the interaction distance is determined to be 0.6 μm by comparing with the observed frequency of translocations in the X-chromosome.

  13. Cytoplasmic translocation of HuR contributes to angiotensin II induced cardiac fibrosis.

    PubMed

    Bai, Danna; Ge, Lan; Gao, Yan; Lu, Xiaozhao; Wang, Haichang; Yang, Guodong

    2015-08-01

    Cardiac fibrosis is one of the key structural changes of the hypertrophied left ventricle in hypertensive heart disease. Increased angiotensin II was found to be important in the hypertension related fibrosis, while the underlying mechanism is unknown. In this study, we found that angiotensin II dose-dependently increased the expression of Col1a1, Col3a1 and α-smooth muscle actin, which were blocked by ROS (reactive oxygen species) scavenger N-acetyl cysteine (NAC). Mechanistically, angiotensin II induced robust ROS generation, which in turn induced cytoplasmic translocation of RNA binding protein HuR. Cytoplasmic translocated HuR increased TGFβ pathway activity and subsequent collagen synthesis. In contrast, knockdown of HuR nearly blocked angiotensin II induced TGFβ activation and collagen synthesis. Taken together, we here identified that angiotensin II promotes collagen synthesis in cardiac fibroblast through ROS-HuR-TGFβ pathway. PMID:26093296

  14. The role of protein kinase C alpha translocation in radiation-induced bystander effect

    PubMed Central

    Fang, Zihui; Xu, An; Wu, Lijun; Hei, Tom K.; Hong, Mei

    2016-01-01

    Ionizing radiation is a well known human carcinogen. Evidence accumulated over the past decade suggested that extranuclear/extracellular targets and events may also play a critical role in modulating biological responses to ionizing radiation. However, the underlying mechanism(s) of radiation-induced bystander effect is still unclear. In the current study, AL cells were irradiated with alpha particles and responses of bystander cells were investigated. We found out that in bystander AL cells, protein kinase C alpha (PKCα) translocated from cytosol to membrane fraction. Pre-treatment of cells with PKC translocation inhibitor chelerythrine chloride suppressed the induced extracellular signal-regulated kinases (ERK) activity and the increased cyclooxygenase 2 (COX-2) expression as well as the mutagenic effect in bystander cells. Furthermore, tumor necrosis factor alpha (TNFα) was elevated in directly irradiated but not bystander cells; while TNFα receptor 1 (TNFR1) increased in the membrane fraction of bystander cells. Further analysis revealed that PKC activation caused accelerated internalization and recycling of TNFR1. Our data suggested that PKCα translocation may occur as an early event in radiation-induced bystander responses and mediate TNFα-induced signaling pathways that lead to the activation of ERK and up-regulation of COX-2. PMID:27165942

  15. Characterization of the plastidic phosphate translocators in the inducible crassulacean acid metabolism plant Mesembryanthemum crystallinum.

    PubMed

    Kore-eda, Shin; Nozawa, Akira; Okada, Yusuke; Takashi, Kazuki; Azad, Muhammad Abul Kalam; Ohnishi, Jun-ichi; Nishiyama, Yoshitaka; Tozawa, Yuzuru

    2013-01-01

    In plant Mesembryanthemum crystallinum, which has the inducible crassulacean acid metabolism (CAM), isoforms of plastidic phosphate translocators (pPTs) are categorized into three subfamilies: the triose phosphate/phosphate translocator (McTPT1), the phosphoenolpyruvate/phosphate translocator (McPPT1), and the glucose 6-phosphate/phosphate translocator (McGPT1 and McGPT2). In order to elucidate the physiological roles of these pPTs in M. crystallinum, we determined the substrate specificity of each pPT isoform. The substrate specificities of McTPT1, McPPT1, and McGPT1 showed overall similarities to those of orthologs that have been characterized. In contrast, for glucose 6-phosphate, McGPT2 showed higher selectivity than McGPT1 and other GPT orthologs. Because the expression of McGTP2 is specific to CAM while that of McGTP1 is constitutively expressed in both the C3- and the CAM-state in M. crystallinum, we propose that McGPT2 functions as a CAM system-specific GPT in this plant. PMID:23832369

  16. Translocation 1; 7 in dyshematopoiesis: possibly induced with a nonrandom geographic distribution

    SciTech Connect

    Scheres, J.M.; Hustinx, T.W.; Holdrinet, R.S.; Geraedts, J.P.; Hagemeijer, A.; van der Blij-Philipsen, M.

    1984-08-01

    Eight patients with various hematologic disorders had an identical chromosomal aberration in their bone marrow or unstimulated peripheral blood, a translocation t(1;7) interpreted as t(1;7)(p11;p11). The translocation chromosome replaced one normal chromosome number7; therefore, the karyotype of the abnormal cells was trisomic for 1q and monosomic for 7q. Including four cases from the literature, a total of 12 patients (4 women, 8 men) with this translocation are known at the moment. The translocation does not seem to be associated with a specific disorder, but almost all patients had a preleukemic syndrome during some stage of their disease. It is very remarkable that 11 of the 12 patients lived in the Netherlands, and 7 patients had a history of iatrogenic exposure to alkylating agents or irradiation; one patient was a radiation worker and another one had a history of toxic exposure to chloramphenicol. It is suggested, therefore, that the t(1;7) is a possibly induced chromosomal aberration with a clearly nonrandom geographic distribution.

  17. DNA damage-induced translocation of S100A11 into the nucleus regulates cell proliferation

    PubMed Central

    2010-01-01

    Background Proteins are able to react in response to distinct stress stimuli by alteration of their subcellular distribution. The stress-responsive protein S100A11 belongs to the family of multifunctional S100 proteins which have been implicated in several key biological processes. Previously, we have shown that S100A11 is directly involved in DNA repair processes at damaged chromatin in the nucleus. To gain further insight into the underlying mechanism subcellular trafficking of S100A11 in response to DNA damage was analyzed. Results We show that DNA damage induces a nucleolin-mediated translocation of S100A11 from the cytoplasm into the nucleus. This translocation is impeded by inhibition of the phosphorylation activity of PKCα. Translocation of S100A11 into the nucleus correlates with an increased cellular p21 protein level. Depletion of nucleolin by siRNA severely impairs translocation of S100A11 into the nucleus resulting in a decreased p21 protein level. Additionally, cells lacking nucleolin showed a reduced colony forming capacity. Conclusions These observations suggest that regulation of the subcellular distribution of S100A11 plays an important role in the DNA damage response and p21-mediated cell cycle control. PMID:21167017

  18. Mitochondrial translocation of Nur77 induced by ROS contributed to cardiomyocyte apoptosis in metabolic syndrome

    SciTech Connect

    Xu, Aibin; Liu, Jingyi; Liu, Peilin; Jia, Min; Wang, Han; Tao, Ling

    2014-04-18

    Highlights: • Metabolic syndrome exacerbated MI/R induced injury accompanied by decreased Nur77. • ROS led to Nur77 translocation in metabolic syndrome. • Inhibiting relocation of Nur77 to mitochondria reduced ROS-induced cardiomyocyte injury in metabolic syndrome. - Abstract: Metabolic syndrome is a major risk factor for cardiovascular diseases, and increased cardiomyocyte apoptosis which contributes to cardiac dysfunction after myocardial ischemia/reperfusion (MI/R) injury. Nur77, a nuclear orphan receptor, is involved in such various cellular events as apoptosis, proliferation, and glucose and lipid metabolism in several cell types. Apoptosis is positively correlated with mitochondrial translocation of Nur77 in the cancer cells. However, the roles of Nur77 on cardiac myocytes in patients with metabolic syndrome remain unclear. The objective of this study was to determine whether Nur77 may contribute to cardiac apoptosis in patients with metabolic syndrome after I/R injury, and, if so, to identify the underlying molecular mechanisms responsible. We used leptin-deficient (ob/ob) mice to make metabolic syndrome models. In this report, we observed that, accompanied by the substantial decline in apoptosis inducer Nur77, MI/R induced cardiac dysfunction was manifested as cardiomyopathy and increased ROS. Using the neonatal rat cardiac myocytes cultured in a high-glucose and high-fat medium, we found that excessive H{sub 2}O{sub 2} led to the significant alteration in mitochondrial membrane potential and translocation of Nur77 from the nucleus to the mitochondria. However, inhibition of the relocation of Nur77 to mitochondria via Cyclosporin A reversed the changes in membrane potential mediated by H{sub 2}O{sub 2} and reduced myocardial cell injury. Therefore, these data provide a potential underlying mechanism for cardiac dysfunction in metabolic syndrome and the suppression of Nur77 translocation may provide an effective approach to reduce cardiac injury in the

  19. Nitric oxide induces thioredoxin-1 nuclear translocation: Possible association with the p21Ras survival pathway

    SciTech Connect

    Arai, Roberto J.; Yodoi, J.; Debbas, V.; Laurindo, Francisco R.; Stern, A.; Monteiro, Hugo P. . E-mail: hpmonte@uol.com.br

    2006-10-06

    One of the major redox-regulating molecules with thiol reducing activity is thioredoxin-1 (TRX-1). TRX-1 is a multifunctional protein that exists in the extracellular millieu, cytoplasm, and nucleus, and has a distinct role in each environment. It is well known that TRX-1 promptly migrates to the nuclear compartment in cells exposed to oxidants. However, the intracellular location of TRX-1 in cells exposed to nitrosothiols has not been investigated. Here, we demonstrated that the exposure of HeLa cells to increasing concentrations of the nitrosothiol S-nitroso-N-acetylpenicillamine (SNAP) promoted TRX-1 nuclear accumulation. The SNAP-induced TRX-1 translocation to the nucleus was inhibited by FPTIII, a selective inhibitor of p21Ras. Furthermore, TRX-1 migration was attenuated in cells stably transfected with NO insensitive p21Ras (p21{sup RasC118S}). Downstream to p21Ras, the MAP Kinases ERK1/2 were activated by SNAP under conditions that promote TRX-1 nuclear translocation. Inhibition of MEK prevented SNAP-stimulated ERK1/2 activation and TRX-1 nuclear migration. In addition, cells treated with p21Ras or MEK inhibitor showed increased susceptibility to cell death induced by SNAP. In conclusion, our observations suggest that the nuclear translocation of TRX-1 is induced by SNAP involving p21Ras survival pathway.

  20. Piperlongumine-Induced Phosphatidylserine Translocation in the Erythrocyte Membrane

    PubMed Central

    Bissinger, Rosi; Malik, Abaid; Warsi, Jamshed; Jilani, Kashif; Lang, Florian

    2014-01-01

    Background: Piperlongumine, a component of Piper longum fruit, is considered as a treatment for malignancy. It is effective by inducing apoptosis. Mechanisms involved in the apoptotic action of piperlongumine include oxidative stress and activation of p38 kinase. In analogy to apoptosis of nucleated cells, erythrocytes may undergo eryptosis, the suicidal death of erythrocytes characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine-exposure at the erythrocyte surface. Signaling involved in eryptosis include increase of cytosolic Ca2+-activity ([Ca2+]i), formation of ceramide, oxidative stress and activation of p38 kinase. Methods: Cell volume was estimated from forward scatter, phosphatidylserine-exposure from annexin V binding, [Ca2+]i from Fluo3 fluorescence, reactive oxygen species from 2',7'-dichlorodihydrofluorescein-diacetate fluorescence, and ceramide abundance from binding of fluorescent antibodies in flow cytometry. Results: A 48 h exposure to piperlongumine (30 µM) was followed by significant decrease of forward scatter and increase of annexin-V-binding. Piperlongumine did not significantly modify [Ca2+]i and the effect was not dependent on presence of extracellular Ca2+. Piperlongumine significantly increased ROS formation and ceramide abundance. Conclusions: Piperlongumine triggers cell membrane scrambling, an effect independent from entry of extracellular Ca2+ but at least partially due to ROS and ceramide formation. PMID:25317837

  1. Surface-adsorption-induced polymer translocation through a nanopore: Effects of the adsorption strength and the surface corrugation

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaoyu; Yu, Wancheng; Luo, Kaifu

    2015-08-01

    The surface corrugation plays an important role in single polymer diffusion on attractive surfaces. However, its effect on dynamics of surface adsorption-induced polymer translocation through a nanopore is not clear. Using three-dimensional Langevin dynamics simulations, we investigate the dynamics of a flexible polymer chain translocation through a nanopore induced by the selective adsorption of translocated segments onto the trans side of the membrane. The translocation probability Pt r a n s increases monotonically, while the mean translocation time τ has a minimum as a function of the adsorption strength ɛ , which are explained from the perspective of the effective driving force for the translocation. With the surface being smoother, τ as well as the scaling exponent α of τ with the chain length N decreases. Finally, we show that the distributions of the translocation time are non-Gaussian even for strong adsorption at a moderate surface corrugation. A nearly Gaussian distribution of the translocation time is observed only for the smoothest surface we studied.

  2. Escherichia coli alpha-haemolysin induces focal leaks in colonic epithelium: a novel mechanism of bacterial translocation.

    PubMed

    Troeger, Hanno; Richter, Jan F; Beutin, Lothar; Günzel, Dorothee; Dobrindt, Ulrich; Epple, Hans-Jörg; Gitter, Alfred H; Zeitz, Martin; Fromm, Michael; Schulzke, Jörg-Dieter

    2007-10-01

    Extraintestinal pathogenic Escherichia coli (ExPEC) are usually harmless colonizer of the intestinal microflora. However, they are capable to translocate and cause life-threatening disease. Translocation of ExPEC isolates was quantified in colonic monolayers. Transepithelial resistance (R(t)) was monitored and local changes in conductivity analysed with conductance scanning. Confocal microscopy visualized the translocation route. Corroboratory experiments were performed on native rat colon. One translocating strain E. coli O4 was identified. This translocation process was associated with an R(t) decrease (36 +/- 1% of initial resistance) beginning only 2 h after inoculation. The sites of translocation were small defects in epithelial integrity (focal leaks) exhibiting highly increased local ion permeability. Translocation was enhanced by preincubation of monolayers with tumour necrosis factor-alpha or interleukin-13. Mutant strains lacking alpha-haemolysin lost the ability to induce focal leaks, while this effect could be restored by re-introducing the haemolysin determinant. Filtrate of a laboratory strain carrying the alpha-haemolysin operon was sufficient for focal leak induction. In native rat colon, E. coli O4 decreased R(t) and immunohistology demonstrated focal leaks resembling those in cell monolayers. E. coli alpha-haemolysin is able to induce focal leaks in colonic cell cultures as well as in native colon. This process represents a novel route of bacterial translocation facilitated by pro-inflammatory cytokines. PMID:17587334

  3. Brillouin-scattering-induced transparency and non-reciprocal light storage

    PubMed Central

    Dong, Chun-Hua; Shen, Zhen; Zou, Chang-Ling; Zhang, Yan-Lei; Fu, Wei; Guo, Guang-Can

    2015-01-01

    Stimulated Brillouin scattering is a fundamental interaction between light and travelling acoustic waves and arises primarily from electrostriction and photoelastic effects, with an interaction strength several orders of magnitude greater than that of other relevant non-linear optical processes. Here we report an experimental demonstration of Brillouin-scattering-induced transparency in a high-quality whispering-gallery-mode optical microresonantor. The triply resonant Stimulated Brillouin scattering process underlying the Brillouin-scattering-induced transparency greatly enhances the light–acoustic interaction, enabling the storage of light as a coherent, circulating acoustic wave with a lifetime up to 10 μs. Furthermore, because of the phase-matching requirement, a circulating acoustic wave can only couple to light with a given propagation direction, leading to non-reciprocal light storage and retrieval. These unique features establish a new avenue towards integrated all-optical switching with low-power consumption, optical isolators and circulators. PMID:25648234

  4. PUMA promotes Bax translocation in FOXO3a-dependent pathway during STS-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Zhang, Yingjie; Chen, Qun

    2009-08-01

    PUMA (p53 up-regulated modulator of apoptosis, also called Bbc3) was first identified as a BH3-only Bcl-2 family protein that is transcriptionally up-regulated by p53 and activated upon p53-dependent apoptotic stimuli, such as treatment with DNA-damaging drugs or UV irradiation. Recently studies have been shown that Puma is also up-regulated in response to certain p53-independent apoptotic stimuli, such as growth factor deprivation or treatment with glucocorticoids or STS (staurosporine). However, the molecular mechanisms of PUMA up-regulation and how PUMA functions in response to p53-independent apoptotic stimuli remain poorly understood. In this study, based on real-time single cell analysis, flow cytometry and western blotting technique, we investigated the function of PUMA in living human lung adenocarcinoma cells (ASTC-a-1) after STS treatment. Our results show that FOXO3a was activated by STS stimulation and then translocated from cytosol to nucleus. The expression of PUMA was up-regulated via a FOXO3a-dependent manner after STS treatment, while p53 had little function in this process. Moreover, cell apoptosis and Bax translocation induced by STS were not blocked by Pifithrin-α (p53 inhibitor), which suggested that p53 was not involved in this signaling pathway. Taken together, these results indicate that PUMA promoted Bax translocation in a FOXO3a-dependment pathway during STS-induced apoptosis, while p53 was dispensable in this process.

  5. Hydrogen sulfide prevents Abeta-induced neuronal apoptosis by attenuating mitochondrial translocation of PTEN.

    PubMed

    Cui, Weigang; Zhang, Yinghua; Yang, Chenxi; Sun, Yiyuan; Zhang, Min; Wang, Songtao

    2016-06-14

    Neuronal cell apoptosis is an important pathological change in Alzheimer's disease (AD). Hydrogen sulfide (H(2)S) is known to be a novel gaseous signaling molecule and a cytoprotectant in many diseases including AD. However, the molecular mechanism of the antiapoptosis activity of H(2)S in AD is not yet fully understood. The aim of the present study is to evaluate the inhibitory effects of H(2)S on Abeta (Aβ)-induced apoptosis and the molecular mechanisms underlying primary neuron cells. Our results showed that sodium hydrosulfide (NaHS), a donor of H(2)S, significantly ameliorated Aβ-induced cell apoptosis. NaHS also reversed the Aβ-induced translocation of the phosphatase and tensin homologs deleted on chromosome 10 (PTEN) from the cytosol to the mitochondria. Furthermore, H(2)S increased the level of p-AKT/AKT significantly. Interestingly, the antiapoptosis effects of H(2)S were blocked down by specific PI3K/AKT inhibitor wortmannin. In conclusion, these data indicate that H(2)S inhibits Aβ-induced neuronal apoptosis by attenuating mitochondrial translocation of PTEN and that activation of PI3K/AKT signaling pathway plays a critical role in H(2)S-mediated neuronal protection. Our findings provide a novel route into the molecular mechanisms of neuronal apoptosis in AD. PMID:27026591

  6. Bridge-Induced Chromosome Translocation in Yeast Relies upon a Rad54/Rdh54-Dependent, Pol32-Independent Pathway

    PubMed Central

    Tosato, Valentina; Sidari, Sabrina; Bruschi, Carlo V.

    2013-01-01

    While in mammalian cells the genetic determinism of chromosomal translocation remains unclear, the yeast Saccharomyces cerevisiae has become an ideal model system to generate ad hoc translocations and analyze their cellular and molecular outcome. A linear DNA cassette carrying a selectable marker flanked by perfect homologies to two chromosomes triggers a bridge-induced translocation (BIT) in budding yeast, with variable efficiency. A postulated two-step process to produce BIT translocants is based on the cooperation between the Homologous Recombination System (HRS) and Break-Induced Replication (BIR); however, a clear indication of the molecular factors underlying the genetic mechanism is still missing. In this work we provide evidence that BIT translocation is elicited by the Rad54 helicase and completed by a Pol32-independent replication pathway. Our results demonstrate also that Rdh54 is involved in the stability of the translocants, suggesting a mitotic role in chromosome pairing and segregation. Moreover, when RAD54 is over-expressed, an ensemble of secondary rearrangements between repeated DNA tracts arise after the initial translocation event, leading to severe aneuploidy with loss of genetic material, which prompts the identification of fragile sites within the yeast genome. PMID:23613757

  7. Nitric Oxide Induction of Parkin Translocation in PTEN-induced Putative Kinase 1 (PINK1) Deficiency

    PubMed Central

    Han, Ji-Young; Kang, Min-Ji; Kim, Kyung-Hee; Han, Pyung-Lim; Kim, Hyun-Seok; Ha, Ji-Young; Son, Jin H.

    2015-01-01

    The failure to trigger mitophagy is implicated in the pathogenesis of familial Parkinson disease that is caused by PINK1 or Parkin mutations. According to the prevailing PINK1-Parkin signaling model, mitophagy is promoted by the mitochondrial translocation of Parkin, an essential PINK1-dependent step that occurs via a previously unknown mechanism. Here we determined that critical concentrations of NO was sufficient to induce the mitochondrial translocation of Parkin even in PINK1 deficiency, with apparent increased interaction of full-length PINK1 accumulated during mitophagy, with neuronal nitric oxide synthase (nNOS). Specifically, optimum levels of NO enabled PINK1-null dopaminergic neuronal cells to regain the mitochondrial translocation of Parkin, which appeared to be significantly suppressed by nNOS-null mutation. Moreover, nNOS-null mutation resulted in the same mitochondrial electron transport chain (ETC) enzyme deficits as PINK1-null mutation. The involvement of mitochondrial nNOS activation in mitophagy was further confirmed by the greatly increased interactions of full-length PINK1 with nNOS, accompanied by mitochondrial accumulation of phospho-nNOS (Ser1412) during mitophagy. Of great interest is that the L347P PINK1 mutant failed to bind to nNOS. The loss of nNOS phosphorylation and Parkin accumulation on PINK1-deficient mitochondria could be reversed in a PINK1-dependent manner. Finally, non-toxic levels of NO treatment aided in the recovery of PINK1-null dopaminergic neuronal cells from mitochondrial ETC enzyme deficits. In summary, we demonstrated the full-length PINK1-dependent recruitment of nNOS, its activation in the induction of Parkin translocation, and the feasibility of NO-based pharmacotherapy for defective mitophagy and ETC enzyme deficits in Parkinson disease. PMID:25716315

  8. Micropipette aspiration of human erythrocytes induces echinocytes via membrane phospholipid translocation.

    PubMed Central

    Artmann, G M; Sung, K L; Horn, T; Whittemore, D; Norwich, G; Chien, S

    1997-01-01

    When a discocytic erythrocyte (RBC) was partially aspirated into a 1.5-microns glass pipette with a high negative aspiration pressure (delta P = -3.9 kPa), held in the pipette for 30 s (holding time, th), and then released, it underwent a discocyte-echinocyte shape transformation. The degree of shape transformation increased with an increase in th. The echinocytes recovered spontaneously to discocytes in approximately 10 min, and there was no significant difference in recovery time at 20.9 degrees C, 29.5 degrees C, and 37.4 degrees C, respectively. At 11 degrees C the recovery time was significantly elevated to 40.1 +/- 6.7 min. At 20.9 degrees C the shape recovery time varied directly with the isotropic RBC tension induced by the pipetting. Sodium orthovanadate (vanadate, 200 microM), which inhibits the phospholipid translocase, blocks the shape recovery. Chlorpromazine (CP, 25 microM) reversed the pipette-induced echinocytic shape to discocytic in < 2 min, and the RBC became a spherostomatocyte-II after another 30 min. It was hypothesized that the increase in cytosolic pressure during the pipette aspiration induced an isotropic tension in the RBC membrane followed by a net inside-to-outside membrane lipid translocation. After a sudden release of the aspiration pressure the cytosolic pressure and the membrane tension normalized immediately, but the translocated phospholipids remained temporarily "trapped" in the outer layer, causing an area excess and hence the echinocytic shape. The phospholipid translocase activity, when not inhibited by vanadate, caused a gradual return of the translocated phospholipids to the inner layer, and the RBC shape recovered with time. Images FIGURE 1 FIGURE 4 FIGURE 5 FIGURE 7 FIGURE 8 PMID:9138589

  9. Inhibition of Drp1 mitochondrial translocation provides neural protection in dopaminergic system in a Parkinson's disease model induced by MPTP.

    PubMed

    Filichia, Emily; Hoffer, Barry; Qi, Xin; Luo, Yu

    2016-01-01

    Accumulating evidence suggest mitochondria-mediated pathways play an important role in dopaminergic neuronal cell death in Parkinson's disease (PD). Drp1, a key regulator of mitochondrial fission, has been shown to be activated and translocated to mitochondria under stress, leading to excessive mitochondria fission and dopaminergic neuronal death in vitro. However, whether Drp1 inhibition can lead to long term stable preservation of dopaminergic neurons in PD-related mouse models remains unknown. In this study, using a classical MPTP animal PD model, we showed for the first time Drp1 activation and mitochondrial translocation in vivo after MPTP administration. Inhibition of Drp1 activation by a selective peptide inhibitor P110, blocked MPTP-induced Drp1 mitochondrial translocation and attenuated dopaminergic neuronal loss, dopaminergic nerve terminal damage and behavioral deficits caused by MPTP. MPTP-induced microglial activation and astrogliosis were not affected by P110 treatment. Instead, inhibition of Drp1 mitochondrial translocation diminished MPTP-induced p53, BAX and PUMA mitochondrial translocation. This study demonstrates that inhibition of Drp1 hyperactivation by a Drp1 peptide inhibitor P110 is neuroprotective in a MPTP animal model. Our data also suggest that the protective effects of P110 treatment might be mediated by inhibiting the p53 mediated apoptotic pathways in neurons through inhibition of Drp1-dependent p53 mitochondrial translocation. PMID:27619562

  10. Dynamin-related protein Drp1 is required for Bax translocation to mitochondria in response to irradiation-induced apoptosis.

    PubMed

    Wang, Ping; Wang, Peiguo; Liu, Becky; Zhao, Jing; Pang, Qingsong; Agrawal, Samir G; Jia, Li; Liu, Feng-Ting

    2015-09-01

    Translocation of the pro-apoptotic protein Bax from the cytosol to the mitochondria is a crucial step in DNA damage-mediated apoptosis, and is also found to be involved in mitochondrial fragmentation. Irradiation-induced cytochrome c release and apoptosis was associated with Bax activation, but not mitochondrial fragmentation. Both Bax and Drp1 translocated from the cytosol to the mitochondria in response to irradiation. However, Drp1 mitochondrial translocation and oligomerization did not require Bax, and failed to induce apoptosis in Bax deficient diffuse large B-cell lymphoma (DLBCL) cells. Using fluorescent microscopy and the intensity correlation analysis, we demonstrated that Bax and Drp1 were colocalized and the levels of colocalization were increased by UV irradiation. Using co-immuno-precipitation, we confirmed that Bax and Drp1 were binding partners. Irradiation induced a time-associated increase in the interaction between active Bax and Drp1. Knocking down Drp1 using siRNA blocked UV irradiation-mediated Bax mitochondrial translocation. In conclusion, our findings demonstrate for the first time, that Drp1 is required for Bax mitochondrial translocation, but Drp1-induced mitochondrial fragmentation alone is not sufficient to induce apoptosis in DLBCL cells. PMID:26093086

  11. PARP-1-modulated AIF translocation is involved in streptomycin-induced cochlear hair cell death.

    PubMed

    Song, Yongdong; Fan, Zhaomin; Bai, Xiaohui; Liu, Wenwen; Han, Yuechen; Xu, Lei; Wang, Mingming; Li, Jianfeng; Zheng, Qingyin; Zhang, Daogong; Wang, Haibo

    2016-06-01

    Conclusion SM-induced dose- and location-dependent cochlear hair cell death in vitro. AIF might be translocated from mitochondria to nucleus and cytoplasm within SM-treated hair cells. The translocation of AIF might be modulated by PARP-1. Objective Streptomycin (SM), one of the widely used aminoglycoside nowadays, is still causing significant permanent sensorineural hearing loss owing to sensory hair cell death. This study was designed to investigate the role of apoptosis-inducing factor (AIF), an important mitochondrial cell death regulator, in SM ototoxicity within neonatal rat cochleae and HEI-OC1 cells. Methods The viability of HEI-OC1 cells was quantified by MTT assay. AIF, PARP-1, and myosin VIIa distributions were achieved by immunofluorescence. mRNA and protein expression of AIF and PARP-1 were examined by q-PCR and Western-blot. Results The hair cell loss was concomitant with the SM concentration variation, and aggravated from apical to basal turn. AIF was detected in nuclear region and AIF mRNA was up-regulated after SM incubation. Besides, AIF protein expression in mitochondria was decreased, whereas in cytosol it was increased. PARP-1 mRNA and protein were also up-regulated. 3-AB could attenuate the cell death and reverse the changes of AIF distribution by blocking PARP-1. PMID:26963167

  12. Oxidative stress induces nuclear translocation of C-terminus of {alpha}-synuclein in dopaminergic cells

    SciTech Connect

    Xu Shengli; Zhou Ming; Yu Shun; Cai Yanning; Zhang Alex; Ueda, Kenji; Chan Piu . E-mail: pbchan@bjsap.org

    2006-03-31

    Growing evidence suggests that oxidative stress is involved in the neuronal degeneration and can promote the aggregation of {alpha}-synuclein. However, the role of {alpha}-synuclein under physiological and pathological conditions remains poorly understood. In the present study, we examined the possible interaction between the {alpha}-synuclein and oxidative stress. In a dopaminergic cell line MES23.5, we have found that the 200 {mu}M H{sub 2}O{sub 2} treatment induced the translocation of {alpha}-synuclein from cytoplasm to nuclei at 30 min post-treatment. The immunoactivity of {alpha}-synuclein became highly intensive in the nuclei after 2 h treatment. The protein translocated to nucleus was a 10 kDa fragment of C-terminus region of {alpha}-synuclein, while full-length {alpha}-synuclein remained in cytoplasm. Thioflavine-S staining suggested that the C-terminal fragment in the nuclei has no {beta}-sheet structures. Our present results indicated that 200 {mu}M H{sub 2}O{sub 2} treatment induces the intranuclear accumulation of the C-terminal fragment of {alpha}-synuclein in dopaminergic neurons, whose role remains to be investigated.

  13. Exercise-induced galanin release facilitated GLUT4 translocation in adipocytes of type 2 diabetic rats.

    PubMed

    Liang, Yan; Sheng, Shudong; Fang, Penghua; Ma, Yinping; Li, Jian; Shi, Qiaojia; Sui, Yumei; Shi, Mingyi

    2012-01-01

    Although galanin has been shown to increase insulin sensitivity in skeletal muscle of rats, there is no literature available about the effect of galanin on Glucose Transporter 4 (GLUT4) translocation from intracellular membrane pools to plasma membranes in adipocytes of type 2 diabetic rats. In the present study M35, a galanin antagonist was used to elucidate whether exercise-induced galanin release increased GLUT4 translocation in adipocytes of streptozotocin-induced diabetic rats. The present findings showed that plasma galanin levels after swimming training in all four trained groups were higher compared with each sedentary control. M35 treatment had an inhibitory effect on glucose infusion rates in the euglycemic-hyperinsulinemic clamp test and GLUT4 mRNA expression levels in adipocytes. Moreover, M35 treatment reduced GLUT4 concentration in both plasma membranes and total cell membranes. The ratios of GLUT4 contents in plasma membranes to total cell membranes in four drug groups were lower compared with each control. These data demonstrate a beneficial role of endogenous galanin to transfer GLUT4 from internal stores to plasma membranes in adipocytes of type 2 diabetic rats. Galanin plays a significant role in regulation of glucose metabolic homeostasis and is an important hormone relative to diabetes. PMID:22079346

  14. Involvement of TR3/Nur77 translocation to the endoplasmic reticulum in ER stress-induced apoptosis

    SciTech Connect

    Liang Bin; Song Xuhong; Liu Gefei; Li Rui; Xie Jianping; Xiao Lifeng; Du Mudan; Zhang Qiaoxia; Xu Xiaoyuan; Gan Xueqiong; Huang Dongyang . E-mail: huangdy@stu.edu.cn

    2007-08-01

    Nuclear orphan receptor TR3/Nur77/NGFI-B is a novel apoptotic effector protein that initiates apoptosis largely by translocating from the nucleus to the mitochondria, causing the release of cytochrome c. However, it is possible that TR3 translocates to other organelles. The present study was designed to determine the intracellular localization of TR3 following CD437-induced nucleocytoplasmic translocation and the mechanisms involved in TR3-induced apoptosis. In human neuroblastoma SK-N-SH cells and human esophageal squamous carcinoma EC109 and EC9706 cells, 5 {mu}M CD437 induced translocation of TR3 to the endoplasmic reticulum (ER). This distribution was confirmed by immunofluorescence analysis, subcellular fractionation analysis and coimmunoprecipitation analysis. The translocated TR3 interacted with ER-targeting Bcl-2; initiated an early release of Ca{sup 2+} from ER; resulted in ER stress and induced apoptosis through ER-specific caspase-4 activation, together with induction of mitochondrial stress and subsequent activation of caspase-9. Our results identified a novel distribution of TR3 in the ER and defined two parallel mitochondrial- and ER-based pathways that ultimately result in apoptotic cell death.

  15. ER Adaptor SCAP Translocates and Recruits IRF3 to Perinuclear Microsome Induced by Cytosolic Microbial DNAs

    PubMed Central

    Yu, Huansha; Liu, Xing; Huang, Lulu; Wang, Qiang; Liu, Heng; Cui, Ye; Tang, Yijun; Zhang, Peng; Wang, Chen

    2016-01-01

    Stimulator of interferon genes (STING, also known as MITA, ERIS or MPYS) induces the activation of TBK1 kinase and IRF3 transcription factor, upon sensing of microbial DNAs. How IRF3 is recruited onto the STING signalosome remains unknown. We report here that silencing of the ER adaptor SCAP markedly impairs the IRF3-responsive gene expression induced by STING. Scap knockdown mice are more susceptible to HSV-1 infection. Interestingly, SCAP translocates from ER, via Golgi, to perinuclear microsome in a STING-dependent manner. Mechanistically, the N-terminal transmembrane domain of SCAP interacts with STING, and the C-terminal cytosolic domain of SCAP binds to IRF3, thus recruiting IRF3 onto STING signalosome. Mis-localization of SCAP abolishes its antiviral function. Collectively, this study characterizes SCAP as an essential adaptor in the STING signaling pathway, uncovering a critical missing link in DNAs-triggered host antiviral responses. PMID:26900919

  16. Acute resistance exercise-induced IGF1 expression and subsequent GLUT4 translocation.

    PubMed

    Kido, Kohei; Ato, Satoru; Yokokawa, Takumi; Makanae, Yuhei; Sato, Koji; Fujita, Satoshi

    2016-08-01

    Acute aerobic exercise (AE) is a major physiological stimulus for skeletal muscle glucose uptake through activation of 5' AMP-activated protein kinase (AMPK). However, the regulation of glucose uptake by acute resistance exercise (RE) remains unclear. To investigate the intracellular regulation of glucose uptake after acute RE versus acute AE, male Sprague-Dawley rats were divided into three groups: RE, AE, or nonexercise control. After fasting for 12 h overnight, the right gastrocnemius muscle in the RE group was exercised at maximum isometric contraction via percutaneous electrical stimulation (3 × 10 sec, 5 sets). The AE group ran on a treadmill (25 m/min, 60 min). Muscle samples were taken 0, 1, and 3 h after completion of the exercises. AMPK, Ca(2+)/calmodulin-dependent protein kinase II, and TBC1D1 phosphorylation were increased immediately after both forms of exercise and returned to baseline levels by 3 h. Muscle IGF1 expression was increased by RE but not AE, and maintained until 3 h after RE Additionally, Akt and AS160 phosphorylation were sustained for 3 h after RE, whereas they returned to baseline levels by 3 h after AE Similarly, GLUT4 translocation remained elevated 3 h after RE, although it returned to the baseline level by 3 h after AE Overall, this study showed that AMPK/TBC1D1 and IGF1/Akt/AS160 signaling were enhanced by acute RE, and that GLUT4 translocation after acute RE was more prolonged than after acute AE These results suggest that acute RE-induced increases in intramuscular IGF1 expression might be a distinct regulator of GLUT4 translocation. PMID:27550988

  17. The Octyl Ester of Ginsenoside Rh2 Induces Lysosomal Membrane Permeabilization via Bax Translocation

    PubMed Central

    Chen, Fang; Zhang, Bing; Sun, Yong; Xiong, Zeng-Xing; Peng, Han; Deng, Ze-Yuan; Hu, Jiang-Ning

    2016-01-01

    Ginsenoside Rh2 is a potential pharmacologically active metabolite of ginseng. Previously, we have reported that an octyl ester derivative of ginsenoside Rh2 (Rh2-O), has been confirmed to possess higher bioavailability and anticancer effect than Rh2 in vitro. In order to better assess the possibility that Rh2-O could be used as an anticancer compound, the underlying mechanism was investigated in this study. The present results revealed that lysosomal destabilization was involved in the early stage of cell apoptosis in HepG2 cells induced by Rh2-O. Rh2-O could induce an early lysosomal membrane permeabilization with the release of lysosomal protease cathepsins to the cytosol in HepG2 cells. The Cat B inhibitor (leu) and Cat D inhibitor (pepA) inhibited Rh2-O-induced HepG2 apoptosis as well as tBid production and Δφm depolarization, indicating that lysosomal permeabilization occurred upstream of mitochondrial dysfunction. In addition, Rh2-O induced a significant increase in the protein levels of DRAM1 and Bax (p < 0.05) in lysosomes of HepG2 cells. Knockdown of Bax partially inhibited Rh2-O-induced Cat D release from lysosomes. Thus it was concluded that Rh2-O induced apoptosis of HepG2 cells through activation of the lysosomal-mitochondrial apoptotic pathway involving the translocation of Bax to the lysosome. PMID:27120618

  18. The Octyl Ester of Ginsenoside Rh2 Induces Lysosomal Membrane Permeabilization via Bax Translocation.

    PubMed

    Chen, Fang; Zhang, Bing; Sun, Yong; Xiong, Zeng-Xing; Peng, Han; Deng, Ze-Yuan; Hu, Jiang-Ning

    2016-01-01

    Ginsenoside Rh2 is a potential pharmacologically active metabolite of ginseng. Previously, we have reported that an octyl ester derivative of ginsenoside Rh2 (Rh2-O), has been confirmed to possess higher bioavailability and anticancer effect than Rh2 in vitro. In order to better assess the possibility that Rh2-O could be used as an anticancer compound, the underlying mechanism was investigated in this study. The present results revealed that lysosomal destabilization was involved in the early stage of cell apoptosis in HepG2 cells induced by Rh2-O. Rh2-O could induce an early lysosomal membrane permeabilization with the release of lysosomal protease cathepsins to the cytosol in HepG2 cells. The Cat B inhibitor (leu) and Cat D inhibitor (pepA) inhibited Rh2-O-induced HepG2 apoptosis as well as tBid production and Δφm depolarization, indicating that lysosomal permeabilization occurred upstream of mitochondrial dysfunction. In addition, Rh2-O induced a significant increase in the protein levels of DRAM1 and Bax (p < 0.05) in lysosomes of HepG2 cells. Knockdown of Bax partially inhibited Rh2-O-induced Cat D release from lysosomes. Thus it was concluded that Rh2-O induced apoptosis of HepG2 cells through activation of the lysosomal-mitochondrial apoptotic pathway involving the translocation of Bax to the lysosome. PMID:27120618

  19. Ischemic stroke induces gut permeability and enhances bacterial translocation leading to sepsis in aged mice

    PubMed Central

    Verma, Rajkumar; Venna, Venugopal R.; Liu, Fudong; Chauhan, Anjali; Koellhoffer, Edward; Patel, Anita; Ricker, Austin; Maas, Kendra; Graf, Joerg; McCullough, Louise D.

    2016-01-01

    Aging is an important risk factor for post-stroke infection, which accounts for a large proportion of stroke-associated mortality. Despite this, studies evaluating post-stroke infection rates in aged animal models are limited. In addition, few studies have assessed gut microbes as a potential source of infection following stroke. Therefore we investigated the effects of age and the role of bacterial translocation from the gut in post-stroke infection in young (8-12 weeks) and aged (18-20 months) C57Bl/6 male mice following transient middle cerebral artery occlusion (MCAO) or sham surgery. Gut permeability was examined and peripheral organs were assessed for the presence of gut-derived bacteria following stroke. Furthermore, sickness parameters and components of innate and adaptive immunity were examined. We found that while stroke induced gut permeability and bacterial translocation in both young and aged mice, only young mice were able to resolve infection. Bacterial species seeding peripheral organs also differed between young (Escherichia) and aged (Enterobacter) mice. Consequently, aged mice developed a septic response marked by persistent and exacerbated hypothermia, weight loss, and immune dysfunction compared to young mice following stroke. PMID:27115295

  20. Bacteriophage Xp10 anti-termination factor p7 induces forward translocation by host RNA polymerase

    PubMed Central

    Zenkin, Nikolay; Severinov, Konstantin; Yuzenkova, Yulia

    2015-01-01

    Regulation of transcription elongation is based on response of RNA polymerase (RNAP) to various pause signals and is modulated by various accessory factors. Here we report that a 7 kDa protein p7 encoded by bacteriophage Xp10 acts as an elongation processivity factor of RNAP of host bacterium Xanthomonas oryzae, a major rice pathogen. Our data suggest that p7 stabilizes the upstream DNA duplex of the elongation complex thus disfavouring backtracking and promoting forward translocated states of the elongation complex. The p7-induced ‘pushing’ of RNAP and modification of RNAP contacts with the upstream edge of the transcription bubble lead to read-through of various types of pauses and termination signals and generally increase transcription processivity and elongation rate, contributing for transcription of an extremely long late genes operon of Xp10. Forward translocation was observed earlier upon the binding of unrelated bacterial elongation factor NusG, suggesting that this may be a general pathway of regulation of transcription elongation. PMID:26038312

  1. Asplenia syndrome in a child with a reciprocal translocation of chromosomes 11 and 20 [46,XX,t(11;20)(q13.1;q13.13)

    SciTech Connect

    Freeman, S.B.; Muraldharan, K.; Pettay, D.

    1994-09-01

    Failure to establish the left-right embryonic axis results in abnormalities of laterality; situs solitus is replaced by situs inversus totalis or various degrees of heterotaxy involving the heart, great vessels, lungs, liver, spleen, and/or bowel. Laterality syndromes are likely to be genetically heterogeneous although specific human genes have not been identified. Families with dominant, recessive, and X-linked laterality syndromes have been reported as well as individuals with situs abnormalities and chromosome rearrangements. The latter offer the possibility of narrowing the gene search to specific chromosome regions. A recent report described an infant with polysplenia syndrome and a paracentric inversion of chromosome 11 [46,XX,inv(11)(q13q25)pat]. We report the second case of a child with laterality abnormalities and a chromosome rearrangement involving a similar breakpoint on chromosome 11. The proband is a 6 y/o female with mental retardation, dysmorphic features, pulmonic stenosis, asplenia, Hirschsprung disease, and a balanced, reciprocal translocation involving chromosomes 11 and 20 [46,XX,t(11;20)(q13,1;q13.13)pat]. Using DNA probes we have excluded uniparental disomy for chromosomes 11 and 20. If a gene for determination of laterality lies in the 11q13 region, the proband`s abnormalities could be the result of her receiving an allele disrupted by the paternal translocation as well as a mutant allele from her mother. To investigate this possibility, we are studying the segregation of maternal chromosome 11 markers in the proband and her balanced carrier and non-carrier siblings.

  2. Fluctuations between multiple EF-G-induced chimeric tRNA states during translocation on the ribosome

    PubMed Central

    Adio, Sarah; Senyushkina, Tamara; Peske, Frank; Fischer, Niels; Wintermeyer, Wolfgang; Rodnina, Marina V.

    2015-01-01

    The coupled translocation of transfer RNA and messenger RNA through the ribosome entails large-scale structural rearrangements, including step-wise movements of the tRNAs. Recent structural work has visualized intermediates of translocation induced by elongation factor G (EF-G) with tRNAs trapped in chimeric states with respect to 30S and 50S ribosomal subunits. The functional role of the chimeric states is not known. Here we follow the formation of translocation intermediates by single-molecule fluorescence resonance energy transfer. Using EF-G mutants, a non-hydrolysable GTP analogue, and fusidic acid, we interfere with either translocation or EF-G release from the ribosome and identify several rapidly interconverting chimeric tRNA states on the reaction pathway. EF-G engagement prevents backward transitions early in translocation and increases the fraction of ribosomes that rapidly fluctuate between hybrid, chimeric and posttranslocation states. Thus, the engagement of EF-G alters the energetics of translocation towards a flat energy landscape, thereby promoting forward tRNA movement. PMID:26072700

  3. Fluctuations between multiple EF-G-induced chimeric tRNA states during translocation on the ribosome.

    PubMed

    Adio, Sarah; Senyushkina, Tamara; Peske, Frank; Fischer, Niels; Wintermeyer, Wolfgang; Rodnina, Marina V

    2015-01-01

    The coupled translocation of transfer RNA and messenger RNA through the ribosome entails large-scale structural rearrangements, including step-wise movements of the tRNAs. Recent structural work has visualized intermediates of translocation induced by elongation factor G (EF-G) with tRNAs trapped in chimeric states with respect to 30S and 50S ribosomal subunits. The functional role of the chimeric states is not known. Here we follow the formation of translocation intermediates by single-molecule fluorescence resonance energy transfer. Using EF-G mutants, a non-hydrolysable GTP analogue, and fusidic acid, we interfere with either translocation or EF-G release from the ribosome and identify several rapidly interconverting chimeric tRNA states on the reaction pathway. EF-G engagement prevents backward transitions early in translocation and increases the fraction of ribosomes that rapidly fluctuate between hybrid, chimeric and posttranslocation states. Thus, the engagement of EF-G alters the energetics of translocation towards a flat energy landscape, thereby promoting forward tRNA movement. PMID:26072700

  4. Fluctuations between multiple EF-G-induced chimeric tRNA states during translocation on the ribosome

    NASA Astrophysics Data System (ADS)

    Adio, Sarah; Senyushkina, Tamara; Peske, Frank; Fischer, Niels; Wintermeyer, Wolfgang; Rodnina, Marina V.

    2015-06-01

    The coupled translocation of transfer RNA and messenger RNA through the ribosome entails large-scale structural rearrangements, including step-wise movements of the tRNAs. Recent structural work has visualized intermediates of translocation induced by elongation factor G (EF-G) with tRNAs trapped in chimeric states with respect to 30S and 50S ribosomal subunits. The functional role of the chimeric states is not known. Here we follow the formation of translocation intermediates by single-molecule fluorescence resonance energy transfer. Using EF-G mutants, a non-hydrolysable GTP analogue, and fusidic acid, we interfere with either translocation or EF-G release from the ribosome and identify several rapidly interconverting chimeric tRNA states on the reaction pathway. EF-G engagement prevents backward transitions early in translocation and increases the fraction of ribosomes that rapidly fluctuate between hybrid, chimeric and posttranslocation states. Thus, the engagement of EF-G alters the energetics of translocation towards a flat energy landscape, thereby promoting forward tRNA movement.

  5. Effects of rifaximin on bacterial translocation in thioacetamide-induced liver injury in rats.

    PubMed

    Harputluoglu, Murat M M; Demirel, Ulvi; Gul, Mehmet; Temel, Ismail; Gursoy, Sule; Selcuk, Engin Burak; Aladag, Murat; Bilgic, Yilmaz; Gunduz, Ercan; Seckin, Yuksel

    2012-08-01

    Intestinal bacterial overgrowth (IBO) and increased mucosal permeability are suggested to increase bacterial translocation (BT) in liver injury. Rifaximin (RIF) is a minimally absorbed oral antimicrobial agent that restores gut microflora imbalance. The aim of the present study was to investigate the effects of RIF on BT frequency in thioacetamide (TAA)-induced liver injury. Group 1 was the control. In group 2 (TAA), rats received TAA daily for 3 days. In group 3 (TAA + RIF), RIF was commenced on the same day as the first dose of TAA. In group 4 (RIF), rats received only RIF. Ileal aspirate Escherichia coli counts were significantly lower in the TAA + RIF group than in TAA group. There was no difference in BT frequency between the TAA and TAA + RIF groups. Our results suggest that factors such as intestinal barrier dysfunction and impaired host immune shield, apart from IBO, play an important role in BT in this model. PMID:22527146

  6. Dynamin-Related Protein 1 Translocates from the Cytosol to Mitochondria during UV-Induced Apoptosis

    NASA Astrophysics Data System (ADS)

    Zhang, Zhenzhen; Wu, Shengnan; Feng, Jie

    2011-01-01

    Mitochondria are dynamic structures that frequently divide and fuse with one another to form interconnecting network. This network disintegrates into punctiform organelles during apoptosis. However, the mechanisms involved in these processes are still not well characterized. In this study, we investigate the role of dynamin-related protein 1 (Drp1), a large GTPase that mediates outer mitochondrial membrane fission, in mitochondrial dynamics in response to UV irradiation in human lung adenocarcinoma cells (ASTC-α-1) and HeLa cells. Using time-lapse fluorescent imaging, we find that Drp1 primarily distributes in cytosol under physiological conditions. After UV treatment, Drp1 translocates from cytosol to mitochondria, indicating the enhancement of Drp1 mitochondrial accumulation. Our results suggest that Drp1 is involved in the regulation of transition from an interconnecting network to a punctiform mitochondrial phenotype during UV-induced apoptosis.

  7. A Comparison of Apical Transportation in Severely Curved Canals Induced by Reciproc and BioRaCe Systems

    PubMed Central

    Nabavizadeh, Mohammadreza; Abbaszadegan, Abbas; Khojastepour, Leila; Amirhosseini, Mohsen; Kiani, Ebrahim

    2014-01-01

    Introduction: Preserving the apical root structure during cleaning and shaping of the canal has always been a challenge in endodontics particularly when the root canals are curved. The purpose of this in vitro study was to compare the apical transportation induced by the Reciproc and BioRaCe rotary systems in preparing the mesiobuccal root canal of the human maxillary molars. Materials and Methods: The mesiobuccal canals of sixty extracted maxillary molars with curvature angle of 25˚-35˚ were selected and randomly assigned into two groups. Each canal was prepared by either Reciproc or BioRaCe rotary systems. A double-digital radiographic technique and AutoCAD software were used to compare the apical transportation at 0.5, 1, 2, 3, 4 and 5 mm distances from the working length (WL). The distance between the master apical rotary file and the initial K-file in the superimposed radiographs determined the amount of apical transportation. An independent t-test was used to compare the groups. The statistical significant level was set at 0.05. Results: Apical transportation of the Reciproc group was significantly greater than the BioRaCe group in all distances (P<0.001). The maximum apical transportation occurred in the Reciproc group at 0.5 mm from the WL (0.048±0.0028 mm) and the minimum occurred for BioRaCe at 5 mm from the WL (0.010±0.0005 mm). Conclusions: The Reciproc system produced significantly more apical transportation than the BioRaCe, but this fact does not seem to negatively alter the clinical success or quality of root canal treatment. PMID:24688580

  8. Isoniazid prevents Nrf2 translocation by inhibiting ERK1 phosphorylation and induces oxidative stress and apoptosis

    PubMed Central

    Verma, Ajeet Kumar; Yadav, Arti; Dewangan, Jayant; Singh, Sarvendra Vikram; Mishra, Manisha; Singh, Pradhyumna Kumar; Rath, Srikanta Kumar

    2015-01-01

    Isoniazid is used either alone or in combination with other drugs for the treatment of tuberculosis. It is also used for the prevention of tuberculosis. Chronic treatment of Isoniazid may cause severe liver damage leading to acute liver failure. The mechanism through which Isoniazid causes liver damage is investigated. Isoniazid treatment generates reactive oxygen species and induces apoptosis in Hep3B cells. It induces antioxidative and apoptotic genes leading to increase in mRNA expression and protein levels in Hep3B cells. Whole genome expression analysis of Hep3B cells treated with Isoniazid has resulted in differential expression of various genes playing prime role in regulation of apoptotic, antioxidative, DNA damage, cell signaling, cell proliferation and differentiation pathways. Isoniazid increased cytosolic Nrf2 protein level while decreased nuclear Nrf2 protein level. It also decreased ERK1 phosphorylation and treatment of Hep3B cells with ERK inhibitor followed by Isoniazid resulting in increased apoptosis in these cells. Two dimensional gel electrophoresis results have also shown differential expression of various protein species including heat shock proteins, proteins playing important role in oxidative stress, DNA damage, apoptosis, cell proliferation and differentiation. Results suggest that Isoniazid induces apoptosis through oxidative stress and also prevents Nrf2 translocation into the nucleus by reducing ERK1 phosphorylation thus preventing cytoprotective effect. PMID:26202867

  9. Nuclear translocation of histone deacetylase 4 induces neuronal death in stroke.

    PubMed

    Yuan, Hui; Denton, Kyle; Liu, Lin; Li, Xue-Jun; Benashski, Sharon; McCullough, Louise; Li, Jun

    2016-07-01

    Mounting evidence suggests that epigenetic modifications play critical roles in the survival/death of stressed neurons. Chief among these modifications is the deacetylation of histones within the chromatin by histone deacetylases (HDACs). HDAC4 is highly expressed in neurons and is usually trapped in cytosol. However, tightly regulated signal-dependent shuttling of this molecule between cytosol and nucleus occurs. Here, we studied the intracellular trafficking of HDAC4 and regulatory mechanisms during stroke. HDAC4 translocated from the cytosol into the nucleus of neurons in response to stroke induced by middle cerebral artery occlusion (MCAO) in mice. Similar translocation was seen after oxygen-glucose deprivation (OGD) in cultured mouse neurons. Expression of nuclear-restricted HDAC4 increased neuronal death after OGD and worsened infarcts and functional deficits in mice following MCAO; however, expression of cytosolic-restricted HDAC4 did not affect outcome after ischemia. In contrast, HDAC4 knockdown with siRNA improved neuronal survival after OGD. Furthermore, expression of nuclear-restricted HDAC4 reduced the acetylation of histones 3 and 4 as well as the levels of pro-survival downstream molecules after OGD. Finally, genetic deletion of calcium/calmodulin-dependent protein kinase IV (CaMKIV) increased the nuclear accumulation of HDAC4 in MCAO model, while overexpression of CaMKIV reduced the levels of nuclear HDAC4 following OGD. When HDAC4 was inhibited, the neuroprotection provided by CaMKIV overexpression was absent during OGD. Our data demonstrate a detrimental role of the nuclear accumulation of HDAC4 following stroke and identify CaMKIV as a key regulator of neuronal intracellular HDAC4 trafficking during stroke. PMID:26969532

  10. Giardia duodenalis induces paracellular bacterial translocation and causes postinfectious visceral hypersensitivity.

    PubMed

    Halliez, Marie C M; Motta, Jean-Paul; Feener, Troy D; Guérin, Gaetan; LeGoff, Laetitia; François, Arnaud; Colasse, Elodie; Favennec, Loic; Gargala, Gilles; Lapointe, Tamia K; Altier, Christophe; Buret, André G

    2016-04-15

    Irritable bowel syndrome (IBS) is the most frequent functional gastrointestinal disorder. It is characterized by abdominal hypersensitivity, leading to discomfort and pain, as well as altered bowel habits. While it is common for IBS to develop following the resolution of infectious gastroenteritis [then termed postinfectious IBS (PI-IBS)], the mechanisms remain incompletely understood. Giardia duodenalis is a cosmopolitan water-borne enteropathogen that causes intestinal malabsorption, diarrhea, and postinfectious complications. Cause-and-effect studies using a human enteropathogen to help investigate the mechanisms of PI-IBS are sorely lacking. In an attempt to establish causality between giardiasis and postinfectious visceral hypersensitivity, this study describes a new model of PI-IBS in neonatal rats infected with G. duodenalis At 50 days postinfection with G. duodenalis (assemblage A or B), long after the parasite was cleared, rats developed visceral hypersensitivity to luminal balloon distension in the jejunum and rectum, activation of the nociceptive signaling pathway (increased c-fos expression), histological modifications (villus atrophy and crypt hyperplasia), and proliferation of mucosal intraepithelial lymphocytes and mast cells in the jejunum, but not in the rectum. G. duodenalis infection also disrupted the intestinal barrier, in vivo and in vitro, which in turn promoted the translocation of commensal bacteria. Giardia-induced bacterial paracellular translocation in vitro correlated with degradation of the tight junction proteins occludin and claudin-4. The extensive observations associated with gut hypersensitivity described here demonstrate that, indeed, in this new model of postgiardiasis IBS, alterations to the gut mucosa and c-fos are consistent with those associated with PI-IBS and, hence, offer avenues for new mechanistic research in the field. PMID:26744469

  11. Nuclear EGFRvIII resists hypoxic microenvironment induced apoptosis via recruiting ERK1/2 nuclear translocation.

    PubMed

    Xie, Hui; Yang, Jinfeng; Xing, Wenjing; Dong, Yucui; Ren, Huan

    2016-02-01

    Glioblastoma (GBM) is the most aggressive type of primary brain tumor. Its interaction with the tumor microenvironment promotes tumor progression. Furthermore, GBM bearing expression of EGFRvIII displays more adaptation to tumor microenvironment related stress. But the mechanisms were poorly understood. Here, we presented evidence that in the human U87MG glioblastoma tumor model, EGFRvIII overexpression led aberrant kinase activation and nuclear translocation of EGFRvIII/ERK1/2 under hypoxia, which induced growth advantage by resisting apoptosis. Additionally, EGFRvIII defective in nuclear entry impaired this capacity in hypoxia adaptation, and partially interrupted ERK1/2 nuclear translocation. Pharmacology or genetic interference ERK1/2 decreased hypoxia resistance triggered by EGFRvIII expression, but not EGFRvIII nuclear translocation. In summary, this study identified a novel role for EGFRvIII in hypoxia tolerance, supporting an important link between hypoxia and subcellular localization alterations of the receptor. PMID:26742423

  12. Insulin induced translocation of Na+/K+-ATPase is decreased in the heart of streptozotocin diabetic rats

    PubMed Central

    Rosta, Klara; Tulassay, Eszter; Enzsoly, Anna; Ronai, Katalin; Szantho, Ambrus; Pandics, Tamas; Fekete, Andrea; Mandl, Peter; Ver, Agota

    2009-01-01

    Aim: To investigate the effect of acute insulin administration on the subcellular localization of Na+/K+-ATPase isoforms in cardiac muscle of healthy and streptozotocin-induced diabetic rats. Methods: Membrane fractions were isolated with subcellular fractionation and with cell surface biotinylation technique. Na+/K+-ATPase subunit isoforms were analysed with ouabain binding assay and Western blotting. Enzyme activity was measured using 3-O-methylfluorescein-phosphatase activity. Results: In control rat heart muscle α1 isoform of Na+/K+ ATPase resides mainly in the plasma membrane fraction, while α2 isoform in the intracellular membrane pool. Diabetes decreased the abundance of α1 isoform (25 %, P<0.05) in plasma membrane and α2 isoform (50%, P<0.01) in the intracellular membrane fraction. When plasma membrane fractions were isolated by discontinuous sucrose gradients, insulin-stimulated translocation of α2- but not α1-subunits was detected. α1-Subunit translocation was only detectable by cell surface biotinylation technique. After insulin administration protein level of α2 increased by 3.3-fold, α1 by 1.37-fold and β1 by 1.51-fold (P<0.02) in the plasma membrane of control, and less than 1.92-fold (P<0.02), 1.19-fold (not significant) and 1.34-fold (P<0.02) in diabetes. The insulin-induced translocation was wortmannin sensitive. Conclusion: This study demonstrate that insulin influences the plasma membrane localization of Na+/K+-ATPase isoforms in the heart. α2 isoform translocation is the most vulnerable to the reduced insulin response in diabetes. α1 isoform also translocates in response to insulin treatment in healthy rat. Insulin mediates Na+/K+-ATPase α1- and α2-subunit translocation to the cardiac muscle plasma membrane via a PI3-kinase-dependent mechanism. PMID:19915586

  13. p52-independent nuclear translocation of RelB promotes LPS-induced attachment

    SciTech Connect

    Saito, T.; Sasaki, C.Y.; Rezanka, L.J.; Ghosh, P.; Longo, D.L.

    2010-01-01

    The NF-{kappa}B signaling pathways have a critical role in the development and progression of various cancers. In this study, we demonstrated that the small cell lung cancer cell line (SCLC) H69 expressed a unique NF-{kappa}B profile as compared to other cancer cell lines. The p105/p50, p100/p52, c-Rel, and RelB protein and mRNA transcripts were absent in H69 cells but these cells expressed RelA/p65. The activation of H69 cells by lipopolysaccharide (LPS) resulted in the induction of RelB and p100 expression. The treatment also induced the nuclear translocation of RelB without the processing of p100 to p52. Furthermore, LPS-induced {beta}1 integrin expression and cellular attachment through an NF-{kappa}B-dependent mechanism. Blocking RelB expression prevented the increase in the expression of {beta}1 integrin and the attachment of H69. Taken together, the results suggest that RelB was responsible for the LPS-mediated attachment and may play an important role in the progression of some cancers.

  14. HIV-1 gp120 induces NFAT nuclear translocation in resting CD4+ T-cells

    SciTech Connect

    Cicala, Claudia . E-mail: ccicala@nih.gov; Arthos, James; Censoplano, Nina; Cruz, Catherine; Chung, Eva; Martinelli, Elena; Lempicki, Richard A.; Natarajan, Ven; VanRyk, Donald; Daucher, Marybeth; Fauci, Anthony S.

    2006-02-05

    The replication of human immunodeficiency virus (HIV) in CD4+ T-cells is strongly dependent upon the state of activation of infected cells. Infection of sub-optimally activated cells is believed to play a critical role in both the transmission of virus and the persistence of CD4+ T-cell reservoirs. There is accumulating evidence that HIV can modulate signal-transduction pathways in a manner that may facilitate replication in such cells. We previously demonstrated that HIV gp120 induces virus replication in resting CD4+ T cells isolated from HIV-infected individuals. Here, we show that in resting CD4+ T-cells, gp120 activates NFATs and induces their translocation into the nucleus. The HIV LTR encodes NFAT recognition sites, and NFATs may play a critical role in promoting viral replication in sub-optimally activated cells. These observations provide insight into a potential mechanism by which HIV is able to establish infection in resting cells, which may have implications for both transmission of HIV and the persistence of viral reservoirs.

  15. Liquid enteral diets induce bacterial translocation by increasing cecal flora without changing intestinal motility.

    PubMed

    Haskel, Y; Udassin, R; Freund, H R; Zhang, J M; Hanani, M

    2001-01-01

    The aim of this study was to determine the contribution of intestinal motility and cecal bacterial overgrowth to liquid diet-induced bacterial translocation (BT). Three different commercially available liquid diets were offered to mice for 1 week. BT to the mesenteric lymph nodes (MLN), spleen, and liver were examined as well as cecal bacterial counts and populations, small bowel length and weight, and histopathologic changes in the ileal and jejunal mucosa. In addition, the effect of the various diets on intestinal motility was measured by the transit index of a charcoal mixture introduced into the stomach. The incidence of BT to the mesenteric lymph nodes was significantly and similarly increased (p < .05) in mice fed Vivonex (30%), Ensure (30%), and Osmolite (33%) compared with chow-fed controls (0%). Compared with chow-fed controls, all three liquid diets were associated with the development of cecal bacterial overgrowth (p < .01). There were no significant changes in the transit index for the three liquid diet groups compared with the chow-fed controls. BT to the MLN was induced by all three liquid diets tested, casting some doubts as to their role in preventing BT in clinical use. BT was associated with a statistically significant increase in cecal bacterial count but was not associated with gut motility changes in this model. In fact, no significant changes in intestinal motility were noted in all groups tested. PMID:11284471

  16. Sulfur mustard induced nuclear translocation of glyceraldehyde-3-phosphate-dehydrogenase (GAPDH).

    PubMed

    Steinritz, Dirk; Weber, Jana; Balszuweit, Frank; Thiermann, Horst; Schmidt, Annette

    2013-12-01

    Sulfur Mustard (SM) is a vesicant chemical warfare agent, which is acutely toxic to a variety of organ systems including skin, eyes, respiratory system and bone marrow. The underlying molecular pathomechanism was mainly attributed to the alkylating properties of SM. However, recent studies have revealed that cellular responses to SM exposure are of more complex nature and include increased protein expression and protein modifications that can be used as biomarkers. In order to confirm already known biomarkers, to detect potential new ones and to further elucidate the pathomechanism of SM, we conducted large-scale proteomic experiments based on a human keratinocyte cell line (HaCaT) exposed to SM. Surprisingly, our analysis identified glyceraldehyde-3-phosphate-dehydrogenase (GAPDH) as one of the up-regulated proteins after exposure of HaCaT cells to SM. In this paper we demonstrate the sulfur mustard induced nuclear translocation of GAPDH in HaCaT cells by 2D gel-electrophoresis (2D GE), immunocytochemistry (ICC), Western Blot (WB) and a combination thereof. 2D GE in combination with MALDI-TOF MS/MS analysis identified GAPDH as an up-regulated protein after SM exposure. Immunocytochemistry revealed a distinct nuclear translocation of GAPDH after exposure to 300μM SM. This finding was confirmed by fractionated WB analysis. 2D GE and subsequent immunoblot staining of GAPDH demonstrated two different spot locations of GAPH (pI 7.0 and pI 8.5) that are related to cytosolic or nuclear GAPDH respectively. After exposure to 300μM SM a significant increase of nuclear GAPDH at pI 8.5 occurred. Nuclear GAPDH has been associated with apoptosis, detection of structural DNA alterations, DNA repair and regulation of genomic integrity and telomere structure. The results of our study add new aspects to the pathophysiology of sulfur mustard toxicity, yet further studies will be necessary to reveal the specific function of nuclear GAPDH in the pathomechanism of sulfur mustard

  17. O-GlcNAcylation of αB-crystallin regulates its stress-induced translocation and cytoprotection.

    PubMed

    Krishnamoorthy, Vigneshwaran; Donofrio, Anthony J; Martin, Jody L

    2013-07-01

    Under normal conditions, the ubiquitously expressed αB-crystallin functions as a chaperone. αB-crystallin has been implicated in a variety of pathologies, consistent with a build-up of protein aggregates, such as neuromuscular disorders, myofibrillar myopathies, and cardiomyopathies. αB-crystallins' cardioprotection is partially attributed to its translocation and binding to cytoskeletal elements in response to stress. The triggers for this translocation are not clearly understood. In the heart, αB-crystallin undergoes at least three significant post-translational modifications: phosphorylation at ser-45 and 59 and O-GlcNAcylation (O-linked attachment of the monosaccharide β-N-acetyl-glucosamine) at thr-170. Whether phosphorylation status drives translocation remains controversial. Therefore, we evaluated the role of αB-crystallins' O-GlcNAcylation in its stress-induced translocation and cytoprotection in cardiomyocytes under stress. Immunoblotting and precipitation experiments with anti-O-GlcNAc antibody (CTD110.6) and glycoprotein staining (Pro-Q Emerald) both demonstrate robust stress-induced O-GlcNAcylation of αB-crystallin. A non-O-GlcNAcylatable αB-crystallin mutant (αB-T170A) showed diminished translocation in response to heat shock and robust phosphorylation at both ser-45 and ser-59. Cell survival assays show a loss of overexpression-associated cytoprotection with the non-glycosylatable mutant to multiple stresses. While ectopic expression of wild-type αB-crystallin strongly stabilized ZsProSensor, a fusion protein rapidly degraded by the proteasome, the non-O-GlcNAcylatable version did not. Therefore, we believe the O-GlcNAcylation of αB-crystallin is a dynamic and important regulator of both its localization and function. PMID:23543138

  18. Stability of the translocation frequency following whole-body irradiation measured in rhesus monkeys

    NASA Technical Reports Server (NTRS)

    Lucas, J. N.; Hill, F. S.; Burk, C. E.; Cox, A. B.; Straume, T.

    1996-01-01

    Chromosome translocations are persistent indicators of prior exposure to ionizing radiation and the development of 'chromosome painting' to efficiently detect translocations has resulted in a powerful biological dosimetry tool for radiation dose reconstruction. However, the actual stability of the translocation frequency with time after exposure must be measured before it can be used reliably to obtain doses for individuals exposed years or decades previously. Human chromosome painting probes were used here to measure reciprocal translocation frequencies in cells from two tissues of 8 rhesus monkeys (Macaca mulatta) irradiated almost three decades previously. Six of the monkeys were exposed in 1965 to whole-body (fully penetrating) radiation and two were unexposed controls. The primates were irradiated as juveniles to single doses of 0.56, 1.13, 2.00, or 2.25 Gy. Blood lymphocytes (and skin fibroblasts from one individual) were obtained for cytogenetic analysis in 1993, near the end of the animals' lifespans. Results show identical dose-response relationships 28 y after exposure in vivo and immediately after exposure in vitro. Because chromosome aberrations are induced with identical frequencies in vivo and in vitro, these results demonstrate that the translocation frequencies induced in 1965 have not changed significantly during the almost three decades since exposure. Finally, our emerging biodosimetry data for individual radiation workers are now confirming the utility of reciprocal translocations measured by FISH in radiation dose reconstruction.

  19. Nuclear-translocated endostatin downregulates hypoxia inducible factor-1α activation through interfering with Zn(II) homeostasis.

