WorldWideScience

Sample records for increased mitotic activity

  1. Mitotic and apoptotic activity in colorectal neoplasia.

    Kohoutova, Darina; Pejchal, Jaroslav; Bures, Jan

    2018-05-18

    Colorectal cancer (CRC) is third most commonly diagnosed cancer worldwide. The aim of the prospective study was to evaluate mitosis and apoptosis of epithelial cells at each stage of colorectal neoplasia. A total of 61 persons were enrolled into the study: 18 patients with non-advanced colorectal adenoma (non-a-A), 13 patients with advanced colorectal adenoma (a-A), 13 patients with CRC and 17 controls: individuals with normal findings on colonoscopy. Biopsy samples were taken from pathology (patients) and healthy mucosa (patients and healthy controls). Samples were formalin-fixed paraffin-embedded and stained with haematoxylin-eosin. Mitotic and apoptotic activity were evaluated in lower and upper part of the crypts and in the superficial compartment. Apoptotic activity was also assessed using detection of activated caspase-3. In controls, mitotic activity was present in lower part of crypts, accompanied with low apoptotic activity. Mitotic and apoptotic activity decreased (to almost zero) in upper part of crypts. In superficial compartment, increase in apoptotic activity was observed. Transformation of healthy mucosa into non-a-A was associated with significant increase of mitotic activity in lower and upper part of the crypts and with significant increase of apoptotic activity in all three compartments; p colorectal neoplasia were observed. Detection of activated caspase-3 confirmed the above findings in apoptotic activity. Significant dysregulation of mitosis and apoptosis during the progression of colorectal neoplasia, corresponding with histology, was confirmed. In patients with sporadic colorectal neoplasia, healthy mucosa does not display different mitotic and apoptotic activity compared to mucosa in healthy controls and therefore adequate endoscopic/surgical removal of colorectal neoplasia is sufficient.

  2. Timeless links replication termination to mitotic kinase activation.

    Jayaraju Dheekollu

    2011-05-01

    Full Text Available The mechanisms that coordinate the termination of DNA replication with progression through mitosis are not completely understood. The human Timeless protein (Tim associates with S phase replication checkpoint proteins Claspin and Tipin, and plays an important role in maintaining replication fork stability at physical barriers, like centromeres, telomeres and ribosomal DNA repeats, as well as at termination sites. We show here that human Tim can be isolated in a complex with mitotic entry kinases CDK1, Auroras A and B, and Polo-like kinase (Plk1. Plk1 bound Tim directly and colocalized with Tim at a subset of mitotic structures in M phase. Tim depletion caused multiple mitotic defects, including the loss of sister-chromatid cohesion, loss of mitotic spindle architecture, and a failure to exit mitosis. Tim depletion caused a delay in mitotic kinase activity in vivo and in vitro, as well as a reduction in global histone H3 S10 phosphorylation during G2/M phase. Tim was also required for the recruitment of Plk1 to centromeric DNA and formation of catenated DNA structures at human centromere alpha satellite repeats. Taken together, these findings suggest that Tim coordinates mitotic kinase activation with termination of DNA replication.

  3. Effect of head-irradiation upon epidermal mitotic activity during wound healing in the adrenalectomized mice

    Kobayashi, Koshi

    1977-01-01

    Epidermal mitotic activity during wound healing was estimated both in the adrenalectomized, head-irradiated mice and in the adrenalectomized, non-irradiated mice, and was compared with those obtained previously from the unoperated, head-irradiated mice. It was found that head-irradiation caused a mitotic depression to a much smaller extent in the adrenalectomized mice than it did in the unoperated mice, though adrenalectomy itself had exerted a great inhibitory effect upon the mitosis induced by an injury. Whether this abscopal effect of head-irradiation upon the mitotic activity was mediated via the adrenals, and whether in the adrenalectomized mice the head-irradiation acted to increase epidermal response to injury, making the mitotic pattern of adrenalectomized mice to come near that of control mice were discussed. (auth.)

  4. Mechanism of APC/CCDC20 activation by mitotic phosphorylation.

    Qiao, Renping; Weissmann, Florian; Yamaguchi, Masaya; Brown, Nicholas G; VanderLinden, Ryan; Imre, Richard; Jarvis, Marc A; Brunner, Michael R; Davidson, Iain F; Litos, Gabriele; Haselbach, David; Mechtler, Karl; Stark, Holger; Schulman, Brenda A; Peters, Jan-Michael

    2016-05-10

    Chromosome segregation and mitotic exit are initiated by the 1.2-MDa ubiquitin ligase APC/C (anaphase-promoting complex/cyclosome) and its coactivator CDC20 (cell division cycle 20). To avoid chromosome missegregation, APC/C(CDC20) activation is tightly controlled. CDC20 only associates with APC/C in mitosis when APC/C has become phosphorylated and is further inhibited by a mitotic checkpoint complex until all chromosomes are bioriented on the spindle. APC/C contains 14 different types of subunits, most of which are phosphorylated in mitosis on multiple sites. However, it is unknown which of these phospho-sites enable APC/C(CDC20) activation and by which mechanism. Here we have identified 68 evolutionarily conserved mitotic phospho-sites on human APC/C bound to CDC20 and have used the biGBac technique to generate 47 APC/C mutants in which either all 68 sites or subsets of them were replaced by nonphosphorylatable or phospho-mimicking residues. The characterization of these complexes in substrate ubiquitination and degradation assays indicates that phosphorylation of an N-terminal loop region in APC1 is sufficient for binding and activation of APC/C by CDC20. Deletion of the N-terminal APC1 loop enables APC/C(CDC20) activation in the absence of mitotic phosphorylation or phospho-mimicking mutations. These results indicate that binding of CDC20 to APC/C is normally prevented by an autoinhibitory loop in APC1 and that its mitotic phosphorylation relieves this inhibition. The predicted location of the N-terminal APC1 loop implies that this loop controls interactions between the N-terminal domain of CDC20 and APC1 and APC8. These results reveal how APC/C phosphorylation enables CDC20 to bind and activate the APC/C in mitosis.

  5. Increased spontaneous mitotic segregation in MMS-sensitive mutants of Saccharomyces cerevisiae

    Prakash, S.; Prakash, L.

    1977-01-01

    Methyl methanesulfonate (MMS)-sensitive mutants of Saccharomyces cerevisiae belonging to four different complementation groups, when homozygous, increase the rate of spontaneous mitotic segregation to canavanine resistance from heterozygous sensitive (can/sup r//+) diploids by 13- to 170-fold. The mms8-1 mutant is MMS and x-ray sensitive and increases the rate of spontaneous mitotic segregation 170-fold. The mms9-1 and mms13-1 mutants are sensitive to x rays and uv, respectively, in addition to MMS, and increase the rate of spontaneous mitotic segregation by 13-fold and 85-fold, respectively. The mutant mms21-1 is sensitive to MMS, x rays and uv and increases the rate of spontaneous mitotic segregation 23-fold

  6. Centrosome Amplification Increases Single-Cell Branching in Post-mitotic Cells.

    Ricolo, Delia; Deligiannaki, Myrto; Casanova, Jordi; Araújo, Sofia J

    2016-10-24

    Centrosome amplification is a hallmark of cancer, although we are still far from understanding how this process affects tumorigenesis [1, 2]. Besides the contribution of supernumerary centrosomes to mitotic defects, their biological effects in the post-mitotic cell are not well known. Here, we exploit the effects of centrosome amplification in post-mitotic cells during single-cell branching. We show that Drosophila tracheal cells with extra centrosomes branch more than wild-type cells. We found that mutations in Rca1 and CycA affect subcellular branching, causing tracheal tip cells to form more than one subcellular lumen. We show that Rca1 and CycA post-mitotic cells have supernumerary centrosomes and that other mutant conditions that increase centrosome number also show excess of subcellular lumen branching. Furthermore, we show that de novo lumen formation is impaired in mutant embryos with fewer centrioles. The data presented here define a requirement for the centrosome as a microtubule-organizing center (MTOC) for the initiation of subcellular lumen formation. We propose that centrosomes are necessary to drive subcellular lumen formation. In addition, centrosome amplification increases single-cell branching, a process parallel to capillary sprouting in blood vessels [3]. These results shed new light on how centrosomes can contribute to pathology independently of mitotic defects. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Mitotically Active Leiomyoma of the Uterus in a Postmenopausal Breast Cancer Patient Receiving Tamoxifen

    I-Feng Liu

    2006-06-01

    Conclusion: Endometrial cancer is rarely noted in breast cancer patients taking tamoxifen. Further, none have reported mitotically active leiomyoma of the uterus. From this case, endometrial proliferation and mitotically active leiomyoma of the uterus may be related to tamoxifen therapy, and should not be neglected in breast cancer patients.

  8. Taxifolin enhances andrographolide-induced mitotic arrest and apoptosis in human prostate cancer cells via spindle assembly checkpoint activation.

    Zhong Rong Zhang

    Full Text Available Andrographolide (Andro suppresses proliferation and triggers apoptosis in many types of cancer cells. Taxifolin (Taxi has been proposed to prevent cancer development similar to other dietary flavonoids. In the present study, the cytotoxic and apoptotic effects of the addition of Andro alone and Andro and Taxi together on human prostate carcinoma DU145 cells were assessed. Andro inhibited prostate cancer cell proliferation by mitotic arrest and activation of the intrinsic apoptotic pathway. Although the effect of Taxi alone on DU145 cell proliferation was not significant, the combined use of Taxi with Andro significantly potentiated the anti-proliferative effect of increased mitotic arrest and apoptosis by enhancing the cleavage of poly(ADP-ribose polymerase, and caspases-7 and -9. Andro together with Taxi enhanced microtubule polymerization in vitro, and they induced the formation of twisted and elongated spindles in the cancer cells, thus leading to mitotic arrest. In addition, we showed that depletion of MAD2, a component in the spindle assembly checkpoint (SAC, alleviated the mitotic block induced by the two compounds, suggesting that they trigger mitotic arrest by SAC activation. This study suggests that the anti-cancer activity of Andro can be significantly enhanced in combination with Taxi by disrupting microtubule dynamics and activating the SAC.

  9. Taxifolin Enhances Andrographolide-Induced Mitotic Arrest and Apoptosis in Human Prostate Cancer Cells via Spindle Assembly Checkpoint Activation

    Wong, Matthew Man-Kin; Chiu, Sung-Kay; Cheung, Hon-Yeung

    2013-01-01

    Andrographolide (Andro) suppresses proliferation and triggers apoptosis in many types of cancer cells. Taxifolin (Taxi) has been proposed to prevent cancer development similar to other dietary flavonoids. In the present study, the cytotoxic and apoptotic effects of the addition of Andro alone and Andro and Taxi together on human prostate carcinoma DU145 cells were assessed. Andro inhibited prostate cancer cell proliferation by mitotic arrest and activation of the intrinsic apoptotic pathway. Although the effect of Taxi alone on DU145 cell proliferation was not significant, the combined use of Taxi with Andro significantly potentiated the anti-proliferative effect of increased mitotic arrest and apoptosis by enhancing the cleavage of poly(ADP-ribose) polymerase, and caspases-7 and -9. Andro together with Taxi enhanced microtubule polymerization in vitro, and they induced the formation of twisted and elongated spindles in the cancer cells, thus leading to mitotic arrest. In addition, we showed that depletion of MAD2, a component in the spindle assembly checkpoint (SAC), alleviated the mitotic block induced by the two compounds, suggesting that they trigger mitotic arrest by SAC activation. This study suggests that the anti-cancer activity of Andro can be significantly enhanced in combination with Taxi by disrupting microtubule dynamics and activating the SAC. PMID:23382917

  10. Mitotic Transcriptional Activation: Clearance of Actively Engaged Pol II via Transcriptional Elongation Control in Mitosis.

    Liang, Kaiwei; Woodfin, Ashley R; Slaughter, Brian D; Unruh, Jay R; Box, Andrew C; Rickels, Ryan A; Gao, Xin; Haug, Jeffrey S; Jaspersen, Sue L; Shilatifard, Ali

    2015-11-05

    Although it is established that some general transcription factors are inactivated at mitosis, many details of mitotic transcription inhibition (MTI) and its underlying mechanisms are largely unknown. We have identified mitotic transcriptional activation (MTA) as a key regulatory step to control transcription in mitosis for genes with transcriptionally engaged RNA polymerase II (Pol II) to activate and transcribe until the end of the gene to clear Pol II from mitotic chromatin, followed by global impairment of transcription reinitiation through MTI. Global nascent RNA sequencing and RNA fluorescence in situ hybridization demonstrate the existence of transcriptionally engaged Pol II in early mitosis. Both genetic and chemical inhibition of P-TEFb in mitosis lead to delays in the progression of cell division. Together, our study reveals a mechanism for MTA and MTI whereby transcriptionally engaged Pol II can progress into productive elongation and finish transcription to allow proper cellular division. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Nitrogen deficiency inhibits leaf blade growth in Lolium perenne by increasing cell cycle duration and decreasing mitotic and post-mitotic growth rates.

    Kavanová, Monika; Lattanzi, Fernando Alfredo; Schnyder, Hans

    2008-06-01

    Nitrogen deficiency severely inhibits leaf growth. This response was analysed at the cellular level by growing Lolium perenne L. under 7.5 mM (high) or 1 mM (low) nitrate supply, and performing a kinematic analysis to assess the effect of nitrogen status on cell proliferation and cell growth in the leaf blade epidermis. Low nitrogen supply reduced leaf elongation rate (LER) by 43% through a similar decrease in the cell production rate and final cell length. The former was entirely because of a decreased average cell division rate (0.023 versus 0.032 h(-1)) and thus longer cell cycle duration (30 versus 22 h). Nitrogen status did not affect the number of division cycles of the initial cell's progeny (5.7), and accordingly the meristematic cell number (53). Meristematic cell length was unaffected by nitrogen deficiency, implying that the division and mitotic growth rates were equally impaired. The shorter mature cell length arose from a considerably reduced post-mitotic growth rate (0.033 versus 0.049 h(-1)). But, nitrogen stress did not affect the position where elongation stopped, and increased cell elongation duration. In conclusion, nitrogen deficiency limited leaf growth by increasing the cell cycle duration and decreasing mitotic and post-mitotic elongation rates, delaying cell maturation.

  12. Effect of copper intrauterine device vs. injectable contraceptive on serum hormone levels and cell mitotic activity in endometrium

    Ebtesam Moustafa Kamal

    2013-09-01

    Conclusion: Either copper intrauterine device or injectable contraceptive usage for more than 9 months results in significant decrease in endometrial proliferative or cell mitotic activity. While copper IUD has no effect on serum estradiol or progesterone levels, DMPA usage increased serum progesterone level with no effect on serum estradiol.

  13. Effect of insulin on the mitotic activity of bone marrow cells after irradiation. [Gamma radiation, rats

    Barkalaya, A I

    1976-02-01

    A total of 236 white rats were given a whole-body gamma dose of 750 R. Part of the rats were given a subcutaneous insulin injection of 0.2 units/kg. After 10, 20, 30 min, 1, 2, 3, 5, 8, 10 and 12 hours the mitotic index was determined in both groups of rats in the bone marrow of the femur. The content of glucose and insulin in the blood was determined. The mitotic index was found to be higher on administering insulin. The use of insulin in radiation sickness intensifies the mitotic activity of bone marrow cells and stimulates the recovery of bone marrow hematopoiesis. 5 references.

  14. Effects of 5-fluorouracil on the mitotic activity of onion root tips apical meristem

    Waldemar Lechowicz

    2015-01-01

    Full Text Available The effects of various concentrations of 5-FU on the mitotic activity of onion root tips apical meristem were investigated during 24-hour incubation in 5-FU and postincubation in water. The incubation in 5-FU caused a reversible inhibition of mitotic activity, and waves of the partially synchronised mitoses were observed during the period of postincubation. The most pronounced synchronisation of mitoses was obtained after incubation in 100 mg/l. 5-FU but the mitotic index of the resumed mitotic activity amounted to only one half of the control value. 5-FU was found to cause some cytological changes in meristematic cells such as enlargement of the nucleoli, change in the interphasic nuclei structure, appearance of subchromatid and chromatid aberrations and micronuclei. The effects of 5-FU on nucleic acids and the cell division cycle ace discussed and compared with the effects of 5-FUdR.

  15. Molecular mechanism of APC/C activation by mitotic phosphorylation.

    Zhang, Suyang; Chang, Leifu; Alfieri, Claudio; Zhang, Ziguo; Yang, Jing; Maslen, Sarah; Skehel, Mark; Barford, David

    2016-05-12

    In eukaryotes, the anaphase-promoting complex (APC/C, also known as the cyclosome) regulates the ubiquitin-dependent proteolysis of specific cell-cycle proteins to coordinate chromosome segregation in mitosis and entry into the G1 phase. The catalytic activity of the APC/C and its ability to specify the destruction of particular proteins at different phases of the cell cycle are controlled by its interaction with two structurally related coactivator subunits, Cdc20 and Cdh1. Coactivators recognize substrate degrons, and enhance the affinity of the APC/C for its cognate E2 (refs 4-6). During mitosis, cyclin-dependent kinase (Cdk) and polo-like kinase (Plk) control Cdc20- and Cdh1-mediated activation of the APC/C. Hyperphosphorylation of APC/C subunits, notably Apc1 and Apc3, is required for Cdc20 to activate the APC/C, whereas phosphorylation of Cdh1 prevents its association with the APC/C. Since both coactivators associate with the APC/C through their common C-box and Ile-Arg tail motifs, the mechanism underlying this differential regulation is unclear, as is the role of specific APC/C phosphorylation sites. Here, using cryo-electron microscopy and biochemical analysis, we define the molecular basis of how phosphorylation of human APC/C allows for its control by Cdc20. An auto-inhibitory segment of Apc1 acts as a molecular switch that in apo unphosphorylated APC/C interacts with the C-box binding site and obstructs engagement of Cdc20. Phosphorylation of the auto-inhibitory segment displaces it from the C-box-binding site. Efficient phosphorylation of the auto-inhibitory segment, and thus relief of auto-inhibition, requires the recruitment of Cdk-cyclin in complex with a Cdk regulatory subunit (Cks) to a hyperphosphorylated loop of Apc3. We also find that the small-molecule inhibitor, tosyl-l-arginine methyl ester, preferentially suppresses APC/C(Cdc20) rather than APC/C(Cdh1), and interacts with the binding sites of both the C-box and Ile-Arg tail motifs. Our

  16. Evidence of activity-specific, radial organization of mitotic chromosomes in Drosophila.

    Yuri G Strukov

    2011-01-01

    Full Text Available The organization and the mechanisms of condensation of mitotic chromosomes remain unsolved despite many decades of efforts. The lack of resolution, tight compaction, and the absence of function-specific chromatin labels have been the key technical obstacles. The correlation between DNA sequence composition and its contribution to the chromosome-scale structure has been suggested before; it is unclear though if all DNA sequences equally participate in intra- or inter-chromatin or DNA-protein interactions that lead to formation of mitotic chromosomes and if their mitotic positions are reproduced radially. Using high-resolution fluorescence microscopy of live or minimally perturbed, fixed chromosomes in Drosophila embryonic cultures or tissues expressing MSL3-GFP fusion protein, we studied positioning of specific MSL3-binding sites. Actively transcribed, dosage compensated Drosophila genes are distributed along the euchromatic arm of the male X chromosome. Several novel features of mitotic chromosomes have been observed. MSL3-GFP is always found at the periphery of mitotic chromosomes, suggesting that active, dosage compensated genes are also found at the periphery of mitotic chromosomes. Furthermore, radial distribution of chromatin loci on mitotic chromosomes was found to be correlated with their functional activity as judged by core histone modifications. Histone modifications specific to active chromatin were found peripheral with respect to silent chromatin. MSL3-GFP-labeled chromatin loci become peripheral starting in late prophase. In early prophase, dosage compensated chromatin regions traverse the entire width of chromosomes. These findings suggest large-scale internal rearrangements within chromosomes during the prophase condensation step, arguing against consecutive coiling models. Our results suggest that the organization of mitotic chromosomes is reproducible not only longitudinally, as demonstrated by chromosome-specific banding

  17. Wnt activation followed by Notch inhibition promotes mitotic hair cell regeneration in the postnatal mouse cochlea

    Li, Wenyan; Chen, Yan; Zhang, Shasha; Tang, Mingliang; Sun, Shan; Chai, Renjie; Li, Huawei

    2016-01-01

    Hair cell (HC) loss is the main cause of permanent hearing loss in mammals. Previous studies have reported that in neonatal mice cochleae, Wnt activation promotes supporting cell (SC) proliferation and Notch inhibition promotes the trans-differentiation of SCs into HCs. However, Wnt activation alone fails to regenerate significant amounts of new HCs, Notch inhibition alone regenerates the HCs at the cost of exhausting the SC population, which leads to the death of the newly regenerated HCs. Mitotic HC regeneration might preserve the SC number while regenerating the HCs, which could be a better approach for long-term HC regeneration. We present a two-step gene manipulation, Wnt activation followed by Notch inhibition, to accomplish mitotic regeneration of HCs while partially preserving the SC number. We show that Wnt activation followed by Notch inhibition strongly promotes the mitotic regeneration of new HCs in both normal and neomycin-damaged cochleae while partially preserving the SC number. Lineage tracing shows that the majority of the mitotically regenerated HCs are derived specifically from the Lgr5+ progenitors with or without HC damage. Our findings suggest that the co-regulation of Wnt and Notch signaling might provide a better approach to mitotically regenerate HCs from Lgr5+ progenitor cells. PMID:27564256

  18. Effects of whole-body and partial-body x irradiation upon epidermal mitotic activity during wound healing in mouse skin

    Kobayashi, K.

    1977-01-01

    Mitotic activity of normal (unwounded) and wounded skin was measured in the control (nonirradiated) and whole-body or partial-body x-irradiated mouse. Higher mitotic activity in the anterior than in the posterior region of the body was found in both the normal and the wounded skin of the control mouse. Whole-body irradiation (500 R) depressed completely the mitotic activity of normal skin 2 to 4 days after irradiation. In spite of this depression in mitotic activity, a surgical incision made 1 to 3 days after irradiation could induce a burst of proliferation after an inhibition of an initial mitosis increase. When the animals were partially irradiated with 500 R 3 days before wounding, it was shown that mitosis at 24 hr after wounding was inhibited markedly by the local effect of irradiation and that mitosis also could be inhibited diversely by the abscopal effect of irradiation. Because of a close similarity of sequential mitotic patterns between whole-body-irradiated and flapped-skin-only-irradiated groups (direct irradiation), the effect of irradiation upon mitosis was considered to be primarily local. Some discussions were made concerning the possible reasons which made a difference in mitotic patterns between the head-only-irradiated group, the irradiated group including the head and other parts of the body except for the skin flap

  19. Number of nuclei, mitotic activity and cell length in Cladophora sp thallus treated with cadmium and chromium

    Monika Krajewska

    2014-01-01

    Full Text Available Cladophora sp., a fresh water, filamentous, multi-nucleate alga growing 16 days in the presence of cadmium and chromium at concentrations 10-4 10-8M was the subject of the experiment. Chromium ions reduced the number of nuclei and mitotic activity, and disturbed the correlation between cell length and number of nuclei, more than cadmium ions. Moreover, both tested metals caused the disappearance of cells with numerous nuclei with time of the culture. Only during the first (1-4 days of culture for both metals the concentration of 10-4M and especially of 10-8M increased the number of nuclei, mitotic index and the length of cells. Apical cells were more sensitive to metals than other thallus cells.

  20. Suspension of Mitotic Activity in Dentate Gyrus of the Hibernating Ground Squirrel

    Victor I. Popov

    2011-01-01

    Full Text Available Neurogenesis occurs in the adult mammalian hippocampus, a region of the brain important for learning and memory. Hibernation in Siberian ground squirrels provides a natural model to study mitosis as the rapid fall in body temperature in 24 h (from 35-36°C to +4–6°C permits accumulation of mitotic cells at different stages of the cell cycle. Histological methods used to study adult neurogenesis are limited largely to fixed tissue, and the mitotic state elucidated depends on the specific phase of mitosis at the time of day. However, using an immunohistochemical study of doublecortin (DCX and BrdU-labelled neurons, we demonstrate that the dentate gyrus of the ground squirrel hippocampus contains a population of immature cells which appear to possess mitotic activity. Our data suggest that doublecortin-labelled immature cells exist in a mitotic state and may represent a renewable pool for generation of new neurons within the dentate gyrus.

  1. Mitotic defects lead to pervasive aneuploidy and accompany loss of RB1 activity in mouse LmnaDhe dermal fibroblasts.

    C Herbert Pratt

    2011-03-01

    Full Text Available Lamin A (LMNA is a component of the nuclear lamina and is mutated in several human diseases, including Emery-Dreifuss muscular dystrophy (EDMD; OMIM ID# 181350 and the premature aging syndrome Hutchinson-Gilford progeria syndrome (HGPS; OMIM ID# 176670. Cells from progeria patients exhibit cell cycle defects in both interphase and mitosis. Mouse models with loss of LMNA function have reduced Retinoblastoma protein (RB1 activity, leading to aberrant cell cycle control in interphase, but how mitosis is affected by LMNA is not well understood.We examined the cell cycle and structural phenotypes of cells from mice with the Lmna allele, Disheveled hair and ears (Lmna(Dhe. We found that dermal fibroblasts from heterozygous Lmna(Dhe (Lmna(Dhe/+ mice exhibit many phenotypes of human laminopathy cells. These include severe perturbations to the nuclear shape and lamina, increased DNA damage, and slow growth rates due to mitotic delay. Interestingly, Lmna(Dhe/+ fibroblasts also had reduced levels of hypophosphorylated RB1 and the non-SMC condensin II-subunit D3 (NCAP-D3, a mitosis specific centromere condensin subunit that depends on RB1 activity. Mitotic check point control by mitotic arrest deficient-like 1 (MAD2L1 also was perturbed in Lmna(Dhe/+ cells. Lmna(Dhe/+ fibroblasts were consistently aneuploid and had higher levels of micronuclei and anaphase bridges than normal fibroblasts, consistent with chromosome segregation defects.These data indicate that RB1 may be a key regulator of cellular phenotype in laminopathy-related cells, and suggest that the effects of LMNA on RB1 include both interphase and mitotic cell cycle control.

  2. Mitotic Defects Lead to Pervasive Aneuploidy and Accompany Loss of RB1 Activity in Mouse LmnaDhe Dermal Fibroblasts

    Pratt, C. Herbert; Curtain, Michelle; Donahue, Leah Rae; Shopland, Lindsay S.

    2011-01-01

    Background Lamin A (LMNA) is a component of the nuclear lamina and is mutated in several human diseases, including Emery-Dreifuss muscular dystrophy (EDMD; OMIM ID# 181350) and the premature aging syndrome Hutchinson-Gilford progeria syndrome (HGPS; OMIM ID# 176670). Cells from progeria patients exhibit cell cycle defects in both interphase and mitosis. Mouse models with loss of LMNA function have reduced Retinoblastoma protein (RB1) activity, leading to aberrant cell cycle control in interphase, but how mitosis is affected by LMNA is not well understood. Results We examined the cell cycle and structural phenotypes of cells from mice with the Lmna allele, Disheveled hair and ears (LmnaDhe). We found that dermal fibroblasts from heterozygous LmnaDhe (LmnaDhe/+) mice exhibit many phenotypes of human laminopathy cells. These include severe perturbations to the nuclear shape and lamina, increased DNA damage, and slow growth rates due to mitotic delay. Interestingly, LmnaDhe/+ fibroblasts also had reduced levels of hypophosphorylated RB1 and the non-SMC condensin II-subunit D3 (NCAP-D3), a mitosis specific centromere condensin subunit that depends on RB1 activity. Mitotic check point control by mitotic arrest deficient-like 1 (MAD2L1) also was perturbed in LmnaDhe /+ cells. LmnaDhe /+ fibroblasts were consistently aneuploid and had higher levels of micronuclei and anaphase bridges than normal fibroblasts, consistent with chromosome segregation defects. Conclusions These data indicate that RB1 may be a key regulator of cellular phenotype in laminopathy-related cells, and suggest that the effects of LMNA on RB1 include both interphase and mitotic cell cycle control. PMID:21464947

  3. Phyllanthus emblica Fruit Extract Activates Spindle Assembly Checkpoint, Prevents Mitotic Aberrations and Genomic Instability in Human Colon Epithelial NCM460 Cells

    Xihan Guo

    2016-09-01

    Full Text Available The fruit of Phyllanthus emblica Linn. (PE has been widely consumed as a functional food and folk medicine in Southeast Asia due to its remarkable nutritional and pharmacological effects. Previous research showed PE delays mitotic progress and increases genomic instability (GIN in human colorectal cancer cells. This study aimed to investigate the similar effects of PE by the biomarkers related to spindle assembly checkpoint (SAC, mitotic aberrations and GIN in human NCM460 normal colon epithelial cells. Cells were treated with PE and harvested differently according to the biomarkers observed. Frequencies of micronuclei (MN, nucleoplasmic bridge (NPB and nuclear bud (NB in cytokinesis-block micronucleus assay were used as indicators of GIN. Mitotic aberrations were assessed by the biomarkers of chromosome misalignment, multipolar division, chromosome lagging and chromatin bridge. SAC activity was determined by anaphase-to- metaphase ratio (AMR and the expression of core SAC gene budding uninhibited by benzimidazoles related 1 (BubR1. Compared with the control, PE-treated cells showed (1 decreased incidences of MN, NPB and NB (p < 0.01; (2 decreased frequencies of all mitotic aberration biomarkers (p < 0.01; and (3 decreased AMR (p < 0.01 and increased BubR1 expression (p < 0.001. The results revealed PE has the potential to protect human normal colon epithelial cells from mitotic and genomic damages partially by enhancing the function of SAC.

  4. Oocyte formation by mitotically active germ cells purified from ovaries of reproductive-age women.

    White, Yvonne A R; Woods, Dori C; Takai, Yasushi; Ishihara, Osamu; Seki, Hiroyuki; Tilly, Jonathan L

    2012-02-26

    Germline stem cells that produce oocytes in vitro and fertilization-competent eggs in vivo have been identified in and isolated from adult mouse ovaries. Here we describe and validate a fluorescence-activated cell sorting-based protocol that can be used with adult mouse ovaries and human ovarian cortical tissue to purify rare mitotically active cells that have a gene expression profile that is consistent with primitive germ cells. Once established in vitro, these cells can be expanded for months and can spontaneously generate 35- to 50-μm oocytes, as determined by morphology, gene expression and haploid (1n) status. Injection of the human germline cells, engineered to stably express GFP, into human ovarian cortical biopsies leads to formation of follicles containing GFP-positive oocytes 1-2 weeks after xenotransplantation into immunodeficient female mice. Thus, ovaries of reproductive-age women, similar to adult mice, possess rare mitotically active germ cells that can be propagated in vitro as well as generate oocytes in vitro and in vivo.

  5. Oocyte formation by mitotically-active germ cells purified from ovaries of reproductive age women

    White, Yvonne A. R.; Woods, Dori C.; Takai, Yasushi; Ishihara, Osamu; Seki, Hiroyuki; Tilly, Jonathan L.

    2012-01-01

    Germline stem cells that produce oocytes in vitro and fertilization-competent eggs in vivo have been identified in and isolated from adult mouse ovaries. Here we describe and validate a FACS-based protocol that can be used with adult mouse ovaries and human ovarian cortical tissue to purify rare mitotically-active cells that exhibit a gene expression profile consistent with primitive germ cells. Once established in vitro, these cells can be expanded for months and spontaneously generate 35–50 µm oocytes, as determined by morphology, gene expression and attainment of haploid (1n) status. Injection of the human germline cells, engineered to stably express GFP, into human ovarian cortical biopsies leads to formation of follicles containing GFP-positive oocytes 1–2 weeks after xenotransplantation into immunodeficient female mice. Thus, ovaries of reproductive-age women, like adult mice, possess rare mitotically-active germ cells that can be propagated in vitro as well as generate oocytes in vitro and in vivo. PMID:22366948

  6. Aurora-B Mediated ATM Serine 1403 Phosphorylation Is Required For Mitotic ATM Activation and the Spindle Checkpoint

    Yang, Chunying; Tang, Xi; Guo, Xiaojing; Niikura, Yohei; Kitagawa, Katsumi; Cui, Kemi; Wong, Stephen T.C.; Fu, Li; Xu, Bo

    2011-01-01

    The ATM kinase plays a critical role in the maintenance of genetic stability. ATM is activated in response to DNA damage and is essential for cell cycle checkpoints. Here, we report that ATM is activated in mitosis in the absence of DNA damage. We demonstrate that mitotic ATM activation is dependent on the Aurora-B kinase and that Aurora-B phosphorylates ATM on serine 1403. This phosphorylation event is required for mitotic ATM activation. Further, we show that loss of ATM function results in...

  7. Action of plasma and liver extract from adult mice on the mitotic activity of young mouse liver.

    García, A L; Inda, A M; Echave Llanos, J M

    1991-06-01

    Inbred C3HS male mice, standardized for periodicity analysis were used. A hundred and seventy 25 +/- 2 days old mice were injected at 16:00 hs with saline, plasma or liver extract from 27 mice 90 days old. Controls were made at 08/16, 12/20, 16/24, 08/40, 12/44, 16/48, 08/64, 12/68 and 16/72 (time of day/time post-injection). The mitotic activity of the hepatocytes and litoral cells were determined. The injection of small doses of extract and plasma inhibits the mitotic activity of hepatocytes during the first and second following days. A compensatory wave appears in the third day. The extract inhibits the mitotic activity of litoral cells in the first day of control only, whereas the plasma inhibits this variable in the second and third day.

  8. Experimental evidence showing that no mitotically active female germline progenitors exist in postnatal mouse ovaries.

    Zhang, Hua; Zheng, Wenjing; Shen, Yan; Adhikari, Deepak; Ueno, Hiroo; Liu, Kui

    2012-07-31

    It has been generally accepted for more than half a century that, in most mammalian species, oocytes cannot renew themselves in postnatal or adult life, and that the number of oocytes is already fixed in fetal or neonatal ovaries. This assumption, however, has been challenged over the past decade. In this study, we have taken an endogenous genetic approach to this question and generated a multiple fluorescent Rosa26(rbw/+);Ddx4-Cre germline reporter mouse model for in vivo and in vitro tracing of the development of female germline cell lineage. Through live cell imaging and de novo folliculogenesis experiments, we show that the Ddx4-expressing cells from postnatal mouse ovaries did not enter mitosis, nor did they contribute to oocytes during de novo folliculogenesis. Our results provide evidence that supports the traditional view that no postnatal follicular renewal occurs in mammals, and no mitotically active Ddx4-expressing female germline progenitors exist in postnatal mouse ovaries.

  9. Effects of polyamines and polyamine biosynthetic inhibitors on mitotic activity of Allium cepa root tips.

    Unal, Meral; Palavan-Unsal, Narcin; Tufekci, M A

    2008-03-01

    The genotoxic and cytotoxic effects of exogenous polyamines (PAs), putrescine (Put), spermidine (Spd), spermine (Spm) and PA biosynthetic inhibitors, alpha-difluoromethylornithine (DFMO), cyclohexilamine (CHA), methylglioxal bis-(guanylhydrazone) (MGBG) were investigated in the root meristems of Allium cepa L. The reduction of mitotic index and the induction of chromosomal aberrations such as bridges, stickiness, c-mitotic anaphases, micronuclei, endoredupliction by PAs and PA biosynthetic inhibitors were observed and these were used as evidence of genotoxicity and cytotoxicity.

  10. Diverse mitotic functions of the cytoskeletal cross-linking protein Shortstop suggest a role in Dynein/Dynactin activity.

    Dewey, Evan B; Johnston, Christopher A

    2017-09-15

    Proper assembly and orientation of the bipolar mitotic spindle is critical to the fidelity of cell division. Mitotic precision fundamentally contributes to cell fate specification, tissue development and homeostasis, and chromosome distribution within daughter cells. Defects in these events are thought to contribute to several human diseases. The underlying mechanisms that function in spindle morphogenesis and positioning remain incompletely defined, however. Here we describe diverse roles for the actin-microtubule cross-linker Shortstop (Shot) in mitotic spindle function in Drosophila Shot localizes to mitotic spindle poles, and its knockdown results in an unfocused spindle pole morphology and a disruption of proper spindle orientation. Loss of Shot also leads to chromosome congression defects, cell cycle progression delay, and defective chromosome segregation during anaphase. These mitotic errors trigger apoptosis in Drosophila epithelial tissue, and blocking this apoptotic response results in a marked induction of the epithelial-mesenchymal transition marker MMP-1. The actin-binding domain of Shot directly interacts with Actin-related protein-1 (Arp-1), a key component of the Dynein/Dynactin complex. Knockdown of Arp-1 phenocopies Shot loss universally, whereas chemical disruption of F-actin does so selectively. Our work highlights novel roles for Shot in mitosis and suggests a mechanism involving Dynein/Dynactin activation. © 2017 Dewey and Johnston. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  11. Caffeine decreases phospho-Chk1 (Ser317) and increases mitotic cells with cyclin B1 and caspase 3 in tumors from UVB-treated mice.

    Lu, Yao-Ping; Lou, You-Rong; Peng, Qing-Yun; Nghiem, Paul; Conney, Allan H

    2011-07-01

    Oral administration of caffeine to mice inhibits UVB-induced carcinogenesis, and these results are paralleled by epidemiology studies indicating that caffeinated coffee and tea intake (but not decaffeinated beverage intake) is associated with decreased incidence of nonmelanoma skin cancer. Topical applications of caffeine to the skin of SKH-1 mice that had previously been treated with UVB inhibited subsequent skin tumor development and stimulated apoptosis in tumors but not in nontumor areas of the epidermis. This study sought to determine the basis of these differential effects on tumor versus nontumor sites that can be induced by caffeine, long after all UVB treatment has ceased. The activation status of the ATR/Chk1 pathway in UVB-induced tumors and uninvolved skin was determined by quantitating phospho-Chk1 (Ser317) and induction of lethal mitosis in vivo in the presence and absence of topical caffeine treatment. In the absence of caffeine, we found that UVB-induced tumors often had islands of phospho-Chk1 (Ser317) staining cells that were not present in nontumor areas of the epidermis. Treatment of mice with topical caffeine significantly diminished phospho-Chk1 (Ser317) staining and increased the number of mitotic cells that expressed cyclin B1 and caspase 3 in tumors, consistent with caffeine-induced lethal mitosis selectively in tumors. We hypothesize that compared with adjacent uninvolved skin, UVB-induced skin tumors have elevated activation of, and dependence on, the ATR/Chk1 pathway long after UVB exposure has ceased and that caffeine can induce apoptosis selectively in tumors by inhibiting this pathway and promoting lethal mitosis.

  12. Anti-mitotic activity towards sea urchin eggs of dichloromethane fraction obtained from Allamanda schottii Pohl (Apocynaceae

    Louisa M. A. Sousa

    Full Text Available Allamanda (Apocynaceae is a genus of climbing shrubs known for producing compounds with a range of biological activities. Previous works have shown the anti-proliferative effect of the ethanolic extract of Allamanda schottii on leukemic cells. The present work was conducted to evaluate the effects of dichloromethane fraction, obtained from Allamanda schottii, on sea urchin Echinometra lucunter eggs, as a multicellular model for evaluating anti-tumor activity. Our results show an inhibition of sea urchin development in a dose-dependent manner in the presence of dichloromethane fraction. The IC50 values for first and third cleavage and blastulae stage were 103.7 µg/mL, 33.1 µg/mL and 10.2 µg/mL, respectively. These results also demonstrate the cumulative effect of this fraction on sea urchin embryos. In the present work, the expressive anti-mitotic activity of dichloromethane fraction towards sea urchin eggs, a multicellular model, reinforces the anti-tumor potential of the Allamanda schotti.

  13. Structurally simplified biphenyl combretastatin A4 derivatives retain in vitro anti-cancer activity dependent on mitotic arrest

    Tarade, Daniel; Ma, Dennis; Pignanelli, Christopher; Mansour, Fadi; Simard, Daniel; van den Berg, Sean; Gauld, James; McNulty, James; Pandey, Siyaram

    2017-01-01

    The cis-stilbene, combretastatin A4 (CA4), is a potent microtubule targeting and vascular damaging agent. Despite promising results at the pre-clinical level and extensive clinical evaluation, CA4 has yet to be approved for therapeutic use. One impediment to the development of CA4 is an inherent conformational instability about the ethylene linker, which joins two aromatic rings. We have previously published preliminary data regarding structurally simplified biphenyl derivatives of CA4, lacking an ethylene linker, which retain anti-proliferative and pro-apoptotic activity, albeit at higher doses. Our current study provides a more comprehensive evaluation regarding the anti-proliferative and pro-apoptotic properties of biphenyl CA4 derivatives in both 2D and 3D cancerous and non-cancerous cell models. Computational analysis has revealed that cytotoxicity of CA4 and biphenyl analogues correlates with predicted tubulin affinity. Additional mechanistic evaluation of the biphenyl derivatives found that their anti-cancer activity is dependent on prolonged mitotic arrest, in a similar manner to CA4. Lastly, we have shown that cancer cells deficient in the extrinsic pathway of apoptosis experience delayed cell death following treatment with CA4 or analogues. Biphenyl derivatives of CA4 represent structurally simplified analogues of CA4, which retain a similar mechanism of action. The biphenyl analogues warrant in vivo examination to evaluate their potential as vascular damaging agents. PMID:28253265

  14. Structurally simplified biphenyl combretastatin A4 derivatives retain in vitro anti-cancer activity dependent on mitotic arrest.

    Daniel Tarade

    Full Text Available The cis-stilbene, combretastatin A4 (CA4, is a potent microtubule targeting and vascular damaging agent. Despite promising results at the pre-clinical level and extensive clinical evaluation, CA4 has yet to be approved for therapeutic use. One impediment to the development of CA4 is an inherent conformational instability about the ethylene linker, which joins two aromatic rings. We have previously published preliminary data regarding structurally simplified biphenyl derivatives of CA4, lacking an ethylene linker, which retain anti-proliferative and pro-apoptotic activity, albeit at higher doses. Our current study provides a more comprehensive evaluation regarding the anti-proliferative and pro-apoptotic properties of biphenyl CA4 derivatives in both 2D and 3D cancerous and non-cancerous cell models. Computational analysis has revealed that cytotoxicity of CA4 and biphenyl analogues correlates with predicted tubulin affinity. Additional mechanistic evaluation of the biphenyl derivatives found that their anti-cancer activity is dependent on prolonged mitotic arrest, in a similar manner to CA4. Lastly, we have shown that cancer cells deficient in the extrinsic pathway of apoptosis experience delayed cell death following treatment with CA4 or analogues. Biphenyl derivatives of CA4 represent structurally simplified analogues of CA4, which retain a similar mechanism of action. The biphenyl analogues warrant in vivo examination to evaluate their potential as vascular damaging agents.

  15. Inhibition of the Ras-ERK pathway in mitotic COS7 cells is due to the inability of EGFR/Raf to transduce EGF signaling to downstream proteins.

    Shi, Huaiping; Zhang, Tianying; Yi, Yongqing; Ma, Yue

    2016-06-01

    Although previous studies have shown that Ras-ERK signaling in mitosis is closed due to the inhibition of signal transduction, the events involved in the molecular mechanisms are still unclear. In the present study, we investigated the Ras-ERK signaling pathway in mitotic COS7 cells. The results demonstrated that treatment with epidermal growth factor (EGF) failed to increase the endocytosis of EGF-EGFR (EGF receptor) complexes in mitotic COS7 cells, although a large amount of endosomes were found in asynchronous COS7 cells. Clathrin expression levels in mitotic COS7 cells were inhibited whereas caveolin expression levels in mitotic COS7 cells were almost unaffected. Y1068 and Y1086 residues of EGFR in the mitotic COS7 cells were activated. However, Grb2 and Shc in the mitotic COS7 cells did not bind to activated EGFR. Ras activity was inhibited in the mitotic COS7 cells whereas its downstream protein, Raf, was obviously phosphorylated by EGF in mitosis. Treatment with phorbol 12-myristate 13-acetate (PMA) also increased the phosphorylation levels of Raf in the mitotic COS7 cells. Nevertheless, Raf phosphorylation in mitosis was significantly inhibited by AG1478. Lastly, activation of EGF-mediated MEK and ERK in the mitotic COS7 cells was obviously inhibited. In summary, our results suggest that the Ras-ERK pathway is inhibited in mitotic COS7 cells which may be the dual result of the difficulty in the transduction of EGF signaling by EGFR or Raf to downstream proteins.

  16. Cdk1 Activates Pre-Mitotic Nuclear Envelope Dynein Recruitment and Apical Nuclear Migration in Neural Stem cells

    Baffet, Alexandre D.; Hu, Daniel J.; Vallee, Richard B.

    2015-01-01

    Summary Dynein recruitment to the nuclear envelope is required for pre-mitotic nucleus-centrosome interactions in nonneuronal cells, and for apical nuclear migration in neural stem cells. In each case, dynein is recruited to the nuclear envelope (NE) specifically during G2, via two nuclear pore-mediated mechanisms involving RanBP2-BicD2 and Nup133-CENP-F. The mechanisms responsible for cell cycle control of this behavior are unknown. We now find that Cdk1 serves as a direct master controller for NE dynein recruitment in neural stem cells and HeLa cells. Cdk1 phosphorylates conserved sites within RanBP2 and activates BicD2 binding and early dynein recruitment. Late recruitment is triggered by a Cdk1-induced export of CENP-F from the nucleus. Forced NE targeting of BicD2 overrides Cdk1 inhibition, fully rescuing dynein recruitment and nuclear migration in neural stem cells. These results reveal how NE dynein recruitment is cell cycle regulated, and identify the trigger mechanism for apical nuclear migration in the brain. PMID:26051540

  17. Effects of low SO/sub 2/ concentrations on the mitotic activity and on the cell cycle of duckweed (Lemna minor L. )

    Stoeckli, B; Braendle, R; Erismann, K H

    1975-01-01

    Duckweed (Lemena minor) has proven to be a suitable indicator for the effects of low SO/sub 2/ concentrations. Therefore, this plant was used to study the mitotic activity as well as the cell cycle under fumigation with sublethal SO/sub 2/ concentrations although to a great extent the morphology of this plant is still unknown. It is also difficult to process this plant cytologically.

  18. Study of DNA synthesis and mitotic activity of hepatocytes and its relation to angiogenesis in hepatectomised tumour bearing mice.

    Andrini, Laura B; García, Marcela N; Inda, Ana María; Errecalde, Ana Lía

    2013-11-01

    Partial hepatectomy (PH) alters serum concentrations of substances involved in cellular proliferation, leading to the compensatory liver hyperplasia. Furthermore, angiogenesis is mainly stimulated by vascular endothelial growth factor (VEGF) and is a fundamental requirement either in liver regeneration or in tumours growth. This study looks at the expression of VEGF, DNA synthesis (DNAs) and mitotic activity (MA) in hepatectomised (H) and hepatectomised-tumour bearing (HTB) mice throughout a 24 h period. Adult male mice were sacrificed every 4 h from 26 to 50 h post-hepatectomy. H mice show a circadian rhythm in VEGF expression with a maximum value of 2.6 ± 0.1 at 08/46 h of day/hours posthepatectomy (HD/HPH); in DNAs, the maximum value was 3.4 ± 0.3 at 16/30 (HD/HPH) and in MA it was 2.3 ± 0.01 at 12/50 (HD/HPH). In HTB animals the peak of VEGF expression appears at 16/30 (HD/HPH) with a maximum value of 3.7 ± 0.1, the peak of DNAs was at 00/38 (HD/HPH) with a value of 4.6 ± 0.3 and the maximum value of MA of 08/46 (HD/HPH) with a value of 3.01 ± 0.3. We can conclude that the presence of the tumour induces modifications in the intensity and the temporal distribution of the circadian curves of VEGF expression, DNAs and MA of hepatectomised animals. © 2013 International Federation for Cell Biology.

  19. The relationship between mitotic rate and depth of invasion in biopsies of malignant melanoma

    Ghasemi Basir HR

    2018-03-01

    Full Text Available Hamid Reza Ghasemi Basir,1,2 Pedram Alirezaei,2 Sara Ahovan,3 Abbas Moradi3 1Department of Pathology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran; 2Psoriasis Research Center, Hamadan University of Medical Sciences, Hamadan, Iran; 3School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran Background: Malignant melanoma of the skin is a potentially lethal neoplasm that generally originates from atypical melanocytes in the dermal–epidermal junction. When the neoplasm penetrates into the dermis, several variables can affect the extent of its spread, among which depth of invasion has the most important prognostic value. Mitotic rate is another prognostic factor that reflects the biological behavior of the neoplasm.Objective: This study was designed to evaluate the probable relationship between the depth of invasion of malignant melanoma and its mitotic rate.Materials and methods: This study was performed on 50 excisional biopsy specimens that had received the diagnosis of malignant melanoma histopathologically. Tumor characteristics including Breslow thickness, Clark level, T-stage, and tumor mitotic rate were recorded.Results: We observed that at higher Clark levels and higher T-stages, and the mean mitotic rate was significantly increased. Moreover, there was a positive and significant correlation between Breslow thickness and mitotic rate. We demonstrated that one unit increase in mitotic rate was correlated with 0.8 mm increase in Breslow thickness of the tumor.Conclusion: In malignant melanoma, mitotic activity may probably indicate the depth of tumor invasion. Therefore, in incisional biopsies where depth of invasion cannot be accurately determined, the mitotic activity may be used to estimate Breslow thickness, which is necessary for planning surgical management. Keywords: melanoma, mitosis, Breslow, invasion, thickness, proliferation

  20. Effect of hydroxyurea on mitotic activity 3H-thymidine and 3H-phenylalanine incorporation in the antheridial filament cells of Chara vulgaris

    Bielecka, A.

    1979-01-01

    Hydroxyurea inhibits mitotic activity in cells of the antheridial filaments of Chara vulgaris by blocking phase S and phase G 2 . Blocking of cells in phase G 2 also occurs in the case of the root meristem cells of Helianthus annuus and Vicia faba var. minor. 3 H-thine incorporation confirmed autoradiographically the blocking of cells of the antheridial filaments in Chara vulgaris at phase S and slowing down of the rate of DNA replication. Incubation with 3 H-phenylalanine demonstrated that hydroxyurea inhibits protein synthesis. (author)

  1. In ovo feeding of creatine pyruvate alters energy reserves, satellite cell mitotic activity and myogenic gene expression of breast muscle in embryos and neonatal broilers.

    Zhao, M M; Gao, T; Zhang, L; Li, J L; Lv, P A; Yu, L L; Gao, F; Zhou, G H

    2017-09-01

    We investigated the effects of in ovo feeding (IOF) of creatine pyruvate (CrPyr) on energy reserves, satellite cell mitotic activity (SCMA) and myogenic gene expression in breast muscle of embryos and neonatal broilers. A total of 960 eggs were randomly allocated into three treatments: 1) non-injected control group, 2) saline group injected with 0.6 mL of physiological saline (0.75%), and 3) CrPyr group injected with 0.6 mL of physiological saline (0.75%) containing 12 mg CrPyr/egg at 17.5 d of incubation. After hatching, a total of 120 male chicks were randomly assigned to each treatment group, with eight replicate sets per group. Selected chicks had body BW close to the average of their pooled group. Our results showed that the total and relative breast muscle weights of broilers subjected to CrPyr treatment were higher than those in the control and saline groups on 19 d of incubation (19 E), the day of hatch, 3 and 7 d post-hatch (P creatine concentrations on 19 E, the day of hatch and 3 d post-hatch, the same treatment increased phosphocreatine concentrations on 19 E. Broilers in the CrPyr group showed higher expression of myogenic differentiation 1 (MyoD) (P < 0.05), myogenin and paired box 7 (Pax7), as well as higher index of SCMA on 3 d post-hatch. However, myostatin mRNA expression in CrPyr-treated broilers was down-regulated on 3 d post-hatch (P < 0.05). These results indicated that IOF of CrPyr increased energy reserves of embryos and SCMA of broilers on 3 d post-hatch, which led to enhanced muscle growth in the late embryos and neonatal broilers. Additionally, IOF of CrPyr increased the activity of satellite cells possibly through up-regulating MyoD, myogenin, and Pax7 mRNA expression and down-regulating myostatin mRNA expression. © 2017 Poultry Science Association Inc.

  2. New mitotic regulators released from chromatin

    Hideki eYokoyama

    2013-12-01

    Full Text Available Faithful action of the mitotic spindle segregates duplicated chromosomes into daughter cells. Perturbations of this process result in chromosome mis-segregation, leading to chromosomal instability and cancer development. Chromosomes are not simply passengers segregated by spindle microtubules but rather play a major active role in spindle assembly. The GTP bound form of the Ran GTPase (RanGTP, produced around chromosomes, locally activates spindle assembly factors. Recent studies have uncovered that chromosomes organize mitosis beyond spindle formation. They distinctly regulate other mitotic events, such as spindle maintenance in anaphase, which is essential for chromosome segregation. Furthermore, the direct function of chromosomes is not only to produce RanGTP but, in addition, to release key mitotic regulators from chromatin. Chromatin-remodeling factors and nuclear pore complex proteins, which have established functions on chromatin in interphase, dissociate from mitotic chromatin and function in spindle assembly or maintenance. Thus, chromosomes actively organize their own segregation using chromatin-releasing mitotic regulators as well as RanGTP.

  3. Assessing and Increasing Physical Activity

    Van Camp, Carole M.; Hayes, Lynda B.

    2012-01-01

    Increasing physical activity is a crucial component of any comprehensive approach to combat the growing obesity epidemic. This review summarizes recent behavioral research on the measurement of physical activity and interventions aimed at increasing physical activity and provides directions for future research.

  4. Bacterial mitotic machineries

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte

    2004-01-01

    Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the P......M protein of plasmid R1 forms F actin-like filaments that separate and move plasmid DNA from mid-cell to the cell poles. Evidence from three different laboratories indicate that the morphogenetic MreB protein may be involved in segregation of the bacterial chromosome.......Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the Par...

  5. A nontranscriptional role for Oct4 in the regulation of mitotic entry

    Zhao, Rui; Deibler, Richard W.; Lerou, Paul H.; Ballabeni, Andrea; Heffner, Garrett C.; Cahan, Patrick; Unternaehrer, Juli J.; Kirschner, Marc W.; Daley, George Q.

    2014-01-01

    Rapid progression through the cell cycle and a very short G1 phase are defining characteristics of embryonic stem cells. This distinct cell cycle is driven by a positive feedback loop involving Rb inactivation and reduced oscillations of cyclins and cyclin-dependent kinase (Cdk) activity. In this setting, we inquired how ES cells avoid the potentially deleterious consequences of premature mitotic entry. We found that the pluripotency transcription factor Oct4 (octamer-binding transcription factor 4) plays an unappreciated role in the ES cell cycle by forming a complex with cyclin–Cdk1 and inhibiting Cdk1 activation. Ectopic expression of Oct4 or a mutant lacking transcriptional activity recapitulated delayed mitotic entry in HeLa cells. Reduction of Oct4 levels in ES cells accelerated G2 progression, which led to increased chromosomal missegregation and apoptosis. Our data demonstrate an unexpected nontranscriptional function of Oct4 in the regulation of mitotic entry. PMID:25324523

  6. Protein synthesis rate measured with l-[1-11C]tyrosine positron emission tomography correlates with mitotic activity and MIB-1 antibody-detected proliferation in human soft tissue sarcomas

    Plaat, B.; Mastik, M.; Molenaar, W.; Kole, A.; Vaalburg, W.; Hoekstra, H.

    1999-01-01

    Protein synthesis rate (PSR) can be assessed in vivo using positron emission tomography with l-[1- 11 C]tyrosine (TYR-PET). Biological activity of soft tissue sarcomas (STS) can be measured in vitro by the mitotic rate and number of proliferating cells. In STS the grade of malignancy, in which the mitotic index plays a major role, is considered to be the major standard in predicting biological tumour behaviour. This study was designed to test the validity of TYR-PET in relation to different histopathological features. In 21 patients with untreated STS, the PSR was measured using TYR-PET. The number of mitoses was counted and tumours were graded according to the grading system of Coindre et al. (Cancer 1986; 58:306-309). Proliferative activity was assessed by immunohistological detection of the Ki-67 nuclear antigen using MIB-1 monoclonal antibody. To test the association between the PSR and these tumour parameters, a correlation analysis was performed. A significant (P<0.05) correlation was found between PSR and the Ki-67 proliferation index (R = 0.54), and between PSR and mitotic rate (R = 0.64). There was no correlation between PSR and tumour grade. The present study in malignant soft tissue tumours relates in vivo tumour metabolism as established with TYR-PET to tumour activity measured in vitro and indicates that the non-invasive method of TYR-PET can estimate the mitotic and proliferative activity in STS. (orig.)

  7. Incorporation of thymidine into onion root meristematic cell nuclei in presence of hydroxyurea and its role in recovery of mitotic activity

    H. Habdas

    2015-01-01

    Hydroxyurea treatment of onion roots induced mitotic block which was released by transfer of bulbs to water, and also to some extent by addition of cold or 3H-thymidine to hydroxyurea solutions. In presence of hydroxyurea there was noted very intense incorporation of 3H-thymidine into cell nuclei, giving labelling index of 40-70%. However, all the mitotic figures appearing in presence of hydroxyurea and 3H-thymidine were unlabelled. On the other hand, labelled mitotic figures were obtained wh...

  8. Effect of tumor promoters on ultraviolet light-induced mutation and mitotic recombination in Saccharomyces cerevisiae

    Kunz, B.A.; Hannan, M.A.; Haynes, R.H.

    1980-01-01

    Recently, it has been suggested that mitotic recombination is involved in tumor promotion. On this basis, one might expect tumor promoters to be recombinagenic. D7 is a diploid strain of yeast in which both mutation and mitotic recombination can be measured. We have used this strain to assay the known tumor promoters, iodacetate, anthralin, and 12-0-tetradecanoylphorbol-13-acetate, and the cocarcinogen, catechol, for mutagenicity, recombinagenicity, and the ability to enhance ultraviolet light (UV)-induced genetic events. In the absence of preirradiation with UV, iodoacetate was found to be recombinagenic whereas catechol was mutagenic; however, in both cases, the effects were small. Iodoacetate, anthralin, and catechol potentiated UV-induced mitotic crossing-over, aberrant colony formation, and mutation, while catechol also increased UV-induced gene conversion. We were unable to detect any mutagenic or recombinagenic effect of 12-0-tetradecanoyl-phorbol-13-acetate in either whole cells or spheroplasts. Our results do not indicate any consistent correlation between tumor-promoting activity and the ability of an agent to induce mitotic recombination in yeast. However, the ability to potentiate UV-induced mutation and mitotic recombination may reflect the cocarcinogenic activity of certain promoters

  9. Profiling DNA damage response following mitotic perturbations

    Pedersen, Ronni Sølvhøi; Karemore, Gopal; Gudjonsson, Thorkell

    2016-01-01

    that a broad spectrum of mitotic errors correlates with increased DNA breakage in daughter cells. Unexpectedly, we find that only a subset of these correlations are functionally linked. We identify the genuine mitosis-born DNA damage events and sub-classify them according to penetrance of the observed...

  10. Mitotic chromosome condensation in vertebrates

    Vagnarelli, Paola

    2012-01-01

    Work from several laboratories over the past 10–15 years has revealed that, within the interphase nucleus, chromosomes are organized into spatially distinct territories [T. Cremer, C. Cremer, Chromosome territories, nuclear architecture and gene regulation in mammalian cells, Nat. Rev. Genet. 2 (2001) 292–301 and T. Cremer, M. Cremer, S. Dietzel, S. Muller, I. Solovei, S. Fakan, Chromosome territories—a functional nuclear landscape, Curr. Opin. Cell Biol. 18 (2006) 307–316]. The overall compaction level and intranuclear location varies as a function of gene density for both entire chromosomes [J.A. Croft, J.M. Bridger, S. Boyle, P. Perry, P. Teague,W.A. Bickmore, Differences in the localization and morphology of chromosomes in the human nucleus, J. Cell Biol. 145 (1999) 1119–1131] and specific chromosomal regions [N.L. Mahy, P.E. Perry, S. Gilchrist, R.A. Baldock, W.A. Bickmore, Spatial organization of active and inactive genes and noncoding DNA within chromosome territories, J. Cell Biol. 157 (2002) 579–589] (Fig. 1A, A'). In prophase, when cyclin B activity reaches a high threshold, chromosome condensation occurs followed by Nuclear Envelope Breakdown (NEB) [1]. At this point vertebrate chromosomes appear as compact structures harboring an attachment point for the spindle microtubules physically recognizable as a primary constriction where the two sister chromatids are held together. The transition from an unshaped interphase chromosome to the highly structured mitotic chromosome (compare Figs. 1A and B) has fascinated researchers for several decades now; however a definite picture of how this process is achieved and regulated is not yet in our hands and it will require more investigation to comprehend the complete process. From a biochemical point of view a vertebrate mitotic chromosomes is composed of DNA, histone proteins (60%) and non-histone proteins (40%) [6]. I will discuss below what is known to date on the contribution of these two different

  11. Mitotic chromosome condensation in vertebrates

    Vagnarelli, Paola, E-mail: P.Vagnarelli@ed.ac.uk

    2012-07-15

    Work from several laboratories over the past 10-15 years has revealed that, within the interphase nucleus, chromosomes are organized into spatially distinct territories [T. Cremer, C. Cremer, Chromosome territories, nuclear architecture and gene regulation in mammalian cells, Nat. Rev. Genet. 2 (2001) 292-301 and T. Cremer, M. Cremer, S. Dietzel, S. Muller, I. Solovei, S. Fakan, Chromosome territories-a functional nuclear landscape, Curr. Opin. Cell Biol. 18 (2006) 307-316]. The overall compaction level and intranuclear location varies as a function of gene density for both entire chromosomes [J.A. Croft, J.M. Bridger, S. Boyle, P. Perry, P. Teague,W.A. Bickmore, Differences in the localization and morphology of chromosomes in the human nucleus, J. Cell Biol. 145 (1999) 1119-1131] and specific chromosomal regions [N.L. Mahy, P.E. Perry, S. Gilchrist, R.A. Baldock, W.A. Bickmore, Spatial organization of active and inactive genes and noncoding DNA within chromosome territories, J. Cell Biol. 157 (2002) 579-589] (Fig. 1A, A'). In prophase, when cyclin B activity reaches a high threshold, chromosome condensation occurs followed by Nuclear Envelope Breakdown (NEB) [1]. At this point vertebrate chromosomes appear as compact structures harboring an attachment point for the spindle microtubules physically recognizable as a primary constriction where the two sister chromatids are held together. The transition from an unshaped interphase chromosome to the highly structured mitotic chromosome (compare Figs. 1A and B) has fascinated researchers for several decades now; however a definite picture of how this process is achieved and regulated is not yet in our hands and it will require more investigation to comprehend the complete process. From a biochemical point of view a vertebrate mitotic chromosomes is composed of DNA, histone proteins (60%) and non-histone proteins (40%) [6]. I will discuss below what is known to date on the contribution of these two different classes

  12. Carbamazepine induces mitotic arrest in mammalian Vero cells

    Perez Martin, J.M.; Fernandez Freire, P.; Labrador, V.; Hazen, M.J.

    2008-01-01

    We reported recently that the anticonvulsant drug carbamazepine, at supratherapeutic concentrations, exerts antiproliferative effects in mammalian Vero cells, but the underlying mechanism has not been elucidated. This motivates us to examine rigorously whether growth arrest was associated with structural changes in cellular organization during mitosis. In the present work, we found that exposure of the cells to carbamazepine led to an increase in mitotic index, mainly due to the sustained block at the metaphase/anaphase boundary, with the consequent inhibition of cell proliferation. Indirect immunofluorescence, using antibodies directed against spindle apparatus proteins, revealed that mitotic arrest was associated with formation of monopolar spindles, caused by impairment of centrosome separation. The final consequence of the spindle defects induced by carbamazepine, depended on the duration of cell cycle arrest. Following the time course of accumulation of metaphase and apoptotic cells during carbamazepine treatments, we observed a causative relationship between mitotic arrest and induction of cell death. Conversely, cells released from the block of metaphase by removal of the drug, continued to progress through mitosis and resume normal proliferation. Our results show that carbamazepine shares a common antiproliferative mechanism with spindle-targeted drugs and contribute to a better understanding of the cytostatic activity previously described in Vero cells. Additional studies are in progress to extend these initial findings that define a novel mode of action of carbamazepine in cultured mammalian cells

  13. Carbamazepine induces mitotic arrest in mammalian Vero cells

    Perez Martin, J.M.; Fernandez Freire, P.; Labrador, V. [Departamento de Biologia, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Hazen, M.J. [Departamento de Biologia, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)], E-mail: mariajose.hazen@uam.es

    2008-01-01

    We reported recently that the anticonvulsant drug carbamazepine, at supratherapeutic concentrations, exerts antiproliferative effects in mammalian Vero cells, but the underlying mechanism has not been elucidated. This motivates us to examine rigorously whether growth arrest was associated with structural changes in cellular organization during mitosis. In the present work, we found that exposure of the cells to carbamazepine led to an increase in mitotic index, mainly due to the sustained block at the metaphase/anaphase boundary, with the consequent inhibition of cell proliferation. Indirect immunofluorescence, using antibodies directed against spindle apparatus proteins, revealed that mitotic arrest was associated with formation of monopolar spindles, caused by impairment of centrosome separation. The final consequence of the spindle defects induced by carbamazepine, depended on the duration of cell cycle arrest. Following the time course of accumulation of metaphase and apoptotic cells during carbamazepine treatments, we observed a causative relationship between mitotic arrest and induction of cell death. Conversely, cells released from the block of metaphase by removal of the drug, continued to progress through mitosis and resume normal proliferation. Our results show that carbamazepine shares a common antiproliferative mechanism with spindle-targeted drugs and contribute to a better understanding of the cytostatic activity previously described in Vero cells. Additional studies are in progress to extend these initial findings that define a novel mode of action of carbamazepine in cultured mammalian cells.

  14. Loss of MAPK Pathway Activation in Post-Mitotic Retinal Cells as Mechanism in MEK Inhibition-Related Retinopathy in Cancer Patients.

    van Dijk, Elon H C; Duits, Danique E M; Versluis, Mieke; Luyten, Gregrorius P M; Bergen, Arthur A B; Kapiteijn, Ellen W; de Lange, Mark J; Boon, Camiel J F; van der Velden, Pieter A

    2016-05-01

    Recently, treatment with MEK inhibitors has been shown to be an effective treatment option for metastatic melanoma. Treatment efficacy is dependent on inhibition of MAPK-related melanoma proliferation. However, targeting of MEK can be accompanied by a time-dependent and reversible serous retinopathy of unknown origin.We analyzed the molecular mechanism by which the MEK inhibitor binimetinib may lead to retinopathy, using neuroretina and cell models of retinal pigment epithelium (RPE).Binimetinib inhibited the MAPK pathway while discontinuation of treatment resulted in reactivation. However, cell proliferation was not inhibited correspondingly during binimetinib treatment of ARPE19 cells. Remarkably, post-mitotic neuroretinal tissue displayed a strong MAPK activation that was lost after binimetinib treatment.We propose that binimetinib-associated retinopathy is correlated with inhibition of the MAPK pathway in multiple retinal components. Retinal cells are able to regain the activation after binimetinib treatment, mimicking the reversibility of the retinopathy. As most retinal cells are nonregenerating, other mechanisms than stimulation of proliferation must be involved.

  15. Interlinked bistable mechanisms generate robust mitotic transitions.

    Hutter, Lukas H; Rata, Scott; Hochegger, Helfrid; Novák, Béla

    2017-10-18

    The transitions between phases of the cell cycle have evolved to be robust and switch-like, which ensures temporal separation of DNA replication, sister chromatid separation, and cell division. Mathematical models describing the biochemical interaction networks of cell cycle regulators attribute these properties to underlying bistable switches, which inherently generate robust, switch-like, and irreversible transitions between states. We have recently presented new mathematical models for two control systems that regulate crucial transitions in the cell cycle: mitotic entry and exit, 1 and the mitotic checkpoint. 2 Each of the two control systems is characterized by two interlinked bistable switches. In the case of mitotic checkpoint control, these switches are mutually activating, whereas in the case of the mitotic entry/exit network, the switches are mutually inhibiting. In this Perspective we describe the qualitative features of these regulatory motifs and show that having two interlinked bistable mechanisms further enhances robustness and irreversibility. We speculate that these network motifs also underlie other cell cycle transitions and cellular transitions between distinct biochemical states.

