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Sample records for increased cdk4 activity

  1. Regulation of cyclin D-dependent kinase 4 (cdk4) by cdk4-activating kinase.

    PubMed Central

    Kato, J Y; Matsuoka, M; Strom, D K; Sherr, C J

    1994-01-01

    The accumulation of assembled holoenzymes composed of regulatory D-type cyclins and their catalytic partner, cyclin-dependent kinase 4 (cdk4), is rate limiting for progression through the G1 phase of the cell cycle in mammalian fibroblasts. Both the synthesis and assembly of D-type cyclins and cdk4 depend upon serum stimulation, but even when both subunits are ectopically overproduced, they do not assemble into complexes in serum-deprived cells. When coexpressed from baculoviral vectors in intact Sf9 insect cells, cdk4 assembles with D-type cyclins to form active protein kinases. In contrast, recombinant D-type cyclin and cdk4 subunits produced in insect cells or in bacteria do not assemble as efficiently into functional holoenzymes when combined in vitro but can be activated in the presence of lysates obtained from proliferating mammalian cells. Assembly of cyclin D-cdk4 complexes in coinfected Sf9 cells facilitates phosphorylation of cdk4 on threonine 172 by a cdk-activating kinase (CAK). Assembly can proceed in the absence of this modification, but cdk4 mutants which cannot be phosphorylated by CAK remain catalytically inactive. Therefore, formation of the cyclin D-cdk4 complex and phosphorylation of the bound catalytic subunit are independently regulated, and in addition to the requirement for CAK activity, serum stimulation is required to promote assembly of the complexes in mammalian cells. Images PMID:8139570

  2. Inactivation of TGF-{beta} signaling in lung cancer results in increased CDK4 activity that can be rescued by ELF

    SciTech Connect

    Baek, Hye Jung; Kim, Sang Soo; Silva, Fabio May da; Volpe, Eugene A.; Evans, Stephen; Mishra, Bibhuti; Mishra, Lopa . E-mail: lopamishra@yahoo.com; Blair Marshall, M. . E-mail: mbm5@gunet.georgetown.edu

    2006-08-11

    Escape from TGF-{beta} inhibition of proliferation is a hallmark of multiple cancers including lung cancer. We explored the role of ELF, crucial TGF-{beta} adaptor protein identified from endodermal progenitor cells, in lung carcinogenesis and cell-cycle regulation. Interestingly, elf {sup -/-} mice develop multiple defects that include lung, liver, and cardiac abnormalities. Four out of 6 lung cancer and mesothelioma cell lines displayed deficiency of ELF expression with increased CDK4 expression. Immunohistochemistry and Western blot analysis of primary human lung cancers also showed decreased ELF expression and overexpression of CDK4. Moreover, rescue of ELF in ELF-deficient cell lines decreased the expression of CDK4 and resulted in accumulation of G1/S checkpoint arrested cells. These results suggest that disruption in TGF-{beta} signaling mediated by loss of ELF in lung cancer leads to cell-cycle deregulation by modulating CDK4 and ELF highlights a key role of TGF-{beta} adaptor protein in suppressing early lung cancer.

  3. Fluorescent peptide biosensor for monitoring CDK4/cyclin D kinase activity in melanoma cell extracts, mouse xenografts and skin biopsies.

    PubMed

    Prével, Camille; Pellerano, Morgan; González-Vera, Juan A; Henri, Pauline; Meunier, Laurent; Vollaire, Julien; Josserand, Véronique; Morris, May C

    2016-11-15

    Melanoma constitutes the most aggressive form of skin cancer, which further metastasizes into a deadly form of cancer. The p16(INK4a)-Cyclin D-CDK4/6-pRb pathway is dysregulated in 90% of melanomas. CDK4/Cyclin D kinase hyperactivation, associated with mutation of CDK4, amplification of Cyclin D or loss of p16(INK4a) leads to increased risk of developing melanoma. This kinase therefore constitutes a key biomarker in melanoma and an emerging pharmacological target, however there are no tools enabling direct detection or quantification of its activity. Here we report on the design and application of a fluorescent peptide biosensor to quantify CDK4 activity in melanoma cell extracts, skin biopsies and melanoma xenografts. This biosensor provides sensitive means of comparing CDK4 activity between different melanoma cell lines and further responds to CDK4 downregulation by siRNA or small-molecule inhibitors. By affording means of monitoring CDK4 hyperactivity consequent to cancer-associated molecular alterations in upstream signaling pathways that converge upon this kinase, this biosensor offers an alternative to immunological identification of melanoma-specific biomarkers, thereby constituting an attractive tool for diagnostic purposes, providing complementary functional information to histological analysis, of particular utility for detection of melanoma onset in precancerous lesions. This is indeed the first fluorescent peptide biosensor which has been successfully implemented to monitor kinase activity in skin samples and melanoma tumour xenografts. Moreover by enabling to monitor response to CDK4 inhibitors, this biosensor constitutes an attractive companion assay to identify compounds of therapeutic relevance for melanoma. PMID:27203461

  4. Fluorescent peptide biosensor for monitoring CDK4/cyclin D kinase activity in melanoma cell extracts, mouse xenografts and skin biopsies.

    PubMed

    Prével, Camille; Pellerano, Morgan; González-Vera, Juan A; Henri, Pauline; Meunier, Laurent; Vollaire, Julien; Josserand, Véronique; Morris, May C

    2016-11-15

    Melanoma constitutes the most aggressive form of skin cancer, which further metastasizes into a deadly form of cancer. The p16(INK4a)-Cyclin D-CDK4/6-pRb pathway is dysregulated in 90% of melanomas. CDK4/Cyclin D kinase hyperactivation, associated with mutation of CDK4, amplification of Cyclin D or loss of p16(INK4a) leads to increased risk of developing melanoma. This kinase therefore constitutes a key biomarker in melanoma and an emerging pharmacological target, however there are no tools enabling direct detection or quantification of its activity. Here we report on the design and application of a fluorescent peptide biosensor to quantify CDK4 activity in melanoma cell extracts, skin biopsies and melanoma xenografts. This biosensor provides sensitive means of comparing CDK4 activity between different melanoma cell lines and further responds to CDK4 downregulation by siRNA or small-molecule inhibitors. By affording means of monitoring CDK4 hyperactivity consequent to cancer-associated molecular alterations in upstream signaling pathways that converge upon this kinase, this biosensor offers an alternative to immunological identification of melanoma-specific biomarkers, thereby constituting an attractive tool for diagnostic purposes, providing complementary functional information to histological analysis, of particular utility for detection of melanoma onset in precancerous lesions. This is indeed the first fluorescent peptide biosensor which has been successfully implemented to monitor kinase activity in skin samples and melanoma tumour xenografts. Moreover by enabling to monitor response to CDK4 inhibitors, this biosensor constitutes an attractive companion assay to identify compounds of therapeutic relevance for melanoma.

  5. CDK4-mediated MnSOD activation and mitochondrial homeostasis in radioadaptive protection.

    PubMed

    Jin, Cuihong; Qin, Lili; Shi, Yan; Candas, Demet; Fan, Ming; Lu, Chung-Ling; Vaughan, Andrew T M; Shen, Rulong; Wu, Larry S; Liu, Rui; Li, Robert F; Murley, Jeffrey S; Woloschak, Gayle; Grdina, David J; Li, Jian Jian

    2015-04-01

    Mammalian cells are able to sense environmental oxidative and genotoxic conditions such as the environmental low-dose ionizing radiation (LDIR) present naturally on the earth's surface. The stressed cells then can induce a so-called radioadaptive response with an enhanced cellular homeostasis and repair capacity against subsequent similar genotoxic conditions such as a high dose radiation. Manganese superoxide dismutase (MnSOD), a primary mitochondrial antioxidant in mammals, has long been known to play a crucial role in radioadaptive protection by detoxifying O2(•-) generated by mitochondrial oxidative phosphorylation. In contrast to the well-studied mechanisms of SOD2 gene regulation, the mechanisms underlying posttranslational regulation of MnSOD for radioprotection remain to be defined. Herein, we demonstrate that cyclin D1/cyclin-dependent kinase 4 (CDK4) serves as the messenger to deliver the stress signal to mitochondria to boost mitochondrial homeostasis in human skin keratinocytes under LDIR-adaptive radioprotection. Cyclin D1/CDK4 relocates to mitochondria at the same time as MnSOD enzymatic activation peaks without significant changes in total MnSOD protein level. The mitochondrial-localized CDK4 directly phosphorylates MnSOD at serine-106 (S106), causing enhanced MnSOD enzymatic activity and mitochondrial respiration. Expression of mitochondria-targeted dominant negative CDK4 or the MnSOD-S106 mutant reverses LDIR-induced mitochondrial enhancement and adaptive protection. The CDK4-mediated MnSOD activation and mitochondrial metabolism boost are also detected in skin tissues of mice receiving in vivo whole-body LDIR. These results demonstrate a unique CDK4-mediated mitochondrial communication that allows cells to sense environmental genotoxic stress and boost mitochondrial homeostasis by enhancing phosphorylation and activation of MnSOD.

  6. CDK4-mediated MnSOD activation and mitochondrial homeostasis in radioadaptive protection.

    PubMed

    Jin, Cuihong; Qin, Lili; Shi, Yan; Candas, Demet; Fan, Ming; Lu, Chung-Ling; Vaughan, Andrew T M; Shen, Rulong; Wu, Larry S; Liu, Rui; Li, Robert F; Murley, Jeffrey S; Woloschak, Gayle; Grdina, David J; Li, Jian Jian

    2015-04-01

    Mammalian cells are able to sense environmental oxidative and genotoxic conditions such as the environmental low-dose ionizing radiation (LDIR) present naturally on the earth's surface. The stressed cells then can induce a so-called radioadaptive response with an enhanced cellular homeostasis and repair capacity against subsequent similar genotoxic conditions such as a high dose radiation. Manganese superoxide dismutase (MnSOD), a primary mitochondrial antioxidant in mammals, has long been known to play a crucial role in radioadaptive protection by detoxifying O2(•-) generated by mitochondrial oxidative phosphorylation. In contrast to the well-studied mechanisms of SOD2 gene regulation, the mechanisms underlying posttranslational regulation of MnSOD for radioprotection remain to be defined. Herein, we demonstrate that cyclin D1/cyclin-dependent kinase 4 (CDK4) serves as the messenger to deliver the stress signal to mitochondria to boost mitochondrial homeostasis in human skin keratinocytes under LDIR-adaptive radioprotection. Cyclin D1/CDK4 relocates to mitochondria at the same time as MnSOD enzymatic activation peaks without significant changes in total MnSOD protein level. The mitochondrial-localized CDK4 directly phosphorylates MnSOD at serine-106 (S106), causing enhanced MnSOD enzymatic activity and mitochondrial respiration. Expression of mitochondria-targeted dominant negative CDK4 or the MnSOD-S106 mutant reverses LDIR-induced mitochondrial enhancement and adaptive protection. The CDK4-mediated MnSOD activation and mitochondrial metabolism boost are also detected in skin tissues of mice receiving in vivo whole-body LDIR. These results demonstrate a unique CDK4-mediated mitochondrial communication that allows cells to sense environmental genotoxic stress and boost mitochondrial homeostasis by enhancing phosphorylation and activation of MnSOD. PMID:25578653

  7. Overexpression of Reg3alpha increases cell growth and the levels of cyclin D1 and CDK4 in insulinoma cells.

    PubMed

    Cui, Wei; De Jesus, Kristine; Zhao, Hong; Takasawa, Shin; Shi, Bingyin; Srikant, Coimbatore B; Liu, Jun-Li

    2009-06-01

    Regenerating gene (Reg) family protein Reg3alpha is normally expressed in pancreatic acinar and endocrine cells. In order to explore its effect on islet beta-cell replication, insulinoma MIN6 cells were stably transfected with murine Reg3alpha cDNA. Determined using real-time PCR and Western blots, the levels of Reg3alpha mRNA and protein in Reg3alpha-transfected clones were increased 10- and 6-fold, respectively. Western blots also revealed that the protein was released into the culture medium, consistent with an endocrine effect. In MTT cell proliferation assay, Reg3alpha-overexpressing cells exhibited a 2-fold increase in the rate of cell growth. In order to investigate the intracellular mechanism, we studied cell cycle regulatory proteins. In Reg3alpha-expressing cells, we detected 2.2- and 2.5-fold increased levels of cyclin D1 and CDK4, respectively, which paralleled a 1.8-fold increase in the rate of Akt phosphorylation. It is established that beta-cell replication is associated with increased cyclin D1 and CDK4 levels; deficiency in CDK4 or cyclin D2 results in reduced beta-cell mass and diabetes. Our results suggest that Reg3alpha stimulates beta-cell replication, by activating Akt kinase and increasing the levels of cyclin D1/CDK4.

  8. Cyclin D1 is dispensable for G1 control in retinoblastoma gene-deficient cells independently of cdk4 activity.

    PubMed Central

    Lukas, J; Bartkova, J; Rohde, M; Strauss, M; Bartek, J

    1995-01-01

    To elucidate the regulator-versus-target relationship in the cyclin D1/cdk4/retinoblastoma protein (pRB) pathway, we examined fibroblasts from RB-1 gene-deficient and RB-1 wild-type littermate mouse embryos (ME) and in human tumor cell lines that differed in the status of the RB-1 gene. The RB+/+ and RB-/- ME fibroblasts expressed similar protein levels of D-type cyclins, cdk4, and cdk6, showed analogous spectra and abundance of cellular proteins complexed with cdk4 and/or cyclins D1 and D2, and exhibited comparable associated kinase activities. Of the two human cell lines established from the same sarcoma biopsy, the RB-positive SKUT1B cells contained cdk4 that was mainly associated with D-type cyclins, contrary to a predominant cdk4-p16INK4 complex in the RB-deficient SKUT1A cells. Antibody-mediated neutralization of cyclin D1 arrested the RB-positive ME and SKUT1B cells in G1, whereas this cyclin appeared dispensable in the RB-deficient ME and SKUT1A cells. Lack of requirement for cyclin D1 therefore correlated with absence of functional pRB, regardless of whether active cyclin D1/cdk4 holoenzyme was present in the cells under study. Consistent with a potential role of cyclin D/cdk4 in phosphorylation of pRB, monoclonal anti-cyclin D1 antibodies supporting the associated kinase activity failed to significantly affect proliferation of RB-positive cells, whereas the antibody DCS-6, unable to coprecipitate cdk4, efficiently inhibited G1 progression and prevented pRB phosphorylation in vivo. These data provide evidence for an upstream control function of cyclin D1/cdk4, and a downstream role for pRB, in the order of events regulating transition through late G1 phase of the mammalian cell division cycle. PMID:7739541

  9. Transforming growth factor beta stabilizes p15INK4B protein, increases p15INK4B-cdk4 complexes, and inhibits cyclin D1-cdk4 association in human mammary epithelial cells.

    PubMed Central

    Sandhu, C; Garbe, J; Bhattacharya, N; Daksis, J; Pan, C H; Yaswen, P; Koh, J; Slingerland, J M; Stampfer, M R

    1997-01-01

    The effects of transforming growth factor beta (TGF-beta) were studied in closely related human mammary epithelial cells (HMEC), both finite-life-span 184 cells and immortal derivatives, 184A1S, and 184A1L5R, which differ in their cell cycle responses to TGF-beta but express type I and type II TGF-beta receptors and retain TGF-beta induction of extracellular matrix. The arrest-resistant phenotype was not due to loss of cyclin-dependent kinase (cdk) inhibitors. TGF-beta was shown to regulate p15INK4B expression at at least two levels: mRNA accumulation and protein stability. In TGF-beta-arrested HMEC, there was not only an increase in p15 mRNA but also a major increase in p5INK4B protein stability. As cdk4- and cdk6-associated p15INK4B increased during TGF-beta arrest of sensitive cells, there was a loss of cyclin D1, p21Cip1, and p27Kip1 from these kinase complexes, and cyclin E-cdk2-associated p27Kip1 increased. In HMEC, p15INK4B complexes did not contain detectable cyclin. p15INK4B from both sensitive and resistant cells could displace in vitro cyclin D1, p21Cip1, and p27Kip1 from cdk4 isolated from sensitive cells. Cyclin D1 could not be displaced from cdk4 in the resistant 184A1L5R cell lysates. Thus, in TGF-beta arrest, p15INK4B may displace already associated cyclin D1 from cdks and prevent new cyclin D1-cdk complexes from forming. Furthermore, p27Kip1 binding shifts from cdk4 to cyclin E-cdk2 during TGF-beta-mediated arrest. The importance of posttranslational regulation of p15INK4B by TGF-beta is underlined by the observation that in TGF-beta-resistant 184A1L5R, although the p15 transcript increased, p15INK4B protein was not stabilized and did not accumulate, and cyclin D1-cdk association and kinase activation were not inhibited. PMID:9111314

  10. Enhanced malignant tumorigenesis in Cdk4 transgenic mice.

    PubMed

    Miliani de Marval, Paula L; Macias, Everardo; Conti, Claudio J; Rodriguez-Puebla, Marcelo L

    2004-03-11

    In a previous study, we reported that overexpression of cyclin-dependent kinase-4 (CDK4) in mouse epidermis results in epidermal hyperplasia, hypertrophy and severe dermal fibrosis. In this study, we have investigated the susceptibility to skin tumor formation by forced expression of CDK4. Skin tumors from transgenic mice showed a dramatic increase in the rate of malignant progression to squamous cell carcinomas (SCC) in an initiation-promotion protocol. Histopathological analysis of papillomas from transgenic mice showed an elevated number of premalignant lesions characterized by dysplasia and marked atypia. Interestingly, transgenic mice also developed tumors in initiated but not promoted skin, demonstrating that CDK4 replaced the action of tumor promoters. These results suggest that expression of cyclin D1 upon ras activation synergizes with CDK4 overexpression. However, cyclin D1 transgenic mice and double transgenic mice for cyclin D1 and CDK4 did not show increased malignant progression in comparison to CDK4 transgenic mice. Biochemical analysis of tumors showed that CDK4 sequesters the CDK2 inhibitors p27Kip1 and p21Cip1, suggesting that indirect activation of CDK2 plays an important role in tumor development. These results indicate that, contrary to the general assumption, the catalytic subunit, CDK4, has higher oncogenic activity than cyclin D1, revealing a potential use of CDK4 as therapeutic target.

  11. Enhanced Malignant Tumorigenesis in Cdk4-Transgenic Mice

    PubMed Central

    Miliani de Marval, Paula L.; Macias, Everardo; Conti, Claudio J.; Rodriguez-Puebla, Marcelo L.

    2010-01-01

    In a previous study, we reported that overexpression of CDK4 in mouse epidermis results in epidermal hyperplasia, hypertrophy and severe dermal fibrosis. In this study, we have investigated the susceptibility to skin tumor formation by forced expression of CDK4. Skin tumors from transgenic mice showed a dramatic increase in the rate of malignant progression to squamous cell carcinomas (SCC) in an initiation-promotion protocol. Histopathological analysis of papillomas from transgenic mice showed an elevated number of premalignant lesions characterized by dysplasia and marked atypia. Interestingly, transgenic mice also developed tumors in initiated but not promoted skin, demonstrating that CDK4 replaced the action of tumor promoters. These results suggest that expression of cyclin D1 upon ras activation synergizes with CDK4 overexpression. However, cyclin D1 transgenic mice and double transgenic mice for cyclin D1 and CDK4 did not show increased malignant progression in comparison to CDK4 transgenic mice. Biochemical analysis of tumors showed that CDK4 sequesters the CDK2 inhibitors p27Kip1 and p21Cip1 suggesting that indirect activation of CDK2 plays an important role in tumor development. These results indicate that, contrary to the general assumption, the catalytic subunit, CDK4, has higher oncogenic activity than cyclin D1, revealing a potential use of CDK4 as therapeutic target. PMID:14647432

  12. cAMP-dependent activation of mammalian target of rapamycin (mTOR) in thyroid cells. Implication in mitogenesis and activation of CDK4.

    PubMed

    Blancquaert, Sara; Wang, Lifu; Paternot, Sabine; Coulonval, Katia; Dumont, Jacques E; Harris, Thurl E; Roger, Pierre P

    2010-07-01

    How cAMP-dependent protein kinases [protein kinase A (PKA)] transduce the mitogenic stimulus elicited by TSH in thyroid cells to late activation of cyclin D3-cyclin-dependent kinase 4 (CDK4) remains enigmatic. Here we show in PC Cl3 rat thyroid cells that TSH/cAMP, like insulin, activates the mammalian target of rapamycin (mTOR)-raptor complex (mTORC1) leading to phosphorylation of S6K1 and 4E-BP1. mTORC1-dependent S6K1 phosphorylation in response to both insulin and cAMP required amino acids, whereas inhibition of AMP-activated protein kinase and glycogen synthase kinase 3 enhanced insulin but not cAMP effects. Unlike insulin, TSH/cAMP did not activate protein kinase B or induce tuberous sclerosis complex 2 phosphorylation at T1462 and Y1571. However, like insulin, TSH/cAMP produced a stable increase in mTORC1 kinase activity that was associated with augmented 4E-BP1 binding to raptor. This could be caused in part by T246 phosphorylation of PRAS40, which was found as an in vitro substrate of PKA. Both in PC Cl3 cells and primary dog thyrocytes, rapamycin inhibited DNA synthesis and retinoblastoma protein phosphorylation induced by TSH and insulin. Although rapamycin reduced cyclin D3 accumulation, the abundance of cyclin D3-CDK4 complexes was not affected. However, rapamycin inhibited the activity of these complexes by decreasing the TSH and insulin-mediated stimulation of activating T172 phosphorylation of CDK4. We propose that mTORC1 activation by TSH, at least in part through PKA-dependent phosphorylation of PRAS40, crucially contributes to mediate cAMP-dependent mitogenesis by regulating CDK4 T172-phosphorylation. PMID:20484410

  13. Incomplete Folding upon Binding Mediates Cdk4/Cyclin D Complex Activation by Tyrosine Phosphorylation of Inhibitor p27 Protein*

    PubMed Central

    Ou, Li; Ferreira, Antonio M.; Otieno, Steve; Xiao, Limin; Bashford, Donald; Kriwacki, Richard W.

    2011-01-01

    p27Kip1 (p27), an intrinsically disordered protein, regulates the various Cdk/cyclin complexes that control cell cycle progression. The kinase inhibitory domain of p27 contains a cyclin-binding subdomain (D1), a Cdk-binding subdomain (D2), and a linker helix subdomain that connects D1 and D2. Here, we report that, despite extensive sequence conservation between Cdk4/cyclin D1 (hereafter Cdk4/cyclin D) and Cdk2/cyclin A, the thermodynamic details describing how the individual p27 subdomains contribute to equally high affinity binding to these two Cdk/cyclin complexes are strikingly different. Differences in enthalpy/entropy compensation revealed that the D2 subdomain of p27 folds incompletely when binding Cdk4/cyclin D versus Cdk2/cyclin A. Incomplete binding-induced folding exposes tyrosine 88 of p27 for phosphorylation by the nonreceptor tyrosine kinase Abl. Importantly, tyrosine phosphorylation (of p27) relieves Cdk inhibition by p27, enabling cell cycle entry. Furthermore, the interaction between a conserved hydrophobic patch on cyclin D and subdomain D1 is much weaker than that with cyclin A; consequently, a construct containing subdomains D1 and LH (p27-D1LH) does not inhibit substrate binding to Cdk4/cyclin D as it does to Cdk2/cyclin A. Our results provide a mechanism by which Cdk4 (within the p27/Cdk4/cyclin D complex) is poised to be activated by extrinsic mitogenic signals that impinge upon p27 at the earliest stage of cell division. More broadly, our results further illustrate the regulatory versatility of intrinsically disordered proteins. PMID:21715330

  14. CDK4 is an essential insulin effector in adipocytes

    PubMed Central

    Lagarrigue, Sylviane; Lopez-Mejia, Isabel C.; Denechaud, Pierre-Damien; Escoté, Xavier; Castillo-Armengol, Judit; Jimenez, Veronica; Chavey, Carine; Giralt, Albert; Lai, Qiuwen; Zhang, Lianjun; Martinez-Carreres, Laia; Delacuisine, Brigitte; Annicotte, Jean-Sébastien; Blanchet, Emilie; Huré, Sébastien; Abella, Anna; Tinahones, Francisco J.; Vendrell, Joan; Dubus, Pierre; Bosch, Fatima; Kahn, C. Ronald; Fajas, Lluis

    2015-01-01

    Insulin resistance is a fundamental pathogenic factor that characterizes various metabolic disorders, including obesity and type 2 diabetes. Adipose tissue contributes to the development of obesity-related insulin resistance through increased release of fatty acids, altered adipokine secretion, and/or macrophage infiltration and cytokine release. Here, we aimed to analyze the participation of the cyclin-dependent kinase 4 (CDK4) in adipose tissue biology. We determined that white adipose tissue (WAT) from CDK4-deficient mice exhibits impaired lipogenesis and increased lipolysis. Conversely, lipolysis was decreased and lipogenesis was increased in mice expressing a mutant hyperactive form of CDK4 (CDK4R24C). A global kinome analysis of CDK4-deficient mice following insulin stimulation revealed that insulin signaling is impaired in these animals. We determined that insulin activates the CCND3-CDK4 complex, which in turn phosphorylates insulin receptor substrate 2 (IRS2) at serine 388, thereby creating a positive feedback loop that maintains adipocyte insulin signaling. Furthermore, we found that CCND3 expression and IRS2 serine 388 phosphorylation are increased in human obese subjects. Together, our results demonstrate that CDK4 is a major regulator of insulin signaling in WAT. PMID:26657864

  15. Cooperativity of Cdk4R24C and Ras in melanoma development.

    PubMed

    Chawla, Rachna; Procknow, Judith A; Tantravahi, Ramana V; Khurana, Jasvir S; Litvin, Judith; Reddy, E Premkumar

    2010-08-15

    The importance of the CDK4 protein in human cancer first became evident following the identification of a germ line mutation in the Cdk4 locus that predisposes humans to melanoma. This mutation results in substitution of arginine with cysteine at position 24 (R24C). In an earlier study, we introduced the R24C mutation into the Cdk4 locus of mice using Cre-loxP-mediated "knock-in" technology and observed a very low incidence of spontaneous melanomas in Cdk4(R24C/R24C) mice. This suggested that additional oncogenic mutations might be required for development of melanomas. Here we report an increased incidence of spontaneous cutaneous melanoma in mice expressing the oncogene HRAS(G12V) in melanocytes on a Cdk4(R24C) background. Treatment of Tyr-HRas:Cdk4(R24C/R24C) mice with the carcinogen, DMBA/TPA resulted in a further increase in the number of nevi and melanomas developed when compared with Tyr-HRas:Cdk4(+/+) mice. In summary, in Tyr-HRas:Cdk4(R24C/R24C) mice, we observed that activated CDK4 cooperates with the oncogenic HRAS(G12V) protein to increase the susceptibility of melanoma development in vivo.

  16. Cooperativity of Cdk4R24C and Ras in melanoma development.

    PubMed

    Chawla, Rachna; Procknow, Judith A; Tantravahi, Ramana V; Khurana, Jasvir S; Litvin, Judith; Reddy, E Premkumar

    2010-08-15

    The importance of the CDK4 protein in human cancer first became evident following the identification of a germ line mutation in the Cdk4 locus that predisposes humans to melanoma. This mutation results in substitution of arginine with cysteine at position 24 (R24C). In an earlier study, we introduced the R24C mutation into the Cdk4 locus of mice using Cre-loxP-mediated "knock-in" technology and observed a very low incidence of spontaneous melanomas in Cdk4(R24C/R24C) mice. This suggested that additional oncogenic mutations might be required for development of melanomas. Here we report an increased incidence of spontaneous cutaneous melanoma in mice expressing the oncogene HRAS(G12V) in melanocytes on a Cdk4(R24C) background. Treatment of Tyr-HRas:Cdk4(R24C/R24C) mice with the carcinogen, DMBA/TPA resulted in a further increase in the number of nevi and melanomas developed when compared with Tyr-HRas:Cdk4(+/+) mice. In summary, in Tyr-HRas:Cdk4(R24C/R24C) mice, we observed that activated CDK4 cooperates with the oncogenic HRAS(G12V) protein to increase the susceptibility of melanoma development in vivo. PMID:20703083

  17. Cdk4 deficiency inhibits skin tumor development but does not affect normal keratinocyte proliferation.

    PubMed

    Rodriguez-Puebla, Marcelo L; Miliani de Marval, Paula L; LaCava, Margaret; Moons, David S; Kiyokawa, Hiroaki; Conti, Claudio J

    2002-08-01

    Most human tumors have mutations that result in deregulation of the cdk4/cyclin-Ink4-Rb pathway. Overexpression of D-type cyclins or cdk4 and inactivation of Ink4 inhibitors are common in human tumors. Conversely, lack of cyclin D1 expression results in significant reduction in mouse skin and mammary tumor development. However, complete elimination of tumor development was not observed in these models, suggesting that other cyclin/cdk complexes play an important role in tumorigenesis. Here we described the effects of cdk4 deficiency on mouse skin proliferation and tumor development. Cdk4 deficiency resulted in a 98% reduction in the number of tumors generated through the two-stage carcinogenesis model. The absence of cdk4 did not affect normal keratinocyte proliferation and both wild-type and cdk4 knockout epidermis are equally affected after topical treatment with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA), resulting in epidermal hyperplasia. In similar fashion, cdk4 knockout keratinocytes proliferated well in an in vivo model of wound-induced proliferation. Biochemical studies in mouse epidermis showed that cdk6 activity increased twofold in cdk4-deficient mice compared to wild-type siblings. These results suggest that therapeutic approaches to inhibit cdk4 activity could provide a target to inhibit tumor development with minimal or no effect in normal tissue.

  18. cdk4 Deficiency Inhibits Skin Tumor Development but Does Not Affect Normal Keratinocyte Proliferation

    PubMed Central

    Rodriguez-Puebla, Marcelo L.; Miliani de Marval, Paula L.; LaCava, Margaret; Moons, David S.; Kiyokawa, Hiroaki; Conti, Claudio J.

    2002-01-01

    Most human tumors have mutations that result in deregulation of the cdk4/cyclin-Ink4-Rb pathway. Overexpression of D-type cyclins or cdk4 and inactivation of Ink4 inhibitors are common in human tumors. Conversely, lack of cyclin D1 expression results in significant reduction in mouse skin and mammary tumor development. However, complete elimination of tumor development was not observed in these models, suggesting that other cyclin/cdk complexes play an important role in tumorigenesis. Here we described the effects of cdk4 deficiency on mouse skin proliferation and tumor development. Cdk4 deficiency resulted in a 98% reduction in the number of tumors generated through the two-stage carcinogenesis model. The absence of cdk4 did not affect normal keratinocyte proliferation and both wild-type and cdk4 knockout epidermis are equally affected after topical treatment with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA), resulting in epidermal hyperplasia. In similar fashion, cdk4 knockout keratinocytes proliferated well in an in vivo model of wound-induced proliferation. Biochemical studies in mouse epidermis showed that cdk6 activity increased twofold in cdk4-deficient mice compared to wild-type siblings. These results suggest that therapeutic approaches to inhibit cdk4 activity could provide a target to inhibit tumor development with minimal or no effect in normal tissue. PMID:12163365

  19. Silencing CDK4 radiosensitizes breast cancer cells by promoting apoptosis

    PubMed Central

    2013-01-01

    Background The discovery of molecular markers associated with various breast cancer subtypes has greatly improved the treatment and outcome of breast cancer patients. Unfortunately, breast cancer cells acquire resistance to various therapies. Mounting evidence suggests that resistance is rooted in the deregulation of the G1 phase regulatory machinery. Methods To address whether deregulation of the G1 phase regulatory machinery contributes to radiotherapy resistance, the MCF10A immortalized human mammary epithelial cell line, ER-PR-Her2+ and ER-PR-Her2- breast cancer cell lines were irradiated. Colony formation assays measured radioresistance, while immunocytochemistry, Western blots, and flow cytometry measured the cell cycle, DNA replication, mitosis, apoptosis, and DNA breaks. Results Molecular markers common to all cell lines were overexpressed, including cyclin A1 and cyclin D1, which impinge on CDK2 and CDK4 activities, respectively. We addressed their potential role in radioresistance by generating cell lines stably expressing small hairpin RNAs (shRNA) against CDK2 and CDK4. None of the cell lines knocked down for CDK2 displayed radiosensitization. In contrast, all cell lines knocked down for CDK4 were significantly radiosensitized, and a CDK4/CDK6 inhibitor sensitized MDA-MB-468 to radiation induced apoptosis. Our data showed that silencing CDK4 significantly increases radiation induced cell apoptosis in cell lines without significantly altering cell cycle progression, or DNA repair after irradiation. Our results indicate lower levels of phospho-Bad at ser136 upon CDK4 silencing and ionizing radiation, which has been shown to signal apoptosis. Conclusion Based on our data we conclude that knockdown of CDK4 activity sensitizes breast cancer cells to radiation by activating apoptosis pathways. PMID:23886499

  20. The CDK4/6 inhibitor PD0332991 reverses epithelial dysplasia associated with abnormal activation of the Cyclin-CDK-Rb pathway

    PubMed Central

    Cabrera, M. Carla; Díaz-Cruz, Edgar S.; Kallakury, Bhaskar V. S.; Pishvaian, Michael J.; Grubbs, Clinton J.; Muccio, Donald D.; Furth, Priscilla A.

    2012-01-01

    Loss of normal growth control is a hallmark of cancer progression. Therefore, understanding the early mechanisms of normal growth regulation and the changes that occur during preneoplasia may provide insights of both diagnostic and therapeutic importance. Models of dysplasia that help elucidate the mechanisms responsible for disease progression are useful in highlighting potential targets for prevention. An important strategy in cancer prevention treatment programs is to reduce hyperplasia and dysplasia. This study identified abnormal up-regulation of cell cycle related proteins Cyclin D1, CDK4, CDK6 and phosphorylated pRb as mechanisms responsible for maintenance of hyperplasia and dysplasia following down-regulation of the initiating viral oncoprotein Simian Virus 40 T Antigen. Significantly, p53 was not required for successful reversal of hyperplasia and dysplasia. Ligand-induced activation of RXR and PPAR gamma agonists attenuated Cyclin D1 and CDK6 but not CDK4 or phosphorylated pRb upregulation with limited reversal of hyperplasia and dysplasia. PD0332991, an orally available CDK4/6 inhibitor, was able to prevent upregulation of Cyclin D1 and CDK6 as well as CDK4 and phosphorylated pRb and this correlated with a more profound reversal of hyperplasia and dysplasia. In summary, the study distinguished CDK4 and phosphorylated pRb as targets for chemoprevention regimens targeting reversal of hyperplasia and dysplasia. PMID:22508966

  1. Biochemical characterizations reveal different properties between CDK4/cyclin D1 and CDK2/cyclin A.

    PubMed

    Kim, Dong-Myung; Yang, Kyungmi; Yang, Beom-Seok

    2003-10-31

    CDK2 and CDK4 known promoter of cell cycling catalyze phosphorylation of RB protein. Enzyme specificity between two CDKs that work at a different cell cycle phase is not clearly understood. In order to define kinase properties of CDK2 and CDK4 in complex with cycline A or cycline D1 in relation to their respective role in cell cycling regulation, we examined enzymatic properties of both CDK4/cycline D1 and CDK2/cycline A in vitro. Association constant, Km for ATP in CDK4/cyclin D1 was found as 418 microM, a value unusually high whereas CDK2/cyclin A was 23 microM, a value close to most of other regulatory protein kinases. Turnover value for both CDK4/cyclin D1 and CDK2/cyclin A were estimated as 3.4 and 3.9 min(-1) respectively. Kinetic efficiency estimation indicates far over one order magnitude less efficiency for CDK4/cyclin D1 than the value of CDK2/cycline A (9.3 pM(-1) min(-1) and 170 pM(-1) min(-1) respectively). In addition, inhibition of cellular CDK4 caused increase of cellular levels of ATP, even though inhibition of CDK2 did not change it noticeably. These data suggest cellular CDK4/cyclin D1 activity is tightly associated with cellular ATP concentration. Also, analysis of phosphorylated serine/threonine sites on RB catalyzed by CDK4/cyclin D1 and CDK2/cyclin A showed significant differences in their preference of phosphorylation sites in RB C-terminal domain. Since RB is known to regulate various cellular proteins by binding and this binding is controlled by its phosphorylation, these data shown here clearly indicate significant difference in their biochemical properties between CDK4/cyclin D1 and CDK2/cyclin A affecting regulation of cellular RB function. PMID:14646596

  2. Progranulin Deficiency Reduces CDK4/6/pRb Activation and Survival of Human Neuroblastoma SH-SY5Y Cells.

    PubMed

    de la Encarnación, Ana; Alquézar, Carolina; Esteras, Noemí; Martín-Requero, Ángeles

    2015-12-01

    Null mutations in GRN are associated with frontotemporal lobar degeneration with TDP-43 inclusions (FTLD-TDP). However, the influence of progranulin (PGRN) deficiency in neurodegeneration is largely unknown. In neuroblastoma cells, silencing of GRN gene causes significantly reduced cell survival after serum withdrawal. The following observations suggest that alterations of the CDK4/6/retinoblastoma protein (pRb) pathway, secondary to changes in PI3K/Akt and ERK1/2 activation induced by PGRN deficiency, are involved in the control of serum deprivation-induced apoptosis: (i) inhibiting CDK4/6 levels or their associated kinase activity by sodium butyrate or PD332991 sensitized control SH-SY5Y cells to serum deprivation-induced apoptosis without affecting survival of PGRN-deficient cells; (ii) CDK4/6/pRb seems to be downstream of the PI3K/Akt and ERK1/2 signaling pathways since their specific inhibitors, LY294002 and PD98059, were able to decrease CDK6-associated kinase activity and induce death of control SH-SY5Y cells; (iii) PGRN-deficient cells show reduced stimulation of PI3K/Akt, ERK1/2, and CDK4/6 activities compared with control cells in the absence of serum; and (iv) supplementation of recombinant human PGRN was able to rescue survival of PGRN-deficient cells. These observations highlight the important role of PGRN-mediated stimulation of the PI3K/Akt-ERK1/2/CDK4/6/pRb pathway in determining the cell fate survival/death under serum deprivation.

  3. Germ line transmission of the Cdk4(R24C) mutation facilitates tumorigenesis and escape from cellular senescence.

    PubMed

    Rane, Sushil G; Cosenza, Stephen C; Mettus, Richard V; Reddy, E Premkumar

    2002-01-01

    Mutations in CDK4 and its key kinase inhibitor p16(INK4a) have been implicated in the genesis and progression of familial human melanoma. The importance of the CDK4 locus in human cancer first became evident following the identification of a germ line CDK4-Arg24Cys (R24C) mutation, which abolishes the ability of CDK4 to bind to p16(INK4a). To determine the role of the Cdk4(R24C) germ line mutation in the genesis of other cancer types, we introduced the R24C mutation in the Cdk4 locus of mice by using Cre-loxP-mediated "knock-in" technology. Cdk4(R24C/R24C) mouse embryo fibroblasts (MEFs) displayed increased Cdk4 kinase activity resulting in hyperphosphorylation of all three members of the Rb family, pRb, p107, and p130. MEFs derived from Cdk4(R24C/R24C) mice displayed decreased doubling times, escape from replicative senescence, and escape sensitivity to contact-induced growth arrest. These MEFs also exhibited a high degree of susceptibility to oncogene-induced transformation, suggesting that the Cdk4(R24C) mutation can serve as a primary event in the progression towards a fully transformed phenotype. In agreement with the in vitro data, homozygous Cdk4(R24C/R24C) mice developed tumors of various etiology within 8 to 10 months of their life span. The majority of these tumors were found in the pancreas, pituitary, brain, mammary tissue, and skin. In addition, Cdk4(R24C/R24C) mice showed extraordinary susceptibility to carcinogens and developed papillomas within the first 8 to 10 weeks following cutaneous application of the carcinogens 9,10-di-methyl-1,2-benz[a]anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA). This report formally establishes that the activation of Cdk4 is sufficient to promote cancer in many tissues. The observation that a wide variety of tumors develop in mice harboring the Cdk4(R24C) mutation offers a genetic proof that Cdk4 activation may constitute a central event in the genesis of many types of cancers in addition to melanoma.

  4. The CDK4/6 inhibitor LY2835219 has potent activity in combination with mTOR inhibitor in head and neck squamous cell carcinoma

    PubMed Central

    Koh, Jiae; Bae, Yeon-Hee; Sun, Jong-Mu; Lee, Se-hoon; Ahn, Jin Seok; Park, Keunchil; Ahn, Myung-Ju

    2016-01-01

    Deletion of CDKN2A (p16) or amplification of CCND1 (cyclin D1) occurs commonly in head and neck squamous cell carcinoma (HNSCC) and induces sustained cyclin-dependent kinase (CDK) 4/6 activation. Here, we report the antiproliferative activity of LY2835219, a selective CDK4/6 inhibitor through inhibition of CDK4/6-dependent Ser780 phosphorylation in retinoblastoma (RB) and induction of cell cycle arrest in HNSCC cells. In addition, we demonstrated the antitumor effects of HNSCC xenografts to LY2835219 in vivo. Given the limited effect in HNSCC as a single-agent treatment with LY2835219, a combinational strategy is required to enhance antitumor activity. At the molecular level, we found that LY2835219 inhibited activation of AKT and ERK, but not mTOR. The combination of LY2835219 with mTOR inhibitor was found to be more effective than either drug alone in vitro and in vivo. Taken together, our findings suggest that a combinational treatment with LY2835219 and mTOR inhibitor is a promising therapeutic approach for HNSCC. PMID:26909611

  5. The prognostic significance and value of cyclin D1, CDK4 and p16 in human breast cancer

    PubMed Central

    2013-01-01

    Introduction Loss of the retinoblastoma protein tumor suppressor gene (RB) coding for a nuclear phosphoprotein that regulates the cell cycle is found in many human cancers and probably leads to disruption of the p16-cyclin D1-CDK4/6-RB pathway. Cyclin D1 is known to activate CDK4, which then phosphorylates the RB protein, leading to cell cycle progression. p16 inhibits CDK4, keeping RB hypophosphorylated and preventing cell cycle progression. The significance of these three markers, cyclin D1, CDK4 and p16, for breast cancer and carcinogenesis is nevertheless still controversial. Methods The material consisted of 102 formalin-fixed human breast cancer samples, in which cyclin D1, CDK4 and p16 expression was evaluated immunohistochemically. The amounts of cyclin D1 mRNA present were analyzed by quantitative real time PCR. Results High cyclin D1 expression statistically significantly correlated with lower tumor grade, estrogen and progesterone receptor positivity and lower proliferation activity in breast tumors and increased breast cancer-specific survival and overall survival. Tumors with high cyclin D1 protein had 1.8 times higher expression of cyclin D1 mRNA. CDK4 expression did not correlate with cyclin D1 expression or the survival data. p16 expression was associated with Human Epidermal Growth Factor Receptor 2 (HER2) negativity and increased breast cancer-specific survival and disease-free survival. No statistical correlations between cyclin D1, CDK4 and p16 were found. Conclusions Cyclin D1 was associated with a good breast cancer prognosis but functioned independently of CDK4. High cyclin D1 expression may be partially due to increased CCND1 transcription. p16 correlated with a better prognosis and may function without CDK4. In conclusion, it appears that cyclin D1, CDK4 and p16 function independently in human breast cancer. PMID:23336272

  6. Cdk2 deficiency decreases ras/CDK4-dependent malignant progression, but not myc-induced tumorigenesis.

    PubMed

    Macias, Everardo; Kim, Yongbaek; Miliani de Marval, Paula L; Klein-Szanto, Andres; Rodriguez-Puebla, Marcelo L

    2007-10-15

    We have previously shown that forced expression of CDK4 in mouse skin (K5CDK4 mice) results in increased susceptibility to squamous cell carcinoma (SCC) development in a chemical carcinogenesis protocol. This protocol induces skin papilloma development, causing a selection of cells bearing activating Ha-ras mutations. We have also shown that myc-induced epidermal proliferation and oral tumorigenesis (K5Myc mice) depends on CDK4 expression. Biochemical analysis of K5CDK4 and K5Myc epidermis as well as skin tumors showed that keratinocyte proliferation is mediated by CDK4 sequestration of p27Kip1 and p21Cip1, and activation of CDK2. Here, we studied the role of CDK2 in epithelial tumorigenesis. In normal skin, loss of CDK2 rescues CDK4-induced, but not myc-induced epidermal hyperproliferation. Ablation of CDK2 in K5CDK4 mice results in decreased incidences and multiplicity of skin tumors as well as malignant progression to SCC. Histopathologic analysis showed that K5CDK4 tumors are drastically more aggressive than K5CDK4/CDK2-/- tumors. On the other hand, we show that CDK2 is dispensable for myc-induced tumorigenesis. In contrast to our previous report of K5Myc/CDK4-/-, K5Myc/CDK2-/- mice developed oral tumors with the same frequency as K5Myc mice. Overall, we have established that ras-induced tumors are more susceptible to CDK2 ablation than myc-induced tumors, suggesting that the efficacy of targeting CDK2 in tumor development and malignant progression is dependent on the oncogenic pathway involved.

  7. Cdk2 deficiency decrease ras/cdk4-dependent malignant progression, but not myc-induced tumorigenesis

    PubMed Central

    Macias, Everardo; Kim, Yongbaek; Miliani de Marval, Paula L.; Klein-Szanto, Andres; Rodriguez-Puebla, Marcelo L.

    2010-01-01

    We have previously shown that forced expression of CDK4 in mouse skin (K5CDK4 mice) results in increased susceptibility to squamous cell carcinomas (SCC) development in a chemical carcinogenesis protocol. This protocol induces skin papilloma development causing a selection of cells bearing activating Ha-ras mutations. We have also demonstrated that myc-induced epidermal proliferation and oral tumorigenesis (K5Myc mice) depends on CDK4 expression. Biochemical analysis of K5CDK4 and K5Myc epidermis as well as skin tumors showed that keratinocyte proliferation is mediated by CDK4 sequestration of p27Kip1 and p21Cip1, and activation of CDK2. Here, we studied the role of CDK2 in epithelial tumorigenesis. In normal skin loss of CDK2 rescues CDK4-induced, but not myc-induce epidermal hyperproliferation. Ablation of CDK2 in K5CDK4 mice results in decrease incidences and multiplicity of skin tumors as well as malignant progression to SCC. Histopathological analysis showed that K5CDK4 tumors are drastically more aggressive than K5CDK4/CDK2−/− tumors. On the other hand, we show that CDK2 is dispensable for myc-induced tumorigenesis. In contrast to our previous report K5Myc/CDK4−/− mice, K5Myc/CDK2−/− mice developed oral tumors with the same frequency as K5Myc mice. Overall we have established that ras-induced tumors are more susceptible to CDK2 ablation than myc-induced tumors, suggesting that the efficacy of targeting CDK2 in tumor development and malignant progression is dependent on the oncogenic pathway involved. PMID:17942901

  8. Evidence for a CDK4-dependent checkpoint in a conditional model of cellular senescence

    PubMed Central

    Brookes, Sharon; Gagrica, Sladjana; Sanij, Elaine; Rowe, Janice; Gregory, Fiona J; Hara, Eiji; Peters, Gordon

    2015-01-01

    Cellular senescence, the stable cell cycle arrest elicited by various forms of stress, is an important facet of tumor suppression. Although much is known about the key players in the implementation of senescence, including the pRb and p53 axes and the cyclin dependent kinase inhibitors p16INK4a and p21CIP1, many details remain unresolved. In studying conditional senescence in human fibroblasts that express a temperature sensitive SV40 large T-antigen (T-Ag), we uncovered an unexpected role for CDK4. At the permissive temperature, where pRb and p53 are functionally compromised by T-Ag, cyclin D-CDK4 complexes are disrupted by the high p16INK4a levels and reduced expression of p21CIP1. In cells arrested at the non-permissive temperature, p21CIP1 promotes reassembly of cyclin D-CDK4 yet pRb is in a hypo-phosphorylated state, consistent with cell cycle arrest. In exploring whether the reassembled cyclin D-CDK4-p21 complexes are functional, we found that shRNA-mediated knockdown or chemical inhibition of CDK4 prevented the increase in cell size associated with the senescent phenotype by allowing the cells to arrest in G1 rather than G2/M. The data point to a role for CDK4 kinase activity in a G2 checkpoint that contributes to senescence. PMID:25695870

  9. Loss of nuclear receptor RXRα in epidermal keratinocytes promotes the formation of Cdk4-activated invasive melanomas.

    PubMed

    Hyter, Stephen; Bajaj, Gaurav; Liang, Xiaobo; Barbacid, Mariano; Ganguli-Indra, Gitali; Indra, Arup Kumar

    2010-10-01

    Keratinocytes contribute to melanocyte transformation by affecting their microenvironment, in part through the secretion of paracrine factors. Here we report a loss of expression of nuclear receptor RXRα in epidermal keratinocytes during human melanoma progression. In the absence of keratinocytic RXRα, in combination with mutant Cdk4, cutaneous melanoma was generated that metastasized to lymph nodes in a bigenic mouse model. Expression of several keratinocyte-derived mitogenic growth factors (Et-1, Hgf, Scf, α-MSH and Fgf 2 ) was elevated in skin of bigenic mice, whereas Fas, E-cadherin and Pten, implicated in apoptosis, cellular invasion and melanomagenesis, respectively, were downregulated within the microdissected melanocytic tumors. We demonstrated that RXRα is recruited on the proximal promoter of both Et-1 and Hgf, possibly directly regulating their transcription in keratinocytes. These studies demonstrate the contribution of keratinocytic paracrine signaling during the cellular transformation and malignant conversion of melanocytes.

  10. Loss of nuclear receptor RXRα in epidermal keratinocytes promotes the formation of Cdk4-activated invasive melanomas.

    PubMed

    Hyter, Stephen; Bajaj, Gaurav; Liang, Xiaobo; Barbacid, Mariano; Ganguli-Indra, Gitali; Indra, Arup Kumar

    2010-10-01

    Keratinocytes contribute to melanocyte transformation by affecting their microenvironment, in part through the secretion of paracrine factors. Here we report a loss of expression of nuclear receptor RXRα in epidermal keratinocytes during human melanoma progression. In the absence of keratinocytic RXRα, in combination with mutant Cdk4, cutaneous melanoma was generated that metastasized to lymph nodes in a bigenic mouse model. Expression of several keratinocyte-derived mitogenic growth factors (Et-1, Hgf, Scf, α-MSH and Fgf 2 ) was elevated in skin of bigenic mice, whereas Fas, E-cadherin and Pten, implicated in apoptosis, cellular invasion and melanomagenesis, respectively, were downregulated within the microdissected melanocytic tumors. We demonstrated that RXRα is recruited on the proximal promoter of both Et-1 and Hgf, possibly directly regulating their transcription in keratinocytes. These studies demonstrate the contribution of keratinocytic paracrine signaling during the cellular transformation and malignant conversion of melanocytes. PMID:20629968

  11. Metabolic re-programming of pancreatic cancer mediated by CDK4/6 inhibition elicits unique vulnerabilities

    PubMed Central

    Franco, Jorge; Balaji, Uthra; Freinkman, Elizaveta; Witkiewicz, Agnieszka K.; Knudsen, Erik S.

    2016-01-01

    Due to loss of p16ink4a in pancreatic ductal adenocarcinoma (PDA), pharmacological suppression of CDK4/6 could represent a potent target for treatment. In PDA models CDK4/6 inhibition had variable effect on cell cycle, but yielded accumulation of ATP and mitochondria. Pharmacological CDK4/6 inhibitors induce cyclin D1 protein levels; however, RB activation was required and sufficient for mitochondrial accumulation. CDK4/6 inhibition stimulated glycolytic and oxidative metabolism and was associated with an increase in mTORC1 activity. MTOR and MEK inhibitors potently cooperate with CDK4/6 inhibition in eliciting cell cycle exit. However, MTOR inhibition fully suppressed metabolism and yielded apoptosis and suppression of tumor growth. The metabolic state mediated by CDK4/6 inhibition increases mitochondrial number and ROS. Concordantly, the suppression of ROS scavenging or BCL2-antagonists cooperated with CDK4/6 inhibition. Together, these data define the impact of therapeutics on PDA metabolism and provide strategies for converting cytostatic response to tumor cell killing. PMID:26804906

  12. Elevated expression of CDK4 in lung cancer

    PubMed Central

    2011-01-01

    Background The aim of the present study was to analyze the expression of Cyclin-dependent kinase 4 (CDK4) in lung cancer and its correlation with clinicopathologic features. Furthermore, the involvement of CDK4-mediated cell cycle progression and its molecular basis were investigated in the pathogenesis of lung cancer. Methods Using immunohistochemistry analysis, we analyzed CDK4 protein expression in 89 clinicopathologically characterized lung cancer patients (59 males and 30 females) with ages ranging from 36 to 78 years and compared them to 23 normal lung tissues. Cases with cytoplasmic and nuclear CDK4 immunostaining score values greater than or equal to 7 were regarded as high expression while scores less than 7 were considered low expression. The correlation between the expression level of CDK4 and clinical features was analyzed. Furthermore, we used lentiviral-mediated shRNA to suppress the expression of CDK4 and investigate its function and molecular mechanism for mediating cell cycle progression. Results The expression level of CDK4 protein was significantly increased in lung cancer tissues compared to normal tissues (P < 0.001). In addition, high levels of CDK4 protein were positively correlated with the status of pathology classification (P = 0.047), lymph node metastasis (P = 0.007), and clinical stage (P = 0.004) of lung cancer patients. Patients with higher CDK4 expression had a markedly shorter overall survival time than patients with low CDK4 expression. Multivariate analysis suggested the level of CDK4 expression was an independent prognostic indicator (P < 0.001) for the survival of patients with lung cancer. Use of lentiviral-mediated shRNA to inhibit the expression of CDK4 in lung cancer cell line A549 not only inhibited cell cycle progression, but also dramatically suppressed cell proliferation, colony formation, and migration. Furthermore, suppressing CDK4 expression also significantly elevated the expression of cell cycle regulator p21

  13. miR-124 downregulation leads to breast cancer progression via LncRNA-MALAT1 regulation and CDK4/E2F1 signal activation

    PubMed Central

    Feng, Tongbao; Shao, Fang; Wu, Qiyong; Zhang, Xiaohang; Xu, Dongqin; Qian, Keqing; Xie, Yewen; Wang, Shizhong; Xu, Ning; Wang, Yong; Qi, Chunjian

    2016-01-01

    The long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been recently shown to be dysregulated in several cancers. However, the mechanisms underlying the role of MALAT1 in breast cancer remain unclear. Herein, we showed that MALAT1 was aberrantly increased in breast cancer tissues and cells. MALAT1-siRNA inhibited breast cancer cell proliferation and cell cycle progression in vitro and in vivo. Furthermore, MALAT1 acted as an endogenous potent regulator by directly binding to miR-124 and down-regulating miR-124 expression. In addition, MALAT1 reversed the inhibitory effect of miR-124 on breast cancer proliferation and was involved in the cyclin-dependent kinase 4 (CDK4) expression. Taken together, our data highlight the pivotal role of MALAT1 in breast cancer tumorigenesis. Moreover, the present study elucidated the MALAT1-miR-124-CDK4/E2F1 signaling pathway in breast cancer, which might provide a new approach for tackling breast cancer. PMID:26918449

  14. miR-124 downregulation leads to breast cancer progression via LncRNA-MALAT1 regulation and CDK4/E2F1 signal activation.

    PubMed

    Feng, Tongbao; Shao, Fang; Wu, Qiyong; Zhang, Xiaohang; Xu, Dongqin; Qian, Keqing; Xie, Yewen; Wang, Shizhong; Xu, Ning; Wang, Yong; Qi, Chunjian

    2016-03-29

    The long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been recently shown to be dysregulated in several cancers. However, the mechanisms underlying the role of MALAT1 in breast cancer remain unclear. Herein, we showed that MALAT1 was aberrantly increased in breast cancer tissues and cells. MALAT1-siRNA inhibited breast cancer cell proliferation and cell cycle progression in vitro and in vivo. Furthermore, MALAT1 acted as an endogenous potent regulator by directly binding to miR-124 and down-regulating miR-124 expression. In addition, MALAT1 reversed the inhibitory effect of miR-124 on breast cancer proliferation and was involved in the cyclin-dependent kinase 4 (CDK4) expression. Taken together, our data highlight the pivotal role of MALAT1 in breast cancer tumorigenesis. Moreover, the present study elucidated the MALAT1-miR-124-CDK4/E2F1 signaling pathway in breast cancer, which might provide a new approach for tackling breast cancer.

  15. Dual Targeting of CDK4 and ARK5 Using a Novel Kinase Inhibitor ON123300 Exerts Potent Anticancer Activity against Multiple Myeloma.

    PubMed

    Perumal, Deepak; Kuo, Pei-Yu; Leshchenko, Violetta V; Jiang, Zewei; Divakar, Sai Krishna Athaluri; Cho, Hearn Jay; Chari, Ajai; Brody, Joshua; Reddy, M V Ramana; Zhang, Weijia; Reddy, E Premkumar; Jagannath, Sundar; Parekh, Samir

    2016-03-01

    Multiple myeloma is a fatal plasma cell neoplasm accounting for over 10,000 deaths in the United States each year. Despite new therapies, multiple myeloma remains incurable, and patients ultimately develop drug resistance and succumb to the disease. The response to selective CDK4/6 inhibitors has been modest in multiple myeloma, potentially because of incomplete targeting of other critical myeloma oncogenic kinases. As a substantial number of multiple myeloma cell lines and primary samples were found to express AMPK-related protein kinase 5(ARK5), a member of the AMPK family associated with tumor growth and invasion, we examined whether dual inhibition of CDK4 and ARK5 kinases using ON123300 results in a better therapeutic outcome. Treatment of multiple myeloma cell lines and primary samples with ON123300 in vitro resulted in rapid induction of cell-cycle arrest followed by apoptosis. ON123300-mediated ARK5 inhibition or ARK5-specific siRNAs resulted in the inhibition of the mTOR/S6K pathway and upregulation of the AMPK kinase cascade. AMPK upregulation resulted in increased SIRT1 levels and destabilization of steady-state MYC protein. Furthermore, ON123300 was very effective in inhibiting tumor growth in mouse xenograft assays. In addition, multiple myeloma cells sensitive to ON123300 were found to have a unique genomic signature that can guide the clinical development of ON123300. Our study provides preclinical evidence that ON123300 is unique in simultaneously inhibiting key oncogenic pathways in multiple myeloma and supports further development of ARK5 inhibition as a therapeutic approach in multiple myeloma.

  16. Staurosporine resistance accompanies DNA tumor virus-induced immortalization and is independent of the expression and activities of ERK1, ERK2, cyclin A, cyclin-dependent kinase (cdk) 2, and cdk4.

    PubMed

    Chang, T; Khalsa, O; Wang, H; Lee, M E; Schlegel, R

    1996-03-01

    Staurosporine, a potent protein kinase inhibitor, has been shown to arrest the growth of a number of normal cell types in the G1 phase of the cell cycle, while having little effect on several transformed lines. We wished to determine whether increased resistance to staurosporine was a common feature of virus-immortalized human cells and whether this phenotype was an early event following the expression of SV40 tumor antigens. Human foreskin keratinocytes immortalized by the SV40 DNA tumor virus displayed an increased resistance to staurosporine-induced growth arrest when compared with normal parental cells, as has been seen in human diploid fibroblasts. Keratinocytes immortalized by human papillomaviruses, or by just the human papillomavirus E6 and E7 oncogenes were also staurosporine resistant, suggesting that this phenotype often accompanies the immortalization of human cells by DNA tumor viruses. Acquisition of staurosporine resistance was a late event during immortalization, because precrisis human diploid fibroblasts that expressed the SV40 large T and small t antigens were not resistant to staurosporine. The same parental cells that were fully immortalized by SV40 were resistant. Staurosporine resistance was not the result of increased activities and/or expression of cyclin A, cyclin-dependent kinase (cdk) 2, cdk4, or the mitogen-activated kinases ERK1 and ERK2. Although increased activities and/or expression of cyclin A and cdk2 and cdk4 proteins, but not ERK1 or ERK2, were associated with immortalization, similar increases were found in staurosporine-sensitive precrisis cells expressing SV40 tumor antigens.