    PubMed

    Guo, Lifang; Chen, Yang; He, Ting; Qi, Feifei; Liu, Guanghua; Fu, Yan; Rao, Chunming; Wang, Junzhi; Luo, Yongzhang

    2015-05-01

    Hypoxia‑inducible factor‑1α (HIF‑1α) is key in tumor progression and aggressiveness as it regulates a series of genes involved in angiogenesis and anaerobic metabolism. Previous studies have shown that the transcriptional levels of HIF‑1α may be downregulated by endostatin. However, the molecular mechanism by which endostatin represses HIF‑1α expression remains unknown. The current study investigated the mechanism by which nuclear‑translocated endostatin suppresses HIF‑1α activation by disrupting Zn(II) homeostasis. Endostatin was observed to downregulate HIF‑1α expression at mRNA and protein levels. Blockage of endostatin nuclear translocation by RNA interference of importin α1/β1 or ectopic expression of NLS‑deficient mutant nucleolin in human umbilical vein endothelial cells co‑transfected with small interfering (si)‑nucleolin siRNA compromises endostatin‑reduced HIF‑1α expression. Nuclear‑translocated apo‑endostatin, but not holo‑endostatin, significantly disrupts the interaction between CBP/p300 and HIF‑1α by disturbing Zn(II) homeostasis, which leads to the transcriptional inactivation of HIF‑1α. The results reveal mechanistic insights into the method by which nuclear‑translocated endostatin downregulates HIF‑1α activation and provides a novel way to investigate the function of endostatin in endothelial cells. PMID:25607980

  20. Melatonin reduces bacterial translocation and apoptosis in trinitrobenzene sulphonic acid-induced colitis of rats

    PubMed Central

    Akcan, Alper; Kucuk, Can; Sozuer, Erdogan; Esel, Duygu; Akyildiz, Hizir; Akgun, Hulya; Muhtaroglu, Sabahattin; Aritas, Yucel

    2008-01-01

    AIM: To investigate the effects of exogenous melatonin on bacterial translocation and apoptosis in a rat ulcerative colitis model. METHODS: Rats were randomly assigned to three groups: groupI: control, group II: experimental colitis, group III: colitis plus melatonin treatment. On d 11 after colitis, plasma tumor necrosis factor-α, portal blood endotoxin levels, colon tissue myeloperoxidase and caspase-3 activity were measured. Bacterial translocation was quantified by blood, lymph node, liver and spleen culture. RESULTS: We observed a significantly reduced incidence of bacterial translocation to the liver, spleen, mesenteric lymph nodes, portal and systemic blood in animals treated with melatonin. Treatment with melatonin significantly decreased the caspase-3 activity in colonic tissues compared to that in trinitrobenzene sulphonic acid- treated rats (16.11 ± 2.46 vs 32.97 ± 3.91, P < 0.01). CONCLUSION: Melatonin has a protective effect on bacterial translocation and apoptosis. PMID:18240350

  1. Detection and Identification of Translocations by Increased Specific Nondisjunction in ASPERGILLUS NIDULANS

    PubMed Central

    Upshall, Alan; Käfer, Etta

    1974-01-01

    A meiotic technique for visual detection of translocations has been applied to ten mitotically identified interchanges, and three new translocations were discovered using this method. Testcrosses between "standard" strains and potential translocation strains—e.g. strains with newly induced mutants or descendants from translocation crosses—are inspected for the frequency of abnormal-looking colonies. In all heterozygous translocation crosses "abnormals" are increased at least tenfold compared to the average control level of 0.15%. Most of these are disomics, and can be recognized by their characteristic phenotypes. Each translocation produces a few specific types, since nondisjunction is increased mainly in the linkage groups involved in the translocation (50–100-fold over control values). Therefore, translocations were not only detected but often tentatively assigned to linkage groups from the analysis of the disomic progeny in crosses. In addition, this technique allows reciprocal and nonreciprocal translocations to be distinguished, since only the latter produce one-third phenotypically abnormal duplication progeny. While results are clearcut in most cases, occasionally problems are encountered, e.g. when morphological mutants segregate in crosses, or when other genetic factors which increase or reduce the frequency of nondisjunction are present in certain strains. PMID:4594334

  2. Membrane translocation of IL-33 receptor in ventilator induced lung injury.

    PubMed

    Yang, Shih-Hsing; Lin, Jau-Chen; Wu, Shu-Yu; Huang, Kun-Lun; Jung, Fang; Ma, Ming-Chieh; Wang Hsu, Guoo-Shyng; Jow, Guey-Mei

    2015-01-01

    Ventilator-induced lung injury is associated with inflammatory mechanism and causes high mortality. The objective of this study was to discover the role of IL-33 and its ST2 receptor in acute lung injury induced by mechanical ventilator (ventilator-induced lung injury; VILI). Male Wistar rats were intubated after tracheostomy and received ventilation at 10 cm H2O of inspiratory pressure (PC10) by a G5 ventilator for 4 hours. The hemodynamic and respiratory parameters were collected and analyzed. The morphological changes of lung injury were also assessed by histological H&E stain. The dynamic changes of lung injury markers such as TNF-α and IL-1β were measured in serum, bronchoalveolar lavage fluid (BALF), and lung tissue homogenization by ELISA assay. During VILI, the IL-33 profile change was detected in BALF, peripheral serum, and lung tissue by ELISA analysis. The Il-33 and ST2 expression were analyzed by immunohistochemistry staining and western blot analysis. The consequence of VILI by H&E stain showed inducing lung congestion and increasing the expression of pro-inflammatory cytokines such as TNF-α and IL-1β in the lung tissue homogenization, serum, and BALF, respectively. In addition, rats with VILI also exhibited high expression of IL-33 in lung tissues. Interestingly, the data showed that ST2L (membrane form) was highly accumulated in the membrane fraction of lung tissue in the PC10 group, but the ST2L in cytosol was dramatically decreased in the PC10 group. Conversely, the sST2 (soluble form) was slightly decreased both in the membrane and cytosol fractions in the PC10 group compared to the control group. In conclusion, these results demonstrated that ST2L translocation from the cytosol to the cell membranes of lung tissue and the down-expression of sST2 in both fractions can function as new biomarkers of VILI. Moreover, IL-33/ST2 signaling activated by mechanically responsive lung injury may potentially serve as a new therapy target. PMID:25815839

  3. Cadmium-induced apoptosis is mediated by the translocation of AIF to the nucleus in rat testes.

    PubMed

    Kim, Jisun; Soh, Jaemog

    2009-07-10

    Cadmium (Cd) is a highly toxic metal that affects a variety of cellular events, such as cell proliferation, differentiation and survival. Cd generates reactive oxygen species (ROS) that induce apoptosis. We previously demonstrated that Cd induces apoptosis in testicular germ cells and that apoptosis was prevented by the administration of ascorbic acid (AA), an ROS scavenger. However, little is known about the signaling pathways underlying Cd-induced apoptosis in rat testes. Here, we report that Cd-induced apoptosis in rat testes was associated with the translocation of apoptosis inducing factor (AIF) from mitochondria to the nucleus, and that this was prevented by treatment with AA. Cd-induced cleavage of poly ADP-ribose polymerase-1 (PARP-1), and this was also inhibited by treatment with AA. Taken together, these results suggest that Cd-induced ROS was responsible for the upregulation of PARP-1, the translocation of AIF to the nucleus, and apoptosis of testicular cells in rat testes. PMID:19433269

  4. Hepatic microtubule acetylation and stability induced by chronic alcohol exposure impair nuclear translocation of STAT3 and STAT5B, but not Smad2/3.

    PubMed

    Fernandez, David J; Tuma, Dean J; Tuma, Pamela L

    2012-12-15

    Although alcoholic liver disease is clinically well described, the molecular basis for alcohol-induced hepatotoxicity is not well understood. Previously, we found that alcohol exposure led to increased microtubule acetylation and stability in polarized, hepatic WIF-B cells and in livers from ethanol-fed rats. Because microtubules are known to regulate transcription factor nuclear translocation and dynamic microtubules are required for translocation of at least a subset of these factors, we examined whether alcohol-induced microtubule acetylation and stability impair nuclear translocation. We examined nuclear delivery of factors representing the two mechanisms by which microtubules regulate translocation. To represent factors that undergo directed delivery, we examined growth hormone-induced STAT5B translocation and IL-6-induced STAT3 translocation. To represent factors that are sequestered in the cytoplasm by microtubule attachment until ligand activation, we examined transforming growth factor-β-induced Smad2/3 translocation. We found that ethanol exposure selectively impaired translocation of the STATs, but not Smad2/3. STAT5B delivery was decreased to a similar extent by addition of taxol (a microtubule-stabilizing drug) or trichostatin A (a deacetylase inhibitor), agents that promote microtubule acetylation in the absence of alcohol. Thus the alcohol-induced impairment of STAT nuclear translocation can be explained by increased microtubule acetylation and stability. Only ethanol treatment impaired STAT5B activation, indicating that microtubules are not important for its activation by Jak2. Furthermore, nuclear exit was not changed in treated cells, indicating that this process is also independent of microtubule acetylation and stability. Together, these results raise the exciting possibility that deacetylase agonists may be effective therapeutics for the treatment of alcoholic liver disease. PMID:23064763

  5. High glucose-induced cytoplasmic translocation of Dnmt3a contributes to CTGF hypo-methylation in mesangial cells.

    PubMed

    Zhang, Hao; Li, Aimei; Zhang, Wei; Huang, Zhijun; Wang, Jianwen; Yi, Bin

    2016-08-01

    Connective tissue growth factor (CTGF) plays an essential role in the pathogenesis of diabetic nephropathy and we have previously identified that high glucose induced the expression of CTGF by decreasing DNA methylation. The aim of the present study was to investigate the underlying mechanisms of the high glucose-induced CTGF hypo-methylation. Human glomerular mesangial cells (hMSCs) were treated with low glucose (5 mM), mannitol (30 mM) or high glucose (30 mM) respectively. Immunofluorescence staining, real-time quantitative PCR and western blotting were performed to determine the subcellular distribution and expression of CTGF and Dnmt3a. ChIP-PCR assay was applied to investigate the capability of Dnmt3a to bind the CpG island of CTGF. Our results showed that high glucose induced both mRNA and protein expressions of CTGF, and led to increased cytoplasmic translocation of Dnmt3a in cultured hMSCs. The nuclear Dnmt3a protein was significantly reduced after high glucose treatment, although the expression of total Dnmt3a protein was not altered. We further discovered that ERK/MAPK signalling contributed to the high glucose-induced cytoplasmic translocation of Dnmt3a. Consequently, less Dnmt3a protein was bound to the CpG island of CTGF promoter, which induced an increase in CTGF expression by epigenetic regulation in the presence of high glucose. In conclusion, high glucose induces cytoplasmic translocation of Dnmt3a, possibly through activating ERK/MAPK signalling pathway, which contributes to the decreased binding of Dnmt3a on CTGF promoter and the subsequent CTGF hypo-methylation in diabetic nephropathy. PMID:27364355

  6. High glucose-induced cytoplasmic translocation of Dnmt3a contributes to CTGF hypo-methylation in mesangial cells

    PubMed Central

    Zhang, Hao; Li, Aimei; Zhang, Wei; Huang, Zhijun; Wang, Jianwen; Yi, Bin

    2016-01-01

    Connective tissue growth factor (CTGF) plays an essential role in the pathogenesis of diabetic nephropathy and we have previously identified that high glucose induced the expression of CTGF by decreasing DNA methylation. The aim of the present study was to investigate the underlying mechanisms of the high glucose-induced CTGF hypo-methylation. Human glomerular mesangial cells (hMSCs) were treated with low glucose (5 mM), mannitol (30 mM) or high glucose (30 mM) respectively. Immunofluorescence staining, real-time quantitative PCR and western blotting were performed to determine the subcellular distribution and expression of CTGF and Dnmt3a. ChIP-PCR assay was applied to investigate the capability of Dnmt3a to bind the CpG island of CTGF. Our results showed that high glucose induced both mRNA and protein expressions of CTGF, and led to increased cytoplasmic translocation of Dnmt3a in cultured hMSCs. The nuclear Dnmt3a protein was significantly reduced after high glucose treatment, although the expression of total Dnmt3a protein was not altered. We further discovered that ERK/MAPK signalling contributed to the high glucose-induced cytoplasmic translocation of Dnmt3a. Consequently, less Dnmt3a protein was bound to the CpG island of CTGF promoter, which induced an increase in CTGF expression by epigenetic regulation in the presence of high glucose. In conclusion, high glucose induces cytoplasmic translocation of Dnmt3a, possibly through activating ERK/MAPK signalling pathway, which contributes to the decreased binding of Dnmt3a on CTGF promoter and the subsequent CTGF hypo-methylation in diabetic nephropathy. PMID:27364355

  7. Role of JNK Activation and Mitochondrial Bax Translocation in Allicin-Induced Apoptosis in Human Ovarian Cancer SKOV3 Cells

    PubMed Central

    Xu, Ling; Yu, Jin; Zhai, Dongxia; Zhang, Danying; Shen, Wei; Bai, Lingling; Cai, Zailong; Yu, Chaoqin

    2014-01-01

    Background. Allicin, the major component of freshly crushed garlic, is one of the most biologically active compounds of garlic; it has been reported to induce apoptosis in cancer cells; however, the mechanism by which allicin exerts its apoptotic effects is not fully understood. The aim of the present study was to further elucidate the apoptotic pathways induced by allicin in the human ovarian cancer cell line SKOV3. Methods. Cell proliferation and apoptosis were measured by cell-counting assay and flow cytometry analysis. Activation of the signaling pathway was screened by human phospho-kinase array analysis, and the activated pathway and its related proteins were further confirmed by western blot analysis. Results. Allicin induced SKOV3 cell apoptosis and JNK phosphorylation in a time- and dose-dependent manner, but these were significantly blocked by SP600125 (an inhibitor of JNK). The findings suggest that JNK phosphorylation is related to the action of allicin on SKOV3 cells. Furthermore, JNK activation induced Bcl-2 family activation, triggered mitochondria-mediated signaling pathways, and led to the translocation of a considerable amount of Bax and cytochrome c release. Conclusions. JNK activation and mitochondrial Bax translocation are involved in allicin-induced apoptosis in SKOV3 cells. Our data input new insights to the literature of allicin-induced apoptosis. PMID:25097657

  8. Mechanism of How Salt-Gradient-Induced Charges Affect the Translocation of DNA Molecules through a Nanopore

    PubMed Central

    He, Yuhui; Tsutsui, Makusu; Scheicher, Ralph H.; Fan, Chun; Taniguchi, Masateru; Kawai, Tomoji

    2013-01-01

    Experiments using nanopores demonstrated that a salt gradient enhances the capture rate of DNA and reduces its translocation speed. These two effects can help to enable electrical DNA sequencing with nanopores. Here, we provide a quantitative theoretical evaluation that shows the positive net charges, which accumulate around the pore entrance due to the salt gradient, are responsible for the two observed effects: they reinforce the electric capture field, resulting in promoted molecule capture rate; and they induce cationic electroosmotic flow through the nanopore, thus significantly retarding the motion of the anionic DNA through the nanopore. Our multiphysical simulation results show that, during the polymer trapping stage, the former effect plays the major role, thus resulting in promoted DNA capture rate, while during the nanopore-penetrating stage the latter effect dominates and consequently reduces the DNA translocation speed significantly. Quantitative agreement with experimental results has been reached by further taking nanopore wall surface charges into account. PMID:23931325

  9. Reciprocal Paracrine Interactions Between Normal Human Epithelial and Mesenchymal Cells Protect Cellular DNA from Radiation-Induced Damage

    SciTech Connect

    Nakazawa, Yuka; Saenko, Vladimir Rogounovitch, Tatiana; Suzuki, Keiji; Mitsutake, Norisato; Matsuse, Michiko; Yamashita, Shunichi

    2008-06-01

    Purpose: To explore whether interactions between normal epithelial and mesenchymal cells can modulate the extent of radiation-induced DNA damage in one or both types of cells. Methods and Materials: Human primary thyrocytes (PT), diploid fibroblasts BJ, MRC-5, and WI-38, normal human mammary epithelial cells (HMEC), and endothelial human umbilical cord vein endothelial cells (HUV-EC-C), cultured either individually or in co-cultures or after conditioned medium transfer, were irradiated with 0.25 to 5 Gy of {gamma}-rays and assayed for the extent of DNA damage. Results: The number of {gamma}-H2AX foci in co-cultures of PT and BJ fibroblasts was approximately 25% lower than in individual cultures at 1 Gy in both types of cells. Reciprocal conditioned medium transfer to individual cultures before irradiation resulted in approximately a 35% reduction of the number {gamma}-H2AX foci at 1 Gy in both types of cells, demonstrating the role of paracrine soluble factors. The DNA-protected state of cells was achieved within 15 min after conditioned medium transfer; it was reproducible and reciprocal in several lines of epithelial cells and fibroblasts, fibroblasts, and endothelial cells but not in epithelial and endothelial cells. Unlike normal cells, human epithelial cancer cells failed to establish DNA-protected states in fibroblasts and vice versa. Conclusions: The results imply the existence of a network of reciprocal interactions between normal epithelial and some types of mesenchymal cells mediated by soluble factors that act in a paracrine manner to protect DNA from genotoxic stress.

  10. Following Strain-Induced Mosaicity Changes of Ferroelectric Thin Films by Ultrafast Reciprocal Space Mapping

    NASA Astrophysics Data System (ADS)

    Schick, D.; Bojahr, A.; Herzog, M.; Gaal, P.; Vrejoiu, I.; Bargheer, M.

    2013-03-01

    We investigate coherent phonon propagation in a thin film of ferroelectric PbZr0.2Ti0.8O3 (PZT) by ultrafast x-ray diffraction experiments, which are analyzed as time-resolved reciprocal space mapping in order to observe the in- and out-of-plane structural dynamics, simultaneously. The mosaic structure of the PZT leads to a coupling of the excited out-of-plane expansion to in-plane lattice dynamics on a picosecond time scale, which is not observed for out-of-plane compression.

  11. An elongation factor G-induced ribosome rearrangement precedes tRNA-mRNA translocation.

    PubMed

    Savelsbergh, Andreas; Katunin, Vladimir I; Mohr, Dagmar; Peske, Frank; Rodnina, Marina V; Wintermeyer, Wolfgang

    2003-06-01

    The elongation cycle of protein synthesis is completed by translocation, a rearrangement during which two tRNAs bound to the mRNA move on the ribosome. The reaction is promoted by elongation factor G (EF-G) and accelerated by GTP hydrolysis. Here we report a pre-steady-state kinetic analysis of translocation. The kinetic model suggests that GTP hydrolysis drives a conformational rearrangement of the ribosome that precedes and limits the rates of tRNA-mRNA translocation and Pi release from EF-G.GDP.Pi. The latter two steps are intrinsically rapid and take place at random. These results indicate that the energy of GTP hydrolysis is utilized to promote the ribosome rearrangement and to bias spontaneous fluctuations within the ribosome-EF-G complex toward unidirectional movement of mRNA and tRNA. PMID:12820965

  12. Study on homoeologous chromosome pairing and translocation induced by 5A/5R X 6A/6R wheat-rye substitution lines.

    PubMed

    Li, Ji-Lin; Wang, Xiao-Ping; Zhong, Li; Xu, Xiang-Ling

    2006-03-01

    This article aims to study the homoeologous chromosome pairing and translocation induced by 5A/5R x 6A/6R wheat-rye substitution lines. To clarify the mechanism of homoeologous chromosome pairing and create wheat-rye translocation lines, two wheat-rye substitution lines, 5A/5R and 6A/6R were crossed. The chromosome behavior of pollen mother cells (PMCs) in meiosis was investigated in hybrid F1. Homoeologous chromosome pairing between wheat and rye occurred in 22.91% of PMC. Wheat-rye translocation lines were identified via C-banding and in situ hybridization (GISH) in hybrid F2 and later generations. In F2 generation, translocations happened in 9 of 45 plants, reached to 20%. These translocation lines were generated from homoeologous chromosome pairing, or mis-division and reconstruction of univalent chromosomes. PMID:16553213

  13. Oroxylin A modulates mitochondrial function and apoptosis in human colon cancer cells by inducing mitochondrial translocation of wild-type p53

    PubMed Central

    Zhou, Yuxin; Ni, Ting; Dai, Yuanyuan; Li, Zhiyu; Guo, Qinglong; Wei, Libin

    2016-01-01

    Oroxylin A is a flavonoid extracted from the root of Scutellaria baicalensis Georgi. We previously demonstrated that oroxylin A induced apoptosis in human colon cancer cells via the mitochondrial pathway. In the present study, we investigated the underlying mechanisms responsible for the mitochondrial apoptotic pathway triggered by oroxylin A. p53 regulates mitochondrial survival, mitochondrial DNA integrity, and protection from oxidative stress. We determined that oroxylin A induces p53 mitochondrial translocation and inhibits SOD2 activity. Additionally, our studies demonstrate that oroxylin A promotes the formation and mitochondrial translocation of the p53-Recql4 complex in HCT-116 cells. Finally, we showed that oroxylin A triggers cytosolic p53 activation, thereby promoting apoptosis. Mitochondrial translocation of p53 was also validated in vivo. Thus, oroxylin A induces mitochondrial translocation of p53 and leads to mitochondrial dysfunction in human colon cancer cells. PMID:26958937

  14. Oroxylin A modulates mitochondrial function and apoptosis in human colon cancer cells by inducing mitochondrial translocation of wild-type p53.

    PubMed

    Qiao, Chen; Lu, Na; Zhou, Yuxin; Ni, Ting; Dai, Yuanyuan; Li, Zhiyu; Guo, Qinglong; Wei, Libin

    2016-03-29

    Oroxylin A is a flavonoid extracted from the root of Scutellaria baicalensis Georgi. We previously demonstrated that oroxylin A induced apoptosis in human colon cancer cells via the mitochondrial pathway. In the present study, we investigated the underlying mechanisms responsible for the mitochondrial apoptotic pathway triggered by oroxylin A. p53 regulates mitochondrial survival, mitochondrial DNA integrity, and protection from oxidative stress. We determined that oroxylin A induces p53 mitochondrial translocation and inhibits SOD2 activity. Additionally, our studies demonstrate that oroxylin A promotes the formation and mitochondrial translocation of the p53-Recql4 complex in HCT-116 cells. Finally, we showed that oroxylin A triggers cytosolic p53 activation, thereby promoting apoptosis. Mitochondrial translocation of p53 was also validated in vivo. Thus, oroxylin A induces mitochondrial translocation of p53 and leads to mitochondrial dysfunction in human colon cancer cells. PMID:26958937

  15. Nuclear translocation of phosphorylated STAT3 regulates VEGF-A-induced lymphatic endothelial cell migration and tube formation

    SciTech Connect

    Okazaki, Hideki; Tokumaru, Sho; Hanakawa, Yasushi; Shiraishi, Ken; Shirakata, Yuji; Dai, Xiuju; Yang, Lijun; Tohyama, Mikiko; Hashimoto, Koji; Sayama, Koji

    2011-09-02

    Highlights: {yields} VEGF-A enhanced lymphatic endothelial cell migration and increased tube formation. {yields} VEGF-A treated lymphatic endothelial cell showed activation of STAT3. {yields} Dominant-negative STAT3 inhibited VEGF-A-induced lymphatic endothelial cell migration and tube formation. -- Abstract: Vascular endothelial growth factor (VEGF) is an endothelial cell-specific growth factor that regulates endothelial functions, and signal transducers and activators of transcription (STATs) are known to be important during VEGF receptor signaling. The aim of this study was to determine whether STAT3 regulates VEGF-induced lymphatic endothelial cell (LEC) migration and tube formation. VEGF-A (33 ng/ml) enhanced LEC migration by 2-fold and increased tube length by 25% compared with the control, as analyzed using a Boyden chamber and Matrigel assay, respectively. Western blot analysis and immunostaining revealed that VEGF-A induced the nuclear translocation of phosphorylated STAT3 in LECs, and this translocation was blocked by the transfection of LECs with an adenovirus vector expressing a dominant-negative mutant of STAT3 (Ax-STAT3F). Transfection with Ax-STAT3F also almost completely inhibited VEGF-A-induced LEC migration and tube formation. These results indicate that STAT3 is essential for VEGF-A-induced LEC migration and tube formation and that STAT3 regulates LEC functions.

  16. Respiratory pattern generator model using Ca++-induced Ca++ release in neurons shows both pacemaker and reciprocal network properties.

    PubMed

    Dunin-Barkowski, W L; Escobar, A L; Lovering, A T; Orem, J M

    2003-10-01

    There are two contradictory explanations for central respiratory rhythmogenesis. One suggests that respiratory rhythm emerges from interaction between inspiratory and expiratory neural semicenters that inhibit each other and thereby provide reciprocal rhythmic activity (Brown 1914). The other uses bursting pacemaker activity of individual neurons to produce the rhythm (Feldman and Cleland 1982). Hybrid models have been developed to reconcile these two seemingly conflicting mechanisms (Smith et al. 2000; Rybak et al. 2001). Here we report computer simulations that demonstrate a unified mechanism of the two types of oscillator. In the model, we use the interaction of Ca(++)-dependent K+ channels (Mifflin et al. 1985) with Ca(++)-induced Ca++ release from intracellular stores (McPherson and Campbell 1993), which was recently revealed in neurons (Hernandez-Cruz et al. 1997; Mitra and Slaughter 2002a,b; Scornik et al. 2001). Our computations demonstrate that uncoupled neurons with these intracellular mechanisms show conditional pacemaker properties (Butera et al. 1999) when exposed to steady excitatory inputs. Adding weak inhibitory synapses (based on increased K+ conductivity) between two model neural pools surprisingly synchronizes the activity of both neural pools. As inhibitory synaptic connections between the two pools increase from zero to higher values, the model produces first dissociated pacemaker activity of individual neurons, then periodic synchronous bursts of all neurons (inspiratory and expiratory), and finally reciprocal rhythmic activity of the neural pools. PMID:14605892

  17. Cyclosporine A Suppressed Glucose Oxidase Induced P53 Mitochondrial Translocation and Hepatic Cell Apoptosis through Blocking Mitochondrial Permeability Transition

    PubMed Central

    Yu, Weihua; Zhang, Xiaodi; Liu, Jiangzheng; Wang, Xin; Li, Shuang; Liu, Rui; Liao, Nai; Zhang, Tao; Hai, Chunxu

    2016-01-01

    P53 is known as a transcription factor to control apoptotic cell death through regulating a series of target genes in nucleus. There is accumulating evidences show that p53 can directly induce cell apoptosis through transcription independent way at mitochondria. However, the mechanism by which p53 translocation into mitochondria in response to oxidative stress remains unclear. Here, glucose oxidase (GOX) was used to induce ROS generation in HepG2 cells and liver tissues of mice. The results showed that p53 was stabilized and translocated to mitochondria in a time and dose dependent manner after GOX exposure. Interestingly, as an inhibitor of mitochondrial permeability transition, cyclosporine A (CsA) was able to effectively reduce GOX mediated mitochondrial p53 distribution without influencing on the expression of p53 target genes including Bcl-2 and Bax. These indicated that CsA could just block p53 entering into mitochondria, but not affect p53-dependent transcription. Meanwhile, CsA failed to inhibit the ROS generation induced by GOX, which indicated that CsA had no antioxidant function. Moreover, GOX induced typical apoptosis characteristics including, mitochondrial dysfunction, accumulation of Bax and release of cytochrome C in mitochondria, accompanied with activation of caspase-9 and caspase-3. These processions were suppressed after pretreatment with CsA and pifithrin-μ (PFT-μ, a specific inhibitor of p53 mitochondrial translocation). In vivo, CsA was able to attenuate p53 mitochondrial distribution and protect mice liver against from GOX mediated apoptotic cell death. Taken together, these suggested that CsA could suppress ROS-mediated p53 mitochondrial distribution and cell apoptosis depended on its inhibition effect to mitochondrial permeability transition. It might be used to rescue the hepatic cell apoptosis in the patients with acute liver injury. PMID:26884717

  18. Blockage of protease-activated receptor 1 ameliorates heat-stress induced intestinal high permeability and bacterial translocation.

    PubMed

    Xu, Qiu-lin; Guo, Xiao-hua; Liu, Jing-xian; Chen, Bin; Liu, Zhi-feng; Su, Lei

    2015-04-01

    Accumulated evidences indicate intestinal lesions play an important role in the pathogenesis of heatstroke. However, the underlying mechanisms by which heat stress causes intestinal barrier dysfunction and bacterial translocation remain unclear. In this study, we investigated the role of protease-activated receptor 1 (PAR1) in heat stress-induced intestinal hyper-permeability and bacterial translocation. Intestinal permeability in heat stressed mouse was evaluated by determining plasma endotoxin concentration and urinal lactulose/mannitol (L/M) ratio with gastric administration of L/M solution. Venous blood, liver, spleen and mesenteric lymph node tissues were collected for bacterial load test. Real time PCR was used to determine ileum PAR1 mRNA expression. In vitro study, permeability was assessed by determining trans-epithelial electrical resistance (TEER) in human intestinal Caco-2 cell line. RWJ-58259, a selective antagonist of PAR1, was used both in vivo and in vitro studies. The results showed that heat stress could increase ileum PAR1 mRNA level, urinal L/M ratio, plasma endotoxin concentration and bacterial load in the blood, spleen and mesenteric lymph nodes. Blocking PAR1 with RWJ-58259 (10 mg/kg) pretreatment could significantly reduce heat stress-induced above changes, but have no role to PAR1 mRNA level. In Caco-2 cells, heat stress-induced high permeability could also be reduced by RWJ-58259 (5-20 µmol/L). In summary, our results demonstrated that PAR1 signaling pathway may play an important role in the heat stress-induced elevation of intestinal permeability, bacterial translocation and the occurrence of endotoxemia. PMID:25492552

  19. Cyclosporine A Suppressed Glucose Oxidase Induced P53 Mitochondrial Translocation and Hepatic Cell Apoptosis through Blocking Mitochondrial Permeability Transition.

    PubMed

    Yu, Weihua; Zhang, Xiaodi; Liu, Jiangzheng; Wang, Xin; Li, Shuang; Liu, Rui; Liao, Nai; Zhang, Tao; Hai, Chunxu

    2016-01-01

    P53 is known as a transcription factor to control apoptotic cell death through regulating a series of target genes in nucleus. There is accumulating evidences show that p53 can directly induce cell apoptosis through transcription independent way at mitochondria. However, the mechanism by which p53 translocation into mitochondria in response to oxidative stress remains unclear. Here, glucose oxidase (GOX) was used to induce ROS generation in HepG2 cells and liver tissues of mice. The results showed that p53 was stabilized and translocated to mitochondria in a time and dose dependent manner after GOX exposure. Interestingly, as an inhibitor of mitochondrial permeability transition, cyclosporine A (CsA) was able to effectively reduce GOX mediated mitochondrial p53 distribution without influencing on the expression of p53 target genes including Bcl-2 and Bax. These indicated that CsA could just block p53 entering into mitochondria, but not affect p53-dependent transcription. Meanwhile, CsA failed to inhibit the ROS generation induced by GOX, which indicated that CsA had no antioxidant function. Moreover, GOX induced typical apoptosis characteristics including, mitochondrial dysfunction, accumulation of Bax and release of cytochrome C in mitochondria, accompanied with activation of caspase-9 and caspase-3. These processions were suppressed after pretreatment with CsA and pifithrin-μ (PFT-μ, a specific inhibitor of p53 mitochondrial translocation). In vivo, CsA was able to attenuate p53 mitochondrial distribution and protect mice liver against from GOX mediated apoptotic cell death. Taken together, these suggested that CsA could suppress ROS-mediated p53 mitochondrial distribution and cell apoptosis depended on its inhibition effect to mitochondrial permeability transition. It might be used to rescue the hepatic cell apoptosis in the patients with acute liver injury. PMID:26884717

  20. A sugar chain at a specific position in the nascent polypeptide chain induces forward movement during translocation through the translocon.

    PubMed

    Yamagishi, Marifu; Fujita, Hidenobu; Morimoto, Fumiko; Kida, Yuichiro; Sakaguchi, Masao

    2011-05-01

    Nascent polypeptide chains synthesized by membrane bound ribosomes are cotranslationally translocated through and integrated into the endoplasmic reticulum translocon. Hydrophobic segments and positive charges on the chain are critical to halt the ongoing translocation. A marginally hydrophobic segment, which cannot be inserted into the membrane by itself, can be a transmembrane segment depending on its downstream positive charges. In certain conditions, positive charges even 60 residues downstream cause the marginally hydrophobic segment to span the membrane by inducing the segment to slide back from the lumen. Here we systematically examined the effect of a core sugar chain on the fate of a marginally hydrophobic segment using a cell-free translation and translocation system. A sugar chain added within 12 residues upstream of the marginally hydrophobic segment prevents the sliding back and promotes forward movement of the polypeptide chain. The sugar chain apparently functions as a ratchet to keep the polypeptide chain in the lumen. We propose that the sugar chain is a third topology determinant of membrane proteins, in addition to a hydrophobic segment and positive charges of the nascent chain. PMID:21278156

  1. Correlation between x-ray reciprocal space maps and magnetic properties of current-induced magnetization switching pseudospin valve structures

    NASA Astrophysics Data System (ADS)

    Siffalovic, P.; Chitu, L.; Halahovets, Y.; Jergel, M.; Senderak, R.; Majkova, E.; Luby, S.

    2007-02-01

    A thorough study of x-ray diffuse scattering from the spin valve structures suitable for current induced magnetization switching is presented. We used complete reciprocal space maps of diffusely scattered x rays to show the effect of bottom Au electrode on the morphology of buried spin valve interfaces. The thickness and roughness of each layer, as well as vertical and lateral roughness correlation lengths, were obtained. The impact of interfaces morphology on the magnetic properties, especially on the increase of spin valve coercivity, was measured and simulated within the frame of Néel magnetostatic coupling model based on the parameters from the x-ray diffuse scattering data. Measurement of x-ray diffuse scattering presents a rapid and nondestructive technique for in-depth and self-contained analysis of spin valve layers and interfaces.

  2. Angiogenin-induced protein kinase B/Akt activation is necessary for angiogenesis but is independent of nuclear translocation of angiogenin in HUVE cells

    SciTech Connect

    Kim, Hye-Mi; Kang, Dong-Ku; Kim, Hak Yong; Kang, Sang Sun; Chang, Soo-Ik . E-mail: sichang@cbnu.ac.kr

    2007-01-12

    Angiogenin, a potent angiogenic factor, binds to endothelial cells and is endocytosed and rapidly translocated to and concentrated in the nucleolus where it binds to DNA. In this study, we report that angiogenin induces transient phosphorylation of protein kinase B/Akt in cultured human umbilical vein endothelial (HUVE) cells. LY294002 inhibits the angiogenin-induced protein kinase B/Akt activation and also angiogenin-induced cell migration in vitro as well as angiogenesis in chick embryo chorioallantoic membrane in vivo without affecting nuclear translocation of angiogenin in HUVE cells. These results suggest that cross-talk between angiogenin and protein kinase B/Akt signaling pathways is essential for angiogenin-induced angiogenesis in vitro and in vivo, and that angiogenin-induced PKB/Akt activation is independent of nuclear translocation of angiogenin in HUVE cells.

  3. Involvement of myristoylated alanine-rich C kinase substrate phosphorylation and translocation in cholecystokinin-induced amylase release in rat pancreatic acini.

    PubMed

    Satoh, Keitaro; Narita, Takanori; Katsumata-Kato, Osamu; Sugiya, Hiroshi; Seo, Yoshiteru

    2016-03-15

    Cholecystokinin (CCK) is a gastrointestinal hormone that induces exocytotic amylase release in pancreatic acinar cells. The activation of protein kinase C (PKC) is involved in the CCK-induced pancreatic amylase release. Myristoylated alanine-rich C kinase substrate (MARCKS) is a ubiquitously expressed substrate of PKC. MARCKS has been implicated in membrane trafficking in several cell types. The phosphorylation of MARCKS by PKC results in the translocation of MARCKS from the membrane to the cytosol. Here, we studied the involvement of MARCKS in the CCK-induced amylase release in rat pancreatic acini. Employing Western blotting, we detected MARCKS protein in the rat pancreatic acini. CCK induced MARCKS phosphorylation. A PKC-δ inhibitor, rottlerin, inhibited the CCK-induced MARCKS phosphorylation and amylase release. In the translocation assay, we also observed CCK-induced PKC-δ activation. An immunohistochemistry study showed that CCK induced MARCKS translocation from the membrane to the cytosol. When acini were lysed by a detergent, Triton X-100, CCK partially induced displacement of the MARCKS from the GM1a-rich detergent-resistant membrane fractions (DRMs) in which Syntaxin2 is distributed. A MARCKS-related peptide inhibited the CCK-induced amylase release. These findings suggest that MARCKS phosphorylation by PKC-δ and then MARCKS translocation from the GM1a-rich DRMs to the cytosol are involved in the CCK-induced amylase release in pancreatic acinar cells. PMID:26744470

  4. Induced Fungal Resistance to Insect Grazing: Reciprocal Fitness Consequences and Fungal Gene Expression in the Drosophila-Aspergillus Model System

    PubMed Central

    Caballero Ortiz, Silvia; Trienens, Monika; Rohlfs, Marko

    2013-01-01

    Background Fungi are key dietary resources for many animals. Fungi, in consequence, have evolved sophisticated physical and chemical defences for repelling and impairing fungivores. Expression of such defences may entail costs, requiring diversion of energy and nutrients away from fungal growth and reproduction. Inducible resistance that is mounted after attack by fungivores may allow fungi to circumvent the potential costs of defence when not needed. However, no information exists on whether fungi display inducible resistance. We combined organism and fungal gene expression approaches to investigate whether fungivory induces resistance in fungi. Methodology/Principal Findings Here we show that grazing by larval fruit flies, Drosophila melanogaster, induces resistance in the filamentous mould, Aspergillus nidulans, to subsequent feeding by larvae of the same insect. Larval grazing triggered the expression of various putative fungal resistance genes, including the secondary metabolite master regulator gene laeA. Compared to the severe pathological effects of wild type A. nidulans, which led to 100% insect mortality, larval feeding on a laeA loss-of-function mutant resulted in normal insect development. Whereas the wild type fungus recovered from larval grazing, larvae eradicated the chemically deficient mutant. In contrast, mutualistic dietary yeast, Saccharomyces cerevisiae, reached higher population densities when exposed to Drosophila larval feeding. Conclusions/Significance Our study presents novel evidence that insect grazing is capable of inducing resistance to further grazing in a filamentous fungus. This phenotypic shift in resistance to fungivory is accompanied by changes in the expression of genes involved in signal transduction, epigenetic regulation and secondary metabolite biosynthesis pathways. Depending on reciprocal insect-fungus fitness consequences, fungi may be selected for inducible resistance to maintain high fitness in fungivore-rich habitats

  5. Electromagnetic Reciprocity.

    SciTech Connect

    Aldridge, David F.

    2014-11-01

    A reciprocity theorem is an explicit mathematical relationship between two different wavefields that can exist within the same space - time configuration. Reciprocity theorems provi de the theoretical underpinning for mod ern full waveform inversion solutions, and also suggest practical strategies for speed ing up large - scale numerical modeling of geophysical datasets . In the present work, several previously - developed electromagnetic r eciprocity theorems are generalized to accommodate a broader range of medi um, source , and receiver types. Reciprocity relations enabling the interchange of various types of point sources and point receivers within a three - dimensional electromagnetic model are derived. Two numerical modeling algorithms in current use are successfully tested for adherence to reciprocity. Finally, the reciprocity theorem forms the point of departure for a lengthy derivation of electromagnetic Frechet derivatives. These mathe matical objects quantify the sensitivity of geophysical electromagnetic data to variatio ns in medium parameters, and thus constitute indispensable tools for solution of the full waveform inverse problem. ACKNOWLEDGEMENTS Sandia National Labor atories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000. Signif icant portions of the work reported herein were conducted under a Cooperative Research and Development Agreement (CRADA) between Sandia National Laboratories (SNL) and CARBO Ceramics Incorporated. The author acknowledges Mr. Chad Cannan and Mr. Terry Pa lisch of CARBO Ceramics, and Ms. Amy Halloran, manager of SNL's Geophysics and Atmospheric Sciences Department, for their interest in and encouragement of this work. Special thanks are due to Dr . Lewis C. Bartel ( recently retired from Sandia National Labo ratories and now a

  6. Cyclosporine A increases hair follicle growth by suppressing apoptosis-inducing factor nuclear translocation: a new mechanism.

    PubMed

    Lan, Shaowei; Liu, Feilin; Zhao, Guifang; Zhou, Tong; Wu, Chunling; Kou, Junna; Fan, Ruirui; Qi, Xiaojuan; Li, Yahui; Jiang, Yixu; Bai, Tingting; Li, Pengdong; Liu, Li; Hao, Deshun; Zhang, Lihong; Li, Yulin; Liu, Jin Yu

    2015-04-01

    Cyclosporine A (CsA) enhances hair growth through caspase-dependent pathways by retarding anagen-to-catagen phase transition in the hair follicle growth cycle. Whether apoptosis-inducing factor (AIF), a protein that induces caspase-independent apoptosis, can regulate the hair follicle cycle in response to CsA is currently unclear. Here, we show that the pro-hair growth properties of CsA are in part due to blockage of AIF nuclear translocation. We first isolate hair follicles from murine dorsal skin. We then used Western blot, immunohistochemistry and immunofluorescence to evaluate the expression and localization of AIF in hair follicles. We also determined whether modulation of AIF was responsible for the effects of CsA at the anagen-to-catagen transition. AIF was expressed in hair follicles during the anagen, catagen and telogen phases. There was significant nuclear translocation of AIF as hair follicles transitioned from anagen to late catagen phase; this was inhibited by CsA, likely due to reduced cyclophilin A expression and attenuated AIF release from mitochondria. However, we note that AIF translocation was not completely eliminated, which likely explains why the transition to catagen phase was severely retarded by CsA, rather than being completely inhibited. We speculate that blockade of the AIF signalling pathway is a critical event required for CsA-dependent promotion of hair growth in mice. The study of AIF-related signalling pathways may provide insight into hair diseases and suggest potential novel therapeutic strategies. PMID:25619112

  7. Aquaporin-mediated long-distance polyphosphate translocation directed towards the host in arbuscular mycorrhizal symbiosis: application of virus-induced gene silencing.

    PubMed

    Kikuchi, Yusuke; Hijikata, Nowaki; Ohtomo, Ryo; Handa, Yoshihiro; Kawaguchi, Masayoshi; Saito, Katsuharu; Masuta, Chikara; Ezawa, Tatsuhiro

    2016-09-01

    Arbuscular mycorrhizal fungi translocate polyphosphate through hyphae over a long distance to deliver to the host. More than three decades ago, suppression of host transpiration was found to decelerate phosphate delivery of the fungal symbiont, leading us to hypothesize that transpiration provides a primary driving force for polyphosphate translocation, probably via creating hyphal water flow in which fungal aquaporin(s) may be involved. The impact of transpiration suppression on polyphosphate translocation through hyphae of Rhizophagus clarus was evaluated. An aquaporin gene expressed in intraradical mycelia was characterized and knocked down by virus-induced gene silencing to investigate the involvement of the gene in polyphosphate translocation. Rhizophagus clarus aquaporin 3 (RcAQP3) that was most highly expressed in intraradical mycelia encodes an aquaglyceroporin responsible for water transport across the plasma membrane. Knockdown of RcAQP3 as well as the suppression of host transpiration decelerated polyphosphate translocation in proportion to the levels of knockdown and suppression, respectively. These results provide the first insight into the mechanism underlying long-distance polyphosphate translocation in mycorrhizal associations at the molecular level, in which host transpiration and the fungal aquaporin play key roles. A hypothetical model of the translocation is proposed for further elucidation of the mechanism. PMID:27136716

  8. Noninvolvement of the X chromosome in radiation-induced chromosome translocations in the human lymphoblastoid cell line TK6

    SciTech Connect

    Jordan, R.; Schwartz, J.L. )

    1994-03-01

    Fluorescence in situ hybridization procedures were used to examine the influence of chromosome locus on the frequency and type of chromosome aberrations induced by [sup 60]Co [gamma] rays in the human lymphoblastoid cell line TK6. Aberrations involving the X chromosome were compared to those involving the similarly sized autosome chromosome 7. When corrected for DNA content, acentric fragments were induced with equal frequency in the X and 7 chromosomes. Dose-dependent increases in chromosomal interchanges involving chromosome 7 were noted, and the frequencies of balanced translocations and dicentrics produced were approximately equal. Chromosome interchanges involving the X chromosome were rare and showed no apparent dose dependence. Thus, while chromosomes 7 and X are equally sensitive to the induction of chromosome breaks, the X chromosome is much less likely to interact with autosomes than chromosome 7. The noninvolvement of the X chromosome in translocations with autosomes may reflect a more peripheral and separate location for the X chromosome in the mammalian nucleus. 20 refs., 2 figs., 1 tab.

  9. The Flavones Apigenin and Luteolin Induce FOXO1 Translocation but Inhibit Gluconeogenic and Lipogenic Gene Expression in Human Cells

    PubMed Central

    Bumke-Vogt, Christiane; Osterhoff, Martin A.; Borchert, Andrea; Guzman-Perez, Valentina; Sarem, Zeinab; Birkenfeld, Andreas L.; Bähr, Volker; Pfeiffer, Andreas F. H.

    2014-01-01

    The flavones apigenin (4′,5,7,-trihydroxyflavone) and luteolin (3′,4′,5,7,-tetrahydroxyflavone) are plant secondary metabolites with antioxidant, antiinflammatory, and anticancer activities. We evaluated their impact on cell signaling pathways related to insulin-resistance and type 2 diabetes. Apigenin and luteolin were identified in our U-2 OS (human osteosarcoma) cell screening assay for micronutrients triggering rapid intracellular translocation of the forkhead box transcription factor O1 (FOXO1), an important mediator of insulin signal transduction. Insulin reversed the translocation of FOXO1 as shown by live cell imaging. The impact on the expression of target genes was evaluated in HepG2 (human hepatoma) cells. The mRNA-expression of the gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pc), the lipogenic enzymes fatty-acid synthase (FASN) and acetyl-CoA-carboxylase (ACC) were down-regulated by both flavones with smaller effective dosages of apigenin than for luteolin. PKB/AKT-, PRAS40-, p70S6K-, and S6-phosphorylation was reduced by apigenin and luteolin but not that of the insulin-like growth factor receptor IGF-1R by apigenin indicating a direct inhibition of the PKB/AKT-signaling pathway distal to the IGF-1 receptor. N-acetyl-L-cysteine did not prevent FOXO1 nuclear translocation induced by apigenin and luteolin, suggesting that these flavones do not act via oxidative stress. The roles of FOXO1, FOXO3a, AKT, sirtuin1 (SIRT1), and nuclear factor (erythroid-derived2)-like2 (NRF2), investigated by siRNA knockdown, showed differential patterns of signal pathways involved and a role of NRF2 in the inhibition of gluconeogenic enzyme expression. We conclude that these flavones show an antidiabetic potential due to reduction of gluconeogenic and lipogenic capacity despite inhibition of the PKB/AKT pathway which justifies detailed investigation in vivo. PMID:25136826

  10. Detection of interchromosomal translocations within the Triticeae by RFLP analysis.

    PubMed

    King, I P; Purdie, K A; Liu, C J; Reader, S M; Pittaway, T S; Orford, S E; Miller, T E

    1994-10-01

    Twenty-three wheat/alien addition or substitution lines were screened using restriction fragment length polymorphisms for the presence or absence of 4/5 and 4/7 reciprocal translocations in the alien chromosomes. Such translocations have previously been identified in wheat and rye. Group 4 and group 5 Aegilops umbellulata, Triticum urartu, and Thinopyrum bessarabicum chromosomes were found to carry 4/5 translocations. Evidence for a 4/7 translocation was also found in Secale montanum. The presence of the 4/5 translocations in T. urartu indicates that the translocation predates the polyploidization of wheat. The implications of these results are discussed. PMID:18470131

  11. Yeast Pol4 Promotes Tel1-Regulated Chromosomal Translocations

    PubMed Central

    Sastre-Moreno, Guillermo; Aguilera, Andrés; Blanco, Luis

    2013-01-01

    DNA double-strand breaks (DSBs) are one of the most dangerous DNA lesions, since their erroneous repair by nonhomologous end-joining (NHEJ) can generate harmful chromosomal rearrangements. PolX DNA polymerases are well suited to extend DSB ends that cannot be directly ligated due to their particular ability to bind to and insert nucleotides at the imperfect template-primer structures formed during NHEJ. Herein, we have devised genetic assays in yeast to induce simultaneous DSBs in different chromosomes in vivo. The repair of these breaks in trans could result in reciprocal chromosomal translocations that were dependent on classical Ku-dependent NHEJ. End-joining events leading to translocations were mainly based on the formation of short base pairing between 3′-overhanging DNA ends coupled to gap-filling DNA synthesis. A major proportion of these events were specifically dependent on yeast DNA polymerase Pol4 activity. In addition, we have discovered that Pol4-Thr540 amino acid residue can be phosphorylated by Tel1/ATM kinase, which could modulate Pol4 activity during NHEJ. Our data suggest that the role of Tel1 in preventing break-induced chromosomal translocations can, to some extent, be due to its stimulating effect on gap-filling activity of Pol4 to repair DSBs in cis. Overall, this work provides further insight to the molecular mechanisms of DSB repair by NHEJ and presents a new perspective to the understanding of how chromosomal translocations are formed in eukaryotic cells. PMID:23874240

  12. Protective Capacity of Resveratrol, a Natural Polyphenolic Compound, against Deoxynivalenol-Induced Intestinal Barrier Dysfunction and Bacterial Translocation.

    PubMed

    Ling, Ka-Ho; Wan, Murphy Lam Yim; El-Nezami, Hani; Wang, Mingfu

    2016-05-16

    Contamination of food/feedstuffs by mycotoxins is a serious problem worldwide, causing severe economic losses and serious health problems in animals/humans. Deoxynivalenol (DON) is a major mycotoxin contaminant and is known to impair intestinal barrier function. Grapes and red wine are rich in polyphenols, such as resveratrol (RES), which has striking antioxidant and anti-inflammatory activities. RES is a food-derived component; therefore, it may be simultaneously present with DON in the gastrointestinal tract. The aim of this study was to explore in vitro protective effects of RES against DON-induced intestinal damage. The results showed that RES could protect DON-induced bacteria translocation because of enhanced of intestinal barrier function by restoring the DON-induced decrease in transepithelial electrical resistance and increase in paracellular permeability. Further mechanistic studies demonstrated that RES protects against DON-induced barrier dysfunction by promoting the assembly of claudin-4 in the tight junction complex. This is probably mediated through modulation of IL-6 and IL-8 secretion via mitogen-activated protein kinase-dependent pathways. Our results imply that RES can protect against DON-induced intestinal damage and that RES may be used as a novel dietary intervention strategy to reduce DON toxicity in animals/humans. PMID:27058607

  13. The inflammatory mediator leukotriene D{sub 4} induces subcellular β-catenin translocation and migration of colon cancer cells

    SciTech Connect

    Salim, Tavga; Sand-Dejmek, Janna; Sjölander, Anita

    2014-02-15

    The abnormal activation of the Wnt/β-catenin pathway frequently occurs in colorectal cancer. The nuclear translocation of β-catenin activates the transcription of target genes that promote cell proliferation, survival, and invasion. The pro-inflammatory mediator leukotriene D{sub 4} (LTD{sub 4}) exerts its effects through the CysLT{sub 1} receptor. We previously reported an upregulation of CysLT{sub 1}R in patients with colon cancer, suggesting the importance of leukotrienes in colon cancer. The aim of this study was to investigate the impact of LTD{sub 4} on Wnt/β-catenin signaling and its effects on proliferation and migration of colon cancer cells. LTD{sub 4} stimulation led to an increase in β-catenin expression, β-catenin nuclear translocation and the subsequent transcription of MYC and CCND1. Furthermore, LTD{sub 4} significantly reduced the expression of E-cadherin and β-catenin at the plasma membrane and increased the migration and proliferation of HCT116 colon cancer cells. The effects of LTD{sub 4} can be blocked by the inhibition of CysLT{sub 1}R. Furthermore, LTD{sub 4} induced the inhibition of glycogen synthase kinase 3 (GSK)-3β activity, indicating a crosstalk between the G-protein-coupled receptor CysLT{sub 1} and the Wnt/β-catenin pathway. In conclusion, LTD{sub 4}, which can be secreted from macrophages and leukocytes in the tumor microenvironment, induces β-catenin translocation and the activation of β-catenin target genes, resulting in the increased proliferation and migration of colon cancer cells. - Highlights: • Leukotriene D{sub 4} (LTD{sub 4}) lowers membrane β-catenin but increases nuclear β-catenin levels in colon cancer cells. • In agreement, LTD{sub 4} triggers inactivation of GSK-3β, activation of TCF/LEF and increased expression of Cyclin D1 and c-Myc. • LTD{sub 4} also caused a significant reduction in the expression of E-cadherin and an increased migration of colon cancer cells.

  14. Dephosphorylation and mitochondrial translocation of cofilin sensitizes human leukemia cells to cerulenin-induced apoptosis via the ROCK1/Akt/JNK signaling pathway

    PubMed Central

    Liu, Yanxia; Li, Jing; Zhang, Hongwei; Hu, Xiaoye; Chen, Yibiao; Liu, Xin; Li, Yunong; Li, Ping; Liu, Ehu; Gao, Ning

    2016-01-01

    In this study, we determined that cerulenin, a natural product inhibitor of fatty acid synthase, induces mitochondrial injury and apoptosis in human leukemia cells through the mitochondrial translocation of cofilin. Only dephosphorylated cofilin could translocate to mitochondria during cerulenin-induced apoptosis. Disruption of the ROCK1/Akt/JNK signaling pathway plays a critical role in the cerulenin-mediated dephosphorylation and mitochondrial translocation of cofilin and apoptosis. In vivo studies demonstrated that cerulenin-mediated inhibition of tumor growth in a mouse xenograft model of leukemia was associated with mitochondrial translocation of cofilin and apoptosis. These data are consistent with a hierarchical model in which induction of apoptosis by cerulenin primarily results from activation of ROCK1, inactivation of Akt, and activation of JNK. This leads to the dephosphorylation and mitochondrial translocation of cofilin and culminates with cytochrome c release, caspase activation, and apoptosis. Our study has revealed a novel role of cofilin in the regulation of mitochondrial injury and apoptosis and suggests that cerulenin is a potential drug for the treatment of leukemia. PMID:26967395

  15. A universal compensator for polarization changes induced by non-reciprocal circular birefringence on a retracing beam

    NASA Astrophysics Data System (ADS)

    Martinelli, Mario; Martelli, Paolo; Fasiello, Annalaura

    2016-05-01

    In this communication we recognize that it is possible to cancel out the effects of the non-reciprocal circular birefringence on a retracing beam. The experimental results demonstrate that a linearly polarized beam is returned into an orthogonal state after retracing through a variable Faraday rotator, by exploiting the reflective action of a Porro prism with edge at 45° with respect to the initial polarization axis, for any amount of non-reciprocal Faraday rotation.

  16. Among-lake reciprocal transplants induce convergent expression of immune genes in threespine stickleback.

    PubMed

    Stutz, William E; Schmerer, Matthew; Coates, Jessica L; Bolnick, Daniel I

    2015-09-01

    Geographic variation in parasite communities can drive evolutionary divergence in host immune genes. However, biotic and abiotic environmental variation can also induce plastic differences in immune function among populations. At present, there is little information concerning the relative magnitudes of heritable vs. induced immune divergence in natural populations. We examined immune gene expression profiles of threespine stickleback (Gasterosteus aculeatus) from six lakes on Vancouver Island, British Columbia. Parasite community composition differs between lake types (large or small, containing limnetic- or benthic-like stickleback) and between watersheds. We observed corresponding differences in immune gene expression profiles among wild-caught stickleback, using a set of seven immune genes representing distinct branches of the immune system. To evaluate the role of environmental effects on this differentiation, we experimentally transplanted wild-caught fish into cages in their native lake, or into a nearby foreign lake. Transplanted individuals' immune gene expression converged on patterns typical of their destination lake, deviating from their native expression profile. Transplant individuals' source population had a much smaller effect, suggesting relatively weak genetic underpinning of population differences in immunity, as viewed through gene expression. This strong environmental regulation of immune gene expression provides a counterpoint to the large emerging literature documenting microevolution and genetic diversification of immune function. Our findings illustrate the value of studying immunity in natural environmental settings where the immune system has evolved and actively functions. PMID:26118468

  17. Actions of translocator protein ligands on neutrophil adhesion and motility induced by G-protein coupled receptor signaling.

    PubMed

    de Lima, Camila Bento; Tamura, Eduardo K; Montero-Melendez, Trindad; Palermo-Neto, João; Perretti, Mauro; Markus, Regina P; Farsky, Sandra Helena Poliselli

    2012-01-13

    The 18 kDa translocator protein (TSPO) also known as the peripheral benzodiazepine receptor (PBR), mediates the transportation of cholesterol and anions from the outer to the inner mitochondrial membrane in different cells types. Although recent evidences indicate a potential role for TSPO in the development of inflammatory processes, the mechanisms involved have not been elucidated. The present study investigated the ability of the specific TSPO ligands, the isoquinoline carboxamide PK11195 and benzodiazepine Ro5-4864, on neutrophil recruitment promoted by the N-formylmethionyl-leucyl-phenylalanine peptide (fMLP), an agonist of G-protein coupled receptor (GPCR). Pre-treatment with Ro5-4864 abrograted fMLP-induced leukocyte-endothelial interactions in mesenteric postcapillary venules in vivo. Moreover, in vitro Ro5-4864 treatment prevented fMLP-induced: (i) L-selectin shedding and overexpression of PECAM-1 on the neutrophil cell surface; (ii) neutrophil chemotaxis and (iii) enhancement of intracellular calcium cations (iCa(+2)). Intriguingly, the two latter effects were augmented by cell treatment with PK11195. An allosteric agonist/antagonist relation may be suggested, as the effects of Ro5-4864 on fMLP-stimulated neutrophils were reverted by simultaneous treatment with PK11195. Taken together, these data highlight TSPO as a modulator of pathways of neutrophil adhesion and locomotion induced by GPCR, connecting TSPO actions and the onset of an innate inflammatory response. PMID:22209795

  18. Impact of tamoxifen on adipocyte lineage tracing: Inducer of adipogenesis and prolonged nuclear translocation of Cre recombinase

    PubMed Central

    Ye, Risheng; Wang, Qiong A.; Tao, Caroline; Vishvanath, Lavanya; Shao, Mengle; McDonald, Jeffery G.; Gupta, Rana K.; Scherer, Philipp E.

    2015-01-01

    Background The selective estrogen receptor modulator tamoxifen, in combination with the Cre-ERT2 fusion protein, has been one of the mainstream methods to induce genetic recombination and has found widespread application in lineage tracing studies. Methods & results Here, we report that tamoxifen exposure at widely used concentrations remains detectable by mass-spectrometric analysis in adipose tissue after a washout period of 10 days. Surprisingly, its ability to maintain nuclear translocation of the Cre-ERT2 protein is preserved beyond 2 months of washout. Tamoxifen treatment acutely leads to transient lipoatrophy, followed by de novo adipogenesis that reconstitutes the original fat mass. In addition, we find a “synthetically lethal” phenotype for adipocytes when tamoxifen treatment is combined with adipocyte-specific loss-of-function mutants, such as an adipocyte-specific PPARγ knockout. This is observed to a lesser extent when alternative inducible approaches are employed. Conclusions These findings highlight the potential for tamoxifen-induced adipogenesis, and the associated drawbacks of the use of tamoxifen in lineage tracing studies, explaining the discrepancy in lineage tracing results from different systems with temporal control of gene targeting. PMID:26629402

  19. Selective translocation of protein kinase C-delta in PC12 cells during nerve growth factor-induced neuritogenesis.

    PubMed Central

    O'Driscoll, K R; Teng, K K; Fabbro, D; Greene, L A; Weinstein, I B

    1995-01-01

    The specific intracellular signals initiated by nerve growth factor (NGF) that lead to neurite formation in PC12 rat pheochromocytoma cells are as of yet unclear. Protein kinase C-delta (PKC delta) is translocated from the soluble to the particulate subcellular fraction during NGF-induced-neuritogenesis; however, this does not occur after treatment with the epidermal growth factor, which is mitogenic but does not induce neurite formation. PC12 cells also contain both Ca(2+)-sensitive and Ca(2+)-independent PKC enzymatic activities, and express mRNA and immunoreactive proteins corresponding to the PKC isoforms alpha, beta, delta, epsilon, and zeta. There are transient decreases in the levels of immunoreactive PKCs alpha, beta, and epsilon after 1-3 days of NGF treatment, and after 7 days there is a 2.5-fold increase in the level of PKC alpha, and a 1.8-fold increase in total cellular PKC activity. NGF-induced PC12 cell neuritogenesis is enhanced by 12-O-tetradecanoyl phorbol-13-acetate (TPA) in a TPA dose- and time-dependent manner, and this differentiation coincides with abrogation of the down-regulation of PKC delta and other PKC isoforms, when the cells are treated with TPA. Thus a selective activation of PKC delta may play a role in neuritogenic signals in PC12 cells. Images PMID:7626808

  20. Cigarette smoke-induced reduction in binding of the salivary translocator protein is not mediated by free radicals.

    PubMed

    Nagler, R; Savulescu, D; Gavish, M

    2016-02-01

    Oral cancer is the most common malignancy of the head and neck and its main inducer is exposure to cigarette smoke (CS) in the presence of saliva. It is commonly accepted that CS contributes to the pathogenesis of oral cancer via reactive free radicals and volatile aldehydes. The 18 kDa translocator protein (TSPO) is an intracellular receptor involved in proliferation and apoptosis, and has been linked to various types of cancer. The presence of TSPO in human saliva has been linked to oral cancer, and its binding affinity to its ligand is reduced following exposure to CS. In the present study we wished to further investigate the mechanism behind the CS-induced reduction of TSPO binding by exploring the possible mediatory role of reactive oxygen species (ROS) and volatile aldehydes in this process. We first analyzed TSPO binding in control saliva and in saliva exposed to CS in the presence and absence of various antioxidants. These experiments found that TSPO binding ability was not reversed by any of the antioxidants added, suggesting that CS exerts its effect on TSPO via mechanisms that do not involve volatile aldehydes and free radicals tested. Next, we analyzed TSPO binding in saliva following addition of exogenous ROS in the form of H2O2. These experiments found that TSPO binding was enhanced due to the treatment, once again showing that the CS-induced TSPO binding reduction is not mediated by this common form of ROS. However, the previously reported CS-induced reduction in salivary TSPO binding together with the role of TSPO in cells and its link to cancer strongly suggest that TSPO has a critical role in the pathogenesis of CS-induced oral cancer. The importance of further elucidating the mechanisms behind it should be emphasized. PMID:26582415

  1. Progesterone receptor-NFκB complex formation is required for progesterone-induced NFκB nuclear translocation and binding onto the p53 promoter.

    PubMed

    Hsu, Sung-Po; Yang, Ho-Ching; Kuo, Chun-Ting; Wen, Heng-Ching; Chen, Li-Ching; Huo, Yen-Nien; Lee, Wen-Sen

    2015-01-01

    We previously demonstrated that progesterone (P4) up-regulates p53 expression in human umbilical venous endothelial cells (HUVECs) through P4 receptor (PR) activation of extranuclear signaling pathways. However, the involvement of nuclear PR in P4-increased p53 expression is still unclear. Here, the molecular mechanism underlying PR-regulated p53 expression in HUVECs was investigated. Treatment with P4 increased nuclear factor of κ light polypeptide gene enhancer in B-cells inhibitor, α phosphorylation (IκBα and nuclear factor-κB (NFκB) nuclear translocation. Interestingly, P4 also increased PR-A, but not PR-B, nuclear translocation in HUVECs. Immunoprecipitation assay illustrated that P4 increased the formation of PR-A-NFκB complex in both the cytosol and the nucleus of HUVEC. Chromatin immunoprecipitation assay showed an interaction between PR and the NFκB binding motif on the p53 promoter. Ablation of the NFκB binding motif in the p53 promoter completely abolished P4-increased p53 promoter activity. In the absence of P4, overexpression of NFκB did not increase NFκB nuclear translocation. In contrast, treatment of NFκB-overexpressing HUVECs with P4 for only 4 hours, which is much shorter than the time (21.5 h) required for P4-induced IκBα phosphorylation, increased NFκB nuclear translocation. Blockade of PR activity abolished this effect. Taken together, these results uncover a novel role of PR for P4-induced NFκB nuclear translocation and suggest that PR-A-NFκB complex formation is required for NFκB nuclear translocation and binding onto the p53 promoter in HUVECs. Our data indicate that both nuclear and extranuclear signaling pathways of PR are involved in P4-regulated p53 expression in HUVECs. PMID:25353185

  2. Asplenia syndrome in a child with a balanced reciprocal translocation of chromosomes 11 and 20 [46,XX,t(11;20)(q13.1;q13.13)

    SciTech Connect

    Freeman, S.B.; May, K.M.; Blackston, R.D.; Muralidharan, K.

    1996-02-02

    We present a 6-year-old girl with a balanced 11;20 translocation [46,XX,t(11;20)(q13.1;q13.13)pat], asplenia, pulmonic stenosis, Hirschsprung disease, minor anomalies, and mental retardation. This case represents the second report of an individual with situs abnormalities and a balanced chromosome rearrangement involving a breakpoint at 11q13. Segregation analysis of markers in the 11q13 region in the proposita and her phenotypically normal carrier sibs did not show a unique combination of maternal and paternal alleles in the patient. We discuss several possible explanations for the simultaneous occurrence of situs abnormalities and a balanced 11;20 translocation. These include (1) chance, (2) a further chromosome rearrangement in the patient, (3) gene disruption and random situs determination, and (4) gene disruption plus transmission of a recessive or imprinted allele from the mother. 30 refs., 1 fig., 2 tabs.

  3. Phosphorylated AKT inhibits the apoptosis induced by DRAM-mediated mitophagy in hepatocellular carcinoma by preventing the translocation of DRAM to mitochondria.

    PubMed

    Liu, K; Shi, Y; Guo, X H; Ouyang, Y B; Wang, S S; Liu, D J; Wang, A N; Li, N; Chen, D X

    2014-01-01

    Increasing autophagy is beneficial for curing hepatocellular carcinoma (HCC). Damage-regulated autophagy modulator (DRAM) was recently reported to induce apoptosis by mediating autophagy. However, the effects of DRAM-mediated autophagy on apoptosis in HCC cells remain unclear. In this study, normal hepatocytes (7702) and HCC cell lines (HepG2, Hep3B and Huh7) were starved for 48 h. Starvation induced apoptosis and autophagy in all cell lines. We determined that starvation also induced DRAM expression and DRAM-mediated autophagy in both normal hepatocytes and HCC cells. However, DRAM-mediated autophagy was involved in apoptosis in normal hepatocytes but not in HCC cells, suggesting that DRAM-mediated autophagy fails to induce apoptosis in hepatoma in response to starvation. Immunoblot and immunofluorescence assays demonstrated that DRAM translocated to mitochondria and induced mitophagy, which led to apoptosis in 7702 cells. In HCC cells, starvation also activated the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, which blocks the translocation of DRAM to mitochondria through the binding of p-AKT to DRAM in the cytoplasm. Inactivation of the PI3K/AKT pathway rescued DRAM translocation to mitochondria; subsequently, mitochondrial DRAM induced apoptosis in HCC cells by mediating mitophagy. Our findings open new avenues for the investigation of the mechanisms of DRAM-mediated autophagy and suggest that promoting DRAM-mediated autophagy together with PI3K/AKT inhibition might be more effective for autophagy-based therapy in hepatoma. PMID:24556693

  4. Curcumin Induces Nrf2 Nuclear Translocation and Prevents Glomerular Hypertension, Hyperfiltration, Oxidant Stress, and the Decrease in Antioxidant Enzymes in 5/6 Nephrectomized Rats

    PubMed Central

    Tapia, Edilia; Soto, Virgilia; Ortiz-Vega, Karla Mariana; Zarco-Márquez, Guillermo; Molina-Jijón, Eduardo; Cristóbal-García, Magdalena; Santamaría, José; García-Niño, Wylly Ramsés; Correa, Francisco; Zazueta, Cecilia; Pedraza-Chaverri, José

    2012-01-01

    Renal injury resulting from renal ablation induced by 5/6 nephrectomy (5/6NX) is associated with oxidant stress, glomerular hypertension, hyperfiltration, and impaired Nrf2-Keap1 pathway. The purpose of this work was to know if the bifunctional antioxidant curcumin may induce nuclear translocation of Nrf2 and prevents 5/6NX-induced oxidant stress, renal injury, decrease in antioxidant enzymes, and glomerular hypertension and hyperfiltration. Four groups of rats were studied: (1) control, (2) 5/6NX, (3) 5/6NX +CUR, and (4) CUR (n = 8–10). Curcumin was given by gavage to NX5/6 +CUR and CUR groups (60 mg/kg/day) starting seven days before surgery. Rats were studied 30 days after NX5/6 or sham surgery. Curcumin attenuated 5/6NX-induced proteinuria, systemic and glomerular hypertension, hyperfiltration, glomerular sclerosis, interstitial fibrosis, interstitial inflammation, and increase in plasma creatinine and blood urea nitrogen. This protective effect was associated with enhanced nuclear translocation of Nrf2 and with prevention of 5/6NX-induced oxidant stress and decrease in the activity of antioxidant enzymes. It is concluded that the protective effect of curcumin against 5/6NX-induced glomerular and systemic hypertension, hyperfiltration, renal dysfunction, and renal injury was associated with the nuclear translocation of Nrf2 and the prevention of both oxidant stress and the decrease of antioxidant enzymes. PMID:22919438

  5. Chebulic acid prevents hepatic fibrosis induced by advanced glycation end-products in LX-2 cell by modulating Nrf2 translocation via ERK pathway.

    PubMed

    Koo, Yun-Chang; Pyo, Min Cheol; Nam, Mi-Hyun; Hong, Chung-Oui; Yang, Sung-Yong; Lee, Kwang-Won

    2016-08-01

    Advanced glycation end-products (AGEs) are formed during normal aging, and at an accelerated rate in metabolic syndrome patients. Nonalcoholic steatohepatitis (NASH) can be caused by the AGEs in plasma, while glyceraldehyde-derived AGEs (glycer-AGEs) are significantly higher in the serum of NASH patients. In this study, we investigated the molecular mechanisms of chebulic acid, isolated from Terminalia chebula Retz., in the inhibition of glycer-AGEs induced production of reactive oxygen species (ROS) and collagen accumulation using the LX-2 cell line. Chebulic acid significantly inhibited the induction of ROS and accumulation of collagen proteins by glycer-AGEs. ERK phosphorylation and total nuclear factor E2-related factor 2 (Nrf2) protein expression were induced by chebulic acid in a dose-dependent manner. Chebulic acid was also found to induce translocation of Nrf2 into the nucleus, which was attenuated by inhibition of ERK phosphorylation through treatment with PD98059. Following translocation of Nrf2, chebulic acid induced the protein expressions of catalytic subunit of γ-glutamylcysteine synthetase and glutathione synthesis. Collagen accumulation was also significantly reduced by chebulic acid treatment. The observed effects of chebulic acid were all inhibited by PD98059 treatment. Taken together, these results suggest that chebulic acid prevents the glycer-AGEs-induced ROS formation of LX-2 cells and collagen accumulation by ERK-phosphorylation-mediated Nrf2 nuclear translocation, which causes upregulation of antioxidant protein production. PMID:27021876

  6. Klotho Prevents NFκB Translocation and Protects Endothelial Cell From Senescence Induced by Uremia.

    PubMed

    Buendía, Paula; Carracedo, Julia; Soriano, Sagrario; Madueño, Juan Antonio; Ortiz, Alberto; Martín-Malo, Alejandro; Aljama, Pedro; Ramírez, Rafael

    2015-10-01

    In patients with renal disease, uremia raises oxidative stress and senescence in endothelial cells, which can lead to endothelial dysfunction and cardiovascular disease. Klotho protein is a β-glucuronidase capable of hydrolyzing steroid β-glucuronides. This protein is recognized as an antiaging gene, that modulate both stress-induced senescence and functional response. The aim of the study was to investigate how senescence and oxidative stress induced by uremia in endothelial cells affects Klotho expression and whether intra or extracellular Klotho has effects on the response of these cells. Senescence and oxidative stress was obtained by exposure to uremic serum. Telomere length, the enzyme β-galactosidase, and oxidative stress were studied by flow cytometry. Nuclear factor kappa B activity was determined by electrophoretic mobility shift assay. The expression of Klotho decreased with the uremia and preceded the manifestations of cell aging. Levels of intracellular Klotho decreases associated to endothelial senescence, and exogenous Klotho prevents cellular senescence by inhibiting the increase in oxidative stress induced by uremia and diminished the nuclear factor kappa B-DNA binding ability. PMID:25246106

  7. Sulfasalazine prevents the increase in TGF-β, COX-2, nuclear NFκB translocation and fibrosis in CCl4-induced liver cirrhosis in the rat.

    PubMed

    Chávez, E; Castro-Sánchez, L; Shibayama, M; Tsutsumi, V; Moreno, M G; Muriel, P

    2012-09-01

    It has been demonstrated that this sulfasalazine (SF) inhibits the nuclear factor κB (NFκB) pathway, which regulates important genes during inflammation and immune answer. The aim of this work was to evaluate the effects of SF on carbon tetrachloride (CCl(4))-induced liver fibrosis. We formed the following experimental groups of rats: controls, damage induced by chronic CCl(4) (0.4 g/kg, intraperitoneally, three times a week for 8 weeks) administration and CCl(4) + SF (100 mg/kg/day, postoperatively for 8 weeks) administration. We determined the activities of alanine aminotransferase (ALT), γ-glutamyl transpeptidase (γ-GTP), cyclooxygenase (COX)-1 and COX-2, lipid peroxidation, glutathione levels, collagen content, expression of transforming growth factor-β (TGF-β) and nuclear translocation of NFκB. SF was capable to inhibit the ALT and γ-GTP elevated levels induced with the CCl(4) administration. SF had antioxidant properties, prevented the lipid peroxidation and the imbalance of reduced and oxidized glutathione produced by CCl(4). Importantly, SF blocked the accumulation of collagen in the liver, the expression of TGF-β, the nuclear translocation of NFκB and the activity of COX-2, all induced with the administration of CCl(4) in the rat. These results show that SF has strong antifibrotic properties because of its antioxidant properties and its ability to prevent nuclear translocation of NFκB and consequently the expression of TGF-β and the activity of COX-2. PMID:22381741

  8. TNFR1/Phox Interaction and TNFR1 Mitochondrial Translocation Thwart Silica-Induced Pulmonary Fibrosis

    PubMed Central

    Fazzi, Fabrizio; Njah, Joel; Di Giuseppe, Michelangelo; Winnica, Daniel E.; Go, Kristina; Sala, Ernest; St Croix, Claudette M.; Watkins, Simon C.; Tyurin, Vladimir A.; Phinney, Donald G.; Fattman, Cheryl L.; Leikauf, George D.; Kagan, Valerian E.