  16. Protein synthesis rate measured with l-[1-{sup 11}C]tyrosine positron emission tomography correlates with mitotic activity and MIB-1 antibody-detected proliferation in human soft tissue sarcomas

    Plaat, B.; Mastik, M.; Molenaar, W. [Department of Pathology, University Hospital Groningen (Netherlands); Kole, A.; Vaalburg, W. [PET Centre, University Hospital Groningen (Netherlands); Hoekstra, H. [Department of Surgical Oncology, University Hospital Groningen (Netherlands)

    1999-04-29

    Protein synthesis rate (PSR) can be assessed in vivo using positron emission tomography with l-[1-{sup 11}C]tyrosine (TYR-PET). Biological activity of soft tissue sarcomas (STS) can be measured in vitro by the mitotic rate and number of proliferating cells. In STS the grade of malignancy, in which the mitotic index plays a major role, is considered to be the major standard in predicting biological tumour behaviour. This study was designed to test the validity of TYR-PET in relation to different histopathological features. In 21 patients with untreated STS, the PSR was measured using TYR-PET. The number of mitoses was counted and tumours were graded according to the grading system of Coindre et al. (Cancer 1986; 58:306-309). Proliferative activity was assessed by immunohistological detection of the Ki-67 nuclear antigen using MIB-1 monoclonal antibody. To test the association between the PSR and these tumour parameters, a correlation analysis was performed. A significant (P<0.05) correlation was found between PSR and the Ki-67 proliferation index (R = 0.54), and between PSR and mitotic rate (R = 0.64). There was no correlation between PSR and tumour grade. The present study in malignant soft tissue tumours relates in vivo tumour metabolism as established with TYR-PET to tumour activity measured in vitro and indicates that the non-invasive method of TYR-PET can estimate the mitotic and proliferative activity in STS. (orig.) With 2 figs., 2 tabs., 30 refs.

  17. Xanthium strumarium extract inhibits mammalian cell proliferation through mitotic spindle disruption mediated by xanthatin.

    Sánchez-Lamar, Angel; Piloto-Ferrer, Janet; Fiore, Mario; Stano, Pasquale; Cozzi, Renata; Tofani, Daniela; Cundari, Enrico; Francisco, Marbelis; Romero, Aylema; González, Maria L; Degrassi, Francesca

    2016-12-24

    Xanthium strumarium L. is a member of the Asteraceae family popularly used with multiple therapeutic purposes. Whole extracts of this plant have shown anti-mitotic activity in vitro suggesting that some components could induce mitotic arrest in proliferating cells. Aim of the present work was to characterize the anti-mitotic properties of the X. strumarium whole extract and to isolate and purify active molecule(s). The capacity of the whole extract to inhibit mitotic progression in mammalian cultured cells was investigated to identify its anti-mitotic activity. Isolation of active component(s) was performed using a bioassay-guided multistep separation procedure in which whole extract was submitted to a progressive process of fractionation and fractions were challenged for their anti-mitotic activity. Our results show for the first time that X. strumarium whole extract inhibits assembly of the mitotic spindle and spindle-pole separation, thereby heavily affecting mitosis, impairing the metaphase to anaphase transition and inducing apoptosis. The purification procedure led to a fraction with an anti-mitotic activity comparable to that of the whole extract. Chemical analysis of this fraction showed that its major component was xanthatin. The present work shows a new activity of X. strumarium extract, i.e. the alteration of the mitotic apparatus in cultured cells that may be responsible for the anti-proliferative activity of the extract. Anti-mitotic activity is shown to be mainly exerted by xanthatin. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Incorporation of thymidine into onion root meristematic cell nuclei in presence of hydroxyurea and its role in recovery of mitotic activity

    Habdas, H.

    1977-01-01

    Hydroxyurea treatment of onion roots induced mitotic block which was released by transfer of bulbs to water, and also to some extent by addition of cold or 3 H-thymidine to hydroxyurea solutions. In presence of hydroxyurea there was noted very intense incorporation of 3 H-thymidine into cell nuclei, giving labelling index of 40-70%. However, all the mitotic figures appearing in presence of hydroxyurea and 3 H-thymidine were unlabelled. On the other hand, labelled mitotic figures were obtained when roots incubated with 3 H-thymidine in presence of hydroxyurea had been transferred to water. Incorporation of 3 H-uridine was unaffected by hydroxyurea. The results show that hydroxyurea arrests onion root meristematic cells, either in the S phase and the G 2 phase. Enhanced incorporation of 3 H-thymidine in the presence of hydroxyurea, and release by added thymidine of the mitotic block indicate that hydroxyurea induces in onion root meristematic cells a particular shortage of thymidylate. (author)

  19. Comparison of stem-spermatogonial renewal and mitotic activity in the #betta#-irratiated mouse and rat

    Erickson, B.H.; Hall, G.G.

    1983-01-01

    The Sprague-Dawley rat exceeds the CRF 1 mouse in number of isolated or purported stem cells per unit area of seminiferous tubule by a factor of 2.1, yet the mouse exceeds the rat in number of first-generation spermatogonia (A 1 ) per unit of tubule by a factor of 1.8. This difference could lead to an interspecies difference in irradiation response and help clarify the identity of spermatogonial stem cell. To test this thesis, mice and rats were irradiated with 600 R of 60 Co #betta#-radiation and killed at postirradiation intervals of 1-16 weeks. Both tubular whole mounts and cross sections were evaluated. The species did not differ in percent survival of isolated spermatogonia, but the mouse exceeded the rat in survival and/or production of A 1 or clonal spermatogonia by a factor of 5. By week 16 after irradiation, the mouse restis had regained 67% of its preirradiation weight, in contrast to the rat's 52%. Clonal renewal was in progress by the end of the 2 (mouse) and 3 (rat) weeks and was substantially complete by the 8 week. In both species the isolated population, however, diminished throughout the first 8 weeks and was renewed between 8 and 16 weeks. Clonal renewal was not accompanied by an increase in the number of isolated spermatogonial mitoses, but was accompanied by increases in the mitotis of pairs and clones and the apparent splitting of existing clones to form additional clones. Thus, the mouse's superiority in the rate and completeness of spermatogonial renewal was apparently due to the attributes of the undifferentiated A 1 spermatogonial clone. (orig.)

  20. ATP depletion during mitotic arrest induces mitotic slippage and APC/CCdh1-dependent cyclin B1 degradation.

    Park, Yun Yeon; Ahn, Ju-Hyun; Cho, Min-Guk; Lee, Jae-Ho

    2018-04-27

    ATP depletion inhibits cell cycle progression, especially during the G1 phase and the G2 to M transition. However, the effect of ATP depletion on mitotic progression remains unclear. We observed that the reduction of ATP after prometaphase by simultaneous treatment with 2-deoxyglucose and NaN 3 did not arrest mitotic progression. Interestingly, ATP depletion during nocodazole-induced prometaphase arrest resulted in mitotic slippage, as indicated by a reduction in mitotic cells, APC/C-dependent degradation of cyclin B1, increased cell attachment, and increased nuclear membrane reassembly. Additionally, cells successfully progressed through the cell cycle after mitotic slippage, as indicated by EdU incorporation and time-lapse imaging. Although degradation of cyclin B during normal mitotic progression is primarily regulated by APC/C Cdc20 , we observed an unexpected decrease in Cdc20 prior to degradation of cyclin B during mitotic slippage. This decrease in Cdc20 was followed by a change in the binding partner preference of APC/C from Cdc20 to Cdh1; consequently, APC/C Cdh1 , but not APC/C Cdc20 , facilitated cyclin B degradation following ATP depletion. Pulse-chase analysis revealed that ATP depletion significantly abrogated global translation, including the translation of Cdc20 and Cdh1. Additionally, the half-life of Cdh1 was much longer than that of Cdc20. These data suggest that ATP depletion during mitotic arrest induces mitotic slippage facilitated by APC/C Cdh1 -dependent cyclin B degradation, which follows a decrease in Cdc20 resulting from reduced global translation and the differences in the half-lives of the Cdc20 and Cdh1 proteins.

  1. APC/C-Cdh1-dependent anaphase and telophase progression during mitotic slippage

    Toda Kazuhiro

    2012-02-01

    Full Text Available Abstract Background The spindle assembly checkpoint (SAC inhibits anaphase progression in the presence of insufficient kinetochore-microtubule attachments, but cells can eventually override mitotic arrest by a process known as mitotic slippage or adaptation. This is a problem for cancer chemotherapy using microtubule poisons. Results Here we describe mitotic slippage in yeast bub2Δ mutant cells that are defective in the repression of precocious telophase onset (mitotic exit. Precocious activation of anaphase promoting complex/cyclosome (APC/C-Cdh1 caused mitotic slippage in the presence of nocodazole, while the SAC was still active. APC/C-Cdh1, but not APC/C-Cdc20, triggered anaphase progression (securin degradation, separase-mediated cohesin cleavage, sister-chromatid separation and chromosome missegregation, in addition to telophase onset (mitotic exit, during mitotic slippage. This demonstrates that an inhibitory system not only of APC/C-Cdc20 but also of APC/C-Cdh1 is critical for accurate chromosome segregation in the presence of insufficient kinetochore-microtubule attachments. Conclusions The sequential activation of APC/C-Cdc20 to APC/C-Cdh1 during mitosis is central to accurate mitosis. Precocious activation of APC/C-Cdh1 in metaphase (pre-anaphase causes mitotic slippage in SAC-activated cells. For the prevention of mitotic slippage, concomitant inhibition of APC/C-Cdh1 may be effective for tumor therapy with mitotic spindle poisons in humans.

  2. The effects of 2,4-dichlorophenoxy acetic acid and isoproturon herbicides on the mitotic activity of wheat (Triticum aestivum L.) root tips

    KUMAR, Sanjay; *, -; ARYA, Shashi Kiran; ROY, Bijoy Krishna; SINGH, Atul Kumar

    2014-01-01

    The effects of the herbicides 2,4-dichlorophenoxy acetic acid and isoproturon on 3 wheat (Triticum aestivum L.) varieties (HUW 234, HUW 468, and HUW 533) were studied with regards to mitotic abnormalities and chromosomal behavior. Pre-soaked seeds were treated with both herbicides at concentrations of 50-1200 ppm. Both 2,4-D and isoproturon were highly mito-inhibitory and induced chromosomal abnormalities, such as precocious movement, stickiness, and chromosome bridges, with and without lagga...

  3. Micromechanics of human mitotic chromosomes

    Sun, Mingxuan; Kawamura, Ryo; Marko, John F

    2011-01-01

    Eukaryote cells dramatically reorganize their long chromosomal DNAs to facilitate their physical segregation during mitosis. The internal organization of folded mitotic chromosomes remains a basic mystery of cell biology; its understanding would likely shed light on how chromosomes are separated from one another as well as into chromosome structure between cell divisions. We report biophysical experiments on single mitotic chromosomes from human cells, where we combine micromanipulation, nano-Newton-scale force measurement and biochemical treatments to study chromosome connectivity and topology. Results are in accord with previous experiments on amphibian chromosomes and support the 'chromatin network' model of mitotic chromosome structure. Prospects for studies of chromosome-organizing proteins using siRNA expression knockdowns, as well as for differential studies of chromosomes with and without mutations associated with genetic diseases, are also discussed

  4. Increasing Youth Physical Activity with Activity Calendars

    Eckler, Seth

    2016-01-01

    Physical educators often struggle with ways to get their students to be active beyond the school day. One strategy to accomplish this is the use of physical activity calendars (PACs). The purpose of this article is to support the use of PACs and give practical advice for creating effective PACs.

  5. A deep learning based strategy for identifying and associating mitotic activity with gene expression derived risk categories in estrogen receptor positive breast cancers.

    Romo-Bucheli, David; Janowczyk, Andrew; Gilmore, Hannah; Romero, Eduardo; Madabhushi, Anant

    2017-06-01

    The treatment and management of early stage estrogen receptor positive (ER+) breast cancer is hindered by the difficulty in identifying patients who require adjuvant chemotherapy in contrast to those that will respond to hormonal therapy. To distinguish between the more and less aggressive breast tumors, which is a fundamental criterion for the selection of an appropriate treatment plan, Oncotype DX (ODX) and other gene expression tests are typically employed. While informative, these gene expression tests are expensive, tissue destructive, and require specialized facilities. Bloom-Richardson (BR) grade, the common scheme employed in breast cancer grading, has been shown to be correlated with the Oncotype DX risk score. Unfortunately, studies have also shown that the BR grade determined experiences notable inter-observer variability. One of the constituent categories in BR grading is the mitotic index. The goal of this study was to develop a deep learning (DL) classifier to identify mitotic figures from whole slides images of ER+ breast cancer, the hypothesis being that the number of mitoses identified by the DL classifier would correlate with the corresponding Oncotype DX risk categories. The mitosis detector yielded an average F-score of 0.556 in the AMIDA mitosis dataset using a 6-fold validation setup. For a cohort of 174 whole slide images with early stage ER+ breast cancer for which the corresponding Oncotype DX score was available, the distributions of the number of mitoses identified by the DL classifier was found to be significantly different between the high vs low Oncotype DX risk groups (P machine classifier trained to separate low/high Oncotype DX risk categories using the mitotic count determined by the DL classifier yielded a 83.19% classification accuracy. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

  6. Inhibition of mitotic-specific histone phophorylation by sodium arsenite

    Cobo, J.M. [Universidad de Alcala de Henares, Madrid (Spain); Valdez, J.G.; Gurley, L.R. [Los Alamos National Lab., NM (United States)

    1994-10-01

    Synchronized cultures of Chinese hamster cells (line CHO) were used to measure the effects of 10{mu}M sodium arsenite on histone phosphorylation. This treatment caused cell proliferation to be temporarily arrested, after which the cells spontaneously resumed cell proliferation in a radiomimetric manner. Immediately following treatment, it was found that sodium arsenite affected only mitotic-specific HI and H3 phosphorylations. Neither interphase, nor mitotic, H2A and H4 phosphorylations were affected, nor was interphase HI Phosphorylation affected. The phosphorylation of HI was inhibited only in mitosis, reducing HI phosphorylation to 38.1% of control levels, which was the level of interphase HI phosphorylation. The phosphorylation of both H3 variants was inhibited in mitosis, the less hydrophobic H3 to 19% and the more hydrophobic H3 to 24% of control levels. These results suggest that sodium arsenite may inhibite cell proliferation by interfering with the cyclin B/p34{sup cdc2} histone kinase activity which is thought to play a key role in regulating the cell cycle. It has been proposed by our laboratory that HI and H3 phosphorylations play a role in restructuring interphase chromatin into metaphase chromosomes. Interference of this process by sodium arsenite may lead to structurally damaged chromosomes resulting in the increased cancer risks known to be produced by arsenic exposure from the environment.

  7. Mcl-1 dynamics influence mitotic slippage and death in mitosis.

    Sloss, Olivia; Topham, Caroline; Diez, Maria; Taylor, Stephen

    2016-02-02

    Microtubule-binding drugs such as taxol are frontline treatments for a variety of cancers but exactly how they yield patient benefit is unclear. In cell culture, inhibiting microtubule dynamics prevents spindle assembly, leading to mitotic arrest followed by either apoptosis in mitosis or slippage, whereby a cell returns to interphase without dividing. Myeloid cell leukaemia-1 (Mcl-1), a pro-survival member of the Bcl-2 family central to the intrinsic apoptosis pathway, is degraded during a prolonged mitotic arrest and may therefore act as a mitotic death timer. Consistently, we show that blocking proteasome-mediated degradation inhibits taxol-induced mitotic apoptosis in a Mcl-1-dependent manner. However, this degradation does not require the activity of either APC/C-Cdc20, FBW7 or MULE, three separate E3 ubiquitin ligases implicated in targeting Mcl-1 for degradation. This therefore challenges the notion that Mcl-1 undergoes regulated degradation during mitosis. We also show that Mcl-1 is continuously synthesized during mitosis and that blocking protein synthesis accelerates taxol induced death-in-mitosis. Modulating Mcl-1 levels also influences slippage; overexpressing Mcl-1 extends the time from mitotic entry to mitotic exit in the presence of taxol, while inhibiting Mcl-1 accelerates it. We suggest that Mcl-1 competes with Cyclin B1 for binding to components of the proteolysis machinery, thereby slowing down the slow degradation of Cyclin B1 responsible for slippage. Thus, modulating Mcl-1 dynamics influences both death-in-mitosis and slippage. However, because mitotic degradation of Mcl-1 appears not to be under the control of an E3 ligase, we suggest that the notion of network crosstalk is used with caution.

  8. Airborne urban particles (Milan winter-PM2.5) cause mitotic arrest and cell death: Effects on DNA, mitochondria, AhR binding and spindle organization

    Gualtieri, Maurizio [Applied Cell Biology and Particles Effects, Department of Environmental Science, University Milano-Bicocca, Piazza della Scienza 1, 20126 Milano (Italy); Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo (Norway); Ovrevik, Johan [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo (Norway); Mollerup, Steen [Section for Toxicology, National Institute of Occupational Health, N-0033 Oslo (Norway); Asare, Nana [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo (Norway); Longhin, Eleonora [Applied Cell Biology and Particles Effects, Department of Environmental Science, University Milano-Bicocca, Piazza della Scienza 1, 20126 Milano (Italy); Dahlman, Hans-Jorgen [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo (Norway); Camatini, Marina [Applied Cell Biology and Particles Effects, Department of Environmental Science, University Milano-Bicocca, Piazza della Scienza 1, 20126 Milano (Italy); Centre Research POLARIS, Department of Environmental Science, University Milano-Bicocca, Piazza della Scienza 1, 20126 Milano (Italy); Holme, Jorn A., E-mail: jorn.holme@fhi.no [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo (Norway)

    2011-08-01

    Highlights: {yields} PM2.5 induces mitotic arrest in BEAS-2B cells. {yields} PM2.5 induces DNA damage and activates DNA damage response. {yields} AhR regulated genes (Cyp1A1, Cyp1B1 and AhRR) are upregulated after PM exposure. {yields} Mitotic spindle assembly is perturbed in PM exposed cells. - Abstract: Airborne particulate matter (PM) is considered to be an important contributor to lung diseases. In the present study we report that Milan winter-PM2.5 inhibited proliferation in human bronchial epithelial cells (BEAS-2B) by inducing mitotic arrest. The cell cycle arrest was followed by an increase in mitotic-apoptotic cells, mitotic slippage and finally an increase in 'classical' apoptotic cells. Exposure to winter-PM10 induced only a slight effect which may be due to the presence of PM2.5 in this fraction while pure combustion particles failed to disturb mitosis. Fewer cells expressing the mitosis marker phospho-histone H3 compared to cells with condensed chromosomes, suggest that PM2.5 induced premature mitosis. PM2.5 was internalized into the cells and often localized in laminar organelles, although particles without apparent plasma membrane covering were also seen. In PM-containing cells mitochondria and lysosomes were often damaged, and in mitotic cells fragmented chromosomes often appeared. PM2.5 induced DNA strands breaks and triggered a DNA-damage response characterized by increased phosphorylation of ATM, Chk2 and H2AX; as well as induced a marked increase in expression of the aryl hydrocarbon receptor (AhR)-regulated genes, CYP1A1, CYP1B1 and AhRR. Furthermore, some disturbance of the organization of microtubules was indicated. It is hypothesized that the induced mitotic arrest and following cell death was due to a premature chromosome condensation caused by a combination of DNA, mitochondrial and spindle damage.

  9. The NIMA Kinase Is Required To Execute Stage-Specific Mitotic Functions after Initiation of Mitosis

    Govindaraghavan, Meera; Lad, Alisha A.

    2014-01-01

    The G2-M transition in Aspergillus nidulans requires the NIMA kinase, the founding member of the Nek kinase family. Inactivation of NIMA results in a late G2 arrest, while overexpression of NIMA is sufficient to promote mitotic events independently of cell cycle phase. Endogenously tagged NIMA-GFP has dynamic mitotic localizations appearing first at the spindle pole body and then at nuclear pore complexes before transitioning to within nuclei and the mitotic spindle and back at the spindle pole bodies at mitotic exit, suggesting that it functions sequentially at these locations. Since NIMA is indispensable for mitotic entry, it has been difficult to determine the requirement of NIMA for subaspects of mitosis. We show here that when NIMA is partially inactivated, although mitosis can be initiated, a proportion of cells fail to successfully generate two daughter nuclei. We further define the mitotic defects to show that normal NIMA function is required for the formation of a bipolar spindle, nuclear pore complex disassembly, completion of chromatin segregation, and the normal structural rearrangements of the nuclear envelope required to generate two nuclei from one. In the remaining population of cells that enter mitosis with inadequate NIMA, two daughter nuclei are generated in a manner dependent on the spindle assembly checkpoint, indicating highly penetrant defects in mitotic progression without sufficient NIMA activity. This study shows that NIMA is required not only for mitotic entry but also sequentially for successful completion of stage-specific mitotic events. PMID:24186954

  10. Robust mitotic entry is ensured by a latching switch

    Chloe Tuck

    2013-07-01

    Cell cycle events are driven by Cyclin dependent kinases (CDKs and by their counter-acting phosphatases. Activation of the Cdk1:Cyclin B complex during mitotic entry is controlled by the Wee1/Myt1 inhibitory kinases and by Cdc25 activatory phosphatase, which are themselves regulated by Cdk1:Cyclin B within two positive circuits. Impairing these two feedbacks with chemical inhibitors induces a transient entry into M phase referred to as mitotic collapse. The pathology of mitotic collapse reveals that the positive circuits play a significant role in maintaining the M phase state. To better understand the function of these feedback loops during G2/M transition, we propose a simple model for mitotic entry in mammalian cells including spatial control over Greatwall kinase phosphorylation. After parameter calibration, the model is able to recapture the complex and non-intuitive molecular dynamics reported by Potapova et al. (Potapova et al., 2011. Moreover, it predicts the temporal patterns of other mitotic regulators which have not yet been experimentally tested and suggests a general design principle of cell cycle control: latching switches buffer the cellular stresses which accompany cell cycle processes to ensure that the transitions are smooth and robust.

  11. Robust mitotic entry is ensured by a latching switch.

    Tuck, Chloe; Zhang, Tongli; Potapova, Tamara; Malumbres, Marcos; Novák, Béla

    2013-01-01

    Cell cycle events are driven by Cyclin dependent kinases (CDKs) and by their counter-acting phosphatases. Activation of the Cdk1:Cyclin B complex during mitotic entry is controlled by the Wee1/Myt1 inhibitory kinases and by Cdc25 activatory phosphatase, which are themselves regulated by Cdk1:Cyclin B within two positive circuits. Impairing these two feedbacks with chemical inhibitors induces a transient entry into M phase referred to as mitotic collapse. The pathology of mitotic collapse reveals that the positive circuits play a significant role in maintaining the M phase state. To better understand the function of these feedback loops during G2/M transition, we propose a simple model for mitotic entry in mammalian cells including spatial control over Greatwall kinase phosphorylation. After parameter calibration, the model is able to recapture the complex and non-intuitive molecular dynamics reported by Potapova et al. (Potapova et al., 2011). Moreover, it predicts the temporal patterns of other mitotic regulators which have not yet been experimentally tested and suggests a general design principle of cell cycle control: latching switches buffer the cellular stresses which accompany cell cycle processes to ensure that the transitions are smooth and robust.

  12. Axin localizes to mitotic spindles and centrosomes in mitotic cells

    Kim, Shi-Mun; Choi, Eun-Jin; Song, Ki-Joon; Kim, Sewoon; Seo, Eunjeong; Jho, Eek-Hoon; Kee, Sun-Ho

    2009-01-01

    Wnt signaling plays critical roles in cell proliferation and carcinogenesis. In addition, numerous recent studies have shown that various Wnt signaling components are involved in mitosis and chromosomal instability. However, the role of Axin, a negative regulator of Wnt signaling, in mitosis has remained unclear. Using monoclonal antibodies against Axin, we found that Axin localizes to the centrosome and along mitotic spindles. This localization was suppressed by siRNA specific for Aurora A kinase and by Aurora kinase inhibitor. Interestingly, Axin over-expression altered the subcellular distribution of Plk1 and of phosphorylated glycogen synthase kinase (GSK3β) without producing any notable changes in cellular phenotype. In the presence of Aurora kinase inhibitor, Axin over-expression induced the formation of cleavage furrow-like structures and of prominent astral microtubules lacking midbody formation in a subset of cells. Our results suggest that Axin modulates distribution of Axin-associated proteins such as Plk1 and GSK3β in an expression level-dependent manner and these interactions affect the mitotic process, including cytokinesis under certain conditions, such as in the presence of Aurora kinase inhibitor

  13. Quantitative phosphoproteomics reveals new roles for the protein phosphatase PP6 in mitotic cells.

    Rusin, Scott F; Schlosser, Kate A; Adamo, Mark E; Kettenbach, Arminja N

    2015-10-13

    Protein phosphorylation is an important regulatory mechanism controlling mitotic progression. Protein phosphatase 6 (PP6) is an essential enzyme with conserved roles in chromosome segregation and spindle assembly from yeast to humans. We applied a baculovirus-mediated gene silencing approach to deplete HeLa cells of the catalytic subunit of PP6 (PP6c) and analyzed changes in the phosphoproteome and proteome in mitotic cells by quantitative mass spectrometry-based proteomics. We identified 408 phosphopeptides on 272 proteins that increased and 298 phosphopeptides on 220 proteins that decreased in phosphorylation upon PP6c depletion in mitotic cells. Motif analysis of the phosphorylated sites combined with bioinformatics pathway analysis revealed previously unknown PP6c-dependent regulatory pathways. Biochemical assays demonstrated that PP6c opposed casein kinase 2-dependent phosphorylation of the condensin I subunit NCAP-G, and cellular analysis showed that depletion of PP6c resulted in defects in chromosome condensation and segregation in anaphase, consistent with dysregulation of condensin I function in the absence of PP6 activity. Copyright © 2015, American Association for the Advancement of Science.

  14. Timely Endocytosis of Cytokinetic Enzymes Prevents Premature Spindle Breakage during Mitotic Exit.

    Cheen Fei Chin

    2016-07-01

    Full Text Available Cytokinesis requires the spatio-temporal coordination of membrane deposition and primary septum (PS formation at the division site to drive acto-myosin ring (AMR constriction. It has been demonstrated that AMR constriction invariably occurs only after the mitotic spindle disassembly. It has also been established that Chitin Synthase II (Chs2p neck localization precedes mitotic spindle disassembly during mitotic exit. As AMR constriction depends upon PS formation, the question arises as to how chitin deposition is regulated so as to prevent premature AMR constriction and mitotic spindle breakage. In this study, we propose that cells regulate the coordination between spindle disassembly and AMR constriction via timely endocytosis of cytokinetic enzymes, Chs2p, Chs3p, and Fks1p. Inhibition of endocytosis leads to over accumulation of cytokinetic enzymes during mitotic exit, which accelerates the constriction of the AMR, and causes spindle breakage that eventually could contribute to monopolar spindle formation in the subsequent round of cell division. Intriguingly, the mitotic spindle breakage observed in endocytosis mutants can be rescued either by deleting or inhibiting the activities of, CHS2, CHS3 and FKS1, which are involved in septum formation. The findings from our study highlight the importance of timely endocytosis of cytokinetic enzymes at the division site in safeguarding mitotic spindle integrity during mitotic exit.

  15. Smurf2 as a novel mitotic regulator: From the spindle assembly checkpoint to tumorigenesis

    Moore Finola E

    2009-07-01

    Full Text Available Abstract The execution of the mitotic program with high fidelity is dependent upon precise spatiotemporal regulation of posttranslational protein modifications. For example, the timely polyubiquitination of critical mitotic regulators by Anaphase Promoting Complex/Cyclosome (APC/C is essential for the metaphase to anaphase transition and mitotic exit. The spindle assembly checkpoint prevents unscheduled activity of APC/C-Cdc20 in early mitosis, allowing bipolar attachment of kinetochores to mitotic spindle and facilitating equal segregation of sister chromatids. The critical effector of the spindle checkpoint, Mitotic arrest deficient 2 (Mad2, is recruited to unattached kinetochores forming a complex with other regulatory proteins to efficiently and cooperatively inhibit APC/C-Cdc20. A weakened and/or dysfunctional spindle checkpoint has been linked to the development of genomic instability in both cell culture and animal models, and evidence suggests that aberrant regulation of the spindle checkpoint plays a critical role in human carcinogenesis. Recent studies have illuminated a network of both degradative and non-degradative ubiquitination events that regulate the metaphase to anaphase transition and mitotic exit. Within this context, our recent work showed that the HECT (Homologous to E6-AP C-terminus-family E3 ligase Smurf2 (Smad specific ubiquitin regulatory factor 2, known as a negative regulator of transforming growth factor-beta (TGF-β signaling, is required for a functional spindle checkpoint by promoting the functional localization and stability of Mad2. Here we discuss putative models explaining the role of Smurf2 as a new regulator in the spindle checkpoint. The dynamic mitotic localization of Smurf2 to the centrosome and other critical mitotic structures provides implications about mitotic checkpoint control dependent on various ubiquitination events. Finally, deregulated Smurf2 activity may contribute to carcinogenesis by

  16. Radiation-induced mitotic catastrophe in PARG-deficient cells

    Ame, J.Ch.; Fouquerel, E.; Dantzer, F.; De Murcia, G.; Schreiber, V. [IREBS-FRE3211 du CNRS, Universite de Strasbourg, ESBS, Bd Sebastien Brant, BP 10413, 67412 Illkirch Cedex (France); Gauthier, L.R.; Boussin, F.D. [Laboratoire de Radiopathologie/INSERM U967, CEA-DSV-IRCM, 92265 Fontenay aux Roses, Cedex 6 (France); Biard, D. [CEA-DSV-IRCM/INSERM U935, Institut A. Lwoff-CNRS, BP 8, 94801 Villejuif cedex (France)

    2009-07-01

    Poly(ADP-ribosyl)ation is a post-translational modification of proteins involved in the regulation of chromatin structure, DNA metabolism, cell division and cell death. Through the hydrolysis of poly(ADP-ribose) (PAR), Poly(ADP-ribose) glyco-hydrolase (PARG) has a crucial role in the control of life-and-death balance following DNA insult. Comprehension of PARG function has been hindered by the existence of many PARG isoforms encoded by a single gene and displaying various subcellular localizations. To gain insight into the function of PARG in response to irradiation, we constitutively and stably knocked down expression of PARG isoforms in HeLa cells. PARG depletion leading to PAR accumulation was not deleterious to undamaged cells and was in fact rather beneficial, because it protected cells from spontaneous single-strand breaks and telomeric abnormalities. By contrast, PARG-deficient cells showed increased radiosensitivity, caused by defects in the repair of single- and double-strand breaks and in mitotic spindle checkpoint, leading to alteration of progression of mitosis. Irradiated PARG-deficient cells displayed centrosome amplification leading to mitotic supernumerary spindle poles, and accumulated aberrant mitotic figures, which induced either polyploidy or cell death by mitotic catastrophe. Our results suggest that PARG could be a novel potential therapeutic target for radiotherapy. (authors)

  17. The fruits of Gleditsia sinensis Lam. inhibits adipogenesis through modulation of mitotic clonal expansion and STAT3 activation in 3T3-L1 cells.

    Lee, Ji-Hye; Go, Younghoon; Lee, Bonggi; Hwang, Youn-Hwan; Park, Kwang Il; Cho, Won-Kyung; Ma, Jin Yeul

    2018-08-10

    Gleditsia sinensis Lam. (G. sinensis) has been used in Oriental medicine for tumor, thrombosis, inflammation-related disease, and obesity. The pharmacological inhibitory effects of fruits of G. sinensis (GFE) on hyperlipidemia have been reported, but its inhibitory effects on adipogenesis and underlying mechanisms have not been elucidated. Herein we evaluated the anti-adipogenic effects of GFE and described the underlying mechanisms. The effects of ethanol extracts of GFE on adipocyte differentiation were examined in 3T3-L1 cells using biochemical and molecular analyses. During the differentiation of 3T3-L1 cells, GFE significantly reduced lipid accumulation and downregulated master adipogenic transcription factors, including CCAAT/enhancer-binding protein-α and peroxisome proliferator-activated receptor-γ, at mRNA and protein levels. These changes led to the suppression of several adipogenic-specific genes and proteins, including fatty acid synthase, sterol regulatory element-binding protein 1, stearoyl-CoA desaturase-1, and acetyl CoA carboxylase. However, the inhibitory effects of GFE on lipogenesis were only shown when GFE is treated in the early stage of adipogenesis within the first two days of differentiation. As a potential mechanism, during the early stages of differentiation, GFE inhibited cell proliferation by a decrease in the expression of DNA synthesis-related proteins and increased p27 expression and suppressed signal transducer and activator of transcription 3 (STAT3) activation induced in a differentiation medium. GFE inhibits lipogenesis by negative regulation of adipogenic transcription factors, which is associated with GFE-mediated cell cycle arrest and STAT3 inhibition. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Different test systems in Aspergillus nidulans for the evaluation of mitotic gene conversion, crossing-over and non-disjunction

    De Bertoldi, M.; Griselli, M.; Consiglio Nazionale delle Ricerche, Pisa; Barale, R.

    1980-01-01

    The wide variety of the genetic alterations produced by environmental mutagens has increased the necessity of using experimental microorganisms to reveal the induction of such genetic events with short-term tests. Aspergillus nidulans, because of its well-developed genetic system and the availability of morphological markers seay to score, can be profitably used in mutagen testing. The constitution of particular diploid strains of A. nidulans able to detect the induction of mitotic gene conversion, mitotic crossing-over and mitotic non-disjunction with selective procedures are described and validated with standard mutagens: methyl methanesulphonate and UV radiation (lacking a specific genetic activity), benomyl and p-fluorophenylalanine (with a specific genetic activity). The possibility of using mammalian metabolic activation of promutagens in A. nidulans in vitro was tested with cyclophosphamide, with positive results in all the tested genetic systems. A method that increases the sensitivity of conidia to mutagenic treatments is described; its application appeared to be particularly useful in experiments on crossing-over and non-disjunction. (orig.)

  19. Changes in Ect2 Localization Couple Actomyosin-Dependent Cell Shape Changes to Mitotic Progression

    Matthews, Helen K.; Delabre, Ulysse; Rohn, Jennifer L.; Guck, Jochen; Kunda, Patricia; Baum, Buzz

    2012-01-01

    Summary As they enter mitosis, animal cells undergo profound actin-dependent changes in shape to become round. Here we identify the Cdk1 substrate, Ect2, as a central regulator of mitotic rounding, thus uncovering a link between the cell-cycle machinery that drives mitotic entry and its accompanying actin remodeling. Ect2 is a RhoGEF that plays a well-established role in formation of the actomyosin contractile ring at mitotic exit, through the local activation of RhoA. We find that Ect2 first...

  20. The influence of serotonin on the mitotic rate in the colonic crypt epithelium and in colonic adenocarcinoma in rats.

    Tutton, P J; Barkla, D H

    1978-01-01

    1. The mitotic rate in the crypts of Lieberkühn of the descending colon and in dimethylhydrazine-induced adenocarcinomata of the descending colon of rat was measured using a stathmokinetic technique. 2. Intraperitoneal injection of a small dose (10 microgram/kg) of serotonin resulted in an increase in the tumour cell mitotic rate. 3. Blockade of serotonin receptors by 2-bromolysergic acid diethylamide and depletion of tissue serotonin levels following injection of DL-6-fluorotryptophan both result in a decrease in the tumour cell mitotic rate. 4. Treatment with serotonin, 2-bromolysergic acid diethylamide and DL-6-fluorotryptophan were all without effect on the colonic crypt cell mitotic rate.

  1. Barriers to increased market-oriented activity

    Bisp, Søren

    1999-01-01

    and related activities still seem to attract relatively few resources is not answered by supplying another checklist or package of facilitators. Based on published conceptual writings and empirical studies this article makes an account of what the intra-organizational barriers may be to increased market......Most research on market orientation has dealt with assessing how market orientation behaviour is related to business performance. This work has established an intense market-oriented activity as significantly and positively related to business performance under most circumstances. In a maturing......-oriented activity. A framework of six generic domains is suggested: Organizational structure, human resource management, market-oriented activity competence, psychological climate, managers' personality characteristics, and individually held beliefs. A model is suggested inter-relating the domains....

  2. Phosphorylation and disassembly of intermediate filaments in mitotic cells

    Chou, Yinghao; Rosevear, E.; Goldman, R.D.

    1989-01-01

    As baby hamster kidney (BHK-21) cells enter mitosis, networks of intermediate filaments (IFs) are transformed into cytoplasmic aggregates of protofilaments. Coincident with this morphological change, the phosphate content of vimentin increases from 0.3 mol of P i per mol of protein in interphase to 1.9 mol of P i per mol of protein in mitosis. A similar increase in phosphate content is observed with desmin, from 0.5 mol of P i per mol of protein to 1.5 mol of P i per mol of protein. Fractionation of mitotic cell lysates by hydroxylapatite column chromatography reveals the presence of two IF protein kinase activities, designated as IF protein kinase I and IF protein kinase II. Comparison of two-dimensional 32 P-labeled phosphopeptide maps of vimentin and desmin phosphorylated in vivo in mitosis, and in vitro using partially purified kinase fractions, reveals extensive similarity in the two sets of phosphorylation sites. Phosphorylation of in vitro polymerized IFs by IF protein kinase II induces complete disassembly as determined by negative-stain electron microscopy. The results support the idea that the disassembly of IFs in mitosis is regulated by the phosphorylation of its subunit proteins

  3. The CRO-1 gene of Saccharomyces cerevisiae controls mitotic crossing over, chromosomal stability and sporulation

    Esposito, M.S.; Maleas, D.T.; Bjornstad, K.A.; Holbrook, L.L.

    1987-01-01

    The properties of a novel temperature-sensitive recombination-defective mutant of Saccharomyces cerevisiae, cro1-1 is described. The cro1-1 mutant is the first instance of a rec mutation that reduces drastically the rates of spontaneous mitotic crossing-over events but not those of gene conversional events. The cro1-1 mutation thus provides evidence that mitotic crossing-over is dependent upon gene products that are not essential for gene conversional events. The cro1-1 mutation also results in enhanced mitotic-chromosomal instability and MATa/MATα cro1-1/cro1-1 mutants are sporulation deficient. These phenotypes indicate that the CRO1 gene modulates mitotic chromosomal integrity and is essential for normal meiosis. The cro1-1 mutant possesses Holliday junction resolvase activity, hence its recombinational defect does not involve failure to execute this putative final recombinational step. 7 refs., 1 fig., 5 tabs

  4. Clusters - Tourism Activity Increase Competitiveness Support

    Carmen IORDACHE

    2010-05-01

    Full Text Available Tourism represents one of those areas with the greatest potential of global expansion. Tourism development strategy in terms of maximizing its positive effects on regional economic increase and implicitly on the national one starts from the premise that in global economy value is created in regions which are defined as particular geographical entities, separated by geographical reasons and not as political-administrative structures, and economic increase is centrally cumulated and valued according to the economic policy and the national legal system.Regional economic system approach based on “cluster” concept is explained by the fact that the regional activities portfolio is based on an inter and intra-industry networking grouped by cluster, in which is created the value that increases as the activity results are leading to the final consumers.This type of communication aims to highlight the tourism role as a factor in regional development, the clustering process significance in obtaining some competitiveness advantages, clusters development in tourism beginnings, and also the identification methodology used to select one touristic area to create the cluster.

  5. Workplace pedometer interventions for increasing physical activity.

    Freak-Poli, Rosanne L A; Cumpston, Miranda; Peeters, Anna; Clemes, Stacy A

    2013-04-30

    The World Health Organization and the World Economic Forum have recommended further research to strengthen current knowledge of workplace health programmes, particularly on effectiveness and using simple instruments. A pedometer is one such simple instrument that can be incorporated in workplace interventions. To assess the effectiveness of pedometer interventions in the workplace for increasing physical activity and improving subsequent health outcomes. Electronic searches of the Cochrane Central Register of Controlled Trials (671 potential papers), MEDLINE (1001), Embase (965), CINAHL (1262), OSH UPDATE databases (75) and Web of Science (1154) from the earliest record to between 30th January and 6th February 2012 yielded 3248 unique records. Reference lists of articles yielded an additional 34 papers. Contact with individuals and organisations did not produce any further records. We included individual and cluster-randomised controlled trials of workplace health promotion interventions with a pedometer component in employed adults. The primary outcome was physical activity and was part of the eligibility criteria. We considered subsequent health outcomes, including adverse effects, as secondary outcomes. Two review authors undertook the screening of titles and abstracts and the full-text papers independently. Two review authors (RFP and MC) independently completed data extraction and risk of bias assessment. We contacted authors to obtain additional data and clarification. We found four relevant studies providing data for 1809 employees, 60% of whom were allocated to the intervention group. All studies assessed outcomes immediately after the intervention had finished and the intervention duration varied between three to six months. All studies had usual treatment control conditions; however one study's usual treatment was an alternative physical activity programme while the other three had minimally active controls. In general, there was high risk of bias mainly

  6. Spatial Reorganization of the Endoplasmic Reticulum during Mitosis Relies on Mitotic Kinase Cyclin A in the Early Drosophila Embryo

    Bergman, Zane J.; Mclaurin, Justin D.; Eritano, Anthony S.; Johnson, Brittany M.; Sims, Amanda Q.; Riggs, Blake

    2015-01-01

    Mitotic cyclin-dependent kinase with their cyclin partners (cyclin:Cdks) are the master regulators of cell cycle progression responsible for regulating a host of activities during mitosis. Nuclear mitotic events, including chromosome condensation and segregation have been directly linked to Cdk activity. However, the regulation and timing of cytoplasmic mitotic events by cyclin:Cdks is poorly understood. In order to examine these mitotic cytoplasmic events, we looked at the dramatic changes in the endoplasmic reticulum (ER) during mitosis in the early Drosophila embryo. The dynamic changes of the ER can be arrested in an interphase state by inhibition of either DNA or protein synthesis. Here we show that this block can be alleviated by micro-injection of Cyclin A (CycA) in which defined mitotic ER clusters gathered at the spindle poles. Conversely, micro-injection of Cyclin B (CycB) did not affect spatial reorganization of the ER, suggesting CycA possesses the ability to initiate mitotic ER events in the cytoplasm. Additionally, RNAi-mediated simultaneous inhibition of all 3 mitotic cyclins (A, B and B3) blocked spatial reorganization of the ER. Our results suggest that mitotic ER reorganization events rely on CycA and that control and timing of nuclear and cytoplasmic events during mitosis may be defined by release of CycA from the nucleus as a consequence of breakdown of the nuclear envelope. PMID:25689737

  7. Community wide interventions for increasing physical activity.

    Baker, Philip R A; Francis, Daniel P; Soares, Jesus; Weightman, Alison L; Foster, Charles

    2015-01-05

    Multi-strategic community wide interventions for physical activity are increasingly popular but their ability to achieve population level improvements is unknown. To evaluate the effects of community wide, multi-strategic interventions upon population levels of physical activity. We searched the Cochrane Public Health Group Segment of the Cochrane Register of Studies,The Cochrane Library, MEDLINE, MEDLINE in Process, EMBASE, CINAHL, LILACS, PsycINFO, ASSIA, the British Nursing Index, Chinese CNKI databases, EPPI Centre (DoPHER, TRoPHI), ERIC, HMIC, Sociological Abstracts, SPORT Discus, Transport Database and Web of Science (Science Citation Index, Social Sciences Citation Index, Conference Proceedings Citation Index). We also scanned websites of the EU Platform on Diet, Physical Activity and Health; Health-Evidence.org; the International Union for Health Promotion and Education; the NIHR Coordinating Centre for Health Technology (NCCHTA); the US Centre for Disease Control and Prevention (CDC) and NICE and SIGN guidelines. Reference lists of all relevant systematic reviews, guidelines and primary studies were searched and we contacted experts in the field. The searches were updated to 16 January 2014, unrestricted by language or publication status. Cluster randomised controlled trials, randomised controlled trials, quasi-experimental designs which used a control population for comparison, interrupted time-series studies, and prospective controlled cohort studies were included. Only studies with a minimum six-month follow up from the start of the intervention to measurement of outcomes were included. Community wide interventions had to comprise at least two broad strategies aimed at physical activity for the whole population. Studies which randomised individuals from the same community were excluded. At least two review authors independently extracted the data and assessed the risk of bias. Each study was assessed for the setting, the number of included components

  8. The reduction of radiation-induced mitotic delay by caffeine: a test of the cyclic AMP hypothesis

    Oleinick, N.L.; Brewer, E.N.; Rustad, R.C.

    1978-01-01

    A study has been made of the reduction in γ-radiation-induced mitotic delay by caffeine in the naturally-synchronous plasmodial slime mould. Physarum polycephalum during late G 2 and early prophase, and the results compared with those obtained with other compounds of similar structure and/or physiological function. The reduction of radiation-induced mitotic delay was related to increasing concentrations of caffeine over at least two orders of magnitude. Pre-irradiation treatment with caffeine had no detectable effect. Caffeine had to be present for most, if not all, of the post-irradiation pre-mitotic period. Other chemicals which are reported to inhibit cyclic AMP phosphodiesterase either reduce or increase radiation-induced mitotic delay. The results therefore indicate that the reduction of mitotic delay by caffeine is not a result of altered cyclic AMP levels. (UK)

  9. Precommitment low-level Neurog3 expression defines a long-lived mitotic endocrine-biased progenitor pool that drives production of endocrine-committed cells

    Bechard, Matthew E.; Bankaitis, Eric D.; Hipkens, Susan B.; Ustione, Alessandro; Piston, David W.; Yang, Yu-Ping; Magnuson, Mark A.; Wright, Christopher V.E.

    2016-01-01

    The current model for endocrine cell specification in the pancreas invokes high-level production of the transcription factor Neurogenin 3 (Neurog3) in Sox9+ bipotent epithelial cells as the trigger for endocrine commitment, cell cycle exit, and rapid delamination toward proto-islet clusters. This model posits a transient Neurog3 expression state and short epithelial residence period. We show, however, that a Neurog3TA.LO cell population, defined as Neurog3 transcriptionally active and Sox9+ and often containing nonimmunodetectable Neurog3 protein, has a relatively high mitotic index and prolonged epithelial residency. We propose that this endocrine-biased mitotic progenitor state is functionally separated from a pro-ductal pool and endows them with long-term capacity to make endocrine fate-directed progeny. A novel BAC transgenic Neurog3 reporter detected two types of mitotic behavior in Sox9+ Neurog3TA.LO progenitors, associated with progenitor pool maintenance or derivation of endocrine-committed Neurog3HI cells, respectively. Moreover, limiting Neurog3 expression dramatically increased the proportional representation of Sox9+ Neurog3TA.LO progenitors, with a doubling of its mitotic index relative to normal Neurog3 expression, suggesting that low Neurog3 expression is a defining feature of this cycling endocrine-biased state. We propose that Sox9+ Neurog3TA.LO endocrine-biased progenitors feed production of Neurog3HI endocrine-committed cells during pancreas organogenesis. PMID:27585590

  10. Exposure of Human Lung Cancer Cells to 8-Chloro-Adenosine Induces G2/M Arrest and Mitotic Catastrophe

    Hong-Yu Zhang

    2004-11-01

    Full Text Available 8-Chloro-adenosine (8-CI-Ado is a potent chemotherapeutic agent whose cytotoxicity in a variety of tumor cell lines has been widely investigated. However, the molecular mechanisms are uncertain. In this study, we found that exposure of human lung cancer cell lines A549 (p53-wt and H1299 (p53-depleted to 8-CI-Ado induced cell arrest in the G2/M phase, which was accompanied by accumulation of binucleated and polymorphonucleated cells resulting from aberrant mitosis and failed cytokinesis. Western blotting showed the loss of phosphorylated forms of Cdc2 and Cdc25C that allowed progression into mitosis. Furthermore, the increase in Ser10-phosphorylated histone H3-positive cells revealed by fluorescence-activated cell sorting suggested that the agent-targeted cells were able to exit the G2 phase and enter the M phase. Immunocytochemistry showed that microtubule and microfilament arrays were changed in exposed cells, indicating that the dynamic instability of microtubules and microfilaments was lost, which may correlate with mitotic dividing failure. Aberrant mitosis resulted in mitotic catastrophe followed by varying degrees of apoptosis, depending on the cell lines. Thus, 8-CI-Ado appears to exert its cytotoxicity toward cells in culture by inducing mitotic catastrophe.

  11. Co-delivery of paclitaxel and cetuximab by nanodiamond enhances mitotic catastrophe and tumor inhibition.

    Lin, Yu-Wei; Raj, Emmanuel Naveen; Liao, Wei-Siang; Lin, Johnson; Liu, Kuang-Kai; Chen, Ting-Hua; Cheng, Hsiao-Chun; Wang, Chi-Ching; Li, Lily Yi; Chen, Chinpiao; Chao, Jui-I

    2017-08-29

    The poor intracellular uptake and non-specific binding of anticancer drugs into cancer cells are the bottlenecks in cancer therapy. Nanocarrier platforms provide the opportunities to improve the drug efficacy. Here we show a carbon-based nanomaterial nanodiamond (ND) that carried paclitaxel (PTX), a microtubule inhibitor, and cetuximab (Cet), a specific monoclonal antibody against epidermal growth factor receptor (EGFR), inducing mitotic catastrophe and tumor inhibition in human colorectal cancer (CRC). ND-PTX blocked the mitotic progression, chromosomal separation, and induced apoptosis in the CRC cells; however, NDs did not induce these effects. Conjugation of ND-PTX with Cet (ND-PTX-Cet) was specifically binding to the EGFR-positive CRC cells and enhanced the mitotic catastrophe and apoptosis induction. Besides, ND-PTX-Cet markedly decreased tumor size in the xenograft EGFR-expressed human CRC tumors of nude mice. Moreover, ND-PTX-Cet induced the mitotic marker protein phospho-histone 3 (Ser10) and apoptotic protein active-caspase 3 for mitotic catastrophe and apoptosis. Taken together, this study demonstrated that the co-delivery of PTX and Cet by ND enhanced the effects of mitotic catastrophe and apoptosis in vitro and in vivo, which may be applied in the human CRC therapy.

  12. Community wide interventions for increasing physical activity.

    Baker, Philip Ra; Francis, Daniel P; Soares, Jesus; Weightman, Alison L; Foster, Charles

    2011-04-13

    Multi-strategic community wide interventions for physical activity are increasingly popular but their ability to achieve population level improvements is unknown. To evaluate the effects of community wide, multi-strategic interventions upon population levels of physical activity. We searched the Cochrane Public Health Group Specialised Register, The Cochrane Library, MEDLINE, MEDLINE in Process, EMBASE, CINAHL, LILACS, PsycINFO, ASSIA, The British Nursing Index, Chinese CNKI databases, EPPI Centre (DoPHER, TRoPHI), ERIC, HMIC, Sociological Abstracts, SPORTDiscus, Transport Database and Web of Science (Science Citation Index, Social Sciences Citation Index, Conference Proceedings Citation Index). We also scanned websites of the EU Platform on Diet, Physical Activity and Health; Health-Evidence.ca; the International Union for Health Promotion and Education; the NIHR Coordinating Centre for Health Technology (NCCHTA) and NICE and SIGN guidelines. Reference lists of all relevant systematic reviews, guidelines and primary studies were followed up. We contacted experts in the field from the National Obesity Observatory Oxford, Oxford University; Queensland Health, Queensland University of Technology, the University of Central Queensland; the University of Tennessee and Washington University; and handsearched six relevant journals. The searches were last updated to the end of November 2009 and were not restricted by language or publication status. Cluster randomised controlled trials, randomised controlled trials (RCT), quasi-experimental designs which used a control population for comparison, interrupted time-series (ITS) studies, and prospective controlled cohort studies (PCCS) were included. Only studies with a minimum six-month follow up from the start of the intervention to measurement of outcomes were included. Community wide interventions had to comprise at least two broad strategies aimed at physical activity for the whole population. Studies which randomised

  13. Increased separase activity and occurrence of centrosome aberrations concur with transformation of MDS.

    Ruppenthal, Sabrina; Kleiner, Helga; Nolte, Florian; Fabarius, Alice; Hofmann, Wolf-Karsten; Nowak, Daniel; Seifarth, Wolfgang

    2018-01-01

    ESPL1/separase, a cysteine endopeptidase, is a key player in centrosome duplication and mitotic sister chromatid separation. Aberrant expression and/or altered separase proteolytic activity are associated with centrosome amplification, aneuploidy, tumorigenesis and disease progression. Since centrosome alterations are a common and early detectable feature in patients with myelodysplastic syndrome (MDS) and cytogenetic aberrations play an important role in disease risk stratification, we examined separase activity on single cell level in 67 bone marrow samples obtained from patients with MDS, secondary acute myeloid leukemia (sAML), de novo acute myeloid leukemia (AML) and healthy controls by a flow cytometric separase activity assay. The separase activity distribution (SAD) value, a calculated measure for the occurrence of cells with prominent separase activity within the analyzed sample, was tested for correlation with the centrosome, karyotype and gene mutation status. We found higher SAD values in bone marrow cells of sAML patients than in corresponding cells of MDS patients. This concurred with an increased incidence of aberrant centrosome phenotypes in sAML vs. MDS samples. No correlation was found between SAD values and the karyotype/gene mutation status. During follow-up of four MDS patients we observed increasing SAD values after transformation to sAML, in two patients SAD values decreased during azacitidine therapy. Cell culture experiments employing MDS-L cells as an in vitro model of MDS revealed that treatment with rigosertib, a PLK1 inhibitor and therapeutic drug known to induce G2/M arrest, results in decreased SAD values. In conclusion, the appearance of cells with unusual high separase activity levels, as indicated by increased SAD values, concurs with the transformation of MDS to sAML and may reflect separase dysregulation potentially contributing to clonal evolution during MDS progression. Separase activity measurement may therefore be useful as a

  14. Mitotic Stress Is an Integral Part of the Oncogene-Induced Senescence Program that Promotes Multinucleation and Cell Cycle Arrest

    Dina Dikovskaya

    2015-09-01

    Full Text Available Oncogene-induced senescence (OIS is a tumor suppression mechanism that blocks cell proliferation in response to oncogenic signaling. OIS is frequently accompanied by multinucleation; however, the origin of this is unknown. Here, we show that multinucleate OIS cells originate mostly from failed mitosis. Prior to senescence, mutant H-RasV12 activation in primary human fibroblasts compromised mitosis, concordant with abnormal expression of mitotic genes functionally linked to the observed mitotic spindle and chromatin defects. Simultaneously, H-RasV12 activation enhanced survival of cells with damaged mitoses, culminating in extended mitotic arrest and aberrant exit from mitosis via mitotic slippage. ERK-dependent transcriptional upregulation of Mcl1 was, at least in part, responsible for enhanced survival and slippage of cells with mitotic defects. Importantly, mitotic slippage and oncogene signaling cooperatively induced senescence and key senescence effectors p21 and p16. In summary, activated Ras coordinately triggers mitotic disruption and enhanced cell survival to promote formation of multinucleate senescent cells.

  15. LOX is a novel mitotic spindle-associated protein essential for mitosis.

    Boufraqech, Myriem; Wei, Darmood; Weyemi, Urbain; Zhang, Lisa; Quezado, Martha; Kalab, Petr; Kebebew, Electron

    2016-05-17

    LOX regulates cancer progression in a variety of human malignancies. It is overexpressed in aggressive cancers and higher expression of LOX is associated with higher cancer mortality. Here, we report a new function of LOX in mitosis. We show that LOX co-localizes to mitotic spindles from metaphase to telophase, and p-H3(Ser10)-positive cells harbor strong LOX staining. Further, purification of mitotic spindles from synchronized cells show that LOX fails to bind to microtubules in the presence of nocodazole, whereas paclitaxel treated samples showed enrichment in LOX expression, suggesting that LOX binds to stabilized microtubules. LOX knockdown leads to G2/M phase arrest; reduced p-H3(Ser10), cyclin B1, CDK1, and Aurora B. Moreover, LOX knockdown significantly increased sensitivity of cancer cells to chemotherapeutic agents that target microtubules. Our findings suggest that LOX has a role in cancer cell mitosis and may be targeted to enhance the activity of microtubule inhibitors for cancer therapy.

  16. Effect of propolis on mitotic and cellular proliferation indices in human blood lymphocytes

    Montoro, A.; Almonacid, M.; Villaescusa, J. [Valencia Hospital Univ. la Fe, Servicio de Proteccion Radiologica (Spain); Barquinero, J. [Barcelona Univ. Autonom, Servicio de Dosimetria Biologica, Unidad de Antropologia, Dept. de Biologia Animal, Vegetal y Ecologia, barcelona (Spain); Barrios, L. [Barcelona Univ. Autonoma, Dept. de Biologia Celular y Fisiologia. Unidad de Biologia Celular (Spain); Verdu, G. [Valencia Univ. Politecnica, Dept. de Ingenieria Quimica y Nuclear (Spain); Perez, J. [Hospital la Fe, Seccion de Radiofisica, Servicio de Radioterapia, valencia (Spain)

    2006-07-01

    The study of the frequency of chromosomal aberrations per cell is the tool used in Biological dosimetry studies. Using dose-effect calibration curve obtained in our laboratory, we can evaluate the radioprotector effect of the EEP (ethanolic extract of propolis) in cultures in vitro. Propolis is the generic name for resinous substance collected by honeybees. The results showed a reduction in chromosomal aberrations's frequency of up to 50 %. The following study consisted of analyzing human peripheral blood lymphocytes exposed to 2 Gy {gamma} rays, in presence and absence of EEP, the change in the frequency of chromosome aberrations was analysed with biological dosimetry. The protection against the formation of dicentric and ring was dose-dependent, but there seemed to be a maximum protection, i.e. a further increase in the concentration of EEP does not show additional protection. This work studies the effect of the EEP of the cellular cycle using the mitotic and cellular proliferation index, as an alternative for the screening cytostatic activity. The results indicate that the lymphocytes which were cultures in presence of EEP exhibited a significant and dependent-concentration decrease in mitotic index and proliferation kinetics. The possible mechanisms involved in the radioprotective influence of EEP are discussed. (authors)

  17. Effect of propolis on mitotic and cellular proliferation indices in human blood lymphocytes

    Montoro, A.; Almonacid, M.; Villaescusa, J.; Barquinero, J.; Barrios, L.; Verdu, G.; Perez, J.

    2006-01-01

    The study of the frequency of chromosomal aberrations per cell is the tool used in Biological dosimetry studies. Using dose-effect calibration curve obtained in our laboratory, we can evaluate the radioprotector effect of the EEP (ethanolic extract of propolis) in cultures in vitro. Propolis is the generic name for resinous substance collected by honeybees. The results showed a reduction in chromosomal aberrations's frequency of up to 50 %. The following study consisted of analyzing human peripheral blood lymphocytes exposed to 2 Gy γ rays, in presence and absence of EEP, the change in the frequency of chromosome aberrations was analysed with biological dosimetry. The protection against the formation of dicentric and ring was dose-dependent, but there seemed to be a maximum protection, i.e. a further increase in the concentration of EEP does not show additional protection. This work studies the effect of the EEP of the cellular cycle using the mitotic and cellular proliferation index, as an alternative for the screening cytostatic activity. The results indicate that the lymphocytes which were cultures in presence of EEP exhibited a significant and dependent-concentration decrease in mitotic index and proliferation kinetics. The possible mechanisms involved in the radioprotective influence of EEP are discussed. (authors)

  18. Active Learning Increases Children's Physical Activity across Demographic Subgroups.

    Bartholomew, John B; Jowers, Esbelle M; Roberts, Gregory; Fall, Anna-Mária; Errisuriz, Vanessa L; Vaughn, Sharon

    2018-01-01

    Given the need to find more opportunities for physical activity within the elementary school day, this study was designed to asses the impact of I-CAN!, active lessons on: 1) student physical activity (PA) outcomes via accelerometry; and 2) socioeconomic status (SES), race, sex, body mass index (BMI), or fitness as moderators of this impact. Participants were 2,493 fourth grade students (45.9% male, 45.8% white, 21.7% low SES) from 28 central Texas elementary schools randomly assigned to intervention (n=19) or control (n=9). Multilevel regression models evaluated the effect of I-CAN! on PA and effect sizes were calculated. The moderating effects of SES, race, sex, BMI, and fitness were examined in separate models. Students in treatment schools took significantly more steps than those in control schools (β = 125.267, SE = 41.327, p = .002, d = .44). I-CAN! had a significant effect on MVPA with treatment schools realizing 80% (β = 0.796, SE =0.251, p = .001; d = .38) more MVPA than the control schools. There were no significant school-level differences on sedentary behavior (β = -0.177, SE = 0.824, p = .83). SES, race, sex, BMI, and fitness level did not moderate the impact of active learning on step count and MVPA. Active learning increases PA within elementary students, and does so consistently across demographic sub-groups. This is important as these sub-groups represent harder to reach populations for PA interventions. While these lessons may not be enough to help children reach daily recommendations of PA, they can supplement other opportunities for PA. This speaks to the potential of schools to adopt policy change to require active learning.

  19. Evidence of Selection against Complex Mitotic-Origin Aneuploidy during Preimplantation Development

    McCoy, Rajiv C.; Demko, Zachary P.; Ryan, Allison; Banjevic, Milena; Hill, Matthew; Sigurjonsson, Styrmir; Rabinowitz, Matthew; Petrov, Dmitri A.

    2015-01-01

    Whole-chromosome imbalances affect over half of early human embryos and are the leading cause of pregnancy loss. While these errors frequently arise in oocyte meiosis, many such whole-chromosome abnormalities affecting cleavage-stage embryos are the result of chromosome missegregation occurring during the initial mitotic cell divisions. The first wave of zygotic genome activation at the 4–8 cell stage results in the arrest of a large proportion of embryos, the vast majority of which contain whole-chromosome abnormalities. Thus, the full spectrum of meiotic and mitotic errors can only be detected by sampling after the initial cell divisions, but prior to this selective filter. Here, we apply 24-chromosome preimplantation genetic screening (PGS) to 28,052 single-cell day-3 blastomere biopsies and 18,387 multi-cell day-5 trophectoderm biopsies from 6,366 in vitro fertilization (IVF) cycles. We precisely characterize the rates and patterns of whole-chromosome abnormalities at each developmental stage and distinguish errors of meiotic and mitotic origin without embryo disaggregation, based on informative chromosomal signatures. We show that mitotic errors frequently involve multiple chromosome losses that are not biased toward maternal or paternal homologs. This outcome is characteristic of spindle abnormalities and chaotic cell division detected in previous studies. In contrast to meiotic errors, our data also show that mitotic errors are not significantly associated with maternal age. PGS patients referred due to previous IVF failure had elevated rates of mitotic error, while patients referred due to recurrent pregnancy loss had elevated rates of meiotic error, controlling for maternal age. These results support the conclusion that mitotic error is the predominant mechanism contributing to pregnancy losses occurring prior to blastocyst formation. This high-resolution view of the full spectrum of whole-chromosome abnormalities affecting early embryos provides insight

  20. Evidence of Selection against Complex Mitotic-Origin Aneuploidy during Preimplantation Development.

    Rajiv C McCoy

    2015-10-01

    Full Text Available Whole-chromosome imbalances affect over half of early human embryos and are the leading cause of pregnancy loss. While these errors frequently arise in oocyte meiosis, many such whole-chromosome abnormalities affecting cleavage-stage embryos are the result of chromosome missegregation occurring during the initial mitotic cell divisions. The first wave of zygotic genome activation at the 4-8 cell stage results in the arrest of a large proportion of embryos, the vast majority of which contain whole-chromosome abnormalities. Thus, the full spectrum of meiotic and mitotic errors can only be detected by sampling after the initial cell divisions, but prior to this selective filter. Here, we apply 24-chromosome preimplantation genetic screening (PGS to 28,052 single-cell day-3 blastomere biopsies and 18,387 multi-cell day-5 trophectoderm biopsies from 6,366 in vitro fertilization (IVF cycles. We precisely characterize the rates and patterns of whole-chromosome abnormalities at each developmental stage and distinguish errors of meiotic and mitotic origin without embryo disaggregation, based on informative chromosomal signatures. We show that mitotic errors frequently involve multiple chromosome losses that are not biased toward maternal or paternal homologs. This outcome is characteristic of spindle abnormalities and chaotic cell division detected in previous studies. In contrast to meiotic errors, our data also show that mitotic errors are not significantly associated with maternal age. PGS patients referred due to previous IVF failure had elevated rates of mitotic error, while patients referred due to recurrent pregnancy loss had elevated rates of meiotic error, controlling for maternal age. These results support the conclusion that mitotic error is the predominant mechanism contributing to pregnancy losses occurring prior to blastocyst formation. This high-resolution view of the full spectrum of whole-chromosome abnormalities affecting early embryos

  1. Dietary flavonoid fisetin induces a forced exit from mitosis by targeting the mitotic spindle checkpoint

    Salmela, Anna-Leena; Pouwels, Jeroen; Varis, Asta; Kukkonen, Anu M.; Toivonen, Pauliina; Halonen, Pasi K.; Perälä, Merja; Kallioniemi, Olli; Gorbsky, Gary J.; Kallio, Marko J.

    2009-01-01

    Fisetin is a natural flavonol present in edible vegetables, fruits and wine at 2–160 μg/g concentrations and an ingredient in nutritional supplements with much higher concentrations. The compound has been reported to exert anticarcinogenic effects as well as antioxidant and anti-inflammatory activity via its ability to act as an inhibitor of cell proliferation and free radical scavenger, respectively. Our cell-based high-throughput screen for small molecules that override chemically induced mitotic arrest identified fisetin as an antimitotic compound. Fisetin rapidly compromised microtubule drug-induced mitotic block in a proteasome-dependent manner in several human cell lines. Moreover, in unperturbed human cancer cells fisetin caused premature initiation of chromosome segregation and exit from mitosis without normal cytokinesis. To understand the molecular mechanism behind these mitotic errors, we analyzed the consequences of fisetin treatment on the localization and phoshorylation of several mitotic proteins. Aurora B, Bub1, BubR1 and Cenp-F rapidly lost their kinetochore/centromere localization and others became dephosphorylated upon addition of fisetin to the culture medium. Finally, we identified Aurora B kinase as a novel direct target of fisetin. The activity of Aurora B was significantly reduced by fisetin in vitro and in cells, an effect that can explain the observed forced mitotic exit, failure of cytokinesis and decreased cell viability. In conclusion, our data propose that fisetin perturbs spindle checkpoint signaling, which may contribute to the antiproliferative effects of the compound. PMID:19395653

  2. Measuring mitotic spindle dynamics in budding yeast

    Plumb, Kemp

    In order to carry out its life cycle and produce viable progeny through cell division, a cell must successfully coordinate and execute a number of complex processes with high fidelity, in an environment dominated by thermal noise. One important example of such a process is the assembly and positioning of the mitotic spindle prior to chromosome segregation. The mitotic spindle is a modular structure composed of two spindle pole bodies, separated in space and spanned by filamentous proteins called microtubules, along which the genetic material of the cell is held. The spindle is responsible for alignment and subsequent segregation of chromosomes into two equal parts; proper spindle positioning and timing ensure that genetic material is appropriately divided amongst mother and daughter cells. In this thesis, I describe fluorescence confocal microscopy and automated image analysis algorithms, which I have used to observe and analyze the real space dynamics of the mitotic spindle in budding yeast. The software can locate structures in three spatial dimensions and track their movement in time. By selecting fluorescent proteins which specifically label the spindle poles and cell periphery, mitotic spindle dynamics have been measured in a coordinate system relevant to the cell division. I describe how I have characterised the accuracy and precision of the algorithms by simulating fluorescence data for both spindle poles and the budding yeast cell surface. In this thesis I also describe the construction of a microfluidic apparatus that allows for the measurement of long time-scale dynamics of individual cells and the development of a cell population. The tools developed in this thesis work will facilitate in-depth quantitative analysis of the non-equilibrium processes in living cells.

  3. Mitotic recombination induced by chemical and physical agents in the yeast Saccharomyces cerevisiae

    Davies, P.J.; Evans, W.E.; Parry, J.M.

    1975-01-01

    The treatment of diploid cultures of yeast with ultraviolet light (uv), γ-rays, nitrous acid (na) and ethyl methane sulphonate (ems) results in increases in cell death, mitotic gene conversion and crossing-over. Acridine orange (ao) treatment, in contrast, was effective only in increasing the frequency of gene conversion. The individual mutagens were effective in the order uv>na>γ-rays>ao>ems. Prior treatment of yeast cultures in starvation medium produced a significant reduction in the yield of induced gene conversion. The results have been interpreted on the basis of a general model of mitotic gene conversion which involves the post-replication repair of induced lesions involving de novo DNA synthesis without genetic exchange. In contrast mitotic crossing-over appears to involve the action of a repair system independent from excision or post-replication repair which involves genetic exchange between homologous chromosomes

  4. Fire activity increasing as climate changes

    Balcerak, Ernie; Showstack, Randy

    2013-01-01

    Analysis of images from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) satellites shows that more than 2.5 million hectares were burned in 2012 from January through August in the United States. The amount is less than a record 3.2 million hectares in 2011 but greater than the area burned in 12 of 15 years since satellite monitoring began, scientists reported at the AGU Fall Meeting. With satellites "we can detect fires as they're actively burning," said Louis Giglio of the University of Maryland, College Park, at a press conference on 4 December. "We can also map the cumulative area burned on the landscape after the fire's over." He noted that "2012 has been a particularly big fire year" in the United States.