  17. Drosophila cyclin D/Cdk4 regulates mitochondrial biogenesis and aging and sensitizes animals to hypoxic stress

    PubMed Central

    Icreverzi, Amalia; Flor de la Cruz, Aida; Van Voorhies, Wayne A

    2012-01-01

    Drosophila cyclin D (CycD) is the single fly ortholog of the mammalian cyclin D1 and promotes both cell cycle progression and cellular growth. However, little is known about how CycD promotes cell growth. We show here that CycD/Cdk4 hyperactivity leads to increased mitochondrial biogenesis (mitobiogenesis), mitochondrial mass, NRF-1 activity (Tfam transcript levels) and metabolic activity in Drosophila, whereas loss of CycD/Cdk4 activity has the opposite effects. Surprisingly, both CycD/Cdk4 addition and loss of function increase mitochondrial superoxide production and decrease lifespan, indicating that an imbalance in mitobiogenesis may lead to oxidative stress and aging. In addition, we provide multiple lines of evidence indicating that CycD/Cdk4 activity affects the hypoxic status of cells and sensitizes animals to hypoxia. Both mitochondrial and hypoxia-related effects can be detected at global transcriptional level. We propose that mitobiogenesis and the hypoxic stress response have an antagonistic relationship, and that CycD/Cdk4 levels regulate mitobiogenesis contemporaneous to the cell cycle, such that only when cells are sufficiently oxygenated can they proliferate. PMID:22293404

  18. Cdk4 functions in multiple cell types to control Drosophila intestinal stem cell proliferation and differentiation.

    PubMed

    Adlesic, Mojca; Frei, Christian; Frew, Ian J

    2016-01-01

    The proliferation of intestinal stem cells (ISCs) and differentiation of enteroblasts to form mature enteroendocrine cells and enterocytes in the Drosophila intestinal epithelium must be tightly regulated to maintain homeostasis. We show that genetic modulation of CyclinD/Cdk4 activity or mTOR-dependent signalling cell-autonomously regulates enterocyte growth, which influences ISC proliferation and enteroblast differentiation. Increased enterocyte growth results in higher numbers of ISCs and defective enterocyte growth reduces ISC abundance and proliferation in the midgut. Adult midguts deficient for Cdk4 show severe disruption of intestinal homeostasis characterised by decreased ISC self-renewal, enteroblast differentiation defects and low enteroendocrine cell and enterocyte numbers. The ISC/enteroblast phenotypes result from a combination of cell autonomous and non-autonomous requirements for Cdk4 function. One non-autonomous consequence of Cdk4-dependent deficient enterocyte growth is high expression of Delta in ISCs and Delta retention in enteroblasts. We postulate that aberrant activation of the Delta-Notch pathway is a possible partial cause of lost ISC stemness. These results support the idea that enterocytes contribute to a putative stem cell niche that maintains intestinal homeostasis in the Drosophila anterior midgut. PMID:26879465

  19. Cdk4 functions in multiple cell types to control Drosophila intestinal stem cell proliferation and differentiation

    PubMed Central

    Adlesic, Mojca; Frei, Christian; Frew, Ian J.

    2016-01-01

    ABSTRACT The proliferation of intestinal stem cells (ISCs) and differentiation of enteroblasts to form mature enteroendocrine cells and enterocytes in the Drosophila intestinal epithelium must be tightly regulated to maintain homeostasis. We show that genetic modulation of CyclinD/Cdk4 activity or mTOR-dependent signalling cell-autonomously regulates enterocyte growth, which influences ISC proliferation and enteroblast differentiation. Increased enterocyte growth results in higher numbers of ISCs and defective enterocyte growth reduces ISC abundance and proliferation in the midgut. Adult midguts deficient for Cdk4 show severe disruption of intestinal homeostasis characterised by decreased ISC self-renewal, enteroblast differentiation defects and low enteroendocrine cell and enterocyte numbers. The ISC/enteroblast phenotypes result from a combination of cell autonomous and non-autonomous requirements for Cdk4 function. One non-autonomous consequence of Cdk4-dependent deficient enterocyte growth is high expression of Delta in ISCs and Delta retention in enteroblasts. We postulate that aberrant activation of the Delta–Notch pathway is a possible partial cause of lost ISC stemness. These results support the idea that enterocytes contribute to a putative stem cell niche that maintains intestinal homeostasis in the Drosophila anterior midgut. PMID:26879465

  20. Cyclin D and cdk4 Are Required for Normal Development beyond the Blastula Stage in Sea Urchin Embryos

    PubMed Central

    Moore, Jennifer C.; Sumerel, Jan L.; Schnackenberg, Bradley J.; Nichols, Jason A.; Wikramanayake, Athula; Wessel, Gary M.; Marzluff, William F.

    2002-01-01

    cdk4 mRNA and protein are constitutively expressed in sea urchin eggs and throughout embryonic development. In contrast, cyclin D mRNA is barely detectable in eggs and early embryos, when the cell cycles consist of alternating S and M phases. Cyclin D mRNA increases dramatically in embryos at the early blastula stage and remains at a constant level throughout embryogenesis. An increase in cdk4 kinase activity occurs concomitantly with the increase in cyclin D mRNA. Ectopic expression of cyclin D mRNA in eggs arrests development before the 16-cell stage and causes eventual embryonic death, suggesting that activation of cyclin D/cdk4 in cleavage cell cycles is lethal to the embryo. In contrast, blocking cyclin D or cdk4 expression with morpholino antisense oligonucleotides results in normal development of early gastrula-stage embryos but abnormal, asymmetric larvae. These results suggest that in sea urchins, cyclin D and cdk4 are required for normal development and perhaps the patterning of the developing embryo, but may not be directly involved in regulating entry into the cell cycle. PMID:12052892

  1. Involvement of cyclin D1/CDK4 and pRb mediated by PI3K/AKT pathway activation in Pb{sup 2+}-induced neuronal death in cultured hippocampal neurons

    SciTech Connect

    Li Chenchen Xing Tairan Tang Mingliang Yong Wu Yan Dan Deng Hongmin Wang Huili Wang Ming Chen Jutao Ruan Diyun

    2008-06-15

    Lead (Pb) is widely recognized as a neurotoxicant. One of the suggested mechanisms of lead neurotoxicity is apoptotic cell death. And the mechanism by which Pb{sup 2+} causes neuronal death is not well understood. The present study sought to examine the obligate nature of cyclin D1/cyclin-dependent kinase 4 (CDK4), phosphorylation of its substrate retinoblastoma protein (pRb) and its select upstream signal phosphoinositide 3-kinase (PI3K)/AKT pathway in the death of primary cultured rat hippocampal neurons evoked by Pb{sup 2+}. Our data showed that lead treatment of primary hippocampal cultures results in dose-dependent cell death. Inhibition of CDK4 prevented Pb{sup 2+}-induced neuronal death significantly but was incomplete. In addition, we demonstrated that the levels of cyclin D1 and pRb/p107 were increased during Pb{sup 2+} treatment. These elevated expression persisted up to 48 h, returning to control levels after 72 h. We also presented pharmacological and morphological evidences that cyclin D1/CDK4 and pRb/p107 were required for such kind of neuronal death. Addition of the PI3K inhibitor LY294002 (30 {mu}M) or wortmannin (100 nM) significantly rescued the cultured hippocampal neurons from death caused by Pb{sup 2+}. And that Pb{sup 2+}-elicited phospho-AKT (Ser473) participated in the induction of cyclin D1 and partial pRb/p107 expression. These results provide evidences that cell cycle elements play a required role in the death of neurons evoked by Pb{sup 2+} and suggest that certain signaling elements upstream of cyclin D1/CDK4 are modified and/or required for this form of neuronal death.

  2. Cyclin D1-CDK4 Controls Glucose Metabolism Independently of Cell Cycle Progression

    PubMed Central

    Lee, Yoonjin; Dominy, John E.; Choi, Yoon Jong; Jurczak, Michael; Tolliday, Nicola; Camporez, Joao Paulo; Chim, Helen; Lim, Ji-Hong; Ruan, Hai-Bin; Yang, Xiaoyong; Vazquez, Francisca; Sicinski, Piotr; Shulman, Gerald I.; Puigserver, Pere

    2014-01-01

    Insulin constitutes a major evolutionarily conserved hormonal axis for maintaining glucose homeostasis1-3; dysregulation of this axis causes diabetes2,4. PGC-1α links insulin signaling to the expression of glucose and lipid metabolic genes5-7. GCN5 acetylates PGC-1α and suppresses its transcriptional activity, whereas SIRT1 deacetylates and activates PGC-1α8,9. Although insulin is a mitogenic signal in proliferative cells10,11, whether components of the cell cycle machinery contribute to insulin’s metabolic action is poorly understood. Herein, we report that insulin activates cyclin D1-CDK4, which, in turn, increases GCN5 acetyltransferase activity and suppresses hepatic glucose production independently of cell cycle progression. Through a cell-based high throughput chemical screen, we identified a CDK4 inhibitor that potently decreases PGC-1α acetylation. Insulin/GSK3β signaling induces cyclin D1 protein stability via sequestering cyclin D1 in the nucleus. In parallel, dietary amino acids increase hepatic cyclin D1 mRNA transcripts. Activated cyclin D1-CDK4 kinase phosphorylates and activates GCN5, which then acetylates and inhibits PGC-1α activity on gluconeogenic genes. Loss of hepatic cyclin D1 results in increased gluconeogenesis and hyperglycemia. In diabetic models, cyclin D1-CDK4 is chronically elevated and refractory to fasting/feeding transitions; nevertheless further activation of this kinase normalizes glycemia. Our findings show that insulin uses components of the cell cycle machinery in post-mitotic cells to control glucose homeostasis independently of cell division. PMID:24870244

  3. A CDK4/6-Dependent Epigenetic Mechanism Protects Cancer Cells from PML-induced Senescence.

    PubMed

    Acevedo, Mariana; Vernier, Mathieu; Mignacca, Lian; Lessard, Frédéric; Huot, Geneviève; Moiseeva, Olga; Bourdeau, Véronique; Ferbeyre, Gerardo

    2016-06-01

    Promyelocytic leukemia (PML) plays a tumor suppressive role by inducing cellular senescence in response to oncogenic stress. However, tumor cell lines fail to engage in complete senescence upon PML activation. In this study, we investigated the mechanisms underlying resistance to PML-induced senescence. Here, we report that activation of the cyclin-dependent kinases CDK4 and CDK6 are essential and sufficient to impair senescence induced by PML expression. Disrupting CDK function by RNA interference or pharmacological inhibition restored senescence in tumor cells and diminished their tumorigenic potential in mouse xenograft models. Complete senescence correlated with an increase in autophagy, repression of E2F target genes, and an gene expression signature of blocked DNA methylation. Accordingly, treatment of tumor cells with inhibitors of DNA methylation reversed resistance to PML-induced senescence. Further, CDK inhibition with palbociclib promoted autophagy-dependent degradation of the DNA methyltransferase DNMT1. Lastly, we found that CDK4 interacted with and phosphorylated DNMT1 in vitro, suggesting that CDK activity is required for its stabilization. Taken together, our findings highlight a potentially valuable feature of CDK4/6 inhibitors as epigenetic modulators to facilitate activation of senescence programs in tumor cells. Cancer Res; 76(11); 3252-64. ©2016 AACR.

  4. Drug Synergy Screen and Network Modeling in Dedifferentiated Liposarcoma Identifies CDK4 and IGF1R as Synergistic Drug Targets

    PubMed Central

    Miller, Martin L.; Molinelli, Evan J.; Nair, Jayasree S.; Sheikh, Tahir; Samy, Rita; Jing, Xiaohong; He, Qin; Korkut, Anil; Crago, Aimee M.; Singer, Samuel; Schwartz, Gary K.; Sander, Chris

    2014-01-01

    Dedifferentiated liposarcoma (DDLS) is a rare but aggressive cancer with high recurrence and low response rates to targeted therapies. Increasing treatment efficacy may require combinations of targeted agents that counteract the effects of multiple abnormalities. To identify a possible multicomponent therapy, we performed a combinatorial drug screen in a DDLS-derived cell line and identified cyclin-dependent kinase 4 (CDK4) and insulin-like growth factor 1 receptor (IGF1R) as synergistic drug targets. We measured the phosphorylation of multiple proteins and cell viability in response to systematic drug combinations and derived computational models of the signaling network. These models predict that the observed synergy in reducing cell viability with CDK4 and IGF1R inhibitors depend on activity of the AKT pathway. Experiments confirmed that combined inhibition of CDK4 and IGF1R cooperatively suppresses the activation of proteins within the AKT pathway. Consistent with these findings, synergistic reductions in cell viability were also found when combining CDK4 inhibition with inhibition of either AKT or epidermal growth factor receptor (EGFR), another receptor similar to IGF1R that activates AKT. Thus, network models derived from context-specific proteomic measurements of systematically perturbed cancer cells may reveal cancer-specific signaling mechanisms and aid in the design of effective combination therapies. PMID:24065146

  5. Pharmacologic inhibition of cdk4/6 arrests the growth of glioblastoma multiforme intracranial xenografts

    PubMed Central

    Michaud, Karine; Solomon, David A.; Oermann, Eric; Kim, Jung-Sik; Zhong, Wei-Zhu; Prados, Michael D.; Ozawa, Tomoko; James, C. David; Waldman, Todd

    2010-01-01

    Activation of cyclin-dependent kinases 4 and 6 (cdk4/6) occurs in the majority of glioblastoma multiforme (GBM) tumors, and represents a promising molecular target for the development of small molecule inhibitors. In the current study we investigated the molecular determinants and in vivo response of diverse GBM cell lines and xenografts to PD-0332991, a cdk4/6 specific inhibitor. In vitro testing of PD-0332991 against a panel of GBM cell lines revealed a potent G1 cell cycle arrest and induction of senescence in each of 16 Rb-proficient cell lines regardless of other genetic lesions, whereas each of 5 cell lines with homozygous inactivation of Rb were completely resistant to treatment. shRNA depletion of Rb expression conferred resistance of GBM cells to PD-0332991, further demonstrating a requirement of Rb for sensitivity to cdk4/6 inhibition. PD-0332991 was found to efficiently cross the blood-brain barrier and proved highly effective in suppressing the growth of intracranial GBM xenograft tumors, including those that had recurred after initial therapy with temozolomide. Remarkably, no mice receiving PD-0332991 had significant disease progression or died while on therapy. Additionally, the combination of PD-0332991 and radiation therapy resulted in significantly increased survival benefit compared with either therapy alone. In total, our results support clinical trial evaluation of PD-0332991 against newly-diagnosed as well as recurrent GBM, and indicate that Rb status is the primary determinant of potential benefit from this therapy. PMID:20354191

  6. Multipotent neurogenic fate of mesenchymal stem cell is determined by Cdk4-mediated hypophosphorylation of Smad-STAT3.

    PubMed

    Kim, Dong-Young; Lee, Janet; Kang, Dongrim; Lee, Do-Hyeong; Kim, Yoon-Ja; Hwang, Sang-Gu; Kim, Dong-Ik; Lee, Chang-Woo; Lee, Kyung-Hoon

    2016-07-01

    Cyclin-dependent kinase (Cdk) in complex with a corresponding cyclin plays a pivotal role in neurogenic differentiation. In particular, Cdk4 activity acts as a signaling switch to direct human mesenchymal stem cells (MSCs) to neural transdifferentiation. However, the molecular evidence of how Cdk4 activity converts MSCs to neurogenic lineage remains unknown. Here, we found that Cdk4 inhibition in human MSCs enriches the populations of neural stem and progenitor pools rather than differentiated glial and neuronal cell pools. Interestingly, Cdk4 inhibition directly inactivates Smads and subsequently STAT3 signaling by hypophosphorylation, and both Cdk4 and Smads levels are linked during the processes of neural transdifferentiation and differentiation. In summary, our results provide novel molecular evidence in which Cdk4 inhibition leads to directing human MSCs to a multipotent neurogenic fate by inactivating Smads-STAT3 signaling. PMID:27192561

  7. The Drosophila Cyclin D–Cdk4 complex promotes cellular growth

    PubMed Central

    Datar, Sanjeev A.; Jacobs, Henning W.; de la Cruz, Aida Flor A.; Lehner, Christian F.; Edgar, Bruce A.

    2000-01-01

    Mammalian cyclin D–Cdk4 complexes have been characterized as growth factor-responsive cell cycle regulators. Their levels rise upon growth factor stimulation, and they can phosphorylate and thus neutralize Retinoblastoma (Rb) family proteins to promote an E2F-dependent transcriptional program and S-phase entry. Here we characterize the in vivo function of Drosophila Cyclin D (CycD). We find that Drosophila CycD–Cdk4 does not act as a direct G1/S-phase regulator, but instead promotes cellular growth (accumulation of mass). The cellular response to CycD–Cdk4-driven growth varied according to cell type. In undifferentiated proliferating wing imaginal cells, CycD–Cdk4 caused accelerated cell division (hyperplasia) without affecting cell cycle phasing or cell size. In endoreplicating salivary gland cells, CycD–Cdk4 caused excessive DNA replication and cell enlargement (hypertrophy). In differentiating eyes, CycD–Cdk4 caused cell enlargement (hypertrophy) in post-mitotic cells. Interaction tests with a Drosophila Rb homolog, RBF, indicate that CycD–Cdk4 can counteract the cell cycle suppressive effects of RBF, but that its growth promoting activity is mediated at least in part via other targets. PMID:10970848

  8. Cytotoxicity of diacetoxyscirpenol is associated with apoptosis by activation of caspase-8 and interruption of cell cycle progression by down-regulation of cdk4 and cyclin B1 in human Jurkat T cells

    SciTech Connect

    Jun, Do Youn; Kim, Jun Seok; Park, Hae Sun; Song, Woo Sun; Bae, Young Seuk; Kim, Young Ho . E-mail: ykim@knu.ac.kr

    2007-07-15

    To understand the mechanism underlying T-cell toxicity of diacetoxyscirpenol (DAS) from Fusarium sambucinum, its apoptogenic as well as growth retardation activity was investigated in human Jurkat T cells. Exposure to DAS (0.01-0.15 {mu}M) caused apoptotic DNA fragmentation along with caspase-8 activation, Bid cleavage, mitochondrial cytochrome c release, activation of caspase-9 and caspase-3, and PARP degradation, without any alteration in the levels of Fas or FasL. Under these conditions, necrosis was not accompanied. The cytotoxicity of DAS was not blocked by the anti-Fas neutralizing antibody ZB-4. Although the DAS-induced apoptotic events were completely prevented by overexpression of Bcl-xL, the cells overexpressing Bcl-xL were unable to divide in the presence of DAS, resulting from the failure of cell cycle progression possibly due to down-regulation in the protein levels of cdk4 and cyclin B1. The DAS-mediated apoptosis and activation of caspase-8, -9, and -3 were abrogated by either pan-caspase inhibitor (z-VAD-fmk) or caspase-8 inhibitor (z-IETD-fmk). While the DAS-mediated apoptosis and activation of caspase-9 and caspase-3 were slightly suppressed by the mitochondrial permeability transition pore inhibitor (CsA), both caspase-8 activation and Bid cleavage were not affected by CsA. The activated normal peripheral T cells possessed a similar susceptibility to the cytotoxicity of DAS. These results demonstrate that the T-cell toxicity of DAS is attributable to not only apoptosis initiated by caspase-8 activation and subsequent mitochondrion-dependent or -independent activation of caspase cascades, which can be regulated by Bcl-xL, but also interruption of cell cycle progression caused by down-regulation of cdk4 and cyclin B1 proteins.

  9. Inhibition of cyclin D-CDK4/CDK6 activity is associated with an E2F-mediated induction of cyclin kinase inhibitor activity.

    PubMed

    Khleif, S N; DeGregori, J; Yee, C L; Otterson, G A; Kaye, F J; Nevins, J R; Howley, P M

    1996-04-30

    Alterations of various components of the cell cycle regulatory machinery that controls the progression of cells from a quiescent to a growing state contribute to the development of many human cancers. Such alterations include the deregulated expression of G1 cyclins, the loss of function of activities such as those of protein p16INK4a that control G1 cyclin-dependent kinase activity, and the loss of function of the retinoblastoma protein (RB), which is normally regulated by the G1 cyclin-dependent kinases. Various studies have revealed an inverse relationship in the expression of p16INK4a protein and the presence of functional RB in many cell lines. In this study we show that p16INK4a is expressed in cervical cancer cell lines in which the RB gene, Rb, is not functional, either as a consequence of Rb mutation or expression of the human papillomavirus E7 protein. We also demonstrate that p16INK4a levels are increased in primary cells in which RB has been inactivated by DNA tumor virus proteins. Given the role of RB in controlling E2F transcription factor activity, we investigated the role of E2F in controlling p16INK4a expression. We found that E2F1 overexpression leads to an inhibition of cyclin D1-dependent kinase activity and induces the expression of a p16-related transcript. We conclude that the accumulation of G1 cyclin-dependent kinase activity during normal G1 progression leads to E2F accumulation through the inactivation of RB, and that this then leads to the induction of cyclin kinase inhibitor activity and a shutdown of G1 kinase activity.

  10. p16/CDKN2 and CDK4 gene mutations in sporadic melanoma development and progression.

    PubMed

    Piccinin, S; Doglioni, C; Maestro, R; Vukosavljevic, T; Gasparotto, D; D'Orazi, C; Boiocchi, M

    1997-02-20

    The p16/CDKN2(MTS1) gene encoding for the p16 inhibitor of cyclin D/CDK4 complexes is frequently mutated and deleted in a large fraction of melanoma cell lines, and p16 germline mutations have also been observed in familial melanomas. Moreover, a CDK4 gene mutation, responsible for a functional resistance of CDK4 kinase to p16 inhibitory activity, has been described to occur in some cases of familial melanoma. These data strongly support the idea that deregulation of the CDK4/cyclin D pathway, via CDKN2 or CDK4 mutations, is of biological significance in the development of melanoma. To shed light on the role of these alterations in the development and progression of sporadic melanoma, 12 primary melanomas and 9 corresponding metastases were analyzed for CDKN2 and CDK4 gene mutations. Of the 12 primary melanomas analyzed, 4 showed the presence of mutational inactivation of the p 16 protein and 2 carried silent mutations. No metastases showed the presence of CDKN2 mutations, indicating that mutations of this cyclin-dependent kinase inhibitor is not common in the progression of sporadic melanoma. On the other hand, the absence, in the metastases, of the CDKN2 mutation detected in the corresponding primary tumors suggests that 9p21 homozygous deletion may play a major role in the metastatic spreading of this type of tumor. None of the cases analyzed showed the presence of an Arg24Cys mutation, which functionally protects CDK4 from p16 inhibition. This indicates that CDK4 mutation plays a minor role in the development and progression of sporadic melanoma.

  11. Cell-cell contact regulates gene expression in CDK4-transformed mouse podocytes

    PubMed Central

    Sakairi, Toru; Abe, Yoshifusa; Jat, Parmijit S.

    2010-01-01

    We transformed mouse podocytes by ectopic expression of cyclin-dependent kinase 4 (CDK4). Compared with podocytes transformed with a thermo-sensitive SV40 large T antigen mutant tsA58U19 (tsT podocytes), podocytes transformed with CDK4 (CDK4 podocytes) exhibited significantly higher expression of nephrin mRNA. Synaptopodin mRNA expression was significantly lower in CDK4 podocytes and in tsT podocytes under growth-permissive conditions (33°C) compared with tsT podocytes under growth-restricted conditions (37°C), which suggests a role for cell cycle arrest in synaptopodin mRNA expression. Confluent CDK4 podocytes showed significantly higher mRNA expression levels for nephrin, synaptopodin, Wilms tumor 1, podocalyxin, and P-cadherin compared with subconfluent cultures. We carried out experiments to clarify roles of various factors in the confluent podocyte cultures; our findings indicate that cell-cell contact promotes expression of five podocyte marker genes studied, that cellular quiescence increases synaptopodin and podocalyxin mRNA expression, and that soluble factors play a role in nephrin mRNA expression. Our findings suggest that CDK4 podocytes are useful tools to study podocyte biology. Furthermore, the role of cell-cell contact in podocyte gene expression may have relevance for podocyte function in vivo. PMID:20668098

  12. Artemisinin blocks prostate cancer growth and cell cycle progression by disrupting Sp1 interactions with the cyclin-dependent kinase-4 (CDK4) promoter and inhibiting CDK4 gene expression.

    PubMed

    Willoughby, Jamin A; Sundar, Shyam N; Cheung, Mark; Tin, Antony S; Modiano, Jaime; Firestone, Gary L

    2009-01-23

    Artemisinin, a naturally occurring component of Artemisia annua, or sweet wormwood, is a potent anti-malaria compound that has recently been shown to have anti-proliferative effects on a number of human cancer cell types, although little is know about the molecular mechanisms of this response. We have observed that artemisinin treatment triggers a stringent G1 cell cycle arrest of LNCaP (lymph node carcinoma of the prostate) human prostate cancer cells that is accompanied by a rapid down-regulation of CDK2 and CDK4 protein and transcript levels. Transient transfection with promoter-linked luciferase reporter plasmids revealed that artemisinin strongly inhibits CDK2 and CDK4 promoter activity. Deletion analysis of the CDK4 promoter revealed a 231-bp artemisinin-responsive region between -1737 and -1506. Site-specific mutations revealed that the Sp1 site at -1531 was necessary for artemisinin responsiveness in the context of the CDK4 promoter. DNA binding assays as well as chromatin immunoprecipitation assays demonstrated that this Sp1-binding site in the CDK4 promoter forms a specific artemisinin-responsive DNA-protein complex that contains the Sp1 transcription factor. Artemisinin reduced phosphorylation of Sp1, and when dephosphorylation of Sp1 was inhibited by treatment of cells with the phosphatase inhibitor okadaic acid, the ability of artemisinin to down-regulate Sp1 interactions with the CDK4 promoter was ablated, rendering the CDK4 promoter unresponsive to artemisinin. Finally, overexpression of Sp1 mostly reversed the artemisinin down-regulation of CDK4 promoter activity and partially reversed the cell cycle arrest. Taken together, our results demonstrate that a key event in the artemisinin anti-proliferative effects in prostate cancer cells is the transcriptional down-regulation of CDK4 expression by disruption of Sp1 interactions with the CDK4 promoter. PMID:19017637

  13. Artemisinin Blocks Prostate Cancer Growth and Cell Cycle Progression by Disrupting Sp1 Interactions with the Cyclin-dependent Kinase-4 (CDK4) Promoter and Inhibiting CDK4 Gene Expression*

    PubMed Central

    Willoughby, Jamin A.; Sundar, Shyam N.; Cheung, Mark; Tin, Antony S.; Modiano, Jaime; Firestone, Gary L.

    2009-01-01

    Artemisinin, a naturally occurring component of Artemisia annua, or sweet wormwood, is a potent anti-malaria compound that has recently been shown to have anti-proliferative effects on a number of human cancer cell types, although little is know about the molecular mechanisms of this response. We have observed that artemisinin treatment triggers a stringent G1 cell cycle arrest of LNCaP (lymph node carcinoma of the prostate) human prostate cancer cells that is accompanied by a rapid down-regulation of CDK2 and CDK4 protein and transcript levels. Transient transfection with promoter-linked luciferase reporter plasmids revealed that artemisinin strongly inhibits CDK2 and CDK4 promoter activity. Deletion analysis of the CDK4 promoter revealed a 231-bp artemisinin-responsive region between -1737 and -1506. Site-specific mutations revealed that the Sp1 site at -1531 was necessary for artemisinin responsiveness in the context of the CDK4 promoter. DNA binding assays as well as chromatin immunoprecipitation assays demonstrated that this Sp1-binding site in the CDK4 promoter forms a specific artemisinin-responsive DNA-protein complex that contains the Sp1 transcription factor. Artemisinin reduced phosphorylation of Sp1, and when dephosphorylation of Sp1 was inhibited by treatment of cells with the phosphatase inhibitor okadaic acid, the ability of artemisinin to down-regulate Sp1 interactions with the CDK4 promoter was ablated, rendering the CDK4 promoter unresponsive to artemisinin. Finally, overexpression of Sp1 mostly reversed the artemisinin down-regulation of CDK4 promoter activity and partially reversed the cell cycle arrest. Taken together, our results demonstrate that a key event in the artemisinin anti-proliferative effects in prostate cancer cells is the transcriptional down-regulation of CDK4 expression by disruption of Sp1 interactions with the CDK4 promoter. PMID:19017637

  14. CDK4 coexpression with Ras generates malignant human epidermal tumorigenesis.

    PubMed

    Lazarov, Mirella; Kubo, Yoshiaki; Cai, Ti; Dajee, Maya; Tarutani, Masahito; Lin, Qun; Fang, Min; Tao, Shiying; Green, Cheryl L; Khavari, Paul A

    2002-10-01

    Ras acts with other proteins to induce neoplasia. By itself, however, strong Ras signaling can suppress proliferation of normal cells. In primary epidermal cells, we found that oncogenic Ras transiently decreases cyclin-dependent kinase (CDK) 4 expression in association with cell cycle arrest in G1 phase. CDK4 co-expression circumvents Ras growth suppression and induces invasive human neoplasia resembling squamous cell carcinoma. Tumorigenesis is dependent on CDK4 kinase function, with cyclin D1 required but not sufficient for this process. In facilitating escape from G1 growth restraints, Ras and CDK4 alter the composition of cyclin D and cyclin E complexes and promote resistance to growth inhibition by INK4 cyclin-dependent kinase inhibitors. These data identify a new role for oncogenic Ras in CDK4 regulation and highlight the functional importance of CDK4 suppression in preventing uncontrolled growth.

  15. Rb and FZR1/Cdh1 determine CDK4/6-cyclin D requirement in C. elegans and human cancer cells.

    PubMed

    The, Inge; Ruijtenberg, Suzan; Bouchet, Benjamin P; Cristobal, Alba; Prinsen, Martine B W; van Mourik, Tim; Koreth, John; Xu, Huihong; Heck, Albert J R; Akhmanova, Anna; Cuppen, Edwin; Boxem, Mike; Muñoz, Javier; van den Heuvel, Sander

    2015-01-01

    Cyclin-dependent kinases 4 and 6 (CDK4/6) in complex with D-type cyclins promote cell cycle entry. Most human cancers contain overactive CDK4/6-cyclin D, and CDK4/6-specific inhibitors are promising anti-cancer therapeutics. Here, we investigate the critical functions of CDK4/6-cyclin D kinases, starting from an unbiased screen in the nematode Caenorhabditis elegans. We found that simultaneous mutation of lin-35, a retinoblastoma (Rb)-related gene, and fzr-1, an orthologue to the APC/C co-activator Cdh1, completely eliminates the essential requirement of CDK4/6-cyclin D (CDK-4/CYD-1) in C. elegans. CDK-4/CYD-1 phosphorylates specific residues in the LIN-35 Rb spacer domain and FZR-1 amino terminus, resembling inactivating phosphorylations of the human proteins. In human breast cancer cells, simultaneous knockdown of Rb and FZR1 synergistically bypasses cell division arrest induced by the CDK4/6-specific inhibitor PD-0332991. Our data identify FZR1 as a candidate CDK4/6-cyclin D substrate and point to an APC/C(FZR1) activity as an important determinant in response to CDK4/6-inhibitors.

  16. A possible usage of a CDK4 inhibitor for breast cancer stem cell-targeted therapy

    SciTech Connect

    Han, Yu Kyeong; Lee, Jae Ho; Park, Ga-Young; Chun, Sung Hak; Han, Jeong Yun; Kim, Sung Dae; Lee, Janet; Lee, Chang-Woo; Yang, Kwangmo; Lee, Chang Geun

    2013-01-25

    Highlights: ► A CDK4 inhibitor may be used for breast cancer stem cell-targeted therapy. ► The CDK4 inhibitor differentiated the cancer stem cell population (CD24{sup −}/CD44{sup +}) of MDA-MB-231. ► The differentiation of the cancer stem cells by the CDK4 inhibitor radiosensitized MDA-MB-231. -- Abstract: Cancer stem cells (CSCs) are one of the main reasons behind cancer recurrence due to their resistance to conventional anti-cancer therapies. Thus, many efforts are being devoted to developing CSC-targeted therapies to overcome the resistance of CSCs to conventional anti-cancer therapies and decrease cancer recurrence. Differentiation therapy is one potential approach to achieve CSC-targeted therapies. This method involves inducing immature cancer cells with stem cell characteristics into more mature or differentiated cancer cells. In this study, we found that a CDK4 inhibitor sensitized MDA-MB-231 cells but not MCF7 cells to irradiation. This difference appeared to be associated with the relative percentage of CSC-population between the two breast cancer cells. The CDK4 inhibitor induced differentiation and reduced the cancer stem cell activity of MDA-MB-231 cells, which are shown by multiple marker or phenotypes of CSCs. Thus, these results suggest that radiosensitization effects may be caused by reducing the CSC-population of MDA-MB-231 through the use of the CDK4 inhibitor. Thus, further investigations into the possible application of the CDK4 inhibitor for CSC-targeted therapy should be performed to enhance the efficacy of radiotherapy for breast cancer.

  17. Overcoming Endocrine Resistance in Hormone-Receptor Positive Advanced Breast Cancer-The Emerging Role of CDK4/6 Inhibitors

    PubMed Central

    O’Sullivan, Ciara C

    2015-01-01

    Dysregulation of the cyclin D and cyclin-dependent kinase (CDK) pathway in cancer cells may inhibit senescence and promote cellular proliferation. By using various different mechanisms, malignant cells may increase cyclin D-dependent activity. The cyclin D-cyclin-dependent kinases 4 and 6 (CDK4/6)-retinoblastoma (Rb) pathway controls the cell cycle restriction point, and is commonly dysregulated in breast cancer; making it a rational target for anticancer therapy. To date, three oral highly selective cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) are in various stages of clinical development: PD0332991 (palbociclib), LEE011 (ribociclib) and LY2835219 (abemaciclib). Results from phase I, II and III trials in hormone-receptor (HR)-positive breast cancer have been encouraging, demonstrating convincing efficacy and a tolerable side-effect profile (mainly uncomplicated neutropenia). This article will review the preclinical and clinical development of the CDK4/6i, as well as reviewing the existing preclinical evidence regarding combination of these agents with chemotherapy and other targeted therapies. Future and ongoing clinical trials, which may expand the potential application of these agents, will also be discussed. In summary, CDK4/6i are exciting compounds which may change the therapeutic landscape of HR-positive breast cancer. PMID:26726315

  18. CDK4/6 inhibitor PD 0332991 sensitizes acute myeloid leukemia to cytarabine-mediated cytotoxicity

    PubMed Central

    Yang, Chenyi; Boyson, Cynthia A.; Di Liberto, Maurizio; Huang, Xiangao; Hannah, Jeffrey; Dorn, David C.; Moore, Malcolm AS; Chen-Kiang, Selina; Zhou, Pengbo

    2015-01-01

    Cyclin-dependent kinase (CDK)4 and CDK6 are frequently overexpressed or hyperactivated in human cancers. Targeting CDK4/CDK6 in combination with cytotoxic killing therefore represents a rational approach to cancer therapy. By selective inhibition of CDK4/CDK6 with PD 0332991, which leads to early G1 arrest and synchronous S phase entry upon release of the G1 block, we have developed a novel strategy to prime acute myeloid leukemia (AML) cells for cytotoxic killing by cytarabine (Ara-C). This sensitization is achieved in part through enrichment of S-phase cells, which maximizes the AML populations for Ara-C incorporation into replicating DNA to elicit DNA damage. Moreover, PD 0332991 trigged apoptosis of AML cells through inhibition of the homeobox (HOX)A9 oncogene expression, reducing the transcription of its target PIM1. Reduced PIM1 synthesis attenuates PIM1-mediated phosphorylation of the pro-apoptotic BAD and activates BAD-dependent apoptosis. In vivo, timely inhibition of CDK4/CDK6 by PD 0332991 and release profoundly suppresses tumor growth in response to reduced doses of Ara-C in a xenograft AML model. Collectively, these data suggest selective and reversible inhibition of CDK4/CDK6 as an effective means to enhance Ara-C killing of AML cells at reduced doses, which has implications for the treatment of elderly AML patients who are unable to tolerate high dose Ara-C therapy. PMID:25744718

  19. CDK4/6 inhibition provides a potent adjunct to Her2-targeted therapies in preclinical breast cancer models

    PubMed Central

    Witkiewicz, Agnieszka K.; Cox, Derek; Knudsen, Erik S.

    2014-01-01

    In spite of the efficacy of Her2-targeted therapies, recurrence and progression remain a challenge for treatment of Her2 positive breast cancer. CDK4/6 controls pathway downstream of Her2, Inhibition of these kinases could represent an important therapeutic approach to augment the effectiveness of standard therapies. In models of acquired resistance to Her2-targeted therapies, Cyclin D1 was inappropriately activated and CDK4/6 inhibition was effective at blocking proliferation by targeting this common pathway associated with resistance. These data were recapitulated in Her2 positive xenografts. Furthermore, in a series of 35 primary breast tumor explants, treatment with PD-0332991 resulted in a greater than 4-fold suppression of the Ki67. The effects of CDK4/6 inhibition were dependent on an intact RB-pathway, and consonantly, loss of RB and high-levels of p16 were associated with resistance to CDK4/6 inhibition. Combination studies illustrated that CDK4/6 inhibition is cooperative with multiple Her2-targeted agents and provides a complementary mechanism of action to T-DM1 to efficiently suppresses the proliferation of residual Her2-positive tumor cell populations that survive T-DM1. Together, these data indicate CDK4/6 is a viable therapeutic target that functions downstream of Her2, and tissue based markers are available to direct rational utilization of CDK4/6 inhibitors in combination with Her2-targeted agents. PMID:25221644

  20. Rarity of CDK4 germline mutations in familial melanoma.

    PubMed

    Goldstein, A M; Chidambaram, A; Halpern, A; Holly, E A; Guerry IV, D; Sagebiel, R; Elder, D E; Tucker, M A

    2002-02-01

    To date, two genes have been implicated in melanoma pathogenesis. The first, CDKN2A, is a tumour suppressor gene with germline mutations detected in 20% of melanoma-prone families. The second, CDK4, is an oncogene with co-segregating germline mutations detected in only three kindreds worldwide. We examined 16 American melanoma-prone families for mutations in all coding exons of CDK4 and screened additional members of two previously reported families with the Arg24Cys germline CDK4 mutation to evaluate the penetrance of the mutation. No new CDK4 mutations were identified. In the two Arg24Cys families, the penetrance was estimated to be 63%. Overall, 12 out of 12 invasive melanoma patients, none out of one in situ melanoma patient, five out of 13 dysplastic naevi patients, two out of 15 unaffected family members, and none out of 10 spouses carried the Arg24Cys mutation. Dysplastic naevi did not strongly co-segregate with the Arg24Cys mutation. Thus the phenotype observed in melanoma-prone CDK4 families appears to be more complex than just the CDK4 mutation. Both genetic and environmental factors are likely to contribute to the occurrence of melanoma and dysplastic naevi in these families. In summary, although CDK4 is a melanoma susceptibility gene, it plays a minor role in hereditary melanoma.

  1. CDK4 regulates cancer stemness and is a novel therapeutic target for triple-negative breast cancer

    PubMed Central

    Dai, Meiou; Zhang, Chenjing; Ali, Ayad; Hong, Xinyuan; Tian, Jun; Lo, Chieh; Fils-Aimé, Nadège; Burgos, Sergio A.; Ali, Suhad; Lebrun, Jean-Jacques

    2016-01-01

    Triple negative breast cancers exhibit very aggressive features and poor patient outcomes. These tumors are enriched in cancer stem cells and exhibit resistance to most treatments and chemotherapy. In this study, we found the cyclin-dependent kinase (CDK4) to act as a cancer stem cell regulator and novel prognostic marker in triple negative breast cancers. We found CDK4 to be highly expressed in these tumors and its expression to correlate with poor overall and relapse free survival outcomes, high tumor grade and poor prognostic features of triple negative breast cancer patients. Moreover, we found that blocking CDK4 expression or kinase activity, using a pharmacological inhibitor prevented breast cancer stem cell self-renewal. Interestingly, suppression of CDK4 expression or kinase activity reversed the basal-B TNBC mesenchymal phenotype to an epithelial- and luminal-like phenotype which correlates with better clinical prognosis. Finally, blocking CDK4 activity efficiently eliminated both normal and chemotherapy-resistant cancer cells in triple negative breast cancers, highlighting CDK4 as a promising novel therapeutic target for these aggressive breast tumors. PMID:27759034

  2. Cdk4 and Cdk6 cooperate in counteracting the INK4 family of inhibitors during murine leukemogenesis.

    PubMed

    Rodríguez-Díez, Esther; Quereda, Victor; Bellutti, Florian; Prchal-Murphy, Michaela; Partida, David; Eguren, Manuel; Kollmann, Karoline; Gómez de Cedrón, Marta; Dubus, Pierre; Cañamero, Marta; Martínez, Dolores; Sexl, Veronika; Malumbres, Marcos

    2014-10-01

    Cdk4 and Cdk6 are related protein kinases that bind d-type cyclins and regulate cell-cycle progression. Cdk4/6 inhibitors are currently being used in advanced clinical trials and show great promise against many types of tumors. Cdk4 and Cdk6 are inhibited by INK4 proteins, which exert tumor-suppressing functions. To test the significance of this inhibitory mechanism, we generated knock-in mice that express a Cdk6 mutant (Cdk6 R31C) insensitive to INK4-mediated inhibition. Cdk6(R/R) mice display altered development of the hematopoietic system without enhanced tumor susceptibility, either in the presence or absence of p53. Unexpectedly, Cdk6 R31C impairs the potential of hematopoietic progenitors to repopulate upon adoptive transfer or after 5-fluorouracil-induced damage. The defects are overcome by eliminating sensitivity of cells to INK4 inhibitors by introducing the INK4-insensitive Cdk4 R24C allele, and INK4-resistant mice are more susceptible to hematopoietic and endocrine tumors. In BCR-ABL-transformed hematopoietic cells, Cdk6 R31C causes increased binding of p16(INK4a) to wild-type Cdk4, whereas cells harboring Cdk4 R24C and Cdk6 R31C are fully insensitive to INK4 inhibitors, resulting in accelerated disease onset. Our observations reveal that Cdk4 and Cdk6 cooperate in hematopoietic tumor development and suggest a role for Cdk6 in sequestering INK4 proteins away from Cdk4.

  3. Simulation of Different Truncated p16INK4a Forms and In Silico Study of Interaction with Cdk4

    PubMed Central

    Fahham, Najmeh; Ghahremani, Mohammad Hossein; Sardari, Soroush; Vaziri, Behrouz; Ostad, Seyed Nasser

    2008-01-01

    Protein-protein interactions studies can greatly increase the amount of structural and functional information pertaining to biologically active molecules and processes. The information obtained from such studies can lead to design and application of new modification in order to obtain a desired bioactivity. Many application packages and servers performing docking, such as HEX, DOT, AUTODOCK, and ZDOCK are now available for predicting the lowest free energy state of a protein complex. In this study, we have focused on cyclin-dependent kinase 4 (Cdk4), a key molecule in the regulation of cell cycle progression at the G1-S phase restriction point and p16INK4a, a tumor suppressor which inhibits Cdk4 activity. Truncated structures were created to find the more critical regions of p16 for interaction. The tertiary structures were determined by ProSAL, GENO3D Web Server. We evaluated their interactions with Cdk4 using two docking systems, HEX 4.5 and DOT 1. Calculations were performed on a high-speed computer. Minimizations and visualizations were carried out by PdbViewer 3.7. Considering shape and shape/electrostatic total energy, structures containing ANK II, III and IV motifs that lack the N-terminal region of the full length p16 molecule showed the best fit complexes among the p16 truncated forms. The free energies were compatible with that of p16 full length original form, the full length. It seems that the N-terminal of the molecule is not crucial for the interaction since the truncated structure containing only this region did not show a good total energy. PMID:19352455

  4. An In Vivo Reporter to Quantitatively and Temporally Analyze the Effects of CDK4/6 Inhibitor-Based Therapies in Melanoma.

    PubMed

    Teh, Jessica L F; Purwin, Timothy J; Greenawalt, Evan J; Chervoneva, Inna; Goldberg, Allison; Davies, Michael A; Aplin, Andrew E

    2016-09-15

    Aberrant cell-cycle progression is a hallmark feature of cancer cells. Cyclin-dependent kinases 4 and 6 (CDK4/6) drive progression through the G1 stage of the cell cycle, at least in part, by inactivating the tumor suppressor, retinoblastoma. CDK4/6 are targetable and the selective CDK4/6 inhibitor, palbociclib, was recently FDA approved for the treatment of estrogen receptor-positive, HER2-negative advanced breast cancer. In cutaneous melanoma, driver mutations in NRAS and BRAF promote CDK4/6 activation, suggesting that inhibitors such as palbociclib are likely to provide therapeutic benefit in combination with BRAF inhibitors and/or MEK inhibitors that are FDA-approved. However, the determinants of the response to CDK4/6 inhibitors alone and in combination with other targeted inhibitors are poorly defined. Furthermore, in vivo systems to quantitatively and temporally measure the efficacy of CDK4/6 inhibitors and determine the extent that CDK activity is reactivated during acquired resistance are lacking. Here, we describe the heterogeneous effects of CDK4/6 inhibitors, the expression of antiapoptotic proteins that associate with response to CDK4/6 and MEK inhibitors, and the development of a luciferase-based reporter system to determine the effects of CDK4/6 inhibitors alone and in combination with MEK inhibitors in melanoma xenografts. These findings are likely to inform on-going and future clinical trials utilizing CDK4/6 inhibitors in cutaneous melanoma. Cancer Res; 76(18); 5455-66. ©2016 AACR. PMID:27488531

  5. Effects of an Indolocarbazole-Derived CDK4 Inhibitor on Breast Cancer Cells

    PubMed Central

    Sun, Yuan; Li, Ying-xia; Wu, Hai-jun; Wu, Si-hung; Wang, Y. Alan; Luo, Dian-zhong; Liao, D. Joshua

    2011-01-01

    Introduction: Cyclin D1 (D1) binds to cyclin-dependent kinases (CDK) 4 or 6 to form a holoenzyme that phosphorylates the Rb protein to promote cell cycle progression from G1 to S phase. Therefore, targeting CDK4/6 may be a good strategy for chemotherapy of cancer. We performed a proof-of-principle study to determine the effect of Naphtho [2, 1-α] pyrrolo [3, 4-c] carbazole-5, 7 (6H, 12H)-dione (NPCD), a novel CDK4 inhibitor, on breast cancer cell lines. Methods: NPCD was synthesized and purified to over 99% purity verified by HPLC. MCF7, MB231, MCF15, T47D and GI101Ap human breast cancer cells were analyzed for the efficacy of NPCD with MTT and clonogenic assays, with FACS and staining for ethidium bromide and acridine orange for cell death and cell cycle profile. Western blot, reverse transcription and PCR were used for studies of gene expression, and co-immunoprecipitation for protein-complex formation. Results: MTT assay showed that NPCD caused growth arrest and apoptosis of MCF7, MDA-MB231, T47D, MCF15 and GI101Ap cells with an IC50 ranging between 3 to 8 µM given as a single dose. The growth arrest persisted for many days after cessation of the treatment, as shown in a clonogenic assay. NPCD could induce or reduce the D1 and CDK4 protein levels, depending on the cell line, but this effect was not correlated with its efficacy. Phosphorylation of D1 at Thr286 was decreased but it unexpectedly did not correlate with the change in D1 level in the cell lines studied. Phosphorylation of the Rb protein was decreased as expected whereas the p27kip1 protein level was decreased unexpectedly. Protein levels of p21cip1, CDK2 and cyclin E were also decreased in some, but not all, of the cell lines, whereas the mRNA levels of D1, CDK4, cyclin E, CDK2, p27kip1 and p21cip1 were increased in different cell lines. Conclusions: NPCD can cause long-lasting growth arrest and cell death of breast cancer cell lines at an IC50 of 3-8 µM. Decreased phosphorylation of Rb by D1-CDK4

  6. CDK4/6 inhibition induces epithelial cell cycle arrest and ameliorates acute kidney injury

    PubMed Central

    DiRocco, Derek P.; Bisi, John; Roberts, Patrick; Strum, Jay; Wong, Kwok-Kin; Sharpless, Norman

    2013-01-01

    Acute kidney injury (AKI) is common and urgently requires new preventative therapies. Expression of a cyclin-dependent kinase (CDK) inhibitor transgene protects against AKI, suggesting that manipulating the tubular epithelial cell cycle may be a viable therapeutic strategy. Broad spectrum small molecule CDK inhibitors are protective in some kidney injury models, but these have toxicities and epithelial proliferation is eventually required for renal repair. Here, we tested a well-tolerated, novel and specific small molecule inhibitor of CDK4 and CDK6, PD 0332991, to investigate the effects of transient cell cycle inhibition on epithelial survival in vitro and kidney injury in vivo. We report that CDK4/6 inhibition induced G0/G1 cycle arrest in cultured human renal proximal tubule cells (hRPTC) at baseline and after injury. Induction of transient G0/G1 cycle arrest through CDK4/6 inhibition protected hRPTC from DNA damage and caspase 3/7 activation following exposure to the nephrotoxins cisplatin, etoposide, and antimycin A. In vivo, mice treated with PD 0332991 before ischemia-reperfusion injury (IRI) exhibited dramatically reduced epithelial progression through S phase 24 h after IRI. Despite reduced epithelial proliferation, PD 0332991 ameliorated kidney injury as reflected by improved serum creatinine and blood urea nitrogen levels 24 h after injury. Inflammatory markers and macrophage infiltration were significantly decreased in injured kidneys 3 days following IRI. These results indicate that induction of proximal tubule cell cycle arrest with specific CDK4/6 inhibitors, or “pharmacological quiescence,” represents a novel strategy to prevent AKI. PMID:24338822

  7. CDK4/6 inhibition induces epithelial cell cycle arrest and ameliorates acute kidney injury.

    PubMed

    DiRocco, Derek P; Bisi, John; Roberts, Patrick; Strum, Jay; Wong, Kwok-Kin; Sharpless, Norman; Humphreys, Benjamin D

    2014-02-15

    Acute kidney injury (AKI) is common and urgently requires new preventative therapies. Expression of a cyclin-dependent kinase (CDK) inhibitor transgene protects against AKI, suggesting that manipulating the tubular epithelial cell cycle may be a viable therapeutic strategy. Broad spectrum small molecule CDK inhibitors are protective in some kidney injury models, but these have toxicities and epithelial proliferation is eventually required for renal repair. Here, we tested a well-tolerated, novel and specific small molecule inhibitor of CDK4 and CDK6, PD 0332991, to investigate the effects of transient cell cycle inhibition on epithelial survival in vitro and kidney injury in vivo. We report that CDK4/6 inhibition induced G0/G1 cycle arrest in cultured human renal proximal tubule cells (hRPTC) at baseline and after injury. Induction of transient G0/G1 cycle arrest through CDK4/6 inhibition protected hRPTC from DNA damage and caspase 3/7 activation following exposure to the nephrotoxins cisplatin, etoposide, and antimycin A. In vivo, mice treated with PD 0332991 before ischemia-reperfusion injury (IRI) exhibited dramatically reduced epithelial progression through S phase 24 h after IRI. Despite reduced epithelial proliferation, PD 0332991 ameliorated kidney injury as reflected by improved serum creatinine and blood urea nitrogen levels 24 h after injury. Inflammatory markers and macrophage infiltration were significantly decreased in injured kidneys 3 days following IRI. These results indicate that induction of proximal tubule cell cycle arrest with specific CDK4/6 inhibitors, or "pharmacological quiescence," represents a novel strategy to prevent AKI.

  8. Biphenyl-4-carboxylic acid [2-(1H-indol-3-yl)-ethyl]-methylamide (CA224), a nonplanar analogue of fascaplysin, inhibits Cdk4 and tubulin polymerization: evaluation of in vitro and in vivo anticancer activity.

    PubMed

    Mahale, Sachin; Bharate, Sandip B; Manda, Sudhakar; Joshi, Prashant; Bharate, Sonali S; Jenkins, Paul R; Vishwakarma, Ram A; Chaudhuri, Bhabatosh

    2014-11-26

    Biphenyl-4-carboxylic acid-[2-(1H-indol-3-yl)-ethyl]-methylamide 1 (CA224) is a nonplanar analogue of fascaplysin (2) that specifically inhibits Cdk4-cyclin D1 in vitro. Compound 1 blocks the growth of cancer cells at G0/G1 phase of the cell cycle. It also blocks the cell cycle at G2/M phase, which is explained by the fact that it inhibits tubulin polymerization. Additionally, it acts as an enhancer of depolymerization for taxol-stabilized tubulin. Western blot analyses of p53-positive cancer cells treated with compound 1 indicated upregulation of p53, p21, and p27 proteins together with downregulation of cyclin B1 and Cdk1. Compound 1 selectively induces apoptosis of SV40 large T-antigen transformed cells and significantly reduces colony formation efficiency, in a dose-dependent manner, of lung cancer cells. It is efficacious at 1/10th of the MTD against human tumors derived from HCT-116 and NCI-H460 cells in SCID mouse models. The promising efficacy of compound 1 in human xenograft models as well as its excellent therapeutic window indicates its potential for clinical development. PMID:25368960

  9. The Role of CDK4/6 Inhibition in Breast Cancer

    PubMed Central

    Dickler, Maura N.

    2015-01-01

    Imbalance of the cyclin D and cyclin-dependent kinase (CDK) pathway in cancer cells may result in diversion away from a pathway to senescence and toward a more proliferative phenotype. Cancer cells may increase cyclin D-dependent activity through a variety of mechanisms. Therapeutic inhibition of CDKs in tumors to negate their evasion of growth suppressors has been identified as a key anticancer strategy. In this review, we outline the development of CDK inhibitory therapy in breast cancer, including the initial experience with the pan-CDK inhibitor flavopiridol and the next generation of oral highly selective CDK4 and CDK6 inhibitors PD0332991 (palbociclib), LEE011 (ribociclib), and LY2835219 (abemaciclib). Data from phase I and II studies in estrogen receptor-positive (ER+) breast cancer demonstrate promising efficacy with manageable toxic effects, chiefly neutropenia. We discuss these studies and the phase III studies that are accruing or nearing completion. We describe the application of such therapy to other breast cancer settings, including HER2-positive breast cancer and the adjuvant treatment of early breast cancer. We also discuss potential concerns surrounding the combination of CDK inhibitors with chemotherapy and their effects on repair of double-strand DNA breaks in cancer cells. Oral highly selective CDK inhibitors show great promise in improving the outcomes of patients with ER+ breast cancer, although caution must apply to their combination with other agents and in the early breast cancer setting. PMID:25876993

  10. Targeting the AKT/GSK3{beta}/Cyclin D1/Cdk4 Survival Signaling Pathway for Eradication of Tumor Radioresistance Acquired by Fractionated Radiotherapy

    SciTech Connect

    Shimura, Tsutomu; Kakuda, Satoshi; Ochiai, Yasushi; Kuwahara, Yoshikazu; Takai, Yoshihiro; Fukumoto, Manabu

    2011-06-01

    Purpose: Radioresistance is a major cause of treatment failure of radiotherapy (RT) in human cancer. We have recently revealed that acquired radioresistance of tumor cells induced by fractionated radiation is attributable to cyclin D1 overexpression as a consequence of the downregulation of GSK3{beta}-dependent cyclin D1 proteolysis mediated by a constitutively activated serine-threonine kinase, AKT. This prompted us to hypothesize that targeting the AKT/GSK3{beta}/cyclin D1 pathway may improve fractionated RT by suppressing acquired radioresistance of tumor cells. Methods and Materials: Two human tumor cell lines with acquired radioresistance were exposed to X-rays after incubation with either an AKT inhibitor, AKT/PKB signaling inhibitor-2 (API-2), or a Cdk4 inhibitor (Cdk4-I). Cells were then subjected to immunoblotting, clonogenic survival assay, cell growth analysis, and cell death analysis with TUNEL and annexin V staining. In vivo radiosensitivity was assessed by growth of human tumors xenografted into nude mice. Results: Treatment with API-2 resulted in downregulation of cyclin D1 expression in cells with acquired radioresistance. Cellular radioresistance disappeared completely both in vitro and in vivo with accompanying apoptosis when treated with API-2. Furthermore, inhibition of cyclin D1/Cdk4 by Cdk4-I was sufficient for abolishing radioresistance. Treatment with either API-2 or Cdk4-I was also effective in suppressing resistance to cis-platinum (II)-diamine-dichloride in the cells with acquired radioresistance. Interestingly, the radiosensitizing effect of API-2 was canceled by overexpression of cyclin D1 whereas Cdk4-I was still able to sensitize cells with cyclin D1 overexpression. Conclusion: Cyclin D1/Cdk4 is a critical target of the AKT survival signaling pathway responsible for tumor radioresistance. Targeting the AKT/GSK3{beta}/cyclin D1/Cdk4 pathway would provide a novel approach to improve fractionated RT and would have an impact on tumor

  11. CDK4/6 and IGF1 receptor inhibitors synergize to suppress the growth of p16INK4A-deficient pancreatic cancers

    PubMed Central

    Heilmann, Andreas M.; Perera, Rushika M.; Ecker, Veronika; Nicolay, Brandon N.; Bardeesy, Nabeel; Benes, Cyril H.; Dyson, Nicholas J.

    2014-01-01

    Loss-of-function mutations in p16INK4A (CDKN2A) occur in approximately 80% of sporadic pancreatic ductal adenocarcinoma (PDAC), contributing to its early progression. While this loss activates the cell cycle-dependent kinases CDK4/6, which have been considered as drug targets for many years, p16INK4A-deficient PDAC cells are inherently resistant to CDK4/6 inhibitors. This study searched for targeted therapies that might synergize with CDK4/6 inhibition in this setting. We report that the IGF1R/IR inhibitor BMS-754807 cooperated with the CDK4/6 inhibitor PD-0332991 to strongly block proliferation of p16INK4A-deficient PDAC cells in vitro and in vivo. Sensitivity to this drug combination correlated with reduced activity of the master cell growth regulator mTORC1. Accordingly, replacing the IGF1R/IR inhibitor with the rapalog inhibitor temsirolimus broadened the sensitivity of PDAC cells to CDK4/6 inhibition. Our results establish targeted therapy combinations with robust cytostatic activity in p16INK4A-deficient PDAC cells and possible implications for improving treatment of a broad spectrum of human cancers characterized by p16INK4A loss. PMID:24986516

  12. Evaluation of germline CDKN2A, ARF, CDK4, PTEN, and BRAF alterations in atypical mole syndrome.

    PubMed

    Celebi, J T; Ward, K M; Wanner, M; Polsky, D; Kopf, A W

    2005-01-01

    Atypical mole syndrome is a sporadic or an inherited condition with an increased risk of melanoma. Germline mutations in the CDKN2A, ARF, CDK4 and somatic mutations in the PTEN and BRAF genes have been associated with melanoma. In this study, we evaluated genes associated with familial and sporadic melanoma for mutations in 28 probands with the atypical mole syndrome. No sequence alterations in the coding regions or in the splice junctions of CDKN2A, ARF, CDK4, PTEN or BRAF were identified. These data suggest that genes evaluated in this study are unlikely to be candidate genes for atypical mole syndrome and support the notion that unknown susceptibility gene/s for this disease exist.

  13. Altered expression of cell cycle regulators Cyclin D1, p14, p16, CDK4 and Rb in nodular melanomas.

    PubMed

    Bachmann, Ingeborg M; Straume, Oddbjørn; Akslen, Lars A

    2004-12-01

    Cell cycle regulating proteins are important in tumour development. To investigate whether alterations in Cyclin D1, p14, CDK4 and Rb are associated with tumour cell proliferation, tumour progression and patient survival in malignant melanoma, we examined 202 vertical growth phase tumours and 68 corresponding metastases for expression of Cyclin D1, p14, CDK4 and Rb, and compared the results with Ki-67 expression, p16 and p53 expression, clinico-pathological variables, and survival data. Nuclear staining of Cyclin D1 was strong in 35% of cases, and correlated with high levels of Rb (p=0.05), but not with survival or other markers tested. Strong staining of p14 was found in 63% of nodular melanomas and was associated with strong p53 expression (p=0.014), and with high levels of CDK4 (p<0.0001). Low p14 expression was associated with increased tumour thickness (p=0.008) and increasing level of invasion (p=0.020). Strong nuclear staining for CDK4 was found in 81% of cases and was associated with tumour thickness below the median value of 3.7 mm and improved survival (log-rank test, p=0.024). Further, 56% of the tumours showed strong nuclear staining for Rb, and these cases were significantly associated with absent/low levels of p16 staining (p=0.030), high levels of p14 (p=0.010), as well as high Ki-67 expression (p=0.005). Our results seem to confirm that the p16-Rb pathway plays an important role in tumour progression and prognosis in vertical growth phase melanomas, whereas alterations in the p14-p53 pathway might be less important.

  14. Clinical Development of the CDK4/6 Inhibitors Ribociclib and Abemaciclib in Breast Cancer.

    PubMed

    Barroso-Sousa, Romualdo; Shapiro, Geoffrey I; Tolaney, Sara M

    2016-06-01

    Clinical and preclinical data support a significant role for inhibitors of the cyclin-dependent kinases (CDKs) 4 and 6 in the treatment of patients with breast cancer. Recently, based on data showing improvement in progression-free survival, the use of palbociclib (Ibrance; Pfizer, Inc.) in combination with endocrine agents was approved to treat patients with hormone receptor-positive advanced disease. Importantly, 2 other CDK4/6 inhibitors, abemaciclib (LY2835219; Lilly) and ribociclib (LEE011; Novartis), are in the late stage of clinical development. In this review, we will focus on clinical data on these 2 new drugs, highlighting their differences compared to palbociclib in terms of single-agent activity, central nervous system penetration, and common adverse events. In addition, we will present the ongoing clinical trials and discuss future directions in the field. PMID:27493615

  15. Discovery of pyrrolospirooxindole derivatives as novel cyclin dependent kinase 4 (CDK4) inhibitors by catalyst-free, green approach.

    PubMed

    Kamal, Ahmed; Mahesh, Rasala; Nayak, V Lakshma; Babu, Korrapati Suresh; Kumar, G Bharath; Shaik, Anver Basha; Kapure, Jeevak Sopanrao; Alarifi, Abdullah

    2016-01-27

    Aiming to develop a new target for the anticancer treatment, a series of 5'H-spiro[indoline-3,4'-pyrrolo [1,2-a]quinoxalin]-2-ones has been synthesized by simple, highly efficient and environmentally friendly method in excellent yields under catalyst-free conditions using ethanol as a green solvent. A simple filtration of the reaction mixture and subsequent drying affords analytically pure products. The synthesized derivatives were evaluated for their antiproliferative activity against five different human cancer cell lines, among the congeners compound 3n showed significant cytotoxicity against the human prostate cancer (DU-145). Flow cytometric analysis revealed that this compound induces cell cycle arrest in the G0/G1 phase and Western blot analysis suggested that reduction in Cdk4 expression level leads to apoptotic cell death. This was further confirmed by mitochondrial membrane potential ((ΔΨm), Annexin V-FITC assay and docking experiments. Furthermore, it was observed that there is an increase in expression levels of cyclin dependent kinase inhibitors like Cip1/p21 and Kip1/p27.