    2014-01-01

    Macrophages play a fundamental role in innate immunity and the pathogenesis of silicosis. Phagocytosis of silica particles is associated with the generation of reactive oxygen species (ROS), secretion of cytokines, such as TNF, and cell death that contribute to silica-induced lung disease. In macrophages, ROS production is executed primarily by activation of the NADPH oxidase (Phox) and by generation of mitochondrial ROS (mtROS); however, the relative contribution is unclear, and the effects on macrophage function and fate are unknown. In this study, we used primary human and mouse macrophages (C57BL/6, BALB/c, and p47phox−/−) and macrophage cell lines (RAW 264.7 and IC21) to investigate the contribution of Phox and mtROS to silica-induced lung injury. We demonstrate that reduced p47phox expression in IC21 macrophages is linked to enhanced mtROS generation, cardiolipin oxidation, and accumulation of cardiolipin hydrolysis products, culminating in cell death. mtROS production is also observed in p47phox−/− macrophages, and p47phox−/− mice exhibit increased inflammation and fibrosis in the lung following silica exposure. Silica induces interaction between TNFR1 and Phox in RAW 264.7 macrophages. Moreover, TNFR1 expression in mitochondria decreased mtROS production and increased RAW 264.7 macrophage survival to silica. These results identify TNFR1/Phox interaction as a key event in the pathogenesis of silicosis that prevents mtROS formation and reduces macrophage apoptosis. PMID:24623132

  9. Elongation factor G-induced structural change in helix 34 of 16S rRNA related to translocation on the ribosome.

    PubMed Central

    Matassova, A B; Rodnina, M V; Wintermeyer, W

    2001-01-01

    During the translocation step of the elongation cycle, two tRNAs together with the mRNA move synchronously and rapidly on the ribosome. The movement is catalyzed by the binding of elongation factor G (EF-G) and driven by GTP hydrolysis. Here we study structural changes of the ribosome related to EF-G binding and translocation by monitoring the accessibility of ribosomal RNA (rRNA) for chemical modification by dimethyl sulfate or cleavage by hydroxyl radicals generated by Fe(II)-EDTA. In the state of the ribosome that is formed upon binding of EF-G but before the movement of the tRNAs takes place, residues 1054,1196, and 1201 in helix 34 in 16S rRNA are strongly protected. The protections depend on EF-G binding, but do not require GTP hydrolysis, and are lost upon translocation. Mutants of EF-G, which are active in ribosome binding and GTP hydrolysis but impaired in translocation, do not bring about the protections. According to cryo-electron microscopy (Stark et al., Cell, 2000, 100:301-309), there is no contact of EF-G with the protected residues of helix 34 in the pretranslocation state, suggesting that the observed protections are due to an induced conformational change. Thus, the present results indicate that EF-G binding to the pretranslocation ribosome induces a structural change of the head of the 30S subunit that is essential for subsequent tRNA-mRNA movement in translocation. PMID:11780642

  10. Retinoic acid induces nuclear FAK translocation and reduces breast cancer cell adhesion through Moesin, FAK, and Paxillin.

    PubMed

    Sanchez, Angel Matías; Shortrede, Jorge Eduardo; Vargas-Roig, Laura María; Flamini, Marina Inés

    2016-07-15

    Breast cancer is the most common malignancy in women, with metastases being the cause of death in 98%. In previous works we have demonstrated that retinoic acid (RA), the main retinoic acid receptor (RAR) ligand, is involved in the metastatic process by inhibiting migration through a reduced expression of the specific migration-related proteins Moesin, c-Src, and FAK. At present, our hypothesis is that RA also acts for short periods in a non-genomic action to cooperate with motility reduction and morphology of breast cancer cells. Here we identify that the administration of 10(-6) M RA (10-20 min) induces the activation of the migration-related proteins Moesin, FAK, and Paxillin in T-47D breast cancer cells. The phosphorylation exerted by the selective agonists for RARα and RARβ, on Moesin, FAK, and Paxillin was comparable to the activation exerted by RA. The RARγ agonist only led to a weak activation, suggesting the involvement of RARα and RARβ in this pathway. We then treated the cells with different inhibitors that are involved in cell signaling to regulate the mechanisms of cell motility. RA failed to activate Moesin, FAK, and Paxillin in cells treated with Src inhibitor (PP2) and PI3K inhibitor (WM), suggesting the participation of Src-PI3K in this pathway. Treatment with 10(-6) M RA for 20 min significantly decreased cell adhesion. However, when cells were treated with 10(-6) M RA and FAK inhibitor, the RA did not significantly inhibit adhesion, suggesting a role of FAK in the adhesion inhibited by RA. By immunofluorescence and immunoblotting analysis we demonstrated that RA induced nuclear FAK translocation leading to a reduced cellular adhesion. These findings provide new information on the actions of RA for short periods. RA participates in cell adhesion and subsequent migration, modulating the relocation and activation of proteins involved in cell migration. PMID:27130522

  11. Overexpression of glutaredoxin protects cardiomyocytes against nitric oxide-induced apoptosis with suppressing the S-nitrosylation of proteins and nuclear translocation of GAPDH

    SciTech Connect

    Inadomi, Chiaki; Murata, Hiroaki; Ihara, Yoshito; Goto, Shinji; Urata, Yoshishige; Yodoi, Junji; Kondo, Takahito; Sumikawa, Koji

    2012-08-31

    Highlights: Black-Right-Pointing-Pointer GRX1 overexpression protects myocardiac H9c2 cells against NO-induced apoptosis. Black-Right-Pointing-Pointer NO-induced nuclear translocation of GAPDH is suppressed in GRX overexpressors. Black-Right-Pointing-Pointer Oxidation of GAPDH by NO is less in GRX overexpressors than in controls. -- Abstract: There is increasing evidence demonstrating that glutaredoxin 1 (GRX1), a cytosolic enzyme responsible for the catalysis of protein deglutathionylation, plays distinct roles in inflammation and apoptosis by inducing changes in the cellular redox system. In this study, we investigated whether and how the overexpression of GRX1 protects cardiomyocytes against nitric oxide (NO)-induced apoptosis. Cardiomyocytes (H9c2 cells) were transfected with the expression vector for mouse GRX1 cDNA, and mock-transfected cells were used as a control. Compared with the mock-transfected cells, the GRX1-transfected cells were more resistant to NO-induced apoptosis. Stimulation with NO significantly increased the nuclear translocation of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a pro-apoptotic protein, in the mock-transfected cells, but did not change GAPDH localization in the GRX1-transfected cells. Furthermore, we found that NO stimulation clearly induced the oxidative modification of GAPDH in the mock-transfected cells, whereas less modification of GAPDH was observed in the GRX1-transfected cells. These data suggest that the overexpression of GRX1 could protect cardiomyocytes against NO-induced apoptosis, likely through the inhibition of the oxidative modification and the nuclear translocation of GAPDH.

  12. Pycnogenol Induces Nuclear Translocation of Apoptosis-inducing Factor and Caspase-independent Apoptosis in MC-3 Human Mucoepidermoid Carcinoma Cell Line

    PubMed Central

    Yang, In-Hyoung; Shin, Ji-Ae; Cho, Sung-Dae

    2014-01-01

    Background: Pycnogenol is extracted from the pine bark of a tree known as Pinus pinaster that has variety biological effects. However, its anticancer activity has not yet been completely studied. The aim of this study is to investigate anticancer effect of pycnogenol in MC-3 human mucoepidermoid carcinoma (MEC) cell line. Methods: We describe the effect of anti-cancer of pycnogenol in MC-3 human oral MEC cells using trypan blue exclusion assay, 3-(4,5-dimethylthiazol-2-yl)-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-tetrazolium (MTS) assay, Western blot, preparation of cytosolic and nuclear fractions, immunocytochemistry and reverse transcriptase polymerase chain reaction. Results: Pycnogenol significantly decreased cell viability and also induced caspase-independent apoptosis. We confirmed that pycnogenol induced the translocation of apoptosis-inducing factor into nucleus and regulated apoptosis. Also, Bak protein stability was partly enhanced by pycnogenol to elevate the expression level of Bak protein. Conclusions: Overall, pycnogenol may be a fascinating therapeutic drug candidate for the treatment of MEC. PMID:25574461

  13. Acetylcholine-induced cation translocation across cell membranes and inactivation of the acetylcholine receptor: chemical kinetic measurements in the millisecond time region.

    PubMed Central

    Cash, D J; Aoshima, H; Hess, G P

    1981-01-01

    Acetylcholine-induced flux of inorganic ions across membranes and inactivation of the acetylcholine receptor were measured at pH 7.0, 1 degrees C, over a 5000-fold concentration range of acetylcholine. Receptor-containing electroplax membrane vesicles prepared from Electrophorus electricus and a quench-flow technique were used, allowing flux to be measured in the 2-msec to 1-min time region. Five different measurements were made: (i) rate of ion translocation with the active state of the receptor, (ii) rate of the slower ion translocation after equilibration of active and inactive receptor states, (iii) rate of inactivation, (iv) equilibrium between active and inactive forms of the receptor, and (v) reactivation of inactivated receptor. The kinetics of the steps in the receptor-controlled ion flux follow single-exponential rate laws, and simple analytical expressions for their ligand concentration dependence can be used. Thus, the rate and equilibrium constants in a scheme that relates the ligand binding steps to ion translocation could be evaluated. It was found that the dependence of the receptor-controlled ion translocation over the concentration range investigated obeys the integrated rate equation based on the proposed mechanism. The flux rate before inactivation was approximately 10(7) ions sec-1 per receptor, which is comparable with that measured electrophysiologically in muscle cells. The half-time of inactivation is approximately 100 msec when the receptor is saturated with acetylcholine. The specific reaction rate of the ion translocation (J) is 3 X 10(7) M-1 sec-1. The results support a minimum reaction mechanism previously proposed on the basis of experiments in which carbamylcholine was used. PMID:6267581

  14. Entropic effects in formation of chromosome territories: towards understanding of radiation-induced gene translocation frequency

    NASA Astrophysics Data System (ADS)

    Gudowska-Nowak, Ewa; Ritter, Sylvia; Durante, Marco; Deperas-Standylo, Joanna; Ciesla, Michal

    2012-07-01

    A detailed understanding of structural organization of biological target, such as geometry of an inter-phase chromosome, is an essential prerequisite for gaining deeper insight into relationship between radiation track structure and radiation-induced biological damage [1]. In particular, coupling of biophysical models aimed to describe architecture of chromosomes and their positioning in a cell nucleus [2-4] with models of local distribution of ionizations caused by passing projectiles, are expected to result in more accurate estimates of aberration induction caused by radiation. There is abundant experimental evidence indicating that arrangements of chromosomes in eukaryotic cell nucleus is non-random and has been evolutionary conserved in specific cell types. Moreover, the radial position of a given chromosome territory (CT) within the cell nucleus has been shown to correlate with its size and gene density. Usually it is assumed that chromosomal geometry and positioning result from the action of specific forces acting locally, such as hydrogen bonds, electrostatic, Van der Waals or hydrophobic interactions operating between nucleosomes and within their interiors. However, it is both desirable and instructive to learn to what extend organization of inter-phase chromosomes is affected by nonspecific entropic forces. In this study we report results of a coarse-grained analysis of a chromatin structure modeled by two distinct approaches. In the first method, we adhere to purely statistical analysis of chromatin packing within a chromosome territory. On the basis of the polymer theory, the chromatin fiber of diameter 30nm is approximated by a chain of spheres, each corresponding to about 30 kbp. Random positioning of the center of the domain is repeated for 1000 spherical nuclei. Configuration of the domain is determined by a random packing of a polymer (a string of identical beads) in estimated fraction of space occupied by a chromosome of a given length and mass

  15. Robertsonian translocations

    SciTech Connect

    1993-12-31

    Chapter 27, describes the occurrence of Robertsonian translocations (RTs), which refer to the recombination of whole chromosome arms, in both monocentric and dicentric chromosomes. The nonrandom participation of acrocentric chromosomes in RTs is documented by various methods, including unbiased ascertainment and ascertainment through trisomy, infertility, unspecified mental retardation, and Prader-Willi syndrome. Causes of nonrandom participation of chromosomes in RTs is presented, as are the following topics: segregation in carriers of RTs and segregation in sperm cells of RT carriers, interchromosomal effects and conclusions. 48 refs., 3 figs., 2 tabs.

  16. Dietary anthocyanins protect endothelial cells against peroxynitrite-induced mitochondrial apoptosis pathway and Bax nuclear translocation: an in vitro approach.

    PubMed

    Paixão, Joana; Dinis, Teresa C P; Almeida, Leonor M

    2011-10-01

    Anthocyanins have received increasing attention because of their relatively high intake in humans and wide range of potential health-promoting effects, including anti-atherogenic properties. Evidences support their vascular protective effects but the involved molecular mechanisms have not been well clarified. The endothelium seems to have a central role in atherogenesis and apoptosis is emerging as a crucial event in this disease progression. Following our previous work on the biochemical pathways underlying peroxynitrite-triggered apoptosis in endothelial cells, here we investigated potential mechanisms responsible for the cytoprotective actions of three common anthocyanins, namely cyanidin- delphinidin- and pelargonidin-3-glucoside, against this process. Beyond their antioxidant properties, all these flavonoids, possessing either catecholic or monophenolic structures, were able to counteract peroxynitrite-induced apoptotic effects in endothelial cells through the inhibition of several crucial signaling cascades. Actually, pre-incubation of cells with 25 μM anthocyanins prevented them from peroxynitrite-mediated apoptosis, which was evaluated by the loss of mitochondrial membrane potential, caspases-9 and-3 activation, the increase in cytoplasmatic Bax levels and the inactivation of the PI3 K/Akt pathway. Moreover, they counteracted the translocation of Bax into the nucleus, as observed by immunocytochemistry and immunoblot, an event shown for the first time in endothelial cells apoptotic process. Such cellular actions could not be inferred from their in vitro antioxidant properties. These results suggest a potential role of dietary anthocyanins in the modulation of several apoptotic signaling pathways triggered by peroxynitrite in endothelial cells, supporting mechanistically their health benefits in the context of prevention of endothelial dysfunction and, ultimately, of atherosclerosis. PMID:21785847

  17. Hsp105 family proteins suppress staurosporine-induced apoptosis by inhibiting the translocation of Bax to mitochondria in HeLa cells

    SciTech Connect

    Yamagishi, Nobuyuki; Ishihara, Keiichi; Saito, Youhei; Hatayama, Takumi . E-mail: hatayama@mb.kyoto-phu.ac.jp

    2006-10-15

    Hsp105 (Hsp105{alpha} and Hsp105{beta}), major heat shock proteins in mammalian cells, belong to a subgroup of the HSP70 family, HSP105/110. Previously, we have shown that Hsp105{alpha} has completely different effects on stress-induced apoptosis depending on cell type. However, the molecular mechanisms by which Hsp105{alpha} regulates stress-induced apoptosis are not fully understood. Here, we established HeLa cells that overexpress either Hsp105{alpha} or Hsp105{beta} by removing doxycycline and examined how Hsp105 modifies staurosporine (STS)-induced apoptosis in HeLa cells. Apoptotic features such as the externalization of phosphatidylserine on the plasma membrane and nuclear morphological changes were induced by the treatment with STS, and the STS-induced apoptosis was suppressed by overexpression of Hsp105{alpha} or Hsp105{beta}. In addition, we found that overexpression of Hsp105{alpha} or Hsp105{beta} suppressed the activation of caspase-3 and caspase-9 by preventing the release of cytochrome c from mitochondria. Furthermore, the translocation of Bax to mitochondria, which results in the release of cytochrome c from the mitochondria, was also suppressed by the overexpression of Hsp105{alpha} or Hsp105{beta}. Thus, it is suggested that Hsp105 suppresses the stress-induced apoptosis at its initial step, the translocation of Bax to mitochondria in HeLa cells.

  18. Water-soluble coenzyme q10 inhibits nuclear translocation of apoptosis inducing factor and cell death caused by mitochondrial complex I inhibition.

    PubMed

    Li, Haining; Chen, Guisheng; Ma, Wanrui; Li, Ping-An Andy

    2014-01-01

    The objectives of the study were to explore the mechanism of rotenone-induced cell damage and to examine the protective effects of water-soluble Coenzyme Q10 (CoQ10) on the toxic effects of rotenone. Murine hippocampal HT22 cells were cultured with mitochondrial complex I inhibitor rotenone. Water-soluble CoQ10 was added to the culture media 3 h prior to the rotenone incubation. Cell viability was determined by alamar blue, reactive oxygen species (ROS) production by dihydroethidine (DHE) and mitochondrial membrane potential by tetramethyl rhodamine methyl ester (TMRM). Cytochrome c, caspase-9 and apoptosis-inducing factor (AIF) were measured using Western blotting after 24 h rotenone incubation. Rotenone caused more than 50% of cell death, increased ROS production, AIF nuclear translocation and reduction in mitochondrial membrane potential, but failed to cause mitochondrial cytochrome c release and caspase-9 activation. Pretreatment with water-soluble CoQ10 enhanced cell viability, decreased ROS production, maintained mitochondrial membrane potential and prevented AIF nuclear translocation. The results suggest that rotenone activates a mitochondria-initiated, caspase-independent cell death pathway. Water-soluble CoQ10 reduces ROS accumulation, prevents the fall of mitochondrial membrane potential, and inhibits AIF translocation and subsequent cell death. PMID:25089873

  19. Comparative kinetics and reciprocal inhibition of nitrate and nitrite uptake in roots of uninduced and induced barley (Hordeum vulgare L.) seedlings

    NASA Technical Reports Server (NTRS)

    Aslam, M.; Travis, R. L.; Huffaker, R. C.

    1992-01-01

    Nitrate and NO2- transport by roots of 8-day-old uninduced and induced intact barley (Hordeum vulgare L. var CM 72) seedlings were compared to kinetic patterns, reciprocal inhibition of the transport systems, and the effect of the inhibitor, p-hydroxymercuribenzoate. Net uptake of NO3- and NO2- was measured by following the depletion of the ions from the uptake solutions. The roots of uninduced seedlings possessed a low concentration, saturable, low Km, possibly a constitutive uptake system, and a linear system for both NO3- and NO2-. The low Km system followed Michaelis-Menten kinetics and approached saturation between 40 and 100 micromolar, whereas the linear system was detected between 100 and 500 micromolar. In roots of induced seedlings, rates for both NO3- and NO2- uptake followed Michaelis-Menten kinetics and approached saturation at about 200 micromolar. In induced roots, two kinetically identifiable transport systems were resolved for each anion. At the lower substrate concentrations, less than 10 micromolar, the apparent low Kms of NO3- and NO2- uptake were 7 and 9 micromolar, respectively, and were similar to those of the low Km system in uninduced roots. At substrate concentrations between 10 and 200 micromolar, the apparent high Km values of NO3- uptake ranged from 34 to 36 micromolar and of NO2- uptake ranged from 41 to 49 micromolar. A linear system was also found in induced seedlings at concentrations above 500 micromolar. Double reciprocal plots indicated that NO3- and NO2- inhibited the uptake of each other competitively in both uninduced and induced seedlings; however, Ki values showed that NO3- was a more effective inhibitor than NO2-. Nitrate and NO2- transport by both the low and high Km systems were greatly inhibited by p-hydroxymercuribenzoate, whereas the linear system was only slightly inhibited.

  20. Moderate extracellular acidification inhibits capsaicin-induced cell death through regulating calcium mobilization, NF-{kappa}B translocation and ROS production in synoviocytes

    SciTech Connect

    Hu, Fen; Yang, Shuang; Zhao, Dan; Zhu, Shuyan; Wang, Yuxiang; Li, Junying

    2012-07-20

    Highlights: Black-Right-Pointing-Pointer Moderate extracellular acidification regulates intracellular Ca{sup 2+} mobilization. Black-Right-Pointing-Pointer Moderate acidification activates NF-{kappa}B nuclear translocation in synoviocytes. Black-Right-Pointing-Pointer Moderate acidification depresses the ROS production induced by capsaicin. Black-Right-Pointing-Pointer Moderate acidification inhibits capsaicin-caused synoviocyte death. -- Abstract: We previously show the expression of transient receptor potential vanilloid 1 (TRPV1) in primary synoviocytes from collagen-induced arthritis (CIA) rats. Capsaicin and lowered extracellular pH from 7.4 to 5.5 induce cell death through TRPV1-mediated Ca{sup 2+} entry and reactive oxygen species (ROS) production. However, under the pathological condition in rheumatoid arthritis, the synovial fluid is acidified to a moderate level (about pH 6.8). In the present study, we examined the effects of pH 6.8 on the TRPV1-mediated cell death. Our finding is different or even opposite from what was observed at pH 5.5. We found that the moderate extracellular acidification (from pH 7.4 to 6.8) inhibited the capsaicin-induced Ca{sup 2+} entry through attenuating the activity of TRPV1. In the mean time, it triggered a phospholipse C (PLC)-related Ca{sup 2+} release from intracellular stores. The nuclear translocation of NF-{kappa}B was found at pH 6.8, and this also depends on PLC activation. Moreover, the capsaicin-evoked massive ROS production and cell death were depressed at pH 6.8, both of which are dependent on the activation of PLC and NF-{kappa}B. Taken together, these results suggested that the moderate extracellular acidification inhibited the capsaicin-induced synoviocyte death through regulating Ca{sup 2+} mobilization, activating NF-{kappa}B nuclear translocation and depressing ROS production.

  1. New mechanism of γ-H2AX generation: Surfactant-induced actin disruption causes deoxyribonuclease I translocation to the nucleus and forms DNA double-strand breaks.

    PubMed

    Zhao, Xiaoxu; Yang, Gang; Toyooka, Tatsushi; Ibuki, Yuko

    2015-12-01

    We previously showed that nonionic surfactants, nonylphenol polyethoxylates (NPEOs), induced phosphorylation of histone H2AX, forming γ-H2AX. In this study, we analyzed the mechanism of γ-H2AX generation by an NPEO with 15 ethylene oxide units (NPEO(15)). In MCF-7 breast carcinoma cells, NPEO(15) treatment induced γ-H2AX in a dose-dependent manner. EDTA and ZnCl2, two inhibitors of deoxyribonuclease I (DNase I), inhibited both the γ-H2AX and DNA double-strand breaks induced by NPEO(15). NPEO(15) disrupted filamentous actin and released free DNase I as detected by cell fractionation analysis. Based on immunofluorescence staining of DNase I and monitoring DNase I-GFP localization, DNase I was translocated from the cytosol to the nucleus of cells after treatment with NPEO(15). This translocation did not occur with the common DNA damage inducers ultraviolet B irradiation and hydrogen peroxide. Other surfactants, Tween 20, Triton X-100 and Nonidet P-40, also generated γ-H2AX. These results show that γ-H2AX induction by surfactants including NPEOs, occurs via a new mechanism involving release of free DNase I with actin disruption. This mechanism is distinct from the process of γ-H2AX generation caused by direct chemically induced DNA damage. PMID:26653977

  2. TLR1/TLR2 agonist induces tumor regression by reciprocal modulation of effector and regulatory T cells.

    PubMed

    Zhang, Yi; Luo, Feifei; Cai, Yuchan; Liu, Nan; Wang, Luman; Xu, Damo; Chu, Yiwei

    2011-02-15

    Using TLR agonists in cancer treatment can have either beneficial or detrimental effects. Therefore, it is important to determine their effect on the tumor growth and understand the underlying mechanisms in animal tumor models. In this study, we report a general immunotherapeutic activity of a synthetic bacterial lipoprotein (BLP), a TLR1/TLR2 agonist, on established lung carcinoma, leukemia, and melanoma in mice. Systemic treatment of 3LL tumor-bearing mice with BLP, but not LPS, led to a dose-dependent tumor regression and a long-lasting protective response against tumor rechallenge. The BLP-mediated tumor remission was neither mediated by a direct tumoricidal activity nor by innate immune cells, because it lacked therapeutic effect in immunodeficient SCID mice. Instead, BLP treatment reduced the suppressive function of Foxp3(+) regulatory T cells (Tregs) and enhanced the cytotoxicity of tumor-specific CTL in vitro and in vivo. Furthermore, adoptive cotransfer of BLP-pretreated but not untreated CTL and Tregs from wild-type but not from TLR2(-/-) mice was sufficient to restore antitumor immunity in SCID mice by reciprocally modulating Treg and CTL function. These results demonstrate that the TLR1/TLR2 agonist BLP may have a general tumor therapeutic property involving reciprocal downregulation of Treg and upregulation of CTL function. This property may play an important role in the development of novel antitumor strategies. PMID:21217015

  3. Novel in vivo model of inducible multidrug resistance in acute lymphoblastic leukemia with chromosomal translocation t(4;11)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acute lymphoblastic leukemia (ALL) with translocation t(4;11) is found in 60-85% of infants with ALL and is classified as high-risk due to the generally poor prognosis for survival. Using the SEM cell line established from a patient with t(4;11) ALL, we evaluated the resistance of these cells to the...

  4. FISH analysis of translocations induced by chronic exposure to Sr radioisotopes: second set of analysis of the Techa River Cohort.

    PubMed

    Vozilova, Alexandra V; Shagina, Natalia B; Degteva, Marina O; Moquet, Jayne; Ainsbury, Elizabeth A; Darroudi, Firouz

    2014-06-01

    Fluorescent in situ hybridisation analysis of stable translocations was performed for 26 residents living along the Techa River (Russia), who were predominantly (95%) exposed to ingested strontium radioisotopes ((89)Sr and (90)Sr) resulting in exposure of their red bone marrow (RBM). Analysis was conducted at the Urals Research Center for Radiation Medicine, Public Health England and Leiden University Medical Center. Each laboratory scored 1000 cells per donor, which resulted in ∼1000 genome equivalents (GE) per donor. The age-dependent spontaneous level of translocations for each donor was evaluated on the basis of data published by Sigurdson et al. (International study of factors affecting human chromosome. Mutat. Res. 2008;652: :112-121). Reconstruction of doses was performed with the 'Techa River Dosimetry System' developed in 2009. In the studied donors, the range of individual cumulated RBM dose was from 0.3 to 3.7 Gy. Analysis of the yield of stable translocations dependent on the individual RBM dose from (89,90)Sr showed a linear dose-response relationship of 0.007 ± 0.002 translocation/GE cell/Gy (R = 0.61, p = 0.001). This set of results was in a good agreement with the previous data reported for 18 donors by Vozilova et al. (Preliminary FISH-based assessment of external dose for residents exposed on the Techa River. PMID:24743760

  5. β-reciprocal polynomials

    NASA Astrophysics Data System (ADS)

    Withers, Christopher S.; Nadarajah, Saralees

    2016-07-01

    A new class of polynomials pn(x) known as β-reciprocal polynomials is defined. Given a parameter ? that is not a root of -1, we show that the only β-reciprocal polynomials are pn(x) ≡ xn. When β is a root of -1, other polynomials are possible. For example, the Hermite polynomials are i-reciprocal, ?.

  6. Reciprocating pellet press

    DOEpatents

    Jones, Charles W.

    1981-04-07

    A machine for pressing loose powder into pellets using a series of reciprocating motions has an interchangeable punch and die as its only accurately machines parts. The machine reciprocates horizontally between powder receiving and pressing positions. It reciprocates vertically to press, strip and release a pellet.

  7. Strychnine blockade of the non-reciprocal inhibition of trigeminal motoneurons induced by stimulation of the parvocellular reticular formation.

    PubMed

    Castillo, P; Pedroarena, C; Chase, M H; Morales, F R

    1991-12-20

    Stimulation of a region within the parvocellular medullary reticular formation (PcRF) that contains somas of premotor interneurons produces short latency inhibitory synaptic potentials (IPSPs) in cat trigeminal motoneurons. The present study was undertaken to determine whether glycinergic synapses are responsible for these IPSPs. The intravenous administration of strychnine, an established glycine antagonist, abolished these PcRF-IPSPs. This effect appears to be specific for glycinergic inhibitory synapses because the short lasting component of the IPSP produced by inferior alveolar nerve (IAN) stimulation was also abolished, whereas, in contrast, the long lasting non-glycinergic component of this IPSP was not suppressed. These results indicate that a glycinergic system in the reticular formation is responsible for the non-reciprocal postsynaptic inhibition of trigeminal motoneurons. PMID:1817740

  8. Aromadendrin Inhibits Lipopolysaccharide-Induced Nuclear Translocation of NF-κB and Phosphorylation of JNK in RAW 264.7 Macrophage Cells

    PubMed Central

    Lee, Jae-Won; Kim, Nam Ho; Kim, Ji-Young; Park, Jun-Ho; Shin, Seung-Yeon; Kwon, Yong-Soo; Lee, Hee Jae; Kim, Sung-Soo; Chun, Wanjoo

    2013-01-01

    Aromadendrin, a flavonol, has been reported to possess a variety of pharmacological activities such as anti-inflammatory, antioxidant, and anti-diabetic properties. However, the underlying mechanism by which aromadendrin exerts its biological activity has not been extensively demonstrated. The objective of this study is to elucidate the anti-inflammatory mechanism of aromadedrin in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. Aromadendrin significantly suppressed LPS-induced excessive production of pro-inflammatory mediators such as nitric oxide (NO) and PGE2. In accordance, aromadendrin attenuated LPSinduced overexpression iNOS and COX-2. In addition, aromadendrin significantly suppressed LPS-induced degradation of IκB, which sequesters NF-κB in cytoplasm, consequently inhibiting the nuclear translocation of pro-inflammatory transcription factor NF- κB. To elucidate the underlying signaling mechanism of anti-inflammatory activity of aromadendrin, MAPK signaling pathway was examined. Aromadendrin significantly attenuated LPS-induced activation of JNK, but not ERK and p38, in a concentration-dependent manner. Taken together, the present study clearly demonstrates that aromadendrin exhibits anti-inflammatory activity through the suppression of nuclear translocation of NF-κB and phosphorylation of JNK in LPS-stimulated RAW 264.7 macrophage cells. PMID:24265867

  9. Structural insights into ribosome translocation.

    PubMed

    Ling, Clarence; Ermolenko, Dmitri N

    2016-09-01

    During protein synthesis, tRNA and mRNA are translocated from the A to P to E sites of the ribosome thus enabling the ribosome to translate one codon of mRNA after the other. Ribosome translocation along mRNA is induced by the universally conserved ribosome GTPase, elongation factor G (EF-G) in bacteria and elongation factor 2 (EF-2) in eukaryotes. Recent structural and single-molecule studies revealed that tRNA and mRNA translocation within the ribosome is accompanied by cyclic forward and reverse rotations between the large and small ribosomal subunits parallel to the plane of the intersubunit interface. In addition, during ribosome translocation, the 'head' domain of small ribosomal subunit undergoes forward- and back-swiveling motions relative to the rest of the small ribosomal subunit around the axis that is orthogonal to the axis of intersubunit rotation. tRNA/mRNA translocation is also coupled to the docking of domain IV of EF-G into the A site of the small ribosomal subunit that converts the thermally driven motions of the ribosome and tRNA into the forward translocation of tRNA/mRNA inside the ribosome. Despite recent and enormous progress made in the understanding of the molecular mechanism of ribosome translocation, the sequence of structural rearrangements of the ribosome, EF-G and tRNA during translocation is still not fully established and awaits further investigation. WIREs RNA 2016, 7:620-636. doi: 10.1002/wrna.1354 For further resources related to this article, please visit the WIREs website. PMID:27117863

  10. Translocation of protein kinase C to membranes induced by TNF does not cause the inhibition of EGF binding to human wish cells.

    PubMed

    Katoh, T; Karasaki, Y; Hirano, H; Gotoh, S; Higashi, K

    1990-04-30

    Tumor necrosis factor (TNF) caused an inhibition of 125I-labeled epidermal growth factor [( 125I]EGF) binding to its receptors of human amniotic (WISH) cells at 5 min after addition of TNF, which reached a maximal level (60-70% reduction) after 15-30 min and declined thereafter. TNF also induced a translocation of protein kinase C activity from the cytosol to the membrane, which peaked at 45-60 min after addition of TNF and almost returned to basal level at 120 min. Furthermore, prolonged incubation of WISH cells with 12-O-tetradecanoylphorbol 13 acetate (TPA) diminished the TPA effect on the inhibition of EGF binding to the cells due to the desensitization of protein kinase C; however, TNF still reduced the EGF binding to the cells pretreated with TPA for a long time. These results indicate that although TNF causes the translocation of protein kinase C to the membrane, activation of protein kinase C is not required for TNF to induce a decrease in EGF binding to the cells. PMID:2334431

  11. Surfactant lipids regulate LPS-induced interleukin-8 production in A549 lung epithelial cells by inhibiting translocation of TLR4 into lipid raft domains

    PubMed Central

    Abate, Wondwossen; Alghaithy, Abdulaziz A.; Parton, Joan; Jones, Kenneth P.; Jackson, Simon K.

    2010-01-01

    In addition to providing mechanical stability, growing evidence suggests that surfactant lipid components can modulate inflammatory responses in the lung. However, little is known of the molecular mechanisms involved in the immunomodulatory action of surfactant lipids. This study investigates the effect of the lipid-rich surfactant preparations Survanta®, Curosurf®, and the major surfactant phospholipid dipalmitoylphosphatidylcholine (DPPC) on interleukin-8 (IL-8) gene and protein expression in human A549 lung epithelial cells using immunoassay and PCR techniques. To examine potential mechanisms of the surfactant lipid effects, Toll-like receptor 4 (TLR4) expression was analyzed by flow cytometry, and membrane lipid raft domains were separated by density gradient ultracentrifugation and analyzed by immunoblotting with anti-TLR4 antibody. The lipid-rich surfactant preparations Survanta®, Curosurf®, and DPPC, at physiological concentrations, significantly downregulated lipopolysaccharide (LPS)-induced IL-8 expression in A549 cells both at the mRNA and protein levels. The surfactant preparations did not affect the cell surface expression of TLR4 or the binding of LPS to the cells. However, LPS treatment induced translocation of TLR4 into membrane lipid raft microdomains, and this translocation was inhibited by incubation of the cells with the surfactant lipid. This study provides important mechanistic details of the immune-modulating action of pulmonary surfactant lipids. PMID:19648651

  12. Targeted Chromosomal Translocations and Essential Gene Knockout Using CRISPR/Cas9 Technology in Caenorhabditis elegans.

    PubMed

    Chen, Xiangyang; Li, Mu; Feng, Xuezhu; Guang, Shouhong

    2015-12-01

    Many genes play essential roles in development and fertility; their disruption leads to growth arrest or sterility. Genetic balancers have been widely used to study essential genes in many organisms. However, it is technically challenging and laborious to generate and maintain the loss-of-function mutations of essential genes. The CRISPR/Cas9 technology has been successfully applied for gene editing and chromosome engineering. Here, we have developed a method to induce chromosomal translocations and produce genetic balancers using the CRISPR/Cas9 technology and have applied this approach to edit essential genes in Caenorhabditis elegans. The co-injection of dual small guide RNA targeting genes on different chromosomes resulted in reciprocal translocation between nonhomologous chromosomes. These animals with chromosomal translocations were subsequently crossed with animals that contain normal sets of chromosomes. The F1 progeny were subjected to a second round of Cas9-mediated gene editing. Through this method, we successfully produced nematode strains with specified chromosomal translocations and generated a number of loss-of-function alleles of two essential genes (csr-1 and mes-6). Therefore, our method provides an easy and efficient approach to generate and maintain loss-of-function alleles of essential genes with detailed genetic background information. PMID:26482793

  13. Nitric oxide and superoxide anion differentially activate poly(ADP-ribose) polymerase-1 and Bax to induce nuclear translocation of apoptosis-inducing factor and mitochondrial release of cytochrome c after spinal cord injury.

    PubMed

    Wu, Kay L H; Hsu, Chin; Chan, Julie Y H

    2009-07-01

    We reported previously that complete spinal cord transection (SCT) results in depression of mitochondrial respiratory chain enzyme activity that triggers apoptosis via sequential activations of apoptosis-inducing factor (AIF)- and caspase-dependent cascades in the injured spinal cord. This study tested the hypothesis that nitric oxide (NO) and superoxide anion (O(2)(.-)) serve as the interposing signals between SCT and impaired mitochondrial respiratory functions. Adult Sprague-Dawley rats manifested a significant increase in NO or O(2)(.-) level in the injured spinal cord during the first 3 days after SCT. The augmented O(2)(.-) production, along with concomitant reduction in mitochondrial respiratory chain enzyme activity or ATP level, nuclear translocation of AIF, cytosolic release of cytochrome c, and DNA fragmentation were reversed by osmotic minipump infusion of a NO trapping agent, carboxy-PTIO, or a superoxide dismutase mimetic, tempol, into the epicenter of the transected spinal cord. Intriguingly, carboxy-PTIO significantly suppressed upregulation of poly(ADP-ribose) polymerase-1 (PARP-1) in the nucleus, attenuated nuclear translocation of AIF, inhibited mitochondrial translocation of Bax and antagonized mitochondrial release of cytochrome c; whereas tempol only inhibited the later two cellular events after SCT. We conclude that overproduction of NO and O(2)(.-) in the injured spinal cord promulgates mitochondrial dysfunction and triggers AIF- and caspase-dependent apoptotic signaling cascades via differential upregulation of nuclear PARP-1 and mitochondrial translocation of Bax. PMID:19473058

  14. DHA down-regulates phenobarbital-induced cytochrome P450 2B1 gene expression in rat primary hepatocytes by attenuating CAR translocation

    SciTech Connect

    Li, C.-C.; Lii, C.-K.; Liu, K.-L.; Yang, J.-J.; Chen, H.-W.

    2007-12-15

    The constitutive androstane receptor (CAR) plays an important role in regulating the expression of detoxifying enzymes, including cytochrome P450 2B (CYP 2B). Phenobarbital (PB) induction of human CYP 2B6 and mouse CYP 2b10 has been shown to be mediated by CAR. Our previous study showed that PB-induced CYP 2B1 expression in rat primary hepatocytes is down-regulated by both n-6 and n-3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA); however, the mechanism for this down-regulation by DHA was previously unknown. The objective of the present study was to determine whether change in CAR translocation is involved in the down-regulation by n-6 and n-3 PUFAs of PB-induced CYP 2B1 expression in rat primary hepatocytes. We used 100 {mu}M arachidonic acid, linoleic acid, eicosapentaenoic acid, and DHA to test this hypothesis. PB triggered the translocation of CAR from the cytosol into the nucleus in a dose-dependent and time-dependent manner in our hepatocyte system, and the CAR distribution in rat primary hepatocytes was significantly affected by DHA. DHA treatment decreased PB-inducible accumulation of CAR in the nuclear fraction and increased it in the cytosolic fraction in a dose-dependent manner. The down-regulation of CYP 2B1 expression by DHA occurred in a dose-dependent manner, and a similar pattern was found for the nuclear accumulation of CAR. The results of immunoprecipitation showed a CAR/RXR heterodimer bound to nuclear receptor binding site 1 (NR-1) of the PB-responsive enhancer module (PBREM) of the CYP 2B1gene. The EMSA results showed that PB-induced CAR binding to NR-1 was attenuated by DHA. Taken together, these results suggest that attenuation of CAR translocation and decreased subsequent binding to NR-1 are involved in DHA's down-regulation of PB-induced CYP 2B1 expression.

  15. Protein-fluctuation-induced water-pore formation in ion channel voltage-sensor translocation across a lipid bilayer membrane

    NASA Astrophysics Data System (ADS)

    Rajapaksha, Suneth P.; Pal, Nibedita; Zheng, Desheng; Lu, H. Peter

    2015-11-01

    We have applied a combined fluorescence microscopy and single-ion-channel electric current recording approach, correlating with molecular dynamics (MD) simulations, to study the mechanism of voltage-sensor domain translocation across a lipid bilayer. We use the colicin Ia ion channel as a model system, and our experimental and simulation results show the following: (1) The open-close activity of an activated colicin Ia is not necessarily sensitive to the amplitude of the applied cross-membrane voltage when the cross-membrane voltage is around the resting potential of excitable membranes; and (2) there is a significant probability that the activation of colicin Ia occurs by forming a transient and fluctuating water pore of ˜15 Å diameter in the lipid bilayer membrane. The location of the water-pore formation is nonrandom and highly specific, right at the insertion site of colicin Ia charged residues in the lipid bilayer membrane, and the formation is intrinsically associated with the polypeptide conformational fluctuations and solvation dynamics. Our results suggest an interesting mechanistic pathway for voltage-sensitive ion channel activation, and specifically for translocation of charged polypeptide chains across the lipid membrane under a transmembrane electric field: the charged polypeptide domain facilitates the formation of hydrophilic water pore in the membrane and diffuses through the hydrophilic pathway across the membrane; i.e., the charged polypeptide chain can cross a lipid membrane without entering into the hydrophobic core of the lipid membrane but entirely through the aqueous and hydrophilic environment to achieve a cross-membrane translocation. This mechanism sheds light on the intensive and fundamental debate on how a hydrophilic and charged peptide domain diffuses across the biologically inaccessible high-energy barrier of the hydrophobic core of a lipid bilayer: The peptide domain does not need to cross the hydrophobic core to move across a

  16. Reciprocity in directed networks

    NASA Astrophysics Data System (ADS)

    Yin, Mei; Zhu, Lingjiong

    2016-04-01

    Reciprocity is an important characteristic of directed networks and has been widely used in the modeling of World Wide Web, email, social, and other complex networks. In this paper, we take a statistical physics point of view and study the limiting entropy and free energy densities from the microcanonical ensemble, the canonical ensemble, and the grand canonical ensemble whose sufficient statistics are given by edge and reciprocal densities. The sparse case is also studied for the grand canonical ensemble. Extensions to more general reciprocal models including reciprocal triangle and star densities will likewise be discussed.

  17. Measurement of background translocation frequencies in individuals with clones

    SciTech Connect

    Wade, M.J.

    1996-08-01

    In the leukemia case the unseparated B and T lymphocytes had a high translocation frequency even after 0.0014, respectively. After purging all clones from the data, the translocation frequencies for Bio 8 and Bio 23 were 0.00750.0014 and 0.0073 metaphases were scored for chromosomal aberrations,, specifically reciprocal translocations, using fluorescence in situ hybridization (FISH). Metaphase spreads were used from two healthy, unexposed individuals (not exposed to radiation, chemotherapy or radiotherapy) and one early B- precursor acute lymphocytic leukemia (ALL) patient (metaphase spreads from both separated T lymphocytes and unseparated B and T lymphocytes were scored). All three individuals had an abnormally high translocation frequency. The high translocation frequencies resulted from clonal expansion of specific translocated chromosomes. I show in this thesis that by purging (discounting or removing) clones from the data of unexposed individuals, one can obtain true background translocation frequencies. In two cases, Bio 8 and Bio 23, the measured translocation frequency for chromosomes 1, 2 and 4 was 0.0124 purging all of the clones from the data. This high translocation frequency may be due to a low frequency of some clones and may not be recognized. The separated T lymphocytes had a higher translocation frequency than expected.

  18. Differential modulatory effects of GSK-3β and HDM2 on sorafenib-induced AIF nuclear translocation (programmed necrosis) in melanoma

    PubMed Central

    2011-01-01

    Background GSK-3β phosphorylates numerous substrates that govern cell survival. It phosphorylates p53, for example, and induces its nuclear export, HDM2-dependent ubiquitination, and proteasomal degradation. GSK-3β can either enhance or inhibit programmed cell death, depending on the nature of the pro-apoptotic stimulus. We previously showed that the multikinase inhibitor sorafenib activated GSK-3β and that this activation attenuated the cytotoxic effects of the drug in various BRAF-mutant melanoma cell lines. In this report, we describe the results of studies exploring the effects of GSK-3β on the cytotoxicity and antitumor activity of sorafenib combined with the HDM2 antagonist MI-319. Results MI-319 alone increased p53 levels and p53-dependent gene expression in melanoma cells but did not induce programmed cell death. Its cytotoxicity, however, was augmented in some melanoma cell lines by the addition of sorafenib. In responsive cell lines, the MI-319/sorafenib combination induced the disappearance of p53 from the nucleus, the down modulation of Bcl-2 and Bcl-xL, the translocation of p53 to the mitochondria and that of AIF to the nuclei. These events were all GSK-3β-dependent in that they were blocked with a GSK-3β shRNA and facilitated in otherwise unresponsive melanoma cell lines by the introduction of a constitutively active form of the kinase (GSK-3β-S9A). These modulatory effects of GSK-3β on the activities of the sorafenib/MI-319 combination were the exact reverse of its effects on the activities of sorafenib alone, which induced the down modulation of Bcl-2 and Bcl-xL and the nuclear translocation of AIF only in cells in which GSK-3β activity was either down modulated or constitutively low. In A375 xenografts, the antitumor effects of sorafenib and MI-319 were additive and associated with the down modulation of Bcl-2 and Bcl-xL, the nuclear translocation of AIF, and increased suppression of tumor angiogenesis. Conclusions Our data demonstrate a

  19. Inhibition of the FKBP family of peptidyl prolyl isomerases induces abortive translocation and degradation of the cellular prion protein

    PubMed Central

    Stocki, Pawel; Sawicki, Maxime; Mays, Charles E.; Hong, Seo Jung; Chapman, Daniel C.; Westaway, David; Williams, David B.

    2016-01-01

    Prion diseases are fatal neurodegenerative disorders for which there is no effective treatment. Because the cellular prion protein (PrPC) is required for propagation of the infectious scrapie form of the protein, one therapeutic strategy is to reduce PrPC expression. Recently FK506, an inhibitor of the FKBP family of peptidyl prolyl isomerases, was shown to increase survival in animal models of prion disease, with proposed mechanisms including calcineurin inhibition, induction of autophagy, and reduced PrPC expression. We show that FK506 treatment results in a profound reduction in PrPC expression due to a defect in the translocation of PrPC into the endoplasmic reticulum with subsequent degradation by the proteasome. These phenotypes could be bypassed by replacing the PrPC signal sequence with that of prolactin or osteopontin. In mouse cells, depletion of ER luminal FKBP10 was almost as potent as FK506 in attenuating expression of PrPC. However, this occurred at a later stage, after translocation of PrPC into the ER. Both FK506 treatment and FKBP10 depletion were effective in reducing PrPSc propagation in cell models. These findings show the involvement of FKBP proteins at different stages of PrPC biogenesis and identify FKBP10 as a potential therapeutic target for the treatment of prion diseases. PMID:26764098

  20. Inhibition of the FKBP family of peptidyl prolyl isomerases induces abortive translocation and degradation of the cellular prion protein.

    PubMed

    Stocki, Pawel; Sawicki, Maxime; Mays, Charles E; Hong, Seo Jung; Chapman, Daniel C; Westaway, David; Williams, David B

    2016-03-01

    Prion diseases are fatal neurodegenerative disorders for which there is no effective treatment. Because the cellular prion protein (PrP(C)) is required for propagation of the infectious scrapie form of the protein, one therapeutic strategy is to reduce PrP(C) expression. Recently FK506, an inhibitor of the FKBP family of peptidyl prolyl isomerases, was shown to increase survival in animal models of prion disease, with proposed mechanisms including calcineurin inhibition, induction of autophagy, and reduced PrP(C) expression. We show that FK506 treatment results in a profound reduction in PrP(C) expression due to a defect in the translocation of PrP(C) into the endoplasmic reticulum with subsequent degradation by the proteasome. These phenotypes could be bypassed by replacing the PrP(C) signal sequence with that of prolactin or osteopontin. In mouse cells, depletion of ER luminal FKBP10 was almost as potent as FK506 in attenuating expression of PrP(C). However, this occurred at a later stage, after translocation of PrP(C) into the ER. Both FK506 treatment and FKBP10 depletion were effective in reducing PrP(Sc) propagation in cell models. These findings show the involvement of FKBP proteins at different stages of PrP(C) biogenesis and identify FKBP10 as a potential therapeutic target for the treatment of prion diseases. PMID:26764098

  1. A small molecule induces integrin β4 nuclear translocation and apoptosis selectively in cancer cells with high expression of integrin β4

    PubMed Central

    Liu, ShuYan; Ge, Di; Chen, LiNa; Zhao, Jing; Su, Le; Zhang, ShangLi; Miao, JunYing; Zhao, BaoXiang

    2016-01-01

    Increased integrin β4 (ITGB4) level is accompanied by malignant progression of multiple carcinomas. However, selective therapeutic strategies against cancer cells expressing a high level of ITGB4 have not been reported. Here, for the first time, we report that a chiral small molecule, SEC, selectively promotes apoptosis in cancer cells expressing a high level of ITGB4 by inducing ITGB4 nuclear translocation. Nuclear ITGB4 can bind to the ATF3 promoter region and activate the expression of ATF3, then upregulate the downstream pro-apoptosis genes. Furthermore, SEC promoted the binding of annexin A7 (ANXA7) to ITGB4 and increased ANXA7 GTPase activity. Activated ANXA7 promoted ITGB4 nuclear translocation by triggering ITGB4 phosphorylation at Y1494. SEC also inhibited the growth of xenograft tumors in the avian embryo model. We identified a small molecule, SEC, with selective pro-apoptosis effects on cancer cells with high expression of ITGB4, both in vitro and in vivo, by triggering the binding of ITGB4 and ANXA7, ITGB4 nuclear trafficking, and pro-apoptosis gene expression. PMID:26918348

  2. Chlorpyrifos Induces MLL Translocations Through Caspase 3-Dependent Genomic Instability and Topoisomerase II Inhibition in Human Fetal Liver Hematopoietic Stem Cells.

    PubMed

    Lu, Chengquan; Liu, Xiaohui; Liu, Chang; Wang, Jian; Li, Chunna; Liu, Qi; Li, Yachen; Li, Shuangyue; Sun, Shu; Yan, Jinsong; Shao, Jing

    2015-10-01

    Household pesticide exposure during pregnancy has been associated with a more than 2-fold increased risk in infant leukemia, and chlorpyrifos (CPF) is among the most frequently applied insecticides. During early fetal development, liver is a hematopoietic organ with majority of cells being CD34(+) hematopoietic stem cells (CD34(+)HSC). The in utero injury to CD34(+)HSC has been known to underlie the pathogenesis of several blood disorders, often involving rearrangements of the mixed-lineage leukemia (MLL) gene on 11q23. In this study, we evaluated the leukemogenic potential of CPF in human fetal liver-derived CD34(+)HSC. Specifically, exposure to 10 μM CPF led to decrease in viability, inhibition in proliferation and induction of DNA double-strand breaks (DSBs) and occurrence of MLL(+) rearrangements. In particular, we observed CPF-mediated cell cycle disturbance as shown by G0/G1 arrest, in contrast to etoposide (VP-16), an anticancer drug used as a positive control and known to induce G2/M arrest. Further study on mechanisms underlying DNA DSBs and MLL(+) rearrangements revealed that CPF might act as topoisomerase II poison, a mechanism of action similar to VP-16. On the other hand, CPF was also shown to induce early apoptosis through active caspase-3 activation, a pathway known to underlie DNA DSBs and MLL(+) translocations. Our data indicate that in utero injury of CD34(+)HSC by CPF may contribute to the increased risk of infant leukemia. Future work will elucidate the mechanism and the type of CPF-induced MLL(+) translocations in HSC. PMID:26198043

  3. Mechanical stretch-induced vascular hypertrophy occurs through modulation of leptin synthesis-mediated ROS formation and GATA-4 nuclear translocation

    PubMed Central

    Ghantous, Crystal M.; Kobeissy, Firas H.; Soudani, Nadia; Rahman, Farah A.; Al-Hariri, Mustafa; Itani, Hana A.; Sabra, Ramzi; Zeidan, Asad

    2015-01-01

    Background: Obesity and hypertension are associated with increased leptin production contributing to cardiovascular remodeling. Mechanisms involving mechanical stretch-induced leptin production and the cross talk between signaling pathways leading to vascular remodeling have not been fully elucidated. Methods and Results: Rat portal vein (RPV) organ culture was used to investigate the effect of mechanical stretch on leptin protein expression in vascular smooth muscle cells (VSMCs). Moreover, the involvement of reactive oxygen species (ROS), the RhoA/ROCK pathway, actin cytoskeleton dynamics and the transcriptional factor GATA-4 activation in mechanical stretch-induced vascular remodeling were investigated. Stretching the RPV for 1 or 24 h significantly increased leptin protein level and ROS formation in VSMCs, which was prevented by 1 h pretreatment with the ROCK inhibitor Y-27632 and the actin cytoskeleton depolymerization agent cytochalasin D. Moreover, Western blotting and immunohistochemistry revealed that mechanical stretch or treatment with 3.1 nmol/L leptin for 24 h significantly increased actin polymerization, as reflected by an increase in the F-actin to G-actin ratio. Increases in blood vessels’ wet weight and [3H]-leucine incorporation following a 24 h treatment with conditioned media from cultured stretched RPVs indicated RPV hypertrophy. This effect was prevented by 1 h pretreatment with anti-leptin antibody, indicating leptin’s crucial role in promoting VSMC hypertrophy. As an index of GATA-4 activation, GATA-4 nuclear translocation was assessed by immunohistochemistry method. Pretreating VSMC with leptin for 1 h significantly activated GATA-4 nuclear translocation, which was potently attenuated by the NADPH oxidase inhibitor apocynin, Y-27632, and cytochalasin D. Conclusion: Our results demonstrate that ROS formation, RhoA/ROCK pathway, and GATA-4 activation play a pivotal role in mechanical stretch-induced leptin synthesis leading to VSMC

  4. Reciprocal NUT spacetimes

    NASA Astrophysics Data System (ADS)

    Momeni, Davood; Chattopadhyay, Surajit; Myrzakulov, Ratbay

    2015-05-01

    In this paper, we study the Ehlers' transformation (sometimes called gravitational duality rotation) for reciprocal static metrics. First, we introduce the concept of reciprocal metric. We prove a theorem which shows how we can construct a certain new static solution of Einstein field equations using a seed metric. Later, we investigate the family of stationary spacetimes of such reciprocal metrics. The key here is a theorem from Ehlers', which relates any static vacuum solution to a unique stationary metric. The stationary metric has a magnetic charge. The spacetime represents Newman-Unti-Tamburino (NUT) solutions. Since any stationary spacetime can be decomposed into a 1 + 3 time-space decomposition, Einstein field equations for any stationary spacetime can be written in the form of Maxwell's equations for gravitoelectromagnetic fields. Further, we show that this set of equations is invariant under reciprocal transformations. An additional point is that the NUT charge changes the sign. As an instructive example, by starting from the reciprocal Schwarzschild as a spherically symmetric solution and reciprocal Morgan-Morgan disk model as seed metrics we find their corresponding stationary spacetimes. Starting from any static seed metric, performing the reciprocal transformation and by applying an additional Ehlers' transformation we obtain a family of NUT spaces with negative NUT factor (reciprocal NUT factors).

  5. Reciprocating Linear Electric Motor

    NASA Technical Reports Server (NTRS)

    Goldowsky, M. P.

    1984-01-01

    Features include structural simplicity and good force/displacement characteristics. Reciprocating motor has simple, rugged construction, relatively low reciprocating weight, improved power delivery, and improved force control. Wear reduced by use of magnetic bearings. Intended to provide drivers for long-lived Stirling-cycle cryogenic refrigerators, concept has less exotic applications, such as fuel pumps.

  6. The Value of Reciprocity

    ERIC Educational Resources Information Center

    Molm, Linda D.; Schaefer, David R.; Collett, Jessica L.

    2007-01-01

    The value of reciprocity in social exchange potentially comprises both instrumental value (the value of the actual benefits received from exchange) and communicative or symbolic value (the expressive and uncertainty reduction value conveyed by features of the act of reciprocity itself). While all forms of exchange provide instrumental value, we…

  7. The Structure of Reciprocity

    ERIC Educational Resources Information Center

    Molm, Linda D.

    2010-01-01

    Reciprocity is one of the defining features of social exchange and social life, yet exchange theorists have tended to take it for granted. Drawing on work from a decade-long theoretical research program, I argue that reciprocity is structured and variable across different forms of exchange, that these variations in the structure of reciprocity…

  8. An Autonomously Reciprocating Transmembrane Nanoactuator.

    PubMed

    Watson, Matthew A; Cockroft, Scott L

    2016-01-22

    Biological molecular machines operate far from equilibrium by coupling chemical potential to repeated cycles of dissipative nanomechanical motion. This principle has been exploited in supramolecular systems that exhibit true machine behavior in solution and on surfaces. However, designed membrane-spanning assemblies developed to date have been limited to simple switches or stochastic shuttles, and true machine behavior has remained elusive. Herein, we present a transmembrane nanoactuator that turns over chemical fuel to drive autonomous reciprocating (back-and-forth) nanomechanical motion. Ratcheted reciprocating motion of a DNA/PEG copolymer threaded through a single α-hemolysin pore was induced by a combination of DNA strand displacement processes and enzyme-catalyzed reactions. Ion-current recordings revealed saw-tooth patterns, indicating that the assemblies operated in autonomous, asymmetric cycles of conformational change at rates of up to one cycle per minute. PMID:26661295

  9. Genetic Architecture of Reciprocal CNVs

    PubMed Central

    Golzio, Christelle; Katsanis, Nicholas

    2013-01-01

    Copy number variants (CNVs) represent a frequent type of lesion in human genetic disorders that typically affects numerous genes simultaneously. This has raised the challenge of understanding which genes within a CNV drive clinical phenotypes. Although CNVs can arise by multiple mechanisms, a subset is driven by local genomic architecture permissive to recombination events that can lead to both deletions and duplications. Phenotypic analyses of patients with such reciprocal CNVs have revealed instances in which the phenotype is either identical or mirrored; strikingly, molecular studies have revealed that such phenotypes are often driven by reciprocal dosage defects of the same transcript. Here we explore how these observations can help the dissection of CNVs and inform the genetic architecture of CNV-induced disorders. PMID:23747035

  10. Epstein-Barr virus latent membrane protein-2A induces ITAM/Syk- and Akt-dependent epithelial migration through αv-integrin membrane translocation.

    PubMed

    Fotheringham, Julie A; Coalson, Nicole E; Raab-Traub, Nancy

    2012-10-01

    Epstein-Barr virus (EBV) is a highly prevalent herpesvirus associated with epithelial cancers, including nasopharyngeal carcinoma (NPC). The EBV protein latent membrane protein 2 (LMP2) is expressed in NPC tumor tissue and has been shown to induce transformation, inhibit differentiation, and promote migration of epithelial cells. In this study, the effect of LMP2A on migration of human epithelial cells was further analyzed. LMP2A expression induced migration in human foreskin keratinocytes (HFK) and HaCaT keratinocytes measured by wound healing scratch assay and chemoattractant-induced Transwell migration assay. The induction of migration by LMP2A required the ITAM signaling domain of LMP2A and activation of the Syk tyrosine kinase. LMP2A-induced Transwell migration required the Akt signaling pathway, and activation of Akt by LMP2A required the ITAM signaling domain of LMP2A. LMP2A also induced phosphorylation of the Akt target GSK3β, a Wnt signaling mediator that has been shown to regulate the activity of focal adhesion kinase (FAK), a tyrosine kinase activated by clustering and ligand interaction of integrins. Inhibition of either FAK or its signaling mediator Src kinase inhibited LMP2A-induced migration. Interestingly, αV-integrin was greatly increased in membrane-enriched fractions by LMP2A, and a neutralizing antibody to αV-integrin blocked migration, suggesting that the effects of LMP2A on membrane-localized αV-integrin promoted migration. The results of this study indicate that LMP2A expression in human epithelial cells induces αV-integrin-dependent migration through a mechanism requiring ITAM-mediated Syk and Akt activation and inducing membrane translocation or stabilization of αV-integrin and FAK activation. The specific effects of LMP2A on an integrin with a diverse repertoire of ligand specificities could promote migration of different cell types and be initiated by multiple chemoattractants. PMID:22837212

  11. A translocator protein 18 kDa ligand, Ro5-4864, inhibits ATP-induced NLRP3 inflammasome activation.

    PubMed

    Lee, Ji-Won; Kim, Leah Eunjung; Shim, Hyun-Jung; Kim, Eun-Kyoung; Hwang, Won Chan; Min, Do Sik; Yu, Seong-Woon

    2016-06-01

    Ro5-4864 and PK11195, prototypical synthetic ligands of translocator protein 18 kDa (TSPO), have shown anti-inflammatory effects in several models of inflammatory diseases; however, their biochemical mechanisms remain poorly understood. Nod-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation as a part of the innate immune system, has been implicated in a variety of inflammatory diseases. Here, we demonstrate for the first time that TSPO ligands, especially Ro5-4864, potently suppressed ATP-induced NLRP3 inflammasome activation in THP-1 and BMDM cells. Detailed action mechanism was further investigated in THP-1 cells. Ro5-4864 efficiently attenuated NLRP3 translocation to mitochondria, inflammasome assembly/oligomerization, activation of caspase-1, and subsequent secretion of the mature forms of interleukin-1β and -18. Ro5-4864 also reduced the production of mitochondrial superoxide and preserved the mitochondrial membrane potential in ATP-treated cells, suggesting that Ro5-4864 may act on mitochondria or more upstream targets in NLRP3 inflammasome signaling. We also observed the distinct effects of the TSPO ligands between THP-1 monocytes and macrophages, which suggested different NLRP3 inflammasome signaling depending on cell type. Collectively, our novel findings demonstrate that Ro5-4864 effectively inhibited ATP-induced NLRP3 inflammasome activation through the prevention of mitochondrial perturbation. Our results indicate Ro5-4864 as a promising candidate for the treatment of NLRP3 inflammasome-related diseases. PMID:27103438

  12. Hexavalent chromium-induced apoptosis of granulosa cells involves selective sub-cellular translocation of Bcl-2 members, ERK1/2 and p53

    SciTech Connect

    Banu, Sakhila K.; Stanley, Jone A.; Lee, JeHoon; Stephen, Sam D.; Arosh, Joe A.; Hoyer, Patricia B.; Burghardt, Robert C.

    2011-03-15

    Hexavalent chromium (CrVI) has been widely used in industries throughout the world. Increased usage of CrVI and atmospheric emission of CrVI from catalytic converters of automobiles, and its improper disposal causes various health hazards including female infertility. Recently we have reported that lactational exposure to CrVI induced a delay/arrest in follicular development at the secondary follicular stage. In order to investigate the underlying mechanism, primary cultures of rat granulosa cells were treated with 10 {mu}M potassium dichromate (CrVI) for 12 and 24 h, with or without vitamin C pre-treatment for 24 h. The effects of CrVI on intrinsic apoptotic pathway(s) were investigated. Our data indicated that CrVI: (i) induced DNA fragmentation and increased apoptosis, (ii) increased cytochrome c release from the mitochondria to cytosol, (iii) downregulated anti-apoptotic Bcl-2, Bcl-XL, HSP70 and HSP90; upregulated pro-apoptotic BAX and BAD, (iv) altered translocation of Bcl-2, Bcl-XL, BAX, BAD, HSP70 and HSP90 to the mitochondria, (v) upregulated p-ERK and p-JNK, and selectively translocated p-ERK to the mitochondria and nucleus, (vi) activated caspase-3 and PARP, and (vii) increased phosphorylation of p53 at ser-6, ser-9, ser-15, ser-20, ser-37, ser-46 and ser-392, increased p53 transcriptional activation, and downregulated MDM-2. Vitamin C pre-treatment mitigated CrVI effects on apoptosis and related pathways. Our study, for the first time provides a clear insight into the effect of CrVI on multiple pathways that lead to apoptosis of granulosa cells which could be mitigated by vitamin C.

  13. BZLF1, an Epstein-Barr virus immediate-early protein, induces p65 nuclear translocation while inhibiting p65 transcriptional function

    SciTech Connect

    Morrison, Thomas E.; Kenney, Shannon C. . E-mail: shann@med.unc.edu

    2004-10-25

    We have previously demonstrated that the Epstein-Barr virus immediate-early BZLF1 protein interacts with, and is inhibited by, the NF-{kappa}B family member p65. However, the effects of BZLF1 on NF-{kappa}B activity have not been intensively studied. Here we show that BZLF1 inhibits p65-dependent gene expression. BZLF1 inhibited the ability of IL-1, as well as transfected p65, to activate the expression of two different NF-{kappa}B-responsive genes, ICAM-1 and I{kappa}B-{alpha}. BZLF1 also reduced the constitutive level of I{kappa}B-{alpha} protein in HeLa and A549 cells, and increased the amount of nuclear NF-{kappa}B to a similar extent as tumor necrosis factor-alpha (TNF-{alpha}) treatment. In spite of this BZLF1-associated increase in the nuclear form of NF-{kappa}B, BZLF1 did not induce binding of NF-{kappa}B to NF-{kappa}B responsive promoters (as determined by chromatin immunoprecipitation assay) in vivo, although TNF-{alpha} treatment induced NF-{kappa}B binding as expected. Overexpression of p65 dramatically inhibited the lytic replication cycle of EBV in 293-EBV cells, confirming that NF-{kappa}B also inhibits BZLF1 transcriptional function. Our results are consistent with a model in which BZLF1 inhibits the transcriptional function of p65, resulting in decreased transcription of I{kappa}B-{alpha}, decreased expression of I{kappa}B-{alpha} protein, and subsequent translocation of NF-{kappa}B to the nucleus. This nuclear translocation of NF-{kappa}B may promote viral latency by negatively regulating BZLF1 transcriptional activity. In situations where p65 activity is limiting in comparison to BZLF1, the ability of BZLF1 to inhibit p65 transcriptional function may protect the virus from the host immune system during the lytic form of infection.

  14. Translocation of Heme Oxygenase-1 to Mitochondria Is a Novel Cytoprotective Mechanism against Non-steroidal Anti-inflammatory Drug-induced Mitochondrial Oxidative Stress, Apoptosis, and Gastric Mucosal Injury*

    PubMed Central

    Bindu, Samik; Pal, Chinmay; Dey, Sumanta; Goyal, Manish; Alam, Athar; Iqbal, Mohd. Shameel; Dutta, Shubham; Sarkar, Souvik; Kumar, Rahul; Maity, Pallab; Bandyopadhyay, Uday

    2011-01-01

    The mechanism of action of heme oxygenase-1 (HO-1) in mitochondrial oxidative stress (MOS)-mediated apoptotic tissue injury was investigated. MOS-mediated gastric mucosal apoptosis and injury were introduced in rat by indomethacin, a non-steroidal anti-inflammatory drug. Here, we report that HO-1 was not only induced but also translocated to mitochondria during gastric mucosal injury to favor repair mechanisms. Furthermore, mitochondrial translocation of HO-1 resulted in the prevention of MOS and mitochondrial pathology as evident from the restoration of the complex I-driven mitochondrial respiratory control ratio and transmembrane potential. Mitochondrial translocation of HO-1 also resulted in time-dependent inhibition of apoptosis. We searched for the plausible mechanisms responsible for HO-1 induction and mitochondrial localization. Free heme, the substrate for HO-1, was increased inside mitochondria during gastric injury, and mitochondrial entry of HO-1 decreased intramitochondrial free heme content, suggesting that a purpose of mitochondrial translocation of HO-1 is to detoxify accumulated heme. Heme may activate nuclear translocation of NF-E2-related factor 2 to induce HO-1 through reactive oxygen species generation. Electrophoretic mobility shift assay and chromatin immunoprecipitation studies indicated nuclear translocation of NF-E2-related factor 2 and its binding to HO-1 promoter to induce HO-1 expression during gastric injury. Inhibition of HO-1 by zinc protoporphyrin aggravated the mucosal injury and delayed healing. Zinc protoporphyrin further reduced the respiratory control ratio and transmembrane potential and enhanced MOS and apoptosis. In contrast, induction of HO-1 by cobalt protoporphyrin reduced MOS, corrected mitochondrial dysfunctions, and prevented apoptosis and gastric injury. Thus, induction and mitochondrial localization of HO-1 are a novel cytoprotective mechanism against MOS-mediated apoptotic tissue injury. PMID:21908612

  15. Cellular delivery and photochemical release of a caged inositol-pyrophosphate induces PH-domain translocation in cellulo

    PubMed Central

    Pavlovic, Igor; Thakor, Divyeshsinh T.; Vargas, Jessica R.; McKinlay, Colin J.; Hauke, Sebastian; Anstaett, Philipp; Camuña, Rafael C.; Bigler, Laurent; Gasser, Gilles; Schultz, Carsten; Wender, Paul A.; Jessen, Henning J.

    2016-01-01

    Inositol pyrophosphates, such as diphospho-myo-inositol pentakisphosphates (InsP7), are an important family of signalling molecules, implicated in many cellular processes and therapeutic indications including insulin secretion, glucose homeostasis and weight gain. To understand their cellular functions, chemical tools such as photocaged analogues for their real-time modulation in cells are required. Here we describe a concise, modular synthesis of InsP7 and caged InsP7. The caged molecule is stable and releases InsP7 only on irradiation. While photocaged InsP7 does not enter cells, its cellular uptake is achieved using nanoparticles formed by association with a guanidinium-rich molecular transporter. This novel synthesis and unprecedented polyphosphate delivery strategy enable the first studies required to understand InsP7 signalling in cells with controlled spatiotemporal resolution. It is shown herein that cytoplasmic photouncaging of InsP7 leads to translocation of the PH-domain of Akt, an important signalling-node kinase involved in glucose homeostasis, from the membrane into the cytoplasm. PMID:26842801

  16. Cellular delivery and photochemical release of a caged inositol-pyrophosphate induces PH-domain translocation in cellulo.

    PubMed

    Pavlovic, Igor; Thakor, Divyeshsinh T; Vargas, Jessica R; McKinlay, Colin J; Hauke, Sebastian; Anstaett, Philipp; Camuña, Rafael C; Bigler, Laurent; Gasser, Gilles; Schultz, Carsten; Wender, Paul A; Jessen, Henning J

    2016-01-01

    Inositol pyrophosphates, such as diphospho-myo-inositol pentakisphosphates (InsP7), are an important family of signalling molecules, implicated in many cellular processes and therapeutic indications including insulin secretion, glucose homeostasis and weight gain. To understand their cellular functions, chemical tools such as photocaged analogues for their real-time modulation in cells are required. Here we describe a concise, modular synthesis of InsP7 and caged InsP7. The caged molecule is stable and releases InsP7 only on irradiation. While photocaged InsP7 does not enter cells, its cellular uptake is achieved using nanoparticles formed by association with a guanidinium-rich molecular transporter. This novel synthesis and unprecedented polyphosphate delivery strategy enable the first studies required to understand InsP7 signalling in cells with controlled spatiotemporal resolution. It is shown herein that cytoplasmic photouncaging of InsP7 leads to translocation of the PH-domain of Akt, an important signalling-node kinase involved in glucose homeostasis, from the membrane into the cytoplasm. PMID:26842801

  17. Dimethyl fumarate induces apoptosis of hematopoietic tumor cells via inhibition of NF-κB nuclear translocation and down-regulation of Bcl-xL and XIAP.