  5. Semaphorin-Plexin Signaling Controls Mitotic Spindle Orientation during Epithelial Morphogenesis and Repair

    Xia, Jingjing; Swiercz, Jakub M.; Bañón-Rodríguez, Inmaculada

    2015-01-01

    Morphogenesis, homeostasis, and regeneration of epithelial tissues rely on the accurate orientation of cell divisions, which is specified by the mitotic spindle axis. To remain in the epithelial plane, symmetrically dividing epithelial cells align their mitotic spindle axis with the plane. Here, we...... show that this alignment depends on epithelial cell-cell communication via semaphorin-plexin signaling. During kidney morphogenesis and repair, renal tubular epithelial cells lacking the transmembrane receptor Plexin-B2 or its semaphorin ligands fail to correctly orient the mitotic spindle, leading...... to severe defects in epithelial architecture and function. Analyses of a series of transgenic and knockout mice indicate that Plexin-B2 controls the cell division axis by signaling through its GTPase-activating protein (GAP) domain and Cdc42. Our data uncover semaphorin-plexin signaling as a central...

  6. Parameters of mitotic recombination in minute mutants of Drosophila melanogaster

    Ferrus, A.

    1975-01-01

    A sample of 16 Minutes, representing 12 loci distributed over all the chromosome arms and including 3 pairs of alleles and 4 deficiencies, has been studied with respect to several developmental and recombinational parameters. Cell marker mutants located in most of the chromosome arms were used to assess (1) spontaneous and x-ray-induced mitotic recombination frequencies of each Minute, and (2) clone sizes of the different cell marker clones. These parameters were analyzed both in the wing disc and in the abdominal histoblasts. Whereas spontaneous frequencies are not affected by the presence of the Minutes studied, the different Minutes characteristically increase the frequency of recombination clones arising after x irradiation. The recombinant clones which are M + /M + are significantly larger than clones in the same fly which retain the M + /M condition. This is particularly striking in clones in the wing disc, slightly so in clones in the tergites. The occurrence of mitotic recombination in the fourth chromosome is reported for the first time. Chaeta length and developmental delay correlates with the recombinational parameters in different ways. Possible causal interrelationships of the different traits of the Minute syndrome are discussed. (U.S.)

  7. Mediator can regulate mitotic entry and direct periodic transcription in fission yeast.

    Banyai, Gabor; Lopez, Marcela Davila; Szilagyi, Zsolt; Gustafsson, Claes M

    2014-11-01

    Cdk8 is required for correct timing of mitotic progression in fission yeast. How the activity of Cdk8 is regulated is unclear, since the kinase is not activated by T-loop phosphorylation and its partner, CycC, does not oscillate. Cdk8 is, however, a component of the multiprotein Mediator complex, a conserved coregulator of eukaryotic transcription that is connected to a number of intracellular signaling pathways. We demonstrate here that other Mediator components regulate the activity of Cdk8 in vivo and thereby direct the timing of mitotic entry. Deletion of Mediator components Med12 and Med13 leads to higher cellular Cdk8 protein levels, premature phosphorylation of the Cdk8 target Fkh2, and earlier entry into mitosis. We also demonstrate that Mediator is recruited to clusters of mitotic genes in a periodic fashion and that the complex is required for the transcription of these genes. We suggest that Mediator functions as a hub for coordinated regulation of mitotic progression and cell cycle-dependent transcription. The many signaling pathways and activator proteins shown to function via Mediator may influence the timing of these cell cycle events. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  8. ATYPICAL MITOTIC FIGURES AND THE MITOTIC INDEX IN CERVICAL INTRAEPITHELIAL NEOPLASIA

    VANLEEUWEN, AM; PIETERS, WJLM; HOLLEMA, H; BURGER, MPM

    1995-01-01

    We surveyed cervical intraepithelial neoplasia (CIN) to quantify the proliferation rate and the presence of normal and atypical mitotic figures. In the cervical tissue specimens of 127 women with CIN, the area with the highest cell proliferation was identified and, at that site, the proliferation

  9. The SUMO protease SENP1 is required for cohesion maintenance and mitotic arrest following spindle poison treatment

    Era, Saho [Fondazione IFOM, Istituto FIRC di Oncologia Molecolare, IFOM-IEO campus, Via Adamello 16, 20139 Milan (Italy); Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshida-Konoe, Sakyo-ku, Kyoto 606-8501 (Japan); Abe, Takuya; Arakawa, Hiroshi [Fondazione IFOM, Istituto FIRC di Oncologia Molecolare, IFOM-IEO campus, Via Adamello 16, 20139 Milan (Italy); Kobayashi, Shunsuke [Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshida-Konoe, Sakyo-ku, Kyoto 606-8501 (Japan); Szakal, Barnabas [Fondazione IFOM, Istituto FIRC di Oncologia Molecolare, IFOM-IEO campus, Via Adamello 16, 20139 Milan (Italy); Yoshikawa, Yusuke; Motegi, Akira; Takeda, Shunichi [Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshida-Konoe, Sakyo-ku, Kyoto 606-8501 (Japan); Branzei, Dana, E-mail: dana.branzei@ifom.eu [Fondazione IFOM, Istituto FIRC di Oncologia Molecolare, IFOM-IEO campus, Via Adamello 16, 20139 Milan (Italy)

    2012-09-28

    Highlights: Black-Right-Pointing-Pointer SENP1 knockout chicken DT40 cells are hypersensitive to spindle poisons. Black-Right-Pointing-Pointer Spindle poison treatment of SENP1{sup -/-} cells leads to increased mitotic slippage. Black-Right-Pointing-Pointer Mitotic slippage in SENP1{sup -/-} cells associates with apoptosis and endoreplication. Black-Right-Pointing-Pointer SENP1 counteracts sister chromatid separation during mitotic arrest. Black-Right-Pointing-Pointer Plk1-mediated cohesion down-regulation is involved in colcemid cytotoxicity. -- Abstract: SUMO conjugation is a reversible posttranslational modification that regulates protein function. SENP1 is one of the six SUMO-specific proteases present in vertebrate cells and its altered expression is observed in several carcinomas. To characterize SENP1 role in genome integrity, we generated Senp1 knockout chicken DT40 cells. SENP1{sup -/-} cells show normal proliferation, but are sensitive to spindle poisons. This hypersensitivity correlates with increased sister chromatid separation, mitotic slippage, and apoptosis. To test whether the cohesion defect had a causal relationship with the observed mitotic events, we restored the cohesive status of sister chromatids by introducing the TOP2{alpha}{sup +/-} mutation, which leads to increased catenation, or by inhibiting Plk1 and Aurora B kinases that promote cohesin release from chromosomes during prolonged mitotic arrest. Although TOP2{alpha} is SUMOylated during mitosis, the TOP2{alpha}{sup +/-} mutation had no obvious effect. By contrast, inhibition of Plk1 or Aurora B rescued the hypersensitivity of SENP1{sup -/-} cells to colcemid. In conclusion, we identify SENP1 as a novel factor required for mitotic arrest and cohesion maintenance during prolonged mitotic arrest induced by spindle poisons.

  10. DNA double-strand breaks and Aurora B mislocalization induced by exposure of early mitotic cells to H2O2 appear to increase chromatin bridges and resultant cytokinesis failure.

    Cho, Min-Guk; Ahn, Ju-Hyun; Choi, Hee-Song; Lee, Jae-Ho

    2017-07-01

    Aneuploidy, an abnormal number of chromosomes that is a hallmark of cancer cells, can arise from tetraploid/binucleated cells through a failure of cytokinesis. Reactive oxygen species (ROS) have been implicated in various diseases, including cancer. However, the nature and role of ROS in cytokinesis progression and related mechanisms has not been clearly elucidated. Here, using time-lapse analysis of asynchronously growing cells and immunocytochemical analyses of synchronized cells, we found that hydrogen peroxide (H 2 O 2 ) treatment at early mitosis (primarily prometaphase) significantly induced cytokinesis failure. Cytokinesis failure and the resultant formation of binucleated cells containing nucleoplasmic bridges (NPBs) seemed to be caused by increases in DNA double-strand breaks (DSBs) and subsequent unresolved chromatin bridges. We further found that H 2 O 2 induced mislocalization of Aurora B during mitosis. All of these effects were attenuated by pretreatment with N-acetyl-L-cysteine (NAC) or overexpression of Catalase. Surprisingly, the PARP inhibitor PJ34 also reduced H 2 O 2 -induced Aurora B mislocalization and binucleated cell formation. Results of parallel experiments with etoposide, a topoisomerase IIα inhibitor that triggers DNA DSBs, suggested that both DNA DSBs and Aurora B mislocalization contribute to chromatin bridge formation. Aurora B mislocalization also appeared to weaken the "abscission checkpoint". Finally, we showed that KRAS-induced binucleated cell formation appeared to be also H 2 O 2 -dependent. In conclusion, we propose that a ROS, mainly H 2 O 2 increases binucleation through unresolved chromatin bridges caused by DNA damage and mislocalization of Aurora B, the latter of which appears to augment the effect of DNA damage on chromatin bridge formation. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. INFLUENCE OF SUMIDAN ON MITOTIC DIVISION IN TRIGONELLA FOENUM GRAECUM L. SPECIES

    Florina Mihaela Axente

    2006-08-01

    Full Text Available : This paper includes the cytogenetic effects induced by sumidan insectofungicide in meristematic cells of Trigonella foenum graecum L. root tips. The increase of pesticide concentration determined the decrease of mitotic index, while the frequency and the type of chromosome aberrations are much greater in treated variants, comparatively with control.

  12. Involvement of CNOT3 in mitotic progression through inhibition of MAD1 expression

    Takahashi, Akinori [Division of Oncology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639 (Japan); Kikuguchi, Chisato [Cell Signal Unit, Okinawa Institute of Science and Technology, Kunigami, Okinawa 904-0412 (Japan); Morita, Masahiro; Shimodaira, Tetsuhiro; Tokai-Nishizumi, Noriko; Yokoyama, Kazumasa; Ohsugi, Miho; Suzuki, Toru [Division of Oncology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639 (Japan); Yamamoto, Tadashi, E-mail: tyamamot@ims.u-tokyo.ac.jp [Division of Oncology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639 (Japan); Cell Signal Unit, Okinawa Institute of Science and Technology, Kunigami, Okinawa 904-0412 (Japan)

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer CNOT3 depletion increases the mitotic index. Black-Right-Pointing-Pointer CNOT3 inhibits the expression of MAD1. Black-Right-Pointing-Pointer CNOT3 destabilizes the MAD1 mRNA. Black-Right-Pointing-Pointer MAD1 knockdown attenuates the CNOT3 depletion-induced mitotic arrest. -- Abstract: The stability of mRNA influences the dynamics of gene expression. The CCR4-NOT complex, the major deadenylase in mammalian cells, shortens the mRNA poly(A) tail and contributes to the destabilization of mRNAs. The CCR4-NOT complex plays pivotal roles in various physiological functions, including cell proliferation, apoptosis, and metabolism. Here, we show that CNOT3, a subunit of the CCR4-NOT complex, is involved in the regulation of the spindle assembly checkpoint, suggesting that the CCR4-NOT complex also plays a part in the regulation of mitosis. CNOT3 depletion increases the population of mitotic-arrested cells and specifically increases the expression of MAD1 mRNA and its protein product that plays a part in the spindle assembly checkpoint. We showed that CNOT3 depletion stabilizes the MAD1 mRNA, and that MAD1 knockdown attenuates the CNOT3 depletion-induced increase of the mitotic index. Basing on these observations, we propose that CNOT3 is involved in the regulation of the spindle assembly checkpoint through its ability to regulate the stability of MAD1 mRNA.

  13. Involvement of CNOT3 in mitotic progression through inhibition of MAD1 expression

    Takahashi, Akinori; Kikuguchi, Chisato; Morita, Masahiro; Shimodaira, Tetsuhiro; Tokai-Nishizumi, Noriko; Yokoyama, Kazumasa; Ohsugi, Miho; Suzuki, Toru; Yamamoto, Tadashi

    2012-01-01

    Highlights: ► CNOT3 depletion increases the mitotic index. ► CNOT3 inhibits the expression of MAD1. ► CNOT3 destabilizes the MAD1 mRNA. ► MAD1 knockdown attenuates the CNOT3 depletion-induced mitotic arrest. -- Abstract: The stability of mRNA influences the dynamics of gene expression. The CCR4–NOT complex, the major deadenylase in mammalian cells, shortens the mRNA poly(A) tail and contributes to the destabilization of mRNAs. The CCR4–NOT complex plays pivotal roles in various physiological functions, including cell proliferation, apoptosis, and metabolism. Here, we show that CNOT3, a subunit of the CCR4–NOT complex, is involved in the regulation of the spindle assembly checkpoint, suggesting that the CCR4–NOT complex also plays a part in the regulation of mitosis. CNOT3 depletion increases the population of mitotic-arrested cells and specifically increases the expression of MAD1 mRNA and its protein product that plays a part in the spindle assembly checkpoint. We showed that CNOT3 depletion stabilizes the MAD1 mRNA, and that MAD1 knockdown attenuates the CNOT3 depletion-induced increase of the mitotic index. Basing on these observations, we propose that CNOT3 is involved in the regulation of the spindle assembly checkpoint through its ability to regulate the stability of MAD1 mRNA.

  14. Revertant mosaicism in epidermolysis bullosa caused by mitotic gene conversion

    Jonkman, MF; Scheffer, H; Stulp, R; Pas, HH; Nijenhuis, Albertine; Heeres, K; Owaribe, K; Pulkkinen, L; Uitto, J

    1997-01-01

    Mitotic gene conversion acting as reverse mutation has not been previously demonstrated in human. We report here that the revertant mosaicism of a compound heterozygous proband with an autosomal recessive genodermatosis, generalized atrophic benign epidermolysis bullosa, is caused by mitotic gene

  15. Mitotic spindle proteomics in Chinese hamster ovary cells.

    Mary Kate Bonner

    Full Text Available Mitosis is a fundamental process in the development of all organisms. The mitotic spindle guides the cell through mitosis as it mediates the segregation of chromosomes, the orientation of the cleavage furrow, and the progression of cell division. Birth defects and tissue-specific cancers often result from abnormalities in mitotic events. Here, we report a proteomic study of the mitotic spindle from Chinese Hamster Ovary (CHO cells. Four different isolations of metaphase spindles were subjected to Multi-dimensional Protein Identification Technology (MudPIT analysis and tandem mass spectrometry. We identified 1155 proteins and used Gene Ontology (GO analysis to categorize proteins into cellular component groups. We then compared our data to the previously published CHO midbody proteome and identified proteins that are unique to the CHO spindle. Our data represent the first mitotic spindle proteome in CHO cells, which augments the list of mitotic spindle components from mammalian cells.

  16. Deficiency of RITA results in multiple mitotic defects by affecting microtubule dynamics.

    Steinhäuser, K; Klöble, P; Kreis, N-N; Ritter, A; Friemel, A; Roth, S; Reichel, J M; Michaelis, J; Rieger, M A; Louwen, F; Oswald, F; Yuan, J

    2017-04-01

    Deregulation of mitotic microtubule (MT) dynamics results in defective spindle assembly and chromosome missegregation, leading further to chromosome instability, a hallmark of tumor cells. RBP-J interacting and tubulin-associated protein (RITA) has been identified as a negative regulator of the Notch signaling pathway. Intriguingly, deregulated RITA is involved in primary hepatocellular carcinoma and other malignant entities. We were interested in the potential molecular mechanisms behind its involvement. We show here that RITA binds to tubulin and localizes to various mitotic MT structures. RITA coats MTs and affects their structures in vitro as well as in vivo. Tumor cell lines deficient of RITA display increased acetylated α-tubulin, enhanced MT stability and reduced MT dynamics, accompanied by multiple mitotic defects, including chromosome misalignment and segregation errors. Re-expression of wild-type RITA, but not RITA Δtub ineffectively binding to tubulin, restores the phenotypes, suggesting that the role of RITA in MT modulation is mediated via its interaction with tubulin. Mechanistically, RITA interacts with tubulin/histone deacetylase 6 (HDAC6) and its suppression decreases the binding of the deacetylase HDAC6 to tubulin/MTs. Furthermore, the mitotic defects and increased MT stability are also observed in RITA -/- mouse embryonic fibroblasts. RITA has thus a novel role in modulating MT dynamics and its deregulation results in erroneous chromosome segregation, one of the major reasons for chromosome instability in tumor cells.

  17. Influence of the circadian rhythm in cell division on radiation-induced mitotic delay in vivo

    Rubin, N.A.

    1980-01-01

    All mitotically active normal tissues in mammals investigated to date demonstrate a circadian rhythm in cell division. The murine corneal epithelium is a practical and advantageous tissue model for studying this phenomenon. In animals synchronized to a light-dark (LD) schedule, one sees predictably reproducible occurrences of peaks and troughs in the mitotic index (MI) within each 24-hour (h) period. One of the harmful effects of ionizing radiation on dividing cells is mitotic delay, reported to be a G 2 block in cells approaching mitosis. Affected cells are not killed but are inhibited from entering mitosis and are delayed for a span of time reported to be dose and cell cycle dependent. In the classical description of mitotic delay, MI of irradiated cells begins to drop in relation to the control, which is plotted as a straight line, uniform throughout the experiment. After the damage is repaired, delayed cells can enter mitosis along with other cells in the pool unaffected by the radiation, resulting in a MI higher than control levels. The span of delay and the occurrence of recovery are assumed to be constant for a given dose and tissue under similar experimental conditions. First described in asynchronously-dividing tissue culture cells, this concept is also extrapolated to the in vivo situation

  18. The flavonoid eupatorin inactivates the mitotic checkpoint leading to polyploidy and apoptosis

    Salmela, Anna-Leena [VTT Technical Research Centre of Finland, Medical Biotechnology, P.O. Box 106, Turku (Finland); Turku Graduate School of Biomedical Sciences, Turku (Finland); Turku Centre for Biotechnology, P.O. Box 123, University of Turku (Finland); Pouwels, Jeroen; Kukkonen-Macchi, Anu [VTT Technical Research Centre of Finland, Medical Biotechnology, P.O. Box 106, Turku (Finland); Waris, Sinikka; Toivonen, Pauliina [Turku Centre for Biotechnology, P.O. Box 123, University of Turku (Finland); Jaakkola, Kimmo [VTT Technical Research Centre of Finland, Medical Biotechnology, P.O. Box 106, Turku (Finland); Maeki-Jouppila, Jenni [VTT Technical Research Centre of Finland, Medical Biotechnology, P.O. Box 106, Turku (Finland); Turku Centre for Biotechnology, P.O. Box 123, University of Turku (Finland); Drug Discovery Graduate School, University of Turku (Finland); Kallio, Lila, E-mail: lila.kallio@vtt.fi [VTT Technical Research Centre of Finland, Medical Biotechnology, P.O. Box 106, Turku (Finland); Kallio, Marko J. [VTT Technical Research Centre of Finland, Medical Biotechnology, P.O. Box 106, Turku (Finland); Turku Centre for Biotechnology, P.O. Box 123, University of Turku (Finland); Centre of Excellence for Translational Genome-Scale Biology, P.O. Box 106, Academy of Finland (Finland)

    2012-03-10

    The spindle assembly checkpoint (SAC) is a conserved mechanism that ensures the fidelity of chromosome distribution in mitosis by preventing anaphase onset until the correct bipolar microtubule-kinetochore attachments are formed. Errors in SAC function may contribute to tumorigenesis by inducing numerical chromosome anomalies (aneuploidy). On the other hand, total disruption of SAC can lead to massive genomic imbalance followed by cell death, a phenomena that has therapeutic potency. We performed a cell-based high-throughput screen with a compound library of 2000 bioactives for novel SAC inhibitors and discovered a plant-derived phenolic compound eupatorin (3 Prime ,5-dihydroxy-4 Prime ,6,7-trimethoxyflavone) as an anti-mitotic flavonoid. The premature override of the microtubule drug-imposed mitotic arrest by eupatorin is dependent on microtubule-kinetochore attachments but not interkinetochore tension. Aurora B kinase activity, which is essential for maintenance of normal SAC signaling, is diminished by eupatorin in cells and in vitro providing a mechanistic explanation for the observed forced mitotic exit. Eupatorin likely has additional targets since eupatorin treatment of pre-mitotic cells causes spindle anomalies triggering a transient M phase delay followed by impaired cytokinesis and polyploidy. Finally, eupatorin potently induces apoptosis in multiple cancer cell lines and suppresses cancer cell proliferation in organotypic 3D cell culture model.

  19. Akt Inhibitor A-443654 Interferes with Mitotic Progression by Regulating Aurora A Kinase Expression

    Xuesong Liu

    2008-08-01

    Full Text Available Both Akt and Aurora A kinase have been shown to be important targets for intervention for cancer therapy. We report here that Compound A (A-443654, a specific Akt inhibitor, interferes with mitotic progression and bipolar spindle formation. Compound A induces G2/M accumulation, defects in centrosome separation, and formation of either monopolar arrays or disorganized spindles. On the basis of gene expression array studies, we identified Aurora A as one of the genes regulated transcriptionally by Akt inhibitors including Compound A. Inhibition of the phosphatidylinositol 3-kinase (PI3K/Akt pathway, either by PI3K inhibitor LY294002 or by Compound A, dramatically inhibits the promoter activity of Aurora A, whereas the mammalian target of rapamycin inhibitor has little effect, suggesting that Akt might be responsible for up-regulating Aurora A for mitotic progression. Further analysis of the Aurora A promoter region indicates that the Ets element but not the Sp1 element is required for Compound A-sensitive transcriptional control of Aurora A. Overexpression of Aurora A in cells treated with Compound A attenuates the mitotic arrest and the defects in bipolar spindle formation induced by Akt inhibition. Our studies suggest that that Akt may promote mitotic progression through the transcriptional regulation of Aurora A.

  20. In-silico modeling of the mitotic spindle assembly checkpoint.

    Bashar Ibrahim

    2008-02-01

    Full Text Available The Mitotic Spindle Assembly Checkpoint ((MSAC is an evolutionary conserved mechanism that ensures the correct segregation of chromosomes by restraining cell cycle progression from entering anaphase until all chromosomes have made proper bipolar attachments to the mitotic spindle. Its malfunction can lead to cancer.We have constructed and validated for the human (MSAC mechanism an in silico dynamical model, integrating 11 proteins and complexes. The model incorporates the perspectives of three central control pathways, namely Mad1/Mad2 induced Cdc20 sequestering based on the Template Model, MCC formation, and APC inhibition. Originating from the biochemical reactions for the underlying molecular processes, non-linear ordinary differential equations for the concentrations of 11 proteins and complexes of the (MSAC are derived. Most of the kinetic constants are taken from literature, the remaining four unknown parameters are derived by an evolutionary optimization procedure for an objective function describing the dynamics of the APC:Cdc20 complex. MCC:APC dissociation is described by two alternatives, namely the "Dissociation" and the "Convey" model variants. The attachment of the kinetochore to microtubuli is simulated by a switching parameter silencing those reactions which are stopped by the attachment. For both, the Dissociation and the Convey variants, we compare two different scenarios concerning the microtubule attachment dependent control of the dissociation reaction. Our model is validated by simulation of ten perturbation experiments.Only in the controlled case, our models show (MSAC behaviour at meta- to anaphase transition in agreement with experimental observations. Our simulations revealed that for (MSAC activation, Cdc20 is not fully sequestered; instead APC is inhibited by MCC binding.

  1. School-Based Health Promotion Initiative Increases Children's Physical Activity

    Cluss, Patricia; Lorigan, Devin; Kinsky, Suzanne; Nikolajski, Cara; McDermott, Anne; Bhat, Kiran B.

    2016-01-01

    Background: Childhood obesity increases health risk, and modest physical activity can impact that risk. Schools have an opportunity to help children become more active. Purpose: This study implemented a program offering extra school-day activity opportunities in a rural school district where 37% of students were obese or overweight in 2005 and…

  2. Dataset from the global phosphoproteomic mapping of early mitotic exit in human cells

    Samuel Rogers

    2015-12-01

    Full Text Available The presence or absence of a phosphorylation on a substrate at any particular point in time is a functional readout of the balance in activity between the regulatory kinase and the counteracting phosphatase. Understanding how stable or short-lived a phosphorylation site is required for fully appreciating the biological consequences of the phosphorylation. Our current understanding of kinases and their substrates is well established; however, the role phosphatases play is less understood. Therefore, we utilized a phosphatase dependent model of mitotic exit to identify potential substrates that are preferentially dephosphorylated. Using this method, we identified >16,000 phosphosites on >3300 unique proteins, and quantified the temporal phosphorylation changes that occur during early mitotic exit (McCloy et al., 2015 [1]. Furthermore, we annotated the majority of these phosphorylation sites with a high confidence upstream kinase using published, motif and prediction based methods. The results from this study have been deposited into the ProteomeXchange repository with identifier PXD001559. Here we provide additional analysis of this dataset; for each of the major mitotic kinases we identified motifs that correlated strongly with phosphorylation status. These motifs could be used to predict the stability of phosphorylated residues in proteins of interest, and help infer potential functional roles for uncharacterized phosphorylations. In addition, we provide validation at the single cell level that serine residues phosphorylated by Cdk are stable during phosphatase dependent mitotic exit. In summary, this unique dataset contains information on the temporal mitotic stability of thousands of phosphorylation sites regulated by dozens of kinases, and information on the potential preference that phosphatases have at both the protein and individual phosphosite level. The compellation of this data provides an invaluable resource for the wider research

  3. Hydrogen peroxide induced loss of heterozygosity correlates with replicative lifespan and mitotic asymmetry in Saccharomyces cerevisiae

    Jackson, Erin D.; Parker, Meighan C.; Gupta, Nilin; Rodrigues, Jenny

    2016-01-01

    Cellular aging in Saccharomyces cerevisiae can lead to genomic instability and impaired mitotic asymmetry. To investigate the role of oxidative stress in cellular aging, we examined the effect of exogenous hydrogen peroxide on genomic instability and mitotic asymmetry in a collection of yeast strains with diverse backgrounds. We treated yeast cells with hydrogen peroxide and monitored the changes of viability and the frequencies of loss of heterozygosity (LOH) in response to hydrogen peroxide doses. The mid-transition points of viability and LOH were quantified using sigmoid mathematical functions. We found that the increase of hydrogen peroxide dependent genomic instability often occurs before a drop in viability. We previously observed that elevation of genomic instability generally lags behind the drop in viability during chronological aging. Hence, onset of genomic instability induced by exogenous hydrogen peroxide treatment is opposite to that induced by endogenous oxidative stress during chronological aging, with regards to the midpoint of viability. This contrast argues that the effect of endogenous oxidative stress on genome integrity is well suppressed up to the dying-off phase during chronological aging. We found that the leadoff of exogenous hydrogen peroxide induced genomic instability to viability significantly correlated with replicative lifespan (RLS), indicating that yeast cells’ ability to counter oxidative stress contributes to their replicative longevity. Surprisingly, this leadoff is positively correlated with an inverse measure of endogenous mitotic asymmetry, indicating a trade-off between mitotic asymmetry and cell’s ability to fend off hydrogen peroxide induced oxidative stress. Overall, our results demonstrate strong associations of oxidative stress to genomic instability and mitotic asymmetry at the population level of budding yeast. PMID:27833823

  4. Comparative effects of ionizing radiation on cycle time and mitotic duration. A time-lapse cinematography study

    D'Hooghe, M.C.; Hemon, D.; Valleron, A.J.; Malaise, E.P.

    1980-01-01

    The effects of 60 Co γ rays on the length of the intermitotic period, the duration of mitosis, and the division probability of EMT6 cells have been studied in vitro using time-lapse cinematography. Irradiation increases the duration of the mitosis and of the cycle in comparable proportions: both parameters are practically doubled by a dose of 10 Gy. When daughters of irradiated cells die, the mitotic delay and lengthening of mitosis of their mother cells are longer than average. Mitotic delay and lengthening of mitosis depend on the age of cells at the moment of irradiation. The mitotic delay increases progressively when cells are irradiated during the first 8 h of their cycle (i.e., before the transition point), whereas mitosis is slightly prolonged. On the other hand, when the cells are irradiated after this transition point the mitotic delay decreases markedly, whereas the lengthening of mitosis increases sharply. These results tend to indicate that two different mechanisms are responsible for mitotic delay and prolongation of mitosis observed after irradiation

  5. Comparative effects of ionizing radiation on cycle time and mitotic duration. A time-lapse cinematography study

    D' Hooghe, M.C. (Institut de Recherches sur le Cancer, Lille, France); Hemon, D.; Valleron, A.J.; Malaise, E.P.

    1980-03-01

    The effects of /sup 60/Co ..gamma.. rays on the length of the intermitotic period, the duration of mitosis, and the division probability of EMT6 cells have been studied in vitro using time-lapse cinematography. Irradiation increases the duration of the mitosis and of the cycle in comparable proportions: both parameters are practically doubled by a dose of 10 Gy. When daughters of irradiated cells die, the mitotic delay and lengthening of mitosis of their mother cells are longer than average. Mitotic delay and lengthening of mitosis depend on the age of cells at the moment of irradiation. The mitotic delay increases progressively when cells are irradiated during the first 8 h of their cycle (i.e., before the transition point), whereas mitosis is slightly prolonged. On the other hand, when the cells are irradiated after this transition point the mitotic delay decreases markedly, whereas the lengthening of mitosis increases sharply. These results tend to indicate that two different mechanisms are responsible for mitotic delay and prolongation of mitosis observed after irradiation.

  6. Regulatory dephosphorylation of CDK at G₂/M in plants: yeast mitotic phosphatase cdc25 induces cytokinin-like effects in transgenic tobacco morphogenesis.

    Lipavská, Helena; Masková, Petra; Vojvodová, Petra

    2011-05-01

    During the last three decades, the cell cycle and its control by cyclin-dependent kinases (CDKs) have been extensively studied in eukaryotes. This endeavour has produced an overall picture that basic mechanisms seem to be largely conserved among all eukaryotes. The intricate regulation of CDK activities includes, among others, CDK activation by CDC25 phosphatase at G₂/M. In plants, however, studies of this regulation have lagged behind as a plant Cdc25 homologue or other unrelated phosphatase active at G₂/M have not yet been identified. Failure to identify a plant mitotic CDK activatory phosphatase led to characterization of the effects of alien cdc25 gene expression in plants. Tobacco, expressing the Schizosaccharomyces pombe mitotic activator gene, Spcdc25, exhibited morphological, developmental and biochemical changes when compared with wild type (WT) and, importantly, increased CDK dephosphorylation at G₂/M. Besides changes in leaf shape, internode length and root development, in day-neutral tobacco there was dramatically earlier onset of flowering with a disturbed acropetal floral capacity gradient typical of WT. In vitro, de novo organ formation revealed substantially earlier and more abundant formation of shoot primordia on Spcdc25 tobacco stem segments grown on shoot-inducing media when compared with WT. Moreover, in contrast to WT, stem segments from transgenic plants formed shoots even without application of exogenous growth regulator. Spcdc25-expressing BY-2 cells exhibited a reduced mitotic cell size due to a shortening of the G₂ phase together with high activity of cyclin-dependent kinase, NtCDKB1, in early S-phase, S/G₂ and early M-phase. Spcdc25-expressing tobacco ('Samsun') cell suspension cultures showed a clustered, more circular, cell phenotype compared with chains of elongated WT cells, and increased content of starch and soluble sugars. Taken together, Spcdc25 expression had cytokinin-like effects on the characteristics studied

  7. Fully functional global genome repair of (6-4) photoproducts and compromised transcription-coupled repair of cyclobutane pyrimidine dimers in condensed mitotic chromatin

    Komura, Jun-ichiro, E-mail: junkom@med.tohoku.ac.jp [Department of Cell Biology, Tohoku University Graduate School of Medicine, Sendai 980-8575 (Japan); Ikehata, Hironobu [Department of Cell Biology, Tohoku University Graduate School of Medicine, Sendai 980-8575 (Japan); Mori, Toshio [Radioisotope Research Center, Nara Medical University, Kashihara, Nara 634-8521 (Japan); Ono, Tetsuya [Department of Cell Biology, Tohoku University Graduate School of Medicine, Sendai 980-8575 (Japan)

    2012-03-10

    During mitosis, chromatin is highly condensed, and activities such as transcription and semiconservative replication do not occur. Consequently, the condensed condition of mitotic chromatin is assumed to inhibit DNA metabolism by impeding the access of DNA-transacting proteins. However, about 40 years ago, several researchers observed unscheduled DNA synthesis in UV-irradiated mitotic chromosomes, suggesting the presence of excision repair. We re-examined this subject by directly measuring the removal of UV-induced DNA lesions by an ELISA and by a Southern-based technique in HeLa cells arrested at mitosis. We observed that the removal of (6-4) photoproducts from the overall genome in mitotic cells was as efficient as in interphase cells. This suggests that global genome repair of (6-4) photoproducts is fully functional during mitosis, and that the DNA in mitotic chromatin is accessible to proteins involved in this mode of DNA repair. Nevertheless, not all modes of DNA repair seem fully functional during mitosis. We also observed that the removal of cyclobutane pyrimidine dimers from the dihydrofolate reductase and c-MYC genes in mitotic cells was very slow. This suggests that transcription-coupled repair of cyclobutane pyrimidine dimers is compromised or non-functional during mitosis, which is probably the consequence of mitotic transcriptional repression. -- Highlights: Black-Right-Pointing-Pointer Global genome repair of (6-4) photoproducts is fully active in mitotic cells. Black-Right-Pointing-Pointer DNA in condensed mitotic chromatin does not seem inaccessible or inert. Black-Right-Pointing-Pointer Mitotic transcriptional repression may impair transcription-coupled repair.

  8. Fully functional global genome repair of (6-4) photoproducts and compromised transcription-coupled repair of cyclobutane pyrimidine dimers in condensed mitotic chromatin

    Komura, Jun-ichiro; Ikehata, Hironobu; Mori, Toshio; Ono, Tetsuya

    2012-01-01

    During mitosis, chromatin is highly condensed, and activities such as transcription and semiconservative replication do not occur. Consequently, the condensed condition of mitotic chromatin is assumed to inhibit DNA metabolism by impeding the access of DNA-transacting proteins. However, about 40 years ago, several researchers observed unscheduled DNA synthesis in UV-irradiated mitotic chromosomes, suggesting the presence of excision repair. We re-examined this subject by directly measuring the removal of UV-induced DNA lesions by an ELISA and by a Southern-based technique in HeLa cells arrested at mitosis. We observed that the removal of (6-4) photoproducts from the overall genome in mitotic cells was as efficient as in interphase cells. This suggests that global genome repair of (6-4) photoproducts is fully functional during mitosis, and that the DNA in mitotic chromatin is accessible to proteins involved in this mode of DNA repair. Nevertheless, not all modes of DNA repair seem fully functional during mitosis. We also observed that the removal of cyclobutane pyrimidine dimers from the dihydrofolate reductase and c-MYC genes in mitotic cells was very slow. This suggests that transcription-coupled repair of cyclobutane pyrimidine dimers is compromised or non-functional during mitosis, which is probably the consequence of mitotic transcriptional repression. -- Highlights: ► Global genome repair of (6-4) photoproducts is fully active in mitotic cells. ► DNA in condensed mitotic chromatin does not seem inaccessible or inert. ► Mitotic transcriptional repression may impair transcription-coupled repair.

  9. Magic with moulds: Meiotic and mitotic crossing over in Neurospora ...

    2006-02-16

    Feb 16, 2006 ... Home; Journals; Journal of Biosciences; Volume 31; Issue 1. Commentary: Magic with moulds: Meiotic and mitotic crossing over in Neurospora inversions and duplications. Durgadas P Kasbekar. Volume 31 Issue 1 March 2006 pp 3-4 ...

  10. Effect of colchicine on mitotic polyploidization and morphological ...

    Ajai

    2012-05-15

    May 15, 2012 ... to diseases and insects and reduction in fertility of flowering plants ..... soaking duration was noticed to cause the treated seeds to give low height .... Addison-. Wesley, London. Stadler J, Phillips RL, Leonard M (1989).Mitotic ...

  11. Expected Increase of Activity of Eta Aquariids Meteor Shower

    Kulikova, N. V.; Chepurova, V. M.

    2018-04-01

    Analysis of the results of modeling disintegration of Comet 1P/Halley after its flare in 1991 has allowed us to predict an increase of the activity of the associated Eta Aquariids meteor shower in April-May 2018.

  12. Increased sternocleidomastoid, but not trapezius, muscle activity in response to increased chewing load.

    Häggman-Henrikson, Birgitta; Nordh, Erik; Eriksson, Per-Olof

    2013-10-01

    Previous findings, during chewing, that boluses of larger size and harder texture result in larger amplitudes of both mandibular and head-neck movements suggest a relationship between increased chewing load and incremental recruitment of jaw and neck muscles. The present report evaluated jaw (masseter and digastric) and neck [sternocleidomastoid (SCM) and trapezius] muscle activity during the chewing of test foods of different sizes and textures by 10 healthy subjects. Muscle activity was recorded by surface electromyography and simultaneous mandibular and head movements were recorded using an optoelectronic technique. Each subject performed continuous jaw-opening/jaw-closing movements whilst chewing small and large boluses of chewing gum and rubber silicone (Optosil). For jaw opening/jaw closing without a bolus, SCM activity was recorded for jaw opening concomitantly with digastric activity. During chewing, SCM activity was recorded for jaw closing concomitantly with masseter activity. Trapezius activity was present in some, but not all, cycles. For the masseter and SCM muscles, higher activity was seen with larger test foods, suggesting increased demand and recruitment of these muscles in response to an increased chewing load. This result reinforces the previous notion of a close functional connection between the jaw and the neck motor systems in jaw actions and has scientific and clinical significance for studying jaw function and dysfunction. © 2013 Eur J Oral Sci.

  13. Jealousy increased by induced relative left frontal cortical activity.

    Kelley, Nicholas J; Eastwick, Paul W; Harmon-Jones, Eddie; Schmeichel, Brandon J

    2015-10-01

    Asymmetric frontal cortical activity may be one key to the process linking social exclusion to jealous feelings. The current research examined the causal role of asymmetric frontal brain activity in modulating jealousy in response to social exclusion. Transcranial direct-current stimulation (tDCS) over the frontal cortex to manipulate asymmetric frontal cortical activity was combined with a modified version of the Cyberball paradigm designed to induce jealousy. After receiving 15 min of tDCS, participants were excluded by a desired partner and reported how jealous they felt. Among individuals who were excluded, tDCS to increase relative left frontal cortical activity caused greater levels of self-reported jealousy compared to tDCS to increase relative right frontal cortical activity or sham stimulation. Limitations concerning the specificity of this effect and implications for the role of the asymmetric prefrontal cortical activity in motivated behaviors are discussed. (c) 2015 APA, all rights reserved).

  14. Mechanical control of mitotic progression in single animal cells

    Cattin, Cedric J.; Düggelin, Marcel; Martinez-Martin, David; Gerber, Christoph; Müller, Daniel J.; Stewart, Martin P.

    2015-01-01

    Despite the importance of mitotic cell rounding in tissue development and cell proliferation, there remains a paucity of approaches to investigate the mechanical robustness of cell rounding. Here we introduce ion beam-sculpted microcantilevers that enable precise force-feedback-controlled confinement of single cells while characterizing their progression through mitosis. We identify three force regimes according to the cell response: small forces (∼5 nN) that accelerate mitotic progression, i...

  15. In vitro autoradiographic studies for determination of mitotic index and labelling index in biopsies of the human oral mucosa

    Etzbach, T.

    1980-01-01

    In order to find the most favourable method of incubation for in-vitro autoradiographies of biopsies of human oral mucosa, tissue biopsies were taken from oral mucosa transplants of 10 patients (7 females, 3 males) and either fixed or incubated at once. The author then investigated the mitotic index of the non-incubated tissue specimens, the mitotic index of the tissue specimens incubated in atmospheric conditions (A), and the mitotic index of the tissue specimens incubated under pressure (B). Simultaneously, autoradiographs of the incubated tissue specimens were prepared in order to determine their labelling indices. The mitotic indices of the non-incubated tissue specimen were found to differ significantly from those of the A-incubated tissue specimens. A similar difference was found between the mitotic indices of the A- and B-incubated tissue biopsies. Further, the labelling indices of A autoradiographs differed significantly from the labelling indices of B autoradiographs. The findings suggest that incubation with an excess oxygen pressure of 2 bar is the method of choice for in-vitro studies of human oral mucosa as the cells retain their specific activity and cell processes will continue unhindered. Further, the findings can be transferred to in-vivo conditions with a reasonable error rate. (orig./MG) [de

  16. Proteasome inhibition enhances the efficacy of volasertib-induced mitotic arrest in AML in vitro and prolongs survival in vivo.

    Schnerch, Dominik; Schüler, Julia; Follo, Marie; Felthaus, Julia; Wider, Dagmar; Klingner, Kathrin; Greil, Christine; Duyster, Justus; Engelhardt, Monika; Wäsch, Ralph

    2017-03-28

    Elderly and frail patients, diagnosed with acute myeloid leukemia (AML) and ineligible to undergo intensive treatment, have a dismal prognosis. The small molecule inhibitor volasertib induces a mitotic block via inhibition of polo-like kinase 1 and has shown remarkable anti-leukemic activity when combined with low-dose cytarabine. We have demonstrated that AML cells are highly vulnerable to cell death in mitosis yet manage to escape a mitotic block through mitotic slippage by sustained proteasome-dependent slow degradation of cyclin B. Therefore, we tested whether interfering with mitotic slippage through proteasome inhibition arrests and kills AML cells more efficiently during mitosis. We show that therapeutic doses of bortezomib block the slow degradation of cyclin B during a volasertib-induced mitotic arrest in AML cell lines and patient-derived primary AML cells. In a xenotransplant mouse model of human AML, mice receiving volasertib in combination with bortezomib showed superior disease control compared to mice receiving volasertib alone, highlighting the potential therapeutic impact of this drug combination.

  17. The effect of mitotic inhibitors on DNA strand size and radiation-associated break repair in Down syndrome fibroblasts

    Woods, W.G.; Steiner, M.E.; Kalvonjian, S.L.

    1985-01-01

    The effect of mitotic inhibitors on formation and repair of DNA breaks was studied in cultured fibroblasts from patients with Down syndrome in order to investigate the hypothesis that the karyotyping procedure itself may play a role in the increased chromosome breakage seen in these cells after gamma radiation exposure. Using the nondenaturing elution and alkaline elution techniques to examine fibroblasts from Down syndrome patients and from controls, no specific abnormalities in Down syndrome cells could be detected after exposure to mitotic inhibitors, including rate and extent of elution of DNA from filters as well as repair of radiation-induced DNA breaks. In both normal and Down syndrome cell strains, however, exposure to mitotic inhibitors was associated with a decrease in cellular DNA strand size, suggesting the presence of drug-induced DNA strand breaks. The mechanism of increased chromosome sensitivity of Down syndrome cells to gamma radiation remains unknown. (orig.)

  18. Building a Better Mousetrap (Exergame) to Increase Youth Physical Activity

    Baranowski, Tom; Maddison, Ralph; Maloney, Ann; Medina, Ernie; Simons, Monique

    Although exergames have been demonstrated to induce moderate levels of physical activity (PA) if played as designed, there is conflicting evidence on use of exergaming leading to increased habitual PA. Exergames have increased PA in some home and school studies, but not others. Exergames have been

  19. Changes in Ect2 Localization Couple Actomyosin-Dependent Cell Shape Changes to Mitotic Progression

    Matthews, Helen K.; Delabre, Ulysse; Rohn, Jennifer L.; Guck, Jochen; Kunda, Patricia; Baum, Buzz

    2012-01-01

    Summary As they enter mitosis, animal cells undergo profound actin-dependent changes in shape to become round. Here we identify the Cdk1 substrate, Ect2, as a central regulator of mitotic rounding, thus uncovering a link between the cell-cycle machinery that drives mitotic entry and its accompanying actin remodeling. Ect2 is a RhoGEF that plays a well-established role in formation of the actomyosin contractile ring at mitotic exit, through the local activation of RhoA. We find that Ect2 first becomes active in prophase, when it is exported from the nucleus into the cytoplasm, activating RhoA to induce the formation of a mechanically stiff and rounded metaphase cortex. Then, at anaphase, binding to RacGAP1 at the spindle midzone repositions Ect2 to induce local actomyosin ring formation. Ect2 localization therefore defines the stage-specific changes in actin cortex organization critical for accurate cell division. PMID:22898780

  20. Increasing physical activity through mobile device interventions: A systematic review.

    Muntaner, Adrià; Vidal-Conti, Josep; Palou, Pere

    2016-09-01

    Physical inactivity is a health problem that affects people worldwide and has been identified as the fourth largest risk factor for overall mortality (contributing to 6% of deaths globally). Many researchers have tried to increase physical activity levels through traditional methods without much success. Thus, many researchers are turning to mobile technology as an emerging method for changing health behaviours. This systematic review sought to summarise and update the existing scientific literature on increasing physical activity through mobile device interventions, taking into account the methodological quality of the studies. The articles were identified by searching the PubMed, SCOPUS and SPORTDiscus databases for studies published between January 2003 and December 2013. Studies investigating efforts to increase physical activity through mobile phone or even personal digital assistant interventions were included. The search results allowed the inclusion of 11 studies that gave rise to 12 publications. Six of the articles included in this review reported significant increases in physical activity levels. The number of studies using mobile devices for interventions has increased exponentially in the last few years, but future investigations with better methodological quality are needed to draw stronger conclusions regarding how to increase physical activity through mobile device interventions. © The Author(s) 2015.

  1. The impact of motivational interventions for increasing physical activity

    Aneci Sobral Rocha

    2010-03-01

    Full Text Available Objective: To assess whether incentives for practicing regular physical activities in fact help raising the frequency of exercising. Methods: Male and female subjects undergoing two to three assessments in the Check-Up Unit of Hospital Israelita Albert Einstein (HIAE were evaluated by noting any increase in levels of physical activity, improvements in mean metabolic unit numbers, and the sensitization index. The International Physical Activity Questionnaire was applied to assess the sample. Results: There were 1,879 subjects – 1,559 (83% males and 320 (17% females – aged 20 to 76 years (mean age = 45.8 years, standard deviation ± 8.8 who underwent a Continued Health Review at the Center for Preventive Medicine of the HIAE, Check-Up Unit, Jardins. Initially, over half of the sample was insufficiently active (sedentary or poorly active; there were more women than men in this group. After the health review, most subjects increased their level of physical activity; this increase was higher among women. Males encouraged three times to exercising showed better results (increased level of physical activity as compared to males encouraged twice for exercising. The best results in females were found in the group that went through two evaluations. This result is due to the fact that the sample of females comprising the group that received incentives on three occasions was small. This was also the only group that showed no increase in mean metabolic units. The sensitization index assessment in the overall sample was very satisfactory, as the expected results were achieved. Conclusions: These results show that motivational interventions are effective for raising the level of physical activity. We concluded that to encourage the practice of regular physical activity through information programs about its health benefits is very important.

  2. Control of the mitotic exit network during meiosis

    Attner, Michelle A.; Amon, Angelika

    2012-01-01

    The mitotic exit network (MEN) is an essential GTPase signaling pathway that triggers exit from mitosis in budding yeast. We show here that during meiosis, the MEN is dispensable for exit from meiosis I but contributes to the timely exit from meiosis II. Consistent with a role for the MEN during meiosis II, we find that the signaling pathway is active only during meiosis II. Our analysis further shows that MEN signaling is modulated during meiosis in several key ways. Whereas binding of MEN components to spindle pole bodies (SPBs) is necessary for MEN signaling during mitosis, during meiosis MEN signaling occurs off SPBs and does not require the SPB recruitment factor Nud1. Furthermore, unlike during mitosis, MEN signaling is controlled through the regulated interaction between the MEN kinase Dbf20 and its activating subunit Mob1. Our data lead to the conclusion that a pathway essential for vegetative growth is largely dispensable for the specialized meiotic divisions and provide insights into how cell cycle regulatory pathways are modulated to accommodate different modes of cell division. PMID:22718910

  3. [Increase of physical activity by improvement of the nutritional status].

    Torún, B

    1989-09-01

    Physical activity is affected by nutritional modifications and, in turn, influences growth, cognition, social behavior, work performance and other functions. Studies in preschool children showed that: 1. A decrease in energy intake during four to seven days reduced the time allocated to energy-demanding activities and increased sedentary activities. 2. Children with mild weight deficit were more sedentary than well-nourished counterparts. 3. Children became more active when nutritional status improved. 4. A 10% reduction in energy intake reduced total energy expenditure by 15% without affecting weight gain nor basal metabolism. Studies of men working in non-mechanized agriculture showed that: 1. Dietary improvements led to faster salaried work, reduction of napping time and greater physical activity after work. 2. An increase in energy intake increased total daily energy expenditure, tending to maintain energy balance and relatively stable body weight within the cyclic variations of the agricultural year. 3. Food supplementation did not necessarily improve productivity. Other labor incentives without dietary improvements increased energy expenditure during working hours, which resulted in weight loss. In conclusion, good health and nutrition provide the biological basis for adequate physical activity that may improve cognitive development, social interactions, economic productivity and the quality of life of an individual or a population, but other incentives are required for the optimal expression of that biologic potential.

  4. Inhibition of the mitotic exit network in response to damaged telomeres.

    Mauricio Valerio-Santiago

    Full Text Available When chromosomal DNA is damaged, progression through the cell cycle is halted to provide the cells with time to repair the genetic material before it is distributed between the mother and daughter cells. In Saccharomyces cerevisiae, this cell cycle arrest occurs at the G2/M transition. However, it is also necessary to restrain exit from mitosis by maintaining Bfa1-Bub2, the inhibitor of the Mitotic Exit Network (MEN, in an active state. While the role of Bfa1 and Bub2 in the inhibition of mitotic exit when the spindle is not properly aligned and the spindle position checkpoint is activated has been extensively studied, the mechanism by which these proteins prevent MEN function after DNA damage is still unclear. Here, we propose that the inhibition of the MEN is specifically required when telomeres are damaged but it is not necessary to face all types of chromosomal DNA damage, which is in agreement with previous data in mammals suggesting the existence of a putative telomere-specific DNA damage response that inhibits mitotic exit. Furthermore, we demonstrate that the mechanism of MEN inhibition when telomeres are damaged relies on the Rad53-dependent inhibition of Bfa1 phosphorylation by the Polo-like kinase Cdc5, establishing a new key role of this kinase in regulating cell cycle progression.

  5. Peroxisome proliferator-activated receptor delta activation leads to increased transintestinal cholesterol efflux

    Vrins, Carlos L. J.; van der Velde, Astrid E.; van den Oever, Karin; Levels, Johannes H. M.; Huet, Stephane; Elferink, Ronald P. J. Oude; Kuipers, Folkert; Groen, Albert K.

    2009-01-01

    Peroxisome proliferator-activated receptor delta (PPAR delta) is involved in regulation of energy homeostasis. Activation of PPAR delta markedly increases fecal neutral sterol secretion, the last step in reverse cholesterol transport. This phenomenon can neither be explained by increased

  6. Peroxisome proliferator-activated receptor delta activation leads to increased transintestinal cholesterol efflux

    Vrins, Carlos L. J.; van der Velde, Astrid E.; van den Oever, Karin; Levels, Johannes H. M.; Huet, Stephane; Oude Elferink, Ronald P. J.; Kuipers, Folkert; Groen, Albert K.

    2009-01-01

    Peroxisome proliferator-activated receptor delta (PPARdelta) is involved in regulation of energy homeostasis. Activation of PPARdelta markedly increases fecal neutral sterol secretion, the last step in reverse cholesterol transport. This phenomenon can neither be explained by increased hepatobiliary

  7. The marine toxin, Yessotoxin, induces apoptosis and increases mitochondrial activity

    Andrea Fernandez-Araujo

    2014-06-01

    Discussion: Colorimetric MTT assay is widely used as a viability measurement method (McHale and L., 1988;Chiba et al., 1998. But after YTX treatment, MTT assay had shown problems to detect a cell viability decrease. In this sense, in primary cardiac cell cultures, a false increment of the proliferation rate opposite to Sulforhodamine B assay (SRB results was reported after YTX treatment (Dell'Ovo et al., 2008. Also the same effect was obtained in different cancer cell lines after assaying anticancer therapies (Ulukaya et al., 2004. In our study, an increase in cell viability using MTT was observed when the number of cells was high, while by using the LDH assay a significant viability decrease was measured. In these conditions, YTX is activating extrinsic apoptosis cell death by increasing caspase 8 activity and caspase 3 levels. The explanation for this increase was found when the mitochondrial activity was quantified cell by cell in a cytometer. In these conditions a significant increment of mitochondrial activity was detected. Since the cell population is too high, the increase in mitochondrial activity that detects the MTT test disguised the decrease of signal due to the cell death and point to a false proliferation increase. In this sense, a mitochondrial activity decrease was observed after 48 hours YTX treatment in BE(2-M17 neuroblastoma cell line (Leira et al., 2002. However, this study was done in a microplate reader with a small number of cells (Leira et al., 2002. Therefore, to measure the viability by MTT assay is very important to take into account the number of cells per condition when the experiment is designed. Alternative assays, such as LDH test, independently of the direct mitochondrial activity, can be used.

  8. Effects of mutagen-sensitive mus mutations on spontaneous mitotic recombination in Aspergillus.

    Zhao, P; Kafer, E

    1992-04-01

    Methyl methane-sulfonate (MMS)-sensitive, radiation-induced mutants of Aspergillus were shown to define nine new DNA repair genes, musK to musS. To test mus mutations for effects on mitotic recombination, intergenic crossing over was assayed between color markers and their centromeres, and intragenic recombination between two distinguishable adE alleles. Of eight mutants analyzed, four showed significant deviations from mus+ controls in both tests. Two mutations, musK and musL, reduced recombination, while musN and musQ caused increases. In contrast, musO diploids produced significantly higher levels only for intragenic recombination. Effects were relatively small, but averages between hypo- and hyperrec mus differed 15-20-fold. In musL diploids, most of the rare color segregants resulted from mitotic malsegregation rather than intergenic crossing over. This indicates that the musL gene product is required for recombination and that DNA lesions lead to chromosome loss when it is deficient. In addition, analysis of the genotypes of intragenic (ad+) recombinants showed that the musL mutation specifically reduced single allele conversion but increased complex conversion types (especially recombinants homozygous for ad+). Similar analysis revealed differences between the effects of two hyperrec mutations; musN apparently caused high levels solely of mitotic crossing over, while musQ increased various conversion types but not reciprocal crossovers. These results suggest that mitotic gene conversion and crossing over, while generally associated, are affected differentially in some of the mus strains of Aspergillus nidulans.

  9. The role of p53 in the response to mitotic spindle damage

    Meek, D.W.

    2000-01-01

    The p53 tumour suppressor protein has defined roles in G1/S and G2/M cell cycle checkpoint in response to a range of cellular stresses including DNA damage, dominant oncogene expression, hypoxia, metabolic changes and viral infection. In addition to these responses, p53 can also be activated when damage occurs to the mitotic spindle. Initially, spindle damage activates a p53-independent checkpoint which functions at the metaphase-anaphase transition and prevents cells from progressing through mitosis until the completion of spindle formation. Cells eventually escape from this block (a process termed 'mitotic slippage'), and an aberrant mitosis ensues in which sister chromatids fail to segregate properly. After a delay period, p53 responds to this mitotic failure by instituting a G1-like growth arrest, with an intact nucleus containing 4N DNA, but without the cells undergoing division. Cells lacking wild-type p53 are still able to arrest transiently at mitosis, and also fail to undergo division, underscoring that the delay in mitosis is p53-independent. However, these cells are not prevented from re-entering the cell cycle and can reduplicate their DNA unchecked, leading to polyploidy. Additionally, p53-null cells which experience spindle failure often show the appearance of micronuclei arising from poorly segregated chromosomes which have de-condensed and been enclosed in a nuclear envelope. The ability of p53 to prevent their formation suggests an additional G2 involvement which prevents nuclear breakdown prior to mitosis. The molecular mechanism by which p53 is able to sense mitotic failure is still unknown, but may be linked to the ability of p53 to regulate duplication of the centrosome, the organelle which nucleates spindle formation. (authors)

  10. Physical activity increases survival after heart valve surgery

    Lund, K.; Sibilitz, Kirstine Lærum; Kikkenborg Berg, Selina

    2016-01-01

    physical activity levels 6-12 months after heart valve surgery and (1) survival, (2) hospital readmission 18-24 months after surgery and (3) participation in exercise-based cardiac rehabilitation. METHODS: Prospective cohort study with registry data from The CopenHeart survey, The Danish National Patient......OBJECTIVES: Increased physical activity predicts survival and reduces risk of readmission in patients with coronary heart disease. However, few data show how physical activity is associated with survival and readmission after heart valve surgery. Objective were to assess the association between...... Register and The Danish Civil Registration System of 742 eligible patients. Physical activity was quantified with the International Physical Activity Questionnaire and analysed using Kaplan-Meier analysis and Cox regression and logistic regression methods. RESULTS: Patients with a moderate to high physical...

  11. Increased renal alpha-epithelial sodium channel (ENAC) protein and increased ENAC activity in normal pregnancy.

    West, Crystal; Zhang, Zheng; Ecker, Geoffrey; Masilamani, Shyama M E

    2010-11-01

    Pregnancy-mediated sodium (Na) retention is required to provide an increase in plasma volume for the growing fetus. The mechanisms responsible for this Na retention are not clear. We first used a targeted proteomics approach and found that there were no changes in the protein abundance compared with virgin rats of the β or γ ENaC, type 3 Na(+)/H(+) exchanger (NHE3), bumetanide-sensitive cotransporter (NKCC2), or NaCl cotransporter (NCC) in mid- or late pregnancy. In contrast, we observed marked increases in the abundance of the α-ENaC subunit. The plasma volume increased progressively during pregnancy with the greatest plasma volume being evident in late pregnancy. ENaC inhibition abolished the difference in plasma volume status between virgin and pregnant rats. To determine the in vivo activity of ENaC, we conducted in vivo studies of rats in late pregnancy (days 18-20) and virgin rats to measure the natriuretic response to ENaC blockade (with benzamil). The in vivo activity of ENaC (U(Na)V postbenzamil-U(Na)V postvehicle) was markedly increased in late pregnancy, and this difference was abolished by pretreatment with the mineralocorticoid receptor antagonist, eplerenone. These findings demonstrate that the increased α-ENaC subunit of pregnancy is associated with an mineralocorticoid-dependent increase in ENaC activity. Further, we show that ENaC activity is a major contributor of plasma volume status in late pregnancy. These changes are likely to contribute to the renal sodium retention and plasma volume expansion required for an optimal pregnancy.

  12. Accumulation of senescent cells in mitotic tissue of aging primates.

    Jeyapalan, Jessie C; Ferreira, Mark; Sedivy, John M; Herbig, Utz

    2007-01-01

    Cellular senescence, a stress induced growth arrest of somatic cells, was first documented in cell cultures over 40 years ago, however its physiological significance has only recently been demonstrated. Using novel biomarkers of cellular senescence we examined whether senescent cells accumulate in tissues from baboons of ages encompassing the entire lifespan of this species. We show that dermal fibroblasts, displaying markers of senescence such as telomere damage, active checkpoint kinase ATM, high levels of heterochromatin proteins and elevated levels of p16, accumulate in skin biopsies from baboons with advancing age. The number of dermal fibroblasts containing damaged telomeres reaches a value of over 15% of total fibroblasts, whereas 80% of cells contain high levels of the heterochromatin protein HIRA. In skeletal muscle, a postmitotic tissue, only a small percentage of myonuclei containing damaged telomeres were detected regardless of animal age. The presence of senescent cells in mitotic tissues might therefore be a contributing factor to aging and age related pathology and provides further evidence that cellular senescence is a physiological event.

  13. Does physical activity increase the risk of unsafe sun exposure?

    Jardine, Andrew; Bright, Margaret; Knight, Libby; Perina, Heather; Vardon, Paul; Harper, Catherine

    2012-04-01

    Recent increases in the prevalence of self-reported participation in physical activity are encouraging and beneficial for health overall. However, the implications for sun safety need to be considered, particularly in Australia, which has the highest incidence of skin cancer in the world. This study investigated the relationship between physical activity and sunburn to determine if there is a need for integration of sun safety in physical activity promotion. During the 2009/10 southern hemisphere summer, 7802 adults aged 18 to 74 years participated in a computer-assisted telephone interview survey which included a range of self-reported health measures including physical activity, sunburn, skin type, sun protection behaviour and demographic questions. Multivariate logistic regression modelling was undertaken to estimate the association between physical activity and sunburn. Those who reported doing any level of physical activity were significantly more likely to report having experienced sunburn in the past 12 months and on the last weekend, compared with those who did none, with the strongest association among those who undertook 7 hours or more. Each hour of physical activity was associated with a modest increase in the odds of experiencing sunburn in the previous 12 months (OR 1.02, 95% CI 1.010-1.037) and weekend (OR 1.04, 95% CI: 1.023-1.065), after adjusting for potential confounding variables. This study highlights the need for sun protection to be given more prominence in physical activity promotion in order to optimise health benefits without increasing the prevalence of sunburn and associated skin cancer risk.

  14. Texting to increase adolescent physical activity: Feasibility assessment

    Feasibility trials assess whether a behavior change program warrants a definite trial evaluation. This paper reports the feasibility of an intervention consisting of Self Determination Theory-informed text messages, pedometers, and goal prompts to increase adolescent physical activity. A 4-group ran...

  15. A Brief History of Research on Mitotic Mechanisms

    J. Richard McIntosh

    2016-12-01

    Full Text Available This chapter describes in summary form some of the most important research on chromosome segregation, from the discovery and naming of mitosis in the nineteenth century until around 1990. It gives both historical and scientific background for the nine chapters that follow, each of which provides an up-to-date review of a specific aspect of mitotic mechanism. Here, we trace the fruits of each new technology that allowed a deeper understanding of mitosis and its underlying mechanisms. We describe how light microscopy, including phase, polarization, and fluorescence optics, provided descriptive information about mitotic events and also enabled important experimentation on mitotic functions, such as the dynamics of spindle fibers and the forces generated for chromosome movement. We describe studies by electron microscopy, including quantitative work with serial section reconstructions. We review early results from spindle biochemistry and genetics, coupled to molecular biology, as these methods allowed scholars to identify key molecular components of mitotic mechanisms. We also review hypotheses about mitotic mechanisms whose testing led to a deeper understanding of this fundamental biological event. Our goal is to provide modern scientists with an appreciation of the work that has laid the foundations for their current work and interests.

  16. Ste12/Fab1 phosphatidylinositol-3-phosphate 5-kinase is required for nitrogen-regulated mitotic commitment and cell size control.

    David Cobley

    Full Text Available Tight coupling of cell growth and cell cycle progression enable cells to adjust their rate of division, and therefore size, to the demands of proliferation in varying nutritional environments. Nutrient stress promotes inhibition of Target Of Rapamycin Complex 1 (TORC1 activity. In fission yeast, reduced TORC1 activity advances mitotic onset and switches growth to a sustained proliferation at reduced cell size. A screen for mutants, that failed to advance mitosis upon nitrogen stress, identified a mutant in the PIKFYVE 1-phosphatidylinositol-3-phosphate 5-kinase fission yeast homolog Ste12. Ste12PIKFYVE deficient mutants were unable to advance the cell cycle to reduce cell size after a nitrogen downshift to poor nitrogen (proline growth conditions. While it is well established that PI(3,5P2 signalling is required for autophagy and that Ste12PIKFYVE mutants have enlarged vacuoles (yeast lysosomes, neither a block to autophagy or mutants that independently have enlarged vacuoles had any impact upon nitrogen control of mitotic commitment. The addition of rapamycin to Ste12PIKFYVE deficient mutants reduced cell size at division to suggest that Ste12PIKFYVE possibly functions upstream of TORC1. ste12 mutants display increased Torin1 (TOR inhibitor sensitivity. However, no major impact on TORC1 or TORC2 activity was observed in the ste12 deficient mutants. In summary, Ste12PIKFYVE is required for nitrogen-stress mediated advancement of mitosis to reduce cell size at division.

  17. Increased NTPDase Activity in Lymphocytes during Experimental Sepsis

    Bertoncheli, Claudia de Mello; Zimmermann, Carine Eloise Prestes; Jaques, Jeandre Augusto dos Santos; Leal, Cláudio Alberto Martins; Ruchel, Jader Betsch; Rocha, Bruna Cipolatto; Pinheiro, Kelly de Vargas; Souza, Viviane do Carmo Gonçalves; Stainki, Daniel Roulim; Luz, Sônia Cristina Almeida; Schetinger, Maria Rosa Chitolina; Leal, Daniela Bitencourt Rosa

    2012-01-01

    We investigated in rats induced to sepsis the activity of ectonucleoside triphosphate diphosphohydrolase (NTPDase; CD39; E.C. 3.6.1.5), an enzyme involved in the modulation of immune responses. After 12 hours of surgery, lymphocytes were isolated from blood and NTPDase activity was determined. It was also performed the histology of kidney, liver, and lung. The results demonstrated an increase in the hydrolysis of adenosine-5′-triphosphate (ATP) (P 0.05). Histological analysis showed several morphological changes in the septic group, such as vascular congestion, necrosis, and infiltration of mononuclear cells. It is known that the intracellular milieu contains much more ATP nucleotides than the extracellular. In this context, the increased ATPasic activity was probably induced as a dynamic response to clean up the elevated ATP levels resulting from cellular death. PMID:22645477

  18. Genetical control of mitotic crossing over in yeast

    Fedorova, I.V.; Marfin, A.B.

    1982-01-01

    Lethal effect of 8 methoxypsoralen (8-MOP) and long-wave ultraviolet radiation (LUR) on diploid and haploid radiosensitive strains of yeast LSaccharomyces cerevisiae has been studied. It is shown that wild type diploids and homozygous with respect to locus rad 2 is considerably more stable than corresponding haploids, while diploid homozygous with respect to rad 54 locus is more sensitive than haploid. Use of the method of repeated irradiation permitted to study capability of radiosensitive diploids to remove 8 MOP-induced DNA photodamages-monoadducts. This process proceeds effectively in the wild type strain and rad 54 rad 54 diploid and was absent in rad 2 rad 2 diploid. Very strong recombinogenous effect of 8-MOP and LUR was discovered when studying mitotic segregation and crossing-over. It is also shown that rad 2 mutation increases slightly and rad 54 mutation decreases sharply frequency of recombination events in yeast cells. It is established by means of the repeated irradiation method that the main contribution to the 8 MOP and LUR recombinogenous effect is made with DNA sutures induced with these agents. Possible participation of different repair systems in the recombination processes induced with 8 MOP and LUR in yeast cells is discussed

  19. Plk1 phosphorylation of IRS2 prevents premature mitotic exit via AKT inactivation

    Chen, Long; Li, Zhiguo; Ahmad, Nihal; Liu, Xiaoqi

    2016-01-01

    Insulin receptor substrate (IRS) proteins play important roles by acting as a platform in transducing signals from transmembrane receptors upon growth factor stimulation. Although tyrosine phosphorylation on IRS proteins plays critical roles in signal transduction, phosphorylation of IRS proteins on serine/threonine residues are believed to play various regulatory roles on IRS protein function. However, studies on serine/threonine phosphorylation of IRS proteins are very limited, especially for insulin receptor substrate 2 (IRS2), one member of the IRS protein family. In this study, we identify Polo-like kinase 1 (Plk1) as the responsible kinase for phosphorylation of IRS2 on two serine residues, Ser 556 and Ser 1098. Phosphorylation of IRS2 on these two serine residues by Plk1 prevents the activation of the PI3K pathway upon growth factor stimulation by inhibiting the binding between IRS2 and the PI3K pathway components and increasing IRS2 protein degradation. Of significance, we show that IRS2 phosphorylation is cell cycle regulated and that Plk1 phosphorylation of IRS2 prevents premature mitotic exit via AKT inactivation. PMID:25830382

  20. Kinesin-8 effects on mitotic microtubule dynamics contribute to spindle function in fission yeast

    Gergely, Zachary R.; Crapo, Ammon; Hough, Loren E.; McIntosh, J. Richard; Betterton, Meredith D.