  16. Caenorhabditis elegans Cyclin D/CDK4 and Cyclin E/CDK2 Induce Distinct Cell Cycle Re-Entry Programs in Differentiated Muscle Cells

    PubMed Central

    Korzelius, Jerome; The, Inge; Ruijtenberg, Suzan; Prinsen, Martine B. W.; Portegijs, Vincent; Middelkoop, Teije C.; Groot Koerkamp, Marian J.; Holstege, Frank C. P.; Boxem, Mike; van den Heuvel, Sander

    2011-01-01

    Cell proliferation and differentiation are regulated in a highly coordinated and inverse manner during development and tissue homeostasis. Terminal differentiation usually coincides with cell cycle exit and is thought to engage stable transcriptional repression of cell cycle genes. Here, we examine the robustness of the post-mitotic state, using Caenorhabditis elegans muscle cells as a model. We found that expression of a G1 Cyclin and CDK initiates cell cycle re-entry in muscle cells without interfering with the differentiated state. Cyclin D/CDK4 (CYD-1/CDK-4) expression was sufficient to induce DNA synthesis in muscle cells, in contrast to Cyclin E/CDK2 (CYE-1/CDK-2), which triggered mitotic events. Tissue-specific gene-expression profiling and single molecule FISH experiments revealed that Cyclin D and E kinases activate an extensive and overlapping set of cell cycle genes in muscle, yet failed to induce some key activators of G1/S progression. Surprisingly, CYD-1/CDK-4 also induced an additional set of genes primarily associated with growth and metabolism, which were not activated by CYE-1/CDK-2. Moreover, CYD-1/CDK-4 expression also down-regulated a large number of genes enriched for catabolic functions. These results highlight distinct functions for the two G1 Cyclin/CDK complexes and reveal a previously unknown activity of Cyclin D/CDK-4 in regulating metabolic gene expression. Furthermore, our data demonstrate that many cell cycle genes can still be transcriptionally induced in post-mitotic muscle cells, while maintenance of the post-mitotic state might depend on stable repression of a limited number of critical cell cycle regulators. PMID:22102824

  17. CDK2 activation in mouse epidermis induces keratinocyte proliferation but does not affect skin tumor development.

    PubMed

    Macias, Everardo; Miliani de Marval, Paula L; De Siervi, Adriana; Conti, Claudio J; Senderowicz, Adrian M; Rodriguez-Puebla, Marcelo L

    2008-08-01

    It has been widely assumed that elevated CDK2 kinase activity plays a contributory role in tumorigenesis. We have previously shown that mice overexpressing CDK4 under control of the keratin 5 promoter (K5CDK4 mice) develop epidermal hyperplasia and increased susceptibility to squamous cell carcinomas. In this model, CDK4 overexpression results in increased CDK2 activity associated with the noncatalytic function of CDK4, sequestration of p21(Cip1) and p27(Kip1). Furthermore, we have shown that ablation of Cdk2 reduces Ras-Cdk4 tumorigenesis, suggesting that increased CDK2 activity plays an important role in Ras-mediated tumorigenesis. To investigate this hypothesis, we generated two transgenic mouse models of elevated CDK2 kinase activity, K5Cdk2 and K5Cdk4(D158N) mice. The D158N mutation blocks CDK4 kinase activity without interfering with its binding capability. CDK2 activation via overexpression of CDK4(D158N), but not of CDK2, resulted in epidermal hyperplasia. We observed elevated levels of p21(Cip1) in K5Cdk2, but not in K5Cdk4(D158N), epidermis, suggesting that CDK2 overexpression elicits a p21(Cip1) response to maintain keratinocyte homeostasis. Surprisingly, we found that neither CDK2 overexpression nor the indirect activation of CDK2 enhanced skin tumor development. Thus, although the indirect activation of CDK2 is sufficient to induce keratinocyte hyperproliferation, activation of CDK2 alone does not induce malignant progression in Ras-mediated tumorigenesis.

  18. CDK2 Activation in Mouse Epidermis Induces Keratinocyte Proliferation but Does Not Affect Skin Tumor Development

    PubMed Central

    Macias, Everardo; Miliani de Marval, Paula L.; De Siervi, Adriana; Conti, Claudio J.; Senderowicz, Adrian M.; Rodriguez-Puebla, Marcelo L.

    2008-01-01

    It has been widely assumed that elevated CDK2 kinase activity plays a contributory role in tumorigenesis. We have previously shown that mice overexpressing CDK4 under control of the keratin 5 promoter (K5CDK4 mice) develop epidermal hyperplasia and increased susceptibility to squamous cell carcinomas. In this model, CDK4 overexpression results in increased CDK2 activity associated with the noncatalytic function of CDK4, sequestration of p21Cip1 and p27Kip1. Furthermore, we have shown that ablation of Cdk2 reduces Ras-Cdk4 tumorigenesis, suggesting that increased CDK2 activity plays an important role in Ras-mediated tumorigenesis. To investigate this hypothesis, we generated two transgenic mouse models of elevated CDK2 kinase activity, K5Cdk2 and K5Cdk4D158N mice. The D158N mutation blocks CDK4 kinase activity without interfering with its binding capability. CDK2 activation via overexpression of CDK4D158N, but not of CDK2, resulted in epidermal hyperplasia. We observed elevated levels of p21Cip1 in K5Cdk2, but not in K5Cdk4D158N, epidermis, suggesting that CDK2 overexpression elicits a p21Cip1 response to maintain keratinocyte homeostasis. Surprisingly, we found that neither CDK2 overexpression nor the indirect activation of CDK2 enhanced skin tumor development. Thus, although the indirect activation of CDK2 is sufficient to induce keratinocyte hyperproliferation, activation of CDK2 alone does not induce malignant progression in Ras-mediated tumorigenesis. PMID:18599613

  19. A large Norwegian family with inherited malignant melanoma, multiple atypical nevi, and CDK4 mutation.

    PubMed

    Molven, Anders; Grimstvedt, Magne B; Steine, Solrun J; Harland, Mark; Avril, Marie-Françoise; Hayward, Nicholas K; Akslen, Lars A

    2005-09-01

    Mutations in two loci encoding cell-cycle-regulatory proteins have been shown to cause familial malignant melanoma. About 20% of melanoma-prone families bear a mutation in the CDKN2A locus, which encodes two unrelated proteins, p16INK4A and p14ARF. Mutations in the other locus, CDK4, are much rarer and have been linked to the disease in only three families worldwide. In the 1960s, a large Norwegian pedigree with multiple atypical nevi and malignant melanomas was identified. Subsequently, six generations and more than 100 family members were traced and 20 cases of melanoma verified. In this article, we report that CDK4 codon 24 is mutated from CGT to CAT (Arg24His) in this unusually large melanoma kindred. Intriguingly, one of the family members had ocular melanoma, but the CDK4 mutation could not be detected in archival tissue samples from this subject. Thus, the case of ocular melanoma in this family was sporadic, suggesting an etiology different from that of the skin tumors. The CDK4 mutation in the Norwegian family was identical to that in melanoma families in France, Australia, and England. Haplotype analysis using microsatellite markers flanking the CDK4 gene and single-nucleotide polymorphisms within the gene did not support the possibility that there was a common founder, but rather indicated at least two independent mutational events. All CDK4 melanoma families known to date have a substitution of amino acid 24. In addition to resulting from selection pressure, this observation may be explained by the CG dinucleotide of codon 24 representing a mutational hot spot in the CDK4 gene.

  20. Immunohistochemical detection of CDK4 and p16INK4 proteins in cutaneous malignant melanoma.

    PubMed

    Wang, Y L; Uhara, H; Yamazaki, Y; Nikaido, T; Saida, T

    1996-02-01

    p16INK4 gene, which encodes a specific inhibitor of cyclin-dependent kinase 4 (CDK4), has been recently reported as an important tumour suppressor gene. It is mapped to chromosome 9p21, which is frequently deleted or mutated in many tumour cell lines including malignant melanoma. Since the CDK4/cyclin D complex propels a cell to go through the G1 check point of the cell cycle, a critical phase of cell division, alteration of the p16INK4 gene could lead a cell to uncontrolled proliferation and malignant transformation. To clarify any role for p16INK4 and CDK4 proteins in the development of human malignant melanoma, we have examined, immunohistochemically, the expression of these two proteins in melanocytic neoplasms including 19 primary lesions of non-familial melanoma. Intense nuclear and/or cytoplasmic expression of the CDK4 protein was observed in 11 of 19 cases (58%) of melanoma. In contrast, virtually no nuclear or cytoplasmic staining for CDK4 protein was detected in 28 benign melanocytic naevi, including six Spitz naevi. Expression of p16INK4 protein was observed in three of 19 melanomas (16%) and in 17 of 28 benign naevi (61%). Inverse expression of CDK4 and p16INK4, at individual cell level, was detected in one case of melanoma. The present study suggests that CDK4 overexpression is characteristic for malignant melanoma, and probably reflects its autonomous accelerated cell proliferation. The expression rate of p16INK4 protein in malignant melanoma was lower than that in benign naevi, although the significance of p16INK4 deletion in melanoma development has not been definitely confirmed.

  1. CDKN2A and CDK4 mutation analysis in Italian melanoma-prone families: functional characterization of a novel CDKN2A germ line mutation.

    PubMed

    Della Torre, G; Pasini, B; Frigerio, S; Donghi, R; Rovini, D; Delia, D; Peters, G; Huot, T J; Bianchi-Scarra, G; Lantieri, F; Rodolfo, M; Parmiani, G; Pierotti, M A

    2001-09-14

    Physical interaction between CDKN2A/p16 and CDK4 proteins regulates the cell cycle progression through the G1 phase and dysfunction of these proteins by gene mutation is implicated in genetic predisposition to melanoma. We analysed 15 Italian melanoma families for germ line mutations in the coding region of the CDKN2A gene and exon 2 of the CDK4 gene. One novel disease-associated mutation (P48T), 3 known pathological mutations (R24P, G101W and N71S) and 2 common polymorphisms (A148T and Nt500 G>C) were identified in the CDKN2A gene. In a family harbouring the R24P mutation, an intronic variant (IVS1, +37 G>C) of uncertain significance was detected in a non-carrier melanoma case. The overall incidence of CDKN2A mutations was 33.3%, but this percentage was higher in families with 3 or more melanoma cases (50%) than in those with only 2 affected relatives (25%). Noteworthy, functional analysis established that the novel mutated protein, while being impaired in cell growth and inhibition assays, retains some in vitro binding to CDK4/6. No variant in the p16-binding region of CDK4 was identified in our families. Our results, obtained in a heterogeneous group of families, support the view that inactivating mutations of CDKN2A contribute to melanoma susceptibility more than activating mutations of CDK4 and that other genetic factors must be responsible for melanoma clustering in a high proportion of families. In addition, they indicate the need for a combination of functional assays to determine the pathogenetic nature of new CDKN2A mutations.

  2. ClC-3 Chloride Channel Proteins Regulate the Cell Cycle by Up-regulating cyclin D1-CDK4/6 through Suppressing p21/p27 Expression in Nasopharyngeal Carcinoma Cells

    PubMed Central

    Ye, Dong; Luo, Hai; Lai, Zhouyi; Zou, Lili; Zhu, Linyan; Mao, Jianwen; Jacob, Tim; Ye, Wencai; Wang, Liwei; Chen, Lixin

    2016-01-01

    It was shown in this study that knockdown of ClC-3 expression by ClC-3 siRNA prevented the activation of hypotonicity-induced chloride currents, and arrested cells at the G0/G1 phase in nasopharyngeal carcinoma CNE-2Z cells. Reconstitution of ClC-3 expression with ClC-3 expression plasmids could rescue the cells from the cell cycle arrest caused by ClC-3 siRNA treatments. Transfection of cells with ClC-3 siRNA decreased the expression of cyclin D1, cyclin dependent kinase 4 and 6, and increased the expression of cyclin dependent kinase inhibitors (CDKIs), p21 and p27. Pretreatments of cells with p21 and p27 siRNAs depleted the inhibitory effects of ClC-3 siRNA on the expression of CDK4 and CDK6, but not on that of cyclin D1, indicating the requirement of p21 and p27 for the inhibitory effects of ClC-3 siRNA on CDK4 and CDK6 expression. ClC-3 siRNA inhibited cells to progress from the G1 phase to the S phase, but pretreatments of cells with p21 and p27 siRNAs abolished the inhibitory effects of ClC-3 siRNA on the cell cycle progress. Our data suggest that ClC-3 may regulate cell cycle transition between G0/G1 and S phases by up-regulation of the expression of CDK4 and CDK6 through suppression of p21 and p27 expression. PMID:27451945

  3. Selective impact of CDK4/6 suppression on patient-derived models of pancreatic cancer

    PubMed Central

    Witkiewicz, Agnieszka K.; Borja, Nicholas A.; Franco, Jorge; Brody, Jonathan R.; Yeo, Charles J.; Mansour, John; Choti, Michael A.; McCue, Peter; Knudsen, Erik S.

    2015-01-01

    Pancreatic ductal adenocarcinoma (PDA) harbors an exceedingly poor prognosis, and is generally considered a therapy-recalcitrant disease due to poor response to conventional chemotherapy coupled with non-actionable genetic drivers (e.g. KRAS mutations). However, PDA frequently loses p16ink4a, thereby leading to deregulation of CDK4/6. Surprisingly, in established cell models and xenografts, CDK4/6 inhibition has a modest effect on proliferation and resistance develops rapidly. To determine if such weak response was an intrinsic feature of PDA, we developed primary tumor explants that maintain the tumor environment and recapitulate feuture of primary PDA. The CDK4/6 inhibitor PD-0332991 was highly efficient at suppressing proliferation in 14 of the 15 explants. In the single resistant explant, we identified the rare loss of the RB tumor suppressor as the basis for resistance. Patient-derived xenografts (PDXs) were developed in parallel, and unlike the xenografts emerging from established cell lines, the PDXs maintained the histoarchitecture of the primary tumor. These PDXs were highly sensitive to CDK4/6 inhibition, yielding a complete suppression of PDA proliferation. Together, these data indicate that primary PDA is sensitive to CDK4/6 inhibition, that specific biomarkers can delineate intrinsic resistance, and that established cell line models may not represent an adequate means for evaluating therapeutic sensitivities. PMID:26158861

  4. Selective impact of CDK4/6 suppression on patient-derived models of pancreatic cancer.

    PubMed

    Witkiewicz, Agnieszka K; Borja, Nicholas A; Franco, Jorge; Brody, Jonathan R; Yeo, Charles J; Mansour, John; Choti, Michael A; McCue, Peter; Knudsen, Erik S

    2015-06-30

    Pancreatic ductal adenocarcinoma (PDA) harbors an exceedingly poor prognosis, and is generally considered a therapy-recalcitrant disease due to poor response to conventional chemotherapy coupled with non-actionable genetic drivers (e.g. KRAS mutations). However, PDA frequently loses p16ink4a, thereby leading to deregulation of CDK4/6. Surprisingly, in established cell models and xenografts, CDK4/6 inhibition has a modest effect on proliferation and resistance develops rapidly. To determine if such weak response was an intrinsic feature of PDA, we developed primary tumor explants that maintain the tumor environment and recapitulate feuture of primary PDA. The CDK4/6 inhibitor PD-0332991 was highly efficient at suppressing proliferation in 14 of the 15 explants. In the single resistant explant, we identified the rare loss of the RB tumor suppressor as the basis for resistance. Patient-derived xenografts (PDXs) were developed in parallel, and unlike the xenografts emerging from established cell lines, the PDXs maintained the histoarchitecture of the primary tumor. These PDXs were highly sensitive to CDK4/6 inhibition, yielding a complete suppression of PDA proliferation. Together, these data indicate that primary PDA is sensitive to CDK4/6 inhibition, that specific biomarkers can delineate intrinsic resistance, and that established cell line models may not represent an adequate means for evaluating therapeutic sensitivities.

  5. Artemisinin triggers a G1 cell cycle arrest of human Ishikawa endometrial cancer cells and inhibits Cyclin Dependent Kinase-4 promoter activity and expression by disrupting NF-kB transcriptional signaling

    PubMed Central

    Tran, Kalvin Q.; Tin, Antony S.; Firestone, Gary L.

    2014-01-01

    Relatively little is known about the anti-proliferative effects of Artemisinin, a naturally occurring anti-malarial compound from Artemisia annua, or sweet wormwood, in human endometrial cancer cells. Artemisinin induced a G1 cell cycle arrest in cultured human Ishikawa endometrial cancer cells and down regulated CDK2 and CDK4 transcript and protein levels. Analysis of CDK4 promoter-luciferase reporter constructs showed that the artemisinin ablation of CDK4 gene expression was accounted for by the loss of CDK4 promoter activity. Chromatin immunoprecipitation demonstrated that artemisinin inhibited nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) subunit p65 and p50 interactions with the endogenous Ishikawa cell CDK4 promoter. Coimmunoprecipitation revealed that artemisinin disrupts endogenous p65 and p50 nuclear translocation via increased protein-protein interactions with IκB-α, an NF-κB inhibitor, and disrupts its interaction with the CDK4 promoter, leading to a loss of CDK4 gene expression. Artemisinin treatment stimulated the cellular levels of IκB-α protein without altering the level of IκB-α transcripts. Finally, expression of exogenous p65 resulted in the accumulation of this NF-κB subunit in the nucleus of artemisinin treated and untreated cells, reversed the artemisinin down-regulation of CDK4 protein expression and promoter activity and prevented the artemisinin induced G1 cell cycle arrest. Taken together, our results demonstrate that a key event in the artemisinin anti-proliferative effects in endometrial cancer cells is the transcriptional down-regulation of CDK4 expression by disruption of NF-κB interactions with the CDK4 promoter. PMID:24296733

  6. Artemisinin triggers a G1 cell cycle arrest of human Ishikawa endometrial cancer cells and inhibits cyclin-dependent kinase-4 promoter activity and expression by disrupting nuclear factor-κB transcriptional signaling.

    PubMed

    Tran, Kalvin Q; Tin, Antony S; Firestone, Gary L

    2014-03-01

    Relatively little is known about the antiproliferative effects of artemisinin, a naturally occurring antimalarial compound from Artemisia annua, or sweet wormwood, in human endometrial cancer cells. Artemisinin induced a G1 cell cycle arrest in cultured human Ishikawa endometrial cancer cells and downregulated cyclin-dependent kinase-2 (CDK2) and CDK4 transcript and protein levels. Analysis of CDK4 promoter-luciferase reporter constructs showed that the artemisinin ablation of CDK4 gene expression was accounted for by the loss of CDK4 promoter activity. Chromatin immunoprecipitation demonstrated that artemisinin inhibited nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) subunit p65 and p50 interactions with the endogenous Ishikawa cell CDK4 promoter. Coimmunoprecipitation revealed that artemisinin disrupts endogenous p65 and p50 nuclear translocation through increased protein-protein interactions with IκB-α, an NF-κB inhibitor, and disrupts its interaction with the CDK4 promoter, leading to a loss of CDK4 gene expression. Artemisinin treatment stimulated the cellular levels of IκB-α protein without altering the level of IκB-α transcripts. Finally, expression of exogenous p65 resulted in the accumulation of this NF-κB subunit in the nucleus of artemisinin-treated and artemisinin-untreated cells, reversed the artemisinin downregulation of CDK4 protein expression and promoter activity, and prevented the artemisinin-induced G1 cell cycle arrest. Taken together, our results demonstrate that a key event in the artemisinin antiproliferative effects in endometrial cancer cells is the transcriptional downregulation of CDK4 expression by disruption of NF-κB interactions with the CDK4 promoter. PMID:24296733

  7. Therapeutic Targeting of the Cyclin D3:CDK4/6 Complex in T Cell Leukemia

    PubMed Central

    Sawai, Catherine; Freund, Jacquelyn; Oh, Philmo; Ndiaye-Lobry, Delphine; Bretz, Jamieson C.; Strikoudis, Alexandros; Genesca, Lali; Trimarchi, Thomas; Kelliher, Michelle A.; Clark, Marcus; Soulier, Jean; Chen-Kiang, Selina; Aifantis, Iannis

    2012-01-01

    SUMMARY D-type cyclins form complexes with cyclin dependent kinases (CDK4/6), and promote cell cycle progression. Although cyclin D functions appear largely tissue specific, we demonstrate that cyclin D3 has unique functions in lymphocyte development and cannot be replaced by cyclin D2, which is also expressed during blood differentiation. We show that only combined deletion of p27Kip1 and Rb is sufficient to rescue the development of Ccnd3−/− thymocytes. Furthermore, we show that a small molecule targeting the kinase function of cyclin D3:CDK4/6 inhibits both cell cycle entry in human T cell acute lymphoblastic leukemia (T-ALL) and disease progression in animal models of T-ALL. These studies identify unique functions for cyclin D3:CDK4/6 complexes and suggest potential therapeutic protocols for this devastating blood tumor. PMID:23079656

  8. Atomic structure of Hsp90-Cdc37-Cdk4 reveals that Hsp90 traps and stabilizes an unfolded kinase.

    PubMed

    Verba, Kliment A; Wang, Ray Yu-Ruei; Arakawa, Akihiko; Liu, Yanxin; Shirouzu, Mikako; Yokoyama, Shigeyuki; Agard, David A

    2016-06-24

    The Hsp90 molecular chaperone and its Cdc37 cochaperone help stabilize and activate more than half of the human kinome. However, both the mechanism by which these chaperones assist their "client" kinases and the reason why some kinases are addicted to Hsp90 while closely related family members are independent are unknown. Our structural understanding of these interactions is lacking, as no full-length structures of human Hsp90, Cdc37, or either of these proteins with a kinase have been elucidated. Here we report a 3.9 angstrom cryo-electron microscopy structure of the Hsp90-Cdc37-Cdk4 kinase complex. Surprisingly, the two lobes of Cdk4 are completely separated with the β4-β5 sheet unfolded. Cdc37 mimics part of the kinase N lobe, stabilizing an open kinase conformation by wedging itself between the two lobes. Finally, Hsp90 clamps around the unfolded kinase β5 strand and interacts with exposed N- and C-lobe interfaces, protecting the kinase in a trapped unfolded state. On the basis of this structure and an extensive amount of previously collected data, we propose unifying conceptual and mechanistic models of chaperone-kinase interactions. PMID:27339980

  9. Chemoproteomics Reveals Novel Protein and Lipid Kinase Targets of Clinical CDK4/6 Inhibitors in Lung Cancer.

    PubMed

    Sumi, Natalia J; Kuenzi, Brent M; Knezevic, Claire E; Remsing Rix, Lily L; Rix, Uwe

    2015-12-18

    Several selective CDK4/6 inhibitors are in clinical trials for non-small cell lung cancer (NSCLC). Palbociclib (PD0332991) is included in the phase II/III Lung-MAP trial for squamous cell lung carcinoma (LUSQ). We noted differential cellular activity between palbociclib and the structurally related ribociclib (LEE011) in LUSQ cells. Applying an unbiased mass spectrometry-based chemoproteomics approach in H157 cells and primary tumor samples, we here report distinct proteome-wide target profiles of these two drug candidates in LUSQ, which encompass novel protein and, for palbociclib only, lipid kinases. In addition to CDK4 and 6, we observed CDK9 as a potent target of both drugs. Palbociclib interacted with several kinases not targeted by ribociclib, such as casein kinase 2 and PIK3R4, which regulate autophagy. Furthermore, palbociclib engaged several lipid kinases, most notably, PIK3CD and PIP4K2A/B/C. Accordingly, we observed modulation of autophagy and inhibition of AKT signaling by palbociclib but not ribociclib.

  10. Atomic structure of Hsp90-Cdc37-Cdk4 reveals that Hsp90 traps and stabilizes an unfolded kinase.

    PubMed

    Verba, Kliment A; Wang, Ray Yu-Ruei; Arakawa, Akihiko; Liu, Yanxin; Shirouzu, Mikako; Yokoyama, Shigeyuki; Agard, David A

    2016-06-24

    The Hsp90 molecular chaperone and its Cdc37 cochaperone help stabilize and activate more than half of the human kinome. However, both the mechanism by which these chaperones assist their "client" kinases and the reason why some kinases are addicted to Hsp90 while closely related family members are independent are unknown. Our structural understanding of these interactions is lacking, as no full-length structures of human Hsp90, Cdc37, or either of these proteins with a kinase have been elucidated. Here we report a 3.9 angstrom cryo-electron microscopy structure of the Hsp90-Cdc37-Cdk4 kinase complex. Surprisingly, the two lobes of Cdk4 are completely separated with the β4-β5 sheet unfolded. Cdc37 mimics part of the kinase N lobe, stabilizing an open kinase conformation by wedging itself between the two lobes. Finally, Hsp90 clamps around the unfolded kinase β5 strand and interacts with exposed N- and C-lobe interfaces, protecting the kinase in a trapped unfolded state. On the basis of this structure and an extensive amount of previously collected data, we propose unifying conceptual and mechanistic models of chaperone-kinase interactions.

  11. Analysis of Latvian familial melanoma patients shows novel variants in the noncoding regions of CDKN2A and that the CDK4 mutation R24H is a founder mutation.

    PubMed

    Veinalde, Rūta; Ozola, Aija; Azarjana, Kristīne; Molven, Anders; Akslen, Lars A; Doniņa, Simona; Proboka, Guna; Cēma, Ingrīda; Baginskis, Ainārs; Pjanova, Dace

    2013-06-01

    Hereditary cutaneous melanoma is associated with mutations in the high-risk CDKN2A gene in about 40% of melanoma-prone families. Mutations in the CDK4 gene are the cause in only a few pedigrees. In this study, we analyzed 20 Latvian familial melanoma probands and carried out a comprehensive analysis of CDKN2A including sequencing of its promoter/intronic regions and deletion screening. We also analyzed the critical second exon of the CDK4 gene. One novel intronic variant (IVS2+82C>T) of the CDKN2A gene and a small deletion (c.-20677_-20682delGTACGC) in its promoter region were found. Genotyping of the novel variants in larger melanoma and control groups indicated that the deletion increases the risk of melanoma (odds ratio=6.353, 95% confidence interval: 1.34-30.22, P=0.0168). The CDK4 gene analysis showed a Latvian melanoma family with the mutation R24H carried on the same haplotype as in two previously described Latvian CDK4-positive families. Our study suggests that the main risk gene in Latvian families with a strong family history of melanoma is CDK4 and that most of the other cases analyzed could be sporadic or associated with low-penetrance risk genes.

  12. Analysis of Latvian familial melanoma patients shows novel variants in the noncoding regions of CDKN2A and that the CDK4 mutation R24H is a founder mutation.

    PubMed

    Veinalde, Rūta; Ozola, Aija; Azarjana, Kristīne; Molven, Anders; Akslen, Lars A; Doniņa, Simona; Proboka, Guna; Cēma, Ingrīda; Baginskis, Ainārs; Pjanova, Dace

    2013-06-01

    Hereditary cutaneous melanoma is associated with mutations in the high-risk CDKN2A gene in about 40% of melanoma-prone families. Mutations in the CDK4 gene are the cause in only a few pedigrees. In this study, we analyzed 20 Latvian familial melanoma probands and carried out a comprehensive analysis of CDKN2A including sequencing of its promoter/intronic regions and deletion screening. We also analyzed the critical second exon of the CDK4 gene. One novel intronic variant (IVS2+82C>T) of the CDKN2A gene and a small deletion (c.-20677_-20682delGTACGC) in its promoter region were found. Genotyping of the novel variants in larger melanoma and control groups indicated that the deletion increases the risk of melanoma (odds ratio=6.353, 95% confidence interval: 1.34-30.22, P=0.0168). The CDK4 gene analysis showed a Latvian melanoma family with the mutation R24H carried on the same haplotype as in two previously described Latvian CDK4-positive families. Our study suggests that the main risk gene in Latvian families with a strong family history of melanoma is CDK4 and that most of the other cases analyzed could be sporadic or associated with low-penetrance risk genes. PMID:23546221

  13. Autochthonous primary and metastatic melanomas in Hgf-Cdk4 R24C mice evade T-cell-mediated immune surveillance.

    PubMed

    Landsberg, Jennifer; Gaffal, Evelyn; Cron, Mira; Kohlmeyer, Judith; Renn, Marcel; Tüting, Thomas

    2010-10-01

    Genetically engineered mouse models offer new opportunities to investigate the role of cell-mediated immunity in the natural progression of melanoma in an immunocompetent host. Here we report that Hgf-Cdk4(R24C) mice spontaneously develop a spectrum of primary melanomas with high penetrance during their first year of life. Malignant transformation proceeds in a stepwise manner from multiple melanocytic nevi to single nodular melanomas and disseminated metastases in most mice. Migrating melanoma cells invade the draining lymph nodes without activating the immune system. Autochthonous primary tumors are destroyed following experimental introduction of immune surveillance using an adoptive lymphocyte transfer approach. However, some tumor cells are able to survive, evade immune cell control, and recur both locally and systemically. Immune tolerance in recurring tumors may be supported by immunosuppressive Gr1(+) myeloid cells. Taken together, our results demonstrate that primary and metastatic melanomas developing spontaneously in Hgf-Cdk4(R24C) mice effectively evade cellular immune surveillance.

  14. MiR-506 suppresses proliferation and induces senescence by directly targeting the CDK4/6-FOXM1 axis in ovarian cancer.

    PubMed

    Liu, Guoyan; Sun, Yan; Ji, Ping; Li, Xia; Cogdell, David; Yang, Da; Parker Kerrigan, Brittany C; Shmulevich, Ilya; Chen, Kexin; Sood, Anil K; Xue, Fengxia; Zhang, Wei

    2014-07-01

    Ovarian carcinoma is the most lethal gynaecological malignancy. Better understanding of the molecular pathogenesis of this disease and effective targeted therapies are needed to improve patient outcomes. MicroRNAs play important roles in cancer progression and have the potential for use as either therapeutic agents or targets. Studies in other cancers have suggested that miR-506 has anti-tumour activity, but its function has yet to be elucidated. We found that deregulation of miR-506 in ovarian carcinoma promotes an aggressive phenotype. Ectopic over-expression of miR-506 in ovarian cancer cells was sufficient to inhibit proliferation and to promote senescence. We also demonstrated that CDK4 and CDK6 are direct targets of miR-506, and that miR-506 can inhibit CDK4/6-FOXM1 signalling, which is activated in the majority of serous ovarian carcinomas. This newly recognized miR-506-CDK4/6-FOXM1 axis provides further insight into the pathogenesis of ovarian carcinoma and identifies a potential novel therapeutic agent.

  15. MiR-506 Suppresses Proliferation and Induces Senescence by Directly Targeting the CDK4/6-FOXM1 Axis in Ovarian Cancer

    PubMed Central

    Liu, Guoyan; Sun, Yan; Ji, Ping; Li, Xia; Cogdell, David; Yang, Da; Parker Kerrigan, Brittany C.; Shmulevich, Ilya; Chen, Kexin; Sood, Anil K.; Xue, Fengxia; Zhang, Wei

    2014-01-01

    Ovarian carcinoma is the most lethal gynecological malignancy. Better understanding of the molecular pathogenesis of this disease and effective targeted therapies are needed to improve patient outcomes. MicroRNAs play important roles in cancer progression and have the potential for use as either therapeutic agents or targets. Studies in other cancers have suggested that miR-506 has antitumor activity, but its function has yet to be elucidated. We found that deregulation of miR-506 in ovarian carcinoma promotes an aggressive phenotype. Ectopic overexpression of miR-506 in ovarian cancer cells was sufficient to inhibit proliferation and to promote senescence. We also demonstrated that CDK4 and CDK6 are direct targets of miR-506, and that miR-506 can inhibit CDK4/6-FOXM1 signaling, which is activated in the majority of serous ovarian carcinomas. This newly recognized miR-506/CDK4/6-FOXM1 axis provides further insight into the pathogenesis of ovarian carcinoma and identifies a potential novel therapeutic agent. PMID:24604117

  16. Analysing the Effect of Mutation on Protein Function and Discovering Potential Inhibitors of CDK4: Molecular Modelling and Dynamics Studies

    PubMed Central

    N, Nagasundaram; Zhu, Hailong; Liu, Jiming; V, Karthick; C, George Priya Doss; Chakraborty, Chiranjib; Chen, Luonan

    2015-01-01

    The cyclin-dependent kinase 4 (CDK4)-cyclin D1 complex plays a crucial role in the transition from the G1 phase to S phase of the cell cycle. Among the CDKs, CDK4 is one of the genes most frequently affected by somatic genetic variations that are associated with various forms of cancer. Thus, because the abnormal function of the CDK4-cyclin D1 protein complex might play a vital role in causing cancer, CDK4 can be considered a genetically validated therapeutic target. In this study, we used a systematic, integrated computational approach to identify deleterious nsSNPs and predict their effects on protein-protein (CDK4-cyclin D1) and protein-ligand (CDK4-flavopiridol) interactions. This analysis resulted in the identification of possible inhibitors of mutant CDK4 proteins that bind the conformations induced by deleterious nsSNPs. Using computational prediction methods, we identified five nsSNPs as highly deleterious: R24C, Y180H, A205T, R210P, and R246C. From molecular docking and molecular dynamic studies, we observed that these deleterious nsSNPs affected CDK4-cyclin D1 and CDK4-flavopiridol interactions. Furthermore, in a virtual screening approach, the drug 5_7_DIHYDROXY_ 2_ (3_4_5_TRI HYDROXYPHENYL) _4H_CHROMEN_ 4_ONE displayed good binding affinity for proteins with the mutations R24C or R246C, the drug diosmin displayed good binding affinity for the protein with the mutation Y180H, and the drug rutin displayed good binding affinity for proteins with the mutations A205T and R210P. Overall, this computational investigation of the CDK4 gene highlights the link between genetic variation and biological phenomena in human cancer and aids in the discovery of molecularly targeted therapies for personalized treatment. PMID:26252490

  17. Rapid growth of invasive metastatic melanoma in carcinogen-treated hepatocyte growth factor/scatter factor-transgenic mice carrying an oncogenic CDK4 mutation.

    PubMed

    Tormo, Damia; Ferrer, Aleix; Gaffal, Evelyn; Wenzel, Jörg; Basner-Tschakarjan, Etiena; Steitz, Julia; Heukamp, Lukas C; Gütgemann, Ines; Buettner, Reinhard; Malumbres, Marcos; Barbacid, Mariano; Merlino, Glenn; Tüting, Thomas

    2006-08-01

    Currently, novel mouse models of melanoma are being generated that recapitulate the histopathology and molecular pathogenesis observed in human disease. Impaired cell-cycle control, which is a hallmark of both familial and sporadic melanoma, promotes slowly growing carcinogen-induced melanomas in the skin of mice carrying a mutated cyclin-dependent kinase 4 (CDK4(R24C)). Deregulated receptor tyrosine kinase signaling, which is another important feature of human melanoma, leads to spontaneous development of metastatic melanoma after a long latency period in mice overexpressing hepatocyte growth factor/scatter factor (HGF/SF mice). Here we report that treatment with 7,12-dimethylbenz[a]anthracene and 12-O-tetradecanoylphorbol-13-acetate induced metastatic melanomas in all HGF/SF mice on the C57BL/6 background, which histologically resemble human melanoma. Importantly, mutant CDK4 dramatically increased the number and the growth kinetics of carcinogen-induced primary melanomas in the skin and promoted the growth of spontaneous metastases in lymph nodes and lungs in all HGF/SF mice within the first 3 months of life. Apart from very few skin papillomas, we did not observe tumors of other histology in carcinogen-treated HGF/SF x CDK4(R24C) mice. This new experimental mouse model can now be exploited to study further the biology of melanoma and evaluate new treatment modalities.

  18. 1α,25 dihydroxi-vitamin D{sub 3} modulates CDK4 and CDK6 expression and localization

    SciTech Connect

    Irazoqui, Ana P.; Heim, Nadia B.; Boland, Ricardo L.; Buitrago, Claudia G.

    2015-03-27

    We recently reported that the vitamin D receptor (VDR) and p38 MAPK participate in pro-differentiation events triggered by 1α,25(OH){sub 2}-vitamin D{sub 3} [1,25D] in skeletal muscle cells. Specifically, our studies demonstrated that 1,25D promotes G0/G1 arrest of cells inducing cyclin D3 and cyclin dependent kinases inhibitors (CKIs) p21{sup Waf1/Cip1} and p27{sup Kip1} expression in a VDR and p38 MAPK dependent manner. In this work we present data indicating that cyclin-dependent kinases (CDKs) 4 and 6 also play a role in the mechanism by which 1,25D stimulates myogenesis. To investigate VDR involvement in hormone regulation of CDKs 4 and 6, we significantly reduced its expression by the use of a shRNA against mouse VDR, generating the skeletal muscle cell line C2C12-VDR. Investigation of changes in cellular cycle regulating proteins by immunoblotting showed that the VDR is involved in the 1,25D –induced CDKs 4 and 6 protein levels at 6 h of hormone treatment. CDK4 levels remains high during S phase peak and G0/G1 arrest while CDK6 expression decreases at 12 h and increases again al 24 h. The up-regulation of CDKs 4 and 6 by 1,25D (6 h) was abolished in C2C12 cells pre-treated with the ERK1/2 inhibitor, UO126. Moreover, CDKs 4 and 6 expression induced by the hormone nor was detected when α and β isoforms of p38 MAPK were inhibited by compound SB203580. Confocal images show that there is not co-localization between VDR and CDKs at 6 h of hormone treatment, however CDK4 and VDR co-localizates in nucleus after 12 h of 1,25D exposure. Of relevance, at this time 1,25D promotes CDK6 localization in a peri-nuclear ring. Our data demonstrate that the VDR, ERK1/2 and p38 MAPK are involved in the control of CDKs 4 and 6 by 1,25D in skeletal muscle cells sustaining the operation of a VDR and MAPKs –dependent mechanism in hormone modulation of myogenesis. - Highlights: • 1,25D modulates CDKs 4 and 6 expression in skeletal muscle cells. • CDK4 co

  19. Cyclic AMP-induced G1 phase arrest mediated by an inhibitor (p27Kip1) of cyclin-dependent kinase 4 activation.

    PubMed

    Kato, J Y; Matsuoka, M; Polyak, K; Massagué, J; Sherr, C J

    1994-11-01

    Cyclic AMP (cAMP) blocks the mitogenic effects of colony-stimulating factor 1 (CSF-1) in macrophages, inducing cell cycle arrest in mid-G1 phase. Complexes between cyclin D1 and cyclin-dependent kinase 4 (cdk4) assemble in growth arrested cells, but cdk4 is not phosphorylated in vivo by the cdk-activating kinase (CAK) and remains inactive. Although undetectable in lysates of cAMP-treated cells, active CAK is recovered after antibody precipitation, indicating that it is not the direct target of inhibition. Levels of the cdk inhibitor p27Klp1 increase in cAMP-treated cells, and its immunodepletion from inhibitory lysates restores CAK-mediated cdk4 activation. Kip1 does not bind to CAK, but its association with cyclin D-cdk4 prevents CAK from phosphorylating and activating the holoenzyme. PMID:7954814

  20. p18 inhibits reprogramming through inactivation of Cdk4/6

    PubMed Central

    Zhu, Shaohua; Cao, Jiani; Sun, Hongyan; Liu, Kun; Li, Yaqiong; Zhao, Tongbiao

    2016-01-01

    Pluripotent stem cells (PSCs), including embryonic and induced pluripotent stem cells (iPSCs), show atypical cell cycle regulation characterized by a high proliferation rate and a shorter G1 phase compared with somatic cells. The mechanisms by which somatic cells remodel their cell cycle to achieve the high proliferation rate of PSCs during reprogramming are unclear. Here we identify that the Ink4 protein p18, which is expressed at high levels in somatic cells but at low levels in PSCs, is a roadblock to successful reprogramming. Mild inhibition of p18 expression enhances reprogramming efficiency, while ectopic expression of p18 completely blocks reprogramming. Mechanistic studies show that expression of wild-type p18, but not a p18D68N mutant which cannot inhibit Cdk4/6, down-regulates expression of Cdk4/6 target genes involved in DNA synthesis (TK, TS, DHFR, PCNA) and cell cycle regulation (CDK1 and CCNA2) and thus inhibits reprogramming. These results indicate that p18 blocks reprogramming by targeting Cdk4/6-mediated cell cycle regulation. Taken together, our results define a novel pathway that inhibits somatic cell reprogramming, and provide a new target to enhance reprogramming efficiency. PMID:27484146

  1. Selective CDK4/6 inhibition with tumor responses by PD0332991 in patients with mantle cell lymphoma.

    PubMed

    Leonard, John P; LaCasce, Ann S; Smith, Mitchell R; Noy, Ariela; Chirieac, Lucian R; Rodig, Scott J; Yu, Jian Q; Vallabhajosula, Shankar; Schoder, Heiko; English, Patricia; Neuberg, Donna S; Martin, Peter; Millenson, Michael M; Ely, Scott A; Courtney, Rachel; Shaik, Naveed; Wilner, Keith D; Randolph, Sophia; Van den Abbeele, Annick D; Chen-Kiang, Selina Y; Yap, Jeffrey T; Shapiro, Geoffrey I

    2012-05-17

    Mantle cell lymphoma (MCL) carries an unfavorable prognosis and requires new treatment strategies. The associated t(11:14) translocation results in enhanced cyclin D1 expression and cyclin D1-dependent kinase activity to promote cell-cycle progression. A pharmacodynamic study of the selective CDK4/6 inhibitor PD0332991 was conducted in 17 patients with relapsed disease, using 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) and 3-deoxy-3[(18)F]fluorothymidine (FLT) positron emission tomography (PET) to study tumor metabolism and proliferation, respectively, in concert with pre- and on-treatment lymph node biopsies to assess retinoblastoma protein (Rb) phosphorylation and markers of proliferation and apoptosis. Substantial reductions in the summed FLT-PET maximal standard uptake value (SUV(max)), as well as in Rb phosphorylation and Ki-67 expression, occurred after 3 weeks in most patients, with significant correlations among these end points. Five patients achieved progression-free survival time of > 1 year (range, 14.9-30.1+ months), with 1 complete and 2 partial responses (18% objective response rate; 90% confidence interval, 5%-40%). These patients demonstrated > 70%, > 90%, and ≥ 87.5% reductions in summed FLT SUV(max) and expression of phospho-Rb and Ki67, respectively, parameters necessary but not sufficient for long-term disease control. The results of the present study confirm CDK4/6 inhibition by PD0332991 at a well-tolerated dose and schedule and suggest clinical benefit in a subset of MCL patients. This study is registered at www.clinicaltrials.gov under identifier NCT00420056.

  2. 3D-QSAR and 3D-QSSR studies of thieno[2,3-d]pyrimidin-4-yl hydrazone analogues as CDK4 inhibitors by CoMFA analysis

    PubMed Central

    Cai, Bao-qin; Jin, Hai-xiao; Yan, Xiao-jun; Zhu, Peng; Hu, Gui-xiang

    2014-01-01

    Aim: To investigate the structural basis underlying potency and selectivity of a series of novel analogues of thieno[2,3-d]pyrimidin-4-yl hydrazones as cyclin-dependent kinase 4 (CDK4) inhibitors and to use this information for drug design strategies. Methods: Three-dimensional quantitative structure-activity relationship (3D-QSAR) and three-dimensional quantitative structure-selectivity relationship (3D-QSSR) models using comparative molecular field analysis (CoMFA) were conducted on a training set of 48 compounds. Partial least squares (PLS) analysis was employed. External validation was performed with a test set of 9 compounds. Results: The obtained 3D-QSAR model (q2=0.724, r2=0.965, r2pred=0.945) and 3D-QSSR model (q2=0.742, r2=0.923, r2pred=0.863) were robust and predictive. Contour maps with good compatibility to active binding sites provided insight into the potentially important structural features required to enhance activity and selectivity. The contour maps indicated that bulky groups at R1 position could potentially enhance CDK4 inhibitory activity, whereas bulky groups at R3 position have the opposite effect. Appropriate incorporation of bulky electropositive groups at R4 position is favorable and could improve both potency and selectivity to CDK4. Conclusion: These two models provide useful information to guide drug design strategies aimed at obtaining potent and selective CDK4 inhibitors. PMID:24122012

  3. Determining the effect of transforming growth factor-β1 on cdk4 and p27 in gastric cancer and cholangiocarcinoma.

    PubMed

    Lee, Sung Ryol; Shin, Jae Wook; Kim, Hyung Ook; Son, Byung Ho; Yoo, Chang Hak; Shin, Jun Ho

    2013-02-01

    Gastric cancer and cholangiocarcinoma are problematic throughout the world due to their destructive malignancy. In attempts to treat cholangiocarcinoma and gastric cancer, researchers often explore the effects of transforming growth factor-β1 (TGF-β1). TGF-β1 plays a crucial role in causing cell cycle arrest and fibrosis in cancer cells. The present study aimed to identify whether TGF-β1 is capable of functioning as an antitumor agent in two cancer cell lines; cholangiocarcinoma and gastric cancer. The downregulation of cyclin dependent kinase (cdk) 4 and the upregulation of p27 were investigated, in order to identify possible antitumor functions of TGF-β1. A number of different methods were implemented, including cell proliferation assay, bicinchoninic acid (BCA) assay and western blot analysis with TGF-β1, AGS (human gastric cancer cell line) and SUN-1196 (human cholangiocarcinoma cell line). In the AGS study, cdk4 values decreased from 1.000 to 0.670 and then to 0.664, with increasing TGF-β1 concentrations of 0, 0.5 and 5 ng/ml, respectively. By contrast, p27 values increased from 1.000 to 1.391 and then to 1.505, with increasing TGF-β1 concentrations of 0, 0.5 and 5 ng/ml, respectively. In the SUN-1196 study, p27 values increased from 0.548 to 0.807 and then to 0.844 with increasing TGF-β1 concentrations of 5, 25 and 50 ng/ml, respectively. Certain concentrations of TGF-β1 play antitumor roles in gastric cancer through the down-regulation of cdk4 and upregulation of p27. Certain TGF-β1 concentrations also have antitumor roles in cholangiocarcinoma through the upregulation of p27. With these results, we came a step closer to finding a cure for cholangiocarcinoma and gastric cancer. PMID:23420090

  4. CDK4/6 Inhibitor PD0332991 in Glioblastoma Treatment: Does It Have a Future?

    PubMed Central

    Schröder, Lisette B. W.; McDonald, Kerrie L.

    2015-01-01

    Glioblastoma is aggressive, highly infiltrating, and the most frequent malignant form of brain cancer. With a median survival time of only 14.6 months, when treated with the standard of care, it is essential to find new therapeutic options. A specific CDK4/6 inhibitor, PD0332991, obtained accelerated approval from the Food and Drug Administration for the treatment of patients with advanced estrogen receptor-positive and HER2-negative breast cancer. Common alterations in the cyclin D1-cyclin-dependent kinase 4/6-retinoblastoma 1 pathway in glioblastoma make PD0332991 also an interesting drug for the treatment of glioblastoma. Promising results in in vitro studies, where patient derived glioblastoma cell lines showed sensitivity to PD0332991, gave motive to start in vivo studies. Outcomes of these studies have been contrasting in terms of PD0332991 efficacy within the brain: more research is necessary to conclude whether CDK4/6 inhibitor can be beneficial in the treatment of glioblastoma. PMID:26649278

  5. CDK4/6 inhibitor suppresses gastric cancer with CDKN2A mutation

    PubMed Central

    Huang, Shiliang; Ye, Hua; Guo, Wenying; Dong, Xianwen; Wu, Nali; Zhang, Xie; Huang, Zhigang

    2015-01-01

    Aim: Gastric cancer is a major health problem and current treatment lacks lasting effect. Targeted therapy for gastric cancer with specific genetic background is in urgent need. Methods: We have studied The Cancer Genomic Atlas (TCGA) and The Genomics of Drug Sensitivity in Cancer (GDSC) databases to reveal genes with high frequency of mutation and possible sensitive compound against such gene mutation. In vitro studies were conducted to validate the in silico findings. Results: CDKN2A is frequently mutated in gastric cancer, revealed in TCGA database. CDK4/6 inhibitor PD-0332991 was sensitive in cancer cells with CDKN2A mutation, revealed in GDSC database. In vitro studies showed that PD-0332991 could selectively inhibit proliferation of gastric cancer cell with CDKN2A mutation. PD-0332991 could also inhibit cell invasion, migration, and colony formation of gastric cancer cell with CDKN2A mutation. PD-0332991 induced cell cycle arrest but not apoptosis. PD-0332991 inhibited xenograft gastric cancer mouse model. Conclusion: Gastric cancer with CDKN2A mutation is sensitive to CDK4/6 inhibitor. PD-0332991 is a potential therapeutic agent for gastric cancer. PMID:26380006

  6. Mitigation of acute kidney injury by cell-cycle inhibitors that suppress both CDK4/6 and OCT2 functions

    PubMed Central

    Pabla, Navjotsingh; Gibson, Alice A.; Buege, Mike; Ong, Su Sien; Li, Lie; Hu, Shuiying; Du, Guoqing; Sprowl, Jason A.; Vasilyeva, Aksana; Janke, Laura J.; Schlatter, Eberhard; Chen, Taosheng; Ciarimboli, Giuliano; Sparreboom, Alex

    2015-01-01

    Acute kidney injury (AKI) is a potentially fatal syndrome characterized by a rapid decline in kidney function caused by ischemic or toxic injury to renal tubular cells. The widely used chemotherapy drug cisplatin accumulates preferentially in the renal tubular cells and is a frequent cause of drug-induced AKI. During the development of AKI the quiescent tubular cells reenter the cell cycle. Strategies that block cell-cycle progression ameliorate kidney injury, possibly by averting cell division in the presence of extensive DNA damage. However, the early signaling events that lead to cell-cycle activation during AKI are not known. In the current study, using mouse models of cisplatin nephrotoxicity, we show that the G1/S-regulating cyclin-dependent kinase 4/6 (CDK4/6) pathway is activated in parallel with renal cell-cycle entry but before the development of AKI. Targeted inhibition of CDK4/6 pathway by small-molecule inhibitors palbociclib (PD-0332991) and ribociclib (LEE011) resulted in inhibition of cell-cycle progression, amelioration of kidney injury, and improved overall survival. Of additional significance, these compounds were found to be potent inhibitors of organic cation transporter 2 (OCT2), which contributes to the cellular accumulation of cisplatin and subsequent kidney injury. The unique cell-cycle and OCT2-targeting activities of palbociclib and LEE011, combined with their potential for clinical translation, support their further exploration as therapeutic candidates for prevention of AKI. PMID:25848011

  7. Mutational analysis of the N-ras, p53, p16INK4a, CDK4, and MC1R genes in human congenital melanocytic naevi.

    PubMed

    Papp, T; Pemsel, H; Zimmermann, R; Bastrop, R; Weiss, D G; Schiffmann, D

    1999-08-01

    Eighteen human congenital melanocytic naevi (CMN) from 17 patients were screened for activating point mutations in the oncogenes N-ras and CDK4 and for sequence variants in the MC1R gene by combined RFLP-PCR/SSCP analysis. In addition, all lesions were screened for deletions and point mutations in the tumour suppressor genes p53 and p16INK4a (CDKN2A) by combined multiplex PCR/SSCP analysis. Positive screening data were specified by sequencing of the corresponding PCR product. Activating point mutations in the N-ras gene (nine CAA (Gln) to AAA (Lys) transversions and one CAA (Gln) to CGA (Arg) transition at codon 61) were detected at high frequency (56%). Furthermore, three missense mutations (V92M) and two silent mutations (CGA (Arg) to CGG (Arg), codon 213, exon 6) were found in the MC1R and p53 genes, respectively. No mutations were found in p16 or CDK4. The activated N-ras oncogene, which is also found in human cutaneous melanomas, may constitute a potential risk factor for melanoma formation within CMN.

  8. Association of CDK4 germline and BRAF somatic mutations in a patient with multiple primary melanomas and BRAF inhibitor resistance.

    PubMed

    Governa, Maurizio; Caprarella, Evelina; Dalla Pozza, Edoardo; Vigato, Enrico; Maritan, Monia; Caputo, Glenda G; Zannoni, Marina; Rosina, Paolo; Elefanti, Lisa; Stagni, Camilla; Menin, Chiara

    2015-10-01

    Many genetic alterations, including predisposing or somatic mutations, may contribute toward the development of melanoma. Although CDKN2A and CDK4 are high-penetrance genes for melanoma, MC1R is a low-penetrance gene that has been associated most consistently with the disease. Moreover, BRAF is the most frequently somatically altered oncogene and is a validated therapeutic target in melanoma. This paper reports a case of multiple primary melanoma with germline CDK4 mutation, MC1R variant, and somatic BRAF mutation in nine out of 10 melanomas, indicating that a common pathogenesis, because of a predisposing genetic background, may be shared among distinct subsequent melanomas of probable clonal origin. After 3 months of targeted therapy with BRAF inhibitor, our patient developed resistance with rapid progression of the disease leading to death. This is the first case in which early resistance to BRAF inhibitor has been reported in a patient with CDK4 germline mutation.

  9. Association of CDK4 germline and BRAF somatic mutations in a patient with multiple primary melanomas and BRAF inhibitor resistance.

    PubMed

    Governa, Maurizio; Caprarella, Evelina; Dalla Pozza, Edoardo; Vigato, Enrico; Maritan, Monia; Caputo, Glenda G; Zannoni, Marina; Rosina, Paolo; Elefanti, Lisa; Stagni, Camilla; Menin, Chiara

    2015-10-01

    Many genetic alterations, including predisposing or somatic mutations, may contribute toward the development of melanoma. Although CDKN2A and CDK4 are high-penetrance genes for melanoma, MC1R is a low-penetrance gene that has been associated most consistently with the disease. Moreover, BRAF is the most frequently somatically altered oncogene and is a validated therapeutic target in melanoma. This paper reports a case of multiple primary melanoma with germline CDK4 mutation, MC1R variant, and somatic BRAF mutation in nine out of 10 melanomas, indicating that a common pathogenesis, because of a predisposing genetic background, may be shared among distinct subsequent melanomas of probable clonal origin. After 3 months of targeted therapy with BRAF inhibitor, our patient developed resistance with rapid progression of the disease leading to death. This is the first case in which early resistance to BRAF inhibitor has been reported in a patient with CDK4 germline mutation. PMID:26110554

  10. Synthetic Lethal Therapy for KRAS Mutant Non-small-cell Lung Carcinoma with Nanoparticle-mediated CDK4 siRNA Delivery

    PubMed Central

    Mao, Cheng-Qiong; Xiong, Meng-Hua; Liu, Yang; Shen, Song; Du, Xiao-Jiao; Yang, Xian-Zhu; Dou, Shuang; Zhang, Pei-Zhuo; Wang, Jun

    2014-01-01

    The KRAS mutation is present in ~20% of lung cancers and has not yet been effectively targeted for therapy. This mutation is associated with a poor prognosis in non-small-cell lung carcinomas (NSCLCs) and confers resistance to standard anticancer treatment drugs, including epidermal growth factor receptor tyrosine kinase inhibitors. In this study, we exploited a new therapeutic strategy based on the synthetic lethal interaction between cyclin-dependent kinase 4 (CDK4) downregulation and the KRAS mutation to deliver micellar nanoparticles (MNPs) containing small interfering RNA targeting CDK4 (MNPsiCDK4) for treatment in NSCLCs harboring the oncogenic KRAS mutation. Following MNPsiCDK4 administration, CDK4 expression was decreased, accompanied by inhibited cell proliferation, specifically in KRAS mutant NSCLCs. However, this intervention was harmless to normal KRAS wild-type cells, confirming the proposed mechanism of synthetic lethality. Moreover, systemic delivery of MNPsiCDK4 significantly inhibited tumor growth in an A549 NSCLC xenograft murine model, with depressed expression of CDK4 and mutational KRAS status, suggesting the therapeutic promise of MNPsiCDK4 delivery in KRAS mutant NSCLCs via a synthetic lethal interaction between KRAS and CDK4. PMID:24496383

  11. The Ras oncogene signals centrosome amplification in mammary epithelial cells through cyclin D1/Cdk4 and Nek2

    PubMed Central

    Zeng, X; Shaikh, FY; Harrison, MK; Adon, AM; Trimboli, AJ; Carroll, KA; Sharma, N; Timmers, C; Chodosh, LA; Leone, G; Saavedra, HI

    2010-01-01

    Centrosome amplification (CA) contributes to carcinogenesis by generating aneuploidy. Elevated frequencies of CA in most benign breast lesions and primary tumors suggest a causative role for CA in breast cancers. Clearly, identifying which and how altered signal transduction pathways contribute to CA is crucial to breast cancer control. Although a causative and cooperative role for c-Myc and Ras in mammary tumorigenesis is well documented, their ability to generate CA during mammary tumor initiation remains unexplored. To answer that question, K-RasG12D and c-Myc were induced in mouse mammary glands. Although CA was observed in mammary tumors initiated by c-Myc or K-RasG12D, it was detected only in premalignant mammary lesions expressing K-RasG12D. CA, both in vivo and in vitro, was associated with increased expression of the centrosome-regulatory proteins, cyclin D1 and Nek2. Abolishing the expression of cyclin D1, Cdk4 or Nek2 in MCF10A human mammary epithelial cells expressing H-RasG12V abrogated Ras-induced CA, whereas silencing cyclin E1 or B2 had no effect. Thus, we conclude that CA precedes mammary tumorigenesis, and interfering with centrosome-regulatory targets suppresses CA. PMID:20581865

  12. Marine steroids as potential anticancer drug candidates: In silico investigation in search of inhibitors of Bcl-2 and CDK-4/Cyclin D1.

    PubMed

    Saikia, Surovi; Kolita, Bhaskor; Dutta, Partha P; Dutta, Deep J; Neipihoi; Nath, Shyamalendu; Bordoloi, Manobjyoti; Quan, Pham Minh; Thuy, Tran Thu; Phuong, Doan Lan; Long, Pham Quoc

    2015-10-01

    Star fishes (Asteroidea) are rich in polar steroids with diverse structural characteristics. The structural modifications of star fish steroids occur at 3β, 4β, 5α, 6α (or β), 7α (or β), 8, 15α (or β) and 16β positions of the steroidal nucleus and in the side chain. Widely found polar steroids in starfishes include polyhydroxysteroids, steroidal sulfates, glycosides, steroid oligoglycosides etc. Bioactivity of these steroids is less studied; only a few reports like antibacterial, cytotoxic activity etc. are available. In continuation of our search for bioactive molecules from natural sources, we undertook in silico screening of steroids from star fishes against Bcl-2 and CDK-4/Cyclin D1 - two important targets of progression and proliferation of cancer cells. We have screened 182 natural steroids from star fishes occurring in different parts of the world and their 282 soft-derivatives by in silico methods. Their physico-chemical properties, drug-likeliness, binding potential with the selected targets, ADMET (absorption, distribution, metabolism, toxicity) were predicted. Further, the results were compared with those of existing steroidal and non steroidal drugs and inhibitors of Bcl-2 and CDK-4/Cyclin D1. The results are promising and unveil that some of these steroids can be potent leads for cancer treatments.

  13. Autochthonous primary and metastatic melanomas in Hgf-Cdk4 R24C mice evade T-cell-mediated immune surveillance.

    PubMed

    Landsberg, Jennifer; Gaffal, Evelyn; Cron, Mira; Kohlmeyer, Judith; Renn, Marcel; Tüting, Thomas

    2010-10-01

    Genetically engineered mouse models offer new opportunities to investigate the role of cell-mediated immunity in the natural progression of melanoma in an immunocompetent host. Here we report that Hgf-Cdk4(R24C) mice spontaneously develop a spectrum of primary melanomas with high penetrance during their first year of life. Malignant transformation proceeds in a stepwise manner from multiple melanocytic nevi to single nodular melanomas and disseminated metastases in most mice. Migrating melanoma cells invade the draining lymph nodes without activating the immune system. Autochthonous primary tumors are destroyed following experimental introduction of immune surveillance using an adoptive lymphocyte transfer approach. However, some tumor cells are able to survive, evade immune cell control, and recur both locally and systemically. Immune tolerance in recurring tumors may be supported by immunosuppressive Gr1(+) myeloid cells. Taken together, our results demonstrate that primary and metastatic melanomas developing spontaneously in Hgf-Cdk4(R24C) mice effectively evade cellular immune surveillance. PMID:20649939

  14. Dual inhibition of CDK4/Rb and PI3K/AKT/mTOR pathways by ON123300 induces synthetic lethality in mantle cell lymphomas.