    PubMed

    Tsubaki, Masanobu; Ogawa, Naoki; Takeda, Tomoya; Sakamoto, Kotaro; Shimaoka, Hirotaka; Fujita, Arisa; Itoh, Tatsuki; Imano, Motohiro; Satou, Takao; Nishida, Shozo

    2014-10-01

    Dimethyl fumarate (DMF) is a fumaric acid ester that is used to treat psoriasis and multiple sclerosis. Recently, DMF was found to exhibit anti-tumor effects. However, the molecular mechanisms underlying these effects have not been elucidated. In this study, we investigated the mechanism of DMF-induced apoptosis in different human hematopoietic tumor cell lines. We found that DMF induced apoptosis in different human hematopoietic tumor cell lines but it did not affect the normal human B lymphocyte cell line RPMI 1788. We also observed a concurrent increase in caspase-3 activity and in the number of Annexin-V-positive cells. Furthermore, an examination of the survival signals, which are activated by apoptotic stimuli, revealed that DMF significantly inhibited nuclear factor-κB (NF-κB) p65 nuclear translocation. In addition, DMF suppressed B-cell lymphoma extra-large (Bcl-xL) and X-linked inhibitor of apoptosis (XIAP) expression whereas Bcl-2, survivin, Bcl-2-associated X protein (Bax), and Bim levels did not change. These results indicated that DMF induced apoptosis by suppressing NF-κB activation, and Bcl-xL and XIAP expression. These findings suggested that DMF might have potential as an anticancer agent that could be used in combination therapy with other anticancer drugs for the treatment of human hematopoietic tumors. PMID:25443417

  18. Centrifugal reciprocating compressor

    NASA Technical Reports Server (NTRS)

    High, W. H.

    1980-01-01

    Efficient compressor uses centrifugal force to compress gas. System incorporates two coupled dc motors, each driving separate centrifugal reciprocating-compressor assembly. Motors are synchronized to accelerate and decelerate alternately.

  19. Hidden patterns of reciprocity.

    PubMed

    Syi

    2014-03-21

    Reciprocity can help the evolution of cooperation. To model both types of reciprocity, we need the concept of strategy. In the case of direct reciprocity there are four second-order action rules (Simple Tit-for-tat, Contrite Tit-for-tat, Pavlov, and Grim Trigger), which are able to promote cooperation. In the case of indirect reciprocity the key component of cooperation is the assessment rule. There are, again, four elementary second-order assessment rules (Image Scoring, Simple Standing, Stern Judging, and Shunning). The eight concepts can be formalized in an ontologically thin way we need only an action predicate and a value function, two agent concepts, and the constant of goodness. The formalism helps us to discover that the action and assessment rules can be paired, and that they show the same patterns. The logic of these patterns can be interpreted with the concept of punishment that has an inherent paradoxical nature. PMID:24368125

  20. Herpesvirus Genome Recognition Induced Acetylation of Nuclear IFI16 Is Essential for Its Cytoplasmic Translocation, Inflammasome and IFN-β Responses.

    PubMed

    Ansari, Mairaj Ahmed; Dutta, Sujoy; Veettil, Mohanan Valiya; Dutta, Dipanjan; Iqbal, Jawed; Kumar, Binod; Roy, Arunava; Chikoti, Leela; Singh, Vivek Vikram; Chandran, Bala

    2015-07-01

    The IL-1β and type I interferon-β (IFN-β) molecules are important inflammatory cytokines elicited by the eukaryotic host as innate immune responses against invading pathogens and danger signals. Recently, a predominantly nuclear gamma-interferon-inducible protein 16 (IFI16) involved in transcriptional regulation has emerged as an innate DNA sensor which induced IL-1β and IFN-β production through inflammasome and STING activation, respectively. Herpesvirus (KSHV, EBV, and HSV-1) episomal dsDNA genome recognition by IFI16 leads to IFI16-ASC-procaspase-1 inflammasome association, cytoplasmic translocation and IL-1β production. Independent of ASC, HSV-1 genome recognition results in IFI16 interaction with STING in the cytoplasm to induce interferon-β production. However, the mechanisms of IFI16-inflammasome formation, cytoplasmic redistribution and STING activation are not known. Our studies here demonstrate that recognition of herpesvirus genomes in the nucleus by IFI16 leads into its interaction with histone acetyltransferase p300 and IFI16 acetylation resulting in IFI16-ASC interaction, inflammasome assembly, increased interaction with Ran-GTPase, cytoplasmic redistribution, caspase-1 activation, IL-1β production, and interaction with STING which results in IRF-3 phosphorylation, nuclear pIRF-3 localization and interferon-β production. ASC and STING knockdowns did not affect IFI16 acetylation indicating that this modification is upstream of inflammasome-assembly and STING-activation. Vaccinia virus replicating in the cytoplasm did not induce nuclear IFI16 acetylation and cytoplasmic translocation. IFI16 physically associates with KSHV and HSV-1 genomes as revealed by proximity ligation microscopy and chromatin-immunoprecipitation studies which is not hampered by the inhibition of acetylation, thus suggesting that acetylation of IFI16 is not required for its innate sensing of nuclear viral genomes. Collectively, these studies identify the increased nuclear

  1. Herpesvirus Genome Recognition Induced Acetylation of Nuclear IFI16 Is Essential for Its Cytoplasmic Translocation, Inflammasome and IFN-β Responses

    PubMed Central

    Ansari, Mairaj Ahmed; Dutta, Sujoy; Veettil, Mohanan Valiya; Dutta, Dipanjan; Iqbal, Jawed; Kumar, Binod; Roy, Arunava; Chikoti, Leela; Singh, Vivek Vikram; Chandran, Bala

    2015-01-01

    The IL-1β and type I interferon-β (IFN-β) molecules are important inflammatory cytokines elicited by the eukaryotic host as innate immune responses against invading pathogens and danger signals. Recently, a predominantly nuclear gamma-interferon-inducible protein 16 (IFI16) involved in transcriptional regulation has emerged as an innate DNA sensor which induced IL-1β and IFN-β production through inflammasome and STING activation, respectively. Herpesvirus (KSHV, EBV, and HSV-1) episomal dsDNA genome recognition by IFI16 leads to IFI16-ASC-procaspase-1 inflammasome association, cytoplasmic translocation and IL-1β production. Independent of ASC, HSV-1 genome recognition results in IFI16 interaction with STING in the cytoplasm to induce interferon-β production. However, the mechanisms of IFI16-inflammasome formation, cytoplasmic redistribution and STING activation are not known. Our studies here demonstrate that recognition of herpesvirus genomes in the nucleus by IFI16 leads into its interaction with histone acetyltransferase p300 and IFI16 acetylation resulting in IFI16-ASC interaction, inflammasome assembly, increased interaction with Ran-GTPase, cytoplasmic redistribution, caspase-1 activation, IL-1β production, and interaction with STING which results in IRF-3 phosphorylation, nuclear pIRF-3 localization and interferon-β production. ASC and STING knockdowns did not affect IFI16 acetylation indicating that this modification is upstream of inflammasome-assembly and STING-activation. Vaccinia virus replicating in the cytoplasm did not induce nuclear IFI16 acetylation and cytoplasmic translocation. IFI16 physically associates with KSHV and HSV-1 genomes as revealed by proximity ligation microscopy and chromatin-immunoprecipitation studies which is not hampered by the inhibition of acetylation, thus suggesting that acetylation of IFI16 is not required for its innate sensing of nuclear viral genomes. Collectively, these studies identify the increased nuclear

  2. Rapamycin ameliorates CCl4-induced liver fibrosis in mice through reciprocal regulation of the Th17/Treg cell balance.

    PubMed

    Gu, Lei; Deng, Wen-Sheng; Sun, Xiao-Fei; Zhou, Hong; Xu, Qing

    2016-08-01

    Previous investigations have suggested that the activation of Th17 cells and/or deficiency of regulatory T cells (Tregs) are involved in the pathogenesis of liver fibrosis. The aim of the present study was to investigate the effect of rapamycin on immune responses in a carbon tetrachloride (CCl4)-induced murine liver fibrosis model. Liver fibrosis was induced by intraperitoneal administration with CCl4. Following injection of CCl4, the mice were treated intraperitoneally with rapamycin (1.25 mg/kg/day) for 8 weeks. Hematoxylin and eosin staining and Masson's trichrome staining were used for histological examination. The protein levels of forkhead/winged helix transcription factor P3, retinoic-acid-related orphan receptor (ROR)‑γt in liver tissue were determined by western blotting, the frequency of Th17 and Treg cells in the liver was evaluated by flow cytometry, and a suppression assay was measured by incorporating [3H]‑thymidine. In addition, to explore the effect of Tregs expanded with rapamycin on hepatic stellate cells (HSC), HSCs were co‑cultured with Tregs from rapamycin or phosphate‑buffered saline‑treated mice. It was found that rapamycin treatment led to a significant reduction in the number of Th17 cells and in the expression levels of ROR‑γt in the liver tissues. Simultaneously, the results of the present study showed a significant increase in the frequency of Tregs and a marked enhancement in the expression of forkhead/winged helix transcription factor P3 in the rapamycin‑treated mice. Furthermore, the Tregs in rapamycin‑treated mice had significantly higher suppressive effects, compared with the cells from mice treated with phospphate‑buffered saline. Consequently, rapamycin treatment prevented the development of CCl4-induced hepatic fibrosis, which was shown by its histological appearances. These results suggested that the immunosuppressive effect of rapamycin on liver fibrosis was associated with the suppression of hepatic

  3. Rapamycin ameliorates CCl4-induced liver fibrosis in mice through reciprocal regulation of the Th17/Treg cell balance

    PubMed Central

    Gu, Lei; Deng, Wen-Sheng; Sun, Xiao-Fei; Zhou, Hong; Xu, Qing

    2016-01-01

    Previous investigations have suggested that the activation of Th17 cells and/or deficiency of regulatory T cells (Tregs) are involved in the pathogenesis of liver fibrosis. The aim of the present study was to investigate the effect of rapamycin on immune responses in a carbon tetrachloride (CCl4)-induced murine liver fibrosis model. Liver fibrosis was induced by intraperitoneal administration with CCl4. Following injection of CCl4, the mice were treated intraperitoneally with rapamycin (1.25 mg/kg/day) for 8 weeks. Hematoxylin and eosin staining and Masson's trichrome staining were used for histological examination. The protein levels of forkhead/winged helix transcription factor P3, retinoic-acid-related orphan receptor (ROR)-γt in liver tissue were determined by western blotting, the frequency of Th17 and Treg cells in the liver was evaluated by flow cytometry, and a suppression assay was measured by incorporating [3H]-thymidine. In addition, to explore the effect of Tregs expanded with rapamycin on hepatic stellate cells (HSC), HSCs were co-cultured with Tregs from rapamycin or phosphate-buffered saline-treated mice. It was found that rapamycin treatment led to a significant reduction in the number of Th17 cells and in the expression levels of ROR-γt in the liver tissues. Simultaneously, the results of the present study showed a significant increase in the frequency of Tregs and a marked enhancement in the expression of forkhead/winged helix transcription factor P3 in the rapamycin-treated mice. Furthermore, the Tregs in rapamycin-treated mice had significantly higher suppressive effects, compared with the cells from mice treated with phospphate-buffered saline. Consequently, rapamycin treatment prevented the development of CCl4-induced hepatic fibrosis, which was shown by its histological appearances. These results suggested that the immunosuppressive effect of rapamycin on liver fibrosis was associated with the suppression of hepatic fibrogenesis and

  4. Borrelia burgdorferi outer membrane protein A induces nuclear translocation of nuclear factor-kappa B and inflammatory activation in human endothelial cells.

    PubMed

    Wooten, R M; Modur, V R; McIntyre, T M; Weis, J J

    1996-11-15

    Lyme disease is caused by infection with Borrelia burgdorferi, and is characterized by bacterial persistence and inflammation in a number of host tissues. B. burgdorferi outer surface lipoproteins possess cytokine stimulatory properties that may be responsible for localized inflammation. B. burgdorferi presence is correlated with severity of disease, and the pathology of many tissues, particularly the arthritic joint, is consistent with localized cytokine production. Spirochete invasion of tissues requires interaction with and penetration of vascular endothelium, suggesting endothelial cells may participate in the inflammation of Lyme disease. In this study, outer surface protein A (OspA), a model B. burgdorferi lipoprotein, was found to be a potent stimulant of nuclear factor-kappa B (NF-kappa B) nuclear translocation in human endothelial cells, resulting in nuclear levels similar to those seen in response to known inflammatory mediators. Only the lipid-modified OspA had activity, and activity was not due to contamination with LPS. Nuclear NF-kappa B was detectable within 15 min, suggesting that OspA directly mediates NF-kappa B nuclear translocation. OspA also rapidly up-regulated endothelial cell production of several proteins whose transcription is dependent on NF-kappa B: the cytokine IL-6; the chemokine IL-8; and the adhesion molecules E-selectin, VCAM-1, and ICAM-1. The adhesion molecules were functional, as demonstrated by enhanced binding of neutrophils to OspA-stimulated endothelial monolayers. These data suggest that OspA may initiate synthesis of many proteins essential for localized inflammation via the direct activation of NF-kappa B-dependent transcription. These observations suggest that the interaction of B. burgdorferi lipoproteins with the endothelium may directly induce the inflammation responsible for the symptoms of Lyme disease. PMID:8906837

  5. Nuclear translocation of annexin 1 following oxygen-glucose deprivation-reperfusion induces apoptosis by regulating Bid expression via p53 binding.

    PubMed

    Li, Xing; Zhao, Yin; Xia, Qian; Zheng, Lu; Liu, Lu; Zhao, Baoming; Shi, Jing

    2016-01-01

    Previous data have suggested that the nuclear translocation of annexin 1 (ANXA1) is involved in neuronal apoptosis after ischemic stroke. As the mechanism and function of ANXA1 nuclear migration remain unclear, it is important to clarify how ANXA1 performs its role as an apoptosis 'regulator' in the nucleus. Here we report that importazole (IPZ), an importin β (Impβ)-specific inhibitor, decreased ANXA1 nuclear accumulation and reduced the rate of neuronal death induced by nuclear ANXA1 migration after oxygen-glucose deprivation-reoxygenation (OGD/R). Notably, ANXA1 interacted with the Bid (BH3-interacting-domain death agonist) promoter directly; however; this interaction could be partially blocked by the p53 inhibitor pifithrin-α (PFT-α). Accordingly, ANXA1 was shown to interact with p53 in the nucleus and this interaction was enhanced following OGD/R. A luciferase reporter assay revealed that ANXA1 was involved in the regulation of p53-mediated transcriptional activation after OGD/R. Consistent with this finding, the nuclear translocation of ANXA1 after OGD/R upregulated the expression of Bid, which was impeded by IPZ, ANXA1 shRNA, or PFT-α. Finally, cell-survival testing demonstrated that silencing ANXA1 could improve the rate of cell survival and decrease the expression of both cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase. These data suggested that Impβ-dependent nuclear ANXA1 migration participates in the OGD/R-dependent induction of neuronal apoptosis. ANXA1 interacts with p53 and promotes p53 transcriptional activity, which in turn regulates Bid expression. Silencing ANXA1 decreases the expression of Bid and suppresses caspase-3 pathway activation, thus improving cell survival after OGD/R. This study provides a novel mechanism whereby ANXA1 regulates apoptosis, suggesting the potential for a previously unidentified treatment strategy in minimizing apoptosis after OGD/R. PMID:27584794

  6. Bacterial translocation and in vivo assessment of intestinal barrier permeability in rainbow trout (Oncorhynchus mykiss) with and without soyabean meal-induced inflammation.

    PubMed

    Mosberian-Tanha, Peyman; Øverland, Margareth; Landsverk, Thor; Reveco, Felipe E; Schrama, Johan W; Roem, Andries J; Agger, Jane W; Mydland, Liv T

    2016-01-01

    The primary aim of this experiment was to evaluate the intestinal barrier permeability in vivo in rainbow trout (Oncorhynchus mykiss) fed increasing levels of soyabean meal (SBM). The relationship between SBM-induced enteritis (SBMIE) and the permeability markers was also investigated. Our results showed that the mean score of morphological parameters was significantly higher as a result of 37·5 % SBM inclusion in the diet, while the scores of fish fed 25 % SBM or lower were not different from those of the fish meal-fed controls (P < 0·05). SBMIE was found in the distal intestine (DI) in 18 % of the fish (eleven of sixty): ten in the 37·5 % SBM-fed group and one in the 25 % SBM-fed group. Sugar markers in plasma showed large variation among individuals probably due to variation in feed intake. We found, however, a significant linear increase in the level of plasma d-lactate with increasing SBM inclusion level (P < 0·0001). Plasma concentration of endotoxin was not significantly different in groups with or without SBMIE. Some individual fish showed high values of endotoxin in blood, but the same individuals did not show any bacterial translocation. Plasma bacterial DNA was detected in 28 % of the fish with SBMIE, and 8 % of non-SBMIE fish (P = 0·07). Plasma concentration of d-lactate was significantly higher in fish with SBMIE (P < 0·0001). To conclude, SBMIE in the DI of rainbow trout was associated with an increase in bacterial translocation and plasma d-lactate concentration, suggesting that these permeability markers can be used to evaluate intestinal permeability in vivo. PMID:27547389

  7. Leptin-induced cardiomyocyte hypertrophy reveals both calcium-dependent and calcium-independent/RhoA-dependent calcineurin activation and NFAT nuclear translocation.

    PubMed

    Rajapurohitam, Venkatesh; Izaddoustdar, Farzad; Martinez-Abundis, Eduardo; Karmazyn, Morris

    2012-12-01

    Leptin, a product of the obesity gene, has been shown to produce cardiac hypertrophy. Although leptin's mechanism of action is poorly understood activation of the RhoA/ROCK pathway has been proposed as a contributing mechanism. The Ca(2+)-dependent phosphatase calcineurin plays a critical role in the hypertrophic program although it is not known whether leptin can activate this signaling pathway or whether there is a relationship between RhoA activation and calcineurin. Accordingly, we determined the effect of leptin on calcineurin activation and assessed the possible role of RhoA. Experiments were performed using cultured neonatal rat ventricular myocytes exposed to 50 ng/ml leptin for 24h which resulted in a robust hypertrophic response. Moreover, leptin significantly increased intracellular Ca(2+) and Na(+) concentrations which was associated with significantly reduced activity of the 3Na(+)-2K(+)ATPase. The hypertrophic response to leptin were completely abrogated by both C3 exoenzyme (C3), a RhoA inhibitor as well as the reverse mode 3Na(+)-1Ca(2+) exchange inhibitor KB-R7943 ((2-[2-[4-(4-nitrobenzyloxy)phenyl] ethyl]isothiourea methanesulfonate), however only the effect of the latter was associated with attenuation of intracellular Ca(2+) concentrations whereas Ca(2+) concentrations were unaffected by C3. Similarly, C3 and KB-R7943 significantly attenuated early leptin-induced increase in calcineurin activity as well as the increase in nuclear translocation of the transcriptional factor nuclear factor of activated T cells. The hypertrophic response to leptin was also associated with increased p38 and ERK1/2 MAPK phosphorylation and increased p38, but not ERK1/2, translocation into nuclei. Both p38 responses as well as hypertrophy were abrogated by KB-R7943 as well as the calcineurin inhibitor FK-506 although ERK1/2 phosphorylation was unaffected. Our study therefore demonstrates a critical role for the calcineurin pathway in mediating leptin-induced

  8. The Gβγ-Src signaling pathway regulates TNF-induced necroptosis via control of necrosome translocation

    PubMed Central

    Li, Lisheng; Chen, Wanze; Liang, Yaoji; Ma, Huabin; Li, Wenjuan; Zhou, Zhenru; Li, Jie; Ding, Yan; Ren, Junming; Lin, Juan; Han, Felicia; Wu, Jianfeng; Han, Jiahuai

    2014-01-01

    Formation of multi-component signaling complex necrosomes is essential for tumor necrosis factor α (TNF)-induced programmed necrosis (also called necroptosis). However, the mechanisms of necroptosis are still largely unknown. We isolated a TNF-resistant L929 mutant cell line generated by retrovirus insertion and identified that disruption of the guanine nucleotide-binding protein γ 10 (Gγ10) gene is responsible for this phenotype. We further show that Gγ10 is involved in TNF-induced necroptosis and Gβ2 is the partner of Gγ10. Src is the downstream effector of Gβ2γ10 in TNF-induced necroptosis because TNF-induced Src activation was impaired upon Gγ10 knockdown. Gγ10 does not affect TNF-induced activation of NF-κB and MAPKs and the formation of necrosomes, but is required for trafficking of necrosomes to their potential functioning site, an unidentified subcellular organelle that can be fractionated into heterotypic membrane fractions. The TNF-induced Gβγ-Src signaling pathway is independent of RIP1/RIP3 kinase activity and necrosome formation, but is required for the necrosome to function. PMID:24513853

  9. Bacterial translocation in experimental uremia.

    PubMed

    de Almeida Duarte, Joãn Bosco; de Aguilar-Nascimento, José Eduardo; Nascimento, Mariana; Nochi, Rubens Jardim

    2004-08-01

    The aim of this study was to investigate whether or not experimental uremia would induce bacterial translocation. Forty male Wistar rats were randomized into two groups: uremic (n = 20) and control (n = 20). Under anesthesia, the upper and lower left renal poles and the marginal lateral parenchyma were excised in uremic group. Seven days later, in a second operation, the liver, spleen and the mesenteric lymph nodes (MLN) were excised and cultured. Blood samples were sent for biochemical analysis (BUN, creatinine, sodium and potassium) and cultured. Specimens of the jejunum (1 cm below the Treitz angle) and ileum (1 cm above the ileocecal valve) were collected and sent for histological examination and scored for the degree of inflammation of the mucosa using a classification proposed by Chiu et al. in 1970. Uremic rats presented higher BUN, creatinine and potassium than controls. Bacterial translocation was more frequent in uremic than in control animals (8/20 (40%) vs. 1/20 (5%); p = 0.02). Translocation in uremic rats was observed mainly at the MLN (all eight cases). Both at the jejunum (uremic = 3 [0-5] vs. control = 2 [0-4]; p = 0.04) and the ileum (uremic - 2 [0-5] vs. control = 0 [0-3]; p = 0.01), inflammation score was higher in uremic rats than in controls. The intestinal mucosa barrier is impaired and bacterial translocation occurs in experimental uremia. PMID:15497213

  10. Evidence for microRNA-31 dependent Bim-Bax interaction preceding mitochondrial Bax translocation during radiation-induced apoptosis.

    PubMed

    Kumar, Ashish; Ghosh, Soma; Chandna, Sudhir

    2015-01-01

    Downregulation of microRNA-31 has been linked with enhanced stress resistance, while its overexpression leads to cell death. In this study, we found mediatory role of microRNA-31 in γ-radiation-induced apoptosis in a model insect cell line Sf9 carrying well-conserved apoptotic machinery. Mature microRNA-31 is perfectly conserved amongst insects; hence we used biotinylated probes designed from Bombyx mori sequence for its successful detection in Sf9 cells. Target identification using Bombyx mori 3'UTRs predicted miR-31's potential role in Lepidopteran apoptosis, which prompted us to investigate alterations in its expression during radiation-induced cell death. We found significant overexpression of Sf-miR-31 following lethal dose (1,000Gy-3,000Gy) irradiation. Its mediatory role was finally confirmed as antisense-microRNA-31 could successfully inhibit radiation-induced cytochrome-c release, caspase-3 activation and apoptosis. While Bax/Bcl-2 expression remained unchanged, lethal radiation doses induced Bim overexpression and direct Bim-Bax interaction (co-immunoprecipitation) which is not yet unequivocally demonstrated during apoptosis. Quite important, these events were found to be dependent on radiation-induced miR-31 overexpression, as antisense-miR-31 inhibited both the responses and resulted in significant inhibition of cell death. Pro-apoptotic role of miR-31 was further confirmed when miR-31 mimic induced apoptosis involving similar Bim/Bax alterations. Therefore, our study reveals an important mediatory role of miR-31 in radiation-induced cell death. PMID:26514984

  11. Direct reciprocity on graphs

    PubMed Central

    Ohtsuki, Hisashi; Nowak, Martin A.

    2008-01-01

    Direct reciprocity is a mechanism for the evolution of cooperation based on the idea of repeated encounters between the same two individuals. Here we examine direct reciprocity in structured populations, where individuals occupy the vertices of a graph. The edges denote who interacts with whom. The graph represents spatial structure or a social network. For birth-death or pairwise comparison updating, we find that evolutionary stability of direct reciprocity is more restrictive on a graph than in a well-mixed population, but the condition for reciprocators to be advantageous is less restrictive on a graph. For death-birth and imitation updating, in contrast, both conditions are easier to fulfill on a graph. Moreover, for all four update mechanisms, reciprocators can dominate defectors on a graph, which is never possible in a well-mixed population. We also study the effect of an error rate, which increases with the number of links per individual; interacting with more people simultaneously enhances the probability of making mistakes. We provide analytic derivations for all results. PMID:17466339

  12. Stress and translocation: alterations in the stress physiology of translocated birds.

    PubMed

    Dickens, Molly J; Delehanty, David J; Romero, L Michael

    2009-06-01

    Translocation and reintroduction have become major conservation actions in attempts to create self-sustaining wild populations of threatened species. However, avian translocations have a high failure rate and causes for failure are poorly understood. While 'stress' is often cited as an important factor in translocation failure, empirical evidence of physiological stress is lacking. Here we show that experimental translocation leads to changes in the physiological stress response in chukar partridge, Alectoris chukar. We found that capture alone significantly decreased the acute glucocorticoid (corticosterone, CORT) response, but adding exposure to captivity and transport further altered the stress response axis (the hypothalamic-pituitary-adrenal axis) as evident from a decreased sensitivity of the negative feedback system. Animals that were exposed to the entire translocation procedure, in addition to the reduced acute stress response and disrupted negative feedback, had significantly lower baseline CORT concentrations and significantly reduced body weight. These data indicate that translocation alters stress physiology and that chronic stress is potentially a major factor in translocation failure. Under current practices, the restoration of threatened species through translocation may unwittingly depend on the success of chronically stressed individuals. This conclusion emphasizes the need for understanding and alleviating translocation-induced chronic stress in order to use most effectively this important conservation tool. PMID:19324794

  13. Stress and translocation: alterations in the stress physiology of translocated birds

    PubMed Central

    Dickens, Molly J.; Delehanty, David J.; Romero, L. Michael

    2009-01-01

    Translocation and reintroduction have become major conservation actions in attempts to create self-sustaining wild populations of threatened species. However, avian translocations have a high failure rate and causes for failure are poorly understood. While ‘stress’ is often cited as an important factor in translocation failure, empirical evidence of physiological stress is lacking. Here we show that experimental translocation leads to changes in the physiological stress response in chukar partridge, Alectoris chukar. We found that capture alone significantly decreased the acute glucocorticoid (corticosterone, CORT) response, but adding exposure to captivity and transport further altered the stress response axis (the hypothalamic–pituitary–adrenal axis) as evident from a decreased sensitivity of the negative feedback system. Animals that were exposed to the entire translocation procedure, in addition to the reduced acute stress response and disrupted negative feedback, had significantly lower baseline CORT concentrations and significantly reduced body weight. These data indicate that translocation alters stress physiology and that chronic stress is potentially a major factor in translocation failure. Under current practices, the restoration of threatened species through translocation may unwittingly depend on the success of chronically stressed individuals. This conclusion emphasizes the need for understanding and alleviating translocation-induced chronic stress in order to use most effectively this important conservation tool. PMID:19324794

  14. Stress-induced nuclear translocation of CDK5 suppresses neuronal death by downregulating ERK activation via VRK3 phosphorylation.

    PubMed

    Song, Haengjin; Kim, Wanil; Choi, Jung-Hyun; Kim, Sung-Hoon; Lee, Dohyun; Park, Choon-Ho; Kim, Sangjune; Kim, Do-Yeon; Kim, Kyong-Tai

    2016-01-01

    Although extracellular signal-related kinase 1/2 (ERK 1/2) activity is generally associated with cell survival, prolonged ERK activation induced by oxidative stress also mediates neuronal cell death. Here we report that oxidative stress-induced cyclin-dependent kinase 5 (CDK5) activation stimulates neuroprotective signaling via phosphorylation of vaccinia-related kinase 3 (VRK3) at Ser 108. The binding of vaccinia H1-related (VHR) phosphatase to phosphorylated VRK3 increased its affinity for phospho-ERK and subsequently downregulated ERK activation. Overexpression of VRK3 protected human neuroblastoma SH-SY5Y cells against hydrogen peroxide (H2O2)-induced apoptosis. However the CDK5 was unable to phosphorylate mutant VRK3, and thus the mutant forms of VRK3 could not attenuate apoptotic process. Suppression of CDK5 activity results in increase of ERK activation and elevation of proapoptotic protein Bak expression in mouse cortical neurons. Results from VRK3-deficient neurons were further confirmed the role of VRK3 phosphorylation in H2O2-evoked ERK regulation. Importantly, we showed an association between phospho-VRK3 levels and the progression of human Alzheimer's disease (AD) and Parkinson's disease (PD). Together our work reveals endogenous protective mechanism against oxidative stress-induced neuronal cell death and suggest VRK3 as a potential therapeutic target in neurodegenerative diseases. PMID:27346674

  15. Stress-induced nuclear translocation of CDK5 suppresses neuronal death by downregulating ERK activation via VRK3 phosphorylation

    PubMed Central

    Song, Haengjin; Kim, Wanil; Choi, Jung-Hyun; Kim, Sung-Hoon; Lee, Dohyun; Park, Choon-Ho; Kim, Sangjune; Kim, Do-Yeon; Kim, Kyong-Tai

    2016-01-01

    Although extracellular signal-related kinase 1/2 (ERK 1/2) activity is generally associated with cell survival, prolonged ERK activation induced by oxidative stress also mediates neuronal cell death. Here we report that oxidative stress-induced cyclin-dependent kinase 5 (CDK5) activation stimulates neuroprotective signaling via phosphorylation of vaccinia-related kinase 3 (VRK3) at Ser 108. The binding of vaccinia H1-related (VHR) phosphatase to phosphorylated VRK3 increased its affinity for phospho-ERK and subsequently downregulated ERK activation. Overexpression of VRK3 protected human neuroblastoma SH-SY5Y cells against hydrogen peroxide (H2O2)-induced apoptosis. However the CDK5 was unable to phosphorylate mutant VRK3, and thus the mutant forms of VRK3 could not attenuate apoptotic process. Suppression of CDK5 activity results in increase of ERK activation and elevation of proapoptotic protein Bak expression in mouse cortical neurons. Results from VRK3-deficient neurons were further confirmed the role of VRK3 phosphorylation in H2O2-evoked ERK regulation. Importantly, we showed an association between phospho-VRK3 levels and the progression of human Alzheimer’s disease (AD) and Parkinson’s disease (PD). Together our work reveals endogenous protective mechanism against oxidative stress-induced neuronal cell death and suggest VRK3 as a potential therapeutic target in neurodegenerative diseases. PMID:27346674

  16. What Drives the Translocation of Proteins?

    NASA Astrophysics Data System (ADS)

    Simon, Sanford M.; Peskin, Charles S.; Oster, George F.

    1992-05-01

    We propose that protein translocation across membranes is driven by biased random thermal motion. This "Brownian ratchet" mechanism depends on chemical asymmetries between the cis and trans sides of the membrane. Several mechanisms could contribute to rectifying the thermal motion of the protein, such as binding and dissociation of chaperonins to the translocating chain, chain coiling induced by pH and/or ionic gradients, glycosylation, and disulfide bond formation. This helps explain the robustness and promiscuity of these transport systems.

  17. AMP-activated protein kinase is required for exercise-induced peroxisome proliferator-activated receptor γ co-activator 1α translocation to subsarcolemmal mitochondria in skeletal muscle

    PubMed Central

    Smith, Brennan K; Mukai, Kazutaka; Lally, James S; Maher, Amy C; Gurd, Brendon J; Heigenhauser, George J F; Spriet, Lawrence L; Holloway, Graham P

    2013-01-01

    In skeletal muscle, mitochondria exist as two subcellular populations known as subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria. SS mitochondria preferentially respond to exercise training, suggesting divergent transcriptional control of the mitochondrial genomes. The transcriptional co-activator peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) and mitochondrial transcription factor A (Tfam) have been implicated in the direct regulation of the mitochondrial genome in mice, although SS and IMF differences may exist, and the potential signalling events regulating the mitochondrial content of these proteins have not been elucidated. Therefore, we examined the potential for PGC-1α and Tfam to translocate to SS and IMF mitochondria in human subjects, and performed experiments in rodents to identify signalling mechanisms regulating these translocation events. Acute exercise in humans and rats increased PGC-1α content in SS but not IMF mitochondria. Acute exposure to 5-aminoimidazole-4-carboxamide-1-β-ribofuranoside in rats recapitulated the exercise effect of increased PGC-1α protein within SS mitochondria only, suggesting that AMP-activated protein kinase (AMPK) signalling is involved. In addition, rendering AMPK inactive (AMPK kinase dead mice) prevented exercise-induced PGC-1α translocation to SS mitochondria, further suggesting that AMPK plays an integral role in these translocation events. In contrast to the conserved PGC-1α translocation to SS mitochondria across species (humans, rats and mice), acute exercise only increased mitochondrial Tfam in rats. Nevertheless, in rat resting muscle PGC-1α and Tfam co-immunoprecipate with α-tubulin, suggesting a common cytosolic localization. These data suggest that exercise causes translocation of PGC-1α preferentially to SS mitochondria in an AMPK-dependent manner. PMID:23297307

  18. Leishmania donovani amastigotes impair gamma interferon-induced STAT1alpha nuclear translocation by blocking the interaction between STAT1alpha and importin-alpha5.

    PubMed

    Matte, Christine; Descoteaux, Albert

    2010-09-01

    The protozoan parasite Leishmania donovani, the etiological agent of visceral leishmaniasis, is renowned for its capacity to sabotage macrophage functions and signaling pathways stimulated by activators such as gamma interferon (IFN-gamma). Our knowledge of the strategies utilized by L. donovani to impair macrophage responsiveness to IFN-gamma remains fragmentary. In the present study, we investigated the impact of an infection by the amastigote stage of L. donovani on IFN-gamma responses and signaling via the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway in mouse bone marrow-derived macrophages. The levels of IFN-gamma-induced expression of major histocompatibility complex class II and inducible nitric oxide synthase (iNOS) were strongly reduced in L. donovani amastigote-infected macrophages. As the expression of those genes is mediated by the transcription factors STAT1alpha and IFN regulatory factor 1 (IRF-1), we investigated their activation in amastigote-infected macrophages treated with IFN-gamma. We found that whereas STAT1alpha protein levels and the levels of phosphorylation on Tyr701 and Ser727 were normal, IRF-1 expression was inhibited in infected macrophages. This inhibition of IRF-1 expression correlated with a defective nuclear translocation of STAT1alpha, and further analyses revealed that the IFN-gamma-induced STAT1alpha association with the nuclear transport adaptor importin-alpha5 was compromised in L. donovani amastigote-infected macrophages. Taken together, our results provide evidence for a novel mechanism used by L. donovani amastigotes to interfere with IFN-gamma-activated macrophage functions and provide a better understanding of the strategies deployed by this parasite to ensure its intracellular survival. PMID:20566692

  19. Paeonol Inhibits Lipopolysaccharide-Induced HMGB1 Translocation from the Nucleus to the Cytoplasm in RAW264.7 Cells.

    PubMed

    Lei, Hang; Wen, Quan; Li, Hui; Du, Shaohui; Wu, Jing-Jing; Chen, Jing; Huang, Haiyuan; Chen, Dongfeng; Li, Yiwei; Zhang, Saixia; Zhou, Jianhong; Deng, Rudong; Yang, Qinglin

    2016-06-01

    Transport of high-mobility group box 1 (HMGB1), a highly conserved non-histone DNA-binding protein, from the nucleus to the cytoplasm is induced by lipopolysaccharide (LPS). Secretion of HMGB1 appears to be a key lethal factor in sepsis, so it is considered to be a therapeutic target. Previous studies have suggested that paeonol (2'-hydroxy-4'-methoxyacetophenone), an active compound of Paeonia lactiflora Pallas, exerts anti-inflammatory effects. However, the effect of paeonol on HMGB1 is unknown. Here, we investigated the effect of paeonol on the expression, location, and secretion of HMGB1 in LPS-induced murine RAW264.7 cells. ELISA revealed HMGB1 supernatant concentrations of 615 ± 30 ng/mL in the LPS group and 600 ± 45, 560 ± 42, and 452 ± 38 ng/mL in cells treated with 0.2, 0.6, or 1 mM paeonol, respectively, suggesting that paeonol inhibits HMGB1 secretion induced by LPS. Immunohistochemistry and Western blotting revealed that paeonol decreased cytoplasmic HMGB1 and increased nuclear HMGB1. Chromatin immunoprecipitation microarrays suggested that HMGB1 relocation to the nucleus induced by paeonol might depress the action of Janus kinase/signal transducers and activators of transcription, chemokine, and mitogen-activated protein kinase pro-inflammatory signaling pathways. Paeonol was also found to inhibit tumor necrosis factor-α promoter activity in a dose-dependent manner. These results indicate that paeonol has the potential to be developed as a novel HMGB1-targeting therapeutic drug for the treatment of inflammatory diseases. PMID:27106477

  20. Geometry of a complex formed by double strand break repair proteins at a single DNA end: recruitment of DNA-PKcs induces inward translocation of Ku protein.

    PubMed

    Yoo, S; Dynan, W S

    1999-12-15

    Ku protein and the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) are essential components of the double-strand break repair machinery in higher eukaryotic cells. Ku protein binds to broken DNA ends and recruits DNA-PKcs to form an enzymatically active complex. To characterize the arrangement of proteins in this complex, we developed a set of photocross-linking probes, each with a single free end. We have previously used this approach to characterize the contacts in an initial Ku-DNA complex, and we have now applied the same technology to define the events that occur when Ku recruits DNA-PKcs. The new probes allow the binding of one molecule of Ku protein and one molecule of DNA-PKcs in a defined position and orientation. Photocross-linking reveals that DNA-PKcs makes direct contact with the DNA termini, occupying an approximately 10 bp region proximal to the free end. Characterization of the Ku protein cross-linking pattern in the presence and absence of DNA-PKcs suggests that Ku binds to form an initial complex at the DNA ends, and that recruitment of DNA-PKcs induces an inward translocation of this Ku molecule by about one helical turn. The presence of ATP had no effect on protein-DNA contacts, suggesting that neither DNA-PK-mediated phosphorylation nor a putative Ku helicase activity plays a role in modulating protein conformation under the conditions tested. PMID:10572166

  1. Reversible cAMP-induced translocation of cytoskeleton-associated 300- to 350-kDa proteins from nucleus to cytoplasm

    SciTech Connect

    Nakayama, Tokiko; Nishizawa, Kimiko; Sato, Chicako )

    1988-08-01

    The authors previously reported that treatment of SV-3Y1 cells in an exponential growth state with db-cAMP plus theophylline induced reversible disappearance of nuclear dots stained by monoclonal anti-microtubule-associated protein (MAP)-1 antibody. In the present study, the authors examined the relation between the intracellular localization and phosphorylation of 300- to 350-kDa proteins that are intracellular antigens for our anti-Map-1 and -2 antibodies. Treatment with db-cAMP plus theophylline was found to result in a reversible decrease in immunofluorescent staining of the nucleus with polyclonal MAP-1 or -2 antibody, and a reversible increase in that of the cytoplasm. Simultaneous treatment with colchicine, colcemid, putrescine, or {alpha}-naphthyl phosphate in the presence of db-cAMP plus theophylline almost prevented this effect of db-cAMP plus theophylline. They examined the cytoplasmic and nuclear fractions by immunoperoxidase staining, immunoprecipitation, and {sup 125}I-protein A with anti-MAP-1 and -2 antibodies. The present research indicated that treatment with db-cAMP plus theophylline resulted in the reversible translocation of 300- to 350-kDa proteins from the nucleus to the cytoplasm accompanied by the dephosphorylation of these proteins.

  2. Disruption of the three cytoskeletal networks in mammalian cells does not affect transcription, translation, or protein translocation changes induced by heat shock.

    PubMed Central

    Welch, W J; Feramisco, J R

    1985-01-01

    Mammalian cells show a complex series of transcriptional and translational switching events in response to heat shock treatment which ultimately lead to the production and accumulation of a small number of proteins, the so-called heat shock (or stress) proteins. We investigated the heat shock response in both qualitative and quantitative ways in cells that were pretreated with drugs that specifically disrupt one or more of the three major cytoskeletal networks. (These drugs alone, cytochalasin E and colcemid, do not result in induction of the heat shock response.) Our results indicated that disruption of the actin microfilaments, the vimentin-containing intermediate filaments, or the microtubules in living cells does not hinder the ability of the cell to undergo an apparently normal heat shock response. Even when all three networks were simultaneously disrupted (resulting in a loose, baglike appearance of the cells), the cells still underwent a complete heat shock response as assayed by the appearance of the heat shock proteins. In addition, the major induced 72-kilodalton heat shock protein was efficiently translocated from the cytoplasm into its proper location in the nucleus and nucleolus irrespective of the condition of the three cytoskeletal elements. Images PMID:4040602

  3. Inhibition of NF-κB translocation by curcumin analogs induces G0/G1 arrest and downregulates thymidylate synthase in colorectal cancer.

    PubMed

    Rajitha, Balney; Belalcazar, Astrid; Nagaraju, Ganji Purnachandra; Shaib, Walid L; Snyder, James P; Shoji, Mamoru; Pattnaik, Subasini; Alam, Afroz; El-Rayes, Bassel F

    2016-04-10

    Cell cycle progression and DNA synthesis are essential steps in cancer cell growth and resistance. Thymidylate synthase (TS) is a therapeutic target for 5FU. Curcumin is a potent inhibitor of NF-κB. EF31 and UBS109 are potent synthetic analogues of curcumin. We tested the hypothesis that inhibition of NF-κB translocation by curcumin and its analogs EF31 and UBS109 can inhibit cell cycle progression and downregulate TS levels in colorectal cancer (CRC) cell lines. Two CRC cell lines (HCT116 and HT-29) were either untreated (control) or treated with IC50 concentrations of curcumin, EF31 UBS109 led to G0/G1 cell cycle arrest. Treatment with curcumin, EF31 or UBS109 inhibited NF-κB, downregulated survival pathways and inhibited cell cycle progression. Arrest in the G0/G1 phase was associated with downregulation of the transcription factor E2F-1 and its target gene TS. NF-κB over-expression induced E2F-1 and TS protein and mRNA levels in both cell lines. EF31 and UBS109 treatment significantly decreased tumor growth in compared to untreated tumors. EF31 and UBS109 are promising agents for the prevention and treatment of CRC. PMID:26850372

  4. SIV-induced Translocation of Bacterial Products in the Liver Mobilizes Myeloid Dendritic and Natural Killer Cells Associated With Liver Damage.

    PubMed

    Evans, Tristan I; Li, Haiying; Schafer, Jamie L; Klatt, Nichole R; Hao, Xing-Pei; Traslavina, Ryan P; Estes, Jacob D; Brenchley, Jason M; Reeves, R Keith

    2016-02-01

    Disruption of the mucosal epithelium during lentivirus infections permits translocation of microbial products into circulation, causing immune activation and driving disease. Although the liver directly filters blood from the intestine and is the first line of defense against gut-derived antigens, the effects of microbial products on the liver are unclear. In livers of normal macaques, minute levels of bacterial products were detectable, but increased 20-fold in simian immunodeficiency virus (SIV)-infected animals. Increased microbial products in the liver induced production of the chemoattractant CXCL16 by myeloid dendritic cells (mDCs), causing subsequent recruitment of hypercytotoxic natural killer (NK) cells expressing the CXCL16 receptor, CXCR6. Microbial accumulation, mDC activation, and cytotoxic NK cell frequencies were significantly correlated with markers of liver damage, and SIV-infected animals consistently had evidence of hepatitis and fibrosis. Collectively, these data indicate that SIV-associated accumulation of microbial products in the liver initiates a cascade of innate immune activation, resulting in liver damage. PMID:26238685

  5. Physiology in conservation translocations

    PubMed Central

    Tarszisz, Esther; Dickman, Christopher R.; Munn, Adam J.

    2014-01-01

    Conservation translocations aim to restore species to their indigenous ranges, protect populations from threats and/or reinstate ecosystem functions. They are particularly important for the conservation and management of rare and threatened species. Despite tremendous efforts and advancement in recent years, animal conservation translocations generally have variable success, and the reasons for this are often uncertain. We suggest that when little is known about the physiology and wellbeing of individuals either before or after release, it will be difficult to determine their likelihood of survival, and this could limit advancements in the science of translocations for conservation. In this regard, we argue that physiology offers novel approaches that could substantially improve translocations and associated practices. As a discipline, it is apparent that physiology may be undervalued, perhaps because of the invasive nature of some physiological measurement techniques (e.g. sampling body fluids, surgical implantation). We examined 232 publications that dealt with translocations of terrestrial vertebrates and aquatic mammals and, defining ‘success’ as high or low, determined how many of these studies explicitly incorporated physiological aspects into their protocols and monitoring. From this review, it is apparent that physiological evaluation before and after animal releases could progress and improve translocation/reintroduction successes. We propose a suite of physiological measures, in addition to animal health indices, for assisting conservation translocations over the short term and also for longer term post-release monitoring. Perhaps most importantly, we argue that the incorporation of physiological assessments of animals at all stages of translocation can have important welfare implications by helping to reduce the total number of animals used. Physiological indicators can also help to refine conservation translocation methods. These approaches fall

  6. Purinergic signaling is required for fluid shear stress-induced NF-{kappa}B translocation in osteoblasts

    SciTech Connect

    Genetos, Damian C.; Karin, Norman J.; Geist, Derik J.; Donahue, Henry J.; Duncan, Randall L.

    2011-04-01

    Fluid shear stress regulates gene expression in osteoblasts, in part by activation of the transcription factor NF-{kappa}B. We examined whether this process was under the control of purinoceptor activation. MC3T3-E1 osteoblasts under static conditions expressed the NF-{kappa}B inhibitory protein I{kappa}B{alpha} and exhibited cytosolic localization of NF-{kappa}B. Under fluid shear stress, I{kappa}B{alpha} levels decreased, and concomitant nuclear localization of NF-{kappa}B was observed. Cells exposed to fluid shear stress in ATP-depleted medium exhibited no significant reduction in I{kappa}B{alpha}, and NF-{kappa}B remained within the cytosol. Similar results were found using oxidized ATP or Brilliant Blue G, P2X{sub 7} receptor antagonists, indicating that the P2X{sub 7} receptor is responsible for fluid shear-stress-induced I{kappa}B{alpha} degradation and nuclear accumulation of NF-{kappa}B. Pharmacologic blockage of the P2Y6 receptor also prevented shear-induced I{kappa}B{alpha} degradation. These phenomena involved neither ERK1/2 signaling nor autocrine activation by P2X{sub 7}-generated lysophosphatidic acid. Our results suggest that fluid shear stress regulates NF-{kappa}B activity through the P2Y{sub 6} and P2X{sub 7} receptor.

  7. Purinergic Signaling is Required for Fluid Shear Stress-Induced NF-kB Translocation in Osteoblasts

    SciTech Connect

    Genetos, Damian C.; Karin, Norman J.; Geist, Derik J.; Donahue, Henry J.; Duncan, Randall L.

    2011-04-01

    Fluid shear stress regulates gene expression in osteoblasts, in part by activation of the transcription factor NF-kB. We examined whether this process was under control of purinoceptor activation. MC3T3-E1 osteoblasts under static conditions expressed the NF-kB inhibitory protein IkB alpha and exhibited cytosolic localization of NF-kB. Under fluid shear stress, IκBα levels decreased, and concomitant nuclear localization of NF-kB was observed. Cells exposed to fluid shear stress in ATP-depleted medium exhibited no significant reduction in IκBα, and NF-kB remained within the cytosol. Similar results were found using oxidized ATP or Brilliant Blue G, P2X7 receptor antagonists, indicating that the P2X7 receptor is responsible for fluid shear-stress-induced IκBα degradation and nuclear accumulation of NF-kB. Pharmacologic blockage of the P2Y6 receptor also prevented shear-induced IkB alpha degradation. These phenomena involved neither ERK1/2 signaling nor autocrine activation by P2X7-generated lysophosphatidic acid. Our results suggest that fluid shear stress regulates NF-kB activity through the P2Y6 and P2X7 receptor.

  8. Staphylococcal enterotoxin B initiates protein kinase C translocation and eicosanoid metabolism while inhibiting thrombin-induced aggregation in human platelets.

    PubMed

    Tran, Uyen; Boyle, Thomas; Shupp, Jeffrey W; Hammamieh, Rasha; Jett, Marti

    2006-08-01

    Staphylococcal enterotoxin (SE) B, a heat-stable toxin secreted by Staphylococcus aureus, has been implicated in the pathogenesis and exacerbation of several critical illnesses. It has been hypothesized that enterotoxins may interact with blood products such as platelets, in addition to T-lymphocytes and renal proximal tubule cells. The aim of this present study was to elucidate whether SEB directly alters human platelet function. Human platelet rich plasma (PRP) was pre-incubated with SEA, SEB, SEC or TSST-1, (at various concentrations and incubation times). After incubation, PRP was exposed to thrombin and aggregation was assessed. Incubation with all toxins tested resulted in decreased aggregation, specifically; exposure to 10mu g/ml of SEB for 30 min caused a 20% decrease and a 49% decrease at 90 min. A similar reduction in aggregation was seen in samples incubated with phorbol myristate acetate, a known stimulator of protein kinase C (PKC). Further, platelets exposed to SEB exhibited an increased plasma membrane PKC activity. Sphingosine, an inhibitor of PKC proved to block the SEB-induced reduction in aggregation. SEB effects on platelet metabolism were investigated using high performance liquid chromatography showing up to a 2-fold increase of active metabolites lipoxin A4 and 12-HETE, as compared to control. These data indicate that SEB is able to induce platelet dysfunction, and these effects may be mediated through activation of PKC. PMID:16550298

  9. Series of Reciprocal Triangular Numbers

    ERIC Educational Resources Information Center

    Bruckman, Paul; Dence, Joseph B.; Dence, Thomas P.; Young, Justin

    2013-01-01

    Reciprocal triangular numbers have appeared in series since the very first infinite series were summed. Here we attack a number of subseries of the reciprocal triangular numbers by methodically expressing them as integrals.

  10. Reciprocal Predicates in Japanese.

    ERIC Educational Resources Information Center

    Ishii, Yasuo

    A study of reciprocals in Japanese compares two kinds: (1) a verbal suffix "aw"; and (2) an NP argument "otagai." Although "otagai" appears to be taken care of by syntactic binding theory, it is proposed that there is no evidence for the existence of a syntactic position of the object NP in the case of "aw." The suffix can be characterized as…

  11. Terahertz wave reciprocal imaging

    NASA Astrophysics Data System (ADS)

    Xu, Jingzhou; Zhang, X.-C.

    2006-04-01

    A reciprocal imaging technology with an encoding/decoding image readout method allows a single detector (such as a heterodyne detector) to produce a two dimensional (2D) image simultaneously. Applying it in a pulsed terahertz imaging system could create a 2D terahertz image with 100pixels per frame which produces the same signal to noise ratio as a signal spot measurement.

  12. Translocation of NF-κB and expression of cyclooxygenase-2 are enhanced by ketamine-induced ulcerative cystitis in rat bladder.

    PubMed

    Juan, Yung-Shun; Lee, Yi-Lun; Long, Cheng-Yu; Wong, Jhen-Hong; Jang, Mei-Yu; Lu, Jian-He; Wu, Wen-Jeng; Huang, Yen-Shun; Chang, Wei-Chiao; Chuang, Shu-Mien

    2015-08-01

    The number of ketamine abusers has increased significantly recently. Ketamine abusers exhibit urinary frequency, urgency, and at times urinary incontinence. Our aim was to investigate the role of transcription factor NF-κB and cyclooxygenase (COX)-2 in ketamine-induced cystitis. Sprague-Dawley rats were distributed into three groups, which received saline or treatment with ketamine or ketamine combined with a Cox-2 inhibitor (parecoxib). In addition, the toxic effect of ketamine and its metabolites were examined by primary urothelial cell culture. The ketamine-treated group displayed bladder hyperactivity and decreased bladder capacity. Treatment with ketamine + COX-2 inhibitor prevented these bladder dysfunctions. These bladder dysfunctions were accompanied by increases in the expression of NF-κB and COX-2 at the protein and mRNA levels. Ketamine treatment also enhanced bladder interstitial fibrosis, whereas ketamine + Cox-2 inhibitor decreased the intensity of fibrosis. Treatment of primary urothelial cells in vitro with ketamine or urine obtained from ketamine-treated rats stimulated the expression of NF-κB p65 and COX-2. Ketamine also initiated NF-κB translocation from cell cytoplasm to nucleus. Treatment with NF-κB inhibitor suppressed Cox-2 mRNA expression. Promoter-deletion analysis revealed that NF-κB was a necessary transcription factor for COX-2 gene (Ptgs2) activation. These results demonstrate that the regulation of COX-2 via the NF-κB pathway is involved in the inflammatory signaling of ketamine-induced cystitis in rat urinary bladder. PMID:26073037

  13. Thyroid hormone-induced cytosol-to-nuclear translocation of rat liver Nrf2 is dependent on Kupffer cell functioning.

    PubMed

    Videla, Luis A; Cornejo, Pamela; Romanque, Pamela; Santibáñez, Catherine; Castillo, Iván; Vargas, Romina

    2012-01-01

    L-3,3',5-triiodothyronine (T(3)) administration upregulates nuclear factor-E2-related factor 2 (Nrf2) in rat liver, which is redox-sensitive transcription factor mediating cytoprotection. In this work, we studied the role of Kupffer cell respiratory burst activity, a process related to reactive oxygen species generation and liver homeostasis, in Nrf2 activation using the macrophage inactivator gadolinium chloride (GdCl(3); 10 mg/kg i.v. 72 h before T(3) [0.1 mg/kg i.p.]) or NADPH oxidase inhibitor apocynin (1.5 mmol/L added to the drinking water for 7 days before T(3)), and determinations were performed 2 h after T(3). T(3) increased nuclear/cytosolic Nrf2 content ratio and levels of heme oxygenase 1 (HO-1), catalytic subunit of glutamate cysteine ligase, and thioredoxin (Western blot) over control values, proteins whose gene transcription is induced by Nrf2. These changes were suppressed by GdCl(3) treatment prior to T(3), an agent-eliciting Kupffer-cell depletion, inhibition of colloidal carbon phagocytosis, and the associated respiratory burst activity, with enhancement in nuclear inhibitor of Nrf2 kelch-like ECH-associated protein 1 (Keap1)/Nrf2 content ratios suggesting Nrf2 degradation. Under these conditions, T(3)-induced tumor necrosis factor-α (TNF-α) response was eliminated by previous GdCl(3) administration. Similar to GdCl(3), apocynin given before T(3) significantly reduced liver Nrf2 activation and HO-1 expression, a NADPH oxidase inhibitor eliciting abolishment of colloidal carbon-induced respiratory burst activity without altering carbon phagocytosis. It is concluded that Kupffer cell functioning is essential for upregulation of liver Nrf2-signaling pathway by T(3). This contention is supported by suppression of the respiratory burst activity of Kupffer cells and the associated reactive oxygen species production by GdCl(3) or apocynin given prior to T(3), thus hindering Nrf2 activation. PMID:22649286

  14. Cowden syndrome-associated germline SDHD variants alter PTEN nuclear translocation through SRC-induced PTEN oxidation.

    PubMed

    Yu, Wanfeng; He, Xin; Ni, Ying; Ngeow, Joanne; Eng, Charis

    2015-01-01

    Germline mutations in the PTEN tumor-suppressor gene and germline variations in succinate dehydrogenase subunit D gene (SDHD-G12S, SDHD-H50R) are associated with a subset of Cowden syndrome and Cowden syndrome-like individuals (CS/CSL) and confer high risk of breast, thyroid and other cancers. However, very little is known about the underlying crosstalk between SDHD and PTEN in CS-associated thyroid cancer. Here, we show SDHD-G12S and SDHD-H50R lead to impaired PTEN function through alteration of its subcellular localization accompanied by resistance to apoptosis and induction of migration in both papillary and follicular thyroid carcinoma cell lines. Other studies have shown elevated proto-oncogene tyrosine kinase (SRC) activity in invasive thyroid cancer cells; so, we explore bosutinib, a specific inhibitor for SRC, to explore SRC as a mediator of SDH-PTEN crosstalk in this context. We show that SRC inhibition could rescue SDHD dysfunction-induced cellular phenotype and tumorigenesis only when wild-type PTEN is expressed, in thyroid cancer lines. Patient lymphoblast cells carrying either SDHD-G12S or SDHD-H50R also show increased nuclear PTEN and more oxidized PTEN after hydrogen peroxide treatment. Like in thyroid cells, bosutinib decreases oxidative PTEN in patient lymphoblast cells carrying SDHD variants, but not in patients carrying both SDHD variants and PTEN truncating mutations. In summary, our data suggest a novel mechanism whereby SDHD germline variants SDHD-G12S or SDHD-H50R induce thyroid tumorigenesis mediated by PTEN accumulation in the nucleus and may shed light on potential treatment with SRC inhibitors like bosutinib in PTEN-wild-type SDHD-variant/mutation positive CS/CSL patients and sporadic thyroid neoplasias. PMID:25149476

  15. Defining chromosomal translocation risks in cancer.

    PubMed

    Hogenbirk, Marc A; Heideman, Marinus R; de Rink, Iris; Velds, Arno; Kerkhoven, Ron M; Wessels, Lodewyk F A; Jacobs, Heinz

    2016-06-28

    Chromosomal translocations are a hallmark of cancer. Unraveling the molecular mechanism of these rare genetic events requires a clear distinction between correlative and causative risk-determinants, where technical and analytical issues can be excluded. To meet this goal, we performed in-depth analyses of publicly available genome-wide datasets. In contrast to several recent reports, we demonstrate that chromosomal translocation risk is causally unrelated to promoter stalling (Spt5), transcriptional activity, or off-targeting activity of the activation-induced cytidine deaminase. Rather, an open chromatin configuration, which is not promoter-specific, explained the elevated translocation risk of promoter regions. Furthermore, the fact that gene size directly correlates with the translocation risk in mice and human cancers further demonstrated the general irrelevance of promoter-specific activities. Interestingly, a subset of translocations observed in cancer patients likely initiates from double-strand breaks induced by an access-independent process. Together, these unexpected and novel insights are fundamental in understanding the origin of chromosome translocations and, consequently, cancer. PMID:27303044

  16. Defining chromosomal translocation risks in cancer

    PubMed Central

    Hogenbirk, Marc A.; Heideman, Marinus R.; de Rink, Iris; Velds, Arno; Kerkhoven, Ron M.; Wessels, Lodewyk F. A.; Jacobs, Heinz

    2016-01-01

    Chromosomal translocations are a hallmark of cancer. Unraveling the molecular mechanism of these rare genetic events requires a clear distinction between correlative and causative risk-determinants, where technical and analytical issues can be excluded. To meet this goal, we performed in-depth analyses of publicly available genome-wide datasets. In contrast to several recent reports, we demonstrate that chromosomal translocation risk is causally unrelated to promoter stalling (Spt5), transcriptional activity, or off-targeting activity of the activation-induced cytidine deaminase. Rather, an open chromatin configuration, which is not promoter-specific, explained the elevated translocation risk of promoter regions. Furthermore, the fact that gene size directly correlates with the translocation risk in mice and human cancers further demonstrated the general irrelevance of promoter-specific activities. Interestingly, a subset of translocations observed in cancer patients likely initiates from double-strand breaks induced by an access-independent process. Together, these unexpected and novel insights are fundamental in understanding the origin of chromosome translocations and, consequently, cancer. PMID:27303044

  17. Epstein-Barr Virus-Induced Gene 3 (EBI3) Blocking Leads to Induce Antitumor Cytotoxic T Lymphocyte Response and Suppress Tumor Growth in Colorectal Cancer by Bidirectional Reciprocal-Regulation STAT3 Signaling Pathway

    PubMed Central

    Liang, Yanfang; Chen, Qianqian; Du, Wenjing; Chen, Can; Li, Feifei; Yang, Jingying; Peng, Jianyu; Kang, Dongping; Lin, Bihua; Chai, Xingxing; Zhou, Keyuan; Zeng, Jincheng

    2016-01-01

    Epstein-Barr virus-induced gene 3 (EBI3) is a member of the interleukin-12 (IL-12) family structural subunit and can form a heterodimer with IL-27p28 and IL-12p35 subunit to build IL-27 and IL-35, respectively. However, IL-27 stimulates whereas IL-35 inhibits antitumor T cell responses. To date, little is known about the role of EBI3 in tumor microenvironment. In this study, firstly we assessed EBI3, IL-27p28, IL-12p35, gp130, and p-STAT3 expression with clinicopathological parameters of colorectal cancer (CRC) tissues; then we evaluated the antitumor T cell responses and tumor growth with a EBI3 blocking peptide. We found that elevated EBI3 may be associated with IL-12p35, gp130, and p-STAT3 to promote CRC progression. EBI3 blocking peptide promoted antitumor cytotoxic T lymphocyte (CTL) response by inducing Granzyme B, IFN-γ production, and p-STAT3 expression and inhibited CRC cell proliferation and tumor growth to associate with suppressing gp130 and p-STAT3 expression. Taken together, these results suggest that EBI3 may mediate a bidirectional reciprocal-regulation STAT3 signaling pathway to assist the tumor escape immune surveillance in CRC. PMID:27247488

  18. Quercetin derivative induces cell death in glioma cells by modulating NF-κB nuclear translocation and caspase-3 activation.

    PubMed

    Kiekow, Cíntia J; Figueiró, Fabrício; Dietrich, Fabrícia; Vechia, Luciana Dalla; Pires, Elisa N S; Jandrey, Elisa H F; Gnoatto, Simone C B; Salbego, Christianne G; Battastini, Ana Maria O; Gosmann, Grace

    2016-03-10

    Treated glioblastoma multiforme (GBM) patients only survive 6 to 14months after diagnosis; therefore, the development of novel therapeutic strategies to treat gliomas remains critically necessary. Considering that phenolic compounds, like quercetin, have the potential to be used in the chemotreatment of gliomas and that some flavonoids exhibit the ability to cross the BBB, in the present study, we investigated the antitumor effect of flavonoids (including chalcones, flavones, flavanones and flavonols). Initially their activities were tested in C6 glioma cells screened using the MTT method, resulting in the selection of chalcone 2 whose feasibility was confirmed by a Trypan Blue exclusion assay in the low μM range on C6 glioma cells. Cell cycle and apoptotic death analyses on C6 glioma cells were also performed, and chalcone 2 increased the apoptosis of the cells but did not alter the cell cycle progression. In addition, treatments with these two compounds were not cytotoxic to hippocampal organotypic cultures, a model of healthy neural cells. Furthermore, the results indicated that 2 induced apoptosis by inhibition of NF-κB and activation of active caspase-3 in glioma cells, suggesting that it is a potential prototype to develop new treatments for GBM in the future. PMID:26802551

  19. A novel selection system for chromosome translocations in Saccharomyces cerevisiae.

    PubMed Central

    Tennyson, Rachel B; Ebran, Nathalie; Herrera, Anissa E; Lindsley, Janet E

    2002-01-01

    Chromosomal translocations are common genetic abnormalities found in both leukemias and solid tumors. While much has been learned about the effects of specific translocations on cell proliferation, much less is known about what causes these chromosome rearrangements. This article describes the development and use of a system that genetically selects for rare translocation events using the yeast Saccharomyces cerevisiae. A translocation YAC was created that contains the breakpoint cluster region from the human MLL gene, a gene frequently involved in translocations in leukemia patients, flanked by positive and negative selection markers. A translocation between the YAC and a yeast chromosome, whose breakpoint falls within the MLL DNA, physically separates the markers and forms the basis for the selection. When RAD52 is deleted, essentially all of the selected and screened cells contain simple translocations. The detectable translocation rates are the same in haploids and diploids, although the mechanisms involved and true translocation rates may be distinct. A unique double-strand break induced within the MLL sequences increases the number of detectable translocation events 100- to 1000-fold. This novel system provides a tractable assay for answering basic mechanistic questions about the development of chromosomal translocations. PMID:11973293

  20. A reciprocating motion-driven rotation mechanism for the ATP synthase.

    PubMed

    Liu, Jiafeng; Fu, Xinmiao; Chang, Zengyi

    2016-01-01

    The ATP synthase (having a typical subunit composition of α3β3γδεab2c8-15) employs an intriguing rotary mechanism for the generation of ATP from ADP and Pi, using energy stored in a transmembrane proton gradient. The conventional rotary model, although being generally accepted, remains difficult to explain certain experimental observations. Here we propose an alternative rotary model for the ATP synthase such that what rotates is the catalytic α3β3 cylinder rather than the central stalk and the membrane-embedded c-ring. Specifically, the membrane translocation of protons would induce a cycled conformational change in the c-ring, leading to a reciprocating motion of the attached central stalk, which in turn drives the unidirectional rotation of the α3β3 cylinder. Such a reciprocating motion-driven rotation mechanism is somehow analogous to the working mechanism of a retractable click ballpoint pen. Our new model not only explains the experimental observations that have been difficult to reconcile with the conventional model but also avoids its theoretical illogicality. PMID:26718355

  1. Bortezomib induces nuclear translocation of IκBα resulting in gene-specific suppression of NF-κB--dependent transcription and induction of apoptosis in CTCL.

    PubMed

    Juvekar, Ashish; Manna, Subrata; Ramaswami, Sitharam; Chang, Tzu-Pei; Vu, Hai-Yen; Ghosh, Chandra C; Celiker, Mahmut Y; Vancurova, Ivana

    2011-02-01

    Cutaneous T-cell lymphoma (CTCL) is characterized by constitutive activation of nuclear factor κB (NF-κB), which plays a crucial role in the survival of CTCL cells and their resistance to apoptosis. NF-κB activity in CTCL is inhibited by the proteasome inhibitor bortezomib; however, the mechanisms remained unknown. In this study, we investigated mechanisms by which bortezomib suppresses NF-κB activity in CTCL Hut-78 cells. We demonstrate that bortezomib and MG132 suppress NF-κB activity in Hut-78 cells by a novel mechanism that consists of inducing nuclear translocation and accumulation of IκBα (nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha), which then associates with NF-κB p65 and p50 in the nucleus and inhibits NF-κB DNA binding activity. Surprisingly, however, while expression of NF-κB-dependent antiapoptotic genes cIAP1 and cIAP2 is inhibited by bortezomib, expression of Bcl-2 is not suppressed. Chromatin immunoprecipitation indicated that cIAP1 and cIAP2 promoters are occupied by NF-κB p65/50 heterodimers, whereas Bcl-2 promoter is occupied predominantly by p50/50 homodimers. Collectively, our data reveal a novel mechanism of bortezomib function in CTCL and suggest that the inhibition of NF-κB-dependent gene expression by bortezomib is gene specific and depends on the subunit composition of NF-κB dimers recruited to NF-κB-responsive promoters. PMID:21224428

  2. Pre-B cell colony enhancing factor induces Nampt-dependent translocation of the insulin receptor out of lipid microdomains in A549 lung epithelial cells.

    PubMed

    Peng, Qianyi; Jia, Song Hui; Parodo, Jean; Ai, Yuhang; Marshall, John C

    2015-02-15

    Pre-B cell colony-enhancing factor (PBEF) is a highly conserved pleiotropic protein reported to be an alternate ligand for the insulin receptor (IR). We sought to clarify the relationship between PBEF and insulin signaling by evaluating the effects of PBEF on the localization of the IRβ chain to lipid rafts in A549 epithelial cells. We isolated lipid rafts from A549 cells and detected the IR by immunoprecipitation from raft fractions or whole cell lysates. Cells were treated with rPBEF, its enzymatic product nicotinamide adenine dinucleotide (NAD), or the Nampt inhibitor daporinad to study the effect of PBEF on IRβ movement. We used coimmunoprecipitation studies in cells transfected with PBEF and IRβ constructs to detect interactions between PBEF, the IRβ, and caveolin-1 (Cav-1). PBEF was present in both lipid raft and nonraft fractions, whereas the IR was found only in lipid raft fractions of resting A549 cells. The IR-, PBEF-, and Cav-1-coimmunoprecipitated rPBEF treatment resulted in the movement of IRβ- and tyrosine-phosphorylated Cav-1 from lipid rafts to nonrafts, an effect that could be blocked by daporinad, suggesting that this effect was facilitated by the Nampt activity of PBEF. The addition of PBEF to insulin-treated cells resulted in reduced Akt phosphorylation of both Ser⁴⁷³ and Thr³⁰⁸. We conclude that PBEF can inhibit insulin signaling through the IR by Nampt-dependent promotion of IR translocation into the nonraft domains of A549 epithelial cells. PBEF-induced alterations in the spatial geometry of the IR provide a mechanistic explanation for insulin resistance in inflammatory states associated with upregulation of PBEF. PMID:25516545

  3. Reciprocity relations in aerodynamics

    NASA Technical Reports Server (NTRS)

    Heaslet, Max A; Spreiter, John R

    1953-01-01

    Reverse flow theorems in aerodynamics are shown to be based on the same general concepts involved in many reciprocity theorems in the physical sciences. Reciprocal theorems for both steady and unsteady motion are found as a logical consequence of this approach. No restrictions on wing plan form or flight Mach number are made beyond those required in linearized compressible-flow analysis. A number of examples are listed, including general integral theorems for lifting, rolling, and pitching wings and for wings in nonuniform downwash fields. Correspondence is also established between the buildup of circulation with time of a wing starting impulsively from rest and the buildup of lift of the same wing moving in the reverse direction into a sharp-edged gust.

  4. Reciprocal and unidirectional scattering of parity-time symmetric structures

    PubMed Central

    Jin, L.; Zhang, X. Z.; Zhang, G.; Song, Z.

    2016-01-01

    Parity-time symmetry is of great interest. The reciprocal and unidirectional features are intriguing besides the symmetry phase transition. Recently, the reciprocal transmission, unidirectional reflectionless and invisibility are intensively studied. Here, we show the reciprocal reflection/transmission in -symmetric system is closely related to the type of symmetry, that is, the axial (reflection) symmetry leads to reciprocal reflection (transmission). The results are further elucidated by studying the scattering of rhombic ring form coupled resonators with enclosed synthetic magnetic flux. The nonreciprocal phase shift induced by the magnetic flux and gain/loss break the parity and time-reversal symmetry but keep the parity-time symmetry. The reciprocal reflection (transmission) and unidirectional transmission (reflection) are found in the axial (reflection) -symmetric ring centre. The explorations of symmetry and asymmetry from symmetry may shed light on novel one-way optical devices and application of -symmetric metamaterials. PMID:26876806

  5. Inhibition of Nuclear Translocation of Apoptosis-Inducing Factor Is an Essential Mechanism of the Neuroprotective Activity of Pigment Epithelium-Derived Factor in a Rat Model of Retinal Degeneration

    PubMed Central

    Murakami, Yusuke; Ikeda, Yasuhiro; Yonemitsu, Yoshikazu; Onimaru, Mitsuho; Nakagawa, Kazunori; Kohno, Ri-ichiro; Miyazaki, Masanori; Hisatomi, Toshio; Nakamura, Makoto; Yabe, Takeshi; Hasegawa, Mamoru; Ishibashi, Tatsuro; Sueishi, Katsuo

    2008-01-01

    Photoreceptor apoptosis is a critical process of retinal degeneration in retinitis pigmentosa (RP), a group of retinal degenerative diseases that result from rod and cone photoreceptor cell death and represent a major cause of adult blindness. We previously demonstrated the efficient prevention of photoreceptor apoptosis by intraocular gene transfer of pigment epithelium-derived factor (PEDF) in animal models of RP; however, the underlying mechanism of the neuroprotective activity of PEDF remains elusive. In this study, we show that an apoptosis-inducing factor (AIF)-related pathway is an essential target of PEDF-mediated neuroprotection. PEDF rescued serum starvation-induced apoptosis, which is mediated by AIF but not by caspases, of R28 cells derived from the rat retina by preventing translocation of AIF into the nucleus. Nuclear translocation of AIF was also observed in the apoptotic photoreceptors of Royal College of Surgeons rats, a well-known animal model of RP that carries a mutation of the Mertk gene. Lentivirus-mediated retinal gene transfer of PEDF prevented the nuclear translocation of AIF in vivo, resulting in the inhibition of the apoptotic loss of their photoreceptors in association with up-regulated Bcl-2 expression, which mediates the mitochondrial release of AIF. These findings clearly demonstrate that AIF is an essential executioner of photoreceptor apoptosis in inherited retinal degeneration and provide a therapeutic rationale for PEDF-mediated neuroprotective gene therapy for individuals with RP. PMID:18845835

  6. BCL2 accelerates inflammation-induced BALB/c plasmacytomas and promotes novel tumors with coexisting T(12;15) and T(6;15) translocations.