    2016-01-01

    Kinesin-8 motor proteins destabilize microtubules. Their absence during cell division is associated with disorganized mitotic chromosome movements and chromosome loss. Despite recent work studying effects of kinesin-8s on microtubule dynamics, it remains unclear whether the kinesin-8 mitotic phenotypes are consequences of their effect on microtubule dynamics, their well-established motor activity, or additional, unknown functions. To better understand the role of kinesin-8 proteins in mitosis, we studied the effects of deletion of the fission yeast kinesin-8 proteins Klp5 and Klp6 on chromosome movements and spindle length dynamics. Aberrant microtubule-driven kinetochore pushing movements and tripolar mitotic spindles occurred in cells lacking Klp5 but not Klp6. Kinesin-8–deletion strains showed large fluctuations in metaphase spindle length, suggesting a disruption of spindle length stabilization. Comparison of our results from light microscopy with a mathematical model suggests that kinesin-8–induced effects on microtubule dynamics, kinetochore attachment stability, and sliding force in the spindle can explain the aberrant chromosome movements and spindle length fluctuations seen. PMID:27146110

  1. Increased physical activity decreases periodontitis risk in men

    Merchant, Anwar T.; Pitiphat, Waranuch; Rimm, Eric B.; Joshipura, Kaumudi

    2003-01-01

    Background: Increased physical activity improves insulin sensitivity and glucose metabolism, and may therefore affect incidence of periodontitis. Methods: We studied the association of physical activity, walking and periodontitis in 39,461 male, US based, health professionals, 40-75 years old at baseline, more than half of whom were dentists, being followed up continuously since 1986. Participants were free of periodontitis, coronary heart disease and stroke at the start of follow-up. Physical activity and periodontitis were measured by validated questionnaires (expressed in metabolic equivalents - METs); the first report of professionally diagnosed periodontitis was considered a case. Results: Periodontitis risk decreased by 3% for every 10-MET increase in average physical activity after adjustment for age, smoking, diabetes, BMI, alcohol consumption and total calories (RR = 0.97; 95% CI: 0.95-0.99). The inverse trend remained significant in the categorical analysis. Compared to men in the lowest quintile of physical activity, those in the highest quintile had a 13% lower risk of periodontitis (RR = 0.87; 95% CI: 0.76-1.01, p-value, test for trend = 0.02). In a sub-sample of men with radiographs (n = 137) the physically active had less average bone loss (β = -0.29, p-value = 0.03) after multivariate adjustment compared to those inactive. Conclusions: In this large-scale prospective study, we found an inverse, linear association between sustained physical activity and periodontitis independent of known risk factors. The benefits of a physically active lifestyle may extend to periodontal health

  2. Exercising self-control increases relative left frontal cortical activation.

    Schmeichel, Brandon J; Crowell, Adrienne; Harmon-Jones, Eddie

    2016-02-01

    Self-control refers to the capacity to override or alter a predominant response tendency. The current experiment tested the hypothesis that exercising self-control temporarily increases approach motivation, as revealed by patterns of electrical activity in the prefrontal cortex. Participants completed a writing task that did vs did not require them to exercise self-control. Then they viewed pictures known to evoke positive, negative or neutral affect. We assessed electroencephalographic (EEG) activity while participants viewed the pictures, and participants reported their trait levels of behavioral inhibition system (BIS) and behavioral activation system (BAS) sensitivity at the end of the study. We found that exercising (vs not exercising) self-control increased relative left frontal cortical activity during picture viewing, particularly among individuals with relatively higher BAS than BIS, and particularly during positive picture viewing. A similar but weaker pattern emerged during negative picture viewing. The results suggest that exercising self-control temporarily increases approach motivation, which may help to explain the aftereffects of self-control (i.e. ego depletion). © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  3. Invasive Glioblastoma Cells Acquire Stemness and Increased Akt Activation

    Jennifer R. Molina

    2010-06-01

    Full Text Available Glioblastoma multiforme (GBM is the most frequent and most aggressive brain tumor in adults. The dismal prognosis is due to postsurgery recurrences arising from escaped invasive tumor cells. The signaling pathways activated in invasive cells are under investigation, and models are currently designed in search for therapeutic targets. We developed here an in vivo model of human invasive GBM in mouse brain from a GBM cell line with moderate tumorigenicity that allowed simultaneous primary tumor growth and dispersal of tumor cells in the brain parenchyma. This strategy allowed for the first time the isolation and characterization of matched sets of tumor mass (Core and invasive (Inv cells. Both cell populations, but more markedly Inv cells, acquired stem cell markers, neurosphere renewal ability, and resistance to rapamycin-induced apoptosis relative to parental cells. The comparative phenotypic analysis between Inv and Core cells showed significantly increased tumorigenicity in vivo and increased invasion with decreased proliferation in vitro for Inv cells. Examination of a large array of signaling pathways revealed extracellular signal-regulated kinase (Erk down-modulation and Akt activation in Inv cells and an opposite profile in Core cells. Akt activation correlated with the increased tumorigenicity, stemness, and invasiveness, whereas Erk activation correlated with the proliferation of the cells. These results underscore complementary roles of the Erk and Akt pathways for GBM proliferation and dispersal and raise important implications for a concurrent inhibitory therapy.

  4. Mechanisms and Regulation of Mitotic Recombination in Saccharomyces cerevisiae

    Symington, Lorraine S.; Rothstein, Rodney; Lisby, Michael

    2014-01-01

    Homology-dependent exchange of genetic information between DNA molecules has a profound impact on the maintenance of genome integrity by facilitating error-free DNA repair, replication, and chromosome segregation during cell division as well as programmed cell developmental events. This chapter will focus on homologous mitotic recombination in budding yeast Saccharomyces cerevisiae. However, there is an important link between mitotic and meiotic recombination (covered in the forthcoming chapter by Hunter et al. 2015) and many of the functions are evolutionarily conserved. Here we will discuss several models that have been proposed to explain the mechanism of mitotic recombination, the genes and proteins involved in various pathways, the genetic and physical assays used to discover and study these genes, and the roles of many of these proteins inside the cell. PMID:25381364

  5. Disappearance of nucleosome positioning in mitotic chromatin in vivo.

    Komura, Jun-ichiro; Ono, Tetsuya

    2005-04-15

    During mitosis, transcription is silenced and most transcription factors are displaced from their recognition sequences. By in vivo footprinting analysis, we have confirmed and extended previous studies showing loss of transcription factors from an RNA polymerase II promoter (c-FOS) and, for the first time, an RNA polymerase III promoter (U6) in HeLa cells. Because little was known about nucleosomal organization in mitotic chromosomes, we performed footprinting analysis for nucleosomes on these promoters in interphase and mitotic cells. During interphase, each of the promoters had a positioned nucleosome in the region intervening between proximal promoter elements and distal enhancer elements, but the strong nucleosome positioning disappeared during mitosis. Thus, the nucleosomal organization that appears to facilitate transcription in interphase cells may be lost in mitotic cells, and nucleosome positioning during mitosis does not seem to be a major component of the epigenetic mechanisms to mark genes for rapid reactivation after this phase.

  6. Mitotic catastrophe is the mechanism of lethality for mutations that confer mutagen sensitivity in Aspergillus nidulans.

    Denison, S H; May, G S

    1994-01-16

    We have examined the consequences of treatment with DNA-damaging agents of uvs mutants and the bimD6 mutant of Aspergillus nidulans. We first established that wild-type Aspergillus undergoes a cell cycle delay following treatment with the DNA-damaging agents methyl methanesulfonate (MMS) or ultraviolet light (UV). We have also determined that strains carrying the bimD6, uvsB110, uvsH77, uvsF201 and the uvsC114 mutations, all of which cause an increased sensitivity to DNA-damaging agents, undergo a cell-cycle delay following DNA damage. These mutations therefore do not represent nonfunctional checkpoints in Aspergillus. However, all of the mutant strains accumulated nuclear defects after a period of delay following mutagen treatment. The nuclear defects in the uvsB110 and bimD6 strains following MMS treatment were shown to be dependent on passage through mitosis after DNA damage, as the defects were prevented with benomyl. Checkpoint controls responding to DNA damage thus only temporarily halt cell-cycle progression in response to DNA damage. The conditional bimD6 mutation also results in a defective mitosis at restrictive temperatures. This mitotic defect is similar to that seen with MMS treatment at temperatures permissive for the mitotic defect. Thus the bimD gene product may perform dual roles, one in DNA repair and the other during the mitotic cell cycle in the absence of damage.

  7. Kalanchoe tubiflora extract inhibits cell proliferation by affecting the mitotic apparatus.

    Hsieh, Yi-Jen; Yang, Ming-Yeh; Leu, Yann-Lii; Chen, Chinpiao; Wan, Chin-Fung; Chang, Meng-Ya; Chang, Chih-Jui

    2012-09-10

    Kalanchoe tubiflora (KT) is a succulent plant native to Madagascar, and is commonly used as a medicinal agent in Southern Brazil. The underlying mechanisms of tumor suppression are largely unexplored. Cell viability and wound-healing were analyzed by MTT assay and scratch assay respectively. Cell cycle profiles were analyzed by FACS. Mitotic defects were analyzed by indirect immunofluoresence images. An n-Butanol-soluble fraction of KT (KT-NB) was able to inhibit cell proliferation. After a 48 h treatment with 6.75 μg/ml of KT, the cell viability was less than 50% of controls, and was further reduced to less than 10% at higher concentrations. KT-NB also induced an accumulation of cells in the G2/M phase of the cell cycle as well as an increased level of cells in the subG1 phase. Instead of disrupting the microtubule network of interphase cells, KT-NB reduced cell viability by inducing multipolar spindles and defects in chromosome alignment. KT-NB inhibits cell proliferation and reduces cell viability by two mechanisms that are exclusively involved with cell division: first by inducing multipolarity; second by disrupting chromosome alignment during metaphase. KT-NB reduced cell viability by exclusively affecting formation of the proper structure of the mitotic apparatus. This is the main idea of the new generation of anti-mitotic agents. All together, KT-NB has sufficient potential to warrant further investigation as a potential new anticancer agent candidate.

  8. Project U-Turn: increasing active transportation in Jackson, Michigan.

    TenBrink, David S; McMunn, Randall; Panken, Sarah

    2009-12-01

    Jackson, Michigan, is a medium-sized city suffering from a bad economy and obesity-related health issues. Nearly 20% of the 36,000 residents live below the poverty line. It is a relatively young city (median age of 30 years) with a mixed ethnicity (20% black, 73% white, 4% Hispanic). The city offers many structured, active recreational opportunities, but has not integrated physical activity into daily life. Project U-Turn aimed to increase active transportation (e.g., biking, walking, and transit use) through an integrated approach to Active Living by Design's community action model and the Michigan Safe Routes to School model. Resources were focused on active living promotions and programs; partnership meetings were the source of changes in policy and physical projects. Each initiative was designed to introduce each of the 5Ps (preparation, promotion, programs, policy, and physical projects) to build support for the partnership's overall work. The partnership collected snapshot data of community walking and biking behavior, percentage of students walking to school, participation in events and programs, and new physical projects. Jackson saw a vast improvement in physical infrastructure and policy and a related increase in walking and biking in the community. The project engaged in purposeful partnership building to implement effective programs and promotions that built support for policy and physical projects. Limited resources were best used by encouraging partners to contribute and coordinate activities using existing staff, funding, and resources. Jackson has seen a shift toward awareness of the benefits of active living on community health, economic development, and environmental awareness.

  9. Chemically modified carboxypeptidase Y with increased amidase activity

    Breddam, K.

    1984-01-01

    Treatment of carboxypeptidase Y with 14 C-iodoacetamide caused a drastic reduction in the peptidase activity towards FA-Phe-Leu-OH while the esterase activity towards FA-Phe-OMe, the amidase activity towards FA-Phe-NH 2 and the peptidyl amino acid amide hydrolase activity towards FA-Phe-Gly-NH 2 were much less affected. The loss of peptidase activity could be correlated with the incorporation of a single equivalent of reagent and it was demonstrated that the site of reaction was a methionyl residue, thus forming a sulfonium derivative. Analogous methionyl modifications were performed: carboxypeptidase Y modified with phenacylbromide hydrolysed substrates with bulky leaving groups in the P position, i.e. -OEt, -OBzl, -Gly-NH 2 ,-Gly-OH, and -Leu-OH, at reduced rates while substrates with small groups in that position, i.e. -OMe and -NH 2 , were hydrolysed with increased rates. These results indicate that the methionyl residue modified by phenacylbromide is located in the S binding site of the enzyme. Similar results were obtained with carboxypeptidase Y modified with m-nitrophen- acylbromide and p-nitrophenacylbromide. The increase in amidase activity and decrease in peptidyl amino acid amide hydrolase activity of carboxypeptidase Y following modification with phenacylbromide, m-nitrophenacylbromide, and p-nitrophenacylbromide was exploited in deamidation of peptide amides. These modified enzymes deamidated peptide amides with the exception of those containing a C-terminal glycyl or seryl residue in yields of 80-100% which is significantly higher than with unmodified carboxypeptidase Y. (author)

  10. Active learning increases student performance in science, engineering, and mathematics.

    Freeman, Scott; Eddy, Sarah L; McDonough, Miles; Smith, Michelle K; Okoroafor, Nnadozie; Jordt, Hannah; Wenderoth, Mary Pat

    2014-06-10

    To test the hypothesis that lecturing maximizes learning and course performance, we metaanalyzed 225 studies that reported data on examination scores or failure rates when comparing student performance in undergraduate science, technology, engineering, and mathematics (STEM) courses under traditional lecturing versus active learning. The effect sizes indicate that on average, student performance on examinations and concept inventories increased by 0.47 SDs under active learning (n = 158 studies), and that the odds ratio for failing was 1.95 under traditional lecturing (n = 67 studies). These results indicate that average examination scores improved by about 6% in active learning sections, and that students in classes with traditional lecturing were 1.5 times more likely to fail than were students in classes with active learning. Heterogeneity analyses indicated that both results hold across the STEM disciplines, that active learning increases scores on concept inventories more than on course examinations, and that active learning appears effective across all class sizes--although the greatest effects are in small (n ≤ 50) classes. Trim and fill analyses and fail-safe n calculations suggest that the results are not due to publication bias. The results also appear robust to variation in the methodological rigor of the included studies, based on the quality of controls over student quality and instructor identity. This is the largest and most comprehensive metaanalysis of undergraduate STEM education published to date. The results raise questions about the continued use of traditional lecturing as a control in research studies, and support active learning as the preferred, empirically validated teaching practice in regular classrooms.

  11. Protein energy malnutrition increases arginase activity in monocytes and macrophages.

    Corware, Karina; Yardley, Vanessa; Mack, Christopher; Schuster, Steffen; Al-Hassi, Hafid; Herath, Shanthi; Bergin, Philip; Modolell, Manuel; Munder, Markus; Müller, Ingrid; Kropf, Pascale

    2014-01-01

    Protein energy malnutrition is commonly associated with immune dysfunctions and is a major factor in susceptibility to infectious diseases. In this study, we evaluated the impact of protein energy malnutrition on the capacity of monocytes and macrophages to upregulate arginase, an enzyme associated with immunosuppression and increased pathogen replication. Our results show that monocytes and macrophages are significantly increased in the bone marrow and blood of mice fed on a protein low diet. No alteration in the capacity of bone marrow derived macrophages isolated from malnourished mice to phagocytose particles, to produce the microbicidal molecule nitric oxide and to kill intracellular Leishmania parasites was detected. However, macrophages and monocytes from malnourished mice express significantly more arginase both in vitro and in vivo. Using an experimental model of visceral leishmaniasis, we show that following protein energy malnutrition, the increased parasite burden measured in the spleen of these mice coincided with increased arginase activity and that macrophages provide a more permissive environment for parasite growth. Taken together, these results identify a novel mechanism in protein energy malnutrition that might contributes to increased susceptibility to infectious diseases by upregulating arginase activity in myeloid cells.

  12. Endothelin-1 activation of ETB receptors leads to a reduced cellular proliferative rate and an increased cellular footprint

    Wilson, Jamie L.; Taylor, Linda; Polgar, Peter

    2012-01-01

    Endothelin-1 (ET-1) is a vasoactive peptide which signals through two G-protein coupled receptors, endothelin receptor A (ETA) and B (ETB). We determined that ET-1 activation of its ETB receptor in stably cDNA transfected CHO cells leads to a 55% reduction in cell number by end-point cell counting and a 35% decrease in cell growth by a real-time cell-substrate impedance-based assay after 24 h of cell growth. When CHO ETB cells were synchronized in the late G1 cell cycle phase, ET-1 delayed their S phase progression compared to control by 30% as determined by [ 3 H]-thymidine incorporation. On the other hand, no such delay was observed during late G2/M to G1 transit when cells were treated with ET-1 after release from mitotic arrest. Using the cell-substrate impedance-based assay, we observed that ET-1 induces opposing morphological changes in CHO ETA and CHO ETB cells with ETB causing an increase in the cell footprint and ETA a decrease. Likewise, in pulmonary artery smooth muscle cells, which express both ETA and ETB receptors, ET-1 induces an ETA-dependent contraction and an ETB dependent dilation. These results are shedding light on a possible beneficial role for ETB in diseases involving ET-1 dysfunction such as pulmonary hypertension. -- Highlights: ► ET- hinders cell proliferation in CHO cells transfected with ETB. ► ET-1 also decreases the rate of DNA synthesis in CHO ETB cells. ► JNK and PI3K appear to be involved in this reduction of DNA synthesis. ► ETB activation in CHO ETB cells and hSMCs leads to dilatory morphological changes. ► In CHO ETA and hSMCs, ETA activation leads to constrictive morphological changes.

  13. Endothelin-1 activation of ETB receptors leads to a reduced cellular proliferative rate and an increased cellular footprint

    Wilson, Jamie L.; Taylor, Linda; Polgar, Peter, E-mail: peterp@bu.edu

    2012-06-10

    Endothelin-1 (ET-1) is a vasoactive peptide which signals through two G-protein coupled receptors, endothelin receptor A (ETA) and B (ETB). We determined that ET-1 activation of its ETB receptor in stably cDNA transfected CHO cells leads to a 55% reduction in cell number by end-point cell counting and a 35% decrease in cell growth by a real-time cell-substrate impedance-based assay after 24 h of cell growth. When CHO ETB cells were synchronized in the late G1 cell cycle phase, ET-1 delayed their S phase progression compared to control by 30% as determined by [{sup 3}H]-thymidine incorporation. On the other hand, no such delay was observed during late G2/M to G1 transit when cells were treated with ET-1 after release from mitotic arrest. Using the cell-substrate impedance-based assay, we observed that ET-1 induces opposing morphological changes in CHO ETA and CHO ETB cells with ETB causing an increase in the cell footprint and ETA a decrease. Likewise, in pulmonary artery smooth muscle cells, which express both ETA and ETB receptors, ET-1 induces an ETA-dependent contraction and an ETB dependent dilation. These results are shedding light on a possible beneficial role for ETB in diseases involving ET-1 dysfunction such as pulmonary hypertension. -- Highlights: Black-Right-Pointing-Pointer ET- hinders cell proliferation in CHO cells transfected with ETB. Black-Right-Pointing-Pointer ET-1 also decreases the rate of DNA synthesis in CHO ETB cells. Black-Right-Pointing-Pointer JNK and PI3K appear to be involved in this reduction of DNA synthesis. Black-Right-Pointing-Pointer ETB activation in CHO ETB cells and hSMCs leads to dilatory morphological changes. Black-Right-Pointing-Pointer In CHO ETA and hSMCs, ETA activation leads to constrictive morphological changes.

  14. Modafinil enhances thalamocortical activity by increasing neuronal electrotonic coupling

    Urbano, Francisco J.; Leznik, Elena; Llinás, Rodolfo R.

    2007-01-01

    Modafinil (Provigil, Modiodal), an antinarcoleptic and mood-enhancing drug, is shown here to sharpen thalamocortical activity and to increase electrical coupling between cortical interneurons and between nerve cells in the inferior olivary nucleus. After irreversible pharmacological block of connexin permeability (i.e., by using either 18β-glycyrrhetinic derivatives or mefloquine), modafinil restored electrotonic coupling within 30 min. It was further established that this restoration is implemented through a Ca2+/calmodulin protein kinase II-dependent step. PMID:17640897

  15. Increased activation in Broca's area after cognitive remediation in schizophrenia.

    Vianin, Pascal; Urben, Sébastien; Magistretti, Pierre; Marquet, Pierre; Fornari, Eleonora; Jaugey, Laure

    2014-03-30

    Functional magnetic resonance imaging (fMRI) was used to measure changes in cerebral activity in patients with schizophrenia after participation in the Cognitive Remediation Program for Schizophrenia and other related disorders (RECOS). As RECOS therapists make use of problem-solving and verbal mediation techniques, known to be beneficial in the rehabilitation of dysexecutive syndromes, we expected an increased activation of frontal areas after remediation. Executive functioning and cerebral activation during a covert verbal fluency task were measured in eight patients with schizophrenia before (T1) and after (T2) 14 weeks of RECOS therapy. The same measures were recorded in eight patients with schizophrenia who did not participate in RECOS at the same intervals of time (TAU group). Increased activation in Broca's area, as well as improvements in performance of executive/frontal tasks, was observed after cognitive training. Metacognitive techniques of verbalization are hypothesized to be the main factor underlying the brain changes observed in the present study. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  16. Using Technology to Increase Physical Activity in Health Profession Students

    Mary Ann Stark

    2016-01-01

    Full Text Available Health profession students may need help establishing and maintaining positive health behaviors when they are in college. This study explored the effectiveness of text messaging as an innovative method for promoting an increase in daily physical activity. A convenience sample (N = 134 was recruited from students at a college of Health and Human Services in Michigan. The participants were randomized into an intervention or control group (n = 67 each. The intervention group received daily affective text messages encouraging more physical activity by taking more steps. The control group received only messages reminding them to report their number of steps. All of the participants received a pedometer, completed a demographics and daily habits questionnaire, and completed the Perceived Stress Scale (PSS. There was no significant difference between the intervention and control groups in their number of daily steps. However, the most inactive participants had a significant increase in steps during the study period. Health profession students’ lifestyle behaviors have consequences, as they become caregivers in our dynamic, demanding health-care system. For those with the greatest need for physical activity, encouraging such activity via text messaging may improve their ability to care for themselves and their clients.

  17. Systematic review of recess interventions to increase physical activity.

    Ickes, Melinda J; Erwin, Heather; Beighle, Aaron

    2013-08-01

    With the rapid increase in obesity rates among youth, efforts to increase physical activity (PA) have become a priority. School-based strategies for PA promotion must be cost-effective, unobtrusive, and linked to improved academic performance. Efforts to maximize recess PA are advocated because of both health and academic benefits. The purpose of this manuscript was to review recess interventions aimed to improve PA among youth, and make recommendations to develop related best practices. An extensive literature search was conducted to include all primary research articles evaluating any recess intervention with PA as an outcome. The included 13 interventions represented both settings within the U.S and internationally, among preschools and elementary/primary schools. A variety of strategies were used within the design and implementation of each of the interventions including: added equipment/materials, markings, zones, teacher involvement, active video games, activity of the week, and activity cards. Of the included studies, 95% demonstrated positive outcomes as a result of the recess intervention. A number of simple, low-cost strategies can be implemented to maximize the amount of recess time students are allotted. Long-term follow-up studies are warranted for each of the recess strategies identified to be effective.

  18. Interactions Increase Forager Availability and Activity in Harvester Ants.

    Evlyn Pless

    Full Text Available Social insect colonies use interactions among workers to regulate collective behavior. Harvester ant foragers interact in a chamber just inside the nest entrance, here called the 'entrance chamber'. Previous studies of the activation of foragers in red harvester ants show that an outgoing forager inside the nest experiences an increase in brief antennal contacts before it leaves the nest to forage. Here we compare the interaction rate experienced by foragers that left the nest and ants that did not. We found that ants in the entrance chamber that leave the nest to forage experienced more interactions than ants that descend to the deeper nest without foraging. Additionally, we found that the availability of foragers in the entrance chamber is associated with the rate of forager return. An increase in the rate of forager return leads to an increase in the rate at which ants descend to the deeper nest, which then stimulates more ants to ascend into the entrance chamber. Thus a higher rate of forager return leads to more available foragers in the entrance chamber. The highest density of interactions occurs near the nest entrance and the entrances of the tunnels from the entrance chamber to the deeper nest. Local interactions with returning foragers regulate both the activation of waiting foragers and the number of foragers available to be activated.

  19. The participation of elevated levels of cyclic GMP in the recovery from radiation-induced mitotic delay

    Daniel, J.W.; Oleinick, N.L.

    1984-01-01

    The levels of cyclic AMP and cyclic GMP have been measured in Physarum plasmodia before and after treatment with gamma-radiation, 2 mM caffeine, or combinations of the two agents compared to the length of the radiation-induced mitotic delay. Caffeine alone produces a rapid transient elevation of cyclic AMP and a slower delayed elevation of cyclic GMP. Irradiation elicits an immediate transient increase in cyclic AMP and a later cyclic GMP increase which accompanies or precedes the delayed mitosis. A composite pattern is produced by combinations of radiation and caffeine, a distinctive feature of which is an elevated level of cyclic GMP near the time of the radiation-delayed and caffeine-promoted mitosis. With pretreatment by caffeine, the least radiation-induced mitotic delay occurs when plasmodia are irradiated during the caffeine-elicited increase in cyclic GMP. The plasmodium becomes refractory to the reduction of mitotic delay by caffeine at approximately the time it becomes refractory to the further elevation of cyclic GMP by caffeine. The data support a role for cyclic AMP in the onset of and for cyclic GMP in the recovery from mitotic delay induced by ionizing radiation. (author)

  20. Serotonin increases synaptic activity in olfactory bulb glomeruli.

    Brill, Julia; Shao, Zuoyi; Puche, Adam C; Wachowiak, Matt; Shipley, Michael T

    2016-03-01

    Serotoninergic fibers densely innervate olfactory bulb glomeruli, the first sites of synaptic integration in the olfactory system. Acting through 5HT2A receptors, serotonin (5HT) directly excites external tufted cells (ETCs), key excitatory glomerular neurons, and depolarizes some mitral cells (MCs), the olfactory bulb's main output neurons. We further investigated 5HT action on MCs and determined its effects on the two major classes of glomerular interneurons: GABAergic/dopaminergic short axon cells (SACs) and GABAergic periglomerular cells (PGCs). In SACs, 5HT evoked a depolarizing current mediated by 5HT2C receptors but did not significantly impact spike rate. 5HT had no measurable direct effect in PGCs. Serotonin increased spontaneous excitatory and inhibitory postsynaptic currents (sEPSCs and sIPSCs) in PGCs and SACs. Increased sEPSCs were mediated by 5HT2A receptors, suggesting that they are primarily due to enhanced excitatory drive from ETCs. Increased sIPSCs resulted from elevated excitatory drive onto GABAergic interneurons and augmented GABA release from SACs. Serotonin-mediated GABA release from SACs was action potential independent and significantly increased miniature IPSC frequency in glomerular neurons. When focally applied to a glomerulus, 5HT increased MC spontaneous firing greater than twofold but did not increase olfactory nerve-evoked responses. Taken together, 5HT modulates glomerular network activity in several ways: 1) it increases ETC-mediated feed-forward excitation onto MCs, SACs, and PGCs; 2) it increases inhibition of glomerular interneurons; 3) it directly triggers action potential-independent GABA release from SACs; and 4) these network actions increase spontaneous MC firing without enhancing responses to suprathreshold sensory input. This may enhance MC sensitivity while maintaining dynamic range. Copyright © 2016 the American Physiological Society.

  1. Nest predation increases with parental activity: separating nest site and parental activity effects.

    Martin, T E; Scott, J; Menge, C

    2000-01-01

    Alexander Skutch hypothesized that increased parental activity can increase the risk of nest predation. We tested this hypothesis using ten open-nesting bird species in Arizona, USA. Parental activity was greater during the nestling than incubation stage because parents visited the nest frequently to feed their young during the nestling stage. However, nest predation did not generally increase with parental activity between nesting stages across the ten study species. Previous investigators h...

  2. Increasing physical activity with mobile devices: a meta-analysis.

    Fanning, Jason; Mullen, Sean P; McAuley, Edward

    2012-11-21

    Regular physical activity has established physical and mental health benefits; however, merely one quarter of the U.S. adult population meets national physical activity recommendations. In an effort to engage individuals who do not meet these guidelines, researchers have utilized popular emerging technologies, including mobile devices (ie, personal digital assistants [PDAs], mobile phones). This study is the first to synthesize current research focused on the use of mobile devices for increasing physical activity. To conduct a meta-analysis of research utilizing mobile devices to influence physical activity behavior. The aims of this review were to: (1) examine the efficacy of mobile devices in the physical activity setting, (2) explore and discuss implementation of device features across studies, and (3) make recommendations for future intervention development. We searched electronic databases (PubMed, PsychINFO, SCOPUS) and identified publications through reference lists and requests to experts in the field of mobile health. Studies were included that provided original data and aimed to influence physical activity through dissemination or collection of intervention materials with a mobile device. Data were extracted to calculate effect sizes for individual studies, as were study descriptives. A random effects meta-analysis was conducted using the Comprehensive Meta-Analysis software suite. Study quality was assessed using the quality of execution portion of the Guide to Community Preventative Services data extraction form. Four studies were of "good" quality and seven of "fair" quality. In total, 1351 individuals participated in 11 unique studies from which 18 effects were extracted and synthesized, yielding an overall weight mean effect size of g = 0.54 (95% CI = 0.17 to 0.91, P = .01). Research utilizing mobile devices is gaining in popularity, and this study suggests that this platform is an effective means for influencing physical activity behavior. Our focus

  3. Playing active video games increases energy expenditure in children.

    Graf, Diana L; Pratt, Lauren V; Hester, Casey N; Short, Kevin R

    2009-08-01

    To compare energy expenditure rates in children playing the physically active video games, Dance Dance Revolution (DDR) and Nintendo's Wii Sports in relation to treadmill walking. Energy expenditure, heart rate, step rate, and perceived exertion were measured in 14 boys and 9 girls (ages 10-13 years; BMI at 3-98th percentile for age and gender) while watching television at rest, playing DDR at 2 skill levels, playing Wii bowling and boxing, and walking at 2.6, 4.2, and 5.7 km/h. Arterial elasticity was measured at rest and immediately after gaming. Compared with watching television, energy expenditure while gaming or walking increased 2- to 3-fold. Similarly, high rates of energy expenditure, heart rate, and perceived exertion were elicited from playing Wii boxing, DDR level 2, or walking at 5.7 km/h. This occurred despite variations in step rate among activities, reflecting greater use of upper body during Wii play (lowest step rate) than during walking (highest step rate) or DDR play. Wii bowling and beginner level DDR elicited a 2-fold increase in energy expenditure compared to television watching. Large-artery elasticity declined immediately after both DDR and Wii. The change was inversely related to the increment in energy expenditure above rest achieved during the activity. Energy expenditure during active video game play is comparable to moderate-intensity walking. Thus, for children who spend considerable time playing electronic screen games for entertainment, physically active games seem to be a safe, fun, and valuable means of promoting energy expenditure.

  4. Delayed cell death associated with mitotic catastrophe in γ-irradiated stem-like glioma cells

    Firat, Elke; Gaedicke, Simone; Tsurumi, Chizuko; Esser, Norbert; Weyerbrock, Astrid; Niedermann, Gabriele

    2011-01-01

    Stem-like tumor cells are regarded as highly resistant to ionizing radiation (IR). Previous studies have focused on apoptosis early after irradiation, and the apoptosis resistance observed has been attributed to reduced DNA damage or enhanced DNA repair compared to non-stem tumor cells. Here, early and late radioresponse of patient-derived stem-like glioma cells (SLGCs) and differentiated cells directly derived from them were examined for cell death mode and the influence of stem cell-specific growth factors. Primary SLGCs were propagated in serum-free medium with the stem-cell mitogens epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF-2). Differentiation was induced by serum-containing medium without EGF and FGF. Radiation sensitivity was evaluated by assessing proliferation, clonogenic survival, apoptosis, and mitotic catastrophe. DNA damage-associated γH2AX as well as p53 and p21 expression were determined by Western blots. SLGCs failed to apoptose in the first 4 days after irradiation even at high single doses up to 10 Gy, but we observed substantial cell death later than 4 days postirradiation in 3 of 6 SLGC lines treated with 5 or 10 Gy. This delayed cell death was observed in 3 of the 4 SLGC lines with nonfunctional p53, was associated with mitotic catastrophe and occurred via apoptosis. The early apoptosis resistance of the SLGCs was associated with lower γH2AX compared to differentiated cells, but we found that the stem-cell culture cytokines EGF plus FGF-2 strongly reduce γH2AX levels. Nonetheless, in two p53-deficient SLGC lines examined γIR-induced apoptosis even correlated with EGF/FGF-induced proliferation and mitotic catastrophe. In a line containing CD133-positive and -negative stem-like cells, the CD133-positive cells proliferated faster and underwent more γIR-induced mitotic catastrophe. Our results suggest the importance of delayed apoptosis, associated mitotic catastrophe, and cellular proliferation for γIR-induced death of

  5. The moyamoya disease susceptibility variant RNF213 R4810K (rs112735431) induces genomic instability by mitotic abnormality

    Hitomi, Toshiaki [Department of Health and Environmental Sciences, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Habu, Toshiyuki [Radiation Biology Center, Kyoto University, Kyoto (Japan); Kobayashi, Hatasu; Okuda, Hiroko; Harada, Kouji H. [Department of Health and Environmental Sciences, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Osafune, Kenji [Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto (Japan); Taura, Daisuke; Sone, Masakatsu [Department of Medicine and Clinical Science, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Asaka, Isao; Ameku, Tomonaga; Watanabe, Akira; Kasahara, Tomoko; Sudo, Tomomi; Shiota, Fumihiko [Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto (Japan); Hashikata, Hirokuni; Takagi, Yasushi [Department of Neurosurgery, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Morito, Daisuke [Faculty of Life Sciences, Kyoto Sangyo University, Kyoto (Japan); Miyamoto, Susumu [Department of Neurosurgery, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Nakao, Kazuwa [Department of Medicine and Clinical Science, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Koizumi, Akio, E-mail: koizumi.akio.5v@kyoto-u.ac.jp [Department of Health and Environmental Sciences, Graduate School of Medicine, Kyoto University, Kyoto (Japan)

    2013-10-04

    Highlights: •Overexpression of RNF213 R4810K inhibited cell proliferation. •Overexpression of RNF213 R4810K had the time of mitosis 4-fold and mitotic failure. •R4810K formed a complex with MAD2 more readily than wild-type. •iPSECs from the MMD patients had elevated mitotic failure compared from the control. •RNF213 R4810K induced mitotic abnormality and increased risk of aneuploidy. -- Abstract: Moyamoya disease (MMD) is a cerebrovascular disease characterized by occlusive lesions in the Circle of Willis. The RNF213 R4810K polymorphism increases susceptibility to MMD. In the present study, we characterized phenotypes caused by overexpression of RNF213 wild type and R4810K variant in the cell cycle to investigate the mechanism of proliferation inhibition. Overexpression of RNF213 R4810K in HeLa cells inhibited cell proliferation and extended the time of mitosis 4-fold. Ablation of spindle checkpoint by depletion of mitotic arrest deficiency 2 (MAD2) did not shorten the time of mitosis. Mitotic morphology in HeLa cells revealed that MAD2 colocalized with RNF213 R4810K. Immunoprecipitation revealed an RNF213/MAD2 complex: R4810K formed a complex with MAD2 more readily than RNF213 wild-type. Desynchronized localization of MAD2 was observed more frequently during mitosis in fibroblasts from patients (n = 3, 61.0 ± 8.2%) compared with wild-type subjects (n = 6, 13.1 ± 7.7%; p < 0.01). Aneuploidy was observed more frequently in fibroblasts (p < 0.01) and induced pluripotent stem cells (iPSCs) (p < 0.03) from patients than from wild-type subjects. Vascular endothelial cells differentiated from iPSCs (iPSECs) of patients and an unaffected carrier had a longer time from prometaphase to metaphase than those from controls (p < 0.05). iPSECs from the patients and unaffected carrier had significantly increased mitotic failure rates compared with controls (p < 0.05). Thus, RNF213 R4810K induced mitotic abnormalities and increased risk of genomic instability.

  6. The moyamoya disease susceptibility variant RNF213 R4810K (rs112735431) induces genomic instability by mitotic abnormality

    Hitomi, Toshiaki; Habu, Toshiyuki; Kobayashi, Hatasu; Okuda, Hiroko; Harada, Kouji H.; Osafune, Kenji; Taura, Daisuke; Sone, Masakatsu; Asaka, Isao; Ameku, Tomonaga; Watanabe, Akira; Kasahara, Tomoko; Sudo, Tomomi; Shiota, Fumihiko; Hashikata, Hirokuni; Takagi, Yasushi; Morito, Daisuke; Miyamoto, Susumu; Nakao, Kazuwa; Koizumi, Akio

    2013-01-01

    Highlights: •Overexpression of RNF213 R4810K inhibited cell proliferation. •Overexpression of RNF213 R4810K had the time of mitosis 4-fold and mitotic failure. •R4810K formed a complex with MAD2 more readily than wild-type. •iPSECs from the MMD patients had elevated mitotic failure compared from the control. •RNF213 R4810K induced mitotic abnormality and increased risk of aneuploidy. -- Abstract: Moyamoya disease (MMD) is a cerebrovascular disease characterized by occlusive lesions in the Circle of Willis. The RNF213 R4810K polymorphism increases susceptibility to MMD. In the present study, we characterized phenotypes caused by overexpression of RNF213 wild type and R4810K variant in the cell cycle to investigate the mechanism of proliferation inhibition. Overexpression of RNF213 R4810K in HeLa cells inhibited cell proliferation and extended the time of mitosis 4-fold. Ablation of spindle checkpoint by depletion of mitotic arrest deficiency 2 (MAD2) did not shorten the time of mitosis. Mitotic morphology in HeLa cells revealed that MAD2 colocalized with RNF213 R4810K. Immunoprecipitation revealed an RNF213/MAD2 complex: R4810K formed a complex with MAD2 more readily than RNF213 wild-type. Desynchronized localization of MAD2 was observed more frequently during mitosis in fibroblasts from patients (n = 3, 61.0 ± 8.2%) compared with wild-type subjects (n = 6, 13.1 ± 7.7%; p < 0.01). Aneuploidy was observed more frequently in fibroblasts (p < 0.01) and induced pluripotent stem cells (iPSCs) (p < 0.03) from patients than from wild-type subjects. Vascular endothelial cells differentiated from iPSCs (iPSECs) of patients and an unaffected carrier had a longer time from prometaphase to metaphase than those from controls (p < 0.05). iPSECs from the patients and unaffected carrier had significantly increased mitotic failure rates compared with controls (p < 0.05). Thus, RNF213 R4810K induced mitotic abnormalities and increased risk of genomic instability

  7. Identification of Pathways Required for the Coordination of Late Mitotic Events in Animal Cells

    Baumgartner, Bridget L; Harper, J. W

    2005-01-01

    ... in genomic instability, a hallmark of cancer. In yeast, a signaling pathway has been identified, called the Mitotic Exit Network, which coordinates mitotic exit and cytokinesis with the end of anaphase...

  8. Identification of Pathways Required for the Coordination of Late Mitotic Events in Animal Cells

    Baumgartner, Bridget

    2004-01-01

    ... in genomic instability, a hallmark of cancer. In yeast, a signaling pathway has been identified, called the Mitotic Exit Network, which coordinates mitotic exit and cytokinesis with the end of anaphase...

  9. Increased dopaminergic activity in socially isolated rats: an electrophysiological study

    Fabricius, Katrine; Helboe, Lone; Fink-Jensen, Anders

    2010-01-01

    The development of animal models mimicking symptoms associated with schizophrenia has been a critical step in understanding the neurobiological mechanisms underlying the disease. Long-term social isolation from weaning in rodents, a model based on the neurodevelopmental hypothesis of schizophrenia......, has been suggested to mimic some of the deficits seen in schizophrenic patients. We confirm in the present study that socially isolated rats display an increase in both spontaneous and d-amphetamine-induced locomotor activity, as well as deficits in sensorimotor gating as assessed in a pre......, and a change of firing activity towards a more irregular and bursting firing pattern. Taken together, our findings suggest that the behavioral phenotype induced by social isolation may be driven by an overactive dopamine system....

  10. Mitotic Stress in Cancer: Tipping the Fine Balance

    Acer

    of these molecules do not fit into the classical definition of oncogenes or tumor suppressor genes. In some cases, both over-expression and decreased expression of these genes result in mitotic arrest. Moreover, some .... The Clinical Collaborators: Dr. Arunabha Sengupta. Dr. Arun Roy. Dr. Jayanta Chakrabarty, CNCI. Prof.

  11. Cdc20 control of cell fate during prolonged mitotic arrest

    Nilsson, Jakob

    2011-01-01

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

  12. Both novelty and expertise increase action observation network activity

    Sook-Lei eLiew

    2013-09-01

    Full Text Available Our experiences with others affect how we perceive their actions. In particular, activity in bilateral premotor and parietal cortices during action observation, collectively known as the action observation network (AON, is modulated by one’s expertise with the observed actions or individuals. However, conflicting reports suggest that AON activity is greatest both for familiar and unfamiliar actions. The current study examines the effects of different types and amounts of experience (e.g., visual, interpersonal, personal on AON activation. fMRI was used to scan 16 healthy participants without prior experience with individuals with amputations (novices, 11 experienced occupational therapists (OTs who had varying amounts of experience with individuals with amputations, and one individual born with below-elbow residual limbs (participant CJ, as they viewed video clips of goal-matched actions performed by an individual with residual limbs and by an individual with hands. Participants were given increased visual exposure to actions performed by both effectors midway through the scanning procedure. Novices demonstrated a large AON response to the initial viewing of an individual with residual limbs compared to one with hands, but this signal was attenuated after they received visual exposure to both effectors. In contrast, OTs, who had moderate familiarity with residual limbs, demonstrated a lower AON response upon initial viewing—similar to novices after they received visual exposure. At the other extreme, CJ, who has extreme familiarity with residual limbs both visually and motorically, shows a largely increased left-lateralized AON response, exceeding that of novices and experienced OTs, when viewing the residual limb compared to hand actions. These results suggest that a nuanced model of AON engagement is needed to explain how cases of both extreme experience (CJ and extreme novelty (novices can result in the greatest AON activity.

  13. Exclusion of NFAT5 from mitotic chromatin resets its nucleo-cytoplasmic distribution in interphase.

    Anaïs Estrada-Gelonch

    Full Text Available BACKGROUND: The transcription factor NFAT5 is a major inducer of osmoprotective genes and is required to maintain the proliferative capacity of cells exposed to hypertonic stress. In response to hypertonicity, NFAT5 translocates to the nucleus, binds to regulatory regions of osmoprotective genes and activates their transcription. Besides stimulus-specific regulatory mechanisms, the activity of transcription factors in cycling cells is also regulated by the passage through mitosis, when most transcriptional processes are downregulated. It was not known whether mitosis could be a point of control for NFAT5. METHODOLOGY/PRINCIPAL FINDINGS: Using confocal microscopy we observed that NFAT5 was excluded from chromatin during mitosis in both isotonic and hypertonic conditions. Analysis of NFAT5 deletions showed that exclusion was mediated by the carboxy-terminal domain (CTD. NFAT5 mutants lacking this domain showed constitutive binding to mitotic chromatin independent of tonicity, which caused them to localize in the nucleus and remain bound to chromatin in the subsequent interphase without hypertonic stimulation. We analyzed the contribution of the CTD, DNA binding, and nuclear import and export signals to the subcellular localization of this factor. Our results indicated that cytoplasmic localization of NFAT5 in isotonic conditions required both the exclusion from mitotic DNA and active nuclear export in interphase. Finally, we identified several regions within the CTD of NFAT5, some of them overlapping with transactivation domains, which were separately capable of causing its exclusion from mitotic chromatin. CONCLUSIONS/SIGNIFICANCE: Our results reveal a multipart mechanism regulating the subcellular localization of NFAT5. The transactivating module of NFAT5 switches its function from an stimulus-specific activator of transcription in interphase to an stimulus-independent repressor of binding to DNA in mitosis. This mechanism, together with export

  14. Increased serum cortisol binding in chronic active hepatitis

    Orbach, O.; Schussler, G.C.

    1989-01-01

    A high serum cortisol concentration, apparently due to increased cortisol-binding globulin (CBG), was found in a patient (index case) with chronic active hepatitis (CAH). We therefore performed further studies to determine whether increased cortisol binding is generally associated with CAH. Serum samples were obtained from 15 hospitalized patients with long-term liver function test elevations but no evidence of cirrhosis, 15 normal subjects without a history of hepatitis, four healthy pregnant women, and 10 alcoholic patients with stigmata of cirrhosis. Serum cortisol binding was measured by an adaptation of a previously described charcoal uptake method. Thyroxine-binding globulin (TBG) and sex hormone-binding globulin were determined by radioimmunoassays. Charcoal uptake of 125I cortisol from sera of normal subjects and additional patients with CAH revealed that increased serum cortisol binding by a saturable site, presumably CBG, was associated with CAH. Cortisol binding was significantly correlated with immunoassayable TBG, suggesting that in CAH, similar mechanisms may be responsible for increasing the serum concentrations of CBG and TBG

  15. Transient extracellular application of gold nanostars increases hippocampal neuronal activity.

    Salinas, Kirstie; Kereselidze, Zurab; DeLuna, Frank; Peralta, Xomalin G; Santamaria, Fidel

    2014-08-20

    With the increased use of nanoparticles in biomedical applications there is a growing need to understand the effects that nanoparticles may have on cell function. Identifying these effects and understanding the mechanism through which nanoparticles interfere with the normal functioning of a cell is necessary for any therapeutic or diagnostic application. The aim of this study is to evaluate if gold nanoparticles can affect the normal function of neurons, namely their activity and coding properties. We synthesized star shaped gold nanoparticles of 180 nm average size. We applied the nanoparticles to acute mouse hippocampal slices while recording the action potentials from single neurons in the CA3 region. Our results show that CA3 hippocampal neurons increase their firing rate by 17% after the application of gold nanostars. The increase in excitability lasted for as much as 50 minutes after a transient 5 min application of the nanoparticles. Further analyses of the action potential shape and computational modeling suggest that nanoparticles block potassium channels responsible for the repolarization of the action potentials, thus allowing the cell to increase its firing rate. Our results show that gold nanoparticles can affect the coding properties of neurons by modifying their excitability.

  16. Dopamine receptor activation increases HIV entry into primary human macrophages.

    Peter J Gaskill

    Full Text Available Macrophages are the primary cell type infected with HIV in the central nervous system, and infection of these cells is a major component in the development of neuropathogenesis and HIV-associated neurocognitive disorders. Within the brains of drug abusers, macrophages are exposed to increased levels of dopamine, a neurotransmitter that mediates the addictive and reinforcing effects of drugs of abuse such as cocaine and methamphetamine. In this study we examined the effects of dopamine on HIV entry into primary human macrophages. Exposure to dopamine during infection increased the entry of R5 tropic HIV into macrophages, irrespective of the concentration of the viral inoculum. The entry pathway affected was CCR5 dependent, as antagonizing CCR5 with the small molecule inhibitor TAK779 completely blocked entry. The effect was dose-dependent and had a steep threshold, only occurring above 108 M dopamine. The dopamine-mediated increase in entry required dopamine receptor activation, as it was abrogated by the pan-dopamine receptor antagonist flupenthixol, and could be mediated through both subtypes of dopamine receptors. These findings indicate that the effects of dopamine on macrophages may have a significant impact on HIV pathogenesis. They also suggest that drug-induced increases in CNS dopamine may be a common mechanism by which drugs of abuse with distinct modes of action exacerbate neuroinflammation and contribute to HIV-associated neurocognitive disorders in infected drug abusers.

  17. Dopamine Receptor Activation Increases HIV Entry into Primary Human Macrophages

    Gaskill, Peter J.; Yano, Hideaki H.; Kalpana, Ganjam V.; Javitch, Jonathan A.; Berman, Joan W.

    2014-01-01

    Macrophages are the primary cell type infected with HIV in the central nervous system, and infection of these cells is a major component in the development of neuropathogenesis and HIV-associated neurocognitive disorders. Within the brains of drug abusers, macrophages are exposed to increased levels of dopamine, a neurotransmitter that mediates the addictive and reinforcing effects of drugs of abuse such as cocaine and methamphetamine. In this study we examined the effects of dopamine on HIV entry into primary human macrophages. Exposure to dopamine during infection increased the entry of R5 tropic HIV into macrophages, irrespective of the concentration of the viral inoculum. The entry pathway affected was CCR5 dependent, as antagonizing CCR5 with the small molecule inhibitor TAK779 completely blocked entry. The effect was dose-dependent and had a steep threshold, only occurring above 108 M dopamine. The dopamine-mediated increase in entry required dopamine receptor activation, as it was abrogated by the pan-dopamine receptor antagonist flupenthixol, and could be mediated through both subtypes of dopamine receptors. These findings indicate that the effects of dopamine on macrophages may have a significant impact on HIV pathogenesis. They also suggest that drug-induced increases in CNS dopamine may be a common mechanism by which drugs of abuse with distinct modes of action exacerbate neuroinflammation and contribute to HIV-associated neurocognitive disorders in infected drug abusers. PMID:25268786

  18. AUTOMATED DETECTION OF MITOTIC FIGURES IN BREAST CANCER HISTOPATHOLOGY IMAGES USING GABOR FEATURES AND DEEP NEURAL NETWORKS

    Maqlin Paramanandam

    2016-11-01

    Full Text Available The count of mitotic figures in Breast cancer histopathology slides is the most significant independent prognostic factor enabling determination of the proliferative activity of the tumor. In spite of the strict protocols followed, the mitotic counting activity suffers from subjectivity and considerable amount of observer variability despite being a laborious task. Interest in automated detection of mitotic figures has been rekindled with the advent of Whole Slide Scanners. Subsequently mitotic detection grand challenge contests have been held in recent years and several research methodologies developed by their participants. This paper proposes an efficient mitotic detection methodology for Hematoxylin and Eosin stained Breast cancer Histopathology Images using Gabor features and a Deep Belief Network- Deep Neural Network architecture (DBN-DNN. The proposed method has been evaluated on breast histopathology images from the publicly available dataset from MITOS contest held at the ICPR 2012 conference. It contains 226 mitoses annotated on 35 HPFs by several pathologists and 15 testing HPFs, yielding an F-measure of 0.74. In addition the said methodology was also tested on 3 slides from the MITOSIS- ATYPIA grand challenge held at the ICPR 2014 conference, an extension of MITOS containing 749 mitoses annotated on 1200 HPFs, by pathologists worldwide. This study has employed 3 slides (294 HPFs from the MITOS-ATYPIA training dataset in its evaluation and the results showed F-measures 0.65, 0.72and 0.74 for each slide. The proposed method is fast and computationally simple yet its accuracy and specificity is comparable to the best winning methods of the aforementioned grand challenges

  19. Activation of the zymogen to urokinase-type plasminogen activator is associated with increased interdomain flexibility

    Behrens, Manja A; Bøtkjær, Kenneth Alrø; Goswami, Sumit

    2011-01-01

    A key regulatory step for serine proteases of the trypsin clan is activation of the initially secreted zymogens, leading to an increase in activity by orders of magnitude. Zymogen activation occurs by cleavage of a single peptide bond near the N-terminus of the catalytic domain. Besides the catal...

  20. Use of active video games to increase physical activity in children: a (virtual) reality?

    Foley, Louise; Maddison, Ralph

    2010-02-01

    There has been increased research interest in the use of active video games (in which players physically interact with images onscreen) as a means to promote physical activity in children. The aim of this review was to assess active video games as a means of increasing energy expenditure and physical activity behavior in children. Studies were obtained from computerized searches of multiple electronic bibliographic databases. The last search was conducted in December 2008. Eleven studies focused on the quantification of the energy cost associated with playing active video games, and eight studies focused on the utility of active video games as an intervention to increase physical activity in children. Compared with traditional nonactive video games, active video games elicited greater energy expenditure, which was similar in intensity to mild to moderate intensity physical activity. The intervention studies indicate that active video games may have the potential to increase free-living physical activity and improve body composition in children; however, methodological limitations prevent definitive conclusions. Future research should focus on larger, methodologically sound intervention trials to provide definitive answers as to whether this technology is effective in promoting long-term physical activity in children.

  1. HYPNOBIRTHING INCREASE PAIN TOLERANCE AND ANXIETY IN ACTIVE PHASE LABOR

    Nursalam Nursalam

    2017-07-01

    Full Text Available Introduction: The main problem of inpartu mother was a labour pain and anxiety. The etiology of labour pain has been determained by dilatation and cervic’s tickness. The objective of this study was to examine the effect of hypnobirthing relaxation on the pain tolerance and anxiety responses in labor. Method: A pre experimental static group comparison purposive sampling design was used in this study. Population were all pregnant women in age of pregnancies between 38 until 39 weeks at RSUD Wangaya Denpasar. There were 12 respondents who met to the inclusion criteria divided into 6 respondents were given hypnobirthing relaxation intervention and 6 respondents as the control group. The independent variable was hypnobirthing relaxation and dependent variables were tolerance of pain and anxiety responses. Data were collected by using observation and questionnaire, then data were analyzed by using Mann Whitney U Test with significance level p=0.05. Result: The result showed that hypnobirthing relaxation had an effect on the pain tolerance and anxiety responses (p=0.015. Discussion: It can be concluded that the hypnobirthing relaxation has an effect to increase the pain tolerance and to decrease anxiety responses in active phase of labour. It is recommended to the hospital that have an ante natal care to hypnobirthing relaxation technique. Further studies should measure the effect of hynobirthing relaxation on increasing of β-endorfin in active phase labour.

  2. Interacting with wildlife tourism increases activity of white sharks.

    Huveneers, Charlie; Watanabe, Yuuki Y; Payne, Nicholas L; Semmens, Jayson M

    2018-01-01

    Anthropogenic activities are dramatically changing marine ecosystems. Wildlife tourism is one of the fastest growing sectors of the tourism industry and has the potential to modify the natural environment and behaviour of the species it targets. Here, we used a novel method to assess the effects of wildlife tourism on the activity of white sharks ( Carcharodon carcharias ). High frequency three-axis acceleration loggers were deployed on ten white sharks for a total of ~9 days. A combination of multivariate and univariate analysis revealed that the increased number of strong accelerations and vertical movements when sharks are interacting with cage-diving operators result in an overall dynamic body acceleration (ODBA) ~61% higher compared with other times when sharks are present in the area where cage-diving occurs. Since ODBA is considered a proxy of metabolic rate, interacting with cage-divers is probably more costly than are normal behaviours of white sharks at the Neptune Islands. However, the overall impact of cage-diving might be small if interactions with individual sharks are infrequent. This study suggests wildlife tourism changes the instantaneous activity levels of white sharks, and calls for an understanding of the frequency of shark-tourism interactions to appreciate the net impact of ecotourism on this species' fitness.

  3. Hypocapnia induces caspase-3 activation and increases Abeta production.

    Xie, Zhongcong; Moir, Robert D; Romano, Donna M; Tesco, Giuseppina; Kovacs, Dora M; Tanzi, Rudolph E

    2004-01-01

    At least half of all cases of early onset (<60) familial Alzheimer's disease (FAD) are caused by any of over 150 mutations in three genes: the amyloid precursor protein (APP), presenilin 1 (PS1), and presenilin 2 (PS2). Mutant forms of PS1 have been shown to sensitize cells to apoptotic cell death. We investigated the effects of hypocapnia, a risk factor for both cognitive and neurodevelopment deficits, on caspase-3 activation, apoptosis, and amyloid beta-protein (Abeta) production, and assessed the influence of the PS1Delta9 FAD mutation on these effects. For this purpose, we exposed stably transfected H4 human neuroglioma cells to conditions consistent with hypocapnia (PCO2<40 mm Hg) and hypocapnia plus hypoxia (PO2<21%). Hypocapnia (20 mm Hg CO2 for 6 h) induced caspase-3 activation and apoptosis; the PS1Delta9 FAD mutation significantly potentiated these effects. Moreover, the combination of hypocapnia (20 mm Hg CO2) and hypoxia (5%O2) induced caspase-3 activation and apoptosis in a synergistic manner. Hypocapnia (5 and 20 mm Hg CO2 for 6 h) also led to an increased Abeta production. The findings suggest that hypocapnia (e.g. during general anesthesia) could exacerbate AD neuropathogenesis. Copyright (c) 2004 S. Karger AG, Basel.

  4. Municipal services as a means of increasing the citizens’ activity

    Olga Valeryevna Yakhina

    2015-06-01

    Full Text Available Objective to propose ways of increasing the activity of Russian citizens through the institution of municipal services. Methods the methodological basis of the study was a systematic and integrated approach to the analysis of the institution of municipal services. The general philosophical method was used as well as general scientific methods of cognition dialectical systemic analysis and synthesis induction and deduction and specific scientific methods comparativelegal formallegal historicallegal sociological systemicfunctional theoreticalprognostic linguolegal methods. In particular the formallegal method was used to study the problem of the legal fixation of administrative regulations statuses the theoreticalprognostic method was used in preparing recommendations to increase the activity of citizens. Results the municipal services are regarded by the author as a way to meet the needs of the population of a particular territory and as a way of interaction between local public authorities and the citizens. The issue of the functioning of emunicipalities is studied as well as the shortcomings in the legal regulation in this field. The problem is discussed of insufficient use of the Internet in the local authoritiesrsquo interaction with citizens. The author suggests ways to improve the Federal Law quotOn the organization of state and municipal servicesquot N 210FZ of July 2 2010 regarding the use of the Internet as a means of feedback between the public authorities and the population of a territory. Special attention is paid to normative legal acts regulating the procedure of municipal services provision i.e. the administrative regulations of local authorities. The emerging challenges in the legal regulation of the specified institution are identified the solutions to the identified problems are proposed. Scientific novelty in 2010 the institution of municipal services has undergone significant modernization thus the necessity to its research

  5. THE INFLUENCE OF CAFFEINE ON MITOTIC DIVISION AT CAPSICUM ANNUUM L.

    Elena Rosu

    2006-08-01

    Full Text Available The paper presents, the caffeine effects in mitotic division at Capsicum annuum L.. The treatment has determined the lessening of the mitotic index (comparative with the control variant, until mitotic division total inhibition, as well as an growth frequency of division aberation in anaphase and telophase.

  6. File list: ALL.Emb.10.AllAg.Mitotic_cycle_13 [Chip-atlas[Archive

    Full Text Available ALL.Emb.10.AllAg.Mitotic_cycle_13 dm3 All antigens Embryo Mitotic cycle 13 SRX75007...1,SRX750082,SRX750080,SRX750072,SRX750083,SRX750081,SRX750070 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Emb.10.AllAg.Mitotic_cycle_13.bed ...

  7. File list: Oth.Emb.20.AllAg.Mitotic_cycle_13 [Chip-atlas[Archive

    Full Text Available Oth.Emb.20.AllAg.Mitotic_cycle_13 dm3 TFs and others Embryo Mitotic cycle 13 SRX750...072,SRX750083 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.Emb.20.AllAg.Mitotic_cycle_13.bed ...

  8. File list: Pol.Emb.05.AllAg.Mitotic_cycle_12 [Chip-atlas[Archive

    Full Text Available Pol.Emb.05.AllAg.Mitotic_cycle_12 dm3 RNA polymerase Embryo Mitotic cycle 12 SRX750...068 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.05.AllAg.Mitotic_cycle_12.bed ...

  9. File list: Oth.Emb.10.AllAg.Mitotic_cycle_13 [Chip-atlas[Archive

    Full Text Available Oth.Emb.10.AllAg.Mitotic_cycle_13 dm3 TFs and others Embryo Mitotic cycle 13 SRX750...072,SRX750083 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.Emb.10.AllAg.Mitotic_cycle_13.bed ...

  10. File list: Oth.Emb.20.AllAg.Mitotic_cycle_14 [Chip-atlas[Archive

    Full Text Available Oth.Emb.20.AllAg.Mitotic_cycle_14 dm3 TFs and others Embryo Mitotic cycle 14 SRX084...385 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.Emb.20.AllAg.Mitotic_cycle_14.bed ...

  11. File list: ALL.Emb.50.AllAg.Mitotic_cycle_12 [Chip-atlas[Archive

    Full Text Available ALL.Emb.50.AllAg.Mitotic_cycle_12 dm3 All antigens Embryo Mitotic cycle 12 SRX75006...8,SRX750069 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Emb.50.AllAg.Mitotic_cycle_12.bed ...

  12. File list: ALL.Emb.05.AllAg.Mitotic_cycle_13 [Chip-atlas[Archive

    Full Text Available ALL.Emb.05.AllAg.Mitotic_cycle_13 dm3 All antigens Embryo Mitotic cycle 13 SRX75008...0,SRX750082,SRX750072,SRX750083,SRX750071,SRX750081,SRX750070 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Emb.05.AllAg.Mitotic_cycle_13.bed ...

  13. File list: His.Emb.05.AllAg.Mitotic_cycle_14 [Chip-atlas[Archive

    Full Text Available His.Emb.05.AllAg.Mitotic_cycle_14 dm3 Histone Embryo Mitotic cycle 14 SRX645129,SRX...RX645131,SRX645102,SRX645109,SRX645101 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Emb.05.AllAg.Mitotic_cycle_14.bed ...

  14. File list: Pol.Emb.10.AllAg.Mitotic_cycle_14 [Chip-atlas[Archive

    Full Text Available Pol.Emb.10.AllAg.Mitotic_cycle_14 dm3 RNA polymerase Embryo Mitotic cycle 14 SRX750...078,SRX750076,SRX750074 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.10.AllAg.Mitotic_cycle_14.bed ...

  15. File list: Pol.Emb.05.AllAg.Mitotic_cycle_13 [Chip-atlas[Archive

    Full Text Available Pol.Emb.05.AllAg.Mitotic_cycle_13 dm3 RNA polymerase Embryo Mitotic cycle 13 SRX750...080,SRX750082,SRX750071 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.05.AllAg.Mitotic_cycle_13.bed ...

  16. File list: ALL.Emb.50.AllAg.Mitotic_cycle_14 [Chip-atlas[Archive

    Full Text Available ALL.Emb.50.AllAg.Mitotic_cycle_14 dm3 All antigens Embryo Mitotic cycle 14 SRX08438...45114 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Emb.50.AllAg.Mitotic_cycle_14.bed ...

  17. File list: Pol.Emb.50.AllAg.Mitotic_cycle_12 [Chip-atlas[Archive

    Full Text Available Pol.Emb.50.AllAg.Mitotic_cycle_12 dm3 RNA polymerase Embryo Mitotic cycle 12 SRX750...068 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.50.AllAg.Mitotic_cycle_12.bed ...

  18. File list: ALL.Emb.10.AllAg.Mitotic_cycle_14 [Chip-atlas[Archive

    Full Text Available ALL.Emb.10.AllAg.Mitotic_cycle_14 dm3 All antigens Embryo Mitotic cycle 14 SRX64512...50075 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Emb.10.AllAg.Mitotic_cycle_14.bed ...

  19. Synthesis and anti-mitotic activity of 2,4- or 2,6-disubstituted- and 2,4,6-trisubstituted-2H-pyrazolo[4,3-c]pyridines

    Milišiunaitė, V.; Arbačiauskienė, E.; Řezníčková, Eva; Jorda, Radek; Malínková, V.; Žukauskaitė, Asta; Holzer, W.; Šačkus, A.; Kryštof, Vladimír

    2018-01-01

    Roč. 150, APR 25 (2018), s. 908-919 ISSN 0223-5234 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Apoptosis * G2/M cell cycle arrest * Pyrazole * Structure-activity relationships Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology Impact factor: 4.519, year: 2016

  20. Charcoal Increases Microbial Activity in Eastern Sierra Nevada Forest Soils

    Zachary W. Carter

    2018-02-01

    Full Text Available Fire is an important component of forests in the western United States. Not only are forests subjected to wildfires, but fire is also an important management tool to reduce fuels loads. Charcoal, a product of fire, can have major impacts on carbon (C and nitrogen (N cycling in forest soils, but it is unclear how these effects vary by dominant vegetation. In this study, soils collected from Jeffrey pine (JP or lodgepole pine (LP dominated areas and amended with charcoal derived from JP or LP were incubated to assess the importance of charcoal on microbial respiration and potential nitrification. In addition, polyphenol sorption was measured in unamended and charcoal-amended soils. In general, microbial respiration was highest at the 1% and 2.5% charcoal additions, but charcoal amendment had limited effects on potential nitrification rates throughout the incubation. Microbial respiration rates decreased but potential nitrification rates increased over time across most treatments. Increased microbial respiration may have been caused by priming of native organic matter rather than the decomposition of charcoal itself. Charcoal had a larger stimulatory effect on microbial respiration in LP soils than JP soils. Charcoal type had little effect on microbial processes, but polyphenol sorption was higher on LP-derived than JP-derived charcoal at higher amendment levels despite surface area being similar for both charcoal types. The results from our study suggest that the presence of charcoal can increase microbial activity in soils, but the exact mechanisms are still unclear.

  1. Rohitukine inhibits in vitro adipogenesis arresting mitotic clonal expansion and improves dyslipidemia in vivo.

    Varshney, Salil; Shankar, Kripa; Beg, Muheeb; Balaramnavar, Vishal M; Mishra, Sunil Kumar; Jagdale, Pankaj; Srivastava, Shishir; Chhonker, Yashpal S; Lakshmi, Vijai; Chaudhari, Bhushan P; Bhatta, Rabi Shankar; Saxena, Anil Kumar; Gaikwad, Anil Nilkanth

    2014-06-01

    We developed a common feature pharmacophore model using known antiadipogenic compounds (CFPMA). We identified rohitukine, a reported chromone anticancer alkaloid as a potential hit through in silico mapping of the in-house natural product library on CFPMA. Studies were designed to assess the antiadipogenic potential of rohitukine. Rohitukine was isolated from Dysoxylum binacteriferum Hook. to ⬧95% purity. As predicted by CFPMA, rohitukine was indeed found to be an antiadipogenic molecule. Rohitukine inhibited lipid accumulation and adipogenic differentiation in a concentration- and exposure-time-dependent manner in 3T3-L1 and C3H10T1/2 cells. Rohitukine downregulated expression of PPARγ, CCAAT/enhancer binding protein α, adipocyte protein 2 (aP2), FAS, and glucose transporter 4. It also suppressed mRNA expression of LPL, sterol-regulatory element binding protein (SREBP) 1c, FAS, and aP2, the downstream targets of PPARγ. Rohitukine arrests cells in S phase during mitotic clonal expansion. Rohitukine was bioavailable, and 25.7% of orally administered compound reached systemic circulation. We evaluated the effect of rohitukine on dyslipidemia induced by high-fat diet in the hamster model. Rohitukine increased hepatic expression of liver X receptor α and decreased expression of SREBP-2 and associated targets. Rohitukine decreased hepatic and gonadal lipid accumulation and ameliorated dyslipidemia significantly. In summary, our strategy to identify a novel antiadipogenic molecule using CFPMA successfully resulted in identification of rohitukine, which confirmed antiadipogenic activity and also exhibited in vivo antidyslipidemic activity. Copyright © 2014 by the American Society for Biochemistry and Molecular Biology, Inc.

  2. Increased microglial catalase activity in multiple sclerosis grey matter.

    Gray, Elizabeth; Kemp, Kevin; Hares, Kelly; Redondo, Julianna; Rice, Claire; Scolding, Neil; Wilkins, Alastair

    2014-04-22

    Chronic demyelination, on-going inflammation, axonal loss and grey matter neuronal injury are likely pathological processes that contribute to disease progression in multiple sclerosis (MS). Although the precise contribution of each process and their aetiological substrates is not fully known, recent evidence has implicated oxidative damage as a major cause of tissue injury in MS. The degree of tissue injury caused by oxidative molecules, such as reactive oxygen species (ROS), is balanced by endogenous anti-oxidant enzymes which detoxify ROS. Understanding endogenous mechanisms which protect the brain against oxidative injury in MS is important, since enhancing anti-oxidant responses is a major therapeutic strategy for preventing irreversible tissue injury in the disease. Our aims were to determine expression and activity levels of the hydrogen peroxide-reducing enzyme catalase in MS grey matter (GM). In MS GM, a catalase enzyme activity was elevated compared to control GM. We measured catalase protein expression by immune dot-blotting and catalase mRNA by a real-time polymerase chain reaction (RT-PCR). Protein analysis studies showed a strong positive correlation between catalase and microglial marker IBA-1 in MS GM. In addition, calibration of catalase mRNA level with reference to the microglial-specific transcript AIF-1 revealed an increase in this transcript in MS. This was reflected by the extent of HLA-DR immunolabeling in MS GM which was significantly elevated compared to control GM. Collectively, these observations provide evidence that microglial catalase activity is elevated in MS grey matter and may be an important endogenous anti-oxidant defence mechanism in MS. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Functional characterisation and drug target validation of a mitotic kinesin-13 in Trypanosoma brucei.

    Kuan Yoow Chan

    2010-08-01

    Full Text Available Mitotic kinesins are essential for faithful chromosome segregation and cell proliferation. Therefore, in humans, kinesin motor proteins have been identified as anti-cancer drug targets and small molecule inhibitors are now tested in clinical studies. Phylogenetic analyses have assigned five of the approximately fifty kinesin motor proteins coded by Trypanosoma brucei genome to the Kinesin-13 family. Kinesins of this family have unusual biochemical properties because they do not transport cargo along microtubules but are able to depolymerise microtubules at their ends, therefore contributing to the regulation of microtubule length. In other eukaryotic genomes sequenced to date, only between one and three Kinesin-13s are present. We have used immunolocalisation, RNAi-mediated protein depletion, biochemical in vitro assays and a mouse model of infection to study the single mitotic Kinesin-13 in T. brucei. Subcellular localisation of all five T. brucei Kinesin-13s revealed distinct distributions, indicating that the expansion of this kinesin family in kinetoplastids is accompanied by functional diversification. Only a single kinesin (TbKif13-1 has a nuclear localisation. Using active, recombinant TbKif13-1 in in vitro assays we experimentally confirm the depolymerising properties of this kinesin. We analyse the biological function of TbKif13-1 by RNAi-mediated protein depletion and show its central role in regulating spindle assembly during mitosis. Absence of the protein leads to abnormally long and bent mitotic spindles, causing chromosome mis-segregation and cell death. RNAi-depletion in a mouse model of infection completely prevents infection with the parasite. Given its essential role in mitosis, proliferation and survival of the parasite and the availability of a simple in vitro activity assay, TbKif13-1 has been identified as an excellent potential drug target.