    PubMed

    Divakar, S K A; Ramana Reddy, M V; Cosenza, S C; Baker, S J; Perumal, D; Antonelli, A C; Brody, J; Akula, B; Parekh, S; Reddy, E Premkumar

    2016-01-01

    This study describes the characterization of a novel kinase inhibitor, ON123300, which inhibits CDK4/6 (cyclin-dependent kinases 4 and 6) and phosphatidylinositol 3 kinase-δ (PI3K-δ) and exhibits potent activity against mantle cell lymphomas (MCLs) both in vitro and in vivo. We examined the effects of PD0332991 and ON123300 on cell cycle progression, modulation of the retinoblastoma (Rb) and PI3K/AKT pathways, and the induction of apoptosis in MCL cell lines and patient-derived samples. When Granta 519 and Z138C cells were incubated with PD0332991 and ON123300, both compounds were equally efficient in their ability to inhibit the phosphorylation of Rb family proteins. However, only ON123300 inhibited the phosphorylation of proteins associated with the PI3K/AKT pathway. Cells treated with PD0332991 rapidly accumulated in the G0/G1 phase of cell cycle as a function of increasing concentration. Although ON123300-treated cells arrested similarly at lower concentrations, higher concentrations resulted in the induction of apoptosis, which was not observed in PD0332991-treated samples. Mouse xenograft assays also showed a strong inhibition of MCL tumor growth in ON123300-treated animals. Finally, treatment of ibrutinib-sensitive and -resistant patient-derived MCLs with ON123300 also triggered apoptosis and inhibition of the Rb and PI3K/AKT pathways, suggesting that this compound might be an effective agent in MCL, including ibrutinib-resistant forms of the disease. PMID:26174628

  15. Cell Cycle Regulating Kinase Cdk4 as a Potential Target for Tumor Cell Treatment and Tumor Imaging

    PubMed Central

    Graf, Franziska; Koehler, Lena; Kniess, Torsten; Wuest, Frank; Mosch, Birgit; Pietzsch, Jens

    2009-01-01

    The cyclin-dependent kinase (Cdk)-cyclin D/retinoblastoma (pRb)/E2F cascade, which controls the G1/S transition of cell cycle, has been found to be altered in many neoplasias. Inhibition of this pathway by using, for example, selective Cdk4 inhibitors has been suggested to be a promising approach for cancer therapy. We hypothesized that appropriately radiolabeled Cdk4 inhibitors are suitable probes for tumor imaging and may be helpful studying cell proliferation processes in vivo by positron emission tomography. Herein, we report the synthesis and biological, biochemical, and radiopharmacological characterizations of two 124I-labeled small molecule Cdk4 inhibitors (8-cyclopentyl-6-iodo-5-methyl-2-(4-piperazin-1-yl-phenylamino)-8H-pyrido[2,3-d]-pyrimidin-7-one (CKIA) and 8-cyclopentyl-6-iodo-5-methyl-2-(5-(piperazin-1-yl)-pyridin-2-yl-amino)-8H-pyrido[2,3-d]pyrimidin-7-one (CKIB)). Our data demonstrate a defined and specific inhibition of tumor cell proliferation through CKIA and CKIB by inhibition of the Cdk4/pRb/E2F pathway emphasizing potential therapeutic benefit of CKIA and CKIB. Furthermore, radiopharmacological properties of [124I]CKIA and [124I]CKIB observed in human tumor cells are promising prerequisites for in vivo biodistribution and imaging studies. PMID:19551155

  16. CDKN2A and CDK4 variants in Latvian melanoma patients: analysis of a clinic-based population.

    PubMed

    Pjanova, Dace; Engele, Ludmila; Randerson-Moor, Juliette A; Harland, Mark; Bishop, D Timothy; Newton Bishop, Julia A; Taylor, Claire; Debniak, Tadeusz; Lubinski, Jan; Kleina, Regina; Heisele, Olita

    2007-06-01

    Germline mutations of the CDKN2A and CDK4 genes explain a significant proportion of familial melanoma. To date, there have been few published estimations of the prevalence of such mutations in sporadic melanoma patients. In this study, we investigated CDKN2A and CDK4 exon 2 for germline mutations in 125 consecutive cutaneous malignant melanoma patients recruited through the Latvian Oncological Center, using amplicon melting analysis and sequencing. No disease-related CDKN2A germline mutations were identified in any of the melanoma patients analysed but the previously described CDK4 mutation, Arg24His, was found in one patient with a family history of melanoma. CDKN2A polymorphisms were studied as putative low penetrance susceptibility genes. The proportion of cases with polymorphisms in this Latvian melanoma population was Ala148Thr (c.442G>A) (6%), 500 C/G (c.*29C>G) (18%), and 540 C/T (c.*69C>T) (20%); however, only the frequency of the Ala148Thr polymorphism was higher in melanoma patients than in 203 controls (6 versus 1%, P=0.03). Ala148Thr has also been reported in association with melanoma in a Polish series but not in an English series. We therefore examined the Ala148Thr carrier's haplotype in 10 Latvian and 39 Polish samples. No significant difference was seen between these populations and the predominant haplotype observed in English samples, giving no indication that the discrepancy could be explained by population differences in linkage disequilibrium. In summary, our results show that germline mutations at the CDKN2A locus are rare in sporadic melanoma in Latvia. The study does, however, provide some additional evidence for a role for the CDKN2A polymorphism Ala148Thr as a low penetrance susceptibility gene. The detected CDK4 exon 2 mutation was found in only the seventh family identified worldwide with a germline CDK4 mutation.

  17. Antitumour potential of BPT: a dual inhibitor of cdk4 and tubulin polymerization.

    PubMed

    Mahale, S; Bharate, S B; Manda, S; Joshi, P; Jenkins, P R; Vishwakarma, R A; Chaudhuri, B

    2015-01-01

    The marine natural product fascaplysin (1) is a potent Cdk4 (cyclin-dependent kinase 4)-specific inhibitor, but is toxic to all cell types possibly because of its DNA-intercalating properties. Through the design and synthesis of numerous fascaplysin analogues, we intended to identify inhibitors of cancer cell growth with good therapeutic window with respect to normal cells. Among various non-planar tryptoline analogues prepared, N-(biphenyl-2-yl) tryptoline (BPT, 6) was identified as a potent inhibitor of cancer cell growth and free from DNA-binding properties owing to its non-planar structure. This compound was tested in over 60 protein kinase assays. It displayed inhibition of Cdk4-cyclin D1 enzyme in vitro far more potently than many other kinases including Cdk family members. Although it blocks growth of cancer cells deficient in the mitotic-spindle checkpoint at the G0/G1 phase of the cell cycle, the block occurs primarily at the G2/M phase. BPT inhibits tubulin polymerization in vitro and acts as an enhancer of tubulin depolymerization of paclitaxel-stabilized tubulin in live cells. Western blot analyses indicated that, in p53-positive cells, BPT upregulates the expression of p53, p21 and p27 proteins, whereas it downregulates the expression of cyclin B1 and Cdk1. BPT selectively kills SV40-transformed mouse embryonic hepatic cells and human fibroblasts rather than untransformed cells. BPT inhibited the growth of several human cancer cells with an IC50<1 μM. The pharmacokinetic study in BALB/c mice indicated good plasma exposure after intravenous administration. It was found to be efficacious at 1/10th the maximum-tolerated dose (1000 mg/kg) against human tumours derived from HCT-116 (colon) and NCI-H460 (lung) cells in SCID (severe-combined immunodeficient) mice models. BPT is a relatively better anticancer agent than fascaplysin with an unusual ability to block two overlapping yet crucial phases of the cell cycle, mitosis and G0/G1. Its ability to

  18. Antitumour potential of BPT: a dual inhibitor of cdk4 and tubulin polymerization

    PubMed Central

    Mahale, S; Bharate, S B; Manda, S; Joshi, P; Jenkins, P R; Vishwakarma, R A; Chaudhuri, B

    2015-01-01

    The marine natural product fascaplysin (1) is a potent Cdk4 (cyclin-dependent kinase 4)-specific inhibitor, but is toxic to all cell types possibly because of its DNA-intercalating properties. Through the design and synthesis of numerous fascaplysin analogues, we intended to identify inhibitors of cancer cell growth with good therapeutic window with respect to normal cells. Among various non-planar tryptoline analogues prepared, N-(biphenyl-2-yl) tryptoline (BPT, 6) was identified as a potent inhibitor of cancer cell growth and free from DNA-binding properties owing to its non-planar structure. This compound was tested in over 60 protein kinase assays. It displayed inhibition of Cdk4-cyclin D1 enzyme in vitro far more potently than many other kinases including Cdk family members. Although it blocks growth of cancer cells deficient in the mitotic-spindle checkpoint at the G0/G1 phase of the cell cycle, the block occurs primarily at the G2/M phase. BPT inhibits tubulin polymerization in vitro and acts as an enhancer of tubulin depolymerization of paclitaxel-stabilized tubulin in live cells. Western blot analyses indicated that, in p53-positive cells, BPT upregulates the expression of p53, p21 and p27 proteins, whereas it downregulates the expression of cyclin B1 and Cdk1. BPT selectively kills SV40-transformed mouse embryonic hepatic cells and human fibroblasts rather than untransformed cells. BPT inhibited the growth of several human cancer cells with an IC50 <1 μM. The pharmacokinetic study in BALB/c mice indicated good plasma exposure after intravenous administration. It was found to be efficacious at 1/10th the maximum-tolerated dose (1000 mg/kg) against human tumours derived from HCT-116 (colon) and NCI-H460 (lung) cells in SCID (severe-combined immunodeficient) mice models. BPT is a relatively better anticancer agent than fascaplysin with an unusual ability to block two overlapping yet crucial phases of the cell cycle, mitosis and G0/G1. Its ability to

  19. miR-1 suppresses the growth of esophageal squamous cell carcinoma in vivo and in vitro through the downregulation of MET, cyclin D1 and CDK4 expression

    PubMed Central

    JIANG, SEN; ZHAO, CHAO; YANG, XIAODI; LI, XIANGYANG; PAN, QING; HUANG, HAIJIN; WEN, XUYANG; SHAN, HUSHENG; LI, QIANWEN; DU, YUNXIANG; ZHAO, YAPING

    2016-01-01

    Several aberrant microRNAs (miRNAs or miRs) have been implicated in esophageal cancer (EC), which is widely prevalent in China. However, their role in EC tumorigenesis has not yet been fully elucidated. In the present study, we determined that miR-1 was downregulated in esophageal squamous cell carcinoma (ESCC) tissues compared with adjacent non-neoplastic tissues using RT-qPCR, and confirmed this using an ESCC cell line. Using a nude mouse xenograft model, we confirmed that the re-expression of miR-1 significantly inhibited ESCC tumor growth. A tetrazolium assay and a trypan blue exclusion assay revealed that miR-1 suppressed ESCC cell proliferation and increased apoptosis, whereas the silencing of miR-1 promoted cell proliferation and decreased apoptosis, suggesting that miR-1 is a novel tumor suppressor. To elucidate the molecular mechanisms of action of miR-1 in ESCC, we investigated putative targets using bioinformatics tools. MET, cyclin D1 and cyclin-dependent kinase 4 (CDK4), which are involved in the hepatocyte growth factor (HGF)/MET signaling pathway, were found to be targets of miR-1. miR-1 expression inversely correlated with MET, cyclin D1 and CDK4 expression in ESCC cells. miR-1 directly targeted MET, cyclin D1 and CDK4, suppressing ESCC cell growth. The newly identified miR-1/MET/cyclin D1/CDK4 axis provides new insight into the molecular mechanisms of ESCC pathogenesis and indicates a novel strategy for the diagnosis and treatment of ESCC. PMID:27247259

  20. Population-based prevalence of CDKN2A and CDK4 mutations in patients with multiple primary melanomas.

    PubMed

    Helsing, Per; Nymoen, Dag Andre; Ariansen, Sarah; Steine, Solrun J; Maehle, Lovise; Aamdal, Steinar; Langmark, Frøydis; Loeb, Mitchell; Akslen, Lars A; Molven, Anders; Andresen, Per Arne

    2008-02-01

    The presence of multiple primary cutaneous melanomas (MPM) has been advocated as guidance to identifying melanoma families. Frequencies of CDKN2A mutations in materials of sporadic MPM cases from pigmented lesion clinics vary between 8 and 15%. Patients with MPM have therefore been regarded as good candidates for CDKN2A mutational screening. We describe a population-based study where all persons in Norway diagnosed with MPM between 1953 and 2004 (n = 738 alive per April 2004) were invited to participate. Three-hundred-and-ninety patients (52.8%) responded confidentially. Mutations in CDKN2A were found in 6.9% of the respondents. Eighty-one MPM patients (20.8%) reported that they belonged to melanoma families, and 17 (21.0%) of these harboured a CDKN2A mutation, compared to 3.2% of the nonfamilial cases. The probability of finding a CDKN2A mutation increased when the patients had three or more melanomas, or a young age of onset of first melanoma. We identified five novel CDKN2A variants (Ala57Gly, Pro81Arg, Ala118Val, Leu130Val, and Arg131Pro) and four that previously have been reported in melanoma families (Glu27X, Met53Ile, Arg87Trp, and Ala127Pro). A large deletion (g.13623_23772del10150) encompassing exon 1alpha and the 5' part of exon 2 was detected in six patients with a family history of melanoma. Three patients, belonging to the same family, had the CDK4 Arg24His mutation. The frequency of CDKN2A mutations was lower than previously reported in other studies, an observation which probably is due to the population-based design of our study.

  1. Involvement of PSMD10, CDK4, and Tumor Suppressors in Development of Intrahepatic Cholangiocarcinoma of Syrian Golden Hamsters Induced by Clonorchis sinensis and N-Nitrosodimethylamine

    PubMed Central

    Uddin, Md. Hafiz; Choi, Min-Ho; Kim, Woo Ho; Jang, Ja-June; Hong, Sung-Tae

    2015-01-01

    Background Clonorchis sinensis is a group-I bio-carcinogen for cholangiocarcinoma (CCA). Although the epidemiological evidence links clonorchiasis and CCA, the underlying molecular mechanism involved in this process is poorly understood. In the present study, we investigated expression of oncogenes and tumor suppressors, including PSMD10, CDK4, p53 and RB in C. sinensis induced hamster CCA model. Methods Different histochemical/immunohistochemical techniques were performed to detect CCA in 4 groups of hamsters: uninfected control (Ctrl.), infected with C. sinensis (Cs), ingested N-nitrosodimethylamine (NDMA), and both Cs infected and NDMA introduced (Cs+NDMA). The liver tissues from all groups were analyzed for gene/protein expressions by quantitative PCR (qPCR) and western blotting. Principal Findings CCA was observed in all hamsters of Cs+NDMA group with well, moderate, and poorly differentiated types measured in 21.8% ± 1.5%, 13.3% ± 1.3%, and 10.8% ± 1.3% of total tissue section areas respectively. All CCA differentiations progressed in a time dependent manner, starting from the 8th week of infection. CCA stroma was characterized with increased collagen type I, mucin, and proliferative cell nuclear antigen (PCNA). The qPCR analysis showed PSMD10, CDK4 and p16INK4 were over-expressed, whereas p53 was under-expressed in the Cs+NDMA group. We observed no change in RB1 at mRNA level but found significant down-regulation of RB protein. The apoptosis related genes, BAX and caspase 9 were found downregulated in the CCA tissue. Gene/protein expressions were matched well with the pathological changes of different groups except the NDMA group. Though the hamsters in the NDMA group showed no marked pathological lesions, we observed over-expression of Akt/PKB and p53 genes proposing molecular interplay in this group which might be related to the CCA initiation in this animal model. Conclusions/Significance The present findings suggest that oncogenes, PSMD10 and CDK4

  2. MicroRNA-206 induces G1 arrest in melanoma by inhibition of CDK4 and Cyclin D.

    PubMed

    Georgantas, Robert W; Streicher, Katie; Luo, Xiaobing; Greenlees, Lydia; Zhu, Wei; Liu, Zheng; Brohawn, Philip; Morehouse, Christopher; Higgs, Brandon W; Richman, Laura; Jallal, Bahija; Yao, Yihong; Ranade, Koustubh

    2014-03-01

    Expression profiling of microRNAs in melanoma lesional skin biopsies compared with normal donor skin biopsies, as well as melanoma cell lines compared with normal melanocytes, revealed that hsa-miR-206 was down-regulated in melanoma (-75.4-fold, P = 1.7 × 10(-4)). MiR-206 has been implicated in a large number of cancers, including breast, lung, colorectal, ovarian, and prostate cancers; however, its role in tumor development remains largely unknown, its biologic function is poorly characterized, and its targets affecting cancer cells are largely unknown. MiR-206 reduced growth and migration/invasion of multiple melanoma cell lines. Bioinformatics identified cell cycle genes CDK2, CDK4, Cyclin C, and Cyclin D1 as strong candidate targets. Western blots and 3'UTR reporter gene assays revealed that miR-206 inhibited translation of CDK4, Cyclin D1, and Cyclin C. Additionally, hsa-miR-206 transfection induced G1 arrest in multiple melanoma cell lines. These observations support hsa-miR-206 as a tumor suppressor in melanoma and identify Cyclin C, Cyclin D1, and CDK4 as miR-206 targets.

  3. MicroRNA-206 induces G1 arrest in melanoma by inhibition of CDK4 and Cyclin D.

    PubMed

    Georgantas, Robert W; Streicher, Katie; Luo, Xiaobing; Greenlees, Lydia; Zhu, Wei; Liu, Zheng; Brohawn, Philip; Morehouse, Christopher; Higgs, Brandon W; Richman, Laura; Jallal, Bahija; Yao, Yihong; Ranade, Koustubh

    2014-03-01

    Expression profiling of microRNAs in melanoma lesional skin biopsies compared with normal donor skin biopsies, as well as melanoma cell lines compared with normal melanocytes, revealed that hsa-miR-206 was down-regulated in melanoma (-75.4-fold, P = 1.7 × 10(-4)). MiR-206 has been implicated in a large number of cancers, including breast, lung, colorectal, ovarian, and prostate cancers; however, its role in tumor development remains largely unknown, its biologic function is poorly characterized, and its targets affecting cancer cells are largely unknown. MiR-206 reduced growth and migration/invasion of multiple melanoma cell lines. Bioinformatics identified cell cycle genes CDK2, CDK4, Cyclin C, and Cyclin D1 as strong candidate targets. Western blots and 3'UTR reporter gene assays revealed that miR-206 inhibited translation of CDK4, Cyclin D1, and Cyclin C. Additionally, hsa-miR-206 transfection induced G1 arrest in multiple melanoma cell lines. These observations support hsa-miR-206 as a tumor suppressor in melanoma and identify Cyclin C, Cyclin D1, and CDK4 as miR-206 targets. PMID:24289491

  4. A mutant allele of BARA/LIN-9 rescues the cdk4 {sup -/-} phenotype by releasing the repression on E2F-regulated genes

    SciTech Connect

    Sandoval, Raudel; Xue Jiaping; Tian Xinyong; Barrett, Kelly; Pilkinton, Mark; Ucker, David S.; Raychaudhuri, Pradip; Kineman, Rhonda D.; Luque, Raul M.; Baida, Gleb; Zou, Xianghong; Kiyokawa, Hiroaki; Valli, V.E.; Cook, James L.; Colamonici, Oscar R. . E-mail: ocolamon@uic.edu

    2006-08-01

    It has been proposed that C. elegans LIN-9 functions downstream of CDK4 in a pathway that regulates cell proliferation. Here, we report that mammalian BARA/LIN-9 is a predominantly nuclear protein that inhibits cell proliferation. More importantly, we demonstrate that BARA/LIN-9 also acts downstream of cyclin D/CDK4 in mammalian cells since (i) its antiproliferative effect is partially blocked by coexpression of cyclin D1, and (ii) a mutant form that lacks the first 84 amino acids rescues several phenotypic alterations observed in mice null for cdk4. Interestingly, mutation of BARA/LIN-9 restores the expression of E2F target genes in CDK4 null MEFs, indicating that the wild-type protein plays a role in the expression of genes required for the G1/S transition.

  5. Prevalence of p16 and CDK4 germline mutations in 48 melanoma-prone families in France. The French Familial Melanoma Study Group.

    PubMed

    Soufir, N; Avril, M F; Chompret, A; Demenais, F; Bombled, J; Spatz, A; Stoppa-Lyonnet, D; Bénard, J; Bressac-de Paillerets, B

    1998-02-01

    Germline mutations in the p16 and CDK4 genes have been reported in a subset of melanoma pedigrees, but their prevalence is not well known. We searched for such germline mutations in 48 French melanoma-prone families selected according to two major criteria: families with at least three affected members (n = 20) or families with two affected members, one of them affected before the age of 50 (n = 28), and one additional minor criterion. Sixteen different p16 germline mutations were found in 21 families, while one germline mutation, Arg24His, was detected in the CDK4 gene. The frequency of p16 gene mutation in our sample (44%) is among the highest rates yet reported and the CDK4 mutation is the second mutation detected in this gene worldwide. In summary, our results show frequent involvement of the p16 gene in familial melanoma and confirm the role of the CDK4 gene as a melanoma-predisposing gene.

  6. Functional, chemical genomic, and super-enhancer screening identify sensitivity to cyclin D1/CDK4 pathway inhibition in Ewing sarcoma

    PubMed Central

    Crompton, Brian; Cowley, Glenn; Vazquez, Francisca; Weir, Barbara A.; Tsherniak, Aviad; Parasuraman, Sudha; Kim, Sunkyu; Alexe, Gabriela; Stegmaier, Kimberly

    2015-01-01

    Ewing sarcoma is an aggressive bone and soft tissue tumor in children and adolescents, with treatment remaining a clinical challenge. This disease is mediated by somatic chromosomal translocations of the EWS gene and a gene encoding an ETS transcription factor, most commonly, FLI1. While direct targeting of aberrant transcription factors remains a pharmacological challenge, identification of dependencies incurred by EWS/FLI1 expression would offer a new therapeutic avenue. We used a combination of super-enhancer profiling, near-whole genome shRNA-based and small-molecule screening to identify cyclin D1 and CDK4 as Ewing sarcoma-selective dependencies. We revealed that super-enhancers mark Ewing sarcoma specific expression signatures and EWS/FLI1 target genes in human Ewing sarcoma cell lines. Particularly, a super-enhancer regulates cyclin D1 and promotes its expression in Ewing sarcoma. We demonstrated that Ewing sarcoma cells require CDK4 and cyclin D1 for survival and anchorage-independent growth. Additionally, pharmacologic inhibition of CDK4 with selective CDK4/6 inhibitors led to cytostasis and cell death of Ewing sarcoma cell lines in vitro and growth delay in an in vivo Ewing sarcoma xenograft model. These results demonstrated a dependency in Ewing sarcoma on CDK4 and cyclin D1 and support exploration of CDK4/6 inhibitors as a therapeutic approach for patients with this disease. PMID:26337082

  7. Establishment of clonal myogenic cell lines from severely affected dystrophic muscles - CDK4 maintains the myogenic population

    PubMed Central

    2011-01-01

    Background A hallmark of muscular dystrophies is the replacement of muscle by connective tissue. Muscle biopsies from patients severely affected with facioscapulohumeral muscular dystrophy (FSHD) may contain few myogenic cells. Because the chromosomal contraction at 4q35 linked to FSHD is thought to cause a defect within myogenic cells, it is important to study this particular cell type, rather than the fibroblasts and adipocytes of the endomysial fibrosis, to understand the mechanism leading to myopathy. Results We present a protocol to establish clonal myogenic cell lines from even severely dystrophic muscle that has been replaced mostly by fat, using overexpression of CDK4 and the catalytic component of telomerase (human telomerase reverse transcriptase; hTERT), and a subsequent cloning step. hTERT is necessary to compensate for telomere loss during in vitro cultivation, while CDK4 prevents a telomere-independent growth arrest affecting CD56+ myogenic cells, but not their CD56- counterpart, in vitro. Conclusions These immortal cell lines are valuable tools to reproducibly study the effect of the FSHD mutation within myoblasts isolated from muscles that have been severely affected by the disease, without the confounding influence of variable amounts of contaminating connective-tissue cells. PMID:21798090

  8. The expression of MDM2/CDK4 gene product in the differential diagnosis of well differentiated liposarcoma and large deep-seated lipoma

    PubMed Central

    Pilotti, S; Torre, G Della; Mezzelani, A; Tamborini, E; Azzarelli, A; Sozzi, G; Pierotti, M A

    2000-01-01

    Ordinary lipomas are cytogenetically characterized by a variety of balanced rearrangements involving chromosome segment 12q13–15, whereas well differentiated liposarcomas (WDL) show supernumerary ring and giant marker chromosomes, known to contain amplified 12q sequences. The tight correlation between the presence of ring chromosomes and both amplification and overexpression of MDM2 and CDK4 genes suggests the exploration of the possibility that immunocytochemistry (ICC) might assist in the differential diagnosis of lipoma-like well differentiated liposarcomas (LL-WDL) and large deep-seated lipomas (LDSL). For this purpose, 21 cases of the former and 19 cases of the latter tumours were analysed by ICC and, according to the availability of material, by molecular and cytogenetic approaches. All lipomas displayed a null MDM2/CDK4 phenotype, whereas all LL-WDL showed MDM2/CDK4 or CDK4 phenotypes. Southern blot analysis performed on 16 suitable cases, complemented by fluorescence in situ hybridization and classical cytogenetic analysis in 11 cases, was consistent with, and further supported the immunophenotyping data. In conclusion, MDM2/CDK4 product-based immunophenotyping appears to represent a valuable method for the categorization of arguable LDSL. © 2000 Cancer Research Campaign PMID:10755400

  9. Transient overexpression of cyclin D2/CDK4/GLP1 genes induces proliferation and differentiation of adult pancreatic progenitors and mediates islet regeneration

    PubMed Central

    Chen, Shuyuan; Shimoda, Masyuki; Chen, Jiaxi; Matsumodo, Shinichi

    2012-01-01

    The molecular mechanism of β-cell regeneration remains poorly understood. Cyclin D2/CDK4 expresses in normal β cells and maintains adult β-cell growth. We hypothesized that gene therapy with cyclin D2/CDK4/GLP-1 plasmids targeted to the pancreas of STZ-treated rats by ultrasound-targeted microbubble destruction (UTMD) would force cell cycle re-entry of residual G0-phase islet cells into G1/S phase to regenerate β cells. A single UTMD treatment induced β-cell regeneration with reversal of diabetes for 6 mo without evidence of toxicity. We observed that this β-cell regeneration was not mediated by self-replication of pre-existing β cells. Instead, cyclin D2/CDK4/GLP-1 initiated robust proliferation of adult pancreatic progenitor cells that exist within islets and terminally differentiate to mature islets with β cells and α cells. PMID:22373529

  10. Cyclin D1/cdk4, estrogen receptors α and β, in N-methyl-N'-nitro-N-nitrosoguanidine-induced rat gastric carcinogenesis: immunohistochemical study.

    PubMed

    Motohashi, Masaya; Wakui, Shin; Muto, Tomoko; Suzuki, Yoshihiko; Shirai, Masaru; Takahashi, Hiroyuki; Hano, Hiroshi

    2011-06-01

    Hyperproliferative cell growth due to cyclin D1/cdk4, marker of cellular proliferation, is considered to be regulated by the expression of estrogen receptors (ERs). We investigated the immunohistochemical expression of cyclin D1/cdk4 and ERs in N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced rat gastric carcinogenesis. The gastric cancer incidence and expression of cyclin D1/ckd4 in gastric carcinogenesis were significantly higher in males than females. Although the ERα expression index was similar in both sexes, the ERβ expression in preneoplastic hyperplastic lesions as well as gastric cancers was significantly higher in females than in males. The present study revealed a gender difference in MNNG-induced rat gastric carcinogenesis that seemed to involve the sex difference in cyclin D1/cdk4 expression, and ERβ expression became evident at the preneoplastic promotion stage in gastric carcinogenesis. PMID:21628965

  11. Increased expression of senescence markers in cystic fibrosis airways.

    PubMed

    Fischer, Bernard M; Wong, Jessica K; Degan, Simone; Kummarapurugu, Apparao B; Zheng, Shuo; Haridass, Prashamsha; Voynow, Judith A

    2013-03-15

    Cystic Fibrosis (CF) is a chronic lung disease characterized by chronic neutrophilic airway inflammation and increased levels of neutrophil elastase (NE) in the airways. We have previously reported that NE treatment triggers cell cycle arrest. Cell cycle arrest can lead to senescence, a complete loss of replicative capacity. Importantly, senescent cells can be proinflammatory and would perpetuate CF chronic inflammation. By immunohistochemistry, we evaluated whether airway sections from CF and control subjects expressed markers of senescence, including p16(INK4a) (p16), a cyclin-dependent kinase inhibitor, phospho-Histone H2A.X (γH2A.X), and phospho-checkpoint 2 kinase (phospho-Chk2), which are also DNA damage response markers. Compared with airway epithelium from control subjects, CF airway epithelium had increased levels of expression of all three senescence markers. We hypothesized that the high load of NE in the CF airway triggers epithelial senescence by upregulating expression of p16, which inhibits cyclin-dependent kinase 4 (CDK4). Normal human bronchial epithelial (NHBE) cells, cultured in air-liquid interface were treated with NE (0, 200, and 500 nM) to induce visible injury. Total cell lysates were collected and evaluated by Western analysis for p16 protein expression and CDK4 kinase activity. NE significantly increased p16 expression and decreased CDK4 kinase activity in NHBE cells. These results support the concept that NE triggers expression of senescence markers in CF airway epithelial cells. PMID:23316069

  12. Genomic rearrangements of the CDKN2A locus are infrequent in Italian malignant melanoma families without evidence of CDKN2A/CDK4 point mutations.

    PubMed

    Vignoli, Marina; Scaini, Maria Chiara; Ghiorzo, Paola; Sestini, Roberta; Bruno, William; Menin, Chiara; Gensini, Francesca; Piazzini, Mauro; Testori, Alessandro; Manoukian, Siranoush; Orlando, Claudio; D'Andrea, Emma; Bianchi-Scarrà, Giovanna; Genuardi, Maurizio

    2008-12-01

    Predisposition to familial cutaneous malignant melanoma has been associated with mutations in the CDKN2A and CDK4 genes. However, only a small subgroup of melanoma pedigrees harbour CDKN2A or CDK4 germline mutations. It is possible that other types of CDKN2A rearrangements, not detectable by routine PCR-based approaches, are involved in a fraction of melanoma cases negative for point sequence changes. In order to gain insights on the possible role of CDKN2A large deletions or duplications in melanoma susceptibility in the Italian population, we screened a series of 124 cutaneous malignant melanoma families referred to five national medical/cancer genetics centres. All probands were negative for point mutations in CDKN2A and CDK4. All samples were tested by MLPA (multiplex ligation-dependent probe amplification), and the results were confirmed by real-time quantitative PCR in a subset of 53 cases. No genomic rearrangements were detected in this series, one of the largest so far investigated. These data suggest that large deletions/duplications in the CDKN2A locus are infrequently involved in the development of familial melanoma in the Italian population. Based on these results, routine search for these rearrangements in CDKN2A- and CDK4-mutation negative melanoma families is not warranted, although it would be reasonable to pursue it in selected cases with very strong family history and/or showing linkage to 9p21.

  13. Assessing and Increasing Physical Activity

    ERIC Educational Resources Information Center

    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.

  14. Prolonged early G1 arrest by selective CDK4/CDK6 inhibition sensitizes myeloma cells to cytotoxic killing through cell cycle–coupled loss of IRF4

    PubMed Central

    Huang, Xiangao; Di Liberto, Maurizio; Jayabalan, David; Liang, Jun; Ely, Scott; Bretz, Jamieson; Shaffer, Arthur L.; Louie, Tracey; Chen, Isan; Randolph, Sophia; Hahn, William C.; Staudt, Louis M.; Niesvizky, Ruben; Moore, Malcolm A. S.

    2012-01-01

    Dysregulation of cyclin-dependent kinase 4 (CDK4) and CDK6 by gain of function or loss of inhibition is common in human cancer, including multiple myeloma, but success in targeting CDK with broad-spectrum inhibitors has been modest. By selective and reversible inhibition of CDK4/CDK6, we have developed a strategy to both inhibit proliferation and enhance cytotoxic killing of cancer cells. We show that induction of prolonged early-G1 arrest (pG1) by CDK4/CDK6 inhibition halts gene expression in early-G1 and prevents expression of genes programmed for other cell-cycle phases. Removal of the early-G1 block leads to S-phase synchronization (pG1-S) but fails to completely restore scheduled gene expression. Consequently, the IRF4 protein required to protect myeloma cells from apoptosis is markedly reduced in pG1 and further in pG1-S in response to cytotoxic agents, such as the proteasome inhibitor bortezomib. The coordinated loss of IRF4 and gain of Bim sensitize myeloma tumor cells to bortezomib-induced apoptosis in pG1 in the absence of Noxa and more profoundly in pG1-S in cooperation with Noxa in vitro. Induction of pG1 and pG1-S by reversible CDK4/CDK6 inhibition further augments tumor-specific bortezomib killing in myeloma xenografts. Reversible inhibition of CDK4/CDK6 in sequential combination therapy thus represents a novel mechanism-based cancer therapy. PMID:22718837

  15. Whole genome sequence analysis links chromothripsis to EGFR, MDM2, MDM4, and CDK4 amplification in glioblastoma

    PubMed Central

    Furgason, John M.; Koncar, Robert F.; Michelhaugh, Sharon K.; Sarkar, Fazlul H.; Mittal, Sandeep; Sloan, Andrew E.; Barnholtz-Sloan, Jill S.; Bahassi, El Mustapha

    2015-01-01

    Background Findings based on recent advances in next-generation sequence analysis suggest that, in some tumors, a single catastrophic event, termed chromothripsis, results in several simultaneous tumorigenic alterations. Previous studies have suggested that glioblastoma (GBM) may exhibit chromothripsis at a higher rate (39%) than other tumors (9%). Primary glioblastoma is an aggressive form of brain cancer that typically appears suddenly in older adults. With aggressive treatment, the median survival time is only 15 months. Their acute onset and widespread genomic instability indicates that chromothripsis may play a key role in their initiation and progression. GBMs are often characterized by EGFR amplification, CDKN2A and PTEN deletion, although approximately 20% of GBMs harbor additional amplifications in MDM2 or MDM4 with CDK4. Methods We used the chromothripsis prediction tool, Shatterproof, in conjunction with a custom whole genome sequence analysis pipeline in order to generate putative regions of chromothripsis. The data derived from this study was further expanded on using fluorescence in situ hybridization (FISH) analysis and susceptibility studies with colony formation assays. Results We show that primary GBMs are associated with higher chromothripsis scores and establish a link between chromothripsis and gene amplification of receptor tyrosine kinases (RTKs), as well as modulators of the TP53 and RB1 pathways. Conclusions Utilizing a newly introduced bioinformatic tool, we provide evidence that chromothripsis is associated with the formation of amplicons containing several oncogenes involved in key pathways that are likely essential for post-chromothriptic cell survival. PMID:26328271

  16. A fine structure genomic map of the region of 12q13 containing SAS and CDK4

    SciTech Connect

    Linder, C.Y.; Elkahloun, A.G.; Su, Y.A.

    1994-09-01

    We have recently adapted a method, originally described by Rackwitz, to the rapid restriction mapping of multiple cosmid DNA samples. Linearization of the cosmids at the lambda cohesive site using lambda terminase is followed by partial digestion with selected restriction enzymes and hybridization to oligonucleotides specific for the right or left hand termini. Partial digestions are performed in a microtiter plate thus allowing up to 12 cosmid clones to be digested with one restriction enzyme. We have applied this rapid restriction mapping method to cosmids derived from a region of chromosome 12q13 that has recently been shown to be amplified in a variety of cancers including malignant fibrous histiocytoma, fibrosarcoma, liposarcoma, osteosarcoma and brain tumors. A small segment of this amplification unit containing three genes, SAS (a membrane protein), CDK4 (a cyclin dependent kinase) and OS-9 (a recently described cDNA) has been analyzed with the system described above. This fine structure genomic map will be useful for completing the expression map of this region as well as characterizing its pattern of amplification in tumor specimens.

  17. Increased Spreading Activation in Depression

    ERIC Educational Resources Information Center

    Foster, Paul S.; Yung, Raegan C.; Branch, Kaylei K.; Stringer, Kristi; Ferguson, Brad J.; Sullivan, William; Drago, Valeria

    2011-01-01

    The dopaminergic system is implicated in depressive disorders and research has also shown that dopamine constricts lexical/semantic networks by reducing spreading activation. Hence, depression, which is linked to reductions of dopamine, may be associated with increased spreading activation. However, research has generally found no effects of…

  18. Strategies to Increase Physical Activity

    PubMed Central

    Tuso, Phillip

    2015-01-01

    The benefits of physical activity are well known and well publicized. Healthy People 2020 has determined that physical activity is one of their key interventions to improve health in America. Despite wide acceptance that physical activity is a low-cost alternative to disease treatment and prevention, most Americans still do not exercise the recommended minimum of 150 minutes per week. Underpinning such recommendations is the growing concern that unless we change our behavior around active living, health care costs to treat preventable disease will become unsustainable and have a substantial impact on the financial health of the US. For this reason, physicians, health care executives, and community leaders are working together to improve total health for all Americans. One key intervention to prevent preventable diseases and to make health care more affordable is to increase the percentage of Americans who are physically active. No single intervention will increase activity rates, but a group of interventions working together in synergy may be the stimulus needed to get Americans moving. The five strategies discussed in this paper include 1) measure physical activity as a vital sign; 2) encourage patients to be physically active at least 150 minutes per week; 3) create healthy environments by making it easier for patients to be physically active where they live, learn, work, play, and pray; 4) monitor disease incidence of patients who are physically active vs those who are not physically active; and 5) spread best practices. PMID:26517440

  19. Melanoma candidate genes CDKN2A/p16/INK4A, p14ARF, and CDK4 sequencing in patients with uveal melanoma with relative high-risk for hereditary cancer predisposition.

    PubMed

    Abdel-Rahman, Mohamed H; Pilarski, Robert; Massengill, James B; Christopher, Benjamin N; Noss, Ryan; Davidorf, Frederick H

    2011-06-01

    The reported frequencies of germline mutations in the melanoma candidate genes are low in patients with uveal melanoma (UM). However, the number of families studied is limited and the majority of the published reports used low-sensitivity techniques for mutational screening. Identifying the frequency of alterations in any of the melanoma genes in patients with UM with increased hereditary cancer risk is important for proper counseling of these patients. We studied a total of 47 patients with UM including three with a family history of UM, 18 with a family and/or personal history of cutaneous melanoma (CM), three with early age at diagnosis (<30), 11 with increased risk for a known familial cancer syndrome, and 12 with a second primary tumor. Germline screening for mutations in CDKN2A, p14ARF, and exon 2 of CDK4 was carried out by direct sequencing. We identified a variant (IVS1-69 C>T) of uncertain significance in exon 1b of p14ARF in one of the patients with UM and his mother who also had UM. The variant was neither detected in any of the other patients with UM nor in 146 controls. We did not identify pathogenic mutations in CDKN2A nor exon 2 of CDK4 gene. Our study supports the low frequency of germline mutation of the CM candidate genes in patients with UM with family histories suggestive of a high risk for hereditary cancer. Germline testing for CDKN2A might be reserved for patients with UM with a family history of two or more CM.

  20. A flexible multiplex bead-based assay for detecting germline CDKN2A and CDK4 variants in melanoma-prone kindreds.

    PubMed

    Lang, Julie M; Shennan, Michael; Njauw, Jenny C-N; Luo, Su; Bishop, Julia N; Harland, Mark; Hayward, Nicholas K; Tucker, Margaret A; Goldstein, Alisa M; Landi, Maria T; Puig, Susana; Gruis, Nelleke A; Bergman, Wilma; Bianchi-Scarra, Giovanna; Ghiorzo, Paola; Hogg, David; Tsao, Hensin

    2011-02-01

    The presence of recurrent high-risk mutations in cyclin-dependent kinase inhibitor 2A/cyclin-dependent kinase 4 (CDKN2A/CDK4) among melanoma-prone families suggests that a high-throughput, multiplex assay could serve as an effective initial screening tool. To this end, we have developed a multiplex bead-based assay for high-throughput CDKN2A/CDK4 genotyping in the context of familial melanoma. Genomic DNA from 1,603 subjects (1,005 in training set and 598 in validation set) were amplified by multiplex PCR using five CDKN2A/CDK4 primer sets followed by multiplex allele-specific primer extension for 39 distinct germline variants. The products were then sorted and analyzed using the Luminex xMAP system. Genotypes were compared with previously determined sequence data. In the Toronto training cohort, all 145 samples with known variants were detected by the bead assay (100% concordance). Analysis of the 598 samples from the GenoMEL validation set led to identification of 150/155 expected variants (96.77%). Overall, the bead assay correctly genotyped 1,540/1,603 (96.07%) of all individuals in the study and 1,540/1,545 (99.68%) of individuals whose variants were represented in the probe set. Out of a total of 62,517 allelic calls, 62,512 (99.99%) were correctly assigned. The multiplex bead-based assay is an accurate method for genotyping CDKN2A/CDK4 variants and is potentially useful in genotyping low-to-moderate melanoma risk single-nucleotide polymorphisms.

  1. A flexible multiplex bead-based assay for detecting germline CDKN2A and CDK4 variants in melanoma-prone kindreds.

    PubMed

    Lang, Julie M; Shennan, Michael; Njauw, Jenny C-N; Luo, Su; Bishop, Julia N; Harland, Mark; Hayward, Nicholas K; Tucker, Margaret A; Goldstein, Alisa M; Landi, Maria T; Puig, Susana; Gruis, Nelleke A; Bergman, Wilma; Bianchi-Scarra, Giovanna; Ghiorzo, Paola; Hogg, David; Tsao, Hensin

    2011-02-01

    The presence of recurrent high-risk mutations in cyclin-dependent kinase inhibitor 2A/cyclin-dependent kinase 4 (CDKN2A/CDK4) among melanoma-prone families suggests that a high-throughput, multiplex assay could serve as an effective initial screening tool. To this end, we have developed a multiplex bead-based assay for high-throughput CDKN2A/CDK4 genotyping in the context of familial melanoma. Genomic DNA from 1,603 subjects (1,005 in training set and 598 in validation set) were amplified by multiplex PCR using five CDKN2A/CDK4 primer sets followed by multiplex allele-specific primer extension for 39 distinct germline variants. The products were then sorted and analyzed using the Luminex xMAP system. Genotypes were compared with previously determined sequence data. In the Toronto training cohort, all 145 samples with known variants were detected by the bead assay (100% concordance). Analysis of the 598 samples from the GenoMEL validation set led to identification of 150/155 expected variants (96.77%). Overall, the bead assay correctly genotyped 1,540/1,603 (96.07%) of all individuals in the study and 1,540/1,545 (99.68%) of individuals whose variants were represented in the probe set. Out of a total of 62,517 allelic calls, 62,512 (99.99%) were correctly assigned. The multiplex bead-based assay is an accurate method for genotyping CDKN2A/CDK4 variants and is potentially useful in genotyping low-to-moderate melanoma risk single-nucleotide polymorphisms. PMID:21085193

  2. Normal repair of ultraviolet radiation-induced DNA damage in familial melanoma without CDKN2A or CDK4 gene mutation.

    PubMed

    Shannon, J A; Matias, C; Luxford, C; Kefford, R F; Mann, G J

    1999-04-01

    Excessive sun exposure and family history are strong risk factors for the development of cutaneous melanoma. Inherited susceptibility to this type of skin cancer could therefore result from constitutively impaired capacity to repair ultraviolet (UV)-induced DNA lesions. While a proportion of familial melanoma kindreds exhibit germline mutations in the cell cycle regulatory gene CDKN2A (p16INK4a) or its protein target, cyclin-dependent kinase 4 (CDK4), the biochemical basis of most familial melanoma is unknown. We have examined lymphoblastoid cell lines from melanoma-affected and unaffected individuals from large hereditary melanoma kindreds which are not attributable to CDKN2A or CDK4 gene mutation. These lines were tested for sensitivity of clonogenic growth to UV radiation and for their ability to repair transfected UV-damaged plasmid templates (host cell reactivation). Two of seven affected-unaffected pairs differed in colony survival after exposure to UVB radiation; however, no significant differences were observed in the host-cell reactivation assays. These results indicate that melanoma susceptibility genes other than CDKN2A and CDK4 do not impair net capacity to repair UV-induced DNA damage.

  3. Prevalence of Germline BAP1, CDKN2A, and CDK4 Mutations in an Australian Population-Based Sample of Cutaneous Melanoma Cases.

    PubMed

    Aoude, Lauren G; Gartside, Michael; Johansson, Peter; Palmer, Jane M; Symmons, Judith; Martin, Nicholas G; Montgomery, Grant W; Hayward, Nicholas K

    2015-04-01

    Mutations in Cyclin-Dependent Kinase Inhibitor 2A (CDKN2A) and Cyclin-Dependent Kinase 4 (CDK4) contribute to susceptibility in approximately 40% of high-density cutaneous melanoma (CMM) families and about 2% of unselected CMM cases. BRCA-1 associated protein-1 (BAP1) has been more recently shown to predispose to CMM and uveal melanoma (UMM) in some families; however, its contribution to CMM development in the general population is unreported. We sought to determine the contribution of these genes to CMM susceptibility in a population-based sample of cases from Australia. We genotyped 1,109 probands from Queensland families and found that approximately 1.31% harbored mutations in CDKN2A, including some with novel missense mutations (p.R22W, p.G35R and p.I49F). BAP1 missense variants occurred in 0.63% of cases but no CDK4 variants were observed in the sample. This is the first estimate of the contribution of BAP1 and CDK4 to a population-based sample of CMM and supports the previously reported estimate of CDKN2A germline mutation prevalence.

  4. Prevalence of Germline BAP1, CDKN2A, and CDK4 Mutations in an Australian Population-Based Sample of Cutaneous Melanoma Cases.

    PubMed

    Aoude, Lauren G; Gartside, Michael; Johansson, Peter; Palmer, Jane M; Symmons, Judith; Martin, Nicholas G; Montgomery, Grant W; Hayward, Nicholas K

    2015-04-01

    Mutations in Cyclin-Dependent Kinase Inhibitor 2A (CDKN2A) and Cyclin-Dependent Kinase 4 (CDK4) contribute to susceptibility in approximately 40% of high-density cutaneous melanoma (CMM) families and about 2% of unselected CMM cases. BRCA-1 associated protein-1 (BAP1) has been more recently shown to predispose to CMM and uveal melanoma (UMM) in some families; however, its contribution to CMM development in the general population is unreported. We sought to determine the contribution of these genes to CMM susceptibility in a population-based sample of cases from Australia. We genotyped 1,109 probands from Queensland families and found that approximately 1.31% harbored mutations in CDKN2A, including some with novel missense mutations (p.R22W, p.G35R and p.I49F). BAP1 missense variants occurred in 0.63% of cases but no CDK4 variants were observed in the sample. This is the first estimate of the contribution of BAP1 and CDK4 to a population-based sample of CMM and supports the previously reported estimate of CDKN2A germline mutation prevalence. PMID:25787093

  5. Direct repression of the oncogene CDK4 by the tumor suppressor miR-486-5p in non-small cell lung cancer

    PubMed Central

    Liang, Chen; Zhang, Bing-Jie; Lu, Sheng-Di; He, Yan-Yun; Wang, Ping; Sun, Qiang-Ling; Jin, You-Xin; Ma, Zhong-Liang

    2016-01-01

    MicroRNAs are a class of non-coding single-stranded RNA, 20-23 nucleotide in length, which can be involved in the regulation of gene expression. Through binding with 3′-untranslated regions (3′-UTR), microRNAs can cause degradation of target mRNAs or inhibition of translation, and thus regulating the expression of genes at the post-transcriptional level. In this study, we found that miR-486-5p was significantly downregulated in non-small cell lung cancer (NSCLC) tissues and cell lines, suggesting that miR-486-5p might function as a tumor suppressor in lung cancer. Additionally, we showed that CDK4, an oncogene that plays an important role in cell cycle G1/S phase progression, was directly targeted by miR-486-5p. Furthermore, our data reveals that knockdown of CDK4 by siRNA can inhibit cell proliferation, promote apoptosis, and impede cell-cycle progression. In epigenetics, the upstream promoter of miR-486-5p was strongly regulated by methylation in NSCLC. Collectively, our results suggest that miR-486-5p could not only inhibit NSCLC by downregulating the expression of CDK4, but also be as a promising and potent therapy in the near future. PMID:27049724

  6. Search for germline alterations in CDKN2A/ARF and CDK4 of 42 Jewish melanoma families with or without neural system tumours.

    PubMed

    Marian, C; Scope, A; Laud, K; Friedman, E; Pavlotsky, F; Yakobson, E; Bressac-de Paillerets, B; Azizi, E

    2005-06-20

    To gain insight into the molecular mechanisms involved in the inherited predisposition to melanoma and associated neural system tumours, 42 Jewish, mainly Ashkenazi, melanoma families with or without neural system tumours were genotyped for germline point mutations and genomic deletions at the CDKN2A/ARF and CDK4 loci. CDKN2A/ARF deletion detection was performed using D9S1748, an intragenic microsatellite marker. Allele dosage at the p14ARF locus was analysed by quantitative real-time PCR employing a TaqMan probe that anneals specifically to exon 1beta of the p14ARF gene. For detecting point mutations, dHPLC and direct sequencing of the coding sequences of CDKN2A/ARF and CDK4 was used. No germline alterations in any of the tested genes were detected among the families under study. We conclude that in the majority of Ashkenazi Jewish families, the genes tested are unlikely to be implicated in the predisposition to melanoma and associated neural system tumours.

  7. Evaluation of genetic melanoma vaccines in cdk4-mutant mice provides evidence for immunological tolerance against authochthonous melanomas in the skin.

    PubMed

    Steitz, Julia; Büchs, Stefanie; Tormo, Damia; Ferrer, Aleix; Wenzel, Jörg; Huber, Christoph; Wölfel, Thomas; Barbacid, Mariano; Malumbres, Marcos; Tüting, Thomas

    2006-01-15

    We evaluated the efficacy of a candidate melanoma vaccine approach in mice genetically prone to develop melanoma due to the introduction of an oncogenic mutation (R24C) in the germline sequence of the cyclin-dependent kinase 4 (cdk4), a protein critically involved in cell cycle regulation. Melanomas were induced in cdk4-mutant mice by chemical carcinogenesis and UVB irradiation. A genetic prime-boost strategy targeting the clinically relevant differentiation antigen tyrosinase-related protein 2 (TRP2) was performed which was able to stimulate a melanocyte-specific cellular immune response associated with localized autoimmune vitiligo-like depigmentation. However, significant destruction of carcinogen-induced autochthonous melanocytic neoplasms in the skin was not observed following immunization. We provide evidence that autochthonous melanomas expressed TRP2 but not the MHC molecule H2-Kb and are immunologically tolerated in the skin. Our results highlight the importance of assessing melanoma vaccines in genetic mouse models that more adequately represent the expected clinical situation in order to identify strategies, which eventually may be of benefit for melanoma patients.

  8. Detection of MDM2/CDK4 amplification in lipomatous soft tissue tumors from formalin-fixed, paraffin-embedded tissue: comparison of multiplex ligation-dependent probe amplification (MLPA) and fluorescence in situ hybridization (FISH).

    PubMed

    Creytens, David; van Gorp, Joost; Ferdinande, Liesbeth; Speel, Ernst-Jan; Libbrecht, Louis

    2015-02-01

    In this study, the detection of MDM2 and CDK4 amplification was evaluated in lipomatous soft tissue tumors using multiplex ligation-dependent probe amplification (MLPA), a PCR-based technique, in comparison with fluorescence in situ hybridization (FISH). These 2 techniques were evaluated in a series of 77 formalin-fixed, paraffin-embedded lipomatous tumors (27 benign adipose tumors, 28 atypical lipomatous tumors/well-differentiated liposarcomas, 18 dedifferentiated liposarcomas, and 4 pleomorphic liposarcomas). Using MLPA, with a cut-off ratio of >2, 36/71 samples (22 atypical lipomatous tumors/well-differentiated liposarcomas, and 14 dedifferentiated liposarcomas) showed MDM2 and CDK4 amplification. Using FISH as gold standard, MLPA showed a sensitivity of 90% (36/40) and a specificity of 100% (31/31) in detecting amplification of MDM2 and CDK4 in lipomatous soft tissue tumors. In case of high-level amplification (MDM2-CDK4/CEP12 ratio >5), concordance was 100%. Four cases of atypical lipomatous tumor/well-differentiated liposarcoma (4/26, 15%) with a low MDM2 and CDK4 amplification level (MDM2-CDK4/CEP12 ratio ranging between 2 and 2.5) detected by FISH showed no amplification by MLPA, although gain of MDM2 and CDK4 (ratios ranging between 1.6 and 1.9) was seen with MLPA. No amplification was detected in benign lipomatous tumors and pleomorphic liposarcomas. Furthermore, there was a very high concordance between the ratios obtained by FISH and MLPA. In conclusion, MLPA proves to be an appropriate and straightforward technique for screening MDM2/CDK4 amplification in lipomatous tumors, especially when a correct cut-off value and reference samples are chosen, and could be considered a good alternative to FISH to determine MDM2 and CDK4 amplification in liposarcomas. Moreover, because MLPA, as a multiplex technique, allows simultaneous detection of multiple chromosomal changes of interest, it could be in the future a very reliable and fast molecular analysis on

  9. Cdk5-mediated inhibition of APC/C-Cdh1 switches on the cyclin D1-Cdk4-pRb pathway causing aberrant S-phase entry of postmitotic neurons

    PubMed Central

    Veas-Pérez de Tudela, Miguel; Maestre, Carolina; Delgado-Esteban, María; Bolaños, Juan P.; Almeida, Angeles

    2015-01-01

    The anaphase-promoting complex/cyclosome (APC/C) is an E3 ubiquitin ligase that regulates cell cycle progression in proliferating cells. To enter the S-phase, APC/C must be inactivated by phosphorylation of its cofactor, Cdh1. In post-mitotic cells such as neurons APC/C-Cdh1 complex is highly active and responsible for the continuous degradation of mitotic cyclins. However, the specific molecular pathway that determines neuronal cell cycle blockade in post-mitotic neurons is unknown. Here, we show that activation of glutamatergic receptors in rat cortical primary neurons endogenously triggers cyclin-dependent kinase-5 (Cdk5)-mediated phosphorylation of Cdh1 leading to its cytoplasmic accumulation and disassembly from the APC3 core protein, causing APC/C inactivation. Conversely, pharmacological or genetic inhibition of Cdk5 promotes Cdh1 ubiquitination and proteasomal degradation. Furthermore, we show that Cdk5-mediated phosphorylation and inactivation of Cdh1 leads to p27 depletion, which switches on the cyclin D1-cyclin-dependent kinase-4 (Cdk4)-retinoblastoma protein (pRb) pathway to allow the S-phase entry of neurons. However, neurons do not proceed through the cell cycle and die by apoptosis. These results indicate that APC/C-Cdh1 actively suppresses an aberrant cell cycle entry and death of neurons, highlighting its critical function in neuroprotection. PMID:26658992

  10. Increasing Youth Physical Activity with Activity Calendars

    ERIC Educational Resources Information Center

    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.

  11. Evaluation of MDM2 and CDK4 amplification by real-time PCR on paraffin wax-embedded material: a potential tool for the diagnosis of atypical lipomatous tumours/well-differentiated liposarcomas.

    PubMed

    Hostein, I; Pelmus, M; Aurias, A; Pedeutour, F; Mathoulin-Pélissier, S; Coindre, J M

    2004-01-01

    Atypical lipomatous tumours/well-differentiated liposarcomas and dedifferentiated liposarcomas are characterized by 12q13-15 region amplification. In contrast, this molecular event has not been reported in benign lipomas. Within the 12q13-15 chromosomal region, the MDM2, SAS, HMGA2, and CDK4 genes are the most frequent targets of amplification. A series of lipomas (36 cases) and liposarcomas (48 cases) was analysed for MDM2 and CDK4 gene amplification by real-time PCR. MDM2 and CDK4 gene amplification was detected in 2.8% and 5.6% of lipomas and 98.2% and 82.4% of liposarcomas, respectively. Moreover, co-amplification of the two genes as well as a higher-level amplification was observed more frequently in dedifferentiated liposarcomas than in atypical lipomatous tumours/well-differentiated liposarcomas. Real-time PCR proved to be a fast and reliable method to characterize lipomas and liposarcomas by quantification of MDM2 and CDK4 gene amplification. It is applicable to paraffin wax-embedded tissues and could be useful when histological diagnosis is difficult.

  12. A blueprint for staging of murine melanocytic lesions based on the Cdk4 ( R24C/R24C ) ::Tyr- NRAS ( Q ) ( 61K ) model.

    PubMed

    Wurm, Elisabeth M T; Lin, Lynlee L; Ferguson, Blake; Lambie, Duncan; Prow, Tarl W; Walker, Graeme J; Soyer, H Peter

    2012-09-01

    It has been shown that gene mutations which drive the development of malignant melanoma (MM) in humans also lead to emergence of MM when engineered mice. However, little attention has been paid to the clinical and histopathological features of melanocytic lesions and their natural history in a given mouse model. This knowledge is crucial to enable us to understand how engineered mutations influence the initiation and evolution of melanocytic lesions, and/or for the use of mice as a preclinical model to test specific treatments. We recently reported the development of melanocytic proliferations along the spectrum of naevi to MM in a Cdk4 ( R24C/R24C ) ::Tyr- NRAS ( Q ) ( 61K ) mouse model. In this study, we followed the development of lesions over time using digital photography and dermoscopy with the aim to correlate the clinical and histopathological features of lesions developing in this model. We identified two types of lesions. The first are slow-growing dermal MMs that emanate from dermal naevi. The second did not emanate from naevi, grew rapidly, and appeared to be solely confined to the subcutaneous fat. We present a simple staging system for the MMs that progress from naevi, based on depth of extension into the dermis and subcutis. This represents a blueprint for documentation and follow-up of MMs in the live animal, which is critical for the proper use of murine melanoma models.

  13. A blueprint for staging of murine melanocytic lesions based on the Cdk4 ( R24C/R24C ) ::Tyr- NRAS ( Q ) ( 61K ) model.

    PubMed

    Wurm, Elisabeth M T; Lin, Lynlee L; Ferguson, Blake; Lambie, Duncan; Prow, Tarl W; Walker, Graeme J; Soyer, H Peter

    2012-09-01

    It has been shown that gene mutations which drive the development of malignant melanoma (MM) in humans also lead to emergence of MM when engineered mice. However, little attention has been paid to the clinical and histopathological features of melanocytic lesions and their natural history in a given mouse model. This knowledge is crucial to enable us to understand how engineered mutations influence the initiation and evolution of melanocytic lesions, and/or for the use of mice as a preclinical model to test specific treatments. We recently reported the development of melanocytic proliferations along the spectrum of naevi to MM in a Cdk4 ( R24C/R24C ) ::Tyr- NRAS ( Q ) ( 61K ) mouse model. In this study, we followed the development of lesions over time using digital photography and dermoscopy with the aim to correlate the clinical and histopathological features of lesions developing in this model. We identified two types of lesions. The first are slow-growing dermal MMs that emanate from dermal naevi. The second did not emanate from naevi, grew rapidly, and appeared to be solely confined to the subcutaneous fat. We present a simple staging system for the MMs that progress from naevi, based on depth of extension into the dermis and subcutis. This represents a blueprint for documentation and follow-up of MMs in the live animal, which is critical for the proper use of murine melanoma models. PMID:22742762

  14. Exergames: Increasing Physical Activity through Effective Instruction

    ERIC Educational Resources Information Center

    Rudella, Jennifer L.; Butz, Jennifer V.

    2015-01-01

    Due to the growing obesity epidemic in the United States, educators must consider new ways to increase physical activity in an effort to address obesity. There are a variety of ways educators can increase physical activity in the classroom, and exergames--video games that require physical movement in order to play--are a modern-day approach to…

  15. Detection of MDM2-CDK4 amplification by fluorescence in situ hybridization in 200 paraffin-embedded tumor samples: utility in diagnosing adipocytic lesions and comparison with immunohistochemistry and real-time PCR.

    PubMed

    Sirvent, Nicolas; Coindre, Jean-Michel; Maire, Georges; Hostein, Isabelle; Keslair, Frédérique; Guillou, Louis; Ranchere-Vince, Dominique; Terrier, Philippe; Pedeutour, Florence

    2007-10-01

    Atypical lipomatous tumor/well-differentiated liposarcomas and dedifferentiated liposarcomas are characterized by the amplification of MDM2 and CDK4 genes. To evaluate the accuracy of fluorescence in situ hybridization (FISH) analysis in the differential diagnosis of adipose tissue tumors, we investigated MDM2-CDK4 status by FISH, real-time polymerase chain reaction (PCR) [quantitative PCR (Q-PCR)] and immunohistochemistry (IHC) in a series of 200 adipose tumors. First, we evaluated MDM2-CDK4 amplification and expression in a series of 94 well-defined adipose tissue tumors. Results showed that FISH was interpretable in 45 of 50 cases (90%), and was more specific and sensitive than Q-PCR and IHC. We then used the same techniques as complementary diagnostic tools in a series of 106 adipose and soft tissue tumors of unclear diagnosis to distinguish between (i) lipomas and atypical lipomatous tumor/well-differentiated liposarcomas, (ii) malignant undifferentiated tumors and dedifferentiated liposarcomas, and (iii) a variety of benign tumors and liposarcomas. Our results indicate that although helpful, IHC alone is often insufficient to solve diagnostic problems. FISH and Q-PCR methods gave concordant results and were equally informative in most cases. However, the proportion of noninterpretable cases was slightly higher with FISH than with Q-PCR. When tumor cells represented a minor component of the tumor tissue, such as with inflammatory tumors, FISH was more powerful than Q-PCR by allowing visualization of individual cells. In conclusion, we recommend that the evaluation of MDM2-CDK4 amplification using FISH or Q-PCR be used to supplement IHC analysis when diagnosis of adipose tissue tumors is not possible based on clinical and histologic information alone.