    PubMed

    Silva, Santiago; Kovalchuk, Alexander L; Kim, Joong Su; Klein, George; Janz, Siegfried

    2003-12-15

    Previous studies on peritoneal plasmacytomas (PCTs) in BALB/c (C) mice suggested that the enforced expression of the death repressor BCL2 in B cells might facilitate the malignant transformation of aberrant B cells containing Myc-activating T(12;15) translocations, generating an improved model of plasmacytomagenesis. To investigate this hypothesis, we backcrossed a human BCL2 transgene onto strain C and performed a PCT induction study with pristane in the newly generated C.BCL2 congenics. In specific pathogen-free-maintained C.BCL2 mice, PCT incidence (19 of 34, 56%) was 24 times higher than in specific pathogen-free-maintained C mice (1 of 44, 2.3%), and tumor onset (113 days) was half that of conventionally maintained C mice (220 days). BCL2 transgenic PCT harbored T(12;15) translocations (12 of 12 tumors) with an unusual clustering of translocation breakpoints in the near 5' flank of Myc (4 of 5 tumors, 80%). Five tumors contained coexisting T(12;15) and T(6;15) translocations (not observed in >300 karyotyped PCTs from conventionally maintained C mice). BCL2 transgenic C57BL/6 mice exclusively developed B lymphomas (11 of 20, 55%) that also contained T(12;15) translocations (11 of 11 cases) with breakpoints in the near 5' flank of Myc (five of five tumors). We conclude that BCL2 accelerates PCT with novel Myc-activating translocations independently of environmental antigen stimulation. Accelerated plasmacytomagenesis in strain C.BCL2 may be useful for designing and testing BCL2 inhibition strategies in human plasma cell tumors overexpressing BCL2, such as Waldenström's macroglobulinemia and multiple myeloma. PMID:14695177

  7. Translocations of Chromosome End-Segments and Facultative Heterochromatin Promote Meiotic Ring Formation in Evening Primroses[W][OPEN

    PubMed Central

    Golczyk, Hieronim; Massouh, Amid; Greiner, Stephan

    2014-01-01

    Due to reciprocal chromosomal translocations, many species of Oenothera (evening primrose) form permanent multichromosomal meiotic rings. However, regular bivalent pairing is also observed. Chiasmata are restricted to chromosomal ends, which makes homologous recombination virtually undetectable. Genetic diversity is achieved by changing linkage relations of chromosomes in rings and bivalents via hybridization and reciprocal translocations. Although the structural prerequisite for this system is enigmatic, whole-arm translocations are widely assumed to be the mechanistic driving force. We demonstrate that this prerequisite is genome compartmentation into two epigenetically defined chromatin fractions. The first one facultatively condenses in cycling cells into chromocenters negative both for histone H3 dimethylated at lysine 4 and for C-banding, and forms huge condensed middle chromosome regions on prophase chromosomes. Remarkably, it decondenses in differentiating cells. The second fraction is euchromatin confined to distal chromosome segments, positive for histone H3 lysine 4 dimethylation and for histone H3 lysine 27 trimethylation. The end-segments are deprived of canonical telomeres but capped with constitutive heterochromatin. This genomic organization promotes translocation breakpoints between the two chromatin fractions, thus facilitating exchanges of end-segments. We challenge the whole-arm translocation hypothesis by demonstrating why reciprocal translocations of chromosomal end-segments should strongly promote meiotic rings and evolution toward permanent translocation heterozygosity. Reshuffled end-segments, each possessing a major crossover hot spot, can furthermore explain meiotic compatibility between genomes with different translocation histories. PMID:24681616

  8. High pressure reciprocating pump

    SciTech Connect

    Besic, D.

    1990-05-01

    This patent describes an improvement in a reciprocating pump having a plunger and a pumping chamber. It comprises: the plunger having a bore communicating with an intersection opening and wherein the plunger incudes a central axis; a suction valve and a discharge valve, each having an axis of actuation parallel to a central axis of the plunger; the suction valve comprising a cylindrical core having a central passageway, and the core is slidably received by a seating member and resiliently biased to the seating member.

  9. The principle of reciprocity.

    PubMed

    Hoult, D I

    2011-12-01

    The circumstances surrounding the realisation that NMR signal reception could be quantified in a simple fundamental manner using Lorentz's Principle of Reciprocity are described. The poor signal-to-noise ratio of the first European superconducting magnet is identified as a major motivating factor, together with the author's need to understand phenomena at a basic level. A summary is then given of the thought processes leading to the very simple pseudo-static formula that has been the basis of signal-to-noise calculations for over a generation. PMID:21889377

  10. Reciprocating magnetic refrigerator

    NASA Technical Reports Server (NTRS)

    Johnson, D. L.

    1985-01-01

    A 4 to 15 K magnetic refrigerator to test as an alternative to the Joule-Thomson circuit as the low temperature stage of a 4 to 300 K closed-cycle refrigerator was developed. The reciprocating magnetic refrigerator consists of two matrices of gadolinium gallium garnet spheres located in tandem on a single piston which alternately moves each matrix into a 7 telsa magnetic field. A separate helium gas circuit is used as the heat exchange mechanism for the low and the high temperature extremes of the magnetic refrigerator. Details of the design and results of the initial refrigerator component tests are presented.

  11. Copper-Induced Translocation of the Wilson Disease Protein ATP7B Independent of Murr1/COMMD1 and Rab7

    PubMed Central

    Weiss, Karl Heinz; Lozoya, Javier Carbajo; Tuma, Sabine; Gotthardt, Daniel; Reichert, Jürgen; Ehehalt, Robert; Stremmel, Wolfgang; Füllekrug, Joachim

    2008-01-01

    Wilson disease is a genetic disorder of copper metabolism. Impaired biliary excretion results in a gradual accumulation of copper, which leads to severe disease. The specific gene defect lies in the Wilson disease protein, ATP7B, a copper-transporting ATPase that is highly active in hepatocytes. The two major functions of ATP7B in the liver are the copper loading of ceruloplasmin in the Golgi apparatus, and the excretion of excess copper into the bile. In response to elevated copper levels, ATP7B shows a unique intracellular trafficking pattern that is required for copper excretion from the Golgi apparatus into dispersed vesicles. We analyzed the translocation of ATP7B by both confocal microscopy and RNA interference, testing current models that suggest the involvement of Murr1/COMMD1 and Rab7 in this pathway. We found that although the ATP7B translocation is conserved among nonhepatic cell lines, there is no co-localization with Murr1/COMMD1 or the Rab marker proteins of the endolysosomal system. Consistent with this finding, the translocation of ATP7B was not impaired by the depletion of either Murr1/COMMD1 or Rab7, or by a dominant-negative Rab7 mutant. In conclusion, our data suggest that the translocation of ATP7B takes place independently of Rab7-regulated endosomal traffic events. Murr1/COMMD1 plays a role in a later step of the copper excretion pathway but is not involved in the translocation of the Wilson disease protein. PMID:18974300

  12. Hypoxia induced E-cadherin involving regulators of Hippo pathway due to HIF-1α stabilization/nuclear translocation in bone metastasis from breast carcinoma

    SciTech Connect

    Maroni, Paola; Matteucci, Emanuela; Drago, Lorenzo; Banfi, Giuseppe; Bendinelli, Paola; Desiderio, Maria Alfonsina

    2015-01-15

    Wwox as a novel molecule in the HIF-1α-HDM2 regulatory loop, necessary for the dynamic regulation of the HIF-1α amount, and we suggested that the reduction of endogenous Wwox free pool under hypoxia might also be due to the interaction with HDM2, sequestering the E3 ubiquitin ligase. We highlighted the importance of nuclear HIF-1α in the biology of metastasis for the mesenchymal-epithelial transition: this phenotype was regulated by Wwox plus hypoxia through E-cadherin target gene, playing a pivotal role in bone metastasis colonization. - Highlights: • E-cadherin accumulates in hypoxic bone metastasis opposite to primary carcinoma. • HIF-1 and PPARγ cooperate in inducing E-cadherin under hypoxia in metastatic cells. • Wwox regulates HIF-1α phosphorylation and nuclear translocation. • Hypoxia plus Wwox prevent HIF-1α degradation via HDM2 forming a regulatory loop.

  13. Translocation of reptating chains

    NASA Astrophysics Data System (ADS)

    Żurek, S.; Drzewiński, A.; van Leeuwen, J. M. J.

    2011-05-01

    Voltage-driven translocation is modeled with the Rubinstein-Duke rules for hopping reptons in one- and two-dimensional lattices. The chain is driven through the pore by a bias potential promoting the transition of stored length in one direction. Coupling states give a semi-periodicity of the process that enables us to relate the properties to the stationary state of the master equation. The exact solution for short chains and Monte Carlo simulations for longer chains are used to calculate displacements, velocities and the translocation time.

  14. Vertically reciprocating auger

    NASA Technical Reports Server (NTRS)

    Etheridge, Mark; Morgan, Scott; Fain, Robert; Pearson, Jonathan; Weldi, Kevin; Woodrough, Stephen B., Jr.

    1988-01-01

    The mathematical model and test results developed for the Vertically Reciprocating Auger (VRA) are summarized. The VRA is a device capable of transporting cuttings that result from below surface drilling. It was developed chiefly for the lunar surface, where conventional fluid flushing while drilling would not be practical. The VRA uses only reciprocating motion and transports material through reflections with the surface above. Particles are reflected forward and land ahead of radially placed fences, which prevent the particles from rolling back down the auger. Three input wave forms are considered to drive the auger. A modified sawtooth wave form was chosen for testing, over a modified square wave or sine wave, due to its simplicity and effectiveness. The three-dimensional mathematical model predicted a sand throughput rate of 0.2667 pounds/stroke, while the actual test setup transported 0.075 pounds/stroke. Based on this result, a correction factor of 0.281 is suggested for a modified sawtooth input.

  15. Reciprocal relations in electroacoustics

    SciTech Connect

    Chassagne, C.; Bedeaux, D.

    2014-07-28

    In a colloidal suspension, one can generate sound waves by the application of an alternating electric field (Electrokinetic Sonic Amplitude, i.e., ESA). Another phenomenon is electrophoresis (Electrophoretic Mobility, i.e., EM) where a colloidal particle moves relative to the solvent in an electric field. Vice versa one can generate electric fields or electric currents by sound waves (Colloid Vibration Potential/Current, i.e., CVP/CVI). In 1988 and 1990, O’Brien [J. Fluid Mech. 190, 71–86 (1988) and O’Brien, J. Fluid Mech. 212, 81–93 (1990)] derived a reciprocal relation between the proportionality coefficients of the EM and CVI phenomena. In this paper, we will generalize his proof by constructing the relevant entropy production from which the linear force-flux relations follow. General relations are derived for electrolyte solutions, of which colloidal suspensions are a particular case. The relations between CVI, CVP, EM, and ESA are discussed. O’Brien's reciprocal relation then follows as an Onsager relation. The relation is valid for any applied electric field frequency, particle surface charge and particle concentration (even in the presence of particle-particle interactions) provided the system is isotropic.

  16. Problem-Elephant Translocation: Translocating the Problem and the Elephant?

    PubMed Central

    Fernando, Prithiviraj; Leimgruber, Peter; Prasad, Tharaka; Pastorini, Jennifer

    2012-01-01

    Human-elephant conflict (HEC) threatens the survival of endangered Asian elephants (Elephas maximus). Translocating “problem-elephants” is an important HEC mitigation and elephant conservation strategy across elephant range, with hundreds translocated annually. In the first comprehensive assessment of elephant translocation, we monitored 16 translocations in Sri Lanka with GPS collars. All translocated elephants were released into national parks. Two were killed within the parks where they were released, while all the others left those parks. Translocated elephants showed variable responses: “homers” returned to the capture site, “wanderers” ranged widely, and “settlers” established home ranges in new areas soon after release. Translocation caused wider propagation and intensification of HEC, and increased elephant mortality. We conclude that translocation defeats both HEC mitigation and elephant conservation goals. PMID:23236404

  17. Simulations of Polymer Translocation

    NASA Astrophysics Data System (ADS)

    Vocks, H.

    2008-07-01

    Transport of molecules across membranes is an essential mechanism for life processes. These molecules are often long, and the pores in the membranes are too narrow for the molecules to pass through as a single unit. In such circumstances, the molecules have to squeeze -- i.e., translocate -- themselves through the pores. DNA, RNA and proteins are such naturally occuring long molecules in a variety of biological processes. Understandably, the process of translocation has been an active topic of current research: not only because it is a cornerstone of many biological processes, but also due to its relevance for practical applications. Translocation is a complicated process in living organisms -- the presence of chaperone molecules, pH, chemical potential gradients, and assisting molecular motors strongly influence its dynamics. Consequently, the translocation process has been empirically studied in great variety in biological literature. Study of translocation as a biophysical process is more recent. Herein, the polymer is simplified to a sequentially connected string of N monomers as it passes through a narrow pore on a membrane. The quantities of interest are the typical time scale for the polymer to leave a confining cell (the ``escape of a polymer from a vesicle'' time scale), and the typical time scale the polymer spends in the pore (the ``dwell'' time scale) as a function of N and other parameters like membrane thickness, membrane adsorption, electrochemical potential gradient, etc. Our research is focused on computer simulations of translocation. Since our main interest is in the scaling properties, we use a highly simplified description of the translocation process. The polymer is described as a self-avoiding walk on a lattice, and its dynamics consists of single-monomer jumps from one lattice site to another neighboring one. Since we have a very efficient program to simulate such polymer dynamics, which we decribe in Chapter 2, we can perform long

  18. What drives the translocation of proteins?

    PubMed Central

    Simon, S M; Peskin, C S; Oster, G F

    1992-01-01

    We propose that protein translocation across membranes is driven by biased random thermal motion. This "Brownian ratchet" mechanism depends on chemical asymmetries between the cis and trans sides of the membrane. Several mechanisms could contribute to rectifying the thermal motion of the protein, such as binding and dissociation of chaperonins to the translocating chain, chain coiling induced by pH and/or ionic gradients, glycosylation, and disulfide bond formation. This helps explain the robustness and promiscuity of these transport systems. Images PMID:1349170

  19. The inhibitory effects of boldine, glaucine, and probucol on TPA-induced down regulation of gap junction function. Relationships to intracellular peroxides, protein kinase C translocation, and connexin 43 phosphorylation.

    PubMed

    Hu, J; Speisky, H; Cotgreave, I A

    1995-11-01

    The naturally occurring antioxidant boldine and its di-methoxy analogue glucine, as well as the drug antioxidant probucol, all inhibit TPA-induced downregulation of gap junctional intercellular communication in WB-F344 rat liver epithelial cells in dose-dependent manners. The compounds were essentially 100% inhibitory to the effect of TPA (10 nM) at 50 microM each. Analysis of the mechanism of the antitumor promotive action of these agents in vitro revealed that boldine and probucol (both at 10 microM) totally inhibited the TPA-induced accumulation of intracellular oxidants. Additionally, boldine, glaucine, and probucol, each at 50 microM, inhibited TPA-induced translocation of protein kinase C (PKC) to the particulate fraction of the cells, with concomitant inhibition of TPA-induced hyperphosphorylation of gap junctional connexin 43 (cx43) and TPA-induced internalisation of cx43 protein from the plasma membrane of the cells. None of the compounds inhibited the binding of (3H)-PDBu to TPA-specific binding sites in the cells. The results indicate that antioxidant molecules, irrespective of structure, possess common antitumor promotive potential in this model of gap junctional intercellular communication. The data also indicate that the compounds may interfere with the promotive function of TPA, at least in part, by the destruction of oxidants within the cells. Xanthine oxidase was excluded as a major source of such intracellular oxidants because allopurinol (50 microM) did not significantly affect either the accumulation of oxidants in the cells or the downregulation of gap junctional communication in response to TPA. Taken together, these data also suggest that TPA-induced oxidants play a role in the translocation of PKC to cellular membranes and it is at this level where the antioxidants may interfere in TPA-induced downregulation of gap junctional function. PMID:7503766

  20. Oncogene Translocations and NHL

    Cancer.gov

    A colloboration with several large population-based cohorts to determine whether the prevalence or level of t14;18 is associated with risk of NHL and to investigate the clonal relationship between translocation-bearing cells and subsequent tumors

  1. Toward a Behavior of Reciprocity

    PubMed Central

    Gernsbacher, Morton Ann

    2014-01-01

    It is frequently believed that autism is characterized by a lack of social or emotional reciprocity. In this article, I question that assumption by demonstrating how many professionals—researchers and clinicians—and likewise many parents, have neglected the true meaning of reciprocity. Reciprocity is “a relation of mutual dependence or action or influence,” or “a mode of exchange in which transactions take place between individuals who are symmetrically placed.” Assumptions by clinicians and researchers suggest that they have forgotten that reciprocity needs to be mutual and symmetrical—that reciprocity is a two-way street. Research is reviewed to illustrate that when professionals, peers, and parents are taught to act reciprocally, autistic children become more responsive. In one randomized clinical trial of “reciprocity training” to parents, their autistic children's language developed rapidly and their social engagement increased markedly. Other demonstrations of how parents and professionals can increase their behavior of reciprocity are provided. PMID:25598865

  2. TNFα Amplifies DNaseI Expression in Renal Tubular Cells while IL-1β Promotes Nuclear DNaseI Translocation in an Endonuclease-Inactive Form

    PubMed Central

    Thiyagarajan, Dhivya; Rekvig, Ole Petter; Seredkina, Natalya

    2015-01-01

    We have demonstrated that the renal endonuclease DNaseI is up-regulated in mesangial nephritis while down-regulated during progression of the disease. To determine the basis for these reciprocal DNaseI expression profiles we analyse processes accounting for an early increase in renal DNaseI expression. Main hypotheses were that i. the mesangial inflammation and secreted pro-inflammatory cytokines directly increase DNaseI protein expression in tubular cells, ii. the anti-apoptotic protein tumor necrosis factor receptor-associated protein 1 (Trap 1) is down-regulated by increased expression of DNaseI due to transcriptional interference, and iii. pro-inflammatory cytokines promote nuclear translocation of a variant of DNaseI. The latter hypothesis emerges from the fact that anti-DNaseI antibodies stained tubular cell nuclei in murine and human lupus nephritis. The present study was performed on human tubular epithelial cells stimulated with pro-inflammatory cytokines. Expression of the DNaseI and Trap 1 genes was determined by qPCR, confocal microscopy, gel zymography, western blot and by immune electron microscopy. Results from in vitro cell culture experiments were analysed for biological relevance in kidneys from (NZBxNZW)F1 mice and human patients with lupus nephritis. Central data indicate that stimulating the tubular cells with TNFα promoted increased DNaseI and reduced Trap 1 expression, while TNFα and IL-1β stimulation induced nuclear translocation of the DNaseI. TNFα-stimulation resulted in 3 distinct effects; increased DNaseI and IL-1β gene expression, and nuclear translocation of DNaseI. IL-1β-stimulation solely induced nuclear DNaseI translocation. Tubular cells stimulated with TNFα and simultaneously transfected with IL-1β siRNA resulted in increased DNaseI expression but no nuclear translocation. This demonstrates that IL-1β promotes nuclear translocation of a cytoplasmic variant of DNaseI since translocation clearly was not dependent on DNase

  3. Retrospective biodosimetry using translocation frequency in a stable cell of occupationally exposed to ionizing radiation

    PubMed Central

    Cho, Min Su; Lee, Jin Kyung; Bae, Keum Seok; Han, Eun-Ae; Jang, Seong Jae; Ha, Wi-Ho; Lee, Seung-Sook; Barquinero, Joan Francesc; Kim, Wan Tae

    2015-01-01

    Two cases of hematological malignancies were reported in an industrial radiography company over a year, which were reasonably suspected of being consequences of prolonged exposure to ionizing radiation because of the higher incidence than expected in the general population. We analyzed chromosomal aberrations in the peripheral blood lymphocytes from the other workers who had been working under similar circumstances as the patients in the company. Among the subjects tested, 10 workers who belonged to the highest band were followed up periodically for 1.5 years since the first analysis. The aim of this study was to clarify pertinence of translocation analysis to an industrial set-up where chronic exposure was commonly expected. To be a useful tool for a retrospective biodosimetry, the aberrations need to be persistent for a decade or longer. Therefore we calculated the decline rates and half-lives of frequency for both a reciprocal translocation and a dicentric chromosome and compared them. In this study, while the frequency of reciprocal translocations was maintained at the initial level, dicentric chromosomes were decreased to 46.9% (31.0–76.5) of the initial frequency over the follow-up period. Our results support the long-term stability of reciprocal translocation through the cell cycle and validate the usefulness of translocation analysis as a retrospective biodosimetry for cases of occupational exposure. PMID:25922373

  4. Retrospective biodosimetry using translocation frequency in a stable cell of occupationally exposed to ionizing radiation.

    PubMed

    Cho, Min Su; Lee, Jin Kyung; Bae, Keum Seok; Han, Eun-Ae; Jang, Seong Jae; Ha, Wi-Ho; Lee, Seung-Sook; Barquinero, Joan Francesc; Kim, Wan Tae

    2015-07-01

    Two cases of hematological malignancies were reported in an industrial radiography company over a year, which were reasonably suspected of being consequences of prolonged exposure to ionizing radiation because of the higher incidence than expected in the general population. We analyzed chromosomal aberrations in the peripheral blood lymphocytes from the other workers who had been working under similar circumstances as the patients in the company. Among the subjects tested, 10 workers who belonged to the highest band were followed up periodically for 1.5 years since the first analysis. The aim of this study was to clarify pertinence of translocation analysis to an industrial set-up where chronic exposure was commonly expected. To be a useful tool for a retrospective biodosimetry, the aberrations need to be persistent for a decade or longer. Therefore we calculated the decline rates and half-lives of frequency for both a reciprocal translocation and a dicentric chromosome and compared them. In this study, while the frequency of reciprocal translocations was maintained at the initial level, dicentric chromosomes were decreased to 46.9% (31.0-76.5) of the initial frequency over the follow-up period. Our results support the long-term stability of reciprocal translocation through the cell cycle and validate the usefulness of translocation analysis as a retrospective biodosimetry for cases of occupational exposure. PMID:25922373

  5. Feeding induces translocation of vacuolar proton ATPase and pendrin to the membrane of leopard shark (Triakis semifasciata) mitochondrion-rich gill cells.

    PubMed

    Roa, Jinae N; Munévar, Christian L; Tresguerres, Martin

    2014-08-01

    In this study we characterized mitochondrion-rich (MR) cells and regulation of acid/base (A/B) relevant ion-transporting proteins in leopard shark (Triakis semifasciata) gills. Immunohistochemistry revealed that leopard shark gills posses two separate cell populations that abundantly express either Na⁺/K⁺-ATPase (NKA) or V-H⁺-ATPase (VHA), but not both ATPases together. Co-immunolocalization with mitochondrial Complex IV demonstrated, for the first time in shark gills, that both NKA- and VHA-rich cells are also MR cells, and that all MR cells are either NKA- or VHA-rich cells. Additionally we localized the anion exchanger pendrin to VHA-rich cells, but not NKA-rich cells. In starved sharks, VHA was localized throughout the cell cytoplasm and pendrin was present at the apical pole (but not in the membrane). However, in a significant number of gill cells from fed leopard sharks, VHA translocated to the basolateral membrane (as previously described in dogfish), and pendrin translocated to the apical membrane. Our results highlight the importance of translocation of ion-transporting proteins to the cell membrane as a regulatory mechanism for A/B regulation. PMID:24746982

  6. SEPT9_i1 is required for the association between HIF-1α and importin-α to promote efficient nuclear translocation

    PubMed Central

    Golan, Maya; Mabjeesh, Nicola J

    2013-01-01

    Septin 9 isoform 1 (SEPT9_i1) protein associates with hypoxia-inducible factor (HIF)-1α to augment HIF-1 transcriptional activity. The first 25 amino acids of SEPT9_i1 (N25) are unique compared with other members of the mammalian septin family. This N25 domain is critical for HIF-1 activation by SEPT9_i1 but not essential for the protein-protein interaction. Here, we show that expression of N25 induces a significant dose-dependent inhibition of HIF-1 transcriptional activity under normoxia and hypoxia without influencing cellular HIF-1α protein levels. In vivo, N25 expression inhibits proliferation, tumor growth and angiogenesis concomitant with decreased expression levels of intratumoral HIF-1 downstream genes. Depletion of endogenous SEPT9_i1 or the exogenous expression of N25 fragment reduces nuclear HIF-1α levels accompanied by reciprocal accumulation of HIF-1α in the cytoplasm. Mechanistically, SEPT9_i1 binds to importin-α through N25 depending on its bipartite nuclear localization signal, to scaffold the association between HIF-1α and importin-α, which leads to facilitating HIF-1α nuclear translocation. Our data explore a new and a previously unrecognized role of a septin protein in the cytoplasmic-nuclear translocation process. This new level in the regulation of HIF-1α translocation is critical for efficient HIF-1 transcriptional activation that could be targeted for cancer therapeutics. PMID:24067372

  7. Trust, Respect, and Reciprocity

    PubMed Central

    Phong, Tran Viet; Nhan, Le Nguyen Thanh; Dung, Nguyen Thanh; Ngan, Ta Thi Dieu; Kinh, Nguyen Van; Parker, Michael; Bull, Susan

    2015-01-01

    International science funders and publishers are driving a growing trend in data sharing. There is mounting pressure on researchers in low- and middle-income settings to conform to new sharing policies, despite minimal empirically grounded accounts of the ethical challenges of implementing the policies in these settings. This study used in-depth interviews and focus group discussions with 48 stakeholders in Vietnam to explore the experiences, attitudes, and expectations that inform ethical and effective approaches to sharing clinical research data. Distinct views on the role of trust, respect, and reciprocity were among those that emerged to inform culturally appropriate best practices. We conclude by discussing the challenges that authors of data-sharing policies should consider in this unique context. PMID:26297747

  8. Reciprocating linear motor

    NASA Technical Reports Server (NTRS)

    Goldowsky, Michael P. (Inventor)

    1987-01-01

    A reciprocating linear motor is formed with a pair of ring-shaped permanent magnets having opposite radial polarizations, held axially apart by a nonmagnetic yoke, which serves as an axially displaceable armature assembly. A pair of annularly wound coils having axial lengths which differ from the axial lengths of the permanent magnets are serially coupled together in mutual opposition and positioned with an outer cylindrical core in axial symmetry about the armature assembly. One embodiment includes a second pair of annularly wound coils serially coupled together in mutual opposition and an inner cylindrical core positioned in axial symmetry inside the armature radially opposite to the first pair of coils. Application of a potential difference across a serial connection of the two pairs of coils creates a current flow perpendicular to the magnetic field created by the armature magnets, thereby causing limited linear displacement of the magnets relative to the coils.

  9. Reciprocating wind engine

    SciTech Connect

    Van Mechelen, B.

    1980-12-09

    A reciprocating wind engine is described which utilizes plural, movably mounted sets of panels to form pistons. Cooperating first and second pistons may be spaced from each other on either side of a central crankshaft. As the wind strikes the surface of a first set of panels, the first piston is moved toward the crankshaft and the second piston is pulled toward the crankshaft from the opposite side. When both pistons are adjacent the crankshaft, the panels on the first or windward piston open to allow the wind to pass therethrough into contact with the panels of the second piston which are closed to present a uniform surface to the wind. The pistons are forced away from the crankshaft to complete one cycle of operation. The output from the crankshaft may be utilized to generate electricity, or for any other suitable purpose. Plural engine segments may be cooperatively joined together to form a bank of such units.

  10. Propofol pretreatment attenuates LPS-induced granulocyte-macrophage colony-stimulating factor production in cultured hepatocytes by suppressing MAPK/ERK activity and NF-{kappa}B translocation

    SciTech Connect

    Jawan, Bruno; Kao, Y.-H.; Goto, Shigeru; Pan, M.-C.; Lin, Y.-C.; Hsu, L.-W.; Nakano, Toshiaki; Lai, C.-Y.; Sun, C.-K.; Cheng, Y.-F.; Tai, M.-H.

    2008-06-15

    Propofol (PPF), a widely used intravenous anesthetic for induction and maintenance of anesthesia during surgeries, was found to possess suppressive effect on host immunity. This study aimed at investigating whether PPF plays a modulatory role in the lipopolysaccharide (LPS)-induced inflammatory cytokine expression in a cell line of rat hepatocytes. Morphological observation and viability assay showed that PPF exhibits no cytotoxicity at concentrations up to 300 {mu}M after 48 h incubation. Pretreatment with 100 {mu}M PPF for 24 h prior to LPS stimulation was performed to investigate the modulatory effect on LPS-induced inflammatory gene production. The results of semi-quantitative RT-PCR demonstrated that PPF pretreatment significantly suppressed the LPS-induced toll-like receptor (TLR)-4, CD14, tumor necrosis factor (TNF)-{alpha}, and granulocyte-macrophage colony-stimulating factor (GM-CSF) gene expression. Western blotting analysis showed that PPF pretreatment potentiated the LPS-induced TLR-4 downregulation. Flow cytometrical analysis revealed that PPF pretreatment showed no modulatory effect on the LPS-upregulated CD14 expression on hepatocytes. In addition, PPF pretreatment attenuated the phosphorylation of mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) and I{kappa}B{alpha}, as well as the nuclear translocation of NF-{kappa}B primed by LPS. Moreover, addition of PD98059, a MAPK kinase inhibitor, significantly suppressed the LPS-induced NF-{kappa}B nuclear translocation and GM-CSF production, suggesting that the PPF-attenuated GM-CSF production in hepatocytes may be attributed to its suppressive effect on MAPK/ERK signaling pathway. In conclusion, PPF as an anesthetic may clinically benefit those patients who are vulnerable to sepsis by alleviating sepsis-related inflammatory response in livers.

  11. Strandwise translocation of a DNA glycosylase on undamaged DNA

    SciTech Connect

    Qi, Yan; Nam, Kwangho; Spong, Marie C.; Banerjee, Anirban; Sung, Rou-Jia; Zhang, Michael; Karplus, Martin; Verdine, Gregory L.

    2012-05-14

    Base excision repair of genotoxic nucleobase lesions in the genome is critically dependent upon the ability of DNA glycosylases to locate rare sites of damage embedded in a vast excess of undamaged DNA, using only thermal energy to fuel the search process. Considerable interest surrounds the question of how DNA glycosylases translocate efficiently along DNA while maintaining their vigilance for target damaged sites. Here, we report the observation of strandwise translocation of 8-oxoguanine DNA glycosylase, MutM, along undamaged DNA. In these complexes, the protein is observed to translocate by one nucleotide on one strand while remaining untranslocated on the complementary strand. We further report that alterations of single base-pairs or a single amino acid substitution (R112A) can induce strandwise translocation. Molecular dynamics simulations confirm that MutM can translocate along DNA in a strandwise fashion. These observations reveal a previously unobserved mode of movement for a DNA-binding protein along the surface of DNA.

  12. ADVANCED RECIPROCATING COMPRESSION TECHNOLOGY (ARCT)

    SciTech Connect

    Danny M. Deffenbaugh; Klaus Brun; Ralph E. Harris; J. Pete Harrell; Robert J. Mckee; J. Jeffrey Moore; Steven J. Svedeman; Anthony J. Smalley; Eugene L. Broerman; Robert A Hart; Marybeth G. Nored; Ryan S. Gernentz; Shane P. Siebenaler

    2005-12-01

    The U.S. natural gas pipeline industry is facing the twin challenges of increased flexibility and capacity expansion. To meet these challenges, the industry requires improved choices in gas compression to address new construction and enhancement of the currently installed infrastructure. The current fleet of installed reciprocating compression is primarily slow-speed integral machines. Most new reciprocating compression is and will be large, high-speed separable units. The major challenges with the fleet of slow-speed integral machines are: limited flexibility and a large range in performance. In an attempt to increase flexibility, many operators are choosing to single-act cylinders, which are causing reduced reliability and integrity. While the best performing units in the fleet exhibit thermal efficiencies between 90% and 92%, the low performers are running down to 50% with the mean at about 80%. The major cause for this large disparity is due to installation losses in the pulsation control system. In the better performers, the losses are about evenly split between installation losses and valve losses. The major challenges for high-speed machines are: cylinder nozzle pulsations, mechanical vibrations due to cylinder stretch, short valve life, and low thermal performance. To shift nozzle pulsation to higher orders, nozzles are shortened, and to dampen the amplitudes, orifices are added. The shortened nozzles result in mechanical coupling with the cylinder, thereby, causing increased vibration due to the cylinder stretch mode. Valve life is even shorter than for slow speeds and can be on the order of a few months. The thermal efficiency is 10% to 15% lower than slow-speed equipment with the best performance in the 75% to 80% range. The goal of this advanced reciprocating compression program is to develop the technology for both high speed and low speed compression that will expand unit flexibility, increase thermal efficiency, and increase reliability and integrity

  13. Lysophosphatidylcholine Triggers TLR2- and TLR4-Mediated Signaling Pathways but Counteracts LPS-Induced NO Synthesis in Peritoneal Macrophages by Inhibiting NF-κB Translocation and MAPK/ERK Phosphorylation

    PubMed Central

    Carneiro, Alan Brito; Iaciura, Bruna Maria Ferreira; Nohara, Lilian Lie; Lopes, Carla Duque; Veas, Esteban Mauricio Cordero; Mariano, Vania Sammartino; Bozza, Patricia Torres; Lopes, Ulisses Gazos; Atella, Georgia Correa; Almeida, Igor Correia; Silva-Neto, Mário Alberto Cardoso

    2013-01-01

    Background Lysophosphatidylcholine (LPC) is the main phospholipid component of oxidized low-density lipoprotein (oxLDL) and is usually noted as a marker of several human diseases, such as atherosclerosis, cancer and diabetes. Some studies suggest that oxLDL modulates Toll-like receptor (TLR) signaling. However, effector molecules that are present in oxLDL particles and can trigger TLR signaling are not yet clear. LPC was previously described as an attenuator of sepsis and as an immune suppressor. In the present study, we have evaluated the role of LPC as a dual modulator of the TLR-mediated signaling pathway. Methodology/Principal Findings HEK 293A cells were transfected with TLR expression constructs and stimulated with LPC molecules with different fatty acid chain lengths and saturation levels. All LPC molecules activated both TLR4 and TLR2-1 signaling, as evaluated by NF-қB activation and IL-8 production. These data were confirmed by Western blot analysis of NF-қB translocation in isolated nuclei of peritoneal murine macrophages. However, LPC counteracted the TLR4 signaling induced by LPS. In this case, NF-қB translocation, nitric oxide (NO) synthesis and the expression of inducible nitric oxide synthase (iNOS) were blocked. Moreover, LPC activated the MAP Kinases p38 and JNK, but not ERK, in murine macrophages. Interestingly, LPC blocked LPS-induced ERK activation in peritoneal macrophages but not in TLR-transfected cells. Conclusions/Significance The above results indicate that LPC is a dual-activity ligand molecule. It is able to trigger a classical proinflammatory phenotype by activating TLR4- and TLR2-1-mediated signaling. However, in the presence of classical TLR ligands, LPC counteracts some of the TLR-mediated intracellular responses, ultimately inducing an anti-inflammatory phenotype; LPC may thus play a role in the regulation of cell immune responses and disease progression. PMID:24312681

  14. Simpler valve for reciprocating engines

    NASA Technical Reports Server (NTRS)

    Akkerman, J. W.

    1978-01-01

    Simpler design eliminating camshafts, cams, and mechanical springs should improve reliability of hydrazine powered reciprocating engines. Valve is expected to improve efficiency, and reduce weight of engines in range up to 50 horsepower.

  15. Moral assessment in indirect reciprocity

    PubMed Central

    Sigmund, Karl

    2012-01-01

    Indirect reciprocity is one of the mechanisms for cooperation, and seems to be of particular interest for the evolution of human societies. A large part is based on assessing reputations and acting accordingly. This paper gives a brief overview of different assessment rules for indirect reciprocity, and studies them by using evolutionary game dynamics. Even the simplest binary assessment rules lead to complex outcomes and require considerable cognitive abilities. PMID:21473870

  16. Group formation through indirect reciprocity

    NASA Astrophysics Data System (ADS)

    Oishi, Koji; Shimada, Takashi; Ito, Nobuyasu

    2013-03-01

    The emergence of group structure of cooperative relations is studied in an agent-based model. It is proved that specific types of reciprocity norms lead individuals to split into two groups only inside of which they are cooperative. The condition for the evolutionary stability of the norms is also obtained. This result suggests reciprocity norms, which usually promote cooperation, can cause society's separation into multiple groups.

  17. Safety of probiotics: translocation and infection.

    PubMed

    Liong, Min-Tze

    2008-04-01

    The long history of safety has contributed to the acceptance of probiotics as a safe food adjunct. Consequently, many probiotic products and their applications have been granted GRAS (generally regarded as safe) status. However, this classification has been frequently generalized for all probiotic strains regardless of their application. Cases of probiotics from the genera Lactobacillus, Leuconostoc, Pediococcus, Enterococcus, and Bifidobacterium have been isolated from infection sites, leading to the postulation that these probiotics can translocate. Probiotic translocation is difficult to induce in healthy humans, and even if it does occur, detrimental effects are rare. Despite this, various reports have documented health-damaging effects of probiotic translocation in immunocompromised patients. Due to probiotics' high degree of safety and their morphological confusion with other pathogenic bacteria, they are often overlooked as contaminants and are least suspected as pathogens. However, the antibiotic resistance of some strains has increased the complexity of their eradication. Probiotic translocation and infection deserve further investigation and should become a facet of safety assessment so the negative effects of probiotics do not outweigh the benefits. PMID:18366533

  18. A reciprocating twin-channel model for ABC transporters.

    PubMed

    Jones, Peter M; George, Anthony M

    2014-08-01

    ABC transporters comprise a large, diverse, and ubiquitous superfamily of membrane active transporters. Their core architecture is a dimer of dimers, comprising two transmembrane (TM) domains that bind substrate, and two ATP-binding cassettes, which use the cell's energy currency to couple substrate translocation to ATP hydrolysis. Despite the availability of over a dozen resolved structures and a wealth of biochemical and biophysical data, this field is bedeviled by controversy and long-standing mechanistic questions remain unresolved. The prevailing paradigm for the ABC transport mechanism is the Switch Model, in which the ATP-binding cassettes dimerize upon binding two ATP molecules, and thence dissociate upon sequential ATP hydrolysis. This cycle of nucleotide-binding domain (NBD) dimerization and dissociation is coupled to a switch between inward- or outward facing conformations of a single TM channel; this alternating access enables substrate binding on one face of the membrane and its release at the other. Notwithstanding widespread acceptance of the Switch Model, there is substantial evidence that the NBDs do not separate very much, if at all, and thus physical separation of the ATP cassettes observed in crystallographic structures may be an artefact. An alternative Constant Contact Model has been proposed, in which ATP hydrolysis occurs alternately at the two ATP-binding sites, with one of the sites remaining closed and containing occluded nucleotide at all times. In this model, the cassettes remain in contact and the active sites swing open in an alternately seesawing motion. Whilst the concept of NBD association/dissociation in the Switch Model is naturally compatible with a single alternating-access channel, the asymmetric functioning proposed by the Constant Contact model suggests an alternating or reciprocating function in the TMDs. Here, a new model for the function of ABC transporters is proposed in which the sequence of ATP binding, hydrolysis, and

  19. Reciprocal feeding facilitation between above- and below-ground herbivores.

    PubMed

    McKenzie, Scott W; Vanbergen, Adam J; Hails, Rosemary S; Jones, T Hefin; Johnson, Scott N

    2013-10-23

    Interspecific interactions between insect herbivores predominantly involve asymmetric competition. By contrast, facilitation, whereby herbivory by one insect benefits another via induced plant susceptibility, is uncommon. Positive reciprocal interactions between insect herbivores are even rarer. Here, we reveal a novel case of reciprocal feeding facilitation between above-ground aphids (Amphorophora idaei) and root-feeding vine weevil larvae (Otiorhynchus sulcatus), attacking red raspberry (Rubus idaeus). Using two raspberry cultivars with varying resistance to these herbivores, we further demonstrate that feeding facilitation occurred regardless of host plant resistance. This positive reciprocal interaction operates via an, as yet, unreported mechanism. Specifically, the aphid induces compensatory growth, possibly as a prelude to greater resistance/tolerance, whereas the root herbivore causes the plant to abandon this strategy. Both herbivores may ultimately benefit from this facilitative interaction. PMID:23883576

  20. DNA Translocations through Solid-State Plasmonic Nanopores

    PubMed Central

    2015-01-01

    Nanopores enable label-free detection and analysis of single biomolecules. Here, we investigate DNA translocations through a novel type of plasmonic nanopore based on a gold bowtie nanoantenna with a solid-state nanopore at the plasmonic hot spot. Plasmonic excitation of the nanopore is found to influence both the sensor signal (nanopore ionic conductance blockade during DNA translocation) and the process that captures DNA into the nanopore, without affecting the duration time of the translocations. Most striking is a strong plasmon-induced enhancement of the rate of DNA translocation events in lithium chloride (LiCl, already 10-fold enhancement at a few mW of laser power). This provides a means to utilize the excellent spatiotemporal resolution of DNA interrogations with nanopores in LiCl buffers, which is known to suffer from low event rates. We propose a mechanism based on plasmon-induced local heating and thermophoresis as explanation of our observations. PMID:25347403

  1. Indirect Reciprocity; A Field Experiment

    PubMed Central

    van Apeldoorn, Jacobien; Schram, Arthur

    2016-01-01

    Indirect reciprocity involves cooperative acts towards strangers, either in response to their kindness to third parties (downstream) or after receiving kindness from others oneself (upstream). It is considered to be important for the evolution of cooperative behavior amongst humans. Though it has been widely studied theoretically, the empirical evidence of indirect reciprocity has thus far been limited and based solely on behavior in laboratory experiments. We provide evidence from an online environment where members can repeatedly ask and offer services to each other, free of charge. For the purpose of this study we created several new member profiles, which differ only in terms of their serving history. We then sent out a large number of service requests to different members from all over the world. We observe that a service request is more likely to be rewarded for those with a profile history of offering the service (to third parties) in the past. This provides clear evidence of (downstream) indirect reciprocity. We find no support for upstream indirect reciprocity (in this case, rewarding the service request after having previously received the service from third parties), however. Our evidence of downstream indirect reciprocity cannot be attributed to reputational effects concerning one’s trustworthiness as a service user. PMID:27043712

  2. Direct reciprocity in structured populations

    PubMed Central

    van Veelen, Matthijs; García, Julián; Rand, David G.; Nowak, Martin A.

    2012-01-01

    Reciprocity and repeated games have been at the center of attention when studying the evolution of human cooperation. Direct reciprocity is considered to be a powerful mechanism for the evolution of cooperation, and it is generally assumed that it can lead to high levels of cooperation. Here we explore an open-ended, infinite strategy space, where every strategy that can be encoded by a finite state automaton is a possible mutant. Surprisingly, we find that direct reciprocity alone does not lead to high levels of cooperation. Instead we observe perpetual oscillations between cooperation and defection, with defection being substantially more frequent than cooperation. The reason for this is that “indirect invasions” remove equilibrium strategies: every strategy has neutral mutants, which in turn can be invaded by other strategies. However, reciprocity is not the only way to promote cooperation. Another mechanism for the evolution of cooperation, which has received as much attention, is assortment because of population structure. Here we develop a theory that allows us to study the synergistic interaction between direct reciprocity and assortment. This framework is particularly well suited for understanding human interactions, which are typically repeated and occur in relatively fluid but not unstructured populations. We show that if repeated games are combined with only a small amount of assortment, then natural selection favors the behavior typically observed among humans: high levels of cooperation implemented using conditional strategies. PMID:22665767

  3. Protein kinase C translocation in human blood platelets

    SciTech Connect

    Wang, Hoauyan; Friedman, E. )

    1990-01-01

    Protein kinase C (PKC) activity and translocation in response to the phorbol ester, phorbol 12-myristate, 13-acetate (PMA), serotonin (5-HT) and thrombin was assessed in human platelets. Stimulation with PMA and 5-HT for 10 minutes or thrombin for 1 minute elicited platelet PKC translocation from cytosol to membrane. The catecholamines, norepinephrine or epinephrine at 10 {mu}M concentrations did not induce redistribution of platelet PKC. Serotonin and the specific 5-HT{sub 2} receptor agonist, 1-(2,5-dimethoxy-4-iodophenyl)-2-amino-propane (DOI) but not the 5-HT{sub 1A} or 5-HT{sub 1B} agonists, ({plus minus}) 8-hydroxy-dipropylamino-tetralin (8-OH-DPAT) or 5-methoxy-3-3-(1,2,3,6-tetrahydro-4-pyridin) 1H-indole succinate (RU 24969) induced dose-dependent PKC translocations. Serotonin-evoked PKC translocation was blocked by selective 5-HT{sub 2} receptor antagonists, ketanserin and spiroperidol. These results suggest that, in human platelets, PMA, thrombin and 5-HT can elicit PKC translocation from cytosol to membrane. Serotonin-induced PKC translocation in platelets is mediated via 5-HT{sub 2} receptors.

  4. Chikusetsusaponin IVa methyl ester induces cell cycle arrest by the inhibition of nuclear translocation of β-catenin in HCT116 cells

    SciTech Connect

    Lee, Kyung-Mi; Yun, Ji Ho; Lee, Dong Hwa; Park, Young Gyun; Son, Kun Ho; Nho, Chu Won; Kim, Yeong Shik

    2015-04-17

    We demonstrate that chikusetsusaponin IVa methyl ester (CME), a triterpenoid saponin from the root of Achyranthes japonica, has an anticancer activity. We investigate its molecular mechanism in depth in HCT116 cells. CME reduces the amount of β-catenin in nucleus and inhibits the binding of β-catenin to specific DNA sequences (TCF binding elements, TBE) in target gene promoters. Thus, CME appears to decrease the expression of cell cycle regulatory proteins such as Cyclin D1, as a representative target for β-catenin, as well as CDK2 and CDK4. As a result of the decrease of the cell cycle regulatory proteins, CME inhibits cell proliferation by arresting the cell cycle at the G0/G1 phase. Therefore, we suggest that CME as a novel Wnt/β-catenin inhibitor can be a putative agent for the treatment of colorectal cancers. - Highlights: • CME inhibits cell proliferation in HCT116 cells. • CME increases cell cycle arrest at G0/G1 phase and apoptosis. • CME attenuates cyclin D1 and regulates cell cycle regulatory proteins. • CME inhibits β-catenin translocation to nucleus.

  5. Characterization and mechanism of stress-induced translocation of 78-kilodalton glucose-regulated protein (GRP78) to the cell surface.

    PubMed

    Tsai, Yuan-Li; Zhang, Yi; Tseng, Chun-Chih; Stanciauskas, Ramunas; Pinaud, Fabien; Lee, Amy S

    2015-03-27

    Glucose-regulated protein (GRP78)/BiP, a major chaperone in the endoplasmic reticulum, is recently discovered to be preferably expressed on the surface of stressed cancer cells, where it regulates critical oncogenic signaling pathways and is emerging as a target for anti-cancer therapy while sparing normal organs. However, because GRP78 does not contain classical transmembrane domains, its mechanism of transport and its anchoring at the cell surface are poorly understood. Using a combination of biochemical, mutational, FACS, and single molecule super-resolution imaging approaches, we discovered that GRP78 majorly exists as a peripheral protein on plasma membrane via interaction with other cell surface proteins including glycosylphosphatidylinositol-anchored proteins. Moreover, cell surface GRP78 expression requires its substrate binding activity but is independent of ATP binding or a membrane insertion motif conserved with HSP70. Unexpectedly, different cancer cell lines rely on different mechanisms for GRP78 cell surface translocation, implying that the process is cell context-dependent. PMID:25673690

  6. Ginkgo biloba Extract (EGb 761®) Inhibits Glutamate-induced Up-regulation of Tissue Plasminogen Activator Through Inhibition of c-Fos Translocation in Rat Primary Cortical Neurons.

    PubMed

    Cho, Kyu Suk; Lee, Ian Myungwon; Sim, Seobo; Lee, Eun Joo; Gonzales, Edson Luck; Ryu, Jong Hoon; Cheong, Jae Hoon; Shin, Chan Young; Kwon, Kyoung Ja; Han, Seol-Heui

    2016-01-01

    EGb 761(®) , a standardized extract of Ginkgo biloba leaves, has antioxidant and antiinflammatory properties in experimental models of neurodegenerative disorders such as stroke and Alzheimer's disease. Tissue plasminogen activator (tPA) acts a neuromodulator and plays a crucial role in the manifestation of neurotoxicity leading to exaggerated neuronal cell death in neurological insult conditions. In this study, we investigated the effects of EGb 761 on the basal and glutamate-induced activity and expression of tPA in rat primary cortical neurons. Under basal condition, EGb 761 inhibited both secreted and cellular tPA activities, without altering tPA mRNA level, as modulated by the activation of p38. Compared with basal condition, EGb 761 inhibited the glutamate-induced up-regulation of tPA mRNA resulting in the normalization of overt tPA activity and expression. c-Fos is a component of AP-1, which plays a critical role in the modulation of tPA expression. Interestingly, EGb 761 inhibited c-Fos nuclear translocation without affecting c-Fos expression in glutamate-induced rat primary cortical neurons. These results demonstrated that EGb 761 can modulate tPA activity under basal and glutamate-stimulated conditions by both translational and transcriptional mechanisms. Thus, EGb 761 could be a potential and effective therapeutic strategy in tPA-excessive neurotoxic conditions. PMID:26478151

  7. Hierarchical Classification by Multi-Level Reciprocity

    ERIC Educational Resources Information Center

    McQuitty, Louis L.

    1970-01-01

    A method is developed and illustrated which relaxes the principle of reciprocity in relation to characteristics of data and classifies in terms of successive levels of reciprocity, using two versions: (a) successive linkages, and (b) core assignments. (Author/RF)

  8. Influence of reciprocal links in social networks.

    PubMed

    Zhu, Yu-Xiao; Zhang, Xiao-Guang; Sun, Gui-Quan; Tang, Ming; Zhou, Tao; Zhang, Zi-Ke

    2014-01-01

    How does reciprocal links affect the function of real social network? Does reciprocal link and non-reciprocal link play the same role? Previous researches haven't displayed a clear picture to us until now according to the best of our knowledge. Motivated by this, in this paper, we empirically study the influence of reciprocal links in two representative real datasets, Sina Weibo and Douban. Our results demonstrate that the reciprocal links play a more important role than non-reciprocal ones in information diffusion process. In particular, not only coverage but also the speed of the information diffusion can be significantly enhanced by considering the reciprocal effect. We give some possible explanations from the perspectives of network connectivity and efficiency. This work may shed some light on the in-depth understanding and application of the reciprocal effect in directed online social networks. PMID:25072242

  9. Influence of Reciprocal Links in Social Networks

    PubMed Central

    Zhu, Yu-Xiao; Zhang, Xiao-Guang; Sun, Gui-Quan; Tang, Ming; Zhou, Tao; Zhang, Zi-Ke

    2014-01-01

    How does reciprocal links affect the function of real social network? Does reciprocal link and non-reciprocal link play the same role? Previous researches haven't displayed a clear picture to us until now according to the best of our knowledge. Motivated by this, in this paper, we empirically study the influence of reciprocal links in two representative real datasets, Sina Weibo and Douban. Our results demonstrate that the reciprocal links play a more important role than non-reciprocal ones in information diffusion process. In particular, not only coverage but also the speed of the information diffusion can be significantly enhanced by considering the reciprocal effect. We give some possible explanations from the perspectives of network connectivity and efficiency. This work may shed some light on the in-depth understanding and application of the reciprocal effect in directed online social networks. PMID:25072242

  10. Means and method of balancing multi-cylinder reciprocating machines

    DOEpatents

    Corey, John A.; Walsh, Michael M.

    1985-01-01

    A virtual balancing axis arrangement is described for multi-cylinder reciprocating piston machines for effectively balancing out imbalanced forces and minimizing residual imbalance moments acting on the crankshaft of such machines without requiring the use of additional parallel-arrayed balancing shafts or complex and expensive gear arrangements. The novel virtual balancing axis arrangement is capable of being designed into multi-cylinder reciprocating piston and crankshaft machines for substantially reducing vibrations induced during operation of such machines with only minimal number of additional component parts. Some of the required component parts may be available from parts already required for operation of auxiliary equipment, such as oil and water pumps used in certain types of reciprocating piston and crankshaft machine so that by appropriate location and dimensioning in accordance with the teachings of the invention, the virtual balancing axis arrangement can be built into the machine at little or no additional cost.

  11. Dynamic Antagonism between Phytochromes and PIF Family Basic Helix-Loop-Helix Factors Induces Selective Reciprocal Responses to Light and Shade in a Rapidly Responsive Transcriptional Network in Arabidopsis[C][W

    PubMed Central

    Leivar, Pablo; Tepperman, James M.; Cohn, Megan M.; Monte, Elena; Al-Sady, Bassem; Erickson, Erika; Quail, Peter H.

    2012-01-01

    Plants respond to shade-modulated light signals via phytochrome (phy)-induced adaptive changes, termed shade avoidance. To examine the roles of Phytochrome-Interacting basic helix-loop-helix Factors, PIF1, 3, 4, and 5, in relaying such signals to the transcriptional network, we compared the shade-responsive transcriptome profiles of wild-type and quadruple pif (pifq) mutants. We identify a subset of genes, enriched in transcription factor–encoding loci, that respond rapidly to shade, in a PIF-dependent manner, and contain promoter G-box motifs, known to bind PIFs. These genes are potential direct targets of phy-PIF signaling that regulate the primary downstream transcriptional circuitry. A second subset of PIF-dependent, early response genes, lacking G-box motifs, are enriched for auxin-responsive loci, and are thus potentially indirect targets of phy-PIF signaling, mediating the rapid cell expansion induced by shade. Comparing deetiolation- and shade-responsive transcriptomes identifies another subset of G-box–containing genes that reciprocally display rapid repression and induction in response to light and shade signals. These data define a core set of transcriptional and hormonal processes that appear to be dynamically poised to react rapidly to light-environment changes via perturbations in the mutually antagonistic actions of the phys and PIFs. Comparing the responsiveness of the pifq and triple pif mutants to light and shade confirms that the PIFs act with overlapping redundancy on seedling morphogenesis and transcriptional regulation but that each PIF contributes differentially to these responses. PMID:22517317

  12. Reciprocal and unidirectional scattering of parity-time symmetric structures.

    PubMed

    Jin, L; Zhang, X Z; Zhang, G; Song, Z

    2016-01-01

    Parity-time (PT) symmetry is of great interest. The reciprocal and unidirectional features are intriguing besides the (PT) symmetry phase transition. Recently, the reciprocal transmission, unidirectional reflectionless and invisibility are intensively studied. Here, we show the reciprocal reflection/transmission in (PT)-symmetric system is closely related to the type of (PT) symmetry, that is, the axial (reflection) (PT) symmetry leads to reciprocal reflection (transmission). The results are further elucidated by studying the scattering of rhombic ring form coupled resonators with enclosed synthetic magnetic flux. The nonreciprocal phase shift induced by the magnetic flux and gain/loss break the parity (P) and time-reversal (T) symmetry but keep the parity-time (PT) symmetry. The reciprocal reflection (transmission) and unidirectional transmission (reflection) are found in the axial (reflection) (PT)-symmetric ring centre. The explorations of symmetry and asymmetry from (PT) symmetry may shed light on novel one-way optical devices and application of (PT)-symmetric metamaterials. PMID:26876806

  13. Do infants detect indirect reciprocity?

    PubMed

    Meristo, Marek; Surian, Luca

    2013-10-01

    In social interactions involving indirect reciprocity, agent A acts prosocially towards B and this prompts C to act prosocially towards A. This happens because A's actions enhanced its reputation in the eyes of third parties. Indirect reciprocity may have been of central importance in the evolution of morality as one of the major mechanisms leading to the selection of helping and fair attitudes. Here we show that 10-month-old infants expect third parties to act positively towards fair donors who have distributed attractive resources equally between two recipients, rather than toward unfair donors who made unequal distributions. Infants' responses were dependent on the reciprocator's perceptual exposure to previous relevant events: they expected the reciprocator to reward the fair donor only when it had seen the distributive actions performed by the donors. We propose that infants were able to generate evaluations of agents that were based on the fairness of their distributive actions and to generate expectations about the social preferences of informed third parties. PMID:23887149

  14. Reciprocity principle and crack identification

    NASA Astrophysics Data System (ADS)

    Andrieux, Stéphane; Ben Abda, Amel; Duong Bui, Huy

    1999-02-01

    In this paper we are concerned with the planar crack identification problem defined by a unique complete elastostatic overdetermined boundary datum. Based on the reciprocity gap principle, we give a direct process for locating the host plane and we establish a new constuctive identifiability result for 3D planar cracks.

  15. Reciprocating Saw for Silicon Wafers

    NASA Technical Reports Server (NTRS)

    Morrison, A. D.; Collins, E. R., Jr.

    1985-01-01

    Concept increases productivity and wafer quality. Cutting wafers from silicon ingots produces smooth wafers at high rates with reduced blade wear. Involves straight reciprocating saw blade and slight rotation of ingot between cutting strokes. Many parallel blades combined to cut many wafers simultaneously from ingot.

  16. Thermal-powered reciprocating pump

    NASA Technical Reports Server (NTRS)

    Sabelman, E. E.

    1972-01-01

    Waste heat from radioisotope thermal generators in spacecraft is transported to keep instruments warm by two-cylinder reciprocating pump powered by energy from warm heat exchange fluid. Each cylinder has thermally nonconductive piston, heat exchange coil, and heat sink surface.

  17. The combination of high-fat diet-induced obesity and chronic ulcerative colitis reciprocally exacerbates adipose tissue and colon inflammation

    PubMed Central

    2011-01-01

    Background This study evaluated the relationship between ulcerative colitis and obesity, which are both chronic diseases characterized by inflammation and increases in immune cells and pro-inflammatory cytokines. Methods Mice with chronic ulcerative colitis induced by 2 cycles of dextran sodium sulfate (DSS) in the first and fourth week of the experiment were fed a high-fat diet (HFD) to induce obesity by 8 weeks. The animals were divided into 4 \\ groups (control, colitis, HFD and colitis + HFD). Results Obesity alone did not raise histopathology scores, but the combination of obesity and colitis worsened the scores in the colon compared to colitis group. Despite the reduction in weight gain, there was increased inflammatory infiltrate in both the colon and visceral adipose tissue of colitis + HFD mice due to increased infiltration of macrophages, neutrophils and lymphocytes. Intravital microscopy of VAT microvasculature showed an increase in leukocyte adhesion and rolling and overexpression of adhesion molecules compared to other groups. Moreover, circulating lymphocytes, monocytes and neutrophils in the spleen and cecal lymph nodes were increased in the colitis + HFD group. Conclusion Our results demonstrated the relationship between ulcerative colitis and obesity as aggravating factors for each disease, with increased inflammation in the colon and adipose tissue and systemic alterations observed in the spleen, lymph nodes and bloodstream. PMID:22073943

  18. Chromosome translocations measured by fluorescence in-situ hybridization: A promising biomarker

    SciTech Connect

    Lucas, J.N.; Straume, T.

    1995-10-01

    A biomarker for exposure and risk assessment would be most useful if it employs an endpoint that is highly quantitative, is stable with time, and is relevant to human risk. Recent advances in chromosome staining using fluorescence in situ hybridization (FISH) facilitate fast and reliable measurement of reciprocal translocations, a kind of DNA damage linked to both prior exposure and risk. In contrast to other biomarkers available, the frequency of reciprocal translocations in individuals exposed to whole-body radiation is stable with time post exposure, has a rather small inter-individual variability, and can be measured accurately at the low levels. Here, the authors discuss results from their studies demonstrating that chromosome painting can be used to reconstruct radiation dose for workers exposed within the dose limits, for individuals exposed a long time ago, and even for those who have been diagnosed with leukemia but not yet undergone therapy.

  19. Capuchin Monkeys Judge Third-Party Reciprocity

    ERIC Educational Resources Information Center

    Anderson, James R.; Takimoto, Ayaka; Kuroshima, Hika; Fujita, Kazuo

    2013-01-01

    Increasing interest is being shown in how children develop an understanding of reciprocity in social exchanges and fairness in resource distribution, including social exchanges between third parties. Although there are descriptions of reciprocity on a one-to-one basis in other species, whether nonhumans detect reciprocity and violations of…

  20. Reciprocal Teaching: Critical Reflection on Practice

    ERIC Educational Resources Information Center

    McAllum, Ruth

    2014-01-01

    This paper highlights reciprocal teaching as an inclusive instructional strategy that has been shown to improve reading comprehension and metacognitive skills. It provides a conceptual background to reciprocal teaching and examines its purpose, strengths and weaknesses. The notion of reciprocal teaching as an evidence-based practice is also…

  1. Reciprocal Regulation of Hypoxia-Inducible Factor 2α and GLI1 Expression Associated With the Radioresistance of Renal Cell Carcinoma

    SciTech Connect

    Zhou, Jiancheng; Wu, Kaijie; Gao, Dexuan; Zhu, Guodong; Wu, Dapeng; Wang, Xinyang; Chen, Yule; Du, Yuefeng; Song, Wenbin; Ma, Zhenkun; Authement, Craig; Saha, Debabrata; Hsieh, Jer-Tsong; He, Dalin

    2014-11-15

    Purpose: Renal cell carcinoma (RCC) is often considered a radioresistant tumor, but the molecular mechanism underlying its radioresistance is poorly understood. This study explored the roles of hypoxia-inducible factor 2α (HIF2α) and sonic hedgehog (SHH)-GLI1 signaling in mediating the radioresistance of RCC cells and to unveil the interaction between these 2 signaling pathways. Methods and Materials: The activities of SHH-GLI1 signaling pathway under normoxia and hypoxia in RCC cells were examined by real-time polymerase chain reaction, Western blot, and luciferase reporter assay. The expression of HIF2α and GLI1 in RCC patients was examined by immunohistochemistry, and their correlation was analyzed. Furthermore, RCC cells were treated with HIF2α-specific shRNA (sh-HIF2α), GLI1 inhibitor GANT61, or a combination to determine the effect of ionizing radiation (IR) on RCC cells based on clonogenic assay and double-strand break repair assay. Results: RCC cells exhibited elevated SHH-GLI1 activities under hypoxia, which was mediated by HIF2α. Hypoxia induced GLI1 activation through SMO-independent pathways that could be ablated by PI3K inhibitor or MEK inhibitor. Remarkably, the SHH-GLI1 pathway also upregulated HIF2α expression in normoxia. Apparently, there was a positive correlation between HIF2α and GLI1 expression in RCC patients. The combination of sh-HIF2α and GLI1 inhibitor significantly sensitized RCC cells to IR. Conclusions: Cross-talk between the HIF2α and SHH-GLI1 pathways was demonstrated in RCC. Cotargeting these 2 pathways, significantly sensitizing RCC cells to IR, provides a novel strategy for RCC treatment.

  2. Genomic Comparison of Translocating and Non-Translocating Escherichia coli

    PubMed Central

    Bachmann, Nathan L.; Katouli, Mohammad; Polkinghorne, Adam

    2015-01-01

    Translocation of E. coli across the gut epithelium can result in fatal sepsis in post-surgical patients. In vitro and in vivo experiments have identified the existence of a novel pathotype of translocating E. coli (TEC) that employs an unknown mechanism for translocating across epithelial cells to the mesenteric lymph nodes and the blood stream in both humans and animal models. In this study the genomes of four TEC strains isolated from the mesenteric lymph nodes of a fatal case of hospitalised patient (HMLN-1), blood of pigs after experimental shock (PC-1) and after non-lethal haemorrhage in rats (KIC-1 and KIC-2) were sequenced in order to identify the genes associated with their adhesion and/or translocation. To facilitate the comparison, the genomes of a non-adhering, non-translocating E. coli (46–4) and adhering but non-translocating E. coli (73–89) were also sequenced and compared. Whole genome comparison revealed that three (HMLN-1, PC-1 and KIC-2) of the four TEC strains carried a genomic island that encodes a Type 6 Secretion System that may contribute to adhesion of the bacteria to gut epithelial cells. The human TEC strain HMLN-1 also carried the invasion ibeA gene, which was absent in the animal TEC strains and is likely to be associated with host-specific translocation. Phylogenetic analysis revealed that the four TEC strains were distributed amongst three distinct E. coli phylogroups, which was supported by the presence of phylogroup specific fimbriae gene clusters. The genomic comparison has identified potential genes that can be targeted with knock-out experiments to further characterise the mechanisms of E. coli translocation. PMID:26317913

  3. Upon intracellular processing, the C-terminal death domain-containing fragment of the p53-inducible PIDD/LRDD protein translocates to the nucleoli and interacts with nucleolin.

    PubMed

    Pick, Robert; Badura, Susanne; Bösser, Susanne; Zörnig, Martin

    2006-11-01

    The p53-inducible and death domain-containing PIDD/LRDD protein has been described as an adaptor protein, which forms large protein complexes with RAIDD, another death domain-containing protein, leading to recruitment, and activation of the initiator caspase-2, and p53-mediated apoptosis. Here, we describe in further detail the proteolytic processing of PIDD/LRDD that occurs in healthy cells before induction of apoptosis. We could demonstrate that the C-terminal fragment containing the PIDD death domain shuttles into the nucleoli. This translocation is mediated by or leads to the interaction of the PIDD death domain with nucleolin, a protein important for rRNA processing within nucleoli and possibly involved in the DNA damage response. Ectopically expressed LRDD and endogenous nucleolin co-localized within the nucleoli, and overexpression of both full-length LRDD and the LRDD death domain sensitized cells for UV-induced apoptosis. When expressed alone, the PIDD/LRDD death domain tended to form large filamentous structures resembling so-called death filaments. The functional consequences of the identified PIDD/nucleolin interaction remain to be elucidated, but may be related to a recently discovered new role for PIDD in the activation of NF-kappaB upon genotoxic stress. PMID:16982033

  4. Linoleic acid derivative DCP-LA ameliorates stress-induced depression-related behavior by promoting cell surface 5-HT1A receptor translocation, stimulating serotonin release, and inactivating GSK-3β.

    PubMed

    Kanno, Takeshi; Tanaka, Akito; Nishizaki, Tomoyuki

    2015-04-01

    Impairment of serotonergic neurotransmission is the major factor responsible for depression and glycogen synthase kinase 3β (GSK-3β) participates in serotonergic transmission-mediated signaling networks relevant to mental illnesses. In the forced-swim test to assess depression-like behavior, the immobility time for mice with restraint stress was significantly longer than that for nonstressed control mice. Postsynaptic cell surface localization of 5-HT1A receptor, but not 5-HT2A receptor, in the hypothalamus for mice with restraint stress was significantly reduced as compared with that for control mice, which highly correlated to prolonged immobility time, i.e., depression-like behavior. The linoleic acid derivative 8-[2-(2-pentyl-cyclopropylmethyl)-cyclopropyl]-octanoic acid (DCP-LA) restored restraint stress-induced reduction of cell surface 5-HT1A receptor and improved depression-like behavior in mice with restraint stress. Moreover, DCP-LA stimulated serotonin release from hypothalamic slices and cancelled restraint stress-induced reduction of GSK-3β phosphorylation at Ser9. Taken together, the results of the present study indicate that DCP-LA could ameliorate depression-like behavior by promoting translocation of 5-HT1A receptor to the plasma membrane on postsynaptic cells, stimulating serotonin release, and inactivating GSK-3β. PMID:24788685

  5. Abdominal radiation causes bacterial translocation

    SciTech Connect

    Guzman-Stein, G.; Bonsack, M.; Liberty, J.; Delaney, J.P.

    1989-02-01

    The purpose of this study was to determine if a single dose of radiation to the rat abdomen leads to bacterial translocation into the mesenteric lymph nodes (MLN). A second issue addressed was whether translocation correlates with anatomic damage to the mucosa. The radiated group (1100 cGy) which received anesthesia also was compared with a control group and a third group which received anesthesia alone but no abdominal radiation. Abdominal radiation lead to 100% positive cultures of MLN between 12 hr and 4 days postradiation. Bacterial translocation was almost nonexistent in the control and anesthesia group. Signs of inflammation and ulceration of the intestinal mucosa were not seen until Day 3 postradiation. Mucosal damage was maximal by Day 4. Bacterial translocation onto the MLN after a single dose of abdominal radiation was not apparently dependent on anatomical, histologic damage of the mucosa.

  6. PGD management scheme for older females with balanced translocations: Do older females have less chance of balanced embryo transfer?

    PubMed Central

    Tulay, Pinar; Gültomruk, Meral; Fındıklı, Necati; Bahçeci, Mustafa

    2016-01-01

    Objective Carriers of reciprocal and Robertsonian translocations have a higher risk of experiencing infertility and repeated miscarriages. It is well established that with advancing maternal age, the risk of aneuploidies in embryos increases. In this study, the chance of developing balanced embryos in translocation carriers with advanced maternal age was analyzed to establish a management scheme for couples seeking fertility treatment and preimplantation genetic diagnosis (PGD). Material and Methods Biopsy was performed on cleavage-stage embryos. Multicolor fluorescence in situ hybridization was used for PGD. The translocation carriers underwent a total of 55 cycles of PGD. Genetics diagnosis and cycle outcomes of PGD cases were examined. Results This study showed that the chance of obtaining a balanced embryo from the Robertsonian translocation carriers was significantly less when the maternal age is advanced. Similar rates for balanced embryos were obtained from the reciprocal translocation carriers. Conclusion The results of this study show that maternal age plays an important role and that genetic counselling and planning for a PGD cycle in translocation carriers, particularly for Robertsonian carriers, must be accordingly adapted. PMID:27403075

  7. Marmoset monkeys evaluate third-party reciprocity

    PubMed Central

    Kawai, Nobuyuki; Yasue, Miyuki; Banno, Taku; Ichinohe, Noritaka

    2014-01-01

    Many non-human primates have been observed to reciprocate and to understand reciprocity in one-to-one social exchanges. A recent study demonstrated that capuchin monkeys are sensitive to both third-party reciprocity and violation of reciprocity; however, whether this sensitivity is a function of general intelligence, evidenced by their larger brain size relative to other primates, remains unclear. We hypothesized that highly pro-social primates, even with a relatively smaller brain, would be sensitive to others' reciprocity. Here, we show that common marmosets discriminated between human actors who reciprocated in social exchanges with others and those who did not. Monkeys accepted rewards less frequently from non-reciprocators than they did from reciprocators when the non-reciprocators had retained all food items, but they accepted rewards from both actors equally when they had observed reciprocal exchange between the actors. These results suggest that mechanisms to detect unfair reciprocity in third-party social exchanges do not require domain-general higher cognitive ability based on proportionally larger brains, but rather emerge from the cooperative and pro-social tendencies of species, and thereby suggest this ability evolved in multiple primate lineages. PMID:24850892

  8. Reciprocal food sharing in the vampire bat

    NASA Astrophysics Data System (ADS)

    Wilkinson, Gerald S.