  4. Increases in Use and Activity Due to Urban Renewal

    Andersen, Henriette Bondo; Christiansen, Lars Breum; Klinker, Charlotte Demant

    2017-01-01

    Introduction Urban green space and other recreational facilities are associated with physical activity. For adolescents living in multistory housing, public outdoor spaces that support physical activity may play an important role in activity promotion strategies. However, stronger evidence for a ...

  5. Increased 5α-reductase activity in idiopathic hirsutism

    Serafini, P.; Lobo, R.A.

    1985-01-01

    In vitro, genital skin 5α-reductase activity (5α-RA) was measured in ten hirsute women with normal androgen levels (idiopathic hirsutism (IH)) and in ten hirsute women with elevated androgen levels (polycystic ovary syndrome (PCO)) in order to determine the influence of secreted androgens on 5α-RA. In vitro 5α-RA was assessed by incubations of skin with 14 C-testosterone (T) for 2 hours, after which steroids were separated and the radioactivity of dihydrotestosterone (DHT) and 5α-androstane 3α-17β-estradiol (3α-diol) in specific eluates were determined. All androgens were normal in IH with the exception of higher levels of 3α-diol glucuronide which were similar to the levels of PCO. The conversion ratio (CR) of T to DHT in IH and PCO were similar, yet significantly greater than the CR of control subjects. The CR of T to 3α-diol in IH and PCO were similar, yet higher than in control subjects. Serum androgens showed no correlation with 5α-RA, while the CR of T to DHT showed a significant positive correlation with the Ferriman and Gallwey score. The increased 5α-RA in IH appears to be independent of serum androgen levels and is, therefore, an inherent abnormality. The term idiopathic is a misnomer, because hirsutism in these patients may be explained on the basis of increased skin 5α-RA

  6. Mitotic chromosome loss in a radiation-sensitive strain of the yeast Saccharomyces cerevisiae

    Mortimer, R.K.; Contopoulou, R.; Schild, D.

    1981-01-01

    Cells of Saccharomyces cerevisiae with mutations in the RAD52 gene have previously been shown to be defective in meiotic and mitotic recombination, in sporulation, and in repair of radiation-induced damage to DNA. In this study we show that diploid cells homozygous for rad52 lose chromosomes at high frequencies and that these frequencies of loss can be increased dramatically by exposure of these cells to x-rays. Genetic analyses of survivors of x-ray treatment demonstrate that chromosome loss events result in the conversion of diploid cells to cells with near haploid chromosome numbers

  7. Increased 5. cap alpha. -reductase activity in idiopathic hirsutism

    Serafini, P.; Lobo, R.A.

    1985-01-01

    In vitro, genital skin 5..cap alpha..-reductase activity (5..cap alpha..-RA) was measured in ten hirsute women with normal androgen levels (idiopathic hirsutism (IH)) and in ten hirsute women with elevated androgen levels (polycystic ovary syndrome (PCO)) in order to determine the influence of secreted androgens on 5..cap alpha..-RA. In vitro 5..cap alpha..-RA was assessed by incubations of skin with /sup 14/C-testosterone (T) for 2 hours, after which steroids were separated and the radioactivity of dihydrotestosterone (DHT) and 5..cap alpha..-androstane 3..cap alpha..-17..beta..-estradiol (3..cap alpha..-diol) in specific eluates were determined. All androgens were normal in IH with the exception of higher levels of 3..cap alpha..-diol glucuronide which were similar to the levels of PCO. The conversion ratio (CR) of T to DHT in IH and PCO were similar, yet significantly greater than the CR of control subjects. The CR of T to 3..cap alpha..-diol in IH and PCO were similar, yet higher than in control subjects. Serum androgens showed no correlation with 5..cap alpha..-RA, while the CR of T to DHT showed a significant positive correlation with the Ferriman and Gallwey score. The increased 5..cap alpha..-RA in IH appears to be independent of serum androgen levels and is, therefore, an inherent abnormality. The term idiopathic is a misnomer, because hirsutism in these patients may be explained on the basis of increased skin 5..cap alpha..-RA.

  8. Single-walled carbon nanotube-induced mitotic disruption⋆

    Sargent, L.M.; Hubbs, A.F.; Young, S.-H.; Kashon, M.L.; Dinu, C.Z.; Salisbury, J.L.; Benkovic, S.A.; Lowry, D.T.; Murray, A.R.; Kisin, E.R.; Siegrist, K.J.; Battelli, L.; Mastovich, J.; Sturgeon, J.L.; Bunker, K.L.

    2011-01-01

    Carbon nanotubes were among the earliest products of nanotechnology and have many potential applications in medicine, electronics, and manufacturing. The low density, small size, and biological persistence of carbon nanotubes create challenges for exposure control and monitoring and make respiratory exposures to workers likely. We have previously shown mitotic spindle aberrations in cultured primary and immortalized human airway epithelial cells exposed to 24, 48 and 96 μg/cm2 single-walled c...

  9. Saccharomyces cerevisiae mutants with enhanced induced mutation and altered mitotic gene conversion.

    Ivanov, E L; Kovaltzova, S V; Korolev, V G

    1989-08-01

    We have developed a method to isolate yeast (Saccharomyces cerevisiae) mutants with enhanced induced mutagenesis based on nitrous acid-induced reversion of the ade2-42 allele. Six mutants have been isolated and designated him (high induced mutagenesis), and 4 of them were studied in more detail. The him mutants displayed enhanced reversion of the ade2-42 allele, either spontaneous or induced by nitrous acid, UV light, and the base analog 6-N-hydroxylaminopurine, but not by gamma-irradiation. It is worth noting that the him mutants turned out not to be sensitive to the lethal effects of the mutagens used. The enhancement in mutation induced by nitrous acid, UV light, and 6-N-hydroxylaminopurine has been confirmed in a forward-mutation assay (induction of mutations in the ADE1, ADE2 genes). The latter agent revealed the most apparent differences between the him mutants and the wild-type strain and was, therefore, chosen for the genetic analysis of mutants, him mutations analyzed behaved as a single Mendelian trait; complementation tests indicated 3 complementation groups (HIM1, HIM2, and HIM3), each containing 1 mutant allele. Uracil-DNA glycosylase activity was determined in crude cell extracts, and no significant differences between the wild-type and him strains were detected. Spontaneous mitotic gene conversion at the ADE2 locus is altered in him1 strains, either increased or decreased, depending on the particular heteroallelic combination. Genetic evidence strongly suggests him mutations to be involved in a process of mismatch correction of molecular heteroduplexes.

  10. Altered behavior in spotted hyenas associated with increased human activity

    Boydston, Erin E.; Kapheim, Karen M.; Watts, Heather E.; Szykman, Micaela; Holekamp, Kay E.

    2003-01-01

    To investigate how anthropogenic activity might affect large carnivores, we studied the behaviour of spotted hyenas (Crocuta crocuta) during two time periods. From 1996 to 1998, we documented the ecological correlates of space utilization patterns exhibited by adult female hyenas defending a territory at the edge of a wildlife reserve in Kenya. Hyenas preferred areas near dense vegetation but appeared to avoid areas containing the greatest abundance of prey, perhaps because these were also the areas of most intensive livestock grazing. We then compared hyena behaviour observed in 1996–98 with that observed several years earlier and found many differences. Female hyenas in 1996–98 were found farther from dens, but closer to dense vegetation and to the edges of their territory, than in 1988–90. Recent females also had larger home ranges, travelled farther between consecutive sightings, and were more nocturnal than in 1988–90. Finally, hyenas occurred in smaller groups in 1996–98 than in 1988–90. We also found several changes in hyena demography between periods. We next attempted to explain differences observed between time periods by testing predictions of hypotheses invoking prey abundance, climate, interactions with lions, tourism and livestock grazing. Our data were consistent with the hypothesis that increased reliance on the reserve for livestock grazing was responsible for observed changes. That behavioural changes were not associated with decreased hyena population density suggests the behavioural plasticity typical of this species may protect it from extinction.

  11. UV-induced mitotic recombination and its dependence on photoreactivation and liquid holding in the rad6-1 mutant of Saccharomyces cerevisiae

    Haladus, E.; Zuk, J.

    1980-01-01

    Spontaneous and UV-induced mitotic recombination was compared in diploids homozygous for rad6-1 mutation and in the wild-type strain carrying heterozygous markers for detecting gene conversion (hom 2-1, hom 2-2) and crossing over (ade 1, ade 2). Diploids homozygous for rad6-1 mutation were characterised by an elevated level of spontaneous and UV-induced mitotic recombination, particularly the intergenic events. Exposure of UV-irradiated strains to visible light resulted in an increased survival and decreased level of mitotic recombination. Liquid holding (LH) differentially affected frequency of mitotic intergenic and intragenic recombination in mutant and wild-type strains, being without any significant effect on cell survival. In a mutant strain intragenic recombination is significantly increased, intergenic only slightly. In the wild-type strain intragenic recombination is slightly decreased but intergenic is not changed by LH. Visible light applied after LH had no effect on survival and mitotic recombination in the wild type, while in the mutant strain photoreactivability of survival was fully preserved and accompanied by a decrease in the frequency of intragenic and intergenic recombination. The results suggest that metabolic pathways responsible for restoring cell survival are independent of or only partly overlapping with those concerning recombination events. (orig.) [de

  12. Mitotic Figure Recognition: Agreement among Pathologists and Computerized Detector

    Christopher Malon

    2012-01-01

    Full Text Available Despite the prognostic importance of mitotic count as one of the components of the Bloom – Richardson grade [3], several studies ([2, 9, 10] have found that pathologists’ agreement on the mitotic grade is fairly modest. Collecting a set of more than 4,200 candidate mitotic figures, we evaluate pathologists' agreement on individual figures, and train a computerized system for mitosis detection, comparing its performance to the classifications of three pathologists. The system’s and the pathologists’ classifications are based on evaluation of digital micrographs of hematoxylin and eosin stained breast tissue. On figures where the majority of pathologists agree on a classification, we compare the performance of the trained system to that of the individual pathologists. We find that the level of agreement of the pathologists ranges from slight to moderate, with strong biases, and that the system performs competitively in rating the ground truth set. This study is a step towards automatic mitosis count to accelerate a pathologist's work and improve reproducibility.

  13. Unconventional functions of mitotic kinases in kidney tumourigenesis

    Pauline eHascoet

    2015-10-01

    Full Text Available Human tumours exhibit a variety of genetic alterations, including point mutations, translocations, gene amplifications and deletions, as well as aneuploid chromosome numbers. For carcinomas, aneuploidy is associated with poor patient outcome for a large variety of tumour types, including breast, colon and renal cell carcinoma. The Renal cell cancer (RCC is a heterogeneous carcinoma consisting of different histologic types. The clear renal cell carcinoma (ccRCC is the most common subtype and represents 85 % of the RCC. Central to the biology of the ccRCC is the loss of function of the Von Hippel Lindau gene but is also associated with genetic instability that could be caused by abrogation of the cell cycle mitotic spindle checkpoint and may involve the Aurora kinases, which regulate centrosome maturation. Aneuploidy can also result from the loss of cell-cell adhesion and apical-basal cell polarity that also may be regulated by the mitotic kinases (Plk1, CK2, DLCK1 and Aurora kinases. In this review, we describe the non mitotic unconventional functions of these kinases in renal tumourigenesis.

  14. Trapezius muscle activity increases during near work activity regardless of accommodation/vergence demand level.

    Richter, H O; Zetterberg, C; Forsman, M

    2015-07-01

    To investigate if trapezius muscle activity increases over time during visually demanding near work. The vision task consisted of sustained focusing on a contrast-varying black and white Gabor grating. Sixty-six participants with a median age of 38 (range 19-47) fixated the grating from a distance of 65 cm (1.5 D) during four counterbalanced 7-min periods: binocularly through -3.5 D lenses, and monocularly through -3.5 D, 0 D and +3.5 D. Accommodation, heart rate variability and trapezius muscle activity were recorded in parallel. General estimating equation analyses showed that trapezius muscle activity increased significantly over time in all four lens conditions. A concurrent effect of accommodation response on trapezius muscle activity was observed with the minus lenses irrespective of whether incongruence between accommodation and convergence was present or not. Trapezius muscle activity increased significantly over time during the near work task. The increase in muscle activity over time may be caused by an increased need of mental effort and visual attention to maintain performance during the visual tasks to counteract mental fatigue.

  15. Processing of Building Binder Materials to Increase their Activation

    Fediuk, R. S.; Garmashov, I. S.; Kuzmin, D. E.; Stoyushko, N. Yu; Gladkova, N. A.

    2018-01-01

    The paper deals modern physical methods of activation of building powder materials. During mechanical activation a composite binder active molecules cement minerals occur in the destruction of the molecular defects in the areas of packaging and breaking metastable phase decompensation intermolecular forces. The process is accompanied by a change in the kinetics of hardening of Portland cement. Activated concrete has a number of features that are used as design characteristics of structures and are due to the structure of the activated binder and its contacts with concrete aggregates. These features also have a significant impact on the nature of the destruction of concrete under load, changing the boundaries of its microcracks and durability.

  16. Kalanchoe tubiflora extract inhibits cell proliferation by affecting the mitotic apparatus

    Hsieh Yi-Jen

    2012-09-01

    Full Text Available Abstract Background Kalanchoe tubiflora (KT is a succulent plant native to Madagascar, and is commonly used as a medicinal agent in Southern Brazil. The underlying mechanisms of tumor suppression are largely unexplored. Methods Cell viability and wound-healing were analyzed by MTT assay and scratch assay respectively. Cell cycle profiles were analyzed by FACS. Mitotic defects were analyzed by indirect immunofluoresence images. Results An n-Butanol-soluble fraction of KT (KT-NB was able to inhibit cell proliferation. After a 48 h treatment with 6.75 μg/ml of KT, the cell viability was less than 50% of controls, and was further reduced to less than 10% at higher concentrations. KT-NB also induced an accumulation of cells in the G2/M phase of the cell cycle as well as an increased level of cells in the subG1 phase. Instead of disrupting the microtubule network of interphase cells, KT-NB reduced cell viability by inducing multipolar spindles and defects in chromosome alignment. KT-NB inhibits cell proliferation and reduces cell viability by two mechanisms that are exclusively involved with cell division: first by inducing multipolarity; second by disrupting chromosome alignment during metaphase. Conclusion KT-NB reduced cell viability by exclusively affecting formation of the proper structure of the mitotic apparatus. This is the main idea of the new generation of anti-mitotic agents. All together, KT-NB has sufficient potential to warrant further investigation as a potential new anticancer agent candidate.

  17. Mechanical design principles of a mitotic spindle.

    Ward, Jonathan J; Roque, Hélio; Antony, Claude; Nédélec, François

    2014-12-18

    An organised spindle is crucial to the fidelity of chromosome segregation, but the relationship between spindle structure and function is not well understood in any cell type. The anaphase B spindle in fission yeast has a slender morphology and must elongate against compressive forces. This 'pushing' mode of chromosome transport renders the spindle susceptible to breakage, as observed in cells with a variety of defects. Here we perform electron tomographic analyses of the spindle, which suggest that it organises a limited supply of structural components to increase its compressive strength. Structural integrity is maintained throughout the spindle's fourfold elongation by organising microtubules into a rigid transverse array, preserving correct microtubule number and dynamically rescaling microtubule length.

  18. Physical Limits on the Precision of Mitotic Spindle Positioning by Microtubule Pushing forces: Mechanics of mitotic spindle positioning.

    Howard, Jonathon; Garzon-Coral, Carlos

    2017-11-01

    Tissues are shaped and patterned by mechanical and chemical processes. A key mechanical process is the positioning of the mitotic spindle, which determines the size and location of the daughter cells within the tissue. Recent force and position-fluctuation measurements indicate that pushing forces, mediated by the polymerization of astral microtubules against- the cell cortex, maintain the mitotic spindle at the cell center in Caenorhabditis elegans embryos. The magnitude of the centering forces suggests that the physical limit on the accuracy and precision of this centering mechanism is determined by the number of pushing microtubules rather than by thermally driven fluctuations. In cells that divide asymmetrically, anti-centering, pulling forces generated by cortically located dyneins, in conjunction with microtubule depolymerization, oppose the pushing forces to drive spindle displacements away from the center. Thus, a balance of centering pushing forces and anti-centering pulling forces localize the mitotic spindles within dividing C. elegans cells. © 2017 The Authors. BioEssays published by Wiley Periodicals, Inc.

  19. 53BP1 nuclear bodies form around DNA lesions generated by mitotic transmission of chromosomes under replication stress

    Lukas, Claudia; Savic, Velibor; Bekker-Jensen, Simon

    2011-01-01

    stress increases the frequency of chromosomal lesions that are transmitted to daughter cells. Throughout G1, these lesions are sequestered in nuclear compartments marked by p53-binding protein 1 (53BP1) and other chromatin-associated genome caretakers. We show that the number of such 53BP1 nuclear bodies...... increases after genetic ablation of BLM, a DNA helicase associated with dissolution of entangled DNA. Conversely, 53BP1 nuclear bodies are partially suppressed by knocking down SMC2, a condensin subunit required for mechanical stability of mitotic chromosomes. Finally, we provide evidence that 53BP1 nuclear...... bodies shield chromosomal fragile sites sequestered in these compartments against erosion. Together, these data indicate that restoration of DNA or chromatin integrity at loci prone to replication problems requires mitotic transmission to the next cell generations....

  20. Increased activity of the mannan-binding lectin complement activation pathway in patients with colorectal cancer

    Ytting, H; Jensenius, Jens Christian; Christensen, I J

    2004-01-01

    BACKGROUND: Postoperative bacterial infectious complications are frequent in patients with colorectal cancer (CRC), with subsequent increased recurrence rates and poor prognosis. Deficiency of the mannan-binding lectin (MBL) complement activation pathway may cause increased risk of infection......: Serum MBL concentrations and MBL/MASP activity were determined using immunofluorometric assays. The levels are presented as the median, inter-quartile range and range. RESULTS: Serum MBL levels were significantly (P cancer (1384 (400-2188) ng/mL) (median...... in the colon or rectum, and disease stages according to Dukes' classification. No statistical difference (P=0.20) in frequency of MBL deficiency was found between the patients (20%) and the donors (27%). CONCLUSIONS: Overall, the MBL complement activation pathway is significantly increased in patients...

  1. Nitric oxide released from JS-K induces cell death by mitotic catastrophe as part of necrosis in glioblastoma multiforme.

    Günzle, Jessica; Osterberg, Nadja; Saavedra, Joseph E; Weyerbrock, Astrid

    2016-09-01

    The nitric oxide (NO) donor JS-K is specifically activated by glutathione S-transferases (GSTs) in GST-overexpressing cells. We have shown the induction of cell death in glioblastoma multiforme (GBM) cells at high JS-K doses but the mechanism remains unclear. The aim of this study was to determine whether NO-induced cell death is triggered by induction of apoptotic or necrotic pathways. For the first time, we demonstrate that NO induces cell death via mitotic catastrophe (MC) with non-apoptotic mechanisms in GBM cells. Moreover, the level of morphological changes indicating MC correlates with increased necrosis. Therefore, we conclude that MC is the main mechanism by which GBM cells undergo cell death after treatment with JS-K associated with necrosis rather than apoptosis. In addition, we show that PARP1 is not an exclusive marker for late apoptosis but is also involved in MC. Activating an alternative way of cell death can be useful for the multimodal cancer therapy of GBM known for its strong anti-apoptotic mechanisms and drug resistance.

  2. [Intragenic mitotic recombination induced by ultraviolet and gamma rays in radiosensitive mutants of Saccharomyces cerevisiae yeasts].

    Zakharov, I A; Kasinova, G V; Koval'tsova, S V

    1983-01-01

    The effect of UV- and gamma-irradiation on the survival and intragenic mitotic recombination (gene conversion) of 5 radiosensitive mutants was studied in comparison with the wild type. The level of spontaneous conversion was similar for RAD, rad2 and rad15, mutations xrs2 and xrs4 increasing and rad54 significantly decreasing it. The frequency of conversion induced by UV-light was greater in rad2, rad15 and xrs2 mutants and lower in xrs4, as compared to RAD. Gamma-irradiation caused induction of gene conversion with an equal frequency in RAD, rad2, rad15. Xrs2 and xrs4 mutations slightly decreased gamma-induced conversion. In rad54 mutant, UV-and gamma-induced conversion was practically absent. In the wild type yeast, a diploid strain is more resistant than a haploid, whereas in rad54 a diploid strain has the same or an increased sensitivity, as compared to a haploid strain (the "inverse ploidy effect"). This effect and also the block of induced mitotic recombination caused by rad54 indicate the presence in the yeast Saccharomyces cerevisiae of repair pathways of UV- and gamma-induced damages acting in diploid cells and realised by recombination. The data obtained as a result of many years' investigation of genetic effects in radiosensitive mutants of yeast are summarised and considered.

  3. Flow cytometric analysis of mitotic cycle perturbation by chemical carcinogens in cultured epithelial cells. [Effects of benzo(a)pyrene-diol-epoxide on mitotic cycle of cultural mouse liver epithelial cells

    Pearlman, Andrew Leonard [Univ. of California, Berkeley, CA (United States)

    1978-08-01

    A system for kinetic analysis of mitotic cycle perturbation by various agents was developed and applied to the study of the mitotic cycle effects and dependency of the chemical carcinogen benzo(a)pyrene-diolepoxide, DE, upon a mouse lever epithelial cell line, NMuLi. The study suggests that the targets of DE action are not confined to DNA alone but may include cytoplasmic structures as well. DE was found to affect cells located in virtually every phase of the mitotic cycle, with cells that were actively synthesizing DNA showing the strongest response. However, the resulting perturbations were not confined to S-phase alone. DE slowed traversal through S-phase by about 40% regardless of the cycle phase of the cells exposed to it, and slowed traversal through G2M by about 50%. When added to G1 cells, DE delayed recruitment of apparently quiescent (G0) cells by 2 hours, and reduced the synchrony of the cohort of cells recruited into active proliferation. The kinetic analysis system consists of four elements: tissue culture methods for propagating and harvesting cell populations; an elutriation centrifugation system for bulk synchronization of cells in various phases of the mitotic cycle; a flow cytometer (FCM), coupled with appropriate staining protocols, to enable rapid analysis of the DNA distribution of any given cell population; and data reduction and analysis methods for extracting information from the DNA histograms produced by the FCM. The elements of the system are discussed. A mathematical analysis of DNA histograms obtained by FCM is presented. The analysis leads to the detailed implementation of a new modeling approach. The new modeling approach is applied to the estimation of cell cycle kinetic parameters from time series of DNA histograms, and methods for the reduction and interpretation of such series are suggested.

  4. Hydralazine administration activates sympathetic preganglionic neurons whose activity mobilizes glucose and increases cardiovascular function.

    Parker, Lindsay M; Damanhuri, Hanafi A; Fletcher, Sophie P S; Goodchild, Ann K

    2015-04-16

    Hypotensive drugs have been used to identify central neurons that mediate compensatory baroreceptor reflex responses. Such drugs also increase blood glucose. Our aim was to identify the neurochemical phenotypes of sympathetic preganglionic neurons (SPN) and adrenal chromaffin cells activated following hydralazine (HDZ; 10mg/kg) administration in rats, and utilize this and SPN target organ destination to ascribe their function as cardiovascular or glucose regulating. Blood glucose was measured and adrenal chromaffin cell activation was assessed using c-Fos immunoreactivity (-ir) and phosphorylation of tyrosine hydroxylase, respectively. The activation and neurochemical phenotype of SPN innervating the adrenal glands and celiac ganglia were determined using the retrograde tracer cholera toxin B subunit, in combination with in situ hybridization and immunohistochemistry. Blood glucose was elevated at multiple time points following HDZ administration but little evidence of chromaffin cell activation was seen suggesting non-adrenal mechanisms contribute to the sustained hyperglycemia. 16±0.1% of T4-T11 SPN contained c-Fos and of these: 24.3±1.4% projected to adrenal glands and 29±5.5% projected to celiac ganglia with the rest innervating other targets. 62.8±1.4% of SPN innervating adrenal glands were activated and 29.9±3.3% expressed PPE mRNA whereas 53.2±8.6% of SPN innervating celiac ganglia were activated and 31.2±8.8% expressed PPE mRNA. CART-ir SPN innervating each target were also activated and did not co-express PPE mRNA. Neurochemical coding reveals that HDZ administration activates both PPE+SPN, whose activity increase glucose mobilization causing hyperglycemia, as well as CART+SPN whose activity drive vasomotor responses mediated by baroreceptor unloading to raise vascular tone and heart rate. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Detection of mitotic nuclei in breast histopathology images using localized ACM and Random Kitchen Sink based classifier.

    Beevi, K Sabeena; Nair, Madhu S; Bindu, G R

    2016-08-01

    The exact measure of mitotic nuclei is a crucial parameter in breast cancer grading and prognosis. This can be achieved by improving the mitotic detection accuracy by careful design of segmentation and classification techniques. In this paper, segmentation of nuclei from breast histopathology images are carried out by Localized Active Contour Model (LACM) utilizing bio-inspired optimization techniques in the detection stage, in order to handle diffused intensities present along object boundaries. Further, the application of a new optimal machine learning algorithm capable of classifying strong non-linear data such as Random Kitchen Sink (RKS), shows improved classification performance. The proposed method has been tested on Mitosis detection in breast cancer histological images (MITOS) dataset provided for MITOS-ATYPIA CONTEST 2014. The proposed framework achieved 95% recall, 98% precision and 96% F-score.

  6. DNA Strand Breaks in Mitotic Germ Cells of Caenorhabditis elegans Evaluated by Comet Assay

    Park, Sojin; Choi, Seoyun; Ahn, Byungchan

    2016-01-01

    DNA damage responses are important for the maintenance of genome stability and the survival of organisms. Such responses are activated in the presence of DNA damage and lead to cell cycle arrest, apoptosis, and DNA repair. In Caenorhabditis elegans, double-strand breaks induced by DNA damaging agents have been detected indirectly by antibodies against DSB recognizing proteins. In this study we used a comet assay to detect DNA strand breaks and to measure the elimination of DNA strand breaks in mitotic germline nuclei of C. elegans. We found that C. elegans brc-1 mutants were more sensitive to ionizing radiation and camptothecin than the N2 wild-type strain and repaired DNA strand breaks less efficiently than N2. This study is the first demonstration of direct measurement of DNA strand breaks in mitotic germline nuclei of C. elegans. This newly developed assay can be applied to detect DNA strand breaks in different C. elegans mutants that are sensitive to DNA damaging agents. PMID:26903030

  7. DNA lesions induced by replication stress trigger mitotic aberration and tetraploidy development.

    Yosuke Ichijima

    Full Text Available During tumorigenesis, cells acquire immortality in association with the development of genomic instability. However, it is still elusive how genomic instability spontaneously generates during the process of tumorigenesis. Here, we show that precancerous DNA lesions induced by oncogene acceleration, which induce situations identical to the initial stages of cancer development, trigger tetraploidy/aneuploidy generation in association with mitotic aberration. Although oncogene acceleration primarily induces DNA replication stress and the resulting lesions in the S phase, these lesions are carried over into the M phase and cause cytokinesis failure and genomic instability. Unlike directly induced DNA double-strand breaks, DNA replication stress-associated lesions are cryptogenic and pass through cell-cycle checkpoints due to limited and ineffective activation of checkpoint factors. Furthermore, since damaged M-phase cells still progress in mitotic steps, these cells result in chromosomal mis-segregation, cytokinesis failure and the resulting tetraploidy generation. Thus, our results reveal a process of genomic instability generation triggered by precancerous DNA replication stress.

  8. RESEARCH ON INCREASING ACTIVE LIFE OF CUTTING TOOLS

    Alin STĂNCIOIU

    2012-05-01

    Full Text Available At the exploitation of dies the defections that occur, due mainly to non operating rules of exploration, the improperly conditions of the machine (press in terms of cinematic precision and the wearing elements in relative motion (ram displacement, wearing guides, etc as the incorrect mounting of dies on the press. When installing dies must consider several aspects. Among the techniques used, especially for restoring the active elements in the work area are rectified frontal surfaces, hard chromating, hardening with electric sparks and charging welding. Were restored active profile and size of the work active elements so after reconditioning they corresponded in terms of dimensional precision and resistance to wear, like initial elements

  9. Effectiveness of Corporate Social Media Activities to Increase Relational Outcomes

    Risius, Marten; Beck, Roman

    2015-01-01

    This study applies social media analytics to investigate the impact of different corporate social media activities on user word of mouth and attitudinal loyalty. We conduct a multilevel analysis of approximately 5 million tweets regarding the main Twitter accounts of 28 large global companies. We...... empirically identify different social media activities in terms of social media management strategies (using social media management tools or the web-frontend client), account types (broadcasting or receiving information), and communicative approaches (conversational or disseminative). We find positive...... effects of social media management tools, broadcasting accounts, and conversational communication on public perception....

  10. A link between mitotic entry and membrane growth suggests a novel model for cell size control.

    Anastasia, Steph D; Nguyen, Duy Linh; Thai, Vu; Meloy, Melissa; MacDonough, Tracy; Kellogg, Douglas R

    2012-04-02

    Addition of new membrane to the cell surface by membrane trafficking is necessary for cell growth. In this paper, we report that blocking membrane traffic causes a mitotic checkpoint arrest via Wee1-dependent inhibitory phosphorylation of Cdk1. Checkpoint signals are relayed by the Rho1 GTPase, protein kinase C (Pkc1), and a specific form of protein phosphatase 2A (PP2A(Cdc55)). Signaling via this pathway is dependent on membrane traffic and appears to increase gradually during polar bud growth. We hypothesize that delivery of vesicles to the site of bud growth generates a signal that is proportional to the extent of polarized membrane growth and that the strength of the signal is read by downstream components to determine when sufficient growth has occurred for initiation of mitosis. Growth-dependent signaling could explain how membrane growth is integrated with cell cycle progression. It could also control both cell size and morphogenesis, thereby reconciling divergent models for mitotic checkpoint function.

  11. Increased expression of T-helper cell activation markers in ...

    Ehab

    expression of these activation markers would be of value in monitoring asthma severity and the response to ... Key words: Children, atopic asthma, T-helper cell subsets, glucocorticoid inhalation, lower respiratory infections, CD45RO ...... budesonide, and placebo on mucosal inflammation and clinical indices in mild asthma.

  12. Counselling increases physical activity behaviour nine weeks after rehabilitation

    van der Ploeg, H P; Streppel, K R M; van der Beek, A J; van der Woude, L H V; Vollenbroek-Hutten, M M R; van Harten, W H; van Mechelen, W

    BACKGROUND: For people with disabilities, a physically active lifestyle can reduce the risk of secondary health problems and improve overall functioning. OBJECTIVES: To determine the effects of the sport stimulation programme "rehabilitation and sports" (R&S) and R&S combined with the daily physical

  13. Compensation in resting metabolism for experimentally increased activity

    Deerenberg, C; Overkamp, GJF; Visser, GH; Daan, S; Heldmaier, G.

    1998-01-01

    To study zebra finch allocation of energy to day and night at two different workloads, we assessed the daily energy turnover from: (1) metabolizable energy of the food, and (2) doubly-labeled water. In both experiments we imposed two levels of activity on captive zebra finches (Taeniopygia guttata),

  14. Sequential phosphorylation of GRASP65 during mitotic Golgi disassembly

    Danming Tang

    2012-09-01

    GRASP65 phosphorylation during mitosis and dephosphorylation after mitosis are required for Golgi disassembly and reassembly during the cell cycle. At least eight phosphorylation sites on GRASP65 have been identified, but whether they are modified in a coordinated fashion during mitosis is so far unknown. In this study, we raised phospho-specific antibodies that recognize phosphorylated T220/T224, S277 and S376 residues of GRASP65, respectively. Biochemical analysis showed that cdc2 phosphorylates all three sites, while plk1 enhances the phosphorylation. Microscopic studies using these antibodies for double and triple labeling demonstrate sequential phosphorylation and dephosphorylation during the cell cycle. S277 and S376 are phosphorylated from late G2 phase through metaphase until telophase when the new Golgi is reassembled. T220/224 is not modified until prophase, but is highly modified from prometaphase to anaphase. In metaphase, phospho-T220/224 signal localizes on both Golgi haze and mitotic Golgi clusters that represent dispersed Golgi vesicles and Golgi remnants, respectively, while phospho-S277 and S376 labeling is more concentrated on mitotic Golgi clusters. Expression of a phosphorylation-resistant GRASP65 mutant T220A/T224A inhibited mitotic Golgi fragmentation to a much larger extent than the expression of the S277A and S376A mutants. In cytokinesis, T220/224 dephosphorylation occurs prior to that of S277, but after S376. This study provides evidence that GRASP65 is sequentially phosphorylated and dephosphorylated during mitosis at different sites to orchestrate Golgi disassembly and reassembly during cell division, with phosphorylation of the T220/224 site being most critical in the process.

  15. Mitotic delay of irradiated cells and its connection with quantity of radiation injuries

    Lobachevskij, P.N.; Fominykh, E.V.

    1989-01-01

    The study is dedicated to development of mathematical approach to interpret radiation-induced mitosic delay. An assumption is made that mitotic delay is conditioned by discrete injuries distributed in cells according to stochasticity of interaction of radiation and target substance. It is supposed to consider the problem on injuries nature causing mitotic delay and to use the developed method for accounting the effect of radiation-induced mitotic delay on registered chromosomal aberration yield. 10 refs.; 2 figs.; 3 tabs

  16. Radiation induced mitotic delay and stimulation of growth

    Feldmann, A.

    1974-01-01

    The mechanisms responsible for the radiation induced mitotic delay and stimulation of growth are discussed in connection with the results of studies in Lemna minor and Lepidium sativum. The action of temperature seems to be of major importance. As many authors suggest that various chemical agents and slight intoxications also affect mitosis in a way similar to that induced by ionizing radiation, the radiation induced stimulation has lost its specific character and approaches might be found for further investigations of this phenomenon. (MG) [de

  17. WDR81 mutations cause extreme microcephaly and impair mitotic progression in human fibroblasts and Drosophila neural stem cells.

    Cavallin, Mara; Rujano, Maria A; Bednarek, Nathalie; Medina-Cano, Daniel; Bernabe Gelot, Antoinette; Drunat, Severine; Maillard, Camille; Garfa-Traore, Meriem; Bole, Christine; Nitschké, Patrick; Beneteau, Claire; Besnard, Thomas; Cogné, Benjamin; Eveillard, Marion; Kuster, Alice; Poirier, Karine; Verloes, Alain; Martinovic, Jelena; Bidat, Laurent; Rio, Marlene; Lyonnet, Stanislas; Reilly, M Louise; Boddaert, Nathalie; Jenneson-Liver, Melanie; Motte, Jacques; Doco-Fenzy, Martine; Chelly, Jamel; Attie-Bitach, Tania; Simons, Matias; Cantagrel, Vincent; Passemard, Sandrine; Baffet, Alexandre; Thomas, Sophie; Bahi-Buisson, Nadia

    2017-10-01

    Microlissencephaly is a rare brain malformation characterized by congenital microcephaly and lissencephaly. Microlissencephaly is suspected to result from abnormalities in the proliferation or survival of neural progenitors. Despite the recent identification of six genes involved in microlissencephaly, the pathophysiological basis of this condition remains poorly understood. We performed trio-based whole exome sequencing in seven subjects from five non-consanguineous families who presented with either microcephaly or microlissencephaly. This led to the identification of compound heterozygous mutations in WDR81, a gene previously associated with cerebellar ataxia, intellectual disability and quadrupedal locomotion. Patient phenotypes ranged from severe microcephaly with extremely reduced gyration with pontocerebellar hypoplasia to moderate microcephaly with cerebellar atrophy. In patient fibroblast cells, WDR81 mutations were associated with increased mitotic index and delayed prometaphase/metaphase transition. Similarly, in vivo, we showed that knockdown of the WDR81 orthologue in Drosophila led to increased mitotic index of neural stem cells with delayed mitotic progression. In summary, we highlight the broad phenotypic spectrum of WDR81-related brain malformations, which include microcephaly with moderate to extremely reduced gyration and cerebellar anomalies. Our results suggest that WDR81 might have a role in mitosis that is conserved between Drosophila and humans. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Detection of mitotic figures in thin melanomas--immunohistochemistry does not replace the careful search for mitotic figures in hematoxylin-eosin stain.

    Ottmann, Karl; Tronnier, Michael; Mitteldorf, Christina

    2015-10-01

    The mitotic rate is an important prognostic criterion in patients with thin melanoma ≤ 1 mm. The aim of this study was to investigate the reproducibility of the mitotic rate in thin melanoma in hematoxylin-eosin (H&E) stain and compare it with the detection of mitotic figures by immunohistochemistry. The number of mitoses stated in the routine diagnostic report in 190 pT1 melanomas was compared with the number gained from re-evaluation of H&E sections and the number detected after staining with the mitotic marker, phosphohistone H3 (PHH3). Two different approaches were used for choosing the "hot spot" for evaluation (dermal vs epidermal/dermal). Comparing routine H&E-stained slides with re-evaluation slides, the number of mitotic figures was slightly variable. However, findings did not result in a change of the tumor stage. In 34% of the tumors with dermal mitotic figures on H&E, mitoses could not be found in the corresponding PHH3 slide anymore. In 4% of the cases, stage relevant mitoses could only be found by PHH3 immunohistochemistry. This is a single center study. Immunohistochemical staining for mitotic figures does not replace a careful evaluation of H&E-stained slides. Immunohistochemical detection of mitosis is only an additional tool; the time-saving effect is therefore negligible. Copyright © 2015 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  19. Trunk muscle activity increases with unstable squat movements.

    Anderson, Kenneth; Behm, David G

    2005-02-01

    The objective of this study was to determine differences in electromyographic (EMG) activity of the soleus (SOL), vastus lateralis (VL), biceps femoris (BF), abdominal stabilizers (AS), upper lumbar erector spinae (ULES), and lumbo-sacral erector spinae (LSES) muscles while performing squats of varied stability and resistance. Stability was altered by doing the squat movement on a Smith machine, a free squat, and while standing on two balance discs. Fourteen male subjects performed the movements. Activities of the SOL, AS, ULES, and LSES were highest during the unstable squat and lowest with the Smith machine protocol (p squats on unstable surfaces may permit a training adaptation of the trunk muscles responsible for supporting the spinal column (i.e., erector spinae) as well as the muscles most responsible for maintaining posture (i.e., SOL).

  20. Comparison of staining of mitotic figures by haematoxylin and eosin-and crystal violet stains, in oral epithelial dysplasia and squamous cell carcinoma

    Ankle Madhuri

    2007-01-01

    Full Text Available Mitosis of cells gives rise to tissue integrity. Defects during mitosis bring about abnormalities. Excessive proliferation of cells due to increased mitosis is one such outcome, which is the hallmark in precancer and cancer. The localization of proliferating cells or their precursors may not be obvious and easy. Establishing an easy way to distinguish these mitotic cells will help in grading and understanding their biological potential. Although immunohistochemistry is an advanced method in use, the cost and time factor makes it less feasible for many laboratories. Selective histochemical stains like toluidine blue, giemsa and crystal violet have been used in tissues including the developing brain, neural tissue and skin. Aim of the study: 1To compare the staining of mitotic cells in haematoxylin and eosin with that in crystal violet. 2To compare the number of mitotic figures present in normal oral mucosa, epithelial dysplasia and oral squamous cell carcinoma in crystal violet-stained sections with that in H and E-stained sections. Materials and Methods: Ten tissues of normal oral mucosa and 15 tissues each of oral epithelial dysplasia seen in tobacco-associated leukoplakia and squamous cell carcinoma were studied to evaluate the selectivity of 1% crystal violet for mitotic figures. The staining was compared with standard H and E staining. Statistical analysis was done using Man-Whitney U test. Results: A statistically significant increase in the mean mitotic count was observed in crystal violet-stained sections of epithelial dysplasia as compared to the H and E-stained sections ( p = 0.0327. A similar increase in the mitotic counts was noted in crystal violet-stained sections of oral squamous cell carcinoma as compared to the H and E-stained sections.( p = 0.0443. No significant difference was found in the mitotic counts determined in dysplasia or carcinoma by either the crystal violet ( p = 0.4429 or the H and E-staining techniques ( p = 0

  1. The HSP90 inhibitor NVP-AUY922 radiosensitizes by abrogation of homologous recombination resulting in mitotic entry with unresolved DNA damage.

    Shane Zaidi

    Full Text Available Heat shock protein 90 (HSP90 is a molecular chaperone responsible for the conformational maintenance of a number of client proteins that play key roles in cell cycle arrest, DNA damage repair and apoptosis following radiation. HSP90 inhibitors exhibit antitumor activity by modulating the stabilisation and activation of HSP90 client proteins. We sought to evaluate NVP-AUY922, the most potent HSP90 inhibitor yet reported, in preclinical radiosensitization studies.NVP-AUY922 potently radiosensitized cells in vitro at low nanomolar concentrations with a concurrent depletion of radioresistance-linked client proteins. Radiosensitization by NVP-AUY922 was verified for the first time in vivo in a human head and neck squamous cell carcinoma xenograft model in athymic mice, as measured by delayed tumor growth and increased surrogate end-point survival (p = <0.0001. NVP-AUY922 was shown to ubiquitously inhibit resolution of dsDNA damage repair correlating to delayed Rad51 foci formation in all cell lines tested. Additionally, NVP-AUY922 induced a stalled mitotic phenotype, in a cell line-dependent manner, in HeLa and HN5 cell lines irrespective of radiation exposure. Cell cycle analysis indicated that NVP-AUY922 induced aberrant mitotic entry in all cell lines tested in the presence of radiation-induced DNA damage due to ubiquitous CHK1 depletion, but resultant downstream cell cycle effects were cell line dependent.These results identify NVP-AUY922 as the most potent HSP90-mediated radiosensitizer yet reported in vitro, and for the first time validate it in a clinically relevant in vivo model. Mechanistic analysis at clinically achievable concentrations demonstrated that radiosensitization is mediated by the combinatorial inhibition of cell growth and survival pathways, ubiquitous delay in Rad51-mediated homologous recombination and CHK1-mediated G(2/M arrest, but that the contribution of cell cycle perturbation to radiosensitization may be cell line

  2. Loss of p120 catenin and links to mitotic alterations, inflammation, and skin cancer

    Perez-Moreno, Mirna; Song, Weimin; Pasolli, H Amalia

    2008-01-01

    Tumor formation involves epigenetic modifications and microenvironmental changes as well as cumulative genetic alterations encompassing somatic mutations, loss of heterozygosity, and aneuploidy. Here, we show that conditional targeting of p120 catenin in mice leads to progressive development...... of skin neoplasias associated with intrinsic NF-kappaB activation. We find that, similarly, squamous cell carcinomas in humans display altered p120 and activated NF-kappaB. We show that epidermal hyperproliferation arising from p120 loss can be abrogated by IkappaB kinase 2 inhibitors. Although...... this underscores the importance of this pathway, the role of NF-kappaB in hyperproliferation appears rooted in its impact on epidermal microenvironment because as p120-null keratinocytes display a growth-arrested phenotype in culture. We trace this to a mitotic defect, resulting in unstable, binucleated cells...

  3. Abrupt onset of mutations in a developmentally regulated gene during terminal differentiation of post-mitotic photoreceptor neurons in mice.

    Ivette M Sandoval

    Full Text Available For sensitive detection of rare gene repair events in terminally differentiated photoreceptors, we generated a knockin mouse model by replacing one mouse rhodopsin allele with a form of the human rhodopsin gene that causes a severe, early-onset form of retinitis pigmentosa. The human gene contains a premature stop codon at position 344 (Q344X, cDNA encoding the enhanced green fluorescent protein (EGFP at its 3' end, and a modified 5' untranslated region to reduce translation rate so that the mutant protein does not induce retinal degeneration. Mutations that eliminate the stop codon express a human rhodopsin-EGFP fusion protein (hRho-GFP, which can be readily detected by fluorescence microscopy. Spontaneous mutations were observed at a frequency of about one per retina; in every case, they gave rise to single fluorescent rod cells, indicating that each mutation occurred during or after the last mitotic division. Additionally, the number of fluorescent rods did not increase with age, suggesting that the rhodopsin gene in mature rod cells is less sensitive to mutation than it is in developing rods. Thus, there is a brief developmental window, coinciding with the transcriptional activation of the rhodopsin locus, in which somatic mutations of the rhodopsin gene abruptly begin to appear.

  4. Xanthene derivatives increase glucose utilization through activation of LKB1-dependent AMP-activated protein kinase.

    Yonghoon Kwon

    Full Text Available 5' AMP-activated protein kinase (AMPK is a highly conserved serine-threonine kinase that regulates energy expenditure by activating catabolic metabolism and suppressing anabolic pathways to increase cellular energy levels. Therefore AMPK activators are considered to be drug targets for treatment of metabolic diseases such as diabetes mellitus. To identify novel AMPK activators, we screened xanthene derivatives. We determined that the AMPK activators 9H-xanthene-9-carboxylic acid {2,2,2-trichloro-1-[3-(3-nitro-phenyl-thioureido]-ethyl}-amide (Xn and 9H-xanthene-9-carboxylic acid {2,2,2-trichloro-1-[3-(3-cyano-phenyl-thioureido]-ethyl}-amide (Xc elevated glucose uptake in L6 myotubes by stimulating translocation of glucose transporter type 4 (GLUT4. Treatment with the chemical AMPK inhibitor compound C and infection with dominant-negative AMPKa2-virus inhibited AMPK phosphorylation and glucose uptake in myotubes induced by either Xn or Xc. Of the two major upstream kinases of AMPK, we found that Xn and Xc showed LKB1 dependency by knockdown of STK11, an ortholog of human LKB1. Single intravenous administration of Xn and Xc to high-fat diet-induced diabetic mice stimulated AMPK phosphorylation of skeletal muscle and improved glucose tolerance. Taken together, these results suggest that Xn and Xc regulate glucose homeostasis through LKB1-dependent AMPK activation and that the compounds are potential candidate drugs for the treatment of type 2 diabetes mellitus.

  5. Motivational Interviewing to Increase Physical Activity in Breast Cancer Survivors

    2011-05-01

    impact of physical activity on depressive symptoms, fatigue, and aerobic fitness over time. 4 BODY TRAINING ACCOMPLISHMENTS The SOW outlined 5...not count fruit drinks like Kooi-Aid, lemonade, Hi-C, cranberry juice drink, Tang, and Twister. Include juice you drank at all mealtimes and between...5. I had trouble keeping my mind on what I was D D D D doing 6. I felt depressed D D D D 7. I felt that everything I did was an effort D D D D

  6. Upregulation of meiosis-specific genes in lymphoma cell lines following genotoxic insult and induction of mitotic catastrophe

    Kalejs, Martins; Ivanov, Andrey; Plakhins, Gregory; Cragg, Mark S; Emzinsh, Dzintars; Illidge, Timothy M; Erenpreisa, Jekaterina

    2006-01-01

    We have previously reported that p53 mutated radioresistant lymphoma cell lines undergo mitotic catastrophe after irradiation, resulting in metaphase arrest and the generation of endopolyploid cells. A proportion of these endopolyploid cells then undergo a process of de-polyploidisation, stages of which are partially reminiscent of meiotic prophase. Furthermore, expression of meiosis-specific proteins of the cancer/testis antigens group of genes has previously been reported in tumours. We therefore investigated whether expression of meiosis-specific genes was associated with the polyploidy response in our tumour model. Three lymphoma cell lines, Namalwa, WI-L2-NS and TK6, of varying p53 status were exposed to a single 10 Gy dose of gamma radiation and their responses assessed over an extended time course. DNA flow cytometry and mitotic counts were used to assess the kinetics and extent of polyploidisation and mitotic progression. Expression of meiotic genes was analysed using RT-PCR and western blotting. In addition, localisation of the meiotic cohesin REC8 and its relation to centromeres was analysed by immunofluorescence. The principal meiotic regulator MOS was found to be significantly post-transcriptionally up-regulated after irradiation in p53 mutated but not p53 wild-type lymphoma cells. The maximum expression of MOS coincided with the maximal fraction of metaphase arrested cells and was directly proportional to both the extent of the arrest and the number of endopolyploid cells that subsequently emerged. The meiotic cohesin REC8 was also found to be up-regulated after irradiation, linking sister chromatid centromeres in the metaphase-arrested and subsequent giant cells. Finally, RT-PCR revealed expression of the meiosis-prophase genes, DMC1, STAG3, SYCP3 and SYCP1. We conclude that multiple meiotic genes are aberrantly activated during mitotic catastrophe in p53 mutated lymphoma cells after irradiation. Furthermore, we suggest that the coordinated expression

  7. A Subpopulation of the K562 Cells Are Killed by Curcumin Treatment after G2/M Arrest and Mitotic Catastrophe.

    Macario Martinez-Castillo

    Full Text Available Curcumin is extensively investigated as a good chemo-preventive agent in the development of many cancers and particularly in leukemia, including treatment of chronic myelogenous leukemia and it has been proposed as an adjuvant for leukemia therapies. Human chronic myeloid leukemia cells (K562, were treated with 20 μM of curcumin, and we found that a subpopulation of these cells were arrested and accumulate in the G2/M phase of the cell cycle. Characterization of this cell subpopulation showed that the arrested cells presented nuclear morphology changes resembling those described for mitotic catastrophe. Mitotic cells displayed abnormal chromatin organization, collapse of the mitotic spindle and abnormal chromosome segregation. Then, these cells died in an apoptosis dependent manner and showed diminution in the protein levels of BCL-2 and XIAP. Moreover, our results shown that a transient activation of the nuclear factor κB (NFκB occurred early in these cells, but decreased after 6 h of the treatment, explaining in part the diminution of the anti-apoptotic proteins. Additionally, P73 was translocated to the cell nuclei, because the expression of the C/EBPα, a cognate repressor of the P73 gene, was decreased, suggesting that apoptosis is trigger by elevation of P73 protein levels acting in concert with the diminution of the two anti-apoptotic molecules. In summary, curcumin treatment might produce a P73-dependent apoptotic cell death in chronic myelogenous leukemia cells (K562, which was triggered by mitotic catastrophe, due to sustained BAX and survivin expression and impairment of the anti-apoptotic proteins BCL-2 and XIAP.

  8. [Genetic control of mitotic crossing-over in yeasts. III. Induction by 8-methoxypsoralen and long-wave UV irradiation (lambda=365 nm)].

    Fedorova, I V; Marfin, S V

    1982-02-01

    The lethal effect of 8-methoxypsoralen (8-MOP) plus 365 nm light has been studied in haploid radiosensitive strains of Saccharomyces cerevisiae. The diploid of wild type and the diploid homozygous for the rad2 mutation (this mutation blocks the excision of UV-induced pyrimidine dimers) were more resistant to the lethal effect of 8-MOP plus 365 nm light than the haploid of wild type and rad2 haploid, respectively. The diploid homozygous for rad54 mutation (the mutation blocks the repair of double-strand breaks in DNA) was more sensitive than haploid rad54. The method of repeated irradiation allowed to study the capacity of radiosensitive diploids to remove monoadducts induced by 8-MOP in DNA. This process was very effective in diploids of wild type and in the rad54 rad54 diploid, while the rad2 rad2 diploid was characterized by nearly complete absence of monoadduct excision. The study of mitotic crossing over and mitotic segregation in yeast diploids, containing a pair of complementing alleles of the ade2 gene (red/pink) has shown a very high recombinogenic effect of 8-MOP plus 365 nm light. The rad2 mutation slightly increased the frequency of mitotic segregation and mitotic crossing over. The rad54 mutation decreased the frequency of mitotic segregation and entirely suppressed mitotic crossing over. The method of repeated irradiation showed that the cross-links, but not monoadducts, are the main cause of high recombinogenic effect of 8-MOP plus 365 nm light. The possible participation of different repair systems in recombinational processes induced by 8-MOP in yeast cells is discussed.

  9. Increasing evidence that bats actively forage at wind turbines.

    Foo, Cecily F; Bennett, Victoria J; Hale, Amanda M; Korstian, Jennifer M; Schildt, Alison J; Williams, Dean A

    2017-01-01

    Although the ultimate causes of high bat fatalities at wind farms are not well understood, several lines of evidence suggest that bats are attracted to wind turbines. One hypothesis is that bats would be attracted to turbines as a foraging resource if the insects that bats prey upon are commonly present on and around the turbine towers. To investigate the role that foraging activity may play in bat fatalities, we conducted a series of surveys at a wind farm in the southern Great Plains of the US from 2011-2016. From acoustic monitoring we recorded foraging activity, including feeding buzzes indicative of prey capture, in the immediate vicinity of turbine towers from all six bat species known to be present at this site. From insect surveys we found Lepidoptera, Coleoptera, and Orthoptera in consistently high proportions over several years suggesting that food resources for bats were consistently available at wind turbines. We used DNA barcoding techniques to assess bat diet composition of (1) stomach contents from 47 eastern red bat ( Lasiurus borealis ) and 24 hoary bat ( Lasiurus cinereus ) carcasses collected in fatality searches, and (2) fecal pellets from 23 eastern red bats that were found on turbine towers, transformers, and tower doors. We found that the majority of the eastern red bat and hoary bat stomachs, the two bat species most commonly found in fatality searches at this site, were full or partially full, indicating that the bats were likely killed while foraging. Although Lepidoptera and Orthoptera dominated the diets of these two bat species, both consumed a range of prey items with individual bats having from one to six insect species in their stomachs at the time of death. The prey items identified from eastern red bat fecal pellets showed similar results. A comparison of the turbine insect community to the diet analysis results revealed that the most abundant insects at wind turbines, including terrestrial insects such as crickets and several

  10. Myeloperoxidase activity is increased in gingival crevicular fluid and whole saliva after fixed orthodontic appliance activation.

    Marcaccini, Andrea M; Amato, Patricia A F; Leão, Fernanda V; Gerlach, Raquel F; Ferreira, Jose T L

    2010-11-01

    Orthodontic tooth movement uses mechanical forces that result in inflammation in the first days. Myeloperoxidase (MPO) is an enzyme found in polymorphonuclear neutrophil (PMN) granules, and it is used to estimate the number of PMN granules in tissues. So far, MPO has not been used to study the inflammatory alterations after the application of orthodontic tooth movement forces. The aim of this study was to determine MPO activity in the gingival crevicular fluid (GCF) and saliva (whole stimulated saliva) of orthodontic patients at different time points after fixed appliance activation. MPO was determined in the GCF and collected by means of periopaper from the saliva of 14 patients with orthodontic fixed appliances. GCF and saliva samples were collected at baseline, 2 hours, and 7 and 14 days after application of the orthodontic force. Mean MPO activity was increased in both the GCF and saliva of orthodontic patients at 2 hours after appliance activation (P orthodontic force probably results in the increased MPO level observed at this time point. MPO might be a good marker to assess inflammation in orthodontic movement; it deserves further studies in orthodontic therapy. Copyright © 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  11. A molecular mechanism of mitotic centrosome assembly in Drosophila

    Conduit, Paul T; Richens, Jennifer H; Wainman, Alan; Holder, James; Vicente, Catarina C; Pratt, Metta B; Dix, Carly I; Novak, Zsofia A; Dobbie, Ian M; Schermelleh, Lothar; Raff, Jordan W

    2014-01-01

    Centrosomes comprise a pair of centrioles surrounded by pericentriolar material (PCM). The PCM expands dramatically as cells enter mitosis, but it is unclear how this occurs. In this study, we show that the centriole protein Asl initiates the recruitment of DSpd-2 and Cnn to mother centrioles; both proteins then assemble into co-dependent scaffold-like structures that spread outwards from the mother centriole and recruit most, if not all, other PCM components. In the absence of either DSpd-2 or Cnn, mitotic PCM assembly is diminished; in the absence of both proteins, it appears to be abolished. We show that DSpd-2 helps incorporate Cnn into the PCM and that Cnn then helps maintain DSpd-2 within the PCM, creating a positive feedback loop that promotes robust PCM expansion around the mother centriole during mitosis. These observations suggest a surprisingly simple mechanism of mitotic PCM assembly in flies. DOI: http://dx.doi.org/10.7554/eLife.03399.001 PMID:25149451

  12. Effects of sport activities on increasing preschool children's creativity

    Mehdi Shahbazi

    2012-10-01

    Full Text Available Torrance tests of creative thinking have been widely used to measure the impact of different items such as creativity on different groups of children. In this study, we perform an empirical study to measure the effects of endurance, power-based and flexibility on a group of children's creativity, originality and flexibility. The study chooses a sample of 341 from 2978 preschool children and distributes a questionnaire among them where 153 were female and 188 of them were male. Cronbach alpha for creativity, originality and fluency were calculated as 0.814, 0.822 and 0.788, respectively. The results of our study indicate that there are some positive and meaningful relationship among three components of creativity, originality and fluency before and after accomplishing test. The impact of test was measured for three types of sport activities including endurance, power-based and flexibility tests. After applying 32 sessions of sporting games, flexibility games represent a mean value of 32.40, which is higher than the other two tests and it maintains meaningful value compared with two other sporting tests of endurance and power base tests.

  13. Application of Pilates principles increases paraspinal muscle activation.

    Andrade, Letícia Souza; Mochizuki, Luís; Pires, Flávio Oliveira; da Silva, Renato André Sousa; Mota, Yomara Lima

    2015-01-01

    To analyze the effect of Pilates principles on the EMG activity of abdominal and paraspinal muscles on stable and unstable surfaces. Surface EMG data about the rectus abdominis (RA), iliocostalis (IL) and lumbar multifidus (MU) of 19 participants were collected while performing three repetitions of a crunch exercise in the following conditions: 1) with no Pilates technique and stable surface (nP + S); 2) with no Pilates technique and unstable surface (nP + U); 3) with Pilates technique and stable surface (P + S); 4) with Pilates and unstable surface (P + U). The EMG Fanalysis was conducted using a custom-made Matlab(®) 10. There was no condition effect in the RA iEMG with stable and unstable surfaces (F(1,290) = 0 p = 0.98) and with and without principles (F(1,290) = 1.2 p = 0.27). IL iEMG was higher for the stable surface condition (F(1,290) = 32.3 p Pilates principles (F(1,290) = 21.9 p Pilates principles (F(1,290) = 84.9 p < 0.001). Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Complexing Methylene Blue with Phosphorus Dendrimers to Increase Photodynamic Activity

    Monika Dabrzalska

    2017-02-01

    Full Text Available The efficiency of photodynamic therapy is limited mainly due to low selectivity, unfavorable biodistribution of photosensitizers, and long-lasting skin sensitivity to light. However, drug delivery systems based on nanoparticles may overcome the limitations mentioned above. Among others, dendrimers are particularly attractive as carriers, because of their globular architecture and high loading capacity. The goal of the study was to check whether an anionic phosphorus dendrimer is suitable as a carrier of a photosensitizer—methylene blue (MB. As a biological model, basal cell carcinoma cell lines were used. We checked the influence of the MB complexation on its singlet oxygen production ability using a commercial fluorescence probe. Next, cellular uptake, phototoxicity, reactive oxygen species (ROS generation, and cell death were investigated. The MB-anionic dendrimer complex (MB-1an was found to generate less singlet oxygen; however, the complex showed higher cellular uptake and phototoxicity against basal cell carcinoma cell lines, which was accompanied with enhanced ROS production. Owing to the obtained results, we conclude that the photodynamic activity of MB complexed with an anionic dendrimer is higher than free MB against basal cell carcinoma cell lines.

  15. Prices dip, activity increases in unrestricted uranium market

    Anon.

    1993-01-01

    April's activity in the restricted uranium market fluctuated in the same range as that observed in March. At the same time, NUKEM detects a weakening of prices in the unrestricted market to $7.45-$7.65. Unrestricted buyers seem to have detected lower prices as well; much of the new demand noted this month emerged in the unrestricted segment of the market. With this issue, NUKEM inaugurates a new market statistic. To better follow developments in the conversion market, we will report a spot price range for conversion services. This price measure will be derived in a manner analogous to NUKEM's other spot market price ranges. We will continue to publish the current NUKEM price range for new contracts for a few months. If you wish to retain the old conversion contract price range in future editions, please contact our US office. Four deals for near term delivery occurred in the uranium market in April, resulting in spot market transaction volume of 2.5 million lbs U3O8 equivalent. In the first week, a US non-utility purchased a small quantity of enriched uranium product from an intermediary in a spot transaction representing about 75,000 lbs U3O8. The second week saw the stealthy purchase of Portland General Electric's inventory of natural and enriched uranium. The buyer of PGE's 1.1 million lbs U3O8 equivalent has achieved an unusual degree of anonymity. Also during the second week, a US utility bought a small quantity of enriched uranium containing less than 25,000 lbs natural U3O8 equivalent

  16. Disturbed mitotic progression and genome segregation are involved in cell transformation mediated by nano-TiO2 long-term exposure

    Huang Shing; Chueh Pinju; Lin Yunwei; Shih Tungsheng; Chuang Showmei

    2009-01-01

    Titanium dioxide (TiO2) nano-particles (< 100 nm in diameter) have been of interest in a wide range of applications, such as in cosmetics and pharmaceuticals because of their low toxicity. However, recent studies have shown that TiO2 nano-particles (nano-TiO2) induce cytotoxicity and genotoxicity in various lines of cultured cells as well as tumorigenesis in animal models. The biological roles of nano-TiO2 are shown to be controversial and no comprehensive study paradigm has been developed to investigate their molecular mechanisms. In this study, we showed that short-term exposure to nano-TiO2 enhanced cell proliferation, survival, ERK signaling activation and ROS production in cultured fibroblast cells. Moreover, long-term exposure to nano-TiO2 not only increased cell survival and growth on soft agar but also the numbers of multinucleated cells and micronucleus (MN) as suggested in confocal microscopy analysis. Cell cycle phase analysis showed G2/M delay and slower cell division in long-term exposed cells. Most importantly, long-term TiO2 exposure remarkably affected mitotic progression at anaphase and telophase leading to aberrant multipolar spindles and chromatin alignment/segregation. Moreover, PLK1 was demonstrated as the target for nano-TiO2 in the regulation of mitotic progression and exit. Notably, a higher fraction of sub-G1 phase population appeared in TiO2-exposed cells after releasing from G2/M synchronization. Our results demonstrate that long-term exposure to nano-TiO2 disturbs cell cycle progression and duplicated genome segregation, leading to chromosomal instability and cell transformation.

  17. CYTOGENETICS EFFECTS INDUCED BY NITRATE OF LEAD ON MITOTIC DIVISION AT ALLIUM CEPA L.

    Silvica Padureanu

    2005-01-01

    The paper presents the influence of nitrate of lead upon the mitotic division of Allium cepa L. The treatment with nitrate of lead has determined the lessening of the mitotic index and the chromosomial mutations. Also nitrate of lead determined in little proportion cells autopoliploid. The experiment prowed that nitrate of lead, known as a polluting agent has a mutagenic potential on the plants.

  18. Regulation of mitotic spindle formation by the RhoA guanine nucleotide exchange factor ARHGEF10

    Satoh Takaya

    2009-07-01

    Full Text Available Abstract Background The Dbl family guanine nucleotide exchange factor ARHGEF10 was originally identified as the product of the gene associated with slowed nerve-conduction velocities of peripheral nerves. However, the function of ARHGEF10 in mammalian cells is totally unknown at a molecular level. ARHGEF10 contains no distinctive functional domains except for tandem Dbl homology-pleckstrin homology and putative transmembrane domains. Results Here we show that RhoA is a substrate for ARHGEF10. In both G1/S and M phases, ARHGEF10 was localized in the centrosome in adenocarcinoma HeLa cells. Furthermore, RNA interference-based knockdown of ARHGEF10 resulted in multipolar spindle formation in M phase. Each spindle pole seems to contain a centrosome consisting of two centrioles and the pericentriolar material. Downregulation of RhoA elicited similar phenotypes, and aberrant mitotic spindle formation following ARHGEF10 knockdown was rescued by ectopic expression of constitutively activated RhoA. Multinucleated cells were not increased upon ARHGEF10 knockdown in contrast to treatment with Y-27632, a specific pharmacological inhibitor for the RhoA effector kinase ROCK, which induced not only multipolar spindle formation, but also multinucleation. Therefore, unregulated centrosome duplication rather than aberration in cytokinesis may be responsible for ARHGEF10 knockdown-dependent multipolar spindle formation. We further isolated the kinesin-like motor protein KIF3B as a binding partner of ARHGEF10. Knockdown of KIF3B again caused multipolar spindle phenotypes. The supernumerary centrosome phenotype was also observed in S phase-arrested osteosarcoma U2OS cells when the expression of ARHGEF10, RhoA or KIF3B was abrogated by RNA interference. Conclusion Collectively, our results suggest that a novel RhoA-dependent signaling pathway under the control of ARHGEF10 has a pivotal role in the regulation of the cell division cycle. This pathway is not involved in

  19. [Stability in association of the peripheral material with mitotic chromosomes].

    Kosykh, M I; Chentsov, Iu S

    2002-01-01

    The localization of nucleolar proteins (fibrillarin and B-23), and of the protein of interphase nuclear matrix (NMP-65) was studied in the perichromosomal material (CM) after of short hypotonic treatment (15% solution of Henks medium) on cultured pig embryonic kidney cells, followed by restoration of isotonic conditions. It is shown that during hypotonic shock the mitotic chromosomes demonstrate reversible swelling, but their periphery is bounded with a rim of PCM, containing antibodies to fibrillarin and NMP-65, but not to B-23. After returning the cells to the initial isotonic medium, all the three proteins can be detected again on the periphery of chromosomes. It suggests the existence of different stability in the association of free proteins with chromosome bodies. Besides, B-23 and fibrillarin could be visualized in residual nucleoli after a complete extraction of histones and DNA from nuclei.

  20. Aurora A's functions during mitotic exit: the Guess Who game

    David eReboutier

    2015-12-01

    Full Text Available Until recently, the knowledge of Aurora A kinase functions during mitosis was limited to pre-metaphase events, particularly centrosome maturation, G2/M transition, and mitotic spindle assembly. However, an involvement of Aurora A in post-metaphase events was also suspected, but not clearly demonstrated due to the technical difficulty to perform the appropriate experiments. Recent developments of both an analog specific version of Aurora A, and of small molecule inhibitors have led to the first demonstration that Aurora A is required for the early steps of cytokinesis. As in pre-metaphase, Aurora A plays diverse functions during anaphase, essentially participating in astral microtubules dynamics and central spindle assembly and functioning. The present review describes the experimental systems used to decipher new functions of Aurora A during late mitosis and situate these functions into the context of cytokinesis mechanisms.

  1. Cremophor EL stimulates mitotic recombination in uvsH//uvsH diploid strain of Aspergillus nidulans

    Cleverson Busso

    2004-03-01

    Full Text Available Cremophor EL is a solubilizer and emulsifier agent used in the pharmaceutical and foodstuff industries. The solvent is the principal constituent of paclitaxel's clinical formulation vehicle. Since mitotic recombination plays a crucial role in multistep carcinogenesis, the study of the recombinagenic potential of chemical compounds is of the utmost importance. In our research genotoxicity of cremophor EL has been studied by using an uvsH//uvsH diploid strain of Aspergillus nidulans. Since it spends a great part of its cell cycle in the G2period, this fungus is a special screening system for the study of mitotic recombination induced by chemical substances. Homozygotization Indexes (HI for paba and bi markers from heterozygous B211//A837 diploid strain were determined for the evaluation of the recombinagenic effect of cremophor EL. It has been shown that cremophor EL induces increase in mitotic crossing-over events at nontoxic concentrations (0.05 and 0.075% v/v.Cremofor EL (CEL é um solubilizante e emulsificante amplamente utilizado nas indústrias farmacêuticas e de gêneros alimentícios. É o principal veículo empregado nas formulações clínicas do antineoplásico paclitaxel. Considerando-se que a recombinação mitótica desempenha importante função no processo de carcinogênese, o estudo de substâncias químicas com potencial recombinagênico assume importância crucial, no sentido de se detectar aquelas que eventualmente possam atuar como promotoras de neoplasias. A genotoxicidade do cremofor EL foi estudada no presente trabalho, utilizando-se uma linhagem diplóide uvsH//uvsH de Aspergillus nidulans. Neste fungo as células vegetativas comumente repousam no período G2 do ciclo celular, facilitando a ocorrência da recombinação mitótica. O efeito recombinagênico do CEL foi avaliado através da determinação dos Índices de Homozigotização para os marcadores nutricionais paba e bi do diplóide heterozigoto B211//A837. Os

  2. Mitotic control of human papillomavirus genome-containing cells is regulated by the function of the PDZ-binding motif of the E6 oncoprotein

    Marsh, Elizabeth K.; Delury, Craig P.; Davies, Nicholas J.; Weston, Christopher J.; Miah, Mohammed A.L.; Banks, Lawrence; Parish, Joanna L.