  16. Analysis of the miR-34a locus in 62 patients with familial cutaneous melanoma negative for CDKN2A/CDK4 screening.

    PubMed

    Cozzolino, Angela M; Pedace, Lucia; Castori, Marco; De Simone, Paola; Preziosi, Nicoletta; Sperduti, Isabella; Panetta, Chiara; Mogini, Valerio; De Bernardo, Carmelilia; Morrone, Aldo; Catricalà, Caterina; Grammatico, Paola

    2012-06-01

    MicroRNAs are small non-coding RNAs, which inhibit expression of specific target genes at the post-transcriptional level and are often misregulated in human cancer. Among them, miR-34a is considered a tumor suppressor with a hypothetical role in melanoma tumorigenesis. In this work, 62 Italian index patients with familial melanoma and negative for CDKN2A/CDK4 screening were investigated for miR-34a germline mutations. Eight novel miR-34a sequence variants were identified at both the heterozygous (c.+259G>A, c.+424G>A, c.+1465C>T, c.+1769C>T, c.+2456T>G, c.+2603C>T, c.+2972T>A, c.+3069T>C) and homozygous (c.+424G>A, c.+1465C>T, c.+1769C>T) states. Molecular screening identified all nucleotide changes in a healthy population of 150 controls and demonstrated that they are common polymorphisms. However, statistically significant differences of allele and genotype frequencies were detected for c.+1465C>T and c.+1769C>T, and borderline values for c.+2456T>G. By stratifying patients by relevant clinical features (presence/absence of multiple primary melanoma, Breslow's thickness, phototype and number of nevi), no significant findings were noted except for an association between the c.+424G>A (heterozygous individual GA) and multiple primary melanoma and phototype III-IV. Our preliminary study suggests that miR-34a, although having a role in late tumorigenesis, does not contribute to the inherited susceptibility to cutaneous melanoma. A function as phenotypic modulator in familial melanoma cannot be excluded.

  17. Analysis of the miR-34a locus in 62 patients with familial cutaneous melanoma negative for CDKN2A/CDK4 screening.

    PubMed

    Cozzolino, Angela M; Pedace, Lucia; Castori, Marco; De Simone, Paola; Preziosi, Nicoletta; Sperduti, Isabella; Panetta, Chiara; Mogini, Valerio; De Bernardo, Carmelilia; Morrone, Aldo; Catricalà, Caterina; Grammatico, Paola

    2012-06-01

    MicroRNAs are small non-coding RNAs, which inhibit expression of specific target genes at the post-transcriptional level and are often misregulated in human cancer. Among them, miR-34a is considered a tumor suppressor with a hypothetical role in melanoma tumorigenesis. In this work, 62 Italian index patients with familial melanoma and negative for CDKN2A/CDK4 screening were investigated for miR-34a germline mutations. Eight novel miR-34a sequence variants were identified at both the heterozygous (c.+259G>A, c.+424G>A, c.+1465C>T, c.+1769C>T, c.+2456T>G, c.+2603C>T, c.+2972T>A, c.+3069T>C) and homozygous (c.+424G>A, c.+1465C>T, c.+1769C>T) states. Molecular screening identified all nucleotide changes in a healthy population of 150 controls and demonstrated that they are common polymorphisms. However, statistically significant differences of allele and genotype frequencies were detected for c.+1465C>T and c.+1769C>T, and borderline values for c.+2456T>G. By stratifying patients by relevant clinical features (presence/absence of multiple primary melanoma, Breslow's thickness, phototype and number of nevi), no significant findings were noted except for an association between the c.+424G>A (heterozygous individual GA) and multiple primary melanoma and phototype III-IV. Our preliminary study suggests that miR-34a, although having a role in late tumorigenesis, does not contribute to the inherited susceptibility to cutaneous melanoma. A function as phenotypic modulator in familial melanoma cannot be excluded. PMID:22198089

  18. Increased alveolar plasminogen activator in early asbestosis

    SciTech Connect

    Cantin, A.; Allard, C.; Begin, R.

    1989-03-01

    Alveolar macrophage-derived plasminogen activator (PA) activity is decreased in some chronic interstitial lung diseases such as idiopathic pulmonary fibrosis and sarcoidosis but increased in experimental models of acute alveolitis. Although asbestos fibers can stimulate alveolar macrophages (AM) to release PA in vitro, the effect of chronic asbestos exposure of the lower respiratory tract on lung PA activity remains unknown. The present study was designed to evaluate PA activity of alveolar macrophages and bronchoalveolar lavage (BAL) fluid in asbestos-exposed sheep and asbestos workers. Forty-three sheep were exposed to either 100 mg UICC chrysotile B asbestos in 100 ml phosphate-buffered saline (PBS) or to 100 ml PBS by tracheal infusion every 2 wk for 18 months. At Month 18, chest roentgenograms were analyzed and alveolar macrophage and extracellular fluid PA activity were measured in samples obtained by BAL. Alveolar macrophage PA activity was increased in the asbestos-exposed sheep compared to control sheep (87.2 +/- 17.3 versus 41.1 +/- 7.2 U/10(5) AM-24 h, p less than 0.05) as was the BAL fluid PA activity (674.9 +/- 168.4 versus 81.3 +/- 19.7 U/mg alb-24 h, p less than 0.01). Among the asbestos-exposed sheep, 10 had normal chest roentgenograms (Group SA) and 15 had irregular interstitial opacities (Group SB). Strikingly, whereas Group SA did not differ from the control group in BAL cellularity or PA activity, Group SB had marked increases in alveolar macrophages (p less than 0.005), AM PA activity (p less than 0.02), and BAL PA activity (p less than 0.001) compared to the control group.

  19. Increased Ribozyme Activity in Crowded Solutions*

    PubMed Central

    Desai, Ravi; Kilburn, Duncan; Lee, Hui-Ting; Woodson, Sarah A.

    2014-01-01

    Noncoding RNAs must function in the crowded environment of the cell. Previous small-angle x-ray scattering experiments showed that molecular crowders stabilize the structure of the Azoarcus group I ribozyme, allowing the ribozyme to fold at low physiological Mg2+ concentrations. Here, we used an RNA cleavage assay to show that the PEG and Ficoll crowder molecules increased the biochemical activity of the ribozyme, whereas sucrose did not. Crowding lowered the Mg2+ threshold at which activity was detected and increased total RNA cleavage at high Mg2+ concentrations sufficient to fold the RNA in crowded or dilute solution. After correcting for solution viscosity, the observed reaction rate was proportional to the fraction of active ribozyme. We conclude that molecular crowders stabilize the native ribozyme and favor the active structure relative to compact inactive folding intermediates. PMID:24337582

  20. Bufalin induces G0/G1 phase arrest through inhibiting the levels of cyclin D, cyclin E, CDK2 and CDK4, and triggers apoptosis via mitochondrial signaling pathway in T24 human bladder cancer cells.

    PubMed

    Huang, Wen-Wen; Yang, Jai-Sing; Pai, Shu-Jen; Wu, Ping-Ping; Chang, Shu-Jen; Chueh, Fu-Shin; Fan, Ming-Jen; Chiou, Shang-Ming; Kuo, Hsiu-Maan; Yeh, Chin-Chung; Chen, Po-Yuan; Tsuzuki, Minoru; Chung, Jing-Gung

    2012-04-01

    Most of the chemotherapy treatments for bladder cancer aim to kill the cancer cells, but a high recurrence rate after medical treatments is still occurred. Bufalin from the skin and parotid venom glands of toad has been shown to induce apoptotic cell death in many types of cancer cell lines. However, there is no report addressing that bufalin induced cell death in human bladder cancer cells. The purpose of this study was investigated the mechanisms of bufalin-induced apoptosis in a human bladder cancer cell line (T24). We demonstrated the effects of bufalin on the cell growth and apoptosis in T24 cells by using DAPI/TUNEL double staining, a PI exclusion and flow cytometric analysis. The effects of bufalin on the production of reactive oxygen species (ROS), the level of mitochondrial membrane potential (ΔΨ(m)), and DNA content including sub-G1 (apoptosis) in T24 cells were also determined by flow cytometry. Western blot analysis was used to examine the expression of G(0)/G(1) phase-regulated and apoptosis-associated protein levels in bufalin-treated T24 cells. The results indicated that bufalin significantly decreased the percentage of viability, induced the G(0)/G(1) phase arrest and triggered apoptosis in T24 cells. The down-regulation of the protein levels for cyclin D, CDK4, cyclin E, CDK2, phospho-Rb, phospho-AKT and Bcl-2 with the simultaneous up-regulation of the cytochrome c, Apaf-1, AIF, caspase-3, -7 and -9 and Bax protein expressions and caspase activities were observed in T24 cells after bufalin treatment. Based on our results, bufalin induces apoptotic cell death in T24 cells through suppressing AKT activity and anti-apoptotic Bcl-2 protein as well as inducing pro-apoptotic Bax protein. The levels of caspase-3, -7 and -9 are also mediated apoptosis in bufalin-treated T24 cells. Therefore, bufalin might be used as a therapeutic agent for the treatment of human bladder cancer in the future.

  1. Bufalin induces G0/G1 phase arrest through inhibiting the levels of cyclin D, cyclin E, CDK2 and CDK4, and triggers apoptosis via mitochondrial signaling pathway in T24 human bladder cancer cells.

    PubMed

    Huang, Wen-Wen; Yang, Jai-Sing; Pai, Shu-Jen; Wu, Ping-Ping; Chang, Shu-Jen; Chueh, Fu-Shin; Fan, Ming-Jen; Chiou, Shang-Ming; Kuo, Hsiu-Maan; Yeh, Chin-Chung; Chen, Po-Yuan; Tsuzuki, Minoru; Chung, Jing-Gung

    2012-04-01

    Most of the chemotherapy treatments for bladder cancer aim to kill the cancer cells, but a high recurrence rate after medical treatments is still occurred. Bufalin from the skin and parotid venom glands of toad has been shown to induce apoptotic cell death in many types of cancer cell lines. However, there is no report addressing that bufalin induced cell death in human bladder cancer cells. The purpose of this study was investigated the mechanisms of bufalin-induced apoptosis in a human bladder cancer cell line (T24). We demonstrated the effects of bufalin on the cell growth and apoptosis in T24 cells by using DAPI/TUNEL double staining, a PI exclusion and flow cytometric analysis. The effects of bufalin on the production of reactive oxygen species (ROS), the level of mitochondrial membrane potential (ΔΨ(m)), and DNA content including sub-G1 (apoptosis) in T24 cells were also determined by flow cytometry. Western blot analysis was used to examine the expression of G(0)/G(1) phase-regulated and apoptosis-associated protein levels in bufalin-treated T24 cells. The results indicated that bufalin significantly decreased the percentage of viability, induced the G(0)/G(1) phase arrest and triggered apoptosis in T24 cells. The down-regulation of the protein levels for cyclin D, CDK4, cyclin E, CDK2, phospho-Rb, phospho-AKT and Bcl-2 with the simultaneous up-regulation of the cytochrome c, Apaf-1, AIF, caspase-3, -7 and -9 and Bax protein expressions and caspase activities were observed in T24 cells after bufalin treatment. Based on our results, bufalin induces apoptotic cell death in T24 cells through suppressing AKT activity and anti-apoptotic Bcl-2 protein as well as inducing pro-apoptotic Bax protein. The levels of caspase-3, -7 and -9 are also mediated apoptosis in bufalin-treated T24 cells. Therefore, bufalin might be used as a therapeutic agent for the treatment of human bladder cancer in the future. PMID:22285700

  2. Addressing childhood obesity through increased physical activity.

    PubMed

    Hills, Andrew P; Okely, Anthony D; Baur, Louise A

    2010-10-01

    Obesity is affecting an increasing proportion of children globally. Despite an appreciation that physical activity is essential for the normal growth and development of children and prevents obesity and obesity-related health problems, too few children are physically active. A concurrent problem is that today's young people spend more time than previous generations did in sedentary pursuits, including watching television and engaging in screen-based games. Active behavior has been displaced by these inactive recreational choices, which has contributed to reductions in activity-related energy expenditure. Implementation of multifactorial solutions considered to offer the best chance of combating these trends is urgently required to redress the energy imbalance that characterizes obesity. The counterproductive 'shame and blame' mentality that apportions responsibility for the childhood obesity problem to sufferers, their parents, teachers or health-care providers needs to be changed. Instead, these groups should offer constant support and encouragement to promote appropriate physical activity in children. Failure to provide activity opportunities will increase the likelihood that the children of today will live less healthy (and possibly shorter) lives than their parents.

  3. Lack of Cyclin-Dependent Kinase 4 Inhibits c-myc Tumorigenic Activities in Epithelial Tissues

    PubMed Central

    Miliani de Marval, Paula L.; Macias, Everardo; Rounbehler, Robert; Sicinski, Piotr; Kiyokawa, Hiroaki; Johnson, David G.; Conti, Claudio J.; Rodriguez-Puebla, Marcelo L.

    2004-01-01

    The proto-oncogene c-myc encodes a transcription factor that is implicated in the regulation of cellular proliferation, differentiation, and apoptosis and that has also been found to be deregulated in several forms of human and experimental tumors. We have shown that forced expression of c-myc in epithelial tissues of transgenic mice (K5-Myc) resulted in keratinocyte hyperproliferation and the development of spontaneous tumors in the skin and oral cavity. Although a number of genes involved in cancer development are regulated by c-myc, the actual mechanisms leading to Myc-induced neoplasia are not known. Among the genes regulated by Myc is the cyclin-dependent kinase 4 (CDK4) gene. Interestingly, previous studies from our laboratory showed that the overexpression of CDK4 led to keratinocyte hyperproliferation, although no spontaneous tumor development was observed. Thus, we tested the hypothesis that CDK4 may be one of the critical downstream genes involved in Myc carcinogenesis. Our results showed that CDK4 inhibition in K5-Myc transgenic mice resulted in the complete inhibition of tumor development, suggesting that CDK4 is a critical mediator of tumor formation induced by deregulated Myc. Furthermore, a lack of CDK4 expression resulted in marked decreases in epidermal thickness and keratinocyte proliferation compared to the results obtained for K5-Myc littermates. Biochemical analysis of the K5-Myc epidermis showed that CDK4 mediates the proliferative activities of Myc by sequestering p21Cip1 and p27Kip1 and thereby indirectly activating CDK2 kinase activity. These results show that CDK4 mediates the proliferative and oncogenic activities of Myc in vivo through a mechanism that involves the sequestration of specific CDK inhibitors. PMID:15314163

  4. Increased flexibility decreases antifreeze protein activity

    PubMed Central

    Patel, Shruti N; Graether, Steffen P

    2010-01-01

    Antifreeze proteins protect several cold-blooded organisms from subzero environments by preventing death from freezing. The Type I antifreeze protein (AFP) isoform from Pseudopleuronectes americanus, named HPLC6, is a 37-residue protein that is a single α-helix. Mutational analysis of the protein showed that its alanine-rich face is important for binding to and inhibiting the growth of macromolecular ice. Almost all structural studies of HPLC6 involve the use of chemically synthesized protein as it requires a native N-terminal aspartate and an amidated C-terminus for full activity. Here, we examine the role of C-terminal amide and C-terminal arginine side chain in the activity, structure, and dynamics of nonamidated Arg37 HPLC6, nonamidated HPLC6 Ala37, amidated HPLC6 Ala37, and fully native HPLC6 using a recombinant bacterial system. The thermal hysteresis (TH) activities of the nonamidated mutants are 35% lower compared with amidated proteins, but analysis of the NMR data and circular dichroism spectra shows that they are all still α-helical. Relaxation data from the two nonamidated mutants indicate that the C-terminal residues are considerably more flexible than the rest of the protein because of the loss of the amide group, whereas the amidated Ala37 mutant has a C-terminus that is as rigid as the wild-type protein and has high TH activity. We propose that an increase in flexibility of the AFP causes it to lose activity because its dynamic nature prevents it from binding strongly to the ice surface. PMID:20936690

  5. Physical activity increases bone mass during growth

    PubMed Central

    Karlsson, Magnus K.; Nordqvist, Anders; Karlsson, Caroline

    2008-01-01

    Background The incidence of fragility fractures has increased during the last half of the 1990′s. One important determinant of fractures is the bone mineral content (BMC) or bone mineral density (BMD), the amount of mineralised bone. If we could increase peak bone mass (the highest value of BMC reached during life) and/or decrease the age-related bone loss, we could possibly improve the skeletal resistance to fracture. Objective This review evaluates the importance of exercise as a strategy to improve peak bone mass, including some aspects of nutrition. Design Publications within the field were searched through Medline (PubMed) using the search words: exercise, physical activity, bone mass, bone mineral content, bone mineral density, BMC, BMD, skeletal structure and nutrition. We included studies dealing with exercise during growth and young adolescence. We preferably based our inferences on randomised controlled trials (RCT), which provide the highest level of evidence. Results Exercise during growth increases peak bone mass. Moderate intensity exercise intervention programs are beneficial for the skeletal development during growth. Adequate nutrition must accompany the exercise to achieve the most beneficial skeletal effects by exercise. Conclusion Exercise during growth seems to enhance the building of a stronger skeleton through a higher peak bone mass and a larger bone size. PMID:19109652

  6. MFG-E8 Activates Proliferation of Vascular Smooth Muscle Cells via Integrin Signaling

    PubMed Central

    Wang, Mingyi; Fu, Zongming; Wu, James; Zhang, Jing; Jiang, Liqun; Khazan, Benjamin; Telljohann, Richard; Zhao, Mingming; Krug, Alexander W.; Pikilidou, Maria; Monticone, Robert E.; Wersto, Robert; Van Eyk, Jennifer; Lakatta, Edward G.

    2012-01-01

    Summary An accumulation of milk fat globule EGF-8 protein (MFG-E8) occurs within the context of arterial wall inflammatory remodeling during aging, hypertension, diabetes mellitus, or atherosclerosis. MFG-E8 induces VSMC invasion, but whether it effects VSMC proliferation, a salient feature of arterial inflammation, is unknown. Here, we show that in the rat arterial wall in vivo, PCNA and Ki67, markers of cell cycle activation, increase with age between 8 and 30-mo. In fresh or early passage VSMC isolated from old aortae, an increase in CDK4 and PCNA, and cell cycle with acceleration of S and G2 phases and reduction of the G1/G0 phase, and an increase in PDGF and its receptors, confer elevated proliferative capacity, compared to young VSMC. Increased co-expression and physical interaction of MFG-E8 and integrin αvβ5 occur with aging in both the rat aortic wall in vivo and in VSMC in vitro. In young VSMC in vitro, MFG-E8 added exogenously, or over-expressed endogenously, triggers phosphorylation of ERK1/2, augmented levels of PCNA and CDK4, increased BrdU incorporation and promotes proliferation, via αvβ5 integrins. MFG-E8 silencing, or its receptor inhibition, or the blockade of ERK1/2 phosphorylation in these cells reduces PCNA and CDK4 levels and decelerates the cell cycle S phase, conferring a reduction in proliferative capacity. Collectively, these results indicate that MFG-E8 in a dose-dependent manner, coordinates the expression of cell cycle molecules and facilitates VSMC proliferation via integrin/ ERK1/2 signaling. Thus, an increase in MFG-E8 signaling is a mechanism of the age-associated increase in aortic VSMC proliferation. PMID:22385834

  7. Discovery of 8-Cyclopentyl-2-[4-(4-methyl-piperazin-1-yl)-phenylamino]-7-oxo-7,8-dihydro-pyrido[2,3-d]pyrimidine-6-carbonitrile (7x) as a Potent Inhibitor of Cyclin-Dependent Kinase 4 (CDK4) and AMPK-Related Kinase 5 (ARK5)

    PubMed Central

    2015-01-01

    The success of imatinib, a BCR-ABL inhibitor for the treatment of chronic myelogenous leukemia, has created a great impetus for the development of additional kinase inhibitors as therapeutic agents. However, the complexity of cancer has led to recent interest in polypharmacological approaches for developing multikinase inhibitors with low toxicity profiles. With this goal in mind, we analyzed more than 150 novel cyano pyridopyrimidine compounds and identified structure–activity relationship trends that can be exploited in the design of potent kinase inhibitors. One compound, 8-cyclopentyl-2-[4-(4-methyl-piperazin-1-yl)-phenylamino]-7-oxo-7,8-dihydro-pyrido[2,3-d]pyrimidine-6-carbonitrile (7x), was found to be the most active, inducing apoptosis of tumor cells at a concentration of approximately 30–100 nM. In vitro kinase profiling revealed that 7x is a multikinase inhibitor with potent inhibitory activity against the CDK4/CYCLIN D1 and ARK5 kinases. Here, we report the synthesis, structure–activity relationship, kinase inhibitory profile, in vitro cytotoxicity, and in vivo tumor regression studies by this lead compound. PMID:24417566

  8. Discovery of 8-cyclopentyl-2-[4-(4-methyl-piperazin-1-yl)-phenylamino]-7-oxo-7,8-dihydro-pyrido[2,3-d]pyrimidine-6-carbonitrile (7x) as a potent inhibitor of cyclin-dependent kinase 4 (CDK4) and AMPK-related kinase 5 (ARK5).

    PubMed

    Reddy, M V Ramana; Akula, Balireddy; Cosenza, Stephen C; Athuluridivakar, Saikrishna; Mallireddigari, Muralidhar R; Pallela, Venkat R; Billa, Vinay K; Subbaiah, D R C Venkata; Bharathi, E Vijaya; Vasquez-Del Carpio, Rodrigo; Padgaonkar, Amol; Baker, Stacey J; Reddy, E Premkumar

    2014-02-13

    The success of imatinib, a BCR-ABL inhibitor for the treatment of chronic myelogenous leukemia, has created a great impetus for the development of additional kinase inhibitors as therapeutic agents. However, the complexity of cancer has led to recent interest in polypharmacological approaches for developing multikinase inhibitors with low toxicity profiles. With this goal in mind, we analyzed more than 150 novel cyano pyridopyrimidine compounds and identified structure-activity relationship trends that can be exploited in the design of potent kinase inhibitors. One compound, 8-cyclopentyl-2-[4-(4-methyl-piperazin-1-yl)-phenylamino]-7-oxo-7,8-dihydro-pyrido[2,3-d]pyrimidine-6-carbonitrile (7x), was found to be the most active, inducing apoptosis of tumor cells at a concentration of approximately 30-100 nM. In vitro kinase profiling revealed that 7x is a multikinase inhibitor with potent inhibitory activity against the CDK4/CYCLIN D1 and ARK5 kinases. Here, we report the synthesis, structure-activity relationship, kinase inhibitory profile, in vitro cytotoxicity, and in vivo tumor regression studies by this lead compound.

  9. The p16(INK4A)/pRb pathway and telomerase activity define a subgroup of Ph+ adult Acute Lymphoblastic Leukemia associated with inferior outcome.

    PubMed

    Chien, Wei W; Catallo, Régine; Chebel, Amel; Baranger, Laurence; Thomas, Xavier; Béné, Marie-Christine; Gerland, Luc M; Schmidt, Aline; Beldjord, Kheira; Klein, Nathalie; Escoffre-Barbe, Martine; Leguay, Thibaut; Huguet, Françoise; Larosa, Fabrice; Hayette, Sandrine; Plesa, Adriana; Ifrah, Norbert; Dombret, Hervé; Salles, Gilles; Chassevent, Agnès; Ffrench, Martine

    2015-04-01

    Adult Acute Lymphoblastic Leukemia (ALL) therapies have been improved by pediatric-like approaches. However, treatment failures and relapses are common and new markers are needed to identify patients with poor prognosis in prospective trials. The p16(INK4A)/CDK4-6/pRb pathway and telomerase activity, which are implicated in cell activation and aging, were analyzed to identify new prognostic markers. Proteins of the p16(INK4A)/CDK4-6/pRb pathway and telomerase activity were analyzed in 123 adult B-cell precursor (BCP) ALL cases included in the GRAALL/GRAAPH trials. We found a significantly increased expression of p16(INK4A) in BCP-ALLs with MLL rearrangement. Telomerase activity was significantly lower in Philadelphia chromosome-negative/IKAROS-deleted (BCR-ABL1(-)/IKAROS(del)) cases compared to Philadelphia chromosome-positive (BCR-ABL1+) BCP-ALLs. In BCR-ABL1+ ALLs, high CDK4 expression, phosphorylated pRb (p-pRb) and telomerase activity were significantly associated with a shorter disease-free survival (DFS) and event-free survival (EFS). Enhanced p16(INK4A) expression was only related to a significantly shorter DFS. In vitro analyses of normal stimulated lymphocytes after short- and long-term cultures demonstrated that the observed protein variations of poor prognosis in BCR-ABL1+ ALLs may be related to cell activation but not to cell aging. For these patients, our findings argue for the development of therapeutic strategies including the addition of new lymphocyte activation inhibitors to current treatments.

  10. Increasing Physical Activity through Recess. Research Brief

    ERIC Educational Resources Information Center

    Beighle, Aaron

    2012-01-01

    Regular physical activity promotes important health benefits, reduces risk for obesity and is linked with enhanced academic performance among students. The U.S. Surgeon General recommends that children engage in at least 60 minutes of moderate physical activity most days of the week, yet fewer than half of children ages 6 to 11 meet that…

  11. Increasing Physical Activity in Individuals with Autism

    ERIC Educational Resources Information Center

    Todd, Teri; Reid, Greg

    2006-01-01

    This study investigated the outcomes of an intervention package on participation in two physical activities: snowshoeing and walking/jogging. Three male secondary school students who had been diagnosed with autism and were attending a school for students with intellectual disabilities participated in a 6-month outdoor physical activity program.…

  12. Ectopic expression of cyclin D3 corrects differentiation of DM1 myoblasts through activation of RNA CUG-binding protein, CUGBP1

    SciTech Connect

    Salisbury, Elizabeth; Sakai, Keiko; Schoser, Benedikt; Huichalaf, Claudia; Schneider-Gold, Christiane; Nguyen, Heather; Wang, Gou-Li; Albrecht, Jeffrey H.; Timchenko, Lubov T.

    2008-07-01

    Differentiation of myocytes is impaired in patients with myotonic dystrophy type 1, DM1. CUG repeat binding protein, CUGBP1, is a key regulator of translation of proteins that are involved in muscle development and differentiation. In this paper, we present evidence that RNA-binding activity of CUGBP1 and its interactions with initiation translation complex eIF2 are differentially regulated during myogenesis by specific phosphorylation and that this regulation is altered in DM1. In normal myoblasts, Akt kinase phosphorylates CUGBP1 at Ser28 and increases interactions of CUGBP1 with cyclin D1 mRNA. During differentiation, CUGBP1 is phosphorylated by cyclinD3-cdk4/6 at Ser302, which increases CUGBP1 binding with p21 and C/EBP{beta} mRNAs. While cyclin D3 and cdk4 are elevated in normal myotubes; DM1 differentiating cells do not increase these proteins. In normal myotubes, CUGBP1 interacts with cyclin D3/cdk4/6 and eIF2; however, interactions of CUGBP1 with eIF2 are reduced in DM1 differentiating cells and correlate with impaired muscle differentiation in DM1. Ectopic expression of cyclin D3 in DM1 cells increases the CUGBP1-eIF2 complex, corrects expression of differentiation markers, myogenin and desmin, and enhances fusion of DM1 myoblasts. Thus, normalization of cyclin D3 might be a therapeutic approach to correct differentiation of skeletal muscle in DM1 patients.

  13. Selective anticancer activity of a hexapeptide with sequence homology to a non-kinase domain of Cyclin Dependent Kinase 4

    PubMed Central

    2011-01-01

    Background Cyclin-dependent kinases 2, 4 and 6 (Cdk2, Cdk4, Cdk6) are closely structurally homologous proteins which are classically understood to control the transition from the G1 to the S-phases of the cell cycle by combining with their appropriate cyclin D or cyclin E partners to form kinase-active holoenzymes. Deregulation of Cdk4 is widespread in human cancer, CDK4 gene knockout is highly protective against chemical and oncogene-mediated epithelial carcinogenesis, despite the continued presence of CDK2 and CDK6; and overexpresssion of Cdk4 promotes skin carcinogenesis. Surprisingly, however, Cdk4 kinase inhibitors have not yet fulfilled their expectation as 'blockbuster' anticancer agents. Resistance to inhibition of Cdk4 kinase in some cases could potentially be due to a non-kinase activity, as recently reported with epidermal growth factor receptor. Results A search for a potential functional site of non-kinase activity present in Cdk4 but not Cdk2 or Cdk6 revealed a previously-unidentified loop on the outside of the C'-terminal non-kinase domain of Cdk4, containing a central amino-acid sequence, Pro-Arg-Gly-Pro-Arg-Pro (PRGPRP). An isolated hexapeptide with this sequence and its cyclic amphiphilic congeners are selectively lethal at high doses to a wide range of human cancer cell lines whilst sparing normal diploid keratinocytes and fibroblasts. Treated cancer cells do not exhibit the wide variability of dose response typically seen with other anticancer agents. Cancer cell killing by PRGPRP, in a cyclic amphiphilic cassette, requires cells to be in cycle but does not perturb cell cycle distribution and is accompanied by altered relative Cdk4/Cdk1 expression and selective decrease in ATP levels. Morphological features of apoptosis are absent and cancer cell death does not appear to involve autophagy. Conclusion These findings suggest a potential new paradigm for the development of broad-spectrum cancer specific therapeutics with a companion diagnostic

  14. Targeted overexpression of CKI-insensitive cyclin-dependent kinase 4 increases functional β-cell number through enhanced self-replication in zebrafish.

    PubMed

    Li, Mingyu; Maddison, Lisette A; Crees, Zachary; Chen, Wenbiao

    2013-06-01

    β-Cells of the islet of Langerhans produce insulin to maintain glucose homeostasis. Self-replication of β-cells is the predominant mode of postnatal β-cell production in mammals, with about 20% of rodent β cells dividing in a 24-hour period. However, replicating β-cells are rare in adults. Induction of self-replication of existing β-cells is a potential treatment for diabetes. In zebrafish larvae, β-cells rarely self-replicate, even under conditions that favor β-cell genesis such overnutrition and β-cell ablation. It is not clear why larval β-cells are refractory to replication. In this study, we tested the hypothesis that insufficient activity of cyclin-dependent kinase 4 may be responsible for the low replication rate by ectopically expressing in β-cells a mutant CDK4 (CDK4(R24C)) that is insensitive to inhibition by cyclin-dependent kinase inhibitors. Our data show that expression of CDK4(R24C) in β-cells enhanced β-cell replication. CDK4(R24C) also dampened compensatory β-cell neogenesis in larvae and improved glucose tolerance in adult zebrafish. Our data indicate that CDK4 inhibition contributes to the limited β-cell replication in larval zebrafish. To our knowledge, this is the first example of genetically induced β-cell replication in zebrafish.

  15. How Active Are Your Students? Increasing Physical Activity in Schools

    ERIC Educational Resources Information Center

    Avery, Marybell; Brandt, Janet

    2010-01-01

    The U. S. Department of Health and Human Services recommends that youth engage in at least 60 minutes of physical activity each day, most of which should be either moderate- or vigorous-intensity aerobic physical activity. Half of this amount (30 minutes) should be achieved during the school day. NASPE provides guidance in the form of a…

  16. Inhibition of Rb Phosphorylation Leads to mTORC2-Mediated Activation of Akt.

    PubMed

    Zhang, Jinfang; Xu, Kai; Liu, Pengda; Geng, Yan; Wang, Bin; Gan, Wenjian; Guo, Jianping; Wu, Fei; Chin, Y Rebecca; Berrios, Christian; Lien, Evan C; Toker, Alex; DeCaprio, James A; Sicinski, Piotr; Wei, Wenyi

    2016-06-16

    The retinoblastoma (Rb) protein exerts its tumor suppressor function primarily by inhibiting the E2F family of transcription factors that govern cell-cycle progression. However, it remains largely elusive whether the hyper-phosphorylated, non-E2F1-interacting form of Rb has any physiological role. Here we report that hyper-phosphorylated Rb directly binds to and suppresses the function of mTORC2 but not mTORC1. Mechanistically, Rb, but not p107 or p130, interacts with Sin1 and blocks the access of Akt to mTORC2, leading to attenuated Akt activation and increased sensitivity to chemotherapeutic drugs. As such, inhibition of Rb phosphorylation by depleting cyclin D or using CDK4/6 inhibitors releases Rb-mediated mTORC2 suppression. This, in turn, leads to elevated Akt activation to confer resistance to chemotherapeutic drugs in Rb-proficient cells, which can be attenuated with Akt inhibitors. Therefore, our work provides a molecular basis for the synergistic usage of CDK4/6 and Akt inhibitors in treating Rb-proficient cancer. PMID:27237051

  17. 43 CFR 4110.3-1 - Increasing active use.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Increasing active use. 4110.3-1 Section... Qualifications and Preference § 4110.3-1 Increasing active use. When monitoring or documented field observations... forage is available, in proportion to their active use; and (2) To other qualified applicants...

  18. 43 CFR 4110.3-1 - Increasing active use.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Increasing active use. 4110.3-1 Section... Qualifications and Preference § 4110.3-1 Increasing active use. When monitoring or documented field observations... forage is available, in proportion to their active use; and (2) To other qualified applicants...

  19. 43 CFR 4110.3-1 - Increasing active use.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Increasing active use. 4110.3-1 Section... Qualifications and Preference § 4110.3-1 Increasing active use. When monitoring or documented field observations... forage is available, in proportion to their active use; and (2) To other qualified applicants...

  20. 43 CFR 4110.3-1 - Increasing active use.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Increasing active use. 4110.3-1 Section... Qualifications and Preference § 4110.3-1 Increasing active use. When monitoring or documented field observations... forage is available, in proportion to their active use; and (2) To other qualified applicants...

  1. Enhancement of DNA repair using topical T4 endonuclease V does not inhibit melanoma formation in Cdk4(R24C/R24C)/Tyr-Nras(Q61K) mice following neonatal UVR.

    PubMed

    Hacker, Elke; Muller, H Konrad; Hayward, Nicholas; Fahey, Paul; Walker, Graeme

    2010-02-01

    To further investigate the use of DNA repair-enhancing agents for skin cancer prevention, we treated Cdk4(R24C/R24C)/Nras(Q61K) mice topically with the T4 endonuclease V DNA repair enzyme (known as Dimericine) immediately prior to neonatal ultraviolet radiation (UVR) exposure, which has a powerful effect in exacerbating melanoma development in the mouse model. Dimericine has been shown to reduce the incidence of basal-cell and squamous cell carcinoma. Unexpectedly, we saw no difference in penetrance or age of onset of melanoma after neonatal UVR between Dimericine-treated and control animals, although the drug reduced DNA damage and cellular proliferation in the skin. Interestingly, epidermal melanocytes removed cyclobutane pyrimidine dimers (CPDs) more efficiently than surrounding keratinocytes. Our study indicates that neonatal UVR-initiated melanomas may be driven by mechanisms other than solely that of a large CPD load and/or their inefficient repair. This is further suggestive of different mechanisms by which UVR may enhance the transformation of keratinocytes and melanocytes.

  2. DACH1 regulates cell cycle progression of myeloid cells through the control of cyclin D, Cdk 4/6 and p21{sup Cip1}

    SciTech Connect

    Lee, Jae-Woong; Kim, Hyeng-Soo; Kim, Seonggon; Hwang, Junmo; Kim, Young Hun; Lim, Ga Young; Sohn, Wern-Joo; Yoon, Suk-Ran; Kim, Jae-Young; Park, Tae Sung; Park, Kwon Moo; Ryoo, Zae Young; Lee, Sanggyu

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer DACH1 increases cyclin D, F and Cdk 1, 4, 6 in mouse myeloid progenitor cells. Black-Right-Pointing-Pointer The knockdown of DACH1 blocked the cell cycle progression of HL-60 cells. Black-Right-Pointing-Pointer The novel effect of DACH1 related with cell cycle regulation and leukemogenesis. -- Abstract: The cell-fate determination factor Dachshund, a component of the Retinal Determination Gene Network (RDGN), has a role in breast tumor proliferation through the repression of cyclin D1 and several key regulators of embryonic stem cell function, such as Nanog and Sox2. However, little is known about the role of DACH1 in a myeloid lineage as a cell cycle regulator. Here, we identified the differential expression levels of extensive cell cycle regulators controlled by DACH1 in myeloid progenitor cells. The forced expression of DACH1 induced p27{sup Kip1} and repressed p21{sup Cip1}, which is a pivotal characteristic of the myeloid progenitor. Furthermore, DACH1 significantly increased the expression of cyclin D1, D3, F, and Cdk 1, 4, and 6 in myeloid progenitor cells. The knockdown of DACH1 blocked the cell cycle progression of HL-60 promyeloblastic cells through the decrease of cyclin D1, D3, F, and Cdk 1, 4, and 6 and increase in p21{sup Cip1}, which in turn decreased the phosphorylation of the Rb protein. The expression of Sox2, Oct4, and Klf4 was significantly up-regulated by the forced expression of DACH1 in mouse myeloid progenitor cells.

  3. Best Practices and Recommendations for Increasing Physical Activity in Youth

    ERIC Educational Resources Information Center

    Erwin, Heather; Beets, Michael W.; Centeio, Erin; Morrow, James R., Jr.

    2014-01-01

    Many efforts to increase the physical activity levels of Americans have been introduced and implemented over the past 20 years. National Physical Activity Guidelines have been established, and the National Physical Activity Plan (NPAP) is now in place, which includes a specific sector dedicated to education. This article addresses the Education…

  4. Technology to promote and increase physical activity in heart failure.

    PubMed

    Franklin, Nina C

    2015-01-01

    Regular physical activity is firmly recommended as part of a multifaceted approach to heart failure (HF) self-management. Unfortunately, research indicates that most patients are less likely to engage in and adhere to such activities. The widespread use of information and communication technology tools and resources offers an innovative and potentially beneficial avenue for increasing physical activity levels in HF patients. This article presents specific ways in which advances in information and communication technologies, including Internet- and mobile-based communications, social media platforms, and self-monitoring health devices, can serve as a means to broadly promote increasing levels of physical activity to improve health outcomes in the HF population.

  5. The recent increase in Atlantic hurricane activity: causes and implications.

    PubMed

    Goldenberg, S B; Landsea, C W; Mestas-Nunez, A M; Gray, W M

    2001-07-20

    The years 1995 to 2000 experienced the highest level of North Atlantic hurricane activity in the reliable record. Compared with the generally low activity of the previous 24 years (1971 to 1994), the past 6 years have seen a doubling of overall activity for the whole basin, a 2.5-fold increase in major hurricanes (>/=50 meters per second), and a fivefold increase in hurricanes affecting the Caribbean. The greater activity results from simultaneous increases in North Atlantic sea-surface temperatures and decreases in vertical wind shear. Because these changes exhibit a multidecadal time scale, the present high level of hurricane activity is likely to persist for an additional approximately 10 to 40 years. The shift in climate calls for a reevaluation of preparedness and mitigation strategies.

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

    PubMed

    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. PMID:25844975

  7. Building a better mousetrap (exergame) to increase youth physical activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While 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 us...

  8. Reduced frontal activation with increasing 2nd language proficiency.

    PubMed

    Stein, Maria; Federspiel, Andrea; Koenig, Thomas; Wirth, Miranka; Lehmann, Christoph; Wiest, Roland; Strik, Werner; Brandeis, Daniel; Dierks, Thomas

    2009-11-01

    The factors influencing the degree of separation or overlap in the neuronal networks responsible for the processing of first and second language are still subject to investigation. This longitudinal study investigates how increasing second language proficiency influences activation differences during lexico-semantic processing of first and second language. Native English speaking exchange students learning German were examined with functional magnetic resonance imaging while reading words in three different languages at two points in time: at the beginning of their stay (day 1) and 5 months later (day 2), when second language proficiency had significantly increased. On day 1, second language words evoked more frontal activation than words from the mother tongue. These differences were diminished on day 2. We therefore conclude that with increasing second language proficiency, lexico-semantic processing of second language words needs less frontal control. Our results demonstrate that lexico-semantic processing of first and second language converges onto similar networks as second language proficiency increases.

  9. Activation of HIF-1α does not increase intestinal tumorigenesis

    PubMed Central

    Xue, Xiang; Ramakrishnan, Sadeesh K.

    2014-01-01

    The hypoxic response is mediated by two transcription factors, hypoxia-inducible factor (HIF)-1α and HIF-2α. These highly homologous transcription factors are induced in hypoxic foci and regulate cell metabolism, angiogenesis, cell proliferation, and cell survival. HIF-1α and HIF-2α are activated early in cancer progression and are important in several aspects of tumor biology. HIF-1α and HIF-2α have overlapping and distinct functions. In the intestine, activation of HIF-2α increases inflammation and colon carcinogenesis in mouse models. Interestingly, in ischemic and inflammatory diseases of the intestine, activation of HIF-1α is beneficial and can reduce intestinal inflammation. HIF-1α is a critical transcription factor regulating epithelial barrier function following inflammation. The beneficial value of pharmacological agents that chronically activate HIF-1α is decreased due to the tumorigenic potential of HIFs. The present study tested the hypothesis that chronic activation of HIF-1α may enhance colon tumorigenesis. Two models of colon cancer were assessed, a sporadic and a colitis-associated colon cancer model. Activation of HIF-1α in intestinal epithelial cells does not increase carcinogenesis or progression of colon cancer. Together, the data provide proof of principle that pharmacological activation of HIF-1α could be a safe therapeutic strategy for inflammatory bowel disease. PMID:24875099

  10. Local school policies increase physical activity in Norwegian secondary schools

    PubMed Central

    Haug, Ellen; Torsheim, Torbjørn; Samdal, Oddrun

    2010-01-01

    SUMMARY The implementation of school policies to support the adoption of physical activity is one of the main strategies recommended to increase physical activity levels among this age group. However, documentation of the effect of such policies is so far limited. The purpose of this study was to explore policy-related practices to support physical activity in Norwegian secondary schools and their association with recess physical activity. Emphasis was given to examine the association between policies and physical activity, over and beyond, individual level interests and environmental factors and to examine cross-level interaction effects. This cross-sectional study was based on a nationally representative sample of Norwegian secondary schools and grade 8 students who participated in the Health Behaviour in School-aged Children (HBSC) 2005/06 study. The final sample comprised 68 schools and 1347 students. Data were collected through questionnaires. The results showed that schools with a written policy for physical activity and schools offering organized non-curricular physical activity several times a week had a higher proportion of students reporting daily participation in recess physical activity. Multilevel logistic regression analysis demonstrated a cross-level main effect of the policy index after controlling for sex, socio-economic status, individual-level interests and the physical environment. A significant contribution of adding the policy index to the prediction of recess physical activity above that provided by the individual-level interests and the physical environment was demonstrated. The results are encouraging and give scientific support to policy documents recommending the implementation of school policies to increase physical activity. PMID:19884244

  11. Texting to increase adolescent physical activity: Feasibility assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. Utilizing Wisconsin Afterschool Programs to Increase Physical Activity in Youth

    ERIC Educational Resources Information Center

    Cavanagh, Bradley D.; Meinen, Amy

    2015-01-01

    Background: Approximately 31.7% of children in the United States are overweight or obese. Interventions in the afterschool setting may help combat childhood obesity. Research exists on interventions in school settings, but a few data exist for interventions about afterschool programs. This study investigates increasing physical activity (PA) in…

  13. Using the Web to Increase Physical Activity in College Students

    ERIC Educational Resources Information Center

    Magoc, Dejan; Tomaka, Joe; Bridges-Arzaga, Amber

    2011-01-01

    Objectives: To evaluate the effectiveness of a theoretically based and Web-delivered intervention using common course technology for increasing physical activity in a college student sample. Methods: One hundred four students randomly participated in either a Web-based intervention involving 7 theory-based learning lessons or a control group that…

  14. Games for increasing physical activity: Mechanisms for change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A small conference was held in Houston, TX, in May 2014, to address how to enhance exergames to increase physical activity. Several leading researchers were asked to address specific topics. Attendees came from across the globe. This Games for Health Journal Special Issue is devoted to sharing the a...

  15. Increased Mitochondrial Activity in Anthrax-Induced Cell Death

    PubMed Central

    Li, Chi

    2009-01-01

    Pathogenesis of anthrax lethal toxin (LT) is attributed to its ability to cause death of infected cells. New work has demonstrated that increase of mitochondrial F1F0 ATPase activity and subsequent depletion of cellular ATP level are critical early events during LT-induced cell death. PMID:26124679

  16. Reduced Frontal Activation with Increasing 2nd Language Proficiency

    ERIC Educational Resources Information Center

    Stein, Maria; Federspiel, Andrea; Koenig, Thomas; Wirth, Miranka; Lehmann, Christoph; Wiest, Roland; Strik, Werner; Brandeis, Daniel; Dierks, Thomas

    2009-01-01

    The factors influencing the degree of separation or overlap in the neuronal networks responsible for the processing of first and second language are still subject to investigation. This longitudinal study investigates how increasing second language proficiency influences activation differences during lexico-semantic processing of first and second…

  17. Increased matriptase zymogen activation in inflammatory skin disorders

    PubMed Central

    Chen, Cheng-Jueng; Wu, Bai-Yao; Tsao, Pai-In; Chen, Chi-Yung; Wu, Mei-Hsuan; Chan, Yee Lam E.; Lee, Herng-Sheng; Johnson, Michael D.; Eckert, Richard L.; Chen, Ya-Wen; Chou, Fengpai; Lin, Chen-Yong

    2011-01-01

    Matriptase, a type 2 transmembrane serine protease, and its inhibitor hepatocyte growth factor activator inhibitor (HAI)-1 are required for normal epidermal barrier function, and matriptase activity is tightly regulated during this process. We therefore hypothesized that this protease system might be deregulated in skin disease. To test this, we examined the level and activation state of matriptase in examples of 23 human skin disorders. We first examined matriptase and HAI-1 protein distribution in normal epidermis. Matriptase was detected at high levels at cell-cell junctions in the basal layer and spinous layers but was present at minimal levels in the granular layer. HAI-1 was distributed in a similar pattern, except that high-level expression was retained in the granular layer. This pattern of expression was retained in most skin disorders. We next examined the distribution of activated matriptase. Although activated matriptase is not detected in normal epidermis, a dramatic increase is seen in keratinocytes at the site of inflammation in 16 different skin diseases. To gain further evidence that activation is associated with inflammatory stimuli, we challenged HaCaT cells with acidic pH or H2O2 and observed matriptase activation. These findings suggest that inflammation-associated reactive oxygen species and tissue acidity may enhance matriptase activation in some skin diseases. PMID:21123732

  18. Chromosome 1 replacement increases brain orexins and antidepressive measures without increasing locomotor activity.

    PubMed

    Feng, Pingfu; Hu, Yufen; Vurbic, Drina; Akladious, Afaf; Strohl, Kingman P

    2014-12-01

    Decreased orexin level has been well demonstrated in patients suffering from narcolepsy, depression accompanied with suicide attempt; obstructive sleep apnea and comorbidity were also demonstrated in these diseases. As C57BL/6J (B6) mice are more "depressed" and have lower brain orexins than A/J mice, B6 mice having chromosome 1 replacement (B6A1 mice) might have restored orexin levels and less depressive behavior. We studied the behavior of 4-6 month old B6, A/J and B6A1 mice with forced swim, tail suspension, and locomotor activity tests. The animals were then sacrificed and hypothalamus and medullas dissected from brain tissue. Orexins-A and -B were determined by radioimmunoassay. Compared with A/J mice, B6 mice displayed several signs of depression, including increased immobility, increased locomotors activity, and decreased orexin A and -B levels in both the hypothalamus and medulla. Compared to B6 mice, B6A1 mice exhibited significantly higher levels of orexins-A and -B in both brain regions. B6A1 mice also exhibited antidepressive features in most of measured variables, including decreased locomotor activity, decreased immobility and increased swim in tail suspension test; compared with B6 mice, however. B6A1 mice also reversed immobility in the early phase of the swim test. In summary, B6 mice exhibited depressive attributes compared with A/J mice, including increased locomotor activity, greater immobility, and decreased brain orexins, these were largely reversed in B6A1 mice. We conclude that orexin levels modulate these B6 behaviors, likely due to expression of A/J alleles on Chromosome 1.

  19. Increasing the hydrogenation activity of commercial catalysts for selective hydrocracking

    SciTech Connect

    Khashagul`gova, N.S.; Freiman, L.L.; Zelentsov, Yu.N.

    1994-07-01

    The catalysts generally used in hydrodewaxing or selective hydrocracking of n-paraffins are zeolites with the pentasil structure: TsVK, TsVM, TsVN, and Ultrasil. For use in the production of high-quality transformer oils from paraffinic feedstocks, these catalysts have not only a high cracking activity but also an adequate hydrogenating activity. Catalysts containing a nickel-molybdenum complex (or nickel molybdate synthesized by a specific method) are higher in hydrogenating activity in comparison with catalysts in which the metals are introduced by coextrusion or impregnation. Precipitation of a nickel-molybdenum complex on a solid support (aluminosilicate or zeolite) tends to increase its hydrogenating activity, so that the content of the hydrogenating metals in the catalyst can be reduced. This report describes studies on catalysts based on TsVM and TsVN high-silica zeolites.

  20. Methods of increasing secretion of polypeptides having biological activity

    DOEpatents

    Merino, Sandra

    2014-05-27

    The present invention relates to methods for producing a secreted polypeptide having biological activity, comprising: (a) transforming a fungal host cell with a fusion protein construct encoding a fusion protein, which comprises: (i) a first polynucleotide encoding a signal peptide; (ii) a second polynucleotide encoding at least a catalytic domain of an endoglucanase or a portion thereof; and (iii) a third polynucleotide encoding at least a catalytic domain of a polypeptide having biological activity; wherein the signal peptide and at least the catalytic domain of the endoglucanase increases secretion of the polypeptide having biological activity compared to the absence of at least the catalytic domain of the endoglucanase; (b) cultivating the transformed fungal host cell under conditions suitable for production of the fusion protein; and (c) recovering the fusion protein, a component thereof, or a combination thereof, having biological activity, from the cultivation medium.

  1. Methods of increasing secretion of polypeptides having biological activity

    DOEpatents

    Merino, Sandra

    2013-10-01

    The present invention relates to methods for producing a secreted polypeptide having biological activity, comprising: (a) transforming a fungal host cell with a fusion protein construct encoding a fusion protein, which comprises: (i) a first polynucleotide encoding a signal peptide; (ii) a second polynucleotide encoding at least a catalytic domain of an endoglucanase or a portion thereof; and (iii) a third polynucleotide encoding at least a catalytic domain of a polypeptide having biological activity; wherein the signal peptide and at least the catalytic domain of the endoglucanase increases secretion of the polypeptide having biological activity compared to the absence of at least the catalytic domain of the endoglucanase; (b) cultivating the transformed fungal host cell under conditions suitable for production of the fusion protein; and (c) recovering the fusion protein, a component thereof, or a combination thereof, having biological activity, from the cultivation medium.

  2. Methods of increasing secretion of polypeptides having biological activity

    SciTech Connect

    Merino, Sandra

    2014-10-28

    The present invention relates to methods for producing a secreted polypeptide having biological activity, comprising: (a) transforming a fungal host cell with a fusion protein construct encoding a fusion protein, which comprises: (i) a first polynucleotide encoding a signal peptide; (ii) a second polynucleotide encoding at least a catalytic domain of an endoglucanase or a portion thereof; and (iii) a third polynucleotide encoding at least a catalytic domain of a polypeptide having biological activity; wherein the signal peptide and at least the catalytic domain of the endoglucanase increases secretion of the polypeptide having biological activity compared to the absence of at least the catalytic domain of the endoglucanase; (b) cultivating the transformed fungal host cell under conditions suitable for production of the fusion protein; and (c) recovering the fusion protein, a component thereof, or a combination thereof, having biological activity, from the cultivation medium.

  3. Methods of increasing secretion of polypeptides having biological activity

    SciTech Connect

    Merino, Sandra

    2015-04-14

    The present invention relates to methods for producing a secreted polypeptide having biological activity, comprising: (a) transforming a fungal host cell with a fusion protein construct encoding a fusion protein, which comprises: (i) a first polynucleotide encoding a signal peptide; (ii) a second polynucleotide encoding at least a catalytic domain of an endoglucanase or a portion thereof; and (iii) a third polynucleotide encoding at least a catalytic domain of a polypeptide having biological activity; wherein the signal peptide and at least the catalytic domain of the endoglucanase increases secretion of the polypeptide having biological activity compared to the absence of at least the catalytic domain of the endoglucanase; (b) cultivating the transformed fungal host cell under conditions suitable for production of the fusion protein; and (c) recovering the fusion protein, a component thereof, or a combination thereof, having biological activity, from the cultivation medium.

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

    PubMed

    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).

  5. Plant species richness increases phosphatase activities in an experimental grassland

    NASA Astrophysics Data System (ADS)

    Hacker, Nina; Wilcke, Wolfgang; Oelmann, Yvonne

    2014-05-01

    Plant species richness has been shown to increase aboveground nutrient uptake requiring the mobilization of soil nutrient pools. For phosphorus (P) the underlying mechanisms for increased P release in soil under highly diverse grassland mixtures remain obscure because aboveground P storage and concentrations of inorganic and organic P in soil solution and differently reactive soil P pools are unrelated (Oelmann et al. 2011). The need of plants and soil microorganisms for P can increase the exudation of enzymes hydrolyzing organically bound P (phosphatases) which might represent an important release mechanism of inorganic P in a competitive environment such as highly diverse grassland mixtures. Our objectives were to test the effects of i) plant functional groups (legumes, grasses, non-leguminous tall and small herbs), and of (ii) plant species richness on microbial P (Pmic) and phosphatase activities in soil. In autumn 2013, we measured Pmic and alkaline phosphomonoesterase and phosphodiesterase activities in soil of 80 grassland mixtures comprising different community compositions and species richness (1, 2, 4, 8, 16, 60) in the Jena Experiment. In general, Pmic and enzyme activities were correlated (r = 0.59 and 0.46 for phosphomonoesterase and phosphodiesterase activities, respectively; p

  6. Increased hurricane activity during the Early Toarcian extreme warmth

    NASA Astrophysics Data System (ADS)

    Bodin, Stephane; Krencker, Francois-Nicolas; Suan, Guillaume; Heimhofer, Ulrich; Immenhauser, Adrian

    2014-05-01

    Theoretical considerations led to the postulation that hurricane activity should increase on a warming planet. Finding physical proof for this relationship remains, however, a difficult task since no clear trend is yet emerging from records of present-day anthropogenic warming. The geological past offers the opportunity to test this hypothesis by assessing episodes of extreme warming events, such as the Toarcian Oceanic Anoxic Event (T-OAE, Early Jurassic, ca. 180 Ma). The T-OAE is characterized by a rapid 4-5°C global warming likely induced by the massive release of greenhouse gases into the atmosphere as a consequence of the activity of the Karoo-Ferrar large igneous province. Within the western Tethyan realm (Morocco, Portugal, France, England, etc.), a systematic increase in the occurrence of storm-related deposits is observed within the shallow-water sediments deposited during the T-OAE, notably at its onset. Increased tempestite occurrences can be observed in both siliciclastic- and carbonate-dominated environments. In the Moroccan High Atlas, hummocky cross-stratification (HCS) occurs ubiquitous within the T-OAE, but is otherwise rare in this tide-dominated basin. Interestingly, the palaeolatitude of the High Atlas Basin (10°N during the Early Jurassic) rules out winter storms as the driving mechanism behind the formation of the HCS, and suggests therefore a significant increase of tropical hurricane activity associated with the Early Toarcian global warming.

  7. Increasing Arabian dust activity and the Indian summer monsoon

    NASA Astrophysics Data System (ADS)

    Solmon, F.; Nair, V. S.; Mallet, M.

    2015-07-01

    Over the past decade, aerosol optical depth (AOD) observations based on satellite and ground measurements have shown a significant increase over Arabia and the Arabian Sea, attributed to an intensification of regional dust activity. Recent studies have also suggested that west Asian dust forcing could induce a positive response of Indian monsoon precipitations on a weekly timescale. Using observations and a regional climate model including interactive slab-ocean and dust aerosol schemes, the present study investigates possible climatic links between the increasing June-July-August-September (JJAS) Arabian dust activity and precipitation trends over southern India during the 2000-2009 decade. Meteorological reanalysis and AOD observations suggest that the observed decadal increase of dust activity and a simultaneous intensification of summer precipitation trend over southern India are both linked to a deepening of JJAS surface pressure conditions over the Arabian Sea. In the first part of the study, we analyze the mean climate response to dust radiative forcing over the domain, discussing notably the relative role of Arabian vs. Indo-Pakistani dust regions. In the second part of the study, we show that the model skills in reproducing regional dynamical patterns and southern Indian precipitation trends are significantly improved only when an increasing dust emission trend is imposed on the basis of observations. We conclude that although interannual climate variability might primarily determine the observed regional pattern of increasing dust activity and precipitation during the 2000-2009 decade, the associated dust radiative forcing might in return induce a critical dynamical feedback contributing to enhancing regional moisture convergence and JJAS precipitations over southern India.

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

    PubMed

    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.

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

    PubMed

    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. PMID:24821756

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

    PubMed Central

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

    2014-01-01

    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. PMID:24821756

  11. Increased serum thymidine kinase activity in acute sarcoidosis.

    PubMed

    Tajima, Syunji; Sando, Yoshichika; Maeno, Toshitaka; Sagawa, Naoki; Nara, Mami; Maeno, Yuri; Nakagawa, Junichi; Ito, Toshio; Hoshino, Yoichi; Suga, Tatsuo; Arai, Masashi; Kurabayashi, Masahiko

    2002-02-01

    This is the first case report of acute sarcoidosis with increased serum thymidine kinase (TK) activity. A 43-year-old male presented fever, swelling of parotid glands, lymphadenopathy, and peripheral neuropathy. Sarcoidosis was pathologically diagnosed by lung and parotid gland biopsy. His serum TK, which was increased to 11.2 U/l at diagnosis (normal <5 U/l), normalized after glucocorticoid therapy. Serum TK has been considered as a good marker of the proliferative activity of various types of neoplasms. Its rise in sarcoidosis has, however, not been described. Because acute sarcoidosis sometimes resembles malignant lymphoma, the possible rise of serum TK in sarcoidosis may be worthy of note. PMID:11868600

  12. JAK-2 V617F mutation increases heparanase procoagulant activity.

    PubMed

    Kogan, Inna; Chap, Dafna; Hoffman, Ron; Axelman, Elena; Brenner, Benjamin; Nadir, Yona

    2016-01-01

    Patients with polycythaemia vera (PV), essential thrombocythaemia (ET) and primary myelofibrosis (PMF) are at increased risk of arterial and venous thrombosis. In patients with ET a positive correlation was observed between JAK-2 V617F mutation, that facilitates erythropoietin receptor signalling, and thrombotic events, although the mechanism involved is not clear. We previously demonstrated that heparanase protein forms a complex and enhances the activity of the blood coagulation initiator tissue factor (TF) which leads to increased factor Xa production and subsequent activation of the coagulation system. The present study was aimed to evaluate heparanase procoagulant activity in myeloproliferative neoplasms. Forty bone marrow biopsies of patients with ET, PV, PMF and chronic myelogenous leukaemia (CML) were immunostained to heparanase, TF and TF pathway inhibitor (TFPI). Erythropoietin receptor positive cell lines U87 human glioma and MCF-7 human breast carcinoma were studied. Heparanase and TFPI staining were more prominent in ET, PV and PMF compared to CML. The strongest staining was in JAK-2 positive ET biopsies. Heparanase level and procoagulant activity were higher in U87 cells transfected to over express JAK-2 V617F mutation compared to control and the effect was reversed using JAK-2 inhibitors (Ruxolitinib, VZ3) and hydroxyurea, although the latter drug did not inhibit JAK-2 phosphorylation. Erythropoietin increased while JAK-2 inhibitors decreased the heparanase level and procoagulant activity in U87 and MCF-7 parental cells. In conclusion, JAK-2 is involved in heparanase up-regulation via the erythropoietin receptor. The present findings may potentially point to a new mechanism of thrombosis in JAK-2 positive ET patients. PMID:26489695

  13. Can nursing students' confidence levels increase with repeated simulation activities?

    PubMed

    Cummings, Cynthia L; Connelly, Linda K

    2016-01-01

    In 2014, nursing faculty conducted a study with undergraduate nursing students on their satisfaction, confidence, and educational practice levels, as it related to simulation activities throughout the curriculum. The study was a voluntary survey conducted on junior and senior year nursing students. It consisted of 30 items based on the Student Satisfaction and Self-Confidence in Learning and the Educational Practices Questionnaire (Jeffries, 2012). Mean averages were obtained for each of the 30 items from both groups and were compared using T scores for unpaired means. The results showed that 8 of the items had a 95% confidence level and when combined the items were significant for p <.001. The items identified were those related to self-confidence and active learning. Based on these findings, it can be assumed that repeated simulation experiences can lead to an increase in student confidence and active learning. PMID:26599594

  14. Can nursing students' confidence levels increase with repeated simulation activities?

    PubMed

    Cummings, Cynthia L; Connelly, Linda K

    2016-01-01

    In 2014, nursing faculty conducted a study with undergraduate nursing students on their satisfaction, confidence, and educational practice levels, as it related to simulation activities throughout the curriculum. The study was a voluntary survey conducted on junior and senior year nursing students. It consisted of 30 items based on the Student Satisfaction and Self-Confidence in Learning and the Educational Practices Questionnaire (Jeffries, 2012). Mean averages were obtained for each of the 30 items from both groups and were compared using T scores for unpaired means. The results showed that 8 of the items had a 95% confidence level and when combined the items were significant for p <.001. The items identified were those related to self-confidence and active learning. Based on these findings, it can be assumed that repeated simulation experiences can lead to an increase in student confidence and active learning.