    1984-03-01

    Behavioural reciprocity can be evolutionarily stable1-3. Initial increase in frequency depends, however, on reciprocal altruists interacting predominantly with other reciprocal altruists either by associating within kin groups or by having sufficient memory to recognize and not aid nonreciprocators. Theory thus suggests that reciprocity should evolve more easily among animals which live in kin groups. Data are available separating reciprocity from nepotism only for unrelated nonhuman animals4. Here, I show that food sharing by regurgitation of blood among wild vampire bats (Desmodus rotundus) depends equally and independently on degree of relatedness and an index of opportunity for recipro cation. That reciprocity operates within groups containing both kin and nonkin is supported further with data on the availability of blood-sharing occasions, estimates of the economics of shar ing blood, and experiments which show that unrelated bats will reciprocally exchange blood in captivity.

  9. Reciprocal uniparental disomy in yeast

    PubMed Central

    Andersen, Sabrina L.; Petes, Thomas D.

    2012-01-01

    In the diploid cells of most organisms, including humans, each chromosome is usually distinguishable from its partner homolog by multiple single-nucleotide polymorphisms. One common type of genetic alteration observed in tumor cells is uniparental disomy (UPD), in which a pair of homologous chromosomes are derived from a single parent, resulting in loss of heterozygosity for all single-nucleotide polymorphisms while maintaining diploidy. Somatic UPD events are usually explained as reflecting two consecutive nondisjunction events. Here we report a previously undescribed mode of chromosome segregation in Saccharomyces cerevisiae in which one cell division produces daughter cells with reciprocal UPD for the same pair of chromosomes without an aneuploid intermediate. One pair of sister chromatids is segregated into one daughter cell and the other pair is segregated into the other daughter cell, mimicking a meiotic chromosome segregation pattern. We term this process “reciprocal uniparental disomy.” PMID:22665764

  10. Piston reciprocating compressed air engine

    SciTech Connect

    Cestero, L.G.

    1987-03-24

    A compressed air engine is described comprising: (a). a reservoir of compressed air, (b). two power cylinders each containing a reciprocating piston connected to a crankshaft and flywheel, (c). a transfer cylinder which communicates with each power cylinder and the reservoir, and contains a reciprocating piston connected to the crankshaft, (d). valve means controlled by rotation of the crankshaft for supplying compressed air from the reservoir to each power cylinder and for exhausting compressed air from each power cylinder to the transfer cylinder, (e). valve means controlled by rotation of the crankshaft for supplying from the transfer cylinder to the reservoir compressed air supplied to the transfer cylinder on the exhaust strokes of the pistons of the power cylinders, and (f). an externally powered fan for assisting the exhaust of compressed air from each power cylinder to the transfer cylinder and from there to the compressed air reservoir.

  11. Surface modification of graphene nanopores for protein translocation

    PubMed Central

    Shan, Y. P.; Tiwari, P. B.; Krishnakumar, P.; Vlassiouk, I.; Li, W.Z.; Wang, X.W.; Darici, Y.; Lindsay, S.M.; Wang, H. D.; Smirnov, S.; He, J.

    2014-01-01

    Studies of DNA translocation through graphene nanopores have revealed their potential for DNA sequencing. Here we report a study of protein translocation through chemically modified graphene nanopores. A transmission electron microscope (TEM) was used to cut nanopores with diameters between 5-20 nm in multilayer graphene prepared by chemical vapor deposition (CVD). After oxygen plasma treatment, the dependence of the measured ionic current on salt concentration and pH was consistent with a small surface charge induced by the formation of carboxyl groups. While translocation of gold nanoparticles (10 nm) was readily detected through such treated pores of a larger diameter, translocation of protein ferritin was not observed either for oxygen plasma treated pores, or for pores modified with mercaptohexadecanoic acid. Ferritin translocation events were reliably observed after the pores were modified with the phospholipid-PEG (DPPE-PEG750) amphiphile. The ion current signature of translocation events was complex, suggesting that a series of interactions between the protein and pore occur during the process. PMID:24231385

  12. Surface modification of graphene nanopores for protein translocation.

    PubMed

    Shan, Y P; Tiwari, P B; Krishnakumar, P; Vlassiouk, I; Li, W Z; Wang, X W; Darici, Y; Lindsay, S M; Wang, H D; Smirnov, S; He, J

    2013-12-13

    Studies of DNA translocation through graphene nanopores have revealed their potential for DNA sequencing. Here we report a study of protein translocation through chemically modified graphene nanopores. A transmission electron microscope (TEM) was used to cut nanopores with diameters between 5 and 20 nm in multilayer graphene prepared by chemical vapor deposition (CVD). After oxygen plasma treatment, the dependence of the measured ionic current on salt concentration and pH was consistent with a small surface charge induced by the formation of carboxyl groups. While translocation of gold nanoparticles (10 nm) was readily detected through such treated pores of a larger diameter, translocation of the protein ferritin was not observed either for oxygen plasma treated pores, or for pores modified with mercaptohexadecanoic acid. Ferritin translocation events were reliably observed after the pores were modified with the phospholipid-PEG (DPPE-PEG750) amphiphile. The ion current signature of translocation events was complex, suggesting that a series of interactions between the protein and pores occurs during the process. PMID:24231385

  13. Reciprocal relations between kinetic curves

    NASA Astrophysics Data System (ADS)

    Yablonsky, G. S.; Gorban, A. N.; Constales, D.; Galvita, V. V.; Marin, G. B.

    2011-01-01

    We study coupled irreversible processes. For linear or linearized kinetics with microreversibility, \\dot{x}=Kx , the kinetic operator K is symmetric in the entropic inner product. This form of Onsager's reciprocal relations implies that the shift in time, exp(Kt), is also a symmetric operator. This generates the reciprocity relations between the kinetic curves. For example, for the Master equation, if we start the process from the i-th pure state and measure the probability pj(t) of the j-th state (j≠i), and, similarly, measure pi(t) for the process, which starts at the j-th pure state, then the ratio of these two probabilities pj(t)/pi(t) is constant in time and coincides with the ratio of the equilibrium probabilities. We study similar and more general reciprocal relations between the kinetic curves. The experimental evidence provided as an example is from the reversible water gas shift reaction over iron oxide catalyst. The experimental data are obtained using Temporal Analysis of Products (TAP) pulse-response studies. These offer excellent confirmation within the experimental error.

  14. Best compression: Reciprocating or rotary?

    SciTech Connect

    Cahill, C.

    1997-07-01

    A compressor is a device used to increase the pressure of a compressible fluid. The inlet pressure can vary from a deep vacuum to a high positive pressure. The discharge pressure can range from subatmospheric levels to tens of thousands of pounds per square inch. Compressors come in numerous forms, but for oilfield applications there are two primary types, reciprocating and rotary. Both reciprocating and rotary compressors are grouped in the intermittent mode of compression. Intermittent is cyclic in nature, in that a specific quantity of gas is ingested by the compressor, acted upon and discharged before the cycle is repeated. Reciprocating compression is the most common form of compression used for oilfield applications. Rotary screw compressors have a long history but are relative newcomers to oilfield applications. The rotary screw compressor-technically a helical rotor compressor-dates back to 1878. That was when the first rotary screw was manufactured for the purpose of compressing air. Today thousands of rotary screw compression packages are being used throughout the world to compress natural gas.

  15. Light-regulated translocation of signaling proteins in Drosophila photoreceptors

    PubMed Central

    Frechter, Shahar; Minke, Baruch

    2007-01-01

    Illumination of Drosophila photoreceptor cells induces multi-facet responses, which include generation of the photoreceptor potential, screening pigment migration and translocation of signaling proteins which is the focus of recent extensive research. Translocation of three signaling molecules is covered in this review: (1) Light-dependent translocation of arrestin from the cytosol to the signaling membrane, the rhabdomere, determines the lifetime of activated rhodopsin. Arrestin translocates in PIP3 and NINAC myosin III dependent manner, and specific mutations which disrupt the interaction between arrestin and PIP3 or NINAC also impair the light-dependant translocation of arrestin and the termination of the response to light. (2) Activation of Drosophila visual G protein, DGq, causes a massive and reversible, translocation of the α subunit from the signaling membrane to the cytosol, accompanied by activity-dependent architectural changes. Analysis of the translocation and the recovery kinetics of DGqα in wild-type flies and specific visual mutants indicated that DGqα is necessary but not sufficient for the architectural changes. (3) The TRP-like (TRPL) but not TRP channels translocate in a light-dependent manner between the rhabdomere and the cell body. As a physiological consequence of this light-dependent modulation of the TRP/TRPL ratio, the photoreceptors of dark-adapted flies operate at a wider dynamic range, which allows the photoreceptors enriched with TRPL to function better in darkness and dim background illumination. Altogether, signal-dependent movement of signaling proteins plays a major role in the maintenance and function of photoreceptor cells. PMID:16458490

  16. The Impact of Variant Philadelphia Chromosome Translocations on the Clinical Course of Chronic Myeloid Leukemia

    PubMed Central

    Eyüpoğlu, Damla; Bozkurt, Süreyya; Haznedaroğlu, İbrahim; Büyükaşık, Yahya; Güven, Deniz

    2016-01-01

    Chronic myeloid leukemia (CML) is genetically characterized by the presence of the reciprocal translocation t(9;22) with the formation of Philadelphia (Ph) chromosome. Sometimes, the Ph translocation is generated by variant rearrangements. The prognostic impact of the variant translocations is still controversial. Among the 180 patients with Ph-positive CML who were treated in Hacettepe University Faculty of Medicine Division of Hematology, variant translocations were detected, and retrospectively clinical and prognostic features were described. Also we performed a comprehensive literature review on the prognosis of such variant cases before and after tyrosine kinase inhibitor era. Five patients (2.7%) had variant Ph chromosomes, involved in the rearrangements were chromosomes 2 (2 cases), 11, 14 and 15. Patients were treated with imatinib or dasatinib. All patients reached a stable major molecular response suggesting a prognosis not worse than standard translocation individuals. Our present data were compatible with the data of previous studies indicating no difference in the prognosis between standard and variant translocations in tyrosine kinase inhibitors era of CML. PMID:27020722

  17. Concentration-dependent bimodal effect of specific 18 kDa translocator protein (TSPO) ligands on cell death processes induced by ammonium chloride: potential implications for neuropathological effects due to hyperammonemia.

    PubMed

    Caballero, Beatriz; Veenman, Leo; Bode, Julia; Leschiner, Svetlana; Gavish, Moshe

    2014-01-01

    The role of the 18-kDa Translocator Protein (TSPO) in cell death induced by NH4Cl (1-50 mM) for 24-72 hours to human glioblastoma U118MG cells was investigated. Cell death was already observed after 48 hours of treatment with NH4Cl at 5 mM. Dose and time-responses curves indicated that 15 mM of NH4Cl applied for 72 hours was the optimal condition for our viability assays. For example, 72 hours of 15 mM of NH4Cl caused a 50.3% increase in propidium iodide uptake, and lactate dehydrogenase release was 41.2% of the positive control, indicating significant increases in cell death. Furthermore, compared to vehicle control, these experimental conditions resulted in a significant decrease of 44.9% of the mitochondrial activity, a 62.3% increase in incidence of collapse of mitochondrial membrane potential, and an increase of 49.0% of cardiolipin peroxidation. In addition, a significant 4.3 fold increase in the maximal binding capacity (Bmax) of TSPO was found in NH4Cl-exposed cells. Surprisingly, western blot analysis and real-time PCR did not demonstrate changes in TSPO expression. We also found that neither NH4Cl nor glutamine (a metabolic product of enhanced NH4Cl levels) inhibited binding of the TSPO ligand [(3)H]PK 11195. Interestingly, we observed a bimodal effect of the TSPO ligands PK 11195, Ro5-4864, and FGIN-1-27 on the toxicity of NH4Cl; such that 1-100 nM concentrations of TSPO ligands were protective, while concentrations above 1 μM enhanced NH4Cl-induced cell death processes. In conclusion, TSPO takes part in a bimodal way in the lethal effects induced by NH4Cl in glial type cells. PMID:24168369

  18. Sleep and exercise: a reciprocal issue?

    PubMed

    Chennaoui, Mounir; Arnal, Pierrick J; Sauvet, Fabien; Léger, Damien

    2015-04-01

    Sleep and exercise influence each other through complex, bilateral interactions that involve multiple physiological and psychological pathways. Physical activity is usually considered as beneficial in aiding sleep although this link may be subject to multiple moderating factors such as sex, age, fitness level, sleep quality and the characteristics of the exercise (intensity, duration, time of day, environment). It is therefore vital to improve knowledge in fundamental physiology in order to understand the benefits of exercise on the quantity and quality of sleep in healthy subjects and patients. Conversely, sleep disturbances could also impair a person's cognitive performance or their capacity for exercise and increase the risk of exercise-induced injuries either during extreme and/or prolonged exercise or during team sports. This review aims to describe the reciprocal fundamental physiological effects linking sleep and exercise in order to improve the pertinent use of exercise in sleep medicine and prevent sleep disorders in sportsmen. PMID:25127157

  19. Clonal Integration of Fragaria orientalis in Reciprocal and Coincident Patchiness Resources: Cost-Benefit Analysis

    PubMed Central

    Zhang, Yunchun; Zhang, Qiaoying

    2013-01-01

    Clonal growth allows plants to spread horizontally and to experience different levels of resources. If ramets remain physiologically integrated, clonal plants can reciprocally translocate resources between ramets in heterogeneous environments. But little is known about the interaction between benefits of clonal integration and patterns of resource heterogeneity in different patches, i.e., coincident patchiness or reciprocal patchiness. We hypothesized that clonal integration will show different effects on ramets in different patches and more benefit to ramets under reciprocal patchiness than to those under coincident patchiness, as well as that the benefit from clonal integration is affected by the position of proximal and distal ramets under reciprocal or coincident patchiness. A pot experiment was conducted with clonal fragments consisting of two interconnected ramets (proximal and distal ramet) of Fragaria orientalis. In the experiment, proximal and distal ramets were grown in high or low availability of resources, i.e., light and water. Resource limitation was applied either simultaneously to both ramets of a clonal fragment (coincident resource limitation) or separately to different ramets of the same clonal fragment (reciprocal resource limitation). Half of the clonal fragments were connected while the other half were severed. From the experiment, clonal fragments growing under coincident resource limitation accumulated more biomass than those under reciprocal resource limitation. Based on a cost-benefit analysis, the support from proximal ramets to distal ramets was stronger than that from distal ramets to proximal ramets. Through division of labour, clonal fragments of F. orientalis benefited more in reciprocal patchiness than in coincident patchiness. While considering biomass accumulation and ramets production, coincident patchiness were more favourable to clonal plant F. orientalis. PMID:24265832

  20. The effects of calcium channel inhibitors and other procedures affecting calcium translocation on drug-induced rhythmic contractions in the rat vas deferens.

    PubMed Central

    Hay, D. W.; Wadsworth, R. M.

    1983-01-01

    In the rat isolated vas deferens, methoxamine 8.1 microM produced an initial phasic response that declined towards baseline and was followed by rhythmic contractions that continued until wash-out. These responses were predominant in the epididymal half. BaCl2 1 mM produced a similar type of response which was not mediated by noradrenaline release or activation of alpha-adrenoceptors. The barium responses were similar in the epididymal and prostatic halves. Incubation in nominally Ca2+-free solution caused abolition or near abolition of rhythmic contractions produced by barium or methoxamine. The initial phasic response to methoxamine was abolished in Ca2+-free solution, whereas that produced by barium persisted. Rhythmic contractions produced by methoxamine or barium were inhibited by Mg2+ (2.4-20 mM) and by La3+ (1-5 mM). Mg2+ had selectivity for inhibition of the frequency of methoxamine- but not barium-induced rhythmic contractions. Despite their dependence on [Ca2+]o, barium- and methoxamine-induced rhythmic contractions were resistant to inhibition by calcium channel inhibitors. Verapamil, nifedipine and flunarazine inhibited the amplitude of rhythmic contractions more readily than the frequency (methoxamine IC50 for verapamil: amplitude = 29.8 +/- 5.40 microM, n = 6, frequency = 96.7 +/- 31.0 microM, n = 5, for nifedipine: amplitude = 2.42 +/- 0.34 microM, n = 7, frequency = 3.24 +/- 0.75 microM, n = 7, and for flunarizine: amplitude = 15.9 +/- 5.95 microM, n = 7, frequency = 153 +/- 28.6 microM, n = 7). There was no differentiation between inhibition of methoxamine and barium-induced responses. Like Mg2+, methoxyverapamil selectively inhibited the frequency of methoxamine-induced contractions (IC50: amplitude = 16.8 +/- 2.86 microM, n = 5, frequency = 2.07 +/- 0.81 microM, n = 5) but not barium-induced contractions (IC50: amplitude = 13.9 +/- 1.95 microM, n = 5, frequency = 48.5 +/- 8.98 microM, n = 5). Diazoxide (43.3-2167 microM) and nitroprusside (3

  1. Fenofibrate-induced nuclear translocation of FoxO3A triggers Bim-mediated apoptosis in glioblastoma cells in vitro

    PubMed Central

    Wilk, Anna; Urbanska, Katarzyna; Grabacka, Maja; Mullinax, Jennifer; Marcinkiewicz, Cezary; Impastato, David; Estrada, John J.; Reiss, Krzysztof

    2012-01-01

    Anti-neoplastic potential of calorie restriction or ligand-induced activation of peroxisome proliferator activated receptors (PPARs) has been demonstrated in multiple studies; however, mechanism(s) by which tumor cells respond to these stimuli remain to be elucidated. One of the potent agonists of PPARα, fenofibrate, is a commonly used lipid-lowering drug with low systemic toxicity. Fenofibrate-induced PPARα transcriptional activity is expected to shift energy metabolism from glycolysis to fatty acid β-oxidation, which in the long-term, could target weak metabolic points of glycolysis-dependent glioblastoma cells. The results of this study demonstrate that 25 μM fenofibrate can effectively repress malignant growth of primary glial tumor cells and glioblastoma cell lines. This cytostatic action involves G1 arrest accompanied by only a marginal level of apoptotic cell death. Although the cells treated with 25 μM fenofibrate remain arrested, the cells treated with 50 μM fenofibrate undergo massive apoptosis, which starts after 72 h of the treatment. This delayed apoptotic event was preceded by FoxO3A nuclear accumulation, FoxO3A phosphorylation on serine residue 413, its elevated transcriptional activity and expression of FoxO-dependent apoptotic protein, Bim. siRNA-mediated inhibition of FoxO3A attenuated fenofibrate-induced apoptosis, indicating a direct involvement of this transcription factor in the fenofibrate action against glioblastoma. These properties of fenofibrate, coupled with its low systemic toxicity, make it a good candidate in support of conventional therapies against glial tumors. PMID:22732497

  2. Berberine activates Nrf2 nuclear translocation and inhibits apoptosis induced by high glucose in renal tubular epithelial cells through a phosphatidylinositol 3-kinase/Akt-dependent mechanism.

    PubMed

    Zhang, Xiuli; Liang, Dan; Lian, Xu; Jiang, Yan; He, Hui; Liang, Wei; Zhao, Yue; Chi, Zhi-Hong

    2016-06-01

    Apoptosis of tubular epithelial cells is a major feature of diabetic kidney disease, and hyperglycemia triggers the generation of free radicals and oxidant stress in tubular cells. Berberine (BBR) is identified as a potential anti-diabetic herbal medicine due to its beneficial effects on insulin sensitivity, glucose metabolism and glycolysis. In this study, the underlying mechanisms involved in the protective effects of BBR on high glucose-induced apoptosis were explored using cultured renal tubular epithelial cells (NRK-52E cells) and human kidney proximal tubular cell line (HK-2 cells). We identified the pivotal role of phosphatidylinositol 3-kinase (PI3K)/Akt in BBR cellular defense mechanisms and revealed the novel effect of BBR on nuclear factor (erythroid-derived 2)-related factor-2 (Nrf2) and heme oxygenase (HO)-1 in NRK-52E and HK-2 cells. BBR attenuated reactive oxygen species production, antioxidant defense (GSH and SOD) and oxidant-sensitive proteins (Nrf2 and HO-1), which also were blocked by LY294002 (an inhibitor of PI3K) in HG-treated NRK-52E and HK-2 cells. Furthermore, BBR improved mitochondrial function by increasing mitochondrial membrane potential. BBR-induced anti-apoptotic function was demonstrated by decreasing apoptotic proteins (cytochrome c, Bax, caspase3 and caspase9). All these findings suggest that BBR exerts the anti-apoptosis effects through activation of PI3K/Akt signal pathways and leads to activation of Nrf2 and induction of Nrf2 target genes, and consequently protecting the renal tubular epithelial cells from HG-induced apoptosis. PMID:26979714

  3. Downside risk of wildlife translocation.

    PubMed

    Chipman, R; Slate, D; Rupprecht, C; Mendoza, M

    2008-01-01

    Translocation has been used successfully by wildlife professionals to enhance or reintroduce populations of rare or extirpated wildlife, provide hunting or wildlife viewing opportunities, farm wild game, and reduce local human-wildlife conflicts. However, accidental and intentional translocations may have multiple unintended negative consequences, including increased stress and mortality of relocated animals, negative impacts on resident animals at release sites, increased conflicts with human interests, and the spread of diseases. Many wildlife professionals now question the practice of translocation, particularly in light of the need to contain or eliminate high profile, economically important wildlife diseases and because using this technique may jeopardize international wildlife disease management initiatives to control rabies in raccoons, coyotes, and foxes in North America. Incidents have been documented where specific rabies variants (Texas gray fox, canine variant in coyotes, and raccoon) have been moved well beyond their current range as a result of translocation, including the emergence of raccoon rabies in the eastern United States. Here, we review and discuss the substantial challenges of curtailing translocation in the USA, focusing on movement of animals by the public, nuisance wildlife control operators, and wildlife rehabilitators. PMID:18634483

  4. Akt phosphorylation is essential for nuclear translocation and retention in NGF-stimulated PC12 cells

    SciTech Connect

    Truong Le Xuan Nguyen; Choi, Joung Woo; Lee, Sang Bae; Ye, Keqiang; Woo, Soo-Dong; Lee, Kyung-Hoon; Ahn, Jee-Yin . E-mail: jyahn@med.skku.ac.kr

    2006-10-20

    Nerve growth factor (NGF) elicits Akt translocation into the nucleus, where it phosphorylates nuclear targets. Here, we describe that Akt phosphorylation can promote the nuclear translocation of Akt and is necessary for its nuclear retention. Overexpression of Akt-K179A, T308A, S473A-mutant failed to show either nuclear translocation or nuclear Akt phosphorylation, whereas expression of wild-type counterpart elicited profound Akt phosphorylation and induced nuclear translocation under NGF stimulation. Employing the PI3K inhibitor and a variety of mutants PI3K, we showed that nuclear translocation of Akt was mediated by activation of PI3K, and Akt phosphorylation status in the nucleus required PI3K activity. Thus the activity of PI3K might contribute to the nuclear translocation of Akt, and that Akt phosphorylation is essential for its nuclear retention under NGF stimulation conditions.

  5. Protein translocation: what's the problem?

    PubMed Central

    Corey, Robin A.; Allen, William J.; Collinson, Ian

    2016-01-01

    We came together in Leeds to commemorate and celebrate the life and achievements of Prof. Stephen Baldwin. For many years we, together with Sheena Radford and Roman Tuma (colleagues also of the University of Leeds), have worked together on the problem of protein translocation through the essential and ubiquitous Sec system. Inspired and helped by Steve we may finally be making progress. My seminar described our latest hypothesis for the molecular mechanism of protein translocation, supported by results collected in Bristol and Leeds on the tractable bacterial secretion process–commonly known as the Sec system; work that will be published elsewhere. Below is a description of the alternative and contested models for protein translocation that we all have been contemplating for many years. This review will consider their pros and cons. PMID:27284038

  6. Protein translocation: what's the problem?

    PubMed

    Corey, Robin A; Allen, William J; Collinson, Ian

    2016-06-15

    We came together in Leeds to commemorate and celebrate the life and achievements of Prof. Stephen Baldwin. For many years we, together with Sheena Radford and Roman Tuma (colleagues also of the University of Leeds), have worked together on the problem of protein translocation through the essential and ubiquitous Sec system. Inspired and helped by Steve we may finally be making progress. My seminar described our latest hypothesis for the molecular mechanism of protein translocation, supported by results collected in Bristol and Leeds on the tractable bacterial secretion process-commonly known as the Sec system; work that will be published elsewhere. Below is a description of the alternative and contested models for protein translocation that we all have been contemplating for many years. This review will consider their pros and cons. PMID:27284038

  7. The mechanics of ribosomal translocation.

    PubMed

    Achenbach, John; Nierhaus, Knud H

    2015-07-01

    The ribosome translates the sequence of codons of an mRNA into the corresponding sequence of amino acids as it moves along the mRNA with a codon-step width of about 10 Å. The movement of the million-dalton complex ribosome is triggered by the universal elongation factor G (EF2 in archaea and eukaryotes) and is termed translocation. Unraveling the molecular details of translocation is one of the most challenging tasks of current ribosome research. In the last two years, enormous progress has been obtained by highly-resolved X-ray and cryo-electron microscopic structures as well as by sophisticated biochemical approaches concerning the trigger and control of the movement of the tRNA2·mRNA complex inside the ribosome during translocation. This review inspects and surveys these achievements. PMID:25514765

  8. Enhanced PKC beta II translocation and PKC beta II-RACK1 interactions in PKC epsilon-induced heart failure: a role for RACK1.

    PubMed

    Pass, J M; Gao, J; Jones, W K; Wead, W B; Wu, X; Zhang, J; Baines, C P; Bolli, R; Zheng, Y T; Joshua, I G; Ping, P

    2001-12-01

    Recent investigations have established a role for the beta II-isoform of protein kinase C (PKC beta II) in the induction of cardiac hypertrophy and failure. Although receptors for activated C kinase (RACKs) have been shown to direct PKC signal transduction, the mechanism through which RACK1, a selective PKC beta II RACK, participates in PKC beta II-mediated cardiac hypertrophy and failure remains undefined. We have previously reported that PKC epsilon activation modulates the expression of RACKs, and that altered epsilon-isoform of PKC (PKC epsilon)-RACK interactions may facilitate the genesis of cardiac phenotypes in mice. Here, we present evidence that high levels of PKC epsilon activity are commensurate with impaired left ventricular function (dP/dt = 6,074 +/- 248 mmHg/s in control vs. 3,784 +/- 269 mmHg/s in transgenic) and significant myocardial hypertrophy. More importantly, we demonstrate that high levels of PKC epsilon activation induce a significant colocalization of PKC beta II with RACK1 (154 +/- 7% of control) and a marked redistribution of PKC beta II to the particulate fraction (17 +/- 2% of total PKC beta II in control mice vs. 49 +/- 5% of total PKC beta II in hypertrophied mice), without compensatory changes of the other eight PKC isoforms present in the mouse heart. This enhanced PKC beta II activation is coupled with increased RACK1 expression and PKC beta II-RACK1 interactions, demonstrating PKC epsilon-induced PKC beta II signaling via a RACK1-dependent mechanism. Taken together with our previous findings regarding enhanced RACK1 expression and PKC epsilon-RACK1 interactions in the setting of cardiac hypertrophy and failure, these results suggest that RACK1 serves as a nexus for at least two isoforms of PKC, the epsilon-isoform and the beta II-isoform, thus coordinating PKC-mediated hypertrophic signaling. PMID:11709417

  9. Prenatal Diagnosis of Rare Familial Unbalanced Translocation of Chromosomes 7 and 12

    PubMed Central

    Tezcan, Berrin; Bredaki, Foteini Emmanouella

    2015-01-01

    Case Details. We report rare familial unbalanced translocation of chromosomes 7 and 12, which was diagnosed prenatally at 20+3 weeks of gestation. Woman's partner had been tested in the past and was found to be a carrier of a balanced translocation; his karyotype showed a balanced reciprocal translocation of 46, XY, t(7;12)(q34;q24,32). Partner's brother had an unbalanced form of the translocation with severe learning disability. The diagnosis of the anomaly was based on two- and three-dimensional ultrasound and microarray analysis. Ultrasonography findings included fetal microcephaly and alobar holoprosencephaly, dysmorphic face (flat occiput, absent nasal bone, microphthalmia, hypotelorism, and single nostril), and hyperechogenic bowel. Genome-wide array analysis and cytogenetic results from the amniotic fluid showed unbalanced translocation in chromosomes 7 and 12 with deletion of an approximately 16.5 Mb and a duplication of 6.1 Mb, respectively, Arr 7q34q36.3(142,668,576-159,161,648)x1,12q24.32q24.33(127,708,720-133,777,560)x3, karyotype (der (7) t(7;12) (q34;q24)pat). This unbalanced translocation was due to the segregation of the father's balanced translocation. In this particular case, the recurrence of an unbalanced translocation in the subsequent pregnancies is estimated to be 20%. Understanding the individuals' phenotype in association with the gain and loss of copy number is important and can further provide us with information on that particular region of the named chromosomes. PMID:26294991

  10. Soil translocation estimates calibrated for moldboard plow depth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past century, one of the biggest culprits of tillage-induced soil erosion and translocation has been the moldboard plow. The distance soil will move by moldboard plow tillage has been shown to be correlated with slope gradient. Lindstrom et al. (1992) developed regression equations describi...

  11. Evolution of spite through indirect reciprocity.

    PubMed Central

    Johnstone, Rufus A.; Bshary, Redouan

    2004-01-01

    How can cooperation persist in the face of a temptation to 'cheat'? Several recent papers have suggested that the answer may lie in indirect reciprocity. Altruistic individuals may benefit by eliciting altruism from observers, rather than (as in direct reciprocity) from the recipient of the aid they provide. Here, we point out that indirect reciprocity need not always favour cooperation; by contrast, it may support spiteful behaviour, which is costly for the both actor and recipient. Existing theory suggests spite is unlikely to persist, but we demonstrate that it may do so when spiteful individuals are less likely to incur aggression from observers (a negative form of indirect reciprocity). PMID:15347514

  12. Reciprocating motion of active deformable particles

    NASA Astrophysics Data System (ADS)

    Tarama, M.; Ohta, T.

    2016-05-01

    Reciprocating motion of an active deformable particle in a homogeneous medium is studied theoretically. For generality, we employ a simple model derived from symmetry considerations for the center-of-mass velocity and elliptical and triangular deformations in two dimensions. We carry out, for the first time, a systematic investigation of the reciprocating motion of a self-propelled particle. It is clarified that spontaneous breaking of the front-rear asymmetry is essential for the reciprocating motion. Moreover, two routes are found for the formation of the reciprocating motion. One is a bifurcation from a motionless stationary state. The other is destabilisation of an oscillatory rectilinear motion.

  13. Antioxidant-induced modification of INrf2 cysteine 151 and PKC-δ-mediated phosphorylation of Nrf2 serine 40 are both required for stabilization and nuclear translocation of Nrf2 and increased drug resistance

    PubMed Central

    Niture, Suryakant K.; Jain, Abhinav K.; Jaiswal, Anil K.

    2009-01-01

    Summary Antioxidants cause dissociation of nuclear factor erythroid 2-related factor 2 (Nrf2) from inhibitor of Nrf2 (INrf2) and so Nrf2:INrf2 can serve as a sensor of oxidative stress. Nrf2 translocates to the nucleus, binds to antioxidant response element (ARE) and activates defensive gene expression, which protects cells. Controversies exist regarding the role of antioxidant-induced modification of INrf2 cysteine 151 or protein kinase C (PKC)-mediated phosphorylation of Nrf2 serine 40 in the release of Nrf2 from INrf2. In addition, the PKC isoform that phosphorylates Nrf2S40 remains unknown. Here, we demonstrate that antioxidant-induced PKC-δ-mediated phosphorylation of Nrf2S40 leads to release of Nrf2 from INrf2. This was evident from specific chemical inhibitors of PKC isoenzymes in reporter assays, in vitro kinase assays with purified Nrf2 and PKC isoenzymes, in vivo analysis with dominant-negative mutants and siRNA against PKC isoforms, use of PKC-δ+/+ and PKC-δ–/– cells, and use of Nrf2S40 phospho-specific antibody. The studies also showed that antioxidant-induced INrf2C151 modification was insufficient for the dissociation of Nrf2 from INrf2. PKC-δ-mediated Nrf2S40 phosphorylation was also required. Nrf2 and mutant Nrf2S40A both bind to INrf2. However, antioxidant treatment led to release of Nrf2 but not Nrf2S40A from INrf2. In addition, Nrf2 and mutant Nrf2S40A both failed to dissociate from mutant INrf2C151A. Furthermore, antioxidant-induced ubiquitylation of INrf2 in PKC-δ+/+ and PKC-δ–/– cells occurred, but Nrf2 failed to be released in PKC-δ–/– cells. The antioxidant activation of Nrf2 reduced etoposide-mediated DNA fragmentation and promoted cell survival in PKC-δ+/+ but not in PKC-δ–/– cells. These data together demonstrate that both modification of INrf2C151 and PKC-δ-mediated phosphorylation of Nrf2S40 play crucial roles in Nrf2 release from INrf2, antioxidant induction of defensive gene expression, promoting cell

  14. SIRT1 interacts with and protects glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from nuclear translocation: Implications for cell survival after irradiation

    SciTech Connect

    Joo, Hyun-Yoo; Woo, Seon Rang; Shen, Yan-Nan; Yun, Mi Yong; Shin, Hyun-Jin; Park, Eun-Ran; Kim, Su-Hyeon; Park, Jeong-Eun; Ju, Yeun-Jin; Hong, Sung Hee; Hwang, Sang-Gu; Cho, Myung-Haing; Kim, Joon; Lee, Kee-Ho

    2012-08-10

    Highlights: Black-Right-Pointing-Pointer SIRT1 serves to retain GAPDH in the cytosol, preventing GAPDH nuclear translocation. Black-Right-Pointing-Pointer When SIRT1 is depleted, GAPDH translocation occurs even in the absence of stress. Black-Right-Pointing-Pointer Upon irradiation, SIRT1 interacts with GAPDH. Black-Right-Pointing-Pointer SIRT1 prevents irradiation-induced nuclear translocation of GAPDH. Black-Right-Pointing-Pointer SIRT1 presence rather than activity is essential for inhibiting GAPDH translocation. -- Abstract: Upon apoptotic stimulation, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a cytosolic enzyme normally active in glycolysis, translocates into the nucleus and activates an apoptotic cascade therein. In the present work, we show that SIRT1 prevents nuclear translocation of GAPDH via interaction with GAPDH. SIRT1 depletion triggered nuclear translocation of cytosolic GAPDH even in the absence of apoptotic stress. Such translocation was not, however, observed when SIRT1 enzymatic activity was inhibited, indicating that SIRT1 protein per se, rather than the deacetylase activity of the protein, is required to inhibit GAPDH translocation. Upon irradiation, SIRT1 prevented irradiation-induced nuclear translocation of GAPDH, accompanied by interaction of SIRT1 and GAPDH. Thus, SIRT1 functions to retain GAPDH in the cytosol, protecting the enzyme from nuclear translocation via interaction with these two proteins. This serves as a mechanism whereby SIRT1 regulates cell survival upon induction of apoptotic stress by means that include irradiation.

  15. Hybrid internal combustion reciprocating engine

    SciTech Connect

    Gonzalez, C.

    1988-08-23

    This patent describes a hybrid type reciprocating internal combustion turbine fuel engine with combined spark ignition, torch-assisted to compression ignition modes comprising: a cylinder; a cylinder head mounted on the cylinder having a substantially planar inner surface; exhaust and inlet valves positioned in the head connected to corresponding exhaust and unthrottled inlet passages; a piston reciprocally mounted within the cylinder having a top surface thereon which surface in the top dead center position of the piston is in close proximity with the inner surface of the cylinder head; a substantially spherical precombustion chamber located in the head; a lineal passage tangentially joining the precombustion chamber with the inner surface of the cylinder head; a pilot fuel injector means and an igniter means both located in the precombustion chamber which inject and ignite a precharge; a main fuel injector means in the cylinder head; a bowl-shaped recess comprising the main combustion chamber located in the top surface of the piston in close proximity with the main injector means in the top dead center position with the lineal passage tangentially aligned with the main combustion chamber, whereby the burning gases exiting the precombustion chamber are directed into the main combustion chamber causing ignition therein.

  16. Hybrid internal combustion reciprocating engine

    SciTech Connect

    Gonzales, C.

    1986-06-17

    A hybrid type reciprocating internal combustion engine is described which consists of: a cylinder, a cylinder head mounted on the cylinder having a substantially planar inner surface; exhaust and inlet valves positioned in the head connected to corresponding exhaust and unthrottled inlet passages; a piston reciprocally mounted within the cylinder having a top surface thereon which surface in the top dead center position of the piston is in close proximity with the inner surface of the head; a precombustion chamber located in the head; a lineal passage tangentially joining the precombustion chamber with the inner surface of the cylinder head; a pilot fuel injector means and an igniter means both located in the precombustion chamber which inject and ignite a precharge; a main fuel injector means in the cylinder head; a bowl shaped recess comprising the main combustion chamber non-concentrically located in the top surface of the piston in close proximity with the main injector means in the top dead center position; a first ramp means located in the top surface of the piston tangentially joining the main combustion chamber recess and substantially aligned with the lineal passage, when the piston is approximately at the top dead center position, whereby the burning gases exiting the precombustion chamber are directed into the main combustion recess; and a second ramp means in the top surface of the piston laterally joining the first ramp means.

  17. Indirect reciprocity with trinary reputations.

    PubMed

    Tanabe, Shoma; Suzuki, Hideyuki; Masuda, Naoki

    2013-01-21

    Indirect reciprocity is a reputation-based mechanism for cooperation in social dilemma situations when individuals do not repeatedly meet. The conditions under which cooperation based on indirect reciprocity occurs have been examined in great details. Most previous theoretical analysis assumed for mathematical tractability that an individual possesses a binary reputation value, i.e., good or bad, which depends on their past actions and other factors. However, in real situations, reputations of individuals may be multiple valued. Another puzzling discrepancy between the theory and experiments is the status of the so-called image scoring, in which cooperation and defection are judged to be good and bad, respectively, independent of other factors. Such an assessment rule is found in behavioral experiments, whereas it is known to be unstable in theory. In the present study, we fill both gaps by analyzing a trinary reputation model. By an exhaustive search, we identify all the cooperative and stable equilibria composed of a homogeneous population or a heterogeneous population containing two types of players. Some results derived for the trinary reputation model are direct extensions of those for the binary model. However, we find that the trinary model allows cooperation under image scoring under some mild conditions. PMID:23123557

  18. Bipropellant propulsion with reciprocating pumps

    NASA Astrophysics Data System (ADS)

    Whitehead, John C.

    1993-06-01

    A pressure regulated gas generator rocket cycle with alternately pressurized pairs of reciprocating pumps offers thrust-on-demand operation with significantly lower inert mass than conventional spacecraft liquid propulsion systems. The operation of bipropellant feed systems with reciprocating pumps is explained, with consideration for both short and long term missions. There are several methods for startup and shutdown of this self-starting pump-fed system, with preference determined by thrust duty cycle and mission duration. Progress to date includes extensive development testing of components unique to this type of system, and several live tests with monopropellant hydrazine. Pneumatic pump control valves which render pistons and bellows automatically responsive to downstream liquid demand are significantly simpler than those described previously. A compact pumpset mounted to central liquid manifolds has a pair of oxidizer pumps pneumatically slaved to a pair of fuel pumps to reduce vibration. A warm gas pressure reducer for tank expulsion can eliminate any remaining need for inert gas storage.

  19. Strandwise translocation of a DNA glycosylase on undamaged DNA.

    PubMed

    Qi, Yan; Nam, Kwangho; Spong, Marie C; Banerjee, Anirban; Sung, Rou-Jia; Zhang, Michael; Karplus, Martin; Verdine, Gregory L

    2012-01-24

    Base excision repair of genotoxic nucleobase lesions in the genome is critically dependent upon the ability of DNA glycosylases to locate rare sites of damage embedded in a vast excess of undamaged DNA, using only thermal energy to fuel the search process. Considerable interest surrounds the question of how DNA glycosylases translocate efficiently along DNA while maintaining their vigilance for target damaged sites. Here, we report the observation of strandwise translocation of 8-oxoguanine DNA glycosylase, MutM, along undamaged DNA. In these complexes, the protein is observed to translocate by one nucleotide on one strand while remaining untranslocated on the complementary strand. We further report that alterations of single base-pairs or a single amino acid substitution (R112A) can induce strandwise translocation. Molecular dynamics simulations confirm that MutM can translocate along DNA in a strandwise fashion. These observations reveal a previously unobserved mode of movement for a DNA-binding protein along the surface of DNA. PMID:22219368

  20. Temperature dependence of DNA translocations through solid-state nanopores

    PubMed Central

    Verschueren, Daniel V.; Jonsson, Magnus P.; Dekker, Cees

    2015-01-01

    In order to gain a better physical understanding of DNA translocations through solid-state nanopores, we study the temperature dependence of λ-DNA translocations through 10 nm-in-diameter silicon-nitride nanopores, both experimentally and theoretically. The measured ionic conductance G, the DNA-induced ionic-conductance blockades ΔG and the event frequency Γ all increase with increasing temperature while the DNA translocation time τ decreases. G and ΔG are accurately described when bulk and surface conductances of the nanopore are considered and access resistance is incorporated appropriately. Viscous drag on the untranslocated part of the DNA coil is found to dominate the temperature dependence of the translocation times and the event rate is well described by a balance between diffusion and electrophoretic motion. The good fit between modeled and measured properties of DNA translocations through solid-state nanopores in this first comprehensive temperature study, suggest that our model captures the relevant physics of the process. PMID:25994084

  1. Electrostatics of polymer translocation events in electrolyte solutions

    NASA Astrophysics Data System (ADS)

    Buyukdagli, Sahin; Ala-Nissila, T.

    2016-07-01

    We develop an analytical theory that accounts for the image and surface charge interactions between a charged dielectric membrane and a DNA molecule translocating through the membrane. Translocation events through neutral carbon-based membranes are driven by a competition between the repulsive DNA-image-charge interactions and the attractive coupling between the DNA segments on the trans and the cis sides of the membrane. The latter effect is induced by the reduction of the coupling by the dielectric membrane. In strong salt solutions where the repulsive image-charge effects dominate the attractive trans-cis coupling, the DNA molecule encounters a translocation barrier of ≈10 kBT. In dilute electrolytes, the trans-cis coupling takes over image-charge forces and the membrane becomes a metastable attraction point that can trap translocating polymers over long time intervals. This mechanism can be used in translocation experiments in order to control DNA motion by tuning the salt concentration of the solution.

  2. Electrostatics of polymer translocation events in electrolyte solutions.

    PubMed

    Buyukdagli, Sahin; Ala-Nissila, T

    2016-07-01

    We develop an analytical theory that accounts for the image and surface charge interactions between a charged dielectric membrane and a DNA molecule translocating through the membrane. Translocation events through neutral carbon-based membranes are driven by a competition between the repulsive DNA-image-charge interactions and the attractive coupling between the DNA segments on the trans and the cis sides of the membrane. The latter effect is induced by the reduction of the coupling by the dielectric membrane. In strong salt solutions where the repulsive image-charge effects dominate the attractive trans-cis coupling, the DNA molecule encounters a translocation barrier of ≈10 kBT. In dilute electrolytes, the trans-cis coupling takes over image-charge forces and the membrane becomes a metastable attraction point that can trap translocating polymers over long time intervals. This mechanism can be used in translocation experiments in order to control DNA motion by tuning the salt concentration of the solution. PMID:27394120

  3. A G-protein subunit translocation embedded network motif underlies GPCR regulation of calcium oscillations.

    PubMed

    Giri, Lopamudra; Patel, Anilkumar K; Karunarathne, W K Ajith; Kalyanaraman, Vani; Venkatesh, K V; Gautam, N

    2014-07-01

    G-protein βγ subunits translocate reversibly from the plasma membrane to internal membranes on receptor activation. Translocation rates differ depending on the γ subunit type. There is limited understanding of the role of the differential rates of Gβγ translocation in modulating signaling dynamics in a cell. Bifurcation analysis of the calcium oscillatory network structure predicts that the translocation rate of a signaling protein can regulate the damping of system oscillation. Here, we examined whether the Gβγ translocation rate regulates calcium oscillations induced by G-protein-coupled receptor activation. Oscillations in HeLa cells expressing γ subunit types with different translocation rates were imaged and quantitated. The results show that differential Gβγ translocation rates can underlie the diversity in damping characteristics of calcium oscillations among cells. Mathematical modeling shows that a translocation embedded motif regulates damping of G-protein-mediated calcium oscillations consistent with experimental data. The current study indicates that such a motif may act as a tuning mechanism to design oscillations with varying damping patterns by using intracellular translocation of a signaling component. PMID:24988358

  4. Return to the wild: Translocation as a tool in conservation of the desert tortoise (Gopherus agassizii)

    USGS Publications Warehouse

    Field, K.J.; Tracy, C.R.; Medica, P.A.; Marlow, R.W.; Corn, P.S.

    2007-01-01

    Translocation could be used as a tool in conservation of the threatened Mojave Desert Tortoise (Gopherus agassizii) by moving individuals from harm's way and into areas where they could contribute to conservation of the species. Numerous factors may affect the success of translocations, including the conditions experienced by tortoises in holding facilities while awaiting translocation. The tortoises available for our translocation study had been provided supplemental water during their years spent in a captive holding facility, potentially inducing carelessness in water conservation. In addition to generally investigating the efficacy of translocation, we compared the effects of continuing with the effects of ceasing the holding facility's water supplementation regimen. After exposure to one of the two water regimens, all tortoises were given the opportunity to hydrate immediately prior to release. We examined behavior, body mass, carapace length, movement, and mortality of tortoises for two activity seasons following release to the wild. Water supplementation was correlated with high rates of carapace growth and distant movements by males after release. Lengthy movements following translocation may be problematic for conservation planning, but this should be evaluated in light of the goals and circumstances of each translocation project. Although the mortality rate was 21.4% in 1997, data suggest that drought conditions at the site rather than the translocation itself negatively affected the tortoises. None of the tortoises died during their second season at the site. Our results indicate that translocation should be considered a useful tool in conservation of the Desert Tortoise.

  5. Implementing Reciprocal Teaching: Was It Effective?

    ERIC Educational Resources Information Center

    Al-Hilawani, Yasser A.; And Others

    This study was conducted to explore the relationship between teaching methods and students' grades at the college level. Subjects, 58 undergraduate students enrolled in 2 introductory education courses, were organized into groups and exposed to one of two teaching methods: the lecture format and reciprocal teaching. Reciprocal teaching engages…

  6. Reciprocal Tutoring: Design with Cognitive Load Sharing

    ERIC Educational Resources Information Center

    Chou, Chih-Yueh; Chan, Tak-Wai

    2016-01-01

    "Reciprocal tutoring," as reported in "Exploring the design of computer supports for reciprocal tutoring" (Chan and Chou 1997), has extended the meaning and scope of "intelligent tutoring" originally implemented in stand alone computers. This research is a follow-up to our studies on a "learning companion…

  7. An Introduction to the Onsager Reciprocal Relations

    ERIC Educational Resources Information Center

    Monroe, Charles W.; Newman, John

    2007-01-01

    The Onsager reciprocal relations are essential to multicomponent transport theory. A discussion of the principles that should be used to derive flux laws for coupled diffusion is presented here. Fluctuation theory is employed to determine the reciprocal relation for transport coefficients that characterize coupled mass and heat transfer in binary…

  8. 78 FR 53792 - Draft Guidance for Reciprocity

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-30

    ... COMMISSION Draft Guidance for Reciprocity AGENCY: Nuclear Regulatory Commission. ACTION: Draft NUREG; request... for reciprocity. The NRC is requesting public comment on draft NUREG-1556, Volume 19, Revision 1...@nrc.gov . The draft NUREG-1556, Volume 19, Revision 1, is available under ADAMS Accession...

  9. Reciprocal Teaching. Information Capsule. Volume 0609

    ERIC Educational Resources Information Center

    Blazer, Christie

    2007-01-01

    Reciprocal teaching is an instructional approach designed to increase students' reading comprehension at all grade levels and in all subject areas. Students are taught cognitive strategies that help them construct meaning from text and simultaneously monitor their reading comprehension. This Information Capsule summarizes reciprocal teaching's…

  10. Education, Gift and Reciprocity: A Preliminary Discussion

    ERIC Educational Resources Information Center

    Sabourin, Eric

    2013-01-01

    This paper analyzes the importance and role of the reciprocity relationship in education. It presents a review on the mobilization of the principle of reciprocity--in the anthropological but also sociological and economic senses--in educational processes, especially in adult education. The study is divided into three parts. The first part analyzes…

  11. Reciprocal Contracting with Families of Adolescents.

    ERIC Educational Resources Information Center

    Lipinski, Judith M.; Lawrence, P. Scott

    The use of reciprocal behavior contracts with families of behavior-problem adolescents was investigated. Most family contracting to date has involved one-way contracts; that is, the child agrees to certain responsibilities for which he will be reinforced by the parents. A reciprocal contract requires the parents, in addition to the child, to agree…

  12. High-performance analysis of single interphase cells with custom DNA probes spanning translocation break points

    NASA Astrophysics Data System (ADS)

    Weier, Heinz-Ulli G.; Munne, S.; Lersch, Robert A.; Marquez, C.; Wu, J.; Pedersen, Roger A.; Fung, Jingly

    1999-06-01

    The chromatin organization of interphase cell nuclei, albeit an object of intense investigation, is only poorly understood. In the past, this has hampered the cytogenetic analysis of tissues derived from specimens where only few cells were actively proliferating or a significant number of metaphase cells could be obtained by induction of growth. Typical examples of such hard to analyze cell systems are solid tumors, germ cells and, to a certain extent, fetal cells such as amniocytes, blastomeres or cytotrophoblasts. Balanced reciprocal translocations that do not disrupt essential genes and thus do not led to disease symptoms exit in less than one percent of the general population. Since the presence of translocations interferes with homologue pairing in meiosis, many of these individuals experience problems in their reproduction, such as reduced fertility, infertility or a history of spontaneous abortions. The majority of translocation carriers enrolled in our in vitro fertilization (IVF) programs carry simple translocations involving only two autosomes. While most translocations are relatively easy to spot in metaphase cells, the majority of cells biopsied from embryos produced by IVF are in interphase and thus unsuitable for analysis by chromosome banding or FISH-painting. We therefore set out to analyze single interphase cells for presence or absence of specific translocations. Our assay, based on fluorescence in situ hybridization (FISH) of breakpoint-spanning DNA probes, detects translocations in interphase by visual microscopic inspection of hybridization domains. Probes are prepared so that they span a breakpoint and cover several hundred kb of DNA adjacent to the breakpoint. On normal chromosomes, such probes label a contiguous stretch of DNA and produce a single hybridization domain per chromosome in interphase cells. The translocation disrupts the hybridization domain and the resulting two fragments appear as physically separated hybridization domains in

  13. Light-Dependent Translocation of Arrestin in Rod Photoreceptors is Signaled Through a Phospholipase C Cascade and Requires ATP

    PubMed Central

    Orisme, Wilda; Li, Jian; Goldmann, Tobias; Bolch, Susan; Wolfrum, Uwe; Smith, W. Clay

    2009-01-01

    Partitioning of cellular components is a critical mechanism by which cells can regulate their activity. In rod photoreceptors, light induces a large-scale translocation of arrestin from the inner segments to the outer segments. The purpose of this project is to elucidate the signaling pathway necessary to initiate arrestin translocation to the outer segments and the mechanism for arrestin translocation. Mouse retinal organotypic cultures and eyes from transgenic Xenopus tadpoles expressing a fusion of GFP and rod arrestin were treated with both activators and inhibitors of proteins in the phosphoinositide pathway. Confocal microscopy was used to image the effects of the pharmacological agents on arrestin translocation in rod photoreceptors. Retinas were also depleted of ATP using potassium cyanide to assess the requirement for ATP in arrestin translocation. In this study, we demonstrate that components of the G-protein-linked phospholipase C (PLC) pathway play a role in initiating arrestin translocation. Our results show that arrestin translocation can be stimulated by activators of PLC and protein kinase C (PKC), and by cholera toxin in the absence of light. Arrestin translocation to the outer segments is significantly reduced by inhibitors of PLC and PKC. Importantly, we find that treatment with potassium cyanide inhibits arrestin translocation in response to light. Collectively, our results suggest that arrestin translocation is initiated by a G-protein-coupled cascade through PLC and PKC signaling. Furthermore, our results demonstrate that at least the initiation of arrestin translocation requires energy input. PMID:19887106

  14. Suitability of amphibians and reptiles for translocation.

    PubMed

    Germano, Jennifer M; Bishop, Phillip J

    2009-02-01

    Translocations are important tools in the field of conservation. Despite increased use over the last few decades, the appropriateness of translocations for amphibians and reptiles has been debated widely over the past 20 years. To provide a comprehensive evaluation of the suitability of amphibians and reptiles for translocation, we reviewed the results of amphibian and reptile translocation projects published between 1991 and 2006. The success rate of amphibian and reptile translocations reported over this period was twice that reported in an earlier review in 1991. Success and failure rates were independent of the taxonomic class (Amphibia or Reptilia) released. Reptile translocations driven by human-wildlife conflict mitigation had a higher failure rate than those motivated by conservation, and more recent projects of reptile translocations had unknown outcomes. The outcomes of amphibian translocations were significantly related to the number of animals released, with projects releasing over 1000 individuals being most successful. The most common reported causes of translocation failure were homing and migration of introduced individuals out of release sites and poor habitat. The increased success of amphibian and reptile translocations reviewed in this study compared with the 1991 review is encouraging for future conservation projects. Nevertheless, more preparation, monitoring, reporting of results, and experimental testing of techniques and reintroduction questions need to occur to improve translocations of amphibians and reptiles as a whole. PMID:19143783

  15. Reciprocity of agonistic support in ravens

    PubMed Central

    Fraser, Orlaith N.; Bugnyar, Thomas

    2012-01-01

    Cooperative behaviour through reciprocation or interchange of valuable services in primates has received considerable attention, especially regarding the timeframe of reciprocation and its ensuing cognitive implications. Much less, however, is known about reciprocity in other animals, particularly birds. We investigated patterns of agonistic support (defined as a third party intervening in an ongoing conflict to attack one of the conflict participants, thus supporting the other) in a group of 13 captive ravens, Corvus corax. We found support for long-term, but not short-term, reciprocation of agonistic support. Ravens were more likely to support individuals who preened them, kin and dominant group members. These results suggest that ravens do not reciprocate on a calculated tit-for-tat basis, but aid individuals from whom reciprocated support would be most useful and those with whom they share a good relationship. Additionally, dyadic levels of agonistic support and consolation (postconflict affiliation from a bystander to the victim) correlated strongly with each other, but we found no evidence to suggest that receiving agonistic support influences the victim’s likelihood of receiving support (consolation) after the conflict ends. Our findings are consistent with an emotionally mediated form of reciprocity in ravens and provide additional support for convergent cognitive evolution in birds and mammals. PMID:22298910

  16. Reciprocity and Ethical Tuberculosis Treatment and Control.

    PubMed

    Silva, Diego S; Dawson, Angus; Upshur, Ross E G

    2016-03-01

    This paper explores the notion of reciprocity in the context of active pulmonary and laryngeal tuberculosis (TB) treatment and related control policies and practices. We seek to do three things: First, we sketch the background to contemporary global TB care and suggest that poverty is a key feature when considering the treatment of TB patients. We use two examples from TB care to explore the role of reciprocity: isolation and the use of novel TB drugs. Second, we explore alternative means of justifying the use of reciprocity through appeal to different moral and political theoretical traditions (i.e., virtue ethics, deontology, and consequentialism). We suggest that each theory can be used to provide reasons to take reciprocity seriously as an independent moral concept, despite any other differences. Third, we explore general meanings and uses of the concept of reciprocity, with the primary intention of demonstrating that it cannot be simply reduced to other more frequently invoked moral concepts such as beneficence or justice. We argue that reciprocity can function as a mid-level principle in public health, and generally, captures a core social obligation arising once an individual or group is burdened as a result of acting for the benefit of others (even if they derive a benefit themselves). We conclude that while more needs to be explored in relation to the theoretical justification and application of reciprocity, sufficient arguments can be made for it to be taken more seriously as a key principle within public health ethics and bioethics more generally. PMID:26797512

  17. Reciprocity of agonistic support in ravens.

    PubMed

    Fraser, Orlaith N; Bugnyar, Thomas

    2012-01-01

    Cooperative behaviour through reciprocation or interchange of valuable services in primates has received considerable attention, especially regarding the timeframe of reciprocation and its ensuing cognitive implications. Much less, however, is known about reciprocity in other animals, particularly birds. We investigated patterns of agonistic support (defined as a third party intervening in an ongoing conflict to attack one of the conflict participants, thus supporting the other) in a group of 13 captive ravens, Corvus corax. We found support for long-term, but not short-term, reciprocation of agonistic support. Ravens were more likely to support individuals who preened them, kin and dominant group members. These results suggest that ravens do not reciprocate on a calculated tit-for-tat basis, but aid individuals from whom reciprocated support would be most useful and those with whom they share a good relationship. Additionally, dyadic levels of agonistic support and consolation (postconflict affiliation from a bystander to the victim) correlated strongly with each other, but we found no evidence to suggest that receiving agonistic support influences the victim's likelihood of receiving support (consolation) after the conflict ends. Our findings are consistent with an emotionally mediated form of reciprocity in ravens and provide additional support for convergent cognitive evolution in birds and mammals. PMID:22298910

  18. Two distinct neural mechanisms underlying indirect reciprocity.

    PubMed

    Watanabe, Takamitsu; Takezawa, Masanori; Nakawake, Yo; Kunimatsu, Akira; Yamasue, Hidenori; Nakamura, Mitsuhiro; Miyashita, Yasushi; Masuda, Naoki

    2014-03-18

    Cooperation is a hallmark of human society. Humans often cooperate with strangers even if they will not meet each other again. This so-called indirect reciprocity enables large-scale cooperation among nonkin and can occur based on a reputation mechanism or as a succession of pay-it-forward behavior. Here, we provide the functional and anatomical neural evidence for two distinct mechanisms governing the two types of indirect reciprocity. Cooperation occurring as reputation-based reciprocity specifically recruited the precuneus, a region associated with self-centered cognition. During such cooperative behavior, the precuneus was functionally connected with the caudate, a region linking rewards to behavior. Furthermore, the precuneus of a cooperative subject had a strong resting-state functional connectivity (rsFC) with the caudate and a large gray matter volume. In contrast, pay-it-forward reciprocity recruited the anterior insula (AI), a brain region associated with affective empathy. The AI was functionally connected with the caudate during cooperation occurring as pay-it-forward reciprocity, and its gray matter volume and rsFC with the caudate predicted the tendency of such cooperation. The revealed difference is consistent with the existing results of evolutionary game theory: although reputation-based indirect reciprocity robustly evolves as a self-interested behavior in theory, pay-it-forward indirect reciprocity does not on its own. The present study provides neural mechanisms underlying indirect reciprocity and suggests that pay-it-forward reciprocity may not occur as myopic profit maximization but elicit emotional rewards. PMID:24591599

  19. Two distinct neural mechanisms underlying indirect reciprocity

    PubMed Central

    Watanabe, Takamitsu; Takezawa, Masanori; Nakawake, Yo; Kunimatsu, Akira; Yamasue, Hidenori; Nakamura, Mitsuhiro; Miyashita, Yasushi; Masuda, Naoki

    2014-01-01

    Cooperation is a hallmark of human society. Humans often cooperate with strangers even if they will not meet each other again. This so-called indirect reciprocity enables large-scale cooperation among nonkin and can occur based on a reputation mechanism or as a succession of pay-it-forward behavior. Here, we provide the functional and anatomical neural evidence for two distinct mechanisms governing the two types of indirect reciprocity. Cooperation occurring as reputation-based reciprocity specifically recruited the precuneus, a region associated with self-centered cognition. During such cooperative behavior, the precuneus was functionally connected with the caudate, a region linking rewards to behavior. Furthermore, the precuneus of a cooperative subject had a strong resting-state functional connectivity (rsFC) with the caudate and a large gray matter volume. In contrast, pay-it-forward reciprocity recruited the anterior insula (AI), a brain region associated with affective empathy. The AI was functionally connected with the caudate during cooperation occurring as pay-it-forward reciprocity, and its gray matter volume and rsFC with the caudate predicted the tendency of such cooperation. The revealed difference is consistent with the existing results of evolutionary game theory: although reputation-based indirect reciprocity robustly evolves as a self-interested behavior in theory, pay-it-forward indirect reciprocity does not on its own. The present study provides neural mechanisms underlying indirect reciprocity and suggests that pay-it-forward reciprocity may not occur as myopic profit maximization but elicit emotional rewards. PMID:24591599

  20. Self-reciprocating radioisotope-powered cantilever

    NASA Astrophysics Data System (ADS)

    Li, Hui; Lal, Amit; Blanchard, James; Henderson, Douglass

    2002-07-01

    A reciprocating cantilever utilizing emitted charges from a millicurie radioisotope thin film is presented. The actuator realizes a direct collected-charge-to-motion conversion. The reciprocation is obtained by self-timed contact between the cantilever and the radioisotope source. A static model balancing the electrostatic and mechanical forces from an equivalent circuit leads to an analytical solution useful for device characterization. Measured reciprocating periods agree with predicted values from the analytical model. A scaling analysis shows that microscale arrays of such cantilevers provide an integrated sensor and actuator platform.

  1. [Identification of the 1RS-7DS.7DL wheat-rye small segment translocation lines].

    PubMed

    Jun, Li; Xinguo, Zhu; Hongshen, Wan; Qin, Wang; Zongxiang, Tang; Shulan, Fu; Zujun, Yang; Manyu, Yang; Wuyun, Yang

    2015-06-01

    Rye (Secale cereale L., RR) is a valuable genetic resource for the improvement of common wheat (Triticum aestivum L., AABBDD). Transferring alien rye genes into wheat by distant hybridization and automatic chromosome doubling is an important and efficient method to boost agronomic traits, disease resistance and widening the gene pool in wheat. In this study, an octoploid triticale CD-13 (AABBDDRR) was obtained via automatic chromosome doubling by crossing landrace Penganbaimaizi (T. aestivum L., AABBDD) and rye "Qinling rye" (S. cereale cv. Qinling, RR). GISH and FISH analyses indicated that CD-13 contained a 1RS-7DS.7DL wheat-rye small segment translocation chromosome. In order to transfer the 1RS-7DS small segment translocation into hexaploid wheat, 58 lines of the F5 inbred population from the cross CD-13 x Chuanmai 42 were screened for rye chromosome segments by GISH and FISH analyses. The results showed that 13 lines contained the 1RS-7DS.7DL small segment translocation chromosome by reciprocal translocation between 1RS and 7DS. These translocation lines carrying 1RS small rye alien segment were tested for the translocation breakpoints and the presence of a storage protein locus Sec-1. The Sec-1 locus was absent in the line 811, a stable 1RS-7DS.7DL small segment translocation line. The translocation breakpoint of 1RS-7DS.7DL of this line was located in the interval of IB267-IAG95 around the telomere of 1RS chromosome. Thousand-kernel weight of the line 811 was much higher than the parent CD-13, but not significantly different from Chuanmai 42. This indicated that 1RS-7DS.7DL small segment translocation had no negative effect on thousand-kernel weight in the genetic background of Chuanmai 42. The line with 1RS-7DS.7DL translocation chromosomes can be used as a new genetic material for further studies of valuable genes and their genetic effect on 1RS small segment. PMID:26351056

  2. A voltage-gated pore for translocation of tRNA

    SciTech Connect

    Koley, Sandip; Adhya, Samit

    2013-09-13

    Highlights: •A tRNA translocating complex was assembled from purified proteins. •The complex translocates tRNA at a membrane potential of ∼60 mV. •Translocation requires Cys and His residues in the Fe–S center of RIC6 subunit. -- Abstract: Very little is known about how nucleic acids are translocated across membranes. The multi-subunit RNA Import Complex (RIC) from mitochondria of the kinetoplastid protozoon Leishmania tropica induces translocation of tRNAs across artificial or natural membranes, but the nature of the translocation pore remains unknown. We show that subunits RIC6 and RIC9 assemble on the membrane in presence of subunit RIC4A to form complex R3. Atomic Force Microscopy of R3 revealed particles with an asymmetric surface groove of ∼20 nm rim diameter and ∼1 nm depth. R3 induced translocation of tRNA into liposomes when the pH of the medium was lowered to ∼6 in the absence of ATP. R3-mediated tRNA translocation could also be induced at neutral pH by a K{sup +} diffusion potential with an optimum of 60–70 mV. Point mutations in the Cys{sub 2}–His{sub 2} Fe-binding motif of RIC6, which is homologous to the respiratory Complex III Fe–S protein, abrogated import induced by low pH but not by K{sup +} diffusion potential. These results indicate that the R3 complex forms a pore that is gated by a proton-generated membrane potential and that the Fe–S binding region of RIC6 has a role in proton translocation. The tRNA import complex of L. tropica thus contains a novel macromolecular channel distinct from the mitochondrial protein import pore that is apparently involved in tRNA import in some species.

  3. Problems with mitigation translocation of herpetofauna.

    PubMed

    Sullivan, Brian K; Nowak, Erika M; Kwiatkowski, Matthew A

    2015-02-01

    Mitigation translocation of nuisance animals is a commonly used management practice aimed at resolution of human-animal conflict by removal and release of an individual animal. Long considered a reasonable undertaking, especially by the general public, it is now known that translocated subjects are negatively affected by the practice. Mitigation translocation is typically undertaken with individual adult organisms and has a much lower success rate than the more widely practiced conservation translocation of threatened and endangered species. Nonetheless, the public and many conservation practitioners believe that because population-level conservation translocations have been successful that mitigation translocation can be satisfactorily applied to a wide variety of human-wildlife conflict situations. We reviewed mitigation translocations of reptiles, including our own work with 3 long-lived species (Gila monsters [Heloderma suspectum], Sonoran desert tortoises [Gopherus morafkai], and western diamond-backed rattlesnakes [Crotalus atrox]). Overall, mitigation translocation had a low success rate when judged either by effects on individuals (in all studies reviewed they exhibited increased movement or increased mortality) or by the success of the resolution of the human-animal conflict (translocated individuals often returned to the capture site). Careful planning and identification of knowledge gaps are critical to increasing success rates in mitigation translocations in the face of increasing pressure to find solutions for species threatened by diverse anthropogenic factors, including climate change and exurban and energy development. PMID:25040040

  4. Cytotoxic Necrotizing Factor-Y Boosts Yersinia Effector Translocation by Activating Rac Protein*

    PubMed Central

    Wolters, Manuel; Boyle, Erin C.; Lardong, Kerstin; Trülzsch, Konrad; Steffen, Anika; Rottner, Klemens; Ruckdeschel, Klaus; Aepfelbacher, Martin

    2013-01-01

    Pathogenic Yersinia spp. translocate the effectors YopT, YopE, and YopO/YpkA into target cells to inactivate Rho family GTP-binding proteins and block immune responses. Some Yersinia spp. also secrete the Rho protein activator cytotoxic necrotizing factor-Y (CNF-Y), but it has been unclear how the bacteria may benefit from Rho protein activation. We show here that CNF-Y increases Yop translocation in Yersinia enterocolitica-infected cells up to 5-fold. CNF-Y strongly activated RhoA and also delayed in time Rac1 and Cdc42, but when individually expressed, constitutively active mutants of Rac1, but not of RhoA, increased Yop translocation. Consistently, knock-out or knockdown of Rac1 but not of RhoA, -B, or -C inhibited Yersinia effector translocation in CNF-Y-treated and control cells. Activation or knockdown of Cdc42 also affected Yop translocation but much less efficiently than Rac. The increase in Yop translocation induced by CNF-Y was essentially independent of the presence of YopE, YopT, or YopO in the infecting Yersinia strain, indicating that none of the Yops reported to inhibit translocation could reverse the CNF-Y effect. In summary, the CNF-Y activity of Yersinia strongly enhances Yop translocation through activation of Rac. PMID:23803609

  5. A surface-scattering model satisfying energy conservation and reciprocity

    NASA Astrophysics Data System (ADS)

    Sasihithlu, Karthik; Dahan, Nir; Hugonin, Jean-Paul; Greffet, Jean-Jacques

    2016-03-01

    Roughness scattering models based on Kirchhoff's approximation or perturbation theory give a good account of the angular distribution of the scattered intensity but do not satisfy energy conservation and reciprocity rigorously. For applications such as solar cells with rough interfaces producing a quasi isotropic intensity in the multiple scattering regime, an accurate model of the angular pattern is not required. Instead, energy conservation and reciprocity must be satisfied with great accuracy. Here we present a surface scattering model based on analysis of scattering from a layer of particles on top of a substrate in the dipole approximation which satisfies both energy conservation and reciprocity and is thus accurate in all frequency ranges. The model takes into account the absorption in the substrate induced by the particles but does not take into account the near-field interactions between the particles. In arriving at this model, we use the effective-medium approach to show how we can proceed from modeling the electromagnetic scattering from a single particle to modeling the scattering from a layer of particles positioned above a substrate, and finally relate this to the bidirectional scattering distribution function of the substrate.

  6. QTL Dissection of Lag Phase in Wine Fermentation Reveals a New Translocation Responsible for Saccharomyces cerevisiae Adaptation to Sulfite

    PubMed Central

    Zimmer, Adrien; Durand, Cécile; Loira, Nicolás; Durrens, Pascal; Sherman, David James; Marullo, Philippe

    2014-01-01

    Quantitative genetics and QTL mapping are efficient strategies for deciphering the genetic polymorphisms that explain the phenotypic differences of individuals within the same species. Since a decade, this approach has been applied to eukaryotic microbes such as Saccharomyces cerevisiae in order to find natural genetic variations conferring adaptation of individuals to their environment. In this work, a QTL responsible for lag phase duration in the alcoholic fermentation of grape juice was dissected by reciprocal hemizygosity analysis. After invalidating the effect of some candidate genes, a chromosomal translocation affecting the lag phase was brought to light using de novo assembly of parental genomes. This newly described translocation (XV-t-XVI) involves the promoter region of ADH1 and the gene SSU1 and confers an increased expression of the sulfite pump during the first hours of alcoholic fermentation. This translocation constitutes another adaptation route of wine yeast to sulfites in addition to the translocation VIII-t-XVI previously described. A population survey of both translocation forms in a panel of domesticated yeast strains suggests that the translocation XV-t-XVI has been empirically selected by human activity. PMID:24489712

  7. QTL dissection of Lag phase in wine fermentation reveals a new translocation responsible for Saccharomyces cerevisiae adaptation to sulfite.

    PubMed

    Zimmer, Adrien; Durand, Cécile; Loira, Nicolás; Durrens, Pascal; Sherman, David James; Marullo, Philippe

    2014-01-01

    Quantitative genetics and QTL mapping are efficient strategies for deciphering the genetic polymorphisms that explain the phenotypic differences of individuals within the same species. Since a decade, this approach has been applied to eukaryotic microbes such as Saccharomyces cerevisiae in order to find natural genetic variations conferring adaptation of individuals to their environment. In this work, a QTL responsible for lag phase duration in the alcoholic fermentation of grape juice was dissected by reciprocal hemizygosity analysis. After invalidating the effect of some candidate genes, a chromosomal translocation affecting the lag phase was brought to light using de novo assembly of parental genomes. This newly described translocation (XV-t-XVI) involves the promoter region of ADH1 and the gene SSU1 and confers an increased expression of the sulfite pump during the first hours of alcoholic fermentation. This translocation constitutes another adaptation route of wine yeast to sulfites in addition to the translocation VIII-t-XVI previously described. A population survey of both translocation forms in a panel of domesticated yeast strains suggests that the translocation XV-t-XVI has been empirically selected by human activity. PMID:24489712

  8. Electronic controller for reciprocating rotary crystallizer

    NASA Technical Reports Server (NTRS)

    Kroes, Roger L.; Reiss, Donald A.; Hester, Howard B.