    2017-01-01

    The function of a conserved PDS95/DLG1/ZO1 (PDZ) binding motif (E6 PBM) at the C-termini of E6 oncoproteins of high-risk human papillomavirus (HPV) types contributes to the development of HPV-associated malignancies. Here, using a primary human keratinocyte-based model of the high-risk HPV18 life cycle, we identify a novel link between the E6 PBM and mitotic stability. In cultures containing a mutant genome in which the E6 PBM was deleted there was an increase in the frequency of abnormal mitoses, including multinucleation, compared to cells harboring the wild type HPV18 genome. The loss of the E6 PBM was associated with a significant increase in the frequency of mitotic spindle defects associated with anaphase and telophase. Furthermore, cells carrying this mutant genome had increased chromosome segregation defects and they also exhibited greater levels of genomic instability, as shown by an elevated level of centromere-positive micronuclei. In wild type HPV18 genome-containing organotypic cultures, the majority of mitotic cells reside in the suprabasal layers, in keeping with the hyperplastic morphology of the structures. However, in mutant genome-containing structures a greater proportion of mitotic cells were retained in the basal layer, which were often of undefined polarity, thus correlating with their reduced thickness. We conclude that the ability of E6 to target cellular PDZ proteins plays a critical role in maintaining mitotic stability of HPV infected cells, ensuring stable episome persistence and vegetative amplification. PMID:28061478

  3. Mitotic control of human papillomavirus genome-containing cells is regulated by the function of the PDZ-binding motif of the E6 oncoprotein.

    Marsh, Elizabeth K; Delury, Craig P; Davies, Nicholas J; Weston, Christopher J; Miah, Mohammed A L; Banks, Lawrence; Parish, Joanna L; Higgs, Martin R; Roberts, Sally

    2017-03-21

    The function of a conserved PDS95/DLG1/ZO1 (PDZ) binding motif (E6 PBM) at the C-termini of E6 oncoproteins of high-risk human papillomavirus (HPV) types contributes to the development of HPV-associated malignancies. Here, using a primary human keratinocyte-based model of the high-risk HPV18 life cycle, we identify a novel link between the E6 PBM and mitotic stability. In cultures containing a mutant genome in which the E6 PBM was deleted there was an increase in the frequency of abnormal mitoses, including multinucleation, compared to cells harboring the wild type HPV18 genome. The loss of the E6 PBM was associated with a significant increase in the frequency of mitotic spindle defects associated with anaphase and telophase. Furthermore, cells carrying this mutant genome had increased chromosome segregation defects and they also exhibited greater levels of genomic instability, as shown by an elevated level of centromere-positive micronuclei. In wild type HPV18 genome-containing organotypic cultures, the majority of mitotic cells reside in the suprabasal layers, in keeping with the hyperplastic morphology of the structures. However, in mutant genome-containing structures a greater proportion of mitotic cells were retained in the basal layer, which were often of undefined polarity, thus correlating with their reduced thickness. We conclude that the ability of E6 to target cellular PDZ proteins plays a critical role in maintaining mitotic stability of HPV infected cells, ensuring stable episome persistence and vegetative amplification.

  4. Warts phosphorylates mud to promote pins-mediated mitotic spindle orientation in Drosophila, independent of Yorkie.

    Dewey, Evan B; Sanchez, Desiree; Johnston, Christopher A

    2015-11-02

    Multicellular animals have evolved conserved signaling pathways that translate cell polarity cues into mitotic spindle positioning to control the orientation of cell division within complex tissue structures. These oriented cell divisions are essential for the development of cell diversity and the maintenance of tissue homeostasis. Despite intense efforts, the molecular mechanisms that control spindle orientation remain incompletely defined. Here, we describe a role for the Hippo (Hpo) kinase complex in promoting Partner of Inscuteable (Pins)-mediated spindle orientation. Knockdown of Hpo, Salvador (Sav), or Warts (Wts) each result in a partial loss of spindle orientation, a phenotype previously described following loss of the Pins-binding protein Mushroom body defect (Mud). Similar to orthologs spanning yeast to mammals, Wts kinase localizes to mitotic spindle poles, a prominent site of Mud localization. Wts directly phosphorylates Mud in vitro within its C-terminal coiled-coil domain. This Mud coiled-coil domain directly binds the adjacent Pins-binding domain to dampen the Pins/Mud interaction, and Wts-mediated phosphorylation uncouples this intramolecular Mud interaction. Loss of Wts prevents cortical Pins/Mud association without affecting Mud accumulation at spindle poles, suggesting phosphorylation acts as a molecular switch to specifically activate cortical Mud function. Finally, loss of Wts in Drosophila imaginal disc epithelial cells results in diminished cortical Mud and defective planar spindle orientation. Our results provide new insights into the molecular basis for dynamic regulation of the cortical Pins/Mud spindle positioning complex and highlight a novel link with an essential, evolutionarily conserved cell proliferation pathway. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. File list: His.Emb.50.AllAg.Mitotic_cycle_7-9 [Chip-atlas[Archive

    Full Text Available His.Emb.50.AllAg.Mitotic_cycle_7-9 dm3 Histone Embryo Mitotic cycle 7-9 SRX645111,S...RX645115,SRX645103,SRX645123,SRX645107,SRX645099,SRX645119 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Emb.50.AllAg.Mitotic_cycle_7-9.bed ...

  6. File list: NoD.Emb.05.AllAg.Mitotic_cycle_12-14 [Chip-atlas[Archive

    Full Text Available NoD.Emb.05.AllAg.Mitotic_cycle_12-14 dm3 No description Embryo Mitotic cycle 12-14 ...http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/NoD.Emb.05.AllAg.Mitotic_cycle_12-14.bed ...

  7. File list: Pol.Emb.10.AllAg.Mitotic_cycle_8-9 [Chip-atlas[Archive

    Full Text Available Pol.Emb.10.AllAg.Mitotic_cycle_8-9 dm3 RNA polymerase Embryo Mitotic cycle 8-9 http...://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.10.AllAg.Mitotic_cycle_8-9.bed ...

  8. File list: ALL.Emb.05.AllAg.Mitotic_cycle_8-9 [Chip-atlas[Archive

    Full Text Available ALL.Emb.05.AllAg.Mitotic_cycle_8-9 dm3 All antigens Embryo Mitotic cycle 8-9 SRX084...383 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Emb.05.AllAg.Mitotic_cycle_8-9.bed ...

  9. File list: InP.Emb.20.AllAg.Mitotic_cycle_8-9 [Chip-atlas[Archive

    Full Text Available InP.Emb.20.AllAg.Mitotic_cycle_8-9 dm3 Input control Embryo Mitotic cycle 8-9 http:...//dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.20.AllAg.Mitotic_cycle_8-9.bed ...

  10. File list: Pol.Emb.05.AllAg.Mitotic_cycle_13-14 [Chip-atlas[Archive

    Full Text Available Pol.Emb.05.AllAg.Mitotic_cycle_13-14 dm3 RNA polymerase Embryo Mitotic cycle 13-14 ...http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.05.AllAg.Mitotic_cycle_13-14.bed ...

  11. File list: Oth.Emb.50.AllAg.Mitotic_cycle_13-14 [Chip-atlas[Archive

    Full Text Available Oth.Emb.50.AllAg.Mitotic_cycle_13-14 dm3 TFs and others Embryo Mitotic cycle 13-14 ...SRX084384 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.Emb.50.AllAg.Mitotic_cycle_13-14.bed ...

  12. File list: Pol.Emb.10.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available Pol.Emb.10.AllAg.Mitotic_cycle_11-13 dm3 RNA polymerase Embryo Mitotic cycle 11-13 ...http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.10.AllAg.Mitotic_cycle_11-13.bed ...

  13. File list: His.Emb.20.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available His.Emb.20.AllAg.Mitotic_cycle_11-13 dm3 Histone Embryo Mitotic cycle 11-13 SRX6451...30,SRX645124,SRX645116,SRX645108,SRX645127,SRX645112,SRX645120 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Emb.20.AllAg.Mitotic_cycle_11-13.bed ...

  14. File list: NoD.Emb.10.AllAg.Mitotic_cycle_7-9 [Chip-atlas[Archive

    Full Text Available NoD.Emb.10.AllAg.Mitotic_cycle_7-9 dm3 No description Embryo Mitotic cycle 7-9 http...://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/NoD.Emb.10.AllAg.Mitotic_cycle_7-9.bed ...

  15. File list: InP.Emb.50.AllAg.Mitotic_cycle_14 [Chip-atlas[Archive

    Full Text Available InP.Emb.50.AllAg.Mitotic_cycle_14 dm3 Input control Embryo Mitotic cycle 14 SRX6451...40,SRX750075,SRX645139 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.50.AllAg.Mitotic_cycle_14.bed ...

  16. File list: InP.Emb.50.AllAg.Mitotic_cycle_7-9 [Chip-atlas[Archive

    Full Text Available InP.Emb.50.AllAg.Mitotic_cycle_7-9 dm3 Input control Embryo Mitotic cycle 7-9 SRX64...5137 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.50.AllAg.Mitotic_cycle_7-9.bed ...

  17. File list: Pol.Emb.20.AllAg.Mitotic_cycle_12-14 [Chip-atlas[Archive

    Full Text Available Pol.Emb.20.AllAg.Mitotic_cycle_12-14 dm3 RNA polymerase Embryo Mitotic cycle 12-14 ...http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.20.AllAg.Mitotic_cycle_12-14.bed ...

  18. File list: Oth.Emb.20.AllAg.Mitotic_cycle_7-9 [Chip-atlas[Archive

    Full Text Available Oth.Emb.20.AllAg.Mitotic_cycle_7-9 dm3 TFs and others Embryo Mitotic cycle 7-9 http...://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.Emb.20.AllAg.Mitotic_cycle_7-9.bed ...

  19. File list: InP.Emb.50.AllAg.Mitotic_cycle_8-9 [Chip-atlas[Archive

    Full Text Available InP.Emb.50.AllAg.Mitotic_cycle_8-9 dm3 Input control Embryo Mitotic cycle 8-9 http:...//dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.50.AllAg.Mitotic_cycle_8-9.bed ...

  20. File list: DNS.Emb.20.AllAg.Mitotic_cycle_12-14 [Chip-atlas[Archive

    Full Text Available DNS.Emb.20.AllAg.Mitotic_cycle_12-14 dm3 DNase-seq Embryo Mitotic cycle 12-14 http:...//dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/DNS.Emb.20.AllAg.Mitotic_cycle_12-14.bed ...

  1. File list: His.Emb.50.AllAg.Mitotic_cycle_13-14 [Chip-atlas[Archive

    Full Text Available His.Emb.50.AllAg.Mitotic_cycle_13-14 dm3 Histone Embryo Mitotic cycle 13-14 http://...dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Emb.50.AllAg.Mitotic_cycle_13-14.bed ...

  2. File list: DNS.Emb.10.AllAg.Mitotic_cycle_12-14 [Chip-atlas[Archive

    Full Text Available DNS.Emb.10.AllAg.Mitotic_cycle_12-14 dm3 DNase-seq Embryo Mitotic cycle 12-14 http:...//dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/DNS.Emb.10.AllAg.Mitotic_cycle_12-14.bed ...

  3. File list: ALL.Emb.20.AllAg.Mitotic_cycle_8-9 [Chip-atlas[Archive

    Full Text Available ALL.Emb.20.AllAg.Mitotic_cycle_8-9 dm3 All antigens Embryo Mitotic cycle 8-9 SRX084...383 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Emb.20.AllAg.Mitotic_cycle_8-9.bed ...

  4. File list: Pol.Emb.20.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available Pol.Emb.20.AllAg.Mitotic_cycle_11-13 dm3 RNA polymerase Embryo Mitotic cycle 11-13 ...http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.20.AllAg.Mitotic_cycle_11-13.bed ...

  5. File list: NoD.Emb.20.AllAg.Mitotic_cycle_7-9 [Chip-atlas[Archive

    Full Text Available NoD.Emb.20.AllAg.Mitotic_cycle_7-9 dm3 No description Embryo Mitotic cycle 7-9 http...://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/NoD.Emb.20.AllAg.Mitotic_cycle_7-9.bed ...

  6. File list: Unc.Emb.50.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available Unc.Emb.50.AllAg.Mitotic_cycle_11-13 dm3 Unclassified Embryo Mitotic cycle 11-13 ht...tp://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Unc.Emb.50.AllAg.Mitotic_cycle_11-13.bed ...

  7. File list: NoD.Emb.05.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available NoD.Emb.05.AllAg.Mitotic_cycle_11-13 dm3 No description Embryo Mitotic cycle 11-13 ...http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/NoD.Emb.05.AllAg.Mitotic_cycle_11-13.bed ...

  8. File list: Unc.Emb.05.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available Unc.Emb.05.AllAg.Mitotic_cycle_11-13 dm3 Unclassified Embryo Mitotic cycle 11-13 ht...tp://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Unc.Emb.05.AllAg.Mitotic_cycle_11-13.bed ...

  9. File list: InP.Emb.05.AllAg.Mitotic_cycle_13-14 [Chip-atlas[Archive

    Full Text Available InP.Emb.05.AllAg.Mitotic_cycle_13-14 dm3 Input control Embryo Mitotic cycle 13-14 h...ttp://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.05.AllAg.Mitotic_cycle_13-14.bed ...

  10. File list: Pol.Emb.50.AllAg.Mitotic_cycle_7-9 [Chip-atlas[Archive

    Full Text Available Pol.Emb.50.AllAg.Mitotic_cycle_7-9 dm3 RNA polymerase Embryo Mitotic cycle 7-9 http...://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.50.AllAg.Mitotic_cycle_7-9.bed ...

  11. File list: Pol.Emb.20.AllAg.Mitotic_cycle_8-9 [Chip-atlas[Archive

    Full Text Available Pol.Emb.20.AllAg.Mitotic_cycle_8-9 dm3 RNA polymerase Embryo Mitotic cycle 8-9 http...://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.20.AllAg.Mitotic_cycle_8-9.bed ...

  12. File list: DNS.Emb.50.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available DNS.Emb.50.AllAg.Mitotic_cycle_11-13 dm3 DNase-seq Embryo Mitotic cycle 11-13 http:...//dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/DNS.Emb.50.AllAg.Mitotic_cycle_11-13.bed ...

  13. File list: Pol.Emb.50.AllAg.Mitotic_cycle_12-14 [Chip-atlas[Archive

    Full Text Available Pol.Emb.50.AllAg.Mitotic_cycle_12-14 dm3 RNA polymerase Embryo Mitotic cycle 12-14 ...http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.50.AllAg.Mitotic_cycle_12-14.bed ...

  14. File list: Pol.Emb.50.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available Pol.Emb.50.AllAg.Mitotic_cycle_11-13 dm3 RNA polymerase Embryo Mitotic cycle 11-13 ...http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.50.AllAg.Mitotic_cycle_11-13.bed ...

  15. File list: Oth.Emb.10.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available Oth.Emb.10.AllAg.Mitotic_cycle_11-13 dm3 TFs and others Embryo Mitotic cycle 11-13 ...http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.Emb.10.AllAg.Mitotic_cycle_11-13.bed ...

  16. File list: ALL.Emb.50.AllAg.Mitotic_cycle_13-14 [Chip-atlas[Archive

    Full Text Available ALL.Emb.50.AllAg.Mitotic_cycle_13-14 dm3 All antigens Embryo Mitotic cycle 13-14 SR...X084384 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Emb.50.AllAg.Mitotic_cycle_13-14.bed ...

  17. File list: Oth.Emb.50.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available Oth.Emb.50.AllAg.Mitotic_cycle_11-13 dm3 TFs and others Embryo Mitotic cycle 11-13 ...http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.Emb.50.AllAg.Mitotic_cycle_11-13.bed ...

  18. File list: ALL.Emb.20.AllAg.Mitotic_cycle_13-14 [Chip-atlas[Archive

    Full Text Available ALL.Emb.20.AllAg.Mitotic_cycle_13-14 dm3 All antigens Embryo Mitotic cycle 13-14 SR...X084384 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Emb.20.AllAg.Mitotic_cycle_13-14.bed ...

  19. File list: His.Emb.20.AllAg.Mitotic_cycle_13-14 [Chip-atlas[Archive

    Full Text Available His.Emb.20.AllAg.Mitotic_cycle_13-14 dm3 Histone Embryo Mitotic cycle 13-14 http://...dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Emb.20.AllAg.Mitotic_cycle_13-14.bed ...

  20. File list: InP.Emb.20.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available InP.Emb.20.AllAg.Mitotic_cycle_11-13 dm3 Input control Embryo Mitotic cycle 11-13 S...RX645138 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.20.AllAg.Mitotic_cycle_11-13.bed ...

  1. File list: InP.Emb.20.AllAg.Mitotic_cycle_12-14 [Chip-atlas[Archive

    Full Text Available InP.Emb.20.AllAg.Mitotic_cycle_12-14 dm3 Input control Embryo Mitotic cycle 12-14 h...ttp://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.20.AllAg.Mitotic_cycle_12-14.bed ...

  2. File list: NoD.Emb.05.AllAg.Mitotic_cycle_7-9 [Chip-atlas[Archive

    Full Text Available NoD.Emb.05.AllAg.Mitotic_cycle_7-9 dm3 No description Embryo Mitotic cycle 7-9 http...://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/NoD.Emb.05.AllAg.Mitotic_cycle_7-9.bed ...

  3. File list: DNS.Emb.05.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available DNS.Emb.05.AllAg.Mitotic_cycle_11-13 dm3 DNase-seq Embryo Mitotic cycle 11-13 http:...//dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/DNS.Emb.05.AllAg.Mitotic_cycle_11-13.bed ...

  4. File list: Unc.Emb.10.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available Unc.Emb.10.AllAg.Mitotic_cycle_11-13 dm3 Unclassified Embryo Mitotic cycle 11-13 ht...tp://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Unc.Emb.10.AllAg.Mitotic_cycle_11-13.bed ...

  5. File list: His.Emb.05.AllAg.Mitotic_cycle_12-14 [Chip-atlas[Archive

    Full Text Available His.Emb.05.AllAg.Mitotic_cycle_12-14 dm3 Histone Embryo Mitotic cycle 12-14 SRX6474...41,SRX647443,SRX647442,SRX647440 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Emb.05.AllAg.Mitotic_cycle_12-14.bed ...

  6. File list: NoD.Emb.10.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available NoD.Emb.10.AllAg.Mitotic_cycle_11-13 dm3 No description Embryo Mitotic cycle 11-13 ...http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/NoD.Emb.10.AllAg.Mitotic_cycle_11-13.bed ...

  7. File list: Pol.Emb.50.AllAg.Mitotic_cycle_8-9 [Chip-atlas[Archive

    Full Text Available Pol.Emb.50.AllAg.Mitotic_cycle_8-9 dm3 RNA polymerase Embryo Mitotic cycle 8-9 http...://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.50.AllAg.Mitotic_cycle_8-9.bed ...

  8. File list: InP.Emb.05.AllAg.Mitotic_cycle_12 [Chip-atlas[Archive

    Full Text Available InP.Emb.05.AllAg.Mitotic_cycle_12 dm3 Input control Embryo Mitotic cycle 12 SRX7500...69 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.05.AllAg.Mitotic_cycle_12.bed ...

  9. File list: Oth.Emb.10.AllAg.Mitotic_cycle_8-9 [Chip-atlas[Archive

    Full Text Available Oth.Emb.10.AllAg.Mitotic_cycle_8-9 dm3 TFs and others Embryo Mitotic cycle 8-9 SRX0...84383 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.Emb.10.AllAg.Mitotic_cycle_8-9.bed ...

  10. File list: InP.Emb.10.AllAg.Mitotic_cycle_12 [Chip-atlas[Archive

    Full Text Available InP.Emb.10.AllAg.Mitotic_cycle_12 dm3 Input control Embryo Mitotic cycle 12 SRX7500...69 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.10.AllAg.Mitotic_cycle_12.bed ...

  11. File list: Unc.Emb.50.AllAg.Mitotic_cycle_12-14 [Chip-atlas[Archive

    Full Text Available Unc.Emb.50.AllAg.Mitotic_cycle_12-14 dm3 Unclassified Embryo Mitotic cycle 12-14 ht...tp://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Unc.Emb.50.AllAg.Mitotic_cycle_12-14.bed ...

  12. File list: His.Emb.50.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available His.Emb.50.AllAg.Mitotic_cycle_11-13 dm3 Histone Embryo Mitotic cycle 11-13 SRX6451...30,SRX645124,SRX645116,SRX645108,SRX645127,SRX645112,SRX645120 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Emb.50.AllAg.Mitotic_cycle_11-13.bed ...

  13. File list: InP.Emb.10.AllAg.Mitotic_cycle_12-14 [Chip-atlas[Archive

    Full Text Available InP.Emb.10.AllAg.Mitotic_cycle_12-14 dm3 Input control Embryo Mitotic cycle 12-14 h...ttp://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.10.AllAg.Mitotic_cycle_12-14.bed ...

  14. File list: Pol.Emb.10.AllAg.Mitotic_cycle_7-9 [Chip-atlas[Archive

    Full Text Available Pol.Emb.10.AllAg.Mitotic_cycle_7-9 dm3 RNA polymerase Embryo Mitotic cycle 7-9 http...://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.10.AllAg.Mitotic_cycle_7-9.bed ...

  15. File list: Unc.Emb.05.AllAg.Mitotic_cycle_13-14 [Chip-atlas[Archive

    Full Text Available Unc.Emb.05.AllAg.Mitotic_cycle_13-14 dm3 Unclassified Embryo Mitotic cycle 13-14 ht...tp://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Unc.Emb.05.AllAg.Mitotic_cycle_13-14.bed ...

  16. File list: InP.Emb.05.AllAg.Mitotic_cycle_13 [Chip-atlas[Archive

    Full Text Available InP.Emb.05.AllAg.Mitotic_cycle_13 dm3 Input control Embryo Mitotic cycle 13 SRX7500...81,SRX750070 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.05.AllAg.Mitotic_cycle_13.bed ...

  17. File list: DNS.Emb.05.AllAg.Mitotic_cycle_12-14 [Chip-atlas[Archive

    Full Text Available DNS.Emb.05.AllAg.Mitotic_cycle_12-14 dm3 DNase-seq Embryo Mitotic cycle 12-14 http:...//dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/DNS.Emb.05.AllAg.Mitotic_cycle_12-14.bed ...

  18. File list: InP.Emb.50.AllAg.Mitotic_cycle_12-14 [Chip-atlas[Archive

    Full Text Available InP.Emb.50.AllAg.Mitotic_cycle_12-14 dm3 Input control Embryo Mitotic cycle 12-14 h...ttp://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.50.AllAg.Mitotic_cycle_12-14.bed ...

  19. File list: NoD.Emb.50.AllAg.Mitotic_cycle_13-14 [Chip-atlas[Archive

    Full Text Available NoD.Emb.50.AllAg.Mitotic_cycle_13-14 dm3 No description Embryo Mitotic cycle 13-14 ...http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/NoD.Emb.50.AllAg.Mitotic_cycle_13-14.bed ...

  20. File list: Oth.Emb.10.AllAg.Mitotic_cycle_13-14 [Chip-atlas[Archive

    Full Text Available Oth.Emb.10.AllAg.Mitotic_cycle_13-14 dm3 TFs and others Embryo Mitotic cycle 13-14 ...SRX084384 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.Emb.10.AllAg.Mitotic_cycle_13-14.bed ...

  1. File list: InP.Emb.10.AllAg.Mitotic_cycle_13-14 [Chip-atlas[Archive

    Full Text Available InP.Emb.10.AllAg.Mitotic_cycle_13-14 dm3 Input control Embryo Mitotic cycle 13-14 h...ttp://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.10.AllAg.Mitotic_cycle_13-14.bed ...

  2. File list: NoD.Emb.50.AllAg.Mitotic_cycle_7-9 [Chip-atlas[Archive

    Full Text Available NoD.Emb.50.AllAg.Mitotic_cycle_7-9 dm3 No description Embryo Mitotic cycle 7-9 http...://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/NoD.Emb.50.AllAg.Mitotic_cycle_7-9.bed ...

  3. Radiation-induced mitotic and meiotic aneuploidy in the yeast Saccharomyces cerevisiae.

    Parry, J M; Sharp, D; Tippins, R S; Parry, E M

    1979-06-01

    A number of genetic systems are described which in yeast may be used to monitor the induction of chromosome aneuploidy during both mitotic and meiotic cell division. Using these systems we have been able to demonstrate the induction of both monosomic and trisomic cells in mitotically dividing cells and disomic spores in meiotically dividing cells after both UV light and X-ray exposure. The frequency of UV-light-induced monosomic colonies were reduced by post-treatment with photoreactivity light and both UV-light- and X-ray-induced monosomic colonies were reduced by liquid holding post-treatment under non-nutrient conditions. Both responses indicate an involvement of DNA-repair mechanisms in the removal of lesions which may lead to monosomy in yeast. This was further confirmed by the response of an excision-defective yeast strain which showed considerably increased sensitivity to the induction of monosomic colonies by UV-light treatment at low doses. Yeast cultures irradiated at different stages of growth showed variation in their responses to both UV-light and X-rays, cells at the exponential phase of growth show maximum sensitivity to the induction of monosomic colonies at low doses whereas stationary phase cultures showed maximum induction of monosomic colonies at high does. The frequencies of X-ray-induced chromosome aneuploidy during meiosis leading to the production of disomic spores was shown to be dependent upon the stage of meiosis at which the yeast cells were exposed to radiation. Cells which had proceeded beyond the DNA synthetic stage of meiosis were shown to produce disomic spores at considerably lower radiation doses than those cells which had only recently been inoculated into sporulation medium. The results obtained suggest that the yeast sustem may be suitable for the study of sensitivities of the various stages of meiotic cell division to the induction of chromosome aneuploidy after radiation exposure.

  4. Increase of corneal epithelium cell radioresistance during regeneration

    Popova, M.F.; Bulyakova, N.V.; Azarova, V.S.

    1985-01-01

    A comparative study of the radiosensitivity of the normal and regenerating cornea epithelium of C 57 Bl mice was performed on the cellular level, the duration of the cell cycle being taken into account. Criteria of radiation injuries were the number of chromosome aberrations, mitotic index and duration of mitotic block. The anterior part of the head was irradiated singly with 1.75, 3.5 or 7.0 Gy and also repeatedly 3.5 + 3.5 at a 24-hours interval. The corneas were fixed 2, 4, 6, 12, 24, 48, 72 and 96 hours after irradiation. In all cases of irradiated mice the regenerating epithelium showed a shorter mitotic block and significantly lower cytogenetic injury as compared with the controls. Effects of fractionated irradiation were only shown in the regenerating epithelium. The results obtained indicate that regenerating epithelium cells of the cornea are significantly more radioresistant than normal epithelium due to activation of post-radiation recovery, and also, possibly, due to an increase in the content of endogenous radioprotectors. (author)

  5. Interphase APC/C-Cdc20 inhibition by cyclin A2-Cdk2 ensures efficient mitotic entry

    Hein, Jamin B; Nilsson, Jakob

    2016-01-01

    Proper cell-cycle progression requires tight temporal control of the Anaphase Promoting Complex/Cyclosome (APC/C), a large ubiquitin ligase that is activated by one of two co-activators, Cdh1 or Cdc20. APC/C and Cdc20 are already present during interphase but APC/C-Cdc20 regulation during...... this window of the cell cycle, if any, is unknown. Here we show that cyclin A2-Cdk2 binds and phosphorylates Cdc20 in interphase and this inhibits APC/C-Cdc20 activity. Preventing Cdc20 phosphorylation results in pre-mature activation of the APC/C-Cdc20 and several substrates, including cyclin B1 and A2......, are destabilized which lengthens G2 and slows mitotic entry. Expressing non-degradable cyclin A2 but not cyclin B1 restores mitotic entry in these cells. We have thus uncovered a novel positive feedback loop centred on cyclin A2-Cdk2 inhibition of interphase APC/C-Cdc20 to allow further cyclin A2 accumulation...

  6. Increased sales and thefts of candy as a function of sales promotion activities: Preliminary findings.

    Carter, N; Kindstedt, A; Melin, L

    1995-01-01

    We used an A-B-A design to evaluate the effects of two commonly used promotional activities-price reduction and increased exposure, in combination and separately-on sales and thefts of candy at a grocery store. The combination of activities and the increased exposure condition produced the greatest increases in sales. The combination of activities was also associated with the greatest increase in thefts.

  7. The effect of increasing autonomy through choice on young children’s physical activity behavior

    Increasing autonomy by manipulating the choice of available physical activity options in a laboratory setting can increase physical activity in older children and adults. However, the effect of manipulating the number of physically active choices has yet to be examined in young children in a gymnas...

  8. An Evaluation of Photographic Activity Schedules to Increase Independent Playground Skills in Young Children with Autism

    Akers, Jessica S.; Higbee, Thomas S.; Pollard, Joy S.; Pellegrino, Azure J.; Gerencser, Kristina R.

    2016-01-01

    We used photographic activity schedules to increase the number of play activities completed by children with autism during unstructured time on the playground. All 3 participants engaged in more playground activities during and after training, and they continued to complete activities when novel photographs were introduced.

  9. Maintaining Genome Stability in Defiance of Mitotic DNA Damage

    Ferrari, Stefano; Gentili, Christian

    2016-01-01

    The implementation of decisions affecting cell viability and proliferation is based on prompt detection of the issue to be addressed, formulation and transmission of a correct set of instructions and fidelity in the execution of orders. While the first and the last are purely mechanical processes relying on the faithful functioning of single proteins or macromolecular complexes (sensors and effectors), information is the real cue, with signal amplitude, duration, and frequency ultimately determining the type of response. The cellular response to DNA damage is no exception to the rule. In this review article we focus on DNA damage responses in G2 and Mitosis. First, we set the stage describing mitosis and the machineries in charge of assembling the apparatus responsible for chromosome alignment and segregation as well as the inputs that control its function (checkpoints). Next, we examine the type of issues that a cell approaching mitosis might face, presenting the impact of post-translational modifications (PTMs) on the correct and timely functioning of pathways correcting errors or damage before chromosome segregation. We conclude this essay with a perspective on the current status of mitotic signaling pathway inhibitors and their potential use in cancer therapy. PMID:27493659

  10. Termini of human chromosomes display elevated rates of mitotic recombination.

    Cornforth, M N; Eberle, R L

    2001-01-01

    The strand-specific in situ hybridization technique of CO-FISH was used to probe telomeres of human mitotic cells in order to determine the spontaneous frequency of crossover. This approach allowed the detection of recombinational crossovers occurring anywhere along the length of individual chromosomes, including reciprocal events taking place between sister chromatids. Although the process of sister chromatid exchange (SCE) is the most prominent type of recombination in somatic mammalian cells, our results show that SCEs accounted for less than a third of the recombinational events revealed by CO-FISH. It is concluded that chromosomal regions near the termini of chromosome arms undergo extraordinarily high rates of spontaneous recombination, producing terminal crossovers whose small size precludes detection by standard cytogenetic methods. That similar results were observed for transformed epithelial cells, as well as primary fibroblasts, suggests that the phenomenon is a common characteristic of human cells. These findings are noteworthy because, although telomeric and subtelomeric DNA is known to be preferentially involved in certain types of recombination, the tips of somatic mammalian chromosomes have not previously been identified as preferred sites for crossover. Implications of these results are discussed in terms of limitations imposed on CO-FISH for its proposed use in directional hybridization mapping.

  11. X-ray induction of mitotic and meiotic chromosome aberrations

    Yao, K.T.S.

    1980-01-01

    In 1964 six pairs of rat kangaroo (Potorous tridactylis) were obtained from Australia. The tissues of these animals were used to initiate cell lines. Since this species has a low chromosome number of six pairs, each pair with its own distinctive morphology, it is particularly favorable for cytogenetic research. In cell cultures derived from the corneal endothelial tissues of one animal there emerged a number of haploid cells. The number of haploid cells in the cultures reached as high as 20% of the total mitotic configurations. The in vitro diploid and haploid mixture cell cultures could be a resemblance or a coincidence to the mixture existence of the diploid primary spermatocytes and the haploid secondary spermatocytes (gametes) in the in vivo testicular tissues of the male animals. It would be interesting to compare reactions of the haploid and diploid cell mixture, either in the cultures or in the testes, to x-ray exposure. Two other studies involving x-ray effects on Chinese hamster oocyte maturation and meiotic chromosomes and the x-ray induction of Chinese hamster spermatocyte meiotic chromosome aberrations have been done in this laboratory. A review of these three studies involving diploid and haploid chromosomes may lead to further research in the x-ray induction of chromosome aberrations

  12. Mitotic chromosome transmission fidelity mutants in Saccharomyces cerevisiae

    Spencer, F.; Gerring, S.L.; Connelly, C.; Hieter, P.

    1990-01-01

    The authors have isolated 136 independent EMS-induced mutations in haploid yeast strains that exhibit decreased chromosome transmission fidelity in mitosis. Eight-five percent of the mutations are recessive and 15% are partially dominant. Complementation analysis between MATa and MATα isolates identifies 11 chromosome transmission fidelity (CTF) complementation groups, the largest of which is identical to CHL1. For 49 independent mutations, no corresponding allele has been recovered in the opposite mating type. The initial screen monitored the stability of a centromere-linked color marker on a nonessential yeast chromosome fragment; the mitotic inheritance of natural yeast chromosome III is also affected by the ctf mutations. Of the 136 isolates identified, seven were inviable at 37 degree and five were inviable at 11 degree. In all cases tested, these temperature conditional lethalities cosegregated with the chromosome instability phenotype. Five additional complementation groups (ctf12 through ctf16) have been defined by complementation analysis of the mutations causing inviability at 37 degree. All of the mutant strains showed normal sensitivity to ultraviolet and γ-irradiation

  13. The Effect of Increasing Autonomy Through Choice on Young Children's Physical Activity Behavior.

    Sanders, Gabriel J; Juvancic-Heltzel, Judith; Williamson, Megan L; Roemmich, James N; Feda, Denise M; Barkley, Jacob E

    2016-04-01

    Increasing autonomy by manipulating the choice of available physical activity options in a laboratory setting can increase physical activity in older children and adults. However, the effect of manipulating the number of physically active choices has yet to be examined in young children in a gymnasium environment. Twenty children (n = 10 girls, 6.1 ± 1.4 years old) individually participated in 2 [low choice (LC), high choice (HC)] free-choice activity conditions for 30 minutes in a 4360 square foot gymnasium. Children had access to 2 or 8 physical activity options in the LC and HC conditions, respectively. Physical activity behavior was measured via accelerometry. Children's 30-minute accelerometer counts increased (P autonomy through choice of a greater number of physically active options increased young children's physical activity participation by 20.5%.

  14. Get Active Orlando: changing the built environment to increase physical activity.

    McCreedy, Malisa; Leslie, Jill G

    2009-12-01

    Active Living by Design's Get Active Orlando partnership (GAO) focused on downtown Orlando's Community Redevelopment Area, including the Parramore Heritage District, home to many low-income and ethnically diverse residents, including many seniors. The area had undergone substantial development, and GAO aimed to incorporate active living considerations into the city's changing landscape. Get Active Orlando conducted a baseline survey of all streets, sidewalks, and bicycle lanes in the project area and identified a sequence of plans and policies in which to incorporate changes identified in the assessment. To create more immediate opportunities for active living, the partnership initiated a senior walking program, a bicycle refurbishment and giveaway program, and community bicycle-riding events, and led a social-marketing campaign that emphasized simple lifestyle changes. Get Active Orlando influenced adoption of public policies supporting active living in Orlando, including the Downtown Transportation Plan, Streetscape Guidelines, Design Standards Review Checklist, and growth management policies. Establishment of the Mayor's Advisory Council on Active Living is testament to the heightened significance of active living in Orlando. Initial assessment data served as a strong platform for policy change. Creating connections across disciplines including land-use planning, transportation, public health, and economic development allowed GAO to secure substantial policy change to influence design of the built environment. Engaging community members, including youth, as leaders was an important factor in program success. The physical environment in Orlando's Community Redevelopment Area is beginning to change as a reflection of a new policy framework designed to support active living.

  15. INCREASED TISSUE TRANSGLUTAMINASE LEVELS ARE ASSOCIATED WITH INCREASED EPILEPTIFORM ACTIVITY IN ELECTROENCEPHALOGRAPHY AMONG PATIENTS WITH CELIAC DISEASE

    Sedat IŞIKAY

    2015-12-01

    Full Text Available Background - Celiac disease is an autoimmune systemic disorder in genetically predisposed individuals precipitated by gluten ingestion. Objective - In this study, we aimed to determine asymptomatic spike-and-wave findings on electroencephalography in children with celiac disease. Methods - A total of 175 children with the diagnosis of celiac disease (study group and 99 age- and sex-matched healthy children as controls (control group were included in the study. In order to determine the effects of gluten free diet on laboratory and electroencephalography findings, the celiac group is further subdivided into two as newly-diagnosed and formerly-diagnosed patients. Medical histories of all children and laboratory findings were all recorded and neurologic statuses were evaluated. All patients underwent a sleep and awake electroencephalography. Results - Among 175 celiac disease patients included in the study, 43 were newly diagnosed while 132 were formerly-diagnosed patients. In electroencephalography evaluation of patients the epileptiform activity was determined in 4 (9.3% of newly diagnosed and in 2 (1.5% of formerly diagnosed patients; on the other hand the epileptiform activity was present in only 1 (1.0% of control cases. There was a statistically significant difference between groups in regards to the presence of epileptiform activity in electroencephalography. Pearson correlation analysis revealed that epileptiform activity in both sleep and awake electroencephalography were positively correlated with tissue transglutaminase levels (P=0.014 and P=0.019, respectively. Conclusion - We have determined an increased epileptiform activity frequency among newly-diagnosed celiac disease patients compared with formerly-diagnosed celiac disease patients and control cases. Moreover the tissue transglutaminase levels were also correlated with the presence of epileptiform activity in electroencephalography. Among newly diagnosed celiac disease patients

  16. Mapping genes by meiotic and UV-induced mitotic recombination in Coprinus cinereus

    Amirkhanian, J.D.; Cowan, J.W.

    1985-01-01

    Three morphological mutants in Coprinus cinereus—one spontaneous (den-2) and two chemically induced (zigand sta)—were assigned to linkage groups and utilized in meiotic and mitotic mapping. Mutants den-2 and zig belong to linkage group III, den-2 being close to the centromere and about 20 map units (mu) from zig. The mutant sta in linkage group ‘G’ is at a distance of about 37 mu from ade-3. Mitotic mapping confirmed the gene order in linkage group III and provided evidence that trp-2 in linkage group ‘G’ was between the centromere and ade-3. These morphological mutants are compact in colony growth and therefore suited to high-density plating. The rarity of spontaneously occurring mitotic segregants suggests that diploids of Coprinus cinereus, heterozygous for morphoiogical markers in repuision, could serve as useful test systems for rapid screening of chemical mutagen/carcinogens via mitotic recombination studies

  17. Histone phosphorylation during radiation-induced mitotic delay in synchronous plasmodia of Physarum polycephalum

    Brewer, E.N.; Oleinick, N.L.

    1980-01-01

    Using the nearly perfect synchrony of the mitotic stages in Physarum plasmodia, and making use of 32 P as a tracer, studies were made to define the time course of histone phosphorylation during the late G2 and prophase and the alterations in that time course accompanying radiation-induced mitotic delay. Histone H1 was phosphorylated throughout the last 2-3 hours of the mitotic cycle coincident with the early stages of chromosome condensation. H1 phosphorylation appeared to be reduced in irradiated plasmodia. It is postulated that a longer time period, i.e. the mitotic delay, may be required to obtain the same eventual level of H1-phosphate. In normal cultures, nucleosome core histones were phosphorylated late in G2 and prophase, the peak corresponding closely with the γ-transition point. In irradiated plasmodia, phosphorylation of the core histones had an extended time course similar to H1. (U.K.)

  18. Radiation-induced mitotic and meiotic aneuploidy in the yeast Saccharomyces cerevisiae

    Parry, J.M.; Sharp, D.; Tippins, R.S.; Parry, E.M.

    1979-01-01

    A number of genetic systems are described which in yeast may be used to monitor the induction of chromosome aneuploidy during both mitotic and meiotic cell division. Using these systems the authors have been able to demonstrate the induction of both monosomic and trisomic cells in mitotically dividing cells and disomic spores in meiotically dividing cells after both UV light and X-ray exposure. (Auth.)

  19. The structure of the mitotic spindle and nucleolus during mitosis in the amebo-flagellate Naegleria.

    Walsh, Charles J

    2012-01-01

    Mitosis in the amebo-flagellate Naegleria pringsheimi is acentrosomal and closed (the nuclear membrane does not break down). The large central nucleolus, which occupies about 20% of the nuclear volume, persists throughout the cell cycle. At mitosis, the nucleolus divides and moves to the poles in association with the chromosomes. The structure of the mitotic spindle and its relationship to the nucleolus are unknown. To identify the origin and structure of the mitotic spindle, its relationship to the nucleolus and to further understand the influence of persistent nucleoli on cellular division in acentriolar organisms like Naegleria, three-dimensional reconstructions of the mitotic spindle and nucleolus were carried out using confocal microscopy. Monoclonal antibodies against three different nucleolar regions and α-tubulin were used to image the nucleolus and mitotic spindle. Microtubules were restricted to the nucleolus beginning with the earliest prophase spindle microtubules. Early spindle microtubules were seen as short rods on the surface of the nucleolus. Elongation of the spindle microtubules resulted in a rough cage of microtubules surrounding the nucleolus. At metaphase, the mitotic spindle formed a broad band completely embedded within the nucleolus. The nucleolus separated into two discreet masses connected by a dense band of microtubules as the spindle elongated. At telophase, the distal ends of the mitotic spindle were still completely embedded within the daughter nucleoli. Pixel by pixel comparison of tubulin and nucleolar protein fluorescence showed 70% or more of tubulin co-localized with nucleolar proteins by early prophase. These observations suggest a model in which specific nucleolar binding sites for microtubules allow mitotic spindle formation and attachment. The fact that a significant mass of nucleolar material precedes the chromosomes as the mitotic spindle elongates suggests that spindle elongation drives nucleolar division.

  20. Increased prevalence of late stage T cell activation antigen (VLA-1) in active juvenile chronic arthritis

    Ødum, Niels; Morling, Niels; Platz, P

    1987-01-01

    The presence of activated T cells as judged from the reaction with monoclonal antibodies (MoAb) against (a) a late stage T cell activation antigen (VLA-1), (b) the interleukin 2 (IL2) receptor (CD25), and (c) four different HLA class II molecules (HLA-DR, DRw52, DQ, and DP) was studied in 15 pati...

  1. Increasing Physical Activity during the School Day through Physical Activity Classes: Implications for Physical Educators

    Adkins, Megan; Bice, Matt; Bartee, Todd; Heelan, Kate

    2015-01-01

    Across the nation schools are adopting health and wellness policies, specifically physical activity (PA) initiatives that aid healthy long-term lifestyles. Interest has been generated about the inclusion of physical activity classes to complement existing physical education classes. Furthermore, discussion has evolved as to if additional…

  2. Utilization during mitotic cell division of loci controlling meiotic recombination and disjunction in Drosophila melanogaster

    Baker, B.S.; Carpenter, A.T.C.; Ripoll, P.

    1978-01-01

    To inquire whether the loci identified by recombination-defective and disjunction-defective meiotic mutants in Drosophila are also utilized during mitotic cell division, the effects of 18 meiotic mutants (representing 13 loci) on mitotic chromosome stability have been examined genetically. To do this, meiotic-mutant-bearing flies heterozygous for recessive somatic cell markers were examined for the frequencies and types of spontaneous clones expressing the cell markers. In such flies, marked clones can arise via mitotic recombination, mutation, chromosome breakage, nondisjunction or chromosome loss, and clones from these different origins can be distinguished. In addition, meiotic mutants at nine loci have been examined for their effects on sensitivity to killing by uv and x rays. Mutants at six of the seven recombination-defective loci examined (mei-9, mei-41, c(3)G, mei-W68, mei-S282, mei-352, mei-218) cause mitotic chromosome instability in both sexes, whereas mutants at one locus (mei-218) do not affect mitotic chromosome stability. Thus many of the loci utilized during meiotic recombination also function in the chromosomal economy of mitotic cells

  3. Identification of Mitosis-Specific Phosphorylation in Mitotic Chromosome-Associated Proteins.

    Ohta, Shinya; Kimura, Michiko; Takagi, Shunsuke; Toramoto, Iyo; Ishihama, Yasushi

    2016-09-02

    During mitosis, phosphorylation of chromosome-associated proteins is a key regulatory mechanism. Mass spectrometry has been successfully applied to determine the complete protein composition of mitotic chromosomes, but not to identify post-translational modifications. Here, we quantitatively compared the phosphoproteome of isolated mitotic chromosomes with that of chromosomes in nonsynchronized cells. We identified 4274 total phosphorylation sites and 350 mitosis-specific phosphorylation sites in mitotic chromosome-associated proteins. Significant mitosis-specific phosphorylation in centromere/kinetochore proteins was detected, although the chromosomal association of these proteins did not change throughout the cell cycle. This mitosis-specific phosphorylation might play a key role in regulation of mitosis. Further analysis revealed strong dependency of phosphorylation dynamics on kinase consensus patterns, thus linking the identified phosphorylation sites to known key mitotic kinases. Remarkably, chromosomal axial proteins such as non-SMC subunits of condensin, TopoIIα, and Kif4A, together with the chromosomal periphery protein Ki67 involved in the establishment of the mitotic chromosomal structure, demonstrated high phosphorylation during mitosis. These findings suggest a novel mechanism for regulation of chromosome restructuring in mitosis via protein phosphorylation. Our study generated a large quantitative database on protein phosphorylation in mitotic and nonmitotic chromosomes, thus providing insights into the dynamics of chromatin protein phosphorylation at mitosis onset.

  4. Low Dopamine D2 Receptor Increases Vulnerability to Obesity Via Reduced Physical Activity, Not Increased Appetitive Motivation.

    Beeler, Jeff A; Faust, Rudolf P; Turkson, Susie; Ye, Honggang; Zhuang, Xiaoxi

    2016-06-01

    The dopamine D2 receptor (D2R) has received much attention in obesity studies. Data indicate that D2R is reduced in obesity and that the TaqA1 D2R variant may be more prevalent among obese persons. It is often suggested that reduced D2R generates a reward deficiency and altered appetitive motivation that induces compulsive eating and contributes to obesity. Although dopamine is known to regulate physical activity, it is often neglected in these studies, leaving open the question of whether reduced D2R contributes to obesity through alterations in energy expenditure and activity. We generated a D2R knockdown (KD) mouse line and assessed both energy expenditure and appetitive motivation under conditions of diet-induced obesity. The KD mice did not gain more weight or show increased appetitive motivation compared with wild-type mice in a standard environment; however, in an enriched environment with voluntary exercise opportunities, KD mice exhibited dramatically lower activity and became more obese than wild-type mice, obtaining no protective benefit from exercise opportunities. These data suggest the primary contribution of altered D2R signaling to obesity lies in altered energy expenditure rather than the induction of compulsive overeating. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  5. LOW DOPAMINE D2 RECEPTOR INCREASES VULNERABILITY TO OBESITY VIA REDUCED PHYSICAL ACTIVITY NOT INCREASED APPETITIVE MOTIVATION

    Beeler, Jeff A.; Faust, Rudolf P.; Turkson, Susie; Ye, Honggang; Zhuang, Xiaoxi

    2015-01-01

    Background The dopamine D2 receptor (D2R) has received much attention in obesity studies. Data indicate that D2R is reduced in obesity and that the TaqA1 D2R variant may be more prevalent among obese persons. It is often suggested that reduced D2R generates a “reward deficiency” and altered appetitive motivation that induces compulsive eating and contributes to obesity. Although dopamine is known to regulate physical activity, it is often neglected in these studies, leaving open the question of whether reduced D2R contributes to obesity through alterations in energy expenditure and activity. Methods We generated a D2R knockdown (KD) mouse line and assessed both energy expenditure and appetitive motivation under conditions of diet-induced obesity. Results The KD mice did not gain more weight or show increased appetitive motivation compared to wild-type (WT) in a standard environment; however, in an enriched environment with voluntary exercise opportunities, KD mice exhibited dramatically lower activity and became more obese than WT, obtaining no protective benefit from exercise opportunities. Conclusions These data suggest the primary contribution of altered D2R signaling to obesity lies in altered energy expenditure rather than the induction of compulsive overeating. PMID:26281715

  6. Can schoolyard improvements increase physical activity for the least active students, or just provide better opportunities for the most active?

    Breum, Lars; Toftager, M.; Troelsen, J.

    2014-01-01

    at the school had equal impact on all students regardless of their PA at baseline [1]. Method The SPACE-study used a cluster randomized controlled study design with a 2-year follow-up, and enrolled 1348 students aged 11–13 years from 14 schools in Denmark. A web-based questionnaire was used to obtain knowledge...... as “the most active”. At the intervention schools the proportion of student who reported good possibilities for outdoor PA increased (71% to 75%), while the proportion decreased at the comparison schools (87% to 68%). The proportion of students reporting to be active daily during recess decreased for all...... of PA during recess and in leisure time. The multicomponent intervention comprised 11 components, and included a combination of changes to the physical environment and organizational changes. Results At baseline, 73% of the students reported to engage in sport outside school and were characterized...

  7. Frequency and mitotic heritability of epimutations in Schistosoma mansoni.

    Roquis, David; Rognon, Anne; Chaparro, Cristian; Boissier, Jerome; Arancibia, Nathalie; Cosseau, Celine; Parrinello, Hugues; Grunau, Christoph

    2016-04-01

    Schistosoma mansoni is a parasitic platyhelminth responsible for intestinal bilharzia. It has a complex life cycle, infecting a freshwater snail of the Biomphalaria genus, and then a mammalian host. Schistosoma mansoni adapts rapidly to new (allopatric) strains of its intermediate host. To study the importance of epimutations in this process, we infected sympatric and allopatric mollusc strains with parasite clones. ChIP-Seq was carried out on four histone modifications (H3K4me3, H3K27me3, H3K27ac and H4K20me1) in parallel with genomewide DNA resequencing (i) on parasite larvae shed by the infected snails and (ii) on adult worms that had developed from the larvae. No change in single nucleotide polymorphisms and no mobilization of transposable elements were observed, but 58-105 copy number variations (CNVs) within the parasite clones in different molluscs were detected. We also observed that the allopatric environment induces three types of chromatin structure changes: (i) host-induced changes on larvae epigenomes in 51 regions of the genome that are independent of the parasites' genetic background, (ii) spontaneous changes (not related to experimental condition or genotype of the parasite) at 64 locations and (iii) 64 chromatin structure differences dependent on the parasite genotype. Up to 45% of the spontaneous, but none of the host-induced chromatin structure changes were transmitted to adults. In our model, the environment induces epigenetic changes at specific loci but only spontaneous epimutations are mitotically heritable and have therefore the potential to contribute to transgenerational inheritance. We also show that CNVs are the only source of genetic variation and occur at the same order of magnitude as epimutations. © 2016 John Wiley & Sons Ltd.

  8. Decreasing Stereotypy in Preschoolers with Autism Spectrum Disorder: The Role of Increased Physical Activity and Function

    McLaughlin, Constance Ann Hylton

    2010-01-01

    This study used increased physical activity during recess to reduce stereotypy in preschoolers with Autism Spectrum Disorder. Results indicate increasing physical activity can be used as an intervention to reduce automatically maintained stereotypy in preschoolers with ASD. The intervention had a lesser effect on a preschooler whose stereotypy was…

  9. Male Adolescents' Reasons for Participating in Physical Activity, Barriers to Participation, and Suggestions for Increasing Participation

    Allison, Kenneth R.; Dwyer, John J. M.; Goldenberg, Ellie; Fein, Allan; Yoshida, Karen K.; Boutilier, Marie

    2005-01-01

    This study explored male adolescents' reasons for participating in moderate and vigorous physical activity, perceived barriers to moderate and vigorous physical activity, and suggestions as to what can be done to increase participation in physical activity. A total of 26 male 15- and 16-year-old adolescents participated in focus group sessions,…

  10. Texting to increase physical activity among teenagers (TXT Me!): Rationale, design, and methods proposal

    Physical activity decreases from childhood through adulthood. Among youth, teenagers (teens) achieve the lowest levels of physical activity, and high school age youth are particularly at risk of inactivity. Effective methods are needed to increase youth physical activity in a way that can be maintai...

  11. Phosphatase PP2A and microtubule-mediated pulling forces disassemble centrosomes during mitotic exit

    Stephen J. Enos

    2018-01-01

    Full Text Available Centrosomes are microtubule-nucleating organelles that facilitate chromosome segregation and cell division in metazoans. Centrosomes comprise centrioles that organize a micron-scale mass of protein called pericentriolar material (PCM from which microtubules nucleate. During each cell cycle, PCM accumulates around centrioles through phosphorylation-mediated assembly of PCM scaffold proteins. During mitotic exit, PCM swiftly disassembles by an unknown mechanism. Here, we used Caenorhabditis elegans embryos to determine the mechanism and importance of PCM disassembly in dividing cells. We found that the phosphatase PP2A and its regulatory subunit SUR-6 (PP2ASUR-6, together with cortically directed microtubule pulling forces, actively disassemble PCM. In embryos depleted of these activities, ∼25% of PCM persisted from one cell cycle into the next. Purified PP2ASUR-6 could dephosphorylate the major PCM scaffold protein SPD-5 in vitro. Our data suggest that PCM disassembly occurs through a combination of dephosphorylation of PCM components and force-driven fragmentation of the PCM scaffold.

  12. Influence of novobiocin on mitotic events and radiation-induced G2-arrest

    Rowley, R.

    1987-01-01

    Novobiocin was used in CHO cells to test for an involvement of topoisomerase II activity in; 1) the induction of, and recovery from, radiation-induced G 2 -arrest and 2) progression through mitosis. Novobiocin blocked recovery from G 2 -arrest with a concentration dependency which suggested that this effect resulted from protein synthesis inhibition. Novobiocin alone, at concentrations above 500 μgml, blocked cell progression in early mitosis. The transition point was distinct from that of protein and RNA synthesis inhibitors and was the only arrest point in mitosis. A similar block was imposed by coumermycin. While this may indicate a requirement for topoisomerase II activity during chromosome condensation, it was also associated with inhibition of histone phosphorylation. Histone H3 phosphorylation is believed to be necessary for chromosome condensation and, when inhibited by novobiocin, correlates with a block in premature chromatin condensation in tsBN2 cells. The authors' data thus unite these two findings, provide an opportunity to analyse the temporal relationship between histone phosphorylation and mitotic events and suggest that topological reorganization of the chromatin is not involved in radiation-induced G 2 arrest

  13. Novel Mad2-targeting miR-493-3p controls mitotic fidelity and cancer cells' sensitivity to paclitaxel.

    Tambe, Mahesh; Pruikkonen, Sofia; Mäki-Jouppila, Jenni; Chen, Ping; Elgaaen, Bente Vilming; Straume, Anne Hege; Huhtinen, Kaisa; Cárpen, Olli; Lønning, Per Eystein; Davidson, Ben; Hautaniemi, Sampsa; Kallio, Marko J

    2016-03-15

    The molecular pathways that contribute to the proliferation and drug response of cancer cells are highly complex and currently insufficiently characterized. We have identified a previously unknown microRNA-based mechanism that provides cancer cells means to stimulate tumorigenesis via increased genomic instability and, at the same time, evade the action of clinically utilized microtubule drugs. We demonstrate miR-493-3p to be a novel negative regulator of mitotic arrest deficient-2 (MAD2), an essential component of the spindle assembly checkpoint that monitors the fidelity of chromosome segregation. The microRNA targets the 3' UTR of Mad2 mRNA thereby preventing translation of the Mad2 protein. In cancer cells, overexpression of miR-493-3p induced a premature mitotic exit that led to increased frequency of aneuploidy and cellular senescence in the progeny cells. Importantly, excess of the miR-493-3p conferred resistance of cancer cells to microtubule drugs. In human neoplasms, miR-493-3p and Mad2 expression alterations correlated with advanced ovarian cancer forms and high miR-493-3p levels were associated with reduced survival of ovarian and breast cancer patients with aggressive tumors, especially in the paclitaxel therapy arm. Our results suggest that intratumoral profiling of miR-493-3p and Mad2 levels can have diagnostic value in predicting the efficacy of taxane chemotherapy.

  14. Increased activity of the mannan-binding lectin complement activation pathway in patients with colorectal cancer

    Ytting, H; Jensenius, Jens Christian; Christensen, I J

    2004-01-01

    in certain patient groups. It is hypothesized that a deficient MBL pathway might be more frequent among patients with CRC than in healthy individuals. The MBL pathway was therefore evaluated in serum obtained preoperatively from 193 patients with primary CRC and in serum from 150 healthy volunteers. METHODS......: Serum MBL concentrations and MBL/MASP activity were determined using immunofluorometric assays. The levels are presented as the median, inter-quartile range and range. RESULTS: Serum MBL levels were significantly (P ..., inter-quartile range) compared with levels in healthy blood donors (924 (230-1476) ng/mL). Similarly, the MBL/MASP activity was significantly (P age, gender, tumour location...

  15. Digital image analysis of Ki67 in hot spots is superior to both manual Ki67 and mitotic counts in breast cancer.

    Stålhammar, Gustav; Robertson, Stephanie; Wedlund, Lena; Lippert, Michael; Rantalainen, Mattias; Bergh, Jonas; Hartman, Johan

    2018-05-01

    During pathological examination of breast tumours, proliferative activity is routinely evaluated by a count of mitoses. Adding immunohistochemical stains of Ki67 provides extra prognostic and predictive information. However, the currently used methods for these evaluations suffer from imperfect reproducibility. It is still unclear whether analysis of Ki67 should be performed in hot spots, in the tumour periphery, or as an average of the whole tumour section. The aim of this study was to compare the clinical relevance of mitoses, Ki67 and phosphohistone H3 in two cohorts of primary breast cancer specimens (total n = 294). Both manual and digital image analysis scores were evaluated for sensitivity and specificity for luminal B versus A subtype as defined by PAM50 gene expression assays, for high versus low transcriptomic grade, for axillary lymph node status, and for prognostic value in terms of prediction of overall and relapse-free survival. Digital image analysis of Ki67 outperformed the other markers, especially in hot spots. Tumours with high Ki67 expression and high numbers of phosphohistone H3-positive cells had significantly increased hazard ratios for all-cause mortality within 10 years from diagnosis. Replacing manual mitotic counts with digital image analysis of Ki67 in hot spots increased the differences in overall survival between the highest and lowest histological grades, and added significant prognostic information. Digital image analysis of Ki67 in hot spots is the marker of choice for routine analysis of proliferation in breast cancer. © 2017 John Wiley & Sons Ltd.

  16. A retinoblastoma orthologue is a major regulator of S-phase, mitotic, and developmental gene expression in Dictyostelium.

    Kimchi Strasser

    Full Text Available The retinoblastoma tumour suppressor, Rb, has two major functions. First, it represses genes whose products are required for S-phase entry and progression thus stabilizing cells in G1. Second, Rb interacts with factors that induce cell-cycle exit and terminal differentiation. Dictyostelium lacks a G1 phase in its cell cycle but it has a retinoblastoma orthologue, rblA.Using microarray analysis and mRNA-Seq transcriptional profiling, we show that RblA strongly represses genes whose products are involved in S phase and mitosis. Both S-phase and mitotic genes are upregulated at a single point in late G2 and again in mid-development, near the time when cell cycling is reactivated. RblA also activates a set of genes unique to slime moulds that function in terminal differentiation.Like its mammalian counterpart Dictyostelium, RblA plays a dual role, regulating cell-cycle progression and transcriptional events leading to terminal differentiation. In the absence of a G1 phase, however, RblA functions in late G2 controlling the expression of both S-phase and mitotic genes.

  17. Sonic hedgehog-expressing basal cells are general post-mitotic precursors of functional taste receptor cells

    Miura, Hirohito; Scott, Jennifer K.; Harada, Shuitsu; Barlow, Linda A.

    2014-01-01

    Background Taste buds contain ~60 elongate cells and several basal cells. Elongate cells comprise three functional taste cell types: I - glial cells, II - bitter/sweet/umami receptor cells, and III - sour detectors. Although taste cells are continuously renewed, lineage relationships among cell types are ill-defined. Basal cells have been proposed as taste bud stem cells, a subset of which express Sonic hedgehog (Shh). However, Shh+ basal cells turnover rapidly suggesting that Shh+ cells are precursors of some or all taste cell types. Results To fate map Shh-expressing cells, mice carrying ShhCreERT2 and a high (CAG-CAT-EGFP) or low (R26RLacZ) efficiency reporter allele were given tamoxifen to activate Cre in Shh+ cells. Using R26RLacZ, lineage-labeled cells occur singly within buds, supporting a post-mitotic state for Shh+ cells. Using either reporter, we show that Shh+ cells differentiate into all three taste cell types, in proportions reflecting cell type ratios in taste buds (I > II > III). Conclusions Shh+ cells are not stem cells, but are post-mitotic, immediate precursors of taste cells. Shh+ cells differentiate into each of the three taste cell types, and the choice of a specific taste cell fate is regulated to maintain the proper ratio within buds. PMID:24590958

  18. Emotional outlook on life predicts increases in physical activity among initially inactive men.

    Baruth, Meghan; Lee, Duck-Chul; Sui, Xuemei; Church, Timothy S; Marcus, Bess H; Wilcox, Sara; Blair, Steven N

    2011-04-01

    This study examined the relationship between emotional outlook on life and change in physical activity among inactive adults in the Aerobics Center Longitudinal Study. A total of 2,132 sedentary adults completed a baseline medical examination and returned for a follow-up examination at least 6 months later. Participants self-reported physical activity level and emotional outlook on life. Emotional outlook on life was significantly and positively related to physical activity participation at the follow-up visit in men but not women. Men who were usually very happy and optimistic at baseline had significantly greater increases in physical activity compared to men who were not happy. Men with a more positive outlook on life (e.g., happier) may be more likely to increase physical activity levels. Physical activity interventions targeting men may be more successful if they first increase happiness.

  19. Increased physical activity ameliorates high fat diet-induced bone resorption in mice

    It has been recognized that mechanical stresses associated with physical activity (PA) have beneficial effects on increasing bone mineral density (BMD) and improving bone quality. On the other hand, high fat diet (HFD) and obesity increase bone marrow adiposity leading to increased excretion of pro-...

  20. Extracellular Histones Increase Tissue Factor Activity and Enhance Thrombin Generation by Human Blood Monocytes.

    Gould, Travis J; Lysov, Zakhar; Swystun, Laura L; Dwivedi, Dhruva J; Zarychanski, Ryan; Fox-Robichaud, Alison E; Liaw, Patricia C

    2016-12-01

    Sepsis is characterized by systemic activation of inflammatory and coagulation pathways in response to infection. Recently, it was demonstrated that histones released into the circulation by dying/activated cells may contribute to sepsis pathology. Although the ability of extracellular histones to modulate the procoagulant activities of several cell types has been investigated, the influence of histones on the hemostatic functions of circulating monocytes is unknown. To address this, we investigated the ability of histones to modulate the procoagulant potential of THP-1 cells and peripheral blood monocytes, and examined the effects of plasmas obtained from septic patients to induce a procoagulant phenotype on monocytic cells. Tissue factor (TF) activity assays were performed on histone-treated THP-1 cells and blood monocytes. Exposure of monocytic cells to histones resulted in increases in TF activity, TF antigen, and phosphatidylserine exposure. Histones modulate the procoagulant activity via engagement of Toll-like receptors 2 and 4, and this effect was abrogated with inhibitory antibodies. Increased TF activity of histone-treated cells corresponded to enhanced thrombin generation in plasma determined by calibrated automated thrombography. Finally, TF activity was increased on monocytes exposed to plasma from septic patients, an effect that was attenuated in plasma from patients receiving unfractionated heparin (UFH). Our studies suggest that increased levels of extracellular histones found in sepsis contribute to dysregulated coagulation by increasing TF activity of monocytes. These procoagulant effects can be partially ameliorated in sepsis patients receiving UFH, thereby identifying extracellular histones as a potential therapeutic target for sepsis treatment.

  1. The Set1/COMPASS histone H3 methyltransferase helps regulate mitosis with the CDK1 and NIMA mitotic kinases in Aspergillus nidulans.

    Govindaraghavan, Meera; Anglin, Sarah Lea; Osmani, Aysha H; Osmani, Stephen A

    2014-08-01

    Mitosis is promoted and regulated by reversible protein phosphorylation catalyzed by the essential NIMA and CDK1 kinases in the model filamentous fungus Aspergillus nidulans. Protein methylation mediated by the Set1/COMPASS methyltransferase complex has also been shown to regulate mitosis in budding yeast with the Aurora mitotic kinase. We uncover a genetic interaction between An-swd1, which encodes a subunit of the Set1 protein methyltransferase complex, with NIMA as partial inactivation of nimA is poorly tolerated in the absence of swd1. This genetic interaction is additionally seen without the Set1 methyltransferase catalytic subunit. Importantly partial inactivation of NIMT, a mitotic activator of the CDK1 kinase, also causes lethality in the absence of Set1 function, revealing a functional relationship between the Set1 complex and two pivotal mitotic kinases. The main target for Set1-mediated methylation is histone H3K4. Mutational analysis of histone H3 revealed that modifying the H3K4 target residue of Set1 methyltransferase activity phenocopied the lethality seen when either NIMA or CDK1 are partially functional. We probed the mechanistic basis of these genetic interactions and find that the Set1 complex performs functions with CDK1 for initiating mitosis and with NIMA during progression through mitosis. The studies uncover a joint requirement for the Set1 methyltransferase complex with the CDK1 and NIMA kinases for successful mitosis. The findings extend the roles of the Set1 complex to include the initiation of mitosis with CDK1 and mitotic progression with NIMA in addition to its previously identified interactions with Aurora and type 1 phosphatase in budding yeast. Copyright © 2014 by the Genetics Society of America.

  2. Plasma factor VII-activating protease is increased by oral contraceptives and induces factor VII activation in-vivo

    Sidelmann, Johannes Jakobsen; Skouby, Sven O.; Kluft, Cornelis

    2011-01-01

    progestins. FSAP genotypes, FSAP and factor VII (FVII) plasma measures were assessed at baseline and after 6 cycles of OC. The 1601GA genotype was present in 49 (8.3%) of the women and was associated with significantly reduced levels of FSAP (P≤0.001). OC use increased FSAP antigen by 25% and FSAP activity......Oral contraceptive (OC) use influences the hemostatic system significantly and is a risk factor for development of cardiovascular disease. Factor VII-activating protease (FSAP) has potential effects on hemostasis. The 1601GA genotype of the 1601G/A polymorphism in the FSAP gene expresses a FSAP...... by 59% (P0.05). The relative increase in FSAP activity was significantly higher in women carrying the 1601GG genotype (63%) than in women carrying 1601GA genotype (50%) (P=0.01) and was associated with an increased activation of FVII. In conclusion: OC use increases the plasma measures of FSAP...

  3. KSHV cell attachment sites revealed by ultra sensitive tyramide signal amplification (TSA) localize to membrane microdomains that are up-regulated on mitotic cells.

    Garrigues, H Jacques; Rubinchikova, Yelena E; Rose, Timothy M

    2014-03-01

    Cell surface structures initiating attachment of Kaposi's sarcoma-associated herpesvirus (KSHV) were characterized using purified hapten-labeled virions visualized by confocal microscopy with a sensitive fluorescent enhancement using tyramide signal amplification (TSA). KSHV attachment sites were present in specific cellular domains, including actin-based filopodia, lamellipodia, ruffled membranes, microvilli and intercellular junctions. Isolated microdomains were identified on the dorsal surface, which were heterogeneous in size with a variable distribution that depended on cellular confluence and cell cycle stage. KSHV binding domains ranged from scarce on interphase cells to dense and continuous on mitotic cells, and quantitation of bound virus revealed a significant increase on mitotic compared to interphase cells. KSHV also bound to a supranuclear domain that was distinct from microdomains in confluent and interphase cells. These results suggest that rearrangement of the cellular membrane during mitosis induces changes in cell surface receptors implicated in the initial attachment stage of KSHV entry. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Override of the radiation-induced mitotic block in human tumour cells by methylxanthines and its relationship to the potentiation of cytotoxicity

    Musk, S.R.R.; Steel, G.G.