  15. Interactions Increase Forager Availability and Activity in Harvester Ants

    PubMed Central

    Pinter-Wollman, Noa; Crow, Sam; Allen, Kelsey; Mathur, Maya B.; Gordon, Deborah M.

    2015-01-01

    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. PMID:26539724

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

    PubMed

    Pless, Evlyn; Queirolo, Jovel; Pinter-Wollman, Noa; Crow, Sam; Allen, Kelsey; Mathur, Maya B; Gordon, Deborah M

    2015-01-01

    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. PMID:26539724

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

    PubMed

    Pless, Evlyn; Queirolo, Jovel; Pinter-Wollman, Noa; Crow, Sam; Allen, Kelsey; Mathur, Maya B; Gordon, Deborah M

    2015-01-01

    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.

  18. [Increasing activity of a monoamine oxidase by random mutation].

    PubMed

    Chen, Xuejun; Ma, Yuanhui; Shao, Jianhua; Lai, Dunyue; Wang, Zhiguo; Chen, Zhenming

    2014-01-01

    The monoamine oxidase mutant A-1 (F210V/L213C) from Aspergillus niger showed some catalytic activity on mexiletine. To futher improve its activity, the mutant was subjected to directed evolution with MegaWHOP PCR (Megaprimer PCR of Whole Plasmid) and selection employing a high-throughput agar plate-based colorimetric screen. This approach led to the identification of a mutant ep-1, which specific activity was 189% of that for A-1. The ep-1 also showed significantly improved enantioselectivity, with the E value increased from 101 to 282; its kinetic k(cat)/K(m) value increased from 0.001 51 mmol/(L x s) to 0.002 89 mmol/(L x s), suggesting that catalytic efficiency of ep-1 had been improved. The mutant showed obviously higher specific activities on 7 of all tested 11 amines substrates, and the others were comparable. Sequence analysis revealed that there was a new mutation T162A on ep-1. The molecular dynamics simulation indicated that T162A may affect the secondary structure of the substrate channel and expand the binding pocket. PMID:24818485

  19. Changes in baseball batters' brain activity with increased pitch choice.

    PubMed

    Ryu, Kwangmin; Kim, Jingu; Ali, Asif; Kim, Woojong; Radlo, Steven J

    2015-09-01

    In baseball, one factor necessary for batters to decide whether to swing or not depends on what type of pitch is thrown. Oftentimes batters will look for their pitch (i.e., waiting for a fastball). In general, when a pitcher has many types of pitches in his arsenal, batters will have greater difficulty deciding upon the pitch thrown. Little research has been investigated the psychophysiology of a batters decision-making processes. Therefore, the primary purpose of this study was to determine how brain activation changes according to an increase in the number of alternatives (NA) available. A total of 15 male college baseball players participated in this study. The stimuli used in this experiment were video clips of a right-handed pitcher throwing fastball, curve, and slider pitches. The task was to press a button after selecting the fastball as the target stimulus from two pitch choices (fastball and curve), and then from three possibilities (fastball, curve, and slider). Functional and anatomic image scanning magnetic resonance imaging (MRI) runs took 4 and 5[Formula: see text]min, respectively. According to our analysis, the right precentral gyrus, left medial frontal gyrus, and right fusiform gyrus were activated when the NA was one. The supplementary motor areas (SMA) and primary motor cortex were activated when there were two alternatives to choose from and the inferior orbitofrontal gyrus was specifically activated with three alternatives. Contrary to our expectations, the NA was not a critical factor influencing the activation of related decision making areas when the NA was compared against one another. These findings highlight that specific brain areas related to decision making were activated as the NA increased.

  20. Changes in baseball batters' brain activity with increased pitch choice.

    PubMed

    Ryu, Kwangmin; Kim, Jingu; Ali, Asif; Kim, Woojong; Radlo, Steven J

    2015-09-01

    In baseball, one factor necessary for batters to decide whether to swing or not depends on what type of pitch is thrown. Oftentimes batters will look for their pitch (i.e., waiting for a fastball). In general, when a pitcher has many types of pitches in his arsenal, batters will have greater difficulty deciding upon the pitch thrown. Little research has been investigated the psychophysiology of a batters decision-making processes. Therefore, the primary purpose of this study was to determine how brain activation changes according to an increase in the number of alternatives (NA) available. A total of 15 male college baseball players participated in this study. The stimuli used in this experiment were video clips of a right-handed pitcher throwing fastball, curve, and slider pitches. The task was to press a button after selecting the fastball as the target stimulus from two pitch choices (fastball and curve), and then from three possibilities (fastball, curve, and slider). Functional and anatomic image scanning magnetic resonance imaging (MRI) runs took 4 and 5[Formula: see text]min, respectively. According to our analysis, the right precentral gyrus, left medial frontal gyrus, and right fusiform gyrus were activated when the NA was one. The supplementary motor areas (SMA) and primary motor cortex were activated when there were two alternatives to choose from and the inferior orbitofrontal gyrus was specifically activated with three alternatives. Contrary to our expectations, the NA was not a critical factor influencing the activation of related decision making areas when the NA was compared against one another. These findings highlight that specific brain areas related to decision making were activated as the NA increased. PMID:26227537

  1. Projecting climate-driven increases in North American fire activity

    NASA Astrophysics Data System (ADS)

    Wang, D.; Morton, D. C.; Collatz, G. J.

    2013-12-01

    Climate regulates fire activity through controls on vegetation productivity (fuels), lightning ignitions, and conditions governing fire spread. In many regions of the world, human management also influences the timing, duration, and extent of fire activity. These coupled interactions between human and natural systems make fire a complex component of the Earth system. Satellite data provide valuable information on the spatial and temporal dynamics of recent fire activity, as active fires, burned area, and land cover information can be combined to separate wildfires from intentional burning for agriculture and forestry. Here, we combined satellite-derived burned area data with land cover and climate data to assess fire-climate relationships in North America between 2000-2012. We used the latest versions of the Global Fire Emissions Database (GFED) burned area product and Modern-Era Retrospective Analysis for Research and Applications (MERRA) climate data to develop regional relationships between burned area and potential evaporation (PE), an integrated dryness metric. Logistic regression models were developed to link burned area with PE and individual climate variables during and preceding the fire season, and optimal models were selected based on Akaike Information Criterion (AIC). Overall, our model explained 85% of the variance in burned area since 2000 across North America. Fire-climate relationships from the era of satellite observations provide a blueprint for potential changes in fire activity under scenarios of climate change. We used that blueprint to evaluate potential changes in fire activity over the next 50 years based on twenty models from the Coupled Model Intercomparison Project Phase 5 (CMIP5). All models suggest an increase of PE under low and high emissions scenarios (Representative Concentration Pathways (RCP) 4.5 and 8.5, respectively), with largest increases in projected burned area across the western US and central Canada. Overall, near

  2. Increased Rho kinase activity in congestive heart failure

    PubMed Central

    Dong, Ming; Liao, James K.; Fang, Fang; Lee, Alex Pui-Wai; Yan, Bryan Ping-Yen; Liu, Ming; Yu, Cheuk-Man

    2012-01-01

    Aims Rho kinases (ROCKs) are the best characterized effectors of the small G-protein RhoA, and play a role in enhanced vasoconstriction in animal models of congestive heart failure (CHF). This study examined if ROCK activity is increased in CHF and how it is associated with the outcome in CHF. Methods and results Patients admitted with CHF (n =178), disease controls (n =31), and normal subjects (n =30) were studied. Baseline ROCK activity was measured by phosphorylation of themyosin-binding subunit in peripheral leucocytes. The patients were followed up for 14.4 ± 7.2 months (range 0.5–26 months) or until the occurrence of cardiac death. The ROCK activity in CHF patients (2.93 ± 0.87) was significantly higher than that of the disease control (2.06 ± 0.38, P < 0.001) and normal control (1.57 ± 0.43, P < 0.001) groups. Similarly, protein levels of ROCK1 and ROCK2 as well as the activity of RhoA in CHF were significantly higher than in disease controls and normal controls (all P < 0.05). Dyspnoea at rest (β =0.338, P < 0.001), low left ventricular ejection fraction (β = –0.277, P < 0.001), and high creatinine (β =0.202, P =0.006) were independent predictors of the baseline ROCK activity in CHF. Forty-five patients died within 2 years follow-up (25.3%). Combining ROCK activity and N-terminal pro brain natriuretic peptide (NT-proBNP) had an incremental value (log rank χ2 =11.62) in predicting long-term mortality when compared with only NT-proBNP (log rank χ2 =5.16, P < 0.05). Conclusion ROCK activity is increased in CHF and it might be associated with the mortality in CHF. ROCK activity might be a complementary biomarker to CHF risk stratification. PMID:22588320

  3. Increasing Children's Physical Activity During the School Day.

    PubMed

    Hatfield, Daniel Philip; Chomitz, Virginia Rall

    2015-06-01

    Insufficient levels of daily physical activity (PA) among children in the USA and worldwide have profound implications for pediatric obesity and children's health and well-being more generally. Public health recommendations highlight the central role that schools play in providing equitable opportunities for PA for all children. This review identifies evidence-based approaches for increasing children's PA throughout the school day and discusses multilevel factors that support implementation of such approaches. Opportunities to increase school-day PA span not only in-school time (e.g., quality recess and physical education, classroom activity breaks) but also time before school (e.g., active commuting initiatives) and after school (e.g., intramural and interscholastic sports programs). For such approaches to impact children's PA, dimensions of implementation such as adoption, fidelity, penetration, implementation costs, and sustainability are critical. Multilevel factors that influence implementation include policies, school environment and organizational factors, teacher and classroom factors, child and family characteristics, and attributes of the PA approach itself. Research and field observations reinforce the importance of understanding challenges specific to working with schools, including multiple stakeholders, competing priorities, limited facilities and staff capacity, and heterogeneity of students. Thus, while schools hold promise as promoters and equalizers of PA engagement for all children, more research is needed on the levers that influence implementation of effective school-based PA policies and programs.

  4. Both novelty and expertise increase action observation network activity.

    PubMed

    Liew, Sook-Lei; Sheng, Tong; Margetis, John L; Aziz-Zadeh, Lisa

    2013-01-01

    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.

  5. Increased Plasminogen Activator (Urokinase) in Tissue Culture After Fibrin Deposition

    PubMed Central

    Bernik, Maria B.

    1973-01-01

    Lysis of fibrin in tissue culture has been shown to be due to plasminogen activator identified immunologically as urokinase. The present study examines fibrinolytic events in culture, particularly mechanisms leading to increased urokinase levels and accelerated fibrinolysis. Deposition of fibrin on cells in culture was followed by a two- to six-fold increase in urokinase in the supernates and rapid disappearance of the fibrin. Investigation of factors that might be responsible for these events (including fibrin, fibrinogen, vasoactive stimuli, and the enzymes thrombin and plasmin) indicated that the enhanced urokinase yields were mediated through plasmin and thrombin. Study of the possible modes of action of thrombin and plasmin indicated that these enzymes are capable of acting on the cells themselves as well as on cell-produced material. The effect on cells was manifested by mitotic activity or, occasionally, cell injury and death. Although these effects influenced urokinase levels, enhanced yields were explained best by the action of enzymes on cellproduced material. Studies with plasmin and thrombin, and also trypsin, indicated that proteolytic enzymes may act in various ways—affect the stability of urokinase, interfere with inhibition of urokinase by naturally occurring inhibitor(s), and induce urokinase activity from inactive material. Plasma and thrombin appeared to act primarily through the latter mechanism. Inactive material, which gave rise to urokinase upon exposure to proteolytic enzymes and which may represent urokinase precursor, was found in cultures of kidney, lung, spleen, and thyroid. Urokinase in such inactive state appears to be readily accessible to activation by enzymes, particularly plasmin and thrombin, thus facilitating removal of fibrin and possibly also providing pathways to excessive fibrinolysis. PMID:4266421

  6. Increased serum cortisol binding in chronic active hepatitis

    SciTech Connect

    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.

  7. Prostate cancer and the increasing role of active surveillance.

    PubMed

    Alonzo, David Gabriel; Mure, Amanda Lynne; Soloway, Mark S

    2013-09-01

    Prostate cancer (PC) is the most often diagnosed non-skin cancer and the second leading cause of cancer-related death among men in the United States. As a result, for many years the American Urological Association (AUA) and the American Cancer Society have issued statements recommending screening for PC, resulting in its widespread implementation in the United States. Recently, the United States Preventative Services Task Force gave PC screening a recommendation of D, that is, against PC screening for all men. The AUA countered this recommendation, stating that since the development of PC screening using prostate-specific antigen, a reduction in PC-specific mortality has been seen, and that the risk reduction occurred in a setting in which many of the patients were not aggressively treated for prostate cancer. Active surveillance may be described as a method to potentially delay or obviate the need for treatment in men with clinically insignificant PC or PC thought to be at low risk for progression. Studies have shown no significant difference in outcome or pathology between men with low risk PC who receive treatment at the point of progression and those undergoing immediate treatment. Ongoing studies are evaluating the efficacy and utility of active surveillance for low-risk PC. Interim results of these studies have shown that approximately 30% of patients progress on active surveillance. However, "progression" does not necessarily mean treatment failure; rarely do patients develop locally advanced or metastatic disease. Active surveillance has also been shown to be cost-effective when compared with immediate treatment for PC. Longer follow-up may continue to show an increased benefit of active surveillance as a reasonable initial approach to the management of men with low-risk, clinically localized PC.

  8. Prescribed Active Learning Increases Performance in Introductory Biology

    PubMed Central

    O'Connor, Eileen; Parks, John W.; Cunningham, Matthew; Hurley, David; Haak, David; Dirks, Clarissa; Wenderoth, Mary Pat

    2007-01-01

    We tested five course designs that varied in the structure of daily and weekly active-learning exercises in an attempt to lower the traditionally high failure rate in a gateway course for biology majors. Students were given daily multiple-choice questions and answered with electronic response devices (clickers) or cards. Card responses were ungraded; clicker responses were graded for right/wrong answers or participation. Weekly practice exams were done as an individual or as part of a study group. Compared with previous versions of the same course taught by the same instructor, students in the new course designs performed better: There were significantly lower failure rates, higher total exam points, and higher scores on an identical midterm. Attendance was higher in the clicker versus cards section; attendance and course grade were positively correlated. Students did better on clicker questions if they were graded for right/wrong answers versus participation, although this improvement did not translate into increased scores on exams. In this course, achievement increases when students get regular practice via prescribed (graded) active-learning exercises. PMID:17548875

  9. Prescribed active learning increases performance in introductory biology.

    PubMed

    Freeman, Scott; O'Connor, Eileen; Parks, John W; Cunningham, Matthew; Hurley, David; Haak, David; Dirks, Clarissa; Wenderoth, Mary Pat

    2007-01-01

    We tested five course designs that varied in the structure of daily and weekly active-learning exercises in an attempt to lower the traditionally high failure rate in a gateway course for biology majors. Students were given daily multiple-choice questions and answered with electronic response devices (clickers) or cards. Card responses were ungraded; clicker responses were graded for right/wrong answers or participation. Weekly practice exams were done as an individual or as part of a study group. Compared with previous versions of the same course taught by the same instructor, students in the new course designs performed better: There were significantly lower failure rates, higher total exam points, and higher scores on an identical midterm. Attendance was higher in the clicker versus cards section; attendance and course grade were positively correlated. Students did better on clicker questions if they were graded for right/wrong answers versus participation, although this improvement did not translate into increased scores on exams. In this course, achievement increases when students get regular practice via prescribed (graded) active-learning exercises.

  10. Ethynylestradiol increases expression and activity of rat liver MRP3.

    PubMed

    Ruiz, María L; Villanueva, Silvina S M; Luquita, Marcelo G; Vore, Mary; Mottino, Aldo D; Catania, Viviana A

    2006-06-01

    We evaluated the effect of ethynylestradiol (EE) administration (5 mg/kg b.wt. s.c., for 5 consecutive days) on the expression and activity of multidrug resistance-associated protein 3 (Mrp3) in rats. Western blotting analysis revealed decreased Mrp2 (-41%) and increased Mrp3 (+200%) expression by EE. To determine the functional impact of up-regulation of Mrp3 versus Mrp2, we measured the excretion of acetaminophen glucuronide (APAP-glu), a common substrate for both transporters, into bile and perfusate in the recirculating isolated perfused liver (IPL) model. APAP-glu was generated endogenously from acetaminophen (APAP), which was administered as a tracer dose (2 micromol/ml) into the perfusate. Biliary excretion of APAP-glu after 60 min of perfusion was reduced in EE-treated rats (-80%). In contrast, excretion into the perfusate was increased by EE (+45%). Liver content of APAP-glu at the end of the experiment was reduced by 36% in the EE group. The total amount of glucuronide remained the same in both groups. Taken together, these results indicate that up-regulation of Mrp3 led to an exacerbated basolateral versus canalicular excretion of conjugated APAP in IPL. We conclude that induced expression of basolateral Mrp3 by EE may represent a compensatory mechanism to prevent intracellular accumulation of common Mrp substrates, either endogenous or exogenous, due to reduced expression and activity of apical Mrp2. PMID:16554369

  11. The Potential for Pocket Parks to Increase Physical Activity

    PubMed Central

    Cohen, Deborah A.; Marsh, Terry; Williamson, Stephanie; Han, Bing; Derose, Kathryn Pitkin; Golinelli, Daniella; McKenzie, Thomas L.

    2014-01-01

    Purpose To assess the use of new pocket parks in low-income neighborhoods. Setting Los Angeles Subjects Parks users and residents living within ½ mile of 3 pocket parks and 15 neighborhood parks Intervention The creation of pocket parks Design Quasi-experimental post-only comparison Measures We used the System of Observing Play and Recreation in Communities (SOPARC) to measure park use and park-based physical activity and surveyed park users and residents about their park use. Analysis We surveyed 392 and 432 household members within one-half mile of the 3 pocket parks before and after park construction, respectively, as well as 71 pocket park users and compared them to 992 neighborhood park users and 342 residents living within ½ mile of other neighborhood parks. We compared pocket park use to playground area use in the larger neighborhood parks. We used descriptive statistics and Generalized Estimating Equations for the analysis. Results Overall, pocket park use compared favorably in promoting moderate-to-vigorous physical activity with that of existing playground space in nearby parks and they were cost-effective at $0.73/MET hour gained. Pocket park visitors walked an average of 0.25 miles to get there. Conclusions Pocket parks, when perceived as attractive and safe destinations, may increase physical activity by encouraging families with children to walk there. Additional strategies and programs may be needed to encourage more residents to use the parks. PMID:24380461

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

    PubMed

    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.

  13. Baicalein induces G1 arrest in oral cancer cells by enhancing the degradation of cyclin D1 and activating AhR to decrease Rb phosphorylation

    SciTech Connect

    Cheng, Ya-Hsin; Li, Lih-Ann; Lin, Pinpin; Cheng, Li-Chuan; Hung, Chein-Hui; Chang, Nai Wen; Lin, Chingju

    2012-09-15

    Baicalein is a flavonoid, known to have anti-inflammatory and anti-cancer effects. As an aryl hydrocarbon receptor (AhR) ligand, baicalein at high concentrations blocks AhR-mediated dioxin toxicity. Because AhR had been reported to play a role in regulating the cell cycle, we suspected that the anti-cancer effect of baicalein is associated with AhR. This study investigated the molecular mechanism involved in the anti-cancer effect of baicalein in oral cancer cells HSC-3, including whether such effect would be AhR-mediated. Results revealed that baicalein inhibited cell proliferation and increased AhR activity in a dose-dependent manner. Cell cycle was arrested at the G1 phase and the expression of CDK4, cyclin D1, and phosphorylated retinoblastoma (pRb) was decreased. When the AhR was suppressed by siRNA, the reduction of pRb was partially reversed, accompanied by a decrease of cell population at G1 phase and an increase at S phase, while the reduction of cyclin D1 and CDK4 did not change. This finding suggests that the baicalein activation of AhR is indeed associated with the reduction of pRb, but is independent of the reduction of cyclin D1 and CDK4. When cells were pre-treated with LiCl, the inhibitor of GSK-3β, the decrease of cyclin D1 was blocked and the reduction of pRb was recovered. The data indicates that in HSC-3 the reduction of pRb is both mediated by baicalein through activation of AhR and facilitation of cyclin D1 degradation, which causes cell cycle arrest at the G1 phase, and results in the inhibition of cell proliferation. -- Highlights: ► Baicalein causes the G1 phase arrest by decreasing Rb phosphorylation. ► Baicalein modulates AhR-mediated cell proliferation. ► Both AhR activation and cyclin D1 degradation results in hypophosphorylation of Rb. ► Baicalein facilitates cyclin D1 degradation by signalling the GSK-3β pathway.

  14. Increased parietal activity after training of interference control.

    PubMed

    Oelhafen, Stephan; Nikolaidis, Aki; Padovani, Tullia; Blaser, Daniela; Koenig, Thomas; Perrig, Walter J

    2013-11-01

    Recent studies suggest that computerized cognitive training leads to improved performance in related but untrained tasks (i.e. transfer effects). However, most study designs prevent disentangling which of the task components are necessary for transfer. In the current study, we examined whether training on two variants of the adaptive dual n-back task would affect untrained task performance and the corresponding electrophysiological event-related potentials (ERPs). Forty three healthy young adults were trained for three weeks with a high or low interference training variant of the dual n-back task, or they were assigned to a passive control group. While n-back training with high interference led to partial improvements in the Attention Network Test (ANT), we did not find transfer to measures of working memory and fluid intelligence. ERP analysis in the n-back task and the ANT indicated overlapping processes in the P3 time range. Moreover, in the ANT, we detected increased parietal activity for the interference training group alone. In contrast, we did not find electrophysiological differences between the low interference training and the control group. These findings suggest that training on an interference control task leads to higher electrophysiological activity in the parietal cortex, which may be related to improvements in processing speed, attentional control, or both.

  15. Writer's cramp: increased dorsal premotor activity during intended writing.

    PubMed

    Delnooz, Cathérine C S; Helmich, Rick C; Medendorp, W P; Van de Warrenburg, Bart P C; Toni, Ivan

    2013-03-01

    Simple writer's cramp (WC) is a task-specific form of dystonia, characterized by abnormal movements and postures of the hand during writing. It is extremely task-specific, since dystonic symptoms can occur when a patient uses a pencil for writing, but not when it is used for sharpening. Maladaptive plasticity, loss of inhibition, and abnormal sensory processing are important pathophysiological elements of WC. However, it remains unclear how those elements can account for its task-specificity. We used fMRI to isolate cerebral alterations associated with the task-specificity of simple WC. Subjects (13 simple WC patients, 20 matched controls) imagined grasping a pencil to either write with it or sharpen it. On each trial, we manipulated the pencil's position and the number of imagined movements, while monitoring variations in motor output with electromyography. We show that simple WC is characterized by abnormally increased activity in the dorsal premotor cortex (PMd) when imagined actions are specifically related to writing. This cerebral effect was independent from the known deficits in dystonia in generating focal motor output and in processing somatosensory feedback. This abnormal activity of the PMd suggests that the task-specific element of simple WC is primarily due to alterations at the planning level, in the computations that transform a desired action outcome into the motor commands leading to that action. These findings open the way for testing the therapeutic value of interventions that take into account the computational substrate of task-specificity in simple WC, e.g. modulations of PMd activity during the planning phase of writing.

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

    PubMed

    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.

  17. L-tyrosine administration increases acetylcholinesterase activity in rats.

    PubMed

    Ferreira, Gabriela K; Carvalho-Silva, Milena; Gonçalves, Cinara L; Vieira, Júlia S; Scaini, Giselli; Ghedim, Fernando V; Deroza, Pedro F; Zugno, Alexandra I; Pereira, Talita C B; Oliveira, Giovanna M T; Kist, Luiza W; Bogo, Maurício R; Schuck, Patrícia F; Ferreira, Gustavo C; Streck, Emilio L

    2012-12-01

    Tyrosinemia is a rare genetic disease caused by mutations on genes that codify enzymes responsible for tyrosine metabolism. Considering that tyrosinemics patients usually present symptoms associated with central nervous system alterations that ranges from slight decreases in intelligence to severe mental retardation, we decided to investigate whether acute and chronic administration of L-tyrosine in rats would affect acetylcholinesterase mRNA expression and enzymatic activity during their development. In our acute protocol, Wistar rats (10 and 30 days old) were killed one hour after a single intraperitoneal L-tyrosine injection (500 mg/kg) or saline. Chronic administration consisted of L-tyrosine (500 mg/kg) or saline injections 12 h apart for 24 days in Wistar rats (7 days old) and rats were killed 12 h after last injection. Acetylcholinesterase activity was measured by Ellman's method and acetylcholinesterase expression was carried out by a semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) assay. We observed that acute (10 and 30 days old rats) and chronic L-tyrosine administration increased acetylcholinesterase activity in serum and all tested brain areas (hippocampus, striatum and cerebral cortex) when compared to control group. Moreover, there was a significant decrease in mRNA levels of acetylcholinesterase in hippocampus was observed after acute protocol (10 and 30 days old rats) and in striatum after chronic protocol. In case these alterations also occur in the brain of the patients, our results may explain, at least in part, the neurological sequelae associated with high plasma concentrations of tyrosine seen in patients affected by tyrosinemia type II. PMID:23046746

  18. L-tyrosine administration increases acetylcholinesterase activity in rats.

    PubMed

    Ferreira, Gabriela K; Carvalho-Silva, Milena; Gonçalves, Cinara L; Vieira, Júlia S; Scaini, Giselli; Ghedim, Fernando V; Deroza, Pedro F; Zugno, Alexandra I; Pereira, Talita C B; Oliveira, Giovanna M T; Kist, Luiza W; Bogo, Maurício R; Schuck, Patrícia F; Ferreira, Gustavo C; Streck, Emilio L

    2012-12-01

    Tyrosinemia is a rare genetic disease caused by mutations on genes that codify enzymes responsible for tyrosine metabolism. Considering that tyrosinemics patients usually present symptoms associated with central nervous system alterations that ranges from slight decreases in intelligence to severe mental retardation, we decided to investigate whether acute and chronic administration of L-tyrosine in rats would affect acetylcholinesterase mRNA expression and enzymatic activity during their development. In our acute protocol, Wistar rats (10 and 30 days old) were killed one hour after a single intraperitoneal L-tyrosine injection (500 mg/kg) or saline. Chronic administration consisted of L-tyrosine (500 mg/kg) or saline injections 12 h apart for 24 days in Wistar rats (7 days old) and rats were killed 12 h after last injection. Acetylcholinesterase activity was measured by Ellman's method and acetylcholinesterase expression was carried out by a semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) assay. We observed that acute (10 and 30 days old rats) and chronic L-tyrosine administration increased acetylcholinesterase activity in serum and all tested brain areas (hippocampus, striatum and cerebral cortex) when compared to control group. Moreover, there was a significant decrease in mRNA levels of acetylcholinesterase in hippocampus was observed after acute protocol (10 and 30 days old rats) and in striatum after chronic protocol. In case these alterations also occur in the brain of the patients, our results may explain, at least in part, the neurological sequelae associated with high plasma concentrations of tyrosine seen in patients affected by tyrosinemia type II.

  19. Wnt Pathway Activation Increases Hypoxia Tolerance during Development

    PubMed Central

    Gersten, Merril; Zhou, Dan; Azad, Priti; Haddad, Gabriel G.; Subramaniam, Shankar

    2014-01-01

    Adaptation to hypoxia, defined as a condition of inadequate oxygen supply, has enabled humans to successfully colonize high altitude regions. The mechanisms attempted by organisms to cope with short-term hypoxia include increased ATP production via anaerobic respiration and stabilization of Hypoxia Inducible Factor 1α (HIF-1α). However, less is known about the means through which populations adapt to chronic hypoxia during the process of development within a life time or over generations. Here we show that signaling via the highly conserved Wnt pathway impacts the ability of Drosophila melanogaster to complete its life cycle under hypoxia. We identify this pathway through analyses of genome sequencing and gene expression of a Drosophila melanogaster population adapted over >180 generations to tolerate a concentration of 3.5–4% O2 in air. We then show that genetic activation of the Wnt canonical pathway leads to increased rates of adult eclosion in low O2. Our results indicate that a previously unsuspected major developmental pathway, Wnt, plays a significant role in hypoxia tolerance. PMID:25093834

  20. Increased oscillatory theta activation evoked by violent digital game events.

    PubMed

    Salminen, Mikko; Ravaja, Niklas

    2008-04-11

    The authors examined electroencephalographic (EEG) oscillatory responses to two violent events, the player character wounding and killing an opponent character with a gun, in the digital game James Bond 007: NightFire. EEG was recorded from 25 (16 male) right-handed healthy young adults. EEG data were segmented into one 1-s baseline epoch before each event and two 1-s epochs after event onset. Power estimates (microV(2)) were derived with the fast Fourier transform (FFT) for each artefact free event. Both of the studied events evoked increased occipital theta (4-6Hz) responses as compared to the pre-event baseline. The wounding event evoked also increased occipital high theta (6-8Hz) response and the killing event evoked low alpha (8-10Hz) asymmetry over the central electrodes, both relative to the pre-event baseline. The results are discussed in light of facial electromyographic and electrodermal activity responses evoked by these same events, and it is suggested that the reported EEG responses may be attributable to affective processes related to these violent game events. PMID:18325669

  1. The inhibition of activated hepatic stellate cells proliferation by arctigenin through G0/G1 phase cell cycle arrest: persistent p27(Kip1) induction by interfering with PI3K/Akt/FOXO3a signaling pathway.

    PubMed

    Li, Ao; Wang, Jun; Wu, Mingjun; Zhang, Xiaoxun; Zhang, Hongzhi

    2015-01-15

    Proliferation of hepatic stellate cells (HSCs) is vital for the development of fibrosis during liver injury. In this study, we describe that arctigenin (ATG), a major bioactive component of Fructus Arctii, exhibited selective cytotoxic activity via inhibiting platelet-derived growth factor-BB (PDGF-BB)-activated HSCs proliferation and arrested cell cycle at G0/G1 phase, which could not be observed in normal human hepatocytes in vitro. The cyclin-dependent kinase (CDK) 4/6 activities could be strongly inhibited by ATG through down-regulation of cyclin D1 and CDK4/6 expression in early G1 phase arrest. In the ATG-treated HSCs, the expression level of p27(Kip1) and the formation of CDK2-p27(Kip1) complex were also increased. p27(Kip1) silencing significantly attenuated the effect of ATG, including cell cycle arrest and suppression of proliferation in activated HSCs. We also found that ATG suppressed PDGF-BB-induced phosphorylation of Akt and its downstream transcription factor Forkhead box O 3a (FOXO3a), decreased binding of FOXO3a to 14-3-3 protein, and stimulated nuclear translocation of FOXO3a in activated HSCs. Furthermore, knockdown of FOXO3a expression by FOXO3a siRNA attenuated ATG-induced up-regulation of p27(Kip1) in activated HSCs. All the above findings suggested that ATG could increase the levels of p27(Kip1) protein through inhibition of Akt and improvement of FOXO3a activity, in turn inhibited the CDK2 kinase activity, and eventually caused an overall inhibition of HSCs proliferation.

  2. The inhibition of activated hepatic stellate cells proliferation by arctigenin through G0/G1 phase cell cycle arrest: persistent p27(Kip1) induction by interfering with PI3K/Akt/FOXO3a signaling pathway.

    PubMed

    Li, Ao; Wang, Jun; Wu, Mingjun; Zhang, Xiaoxun; Zhang, Hongzhi

    2015-01-15

    Proliferation of hepatic stellate cells (HSCs) is vital for the development of fibrosis during liver injury. In this study, we describe that arctigenin (ATG), a major bioactive component of Fructus Arctii, exhibited selective cytotoxic activity via inhibiting platelet-derived growth factor-BB (PDGF-BB)-activated HSCs proliferation and arrested cell cycle at G0/G1 phase, which could not be observed in normal human hepatocytes in vitro. The cyclin-dependent kinase (CDK) 4/6 activities could be strongly inhibited by ATG through down-regulation of cyclin D1 and CDK4/6 expression in early G1 phase arrest. In the ATG-treated HSCs, the expression level of p27(Kip1) and the formation of CDK2-p27(Kip1) complex were also increased. p27(Kip1) silencing significantly attenuated the effect of ATG, including cell cycle arrest and suppression of proliferation in activated HSCs. We also found that ATG suppressed PDGF-BB-induced phosphorylation of Akt and its downstream transcription factor Forkhead box O 3a (FOXO3a), decreased binding of FOXO3a to 14-3-3 protein, and stimulated nuclear translocation of FOXO3a in activated HSCs. Furthermore, knockdown of FOXO3a expression by FOXO3a siRNA attenuated ATG-induced up-regulation of p27(Kip1) in activated HSCs. All the above findings suggested that ATG could increase the levels of p27(Kip1) protein through inhibition of Akt and improvement of FOXO3a activity, in turn inhibited the CDK2 kinase activity, and eventually caused an overall inhibition of HSCs proliferation. PMID:25498792

  3. Cyclin D activates the Rb tumor suppressor by mono-phosphorylation

    PubMed Central

    Narasimha, Anil M; Kaulich, Manuel; Shapiro, Gary S; Choi, Yoon J; Sicinski, Piotr; Dowdy, Steven F

    2014-01-01

    The widely accepted model of G1 cell cycle progression proposes that cyclin D:Cdk4/6 inactivates the Rb tumor suppressor during early G1 phase by progressive multi-phosphorylation, termed hypo-phosphorylation, to release E2F transcription factors. However, this model remains unproven biochemically and the biologically active form(s) of Rb remains unknown. In this study, we find that Rb is exclusively mono-phosphorylated in early G1 phase by cyclin D:Cdk4/6. Mono-phosphorylated Rb is composed of 14 independent isoforms that are all targeted by the E1a oncoprotein, but show preferential E2F binding patterns. At the late G1 Restriction Point, cyclin E:Cdk2 inactivates Rb by quantum hyper-phosphorylation. Cells undergoing a DNA damage response activate cyclin D:Cdk4/6 to generate mono-phosphorylated Rb that regulates global transcription, whereas cells undergoing differentiation utilize un-phosphorylated Rb. These observations fundamentally change our understanding of G1 cell cycle progression and show that mono-phosphorylated Rb, generated by cyclin D:Cdk4/6, is the only Rb isoform in early G1 phase. DOI: http://dx.doi.org/10.7554/eLife.02872.001 PMID:24876129

  4. Functional ablation of pRb activates Cdk2 and causes antiestrogen resistance in human breast cancer cells.

    PubMed

    Varma, Hemant; Skildum, Andrew J; Conrad, Susan E

    2007-12-05

    Estrogens are required for the proliferation of hormone dependent breast cancer cells, making estrogen receptor (ER) positive tumors amenable to endocrine therapies such as antiestrogens. However, resistance to these agents remains a significant cause of treatment failure. We previously demonstrated that inactivation of the retinoblastoma protein (pRb) family tumor suppressors causes antiestrogen resistance in MCF-7 cells, a widely studied model of estrogen responsive human breast cancers. In this study, we investigate the mechanism by which pRb inactivation leads to antiestrogen resistance. Cdk4 and cdk2 are two key cell cycle regulators that can phosphorylate and inactivate pRb, therefore we tested whether these kinases are required in cells lacking pRb function. pRb family members were inactivated in MCF-7 cells by expressing polyomavirus large tumor antigen (PyLT), and cdk activity was inhibited using the cdk inhibitors p16(INK4A) and p21(Waf1/Cip1). Cdk4 activity was no longer required in cells lacking functional pRb, while cdk2 activity was required for proliferation in both the presence and absence of pRb function. Using inducible PyLT cell lines, we further demonstrated that pRb inactivation leads to increased cyclin A expression, cdk2 activation and proliferation in antiestrogen arrested cells. These results demonstrate that antiestrogens do not inhibit cdk2 activity or proliferation of MCF-7 cells in the absence of pRb family function, and suggest that antiestrogen resistant breast cancer cells resulting from pRb pathway inactivation would be susceptible to therapies that target cdk2.

  5. Effect of Increasing the Choice of Active Options on Children’s Physical Activity

    PubMed Central

    Feda, Denise M.; Lambiase, Maya J.; McCarthy, Thomas F.; Barkley, Jacob E.; Roemmich, James. N.

    2012-01-01

    Objectives To determine whether increasing the choice of physical activity options increases the duration and intensity of children’s physically active play. Design This cross-sectional laboratory study included gender (male, female) and choice group [single toy (no choice), three toys (low choice), five toys (high choice)] as between participant factors. Methods Boys and girls (n = 36, 8–12 y) were stratified, randomly assigned to a choice group that always provided access to each participant’s most liked active toy(s), and allowed 60 min of free time. The same sedentary alternatives were freely available to all participants. Physical activity outcomes were measured by accelerometry, heart rate, and direct observation. Results The number of active toys the children played with increased (p < 0.001) across each choice group. Minutes spent in MPA were greater in the low choice (p < 0.05) and high choice (p < 0.02) groups than the no choice group. Active play time was greater (p < 0.01) in the low choice (79%) and high choice (95%) groups compared to the no choice group. Girls in the low and high choice groups had greater (p < 0.05) percent heart rate reserve when compared to girls in the no choice group. There was no difference in the boys’ percent heart rate reserve between the no choice, low choice and high choice groups. Conclusions Increasing the choice of active toys increases both the duration and intensity of physically active play, especially in girls. PMID:22342111

  6. Fluid Shear Stress Increases Neutrophil Activation via Platelet-Activating Factor

    PubMed Central

    Mitchell, Michael J.; Lin, Kimberly S.; King, Michael R.

    2014-01-01

    Leukocyte exposure to hemodynamic shear forces is critical for physiological functions including initial adhesion to the endothelium, the formation of pseudopods, and migration into tissues. G-protein coupled receptors on neutrophils, which bind to chemoattractants and play a role in neutrophil chemotaxis, have been implicated as fluid shear stress sensors that control neutrophil activation. Recently, exposure to physiological fluid shear stresses observed in the microvasculature was shown to reduce neutrophil activation in the presence of the chemoattractant formyl-methionyl-leucyl-phenylalanine. Here, however, human neutrophil preexposure to uniform shear stress (0.1–2.75 dyn/cm2) in a cone-and-plate viscometer for 1–120 min was shown to increase, rather than decrease, neutrophil activation in the presence of platelet activating factor (PAF). Fluid shear stress exposure increased PAF-induced neutrophil activation in terms of L-selectin shedding, αMβ2 integrin activation, and morphological changes. Neutrophil activation via PAF was found to correlate with fluid shear stress exposure, as neutrophil activation increased in a shear stress magnitude- and time-dependent manner. These results indicate that fluid shear stress exposure increases neutrophil activation by PAF, and, taken together with previous observations, differentially controls how neutrophils respond to chemoattractants. PMID:24853753

  7. Acid-activated biochar increased sulfamethazine retention in soils.

    PubMed

    Vithanage, Meththika; Rajapaksha, Anushka Upamali; Zhang, Ming; Thiele-Bruhn, Sören; Lee, Sang Soo; Ok, Yong Sik

    2015-02-01

    Sulfamethazine (SMZ) is an ionizable and highly mobile antibiotic which is frequently found in soil and water environments. We investigated the sorption of SMZ onto soils amended with biochars (BCs) at varying pH and contact time. Invasive plants were pyrolyzed at 700 °C and were further activated with 30 % sulfuric (SBBC) and oxalic (OBBC) acids. The sorption rate of SMZ onto SBBC and OBBC was pronouncedly pH dependent and was decreased significantly when the values of soil pH increased from 3 to 5. Modeled effective sorption coefficients (K D,eff) values indicated excellent sorption on SBBC-treated loamy sand and sandy loam soils for 229 and 183 L/kg, respectively. On the other hand, the low sorption values were determined for OBBC- and BBC700-treated loamy sand and sandy loam soils. Kinetic modeling demonstrated that the pseudo second order model was the best followed by intra-particle diffusion and the Elovich model, indicating that multiple processes govern SMZ sorption. These findings were also supported by sorption edge experiments based on BC characteristics. Chemisorption onto protonated and ligand containing functional groups of the BC surface, and diffusion in macro-, meso-, and micro-pores of the acid-activated BCs are the proposed mechanisms of SMZ retention in soils. Calculated and experimental q e (amount adsorbed per kg of the adsorbent at equilibrium) values were well fitted to the pseudo second order model, and the predicted maximum equilibrium concentration of SBBC for loamy sand soils was 182 mg/kg. Overall, SBBC represents a suitable soil amendment because of its high sorption rate of SMZ in soils.

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

    USGS Publications Warehouse

    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.

  9. Altered behaviour in spotted hyenas associated with increased human activity

    USGS Publications Warehouse

    Boydston, E.E.; Kapheim, K.M.; Watts, H.E.; Szykman, M.; Holekamp, K.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. ?? 2003 The Zoological Society of London.

  10. Platelet-activating factor-induced increases in glucose kinetics

    SciTech Connect

    Lang, C.H.; Dobrescu, C.; Hargrove, D.M.; Bagby, G.J.; Spitzer, J.J. )

    1988-02-01

    Platelet-activating factor (PAF) is a postulated mediator of many of the early hemodynamic effects of endotoxin. The aim of the present study was to determine whether in vivo administration of PAF could produce alterations in whole-body glucose metabolism that would mimic those seen during endotoxemia. Glucose kinetics were assessed in chronically catheterized conscious rats by the constant infusion of (6-{sup 3}H)- and (U-{sup 14}C)glucose before and for 4 h after either a bolus injection or a constant infusion of PAF. The bolus injection of PAF elevated the rate of glucose appearance (R{sub a}; 44%) for 1.5 h. The lower PAF infusion rate decreased blood pressure 11% to 104 mmHg, whereas the higher infusion rate decreased pressure 34% to 77 mmHg. Both PAF infusion rates produced elevations in plasma glucose and glucose R{sub a} throughout the 4-h infusion period in a dose-related manner. The PAF infusions also induced dose-related increases in plasma glucagon and catecholamine levels throughout the infusion period. Because the constant infusion of PAF did stimulate many of the hemodynamic and metabolic alterations produced by endotoxin, this study provides additional support for the potential importance of PAF as a mediator of the early hemodynamic and metabolic sequela of endotoxin shock. Furthermore, the PAF-induced changes in glucose metabolism appear to be mediated by the resultant elevation in plasma catecholamines.

  11. Nest predation increases with parental activity: Separating nest site and parental activity effects

    USGS Publications Warehouse

    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 have found similar results. We tested whether nest site effects might yield higher predation during incubation because the most obvious sites are depredated most rapidly. We conducted experiments using nest sites from the previous year to remove parental activity. Our results showed that nest sites have highly repeatable effects on nest predation risk; poor nest sites incurred rapid predation and caused predation rates to be greater during the incubation than nestling stage. This pattern also was exhibited in a bird species with similar (i.e. controlled) parental activity between nesting stages. Once nest site effects are taken into account, nest predation shows a strong proximate increase with parental activity during the nestling stage within and across species. Parental activity and nest sites exert antagonistic influences on current estimates of nest predation between nesting stages and both must be considered in order to understand current patterns of nest predation, which is an important source of natural selection.

  12. Src activity increases and Yes activity decreases during mitosis of human colon carcinoma cells.

    PubMed Central

    Park, J; Cartwright, C A

    1995-01-01

    Src and Yes protein-tyrosine kinase activities are elevated in malignant and premalignant tumors of the colon. To determine whether Src activity is elevated throughout the human colon carcinoma cell cycle as it is in polyomavirus middle T antigen- or F527 Src-transformed cells, and whether Yes activity, which is lower than that of Src in the carcinoma cells, is regulated differently, we measured their activities in cycling cells. We observed that the activities of both kinases were higher throughout all phases of the HT-29 colon carcinoma cell cycle than in corresponding phases of the fibroblast cycle. In addition, during mitosis of HT-29 cells, Src specific activity increased two- to threefold more, while Yes activity and abundance decreased threefold. The decreased steady-state protein levels of Yes during mitosis appeared to be due to both decreased synthesis and increased degradation of the protein. Inhibition of tyrosine but not serine/threonine phosphatases abolished the mitotic activation of Src. Mitotic Src was phosphorylated at novel serine and threonine sites and dephosphorylated at Tyr-527. Two cellular proteins (p160 and p180) were phosphorylated on tyrosine only during mitosis. Tyrosine phosphorylation of several other proteins decreased during mitosis. Thus, Src in HT-29 colon carcinoma cells, similar to Src complexed to polyomavirus middle T antigen or activated by mutation at Tyr-527, is highly active in all phases of the cell cycle. Moreover, Src activity further increases during mitosis, whereas Yes activity and abundance decrease. Thus, Src and Yes appear to be regulated differently during mitosis of HT-29 colon carcinoma cells. PMID:7739521

  13. Aerobic training in rats increases skeletal muscle sphingomyelinase and serine palmitoyltransferase activity, while decreasing ceramidase activity.

    PubMed

    Błachnio-Zabielska, Agnieszka; Zabielski, Piotr; Baranowski, Marcin; Gorski, Jan

    2011-03-01

    Sphingolipids are important components of cell membranes that may also serve as cell signaling molecules; ceramide plays a central role in sphingolipid metabolism. The aim of this study was to examine the effect of 5 weeks of aerobic training on key enzymes and intermediates of ceramide metabolism in skeletal muscles. The experiments were carried out on rats divided into two groups: (1) sedentary and (2) trained for 5 weeks (on a treadmill). The activity of serine palmitoyltransferase (SPT), neutral and acid sphingomyelinase (nSMase and aSMase), neutral and alkaline ceramidases (nCDase and alCDase) and the content of sphingolipids was determined in three types of skeletal muscle. We also measured the fasting plasma insulin and glucose concentration for calculating HOMA-IR (homeostasis model assessment) for estimating insulin resistance. We found that the activities of aSMase and SPT increase in muscle in the trained group. These changes were followed by elevation in the content of sphinganine. The activities of both isoforms of ceramidase were reduced in muscle in the trained group. Although the activities of SPT and SMases increased and the activity of CDases decreased, the ceramide content did not change in any of the studied muscle. Although ceramide level did not change, we noticed increased insulin sensitivity in trained animals. It is concluded that training affects the activity of key enzymes of ceramide metabolism but also activates other metabolic pathways which affect ceramide metabolism in skeletal muscles.

  14. Hydrostatic Pressure Increases the Catalytic Activity of Amyloid Fibril Enzymes.

    PubMed

    Luong, Trung Quan; Erwin, Nelli; Neumann, Matthias; Schmidt, Andreas; Loos, Cornelia; Schmidt, Volker; Fändrich, Marcus; Winter, Roland

    2016-09-26

    We studied the combined effects of pressure (0.1-200 MPa) and temperature (22, 30, and 38 °C) on the catalytic activity of designed amyloid fibrils using a high-pressure stopped-flow system with rapid UV/Vis absorption detection. Complementary FT-IR spectroscopic data revealed a remarkably high pressure and temperature stability of the fibrillar systems. High pressure enhances the esterase activity as a consequence of a negative activation volume at all temperatures (about -14 cm(3)  mol(-1) ). The enhancement is sustained in the whole temperature range covered, which allows a further acceleration of the enzymatic activity at high temperatures (activation energy 45-60 kJ mol(-1) ). Our data reveal the great potential of using both pressure and temperature modulation to optimize the enzyme efficiency of catalytic amyloid fibrils.

  15. Opportunities for public health to increase physical activity among youths.

    PubMed

    Piercy, Katrina L; Dorn, Joan M; Fulton, Janet E; Janz, Kathleen F; Lee, Sarah M; McKinnon, Robin A; Pate, Russell R; Pfeiffer, Karin A; Young, Deborah Rohm; Troiano, Richard P; Lavizzo-Mourey, Risa

    2015-03-01

    Despite the well-known benefits of youths engaging in 60 or more minutes of daily physical activity, physical inactivity remains a significant public health concern. The 2008 Physical Activity Guidelines for Americans (PAG) provides recommendations on the amount of physical activity needed for overall health; the PAG Midcourse Report (2013) describes effective strategies to help youths meet these recommendations. Public health professionals can be dynamic change agents where youths live, learn, and play by changing environments and policies to empower youths to develop regular physical activity habits to maintain throughout life. We have summarized key findings from the PAG Midcourse Report and outlined actions that public health professionals can take to ensure that all youths regularly engage in health-enhancing physical activity. PMID:25602864

  16. Hydrostatic Pressure Increases the Catalytic Activity of Amyloid Fibril Enzymes.

    PubMed

    Luong, Trung Quan; Erwin, Nelli; Neumann, Matthias; Schmidt, Andreas; Loos, Cornelia; Schmidt, Volker; Fändrich, Marcus; Winter, Roland

    2016-09-26

    We studied the combined effects of pressure (0.1-200 MPa) and temperature (22, 30, and 38 °C) on the catalytic activity of designed amyloid fibrils using a high-pressure stopped-flow system with rapid UV/Vis absorption detection. Complementary FT-IR spectroscopic data revealed a remarkably high pressure and temperature stability of the fibrillar systems. High pressure enhances the esterase activity as a consequence of a negative activation volume at all temperatures (about -14 cm(3)  mol(-1) ). The enhancement is sustained in the whole temperature range covered, which allows a further acceleration of the enzymatic activity at high temperatures (activation energy 45-60 kJ mol(-1) ). Our data reveal the great potential of using both pressure and temperature modulation to optimize the enzyme efficiency of catalytic amyloid fibrils. PMID:27573584

  17. Proteinase-activated receptors induce nonoxidative, antimicrobial peptides and increased antimicrobial activity in human mononuclear phagocytes.

    PubMed

    Lippuner, Nadine; Morell, Bernhard; Schaffner, Andreas; Schaer, Dominik J

    2007-02-01

    As thrombin and SFLLRNPNDKYEPF (SFLLRN-14), a synthetic ligand, mainly of the proteinase-activated receptor-1 (PAR-1), induce in monocytes the synthesis and secretion of chemokines, the PAR pathway can be viewed as a mononuclear phagocyte-activating principle. Classically, antimicrobial activity of mononuclear phagocytes is the measure for activation. Here, we investigated whether thrombin or SFLLRN-14 increases the antimicrobial activity of human monocytes and compared these effects to those of IFN-gamma. Furthermore, we measured the effects of these agents on the secretion of reactive oxygen intermediates and the antimicrobial activity of acid peptide extracts from monocytes. Human monocytes were exposed to maximally active concentrations of thrombin, SFLLRN-14, and IFN-gamma. Human monocytes treated with thrombin or SFLLRN-14 and then challenged with Salmonella enterica serovar typhimurium, including its attenuated mutant phoP, or Listeria monocytogenes killed, within 3 h, significantly more bacteria than control cells, an effect comparable with or surpassing the effect of IFN-gamma. This finding establishes the proteinase-PAR pathway as a potent, alternate activation pathway of mononuclear phagocytes. Thrombin and SFLLRN-14 had no significant effects on the amount of H(2)O(2) secreted by monocytes. This was in contrast to IFN-gamma, which as expected, increased the secretion of H(2)O(2) by approximately fourfold. Thrombin and SFLLRN-14, but not IFN-gamma, however, significantly increased the antimicrobial activity of acid peptide extracts of monocytes in a radial diffusion assay. Taken together, these findings suggest that IFN-gamma and thrombin differentially regulate oxidative and nonoxidative killing systems of human monocytes. PMID:17095611

  18. ROFA INCREASES CASPASE-3 ACTIVITY IN HUMAN ALVEOLAR MACRAPHAGE

    EPA Science Inventory

    Exposure to air pollution particles produces pulmonary inflammation and injury, but the mechanisms of this injury are unclear. Apoptosis, involving activation of caspases, may be one potential mechanism. In this study, we hypothesized that ROFA, a constituent of air pollution...

  19. Smoking further increases platelet activity in patients with mild hypertension.

    PubMed

    Gleerup, G; Winther, K

    1996-01-01

    In this study the authors examine whether smoking further heightens platelet activity and reduces fibrinolysis above that already present in mild hypertension. Ten smokers and 11 non-smokers, all with mild hypertension (defined as a diastolic pressure between 90 and 110 mm Hg) were compared for their platelet activity in vitro and in vivo and for their fibrinolytic activity. Successive measurements were made with the patients lying at rest after they had assumed the erect posture for 10 min and at the end of a 5-min moderately strenuous exercise test. The threshold for platelet aggregation by ADP in vitro was significantly lower in samples taken from the smokers at rest (1.4 +/- 0.9 mumol L(-1)) than in the non-smokers (3.5 +/- 2.5 mumol L(-1)), and the difference persisted both in the upright posture and after exercise. The level of platelet release of beta-thromboglobulin was, likewise, higher in the smokers in the upright posture. Neither standing up nor physical exercise had any significant influence on either of these two indices of platelet activity. The euglobulin clot lysis time was slightly longer in the smokers than in the non-smokers in all three experimental situations, but the differences were not significant. Inhibitor of tissue plasminogen activator was not materially different in the two groups (Table 2). The results indicate that smoking adds a further element of heightened platelet activity to that inherently present in hypertension.

  20. State Legislation Related to Increasing Physical Activity: 2006-2012

    PubMed Central

    Eyler, Amy A.; Budd, Elizabeth; Camberos, Gabriela J.; Yan, Yan; Brownson, Ross C.

    2016-01-01

    Background Strategies to improve physical activity prevalence often include policy and environmental changes. State-level policies can be influential in supporting access and opportunities for physical activity in schools and communities. The purpose of this study was to explore the prevalence of state legislation related to physical activity and identify the correlates of enactment of this legislation. Methods An online legislative database was used to collect bills from 50 states in the U.S. from 2006-2012 for ten topics related to physical activity. Bills were coded for content and compiled into a database with state-level variables (e.g., obesity prevalence). With enactment status as the outcome, bivariate and multivariate analyses were conducted. Results Of the 1542 bills related to physical activity introduced, 30% (N=460) were enacted. Bills on public transportation and trails were more likely to be enacted than those without these topics. Primary sponsorship by the Republican Party, bipartisan sponsorship, and mention of specific funding amounts were also correlates of enactment. Conclusion Policy surveillance of bills and correlates of enactment are important for understanding patterns in legislative support for physical activity. This information can be used to prioritize advocacy efforts and identify ways for research to better inform policy. PMID:26104603

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

    PubMed

    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.

  2. Dipeptides Increase Functional Activity of Human Skin Fibroblasts.

    PubMed

    Malinin, V V; Durnova, A O; Polyakova, V O; Kvetnoi, I M

    2015-05-01

    We analyzed the effect of dipeptide Glu-Trp and isovaleroyl-Glu-Trp in concentrations of 0.2, 2 and 20 μg/ml and Actovegin preparation on functional activity of human skin fibroblasts. Dipeptides, especially Glu-Trp, produce a stimulating effect on human skin fibroblasts and their effect is equivalent to that of Actovegin. Dipeptides stimulate cell renewal processes by activating synthesis of Ki-67 and reducing expression of caspase-9 and enhance antioxidant function of the cells by stimulating the expression of Hsp-90 and inducible NO-synthase. These findings suggest that dipeptides are promising candidates for preparations stimulating reparative processes.

  3. Synergistic activity of BET protein antagonist-based combinations in mantle cell lymphoma cells sensitive or resistant to ibrutinib

    PubMed Central

    Sun, Baohua; Shah, Bhavin; Fiskus, Warren; Qi, Jun; Rajapakshe, Kimal; Coarfa, Cristian; Li, Li; Devaraj, Santhana G. T.; Sharma, Sunil; Zhang, Liang; Wang, Michael L.; Saenz, Dyana T.; Krieger, Stephanie; Bradner, James E.

    2015-01-01

    Mantle cell lymphoma (MCL) cells exhibit increased B-cell receptor and nuclear factor (NF)-κB activities. The bromodomain and extra-terminal (BET) protein bromodomain 4 is essential for the transcriptional activity of NF-κB. Here, we demonstrate that treatment with the BET protein bromodomain antagonist (BA) JQ1 attenuates MYC and cyclin-dependent kinase (CDK)4/6, inhibits the nuclear RelA levels and the expression of NF-κB target genes, including Bruton tyrosine kinase (BTK) in MCL cells. Although lowering the levels of the antiapoptotic B-cell lymphoma (BCL)2 family proteins, BA treatment induces the proapoptotic protein BIM and exerts dose-dependent lethality against cultured and primary MCL cells. Cotreatment with BA and the BTK inhibitor ibrutinib synergistically induces apoptosis of MCL cells. Compared with each agent alone, cotreatment with BA and ibrutinib markedly improved the median survival of mice engrafted with the MCL cells. BA treatment also induced apoptosis of the in vitro isolated, ibrutinib-resistant MCL cells, which overexpress CDK6, BCL2, Bcl-xL, XIAP, and AKT, but lack ibrutinib resistance-conferring BTK mutation. Cotreatment with BA and panobinostat (pan-histone deacetylase inhibitor) or palbociclib (CDK4/6 inhibitor) or ABT-199 (BCL2 antagonist) synergistically induced apoptosis of the ibrutinib-resistant MCL cells. These findings highlight and support further in vivo evaluation of the efficacy of the BA-based combinations with these agents against MCL, including ibrutinib-resistant MCL. PMID:26254443

  4. Increasing Pupil Physical Activity: A Comprehensive Professional Development Effort

    ERIC Educational Resources Information Center

    Kulinna, Pamela Hodges

    2012-01-01

    Study aim: To determine if pupil physical activity and Body Mass Index classifications maintained or improved after a one-year professional development program involving both classroom and physical education teachers. Guskey's model of teacher change guided this study. Material and methods: Indigenous children from ten schools (N = 320) in grades…

  5. Soil disturbance increases soil microbial enzymatic activity in arid ecoregion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Functional diversity of the soil microbial community is commonly used in the assessment of soil health as it relates to the activity of soil microflora involved in carbon cycling. Soil microbes in different microenvironments will have varying responses to different substrates, thus catabolic fingerp...

  6. Increasing Physical Activity of Children during School Recess

    ERIC Educational Resources Information Center

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

    2015-01-01

    Physical activity is crucial for children's health. Fitbit accelerometers were used to measure steps of 6 elementary students during recess. The intervention included reinforcement, self-monitoring, goal setting, and feedback. Steps taken during the intervention phase (M?=?1,956 steps) were 47% higher than in baseline (M?=?1,326 steps), and the…

  7. Somatosensory Anticipatory Alpha Activity Increases to Suppress Distracting Input

    ERIC Educational Resources Information Center

    Haegens, Saskia; Luther, Lisa; Jensen, Ole

    2012-01-01

    Effective processing of sensory input in daily life requires attentional selection and amplification of relevant input and, just as importantly, attenuation of irrelevant information. It has been proposed that top-down modulation of oscillatory alpha band activity (8-14 Hz) serves to allocate resources to various regions, depending on task…

  8. VERB [TM] Summer Scorecard: Increasing Tween Girls' Vigorous Physical Activity

    ERIC Educational Resources Information Center

    Alfonso, Moya L.; Thompson, Zachary; McDermott, Robert J.; Colquitt, Gavin; Jones, Jeffery A.; Bryant, Carol A.; Courtney, Anita H.; Davis, Jenna L.; Zhu, Yiliang

    2013-01-01

    Objective: We assessed changes in the frequency of self-reported physical activity (PA) among tween girls exposed and not exposed to the VERB [TM] Summer Scorecard (VSS) intervention in Lexington, Kentucky, during 2004, 2006, and 2007. Methods: Girls who reported 0-1 day per week of PA were classi?ed as having "little or no" PA. Girls who reported…

  9. Texting to increase physical activity in teens: Development & preliminary

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our purpose was to present formative research and preliminary results for a self-determination-theory (SDT)-based text messages to promote physical activity (PA) among teens. Thirty 14- to 17-year olds, stratified by gender and race/ethnicity (Black, Hispanic, White), were recruited to participate i...

  10. Diagnostic performance of increased prolidase activity in schizophrenia.

    PubMed

    Güneş, Mehmet; Bulut, Mahmut; Demir, Süleyman; İbiloğlu, Aslıhan Okan; Kaya, Mehmet Cemal; Atlı, Abdullah; Kaplan, İbrahim; Camkurt, Mehmet Akif; Sir, Aytekin

    2016-02-01

    We investigated whether prolidase activity has a diagnostic test value in schizophrenia and assessed the relation between prolidase activity and sociodemographic-clinical characteristics of patients with schizophrenia. Fifty patients with schizophrenia (diagnosed as schizophrenia according to DSM-V criteria) and 50 healthy volunteers were included in this study. Case and control groups had a similar distribution in age, sex, body mass index (BMI), and smoking status. Serum prolidase activity was measured in both groups and was determined to be significantly higher in the patient group (509.706±41.918) compared to the control group (335.4±13.6; t=6.231; p=0.0001). A cut-off point of 392.65U/L prolidase was determined for diagnostic measures from the plotted ROC curve. The area under the ROC curve was 1.000, which was significant (p<0.0001). Higher values were assigned as the disease state. Both positive predictive value (PPV) and negative predictive value (NPV) were 100% at the cut-off point of 392.650U/L. The prolidase levels of the control group were all below the cut-off point. There were no statistically significant differences between the two groups with regard to age, gender, or BMI (p>0.05), and no correlation was found between mean prolidase activity and age of onset of the disease, family history, disease duration, number of hospitalizations, subtypes of schizophrenia, PANSS scores or sub-scores, CGI-S scores, S-A scale scores, and the antipsychotic treatment (p>0.05). The results of this study indicate that serum prolidase activity may be a useful diagnostic test for schizophrenia; however, further studies are needed to verify this.