    1988-01-01

    An electronic controller for a reciprocating rotary crystallizer is described. The heart of this system is the electronic timer circuit. A schematic along with a detailed description of its operation is given.

  9. 30 CFR 57.13010 - Reciprocating-type air compressors.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Reciprocating-type air compressors. 57.13010... Air and Boilers § 57.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors... than 25 percent. (b) However, this standard does not apply to reciprocating-type air compressors...

  10. 30 CFR 57.13010 - Reciprocating-type air compressors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Reciprocating-type air compressors. 57.13010... Air and Boilers § 57.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors... than 25 percent. (b) However, this standard does not apply to reciprocating-type air compressors...

  11. 32 CFR 148.1 - Intergency reciprocal acceptance .

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Intergency reciprocal acceptance . 148.1 Section... Reciprocity of Use and Inspections of Facilities § 148.1 Intergency reciprocal acceptance . Interagency reciprocal acceptance of security policies and procedures for approving, accrediting, and maintaining...

  12. 32 CFR 148.1 - Intergency reciprocal acceptance .

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 1 2011-07-01 2011-07-01 false Intergency reciprocal acceptance . 148.1 Section... Reciprocity of Use and Inspections of Facilities § 148.1 Intergency reciprocal acceptance . Interagency reciprocal acceptance of security policies and procedures for approving, accrediting, and maintaining...

  13. Klippel-Trenaunay-Weber syndrome associated with a 5:11 balanced translocation.

    PubMed

    Whelan, A J; Watson, M S; Porter, F D; Steiner, R D

    1995-12-01

    We report on a case of Klippel-Trenaunay Weber syndrome (KTWS) associated with a reciprocal translocation [46,XX,t (5;11) (q13.3;p15.1)]. The patient has developmental delay and minor anomalies in addition to classic findings of KTWS. These data support the notion that Klippel-Trenaunay-Weber syndrome may be due to a single gene defect and suggests the possible localization of a Klippel-Trenaunay-Weber gene(s) to 5q or 11p. PMID:8585570

  14. Klippel-Trenaunay-Weber syndrome associated with a 5:11 balanced translocation

    SciTech Connect

    Whelan, A.J.; Watson, M.S.; Porter, F.D.; Steiner, R.D. |

    1995-12-04

    We report on a case of Klippel-Trenaunay Weber syndrome (KTWS) associated with a reciprocal translocation [46,XX,t(5;11)(q13.3; p15.1)]. The patient had developmental delay and minor anomalies in addition to classic findings of KTWS. These data support the notion that Klippel-Trenaunay-Weber syndrome may be due to a single gene defect and suggests the possible localization of a Klippel-Trenaunay-Weber gene(s) to 5q or 11p. 12 refs., 2 figs.

  15. Successive Translocation of the Rings in a [3]Rotaxane.

    PubMed

    Jagesar, Dhiredj C; Wiering, Piet G; Kay, Euan R; Leigh, David A; Brouwer, Albert M

    2016-06-17

    A [2]rotaxane, a [3]rotaxane and the corresponding thread containing two succinamide (succ) binding stations and a central redox-active pyromellitimide (pmi) station were studied. Infrared spectroelectrochemical experiments revealed the translocation of the macrocycle between the succinamide station and the electrochemically reduced pmi station (radical anion and dianion). Remarkably, in the [3]rotaxane, the rings can be selectively translocated. One-electron reduction leads to the translocation of one of the two macrocycles from the succinamide to the pyromellitimide station, whereas activation of the shuttle through two-electron reduction results in the translocation of both macrocycles: the dianion, due to its higher electron density and hence greater hydrogen-bond accepting affinity, is hydrogen bonded to both macrocycles. Systems with such an on-command contraction are known as molecular muscles. The relative strengths of the binding between the macrocycle and the imide anions could be estimated from the hydrogen-bond-induced shifts in the C=O stretching frequencies of hydrogen-bond accepting amide groups of the macrocycle. PMID:26918870

  16. Chromosomal Translocations in Black Flies (Diptera: Simuliidae)—Facilitators of Adaptive Radiation?

    PubMed Central

    Adler, Peter H.; Yadamsuren, Oyunchuluun; Procunier, William S.

    2016-01-01

    A macrogenomic investigation of a Holarctic clade of black flies—the Simulium cholodkovskii lineage—provided a platform to explore the implications of a unique, synapomorphic whole-arm interchange in the evolution of black flies. Nearly 60 structural rearrangements were discovered in the polytene complement of the lineage, including 15 common to all 138 analyzed individuals, relative to the central sequence for the entire subgenus Simulium. Three species were represented, of which two Palearctic entities (Simulium cholodkovskii and S. decimatum) were sympatric; an absence of hybrids confirmed their reproductive isolation. A third (Nearctic) entity had nonhomologous sex chromosomes, relative to the other species, and is considered a separate species, for which the name Simulium nigricoxum is revalidated. A cytophylogeny is inferred and indicates that the two Palearctic taxa are sister species and these, in turn, are the sister group of the Nearctic species. The rise of the S. cholodkovskii lineage encompassed complex chromosomal and genomic restructuring phenomena associated with speciation in black flies, viz. expression of one and the same rearrangement as polymorphic, fixed, or sex linked in different species; taxon-specific differentiation of sex chromosomes; and reciprocal translocation of chromosome arms. The translocation is hypothesized to have occurred early in male spermatogonia, with the translocated chromosomal complement being transmitted to the X- and Y-bearing sperm during spermatogenesis, resulting in alternate disjunction of viable F1 translocation heterozygotes and the eventual formation of more viable and selectable F2 translocation homozygous progeny. Of 11 or 12 independently derived whole-arm interchanges known in the family Simuliidae, at least six are associated with subsequent speciation events, suggesting a facilitating role of translocations in adaptive radiations. The findings are discussed in the context of potential structural and

  17. Chromosomal Translocations in Black Flies (Diptera: Simuliidae)-Facilitators of Adaptive Radiation?

    PubMed

    Adler, Peter H; Yadamsuren, Oyunchuluun; Procunier, William S

    2016-01-01

    A macrogenomic investigation of a Holarctic clade of black flies-the Simulium cholodkovskii lineage-provided a platform to explore the implications of a unique, synapomorphic whole-arm interchange in the evolution of black flies. Nearly 60 structural rearrangements were discovered in the polytene complement of the lineage, including 15 common to all 138 analyzed individuals, relative to the central sequence for the entire subgenus Simulium. Three species were represented, of which two Palearctic entities (Simulium cholodkovskii and S. decimatum) were sympatric; an absence of hybrids confirmed their reproductive isolation. A third (Nearctic) entity had nonhomologous sex chromosomes, relative to the other species, and is considered a separate species, for which the name Simulium nigricoxum is revalidated. A cytophylogeny is inferred and indicates that the two Palearctic taxa are sister species and these, in turn, are the sister group of the Nearctic species. The rise of the S. cholodkovskii lineage encompassed complex chromosomal and genomic restructuring phenomena associated with speciation in black flies, viz. expression of one and the same rearrangement as polymorphic, fixed, or sex linked in different species; taxon-specific differentiation of sex chromosomes; and reciprocal translocation of chromosome arms. The translocation is hypothesized to have occurred early in male spermatogonia, with the translocated chromosomal complement being transmitted to the X- and Y-bearing sperm during spermatogenesis, resulting in alternate disjunction of viable F1 translocation heterozygotes and the eventual formation of more viable and selectable F2 translocation homozygous progeny. Of 11 or 12 independently derived whole-arm interchanges known in the family Simuliidae, at least six are associated with subsequent speciation events, suggesting a facilitating role of translocations in adaptive radiations. The findings are discussed in the context of potential structural and

  18. A Williams syndrome patient with a familial t(6;7) translocation and deletion of the elastin gene

    SciTech Connect

    Pober, B.R.; Gibson, L.H.; Yang-Feng, T.L.

    1994-09-01

    Discovery of a {open_quotes}balanced{close_quotes} reciprocal translocation [46,XX,t(6;7)(q11.2;q11.23)] on routine amniocentesis prompted clinical and cytogenetic study of additional family members. The same t(6;7) translocation was found in the clincally normal father and in a sibling with Williams syndrome (WS). WS had been diagnosed previously according to clinical criteria including distinctive facial features, supravalvar aortic stenosis requiring surgical repair, dental abnormalties and developmental delay. A clinically normal female was delivered and the translocation was confirmed with a cord blood specimen. Hemizygosity for the gene, elastin, (which has been mapped to the chromosome 7 translocation breakpoint, 7q11.23, in this family) appears to be a cause of WS. We therefore investigated whether the t(6;7) in the phenotypically normal father represented more than a simple reciprocal translocation. FISH using a chromosome 7 specific library revealed no differences between the cytogenetically identical, yet phenotypically distinct, father and son. Hybridization with a cosmid MR127D4 containing elastin sequence showed that the WS patient was missing one allele from the derivative chromosome 7 whereas both his mother and father had two copies of the elastin gene. This family indicates that the de novo loss of one copy of the elastin gene produces the recognizable phenotype of Williams syndrome. Molecular characterization (with additional probes) of the extent of this de novo deletion near the translocation breakpoint is in progress. This information will be valuable for defining the WS-critical region and will lead to a better understanding of the molecular basis for WS.

  19. Sequence analysis of the breakpoint regions of an X;5 translocation in a female with Duchenne muscular dystrophy

    SciTech Connect

    Bakel, I. van; Holt, S.; Craig, I.

    1995-08-01

    X;autosome translocations in females with Duchenne muscular dystrophy (DMD) provide an opportunity to study the mechanisms responsible for chromosomal rearrangements that occur in the germ line. We describe here a detailed molecular analysis of the translocation breakpoints of an X;autosome reciprocal translocation, t(X;5) (p21;q31.1), in a female with DMD. Cosmid clones that contained the X-chromosome breakpoint region were identified, and subclones that hybridized to the translocation junction fragment in restriction digests of the patient`s DNA were isolated and sequenced. Primers designed from the X-chromosomal sequence were used to obtain the junction fragments on the der(X) and the der(5) by inverse PCR. The resultant clones were also cloned and sequenced, and this information used to isolate the chromosome 5 breakpoint region. Comparison of the DNA sequences of the junction fragments with those of the breakpoint regions on chromosomes X and 5 revealed that the translocation arose by nonhomologous recombination with an imprecise reciprocal exchange. Four and six base pairs of unknown origin are inserted at the exchange points of the der(X) and der(5), respectively, and three nucleotides are deleted from the X-chromosome sequence. Two features were found that may have played a role in the generation of the translocation. These were (1) a repeat motif with an internal homopyrimidine stretch 10 bp upstream from the X-chromosome breakpoint and (2) a 9-bp sequence of 78% homology located near the breakpoints on chromosomes 5 and X. 32 refs., 4 figs., 2 tabs.

  20. Gnome and other effects of a small translocation in the mouse.

    PubMed

    Hollander, W F; Waggie, K S

    1977-01-01

    A semisterile F1 male mouse from an X-ray experiment produced about 25 percent lethal gnome young in outcrosses. These animals were about half normal size, with short tail and small eyes, and died at birth. Surviving progeny were of four classes: 1) like the sire, 2) semisterile, 3) normal, and 4) gnome-producing, but not semisterile. Two independent reciprocal translocations have been identified from the original male, one of the classic type giving semisterile heterozygotes and involving chromosomes 5 and 15. The second translocation seems to be very small, giving the gnome type as one duplication-deficiency product, and the other unbalanced type seeming to pass for normal, although large body size and occasional agnathism may be produced. The small translocation has been found linked with the loci of v (waltzing) and Sl (steel) on chromosome 10. Cytological study has not revealed obvious structural changes. The translocation is now maintained in the homozygous state. The designation T(10;?)2Ho is proposed. PMID:559018

  1. FISH analysis with locus-specific probes in sperm from two translocation carrier men.

    PubMed

    Durak, B; Ozön, Y H; Ozdemir, M; Artan, S; Basaran, N; Basaran, S; Ozkinay, C

    1999-08-01

    Meiotic segregation of normal and derivative chromosomes was analysed in sperm samples from two balanced reciprocal translocation carrier men by use of dual-colour fluorescence in situ hybridisation (FISH) technique. The translocations were t(4;8)(p15;p12) and t(15;22)(q(23:q13.2), and the digoxigenin-labelled FISH probes were specific to either the translocated or centric segments of the chromosomes involved in the translocations. A total of 1000 spermatozoa for each probe were analysed and the modes of segregation were described on the basis of signals in each sperm cell. The mean frequency of alternate and/or adjacent-1 (adj-1) segregation types was 69.47%, whereas they were 30.51 and 78.70% for the adjacent-2 (adj-2) and alternate/adj-2 segregation types, respectively. This study illustrated that FISH is a valuable technique for analysing the meiotic segregation products of the heterozygotes in respect to aneuploidy risk. PMID:10517249

  2. Dominant-lethal mutations and heritable translocations in mice

    SciTech Connect

    Generoso, W.M.

    1983-01-01

    Chromosome aberrations are a major component of radiation or chemically induced genetic damage in mammalian germ cells. The types of aberration produced are dependent upon the mutagen used and the germ-cell stage treated. For example, in male meiotic and postmeiotic germ cells certain alkylating chemicals induce both dominant-lethal mutations and heritable translocations while others induce primarily dominant-lethal mutations. Production of these two endpoints appears to be determined by the stability of alkylation products with the chromosomes. If the reaction products are intact in the male chromosomes at the time of sperm entry, they may be repaired in fertilized eggs. If repair is not effected and the alkylation products persist to the time of pronuclear chromosome replication, they lead to chromatid-type aberrations and eventually to dominant-lethality. The production of heritable translocations, on the other hand, requires a transformation of unstable alkylation products into suitable intermediate lesions. The process by which these lesions are converted into chromosome exchange within the male genome takes place after sperm enters the egg but prior to the time of pronuclear chromosome replication (i.e., chromosome-type). Thus, dominant-lethal mutations result from both chromatid- and chromosome-type aberrations while heritable translocations result primarily from the latter type. DNA target sites associated with the production of these two endpoints are discussed.

  3. Complex Y-linked translocations in Delia antiqua produced by irradiation of a fertile Y-linked translocation.

    PubMed

    Robinson, A S; van Heemert, K

    1981-02-01

    In the onion fly, Delia antiqua, a fertile, Y-linked translocation involving chromosomes Y and 2 was irradiated with fast neutrons to induce new complexes involving the Y-chromosome. This chromosome is male determining in the onion fly. Such complexes can be used for the development of genetic sexing systems and also for the introduction of sterility into field populations following release. Irradiation reduced egg fertility by 54 per cent and significantly reduced larval survival but it had no effect on the F1 sex ratio. By measuring the fertility of 807 F1 males following outcrossing, 112 semi-sterile progenies were isolated of which 11 were lost, 29 showed no inheritance of the semi-sterility, 59 were new autosomal translocations and 13 were new complex Y-linked translocations. This classification was accomplished by checking the fertilities of outcrossed F2 males and females. Following cytological observation it was revealed that one of these new complexes involved four chromosome pairs, the remainder involved three. There appeared to be no correlation between the fertility of the translocation and the complexity of the rearrangement. The utilization of these rearrangements in the development of the genetic sexing technique for the onion fly is discussed, together with an assessment of their use for fertility reduction in natural populations. PMID:7263278

  4. Translocation (Y;12) in lipoma.

    PubMed

    Liang, Cher-Wei; Mariño-Enríquez, Adrian; Johannessen, Catherine; Hornick, Jason L; Dal Cin, Paola

    2011-01-01

    Lipomas are the most common benign mesenchymal neoplasm in adults, and have been extensively characterized at the cytogenetic level. Chromosomal aberrations have been observed in the majority of lipomas, two-thirds of which involve chromosomal region 12q14.3. To date, structural rearrangements have been reported affecting every chromosome except chromosome Y. Here we report a case of a lipoma that shows a novel apparently balanced translocation involving chromosomes Y and 12. Fluorescence in situ hybridization using a break-apart HMGA2 in-house probe set detected a single signal on the normal chromosome 12 but not on either the derivative chromosome Y or 12, indicating a cryptic loss of 12q14.3, where HMGA2 is mapped. Immunohistochemical studies, however, revealed overexpression of HMGA2 with nuclear expression in the majority of tumor cells, whereas MDM2 and CDK4 were negative. The overexpression of HMGA2 may be caused by a cryptic chromosomal aberration affecting either the cytogenetically unaltered HMGA2 allele or HMGA2 regulators elsewhere. The current case broadens our knowledge about the translocation partners of HMGA2 in lipomas and highlights the biological complexity in regulating HMGA2 expression. PMID:21356192

  5. Haloarchaeal Protein Translocation via the Twin Arginine Translocation Pathway

    SciTech Connect

    Pohlschroder Mechthild

    2009-02-03

    Protein transport across hydrophobic membranes that partition cellular compartments is essential in all cells. The twin arginine translocation (Tat) pathway transports proteins across the prokaryotic cytoplasmic membranes. Distinct from the universally conserved Sec pathway, which secretes unfolded proteins, the Tat machinery is unique in that it secretes proteins in a folded conformation, making it an attractive pathway for the transport and secretion of heterologously expressed proteins that are Sec-incompatible. During the past 7 years, the DOE-supported project has focused on the characterization of the diversity of bacterial and archaeal Tat substrates as well as on the characterization of the Tat pathway of a model archaeon, Haloferax volcanii, a member of the haloarchaea. We have demonstrated that H. volcanii uses this pathway to transport most of its secretome.

  6. The Evaluational Consequences of Topic Reciprocity and Self-Disclosure Reciprocity.

    ERIC Educational Resources Information Center

    Hosman, Lawrence A.

    1987-01-01

    Investigates the hypothesis that messages reciprocating both topic and intimacy would be more positively evaluated than those reciprocating neither. Results support the hypothesis for initial low intimacy messages, and partially support it for initial high intimacy messages. Examines results in terms of competing interactional goals in a…

  7. Production and Identification of Wheat-Agropyron cristatum 2P Translocation Lines.

    PubMed

    Li, Huanhuan; Lv, Mingjie; Song, Liqiang; Zhang, Jinpeng; Gao, Ainong; Li, Lihui; Liu, Weihua

    2016-01-01

    Agropyron cristatum (L.) Gaertn. (2n = 28, PPPP), a wild relative of common wheat, possesses many potentially valuable traits that can be transferred to common wheat through breeding programs. The wheat-A. cristatum disomic addition and translocation lines can be used as bridge materials to introduce alien chromosomal segments to wheat. Wheat-A. cristatum 2P disomic addition line II-9-3 was highly resistant to powdery mildew and leaf rust, which was reported in our previous study. However, some translocation lines induced from II-9-3 have not been reported. In this study, some translocation lines were induced from II-9-3 by 60Co-γ irradiation and gametocidal chromosome 2C and then identified by cytological methods. Forty-nine wheat-A. cristatum translocation lines were obtained and various translcoation types were identified by GISH (genomic in situ hybridization), such as whole-arm, segmental and intercalary translocations. Dual-color FISH (fluorescent in situ hybridization) was applied to identify the wheat chromosomes involved in the translocations, and the results showed that A. cristatum 2P chromosome segments were translocated to the different wheat chromosomes, including 1A, 2A, 3A, 4A, 5A, 6A, 7A, 3B, 5B, 7B, 1D, 4D and 6D. Many different types of wheat-A. cristatum alien translocation lines would be valuable for not only identifying and cloning A. cristatum 2P-related genes and understanding the genetics and breeding effects of the translocation between A. cristatum chromosome 2P and wheat chromosomes, but also providing new germplasm resources for the wheat genetic improvement. PMID:26731742

  8. Production and Identification of Wheat-Agropyron cristatum 2P Translocation Lines

    PubMed Central

    Li, Huanhuan; Lv, Mingjie; Song, Liqiang; Zhang, Jinpeng; Gao, Ainong; Li, Lihui; Liu, Weihua

    2016-01-01

    Agropyron cristatum (L.) Gaertn. (2n = 28, PPPP), a wild relative of common wheat, possesses many potentially valuable traits that can be transferred to common wheat through breeding programs. The wheat-A. cristatum disomic addition and translocation lines can be used as bridge materials to introduce alien chromosomal segments to wheat. Wheat-A. cristatum 2P disomic addition line II-9-3 was highly resistant to powdery mildew and leaf rust, which was reported in our previous study. However, some translocation lines induced from II-9-3 have not been reported. In this study, some translocation lines were induced from II-9-3 by 60Co-γ irradiation and gametocidal chromosome 2C and then identified by cytological methods. Forty-nine wheat-A. cristatum translocation lines were obtained and various translcoation types were identified by GISH (genomic in situ hybridization), such as whole-arm, segmental and intercalary translocations. Dual-color FISH (fluorescent in situ hybridization) was applied to identify the wheat chromosomes involved in the translocations, and the results showed that A. cristatum 2P chromosome segments were translocated to the different wheat chromosomes, including 1A, 2A, 3A, 4A, 5A, 6A, 7A, 3B, 5B, 7B, 1D, 4D and 6D. Many different types of wheat-A. cristatum alien translocation lines would be valuable for not only identifying and cloning A. cristatum 2P-related genes and understanding the genetics and breeding effects of the translocation between A. cristatum chromosome 2P and wheat chromosomes, but also providing new germplasm resources for the wheat genetic improvement. PMID:26731742

  9. RNase A Does Not Translocate the Alpha-Hemolysin Pore

    PubMed Central

    Krasniqi, Besnik; Lee, Jeremy S.

    2014-01-01

    The application of nanopore sensing utilizing the α-hemolysin pore to probe proteins at single-molecule resolution has expanded rapidly. In some studies protein translocation through the α-hemolysin has been reported. However, there is no direct evidence, as yet, that proteins can translocate the α-hemolysin pore. The biggest challenge to obtaining direct evidence is the lack of a highly sensitive assay to detect very low numbers of protein molecules. Furthermore, if an activity based assay is applied then the proteins translocating by unfolding should refold back to an active confirmation for the assay technique to work. To overcome these challenges we selected a model enzyme, ribonuclease A, that readily refolds to an active conformation even after unfolding it with denaturants. In addition we have developed a highly sensitive reverse transcription polymerase chain reaction based activity assay for ribonuclease A. Initially, ribonuclease A, a protein with a positive net charge and dimensions larger than the smallest diameter of the pore, was subjected to nanopore analysis under different experimental conditions. Surprisingly, although the protein was added to the cis chamber (grounded) and a positive potential was applied, the interaction of ribonuclease A with α-hemolysin pore induced small and large blockade events in the presence and the absence of a reducing and/or denaturing agent. Upon measuring the zeta potential, it was found that the protein undergoes a charge reversal under the experimental conditions used for nanopore sensing. From the investigation of the effect of voltage on the interaction of ribonuclease A with the α-hemolysin pore, it was impossible to conclude if the events observed were translocations. However, upon testing for ribonuclease A activity on the trans chamber it was found that ribonuclease A does not translocate the α-hemolysin pore. PMID:24505349

  10. Reciprocating flow-based centrifugal microfluidics mixer

    NASA Astrophysics Data System (ADS)

    Noroozi, Zahra; Kido, Horacio; Micic, Miodrag; Pan, Hansheng; Bartolome, Christian; Princevac, Marko; Zoval, Jim; Madou, Marc

    2009-07-01

    Proper mixing of reagents is of paramount importance for an efficient chemical reaction. While on a large scale there are many good solutions for quantitative mixing of reagents, as of today, efficient and inexpensive fluid mixing in the nanoliter and microliter volume range is still a challenge. Complete, i.e., quantitative mixing is of special importance in any small-scale analytical application because the scarcity of analytes and the low volume of the reagents demand efficient utilization of all available reaction components. In this paper we demonstrate the design and fabrication of a novel centrifugal force-based unit for fast mixing of fluids in the nanoliter to microliter volume range. The device consists of a number of chambers (including two loading chambers, one pressure chamber, and one mixing chamber) that are connected through a network of microchannels, and is made by bonding a slab of polydimethylsiloxane (PDMS) to a glass slide. The PDMS slab was cast using a SU-8 master mold fabricated by a two-level photolithography process. This microfluidic mixer exploits centrifugal force and pneumatic pressure to reciprocate the flow of fluid samples in order to minimize the amount of sample and the time of mixing. The process of mixing was monitored by utilizing the planar laser induced fluorescence (PLIF) technique. A time series of high resolution images of the mixing chamber were analyzed for the spatial distribution of light intensities as the two fluids (suspension of red fluorescent particles and water) mixed. Histograms of the fluorescent emissions within the mixing chamber during different stages of the mixing process were created to quantify the level of mixing of the mixing fluids. The results suggest that quantitative mixing was achieved in less than 3 min. This device can be employed as a stand alone mixing unit or may be integrated into a disk-based microfluidic system where, in addition to mixing, several other sample preparation steps may be

  11. Phosphorus Compounds in Translocating Phloem

    PubMed Central

    Bieleski, R. L.

    1969-01-01

    Phosphate-32P was introduced into a turnip leaf, and 3 hr later, the vascular bundles were stripped from the petiole and their phosphate ester pattern was studied. The pattern did not alter along their length and was like that of other tissues. Pumpkin leaves were painted with phosphate-32P; and later, the petioles were cut, the sieve tube exudates were collected and their phosphate ester patterns were studied. Exudates collected after 10 min had a high proportion of their 32P present in Pi and nucleoside triphosphates, while exudates collected after long translocation times (4-22 hr) had a lower proportion in these, and a higher proportion in hexose monophosphates and UDP glucose. In general, the ester patterns were like those of other tissues. The results indicate that sieve tubes are metabolically active, and that Pi is the primary form in which phosphorus moves in the phloem. Images PMID:16657091

  12. DNA translocation through graphene nanopores.

    PubMed

    Merchant, Christopher A; Healy, Ken; Wanunu, Meni; Ray, Vishva; Peterman, Neil; Bartel, John; Fischbein, Michael D; Venta, Kimberly; Luo, Zhengtang; Johnson, A T Charlie; Drndić, Marija

    2010-08-11

    We report on DNA translocations through nanopores created in graphene membranes. Devices consist of 1-5 nm thick graphene membranes with electron-beam sculpted nanopores from 5 to 10 nm in diameter. Due to the thin nature of the graphene membranes, we observe larger blocked currents than for traditional solid-state nanopores. However, ionic current noise levels are several orders of magnitude larger than those for silicon nitride nanopores. These fluctuations are reduced with the atomic-layer deposition of 5 nm of titanium dioxide over the device. Unlike traditional solid-state nanopore materials that are insulating, graphene is an excellent electrical conductor. Use of graphene as a membrane material opens the door to a new class of nanopore devices in which electronic sensing and control are performed directly at the pore. PMID:20698604

  13. Chromosomal translocations deregulating c-myc are associated with normal immune responses.

    PubMed

    Roschke, V; Kopantzev, E; Dertzbaugh, M; Rudikoff, S

    1997-06-26

    Plasmacytomas induced in BALB/c mice by pristane consistently evidence chromosomal translocations involving the c-myc gene and one of the Ig loci. This observation has lead to the suggestion that c-myc deregulation is a critical event in the generation of such tumors. However, it is not clear whether c-myc translocation is related to pristane treatment or occurs in normal lymphocyte populations nor whether such translocations occur normally, and at similar frequencies, in strains genetically resistant to plasmacytoma development, such as DBA/2. In order to address these questions, a Long Distance PCR assay with single copy sensitivity was employed to assess the frequency of c-myc/IgA translocations in normal and immunized mice of both plasmacytoma resistant and susceptible lineages in the absence of pristane treatment. Our data demonstrate that spontaneous translocations occur in normal DBA/2 and BALB/c mice with no significant differences in frequency. A 3-5-fold increase in translocation frequency was observed in mice immunized with cholera toxin, a strong stimulator of IgA responses. We conclude that c-myc deregulation by chromosomal translocation is associated with normal physiological processes of B-cell differentiation and, as such, can not be the determining factor leading to malignancy. PMID:9223664

  14. Theory of reciprocating contact for viscoelastic solids

    NASA Astrophysics Data System (ADS)

    Putignano, Carmine; Carbone, Giuseppe; Dini, Daniele

    2016-04-01

    A theory of reciprocating contacts for linear viscoelastic materials is presented. Results are discussed for the case of a rigid sphere sinusoidally driven in sliding contact with a viscoelastic half-space. Depending on the size of the contact, the frequency and amplitude of the reciprocating motion, and on the relaxation time of the viscoelastic body, we establish that the contact behavior may range from the steady-state viscoelastic solution, in which traction forces always oppose the direction of the sliding rigid punch, to a more elaborate trend, which is due to the strong interaction between different regions of the path covered during the reciprocating motion. Practical implications span a number of applications, ranging from seismic engineering to biotechnology.

  15. Reciprocation and altruism in social cooperation.

    PubMed

    Safin, Vasiliy; Arfer, Kodi B; Rachlin, Howard

    2015-07-01

    Altruistic behavior benefits other individuals at a cost to oneself. The purpose of the present experiment was to study altruistic behavior by players (P) in 2-person iterated prisoner's dilemma games in which reciprocation by the other player (OP) was impossible, and this impossibility was clear to P. Altruism by P could not therefore be attributed to expectation of reciprocation. The cost to P of altruistic behavior was constant throughout the study, but the benefit to OP from P's cooperation differed between groups and conditions. Rate of cooperation was higher when benefit to OP was higher. Thus altruism (not attributable to expectation of reciprocation) can be a significant factor in interpersonal relationships as studied in iterated prisoner's dilemma games, and needs to be taken into account in their analysis. PMID:25907149

  16. Modelling fluid flow in a reciprocating compressor

    NASA Astrophysics Data System (ADS)

    Tuhovcak, Jan; Hejčík, Jiří; Jícha, Miroslav

    2015-05-01

    Efficiency of reciprocating compressor is strongly dependent on the valves characteristics, which affects the flow through the suction and discharge line. Understanding the phenomenon inside the compressor is necessary step in development process. Commercial CFD tools offer wide capabilities to simulate the flow inside the reciprocating compressor, however they are too complicated in terms of computational time and mesh creation. Several parameters describing compressor could be therefore examined without the CFD analysis, such is valve characteristic, flow through the cycle and heat transfer. The aim of this paper is to show a numerical tool for reciprocating compressor based on the energy balance through the cycle, which provides valve characteristics, flow through the cycle and heat losses from the cylinder. Spring-damping-mass model was used for the valve description. Boundary conditions were extracted from the performance test of 4-cylinder semihermetic compressor and numerical tool validation was performed with indicated p-V diagram comparison.

  17. Reciprocating Feed System Development Status

    NASA Technical Reports Server (NTRS)

    Trewek, Mary (Technical Monitor); Blackmon, James B.; Eddleman, David E.

    2005-01-01

    The reciprocating feed system (RFS) is an alternative means of providing high pressure propellant flow at low cost and system mass, with high fail-operational reliability. The RFS functions by storing the liquid propellants in large, low-pressure tanks and then expelling each propellant through two or three small, high-pressure tanks. Each RFS tank is sequentially filled, pressurized, expelled, vented, and refilled so as to provide a constant, or variable, mass flow rate to the engine. This type of system is much lighter than a conventional pressure fed system in part due to the greatly reduced amount of inert tank weight. The delivered payload for an RFS is superior to that of conventional pressure fed systems for conditions of high total impulse and it is competitive with turbopump systems, up to approximately 2000 psi. An advanced version of the RFS uses autogenous pressurization and thrust augmentation to achieve higher performance. In this version, the pressurization gases are combusted in a small engine, thus making the pressurization system, in effect, part of the propulsion system. The RFS appears to be much less expensive than a turbopump system, due to reduced research and development cost and hardware cost, since it is basically composed of small high- pressure tanks, a pressurization system, and control valves. A major benefit is the high reliability fail-operational mode; in the event of a failure in one of the three tank-systems, it can operate on the two remaining tanks. Other benefits include variable pressure and flow rates, ease of engine restart in micro-gravity, and enhanced propellant acquisition and control under adverse acceleration conditions. We present a system mass analysis tool that accepts user inputs for various design and mission parameters and calculates such output values payload and vehicle weights for the conventional pressure fed system, the RFS, the Autogenous Pressurization Thrust Augmentation (APTA) RFS, and turbopump systems

  18. Extra skeletal Soft Tissue Ewing’s Sarcoma with Variant Translocation of Chromosome t (4; 22) (q35; q12)-A Case Report

    PubMed Central

    Nagaraj, Prashanth; H, Srinivas C; Rao, Raghavendra; Manohar, Sandesh

    2013-01-01

    Introduction: Ewing’s sarcomas is a rare primitive neuroectodermal tumour (PNET) which has an annual incidence of 2.9 /million population in USA 1Jeffery Toretsky et al (2008) They are very uncommon in African and Asian population. It is commonly associated with reciprocal translocation between chromosome 11 and 12 t (11:12) or less frequently the t(21;22)(q22;ql 2) translocation. It is highly aggressive tumor which is PAS- and CD99 (MIC2)-positive relatively few variant translocations have been reported in primary Ewing’s sarcomas (ES). Case Report: We are hereby presenting a case of extra skeletal soft tissue Ewing’s sarcoma with unusual translocation of chromosome t (4, 22) (q35, q12). Patient presented to us in advanced stage with pulmonary metastasis and lower limb neurological deficit. Relatively few variant translocations have been reported in primary Ewing’s sarcomas (ES). To date, 13 variants of the EWS fusion gene have been described in literature. They are extremely rare, representing altogether < 1% of the cases’ 23we are reporting a case of a variant simple translocation of chromosome t (4; 22) (q35;1 2). In our exhaustive literature search we could find only one case of complex translocation which was identified in a dysmorphic 15-year-old girl, t (4:11; 22)(q21; q24; q12) reported by Squire Jet al (1993). Conclusion: This type of translocation is extremely rare and has not been reported in the literature so far. Clinical presentation was initial indolent but later at the time patient presented to our institute he had developed pulmonary metastases and paraplegia due to involvement of spine. Our case report will provide new insight about rare translocation types in Ewing’s sarcoma and understand their clinical behavior of Ewing’s sarcoma with such type of translocation. PMID:27298923

  19. Feasibility analysis of reciprocating magnetic heat pumps

    NASA Technical Reports Server (NTRS)

    Larson, A. V.; Hartley, J. G.; Shelton, Sam V.; Smith, M. M.

    1989-01-01

    A reciprocating gadolinium core in a regeneration fluid column in the warm bore of a superconducting solenoidal magnet is considered for magnetic refrigeration in 3.517 MW (1000 ton) applications. A procedure is presented to minimize the amount of superconducting cable needed in the magnet design. Estimated system capital costs for an ideal magnetic refrigerator of this type become comparable to conventional chillers as the frequency of reciprocation approaches 10 Hertz. A 1-D finite difference analysis of a regenerator cycling at 0.027 Hertz is presented which exhibits some of the features seen in the experiments of G. V. Brown.

  20. [The experience in employing reciprocal gait orthoses].

    PubMed

    Radło, W; Miklaszewski, K; Gasińska, M; Michno, P

    1999-01-01

    The paper presents the experience of the authors in employing reciprocal gait orthoses in a group of 23 patients age 3-25 years (mean age 7.8 years). The orthoses were indicated in patients with flaccid paresis (17 children with myelodysplasia and 3 patients with traumatic paraplegia) and with arthrogryposis (3 patients). The follow-up period was 6 months to 5 years (mean 2.4 years). The authors discuss the principles of construction and operation of reciprocal gait orthoses and types of patients in whom they are recommended. The principles of learning walking and using the orthosis are also presented. PMID:10367535

  1. Multiple Ty-mediated chromosomal translocations lead to karyotype changes in a wine strain of Saccharomyces cerevisiae.

    PubMed

    Rachidi, N; Barre, P; Blondin, B

    1999-06-01

    Enological strains of Saccharomyces cerevisiae display a high level of chromosome length polymorphism, but the molecular basis of this phenomenon has not yet been clearly defined. In order to gain further insight into the molecular mechanisms responsible for the karyotypic variability, we examined the chromosomal constitution of a strain known to possess aberrant chromosomes. Our data revealed that the strain carries four rearranged chromosomes resulting from two reciprocal translocations between chromosomes III and I, and chromosomes III and VII. The sizes of the chromosomal fragments exchanged through translocation range from 40 to 150 kb. Characterization of the breakpoints indicated that the translocations involved the RAHS of chromosome III, a transposition hot-spot on the right arm of chromosome I and a region on the left arm of chromosome VII. An analysis of the junctions showed that in all cases Ty elements were present and suggested that the translocations result from recombination between transposable Ty elements. The evidence for multiple translocations mediated by Ty elements in a single strain suggests that spontaneous Ty-driven rearrangement could be quite common and may play a major role in the alteration of karyotypes in natural and industrial yeasts. PMID:10394922

  2. From Born Reciprocity to Reciprocal Relativity: A Paradigm for Space-Time Physics

    NASA Astrophysics Data System (ADS)

    Jarvis, Peter

    Born's principle of reciprocity -- the exchangeability of relativistic energy-momentum and time-position -- can be seen as a discrete element of a continuous group of symmetry transformations which transcend relativity. Invariance under the semi-direct product of the Weyl-Heisenberg group H(4) of canonical commutation relations with the non-compact unitary group U(3, 1) -- the so-called quaplectic group U(3, 1) ⋉ H(4) -- has been considered by Low as an extension of Born reciprocity to a fundamental symmetry principle of `reciprocal relativity' for the physics of non-inertial frames and high energy processes...

  3. Genomic Hallmarks of Genes Involved in Chromosomal Translocations in Hematological Cancer

    PubMed Central

    Shugay, Mikhail; Ortiz de Mendíbil, Iñigo; Vizmanos, José L.; Novo, Francisco J.

    2012-01-01

    Reciprocal chromosomal translocations (RCTs) leading to the formation of fusion genes are important drivers of hematological cancers. Although the general requirements for breakage and fusion are fairly well understood, quantitative support for a general mechanism of RCT formation is still lacking. The aim of this paper is to analyze available high-throughput datasets with computational and robust statistical methods, in order to identify genomic hallmarks of translocation partner genes (TPGs). Our results show that fusion genes are generally overexpressed due to increased promoter activity of 5′ TPGs and to more stable 3′-UTR regions of 3′ TPGs. Furthermore, expression profiling of 5′ TPGs and of interaction partners of 3′ TPGs indicates that these features can help to explain tissue specificity of hematological translocations. Analysis of protein domains retained in fusion proteins shows that the co-occurrence of specific domain combinations is non-random and that distinct functional classes of fusion proteins tend to be associated with different components of the gene fusion network. This indicates that the configuration of fusion proteins plays an important role in determining which 5′ and 3′ TPGs will combine in specific fusion genes. It is generally accepted that chromosomal proximity in the nucleus can explain the specific pairing of 5′ and 3′ TPGS and the recurrence of hematological translocations. Using recently available data for chromosomal contact probabilities (Hi-C) we show that TPGs are preferentially located in early replicated regions and occupy distinct clusters in the nucleus. However, our data suggest that, in general, nuclear position of TPGs in hematological cancers explains neither TPG pairing nor clinical frequency. Taken together, our results support a model in which genomic features related to regulation of expression and replication timing determine the set of candidate genes more likely to be translocated in

  4. Mapping the breakpoints of an individual with congenital glaucoma and a 6:13 translocation

    SciTech Connect

    Nishimura, D.Y.; Patil, S.; Alward, W.L.M.

    1994-09-01

    We have identified an individual with a balanced translocation involving the short arm of chromosome 6 (6p25) and the long arm of chromosome 13 (13q22). This person was found to have congenital glaucoma along with other anomalies. The identification of a second individual with both congenital glaucoma and an unbalanced translocation involving the distal short arm of chromosome 6 suggested that this region of chromosome 6 might be involved in at least some cases of congenital glaucoma. Therefore, we wished to characterize the two breakpoints with an emphasis on the 6p25 breakpoint. Somatic cell hybrids were used to isolate the two translocated chromosomes away from the normal 6 and 13. Two hybrids were identified which contained the distal region of chromosome 6p, while a third hybrid contained the reciprocal translocated chromosome. Characterization of the hybrids demonstrated that the breakpoint on chromosome 6p lies between the markers D6S344 and D6S477, while the chromosome 13 breakpoint lies between the markers D13S160 and D13S170. The distances between the flanking markers on both of the chromosomes are less than 5 cM. The lack of genetic markers within the 6p25 region made it difficult to accurately map the location of the breakpoint in this region. However, we were able to demonstrate that at least two markers are distal to the 6p25 breakpoint. We are working to improve the quality of both the genetic and physical maps of 6p25 and 13q22 in an attempt to further refine the localization of the breakpoints. Preliminary work on the individual with the unbalanced translocation suggests that the 6p deletion in this person includes the 6p25 breakpoints.

  5. APOBEC family mutational signatures are associated with poor prognosis translocations in multiple myeloma

    PubMed Central

    Walker, Brian A; Wardell, Christopher P; Murison, Alex; Boyle, Eileen M; Begum, Dil B; Dahir, Nasrin M; Proszek, Paula Z; Melchor, Lorenzo; Pawlyn, Charlotte; Kaiser, Martin F; Johnson, David C; Qiang, Ya-Wei; Jones, John R; Cairns, David A; Gregory, Walter M; Owen, Roger G; Cook, Gordon; Drayson, Mark T; Jackson, Graham H; Davies, Faith E; Morgan, Gareth J

    2015-01-01

    We have sequenced 463 presenting cases of myeloma entered into the UK Myeloma XI study using whole exome sequencing. Here we identify mutations induced as a consequence of misdirected AID in the partner oncogenes of IGH translocations, which are activating and associated with impaired clinical outcome. An APOBEC mutational signature is seen in 3.8% of cases and is linked to the translocation mediated deregulation of MAF and MAFB, a known poor prognostic factor. Patients with this signature have an increased mutational load and a poor prognosis. Loss of MAF or MAFB expression results in decreased APOBEC3B and APOBEC4 expression, indicating a transcriptional control mechanism. Kataegis, a further mutational pattern associated with APOBEC deregulation, is seen at the sites of the MYC translocation. The APOBEC mutational signature seen in myeloma is, therefore, associated with poor prognosis primary and secondary translocations and the molecular mechanisms involved in generating them. PMID:25904160

  6. mRNA Translocation Occurs During the Second Step of Ribosomal Intersubunit Rotation

    PubMed Central

    Ermolenko, Dmitri N.; Noller, Harry F.

    2010-01-01

    During protein synthesis, mRNA and tRNA undergo coupled translocation through the ribosome in a process that is catalyzed by elongation factor EF-G. Based on cryo-EM reconstructions, counterclockwise and clockwise rotational movements between the large and small ribosomal subunits have been implicated in a proposed ratcheting mechanism to drive the unidirectional movement of translocation. We have used a combination of two fluorescence-based approaches to study the timing of these events: Intersubunit FRET measurements to observe relative rotational movement of the subunits and a fluorescence quenching assay to monitor translocation of mRNA. Binding of EF-G·GTP first induces rapid counterclockwise intersubunit rotation, followed by a slower, clockwise reversal of the rotational movement. Comparison of the rates of these movements reveals that mRNA translocation occurs during the second, clockwise rotation event, corresponding to the transition from the hybrid state to the classical state. PMID:21399643

  7. Association between simple sequence repeat-rich chromosome regions and intergenomic translocation breakpoints in natural populations of allopolyploid wild wheats

    PubMed Central

    Molnár, István; Cifuentes, Marta; Schneider, Annamária; Benavente, Elena; Molnár-Láng, Márta

    2011-01-01

    Background and Aims Repetitive DNA sequences are thought to be involved in the formation of chromosomal rearrangements. The aim of this study was to analyse the distribution of microsatellite clusters in Aegilops biuncialis and Aegilops geniculata, and its relationship with the intergenomic translocations in these allotetraploid species, wild genetic resources for wheat improvement. Methods The chromosomal localization of (ACG)n and (GAA)n microsatellite sequences in Ae. biuncialis and Ae. geniculata and in their diploid progenitors Aegilops comosa and Aegilops umbellulata was investigated by sequential in situ hybridization with simple sequence repeat (SSR) probes and repeated DNA probes (pSc119·2, Afa family and pTa71) and by dual-colour genomic in situ hybridization (GISH). Thirty-two Ae. biuncialis and 19 Ae. geniculata accessions were screened by GISH for intergenomic translocations, which were further characterized by fluorescence in situ hybridization and GISH. Key Results Single pericentromeric (ACG)n signals were localized on most U and on some M genome chromosomes, whereas strong pericentromeric and several intercalary and telomeric (GAA)n sites were observed on the Aegilops chromosomes. Three Ae. biuncialis accessions carried 7Ub–7Mb reciprocal translocations and one had a 7Ub–1Mb rearrangement, while two Ae. geniculata accessions carried 7Ug–1Mg or 5Ug–5Mg translocations. Conspicuous (ACG)n and/or (GAA)n clusters were located near the translocation breakpoints in eight of the ten translocated chromosomes analysed, SSR bands and breakpoints being statistically located at the same chromosomal site in six of them. Conclusions Intergenomic translocation breakpoints are frequently mapped to SSR-rich chromosomal regions in the allopolyploid species examined, suggesting that microsatellite repeated DNA sequences might facilitate the formation of those chromosomal rearrangements. The (ACG)n and (GAA)n SSR motifs serve as additional chromosome markers

  8. Tuition Reciprocity in the United States

    ERIC Educational Resources Information Center

    Stewart, Gregory; Wright, Dianne Brown; Kennedy, Angelica

    2008-01-01

    Reciprocity agreements are contracts between two or more parties whereby students pay reduced tuition rates. The rate of reduction is determined by the parameters set forth in each individual state's agreement but may range from a modest reduction in fees to a waiver of full non-resident tuition. In addition to providing tuition relief,…

  9. Evolving the ingredients for reciprocity and spite

    PubMed Central

    Hauser, Marc; McAuliffe, Katherine; Blake, Peter R.

    2009-01-01

    Darwin never provided a satisfactory account of altruism, but posed the problem beautifully in light of the logic of natural selection. Hamilton and Williams delivered the necessary satisfaction by appealing to kinship, and Trivers showed that kinship was not necessary as long as the originally altruistic act was conditionally reciprocated. From the late 1970s to the present, the kinship theories in particular have been supported by considerable empirical data and elaborated to explore a number of other social interactions such as cooperation, selfishness and punishment, giving us what is now a rich description of the nature of social relationships among organisms. There are, however, two forms of theoretically possible social interactions—reciprocity and spite—that appear absent or nearly so in non-human vertebrates, despite considerable research efforts on a wide diversity of species. We suggest that the rather weak comparative evidence for these interactions is predicted once we consider the requisite socioecological pressures and psychological mechanisms. That is, a consideration of ultimate demands and proximate prerequisites leads to the prediction that reciprocity and spite should be rare in non-human animals, and common in humans. In particular, reciprocity and spite evolved in humans because of adaptive demands on cooperation among unrelated individuals living in large groups, and the integrative capacities of inequity detection, future-oriented decision-making and inhibitory control. PMID:19805432

  10. Reciprocal Teaching. What Works Clearinghouse Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2013

    2013-01-01

    "Reciprocal teaching" is an instructional method designed to help teach reading comprehension skills to students with adequate decoding proficiency. During initial instructional sessions, the teacher introduces four comprehension strategies: summarizing, questioning, clarifying, and predicting. Then, the teacher and student read several…

  11. Development of Trust and Reciprocity in Adolescence

    ERIC Educational Resources Information Center

    van den Bos, Wouter; Westenberg, Michiel; van Dijk, Eric; Crone, Eveline A.

    2010-01-01

    We investigate the development of two types of prosocial behavior, trust and reciprocity, as defined using a game-theoretical task that allows investigation of real-time social interaction, among 4 age groups from 9 to 25 years. By manipulating the possible outcome alternatives, we could distinguish among important determinants of trust and…

  12. A WRKY Transcription Factor Regulates Fe Translocation under Fe Deficiency.

    PubMed

    Yan, Jing Ying; Li, Chun Xiao; Sun, Li; Ren, Jiang Yuan; Li, Gui Xin; Ding, Zhong Jie; Zheng, Shao Jian

    2016-07-01

    Iron (Fe) deficiency affects plant growth and development, leading to reduction of crop yields and quality. Although the regulation of Fe uptake under Fe deficiency has been well studied in the past decade, the regulatory mechanism of Fe translocation inside the plants remains unknown. Here, we show that a WRKY transcription factor WRKY46 is involved in response to Fe deficiency. Lack of WRKY46 (wrky46-1 and wrky46-2 loss-of-function mutants) significantly affects Fe translocation from root to shoot and thus causes obvious chlorosis on the new leaves under Fe deficiency. Gene expression analysis reveals that expression of a nodulin-like gene (VACUOLAR IRON TRANSPORTER1-LIKE1 [VITL1]) is dramatically increased in wrky46-1 mutant. VITL1 expression is inhibited by Fe deficiency, while the expression of WRKY46 is induced in the root stele. Moreover, down-regulation of VITL1 expression can restore the chlorosis phenotype on wrky46-1 under Fe deficiency. Further yeast one-hybrid and chromatin immunoprecipitation experiments indicate that WRKY46 is capable of binding to the specific W-boxes present in the VITL1 promoter. In summary, our results demonstrate that WRKY46 plays an important role in the control of root-to-shoot Fe translocation under Fe deficiency condition via direct regulation of VITL1 transcript levels. PMID:27208259

  13. 30 CFR 56.13010 - Reciprocating-type air compressors.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Reciprocating-type air compressors. 56.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air...

  14. 30 CFR 56.13010 - Reciprocating-type air compressors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Reciprocating-type air compressors. 56.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air...

  15. 30 CFR 56.13010 - Reciprocating-type air compressors.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Reciprocating-type air compressors. 56.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air...

  16. 27 CFR 28.23 - Reciprocating foreign countries.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Reciprocating foreign... Lading for Use on Certain Vessels and Aircraft § 28.23 Reciprocating foreign countries. The appropriate... other countries, which it is claimed reciprocate similar privileges to aircraft of the United...

  17. Familial Reciprocity and Subjective Well-Being in Ghana

    ERIC Educational Resources Information Center

    Tsai, Ming-Chang; Dzorgbo, Dan-Bright S.

    2012-01-01

    The authors investigated variations in reciprocity and the impact of reciprocity on well-being in a West African society. They hypothesized that household size and income diversity encourage reciprocity, which in turn enhances subjective well-being. In empirical testing of these hypotheses the authors used the data of the Core Welfare Indicators…

  18. 32 CFR 634.16 - Reciprocal state-military action.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Reciprocal state-military action. 634.16 Section... Reciprocal state-military action. (a) Commanders will recognize the interests of the states in matters of POV... formal military reciprocity, the procedures below will be adopted: (1) Commanders will recognize...

  19. 32 CFR 634.16 - Reciprocal state-military action.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Reciprocal state-military action. 634.16 Section... Reciprocal state-military action. (a) Commanders will recognize the interests of the states in matters of POV... formal military reciprocity, the procedures below will be adopted: (1) Commanders will recognize...

  20. 32 CFR 634.16 - Reciprocal state-military action.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Reciprocal state-military action. 634.16 Section... Reciprocal state-military action. (a) Commanders will recognize the interests of the states in matters of POV... formal military reciprocity, the procedures below will be adopted: (1) Commanders will recognize...

  1. Intersubunit movement is required for ribosomal translocation

    PubMed Central

    Horan, Lucas H.; Noller, Harry F.

    2007-01-01

    Translocation of tRNA and mRNA during protein synthesis is believed to be coupled to structural changes in the ribosome. The “ratchet model,” based on cryo-EM reconstructions of ribosome complexes, invokes relative movement of the 30S and 50S ribosomal subunits in this process; however, evidence that directly demonstrates a requirement for intersubunit movement during translocation is lacking. To address this problem, we created an intersubunit disulfide cross-link to restrict potential movement. The cross-linked ribosomes were unable to carry out polypeptide synthesis; this inhibition was completely reversed upon reduction of the disulfide bridge. In vitro assays showed that the cross-linked ribosomes were specifically blocked in elongation factor G-dependent translocation. These findings show that intersubunit movement is required for ribosomal translocation, accounting for the universal two-subunit architecture of ribosomes. PMID:17360328

  2. Translocation and clustering of endosomes and lysosomes depends on microtubules.

    PubMed

    Matteoni, R; Kreis, T E

    1987-09-01

    Indirect immunofluorescence labeling of normal rat kidney (NRK) cells with antibodies recognizing a lysosomal glycoprotein (LGP 120; Lewis, V., S.A. Green, M. Marsh, P. Vihko, A. Helenius, and I. Mellman, 1985, J. Cell Biol., 100:1839-1847) reveals that lysosomes accumulate in the region around the microtubule-organizing center (MTOC). This clustering of lysosomes depends on microtubules. When the interphase microtubules are depolymerized by treatment of the cells with nocodazole or during mitosis, the lysosomes disperse throughout the cytoplasm. Lysosomes recluster rapidly (within 30-60 min) in the region of the centrosomes either upon removal of the drug, or, in telophase, when repolymerization of interphase microtubules has occurred. During this translocation process the lysosomes can be found aligned along centrosomal microtubules. Endosomes and lysosomes can be visualized by incubating living cells with acridine orange. We have analyzed the movement of these labeled endocytic organelles in vivo by video-enhanced fluorescence microscopy. Translocation of endosomes and lysosomes occurs along linear tracks (up to 10 microns long) by discontinuous saltations (with velocities of up to 2.5 microns/s). Organelles move bidirectionally with respect to the MTOC. This movement ceases when microtubules are depolymerized by treatment of the cells with nocodazole. After nocodazole washout and microtubule repolymerization, the translocation and reclustering of fluorescent organelles predominantly occurs in a unidirectional manner towards the area of the MTOC. Organelle movement remains unaffected when cells are treated with cytochalasin D, or when the collapse of intermediate filaments is induced by microinjected monoclonal antivimentin antibodies. It can be concluded that translocation of endosomes and lysosomes occurs along microtubules and is independent of the intermediate filament and microfilament networks. PMID:3308906

  3. Hereditary pancreatitis associated with a balanced translocation (5q;11p)

    SciTech Connect

    Dasouki, J.J.; Summar, M.L.; Mixon, C.

    1994-09-01

    Dominantly inherited pancreatitis was first described by Comfort and Steinberg in 1952. It is estimated to account for <1% of all childhood pancreatitis cases. Patients as young as 17 months of age were reported. Presentation varies from acute abdominal pain mimicking familial Mediterranean fever to more chronic steatorrhea causing malabsorption. Urinary excretion of cystine in both affected and unaffected family members is an unexplained feature. Our 37 year old, G{sub 1}P{sub 0{minus}1} proband is known to have familial pancreatitis which complicated her current pregnancy. Family history was also positive in her mother and a sister who has a 12 year old daughter with recurrent abdominal pain. The proband sought genetic counselling because her amniocentesis showed a male fetus with an apparently balanced reciprocal translocation: t(5;11)(q13;p15). A detailed fetal ultrasound examination failed to show any abnormality. On chromosomal analysis, the proband was found to have a similar translocation. Her plasma aminogram was normal, however the spot and 24 hour urine aminograms demonstrated generalized aminoaciduria. This is the first report of hereditary pancreatitis with a segregating balanced autosomal translocation which may be etiologically important. In addition, unlike what was described previously, the aminoaciduria was generalized and nonspecific. Molecular analysis of the genes located in the breakpoint region may prove to be helpful in identifying the responsible gene and the delineation of the pathogenesis of this developmental disorder.

  4. Ratcheting up protein translocation with anthrax toxin

    PubMed Central

    Feld, Geoffrey K; Brown, Michael J; Krantz, Bryan A

    2012-01-01

    Energy-consuming nanomachines catalyze the directed movement of biopolymers in the cell. They are found both dissolved in the aqueous cytosol as well as embedded in lipid bilayers. Inquiries into the molecular mechanism of nanomachine-catalyzed biopolymer transport have revealed that these machines are equipped with molecular parts, including adjustable clamps, levers, and adaptors, which interact favorably with substrate polypeptides. Biological nanomachines that catalyze protein transport, known as translocases, often require that their substrate proteins unfold before translocation. An unstructured protein chain is likely entropically challenging to bind, push, or pull in a directional manner, especially in a way that produces an unfolding force. A number of ingenious solutions to this problem are now evident in the anthrax toxin system, a model used to study protein translocation. Here we highlight molecular ratchets and current research on anthrax toxin translocation. A picture is emerging of proton-gradient-driven anthrax toxin translocation, and its associated ratchet mechanism likely applies broadly to other systems. We suggest a cyclical thermodynamic order-to-disorder mechanism (akin to a heat-engine cycle) is central to underlying protein translocation: peptide substrates nonspecifically bind to molecular clamps, which possess adjustable affinities; polypeptide substrates compress into helical structures; these clamps undergo proton-gated switching; and the substrate subsequently expands regaining its unfolded state conformational entropy upon translocation. PMID:22374876

  5. Driven Polymer Translocation into a Crosslinked Gel

    NASA Astrophysics Data System (ADS)

    Sean, David; Slater, Gary

    2015-03-01

    In a typical polymer translocation setup, a thin membrane is used to separate two chambers and a polyelectrolyte is driven by an electric field to translocate from one side of the membrane to the other via a small nanopore. However, the high translocation rate that results from the forces required to drive this process makes optical and/or electrical analysis of the translocating polymer challenging. Using coarse-grained Langevin Dynamics simulations we investigate how the translocation process can be slowed down by placing a crosslinked gel on the trans-side of the membrane. Since the driving electric field is localized in the neighborhood of the nanopore, electrophoretic migration is only achieved by a ``pushing'' action from the polymer segment residing in the nanopore. For the case of a flexible polymer we find that the polymer fills the gel pores via multiple ``herniation'' processes, whereas for a semi-flexible chain in a tight gel there are no hernias and the polymer follows a smooth curvilinear path. Moreover, for the case of a semi-flexible polymer the gel makes the translocation process more uniform by reducing the acceleration at the end of the process.

  6. Translocation of DNA across bacterial membranes.

    PubMed Central

    Dreiseikelmann, B

    1994-01-01

    DNA translocation across bacterial membranes occurs during the biological processes of infection by bacteriophages, conjugative DNA transfer of plasmids, T-DNA transfer, and genetic transformation. The mechanism of DNA translocation in these systems is not fully understood, but during the last few years extensive data about genes and gene products involved in the translocation processes have accumulated. One reason for the increasing interest in this topic is the discussion about horizontal gene transfer and transkingdom sex. Analyses of genes and gene products involved in DNA transfer suggest that DNA is transferred through a protein channel spanning the bacterial envelope. No common model exists for DNA translocation during phage infection. Perhaps various mechanisms are necessary as a result of the different morphologies of bacteriophages. The DNA translocation processes during conjugation, T-DNA transfer, and transformation are more consistent and may even be compared to the excretion of some proteins. On the basis of analogies and homologies between the proteins involved in DNA translocation and protein secretion, a common basic model for these processes is presented. PMID:7968916

  7. Translocation of Helicobacter pylori CagA into Gastric Epithelial Cells by Type IV Secretion

    NASA Astrophysics Data System (ADS)

    Odenbreit, Stefan; Püls, Jürgen; Sedlmaier, Bettina; Gerland, Elke; Fischer, Wolfgang; Haas, Rainer

    2000-02-01

    The Gram-negative bacterium Helicobacter pylori is a causative agent of gastritis and peptic ulcer disease in humans. Strains producing the CagA antigen (cagA+) induce strong gastric inflammation and are strongly associated with gastric adenocarcinoma and MALT lymphoma. We show here that such strains translocate the bacterial protein CagA into gastric epithelial cells by a type IV secretion system, encoded by the cag pathogenicity island. CagA is tyrosine-phosphorylated and induces changes in the tyrosine phosphorylation state of distinct cellular proteins. Modulation of host cells by bacterial protein translocation adds a new dimension to the chronic Helicobacter infection with yet unknown consequences.

  8. MicroRNA-21 Promotes Proliferation of Fibroblast-Like Synoviocytes through Mediation of NF-κB Nuclear Translocation in a Rat Model of Collagen-Induced Rheumatoid Arthritis

    PubMed Central

    Xian, Pei-Feng; Yang, Lu; Wang, Sheng-Xu

    2016-01-01

    MicroRNA-21 (miR-21) is overexpressed in patients with rheumatoid arthritis (RA). This study was designed to investigate the effect and mechanism of miR-21 on cell proliferation in fibroblast-like synoviocytes (FLS) of RA. FLS were primary-cultured from a rat RA model. RA-FLS and normal FLS were infected with lentivirus (anti-miR-21 or pro-miR-21) for overexpression or downregulation of miR-21, respectively. The effects of miR-21 overexpression or inhibition on nucleoprotein NF-κB levels and FLS cell proliferation were evaluated by western blotting and MTT assays. The effects of an inhibitor of NF-κB nuclear translocation (BAY 11-7082) were also evaluated. The results showed that the levels of miR-21 and nucleoprotein NF-κB were increased in FLS of RA model rats compared to the control group. Downregulation of miR-21 in RA FLS led to a significant decrease in nucleoprotein NF-κB levels and cell proliferation rates compared to the antinegative control (NC) group. However, miR-21 overexpression in normal FLS resulted in a significant increase of nucleoprotein NF-κB levels and cell proliferation rates compared to the pro-NC group. The effects of miR-21 overexpression were reversed by BAY 11-7082. We concluded that upregulated miR-21 in FLS in RA model rats may promote cell proliferation by facilitating NF-κB nuclear translocation, thus affecting the NF-κB pathway. PMID:27429986

  9. Autocrine Signaling Underlies Fast Repetitive Plasma Membrane Translocation of Conventional and Novel Protein Kinase C Isoforms in β Cells.

    PubMed

    Wuttke, Anne; Yu, Qian; Tengholm, Anders

    2016-07-15

    PKC signaling has been implicated in the regulation of many cell functions, including metabolism, cell death, proliferation, and secretion. Activation of conventional and novel PKC isoforms is associated with their Ca(2+)- and/or diacylglycerol (DAG)-dependent translocation to the plasma membrane. In β cells, exocytosis of insulin granules evokes brief (<10 s) local DAG elevations ("spiking") at the plasma membrane because of autocrine activation of P2Y1 purinoceptors by ATP co-released with insulin. Using total internal reflection microscopy, fluorescent protein-tagged PKCs, and signaling biosensors, we investigated whether DAG spiking causes membrane recruitment of PKCs and whether different classes of PKCs show characteristic responses. Glucose stimulation of MIN6 cells triggered DAG spiking with concomitant repetitive translocation of the novel isoforms PKCδ, PKCϵ, and PKCη. The conventional PKCα, PKCβI, and PKCβII isoforms showed a more complex pattern with both rapid and slow translocation. K(+) depolarization-induced PKCϵ translocation entirely mirrored DAG spiking, whereas PKCβI translocation showed a sustained component, reflecting the subplasma membrane Ca(2+) concentration ([Ca(2+)]pm), with additional effect during DAG spikes. Interference with DAG spiking by purinoceptor inhibition prevented intermittent translocation of PKCs and reduced insulin secretion but did not affect [Ca(2+)]pm elevation or sustained PKCβI translocation. The muscarinic agonist carbachol induced pronounced transient PKCβI translocation and sustained recruitment of PKCϵ. When rise of [Ca(2+)]pm was prevented, the carbachol-induced DAG and PKCϵ responses were somewhat reduced, but PKCβI translocation was completely abolished. We conclude that exocytosis-induced DAG spikes efficiently recruit both conventional and novel PKCs to the β cell plasma membrane. PKC signaling is thus implicated in autocrine regulation of β cell function. PMID:27226533

  10. Autocrine Signaling Underlies Fast Repetitive Plasma Membrane Translocation of Conventional and Novel Protein Kinase C Isoforms in β Cells*

    PubMed Central

    Wuttke, Anne; Yu, Qian; Tengholm, Anders

    2016-01-01

    PKC signaling has been implicated in the regulation of many cell functions, including metabolism, cell death, proliferation, and secretion. Activation of conventional and novel PKC isoforms is associated with their Ca2+- and/or diacylglycerol (DAG)-dependent translocation to the plasma membrane. In β cells, exocytosis of insulin granules evokes brief (<10 s) local DAG elevations (“spiking”) at the plasma membrane because of autocrine activation of P2Y1 purinoceptors by ATP co-released with insulin. Using total internal reflection microscopy, fluorescent protein-tagged PKCs, and signaling biosensors, we investigated whether DAG spiking causes membrane recruitment of PKCs and whether different classes of PKCs show characteristic responses. Glucose stimulation of MIN6 cells triggered DAG spiking with concomitant repetitive translocation of the novel isoforms PKCδ, PKCϵ, and PKCη. The conventional PKCα, PKCβI, and PKCβII isoforms showed a more complex pattern with both rapid and slow translocation. K+ depolarization-induced PKCϵ translocation entirely mirrored DAG spiking, whereas PKCβI translocation showed a sustained component, reflecting the subplasma membrane Ca2+ concentration ([Ca2+]pm), with additional effect during DAG spikes. Interference with DAG spiking by purinoceptor inhibition prevented intermittent translocation of PKCs and reduced insulin secretion but did not affect [Ca2+]pm elevation or sustained PKCβI translocation. The muscarinic agonist carbachol induced pronounced transient PKCβI translocation and sustained recruitment of PKCϵ. When rise of [Ca2+]pm was prevented, the carbachol-induced DAG and PKCϵ responses were somewhat reduced, but PKCβI translocation was completely abolished. We conclude that exocytosis-induced DAG spikes efficiently recruit both conventional and novel PKCs to the β cell plasma membrane. PKC signaling is thus implicated in autocrine regulation of β cell function. PMID:27226533

  11. First-trimester combined screening is effective for the detection of unbalanced chromosomal translocations at 11 to 12 weeks of gestation.

    PubMed

    Huang, Shangyu; Chang, Chialin; Cheng, Pojen; Hsiao, Chinghua; Soong, Yungkuei; Duan, Tao

    2014-05-01

    The first trimester combined screening, which analyzes fetal nuchal translucency and levels of free β-human chorionic gonadotropin (β-hCG) and pregnancy-associated plasma protein A (PAPP-A) in maternal serum, is routinely used to detect abnormal pregnancies associated with Down syndrome and other trisomy aneuploidies. Based on the hypothesis that major chromosomal translocations could lead to similar biochemical and developmental outcomes during early embryo development, we compared these markers among pregnancies with normal, balanced, or unbalanced fetal karyotypes. Among the parents, 71 (73%) carry balanced reciprocal translocation and 26 (27%) have Robertsonian translocation. Of the 97 pregnancies tested, 39 (40%), 37 (37%), and 22 (23%) fetuses had normal karyotype, balanced chromosomal translocations, and unbalanced chromosomal translocations, respectively. Importantly, we found that pregnancies with an unbalanced translocation had significantly higher free β-hCG multiple of the median (MoM) and larger nuchal translucency thickness than those with normal karyotype or balanced translocations. Analysis showed that the area under a receiver operating characteristic curve (AUC) is 0.716, 0.820, and 0.936 for free β-hCG MoM, PAPP-A MoM, and fetal nuchal translucency, respectively. When these 3 independent factors were combined, the AUC reached 0.976. In addition, logistic regression showed that the most optimal model for predicting an unbalanced chromosomal translocation is a combination of PAPP-A and nuchal translucency with an AUC of 0.980. Therefore, the first trimester combined screening is not only effective in the screening of Down syndrome and other trisomy abnormalities but also has high sensitivity for the detection of unbalanced chromosomal translocations in fetuses. PMID:24177714

  12. Olomoucine inhibits cathepsin L nuclear translocation, activates autophagy and attenuates toxicity of 6-hydroxydopamine.

    PubMed

    Fei, Xi-Feng; Qin, Zheng-Hong; Xiang, Bei; Li, Ling-Yun; Han, Feng; Fukunaga, Kohji; Liang, Zhong-Qin

    2009-04-01

    The finding of nuclear translocation of cathepsin L and its ability to process the CDP/Cux transcription factor uncovers an important role of cathepsin L in control of cell cycle progression. As the expression of certain cell cycle regulators is associated with nigral neuronal death, the present study was sought to investigate if nuclear translocation of cathepsin L and expression of certain cyclins were induced in DA neurons by 6-hydroxydopamine (6-OHDA). The neuroprotective effects of the cell cycle inhibitor olomoucine against 6-OHDA-induced death of nigral neurons were examined. Using immunocytochemistry and real-time PCR we demonstrated that cyclin D1, cyclin B1 and proliferating cell nuclear antigen (PCNA) were aberrantly expressed in some dopaminergic neurons after 6-OHDA infusion. The nuclear translocation of cathepsin L and up-regulation of LC3, a protein involved in autophagy, were observed in nigral DA neurons. Olomoucine, a cyclin dependent kinase (CDK) inhibitor, reduced contralateral rotations and the loss of TH-positive neurons in substantia nigra induced by lesion with 6-OHDA. Pretreatment of rats or primary DA neurons with olomoucine resulted in a partial blockade of nuclear translocation of cathepsin L. Olomoucine also increased the expression of punctate LC3 immunoreactivity, indicating activation of autophagy. These findings suggest that olomoucine may exert neuroprotective effects through inhibiting cathepsin L nuclear translocation and activating autophagy. PMID:19368812

  13. Production and identification of wheat - Agropyron cristatum (1.4P) alien translocation lines.

    PubMed

    Liu, Wei-Hua; Luan, Yang; Wang, Jing-Chang; Wang, Xiao-Guang; Su, Jun-Ji; Zhang, Jin-Peng; Yang, Xin-Ming; Gao, Ai-Nong; Li, Li-Hui

    2010-06-01

    The P genome of Agropyron Gaertn., a wild relative of wheat, contains an abundance of desirable genes that can be utilized as genetic resources to improve wheat. In this study, wheat - Aegilops cylindrica Host gametocidal chromosome 2C addition lines were crossed with wheat - Agropyron cristatum (L.) Gaertn. disomic addition line accession II-21 with alien recombinant chromosome (1.4)P. We successfully induced wheat - A. cristatum alien chromosomal translocations for the first time. The frequency of translocation in the progeny was 3.75%, which was detected by molecular markers and genomic in situ hybridization (GISH). The translocation chromosomes were identified by dual-color GISH /fluorescence in situ hybridization (FISH). The P genomic DNA was used as probe to detect the (1.4)P chromosome fragment, and pHvG39, pAs1, or pSc119.2 repeated sequences were used as probes to identify wheat translocated chromosomes. The results showed that six types of translocations were identified in the three wheat - A. cristatum alien translocation lines, including the whole arm or terminal portion of a (1.4)P chromosome. The (1.4)P chromosome fragments were translocated to wheat chromosomes 1B, 2B, 5B, and 3D. The breakpoints were located at the centromeres of 1B and 2B, the pericentric locations of 5BS, and the terminals of 5BL and 3DS. In addition, we obtained 12 addition-deletion lines that contained alien A. cristatum chromosome (1.4)P in wheat background. All of these wheat - A. cristatum alien translocation lines and addition-deletion lines would be valuable for identifying A. cristatum chromosome (1.4)P-related genes and providing genetic resources and new germplasm accessions for the genetic improvement of wheat. The specific molecular markers of A. cristatum (1.4)P chromosome have been developed and used to track the (1.4)P chromatin. PMID:20555436

  14. Inheritance of a Chromosome 3 and 21 Translocation in the Fetuses, with One also Having Trisomy 21, in Three Pregnancies in One Family.