    1990-01-01

    Caffeine, theophylline, theobromine and paraxanthine, were tested for ability to override mitotic block induced by ionizing radiation in the human bladder carcinoma cell line RT112. All were found to partially override the block, at a concentration of 1mM in the order caffeine > theophylline > theobromine = paraxanthine. At a concentration of 1 mM only caffeine was found to potentiate cell killing as well as causing block override; at higher concentrations all had a significant effect on survival but little or no further influence on the degree of block override. It is concluded that override of a mitotic block is not in itself sufficient to cause increased killing when irradiated cells are incubated in the presence of caffeine, and that caffeine exerts its potentiating effect by directly inhibiting repair of damage in DNA or by causing override of radiation-induced inhibition of DNA synthesis. (author)

  5. Override of the radiation-induced mitotic block in human tumour cells by methylxanthines and its relationship to the potentiation of cytotoxicity

    Musk, S.R.R.; Steel, G.G. (Institute of Cancer Research, Sutton (UK). Surrey Branch)

    1990-06-01

    Caffeine, theophylline, theobromine and paraxanthine, were tested for ability to override mitotic block induced by ionizing radiation in the human bladder carcinoma cell line RT112. All were found to partially override the block, at a concentration of 1mM in the order caffeine > theophylline > theobromine = paraxanthine. At a concentration of 1 mM only caffeine was found to potentiate cell killing as well as causing block override; at higher concentrations all had a significant effect on survival but little or no further influence on the degree of block override. It is concluded that override of a mitotic block is not in itself sufficient to cause increased killing when irradiated cells are incubated in the presence of caffeine, and that caffeine exerts its potentiating effect by directly inhibiting repair of damage in DNA or by causing override of radiation-induced inhibition of DNA synthesis. (author).

  6. Low Amount of Salinomycin Greatly Increases Akt Activation, but Reduces Activated p70S6K Levels

    Sungpil Yoon

    2013-08-01

    Full Text Available The present study identified a novel salinomycin (Sal-sensitization mechanism in cancer cells. We analyzed the signal proteins Akt, Jnk, p38, Jak, and Erk1/2 in cancer cell lines that had arrested growth following low amounts of Sal treatment. We also tested the signal molecules PI3K, PDK1, GSK3β, p70S6K, mTOR, and PTEN to analyze the PI3K/Akt/mTOR pathway. The results showed that Sal sensitization positively correlates with large reductions in p70S6K activation. Interestingly, Akt was the only signal protein to be significantly activated by Sal treatment. The Akt activation appeared to require the PI3K pathway as its activation was abolished by the PI3K inhibitors LY294002 and wortmannin. The Akt activation by Sal was conserved in the other cell lines analyzed, which originated from other organs. Both Akt activation and C-PARP production were proportionally increased with increased doses of Sal. In addition, the increased levels of pAkt were not reduced over the time course of the experiment. Co-treatment with Akt inhibitors sensitized the Sal-treated cancer cells. The results thereby suggest that Akt activation is increased in cells that survive Sal treatment and resist the cytotoxic effect of Sal. Taken together; these results indicate that Akt activation may promote the resistance of cancer cells to Sal.

  7. Social capital, desire to increase physical activity and leisure-time physical activity: A population-based study.

    Lindström, Martin

    2011-01-01

    OBJECTIVES: To investigate the associations between social capital (trust) and leisure-time physical activity. STUDY DESIGN: The 2004 Public Health Survey in Skåne is a cross-sectional study. METHODS: In total, 27,757 individuals aged 18-80 years answered a postal questionnaire (59% participation). Logistic regression models were used to investigate the associations between trust, desire to increase physical activity and leisure-time physical activity. RESULTS: ...

  8. File list: ALL.Emb.20.AllAg.Mitotic_cycle_7-9 [Chip-atlas[Archive

    Full Text Available ALL.Emb.20.AllAg.Mitotic_cycle_7-9 dm3 All antigens Embryo Mitotic cycle 7-9 SRX645...111,SRX645115,SRX645103,SRX645123,SRX645107,SRX645137,SRX645099,SRX645119 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Emb.20.AllAg.Mitotic_cycle_7-9.bed ...

  9. File list: ALL.Emb.20.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available ALL.Emb.20.AllAg.Mitotic_cycle_11-13 dm3 All antigens Embryo Mitotic cycle 11-13 SR...X645130,SRX645124,SRX645116,SRX645108,SRX645127,SRX645112,SRX645138,SRX645120 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Emb.20.AllAg.Mitotic_cycle_11-13.bed ...

  10. File list: ALL.Emb.05.AllAg.Mitotic_cycle_11-13 [Chip-atlas[Archive

    Full Text Available ALL.Emb.05.AllAg.Mitotic_cycle_11-13 dm3 All antigens Embryo Mitotic cycle 11-13 SR...X645108,SRX645116,SRX645127,SRX645124,SRX645130,SRX645112,SRX645120,SRX645138 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Emb.05.AllAg.Mitotic_cycle_11-13.bed ...

  11. Increased active von Willebrand factor during disease development in the aging diabetic patient population.

    Chen, Shuang Feng; Xia, Zuo Li; Han, Ji Ju; Wang, Yi Ting; Wang, Ji Yue; Pan, Shao Dong; Wu, Ya Ping; Zhang, Bin; Li, Guang Yao; Du, Jing Wei; Gao, Hen Qiang; de Groot, Philip G; de Laat, Bas; Hollestelle, Martine J

    2013-02-01

    Type 2 diabetes is known to cause endothelial activation resulting in the secretion of von Willebrand factor (VWF). We have shown that levels of VWF in a glycoprotein Ib-binding conformation are increased in specific clinical settings. The aim of the current study is to investigate whether active VWF levels increase during aging and the development of diabetes within the population of patients suffering from type 2 diabetes. Patients and controls were divided into two groups based on age: older and younger than 60 years of age. VWF antigen, VWF propeptide, VWF activation factor and total active VWF were measured. Patients older than 60 years of age had increased levels of total active VWF, VWF activation factor and VWF propeptide compared to younger patients and controls. All measured VWF parameters were associated with age in diabetic patients. Total active VWF and VWF propeptide correlated with the period of being diagnosed with diabetes. Regression analyses showed that especially the VWF activation factor was strongly associated with diabetes in patients older than 60 years of age. In conclusion, we found that the conformation of VWF could be involved in the disease process of diabetes and that the VWF in a glycoprotein Ib-binding conformation could play a role as risk marker during the development of diabetes in combination with an increase in age. Our study shows that the active quality of VWF was more important than the quantity.

  12. Gonadotropin stimulates oocyte translation by increasing magnesium activity through intracellular potassium-magnesium exchange

    Horowitz, S.B.; Tluczek, L.J.

    1989-01-01

    We previously showed that gonadotropin increases the K + activity in Xenopus oocytes and that this is a signal for increased translation. However, K + need not act to control synthesis directly but may act through an unidentified downstream effector. Using microinjection to vary the salt content of oocytes and concomitantly measuring [ 3 H]leucine incorporation, we found that small changes in Mg 2+ greatly affect translation rates. (Ca 2+ had little influence.) By measuring intracellular ion activities, we found that oocyte cations existed in a buffer-like (ion-exchange) equilibrium in which K + and Mg 2+ are the preponderant monovalent and divalent cations. Hence, increasing cellular K + activity might increase translation by causing Mg 2+ activity to rise. If so, the increased translation rates produced by hormone treatment or K + injection would be prevented by EDTA, a Mg 2+ chelating agent. This prediction was tested and confirmed. We conclude that, when gonadotropin increases K + activity, the cell's internal ion-exchange equilibrium is altered thereby increasing Mg 2+ activity and this up-regulates translation

  13. The rate of synthesis and decomposition of tissue proteins in hypokinesia and increased muscular activity

    Fedorov, I. V.; Chernyy, A. V.; Fedorov, A. I.

    1978-01-01

    During hypokinesia and physical loading (swimming) of rats, the radioactivity of skeletal muscle, liver, kidney, heart, and blood proteins was determined after administration of radioactive amino acids. Tissue protein synthesis decreased during hypokinesia, and decomposition increased. Both synthesis and decomposition increased during physical loading, but anabolic processes predominated in the total tissue balance. The weights of the animals decreased in hypokinesia and increased during increased muscle activity.

  14. Active Choice and Financial Incentives to Increase Rates of Screening Colonoscopy-A Randomized Controlled Trial.

    Mehta, Shivan J; Feingold, Jordyn; Vandertuyn, Matthew; Niewood, Tess; Cox, Catherine; Doubeni, Chyke A; Volpp, Kevin G; Asch, David A

    2017-11-01

    Behavioral economic approaches could increase uptake for colorectal cancer screening. We performed a randomized controlled trial of 2245 employees to determine whether an email containing a phone number for scheduling (control), an email with the active choice to opt in or opt out (active choice), or the active choice email plus a $100 incentive (financial incentive) increased colonoscopy completion within 3 months. Higher proportions of participants in the financial incentive group underwent screening (3.7%) than in the control (1.6%) or active choice groups (1.5%) (P = .01 and P < .01). We found no difference in uptake of screening between the active choice and control groups (P = .88). The $100 conditional incentive modestly but significantly increased colonoscopy use. ClinicalTrials.gov no: NCT02660671. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

  15. Prediction of Positions of Active Compounds Makes It Possible To Increase Activity in Fragment-Based Drug Development

    Yoshifumi Fukunishi

    2011-05-01

    Full Text Available We have developed a computational method that predicts the positions of active compounds, making it possible to increase activity as a fragment evolution strategy. We refer to the positions of these compounds as the active position. When an active fragment compound is found, the following lead generation process is performed, primarily to increase activity. In the current method, to predict the location of the active position, hydrogen atoms are replaced by small side chains, generating virtual compounds. These virtual compounds are docked to a target protein, and the docking scores (affinities are examined. The hydrogen atom that gives the virtual compound with good affinity should correspond to the active position and it should be replaced to generate a lead compound. This method was found to work well, with the prediction of the active position being 2 times more efficient than random synthesis. In the current study, 15 examples of lead generation were examined. The probability of finding active positions among all hydrogen atoms was 26%, and the current method accurately predicted 60% of the active positions.

  16. Increasing Physical Activity among Adults with Disabilities: Doctors Can Play a Key Role

    In this podcast, Dr. Dianna Carroll, a senior health scientist with CDC’s Division of Human Development and Disability, talks about the role of doctors and other health professionals in increasing physical activity among adults with disabilities.

  17. Localization of latency-associated nuclear antigen (LANA) on mitotic chromosomes

    Rahayu, Retno; Ohsaki, Eriko; Omori, Hiroko; Ueda, Keiji

    2016-01-01

    In latent infection of Kaposi's sarcoma-associated herpesvirus (KSHV), viral gene expression is extremely limited and copy numbers of viral genomes remain constant. Latency-associated nuclear antigen (LANA) is known to have a role in maintaining viral genome copy numbers in growing cells. Several studies have shown that LANA is localized in particular regions on mitotic chromosomes, such as centromeres/pericentromeres. We independently examined the distinct localization of LANA on mitotic chromosomes during mitosis, using super-resolution laser confocal microscopy and correlative fluorescence microscopy–electron microscopy (FM-EM) analyses. We found that the majority of LANA were not localized at particular regions such as telomeres/peritelomeres, centromeres/pericentromeres, and cohesion sites, but at the bodies of condensed chromosomes. Thus, LANA may undergo various interactions with the host factors on the condensed chromosomes in order to tether the viral genome to mitotic chromosomes and realize faithful viral genome segregation during cell division. - Highlights: • This is the first report showing LANA dots on mitotic chromosomes by fluorescent microscopy followed by electron microscopy. • LANA dots localized randomly on condensed chromosomes other than centromere/pericentromere and telomere/peritelomre. • Cellular mitotic checkpoint should not be always involved in the segregation of KSHV genomes in the latency.

  18. High frequency induction of mitotic recombination by ionizing radiation in Mlh1 null mouse cells

    Wang Qi; Ponomareva, Olga N.; Lasarev, Michael; Turker, Mitchell S.

    2006-01-01

    Mitotic recombination in somatic cells involves crossover events between homologous autosomal chromosomes. This process can convert a cell with a heterozygous deficiency to one with a homozygous deficiency if a mutant allele is present on one of the two homologous autosomes. Thus mitotic recombination often represents the second mutational step in tumor suppressor gene inactivation. In this study we examined the frequency and spectrum of ionizing radiation (IR)-induced autosomal mutations affecting Aprt expression in a mouse kidney cell line null for the Mlh1 mismatch repair (MMR) gene. The mutant frequency results demonstrated high frequency induction of mutations by IR exposure and the spectral analysis revealed that most of this response was due to the induction of mitotic recombinational events. High frequency induction of mitotic recombination was not observed in a DNA repair-proficient cell line or in a cell line with an MMR-independent mutator phenotype. These results demonstrate that IR exposure can initiate a process leading to mitotic recombinational events and that MMR function suppresses these events from occurring

  19. Localization of latency-associated nuclear antigen (LANA) on mitotic chromosomes

    Rahayu, Retno; Ohsaki, Eriko [Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan); Omori, Hiroko [Central Instrumentation Laboratory Research Institute for Microbial Diseases (BIKEN), Osaka University, Osaka 565-0871 (Japan); Ueda, Keiji, E-mail: kueda@virus.med.osaka-u.ac.jp [Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan)

    2016-09-15

    In latent infection of Kaposi's sarcoma-associated herpesvirus (KSHV), viral gene expression is extremely limited and copy numbers of viral genomes remain constant. Latency-associated nuclear antigen (LANA) is known to have a role in maintaining viral genome copy numbers in growing cells. Several studies have shown that LANA is localized in particular regions on mitotic chromosomes, such as centromeres/pericentromeres. We independently examined the distinct localization of LANA on mitotic chromosomes during mitosis, using super-resolution laser confocal microscopy and correlative fluorescence microscopy–electron microscopy (FM-EM) analyses. We found that the majority of LANA were not localized at particular regions such as telomeres/peritelomeres, centromeres/pericentromeres, and cohesion sites, but at the bodies of condensed chromosomes. Thus, LANA may undergo various interactions with the host factors on the condensed chromosomes in order to tether the viral genome to mitotic chromosomes and realize faithful viral genome segregation during cell division. - Highlights: • This is the first report showing LANA dots on mitotic chromosomes by fluorescent microscopy followed by electron microscopy. • LANA dots localized randomly on condensed chromosomes other than centromere/pericentromere and telomere/peritelomre. • Cellular mitotic checkpoint should not be always involved in the segregation of KSHV genomes in the latency.

  20. Statins Activate Human PPAR Promoter and Increase PPAR mRNA Expression and Activation in HepG2 Cells

    Makoto Seo

    2008-01-01

    Full Text Available Statins increase peroxisome proliferator-activated receptor (PPAR mRNA expression, but the mechanism of this increased PPAR production remains elusive. To examine the regulation of PPAR production, we examined the effect of 7 statins (atorvastatin, cerivastatin, fluvastatin, pitavastatin, pravastatin, rosuvastatin, and simvastatin on human PPAR promoter activity, mRNA expression, nuclear protein levels, and transcriptional activity. The main results are as follows. (1 Majority of statins enhanced PPAR promoter activity in a dose-dependent manner in HepG2 cells transfected with the human PPAR promoter. This enhancement may be mediated by statin-induced HNF-4. (2 PPAR mRNA expression was increased by statin treatment. (3 The PPAR levels in nuclear fractions were increased by statin treatment. (4 Simvastatin, pravastatin, and cerivastatin markedly enhanced transcriptional activity in 293T cells cotransfected with acyl-coenzyme A oxidase promoter and PPAR/RXR expression vectors. In summary, these data demonstrate that PPAR production and activation are upregulated through the PPAR promoter activity by statin treatment.

  1. Targeting Reductions in Sitting Time to Increase Physical Activity and Improve Health.

    Keadle, Sarah K; Conroy, David E; Buman, Matthew P; Dunstan, David W; Matthews, Charles E

    2017-08-01

    : New evidence suggests that reductions in sedentary behavior may increase physical activity and improve health. These findings point to new behavioral targets for intervention and new ways to think about intervening to increase overall physical activity in the population. This report provides a knowledge update reflecting the rapid accumulation of new evidence related to sedentary behavior and health among adults. Recent observational studies suggest that leveraging the time-inverse relationship between sedentary and active behaviors by replacing sitting with standing, light- or moderate-intensity activity can have important health benefits, particularly among less active adults. Clinical studies are providing evidence of the probable physiologic mechanisms underlying these associations, as well as insights into the cardiometabolic impact of breaking up and reducing sedentary behavior. In contrast to the well-established behavioral theories that guide the development and dissemination of evidence-based interventions to increase moderate- to vigorous-intensity physical activity, much less is known about how to reduce sedentary time to increase daily activities. It has become clear that the environmental, social, and individual level determinants for sedentary time are distinct from those linked to the adoption and maintenance of moderate- to vigorous-intensity physical activity. As a result, novel intervention strategies that focus on sitting and lower-intensity activities by leveraging the surrounding environment (e.g., workplace, school, and home) as well as individual-level cues and habits of sedentary behavior are being tested to increase the potency of interventions designed to increase overall physical activity. Herein we summarize the solutions-oriented research across the behavioral research framework, with a focus on highlighting areas of synergy across disciplines and identifying gaps for future research.

  2. Seeing Is Eating: How and When Activation of a Negative Stereotype Increases Stereotype-Conducive Behavior

    Margaret C. Campbell; Gina S. Mohr

    2011-01-01

    This research investigates the effect of activation of a negative stereotype on behaviors that are perceived to increase the chance of becoming a member of the stereotyped group. Activation of a negative stereotype (the overweight stereotype) is shown to lead to stereotype-consistent goal commitment (low health goal commitment), which partially explains increases in stereotype-conducive behavior (eating indulgent foods). Two theoretically relevant moderators are proposed and supported. Increa...

  3. Increased PDGFRα Activation Disrupts Connective Tissue Development and Drives Systemic Fibrosis

    Olson, Lorin E.; Soriano, Philippe

    2009-01-01

    PDGF signaling regulates the development of mesenchymal cell types in the embryo and in the adult, but the role of receptor activation in tissue homeostasis has not been investigated. We have generated conditional knockin mice with mutations in PDGFRα that drive increased kinase activity under the control of the endogenous PDGFRα promoter. In embryos, increased PDGFRα signaling leads to hyperplasia of stromal fibroblasts that disturbs normal smooth muscle tissue in radially patterned organs. ...

  4. Increasing Children's Voluntary Physical Activity Outside of School Hours Through Targeting Social Cognitive Theory Variables.

    Annesi, James J; Walsh, Stephanie M; Greenwood, Brittney L

    2016-10-01

    Volume of moderate-to-vigorous physical activity completed during the elementary school day is insufficient, and associated with health risks. Improvements in theory-based psychosocial factors might facilitate increased out-of-school physical activity. A behaviorally based after-school care protocol, Youth Fit 4 Life, was tested for its association with increased voluntary, out-of-school physical activity and improvements in its theory-based psychosocial predictors in 9- to 12-year-olds. Increases over 12 weeks in out-of-school physical activity, and improvements in self-regulation for physical activity, exercise self-efficacy, and mood, were significantly greater in the Youth Fit 4 Life group (n = 88) when contrasted with a typical care control group (n = 57). Changes in the 3 psychosocial variables significantly mediated the group-physical activity change relationship (R(2) = .31, P theory-based psychosocial changes within a structured after-school care physical activity program was associated with increases in children's overall time being physically active. After replication, large scale application will be warranted. © The Author(s) 2016.

  5. Increased MMP-2 activity during intervertebral disc degeneration is correlated to MMP-14 levels

    Rutges, J. P. H. J.; Kummer, J. A.; Oner, F. C.; Verbout, A. J.; Roestenburg, H. J. A.; Dhert, W. J. A.; Creemers, L. B.

    Intervertebral disc (IVD) degeneration is associated with the increased expression of several matrix metalloproteinases (MMPs), in particular MMP-2. However, little is known about the actual activity of MMP-2 in healthy and degenerated discs, or what mechanisms are involved in its activation. A

  6. Focused Campaign Increases Activity among Participants in "Nature's Notebook," a Citizen Science Project

    Crimmins, Theresa M.; Weltzin, Jake F.; Rosemartin, Alyssa H.; Surina, Echo M.; Marsh, Lee; Denny, Ellen G.

    2014-01-01

    Science projects, which engage non-professional scientists in one or more stages of scientific research, have been gaining popularity; yet maintaining participants' activity level over time remains a challenge. The objective of this study was to evaluate the potential for a short-term, focused campaign to increase participant activity in a…

  7. Does Physical Activity Increase Life Expectancy? A Review of the Literature

    C. D. Reimers

    2012-01-01

    Full Text Available Physical activity reduces many major mortality risk factors including arterial hypertension, diabetes mellitus type 2, dyslipidemia, coronary heart disease, stroke, and cancer. All-cause mortality is decreased by about 30% to 35% in physically active as compared to inactive subjects. The purpose of this paper was to synthesize the literature on life expectancy in relation to physical activity. A systematic PubMed search on life expectancy in physically active and inactive individuals was performed. In addition, articles comparing life expectancy of athletes compared to that of nonathletes were reviewed. Results of 13 studies describing eight different cohorts suggest that regular physical activity is associated with an increase of life expectancy by 0.4 to 6.9 years. Eleven studies included confounding risk factors for mortality and revealed an increase in life expectancy by 0.4 to 4.2 years with regular physical activity. Eleven case control studies on life expectancy in former athletes revealed consistently greater life expectancy in aerobic endurance athletes but inconsistent results for other athletes. None of these studies considered confounding risk factors for mortality. In conclusion, while regular physical activity increases life expectancy, it remains unclear if high-intensity sports activities further increase life expectancy.

  8. Increase the Performance of Companies in the Energy Sector by Implementing the Activity-Based Costing

    Letitia-Maria Rof; Sorinel Capusneanu

    2015-01-01

    This article highlights the increasing performances as result of implementation stages of the ActivityBased Costing in the companies operating in the energy sector in Romania. There are presented some aspects of the usefulness of applying the Activity-Based Costing in the energy sector and the advantages it offers compared to traditional costing. There are also outlined the steps for applying the Activity-Based Costing and its implementation in the largest hydropower producer in Romania. The ...

  9. The FEAR protein Slk19 restricts Cdc14 phosphatase to the nucleus until the end of anaphase, regulating its participation in mitotic exit in Saccharomyces cerevisiae.

    Ann Marie E Faust

    Full Text Available In Saccharomyces cerevisiae mitosis, the protein Slk19 plays an important role in the initial release of Cdc14 phosphatase from the nucleolus to the nucleus in early anaphase, an event that is critical for proper anaphase progression. A role for Slk19 in later mitotic stages of Cdc14 regulation, however, has not been demonstrated. While investigating the role of Slk19 post-translational modification on Cdc14 regulation, we found that a triple point mutant of SLK19, slk19(3R (three lysine-to-arginine mutations, strongly affects Cdc14 localization during late anaphase and mitotic exit. Using fluorescence live-cell microscopy, we found that, similar to slk19Δ cells, slk19(3R cells exhibit no defect in spindle stability and only a mild defect in spindle elongation dynamics. Unlike slk19Δcells, however, slk19(3R cells exhibit no defect in Cdc14 release from the nucleolus to the nucleus. Instead, slk19(3R cells are defective in the timing of Cdc14 movement from the nucleus to the cytoplasm at the end of anaphase. This mutant has a novel phenotype: slk19(3R causes premature Cdc14 movement to the cytoplasm prior to, rather than concomitant with, spindle disassembly. One consequence of this premature Cdc14 movement is the inappropriate activation of the mitotic exit network, made evident by the fact that slk19(3R partially rescues a mutant of the mitotic exit network kinase Cdc15. In conclusion, in addition to its role in regulating Cdc14 release from the nucleolus to the nucleus, we found that Slk19 is also important for regulating Cdc14 movement from the nucleus to the cytoplasm at the end of anaphase.

  10. Variations in DNA synthesis and mitotic indices in hepatocytes and sinusoid litoral cells of adult intact male mouse along a circadian time span.

    Surur, J M; Moreno, F R; Badrán, A F; Llanos, J M

    1985-01-01

    Variations of DNA synthesis (DNAS) and mitotic indices along a circadian time span are described in the hepatocyte and sinusoid litoral cell populations of adult intact male mouse liver. Standardized (light from 0600 to 1800) mice were killed in groups of six to nine animals, every 2-4 hr along a circadian time span. Hepatocytes show significant peaks in the synthesis of DNA and the mitotic activity at 0200 and 1400, respectively. These results correspond to those previously described by us in young immature liver, regenerating liver and hepatomas. The phase differences between these peaks and the differences between their absolute values are discussed. Also considered are the practical consequences of our findings for experimental design. The curve of DNA synthesis of sinusoid litoral cells show a peak at 0200. The mitotic index show a bimodal waveform with peaks at 0800 and 2000. The existence of four different cell populations composing the so called sinusoid litoral cells and also the migration into and out of the liver of some macrophages considered as litoral (Kupffer) cells in our counts, makes interpretation of the curves somewhat complicated and deserves further analysis.

  11. Torin1-mediated TOR kinase inhibition reduces Wee1 levels and advances mitotic commitment in fission yeast and HeLa cells.

    Atkin, Jane; Halova, Lenka; Ferguson, Jennifer; Hitchin, James R; Lichawska-Cieslar, Agata; Jordan, Allan M; Pines, Jonathon; Wellbrock, Claudia; Petersen, Janni

    2014-03-15

    The target of rapamycin (TOR) kinase regulates cell growth and division. Rapamycin only inhibits a subset of TOR activities. Here we show that in contrast to the mild impact of rapamycin on cell division, blocking the catalytic site of TOR with the Torin1 inhibitor completely arrests growth without cell death in Schizosaccharomyces pombe. A mutation of the Tor2 glycine residue (G2040D) that lies adjacent to the key Torin-interacting tryptophan provides Torin1 resistance, confirming the specificity of Torin1 for TOR. Using this mutation, we show that Torin1 advanced mitotic onset before inducing growth arrest. In contrast to TOR inhibition with rapamycin, regulation by either Wee1 or Cdc25 was sufficient for this Torin1-induced advanced mitosis. Torin1 promoted a Polo and Cdr2 kinase-controlled drop in Wee1 levels. Experiments in human cell lines recapitulated these yeast observations: mammalian TOR (mTOR) was inhibited by Torin1, Wee1 levels declined and mitotic commitment was advanced in HeLa cells. Thus, the regulation of the mitotic inhibitor Wee1 by TOR signalling is a conserved mechanism that helps to couple cell cycle and growth controls.

  12. The effects of pulse cycloheximide treatments on the light-induced recovery of mitotic divisions in antheridial filaments of Chara vulgaris

    Maria Kwiatkowska

    2014-01-01

    Full Text Available Within the proliferative period of spermatogenesis in Chara vulgaris, the progression throughout successive cell divisions in antheridial filaments is greatly influenced by changes in photoperiodic conditions. The extended (4-day period of total darkness brings about cell cycle arrest in the early G2 phase. The recovery of mitosis requires about 20 hours of exposition to light. In the present study, a series of 8 pulse incubations of plants in cycloheximide (Cx; 2.5 mg/I, 2.5 h each pulse were performed within the period elapsing till the resumption of mitotic divisions. Depending on the time of treatment, the effects induced by Cx vary considerably. Within the first 10 hs of exposition to light, incubations with Cx result in the delays of mitoses; within the period between the 10th and the 17th h, mitotic divisions become blocked, and, following the 17.5 h of light-induced recovery, no influence of Cx is noticed on mitotic activity, as compared with the untreaed control plants. The obtained results provide a starting point for the characteristic of proteins synthesized during the G2 phase and a preliminary study on those mechanisms, which become engaged in the regulation of the G1-deficient cell cycle evidenced in antheridial filaments of Chara.

  13. Bilateral lesions of suprachiasmatic nuclei affect circadian rhythms in [3H]-thymidine incorporation into deoxyribonucleic acid in mouse intestinal tract, mitotic index of corneal epithelium, and serum corticosterone

    Scheving, L.E.; Tsai, T.H.; Powell, E.W.; Pasley, J.N.; Halberg, F.; Dunn, J.

    1983-01-01

    Investigations into the role of the suprachiasmatic nuclei (SCN) in the coordination of circadian rhythms have presented differing results. Several reports have shown that ablation of the suprachiasmatic nuclei (SCNA) alters the phase and amplitude of rhythms but does not abolish them. The present study investigates the effect of SCNA on the rhythms in cell proliferation in various regions of the intestinal tract as measured by the incorporation of [ 3 H]-thymidine into deoxyribonucleic acid, in the mitotic activity of the corneal epithelium, and in serum corticosterone levels. The study involved mice with verified lesions of the SCN (six to 13 mice per time point) and control groups of both sham-operated and unoperated mice (seven of each per time point). The mice were killed in groups that represented seven time points over a single 24 hr span (3 hr intervals with the 0800 hr sampled both at start and end of the series). The tissues examined were the tongue, esophagus, gastric stomach, and colon for DNA synthesis, the corneal epithelium for mitotic index, and blood serum for corticosterone level. The most consistent result of SCNA was a phase advance in the rhythms in cell proliferation in the tongue, esophagus, gastric stomach, colon, and corneal epithelium. A reduction in rhythm amplitude occurred in the tongue, esophagus, and corneal epithelium; however, there was an amplitude increase for the stomach, colon, and serum corticosterone. The mesor (rhythm-adjusted mean) was increased by SCNA in all tissues except the corneal epithelium. These findings further support the role of the suprachiasmatic nuclear area in the control of rhythms in cell proliferation and corticosterone production, by acting as a ''phase-resetter'' and as a modulator of rhythm amplitude

  14. Increased activities of mitochondrial enzymes in white adipose tissue in trained rats

    Stallknecht, B; Vinten, J; Ploug, T

    1991-01-01

    of 8-12 rats were swim trained for 10 wk or served as either sedentary, sham swim-trained, or cold-stressed controls. White adipose tissue was removed, and the activities of the respiratory chain enzyme cytochrome-c oxidase (CCO) and of the enzyme malate dehydrogenase (MDH), which participates...... 0.05). In female rats the CCO activity expressed per milligram protein was increased 4.5-fold in the trained compared with the sedentary control rats (P less than 0.01). Neither cold stress nor sham swim training increased CCO or MDH activities in white adipose tissue (P greater than 0...

  15. Building an urban park increases the intention of adults to practice physical activity

    Raphaelly Machado Felix

    Full Text Available Abstract Physical activity levels in adults are low and strategies should be put in place to change this. The aim of this study was to investigate whether building an urban park can increase adult neighborhood residents' intentions to partake in physical activity. In total, 395 adults living near where the park was being built participated in the study. The following information was collected: sociodemographic characteristics, current physical activity levels, and intention to use the park for physical activity. Around 80% of the subjects intended to use the park for physical activity. This frequency was higher among those who were classified as physically active and gradually higher as the distance between the home of the subject and the park decreased (p < 0.05. The offer of a public leisure space can contribute positively to changing population behavior related to regular physical activity.

  16. A systematic review of workplace health promotion interventions for increasing physical activity.

    Malik, Sumaira H; Blake, Holly; Suggs, L Suzanne

    2014-02-01

    The benefits of an active lifestyle are widely documented, yet studies show that only a small proportion of adults engage in sufficient levels of physical activity. The workplace presents an ideal avenue for delivering initiatives to promote physical activity, overcoming commonly cited barriers such as a 'lack of time' and providing access to a large intersection of society. The purpose of this study was to (1) explore the types of interventions workplaces implement to promote physical activity among staff, (2) describe the characteristics of those interventions, (3) understand whether these interventions positively impact on activity levels, and (4) assess the methodological quality of studies. A systematic review of workplace physical activity interventions published up to April 2011 was conducted to identify types of interventions and their outcomes. Of the 58 studies included, the majority utilized health promotion initiatives. There were six physical activity/exercise interventions, 13 counselling/support interventions, and 39 health promotion messages/information interventions. Thirty-two of these studies showed a statistically significant increase in a measure of physical activity against a control group at follow-up. While the studies included in this review show some evidence that workplace physical activity interventions can be efficacious, overall the results are inconclusive. Despite the proliferation of research in this area, there is still a need for more well-designed studies to fully determine the effectiveness of workplace interventions for increasing physical activity and to identify the types of interventions that show the most promise. © 2013 The British Psychological Society.

  17. Active Early: one-year policy intervention to increase physical activity among early care and education programs in Wisconsin

    Tara L. LaRowe

    2016-07-01

    Full Text Available Abstract Background Early childcare and education (ECE is a prime setting for obesity prevention and the establishment of healthy behaviors. The objective of this quasi-experimental study was to examine the efficacy of the Active Early guide, which includes evidenced-based approaches, provider resources, and training, to improve physical activity opportunities through structured (i.e. teacher-led activity and environmental changes thereby increasing physical activity among children, ages 2–5 years, in the ECE setting. Methods Twenty ECE programs in Wisconsin, 7 family and 13 group, were included. An 80-page guide, Active Early, was developed by experts and statewide partners in the fields of ECE, public health, and physical activity and was revised by ECE providers prior to implementation. Over 12 months, ECE programs received on-site training and technical assistance to implement the strategies and resources provided in the Active Early guide. Main outcome measures included observed minutes of teacher-led physical activity, physical activity environment measured by the Environment and Policy Assessment and Observation (EPAO instrument, and child physical activity levels via accelerometry. All measures were collected at baseline, 6 months, and 12 months and were analyzed for changes over time. Results Observed teacher-led physical activity significantly increased from 30.9 ± 22.7 min at baseline to 82.3 ± 41.3 min at 12 months. The change in percent time children spent in sedentary activity decreased significantly after 12 months (−4.4 ± 14.2 % time, −29.2 ± 2.6 min, p < 0.02. Additionally, as teacher led-activity increased, percent time children were sedentary decreased (r = −0.37, p < 0.05 and percent time spent in light physical activity increased (r = 0.35, p < 0.05. Among all ECE programs, the physical activity environment improved significantly as indicated by multiple sub-scales of

  18. Will a game cause increased fruit/vegetable intake and physical activity in elementary school children?

    Trimble, Derek

    2017-01-01

    Background Incentives increase healthy lifestyle choices. Schools don’t have financial resources for an incentive program. Research Question Is there a way to increase fruit and vegetable intake and physical activity in elementary school children at little or no cost to the school?

  19. Lumbricus terrestris L. activity increases the availability of metals and their accumulation in maize and barley

    Ruiz, E. [Department of Chemical Engineering, School of Civil Engineering, University of Castilla-La Mancha, Avenida Camilo Jose Cela, s/n, 13071 Ciudad Real (Spain); Alonso-Azcarate, J. [Department of Physical Chemistry, Faculty of Environmental Sciences, University of Castilla-La Mancha, Avenida Carlos III, s/n, 45071 Toledo (Spain); Rodriguez, L., E-mail: Luis.Rromero@uclm.es [Department of Chemical Engineering, School of Civil Engineering, University of Castilla-La Mancha, Avenida Camilo Jose Cela, s/n, 13071 Ciudad Real (Spain)

    2011-03-15

    The effect of the earthworm Lumbricus terrestris L. on metal availability in two mining soils was assessed by means of chemical extraction methods and a pot experiment using crop plants. Results from single and sequential extractions showed that L. terrestris had a slight effect on metal fractionation in the studied soils: only metals bound to the soil organic matter were significantly increased in some cases. However, we found that L. terrestris significantly increased root, shoot and total Pb and Zn concentrations in maize and barley for the soil with the highest concentrations of total and available metals. Specifically, shoot Pb concentration was increased by a factor of 7.5 and 3.9 for maize and barley, respectively, while shoot Zn concentration was increased by a factor of 3.7 and 1.7 for maize and barley, respectively. Our results demonstrated that earthworm activity increases the bioavailability of metals in soils. - Research highlights: > Lumbricus terrestris L. activity increases the bioavailability of metals in soils. > Earthworm activity can significantly increase total, shoot and root metal concentrations for crop plants. > Both bioassays and chemical extraction methods are necessary for assessing the bioavailability of metals in contaminated soils. - Lumbricus terrestris L. activity increases the bioavailability of metals in soils and total, shoot and root metal concentrations for maize and barley.

  20. Glucocorticoid receptor number predicts increase in amygdala activity after severe stress

    Geuze, Elbert; van Wingen, Guido A.; van Zuiden, Mirjam; Rademaker, Arthur R.; Vermetten, Eric; Kavelaars, Annemieke; Fernández, Guillén; Heijnen, Cobi J.

    2012-01-01

    Introduction: Individuals who are exposed to a traumatic event are at increased risk of developing psychiatric disorders such as posttraumatic stress disorder (PTSD). Studies have shown that increased amygdala activity is frequently found in patients with PTSD. In addition, pre-trauma glucocorticoid

  1. Lumbricus terrestris L. activity increases the availability of metals and their accumulation in maize and barley

    Ruiz, E.; Alonso-Azcarate, J.; Rodriguez, L.

    2011-01-01

    The effect of the earthworm Lumbricus terrestris L. on metal availability in two mining soils was assessed by means of chemical extraction methods and a pot experiment using crop plants. Results from single and sequential extractions showed that L. terrestris had a slight effect on metal fractionation in the studied soils: only metals bound to the soil organic matter were significantly increased in some cases. However, we found that L. terrestris significantly increased root, shoot and total Pb and Zn concentrations in maize and barley for the soil with the highest concentrations of total and available metals. Specifically, shoot Pb concentration was increased by a factor of 7.5 and 3.9 for maize and barley, respectively, while shoot Zn concentration was increased by a factor of 3.7 and 1.7 for maize and barley, respectively. Our results demonstrated that earthworm activity increases the bioavailability of metals in soils. - Research highlights: → Lumbricus terrestris L. activity increases the bioavailability of metals in soils. → Earthworm activity can significantly increase total, shoot and root metal concentrations for crop plants. → Both bioassays and chemical extraction methods are necessary for assessing the bioavailability of metals in contaminated soils. - Lumbricus terrestris L. activity increases the bioavailability of metals in soils and total, shoot and root metal concentrations for maize and barley.

  2. Increasing Physical Activity in Preschool: A Pilot Study to Evaluate Animal Trackers

    Williams, Christine L.; Carter, Betty Jean; Kibbe, Debra L.; Dennison, David

    2009-01-01

    Objective: This report describes a pilot study to evaluate Animal Trackers (AT), a preschool program designed to (1) increase structured physical activity (PA) during the preschool day; (2) increase practice of gross motor skills; (3) provide teachers with an easy-to-use PA program regardless of teacher experience; and (4) implement a teacher…

  3. Prolonged seizure activity leads to increased Protein Kinase A activation in the rat pilocarpine model of status epilepticus.

    Bracey, James M; Kurz, Jonathan E; Low, Brian; Churn, Severn B

    2009-08-04

    Status epilepticus is a life-threatening form of seizure activity that represents a major medical emergency associated with significant morbidity and mortality. Protein Kinase A is an important regulator of synaptic strength that may play an important role in the development of status epilepticus-induced neuronal pathology. This study demonstrated an increase in PKA activity against exogenous and endogenous substrates during later stages of SE. As SE progressed, a significant increase in PKA-mediated phosphorylation of an exogenous peptide substrate was demonstrated in cortical structures. The increased activity was not due to altered expression of either regulatory or catalytic subunits of the enzyme. Through the use of phospho-specific antibodies, this study also investigated the effects of SE on the phosphorylation of the GluR1 subunit of the AMPA subtype of glutamate receptor. After the onset of continuous seizure activity, an increase in phosphorylation of the PKA site on the GluR1 subunit of the AMPA receptor was observed. These data suggest a potential mechanism by which SE may increase neuronal excitability in the cortex, potentially leading to maintenance of seizure activity or long-term neuronal pathology.

  4. The Effect Of PHA And SEA On Mitotic Index Of Lymphocyte Cell Of Macaca Fasciulare

    Lubis, Masnelli; Iwiq-Indrawati

    2003-01-01

    The observation of influences of PHA (phytohemagglutinin) and SEA (staphilucoccal enterotoxin A) on mitotic index of lymphocyte of Macaca Fascicularis had been done. Half milliliters of lymphocyte cells stimulated with PHA or SEA were cultured in 10 ml RPMI + 1.0 ml Fetal Bouvine Serum (FBS ) + 0.1 ml L-glutamine + 0.15 ml PHA or 0.1 ml SEA ( 0.5 μg/ml ) + 0.1 ml Colchisin on 37 degree C for 96 hours. The result demonstrated that the frequency of mitotic index stimulated with PHA was higher than that of SEA. The average of mitotic index with PHA was 18.56 %, and with SEA was 8.3 %. (author)

  5. Potential to increase active commuting level in university area (Case study: Universitas Gadjah Mada)

    Devi, M. K.

    2017-06-01

    In order to alleviate the negative impacts of motorized vehicle use as well as create sustainable environment within campus area, it is pivotal to encourage mode shifting among university students. Active transport modes such as walking, cycling, and using public transport can be considered as alternative modes. This paper tried to identify the potential to increase active commuting in UGM by understanding student’s travel behavior. ANOVA test was employed to identify the perceptions between students across residential zones toward motivators and barriers to actively commute. The findings were used to propose strategies for increasing active commuting level in UGM, which are: reducing barriers to actively commute, improving public transport services, improving walking and cycling facilities, and introducing programs to discourage motorized vehicle use.

  6. Evaluation of a faculty development program aimed at increasing residents' active learning in lectures.

    Desselle, Bonnie C; English, Robin; Hescock, George; Hauser, Andrea; Roy, Melissa; Yang, Tong; Chauvin, Sheila W

    2012-12-01

    Active engagement in the learning process is important to enhance learners' knowledge acquisition and retention and the development of their thinking skills. This study evaluated whether a 1-hour faculty development workshop increased the use of active teaching strategies and enhanced residents' active learning and thinking. Faculty teaching in a pediatrics residency participated in a 1-hour workshop (intervention) approximately 1 month before a scheduled lecture. Participants' responses to a preworkshop/postworkshop questionnaire targeted self-efficacy (confidence) for facilitating active learning and thinking and providing feedback about workshop quality. Trained observers assessed each lecture (3-month baseline phase and 3-month intervention phase) using an 8-item scale for use of active learning strategies and a 7-item scale for residents' engagement in active learning. Observers also assessed lecturer-resident interactions and the extent to which residents were asked to justify their answers. Responses to the workshop questionnaire (n  =  32/34; 94%) demonstrated effectiveness and increased confidence. Faculty in the intervention phase demonstrated increased use of interactive teaching strategies for 6 items, with 5 reaching statistical significance (P ≤ .01). Residents' active learning behaviors in lectures were higher in the intervention arm for all 7 items, with 5 reaching statistical significance. Faculty in the intervention group demonstrated increased use of higher-order questioning (P  =  .02) and solicited justifications for answers (P  =  .01). A 1-hour faculty development program increased faculty use of active learning strategies and residents' engagement in active learning during resident core curriculum lectures.

  7. Clofibrate-induced increases in peroxisomal proteins: effect on synthesis, degradation, and mRNA activity

    Mortensen, R.M.

    1983-01-01

    The effect of clofibrate on the polypeptide composition of peroxisomes was determined. A simple method was developed for the isolation of peroxisomes with a purity of 90-95% using sedimentation in a metrizamide gradient. The specific activities of HD did not change with clofibrate treatment so that the increases in enzyme activities are solely due to increases in protein amounts. The hepatic concentration of HD increased 63 times. The HD synthesis rate, as measured by the incorporation of [ 3 H]leucine, increased 74 times, so that the increase in the synthesis was sufficient to account for the increase in protein. Clofibrate caused no discernible change in the degradation rate of HD labeled with [ 14 C]bicarbonate. The half-life of HD was approximately 2 days. The translatable mRBA coding for HD increased 55 times. This value is not significantly different from the increase in HD protein or in HD synthesis. This observation was also true for several other peroxisomal proteins. Therefore, clofibrate causes an increase in the mRNA activity, which increases the synthesis of HD leading to an accumulation of protein and enzyme activity. The kinetics of the clofibrate-induced changes in HD synthesis rate, protein level, and enzymatic activity was analyzed using a simple model which included the half-lives of the drug, mRNA, and protein. The best fit of the model to the data gave an mRNA half-life of 10 hours and a protein half-life of 1.8 days, with no significant change by clofibrate

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

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

    2012-02-01

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

  9. Inhibiting effect of plasma from normal and tumour bearing mice on the mitotic rate of regenerating liver.

    Echave Llanos, J M; Moreno, F R; Badrán, A F

    1986-01-01

    Plasma from normal mice and from mice bearing the ES2 transplantable malignant tumour was injected intraperitoneally at a dose of 0.01 ml/g body weight in partially hepatectomized mice. Control animals were injected with a solution of sodium citrate in saline. The recipients were killed at the first (14:00 hours/48 h). These times are the time of day and the number of h after partial hepatectomy and second (14:00 hours/72 h) peak times after partial hepatectomy. The number of colchicine metaphases per 1000 nuclei was determined for hepatocytes and litoral cells. A different effect was obtained with plasma from tumour-bearing compared with normal mice. Plasma from both sources when injected 26 h after partial hepatectomy (16:00 hours/26 h) inhibited the mitotic activity of hepatocytes at the next peak of regenerative activity (14:00 hours/48 h). The plasma from tumour-bearing mice also inhibited the peak on the following day (14:00 hours/72 h), whereas plasma from normal mice had no inhibitory effect and, indeed, a compensatory wave was observed at this time. Furthermore, plasma from tumour-bearing mice also showed an inhibitory effect at the first peak (14:00 hours/48 h) when injected at the time of partial hepatectomy (14:00 hours/00 h) or at 22 h before partial hepatectomy (16:00 hours/-22 h) whereas the injection of plasma from normal mice at these times had no inhibitory effect. In the litoral cells the injection of plasma from tumour-bearing mice made 22 h before hepatectomy (16:00 hours/-22 h) led to a stimulation of mitotic activity which was controlled at 14:00 hours/48 h.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Increasing brain angiotensin converting enzyme 2 activity decreases anxiety-like behavior in male mice by activating central Mas receptors.

    Wang, Lei; de Kloet, Annette D; Pati, Dipanwita; Hiller, Helmut; Smith, Justin A; Pioquinto, David J; Ludin, Jacob A; Oh, S Paul; Katovich, Michael J; Frazier, Charles J; Raizada, Mohan K; Krause, Eric G

    2016-06-01

    Over-activation of the brain renin-angiotensin system (RAS) has been implicated in the etiology of anxiety disorders. Angiotensin converting enzyme 2 (ACE2) inhibits RAS activity by converting angiotensin-II, the effector peptide of RAS, to angiotensin-(1-7), which activates the Mas receptor (MasR). Whether increasing brain ACE2 activity reduces anxiety by stimulating central MasR is unknown. To test the hypothesis that increasing brain ACE2 activity reduces anxiety-like behavior via central MasR stimulation, we generated male mice overexpressing ACE2 (ACE2 KI mice) and wild type littermate controls (WT). ACE2 KI mice explored the open arms of the elevated plus maze (EPM) significantly more than WT, suggesting increasing ACE2 activity is anxiolytic. Central delivery of diminazene aceturate, an ACE2 activator, to C57BL/6 mice also reduced anxiety-like behavior in the EPM, but centrally administering ACE2 KI mice A-779, a MasR antagonist, abolished their anxiolytic phenotype, suggesting that ACE2 reduces anxiety-like behavior by activating central MasR. To identify the brain circuits mediating these effects, we measured Fos, a marker of neuronal activation, subsequent to EPM exposure and found that ACE2 KI mice had decreased Fos in the bed nucleus of stria terminalis but had increased Fos in the basolateral amygdala (BLA). Within the BLA, we determined that ∼62% of GABAergic neurons contained MasR mRNA and expression of MasR mRNA was upregulated by ACE2 overexpression, suggesting that ACE2 may influence GABA neurotransmission within the BLA via MasR activation. Indeed, ACE2 overexpression was associated with increased frequency of spontaneous inhibitory postsynaptic currents (indicative of presynaptic release of GABA) onto BLA pyramidal neurons and central infusion of A-779 eliminated this effect. Collectively, these results suggest that ACE2 may reduce anxiety-like behavior by activating central MasR that facilitate GABA release onto pyramidal neurons within the

  11. Increased CSF-BACE1 activity associated with decreased hippocampus volume in Alzheimer's disease.

    Ewers, Michael

    2012-02-01

    The enzyme beta-secretase (BACE1) is essentially involved in the production of cerebral amyloidogenic pathology in Alzheimer\\'s disease (AD). The measurement of BACE1 activity in cerebrospinal fluid (CSF) has been reported, which may render CSF measurement of BACE1 a potential biomarker candidate of AD. In order to investigate whether BACE1 protein activity is correlated with regional brain atrophy in AD, we investigated the association between CSF levels of BACE1 and MRI-assessed hippocampus volume in patients with AD (n = 30). An increase in CSF-BACE1 activity was associated with decreased left and right hippocampus volume corrected for global head volume in the AD patients. Boot-strapped regression analysis showed that increased CSF levels of BACE1 activity were associated with increased CSF concentration of total tau but not amyloid-beta1-42 in AD. White matter hyperintensities did not influence the results. BACE1 activity and protein levels were significantly increased in AD compared to 19 elderly healthy controls. Thus, the CSF biomarker candidate of BACE1 activity was associated with hippocampus atrophy in AD in a robust manner and may reflect neurotoxic amyloid-beta-related processes.

  12. Shale gas activity and increased rates of sexually transmitted infections in Ohio, 2000-2016.

    Nicole C Deziel

    Full Text Available The growing shale gas ("fracking" industry depends on a mobile workforce, whose influx could have social impacts on host communities. Sexually transmitted infections (STIs can increase through sexual mixing patterns associated with labor migration. No prior studies have quantified the relationship between shale gas activity and rates of three reportable STIs: chlamydia, gonorrhea, and syphilis.We conducted a longitudinal, ecologic study from 2000-2016 in Ohio, situated in a prolific shale gas region in the United States (US. Data on reported cases of chlamydia, gonorrhea, and syphilis by county and year were obtained from the Ohio Department of Health. All 88 counties were classified as none, low, and high shale gas activity in each year, using data from the Ohio Department of Natural Resources. Annual rate ratios (RR and 95% confidence intervals (95% CIs were calculated from mixed-effects Poisson regression models evaluating the relationship between shale gas activity and reported annual STI rates while adjusting for secular trends and potential confounders obtained from the US Census.Compared to counties with no shale gas activity, counties with high activity had 21% (RR = 1.21; 95%CI = 1.08-1.36 increased rates of chlamydia and 19% (RR = 1.27; 95%CI 0.98-1.44 increased rates of gonorrhea, respectively. No association was observed for syphilis.This first report of a link between shale gas activity and increased rates of both chlamydia and gonorrhea may inform local policies and community health efforts.

  13. Sex differences in functional activation patterns revealed by increased emotion processing demands.

    Hall, Geoffrey B C; Witelson, Sandra F; Szechtman, Henry; Nahmias, Claude

    2004-02-09

    Two [O(15)] PET studies assessed sex differences regional brain activation in the recognition of emotional stimuli. Study I revealed that the recognition of emotion in visual faces resulted in bilateral frontal activation in women, and unilateral right-sided activation in men. In study II, the complexity of the emotional face task was increased through tje addition of associated auditory emotional stimuli. Men again showed unilateral frontal activation, in this case to the left; whereas women did not show bilateral frontal activation, but showed greater limbic activity. These results suggest that when processing broader cross-modal emotional stimuli, men engage more in associative cognitive strategies while women draw more on primary emotional references.

  14. Estrogen increases Nrf2 activity through activation of the PI3K pathway in MCF-7 breast cancer cells

    Wu, Juanjuan, E-mail: jwu32@emory.edu [Department of Gynecology and Obstetrics, Emory University School of Medicine, 101 Woodruff Circle, Suite 4211 WMB, Atlanta, GA 30322 (United States); Williams, Devin [Department of Obstetrics and Gynecology, Morehouse School of Medicine, Atlanta, GA 30310 (United States); Walter, Grant A. [Department of Gynecology and Obstetrics, Emory University School of Medicine, 101 Woodruff Circle, Suite 4211 WMB, Atlanta, GA 30322 (United States); Thompson, Winston E. [Department of Obstetrics and Gynecology, Morehouse School of Medicine, Atlanta, GA 30310 (United States); Sidell, Neil [Department of Gynecology and Obstetrics, Emory University School of Medicine, 101 Woodruff Circle, Suite 4211 WMB, Atlanta, GA 30322 (United States)

    2014-11-01

    The actions of the transcription factor Nuclear factor erythroid 2-related factor (Nrf2) in breast cancer have been shown to include both pro-oncogenic and anti-oncogenic activities which is influenced, at least in part, by the hormonal environment. However, direct regulation of Nrf2 by steroid hormones (estrogen and progesterone) has received only scant attention. Nrf2 is known to be regulated by its cytosolic binding protein, Kelch-like ECH-associated protein 1 (Keap1), and by a Keap1-independent mechanism involving a series of phosphorylation steps mediated by phosphatidylinositol 3-kinase (PI3K) and glycogen synthase kinase 3 beta (GSK3β). Here, we report that estrogen (E2) increases Nrf2 activity in MCF7 breast cancer cells through activation of the PI3K/GSK3β pathway. Utilizing antioxidant response element (ARE)-containing luciferase reporter constructs as read-outs for Nrf2 activity, our data indicated that E2 increased ARE activity >14-fold and enhanced the action of the Nrf2 activators, tertiary butylhydroquinone (tBHQ) and sulforaphane (Sul) 4 to 9 fold compared with cells treated with tBHQ or Sul as single agents. This activity was shown to be an estrogen receptor-mediated phenomenon and was antagonized by progesterone. In addition to its action on the reporter constructs, mRNA and protein levels of heme oxygenase 1, an endogenous target gene of Nrf2, was markedly upregulated by E2 both alone and in combination with tBHQ. Importantly, E2-induced Nrf2 activation was completely suppressed by the PI3K inhibitors LY294002 and Wortmannin while the GSK3β inhibitor CT99021 upregulated Nrf2 activity. Confirmation that E2 was, at least partly, acting through the PI3K/GSK3β pathway was indicated by our finding that E2 increased the phosphorylation status of both GSK3β and Akt, a well-characterized downstream target of PI3K. Together, these results demonstrate a novel mechanism by which E2 can regulate Nrf2 activity in estrogen receptor-positive breast cancer

  15. Increased p21ras activity in human fibroblasts transduced with survivin enhances cell proliferation

    Temme, Achim; Diestelkoetter-Bachert, Petra; Schmitz, Marc; Morgenroth, Agnieszka; Weigle, Bernd; Rieger, Michael A.; Kiessling, Andrea; Rieber, E. Peter

    2005-01-01

    Survivin is critically involved in mitosis and when overexpressed enhances the activity of the Aurora B kinase, a serine-threonine kinase belonging to the family of oncogenic Aurora/IpI1p-related kinases. Both proteins interact with Ras GTPase-activating protein suggesting an impact on the Ras pathway. This study aimed at defining the role of survivin in proliferation and potential transformation of cells. When survivin was overexpressed in normal human lung fibroblasts, the characteristic track lanes of fibroblasts were disturbed and the rate of cell proliferation was increased. An enhanced level of p21 ras mRNA and protein expression and concomitant rise in levels of activated p21 ras were observed. Despite increased proliferation cell survival remained dependent on serum and cells were not able to form colonies in soft agar assays. These data suggest that overexpression of survivin increases cell growth but, despite the increase in active p21 ras , is not sufficient to transform primary cells. Yet, in addition to its anti-apoptotic function it might contribute to the accelerated growth of tumour cells by increasing p21 ras activity

  16. Superoxide dismutase and catalase conjugated to polyethylene glycol increases endothelial enzyme activity and oxidant resistance

    Beckman, J.S.; Minor, R.L. Jr.; White, C.W.; Repine, J.E.; Rosen, G.M.; Freeman, B.A.

    1988-01-01

    Covalent conjugation of superoxide dismutase and catalase with polyethylene glycol (PEG) increases the circulatory half-lives of these enzymes from 125 I-PEG-catalase or 125 I-PEG-superoxide dismutase produced a linear, concentration-dependent increase in cellular enzyme activity and radioactivity. Fluorescently labeled PEG-superoxide dismutase incubated with endothelial cells showed a vesicular localization. Mechanical injury to cell monolayers, which is known to stimulate endocytosis, further increased the uptake of fluorescent PEG-superoxide dismutase. Addition of PEG and PEG-conjugated enzymes perturbed the spin-label binding environment, indicative of producing an increase in plasma membrane fluidity. Thus, PEG conjugation to superoxide dismutase and catalase enhances cell association of these enzymes in a manner which increases cellular enzyme activities and provides prolonged protection from partially reduced oxygen species

  17. Dietary resveratrol administration increases MnSOD expression and activity in mouse brain

    Robb, Ellen L.; Winkelmolen, Lieke; Visanji, Naomi; Brotchie, Jonathan; Stuart, Jeffrey A.

    2008-01-01

    trans-Resveratrol (3,4',5-trihydroxystilbene; RES) is of interest for its reported protective effects in a variety of pathologies, including neurodegeneration. Many of these protective properties have been attributed to the ability of RES to reduce oxidative stress. In vitro studies have shown an increase in antioxidant enzyme activities following exposure to RES, including upregulation of mitochondrial superoxide dismutase, an enzyme that is capable of reducing both oxidative stress and cell death. We sought to determine if a similar increase in endogenous antioxidant enzymes is observed with RES treatment in vivo. Three separate modes of RES delivery were utilized; in a standard diet, a high fat diet and through a subcutaneous osmotic minipump. RES given in a high fat diet proved to be effective in elevating antioxidant capacity in brain resulting in an increase in both MnSOD protein level (140%) and activity (75%). The increase in MnSOD was not due to a substantial proliferation of mitochondria, as RES treatment induced a 10% increase in mitochondrial abundance (Citrate Synthase activity). The potential neuroprotective properties of MnSOD have been well established, and we demonstrate that a dietary delivery of RES is able to increase the expression and activity of this enzyme in vivo

  18. Changes in zooxanthellae density, morphology, and mitotic index in hermatypic corals and anemones exposed to cyanide.

    Cervino, J M; Hayes, R L; Honovich, M; Goreau, T J; Jones, S; Rubec, P J

    2003-05-01

    Sodium cyanide (NaCN) is widely used for the capture of reef fish throughout Southeast Asia and causes extensive fish mortality, but the effect of NaCN on reef corals remains debated. To document the impact of cyanide exposure on corals, the species Acropora millepora, Goniopora sp., Favites abdita, Trachyphyllia geoffrio, Plerogyra sp., Heliofungia actinformis, Euphyllia divisa, and Scarophyton sp., and the sea anemone Aiptasia pallida were exposed to varying concentrations of cyanide for varying time periods. Corals were exposed to 50, 100, 300, and 600 mg/l of cyanide ion (CN(-)) for 1-2 min (in seawater, the CN(-) forms hydrocyanic acid). These concentrations are much lower than those reportedly used by fish collectors. Exposed corals and anemones immediately retracted their tentacles and mesenterial filaments, and discharged copious amounts of mucus containing zooxanthellae. Gel electrophoreses techniques found changes in protein expression in both zooxanthellae and host tissue. Corals and anemones exposed to cyanide showed an immediate increase in mitotic cell division of their zooxenthellae, and a decrease in zooxanthellae density. In contrast, zooxanthellae cell division and density remained constant in controls. Histopathological changes included gastrodermal disruption, mesogleal degradation, and increased mucus in coral tissues. Zooxanthellae showed pigment loss, swelling, and deformation. Mortality occurred at all exposure levels. Exposed specimens experienced an increase in the ratio of gram-negative to gram-positive bacteria on the coral surface. The results demonstrate that exposure cyanide causes mortality to corals and anemones, even when applied at lower levels than that used by fish collectors. Even brief exposure to cyanide caused slow-acting and long-term damage to corals and their zooxanthellae.

  19. Activation of the Ca2+-sensing receptors increases currents through inward rectifier K+ channels via activation of phosphatidylinositol 4-kinase.

    Liu, Chung-Hung; Chang, Hsueh-Kai; Lee, Sue-Ping; Shieh, Ru-Chi

    2016-11-01

    Inward rectifier K + channels are important for maintaining normal electrical function in many cell types. The proper function of these channels requires the presence of membrane phosphoinositide 4,5-bisphosphate (PIP 2 ). Stimulation of the Ca 2+ -sensing receptor CaR, a pleiotropic G protein-coupled receptor, activates both G q/11 , which decreases PIP 2 , and phosphatidylinositol 4-kinase (PI-4-K), which, conversely, increases PIP 2 . How membrane PIP 2 levels are regulated by CaR activation and whether these changes modulate inward rectifier K + are unknown. In this study, we found that activation of CaR by the allosteric agonist, NPSR568, increased inward rectifier K + current (I K1 ) in guinea pig ventricular myocytes and currents mediated by Kir2.1 channels exogenously expressed in HEK293T cells with a similar sensitivity. Moreover, using the fluorescent PIP 2 reporter tubby-R332H-cYFP to monitor PIP 2 levels, we found that CaR activation in HEK293T cells increased membrane PIP 2 concentrations. Pharmacological studies showed that both phospholipase C (PLC) and PI-4-K are activated by CaR stimulation with the latter played a dominant role in regulating membrane PIP 2 and, thus, Kir currents. These results provide the first direct evidence that CaR activation upregulates currents through inward rectifier K + channels by accelerating PIP 2 synthesis. The regulation of I K1 plays a critical role in the stability of the electrical properties of many excitable cells, including cardiac myocytes and neurons. Further, synthetic allosteric modulators that increase CaR activity have been used to treat hyperparathyroidism, and negative CaR modulators are of potential importance in the treatment of osteoporosis. Thus, our results provide further insight into the roles played by CaR in the cardiovascular system and are potentially valuable for heart disease treatment and drug safety.

  20. Increased angiotensin-converting enzyme activity in the left ventricle after infarction

    V.C.W. Busatto

    1997-05-01

    Full Text Available An increase in angiotensin-converting enzyme (ACE activity has been observed in the heart after myocardial infarction (MI. Since most studies have been conducted in chronically infarcted individuals exhibiting variable degrees of heart failure, the present study was designed to determine ACE activity in an earlier phase of MI, before heart failure development. MI was produced in 3-month old male Wistar rats by ligation of the anterior branches of the left coronary artery, control rats underwent sham surgery and the animals were studied 7 or 15 days later. Hemodynamic data obtained for the anesthetized animals showed normal values of arterial blood pressure and of end-diastolic pressure in the right and left ventricular cavities of MI rats. Right and left ventricular (RV, LV muscle and scar tissue homogenates were prepared to determine ACE activity in vitro by measuring the velocity of His-Leu release from the synthetic substrate Hyp-His-Leu. ACE activity was corrected to the tissue wet weight and is reported as nmol His-Leu g-1 min-1. No significant change in ACE activity in the RV homogenates was demonstrable. A small nonsignificant increase of ACE activity (11 ± 9%; P0.05 was observed 7 days after MI in the surviving left ventricular muscle. Two weeks after surgery, however, ACE activity was 46 ± 11% (P<0.05 higher in infarcted rats compared to sham-operated rats. The highest ACE activity was demonstrable in the scar tissue homogenate. In rats studied two weeks after surgery, ACE activity in the LV muscle increased from 105 ± 7 nmol His-Leu g-1 min-1 in control hearts to 153 ± 11 nmol His-Leu g-1 min-1 (P<0.05 in the remaining LV muscle of MI rats and to 1051 ± 208 nmol His-Leu g-1 min-1 (P<0.001 in the fibrous scar. These data indicate that ACE activity increased in the heart after infarction before heart failure was demonstrable by hemodynamic measurements. Since the blood vessels of the scar drain to the remaining LV myocardium, the

  1. Long-term aerobic exercise increases redox-active iron through nitric oxide in rat hippocampus.

    Chen, Qian; Xiao, De-Sheng

    2014-01-30

    Adult hippocampus is highly vulnerable to iron-induced oxidative stress. Aerobic exercise has been proposed to reduce oxidative stress but the findings in the hippocampus are conflicting. This study aimed to observe the changes of redox-active iron and concomitant regulation of cellular iron homeostasis in the hippocampus by aerobic exercise, and possible regulatory effect of nitric oxide (NO). A randomized controlled study was designed in the rats with swimming exercise treatment (for 3 months) and/or an unselective inhibitor of NO synthase (NOS) (L-NAME) treatment. The results from the bleomycin-detectable iron assay showed additional redox-active iron in the hippocampus by exercise treatment. The results from nonheme iron content assay, combined with the redox-active iron content, showed increased storage iron content by exercise treatment. NOx (nitrate plus nitrite) assay showed increased NOx content by exercise treatment. The results from the Western blot assay showed decreased ferroportin expression, no changes of TfR1 and DMT1 expressions, increased IRP1 and IRP2 expression, increased expressions of eNOS and nNOS rather than iNOS. In these effects of exercise treatment, the increased redox-active iron content, storage iron content, IRP1 and IRP2 expressions were completely reversed by L-NAME treatment, and decreased ferroportin expression was in part reversed by L-NAME. L-NAME treatment completely inhibited increased NOx and both eNOS and nNOS expression in the hippocampus. Our findings suggest that aerobic exercise could increase the redox-active iron in the hippocampus, indicating an increase in the capacity to generate hydroxyl radicals through the Fenton reactions, and aerobic exercise-induced iron accumulation in the hippocampus might mainly result from the role of the endogenous NO. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Increased cell surface metallopeptidase activity in cells undergoing UV-induced apoptosis

    Piva, T.J.; Davern, C.M.; Ellem, K.A.O.

    1999-01-01

    Full text: We have previously shown that UVC irradiation activated a range of cell surface peptidases (CSP) in HeLa cell monolayer cultures 20 h post-irradiation (1). In cells undergoing apoptosis there is an increase in CSP activity compared to control viable cells in cultures which have been treated by a wide range of agents including UV-irradiation (2). In order to further understand the mechanism involved in this process, we induced apoptosis in HeLa cells using 500 Jm -2 UVB. The separation of viable, apoptotic and necrotic cells of irradiated HeLa cell cultures was made by FACS analysis and sorting. The three populations were distinguished by their staining with PI and Hoechst 33342 dyes. CSP activity was measured using the P9 assay developed in this laboratory (1-3). The viable fraction of the irradiated cells had a higher level of CSP activity compared to unirradiated controls. The level of CSP activity in the apoptotic fraction was higher than that of the viable fraction, however that of the necrotic fraction was significantly lower. This finding agreed with that seen in UVC-irradiated (50 Jm -2 ) cultures (2). In order to elucidate the mechanism by which CSP activity was increased in UVB-irradiated cells undergoing apoptosis, the cultures were treated with the following agents: bestatin, aminopeptidase inhibitor, DEVD, caspase 3 inhibitor, and 3-aminobenzamide (3AB), PARP activation inhibitor. Bestatin and DEVD did not affect the level of CSP activity in the different cell subpopulations following UVB-irradiation. Treatment with 3AB abolished the increased CSP activity seen in the viable and apoptotic fraction following UVB-irradiation. All treated cells had the same morphology as observed under EM. The degree of phosphatidylserine eversion on the cell membrane was similar as were the cleavage profiles of PARP and actin. Only DEVD-treated cells had reduced caspase 3 activity which confirmed that the activation of CSP activity in apoptotic cells is

  3. Integrative exercise and lifestyle intervention increases leisure-time activity in breast cancer patients

    Casla, Soraya; Hojman, Pernille; Cubedo, Ricardo

    2014-01-01

    BACKGROUND: Physical activity has been demonstrated to increase survival in breast cancer patients, but few breast cancer patients meet the general recommendations for physical activity. The aim of this pilot study was to investigate if a supervised integrated counseling and group-based exercise...... program could increase leisure-time activity in women with breast cancer. METHODS: This pilot project, designed as a single-arm study with pre-post testing, consisted of 24 classes of combined aerobic and strength exercise training as well as classes on dietary and health behavior. A total of 48 women...... with breast cancer who were undergoing or had recently completed anticancer treatment completed the study. Leisure-time physical activity, grip strength, functional capacity, quality of life (QoL), and depression were assessed at baseline, after intervention, and at the 12-week follow-up after intervention...

  4. Acute Exercise Increases Plasma Total Antioxidant Status and Antioxidant Enzyme Activities in Untrained Men

    C. Berzosa

    2011-01-01

    Full Text Available Antioxidant defences are essential for cellular redox regulation. Since free-radical production may be enhanced by physical activity, herein, we evaluated the effect of acute exercise on total antioxidant status (TAS and the plasma activities of catalase, glutathione reductase, glutathione peroxidase, and superoxide dismutase and its possible relation to oxidative stress resulting from exercise. Healthy untrained male subjects (=34 performed three cycloergometric tests, including maximal and submaximal episodes. Venous blood samples were collected before and immediately after each different exercise. TAS and enzyme activities were assessed by spectrophotometry. An increase of the antioxidant enzyme activities in plasma was detected after both maximal and submaximal exercise periods. Moreover, under our experimental conditions, exercise also led to an augmentation of TAS levels. These findings are consistent with the idea that acute exercise may play a beneficial role because of its ability to increase antioxidant defense mechanisms through a redox sensitive pathway.