  11. Avian Reovirus Protein p17 Functions as a Nucleoporin Tpr Suppressor Leading to Activation of p53, p21 and PTEN and Inactivation of PI3K/AKT/mTOR and ERK Signaling Pathways.

    PubMed

    Huang, Wei-Ru; Chiu, Hung-Chuan; Liao, Tsai-Ling; Chuang, Kuo-Pin; Shih, Wing-Ling; Liu, Hung-Jen

    2015-01-01

    Avian reovirus (ARV) protein p17 has been shown to regulate cell cycle and autophagy by activation of p53/PTEN pathway; nevertheless, it is still unclear how p53 and PTEN are activated by p17. Here, we report for the first time that p17 functions as a nucleoporin Tpr suppressor that leads to p53 nuclear accumulation and consequently activates p53, p21, and PTEN. The nuclear localization signal (119IAAKRGRQLD128) of p17 has been identified for Tpr binding. This study has shown that Tpr suppression occurs by p17 interacting with Tpr and by reducing the transcription level of Tpr, which together inhibit Tpr function. In addition to upregulation of PTEN by activation of p53 pathway, this study also suggests that ARV protein p17 acts as a positive regulator of PTEN. ARV p17 stabilizes PTEN by stimulating phosphorylation of cytoplasmic PTEN and by elevating Rak-PTEN association to prevent it from E3 ligase NEDD4-1 targeting. To activate PTEN, p17 is able to promote β-arrestin-mediated PTEN translocation from the cytoplasm to the plasma membrane via a Rock-1-dependent manner. The accumulation of p53 in the nucleus induces the PTEN- and p21-mediated downregulation of cyclin D1 and CDK4. Furthermore, Tpr and CDK4 knockdown increased virus production in contrast to depletion of p53, PTEN, and LC3 reducing virus yield. Taken together, our data suggest that p17-mediated Tpr suppression positively regulates p53, PTEN, and p21 and negatively regulates PI3K/AKT/mTOR and ERK signaling pathways, both of which are beneficial for virus replication. PMID:26244501

  12. Avian Reovirus Protein p17 Functions as a Nucleoporin Tpr Suppressor Leading to Activation of p53, p21 and PTEN and Inactivation of PI3K/AKT/mTOR and ERK Signaling Pathways.

    PubMed

    Huang, Wei-Ru; Chiu, Hung-Chuan; Liao, Tsai-Ling; Chuang, Kuo-Pin; Shih, Wing-Ling; Liu, Hung-Jen

    2015-01-01

    Avian reovirus (ARV) protein p17 has been shown to regulate cell cycle and autophagy by activation of p53/PTEN pathway; nevertheless, it is still unclear how p53 and PTEN are activated by p17. Here, we report for the first time that p17 functions as a nucleoporin Tpr suppressor that leads to p53 nuclear accumulation and consequently activates p53, p21, and PTEN. The nuclear localization signal (119IAAKRGRQLD128) of p17 has been identified for Tpr binding. This study has shown that Tpr suppression occurs by p17 interacting with Tpr and by reducing the transcription level of Tpr, which together inhibit Tpr function. In addition to upregulation of PTEN by activation of p53 pathway, this study also suggests that ARV protein p17 acts as a positive regulator of PTEN. ARV p17 stabilizes PTEN by stimulating phosphorylation of cytoplasmic PTEN and by elevating Rak-PTEN association to prevent it from E3 ligase NEDD4-1 targeting. To activate PTEN, p17 is able to promote β-arrestin-mediated PTEN translocation from the cytoplasm to the plasma membrane via a Rock-1-dependent manner. The accumulation of p53 in the nucleus induces the PTEN- and p21-mediated downregulation of cyclin D1 and CDK4. Furthermore, Tpr and CDK4 knockdown increased virus production in contrast to depletion of p53, PTEN, and LC3 reducing virus yield. Taken together, our data suggest that p17-mediated Tpr suppression positively regulates p53, PTEN, and p21 and negatively regulates PI3K/AKT/mTOR and ERK signaling pathways, both of which are beneficial for virus replication.

  13. Increased prevalence of late stage T cell activation antigen (VLA-1) in active juvenile chronic arthritis.

    PubMed Central

    Odum, N; Morling, N; Platz, P; Hofmann, B; Ryder, L P; Heilmann, C; Pedersen, F K; Nielsen, L P; Friis, J; Svejgaard, A

    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 patients with active juvenile chronic arthritis (JCA), 10 patients with JCA in remission, and 11 age matched, healthy controls. In addition, the distribution of T 'helper/inducer' (CD4+), T 'suppressor/inducer' (CD4+, Leu8+), T 'suppressor/cytotoxic' (CD8+), and 'natural killer' (NK) cells (CD16+) was studied. Twenty patients and six controls were investigated for the capability to stimulate alloreactivated primed lymphocytes. The prevalence of VLA-1 positive, large cells was significantly increased to 5% (median value) in active JCA as compared with JCA in remission (2%, p less than 0.05) and controls (1%, p less than 0.05), whereas no significant difference between JCA in remission and controls was observed. Except for two patients with active JCA, less than 1% IL2 receptor bearing cells were found in patients with JCA and controls. No significant difference in the prevalence and expression of the various HLA class II antigens was observed between the groups. Similarly, no significant differences in stimulatory capability in secondary mixed lymphocyte culture (MLC) were seen. The distribution of T helper/inducer (CD4+), T suppressor/cytotoxic (CD8+), and NK cells was similar in active JCA, JCA in remission, and controls. The prevalence of T suppressor/inducer (CD4+,Leu8+) cells was higher in remission JCA (17%) than in active JCA (11%) and controls (10%). This increase, however, did not reach statistical significance. In conclusion, late stage but not early stage T cell activation antigens were increased in patients with active JCA as compared with patients with JCA in remission and control, whereas some patients in remission had an increased prevalence of T suppressor

  14. T Lymphocyte Activation Threshold is Increased in Reduced Gravity

    NASA Technical Reports Server (NTRS)

    Adams, Charley L.; Gonzalez, M.; Sams, C. F.

    2000-01-01

    There have been substantial advances in molecular and cellular biology that have provided new insight into the biochemical and genetic basis of lymphocyte recognition, activation and expression of distinct functional phenotypes. It has now become evident that for both T and B cells, stimuli delivered through their receptors can result in either clonal expansion or apoptosis. In the case of T cells, clonal expansion of helper cells is accompanied by differentiation into two major functional subsets which regulate the immune response. The pathways between the membrane and the nucleus and their molecular components are an area of very active investigation. This meeting will draw together scientists working on diverse aspects of this problem, including receptor ligand interactions, intracellular pathways that transmit receptor mediated signals and the effect of such signal transduction pathways on gene regulation. The aim of this meeting is to integrate the information from these various experimental approaches into a new synthesis and molecular explanation of T cell activation, differentiation and death.

  15. Increased physical activity has a greater effect than reduced energy intake on lifestyle modification-induced increases in testosterone

    PubMed Central

    Kumagai, Hiroshi; Zempo-Miyaki, Asako; Yoshikawa, Toru; Tsujimoto, Takehiko; Tanaka, Kiyoji; Maeda, Seiji

    2016-01-01

    Obesity has reached epidemic proportions worldwide. Obesity results in reduced serum testosterone levels, which causes many disorders in men. Lifestyle modifications (increased physical activity and calorie restriction) can increase serum testosterone levels. However, it is unknown whether increased physical activity or calorie restriction during lifestyle modifications has a greater effects on serum testosterone levels. Forty-one overweight and obese men completed a 12-week lifestyle modification program (aerobic exercise training and calorie restriction). We measured serum testosterone levels, the number of steps, and the total energy intake. We divided participants into two groups based on the median change in the number of steps (high or low physical activities) or that in calorie restriction (high or low calorie restrictions). After the program, serum testosterone levels were significantly increased. Serum testosterone levels in the high physical activity group were significantly higher than those in the low activity group. This effect was not observed between the groups based on calorie restriction levels. We found a significant positive correlation between the changes in serum testosterone levels and the number of steps. Our results suggested that an increase in physical activity greatly affected the increased serum testosterone levels in overweight and obese men during lifestyle modification. PMID:26798202

  16. Density increase due to active feedback in mirror machine

    NASA Astrophysics Data System (ADS)

    Seemann, Omri; Be'Ery, Ilan

    2014-10-01

    Mirror machines are one of the schemes for future fusion systems. Its main drawbacks are the flute instability and being open ended which results in plasma losses. A feedback system is used to stabilize the flute instability in a table top mirror machine with a continuous plasma source and RF heating. Under certain source density and temperature conditions, although the plasma was stabilized, plasma density increase was not measured. After decreasing the source density and increasing the temperature, Plasma density increase was achieved. It is theorized that these results are due to transition of the plasma main loss mechanism from collision dominated to instability dominated. In the former, the main density loss is through diffusion and In the latter, it is through flute instability which drives the plasma to the edge of the vacuum chamber. Future research directions are discussed for a planned machine which should achieve higher temperatures and better diagnostic capabilities. The research will focus on magnetic actuators and passive RF stabilization.

  17. Digoxin is a selective modifier increasing platinum drug anticancer activity.

    PubMed

    Bogush, T A; Chernov, V Yu; Dudko, E A; Shprakh, Z S; Bogush, E A; Polotsky, B E; Tjulandin, S A; Davydov, M I

    2016-05-01

    Using the model of breast cancer Ehrlich ascites tumor in mice, we showed that a sigle intraperitoneal injection of cardiac glycoside digoxin 1 h before the intraperitoneal injection of cisplatin increased the anticancer effect of the cytostatic drug more than twice when recalculated for the dose. It is assumed that the modifying effect of digoxin is determined by the direct inhibition of glycolysis in tumor cells. Taking into account the design of the study, we consider promising the clinical evaluation of the effectiveness of digoxin as a modifier of cisplatin efficiency in intracavitary therapy of ascites cancers with pleural and abdominal dissenmination. PMID:27417726

  18. Molecular evidence for increased antitumor activity of gemcitabine in combination with a cyclin-dependent kinase inhibitor, P276-00 in pancreatic cancers

    PubMed Central

    2012-01-01

    Background P276-00 is a novel cyclin-dependent kinase inhibitor currently in Phase II clinical trials. Gemcitabine is a standard of care for the treatment of pancreatic cancer. The present study investigated the effect of the combination of P276-00 and gemcitabine in five pancreatic cancer cell lines. Methods Cytotoxic activity was evaluated by Propidium Iodide assay. Cell cycle and apoptosis was analyzed by flow cytometry. Genes and proteins known to inhibit apoptosis and contribute to chemoresistance were analysed using western blot analysis and RT-PCR. In vivo efficacy was studied in PANC-1 xenograft model. Results The combination of gemcitabine followed by P276-00 was found to be highly to weakly synergistic in various pancreatic cancer cell lines as assessed by the combination index. Enhancement of apoptosis in PANC-1 cells and decrease in the antiapoptotic protein Bcl-2 and survivin was seen. P276-00 potentiated the gemcitabine-induced cytotoxicity by modulation of proteins involved in chemoresistance to gemcitabine and cell cycle viz. antiapoptotic proteins p8 and cox-2, proapoptotic protein BNIP3 and cell cycle related proteins Cdk4 and cyclin D1. The above results could explain the novel mechanisms of action of the combination therapy. We also show here that gemcitabine in combination with P276-00 is much more effective as an antitumor agent compared with either agent alone in the PANC-1 xenograft tumor model in SCID mice. Conclusions The chemosensitzation of pancreatic tumors to gemcitabine would likely be an important and novel strategy for treatment of pancreatic cancer and enable the use of lower and safer concentrations, to pave the way for a more effective treatment in this devastating disease. Phase IIb clinical trials of P276-00 in combination with gemcitabine in pancreatic cancer patients are ongoing. PMID:22873289

  19. Biotin uptake into human peripheral blood mononuclear cells increases early in the cell cycle, increasing carboxylase activities.

    PubMed

    Stanley, J Steven; Mock, Donald M; Griffin, Jacob B; Zempleni, Janos

    2002-07-01

    Cells respond to proliferation with increased accumulation of biotin, suggesting that proliferation enhances biotin demand. Here we determined whether peripheral blood mononuclear cells (PBMC) increase biotin uptake at specific phases of the cell cycle, and whether biotin is utilized to increase biotinylation of carboxylases. Biotin uptake was quantified in human PBMC that were arrested chemically at specific phases of the cell cycle, i.e., biotin uptake increased in the G1 phase of the cycle [658 +/- 574 amol biotin/(10(6) cells x 30 min)] and remained increased during phases S, G2, and M compared with quiescent controls [200 +/- 62 amol biotin/(10(6) cells x 30 min)]. The abundance of the sodium-dependent multivitamin transporter (SMVT, which transports biotin) was similar at all phases of the cell cycle, suggesting that transporters other than SMVT or splicing variants of SMVT may account for the increased biotin uptake observed in proliferating cells. Activities of biotin-dependent 3-methylcrotonyl-CoA carboxylase and propionyl-CoA carboxylase were up to two times greater in proliferating PBMC compared with controls. The abundance of mRNA encoding 3-methylcrotonyl-CoA carboxylase and propionyl-CoA carboxylase paralleled carboxylase activities, suggesting that PBMC respond to proliferation with increased expression of genes encoding carboxylases. Similarly, expression of the gene encoding holocarboxylase synthetase (which catalyzes binding of biotin to carboxylases) increased in response to proliferation, suggesting that cellular capacity to biotinylate carboxylases was increased. In summary, these findings suggest that PBMC respond to proliferation with increased biotin uptake early in the cell cycle, and that biotin is utilized to increase activities of two of the four biotin-requiring carboxylases.

  20. Development of a universal approach to increase physical activity among adolescents: the GoActive intervention

    PubMed Central

    Corder, Kirsten; Schiff, Annie; Kesten, Joanna M; van Sluijs, Esther M F

    2015-01-01

    Objectives To develop a physical activity (PA) promotion intervention for adolescents using a process addressing gaps in the literature while considering participant engagement. We describe the initial development stages; (1) existing evidence, (2) large scale opinion gathering and (3) developmental qualitative work, aiming (A) to gain insight into how to increase PA among the whole of year 9 (13–14 years-old) by identifying elements for intervention inclusion (B) to improve participant engagement and (C) to develop and refine programme design. Methods Relevant systematic reviews and longitudinal analyses of change were examined. An intervention was developed iteratively with older adolescents (17.3±0.5 years) and teachers, using the following process: (1) focus groups with (A) adolescents (n=26) and (B) teachers (n=4); (2) individual interviews (n=5) with inactive and shy adolescents focusing on engagement and programme acceptability. Qualitative data were analysed thematically. Results Limitations of the existing literature include lack of evidence on whole population approaches, limited adolescent involvement in intervention development, and poor participant engagement. Qualitative work suggested six themes which may encourage adolescents to do more PA; choice, novelty, mentorship, competition, rewards and flexibility. Teachers discussed time pressures as a barrier to encouraging adolescent PA and suggested between-class competition as a strategy. GoActive aims to increase PA through increased peer support, self-efficacy, group cohesion, self-esteem and friendship quality, and is implemented in tutor groups using a student-led tiered-leadership system. Conclusions We have followed an evidence-based iterative approach to translate existing evidence into an adolescent PA promotion intervention. Qualitative work with adolescents and teachers supported intervention design and addressed lack of engagement with health promotion programmes within this age group

  1. Increasing discordant antioxidant protein levels and enzymatic activities contribute to increasing redox imbalance observed during human prostate cancer progression

    PubMed Central

    Chaiswing, Luksana; Zhong, Weixiong; Oberley, Terry D.

    2014-01-01

    A metabolomics study demonstrated a decrease in glutathione and an increase in cysteine (Cys) levels in human prostate cancer (PCa) tissues as Gleason scores increased, indicating redox imbalance with PCa progression. These results were extended in the present study by analyzing redox state of the protein thioredoxin 1 (Trx1) and sulfinylation (SO3) of peroxiredoxins (Prxs) (PrxsSO3) in PCa tissues and cell lines. Lysates of paired human PCa tissues with varying degree of aggressiveness and adjacent benign (BN) tissues were used for analysis. Redox western blot analysis of Trx1 demonstrated low levels of reduced and high levels of oxidized Trx1 (functional and non-functional, respectively) in high grade PCa (Gleason scores 4+4 to 4+5) in comparison to intermediate grade PCa (Gleason scores 3+3 to 3+4) or BN tissues. PrxsSO3 were increased in high grade PCa. Oxidized Trx1 and PrxsSO3 are indicators of oxidative stress. To study whether redox imbalance may potentially affect enzyme activities of antioxidant proteins (AP), we determined levels of selected AP in PCa tissues by western blot analysis and found that mitochondrial manganese superoxide dismutase (MnSOD), Prx 3, and Trx1 were increased in high grade PCa tissues when compared with BN tissues. Enzyme activities of MnSOD in high grade PCa tissues were significantly increased but at a lower magnitude when compared with the levels of MnSOD protein (0.5 folds vs. 2 folds increase). Trx1 activity was not changed in high grade PCa tissues despite a large increase in Trx1 protein expression. Further studies demonstrated a significant increase in posttranslational modifications of tyrosine and lysine residues in MnSOD protein and oxidation of Cys at active site (Cys 32 and Cys 35) and regulatory site (Cys 62 and Cys 69) of Trx1 in high grade PCa compared to BN tissues. These discordant changes between protein levels and enzyme activities are consistent with protein inactivation by redox imbalance and

  2. Playground Designs to Increase Physical Activity Levels during School Recess: A Systematic Review

    ERIC Educational Resources Information Center

    Escalante, Yolanda; García-Hermoso, Antonio; Backx, Karianne; Saavedra, Jose M.

    2014-01-01

    School recess provides a major opportunity to increase children's physical activity levels. Various studies have described strategies to increase levels of physical activity. The purpose of this systematic review is therefore to examine the interventions proposed as forms of increasing children's physical activity levels during recess. A…

  3. Increased Biomass Yield of Lactococcus lactis by Reduced Overconsumption of Amino Acids and Increased Catalytic Activities of Enzymes

    PubMed Central

    Adamberg, Kaarel; Seiman, Andrus; Vilu, Raivo

    2012-01-01

    Steady state cultivation and multidimensional data analysis (metabolic fluxes, absolute proteome, and transcriptome) are used to identify parameters that control the increase in biomass yield of Lactococcus lactis from 0.10 to 0.12 C-mol C-mol−1 with an increase in specific growth rate by 5 times from 0.1 to 0.5 h−1. Reorganization of amino acid consumption was expressed by the inactivation of the arginine deiminase pathway at a specific growth rate of 0.35 h−1 followed by reduced over-consumption of pyruvate directed amino acids (asparagine, serine, threonine, alanine and cysteine) until almost all consumed amino acids were used only for protein synthesis at maximal specific growth rate. This balanced growth was characterized by a high glycolytic flux carrying up to 87% of the carbon flow and only amino acids that relate to nucleotide synthesis (glutamine, serine and asparagine) were consumed in higher amounts than required for cellular protein synthesis. Changes in the proteome were minor (mainly increase in the translation apparatus). Instead, the apparent catalytic activities of enzymes and ribosomes increased by 3.5 times (0.1 vs 0.5 h−1). The apparent catalytic activities of glycolytic enzymes and ribosomal proteins were seen to follow this regulation pattern while those of enzymes involved in nucleotide metabolism increased more than the specific growth rate (over 5.5 times). Nucleotide synthesis formed the most abundant biomonomer synthetic pathway in the cells with an expenditure of 6% from the total ATP required for biosynthesis. Due to the increase in apparent catalytic activity, ribosome translation was more efficient at higher growth rates as evidenced by a decrease of protein to mRNA ratios. All these effects resulted in a 30% decrease of calculated ATP spilling (0.1 vs 0.5 h−1). Our results show that bioprocesses can be made more efficient (using a balanced metabolism) by varying the growth conditions. PMID:23133574

  4. Increased hepcidin in transferrin-treated thalassemic mice correlates with increased liver BMP2 expression and decreased hepatocyte ERK activation

    PubMed Central

    Chen, Huiyong; Choesang, Tenzin; Li, Huihui; Sun, Shuming; Pham, Petra; Bao, Weili; Feola, Maria; Westerman, Mark; Li, Guiyuan; Follenzi, Antonia; Blanc, Lionel; Rivella, Stefano; Fleming, Robert E.; Ginzburg, Yelena Z.

    2016-01-01

    Iron overload results in significant morbidity and mortality in β-thalassemic patients. Insufficient hepcidin is implicated in parenchymal iron overload in β-thalassemia and approaches to increase hepcidin have therapeutic potential. We have previously shown that exogenous apo-transferrin markedly ameliorates ineffective erythropoiesis and increases hepcidin expression in Hbbth1/th1 (thalassemic) mice. We utilize in vivo and in vitro systems to investigate effects of exogenous apo-transferrin on Smad and ERK1/2 signaling, pathways that participate in hepcidin regulation. Our results demonstrate that apo-transferrin increases hepcidin expression in vivo despite decreased circulating and parenchymal iron concentrations and unchanged liver Bmp6 mRNA expression in thalassemic mice. Hepatocytes from apo-transferrin-treated mice demonstrate decreased ERK1/2 pathway and increased serum BMP2 concentration and hepatocyte BMP2 expression. Furthermore, hepatocyte ERK1/2 phosphorylation is enhanced by neutralizing anti-BMP2/4 antibodies and suppressed in vitro in a dose-dependent manner by BMP2, resulting in converse effects on hepcidin expression, and hepatocytes treated with MEK/ERK1/2 inhibitor U0126 in combination with BMP2 exhibit an additive increase in hepcidin expression. Lastly, bone marrow erythroferrone expression is normalized in apo-transferrin treated thalassemic mice but increased in apo-transferrin injected wild-type mice. These findings suggest that increased hepcidin expression after exogenous apo-transferrin is in part independent of erythroferrone and support a model in which apo-transferrin treatment in thalassemic mice increases BMP2 expression in the liver and other organs, decreases hepatocellular ERK1/2 activation, and increases nuclear Smad to increase hepcidin expression in hepatocytes. PMID:26635037

  5. [Adaptive increase of serotonergic system activity in tissues of half-migratory and migratory fish at increased water salinity].

    PubMed

    2013-01-01

    The article deals with studies of the serotoninergic system activity in different tissues of half-migratory fish--the Caspian roach (Rutilus rutilus caspicus) and carpbream (Abramis brama orientalis)--and migratory fish--shemaya (Chalcalburnus chalcoides) caught in fresh and brackish waters, as well as in the common carp (Cyprinus carpio L.) tissues under effect of brackish water in model experiments. Using indirect solid-phase ELISA-test, the serotoninergic system activity was evaluated by measuring in the tissues of the studied fish the serotonin-modulated anticonsolidation protein (SMAP) which is in linear relationship with serotonin level. There was found a significant elevation of the SMAP levels in the brain of the Caspian roach, carpbream, shemaya, and the common carp under effect of increased water sainity. The revealed increase of the SMAP content in brains of the Caspian roach, carpbream, shemaya, and the common carp under action of increased water salinity reflects the corresponding elevated activity of the serotoninergic system and indicates involvement of adaptive readjustments in the animals' body. PMID:25509051

  6. [Adaptive increase of serotonergic system activity in tissues of half-migratory and migratory fish at increased water salinity].

    PubMed

    Mustafaev, N J; Mekhtiev, A A

    2013-01-01

    The article deals with studies of the serotoninergic system activity in different tissues of half-migratory fish--the Caspian roach (Rutilus rutilus caspicus) and carpbream (Abramis brama orientalis)--and migratory fish--shemaya (Chalcalburnus chalcoides) caught in fresh and brackish waters, as well as in the common carp (Cyprinus carpio L.) tissues under effect of brackish water in model experiments. Using indirect solid-phase ELISA-test, the serotoninergic system activity was evaluated by measuring in the tissues of the studied fish the serotonin-modulated anticonsolidation protein (SMAP) which is in linear relationship with serotonin level. There was found a significant elevation of the SMAP levels in the brain of the Caspian roach, carpbream, shemaya, and the common carp under effect of increased water sainity. The revealed increase of the SMAP content in brains of the Caspian roach, carpbream, shemaya, and the common carp under action of increased water salinity reflects the corresponding elevated activity of the serotoninergic system and indicates involvement of adaptive readjustments in the animals' body. PMID:25490850

  7. Community-based exergaming program increases physical activity and perceived wellness in older adults.

    PubMed

    Strand, Kara A; Francis, Sarah L; Margrett, Jennifer A; Franke, Warren D; Peterson, Marc J

    2014-07-01

    Exergaming may be an effective strategy to increase physical activity participation among rural older adults. This pilot project examined the effects of a 24-wk exergaming and wellness program (8 wk onsite exergaming, 16-wk wellness newsletter intervention) on physical activity participation and subjective health in 46 rural older adults. Sociodemographic data and self-reported physical activity were analyzed using descriptive statistics and Cochran's Q, respectively. Qualitative data were reviewed, categorized on the basis of theme, and tabulated for frequency. Increased physical activity and perceived health were the most reported perceived positive changes. Significant increases in physical activity participation were maintained among participants who were physically inactive at baseline. Best-liked features were physical activity and socialization. Findings suggest that this pilot exergaming and wellness program is effective in increasing physical activity in sedentary rural older adults, increasing socialization, and increasing subjective physical health among rural older adults.

  8. Vertebrate blood cell volume increases with temperature: implications for aerobic activity.

    PubMed

    Gillooly, James F; Zenil-Ferguson, Rosana

    2014-01-01

    Aerobic activity levels increase with body temperature across vertebrates. Differences in these levels, from highly active to sedentary, are reflected in their ecology and behavior. Yet, the changes in the cardiovascular system that allow for greater oxygen supply at higher temperatures, and thus greater aerobic activity, remain unclear. Here we show that the total volume of red blood cells in the body increases exponentially with temperature across vertebrates, after controlling for effects of body size and taxonomy. These changes are accompanied by increases in relative heart mass, an indicator of aerobic activity. The results point to one way vertebrates may increase oxygen supply to meet the demands of greater activity at higher temperatures.

  9. Promising School-Based Strategies and Intervention Guidelines to Increase Physical Activity of Adolescents

    ERIC Educational Resources Information Center

    Pardo, Berta Murillo; Bengoechea, Enrique Garcia; Lanaspa, Eduardo Generelo; Bush, Paula L.; Casterad, Javier Zaragoza; Clemente, Jose A. Julian; Gonzalez, Luis Garcia

    2013-01-01

    This narrative review describes the available scientific evidence regarding promising school-based strategies to increase physical activity of adolescents. We conducted a literature search for studies published up to 2011, regarding adolescent physical activity intervention studies that resulted in increased physical activity (regardless of…

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Cell cycle arrest mediated by the MEK/mitogen-activated protein kinase pathway

    PubMed Central

    Pumiglia, Kevin M.; Decker, Stuart J.

    1997-01-01

    The mitogen-activated protein kinase (MAPK) cascade plays a crucial role in the transduction of extracellular signals into responses governing growth and differentiation. The effects of a specific inhibitor of the MAPK kinase (MEK)/MAPK pathway (PD98059) on nerve growth factor (NGF)-induced growth arrest and inhibition of cell cycle-dependent kinases (CDKs) have been examined. Treatment of NIH 3T3 cells expressing TRKA with PD98059 dramatically reversed the complete inhibition of growth of these cells caused by NGF. PD98059 also blocked the ability of NGF to inhibit the activities of CDK4 and CDK2, while partially preventing NGF induction of p21Cip1/WAF1. To independently evaluate the involvement of the MEK/MAPK pathway in growth arrest, an inducible activated form of the Raf-1 protooncogene (ΔRAF-1:ER) was expressed in these cells. Activation of ΔRAF-1:ER resulted in a prolonged increase in MAPK activity and growth arrest of these cells, with concomitant induction of p21Cip1/WAF1 and inhibition of CDK2 activity. These effects of ΔRAF-1:ER activation were all reversed by treatment of cells with PD98059. These data indicate that in addition to functioning as a positive effector of growth, stimulation of the MEK/MAPK pathway can result in an inhibition of CDK activity and cell cycle arrest. PMID:9012803

  12. Increased von Willebrand factor levels in patients with systemic lupus erythematosus reflect inflammation rather than increased propensity for platelet activation

    PubMed Central

    Raymond, Warren D; Eilertsen, Gro Østli

    2016-01-01

    Background von Willebrand factor (VWF) is involved in platelet plug formation and protein transport. Increased VWF levels in systemic lupus erythematous (SLE) are considered risk factors for vascular events. VWF protein levels, however, do not accurately reflect its platelet-aggregating function, which has not been examined in SLE. Methods Cross-sectional study with clinical and laboratory data obtained in patients with SLE (n=92) from a regional lupus registry. VWF function was determined by ristocetin-induced platelet aggregation (VWF ristocetin cofactor, VWF:RCo) and VWF levels by turbidimetric assay (VWF antigen, VWF:Ag). The platelet-aggregating activity per VWF unit was estimated by the VWF RCo/Ag ratio. Healthy controls served as comparators and associations were evaluated by non-parametric methods. Results VWF:Ag (142% vs 107%, p=0.001) and VWF:RCo levels (123% vs 78%, p<0.041) were increased in patients with SLE, but VWF RCo/Ag ratio was similar as in controls (0.83 vs 0.82, p=0.8). VWF:Ag levels were higher in patients experiencing serositis but unrelated to other manifestations, thrombotic disease, Systemic Lupus Erythematous Disease Activity Index 2000 or Systemic Lupus International Collaborative Clinics-Damage Index. VWF:Ag levels correlated significantly with VWF:RCo levels (Rs 0.8, p<0.001), erythrocyte sedimentation rate (ESR) (Rs 0.32, p<0.01), anti-dsDNA Ab (Rs 0.27, p<0.01), total IgG (Rs 0.33 p<0.01), fibrinogen (Rs 0.28, p<0.01) and ceruloplasmin (Rs 0.367, p<0.01) levels. VWF:RCo levels were not related to clinical findings but were correlated with ESR, anti-dsDNA and transferrin levels. No serological associations existed for VWF RCo/Ag ratio (all p>0.2). Conclusions In this SLE cohort, VWF:Ag behaved similarly to acute-phase reactants, but VWF:Ag increases were not matched by increases in functional activity per unit of VWF. Thus, more VWF did not increase the propensity for platelet aggregation in SLE.

  13. Increased von Willebrand factor levels in patients with systemic lupus erythematosus reflect inflammation rather than increased propensity for platelet activation

    PubMed Central

    Raymond, Warren D; Eilertsen, Gro Østli

    2016-01-01

    Background von Willebrand factor (VWF) is involved in platelet plug formation and protein transport. Increased VWF levels in systemic lupus erythematous (SLE) are considered risk factors for vascular events. VWF protein levels, however, do not accurately reflect its platelet-aggregating function, which has not been examined in SLE. Methods Cross-sectional study with clinical and laboratory data obtained in patients with SLE (n=92) from a regional lupus registry. VWF function was determined by ristocetin-induced platelet aggregation (VWF ristocetin cofactor, VWF:RCo) and VWF levels by turbidimetric assay (VWF antigen, VWF:Ag). The platelet-aggregating activity per VWF unit was estimated by the VWF RCo/Ag ratio. Healthy controls served as comparators and associations were evaluated by non-parametric methods. Results VWF:Ag (142% vs 107%, p=0.001) and VWF:RCo levels (123% vs 78%, p<0.041) were increased in patients with SLE, but VWF RCo/Ag ratio was similar as in controls (0.83 vs 0.82, p=0.8). VWF:Ag levels were higher in patients experiencing serositis but unrelated to other manifestations, thrombotic disease, Systemic Lupus Erythematous Disease Activity Index 2000 or Systemic Lupus International Collaborative Clinics-Damage Index. VWF:Ag levels correlated significantly with VWF:RCo levels (Rs 0.8, p<0.001), erythrocyte sedimentation rate (ESR) (Rs 0.32, p<0.01), anti-dsDNA Ab (Rs 0.27, p<0.01), total IgG (Rs 0.33 p<0.01), fibrinogen (Rs 0.28, p<0.01) and ceruloplasmin (Rs 0.367, p<0.01) levels. VWF:RCo levels were not related to clinical findings but were correlated with ESR, anti-dsDNA and transferrin levels. No serological associations existed for VWF RCo/Ag ratio (all p>0.2). Conclusions In this SLE cohort, VWF:Ag behaved similarly to acute-phase reactants, but VWF:Ag increases were not matched by increases in functional activity per unit of VWF. Thus, more VWF did not increase the propensity for platelet aggregation in SLE. PMID:27651919

  14. Increasing Physical Activity during the School Day through Physical Activity Classes: Implications for Physical Educators

    ERIC Educational Resources Information Center

    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…

  15. Evidence-Based Practice Guideline: Increasing Physical Activity in Schools--Kindergarten through 8th Grade

    ERIC Educational Resources Information Center

    Bagby, Karen; Adams, Susan

    2007-01-01

    Because of the growing obesity epidemic across all age groups in the United States, interventions to increase physical activity and reduce sedentary behaviors have become a priority. Evidence is growing that interventions to increase physical activity and reduce sedentary behaviors have positive results and are generally inexpensive to implement.…

  16. Men on the Move: A Pilot Program to Increase Physical Activity among African American Men

    ERIC Educational Resources Information Center

    Griffith, Derek M.; Allen, Julie Ober; Johnson-Lawrence, Vicki; Langford, Aisha

    2014-01-01

    Despite the important contribution increasing physical activity levels may play in reducing chronic disease morbidity and mortality, there is a paucity of interventions and research indicating how to improve physical activity levels in African American men. "Men on the Move" was a pilot study to increase African American men's…

  17. Decreasing Stereotypy in Preschoolers with Autism Spectrum Disorder: The Role of Increased Physical Activity and Function

    ERIC Educational Resources Information Center

    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…

  18. Increasing Activity Attendance and Engagement in Individuals with Dementia Using Descriptive Prompts

    ERIC Educational Resources Information Center

    Brenske, Shasta; Rudrud, Eric H.; Schulze, Kimberly A.; Rapp, John T.

    2008-01-01

    The effects of providing descriptive prompts to increase activity attendance and engagement in 6 individuals with dementia were evaluated using a reversal design. The results showed that providing descriptive prompts increased activity attendance and engagement for all participants. The results support the use of antecedent interventions for…

  19. 26 CFR 1.280C-4 - Credit for increasing research activities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 3 2011-04-01 2011-04-01 false Credit for increasing research activities. 1... increasing research activities. (a) In general. The election under section 280C(c)(3) to have the provisions... 41(a) determined by the method provided in section 280C(c)(3)(B) on an original return for...

  20. Use of a lag differential reinforcement contingency to increase varied selections of classroom activities.

    PubMed

    Cammilleri, Anthony P; Hanley, Gregory P

    2005-01-01

    The present study evaluated the effects of a lag differential reinforcement contingency on 2 students' activity selections using reversal designs. Results showed that the lag contingency was responsible for promoting increased novel selections, engagement in diverse activities, and greater progress with respect to programmed academic activities.

  1. Male Adolescents' Reasons for Participating in Physical Activity, Barriers to Participation, and Suggestions for Increasing Participation

    ERIC Educational Resources Information Center

    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,…

  2. Use of an open-loop system to increase physical activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the effectiveness of an open-loop system that reinforces physical activity with TV watching to increase children’s physical activity. Non-overweight, sedentary boys and girls (8-12 y) were randomized to a group that received feedback of activity counts + reinforcement for physic...

  3. Texting to increase physical activity among teenagers (TXT Me!): Rationale, design, and methods proposal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. Use of a Lag Differential Reinforcement Contingency to Increase Varied Selections of Classroom Activities

    ERIC Educational Resources Information Center

    Cammilleri, Anthony P.; Hanley, Gregory P.

    2005-01-01

    The present study evaluated the effects of a lag differential reinforcement contingency on 2 students' activity selections using reversal designs. Results showed that the lag contingency was responsible for promoting increased novel selections, engagement in diverse activities, and greater progress with respect to programmed academic activities.

  5. Decreased fibrinolytic activity and increased platelet function in hypertension. Possible influence of calcium antagonism.

    PubMed

    Gleerup, G; Winther, K

    1991-02-01

    Twelve patients with mild hypertension were compared, after 14 days of placebo, with an age- and gender-matched group of 12 healthy volunteers for platelet aggregability and fibrinolytic activity. Following this, 10 of the 12 hypertensives were treated with the calcium antagonist isradipine for 12 months. Blood was drawn for determinations of platelet aggregation and fibrinolytic activity after two weeks and 12 months of treatment. Platelet aggregation tended to increase in the hypertensives compared with controls, indicated by a lowering of the adenosine diphosphate (ADP) threshold value for irreversible aggregation. Tissue-plasminogen activator (t-PA) activity was significantly decreased in hypertensives compared to controls (P less than .05). During therapy, platelet aggregation decreased and t-PA activity increased (P less than .05). The present data suggest that fibrinolytic activity is decreased and platelet aggregation increased in mild hypertension. Besides the blood pressure-lowering effect, isradipine may protect against thromboembolic diseases by modifying platelet function and fibrinolytic activity.

  6. INCREASED ENDOCRINE ACTIVITY OF XENOBIOTIC CHEMICALS AS MEDIATED BY METABOLIC ACTIVATION

    EPA Science Inventory

    This research is part of an effort to develop in vitro assays and QSARs applicable to untested chemicals on EPA inventories through study of estrogen receptor (ER) binding and estrogen mediated gene expression in fish. The current effort investigates metabolic activation of chemi...

  7. Feasibility and Effects of Short Activity Breaks for Increasing Preschool-Age Children's Physical Activity Levels

    ERIC Educational Resources Information Center

    Alhassan, Sofiya; Nwaokelemeh, Ogechi; Mendoza, Albert; Shitole, Sanyog; Puleo, Elaine; Pfeiffer, Karin A.; Whitt-Glover, Melicia C.

    2016-01-01

    Background: We examined the effects of short bouts of structured physical activity (SBS-PA) implemented within the classroom setting as part of designated gross-motor playtime on preschoolers PA. Methods: Preschools were randomized to SBS-PA (centers, N = 5; participants, N = 141) or unstructured free playtime (UPA) (centers, N = 5; participants,…

  8. Vertebrate blood cell volume increases with temperature: implications for aerobic activity

    PubMed Central

    Zenil-Ferguson, Rosana

    2014-01-01

    Aerobic activity levels increase with body temperature across vertebrates. Differences in these levels, from highly active to sedentary, are reflected in their ecology and behavior. Yet, the changes in the cardiovascular system that allow for greater oxygen supply at higher temperatures, and thus greater aerobic activity, remain unclear. Here we show that the total volume of red blood cells in the body increases exponentially with temperature across vertebrates, after controlling for effects of body size and taxonomy. These changes are accompanied by increases in relative heart mass, an indicator of aerobic activity. The results point to one way vertebrates may increase oxygen supply to meet the demands of greater activity at higher temperatures. PMID:24765580

  9. MAP kinase activity increases during mitosis in early sea urchin embryos.

    PubMed

    Philipova, R; Whitaker, M

    1998-09-01

    A MBP kinase activity increases at mitosis during the first two embryonic cell cycles of the sea urchin embryo. The activity profile of the MBP kinase is the same both in whole cell extracts and after immunoprecipitation with an anti-MAP kinase antibody (2199). An in-gel assay of MBP activity also shows the same activity profile. The activity is associated with the 44 kDa protein that cross-reacts with anti-MAP kinase antibodies. The 44 kDa protein shows cross-reactivity to anti-phosphotyrosine and MAP kinase-directed anti-phosphotyrosine/phosphothreonine antibodies at the times that MBP kinase activity is high. The 2199 antibody co-precipitates some histone H1 kinase activity, but the MBP kinase activity cannot be accounted for by histone H1 kinase-dependent phosphorylation of MBP. The MAP kinase 2199 antibody was used to purify the MBP kinase activity. Peptide sequencing after partial digestion shows the protein to be homologous to MAP kinases from other species. These data demonstrate that MAP kinase activation during nuclear division is not confined to meiosis, but also occurs during mitotic cell cycles. MAP kinase activity in immunoprecipitates also increases immediately after fertilization, which in the sea urchin egg occurs at interphase of the cell cycle. Treating unfertilized eggs with the calcium ionophore A23187 stimulates the increase in MAP kinase activity, demonstrating that a calcium signal can activate MAP kinase and suggesting that the activation of MAP kinase at fertilization is due to the fertilization-induced increase in cytoplasmic free calcium concentration. This signalling pathway must differ from the pathway responsible for calcium-induced inactivation of MAP kinase activity that is found in eggs that are fertilized in meiotic metaphase. PMID:9701549

  10. Geomagnetic activity during the previous day is correlated with increased consumption of sucrose during subsequent days: is increased geomagnetic activity aversive?

    PubMed

    Galic, M A; Persinger, M A

    2004-06-01

    In five separate blocks over a period of several months for 33 female rats the amount of geomagnetic activity during the day before ad libitum access to 10% sucrose or water was positively correlated with the volume of sucrose consumed per 24-hr. period. The strength of the correlation (.62 to .77) declined over the subsequent 10 days from between .12 to -.18 and resembled an extinction curve. In a subsequent experiment four rats exposed to 5 nT to 8 nT, 0.5-Hz magnetic fields that ceased for 30 min. once every 4 hr. for 4 days consumed 11% more sucrose than the four rats exposed to no field. We suggest that the initial consumption of 10% sucrose may have been reinforced because it diminished the aversive physiological effects associated with the increased geomagnetic activity. However, over the subsequent days, as geomagnetic activity decreased or habituation occurred, negative reinforcement did not maintain this behavior.

  11. The rate of synthesis and decomposition of tissue proteins in hypokinesia and increased muscular activity

    NASA Technical Reports Server (NTRS)

    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.

  12. Increasing Spontaneous Retinal Activity before Eye Opening Accelerates the Development of Geniculate Receptive Fields

    PubMed Central

    Davis, Zachary W.; Chapman, Barbara

    2015-01-01

    Visually evoked activity is necessary for the normal development of the visual system. However, little is known about the capacity for patterned spontaneous activity to drive the maturation of receptive fields before visual experience. Retinal waves provide instructive retinotopic information for the anatomical organization of the visual thalamus. To determine whether retinal waves also drive the maturation of functional responses, we increased the frequency of retinal waves pharmacologically in the ferret (Mustela putorius furo) during a period of retinogeniculate development before eye opening. The development of geniculate receptive fields after receiving these increased neural activities was measured using single-unit electrophysiology. We found that increased retinal waves accelerate the developmental reduction of geniculate receptive field sizes. This reduction is due to a decrease in receptive field center size rather than an increase in inhibitory surround strength. This work reveals an instructive role for patterned spontaneous activity in guiding the functional development of neural circuits. SIGNIFICANCE STATEMENT Patterned spontaneous neural activity that occurs during development is known to be necessary for the proper formation of neural circuits. However, it is unknown whether the spontaneous activity alone is sufficient to drive the maturation of the functional properties of neurons. Our work demonstrates for the first time an acceleration in the maturation of neural function as a consequence of driving patterned spontaneous activity during development. This work has implications for our understanding of how neural circuits can be modified actively to improve function prematurely or to recover from injury with guided interventions of patterned neural activity. PMID:26511250

  13. Do increases in physical activity encourage positive beliefs about further change in the ProActive cohort?

    PubMed

    Hardeman, Wendy; Michie, Susan; Kinmonth, Ann Louise; Sutton, Stephen

    2011-07-01

    Effects of behaviour change on cognitions are rarely examined within the Theory of Planned Behaviour. We tested whether increases in physical activity resulted in more positive beliefs about further change among a cohort of sedentary adults participating in a behavioural intervention trial (ProActive). At baseline, 6 and 12 months, 365 adults completed questionnaires assessing physical activity and cognitions about becoming more active over the coming year. Objective activity was assessed at baseline and 12 months. Participants reporting larger increases in activity were no more positive about making further increases than those reporting less behaviour change (p-values>0.05). Participants with larger increases in objective activity reported weaker perceived control (β=-0.342; p=0.001) and more negative instrumental attitudes (β=-0.230; p=0.017) at 12 months. Participants may have felt that they had changed enough or measures of perceived success may be more sensitive to behaviour change. Alternatively, long measurement intervals may have missed immediate cognitive and affective consequences of behaviour change, or such effects may require participants to consistently self-monitor or receive feedback on performance. Future studies could test the effect of such techniques on physical activity and a wider range of cognitive, affective and physiological consequences, using more frequent measurement intervals. PMID:21500102

  14. Resistance training increases total energy expenditure and free-living physical activity in older adults.

    PubMed

    Hunter, G R; Wetzstein, C J; Fields, D A; Brown, A; Bamman, M M

    2000-09-01

    The purpose of this study was to determine what effects 26 wk of resistance training have on resting energy expenditure (REE), total free-living energy expenditure (TEE), activity-related energy expenditure (AEE), engagement in free-living physical activity as measured by the activity-related time equivalent (ARTE) index, and respiratory exchange ratio (RER) in 61- to 77-yr-old men (n = 8) and women (n = 7). Before and after training, body composition (four-compartment model), strength, REE, TEE (doubly labeled water), AEE (TEE - REE + thermic response to meals), and ARTE (AEE adjusted for energy cost of standard activities) were evaluated. Strength (36%) and fat-free mass (2 kg) significantly increased, but body weight did not change. REE increased 6.8%, whereas resting RER decreased from 0.86 to 0.83. TEE (12%) and ARTE (38%) increased significantly, and AEE (30%) approached significance (P = 0.06). The TEE increase remained significant even after adjustment for the energy expenditure of the resistance training. In response to resistance training, TEE increased and RER decreased. The increase in TEE occurred as a result of increases in both REE and physical activity. These results suggest that resistance training may have value in increasing energy expenditure and lipid oxidation rates in older adults, thereby improving their metabolic profiles.

  15. Decreasing excessive media usage while increasing physical activity: a single-subject research study.

    PubMed

    Larwin, Karen H; Larwin, David A

    2008-11-01

    The Kaiser Family Foundation released a report entitled Kids and Media Use in the United States that concluded that children's use of media--including television, computers, Internet, video games, and phones--may be one of the primary contributor's to the poor fitness and obesity of many of today's adolescents. The present study examines the potential of increasing physical activity and decreasing media usage in a 14-year-old adolescent female by making time spent on the Internet and/or cell phone contingent on physical activity. Results of this investigation indicate that requiring the participant to earn her media-usage time did correspond with an increase in physical activity and a decrease in media-usage time relative to baseline measures. Five weeks after cessation of the intervention, the participant's new level of physical activity was still being maintained. One year after the study, the participant's level of physical activity continued to increase. PMID:18544746

  16. Bacterial Manipulation of NK Cell Regulatory Activity Increases Susceptibility to Listeria monocytogenes Infection

    PubMed Central

    Guthrie, Brandon S.; Schmidt, Rebecca L.; Jamieson, Amanda; Merkel, Patricia; Knight, Vijaya; Cole, Caroline M.; Raulet, David H.; Lenz, Laurel L.

    2016-01-01

    Natural killer (NK) cells produce interferon (IFN)-γ and thus have been suggested to promote type I immunity during bacterial infections. Yet, Listeria monocytogenes (Lm) and some other pathogens encode proteins that cause increased NK cell activation. Here, we show that stimulation of NK cell activation increases susceptibility during Lm infection despite and independent from robust NK cell production of IFNγ. The increased susceptibility correlated with IL-10 production by responding NK cells. NK cells produced IL-10 as their IFNγ production waned and the Lm virulence protein p60 promoted induction of IL-10 production by mouse and human NK cells. NK cells consequently exerted regulatory effects to suppress accumulation and activation of inflammatory myeloid cells. Our results reveal new dimensions of the role played by NK cells during Lm infection and demonstrate the ability of this bacterial pathogen to exploit the induction of regulatory NK cell activity to increase host susceptibility. PMID:27295349

  17. Increasing Spontaneous Retinal Activity before Eye Opening Accelerates the Development of Geniculate Receptive Fields.

    PubMed

    Davis, Zachary W; Chapman, Barbara; Cheng, Hwai-Jong

    2015-10-28

    Visually evoked activity is necessary for the normal development of the visual system. However, little is known about the capacity for patterned spontaneous activity to drive the maturation of receptive fields before visual experience. Retinal waves provide instructive retinotopic information for the anatomical organization of the visual thalamus. To determine whether retinal waves also drive the maturation of functional responses, we increased the frequency of retinal waves pharmacologically in the ferret (Mustela putorius furo) during a period of retinogeniculate development before eye opening. The development of geniculate receptive fields after receiving these increased neural activities was measured using single-unit electrophysiology. We found that increased retinal waves accelerate the developmental reduction of geniculate receptive field sizes. This reduction is due to a decrease in receptive field center size rather than an increase in inhibitory surround strength. This work reveals an instructive role for patterned spontaneous activity in guiding the functional development of neural circuits. PMID:26511250

  18. Ginsenoside Rb1 increases insulin sensitivity by activating AMP-activated protein kinase in male rats.

    PubMed

    Shen, Ling; Haas, Michael; Wang, David Q-H; May, Aaron; Lo, Chunmin C; Obici, Silvana; Tso, Patrick; Woods, Stephen C; Liu, Min

    2015-09-01

    Although ginseng has been reported to ameliorate hyperglycemia in animal models and clinical studies, the molecular mechanisms are largely unknown. We previously reported that chronic treatment with ginsenoside Rb1 (Rb1), a major component of ginseng, significantly reduced fasting glucose and improved glucose tolerance in high-fat diet (HFD)-induced obese rats. These effects were greater than those observed in pair-fed rats, suggesting a direct effect of Rb1 on glucose homeostasis, and this possibility was confirmed in the present study. In lean rats fed standard rodent chow, 5-day treatment with Rb1 significantly improved glucose tolerance and enhanced insulin sensitivity. Notably, those effects were not accompanied by reduced food intake or changed body weight. To elucidate the underlying molecular mechanisms, rats fed a HFD for 4 weeks were treated with Rb1 for 5 days. Subsequently, euglycemic-hyperinsulinemic clamp studies found that compared to vehicle, Rb1, while not changing food intake or body weight, significantly increased glucose infusion rate required to maintain euglycemia. Consistent with this, insulin-induced inhibition of hepatic gluconeogenesis was significantly enhanced and hepatic phosphoenolpyruvate carboxykinase and glucose-6-phosphatase gene expression was suppressed. Additionally, glucose uptake was significantly increased in skeletal muscle. While proximal insulin signaling was not changed after Rb1 treatment, increased phosphorylation of TBC1D4, a downstream target of AMPK signaling, appears to be a key part of the mechanism for Rb1-stimulated glucose uptake in skeletal muscle. These findings indicate that Rb1 has multiple effects on glucose homeostasis, and provide strong rationale for further evaluation of its potential therapeutic role. PMID:26359241

  19. Using targeted messaging to increase physical activity in older adults: a review.

    PubMed

    Ostrander, Rachel E; Thompson, Hilaire J; Demiris, George

    2014-09-01

    Physical activity has many benefits for older adults; however, motivating older adults to engage in and maintain optimal levels of physical activity can be challenging for health care providers. A comprehensive literature review was performed to determine whether any evidence-based methods of delivery or particular content for targeted messaging exist that result in actual improvements in physical activity of older adults. Findings of the review demonstrate that messaging directed toward older adults to be physically active resulted in improvements in physical activity up to 1 year. Across studies many different modes of message delivery were shown to be effective. Message content, whether tailored or not, resulted in significant increases in physical activity. There is evidence to support the use of environmentally mediated messaging (i.e., local walking paths) for stronger results. Targeting the client's stage of change, having an activity partner if preferred, and scheduling physical activity also contribute to improved effects.

  20. Increase in multidrug transport activity is associated with oocyte maturation in sea stars.

    PubMed

    Roepke, Troy A; Hamdoun, Amro M; Cherr, Gary N

    2006-12-01

    In this study, we report on the presence of efflux transporter activity before oocyte maturation in sea stars and its upregulation after maturation. This activity is similar to the multidrug resistance (MDR) activity mediated by ATP binding cassette (ABC) efflux transporters. In sea star oocytes the efflux activity, as measured by exclusion of calcein-am, increased two-fold 3 h post-maturation. Experiments using specific and non-specific dyes and inhibitors demonstrated that the increase in transporter activity involves an ABCB protein, P-glycoprotein (P-gp), and an ABCC protein similar to the MDR-associated protein (MRP)-like transporters. Western blots using an antibody directed against mammalian P-gp recognized a 45 kDa protein in sea star oocytes that increased in abundance during maturation. An antibody directed against sea urchin ABCC proteins (MRP) recognized three proteins in immature oocytes and two in mature oocytes. Experiments using inhibitors suggest that translation and microtubule function are both required for post-maturation increases in transporter activity. Immunolabeling revealed translocation of stored ABCB proteins to the plasma cell membrane during maturation, and this translocation coincided with increased transport activity. These MDR transporters serve protective roles in oocytes and eggs, as demonstrated by sensitization of the oocytes to the maturation inhibitor, vinblastine, by MRP and PGP-specific transporter inhibitors.

  1. Physical Activity and Executive Control: Implications for Increased Cognitive Health during Older Adulthood

    ERIC Educational Resources Information Center

    Hillman, Charles H.; Belopolsky, Artem V.; Snook, Erin M.; Kramer, Arthur F.; McAuley, Edward

    2004-01-01

    Electrocortical and behavioral responses of low, moderate, and high physically active older adults where compared with a younger control group on neutral and incompatible conditions of a flankers task. Compared to younger adults, high and moderate active older adults exhibited increased event-related potentials component P3 amplitude for the…

  2. Newspaper Content Analysis in Evaluation of a Community-Based Participatory Project to Increase Physical Activity

    ERIC Educational Resources Information Center

    Granner, Michelle L.; Sharpe, Patricia A.; Burroughs, Ericka L.; Fields, Regina; Hallenbeck, Joyce

    2010-01-01

    This study conducted a newspaper content analysis as part of an evaluation of a community-based participatory research project focused on increasing physical activity through policy and environmental changes, which included activities related to media advocacy and media-based community education. Daily papers (May 2003 to December 2005) from both…

  3. Carnosine: effect on aging-induced increase in brain regional monoamine oxidase-A activity.

    PubMed

    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.

  4. Increasing Student Physical Activity during the School Day: Opportunities for the Physical Educator

    ERIC Educational Resources Information Center

    Brewer, Joan D.; Luebbers, Paul E.; Shane, Shawna D.

    2009-01-01

    America is facing an obesity epidemic--one that is difficult to ignore. In order to combat the nation's obesity crisis, it is imperative that schools find ways to increase the physical activity levels of students during the school day, as well as encourage additional activity outside of school. By teaching youth to incorporate physical activity…

  5. Focused Campaign Increases Activity among Participants in "Nature's Notebook," a Citizen Science Project

    ERIC Educational Resources Information Center

    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…

  6. Angiotensin II increases diacylglycerol in calf adrenal glomerulosa cells by activating de novo phospholipid synthesis

    SciTech Connect

    Foster, R.H.; Farese, R.V. )

    1989-01-01

    Effects of angiotension II (AII) on diacylglycerol (DAG) synthesis were examined in calf adrenal glomerulosa cells. AII provoked rapid increases in ({sup 3}H) glycerol-labeling and content of DAG. Effects on ({sup 3}H) glycerol-labeling of DAG were observed both in cells prelabeled with ({sup 3}H) glycerol for 60 minutes, and when AII and ({sup 3}H) glycerol were added simultaneously. Increases in ({sup 3}H) DAG labeling were associated with increases in total glycerolipid labeling, and in simultaneous addition experiments, were preceded by increased ({sup 3}H) phosphatidic acid (PA) labeling. Labeling of glycerol-3-PO{sub 4}, on the other hand, was not increased by AII, suggesting that increases in lipid labeling were not due to prior increases in precursor specific activity. ACTH, which were not increase precursor specific activity. ACTH, which does not increase the hydrolysis of inositol-phospholipids appreciably in this tissue, provoked increases in content and ({sup 3}H) glycerol-labeling of DAG, which were only slightly less than those provoked by AII. Thus, part of the AII-induced increase in DAG may also be derived from sources other than inositol-phospholipids. Moreover, AII-induced increase in DAG appear to be at least partly derived from increased de novo synthesis of PA.

  7. Effects of increasing physical activity on foot structure and ankle muscle strength in adults with obesity

    PubMed Central

    Zhao, Xiaoguang; Tsujimoto, Takehiko; Kim, Bokun; Katayama, Yasutomi; Wakaba, Kyousuke; Wang, Zhennan; Tanaka, Kiyoji

    2016-01-01

    [Purpose] The purpose of this study was to examine the effects of increasing physical activity on foot structure and ankle muscle strength in adults with obesity and to verify whether the rate of change in foot structure is related to that in ankle muscle strength. [Subjects and Methods] Twenty-seven adults with obesity completed a 12-week program in which the intensity of physical activity performed was gradually increased. Physical activity was monitored using a three-axis accelerometer. Foot structure was assessed using a three-dimensional foot scanner, while ankle muscle strength was measured using a dynamometry. [Results] With the increasing physical activity, the participants’ feet became thinner (the rearfoot width, instep height, and girth decreased) and the arch became higher (the arch height index increased) and stiffer (the arch stiffness index increased); the ankle muscle strength also increased after the intervention. Additionally, the changes in the arch height index and arch stiffness index were not associated with changes in ankle muscle strength. [Conclusion] Increasing physical activity may be one possible approach to improve foot structure and function in individuals with obesity.

  8. Effects of increasing physical activity on foot structure and ankle muscle strength in adults with obesity.

    PubMed

    Zhao, Xiaoguang; Tsujimoto, Takehiko; Kim, Bokun; Katayama, Yasutomi; Wakaba, Kyousuke; Wang, Zhennan; Tanaka, Kiyoji

    2016-08-01

    [Purpose] The purpose of this study was to examine the effects of increasing physical activity on foot structure and ankle muscle strength in adults with obesity and to verify whether the rate of change in foot structure is related to that in ankle muscle strength. [Subjects and Methods] Twenty-seven adults with obesity completed a 12-week program in which the intensity of physical activity performed was gradually increased. Physical activity was monitored using a three-axis accelerometer. Foot structure was assessed using a three-dimensional foot scanner, while ankle muscle strength was measured using a dynamometry. [Results] With the increasing physical activity, the participants' feet became thinner (the rearfoot width, instep height, and girth decreased) and the arch became higher (the arch height index increased) and stiffer (the arch stiffness index increased); the ankle muscle strength also increased after the intervention. Additionally, the changes in the arch height index and arch stiffness index were not associated with changes in ankle muscle strength. [Conclusion] Increasing physical activity may be one possible approach to improve foot structure and function in individuals with obesity. PMID:27630426

  9. Effects of increasing physical activity on foot structure and ankle muscle strength in adults with obesity

    PubMed Central

    Zhao, Xiaoguang; Tsujimoto, Takehiko; Kim, Bokun; Katayama, Yasutomi; Wakaba, Kyousuke; Wang, Zhennan; Tanaka, Kiyoji

    2016-01-01

    [Purpose] The purpose of this study was to examine the effects of increasing physical activity on foot structure and ankle muscle strength in adults with obesity and to verify whether the rate of change in foot structure is related to that in ankle muscle strength. [Subjects and Methods] Twenty-seven adults with obesity completed a 12-week program in which the intensity of physical activity performed was gradually increased. Physical activity was monitored using a three-axis accelerometer. Foot structure was assessed using a three-dimensional foot scanner, while ankle muscle strength was measured using a dynamometry. [Results] With the increasing physical activity, the participants’ feet became thinner (the rearfoot width, instep height, and girth decreased) and the arch became higher (the arch height index increased) and stiffer (the arch stiffness index increased); the ankle muscle strength also increased after the intervention. Additionally, the changes in the arch height index and arch stiffness index were not associated with changes in ankle muscle strength. [Conclusion] Increasing physical activity may be one possible approach to improve foot structure and function in individuals with obesity. PMID:27630426

  10. Promising school-based strategies and intervention guidelines to increase physical activity of adolescents.

    PubMed

    Murillo Pardo, Berta; García Bengoechea, Enrique; Generelo Lanaspa, Eduardo; Bush, Paula L; Zaragoza Casterad, Javier; Julián Clemente, José A; García González, Luis

    2013-06-01

    This narrative review describes the available scientific evidence regarding promising school-based strategies to increase physical activity of adolescents. We conducted a literature search for studies published up to 2011, regarding adolescent physical activity intervention studies that resulted in increased physical activity (regardless of measurement) and reviewed 52 intervention articles and 21 review articles. We identified several promising strategies and grouped into five broad intervention guidelines. These guidelines are as follows: (i) design multi-component interventions that foster the empowerment of members of the school community; (ii) develop improvements to Physical Education curricula as a strategy to promote physical activity to adolescents; (iii) design and implement non-curricular programmes and activities to promote physical activity; (iv) include computer-tailored interventions during the implementation and monitoring of physical activity promotion programmes and (v) design and implement specific strategies that respond to the interests and needs of girls. On the basis of our review of the adolescent physical activity promotion literature, we suggest that these five guidelines should be taken into account in school-based interventions geared towards achieving an increase in adolescent physical activity.

  11. Restricting opportunities to be active during school time: do children compensate by increasing physical activity levels after school?