    PubMed

    Pazarbasi, A; Demirhan, O; Alptekin, D; Ozgunen, Ft; Ozpak, L; Yilmaz, Mb; Nazlican, E; Tanriverdi, N; Luleyap, U; Gümürdülü, D

    2013-12-01

    The majority of chromosome rearrangements are balanced reciprocal and Robertsonian translocations. It is now known that such abnormalities cause no phenotypic effect on the carrier but lead to increased risk of producing unbalanced gametes. Here, we report the inheritance of a translocation between chromosomes 3 and 21 in a family with one of two fetuses with Down Syndrome carrying the same translocation and the other also carrying the same translocation without the additional chromosome 21. Chromosomal analysis from fetal amniotic fluid and peripheral blood lymphocytes from the family were performed at the Çukurova University Hospital at Adana, Turkey. We assessed a family in which the translocation between chromosomes 3 and 21 segregates: one of the three progenies carried the 47,XX,+21,t(3;21)(q21;q22) karyotype and presented with Down Syndrome; another of the three progenies carried the 46,XX,t(3;21) (q21;q22) karyotype and the third had the 46,XY karyotype. Their mother is phenotypically normal. Apparently this rearrangement occurred due to an unbalanced chromosome segregation of the mother [t(3;21)(q21;q22)mat]. This family will enable us to explain the behavior of segregation patterns and the mechanism for each type of translocation from carrier to carrier and their effects on reproduction and numerical aberrations. These findings can be used in clinical genetics and may be used as an effective tool for reproductive guidance and genetic counseling. PMID:24778571

  15. Translocation between membranes and cytosol of p42IP4, a specific inositol 1,3,4,5-tetrakisphosphate/phosphatidylinositol 3,4, 5-trisphosphate-receptor protein from brain, is induced by inositol 1,3,4,5-tetrakisphosphate and regulated by a membrane-associated 5-phosphatase.

    PubMed

    Stricker, R; Adelt, S; Vogel, G; Reiser, G

    1999-10-01

    The highly conserved 42-kDa protein, p42IP4 was identified recently from porcine brain. It has also been identified similarly in bovine, rat and human brain as a protein with two pleckstrin homology domains that binds Ins(1,3,4,5)P4 and PtdIns(3,4,5)P3 with high affinity and selectivity. The brain-specific p42IP4 occurs both as membrane-associated and cytosolic protein. Here, we investigate whether p42IP4 can be translocated from membranes by ligand interaction. p42IP4 is released from cerebellar membranes by incubation with Ins(1,3,4,5)P4. This dissociation is concentration-dependent (> 100 nM), occurs within a few minutes and and is ligand-specific. p42IP4 specifically associates with PtdIns(3, 4,5)P3-containing lipid vesicles and can dissociate from these vesicles by addition of Ins(1,3,4,5)P4. p42IP4 is only transiently translocated from the membranes as Ins(1,3,4,5)P4 can be degraded by a membrane-associated 5-phosphatase to Ins(1,3,4)P3. Then, p42IP4 re-binds to the membranes from which it can be re-released by re-addition of Ins(1,3,4,5)P4. Thus, Ins(1,3,4,5)P4 specifically induces the dissociation from membranes of a PtdIns(3,4,5)P3 binding protein that can reversibly re-associate with the membranes. Quantitative analysis of the inositol phosphates in rat brain tissue revealed a concentration of Ins(1,3,4,5)P4 comparable to that required for p42IP4 translocation. Thus, in vivo p42IP4 might interact with membranes in a ligand-controlled manner and be involved in physiological processes induced by the two second messengers Ins(1,3,4,5)P4 and PtdIns(3,4,5)P3. PMID:10504414

  16. Thermodynamic Constraints on Reflectance Reciprocity and Kirchhoff's Law.

    PubMed

    Snyder, W C; Wan, Z; Li, X

    1998-06-01

    Contrary to common belief, neither reciprocity of the bidirectional reflectance distribution function (BRDF) nor the directional form of Kirchhoff's electromagnetic radiation law can be demonstrated on the basis of energy conservation. The BRDF is generally considered reciprocal as an extension of Helmholtz reciprocity, but Helmholtz reciprocity does not always hold. We describe the flaw in a thermodynamic demonstration of reciprocity that uses an enclosure calculation. Some conclusions can be drawn from the enclosure calculation, but reciprocity requires more restrictive conditions. We conclude that, although they can be violated, reciprocity and the directional form of Kirchhoff's law generally hold because of the quantum-mechanical principle of time-reversal invariance, which applies to most materials. PMID:18273310

  17. Condition monitoring of reciprocating seal based on FBG sensors

    NASA Astrophysics Data System (ADS)

    Zhao, Xiuxu; Zhang, Shuanshuan; Wen, Pengfei; Zhen, Wenhan; Ke, Wei

    2016-07-01

    The failure of hydraulic reciprocating seals will seriously affect the normal operation of hydraulic reciprocating machinery, so the potential fault condition monitoring of reciprocating seals is very important. However, it is extremely difficult because of the limitation of reciprocating motion and the structure constraints of seal groove. In this study, an approach using fiber Bragg grating (FBG) sensors is presented. Experimental results show that the contact strain changes of a reciprocating seal can be detected by FBG sensors in the operation process of the hydraulic cylinders. The failure condition of the reciprocating seal can be identified by wavelet packet energy entropy, and the center frequency of power spectrum analysis. It can provide an effective solution for the fault prevention and health management of reciprocating hydraulic rod seals.

  18. Reciprocal Suffering: Caregiver Concerns During Hospice Care

    PubMed Central

    Wittenberg-Lyles, Elaine; Demiris, George; Oliver, Debra Parker; Burt, Stephanie

    2010-01-01

    Context For many hospice caregivers, the constancy and difficulty of caregiving impact their physical quality of life and cause depression, psychological distress, guilt, loneliness, and restrictions on social activities. Objectives Deviating from traditional unidimensional research on hospice caregivers, this study explored the transactional nature of reciprocal suffering by examining caregiver concerns through four dimensions: physical, psychological, social, and spiritual. Methods Researchers analyzed audiotapes of intervention discussions between hospice caregivers and research social workers. Results Results indicated that of the 125 pain talk utterances, the majority referenced psychological concern (49%), followed by physical (28%), social (22%), and spiritual (2%). Reflections on concerns revealed a global perspective of caregiving, which highlighted the patient’s needs juxtaposed to the caregiver’s recognized limitations. Conclusion By examining the reciprocal nature of suffering for caregivers, this study reinforced the need for assessing caregivers in hospice care, with specific emphasis on the importance of providing caregiver education on pain management. PMID:21146356

  19. Microelectromechanical reciprocating-tooth indexing apparatus

    SciTech Connect

    Allen, J.J..

    1999-09-28

    An indexing apparatus is disclosed that can be used to rotate a gear or move a rack in a precise, controllable manner. The indexing apparatus, based on a reciprocating shuttle driven by one or more actuators, can be formed either as a micromachine, or as a millimachine. The reciprocating shuttle of the indexing apparatus can be driven by a thermal, electrostatic or electromagnetic actuator, with one or more wedge-shaped drive teeth of the shuttle being moveable to engage and slide against indexing teeth on the gear or rack, thereby moving the gear or rack. The indexing apparatus can be formed by either surface micromachining processes or LIGA processes, depending on the size of the apparatus that is to be formed.

  20. Reciprocity in Adolescent and Caregiver Violence

    PubMed Central

    Bartle-Haring, Suzanne; Slesnick, Natasha; Carmona, Jasmin

    2014-01-01

    Over a 2-year period, with assessments every six months, the reciprocity in violent behaviors (verbal and physical) was investigated in a sample of 161 adolescents, who met the criteria for substance or alcohol abuse or dependence, and their caregivers, who participated in a clinical trial for family treatment for adolescent substance abuse. Using observed variables in a structural equation model with panel data, there was very little stability in violent behaviors across time from the perspectives of both the adolescents and caregivers. Evidence for violence reciprocity between adolescent and caregiver was demonstrated toward the end of the study period. The results are discussed in the context of previous literature about adolescent-to-parent violence. PMID:25684856

  1. Microelectromechanical reciprocating-tooth indexing apparatus

    DOEpatents

    Allen, James J.

    1999-01-01

    An indexing apparatus is disclosed that can be used to rotate a gear or move a rack in a precise, controllable manner. The indexing apparatus, based on a reciprocating shuttle driven by one or more actuators, can be formed either as a micromachine, or as a millimachine. The reciprocating shuttle of the indexing apparatus can be driven by a thermal, electrostatic or electromagnetic actuator, with one or more wedge-shaped drive teeth of the shuttle being moveable to engage and slide against indexing teeth on the gear or rack, thereby moving the gear or rack. The indexing apparatus can be formed by either surface micromachining processes or LIGA processes, depending on the size of the apparatus that is to be formed.

  2. Interdependent network reciprocity in evolutionary games

    NASA Astrophysics Data System (ADS)

    Wang, Zhen; Szolnoki, Attila; Perc, Matjaž

    2013-01-01

    Besides the structure of interactions within networks, also the interactions between networks are of the outmost importance. We therefore study the outcome of the public goods game on two interdependent networks that are connected by means of a utility function, which determines how payoffs on both networks jointly influence the success of players in each individual network. We show that an unbiased coupling allows the spontaneous emergence of interdependent network reciprocity, which is capable to maintain healthy levels of public cooperation even in extremely adverse conditions. The mechanism, however, requires simultaneous formation of correlated cooperator clusters on both networks. If this does not emerge or if the coordination process is disturbed, network reciprocity fails, resulting in the total collapse of cooperation. Network interdependence can thus be exploited effectively to promote cooperation past the limits imposed by isolated networks, but only if the coordination between the interdependent networks is not disturbed.

  3. Dynamic Reciprocity in the Wound Microenvironment

    PubMed Central

    Schultz, Gregory S.; Davidson, Jeffrey M.; Kirsner, Robert S.; Bornstein, Paul; Herman, Ira M.

    2011-01-01

    Here, we define dynamic reciprocity (DR) as an ongoing, bidirectional interaction amongst cells and their surrounding microenvironment. In the review, we posit that DR is especially meaningful during wound healing as the DR-driven biochemical, biophysical and cellular responses to injury play pivotal roles in regulating tissue regenerative responses. Such cell-extracellular matrix interactions not only guide and regulate cellular morphology, but cellular differentiation, migration, proliferation, and survival during tissue development, including e.g. embryogenesis, angiogenesis, as well as during pathologic processes including cancer diabetes, hypertension and chronic wound healing. Herein, we examine DR within the wound microenvironment while considering specific examples across acute and chronic wound healing. This review also considers how a number of hypotheses that attempt to explain chronic wound pathophysiology, which may be understood within the DR framework. The implications of applying the principles of dynamic reciprocity to optimize wound care practice and future development of innovative wound healing therapeutics are also briefly considered. PMID:21362080

  4. Time Domain Modelling of a Reciprocating Engine

    NASA Astrophysics Data System (ADS)

    Li, H.; Stone, B. J.

    1999-01-01

    This paper describes the application of a time domain systems approach to the modelling of a reciprocating engine. The engine model includes the varying inertia effects resulting from the motion of the piston and con-rod. The cylinder pressure measured under operating conditions is used to force the model and the resulting motion compared with the measured response. The results obtained indicate that the model is very good.

  5. Reciprocal allopreening in the Brownheaded Nuthatch

    USGS Publications Warehouse

    Barbour, D.B.; DeGange, A.R.

    1982-01-01

    In his extensive reviews of allopreening, Harrison (1965, 1969) did not record this behavior for the Sittidae, nor did Kilham (1968, 1972, 1973) mention observing this behavior in either White-breasted (Sitta carolinensis) or Red-breasted (S. canadensis) nuthatches. Norris (1958: 187), however, mentioned the occurrence of allopreening in Brown-headed Nuthatches (S. pusilia), in passing. Here we relate our observations of reciprocal allopreening between two Brown-headed Nuthatches.

  6. Variable-Aperture Reciprocating Reed Valve

    NASA Technical Reports Server (NTRS)

    Lindner, Jeffrey L. (Inventor); Myers, W. Neill (Inventor); Kelley, Anthony R. (Inventor); Yang, Hong Q. (Inventor)

    2015-01-01

    A variable-aperture reciprocating reed valve includes a valve body defining a through hole region having a contoured-profile portion. A semi-rigid plate is affixed on one side thereof to the valve body to define a cantilever extending across the through hole region. At least one free edge of the cantilever opposes the contoured-profile portion of the through hole region in a non-contact relationship.

  7. Feasibility analysis of reciprocating magnetic heat pumps

    NASA Technical Reports Server (NTRS)

    Larson, A. V.; Hartley, J. G.; Shelton, S. V.; Smith, M. M.

    1986-01-01

    The conceptual design selected for detailed system analysis and optimization is the reciprocating gadolinium core in a regenerative fluid column within the bore of a superconducting magnet. The thermodynamic properties of gadolinium are given. A computerized literature search for relevant papers was conducted and is being analyzed. Contact was made with suppliers of superconducting magnets and accessories, magnetic materials, and various types of hardware. A description of the model for the thermal analysis of the core and regenerator fluids is included.

  8. Dynamic deformation capability of a red blood cell under a cyclically reciprocating shear stress.

    PubMed

    Watanabe, N; Yasuda, T; Kataoka, H; Takatani, S

    2004-01-01

    Red blood cells (RBCs) in the cardiovascular devices are exposed to varying degree of the shear stress from all the directions. However the RBCs' deformability or the deformation capability under such a shear stress is not well understood. In this study, we designed and built a system that can induce a cyclically reciprocating shear stress to a RBC suspension. The arm of the cyclically reciprocating shear stress device was attached to the upper piece of the parallel glass plates between which a suspension of human RBCs (1% hematocrit whole blood diluted in a 32 weight% dextran phosphate buffer solution) was contained. The cyclic reciprocating motion of the upper glass plate of 3.0 mm stroke length was produced using a slider-crank shaft mechanism that was linked to an eccentric cam-motor system. Each rotation of the motor produced a 3.0 mm stroke each in the forward and backward direction of the slider block. The clearance between the two glass plates was adjusted to 30 micrometer. The cyclic reciprocating glass plate apparatus was attached to a light microscope stage (IX71 Olympus with x40 objective lens) for illumination with a 350 watt metal halide light source. A high speed camera (MEMREMCAM fx-K3 Nac, 5000 frames per second with shutter kept open) was attached to the microscope to capture the deformation process of the RBCs under cyclic shear stress. The preliminary result indicated that the correlation between the amplitude of the maximum shear stress and the RBCs' deformability. This indicates a potential application of the cyclic reciprocating device to evaluate the temporal response of the RBCs deformability prior to its destruction. The future study will focus on the study of the relative velocity of the erythrocytes with respect to the velocity of the reciprocating plate. PMID:17271457

  9. Microbiology of bacterial translocation in humans

    PubMed Central

    O'Boyle, C; MacFie, J; Mitchell, C; Johnstone, D; Sagar, P; Sedman, P

    1998-01-01

    Background—Gut translocation of bacteria has been shown in both animal and human studies. Evidence from animal studies that links bacterial translocation to the development of postoperative sepsis and multiple organ failure has yet to be confirmed in humans. 
Aims—To examine the spectrum of bacteria involved in translocation in surgical patients undergoing laparotomy and to determine the relation between nodal migration of bacteria and the development of postoperative septic complications. 
Methods—Mesenteric lymph nodes (MLN), serosal scrapings, and peripheral blood from 448 surgical patients undergoing laparotomy were analysed using standard microbiological techniques. 
Results—Bacterial translocation was identified in 69 patients (15.4%). The most common organism identified was Escherichia coli (54%). Both enteric bacteria, typical of indigenous intestinal flora, and non-enteric bacteria were isolated. Postoperative septic complications developed in 104 patients (23%). Enteric organisms were responsible in 74% of patients. Forty one per cent of patients who had evidence of bacterial translocation developed sepsis compared with 14% in whom no organisms were cultured (p<0.001). Septic morbidity was more frequent when a greater diversity of bacteria resided within the MLN, but this was not statistically significant. 
Conclusion—Bacterial translocation is associated with a significant increase in the development of postoperative sepsis in surgical patients. The organisms responsible for septic morbidity are similar in spectrum to those observed in the mesenteric lymph nodes. These data strongly support the gut origin hypothesis of sepsis in humans. 

 Keywords: bacterial translocation; mesenteric lymph nodes; serosal scrapings; enteric bacteria; postoperative sepsis PMID:9505882

  10. Molecular studies of free and translocation trisomy

    SciTech Connect

    Robinson, W.P.; Bernasconi, F.; Lefort, G.

    1994-09-01

    Twenty cases of trisomy 13 were examined with molecular markers to determine the origin of the extra chromosome. Six cases had translocation trisomy: two de novo rob(13q;14q), one paternally derived rob(13q;14q), two de novo t(13q;13q), and one mosaic de novo t(13q;14q), one paternally derived rob(13q;14q), two de novo t(13q;13q), and one mosaic de novo t(13q;13q)r(13). Eighteen of nineteen informative patients were consistant with a maternal origin of the extra chromosome. Lack of a third allele at any locus in any of the three t(13q;13q) cases indicate that all were most likely isochromosomes of post-meiotic origin. In addition, two free trisomy cases were compatible with a somatic origin. Two mosaic free trisomy-13 cases, however, were both consistent with a maternal meiotic origin. The patient with a paternal inheritance of the translocation chromosome was purely coincidental. Since there is not a significantly increased risk for unbalanced offspring of a t(13;14) carrier and most trisomies are maternal in origin, this result should not be surprising; however it illustrates that one cannot infer the origin of translocation trisomy based on parental origin of the translocation. One balanced (non-trisomic) case with a non-mosaic 45,-13,-13,+t(13;13) karyotype was also investigated and was determined to be a somatic Robertsonian translocation between the maternal and paternal homologs, as has been found for all homologous Robertsonian translocations so far investigated. It is therefore also incorrect to assume in de novo translocation cases that the two involved chromosomes are even from the same parent. We cannot therefore infer anything about the origin of the chromosomes 13 and 14 involved in the two cases with de novo t(13q;14q) plus a maternally derived trisomy 13.

  11. Enhanced cadmium efflux and root-to-shoot translocation are conserved in the hyperaccumulator Sedum alfredii (Crassulaceae family).

    PubMed

    Zhang, Zhongchun; Yu, Qi; Du, Hanying; Ai, Wenli; Yao, Xuan; Mendoza-Cózatl, David G; Qiu, Baosheng

    2016-06-01

    Investigation on the molecular mechanisms of cadmium hyperaccumulation has been mostly focused on members of the Brassicaceae family. Here, we show using hyperaccumulating (HP) and nonhyperaccumulating (NHP) populations of Sedum alfredii (Crassulaceae), that Cd hypertolerance correlates with higher Cd efflux rates and less cadmium accumulation in suspension cells and roots. The heavy metal ATPase HMA2, but not HMA4, was highly expressed in suspension cultures and roots from HP plants compared to NHP cells and plants. Reciprocal grafting also showed that Cd translocation is more efficient in HP plants. These results suggest that cadmium efflux is a conserved mechanism among natural cadmium hyperaccumulator species. PMID:27222256

  12. Nutating spider crank reciprocating piston machine

    SciTech Connect

    Shaffer, J.E.

    1991-07-02

    This patent describes reciprocating piston apparatus. It comprises a housing; a shaft journalled on the housing for rotation about a shaft axis; a plurality of cylinders each having a central longitudinal axis and disposed parallel to the shaft axis and located on the housing at positions angularly-spaced circumferentially about the shaft; a plurality of double-acting pistons having piston axes and centers, each the piston having a transverse bore therein and being respectively mounted for reciprocation within corresponding ones of the cylinders, each the bore having a longitudinal central axis normal to the respective cylinder axis; a mutating spider having a central hub portion mounted on the shaft obliquely of the shaft axis, and having a plurality of branches extending radially outward from the hub portion and terminating at terminal ends; and means directly connecting the terminal ends centrally to corresponding ones of the bores for transferring motion between reciprocation of the pistons and rotation of the shaft, and for restraining the spider from rotating with the shaft.

  13. Compression ratio control in reciprocating piston engines

    SciTech Connect

    Doundoulakis, G.J.

    1989-08-29

    The patent describes compression ratio control for reciprocating piston engines. It comprises: a reciprocating engine crankcase; a plurality of compression/expansion cylinders rigidly attached to the crankcase; each of the cylinders including a curved surface and a cylinder head; a fuel mixture in-taken in the cylinders; a piston reciprocating along each cylinder's curved surface for providing compression/expansion to the fuel mixture; a crank mechanism including a crankshaft rotating about an axial line that is substantially equidistant from the heads, crankcheek lobes radially extending from the crankshaft, crankpins inside and in contact with crankpin bearings, axially extending between the crankcheek lobes, and crankshaft journal bearings for providing low frictional support to the crankshaft; a connecting rod for each of the cylinders connecting the piston with the crankpin; crankshaft positioning; a first transmission gear, a crankshaft gear for meshing with the transmission gear, and a slot cut on the crankcase; wherein the constraint in the displacement of the crankshaft in the horizontal sense is provided by the vertical edges of the slot, and wherein the vertical edges of the slot are preferably being curved with a radius of curvature substantially equal to the average pitch diameter of the crankshaft gear and thee first transmission gear for accurate meshing of the gears.

  14. Differential effect of glucocorticoid receptor antagonists on glucocorticoid receptor nuclear translocation and DNA binding

    PubMed Central

    Spiga, Francesca; Knight, David M; Droste, Susanne K; Conway-Campbell, Becky; Kershaw, Yvonne; MacSweeney, Cliona P; Thomson, Fiona J; Craighead, Mark; Peeters, Bernard WMM; Lightman, Stafford L

    2016-01-01

    The effects of RU486 and S-P, a more selective glucocorticoid receptor antagonist from Schering-Plough, were investigated on glucocorticoid receptor nuclear translocation and DNA binding. In the in vitro study, AtT20 cells were treated with vehicle or with RU486, S-P or corticosterone (3–300 nM) or co-treated with vehicle or glucocorticoid receptor antagonists (3–300 nM) and 30 nM corticosterone. Both glucocorticoid receptor antagonists induced glucocorticoid receptor nuclear translocation but only RU486 induced DNA binding. RU486 potentiated the effect of corticosterone on glucocorticoid receptor nuclear translocation and DNA binding, S-P inhibited corticosterone-induced glucocorticoid receptor nuclear translocation, but not glucocorticoid receptor-DNA binding. In the in vivo study, adrenalectomized rats were treated with vehicle, RU486 (20 mg/kg) and S-P (50 mg/kg) alone or in combination with corticosterone (3 mg/kg). RU486 induced glucocorticoid receptor nuclear translocation in the pituitary, hippocampus and prefrontal cortex and glucocorticoid receptor-DNA binding in the hippocampus, whereas no effect of S-P on glucocorticoid receptor nuclear translocation or DNA binding was observed in any of the areas analysed. These findings reveal differential effects of RU486 and S-P on areas involved in regulation of hypothalamic–pituitary–adrenal axis activity in vivo and they are important in light of the potential use of this class of compounds in the treatment of disorders associated with hyperactivity of the hypothalamic–pituitary–adrenal axis. PMID:20093322

  15. First Birth after Sperm Selection through Discontinuous Gradient Centrifugation and Artificial Insemination from a Chromosomal Translocation Carrier.

    PubMed

    Rouen, Alexandre; Hyon, Capucine; Balet, Richard; Joyé, Nicole; Cassuto, Nino Guy; Siffroi, Jean-Pierre

    2014-01-01

    Introduction. Balanced chromosomal carriers, though usually healthy, are confronted with recurrent spontaneous abortions and malformations in the offspring. Those are related to the transmission of an abnormal, chromosomally unbalanced genotype. We evidenced that the proportion of unbalanced spermatozoa can be significantly decreased through a sperm preparation process called discontinuous gradient centrifugation (DGC). We therefore started offering intrauterine inseminations with this procedure to couples with a male translocation carriers. Case Presentation. We report the case of a 37-year-old man carrying a t(3;10)(q25;p13) reciprocal translocation. He and his partner had had trouble conceiving for ten years and had four spontaneous abortions. DGC in this patient decreased the proportion of unbalanced spermatozoa from 63.6% to 52.3%. They were therefore offered intrauterine insemination with DGC, which eventually led to the birth of a healthy female child carrying the paternal translocation. Conclusion. We showed that translocation carriers could be offered intrauterine inseminations with DGC. Before this, the only two options were natural conception with prenatal diagnosis and termination of chromosomally unbalanced fetuses or preimplantation genetic diagnosis, which is a much heavier and costly procedure. We are currently offering this option through a multicentric program in France, and this is the first birth originating from it. PMID:24587925

  16. Stochastic resonance during a polymer translocation process.

    PubMed

    Mondal, Debasish; Muthukumar, M

    2016-04-14

    We have studied the occurrence of stochastic resonance when a flexible polymer chain undergoes a single-file translocation through a nano-pore separating two spherical cavities, under a time-periodic external driving force. The translocation of the chain is controlled by a free energy barrier determined by chain length, pore length, pore-polymer interaction, and confinement inside the donor and receiver cavities. The external driving force is characterized by a frequency and amplitude. By combining the Fokker-Planck formalism for polymer translocation and a two-state model for stochastic resonance, we have derived analytical formulas for criteria for emergence of stochastic resonance during polymer translocation. We show that no stochastic resonance is possible if the free energy barrier for polymer translocation is purely entropic in nature. The polymer chain exhibits stochastic resonance only in the presence of an energy threshold in terms of polymer-pore interactions. Once stochastic resonance is feasible, the chain entropy controls the optimal synchronization conditions significantly. PMID:27083746

  17. Stochastic resonance during a polymer translocation process

    NASA Astrophysics Data System (ADS)

    Mondal, Debasish; Muthukumar, M.

    2016-04-01

    We have studied the occurrence of stochastic resonance when a flexible polymer chain undergoes a single-file translocation through a nano-pore separating two spherical cavities, under a time-periodic external driving force. The translocation of the chain is controlled by a free energy barrier determined by chain length, pore length, pore-polymer interaction, and confinement inside the donor and receiver cavities. The external driving force is characterized by a frequency and amplitude. By combining the Fokker-Planck formalism for polymer translocation and a two-state model for stochastic resonance, we have derived analytical formulas for criteria for emergence of stochastic resonance during polymer translocation. We show that no stochastic resonance is possible if the free energy barrier for polymer translocation is purely entropic in nature. The polymer chain exhibits stochastic resonance only in the presence of an energy threshold in terms of polymer-pore interactions. Once stochastic resonance is feasible, the chain entropy controls the optimal synchronization conditions significantly.

  18. Dynamic Antagonism between Phytochromes and PIF Family Basic Helix-Loop-Helix Factors Induces Selective Reciprocal Responses to Light and Shade in a Rapidly Responsive Transcriptional Network in Arabidopsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants respond to shade-modulated light signals via phytochrome (phy)-induced adaptive changes, termed shade avoidance. To examine the roles of Phytochrome-Interacting basic helix-loop-helix Factors, PIF1, 3, 4, and 5, in relaying such signals to the transcriptional network, we compared the shade-re...

  19. Stochastic resonance during a polymer translocation process

    NASA Astrophysics Data System (ADS)

    Mondal, Debasish; Muthukumar, Murugappan

    We study the translocation of a flexible polymer in a confined geometry subjected to a time-periodic external drive to explore stochastic resonance. We describe the equilibrium translocation process in terms of a Fokker-Planck description and use a discrete two-state model to describe the effect of the external driving force on the translocation dynamics. We observe that no stochastic resonance is possible if the associated free-energy barrier is purely entropic in nature. The polymer chain experiences a stochastic resonance effect only in presence of an energy threshold in terms of polymer-pore interaction. Once stochastic resonance is feasible, the chain entropy controls the optimal synchronization conditions significantly.

  20. DNA nanopore translocation in glutamate solutions

    NASA Astrophysics Data System (ADS)

    Plesa, C.; van Loo, N.; Dekker, C.

    2015-08-01

    Nanopore experiments have traditionally been carried out with chloride-based solutions. Here we introduce silver/silver-glutamate-based electrochemistry as an alternative, and study the viscosity, conductivity, and nanopore translocation characteristics of potassium-, sodium-, and lithium-glutamate solutions. We show that it has a linear response at typical voltages and can be used to detect DNA translocations through a nanopore. The glutamate anion also acts as a redox-capable thickening agent, with high-viscosity solutions capable of slowing down the DNA translocation process by up to 11 times, with a corresponding 7 time reduction in signal. These results demonstrate that glutamate can replace chloride as the primary anion in nanopore resistive pulse sensing.

  1. Analyzing disease risks associated with translocations.

    PubMed

    Sainsbury, Anthony W; Vaughan-Higgins, Rebecca J

    2012-06-01

    Translocations of species are expected to be used increasingly to counter the undesirable effects of anthropogenic changes to ecosystems, including loss of species. Methods to assess the risk of disease associated with translocations have been compiled in a comprehensive manual of disease-risk analysis for movement of domestic animals. We used this manual to devise a qualitative method for assessing the probability of the occurrence of disease in wild animals associated with translocations. We adapted the method such that we considered a parasite (any agent of infectious or noninfectious disease) a hazard if it or the host had crossed an ecological or geographical barrier and was novel to the host. We included in our analyses hazards present throughout the translocation pathway derived from the interactions between host immunity and the parasite, the effect of parasites on populations, the effect of noninfectious disease agents, and the effect of stressors on host-parasite interactions. We used the reintroduction of Eurasian Cranes (Grus grus) to England to demonstrate our method. Of the 24 hazards identified, 1 was classified as high risk (coccidia) and 5 were medium risk (highly pathogenic avian influenza virus, Mycobacterium avium, Aspergillus fumigatus, tracheal worms [Syngamus sp. and Cyathostoma sp.], and Tetrameres spp.). Seventeen other hazards were considered low or very low risk. In the absence of better information on the number, identity, distribution, and pathogenicity of parasites of wild animals, there is uncertainty in the risk of disease to translocated animals and recipient populations. Surveys of parasites in source and destination populations and detailed health monitoring after release will improve the information available for future analyses of disease risk. We believe our method can be adapted to assess the risks of disease in other translocated populations. PMID:22533691

  2. Variant complex translocations involving chromosomes 1, 9, 9, 15 and 17 in acute promyelocytic leukemia without RAR alpha/PML gene fusion rearrangement.

    PubMed

    Gogineni, S K; Shah, H O; Chester, M; Lin, J H; Garrison, M; Alidina, A; Bayani, E; Verma, R S

    1997-04-01

    Acute promyelocytic leukemia (APL;M3) is specifically characterized by a predominance of malignant promyelocytes having atypical reciprocal translocation involving chromosome 15 and 17 [t(15;17)(q22;q11)] resulting in the fusion of retinoic acid receptor alpha (RAR alpha) on chromosome 17 and the putative transcription factor gene PML, ie the translocation generates two fusion transcripts, PML/RAR alpha and RAR alpha/PML. We describe a patient with clinical and morphologic characteristics of atypical APL but with a previously undescribed variant translocation. A 35-year-old Hispanic having atypical APL was referred for cytogenetic evaluation. The cytogenetic findings with GTG-banding coupled with FISH analysis revealed the following karyotype: 46,XX,der(9)t(1;9)(q25;q34)der(9)t(9;?)(q34;?), t(15;17)(q22;q11)ish. der(9)t(1;9)(q25;q34)(WCP1+,WCP9+),t(9;17;15)(q34;q11;q22) (WCP9+,WCP15+,PML+;WCP17+,RAR alpha +;WCP15+,WCP17+,PML-)[20]/46,XX[5]. The chromosome 17q was translocated to the chromosome 15q. However, chromosome 15q including the PML gene normally translocating to 17q and creating the RAR alpha/PML fusion gene, translocated to chromosome 9q. Does this patient have another subset of APL? Or is the genetics of APL different in cases with variant translocations as opposed to those with atypical t(15;17) translocation, though in the majority of the cases their clinical presentation remains the same. PMID:9096691

  3. Protein Translocation across the Rough Endoplasmic Reticulum

    PubMed Central

    Mandon, Elisabet C.; Trueman, Steven F.; Gilmore, Reid

    2013-01-01

    The rough endoplasmic reticulum is a major site of protein biosynthesis in all eukaryotic cells, serving as the entry point for the secretory pathway and as the initial integration site for the majority of cellular integral membrane proteins. The core components of the protein translocation machinery have been identified, and high-resolution structures of the targeting components and the transport channel have been obtained. Research in this area is now focused on obtaining a better understanding of the molecular mechanism of protein translocation and membrane protein integration. PMID:23251026

  4. Valve dynamic and thermal cycle model in stepless capacity regulation for reciprocating compressor

    NASA Astrophysics Data System (ADS)

    Jin, Jiangming; Hong, Weirong

    2012-11-01

    The existing researches of stepless capacity regulation system by depressing the suction valve for reciprocation compressor always adopt hypothesis that the compressor valves are open or close instantaneously, the valve dynamic has not been taken account into thermal cycle computation, the influence of capacity regulation system on suction valves dynamic performance and cylinder thermal cycle operation has not been considered. This paper focuses on theoretical and experimental analysis of the valve dynamic and thermal cycle for reciprocating compressor in the situation of stepless capacity regulation. The valve dynamics equation, gas forces for normal and back flow, and the cylinder pressure varying with suction valve unloader moment during compression thermal cycle are discussed. A new valve dynamic model based on L-K real gas state equation for reciprocating compressor is first deduced to reduce the calculation errors induced by the ideal gas state equation. The variations of valve dynamic and cylinder pressure during part of compression stroke are calculated numerically. The calculation results reveal the non-normal thermal cycle and operation condition of compressor in stepless capacity regulation situation. The numerical simulation results of the valve dynamic and thermal cycle parameters are also verified by the stepless capacity regulation experiments in the type of 3L-10-8 reciprocating compressor. The experimental results agree with the numerical simulation results, which show that the theoretical models proposed are effective and high-precision. The proposed theoretical models build the theoretical foundation to design the real stepless capacity regulation system.

  5. Corticospinal and reciprocal inhibition actions on human soleus motoneuron activity during standing and walking

    PubMed Central

    Hanna-Boutros, Berthe; Sangari, Sina; Giboin, Louis-Solal; El Mendili, Mohamed-Mounir; Lackmy-Vallée, Alexandra; Marchand-Pauvert, Véronique; Knikou, Maria

    2015-01-01

    Reciprocal Ia inhibition constitutes a key segmental neuronal pathway for coordination of antagonist muscles. In this study, we investigated the soleus H-reflex and reciprocal inhibition exerted from flexor group Ia afferents on soleus motoneurons during standing and walking in 15 healthy subjects following transcranial magnetic stimulation (TMS). The effects of separate TMS or deep peroneal nerve (DPN) stimulation and the effects of combined (TMS + DPN) stimuli on the soleus H-reflex were assessed during standing and at mid- and late stance phases of walking. Subthreshold TMS induced short-latency facilitation on the soleus H-reflex that was present during standing and at midstance but not at late stance of walking. Reciprocal inhibition was increased during standing and at late stance but not at the midstance phase of walking. The effects of combined TMS and DPN stimuli on the soleus H-reflex significantly changed between tasks, resulting in an extra facilitation of the soleus H-reflex during standing and not during walking. Our findings indicate that corticospinal inputs and Ia inhibitory interneurons interact at the spinal level in a task-dependent manner, and that corticospinal modulation of reciprocal Ia inhibition is stronger during standing than during walking. PMID:25825912

  6. Neural correlate of human reciprocity in social interactions

    PubMed Central

    Sakaiya, Shiro; Shiraito, Yuki; Kato, Junko; Ide, Hiroko; Okada, Kensuke; Takano, Kouji; Kansaku, Kenji

    2013-01-01

    Reciprocity plays a key role maintaining cooperation in society. However, little is known about the neural process that underpins human reciprocity during social interactions. Our neuroimaging study manipulated partner identity (computer, human) and strategy (random, tit-for-tat) in repeated prisoner's dilemma games and investigated the neural correlate of reciprocal interaction with humans. Reciprocal cooperation with humans but exploitation of computers by defection was associated with activation in the left amygdala. Amygdala activation was also positively and negatively correlated with a preference change for human partners following tit-for-tat and random strategies, respectively. The correlated activation represented the intensity of positive feeling toward reciprocal and negative feeling toward non-reciprocal partners, and so reflected reciprocity in social interaction. Reciprocity in social interaction, however, might plausibly be misinterpreted and so we also examined the neural coding of insight into the reciprocity of partners. Those with and without insight revealed differential brain activation across the reward-related circuitry (i.e., the right middle dorsolateral prefrontal cortex and dorsal caudate) and theory of mind (ToM) regions [i.e., ventromedial prefrontal cortex (VMPFC) and precuneus]. Among differential activations, activation in the precuneus, which accompanied deactivation of the VMPFC, was specific to those without insight into human partners who were engaged in a tit-for-tat strategy. This asymmetric (de)activation might involve specific contributions of ToM regions to the human search for reciprocity. Consequently, the intensity of emotion attached to human reciprocity was represented in the amygdala, whereas insight into the reciprocity of others was reflected in activation across the reward-related and ToM regions. This suggests the critical role of mentalizing, which was not equated with reward expectation during social interactions

  7. Mechanochemical aspects of axonemal dynein activity studied by in vitro microtubule translocation.

    PubMed

    Hamasaki, T; Holwill, M E; Barkalow, K; Satir, P

    1995-12-01

    We have determined the relationship between microtubule length and translocation velocity from recordings of bovine brain microtubules translocating over a Paramecium 22S dynein substratum in an in vitro assay chamber. For comparison with untreated samples, the 22S dynein has been subjected to detergent and/or to pretreatments that induce phosphorylation of an associated 29 kDa light chain. Control and treated dyneins have been used at the same densities in the translocation assays. In any given condition, translocation velocity (v) shows an initial increase with microtubule length (L) and then reaches a plateau. This situation may be represented by a hyperbola of the general form v = aL/(L+b), which is formally analogous to the Briggs-Haldane relationship, which we have used to interpret our data. The results indicate that the maximum translocation velocity Vo(= a) is increased by pretreatment, whereas the length constant KL(= b), which corresponds to Km, does not change with pretreatment, implying that the mechanochemical properties of the pretreated dyneins differ from those of control dyneins. The conclusion that KL is constant for defined in vitro assays rules out the possibility that the velocity changes seen are caused by changes in geometry in the translocation assays or by the numbers of dyneins or dynein heads needed to produce maximal translocational velocity. From our analysis, we determine that f, the fraction of cycle time during which the dynein is in the force-generating state, is small--roughly 0.01, comparable to the f determined previously for heavy meromyosin. The practical limits of these mechanochemical changes imply that the maximum possible ciliary beat frequency is about 120 Hz, and that in the physiological range of 5-60 Hz, beat frequency could be controlled by varying the numbers of phosphorylated outer arm dyneins along an axonemal microtubule. PMID:8599664

  8. Reciprocal invisibility cloak based on complementary media

    NASA Astrophysics Data System (ADS)

    Yang, J. J.; Huang, M.; Yang, C. F.; Yu, J.

    2011-02-01

    The first invisibility cloak was proposed by Pendry et al. [Science 312, 1780 (2006)]. But the object enclosed in this original cloak is "blind", that is, it cannot see the outside world, since no electromagnetic waves can reach within the cloaked space. Based on the concept of complementary media, we propose a reciprocal invisibility cloak, in which the hidden object can see the outside world, but its presence cannot be detected by electromagnetic wave. The performance of the cloak has been verified by full-wave simulations.

  9. Designing topological bands in reciprocal space.

    PubMed

    Cooper, N R; Moessner, R

    2012-11-21

    Motivated by new capabilities to realize artificial gauge fields in ultracold atomic systems, and by their potential to access correlated topological phases in lattice systems, we present a new strategy for designing topologically nontrivial band structures. Our approach is simple and direct: it amounts to considering tight-binding models directly in reciprocal space. These models naturally cause atoms to experience highly uniform magnetic flux density and lead to topological bands with very narrow dispersion, without fine-tuning of parameters. Further, our construction immediately yields instances of optical Chern lattices, as well as band structures with Chern numbers of magnitude larger than one. PMID:23215598

  10. Reciprocating magnetic refrigerator employing tandem porous matrices within a reciprocating displacer

    NASA Technical Reports Server (NTRS)

    Johnson, D. L. (Inventor)

    1985-01-01

    Disclosed is a method and apparatus for a magnetic refrigeration system. A continuously reciprocating displacer houses at least a pair of paramagnetic substances each of which is alternately driven into and out of a magnetic field. Two separate bidirectional pumping systems flow helium gas through the displacer and through both paramagnetic substances to create heat exchange conditions at two separate temperature extremes.

  11. Institutionalize Reciprocity to Overcome the Public Goods Provision Problem

    PubMed Central

    2016-01-01

    Cooperation is fundamental to human societies, and one of the important paths for its emergence and maintenance is reciprocity. In prisoner’s dilemma (PD) experiments, reciprocal strategies are often effective at attaining and maintaining high cooperation. In many public goods (PG) games or n-person PD experiments, however, reciprocal strategies are not successful at engendering cooperation. In the present paper, we attribute this difficulty to a coordination problem against free riding among reciprocators: Because it is difficult for the reciprocators to coordinate their behaviors against free riders, this may lead to inequality among players, which will demotivate them from cooperating in future rounds. We propose a new mechanism, institutionalized reciprocity (IR), which refers to embedding the reciprocal strategy as an institution (i.e., institutionalizing the reciprocal strategy). We experimentally demonstrate that IR can prevent groups of reciprocators from falling into coordination failure and achieve high cooperation in PG games. In conclusion, we argue that a natural extension of the present study will be to investigate the possibility of IR to serve as a collective punishment system. PMID:27248493

  12. Institutionalize Reciprocity to Overcome the Public Goods Provision Problem.

    PubMed

    Ozono, Hiroki; Kamijo, Yoshio; Shimizu, Kazumi

    2016-01-01

    Cooperation is fundamental to human societies, and one of the important paths for its emergence and maintenance is reciprocity. In prisoner's dilemma (PD) experiments, reciprocal strategies are often effective at attaining and maintaining high cooperation. In many public goods (PG) games or n-person PD experiments, however, reciprocal strategies are not successful at engendering cooperation. In the present paper, we attribute this difficulty to a coordination problem against free riding among reciprocators: Because it is difficult for the reciprocators to coordinate their behaviors against free riders, this may lead to inequality among players, which will demotivate them from cooperating in future rounds. We propose a new mechanism, institutionalized reciprocity (IR), which refers to embedding the reciprocal strategy as an institution (i.e., institutionalizing the reciprocal strategy). We experimentally demonstrate that IR can prevent groups of reciprocators from falling into coordination failure and achieve high cooperation in PG games. In conclusion, we argue that a natural extension of the present study will be to investigate the possibility of IR to serve as a collective punishment system. PMID:27248493

  13. Biopersistence and brain translocation of aluminum adjuvants of vaccines.

    PubMed

    Gherardi, Romain Kroum; Eidi, Housam; Crépeaux, Guillemette; Authier, François Jerome; Cadusseau, Josette

    2015-01-01

    Aluminum oxyhydroxide (alum) is a crystalline compound widely used as an immunological adjuvant of vaccines. Concerns linked to the use of alum particles emerged following recognition of their causative role in the so-called macrophagic myofasciitis (MMF) lesion detected in patients with myalgic encephalomyelitis/chronic fatigue/syndrome. MMF revealed an unexpectedly long-lasting biopersistence of alum within immune cells in presumably susceptible individuals, stressing the previous fundamental misconception of its biodisposition. We previously showed that poorly biodegradable aluminum-coated particles injected into muscle are promptly phagocytosed in muscle and the draining lymph nodes, and can disseminate within phagocytic cells throughout the body and slowly accumulate in brain. This strongly suggests that long-term adjuvant biopersistence within phagocytic cells is a prerequisite for slow brain translocation and delayed neurotoxicity. The understanding of basic mechanisms of particle biopersistence and brain translocation represents a major health challenge, since it could help to define susceptibility factors to develop chronic neurotoxic damage. Biopersistence of alum may be linked to its lysosome-destabilizing effect, which is likely due to direct crystal-induced rupture of phagolysosomal membranes. Macrophages that continuously perceive foreign particles in their cytosol will likely reiterate, with variable interindividual efficiency, a dedicated form of autophagy (xenophagy) until they dispose of alien materials. Successful compartmentalization of particles within double membrane autophagosomes and subsequent fusion with repaired and re-acidified lysosomes will expose alum to lysosomal acidic pH, the sole factor that can solubilize alum particles. Brain translocation of alum particles is linked to a Trojan horse mechanism previously described for infectious particles (HIV, HCV), that obeys to CCL2, signaling the major inflammatory monocyte chemoattractant

  14. ATM-mediated PTEN phosphorylation promotes PTEN nuclear translocation and autophagy in response to DNA-damaging agents in cancer cells.

    PubMed

    Chen, Jing-Hong; Zhang, Peng; Chen, Wen-Dan; Li, Dan-Dan; Wu, Xiao-Qi; Deng, Rong; Jiao, Lin; Li, Xuan; Ji, Jiao; Feng, Gong-Kan; Zeng, Yi-Xin; Jiang, Jian-Wei; Zhu, Xiao-Feng

    2015-01-01

    PTEN (phosphatase and tensin homolog), a tumor suppressor frequently mutated in human cancer, has various cytoplasmic and nuclear functions. PTEN translocates to the nucleus from the cytoplasm in response to oxidative stress. However, the mechanism and function of the translocation are not completely understood. In this study, topotecan (TPT), a topoisomerase I inhibitor, and cisplatin (CDDP) were employed to induce DNA damage. The results indicate that TPT or CDDP activates ATM (ATM serine/threonine kinase), which phosphorylates PTEN at serine 113 and further regulates PTEN nuclear translocation in A549 and HeLa cells. After nuclear translocation, PTEN induces autophagy, in association with the activation of the p-JUN-SESN2/AMPK pathway, in response to TPT. These results identify PTEN phosphorylation by ATM as essential for PTEN nuclear translocation and the subsequent induction of autophagy in response to DNA damage. PMID:25701194

  15. Familial cryptic translocation in Angelman syndrome

    SciTech Connect

    Weyerts, L.K.; Wiley, J.E.; Loud, K.M.

    1994-09-01

    The majority of patients with Angelman syndrome have been shown to have a cytogenetic or molecular deletion on the maternally derived chromosome 15. We report on a case of Angelman syndrome in which this deletion occurs as an unbalanced cryptic translocation involving chromosomes 14 and 15. The proband was diagnosed clinically as having Angelman syndrome. Multiple cytogenetic studies were done without detecting any deletion. When DNA probes (Oncor) specific for the Prader Willi/Angelman locus became available, the patient was restudied and found to be deleted for {open_quotes}region A{close_quotes} (D15S11) but not for {open_quotes}region B{close_quotes} (GABRB3). No other abnormality was detected. The proband`s mother was then studied. The chromosome 15 marker probe and D15S11 were detected on different chromosomes. Using alpha-satellite probes, a cryptic 14;15 translocation was uncovered. This balanced translocation was also found to be carried by the sister of the proband. This case, along with a case presented at the 1993 ASHG meeting, illustrates the need for using acrocentric probes when studying Angelman syndrome patients. The proband was studied using additional probes specific for this region and found to be deleted for SNRPN but not for D15S10. The breakpoint of the translocation in this patient delineates the smallest deletion of the Angelman syndrome region reported to date and therefore may represent the specific gene involved.

  16. Structural basis of viral RNA-dependent RNA polymerase catalysis and translocation.

    PubMed

    Shu, Bo; Gong, Peng

    2016-07-12

    Viral RNA-dependent RNA polymerases (RdRPs) play essential roles in viral genome replication and transcription. We previously reported several structural states of the poliovirus RdRP nucleotide addition cycle (NAC) that revealed a unique palm domain-based active site closure mechanism and proposed a six-state NAC model including a hypothetical state representing translocation intermediates. Using the RdRP from another human enterovirus, enterovirus 71, here we report seven RdRP elongation complex structures derived from a crystal lattice that allows three NAC events. These structures suggested a key order of events in initial NTP binding and NTP-induced active site closure and revealed a bona fide translocation intermediate featuring asymmetric movement of the template-product duplex. Our work provides essential missing links in understanding NTP recognition and translocation mechanisms in viral RdRPs and emphasizes the uniqueness of the viral RdRPs compared with other processive polymerases. PMID:27339134

  17. Ion translocation by the Escherichia coli NADH:ubiquinone oxidoreductase (complex I).

    PubMed

    Friedrich, T; Stolpe, S; Schneider, D; Barquera, B; Hellwig, P

    2005-08-01

    The energy-converting NADH:ubiquinone oxidoreductase, also known as respiratory complex I, couples the transfer of electrons from NADH to ubiquinone with the translocation of ions across the membrane. It was assumed that the complex exclusively works as a proton pump. Recently, it has been proposed that complex I from Klebsiella pneumoniae and Escherichia coli work as Na+ pumps. We have used an E. coli complex I preparation to determine the type of ion(s) translocated by means of enzyme activity, generation of a membrane potential and redox-induced Fourier-transform infrared spectroscopy. We did not find any indications for Na+ translocation by the E. coli complex I. PMID:16042610

  18. Novel Translocation Responses of Cytosolic Phospholipase A2α Fluorescent Proteins

    PubMed Central

    Wooten, Rhonda E.; Willingham, Mark C.; Daniel, Larry W.; Leslie, Christina C.; Rogers, LeAnn C.; Sergeant, Susan; O’Flaherty, Joseph T.

    2008-01-01

    Cytosolic phospholipase A2 (cPLA2)α responds to the rise in cytosolic Ca2+ ([Ca2+]i) attending cell stimulation by moving to intracellular membranes, releasing arachidonic acid (AA) from these membranes, and thereby initiating the synthesis of various lipid mediators. Under some conditions, however, cPLA2α translocation occurs without any corresponding changes in [Ca2+]i. The signal for such responses has not been identified. Using confocal microscopy to track fluorescent proteins fused to cPLA2α or cPLA2α’s C2 domain, we find that AA mimics Ca2+ ionophores in stimulating cPLA2α translocations to the perinuclear ER and to a novel site, the lipid body. Unlike the ionophores, AA acted independently of [Ca2+]i rises and did not translocate the proteins to the Golgi. AA’s action did not involve its metabolism to eicosanoids or acylation into cellular lipids. Receptor agonists also stimulated translocations targeting lipid bodies. We propose that AA is a signal for Ca2+-independent cPLA2α translocation and that lipid bodies are common targets of cPLA2α and contributors to stimulus-induced lipid mediator synthesis. PMID:18406359

  19. Novel translocation responses of cytosolic phospholipase A2alpha fluorescent proteins.

    PubMed

    Wooten, Rhonda E; Willingham, Mark C; Daniel, Larry W; Leslie, Christina C; Rogers, LeAnn C; Sergeant, Susan; O'Flaherty, Joseph T

    2008-08-01

    Cytosolic phospholipase A2 (cPLA2)alpha responds to the rise in cytosolic Ca2+ ([Ca2+]i) attending cell stimulation by moving to intracellular membranes, releasing arachidonic acid (AA) from these membranes, and thereby initiating the synthesis of various lipid mediators. Under some conditions, however, cPLA2alpha translocation occurs without any corresponding changes in [Ca2+]i. The signal for such responses has not been identified. Using confocal microscopy to track fluorescent proteins fused to cPLA2alpha or cPLA2alpha's C2 domain, we find that AA mimics Ca2+ ionophores in stimulating cPLA(2)alpha translocations to the perinuclear ER and to a novel site, the lipid body. Unlike the ionophores, AA acted independently of [Ca2+](i) rises and did not translocate the proteins to the Golgi. AA's action did not involve its metabolism to eicosanoids or acylation into cellular lipids. Receptor agonists also stimulated translocations targeting lipid bodies. We propose that AA is a signal for Ca2+-independent cPLA2alpha translocation and that lipid bodies are common targets of cPLA2alpha and contributors to stimulus-induced lipid mediator synthesis. PMID:18406359

  20. Translocation of Vibrio parahaemolyticus across an in vitro M cell model.

    PubMed

    Finn, Rebecca; Ahmad, Tauseef; Coffey, Eleanor T; Brayden, David J; Baird, Alan W; Boyd, Aoife

    2014-01-01

    Consumption of Vibrio parahaemolyticus via contaminated shellfish results in inflammatory gastroenteritis characterised by severe diarrhoea, nausea and stomach cramps. This study investigated the translocation of V. parahaemolyticus across a Peyer's patch M cell-like Caco-2/Raji B co-culture model system, as M cells represent a primary site of infection for many pathogenic bacteria. Vibrio parahaemolyticus translocated across co-culture monolayers in higher numbers as compared to Caco-2 monolayers. Moreover, the bacteria induced a greater disruption of the transepithelial resistance in M cell-like co-cultures than in Caco-2 monocultures. Virulence factors associated with this pathogen include two type three secretion systems (TTSS-1 and TTSS-2). TTSS-1 had no effect on translocation efficiency, with TTSS-2 exhibiting a modest enhancing effect. ERK activity was required for optimal translocation 1 h postinfection, however, neither ERK nor the JNK and p38 MAPK were required at 2 h pi. Additionally, TER disruption in response to bacterial infection occurred independently of the TTSS and MAPK activation. It was concluded that V. parahaemolyticus causes TER disruption of M cell-like co-cultures and translocates in high numbers across the M cell-like co-culture monolayer. These data implicate M cells as important sites for V. parahaemolyticus invasion across the intestinal epithelium during infection. PMID:24188736

  1. Distinct functions of elongation factor G in ribosome recycling and translocation

    PubMed Central

    Savelsbergh, Andreas; Rodnina, Marina V.; Wintermeyer, Wolfgang

    2009-01-01

    Elongation factor G (EF-G) promotes the translocation step in bacterial protein synthesis and, together with ribosome recycling factor (RRF), the disassembly of the post-termination ribosome. Unlike translocation, ribosome disassembly strictly requires GTP hydrolysis by EF-G. Here we report that ribosome disassembly is strongly inhibited by vanadate, an analog of inorganic phosphate (Pi), indicating that Pi release is required for ribosome disassembly. In contrast, the function of EF-G in single-round translocation is not affected by vanadate, while the turnover reaction is strongly inhibited. We also show that the antibiotic fusidic acid blocks ribosome disassembly by EF-G/RRF at a 1000-fold lower concentration than required for the inhibition of EF-G turnover in vitro and close to the effective inhibitory concentration in vivo, suggesting that the antimicrobial activity of fusidic acid is primarily due to the direct inhibition of ribosome recycling. Our results indicate that conformational coupling between EF-G and the ribosome is principally different in translocation and ribosome disassembly. Pi release is not required for the mechanochemical function of EF-G in translocation, whereas the interactions between RRF and EF-G introduce tight coupling between the conformational change of EF-G induced by Pi release and ribosome disassembly. PMID:19324963

  2. Hydrodynamics of diamond-shaped gradient nanopillar arrays for effective DNA translocation into nanochannels.

    PubMed

    Wang, Chao; Bruce, Robert L; Duch, Elizabeth A; Patel, Jyotica V; Smith, Joshua T; Astier, Yann; Wunsch, Benjamin H; Meshram, Siddharth; Galan, Armand; Scerbo, Chris; Pereira, Michael A; Wang, Deqiang; Colgan, Evan G; Lin, Qinghuang; Stolovitzky, Gustavo

    2015-02-24

    Effective DNA translocation into nanochannels is critical for advancing genome mapping and future single-molecule DNA sequencing technologies. We present the design and hydrodynamic study of a diamond-shaped gradient pillar array connected to nanochannels for enhancing the success of DNA translocation events. Single-molecule fluorescence imaging is utilized to interrogate the hydrodynamic interactions of the DNA with this unique structure, evaluate key DNA translocation parameters, including speed, extension, and translocation time, and provide a detailed mapping of the translocation events in nanopillar arrays coupled with 10 and 50 μm long channels. Our analysis reveals the important roles of diamond-shaped nanopillars in guiding DNA into as small as 30 nm channels with minimized clogging, stretching DNA to nearly 100% of their dyed contour length, inducing location-specific straddling of DNA at nanopillar interfaces, and modulating DNA speeds by pillar geometries. Importantly, all critical features down to 30 nm wide nanochannels are defined using standard photolithography and fabrication processes, a feat aligned with the requirement of high-volume, low-cost production. PMID:25626162

  3. Reciprocating piston pump system with screw drive

    NASA Technical Reports Server (NTRS)

    Perkins, Gerald S. (Inventor); Moore, Nicholas R. (Inventor)

    1981-01-01

    A pump system of the reciprocating piston type is described, which facilitates direct motor drive and cylinder sealing. A threaded middle potion of the piston is engaged by a nut connected to rotate with the rotor of an electric motor, in a manner that minimizes loading on the rotor by the use of a coupling that transmits torque to the nut but permits it to shift axially and radially with respect to the rotor. The nut has a threaded hydrostatic bearing for engaging the threaded piston portion, with an oil-carrying groove in the nut being interrupted. A fluid emitting seal located at the entrance to each cylinder, can serve to center the piston within the cylinder, wash the piston, and to aid in sealing. The piston can have a long stroke to diameter ratio to minimize reciprocations and wear on valves at high pressures. The voltage applied to the motor can be reversed prior to the piston reaching the end of its stroke, to permit pressure on the piston to aid in reversing the motor.

  4. Dynamic Reciprocity in Cell-Scaffold Interactions

    PubMed Central

    Mauney, Joshua R.; Adam, Rosalyn M.

    2014-01-01

    Tissue engineering in urology has shown considerable promise. However, there is still much to understand, particularly regarding the interactions between scaffolds and their host environment, how these interactions regulate regeneration and how they may be enhanced for optimal tissue repair. In this review, we discuss the concept of dynamic reciprocity as applied to tissue engineering, i.e. how bi-directional signaling between implanted scaffolds and host tissues such as the bladder drives the process of constructive remodeling to ensure successful graft integration and tissue repair. The impact of scaffold content and configuration, the contribution of endogenous and exogenous bioactive factors, the influence of the host immune response and the functional interaction with mechanical stimulation are all considered. In addition, the temporal relationships of host tissue ingrowth, bioactive factor mobilization, scaffold degradation and immune cell infiltration, as well as the reciprocal signaling between discrete cell types and scaffolds are discussed. Improved understanding of these aspects of tissue repair will identify opportunities for optimization of repair that could be exploited to enhance regenerative medicine strategies for urology in future studies. PMID:25453262

  5. Variant (6;15) translocations in murine plasmacytomas involve a chromosome 15 locus at least 72 kb from the c-myc oncogene.

    PubMed Central

    Cory, S; Graham, M; Webb, E; Corcoran, L; Adams, J M

    1985-01-01

    The variant (6;15) translocations in murine plasmacytomas join the myc oncogene-bearing band of chromosome 15 and the immunoglobulin kappa band of chromosome 6. We recently cloned a region from chromosome 15 linked to C kappa and have now used probes from that region to define the major locus of plasmacytoma variant translocations, which we denote pvt-1. In five of nine plasmacytomas we analysed, the 6;15 translocation resulted from reciprocal recombination between the C kappa locus and a 4.5-kb region of pvt-1. Moreover, nearby we located the region shown by others to have undergone a complex (15;12;6) translocation in plasmacytoma PC7183. All the chromosome 6 breakpoints fell between 1 and 3 kb 5' to C kappa but only two were near J kappa genes. Thus the J kappa -C kappa region appears to be a recombination 'hot spot' in lymphocytes, but the breaks are unlikely to be mediated via V/J recombination enzymes. Comparison of a cloned 108-kb region across pvt-1 and another of 52 kb across c-myc established that the pvt-1 breakpoints lie at least 72 kb from the c-myc promoters. Since c-myc is expressed at a substantial level, the 6;15 translocation apparently activates c-myc. Activation may occur directly, at a remarkable distance along the chromosome, or indirectly, via a putative pvt-1 gene product. Images Fig. 3. Fig. 5. PMID:3924592

  6. The t(8;9)(p22;p24) translocation in atypical chronic myeloid leukaemia yields a new PCM1-JAK2 fusion gene.

    PubMed

    Bousquet, Marina; Quelen, Cathy; De Mas, Véronique; Duchayne, Eliane; Roquefeuil, Blandine; Delsol, Georges; Laurent, Guy; Dastugue, Nicole; Brousset, Pierre

    2005-11-01

    Several tyrosine kinase genes are involved in chromosomal translocations in chronic myeloproliferative disorders, but there are still uncharacterized translocations in some cases. We report two such cases corresponding to atypical chronic myeloid leukaemia with a t(8;9)(p22;p24) translocation. By fluorescence in situ hybridisation (FISH) on the corresponding metaphases with a bacterial artificial chromosome probe encompassing the janus kinase 2 (JAK2) gene at 9p24, we observed a split for both patients, suggesting that this gene was rearranged. The locus at 8p22 contains different candidate genes including the pericentriolar material 1 gene (PCM1), already implicated in reciprocal translocations. The rearrangement of the PCM1 gene was demonstrated by FISH, for both patients. By RT-PCR, we confirmed the fusion of 3' part of JAK2 with the 5' part of PCM1. Sequence analysis of the chimeric PCM1-JAK2 mRNA suggests that the putative protein displays the coiled-coil domains of PCM1 and the tyrosine kinase domain of JAK2. This new translocation identifies JAK2 as a possible therapeutic target for compounds with anti-tyrosine kinase activity. PMID:16091753

  7. Reciprocity-enhanced optical communication through atmospheric turbulence - part II: communication architectures and performance

    NASA Astrophysics Data System (ADS)

    Puryear, Andrew L.; Shapiro, Jeffrey H.; Parenti, Ronald R.

    2012-10-01

    Free-space optical communication provides rapidly deployable, dynamic communication links that are capable of very high data rates compared with those of radio-frequency systems. As such, free-space optical communication is ideal for mobile platforms, for platforms that require the additional security afforded by the narrow divergence of a laser beam, and for systems that must be deployed in a relatively short time frame. In clear-weather conditions the data rate and utility of free-space optical communication links are primarily limited by fading caused by micro-scale atmospheric temperature variations that create parts-per-million refractive-index fluctuations known as atmospheric turbulence. Typical communication techniques to overcome turbulence-induced fading, such as interleavers with sophisticated codes, lose viability as the data rate is driven higher or the delay requirement is driven lower. This paper, along with its companion [J. H. Shapiro and A. Puryear, "Reciprocity-Enhanced Optical Communication through Atmospheric Turbulence-Part I: Reciprocity Proofs and Far-Field Power Transfer"], present communication systems and techniques that exploit atmospheric reciprocity to overcome turbulence which are viable for high data rate and low delay requirement systems. Part I proves that reciprocity is exhibited under rather general conditions, and derives the optimal power-transfer phase compensation for far-field operation. The Part II paper presents capacity-achieving architectures that exploit reciprocity to overcome the complexity and delay issues that limit state-of-the art free-space optical communications. Further, this paper uses theoretical turbulence models to determine the performance—delay, throughput, and complexity—of the proposed architectures.

  8. Investigating binding particles distribution effects on polymer translocation through nanopore

    NASA Astrophysics Data System (ADS)

    Haji Abdolvahab, Rouhollah

    2016-03-01

    Chaperone driven polymer translocation is an important model for biopolymer's translocation in vivo. Binding proteins spatial distribution is a significant factor in calculating the translocation time of the polymer in this type of translocation. Here using a dynamical Monte Carlo simulation we compare the results of the usual uniform distribution with the exponential distribution of different rates for a stiff polymer. Our simulation results show that just by changing the chaperones spatial distribution the translocation time of the biopolymer will change by as large as an order. It can change the translocation regime of the polymer completely from a diffusive to a ballistic one. Although generally increasing the exponential rate and the background concentration will increase the translocation velocity, it is not always true and one should consider both the sequence and the background concentration. We show that the results depend on the sequence and changing the distribution rates for increasing the translocation velocity will change the whole Probability Density Function (PDF) of the polymer translocation time accordance to its sequence. The translocation time sequence dependency will change in the extreme cases e.g. in the high exponential rate. Investigating the binding protein size, λ, also shows the importance of the so called parking lot effect in distribution dependency of the translocation velocity. Although there is not any important dependency for λ = 1, translocation time depends clearly on the chaperone spatial distribution for the case of λ ≥ 2.

  9. Contributions of follicle size to establishment and maintenance of pregnancy in suckled beef cows using reciprocal embryo transfer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    GnRH-induced ovulation of a small dominant follicle reduced pregnancy success in cattle. A reciprocal embryo transfer study was conducted at Fort Keogh from 2007 to 2009 in order to differentiate between follicular effects on pregnancy mediated through oocyte quality or uterine environment. Suckle...

  10. Specific inhibition of the translocation of a subset of Escherichia coli TAT substrates by the TorA signal peptide.

    PubMed

    Chanal, Angélique; Santini, Claire-Lise; Wu, Long-Fei

    2003-03-28

    The SufI protein and the trimethylamine N-oxide reductase (TorA) are the two best-characterized prototype proteins exported by the Escherichia coli TAT system. Whereas SufI does not contain cofactors, TorA is a molybdo-enzyme and the acquisition of the molybdo-cofactor is a prerequisite for its translocation. The overproduction of each protein leads to the saturation of its translocation, but it was unknown if the overproduction of one substrate could saturate the TAT apparatus and block thus the translocation of other TAT substrates. Here, we showed that the overproduction of SufI saturated only its own translocation, but had no effect of the translocation of TorA and other TAT substrate analyzed. To dissect the saturation mechanism of TorA translocation, we shortened by about one-third of the TorA protein and removed nine consensus molybdo-cofactor-binding ligands. Like SufI, the truncated TorA (TorA502) did not contain cofactor and would not compete with the full length TorA for molybdo-cofactor acquisition. The overproduction of TorA502 completely inhibited the export of the full length TorA and dimethyl sulfoxide (DMSO) reductase, but had no effect on the translocation of SufI, nitrate-induced formate dehydrogenase and hydrogenase-2. Importantly, deletion of the twin-arginine signal peptide of TorA502 abolished the inhibitory effect. Moreover, the overproduction of the TorA signal peptide fused to the green fluorescence protein (GFP) was sufficient to block the TorA translocation. These results demonstrated that the twin-arginine signal peptide of the TorA protein specifically inhibits the translocation of a subset of TAT substrates, probably at the step of their targeting to the TAT apparatus. PMID:12634052

  11. 26 CFR 521.116 - Reciprocal administrative assistance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 19 2011-04-01 2010-04-01 true Reciprocal administrative assistance. 521.116... of Denmark and of Danish Corporations § 521.116 Reciprocal administrative assistance. (a) General. (1) By Article XVII of the convention, the United States and Denmark adopt the principle of exchange...

  12. Using Excel's Matrix Operations to Facilitate Reciprocal Cost Allocations

    ERIC Educational Resources Information Center

    Leese, Wallace R.; Kizirian, Tim

    2009-01-01

    The reciprocal method of service department cost allocation requires linear equations to be solved simultaneously. These computations are often so complex as to cause the abandonment of the reciprocal method in favor of the less sophisticated direct or step-down methods. Here is a short example demonstrating how Excel's sometimes unknown matrix…

  13. Reciprocal Borrowing Patterns in the North Suburban Library System.

    ERIC Educational Resources Information Center

    Able Consultants, DeKalb, IL.

    During a 5-day period in 1990, a total of 1,401 reciprocal borrowers in the North Suburban Library System (NSLS) received questionnaires asking about their choice of library and other aspects of borrowing behavior to provide data on the reciprocal borrowing characteristics and patterns within the system. This survey was designed to identify the…

  14. 2005 Reciprocity Agreements and Other Student Exchange Options

    ERIC Educational Resources Information Center

    Washington Higher Education Coordinating Board, 2005

    2005-01-01

    The Higher Education Coordinating Board (HECB) is required by state law to report to the governor and legislature every two years on the status of Washington's state-level reciprocity agreements with Idaho, Oregon, and British Columbia. Reciprocity agreements allow some Washington students to attend public colleges in other states and pay lower…

  15. Accepting Roles Created for Us: The Ethics of Reciprocity.

    ERIC Educational Resources Information Center

    Powell, Katrina M.; Takayoshi, Pamela

    2003-01-01

    Argues that seeing reciprocity as a context-based process of definition and re-definition of the relationship between participants and researchers helps them understand how research projects can benefit participants in ways that they desire. Considers the ethical dimensions of reciprocal research relationships. Uses the authors' own research…

  16. 47 CFR 51.711 - Symmetrical reciprocal compensation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Symmetrical reciprocal compensation. 51.711 Section 51.711 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES... Traffic § 51.711 Symmetrical reciprocal compensation. (a) Rates for transport and termination of...

  17. Symmetry-based reciprocity: evolutionary constraints on a proximate mechanism

    PubMed Central

    Campennì, Marco

    2016-01-01

    Background. While the evolution of reciprocal cooperation has attracted an enormous attention, the proximate mechanisms underlying the ability of animals to cooperate reciprocally are comparatively neglected. Symmetry-based reciprocity is a hypothetical proximate mechanism that has been suggested to be widespread among cognitively unsophisticated animals. Methods. We developed two agent-based models of symmetry-based reciprocity (one relying on an arbitrary tag and the other on interindividual proximity) and tested their ability both to reproduce significant emergent features of cooperation in group living animals and to promote the evolution of cooperation. Results. Populations formed by agents adopting symmetry-based reciprocity showed differentiated “social relationships” and a positive correlation between cooperation given and received: two common aspects of animal cooperation. However, when reproduction and selection across multiple generations were added to the models, agents adopting symmetry-based reciprocity were outcompeted by selfish agents that never cooperated. Discussion. In order to evolve, hypothetical proximate mechanisms must be able to stand competition from alternative strategies. While the results of our simulations require confirmation using analytical methods, we provisionally suggest symmetry-based reciprocity is to be abandoned as a possible proximate mechanism underlying the ability of animals to reciprocate cooperative interactions. PMID:26998412

  18. Reciprocal Relationships between Math Self-Concept and Math Anxiety

    ERIC Educational Resources Information Center

    Ahmed, Wondimu; Minnaert, Alexander; Kuyper, Hans; van der Werf, Greetje

    2012-01-01

    The present study examined the reciprocal relationships between self-concept and anxiety in mathematics. A sample of 495 grade 7 students (51% girls) completed self-report measures assessing self-concept and anxiety three times in a school year. Structural equation modeling was used to test a cross-lagged panel model of reciprocal effects between…

  19. An Analysis of Direct Reciprocal Borrowing among Quebec University Libraries

    ERIC Educational Resources Information Center

    Duy, Joanna C.; Lariviere, Vincent

    2013-01-01

    An analysis of Quebec academic libraries' direct reciprocal borrowing statistics from 2005 to 2010 reveals that the physical distance separating universities plays an important role in determining the amount of direct reciprocal borrowing activity conducted between institutions. Significant statistical correlations were also seen between the…

  20. Transient nature of cooperation by pay-it-forward reciprocity

    PubMed Central

    Horita, Yutaka; Takezawa, Masanori; Kinjo, Takuji; Nakawake, Yo; Masuda, Naoki

    2016-01-01

    Humans often forward kindness received from others to strangers, a phenomenon called the upstream or pay-it-forward indirect reciprocity. Some field observations and laboratory experiments found evidence of pay-it-forward reciprocity in which chains of cooperative acts persist in social dilemma situations. Theoretically, however, cooperation based on pay-it-forward reciprocity is not sustainable. We carried out laboratory experiments of a pay-it-forward indirect reciprocity game (i.e., chained gift-giving game) on a large scale in terms of group size and time. We found that cooperation consistent with pay-it-forward reciprocity occurred only in a first few decisions per participant and that cooperation originated from inherent pro-sociality of individuals. In contrast, the same groups of participants showed persisting chains of cooperation in a different indirect reciprocity game in which participants earned reputation by cooperating. Our experimental results suggest that pay-it-forward reciprocity is transient and disappears when a person makes decisions repeatedly, whereas the reputation-based reciprocity is stable in the same situation. PMID:26786178