  5. INCREASING EFL STUDENTS’ WRITING ABILITIES USING PEER RESPONSE ACTIVITIES VIA FACEBOOK

    M. Zaini Miftah

    2016-12-01

    Full Text Available This study was aimed to increase EFL students’ abilities in writing argumentative essay via Facebook by developing peer response activities. The classroom action research was employed in cyclic activities. The subjects were 25 Indonesian fourth-year undergraduate EFL students who enrolled in Writing III course. The data were gained from writing task, observation, and field notes. The result shows that this strategy with the appropriate instructional procedures can increase the EFL students’ abilities in writing argumentative essay. It is indicated by the increases of the students’ writing achievement and involvement in writing class during peer response activities via Facebook. Hence, it gives insights to employ this way as an alternative teaching technique in writing classroom because of its effectiveness.

  6. Increasing EFL Students’ Writing Abilities Using Peer Response Activities via Facebook

    M. Zaini Miftah

    2016-12-01

    Full Text Available This study was aimed to increase EFL students’ abilities in writing argumentative essay via Facebook by developing peer response activities. The classroom action research was employed in cyclic activities. The subjects were 25 Indonesian fourth-year undergraduate EFL students who enrolled in Writing III course. The data were gained from writing task, observation, and field notes. The result shows that this strategy with the appropriate instructional procedures can increase the EFL students’ abilities in writing argumentative essay. It is indicated by the increases of the students’ writing achievement and involvement in writing class during peer response activities via Facebook. Hence, it gives insights to employ this way as an alternative teaching technique in writing classroom because of its effectiveness.

  7. The Drosophila Microtubule-Associated Protein Mars Stabilizes Mitotic Spindles by Crosslinking Microtubules through Its N-Terminal Region

    Zhang, Gang; Beati, Hamze; Nilsson, Jakob

    2013-01-01

    Correct segregation of genetic material relies on proper assembly and maintenance of the mitotic spindle. How the highly dynamic microtubules (MTs) are maintained in stable mitotic spindles is a key question to be answered. Motor and non-motor microtubule associated proteins (MAPs) have been...

  8. Variation in sensitivity to #betta#-ray-induced chromosomal aberrations during the mitotic cycle of the sea urchin egg

    Ejima, Y.; Nakamura, I.; Shiroya, T.

    1982-01-01

    Sea urchin eggs were irradiated with 137 Cs #betta# rays at various stages of the mitotic cycle, and chromosomal aberrations at the first postirradiation mitosis and embryonic abnormalities at later developmental stages were examined. The radiosensitivity of the eggs to both endpoints varied in parallel with the mitotic stage at the time of irradiation, suggesting a possible relationship between chromosomal damage and embryonic abnormalities

  9. Carnosine: effect on aging-induced increase in brain regional monoamine oxidase-A activity.

    Banerjee, Soumyabrata; Poddar, Mrinal K

    2015-03-01

    Aging is a natural biological process associated with several neurological disorders along with the biochemical changes in brain. Aim of the present investigation is to study the effect of carnosine (0.5-2.5μg/kg/day, i.t. for 21 consecutive days) on aging-induced changes in brain regional (cerebral cortex, hippocampus, hypothalamus and pons-medulla) mitochondrial monoamine oxidase-A (MAO-A) activity with its kinetic parameters. The results of the present study are: (1) The brain regional mitochondrial MAO-A activity and their kinetic parameters (except in Km of pons-medulla) were significantly increased with the increase of age (4-24 months), (2) Aging-induced increase of brain regional MAO-A activity including its Vmax were attenuated with higher dosages of carnosine (1.0-2.5μg/kg/day) and restored toward the activity that observed in young, though its lower dosage (0.5μg/kg/day) were ineffective in these brain regional MAO-A activity, (3) Carnosine at higher dosage in young rats, unlike aged rats significantly inhibited all the brain regional MAO-A activity by reducing their only Vmax excepting cerebral cortex, where Km was also significantly enhanced. These results suggest that carnosine attenuated the aging-induced increase of brain regional MAO-A activity by attenuating its kinetic parameters and restored toward the results of MAO-A activity that observed in corresponding brain regions of young rats. Copyright © 2014 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  10. Construction of Mutant Glucose Oxidases with Increased Dye-Mediated Dehydrogenase Activity

    Horaguchi, Yohei; Saito, Shoko; Kojima, Katsuhiro; Tsugawa, Wakako; Ferri, Stefano; Sode, Koji

    2012-01-01

    Mutagenesis studies on glucose oxidases (GOxs) were conducted to construct GOxs with reduced oxidase activity and increased dehydrogenase activity. We focused on two representative GOxs, of which crystal structures have already been reported—Penicillium amagasakiense GOx (PDB ID; 1gpe) and Aspergillus niger GOx (PDB ID; 1cf3). We constructed oxygen-interacting structural models for GOxs, and predicted the residues responsible for oxidative half reaction with oxygen on the basis of the crystal structure of cholesterol oxidase as well as on the fact that both enzymes are members of the glucose/methanol/choline (GMC) oxidoreductase family. Rational amino acid substitution resulted in the construction of an engineered GOx with drastically decreased oxidase activity and increased dehydrogenase activity, which was higher than that of the wild-type enzyme. As a result, the dehydrogenase/oxidase ratio of the engineered enzyme was more than 11-fold greater than that of the wild-type enzyme. These results indicate that alteration of the dehydrogenase/oxidase activity ratio of GOxs is possible by introducing a mutation into the putative functional residues responsible for oxidative half reaction with oxygen of these enzymes, resulting in a further increased dehydrogenase activity. This is the first study reporting the alteration of GOx electron acceptor preference from oxygen to an artificial electron acceptor. PMID:23203056

  11. Construction of Mutant Glucose Oxidases with Increased Dye-Mediated Dehydrogenase Activity

    Koji Sode

    2012-11-01

    Full Text Available Mutagenesis studies on glucose oxidases (GOxs were conducted to construct GOxs with reduced oxidase activity and increased dehydrogenase activity. We focused on two representative GOxs, of which crystal structures have already been reported—Penicillium amagasakiense GOx (PDB ID; 1gpe and Aspergillus niger GOx (PDB ID; 1cf3. We constructed oxygen-interacting structural models for GOxs, and predicted the residues responsible for oxidative half reaction with oxygen on the basis of the crystal structure of cholesterol oxidase as well as on the fact that both enzymes are members of the glucose/methanol/choline (GMC oxidoreductase family. Rational amino acid substitution resulted in the construction of an engineered GOx with drastically decreased oxidase activity and increased dehydrogenase activity, which was higher than that of the wild-type enzyme. As a result, the dehydrogenase/oxidase ratio of the engineered enzyme was more than 11-fold greater than that of the wild-type enzyme. These results indicate that alteration of the dehydrogenase/oxidase activity ratio of GOxs is possible by introducing a mutation into the putative functional residues responsible for oxidative half reaction with oxygen of these enzymes, resulting in a further increased dehydrogenase activity. This is the first study reporting the alteration of GOx electron acceptor preference from oxygen to an artificial electron acceptor.

  12. Construction of mutant glucose oxidases with increased dye-mediated dehydrogenase activity.

    Horaguchi, Yohei; Saito, Shoko; Kojima, Katsuhiro; Tsugawa, Wakako; Ferri, Stefano; Sode, Koji

    2012-11-02

    Mutagenesis studies on glucose oxidases (GOxs) were conducted to construct GOxs with reduced oxidase activity and increased dehydrogenase activity. We focused on two representative GOxs, of which crystal structures have already been reported—Penicillium amagasakiense GOx (PDB ID; 1gpe) and Aspergillus niger GOx (PDB ID; 1cf3). We constructed oxygen-interacting structural models for GOxs, and predicted the residues responsible for oxidative half reaction with oxygen on the basis of the crystal structure of cholesterol oxidase as well as on the fact that both enzymes are members of the glucose/methanol/choline (GMC) oxidoreductase family. Rational amino acid substitution resulted in the construction of an engineered GOx with drastically decreased oxidase activity and increased dehydrogenase activity, which was higher than that of the wild-type enzyme. As a result, the dehydrogenase/oxidase ratio of the engineered enzyme was more than 11-fold greater than that of the wild-type enzyme. These results indicate that alteration of the dehydrogenase/oxidase activity ratio of GOxs is possible by introducing a mutation into the putative functional residues responsible for oxidative half reaction with oxygen of these enzymes, resulting in a further increased dehydrogenase activity. This is the first study reporting the alteration of GOx electron acceptor preference from oxygen to an artificial electron acceptor.

  13. Troxerutin Reduces Kidney Damage against BDE-47-Induced Apoptosis via Inhibiting NOX2 Activity and Increasing Nrf2 Activity

    Qun Shan

    2017-01-01

    Full Text Available 2,2,4,4-Tetrabromodiphenyl ether (BDE-47, one of the persistent organic pollutants, seriously influences the quality of life; however, its pathological mechanism remains unclear. Troxerutin is a flavonoid with pharmacological activity of antioxidation and anti-inflammation. In the present study, we investigated troxerutin against BDE-47-induced kidney cell apoptosis and explored the underlying mechanism. The results show that troxerutin reduced renal cell apoptosis and urinary protein secretion in BDE-47-treated mice. Western blot analysis shows that troxerutin supplement enhanced the ratio of Bcl-2/Bax; inhibited the release of cytochrome c from mitochondria, the activation of procaspase-9 and procaspase-3, and the cleavage of PARP; and reduced FAS, FASL, and caspase-8 levels induced by BDE-47. In addition, troxerutin decreased the production of reactive oxygen species (ROS and increased the activities of antioxidative enzymes. Furthermore, troxerutin blunted Nrf2 ubiquitylation, enhanced the activity of Nrf2, decreased the activity of NOX2, and ameliorated kidney oxidant status of BDE-47-treated mice. Together, these results confirm that troxerutin could alleviate the cytotoxicity of BDE-47 through antioxidation and antiapoptosis, which suggests that its protective mechanism is involved in the inhibition of apoptosis via suppressing NOX2 activity and increasing Nrf2 signaling pathway.

  14. Acrolein activates matrix metalloproteinases by increasing reactive oxygen species in macrophages.

    O'Toole, Timothy E; Zheng, Yu-Ting; Hellmann, Jason; Conklin, Daniel J; Barski, Oleg; Bhatnagar, Aruni

    2009-04-15

    Acrolein is a ubiquitous component of environmental pollutants such as automobile exhaust, cigarette, wood, and coal smoke. It is also a natural constituent of several foods and is generated endogenously during inflammation or oxidation of unsaturated lipids. Because increased inflammation and episodic exposure to acrolein-rich pollutants such as traffic emissions or cigarette smoke have been linked to acute myocardial infarction, we examined the effects of acrolein on matrix metalloproteinases (MMPs), which destabilize atherosclerotic plaques. Our studies show that exposure to acrolein resulted in the secretion of MMP-9 from differentiated THP-1 macrophages. Acrolein-treatment of macrophages also led to an increase in reactive oxygen species (ROS), free intracellular calcium ([Ca2+](i)), and xanthine oxidase (XO) activity. ROS production was prevented by allopurinol, but not by rotenone or apocynin and by buffering changes in [Ca2+](I) with BAPTA-AM. The increase in MMP production was abolished by pre-treatment with the antioxidants Tiron and N-acetyl cysteine (NAC) or with the xanthine oxidase inhibitors allopurinol or oxypurinol. Finally, MMP activity was significantly stimulated in aortic sections from apoE-null mice containing advanced atherosclerotic lesions after exposure to acrolein ex vivo. These observations suggest that acrolein exposure results in MMP secretion from macrophages via a mechanism that involves an increase in [Ca2+](I), leading to xanthine oxidase activation and an increase in ROS production. ROS-dependent activation of MMPs by acrolein could destabilize atherosclerotic lesions during brief episodes of inflammation or pollutant exposure.

  15. Acrolein activates matrix metalloproteinases by increasing reactive oxygen species in macrophages

    O'Toole, Timothy E.; Zheng Yuting; Hellmann, Jason; Conklin, Daniel J.; Barski, Oleg; Bhatnagar, Aruni

    2009-01-01

    Acrolein is a ubiquitous component of environmental pollutants such as automobile exhaust, cigarette, wood, and coal smoke. It is also a natural constituent of several foods and is generated endogenously during inflammation or oxidation of unsaturated lipids. Because increased inflammation and episodic exposure to acrolein-rich pollutants such as traffic emissions or cigarette smoke have been linked to acute myocardial infarction, we examined the effects of acrolein on matrix metalloproteinases (MMPs), which destabilize atherosclerotic plaques. Our studies show that exposure to acrolein resulted in the secretion of MMP-9 from differentiated THP-1 macrophages. Acrolein-treatment of macrophages also led to an increase in reactive oxygen species (ROS), free intracellular calcium ([Ca 2+ ] i ), and xanthine oxidase (XO) activity. ROS production was prevented by allopurinol, but not by rotenone or apocynin and by buffering changes in [Ca 2+ ] I with BAPTA-AM. The increase in MMP production was abolished by pre-treatment with the antioxidants Tiron and N-acetyl cysteine (NAC) or with the xanthine oxidase inhibitors allopurinol or oxypurinol. Finally, MMP activity was significantly stimulated in aortic sections from apoE-null mice containing advanced atherosclerotic lesions after exposure to acrolein ex vivo. These observations suggest that acrolein exposure results in MMP secretion from macrophages via a mechanism that involves an increase in [Ca 2+ ] I , leading to xanthine oxidase activation and an increase in ROS production. ROS-dependent activation of MMPs by acrolein could destabilize atherosclerotic lesions during brief episodes of inflammation or pollutant exposure.

  16. Increasing acidification of nonreplicating Lactococcus lactis Delta thyA mutants by incorporating ATPase activity

    Pedersen, Martin Bastian; Købmann, Brian Jensen; Jensen, Peter Ruhdal

    2002-01-01

    % of that of exponentially growing MBP71. However, when nonspecific ATPase activity was incorporated into MBP71, the lactic acid flux was restored to 100% but not above that point, indicating that control over the flux switched from ATP demand to ATP supply (i.e., to sugar transport and glycolysis). As determined by growing...... nonreplicating cells with high ATPase activity on various sugar sources, it appeared that glycolysis exerted the majority of the control. ATPase activity also stimulated the rate of acidification by noureplicating MBP71 growing in milk, and pH 5.2 was reached 40% faster than it was without ATPase activity. We...... concluded that ATPase activity is a functional means of increasing acidification by nonreplicating L. lactis....

  17. Apple, Cherry, and Blackcurrant Increases Nuclear Factor Kappa B Activation in Liver of Transgenic Mice

    Balstad, Trude; Paur, Ingvild; Poulsen, Morten

    2010-01-01

    Nuclear factor kappa B (NF-B) is essential in normal physiology, and several human disorders involve inappropriate regulation of NF-B. Diets dominated by plant-based foods protect against chronic diseases, and several food derived compounds have been identified as promising NF-B modulators. We...... investigated the effects of diets supplemented with apple, blackcurrant, or cherries on lipopolysaccharide (LPS)-induced NF-B activation in transgenic NF-B-luciferase mice. Whole body and organ specific NF-B activities were determined. The mice had ad libitum access to the respective experimental diets for 7...... slightly higher whole-body NF-B activation at 4 h, and all 3 experimental groups had higher NF-B activation at 6 h. LPS-induced NF-B activation in liver was increased with all 3 experimental diets, but no effects were observed in other organs. Our findings indicate that high intakes of lyophilized fruits...

  18. Increased premotor cortex activation in high functioning autism during action observation.

    Perkins, Tom J; Bittar, Richard G; McGillivray, Jane A; Cox, Ivanna I; Stokes, Mark A

    2015-04-01

    The mirror neuron (MN) hypothesis of autism has received considerable attention, but to date has produced inconsistent findings. Using functional MRI, participants with high functioning autism or Asperger's syndrome were compared to typically developing individuals (n=12 in each group). Participants passively observed hand gestures that included waving, pointing, and grasping. Concerning the MN network, both groups activated similar regions including prefrontal, inferior parietal and superior temporal regions, with the autism group demonstrating significantly greater activation in the dorsal premotor cortex. Concerning other regions, participants with autism demonstrated increased activity in the anterior cingulate and medial frontal gyrus, and reduced activation in calcarine, cuneus, and middle temporal gyrus. These results suggest that during observation of hand gestures, frontal cortex activation is affected in autism, which we suggest may be linked to abnormal functioning of the MN system. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Estimation of transient increases in bleeding risk associated with physical activity in children with haemophilia

    Latimer Jane

    2008-06-01

    Full Text Available Abstract Background Although it is widely appreciated that vigorous physical activity can increase the risk of bleeding episodes in children with haemophilia, the magnitude of the increase in risk is not known. Accurate risk estimates could inform decisions made by children with haemophilia and their parents about participation in physical activity and aid the development of optimal prophylactic schedules. The aim of this study is to provide an accurate estimate of the risks of bleeding associated with vigorous physical activity in children with haemophilia. Methods/Design The study will be a case-crossover study nested within a prospective cohort study. Children with moderate or severe haemophilia A or B, recruited from two paediatric haematology departments in Australia, will participate in the study. The child, or the child's parent or guardian, will report bleeding episodes experienced over a 12-month period. Following a bleeding episode, the participant will be interviewed by telephone about exposures to physical activity in the case period (8 hours before the bleed and 2 control periods (an 8 hour period at the same time on the day preceding the bleed and an 8 hour period two days preceding the bleed. Conditional logistic regression will be used to estimate the risk of participating in vigorous physical activity from measures of exposure to physical activity in the case and control periods. Discussion This case-control study will provide estimates of the risk of participation in vigorous physical activity in children with haemophilia.

  20. Comparative Effectiveness of After-School Programs to Increase Physical Activity

    Sabina B. Gesell

    2013-01-01

    Full Text Available Background. We conducted a comparative effectiveness analysis to evaluate the difference in the amount of physical activity children engaged in when enrolled in a physical activity-enhanced after-school program based in a community recreation center versus a standard school-based after-school program. Methods. The study was a natural experiment with 54 elementary school children attending the community ASP and 37 attending the school-based ASP. Accelerometry was used to measure physical activity. Data were collected at baseline, 6 weeks, and 12 weeks, with 91% retention. Results. At baseline, 43% of the multiethnic sample was overweight/obese, and the mean age was 7.9 years (SD = 1.7. Linear latent growth models suggested that the average difference between the two groups of children at Week 12 was 14.7 percentage points in moderate-vigorous physical activity (P<.001. Cost analysis suggested that children attending traditional school-based ASPs—at an average cost of $17.67 per day—would need an additional daily investment of $1.59 per child for 12 weeks to increase their moderate-vigorous physical activity by a model-implied 14.7 percentage points. Conclusions. A low-cost, alternative after-school program featuring adult-led physical activities in a community recreation center was associated with increased physical activity compared to standard-of-care school-based after-school program.

  1. Improvements in knee biomechanics during walking are associated with increased physical activity after total knee arthroplasty.

    Arnold, John B; Mackintosh, Shylie; Olds, Timothy S; Jones, Sara; Thewlis, Dominic

    2015-12-01

    Total knee arthroplasty (TKA) in people with knee osteoarthritis increases knee-specific and general physical function, but it has not been established if there is a relationship between changes in these elements of functional ability. This study investigated changes and relationships between knee biomechanics during walking, physical activity, and use of time after TKA. Fifteen people awaiting TKA underwent 3D gait analysis before and six months after surgery. Physical activity and use of time were determined in free-living conditions from a high resolution 24-h activity recall. After surgery, participants displayed significant improvements in sagittal plane knee biomechanics and improved their physical activity profiles, standing for 105 more minutes (p=0.001) and performing 64 min more inside chores on average per day (p=0.008). Changes in sagittal plane knee range of motion (ROM) and peak knee flexion positively correlated with changes in total daily energy expenditure, time spent undertaking moderate to vigorous physical activity, inside chores and passive transport (r=0.52-0.66, p=0.005-0.047). Restoration of knee function occurs in parallel and is associated with improvements in physical activity and use of time after TKA. Increased functional knee ROM is required to support improvements in total and context specific physical activity. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  2. AM fungal exudates activate MAP kinases in plant cells in dependence from cytosolic Ca(2+) increase.

    Francia, Doriana; Chiltz, Annick; Lo Schiavo, Fiorella; Pugin, Alain; Bonfante, Paola; Cardinale, Francesca

    2011-09-01

    The molecular dialogue occurring prior to direct contact between the fungal and plant partners of arbuscular-mycorrhizal (AM) symbioses begins with the release of fungal elicitors, so far only partially identified chemically, which can activate specific signaling pathways in the host plant. We show here that the activation of MAPK is also induced by exudates of germinating spores of Gigaspora margarita in cultured cells of the non-leguminous species tobacco (Nicotiana tabacum), as well as in those of the model legume Lotus japonicus. MAPK activity peaked about 15 min after the exposure of the host cells to the fungal exudates (FE). FE were also responsible for a rapid and transient increase in free cytosolic Ca(2+) in Nicotiana plumbaginifolia and tobacco cells, and pre-treatment with a Ca(2+)-channel blocker (La(3+)) showed that in these cells, MAPK activation was dependent on the cytosolic Ca(2+) increase. A partial dependence of MAPK activity on the common Sym pathway could be demonstrated for a cell line of L. japonicus defective for LjSym4 and hence unable to establish an AM symbiosis. Our results show that MAPK activation is triggered by an FE-induced cytosolic Ca(2+) transient, and that a Sym genetic determinant acts to modulate the intensity and duration of this activity. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  3. Loading of PAX3 to Mitotic Chromosomes Is Mediated by Arginine Methylation and Associated with Waardenburg Syndrome*

    Wu, Tsu-Fang; Yao, Ya-Li; Lai, I-Lu; Lai, Chien-Chen; Lin, Pei-Lun; Yang, Wen-Ming

    2015-01-01

    PAX3 is a transcription factor critical to gene regulation in mammalian development. Mutations in PAX3 are associated with Waardenburg syndrome (WS), but the mechanism of how mutant PAX3 proteins cause WS remains unclear. Here, we found that PAX3 loads on mitotic chromosomes using its homeodomain. PAX3 WS mutants with mutations in homeodomain lose the ability to bind mitotic chromosomes. Moreover, loading of PAX3 on mitotic chromosomes requires arginine methylation, which is regulated by methyltransferase PRMT5 and demethylase JMJD6. Mutant PAX3 proteins that lose mitotic chromosome localization block cell proliferation and normal development of zebrafish. These results reveal the molecular mechanism of PAX3s loading on mitotic chromosomes and the importance of this localization pattern in normal development. Our findings suggest that PAX3 WS mutants interfere with the normal functions of PAX3 in a dominant negative manner, which is important to the understanding of the pathogenesis of Waardenburg syndrome. PMID:26149688

  4. The Drosophila Microtubule-Associated Protein Mars Stabilizes Mitotic Spindles by Crosslinking Microtubules through Its N-Terminal Region

    Zhang, Gang; Beati, Hamze; Nilsson, Jakob; Wodarz, Andreas

    2013-01-01

    Correct segregation of genetic material relies on proper assembly and maintenance of the mitotic spindle. How the highly dynamic microtubules (MTs) are maintained in stable mitotic spindles is a key question to be answered. Motor and non-motor microtubule associated proteins (MAPs) have been reported to stabilize the dynamic spindle through crosslinking adjacent MTs. Mars, a novel MAP, is essential for the early development of Drosophila embryos. Previous studies showed that Mars is required for maintaining an intact mitotic spindle but did not provide a molecular mechanism for this function. Here we show that Mars is able to stabilize the mitotic spindle in vivo. Both in vivo and in vitro data reveal that the N-terminal region of Mars functions in the stabilization of the mitotic spindle by crosslinking adjacent MTs. PMID:23593258

  5. The Drosophila microtubule-associated protein mars stabilizes mitotic spindles by crosslinking microtubules through its N-terminal region.

    Gang Zhang

    Full Text Available Correct segregation of genetic material relies on proper assembly and maintenance of the mitotic spindle. How the highly dynamic microtubules (MTs are maintained in stable mitotic spindles is a key question to be answered. Motor and non-motor microtubule associated proteins (MAPs have been reported to stabilize the dynamic spindle through crosslinking adjacent MTs. Mars, a novel MAP, is essential for the early development of Drosophila embryos. Previous studies showed that Mars is required for maintaining an intact mitotic spindle but did not provide a molecular mechanism for this function. Here we show that Mars is able to stabilize the mitotic spindle in vivo. Both in vivo and in vitro data reveal that the N-terminal region of Mars functions in the stabilization of the mitotic spindle by crosslinking adjacent MTs.

  6. The Drosophila microtubule-associated protein mars stabilizes mitotic spindles by crosslinking microtubules through its N-terminal region.

    Zhang, Gang; Beati, Hamze; Nilsson, Jakob; Wodarz, Andreas

    2013-01-01

    Correct segregation of genetic material relies on proper assembly and maintenance of the mitotic spindle. How the highly dynamic microtubules (MTs) are maintained in stable mitotic spindles is a key question to be answered. Motor and non-motor microtubule associated proteins (MAPs) have been reported to stabilize the dynamic spindle through crosslinking adjacent MTs. Mars, a novel MAP, is essential for the early development of Drosophila embryos. Previous studies showed that Mars is required for maintaining an intact mitotic spindle but did not provide a molecular mechanism for this function. Here we show that Mars is able to stabilize the mitotic spindle in vivo. Both in vivo and in vitro data reveal that the N-terminal region of Mars functions in the stabilization of the mitotic spindle by crosslinking adjacent MTs.

  7. Diagnosis and characterization of mania: Quantifying increased energy and activity in the human behavioral pattern monitor

    Perry, William; McIlwain, Meghan; Kloezeman, Karen; Henry, Brook L.; Minassian, Arpi

    2016-01-01

    Increased energy or activity is now an essential feature of the mania of Bipolar Disorder (BD) according to DSM-5. This study examined whether objective measures of increased energy can differentiate manic BD individuals and provide greater diagnostic accuracy compared to rating scales, extending the work of previous studies with smaller samples. We also tested the relationship between objective measures of energy and rating scales. 50 hospitalized manic BD patients were compared to healthy s...

  8. MMS-induced primary aneuploidy and other genotoxic effects in mitotic cells of Aspergillus.

    Käfer, E

    1988-10-01

    The possibility of more than 1 target for genotoxic effects of methyl methanesulphonate (MMS) was investigated, using mitotic test systems of the fungus Aspergillus. Haploid and diploid strains were exposed, either as dormant conidia or during mitosis, and analysed for induced aneuploidy and effects on genetic segregation. MMS treatment of haploid strains resulted in dose-dependent increases of stable mutants with altered phenotypes and semi-stable unbalanced aberrations (presumably duplications). In addition, but only in dividing cells, MMS induced unstable aneuploids. These mostly were hyperhaploid with few extra chromosomes and could be identified by comparison with standard disomic phenotypes. When well-marked diploids were treated 3 types of effect could be distinguished, using genetic and phenotypic criteria: (1) Clastogenic and mutagenic effects which caused dose-dependent increases of partial aneuploids with various abnormal phenotypes. These showed secondary genetic segregation of all types and produced euploid normal sectors by eliminating damaged chromosome segments. In addition, but only in dividing nuclei, MMS induced 2 types of segregation: (2) Reciprocal crossing-over at high frequency, recognisable as half or quarter colonies of mutant colour and in some cases as 'twin spots' (i.e., complementary pairs); (3) Trisomics and other aneuploids which showed characteristic phenotypes and expected segregation of markers: the types recovered indicate random malsegregation of chromosomes (occasional deviations resulted from coincidence with induced crossing-over). These results suggest that MMS may have 2 (or more) targets for genotoxic effects: DNA, as evident from induced mutations and aberrations, and from induced recombination in dividing cells; some non-DNA target (nucleotide or protein) essential for nuclear division and susceptible to alkylation, resulting in malsegregation and primary aneuploidy.

  9. Increased SBPase activity improves photosynthesis and grain yield in wheat grown in greenhouse conditions.

    Driever, Steven M; Simkin, Andrew J; Alotaibi, Saqer; Fisk, Stuart J; Madgwick, Pippa J; Sparks, Caroline A; Jones, Huw D; Lawson, Tracy; Parry, Martin A J; Raines, Christine A

    2017-09-26

    To meet the growing demand for food, substantial improvements in yields are needed. This is particularly the case for wheat, where global yield has stagnated in recent years. Increasing photosynthesis has been identified as a primary target to achieve yield improvements. To increase leaf photosynthesis in wheat, the level of the Calvin-Benson cycle enzyme sedoheptulose-1,7-biphosphatase (SBPase) has been increased through transformation and expression of a Brachypodium distachyon SBPase gene construct. Transgenic lines with increased SBPase protein levels and activity were grown under greenhouse conditions and showed enhanced leaf photosynthesis and increased total biomass and dry seed yield. This showed the potential of improving yield potential by increasing leaf photosynthesis in a crop species such as wheat. The results are discussed with regard to future strategies for further improvement of photosynthesis in wheat.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'. © 2017 The Authors.

  10. Rapid eye movement sleep deprivation induces an increase in acetylcholinesterase activity in discrete rat brain regions

    Benedito M.A.C.

    2001-01-01

    Full Text Available Some upper brainstem cholinergic neurons (pedunculopontine and laterodorsal tegmental nuclei are involved in the generation of rapid eye movement (REM sleep and project rostrally to the thalamus and caudally to the medulla oblongata. A previous report showed that 96 h of REM sleep deprivation in rats induced an increase in the activity of brainstem acetylcholinesterase (Achase, the enzyme which inactivates acetylcholine (Ach in the synaptic cleft. There was no change in the enzyme's activity in the whole brain and cerebrum. The components of the cholinergic synaptic endings (for example, Achase are not uniformly distributed throughout the discrete regions of the brain. In order to detect possible regional changes we measured Achase activity in several discrete rat brain regions (medulla oblongata, pons, thalamus, striatum, hippocampus and cerebral cortex after 96 h of REM sleep deprivation. Naive adult male Wistar rats were deprived of REM sleep using the flower-pot technique, while control rats were left in their home cages. Total, membrane-bound and soluble Achase activities (nmol of thiocholine formed min-1 mg protein-1 were assayed photometrically. The results (mean ± SD obtained showed a statistically significant (Student t-test increase in total Achase activity in the pons (control: 147.8 ± 12.8, REM sleep-deprived: 169.3 ± 17.4, N = 6 for both groups, P<0.025 and thalamus (control: 167.4 ± 29.0, REM sleep-deprived: 191.9 ± 15.4, N = 6 for both groups, P<0.05. Increases in membrane-bound Achase activity in the pons (control: 171.0 ± 14.7, REM sleep-deprived: 189.5 ± 19.5, N = 6 for both groups, P<0.05 and soluble enzyme activity in the medulla oblongata (control: 147.6 ± 16.3, REM sleep-deprived: 163.8 ± 8.3, N = 6 for both groups, P<0.05 were also observed. There were no statistically significant differences in the enzyme's activity in the other brain regions assayed. The present findings show that the increase in Achase activity

  11. Alkalosis and Dialytic Clearance of Phosphate Increases Phosphatase Activity: A Hidden Consequence of Hemodialysis.

    Ricardo Villa-Bellosta

    Full Text Available Extracellular pyrophosphate is a potent endogenous inhibitor of vascular calcification, which is degraded by alkaline phosphatase (ALP and generated by hydrolysis of ATP via ectonucleotide pyrophosphatase/phosphodiesterase 1 (eNPP1. ALP activity (as routinely measured in clinical practice represents the maximal activity (in ideal conditions, but not the real activity (in normal or physiological conditions. For the first time, the present study investigated extracellular pyrophosphate metabolism during hemodialysis sessions (including its synthesis via eNPP1 and its degradation via ALP in physiological conditions.45 patients in hemodialysis were studied. Physiological ALP activity represents only 4-6% of clinical activity. ALP activity increased post-hemodialysis by 2% under ideal conditions (87.4 ± 3.3 IU/L vs. 89.3 ± 3.6 IU/L and 48% under physiological conditions (3.5 ± 0.2 IU/L vs. 5.2 ± 0.2 IU/L. Pyrophosphate synthesis by ATP hydrolysis remained unaltered post-hemodialysis. Post-hemodialysis plasma pH (7.45 ± 0.02 significantly increased compared with the pre-dialysis pH (7.26 ± 0.02. The slight variation in pH (~0.2 units induced a significant increase in ALP activity (9%. Addition of phosphate in post-hemodialysis plasma significantly decreased ALP activity, although this effect was not observed with the addition of urea. Reduction in phosphate levels and increment in pH were significantly associated with an increase in physiological ALP activity post-hemodialysis. A decrease in plasma pyrophosphate levels (3.3 ± 0.3 μmol/L vs. 1.9 ± 0.1 μmol/L and pyrophosphate/ATP ratio (1.9 ± 0.2 vs. 1.4 ± 0.1 post-hemodialysis was also observed.Extraction of uremic toxins, primarily phosphate and hydrogen ions, dramatically increases the ALP activity under physiological conditions. This hitherto unknown consequence of hemodialysis suggests a reinterpretation of the clinical value of this parameter.

  12. Reactive oxygen species mediate TNFR1 increase after TRPV1 activation in mouse DRG neurons

    Westlund Karin N

    2009-06-01

    Full Text Available Abstract Background Transient receptor potential vanilloid subtype 1 (TRPV1 is activated by low pH/protons and is well known to be involved in hyperalgesia during inflammation. Tumor necrosis factor α (TNF-α, a proinflammatory cytokine, is involved in nociceptive responses causing hyperalgesia through TNF receptor type 1 (TNFR1 activation. Reactive oxygen species (ROS production is also prominently increased in inflamed tissue. The present study investigated TNFR1 receptors in primary cultured mouse dorsal root ganglion (DRG neurons after TRPV1 activation and the involvement of ROS. C57BL/6 mice, both TRPV1 knockout and wild type, were used for immunofluorescent and live cell imaging. The L4 and L5 DRGs were dissected bilaterally and cultured overnight. TRPV1 was stimulated with capsaicin or its potent analog, resiniferatoxin. ROS production was measured with live cell imaging and TNFR1 was detected with immunofluorescence in DRG primary cultures. The TRPV1 knockout mice, TRPV1 antagonist, capsazepine, and ROS scavenger, N-tert-Butyl-α-phenylnitrone (PBN, were employed to explore the functional relationship among TRPV1, ROS and TNFR1 in these studies. Results The results demonstrate that TRPV1 activation increases TNFR1 receptors and ROS generation in primary cultures of mouse DRG neurons. Activated increases in TNFR1 receptors and ROS production are absent in TRPV1 deficient mice. The PBN blocks increases in TNFR1 and ROS production induced by capsaicin/resiniferatoxin. Conclusion TRPV1 activation increases TNFR1 in cultured mouse DRG neurons through a ROS signaling pathway, a novel sensitization mechanism in DRG neurons.

  13. Transient Receptor Potential Vanilloid 4 Activation-Induced Increase in Glycine-Activated Current in Mouse Hippocampal Pyramidal Neurons

    Mengwen Qi

    2018-02-01

    Full Text Available Background/Aims: Glycine plays an important role in regulating hippocampal inhibitory/ excitatory neurotransmission through activating glycine receptors (GlyRs and acting as a co-agonist of N-methyl-d-aspartate-type glutamate receptors. Activation of transient receptor potential vanilloid 4 (TRPV4 is reported to inhibit hippocampal A-type γ-aminobutyric acid receptor, a ligand-gated chloride ion channel. GlyRs are also ligand-gated chloride ion channels and this paper aimed to explore whether activation of TRPV4 could modulate GlyRs. Methods: Whole-cell patch clamp recording was employed to record glycine-activated current (IGly and Western blot was conducted to assess GlyRs subunits protein expression. Results: Application of TRPV4 agonist (GSK1016790A or 5,6-EET increased IGly in mouse hippocampal CA1 pyramidal neurons. This action was blocked by specific antagonists of TRPV4 (RN-1734 or HC-067047 and GlyR (strychnine, indicating that activation of TRPV4 increases strychnine-sensitive GlyR function in mouse hippocampal pyramidal neurons. GSK1016790A-induced increase in IGly was significantly attenuated by protein kinase C (PKC (BIM II or D-sphingosine or calcium/calmodulin-dependent protein kinase II (CaMKII (KN-62 or KN-93 antagonists but was unaffected by protein kinase A or protein tyrosine kinase antagonists. Finally, hippocampal protein levels of GlyR α1 α2, α3 and β subunits were not changed by treatment with GSK1016790A for 30 min or 1 h, but GlyR α2, α3 and β subunits protein levels increased in mice that were intracerebroventricularly (icv. injected with GSK1016790A for 5 d. Conclusion: Activation of TRPV4 increases GlyR function and expression, and PKC and CaMKII signaling pathways are involved in TRPV4 activation-induced increase in IGly. This study indicates that GlyRs may be effective targets for TRPV4-induced modulation of hippocampal inhibitory neurotransmission.

  14. Exogenous Methyl Jasmonate Treatment Increases Glucosinolate Biosynthesis and Quinone Reductase Activity in Kale Leaf Tissue

    Ku, Kang-Mo; Jeffery, Elizabeth H.; Juvik, John A.

    2014-01-01

    Methyl jasmonate (MeJA) spray treatments were applied to the kale varieties ‘Dwarf Blue Curled Vates’ and ‘Red Winter’ in replicated field plantings in 2010 and 2011 to investigate alteration of glucosinolate (GS) composition in harvested leaf tissue. Aqueous solutions of 250 µM MeJA were sprayed to saturation on aerial plant tissues four days prior to harvest at commercial maturity. The MeJA treatment significantly increased gluconasturtiin (56%), glucobrassicin (98%), and neoglucobrassicin (150%) concentrations in the apical leaf tissue of these genotypes over two seasons. Induction of quinone reductase (QR) activity, a biomarker for anti-carcinogenesis, was significantly increased by the extracts from the leaf tissue of these two cultivars. Extracts of apical leaf tissues had greater MeJA mediated increases in phenolics, glucosinolate concentrations, GS hydrolysis products, and QR activity than extracts from basal leaf tissue samples. The concentration of the hydrolysis product of glucoraphanin, sulforphane was significantly increased in apical leaf tissue of the cultivar ‘Red Winter’ in both 2010 and 2011. There was interaction between exogenous MeJA treatment and environmental conditions to induce endogenous JA. Correlation analysis revealed that indole-3-carbanol (I3C) generated from the hydrolysis of glucobrassicin significantly correlated with QR activity (r = 0.800, Pkale leaf tissues of both cultivars in 2011. Correlation analysis of these results indicated that sulforaphane, NI3C, neoascorbigen, I3C, and diindolylmethane were all significantly correlated with QR activity. Thus, increased QR activity may be due to combined increases in phenolics (quercetin and kaempferol) and GS hydrolysis product concentrations rather than by individual products alone. PMID:25084454

  15. Induction of mitotic recombination by UV and diepoxybutane and its enhancement by hydroxyurea in Saccharomyces cerevisae

    Zaborowska, D.; Swietlinska, Z.; Zuk, J. (Polska Akademia Nauk, Warsaw. Inst. Biochemii i Biofizyki)

    1983-04-01

    Mitotic inter- and intra-genic recombination was induced by UV-irradiation and treatment with diepoxybutane (DEB) in 2 heteroallelic diploid strains of Saccharomyces cerevisiae SBTD and D7. Induction of the events tested was strongly potentiated by plating of mutagen-treated cells on growth media containing 0.03 M hydroxyurea (HU).

  16. Frequencies of mutagen-induced coincident mitotic recombination at unlinked loci in Saccharomyces cerevisiae

    Freeman, Kathryn M. [Department of Biology, College of the Holy Cross, One College Street, Worcester, MA 01610-2395 (United States); Hoffmann, George R. [Department of Biology, College of the Holy Cross, One College Street, Worcester, MA 01610-2395 (United States)]. E-mail: ghoffmann@holycross.edu

    2007-03-01

    Frequencies of coincident genetic events were measured in strain D7 of Saccharomyces cerevisiae. This diploid strain permits the detection of mitotic gene conversion involving the trp5-12 and trp5-27 alleles, mitotic crossing-over and gene conversion leading to the expression of the ade2-40 and ade2-119 alleles as red and pink colonies, and reversion of the ilv1-92 allele. The three genes are on different chromosomes, and one might expect that coincident (simultaneous) genetic alterations at two loci would occur at frequencies predicted by those of the single alterations acting as independent events. Contrary to this expectation, we observed that ade2 recombinants induced by bleomycin, {beta}-propiolactone, and ultraviolet radiation occur more frequently among trp5 convertants than among total colonies. This excess among trp5 recombinants indicates that double recombinants are more common than expected for independent events. No similar enrichment was found among Ilv{sup +} revertants. The possibility of an artifact in which haploid yeasts that mimic mitotic recombinants are generated by a low frequency of cryptic meiosis has been excluded. Several hypotheses that can explain the elevated incidence of coincident mitotic recombination have been evaluated, but the cause remains uncertain. Most evidence suggests that the excess is ascribable to a subset of the population being in a recombination-prone state.

  17. Prediction of X-ray induced mitotic delay and recovery of G2 cells

    Easton, D.M.; Schneiderman, M.H.

    1987-01-01

    A mathematical model is presented that predicts the delay of mitosis caused by X-irradiation of an asynchronous, exponentially growing cell culture. In the model, based on Gompertz kinetics, the driving function to generate the curves is a simple exponential decay expression. For the delayed mitotic progress curves, this function characterizes the distribution of the time required for cells to enter mitosis. (author)

  18. Discrimination of bromodeoxyuridine labelled and unlabelled mitotic cells in flow cytometric bromodeoxyuridine/DNA analysis

    Jensen, P O; Larsen, J K; Christensen, I J

    1994-01-01

    Bromodeoxyuridine (BrdUrd) labelled and unlabelled mitotic cells, respectively, can be discriminated from interphase cells using a new method, based on immunocytochemical staining of BrdUrd and flow cytometric four-parameter analysis of DNA content, BrdUrd incorporation, and forward and orthogona...

  19. Cell cycle-dependent SUMO-1 conjugation to nuclear mitotic apparatus protein (NuMA)

    Seo, Jae Sung; Kim, Ha Na; Kim, Sun-Jick; Bang, Jiyoung; Kim, Eun-A; Sung, Ki Sa [Department of Biological Sciences, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Yoon, Hyun-Joo [TissueGene Inc. 9605 Medical Center Dr., Rockville, MD 20850 (United States); Yoo, Hae Yong [Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Samsung Medical Center, Sungkyunkwan University, Seoul 135-710 (Korea, Republic of); Choi, Cheol Yong, E-mail: choicy@skku.ac.kr [Department of Biological Sciences, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-01-03

    Highlights: •NuMA is modified by SUMO-1 in a cell cycle-dependent manner. •NuMA lysine 1766 is the primary target site for SUMOylation. •SUMOylation-deficient NuMA induces multiple spindle poles during mitosis. •SUMOylated NuMA induces microtubule bundling. -- Abstract: Covalent conjugation of proteins with small ubiquitin-like modifier 1 (SUMO-1) plays a critical role in a variety of cellular functions including cell cycle control, replication, and transcriptional regulation. Nuclear mitotic apparatus protein (NuMA) localizes to spindle poles during mitosis, and is an essential component in the formation and maintenance of mitotic spindle poles. Here we show that NuMA is a target for covalent conjugation to SUMO-1. We find that the lysine 1766 residue is the primary NuMA acceptor site for SUMO-1 conjugation. Interestingly, SUMO modification of endogenous NuMA occurs at the entry into mitosis and this modification is reversed after exiting from mitosis. Knockdown of Ubc9 or forced expression of SENP1 results in impairment of the localization of NuMA to mitotic spindle poles during mitosis. The SUMOylation-deficient NuMA mutant is defective in microtubule bundling, and multiple spindles are induced during mitosis. The mitosis-dependent dynamic SUMO-1 modification of NuMA might contribute to NuMA-mediated formation and maintenance of mitotic spindle poles during mitosis.

  20. Mitotic phosphorylation of VCIP135 blocks p97ATPase-mediated Golgi membrane fusion

    Totsukawa, Go; Matsuo, Ayaka; Kubota, Ayano; Taguchi, Yuya; Kondo, Hisao, E-mail: hk228@med.kyushu-u.ac.jp

    2013-04-05

    Highlights: •VCIP135 is mitotically phosphorylated on Threonine-760 and Serine-767 by Cdc2. •Phosphorylated VCIP135 does not bind to p97ATPase. •The phosphorylation of VCIP135 inhibits p97ATPase-mediated Golgi membrane fusion. -- Abstract: In mammals, the Golgi apparatus is disassembled early mitosis and reassembled at the end of mitosis. For Golgi disassembly, membrane fusion needs to be blocked. Golgi biogenesis requires two distinct p97ATPase-mediated membrane fusion, the p97/p47 and p97/p37 pathways. We previously reported that p47 phosphorylation on Serine-140 and p37 phosphorylation on Serine-56 and Threonine-59 result in mitotic inhibition of the p97/p47 and the p97/p37 pathways, respectively [11,14]. In this study, we show another mechanism of mitotic inhibition of p97-mediated Golgi membrane fusion. We clarified that VCIP135, an essential factor in both p97 membrane fusion pathways, is phosphorylated on Threonine-760 and Serine-767 by Cdc2 at mitosis and that this phosphorylated VCIP135 does not bind to p97. An in vitro Golgi reassembly assay revealed that VCIP135(T760E, S767E), which mimics mitotic phosphorylation, caused no cisternal regrowth. Our results indicate that the phosphorylation of VCIP135 on Threonine-760 and Serine-767 inhibits p97-mediated Golgi membrane fusion at mitosis.

  1. Frequencies of mutagen-induced coincident mitotic recombination at unlinked loci in Saccharomyces cerevisiae

    Freeman, Kathryn M.; Hoffmann, George R.

    2007-01-01

    Frequencies of coincident genetic events were measured in strain D7 of Saccharomyces cerevisiae. This diploid strain permits the detection of mitotic gene conversion involving the trp5-12 and trp5-27 alleles, mitotic crossing-over and gene conversion leading to the expression of the ade2-40 and ade2-119 alleles as red and pink colonies, and reversion of the ilv1-92 allele. The three genes are on different chromosomes, and one might expect that coincident (simultaneous) genetic alterations at two loci would occur at frequencies predicted by those of the single alterations acting as independent events. Contrary to this expectation, we observed that ade2 recombinants induced by bleomycin, β-propiolactone, and ultraviolet radiation occur more frequently among trp5 convertants than among total colonies. This excess among trp5 recombinants indicates that double recombinants are more common than expected for independent events. No similar enrichment was found among Ilv + revertants. The possibility of an artifact in which haploid yeasts that mimic mitotic recombinants are generated by a low frequency of cryptic meiosis has been excluded. Several hypotheses that can explain the elevated incidence of coincident mitotic recombination have been evaluated, but the cause remains uncertain. Most evidence suggests that the excess is ascribable to a subset of the population being in a recombination-prone state

  2. Induction of mitotic recombination by UV and diepoxybutane and its enhancement by hydroxyurea in Saccharomyces cerevisae

    Zaborowska, D.; Swietlinska, Z.; Zuk, J.

    1983-01-01

    Mitotic inter- and intra-genic recombination was induced by UV-irradiation and treatment with diepoxybutane (DEB) in 2 heteroallelic diploid strains of Saccharomyces cerevisiae SBTD and D7. Induction of the events tested was strongly potentiated by plating of mutagen-treated cells on growth media containing 0.03 M hydroxyurea (HU). (orig.)

  3. Nandrolone reduces activation of Notch signaling in denervated muscle associated with increased Numb expression

    Liu, Xin-Hua; Yao, Shen; Qiao, Rui-Fang; Levine, Alice C.; Kirschenbaum, Alexander; Pan, Jiangping; Wu, Yong; Qin, Weiping; Bauman, William A.; Cardozo, Christopher P.

    2011-01-01

    Highlights: → Nerve transection increased Notch signaling in paralyzed muscle. → Nandrolone prevented denervation-induced Notch signaling. → Nandrolone induced the expression of an inhibitor of the Notch signaling, Numb. → Reduction of denervation-induced Notch signaling by nandrolone is likely through upregulation of Numb. -- Abstract: Nandrolone, an anabolic steroid, slows denervation-atrophy in rat muscle. The molecular mechanisms responsible for this effect are not well understood. Androgens and anabolic steroids activate Notch signaling in animal models of aging and thereby mitigate sarcopenia. To explore the molecular mechanisms by which nandrolone prevents denervation-atrophy, we investigated the effects of nandrolone on Notch signaling in denervated rat gastrocnemius muscle. Denervation significantly increased Notch activity reflected by elevated levels of nuclear Notch intracellular domain (NICD) and expression of Hey1 (a Notch target gene). Activation was greatest at 7 and 35 days after denervation but remained present at 56 days after denervation. Activation of Notch in denervated muscle was prevented by nandrolone associated with upregulated expression of Numb mRNA and protein. These data demonstrate that denervation activates Notch signaling, and that nandrolone abrogates this response associated with increased expression of Numb, suggesting a potential mechanism by which nandrolone reduces denervation-atrophy.

  4. Nandrolone reduces activation of Notch signaling in denervated muscle associated with increased Numb expression

    Liu, Xin-Hua [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Yao, Shen; Qiao, Rui-Fang; Levine, Alice C. [Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Kirschenbaum, Alexander [Department of Urology, Mount Sinai School of Medicine, New York, NY 10029 (United States); Pan, Jiangping; Wu, Yong [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Qin, Weiping [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Bauman, William A. [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Rehabilitation Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Cardozo, Christopher P., E-mail: chris.cardozo@mssm.edu [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Rehabilitation Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States)

    2011-10-14

    Highlights: {yields} Nerve transection increased Notch signaling in paralyzed muscle. {yields} Nandrolone prevented denervation-induced Notch signaling. {yields} Nandrolone induced the expression of an inhibitor of the Notch signaling, Numb. {yields} Reduction of denervation-induced Notch signaling by nandrolone is likely through upregulation of Numb. -- Abstract: Nandrolone, an anabolic steroid, slows denervation-atrophy in rat muscle. The molecular mechanisms responsible for this effect are not well understood. Androgens and anabolic steroids activate Notch signaling in animal models of aging and thereby mitigate sarcopenia. To explore the molecular mechanisms by which nandrolone prevents denervation-atrophy, we investigated the effects of nandrolone on Notch signaling in denervated rat gastrocnemius muscle. Denervation significantly increased Notch activity reflected by elevated levels of nuclear Notch intracellular domain (NICD) and expression of Hey1 (a Notch target gene). Activation was greatest at 7 and 35 days after denervation but remained present at 56 days after denervation. Activation of Notch in denervated muscle was prevented by nandrolone associated with upregulated expression of Numb mRNA and protein. These data demonstrate that denervation activates Notch signaling, and that nandrolone abrogates this response associated with increased expression of Numb, suggesting a potential mechanism by which nandrolone reduces denervation-atrophy.

  5. Acute administration of fenproporex increased acetylcholinesterase activity in brain of young rats.

    Teodorak, Brena P; Ferreira, Gabriela K; Scaini, Giselli; Wessler, Letícia B; Heylmann, Alexandra S; Deroza, Pedro; Valvassori, Samira S; Zugno, Alexandra I; Quevedo, João; Streck, Emilio L

    2015-08-01

    Fenproporex is the second most commonly amphetamine-based anorectic consumed worldwide; this drug is rapidly converted into amphetamine, in vivo, and acts by increasing dopamine levels in the synaptic cleft. Considering that fenproporex effects on the central nervous system are still poorly known and that acetylcholinesterase is a regulatory enzyme which is involved in cholinergic synapses and may indirectly modulate the release of dopamine, the present study investigated the effects of acute administration of fenproporex on acetylcholinesterase activity in brain of young rats. Young male Wistar rats received a single injection of fenproporex (6.25, 12.5 or 25mg/kg i.p.) or vehicle (2% Tween 80). Two hours after the injection, the rats were killed by decapitation and the brain was removed for evaluation of acetylcholinesterase activity. Results showed that fenproporex administration increased acetylcholinesterase activity in the hippocampus and posterior cortex, whereas in the prefrontal cortex, striatum and cerebellum the enzyme activity was not altered. In conclusion, in the present study we demonstrated that acute administration of fenproporex exerts an effect in the cholinergic system causing an increase in the activity of acetylcholinesterase in a dose-dependent manner in the hippocampus and posterior cortex. Thus, we suggest that the imbalance in cholinergic homeostasis could be considered as an important pathophysiological mechanism underlying the brain damage observed in patients who use amphetamines such as fenproporex.

  6. Acute administration of fenproporex increased acetylcholinesterase activity in brain of young rats

    BRENA P. TEODORAK

    2015-08-01

    Full Text Available Fenproporex is the second most commonly amphetamine-based anorectic consumed worldwide; this drug is rapidly converted into amphetamine, in vivo, and acts by increasing dopamine levels in the synaptic cleft. Considering that fenproporex effects on the central nervous system are still poorly known and that acetylcholinesterase is a regulatory enzyme which is involved in cholinergic synapses and may indirectly modulate the release of dopamine, the present study investigated the effects of acute administration of fenproporex on acetylcholinesterase activity in brain of young rats. Young male Wistar rats received a single injection of fenproporex (6.25, 12.5 or 25mg/kg i.p. or vehicle (2% Tween 80. Two hours after the injection, the rats were killed by decapitation and the brain was removed for evaluation of acetylcholinesterase activity. Results showed that fenproporex administration increased acetylcholinesterase activity in the hippocampus and posterior cortex, whereas in the prefrontal cortex, striatum and cerebellum the enzyme activity was not altered. In conclusion, in the present study we demonstrated that acute administration of fenproporex exerts an effect in the cholinergic system causing an increase in the activity of acetylcholinesterase in a dose-dependent manner in the hippocampus and posterior cortex. Thus, we suggest that the imbalance in cholinergic homeostasis could be considered as an important pathophysiological mechanism underlying the brain damage observed in patients who use amphetamines such as fenproporex.

  7. rTMS Induced Tinnitus Relief Is Related to an Increase in Auditory Cortical Alpha Activity

    Müller, Nadia; Lorenz, Isabel; Langguth, Berthold; Weisz, Nathan

    2013-01-01

    Chronic tinnitus, the continuous perception of a phantom sound, is a highly prevalent audiological symptom. A promising approach for the treatment of tinnitus is repetitive transcranial magnetic stimulation (rTMS) as this directly affects tinnitus-related brain activity. Several studies indeed show tinnitus relief after rTMS, however effects are moderate and vary strongly across patients. This may be due to a lack of knowledge regarding how rTMS affects oscillatory activity in tinnitus sufferers and which modulations are associated with tinnitus relief. In the present study we examined the effects of five different stimulation protocols (including sham) by measuring tinnitus loudness and tinnitus-related brain activity with Magnetoencephalography before and after rTMS. Changes in oscillatory activity were analysed for the stimulated auditory cortex as well as for the entire brain regarding certain frequency bands of interest (delta, theta, alpha, gamma). In line with the literature the effects of rTMS on tinnitus loudness varied strongly across patients. This variability was also reflected in the rTMS effects on oscillatory activity. Importantly, strong reductions in tinnitus loudness were associated with increases in alpha power in the stimulated auditory cortex, while an unspecific decrease in gamma and alpha power, particularly in left frontal regions, was linked to an increase in tinnitus loudness. The identification of alpha power increase as main correlate for tinnitus reduction sheds further light on the pathophysiology of tinnitus. This will hopefully stimulate the development of more effective therapy approaches. PMID:23390539

  8. Premitotic assembly of human CENPs -T and -W switches centromeric chromatin to a mitotic state.

    Lisa Prendergast

    2011-06-01

    Full Text Available Centromeres are differentiated chromatin domains, present once per chromosome, that direct segregation of the genome in mitosis and meiosis by specifying assembly of the kinetochore. They are distinct genetic loci in that their identity in most organisms is determined not by the DNA sequences they are associated with, but through specific chromatin composition and context. The core nucleosomal protein CENP-A/cenH3 plays a primary role in centromere determination in all species and directs assembly of a large complex of associated proteins in vertebrates. While CENP-A itself is stably transmitted from one generation to the next, the nature of the template for centromere replication and its relationship to kinetochore function are as yet poorly understood. Here, we investigate the assembly and inheritance of a histone fold complex of the centromere, the CENP-T/W complex, which is integrated with centromeric chromatin in association with canonical histone H3 nucleosomes. We have investigated the cell cycle regulation, timing of assembly, generational persistence, and requirement for function of CENPs -T and -W in the cell cycle in human cells. The CENP-T/W complex assembles through a dynamic exchange mechanism in late S-phase and G2, is required for mitosis in each cell cycle and does not persist across cell generations, properties reciprocal to those measured for CENP-A. We propose that the CENP-A and H3-CENP-T/W nucleosome components of the centromere are specialized for centromeric and kinetochore activities, respectively. Segregation of the assembly mechanisms for the two allows the cell to switch between chromatin configurations that reciprocally support the replication of the centromere and its conversion to a mitotic state on postreplicative chromatin.

  9. Alpha-Amylase Activity in Blood Increases after Pharmacological, But Not Psychological, Activation of the Adrenergic System.

    Urs M Nater

    Full Text Available Alpha-amylase in both blood and saliva has been used as a diagnostic parameter. While studies examining alpha-amylase activity in saliva have shown that it is sensitive to physiological and psychological challenge of the adrenergic system, no challenge studies have attempted to elucidate the role of the adrenergic system in alpha-amylase activity in blood. We set out to examine the impact of psychological and pharmacological challenge on alpha-amylase in blood in two separate studies.In study 1, healthy subjects were examined in a placebo-controlled, double-blind paradigm using yohimbine, an alpha2-adrenergic antagonist. In study 2, subjects were examined in a standardized rest-controlled psychosocial stress protocol. Alpha-amylase activity in blood was repeatedly measured in both studies.Results of study 1 showed that alpha-amylase in blood is subject to stronger increases after injection of yohimbine compared to placebo. In study 2, results showed that there was no significant effect of psychological stress compared to rest.Alpha-amylase in blood increases after pharmacological activation of the adrenergic pathways suggesting that sympathetic receptors are responsible for these changes. Psychological stress, however, does not seem to have an impact on alpha-amylase in blood. Our findings provide insight into the mechanisms underlying activity changes in alpha-amylase in blood in healthy individuals.

  10. Decreasing Sports Activity with Increasing Age? Findings from a 20-Year Longitudinal and Cohort Sequence Analysis

    Breuer, Christoph; Wicker, Pamela

    2009-01-01

    According to cross-sectional studies in sport science literature, decreasing sports activity with increasing age is generally assumed. In this paper, the validity of this assumption is checked by applying more effective methods of analysis, such as longitudinal and cohort sequence analyses. With the help of 20 years' worth of data records from the…

  11. Increase in Operator's Sympathetic Nerve Activity during Complicated Hepatobiliary Surgery: Evidence for Surgeons' Mental Stress.

    Yamanouchi, Kosho; Hayashida, Naomi; Kuba, Sayaka; Sakimura, Chika; Kuroki, Tamotsu; Togo, Michita; Katayama, Noritada; Takamura, Noboru; Eguchi, Susumu

    2015-11-01

    Surgeons often experience stress during operations. The heart rate variability (HRV) is the variability in the beat-to-beat interval, which has been used as parameters of stress. The purpose of this study was to evaluate mental stress of surgeons before, during and after operations, especially during pancreaticoduodenectomy (PD) and living donor liver transplantation (LDLT). Additionally, the parameters were compared in various procedures during the operations. By frequency domain method using electrocardiograph, we measured the high frequency (HF) component, representing the parasympathetic activity, and the low frequency (LF)/HF ratio, representing the sympathetic activity. In all 5 cases of PD, the surgeon showed significantly lower HF component and higher LF/HF during operation, indicating predominance of sympathetic nervous system and increased stress, than those before the operation (p operation. Out of the 4 LDLT cases, the value of HF was decreased in two and the LF/HF increased in three cases (p operation compared to those before the operation. In all cases, the value of HF was decreased and/or the LF/HF increased significantly during the reconstruction of the vessels or bile ducts than during the removal of the liver. Thus, sympathetic nerve activity increased during hepatobiliary surgery compared with the level before the operation, and various procedures during the operations induced diverse changes in the autonomic nervous activities. The HRV analysis could assess the chronological changes of mental stress by measuring the autonomic nervous balances.

  12. Increase in natural killer cell activity during diethylcarbamazine treatment of patients with filariasis

    Pedersen, B K; Bygbjerg, Ib Christian; Svenson, M

    1987-01-01

    Two patients, one with Bancroftian filariasis and the other with onchocerciasis, and two healthy controls were treated with diethylcarbamazine (DEC). The natural killer (NK) cell activity of the two patients increased during DEC treatment to 2.5 and 2.8 times, respectively, while that of the cont...

  13. Effects of increasing use of trifluralin and glyphosate on the microbial activity of a lea soil

    Barros, Edna Santos de; Monteiro, Regina Teresa Rosim; Peixoto, Maria de Fatima da Silva Pinto; Fay, Elizabeth Francisconi

    1997-01-01

    This work considers the importance of the glyphosate and trifluralin, which are the most used herbicides by the brazilian plantations, applying approximately fifteen and nine millions of liters by crop, respectively, for the evaluation of the increasing use of these herbicides effects on the microbial activity of a lea soil which are used for beans cultivation

  14. Increasing physical activity in patients with mental illness--A randomized controlled trial.

    Göhner, Wiebke; Dietsche, Christine; Fuchs, Reinhard

    2015-11-01

    The objective of the study was to evaluate whether a motivational-volitional intervention program offered in addition to an existing sport program during stationary treatment is capable of establishing a post-stationary increase in physical activity in persons with mental illness. N=112 in-patients were initially randomly assigned to the control group (CG; standard rehabilitation) or intervention group (IG; standard rehabilitation plus intervention). Assessments were conducted at four measurement points. At 6 months follow up, the level of exercise in the IG was 95 min/week higher than in the CG (p=.02). The participants of the IG were able to increase their level of goal intention until 6 months follow up (t2: p=.03; t4: p=.005); levels of self-efficacy of the IG increased during intervention (t2: p=.001). Changes in volitional aspects were significant over time (t1-t3), but not specifically for the IG. The intervention was effective at increasing the level of physical activity in patients with mental illness who were initially minimally active. Our results suggest that it could be of great use to place the emphasis of a physical activity-enhancing intervention on its motivational effect since volitional aspects are already taken into sufficient account in standard rehabilitation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Reduced Response to Activated Protein C Is Associated with Increased Risk for Cerebrovascular Disease

    Bom, J.G. van der; Bots, M.L.; Haverkate, F.; Slagboom, P.E.; Meijer, P.; Jong, P.T.V.M. de; Hofman, A.; Grobbee, D.E.; Kluft, C.

    1996-01-01

    Background: Resistance to activated protein C (APC), which results from various factors, including a mutation in the gene for coagulant factor V, has been associated with increased risk for venous thrombosis. However, its relation to arterial disease is still not well defined. Objective: To

  16. 75 FR 64348 - BOEMRE Information Collection Activity: 1010-0182, Increased Safety Measures for Energy...

    2010-10-19

    ... No. BOEM-2010-0052] BOEMRE Information Collection Activity: 1010-0182, Increased Safety Measures for... the likelihood of blowouts, loss of well control, fires, spillages, physical obstruction to other... subsequent oil spill in the Gulf of Mexico. These events highlight the importance of ensuring safe operations...

  17. Developmental Vitamin D (DVD) Deficiency Reduces Nurr1 and TH Expression in Post-mitotic Dopamine Neurons in Rat Mesencephalon.

    Luan, Wei; Hammond, Luke Alexander; Cotter, Edmund; Osborne, Geoffrey William; Alexander, Suzanne Adele; Nink, Virginia; Cui, Xiaoying; Eyles, Darryl Walter

    2018-03-01

    Developmental vitamin D (DVD) deficiency has been proposed as an important risk factor for schizophrenia. Our previous study using Sprague Dawley rats found that DVD deficiency disrupted the ontogeny of mesencephalic dopamine neurons by decreasing the mRNA level of a crucial differentiation factor of dopamine cells, the nuclear receptor related 1 protein (Nurr1). However, it remains unknown whether this reflects a reduction in dopamine cell number or in Nurr1 expression. It is also unclear if any particular subset of developing dopamine neurons in the mesencephalon is selectively affected. In this study, we employed state-of-the-art spinning disk confocal microscopy optimized for the imaging of tissue sections and 3D segmentation to assess post-mitotic dopamine cells on a single-cell basis in the rat mesencephalon at embryonic day 15. Our results showed that DVD deficiency did not alter the number, morphology, or positioning of post-mitotic dopamine cells. However, the ratio of Nurr1+TH+ cells in the substantia nigra pars compacta (SNc) compared with the ventral tegmental area (VTA) was increased in DVD-deficient embryos. In addition, the expression of Nurr1 in immature dopamine cells and mature dopamine neurons in the VTA was decreased in DVD-deficient group. Tyrosine hydroxylase was selectively reduced in SNc of DVD-deficient mesencephalon. We conclude that DVD deficiency induced early alterations in mesencephalic dopamine development may in part explain the abnormal dopamine-related behaviors found in this model. Our findings may have broader implications for how certain environmental risk factors for schizophrenia may shape the ontogeny of dopaminergic systems and by inference increase the risk of schizophrenia.

  18. Increased Granulocyte Heparanase Activity in Neutrophils from Patients with Lupus Nephritis and Idiopathic Membranous Nephropathy.

    Szymczak, Maciej; Kuźniar, Jakub; Kopeć, Wacław; Żabińska, Marcelina; Marchewka, Zofia; Kościelska-Kasprzak, Katarzyna; Klinger, Marian

    2017-02-01

    Heparanase is a β-glucuronidase that cleaves sugar chains of heparan sulfate proteoglycans. It is believed that heparanase may be involved in the pathogenesis of proteinuria. The aim of this study was to assess the significance of heparanase in the pathogenesis of particular glomerulonephritis types. The evaluation of heparanase activity in serum, urine, and granulocytes and superoxide dismutase (SOD) activity in granulocytes of patients with lupus nephritis (n = 17), membranous nephropathy (n = 11), IgA nephropathy (n = 12), focal and segmental glomerulosclerosis (n = 18), mesangiocapillary glomerulonephritis (n = 12) and in 19 healthy volunteers were performed. The heparanase activity in granulocytes of patients with lupus nephritis and membranous nephropathy was higher than heparanase activity in granulocytes in the control group (p = 0.02 in both cases). This is the first observation of this phenomenon. There was no difference between SOD activity in granulocytes of patients with all assessed types of glomerulonephritis and the control group. A positive correlation between heparanase activity in urine and double-strain DNA antibodies (r = 0.51; p = 0.04), and reverse correlations between heparanase in urine and hemolytic activity of the complement (r = -0.57; p = 0.03) in the lupus nephritis group, and between heparanase activity in granulocytes and serum total protein level (r = -0.69; p = 0.02) in membranous nephropathy were observed. Increase in heparanase activity without changes in superoxide dismutase activity in the granulocytes from patients with lupus nephritis and membranous nephropathy was observed. It may be used as one of the markers of these disease activities.

  19. Anti-mitotic potential of 7-diethylamino-3(2′-benzoxazolyl)-coumarin in 5-fluorouracil-resistant human gastric cancer cell line SNU620/5-FU

    Kim, Nam Hyun; Kim, Su-Nam; Oh, Joa Sub; Lee, Seokjoon; Kim, Yong Kee

    2012-01-01

    Highlights: ► DBC exerts antiproliferative potential against 5FU-resistant human gastric cancer cells. ► This effect is mediated by destabilization of microtubules and subsequent mitotic arrest. ► DBC enhances apoptosis via caspase activation and downregulation of antiapoptotic genes. -- Abstract: In this study, we investigate an anti-mitotic potential of the novel synthetic coumarin-based compound, 7-diethylamino-3(2′-benzoxazolyl)-coumarin, in 5-fluorouracil-resistant human gastric cancer cell line SNU-620-5FU and its parental cell SNU-620. It exerts the anti-proliferative effects with similar potencies against both cancer cells, which is mediated by destabilization of microtubules and subsequent mitotic arrest. Furthermore, this compound enhances caspase-dependent apoptotic cell death via decreased expression of anti-apoptotic genes. Taken together, our data strongly support anti-mitotic potential of 7-diethylamino-3(2′-benzoxazolyl)-coumarin against drug-resistant cancer cells which will prompt us to further develop as a novel microtubule inhibitor for drug-resistant cancer chemotherapy.

  20. Increased Arf/p53 activity in stem cells, aging and cancer.

    Carrasco-Garcia, Estefania; Moreno, Manuel; Moreno-Cugnon, Leire; Matheu, Ander

    2017-04-01

    Arf/p53 pathway protects the cells against DNA damage induced by acute stress. This characteristic is the responsible for its tumor suppressor activity. Moreover, it regulates the chronic type of stress associated with aging. This is the basis of its anti-aging activity. Indeed, increased gene dosage of Arf/p53 displays elongated longevity and delayed aging. At a cellular level, it has been recently shown that increased dosage of Arf/p53 delays age-associated stem cell exhaustion and the subsequent decline in tissue homeostasis and regeneration. However, p53 can also promote aging if constitutively activated. In this context, p53 reduces tissue regeneration, which correlates with premature exhaustion of stem cells. We discuss here the current evidence linking the Arf/p53 pathway to the processes of aging and cancer through stem cell regulation. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.