    PubMed

    Dale, D; Corbin, C B; Dale, K S

    2000-09-01

    Opportunities for children to be physically active during school time are sparse and becoming increasingly so. The purpose of this investigation was to determine if children would compensate for school days (9 a.m.-3 p.m.) of restricted physical activity opportunities by increasing activity levels after school (3 p.m.-7:30 p.m.). Third and fourth grade children (N = 76) each wore a CSA accelerometer for 4 nonconsecutive days. Two days were categorized as active--during school, all children participated in outdoor recess and physical education class. Two days were categorized as restricted--all children spent their recess time indoors at a computer terminal, and no physical education class was scheduled. Dependent t tests revealed that children did not compensate for a sedentary school day by increasing their levels of physical activity after school. In fact, average movement counts per minute were higher in the 3 p.m.-7:30 p.m. period following the active day (525 counts.min-1) versus the restricted day (186 counts.min-1). These findings suggest cause for concern if children's opportunities to be active within school time are limited. Several reasons are given as to why children did not compensate or "make up" for the physical activity opportunities missed during the restricted school day.

  12. Activation of intestinal peroxisome proliferator-activated receptor-α increases high-density lipoprotein production

    PubMed Central

    Colin, Sophie; Briand, Olivier; Touche, Véronique; Wouters, Kristiaan; Baron, Morgane; Pattou, François; Hanf, Rémy; Tailleux, Anne; Chinetti, Giulia; Staels, Bart; Lestavel, Sophie

    2013-01-01

    Aims Peroxisome Proliferator-Activated Receptor (PPAR) α is a transcription factor controlling lipid metabolism in liver, heart, muscle and macrophages. PPARα-activation increases plasma HDL-cholesterol and exerts hypotriglyceridemic actions via the liver. However, the intestine expresses PPARα, produces HDL and chylomicrons and is exposed to diet-derived PPARα ligands. Therefore, we examined the effects of PPARα-activation on intestinal lipid and lipoprotein metabolism. Methods and Results The impact of PPARα-activation was evaluated in term of HDL-related gene expression in mice, ex-vivo in human jejunal biopsies and in Caco-2/TC7 cells. ApoAI/HDL secretion, cholesterol esterification and trafficking were also studied in-vitro. In parallel to improving plasma lipid profiles and increasing liver and intestinal expression of fatty-acid-oxidation genes, treatment with the dual PPARα/δ-ligand GFT505 resulted in a more pronounced increase of plasma HDL compared to fenofibrate in mice. GFT505, but not fenofibrate, increased the expression of HDL-production genes such as apolipoprotein-AI and ATP-Binding-Cassette-A1 transporter in murine intestines. A similar increase was observed upon PPARα-activation of human biopsies and Caco-2/TC7 cells. Additionally, HDL secretion by Caco-2/TC7 cells increased. Moreover, PPARα-activation decreased the cholesterol-esterification capacity of Caco-2/TC7 cells, modified cholesterol trafficking and reduced apolipoprotein-B secretion. Conclusions PPARα-activation reduces cholesterol esterification, suppresses chylomicron- and increases HDL-secretion by enterocytes. These results identify the intestine as a target organ of PPARα-ligands with entero-hepatic tropism to reduce atherogenic dyslipidemia. PMID:22843443

  13. Increasing Physical Activity in Preschool: A Pilot Study to Evaluate Animal Trackers

    ERIC Educational Resources Information Center

    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…

  14. Increasing western US forest wildfire activity: sensitivity to changes in the timing of spring.

    PubMed

    Westerling, Anthony LeRoy

    2016-06-01

    Prior work shows western US forest wildfire activity increased abruptly in the mid-1980s. Large forest wildfires and areas burned in them have continued to increase over recent decades, with most of the increase in lightning-ignited fires. Northern US Rockies forests dominated early increases in wildfire activity, and still contributed 50% of the increase in large fires over the last decade. However, the percentage growth in wildfire activity in Pacific northwestern and southwestern US forests has rapidly increased over the last two decades. Wildfire numbers and burned area are also increasing in non-forest vegetation types. Wildfire activity appears strongly associated with warming and earlier spring snowmelt. Analysis of the drivers of forest wildfire sensitivity to changes in the timing of spring demonstrates that forests at elevations where the historical mean snow-free season ranged between two and four months, with relatively high cumulative warm-season actual evapotranspiration, have been most affected. Increases in large wildfires associated with earlier spring snowmelt scale exponentially with changes in moisture deficit, and moisture deficit changes can explain most of the spatial variability in forest wildfire regime response to the timing of spring.This article is part of the themed issue 'The interaction of fire and mankind'.

  15. Increasing western US forest wildfire activity: sensitivity to changes in the timing of spring.

    PubMed

    Westerling, Anthony LeRoy

    2016-06-01

    Prior work shows western US forest wildfire activity increased abruptly in the mid-1980s. Large forest wildfires and areas burned in them have continued to increase over recent decades, with most of the increase in lightning-ignited fires. Northern US Rockies forests dominated early increases in wildfire activity, and still contributed 50% of the increase in large fires over the last decade. However, the percentage growth in wildfire activity in Pacific northwestern and southwestern US forests has rapidly increased over the last two decades. Wildfire numbers and burned area are also increasing in non-forest vegetation types. Wildfire activity appears strongly associated with warming and earlier spring snowmelt. Analysis of the drivers of forest wildfire sensitivity to changes in the timing of spring demonstrates that forests at elevations where the historical mean snow-free season ranged between two and four months, with relatively high cumulative warm-season actual evapotranspiration, have been most affected. Increases in large wildfires associated with earlier spring snowmelt scale exponentially with changes in moisture deficit, and moisture deficit changes can explain most of the spatial variability in forest wildfire regime response to the timing of spring.This article is part of the themed issue 'The interaction of fire and mankind'. PMID:27216510

  16. Heparanase procoagulant activity, factor Xa, and plasminogen activator inhibitor 1 are increased in shift work female nurses.

    PubMed

    Nadir, Yona; Saharov, Gleb; Hoffman, Ron; Keren-Politansky, Anat; Tzoran, Inna; Brenner, Benjamin; Shochat, Tamar

    2015-07-01

    Epidemiologic studies indicate on an increased risk of cardiovascular disease and cancer in shift workers, although the underlying mechanism is obscure. Heparanase directly enhances tissue factor (TF) activity leading to increased factor Xa production and subsequent activation of the coagulation system. In the present study, a comparison of coagulation markers among healthy shift working (SW) vs. healthy daytime working (DW) female nurses was performed. Thirty SW and 30 DW female nurses were enrolled. For each of the 60 participants, blood was drawn between 7:00 and 8:00 a.m. and at least 8 h after the last work shift. Plasma was studied for coagulation marker that included TF/heparanase procoagulant activity, TF activity, heparanase procoagulant activity, heparanase level, factor Xa level, plasminogen activator inhibitor 1 (PAI-1), plasminogen, α2-antiplasmin, fibrinogen, global protein C, von Willebrand factor, and D-dimer by chromogenic assays and enzyme-linked immunosorbent assays (ELISAs). Sleep quality was assessed by self-report according to the Pittsburgh Sleep Quality Index. The heparanase procoagulant activity increased by 2-fold and the TF/heparanase procoagulant activity increased by 1.5-fold in SW nurses compared to DW nurses (P < 0.05). Factor Xa levels and PAI-1 levels were significantly higher among SW nurses compared to the DW group (22 vs. 18 ng/ml, P < 0.05, and 32 vs. 22 ng/ml, P < 0.005, respectively). No significant differences were found in the other tested coagulation markers between the study groups. Heparanase procoagulant activity, factor Xa level, and PAI-1 level were significantly higher in SW nurses compared to the DW group. These alterations of blood coagulation activation may potentially contribute to cardiovascular and cancer morbidity.

  17. USING THE Internet TO INCREASE Physical Activity IN A FAITH COMMUNITY.

    PubMed

    Washington, Enrika; Weed, Latricia Diane; Vardaman, Shellye A

    2015-01-01

    Physical inactivity is the biggest public health problem of the 21st Century. Additionally, minority populations have higher rates of obesity and obesity-related illnesses, supporting the need to develop culturally-appropriate physical activity interventions for these populations. For African Americans (AAs), churches promote spiritual, mental, and physical well-being. The Internet offers an innovative medium to produce health behavior change and may be ideal to use with AAs in a church setting. A simple, no-cost, 8-week, Internet-delivered intervention to increase physical activity was piloted in an AA church. Level of activity increased, whereas time spent sitting decreased. PMID:26211303

  18. Increased anterior insula activity in anxious individuals is linked to diminished perceived control

    PubMed Central

    Alvarez, R P; Kirlic, N; Misaki, M; Bodurka, J; Rhudy, J L; Paulus, M P; Drevets, W C

    2015-01-01

    Individuals with high-trait anxiety frequently report decreased perceived control. However, it is unclear how these processes are instantiated at a neural level. Prior research suggests that individuals prone to anxiety may have exaggerated activity in the anterior insula and altered activity in the cingulate cortex during anticipation of aversive events. Thus, we hypothesized that anxiety proneness influences anterior insula activation during anticipation of unpredictable threat through decreased perceived control. Forty physically healthy adults underwent neuroimaging while they explored computer-simulated contexts associated either with or without the threat of an unpredictable shock. Skin conductance, anxiety ratings and blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging were used to assess responses to threat versus no threat. Perceived control was measured using the Anxiety Control Questionnaire-Revised. Mediation analysis examined how anxiety proneness influenced BOLD activity. Anticipation of unpredictable threat resulted in increased skin conductance responses, anxiety ratings and enhanced activation in bilateral insula, anterior midcingulate cortex (aMCC) and bed nucleus of the stria terminalis. Individuals with greater anxiety proneness and less perceived control showed greater activity in dorsal anterior insula (dAI). Perceived control mediated the relationship between anxiety proneness and dAI activity. Increased dAI activity was associated with increased activity in aMCC, which correlated with increased exploratory behavior. Results provide evidence that exaggerated insula activation during the threat of unpredictable shock is directly related to low perceived control in anxiety-prone individuals. Perceived control thus may constitute an important treatment target to modulate insula activity during anxious anticipation in anxiety-disordered individuals. PMID:26125154

  19. Increased physical activity decreases hepatic free fatty acid uptake: a study in human monozygotic twins

    PubMed Central

    Hannukainen, Jarna C; Nuutila, Pirjo; Ronald, Borra; Kaprio, Jaakko; Kujala, Urho M; Janatuinen, Tuula; Heinonen, Olli J; Kapanen, Jukka; Viljanen, Tapio; Haaparanta, Merja; Rönnemaa, Tapani; Parkkola, Riitta; Knuuti, Juhani; Kalliokoski, Kari K

    2007-01-01

    Exercise is considered to be beneficial for free fatty acid (FFA) metabolism, although reports of the effects of increased physical activity on FFA uptake and oxidation in different tissues in vivo in humans have been inconsistent. To investigate the heredity-independent effects of physical activity and fitness on FFA uptake in skeletal muscle, the myocardium, and liver we used positron emission tomography (PET) in nine healthy young male monozygotic twin pairs discordant for physical activity and fitness. The cotwins with higher physical activity constituting the more active group had a similar body mass index but less body fat and 18 ± 10% higher V˙O2,max (P < 0.001) compared to the less active brothers with lower physical activity. Low-intensity knee-extension exercise increased skeletal muscle FFA and oxygen uptake six to 10 times compared to resting values but no differences were observed between the groups at rest or during exercise. At rest the more active group had lower hepatic FFA uptake compared to the less active group (5.5 ± 4.3 versus 9.0 ± 6.1 μmol (100 ml)−1 min−1, P = 0.04). Hepatic FFA uptake associated significantly with body fat percentage (P = 0.05). Myocardial FFA uptake was similar between the groups. In conclusion, in the absence of the confounding effects of genetic factors, moderately increased physical activity and aerobic fitness decrease body adiposity even in normal-weighted healthy young adult men. Further, increased physical activity together with decreased intra-abdominal adiposity seems to decrease hepatic FFA uptake but has no effects on skeletal muscle or myocardial FFA uptake. PMID:17053033

  20. BrO/SO2 ratios at Popocatepetl volcano during increased activity in 2012

    NASA Astrophysics Data System (ADS)

    Fickel, M.; Delgado Granados, H.

    2012-12-01

    Since its reactivation in 1994 after many decades of inactivity, Popocatepetl volcano has been showing long periods of quiescent degassing and some events of intensified activity in connection with dome building and destruction processes. During a period of increased activity of the volcano, which began in April 2012, mobile ultraviolet DOAS measurements and stationary DOAS scans were performed to quantify SO2 fluxes and BrO/SO2 ratios within the volcanic plume. The results of these measurements are presented in the context of the volcanic activity, which consisted of increased emission of gas and ash and Vulcanian type explosions. In general, SO2 emissions were high during the period April-June 2012 and so the BrO emissions, however, the BrO/SO2 ratios did not change strongly before, during and after the increased activity.

  1. Calpain activity and expression are increased in splenic inflammatory cells associated with experimental allergic encephalomyelitis.

    PubMed

    Shields, D C; Schaecher, K E; Goust, J M; Banik, N L

    1999-09-01

    Since calcium-activated neutral proteinase (calpain) activity and expression are significantly increased in activated glial/inflammatory cells in the central nervous system of animals with autoimmune demyelinating diseases, this enzyme may also play a role in peripheral organ systems in these diseases. In this study, the activity and expression of calpain and the endogenous inhibitor, calpastatin, were evaluated at transcriptional and translational levels in spleens of Lewis rats with acute experimental allergic encephalomyelitis (EAE) prior to the onset of clinical symptoms. Calpain activity and translational expression were increased by 475.5% and 44.3% respectively, on day 4 post-induction in adjuvant controls and animals with EAE. These levels remained elevated compared to normal controls on days 8 and 12. Calpastatin translational expression was similarly increased at these time points although transcriptional expression was not significantly altered at any time following induction of EAE. Likewise, transcriptional expression of mu-calpain was unchanged following induction, while small increases in m-calpain transcriptional expression were observed on days 2 and 8. Most calpain expression was observed in activated splenic macrophages at day 8 post-induction even though activated T cells were also calpain positive. In spinal cords of animals with EAE, calpain expression was significantly increased in rats with severe disease compared to those exhibiting only mild symptoms at day 12 post-induction. Thus, prior to symptomatic EAE, increased calpain activity and expression in peripheral lymphoid organs may play an important role in T cell migration and subsequent disease progression. PMID:10496171

  2. Rapid increases in ventilation accompany the transition from passive to active movement.

    PubMed

    Bell, Harold J; Duffin, James

    2006-06-01

    We used a novel movement transition technique to look for evidence of a rapid onset drive to breathe related to the active component of exercise in humans. Ten volunteers performed the following transitions in a specially designed tandem exercise chair apparatus: rest to passive movement, passive to active movement, and rest to active movement. The transition from rest to active exercise was accompanied by an immediate increase in ventilation, as was the transition from rest to passive leg movement (Delta = 6.06 +/- 1.09 l min(-1), p < 0.001 and Delta = 3.30 +/- 0.57 l min(-1), p = 0.002, respectively). When subjects actively assumed the leg movements, ventilation again increased immediately and significantly (Delta = 2.55 +/- 0.52 l min(-1), p = 0.032). Ventilation at the first point of active exercise was the same when started either from rest or from a background of passive leg movement (p = 1.00). We conclude that the use of a transition from passive to active leg movements in humans recruits a ventilatory drive related to the active component of exercise, and this can be discerned as a rapid increase in breathing.

  3. Cytochrome oxidase activity is increased in +/Lc Purkinje cells destined to die.

    PubMed

    Vogel, M W; Fan, H; Sydnor, J; Guidetti, P

    2001-10-01

    +/Lc Purkinje cells degenerate postnatally because of a gain-of-function mutation in the delta2 glutamate receptor (Grid2) that causes a constitutive Na+ current leak. The effect of the resulting chronic depolarization on Purkinje cell metabolism was investigated by measuring levels of cytochrome oxidase (COX) activity in Purkinje cell dendrites using quantitative densitometry. Analysis of wild type controls and +/Lc mutants at P10, P15 and P25 showed that levels of COX activity were significantly increased above control levels by P15 and continued to increase through P25. The increase in COX activity is likely to reflect an increase in oxidative phosphorylation to accommodate the energy demands of removing excess Na+ and Ca2+ entering the Purkinje cells in response to the Grid2 leak current.

  4. Peripheral Sensitization Increases Opioid Receptor Expression and Activation by Crotalphine in Rats

    PubMed Central

    Zambelli, Vanessa Olzon; Fernandes, Ana Carolina de Oliveira; Gutierrez, Vanessa Pacciari; Ferreira, Julio Cesar Batista; Parada, Carlos Amilcar; Mochly-Rosen, Daria; Cury, Yara

    2014-01-01

    Inflammation enhances the peripheral analgesic efficacy of opioid drugs, but the mechanisms involved in this phenomenon have not been fully elucidated. Crotalphine (CRP), a peptide that was first isolated from South American rattlesnake C.d. terrificus venom, induces a potent and long-lasting anti-nociceptive effect that is mediated by the activation of peripheral opioid receptors. Because the high efficacy of CRP is only observed in the presence of inflammation, we aimed to elucidate the mechanisms involved in the CRP anti-nociceptive effect induced by inflammation. Using real-time RT-PCR, western blot analysis and ELISA assays, we demonstrate that the intraplantar injection of prostaglandin E2 (PGE2) increases the mRNA and protein levels of the µ- and κ-opioid receptors in the dorsal root ganglia (DRG) and paw tissue of rats within 3 h of the injection. Using conformation state-sensitive antibodies that recognize activated opioid receptors, we show that PGE2, alone does not increase the activation of these opioid receptors but that in the presence of PGE2, the activation of specific opioid receptors by CRP and selective µ- and κ-opioid receptor agonists (positive controls) increases. Furthermore, PGE2 down-regulated the expression and activation of the δ-opioid receptor. CRP increased the level of activated mitogen-activated protein kinases in cultured DRG neurons, and this increase was dependent on the activation of protein kinase Cζ. This CRP effect was much more prominent when the cells were pretreated with PGE2. These results indicate that the expression and activation of peripheral opioid receptors by opioid-like drugs can be up- or down-regulated in the presence of an acute injury and that acute tissue injury enhances the efficacy of peripheral opioids. PMID:24594607

  5. Peripheral sensitization increases opioid receptor expression and activation by crotalphine in rats.

    PubMed

    Zambelli, Vanessa Olzon; Fernandes, Ana Carolina de Oliveira; Gutierrez, Vanessa Pacciari; Ferreira, Julio Cesar Batista; Parada, Carlos Amilcar; Mochly-Rosen, Daria; Cury, Yara

    2014-01-01

    Inflammation enhances the peripheral analgesic efficacy of opioid drugs, but the mechanisms involved in this phenomenon have not been fully elucidated. Crotalphine (CRP), a peptide that was first isolated from South American rattlesnake C.d. terrificus venom, induces a potent and long-lasting anti-nociceptive effect that is mediated by the activation of peripheral opioid receptors. Because the high efficacy of CRP is only observed in the presence of inflammation, we aimed to elucidate the mechanisms involved in the CRP anti-nociceptive effect induced by inflammation. Using real-time RT-PCR, western blot analysis and ELISA assays, we demonstrate that the intraplantar injection of prostaglandin E2 (PGE2) increases the mRNA and protein levels of the µ- and κ-opioid receptors in the dorsal root ganglia (DRG) and paw tissue of rats within 3 h of the injection. Using conformation state-sensitive antibodies that recognize activated opioid receptors, we show that PGE2, alone does not increase the activation of these opioid receptors but that in the presence of PGE2, the activation of specific opioid receptors by CRP and selective µ- and κ-opioid receptor agonists (positive controls) increases. Furthermore, PGE2 down-regulated the expression and activation of the δ-opioid receptor. CRP increased the level of activated mitogen-activated protein kinases in cultured DRG neurons, and this increase was dependent on the activation of protein kinase Cζ. This CRP effect was much more prominent when the cells were pretreated with PGE2. These results indicate that the expression and activation of peripheral opioid receptors by opioid-like drugs can be up- or down-regulated in the presence of an acute injury and that acute tissue injury enhances the efficacy of peripheral opioids.

  6. Increased expression of the Ras suppressor Rsu-1 enhances Erk-2 activation and inhibits Jun kinase activation.

    PubMed

    Masuelli, L; Cutler, M L

    1996-10-01

    Studies were undertaken to determine the effect of the Ras suppressor Rsu-1 on Ras signal transduction pathways in two different cell backgrounds. An expression vector containing the mouse rsu-1 cDNA under the control of a mouse mammary tumor virus promoter was introduced into NIH 3T3 cells and the pheochromocytoma cell line PC12. Cell lines developed in the NIH 3T3 background expressed p33rsu-1 at approximately twice the normal endogenous level. However, PC12 cell clones which expressed p33rsu-1 at an increased level in a regulatable fashion in response to dexamethasone were isolated. Analysis of proteins involved in regulation of Ras and responsive to Ras signal transduction revealed similar changes in the two cell backgrounds in the presence of elevated p33rsu-1. There was an increase in the level of SOS, the guanine nucleotide exchange factor, and an increase in the percentage of GTP-bound Ras. In addition, there was an increase in the amount of p120 Ras-specific GTPase-activating protein (GAP) and GAP-associated p190. However, a decrease in Ras GTPase-activating activity was detected in lysates of the Rsu-1 transfectants, and immunoprecipitated p120 GAP from the Rsu-1 transfectants showed less Ras GTPase-activating activity than GAP from control cells. Activation of Erk-2 kinase by growth factor and tetradecanyol phorbol acetate was greater in the Rsu-1 transfectants than in control cells. However, c-Jun amino-terminal kinase activity (Jun kinase) was not activatable by epidermal growth factor in Rsu-1 PC12 cell transfectants, in contrast to the PC12 vector control cell line. Transient expression of p33rsu-1 in Cos1 cells following cotransfection with either hemagglutinin-tagged Jun kinase or hemagglutinin-tagged Erk-2 revealed that Rsu-1 expression inhibited constitutive Jun kinase activity while enhancing Erk-2 activity. Detection of in vitro binding of Rsu-1 to Raf-1 suggested that in Rsu-1 transfectants, increased activation of the Raf-1 pathway occurred

  7. Fixed Foot Balance Training Increases Rectus Femoris Activation During Landing and Jump Height in Recreationally Active Women

    PubMed Central

    Kean, Crystal O.; Behm, David G.; Young, Warren B.

    2006-01-01

    The objective of this study was to determine the effects of fixed foot and functionally directed balance training on static balance time, muscle activation during landing, vertical jump height and sprint time. Twenty-four recreationally active females were tested pre- and post-training (fixed foot balance training, n= 11, functionally directed balance training, n = 7 and control group, n = 6). Experimental subjects completed either fixed foot or functionally directed balance exercises 4 times/week for 6 weeks. Surface electromyography (EMG) was used to assess preparatory and reactive muscle activity of the rectus femoris (RF), biceps femoris (BF), and the soleus during one- and two-foot landings following a jump. Maximum vertical jump height, static balance and 20-meter sprint times were also examined. The fixed foot balance-training group showed a 33% improvement (p < 0.05) in static balance time and 9% improvement in jump height. Neither type of training improved sprint times. Further analysis revealed significant (p < 0.05) overall (data collapsed over groups and legs) increases in reactive RF activity when landing. Independently, the fixed foot balance group showed a 33% increase in reactive RF activity (p < 0.01). Overall, there was also significantly less reactive co-activation following training (p < 0.05). It appears that fixed foot balance training for recreationally active women may provide greater RF activity when landing and increased countermovement jump height. Key points Balance training increased rectus femoris EMG activity upon landing from a stride. Fixed foot balance training improved countermovement jump height. Neither fixed foot nor functionally directed balance training elicited changes in sprint times. PMID:24198691

  8. Activation of muscarinic receptors in porcine airway smooth muscle elicits a transient increase in phospholipase D activity.

    PubMed

    Mamoon, A M; Smith, J; Baker, R C; Farley, J M

    1999-01-01

    Phospholipase D (PLD) is a phosphodiesterase that catalyses hydrolysis of phosphatidylcholine to produce phosphatidic acid and choline. In the presence of ethanol, PLD also catalyses the formation of phosphatidylethanol, which is a unique characteristic of this enzyme. Muscarinic receptor-induced changes in the activity of PLD were investigated in porcine tracheal smooth muscle by measuring the formation of [3H]phosphatidic acid ([3H]PA) and [3H]phosphatidylethanol ([3H]PEth) after labeling the muscle strips with [3H]palmitic acid. The cholinergic receptor agonist acetylcholine (Ach) significantly but transiently increased formation of both [3H]PA and [3H]PEth in a concentration-dependent manner (>105-400% vs. controls in the presence of 10(-6) to 10(-4) M Ach) when pretreated with 100 mM ethanol. The Ach receptor-mediated increase in PLD activity was inhibited by atropine (10(-6) M), indicating that activation of PLD occurred via muscarinic receptors. Activation of protein kinase C (PKC) by phorbol-12-myristate-13-acetate (PMA) increased PLD activity that was effectively blocked by the PKC inhibitors calphostin C (10(-8) to 10(-6) M) and GFX (10(-8) to 10(-6) M). Ach-induced increases in PLD activity were also significantly, but incompletely, inhibited by both GFX and calphostin C. From the present data, we conclude that in tracheal smooth muscle, muscarinic acetylcholine receptor-induced PLD activation is transient in nature and coupled to these receptors via PKC. However, PKC activation is not solely responsible for Ach-induced activation of PLD in porcine tracheal smooth muscle.

  9. Transgenic Expression of Cyclin-Dependent Kinase 4 Results in Epidermal Hyperplasia, Hypertrophy, and Severe Dermal Fibrosis

    PubMed Central

    Miliani de Marval, Paula L.; Gimenez-Conti, Irma B.; LaCava, Margaret; Martinez, Luis A.; Conti, Claudio J.; Rodriguez-Puebla, Marcelo L.

    2001-01-01

    In a previous report we have described the effects of expression of D-type cyclins in epithelial tissues of transgenic mice. To study the involvement of the D-type cyclin partner cyclin-dependent kinase 4 (CDK4) in epithelial growth and differentiation, transgenic mice were generated carrying the CDK4 gene under the control of a keratin 5 promoter. As expected, transgenic mice showed expression of CDK4 in the epidermal basal-cell layer. Epidermal proliferation increased dramatically and basal cell hyperplasia and hypertrophy were observed. The hyperproliferative phenotype of these transgenic mice was independent of D-type cyclin expression because no overexpression of these proteins was detected. CDK4 and CDK2 kinase activities increased in transgenic animals and were associated with elevated binding of p27Kip1 to CDK4. Expression of CDK4 in the epidermis results in an increased spinous layer compared with normal epidermis, and a mild hyperkeratosis in the cornified layer. In addition to epidermal changes, severe dermal fibrosis was observed and part of the subcutaneous adipose tissue was replaced by connective tissue. Also, abnormal expression of keratin 6 associated with the hyperproliferative phenotype was observed in transgenic epidermis. This model provides in vivo evidence for the role of CDK4 as a mediator of proliferation in epithelial cells independent of D-type cyclin expression. PMID:11438484

  10. Running increases neurogenesis without retinoic acid receptor activation in the adult mouse dentate gyrus.

    PubMed

    Aberg, Elin; Perlmann, Thomas; Olson, Lars; Brené, Stefan

    2008-01-01

    Both vitamin A deficiency and high doses of retinoids can result in learning and memory impairments, depression as well as decreases in cell proliferation, neurogenesis and cell survival. Physical activity enhances hippocampal neurogenesis and can also exert an antidepressant effect. Here we elucidate a putative link between running, retinoid signaling, and neurogenesis in hippocampus. Adult transgenic reporter mice designed to detect ligand-activated retinoic acid receptors (RAR) or retinoid X receptors (RXR) were used to localize the distribution of activated RAR or RXR at the single-cell level in the brain. Two months of voluntary wheel-running induced an increase in hippocampal neurogenesis as indicated by an almost two-fold increase in doublecortin-immunoreactive cells. Running activity was correlated with neurogenesis. Under basal conditions a distinct pattern of RAR-activated cells was detected in the granule cell layer of the dentate gyrus (DG), thalamus, and cerebral cortex layers 3-4 and to a lesser extent in hippocampal pyramidal cell layers CA1-CA3. Running did not change the number of RAR-activated cells in the DG. There was no correlation between running and RAR activation or between RAR activation and neurogenesis in the DG of hippocampus. Only a few scattered activated retinoid X receptors were found in the DG under basal conditions and after wheel-running, but RXR was detected in other areas such as in the hilus region of hippocampus and in layer VI of cortex cerebri. RAR agonists affect mood in humans and reduce neurogenesis, learning and memory in animal models. In our study, long-term running increased neurogenesis but did not alter RAR ligand activation in the DG in individually housed mice. Thus, our data suggest that the effects of exercise on neurogenesis and other plasticity changes in the hippocampal formation are mediated by mechanisms that do not involve retinoid receptor activation.

  11. Changes in muscle activation patterns when running step rate is increased.

    PubMed

    Chumanov, Elizabeth S; Wille, Christa M; Michalski, Max P; Heiderscheit, Bryan C

    2012-06-01

    Running with a step rate 5-10% greater than one's preferred can substantially reduce lower extremity joint moments and powers, and has been suggested as a possible strategy to aid in running injury management. The purpose of this study was to examine how neuromuscular activity changes with an increase in step rate during running. Forty-five injury-free, recreational runners participated in this study. Three-dimensional motion, ground reaction forces, and electromyography (EMG) of 8 muscles (rectus femoris, vastus lateralis, medial gastrocnemius, tibialis anterior, medial and lateral hamstrings, and gluteus medius and maximus) were recorded as each subject ran at their preferred speed for three different step rate conditions: preferred, +5% and +10% of preferred. Outcome measures included mean normalized EMG activity for each muscle at specific periods during the gait cycle. Muscle activities were found to predominantly increase during late swing, with no significant change in activities during the loading response. This increased muscle activity in anticipation of foot-ground contact likely alters the landing posture of the limb and the subsequent negative work performed by the joints during stance phase. Further, the increased activity observed in the gluteus maximus and medius suggests running with a greater step rate may have therapeutic benefits to those with anterior knee pain.

  12. Hyperthyroidism increases the uncoupled ATPase activity and heat production by the sarcoplasmic reticulum Ca2+-ATPase.

    PubMed Central

    Arruda, Ana Paula; Da-Silva, Wagner S; Carvalho, Denise P; De Meis, Leopoldo

    2003-01-01

    The sarcoplasmic reticulum Ca2+-ATPase is able to modulate the distribution of energy released during ATP hydrolysis, so that a portion of energy is used for Ca2+ transport (coupled ATPase activity) and a portion is converted into heat (uncoupled ATPase activity). In this report it is shown that T4 administration to rabbits promotes an increase in the rates of both the uncoupled ATPase activity and heat production in sarcoplasmic reticulum vesicles, and that the degree of activation varies depending on the muscle type used. In white muscles hyperthyroidism promotes a 0.8-fold increase of the uncoupled ATPase activity and in red muscle a 4-fold increase. The yield of vesicles from hyperthyroid muscles is 3-4-fold larger than that obtained from normal muscles; thus the rate of heat production by the Ca2+-ATPase expressed in terms of g of muscle in hyperthyroidism is increased by a factor of 3.6 in white muscles and 12.0 in red muscles. The data presented suggest that the Ca2+-ATPase uncoupled activity may represent one of the heat sources that contributes to the enhanced thermogenesis noted in hyperthyroidism. PMID:12887329

  13. Large contribution of sea surface warming to recent increase in Atlantic hurricane activity.

    PubMed

    Saunders, Mark A; Lea, Adam S

    2008-01-31

    Atlantic hurricane activity has increased significantly since 1995 (refs 1-4), but the underlying causes of this increase remain uncertain. It is widely thought that rising Atlantic sea surface temperatures have had a role in this, but the magnitude of this contribution is not known. Here we quantify this contribution for storms that formed in the tropical North Atlantic, Caribbean Sea and Gulf of Mexico; these regions together account for most of the hurricanes that make landfall in the United States. We show that a statistical model based on two environmental variables--local sea surface temperature and an atmospheric wind field--can replicate a large proportion of the variance in tropical Atlantic hurricane frequency and activity between 1965 and 2005. We then remove the influence of the atmospheric wind field to assess the contribution of sea surface temperature. Our results indicate that the sensitivity of tropical Atlantic hurricane activity to August-September sea surface temperature over the period we consider is such that a 0.5 degrees C increase in sea surface temperature is associated with a approximately 40% increase in hurricane frequency and activity. The results also indicate that local sea surface warming was responsible for approximately 40% of the increase in hurricane activity relative to the 1950-2000 average between 1996 and 2005. Our analysis does not identify whether warming induced by greenhouse gases contributed to the increase in hurricane activity, but the ability of climate models to reproduce the observed relationship between hurricanes and sea surface temperature will serve as a useful means of assessing whether they are likely to provide reliable projections of future changes in Atlantic hurricane activity.

  14. Exogenous methyl jasmonate treatment increases glucosinolate biosynthesis and quinone reductase activity in kale leaf tissue.

    PubMed

    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, P<0.001). Concentrations required to double the specific QR activity (CD values) of I3C was calculated at 230 µM, which is considerably weaker at induction than other isothiocyanates like sulforphane. To confirm relationships between GS hydrolysis products and QR activity, a range of concentrations of MeJA sprays were applied to kale 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

  15. Increasing activity and thermal resistance of Bacillus gibsonii alkaline protease (BgAP) by directed evolution.

    PubMed

    Martinez, Ronny; Jakob, Felix; Tu, Ran; Siegert, Petra; Maurer, Karl-Heinz; Schwaneberg, Ulrich

    2013-03-01

    Bacillus gibsonii Alkaline Protease (BgAP) is a recently reported subtilisin protease exhibiting activity and stability properties suitable for applications in laundry and dish washing detergents. However, BgAP suffers from a significant decrease of activity at low temperatures. In order to increase BgAP activity at 15°C, a directed evolution campaign based on the SeSaM random mutagenesis method was performed. An optimized microtiter plate expression system in B. subtilis was established and classical proteolytic detection methods were adapted for high throughput screening. In parallel, the libraries were screened for increased residual proteolytic activity after incubation at 58°C. Three iterative rounds of directed BgAP evolution yielded a set of BgAP variants with increased specific activity (K(cat)) at 15°C and increased thermal resistance. Recombination of both sets of amino acid substitutions resulted finally in variant MF1 with a 1.5-fold increased specific activity (15°C) and over 100 times prolonged half-life at 60°C (224 min compared to 2 min of the WT BgAP). None of the introduced amino acid substitutions were close to the active site of BgAP. Activity-altering amino acid substitutions were from non-charged to non-charged or from sterically demanding to less demanding. Thermal stability improvements were achieved by substitutions to negatively charged amino acids in loop areas of the BgAP surface which probably fostered ionic and hydrogen bonds interactions.

  16. Oxytocin increases VTA activation to infant and sexual stimuli in nulliparous and postpartum women.

    PubMed

    Gregory, Rebecca; Cheng, Hu; Rupp, Heather A; Sengelaub, Dale R; Heiman, Julia R

    2015-03-01

    After giving birth, women typically experience decreased sexual desire and increased responsiveness to infant stimuli. These postpartum changes may be viewed as a trade-off in reproductive interests, which could be due to alterations in brain activity including areas associated with reward. The goal of this study was to describe the roles of oxytocin and parity on reward area activation in response to reproductive stimuli, specifically infant and sexual images. Because they have been shown to be associated with reward, the ventral tegmental area (VTA) and nucleus accumbens (NAc) were targeted as areas of expected alterations in activity. Oxytocin was chosen as a potential mediator of reproductive trade-offs because of its relationship to both mother-infant interactions, including breastfeeding and bonding, and sexual responses. We predicted that postpartum women would show higher reward area activation to infant stimuli and nulliparous women would show higher activation to sexual stimuli and that oxytocin would increase activation to infant stimuli in nulliparous women. To test this, we measured VTA and NAc activation using fMRI in response to infant photos, sexual photos, and neutral photos in 29 postpartum and 30 nulliparous women. Participants completed the Sexual Inhibition (SIS) and Sexual Excitation (SES) Scales and the Brief Index of Sexual Function for Women (BISF-W), which includes a sexual desire dimension, and received either oxytocin or placebo nasal spray before viewing crying and smiling infant and sexual images in an fMRI scanner. For both groups of women, intranasal oxytocin administration increased VTA activation to both crying infant and sexual images but not to smiling infant images. We found that postpartum women showed lower SES, higher SIS, and lower sexual desire compared to nulliparous women. Across parity groups, SES scores were correlated with VTA activation and subjective arousal ratings to sexual images. In postpartum women, sexual

  17. Oxytocin increases VTA activation to infant and sexual stimuli in nulliparous and postpartum women.

    PubMed

    Gregory, Rebecca; Cheng, Hu; Rupp, Heather A; Sengelaub, Dale R; Heiman, Julia R

    2015-03-01

    After giving birth, women typically experience decreased sexual desire and increased responsiveness to infant stimuli. These postpartum changes may be viewed as a trade-off in reproductive interests, which could be due to alterations in brain activity including areas associated with reward. The goal of this study was to describe the roles of oxytocin and parity on reward area activation in response to reproductive stimuli, specifically infant and sexual images. Because they have been shown to be associated with reward, the ventral tegmental area (VTA) and nucleus accumbens (NAc) were targeted as areas of expected alterations in activity. Oxytocin was chosen as a potential mediator of reproductive trade-offs because of its relationship to both mother-infant interactions, including breastfeeding and bonding, and sexual responses. We predicted that postpartum women would show higher reward area activation to infant stimuli and nulliparous women would show higher activation to sexual stimuli and that oxytocin would increase activation to infant stimuli in nulliparous women. To test this, we measured VTA and NAc activation using fMRI in response to infant photos, sexual photos, and neutral photos in 29 postpartum and 30 nulliparous women. Participants completed the Sexual Inhibition (SIS) and Sexual Excitation (SES) Scales and the Brief Index of Sexual Function for Women (BISF-W), which includes a sexual desire dimension, and received either oxytocin or placebo nasal spray before viewing crying and smiling infant and sexual images in an fMRI scanner. For both groups of women, intranasal oxytocin administration increased VTA activation to both crying infant and sexual images but not to smiling infant images. We found that postpartum women showed lower SES, higher SIS, and lower sexual desire compared to nulliparous women. Across parity groups, SES scores were correlated with VTA activation and subjective arousal ratings to sexual images. In postpartum women, sexual

  18. Oxytocin increases VTA activation to infant and sexual stimuli in nulliparous and postpartum women

    PubMed Central

    Gregory, Rebecca; Cheng, Hu; Rupp, Heather A.; Sengelaub, Dale R.; Heiman, Julia R.

    2015-01-01

    After giving birth, women typically experience decreased sexual desire and increased responsiveness to infant stimuli. These postpartum changes may be viewed as a trade-off in reproductive interests, which could be due to alterations in brain activity including areas associated with reward. The goal of this study was to describe the roles of oxytocin and parity on reward area activation in response to reproductive stimuli, specifically infant and sexual images. Because they have been shown to be associated with reward, the ventral tegmental area (VTA) and nucleus accumbens (NAc) were targeted as areas of expected alterations in activity. Oxytocin was chosen as a potential mediator of reproductive trade-offs because of its relationship to both mother–infant interactions, including breastfeeding and bonding, and sexual responses. We predicted that postpartum women would show higher reward area activation to infant stimuli and nulliparous women would show higher activation to sexual stimuli and that oxytocin would increase activation to infant stimuli in nulliparous women. To test this, we measured VTA and NAc activation using fMRI in response to infant photos, sexual photos, and neutral photos in 29 postpartum and 30 nulliparous women. Participants completed the Sexual Inhibition (SIS) and Sexual Excitation (SES) Scales and the Brief Index of Sexual Function for Women (BISF-W), which includes a sexual desire dimension, and received either oxytocin or placebo nasal spray before viewing crying and smiling infant and sexual images in an fMRI scanner. For both groups of women, intranasal oxytocin administration increased VTA activation to both crying infant and sexual images but not to smiling infant images. We found that postpartum women showed lower SES, higher SIS, and lower sexual desire compared to nulliparous women. Across parity groups, SES scores were correlated with VTA activation and subjective arousal ratings to sexual images. In postpartum women, sexual

  19. Fenofibrate activates AMPK and increases eNOS phosphorylation in HUVEC

    SciTech Connect

    Murakami, Hisashi; Murakami, Ryuichiro . E-mail: ryuichi@med.nagoya-u.ac.jp; Kambe, Fukushi; Cao, Xia; Takahashi, Ryotaro; Asai, Toru; Hirai, Toshihisa; Numaguchi, Yasushi; Okumura, Kenji; Seo, Hisao; Murohara, Toyoaki

    2006-03-24

    Fenofibrate improves endothelial function by lipid-lowering and anti-inflammatory effects. Additionally, fenofibrate has been demonstrated to upregulate endothelial nitric oxide synthase (eNOS). AMP-activated protein kinase (AMPK) has been reported to phosphorylate eNOS at Ser-1177 and stimulate vascular endothelium-derived nitric oxide (NO) production. We report here that fenofibrate activates AMPK and increases eNOS phosphorylation and NO production in human umbilical vein endothelial cells (HUVEC). Incubation of HUVEC with fenofibrate increased the phosphorylation of AMPK and acetyl-CoA carboxylase. Fenofibrate simultaneously increased eNOS phosphorylation and NO production. Inhibitors of protein kinase A and phosphatidylinositol 3-kinase failed to suppress the fenofibrate-induced eNOS phosphorylation. Neither bezafibrate nor WY-14643 activated AMPK in HUVEC. Furthermore, fenofibrate activated AMPK without requiring any transcriptional activities. These results indicate that fenofibrate stimulates eNOS phosphorylation and NO production through AMPK activation, which is suggested to be a novel characteristic of this agonist and unrelated to its effects on peroxisome proliferator-activated receptor {alpha}.

  20. Flaking process increases the NF-κB inhibition activity and melanoidin extractability of coffee

    PubMed Central

    Chu, Yi-Fang; Hu, Kang; Hatzold, Thomas; Black, Richard M; Chen, Don

    2013-01-01

    Research on the health impacts of coffee has escalated. However, few studies were devoted to understanding the potential impact of mechanical processing on coffee's chemistry and subsequent health implications. Coffee flaking is a commonly used process to improve extractability and aroma characteristics. In this study, we studied the biochemical activity, chemical composition, and microstructure of coffee before and after flaking. We found that flaked coffee extract had 3.3-fold higher activity in inhibiting nuclear factor-kappa B (NF-κB) activation than regular coffee extract. Interestingly, flaking did not significantly alter the amount of coffee phenolics. It increased coffee melanoidin, by 2.1-fold, which likely contributed to the observed higher activity in inhibiting NF-κB activation. Flaking crushed cell walls revealed by microscopy might possibly result in disruption of polysaccharide entanglement and release of high-molecular-weight compounds, such as melanoidins. Consequently, the increased melanoidin content in the brew resulted in the increased inhibition of NF-κB activation. Small molecules, like coffee phenolics, are readily soluble in water during coffee brewing even without flaking, suggesting that flaking has no effect on its extractability. In summary, our investigation revealed that flaking enhanced NF-κB inhibition activity, possibly through the release of melanoidins from crushed cell microstructures. PMID:24804042

  1. Flaking process increases the NF-κB inhibition activity and melanoidin extractability of coffee.

    PubMed

    Chu, Yi-Fang; Hu, Kang; Hatzold, Thomas; Black, Richard M; Chen, Don

    2013-09-01

    Research on the health impacts of coffee has escalated. However, few studies were devoted to understanding the potential impact of mechanical processing on coffee's chemistry and subsequent health implications. Coffee flaking is a commonly used process to improve extractability and aroma characteristics. In this study, we studied the biochemical activity, chemical composition, and microstructure of coffee before and after flaking. We found that flaked coffee extract had 3.3-fold higher activity in inhibiting nuclear factor-kappa B (NF-κB) activation than regular coffee extract. Interestingly, flaking did not significantly alter the amount of coffee phenolics. It increased coffee melanoidin, by 2.1-fold, which likely contributed to the observed higher activity in inhibiting NF-κB activation. Flaking crushed cell walls revealed by microscopy might possibly result in disruption of polysaccharide entanglement and release of high-molecular-weight compounds, such as melanoidins. Consequently, the increased melanoidin content in the brew resulted in the increased inhibition of NF-κB activation. Small molecules, like coffee phenolics, are readily soluble in water during coffee brewing even without flaking, suggesting that flaking has no effect on its extractability. In summary, our investigation revealed that flaking enhanced NF-κB inhibition activity, possibly through the release of melanoidins from crushed cell microstructures. PMID:24804042

  2. Increased serum mitochondrial creatine kinase activity as a risk for hepatocarcinogenesis in chronic hepatitis C patients.

    PubMed

    Enooku, Kenichiro; Nakagawa, Hayato; Soroida, Yoko; Ohkawa, Ryunosuke; Kageyama, Yuko; Uranbileg, Baasanjav; Watanabe, Naoko; Tateishi, Ryosuke; Yoshida, Haruhiko; Koike, Kazuhiko; Yatomi, Yutaka; Ikeda, Hitoshi

    2014-08-15

    Serum mitochondrial creatine kinase (MtCK) activity was reportedly increased in cirrhotic patients although less prominent than that in hepatocellular carcinoma (HCC) patients. To elucidate the clinical significance of serum MtCK activity in chronic liver disease, 171 chronic hepatitis C patients were enrolled. Serum MtCK activity in study subjects was correlated with serum albumin, platelet counts, liver stiffness values and serum aspartate and alanine aminotransferase. In mouse fibrotic liver induced by bile duct ligation, ubiquitous MtCK mRNA and protein expressions were significantly enhanced and its immunoreactivity was increased, predominantly in hepatocytes. During the mean follow-up period of 2.7 years, HCC developed in 21 patients, in whom serum MtCK activity was significantly higher than that in patients without HCC development. Multivariate Cox regression analysis revealed that higher serum MtCK activity was a risk for HCC development. A cutoff value of MtCK for the prediction of HCC development was determined as 9.0 U/L on receiver operating characteristics analysis, where area under receiver operating characteristics curve was 0.754, with a sensitivity of 61.9%, a specificity of 92.8% and a high negative predictive value of 94.2%. Cumulative incidence of HCC was significantly higher in patients with serum MtCK activity of >9.0 U/L compared to those with serum MtCK activity of ≤ 9.0 U/L even in patients with elevated liver stiffness value, >15 kPa. In conclusion, serum MtCK activity may be increased correlatively with the stage of liver fibrosis and hepatocellular damage. Increased serum MtCK activity is an independent risk for hepatocarcinogenesis in chronic hepatitis C patients. PMID:24420733

  3. Increased β-cyanoalanine nitrilase activity improves cyanide tolerance and assimilation in Arabidopsis.

    PubMed

    O'Leary, Brendan; Preston, Gail M; Sweetlove, Lee J

    2014-01-01

    Plants naturally produce cyanide (CN) which is maintained at low levels in their cells by a process of rapid assimilation. However, high concentrations of environmental CN associated with activities such as industrial pollution are toxic to plants. There is thus an interest in increasing the CN detoxification capacity of plants as a potential route to phytoremediation. Here, Arabidopsis seedlings overexpressing the Pseudomonas fluorescens β-cyanoalanine nitrilase pinA were compared with wild-type and a β-cyanoalanine nitrilase knockout line (ΔAtnit4) for growth in the presence of exogenous CN. After incubation with CN, +PfpinA seedlings had increased root length, increased fresh weight, and decreased leaf bleaching compared with wild-type, indicating increased CN tolerance. The increased tolerance was achieved without an increase in β-cyanoalanine synthase activity, the other enzyme in the cyanide assimilation pathway, suggesting that nitrilase activity is the limiting factor for cyanide detoxification. Labeling experiments with [¹³C]KCN demonstrated that the altered CN tolerance could be explained by differences in flux from CN to Asn caused by altered β-cyanoalanine nitrilase activity. Metabolite profiling after CN treatment provided new insight into downstream metabolism, revealing onward metabolism of Asn by the photorespiratory nitrogen cycle and accumulation of aromatic amino acids.

  4. Dietary resveratrol administration increases MnSOD expression and activity in mouse brain

    SciTech Connect

    Robb, Ellen L.; Winkelmolen, Lieke; Visanji, Naomi; Brotchie, Jonathan; Stuart, Jeffrey A.

    2008-07-18

    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.

  5. Long-term aerobic exercise increases redox-active iron through nitric oxide in rat hippocampus.

    PubMed

    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.

  6. Increasing brain angiotensin converting enzyme 2 activity decreases anxiety-like behavior in male mice by activating central Mas receptors.

    PubMed

    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

  7. Methylglyoxal increases cardiomyocyte ischemia-reperfusion injury via glycative inhibition of thioredoxin activity

    PubMed Central

    Wang, Xiao-Liang; Lau, Wayne B.; Yuan, Yue-Xing; Wang, Ya-Jing; Yi, Wei; Christopher, Theodore A.; Lopez, Bernard L.; Liu, Hui-Rong

    2010-01-01

    Diabetes mellitus (DM) is closely related to cardiovascular morbidity and mortality, but the specific molecular basis linking DM with increased vulnerability to cardiovascular injury remains incompletely understood. Methylglyoxal (MG), a precursor to advanced glycation end products (AGEs), is increased in diabetic patient plasma, but its role in diabetic cardiovascular complications is unclear. Thioredoxin (Trx), a cytoprotective molecule with antiapoptotic function, has been demonstrated to be vulnerable to glycative inhibition, but whether Trx is glycatively inhibited by MG, thus contributing to increased cardiac injury, has never been investigated. Cultured H9c2 cardiomyocytes were treated with MG (200 μM) for 6 days. The following were determined pre- and post-simulated ischemia-reperfusion (SI-R; 8 h of hypoxia followed by 3 h of reoxygenation): cardiomyocyte death/apoptosis, Trx expression and activity, AGE formation, Trx-apoptosis-regulating kinase-1 (Trx-ASK1) complex formation, and p38 mitogen-activated protein kinase (MAPK) phosphorylation and activity. Compared with vehicle, MG significantly increased SI-R-induced cardiomyocyte LDH release and apoptosis (P < 0.01). Prior to SI-R, Trx activity was reduced in MG-treated cells, but Trx expression was increased moderately. Moreover, Trx-ASK1 complex formation was reduced, and both p38 MAPK activity and phosphorylation were increased. To investigate the effects of MG on Trx directly, recombinant human Trx (hTrx) was incubated with MG in vitro. Compared with vehicle, MG incubation markedly increased CML formation (a glycation footprint) and inhibited Trx activity. Finally, glycation inhibitor aminoguanidine administration during MG treatment of cultured cells reduced AGE formation, increased Trx activity, restored Trx-ASK1 interaction, and reduced p38 MAPK phosphorylation and activity, caspase-3 activation, and LDH release (P < 0.01). We demonstrated for the first time that methylglyoxal sensitized cultured

  8. Interventions to Increase Physical Activity in Children Aged 2-5 Years: A Systematic Review.

    PubMed

    Ling, Jiying; Robbins, Lorraine B; Wen, Fujun; Peng, Wei

    2015-08-01

    Comprehensive evaluation of prior interventions designed to increase preschoolers' physical activity is lacking. This systematic review aimed to examine the effect of interventions on objectively measured physical activity in children aged 2-5 years. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. In May 2014, we searched PubMed, CINAHL, PsycINFO, ERIC, SPORTDiscus, Cochrane, and Embase. Two reviewers independently identified and appraised the studies. Twenty-four articles describing 23 independent studies and 20 unique interventions met inclusion criteria. Of the 8 interventions resulting in a significant effect in objectively measured physical activity, all were center-based and included a structured physical activity component, 6 included multiple components, 5 integrated theories or models, and 4 actively involved parents. Seven of the 8 were randomized controlled trials. Due to the heterogeneity of the study designs, physical activity measures, and interventions, drawing definitive conclusions was difficult. Although the overall intervention effect was less than optimal, the review indicated that theory-driven, multicomponent interventions including a structured physical activity component and targeting both parents and their children may be a promising approach for increasing preschoolers' physical activity and warrant continued investigation using rigorous designs to identify those that are most effective.

  9. Selective Estrogen Receptor Modulation Increases Hippocampal Activity during Probabilistic Association Learning in Schizophrenia.

    PubMed

    Kindler, Jochen; Weickert, Cynthia Shannon; Skilleter, Ashley J; Catts, Stanley V; Lenroot, Rhoshel; Weickert, Thomas W

    2015-09-01

    People with schizophrenia show probabilistic association learning impairment in conjunction with abnormal neural activity. The selective estrogen receptor modulator (SERM) raloxifene preserves neural activity during memory in healthy older men and improves memory in schizophrenia. Here, we tested the extent to which raloxifene modifies neural activity during learning in schizophrenia. Nineteen people with schizophrenia participated in a twelve-week randomized, double-blind, placebo-controlled, cross-over adjunctive treatment trial of the SERM raloxifene administered orally at 120 mg daily to assess brain activity during probabilistic association learning using functional magnetic resonance imaging (fMRI). Raloxifene improved probabilistic association learning and significantly increased fMRI BOLD activity in the hippocampus and parahippocampal gyrus relative to placebo. A separate region of interest confirmatory analysis in 21 patients vs 36 healthy controls showed a positive association between parahippocampal neural activity and learning in patients, but no such relationship in the parahippocampal gyrus of healthy controls. Thus, selective estrogen receptor modulation by raloxifene concurrently increases activity in the parahippocampal gyrus and improves probabilistic association learning in schizophrenia. These results support a role for estrogen receptor modulation of mesial temporal lobe neural activity in the remediation of learning disabilities in both men and women with schizophrenia.

  10. Estrogen increases Nrf2 activity through activation of the PI3K pathway in MCF-7 breast cancer cells

    SciTech Connect

    Wu, Juanjuan; Williams, Devin; Walter, Grant A.; Thompson, Winston E.; Sidell, Neil

    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

  11. Peers increase adolescent risk taking by enhancing activity in the brain’s reward circuitry

    PubMed Central

    Chein, Jason; Albert, Dustin; O’Brien, Lia; Uckert, Kaitlyn; Steinberg, Laurence

    2010-01-01

    The presence of peers increases risk taking among adolescents but not adults. We posited that the presence of peers may promote adolescent risk taking by sensitizing brain regions associated with the anticipation of potential rewards. Using fMRI, we measured brain activity in adolescents, young adults, and adults as they made decisions in a simulated driving task. Participants completed one task block while alone, and one block while their performance was observed by peers in an adjacent room. During peer observation blocks, adolescents selectively demonstrated greater activation in reward-related brain regions, including the ventral striatum and orbitofrontal cortex, and activity in these regions predicted subsequent risk taking. Brain areas associated with cognitive control were less strongly recruited by adolescents than adults, but activity in the cognitive control system did not vary with social context. Results suggest that the presence of peers increases adolescent risk taking by heightening sensitivity to the potential reward value of risky decisions. PMID:21499511

  12. Engineering of TM1459 from Thermotoga maritima for Increased Oxidative Alkene Cleavage Activity

    PubMed Central

    Fink, Matthias; Trunk, Sarah; Hall, Mélanie; Schwab, Helmut; Steiner, Kerstin

    2016-01-01

    Oxidative cleavage of alkenes is a widely employed process allowing oxyfunctionalization to corresponding carbonyl compounds. Recently, a novel biocatalytic oxidative alkene cleavage activity on styrene derivatives was identified in TM1459 from Thermotoga maritima. In this work we engineered the enzyme by site-saturation mutagenesis of active site amino acids to increase its activity and to broaden its substrate scope. A high-throughput assay for the detection of the ketone products was successfully developed. Several variants with up to twofold improved conversion level of styrene derivatives were successfully identified. Especially, changes in or removal of the C-terminus of TM1459 increased the activity most significantly. These best variants also displayed a slightly enlarged substrate scope. PMID:27713741

  13. Increased activity in frontal motor cortex compensates impaired speech perception in older adults

    PubMed Central

    Du, Yi; Buchsbaum, Bradley R.; Grady, Cheryl L.; Alain, Claude

    2016-01-01

    Understanding speech in noisy environments is challenging, especially for seniors. Although evidence suggests that older adults increasingly recruit prefrontal cortices to offset reduced periphery and central auditory processing, the brain mechanisms underlying such compensation remain elusive. Here we show that relative to young adults, older adults show higher activation of frontal speech motor areas as measured by functional MRI during a syllable identification task at varying signal-to-noise ratios. This increased activity correlates with improved speech discrimination performance in older adults. Multivoxel pattern classification reveals that despite an overall phoneme dedifferentiation, older adults show greater specificity of phoneme representations in frontal articulatory regions than auditory regions. Moreover, older adults with stronger frontal activity have higher phoneme specificity in frontal and auditory regions. Thus, preserved phoneme specificity and upregulation of activity in speech motor regions provide a means of compensation in older adults for decoding impoverished speech representations in adverse listening conditions. PMID:27483187

  14. Ionizing radiations increase the activity of the cell surface glycohydrolases and the plasma membrane ceramide content.

    PubMed

    Aureli, Massimo; Bassi, Rosaria; Prinetti, Alessandro; Chiricozzi, Elena; Pappalardi, Brigida; Chigorno, Vanna; Di Muzio, Nadia; Loberto, Nicoletta; Sonnino, Sandro

    2012-12-01

    We detected significant levels of β-glucosidase, β-galactosidase, sialidase Neu3 and sphingomyelinase activities associated with the plasma membrane of fibroblasts from normal and Niemann-Pick subjects and of cells from breast, ovary, colon and neuroblastoma tumors in culture. All of the cells subjected to ionizing radiations showed an increase of the activity of plasma membrane β-glucosidase, β-galactosidase and sialidase Neu3, in addition of the well known increase of activity of plasma membrane sphingomyelinase, under similar conditions. Human breast cancer cell line T47D was studied in detail. In these cells the increase of activity of β-glucosidase and β-galactosidase was parallel to the increase of irradiation dose up to 60 Gy and continued with time, at least up to 72 h from irradiation. β-glucosidase increased up to 17 times and β-galactosidase up to 40 times with respect to control. Sialidase Neu3 and sphingomyelinase increased about 2 times at a dose of 20 Gy but no further significant differences were observed with increase of radiation dose and time. After irradiation, we observed a reduction of cell proliferation, an increase of apoptotic cell death and an increase of plasma membrane ceramide up to 3 times, with respect to control cells. Tritiated GM3 ganglioside has been administered to T47D cells under conditions that prevented the lysosomal catabolism. GM3 became component of the plasma membranes and was transformed into LacCer, GlcCer and ceramide. The quantity of ceramide produced in irradiated cells was about two times that of control cells.

  15. Increased Myeloperoxidase Activity and Protein Nitration Are Indicators of Inflammation in Patients with Chagas' Disease▿

    PubMed Central

    Dhiman, Monisha; Estrada-Franco, Jose Guillermo; Pando, Jasmine M.; Ramirez-Aguilar, Francisco J.; Spratt, Heidi; Vazquez-Corzo, Sara; Perez-Molina, Gladys; Gallegos-Sandoval, Rosa; Moreno, Roberto; Garg, Nisha Jain

    2009-01-01

    In this study, we investigated whether inflammatory responses contribute to oxidative/nitrosative stress in patients with Chagas' disease. We used three tests (enzyme-linked immunosorbent assay, immuno-flow cytometry, and STAT-PAK immunochromatography) to screen human serum samples (n = 1,481) originating from Chiapas, Mexico, for Trypanosoma cruzi-specific antibodies. We identified 121 subjects who were seropositive for T. cruzi-specific antibodies, a finding indicative of an 8.5% seroprevalence in the rural population from Chiapas. Seropositive and seronegative subjects were examined for plasma levels of biomarkers of inflammation, i.e., myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS), and xanthine oxidase (XOD), as well as for oxidative (advanced oxidation protein products [AOPPs]) and nitrosative (3-nitrotyrosine [3NT]) biomarkers. The seropositive subjects exhibited a significant increase in MPO activity and protein level, the indicator of neutrophil activation. Subsequently, a corresponding increase in AOPP contents, formed by MPO-dependent hypochlorous acid and chloramine formation, was noted in seropositive subjects. The plasma level of 3NT was significantly increased in seropositive subjects, yet we observed no change in XOD activity (O2− source) and nitrate/nitrite contents (denotes iNOS activation and NO production), which implied that direct peroxynitrite formation does not contribute to increased nitrosative damage in chagasic subjects. Instead, a positive correlation between increased MPO activity and protein 3NT formation was observed, which suggested to us that MPO-dependent formation of nitrylchloride that occurs in the presence of physiological NO and O2− concentrations contributes to protein nitration. Overall, our data demonstrate that T. cruzi-induced neutrophil activation is pathological and contributes to MPO-mediated collateral protein oxidative and nitrosative damage in human patients with Chagas' disease. Therapies

  16. Carbon-Degrading Enzyme Activities Stimulated by Increased Nutrient Availability in Arctic Tundra Soils

    PubMed Central

    Koyama, Akihiro; Wallenstein, Matthew D.; Simpson, Rodney T.; Moore, John C.

    2013-01-01

    Climate-induced warming of the Arctic tundra is expected to increase nutrient availability to soil microbes, which in turn may accelerate soil organic matter (SOM) decomposition. We increased nutrient availability via fertilization to investigate the microbial response via soil enzyme activities. Specifically, we measured potential activities of seven enzymes at four temperatures in three soil profiles (organic, organic/mineral interface, and mineral) from untreated native soils and from soils which had been fertilized with nitrogen (N) and phosphorus (P) since 1989 (23 years) and 2006 (six years). Fertilized plots within the 1989 site received annual additions of 10 g N⋅m-2⋅year-1 and 5 g P⋅m-2⋅year-1. Within the 2006 site, two fertilizer regimes were established – one in which plots received 5 g N⋅m-2⋅year-1 and 2.5 g P⋅m-2⋅year-1 and one in which plots received 10 g N⋅m-2⋅year-1 and 5 g P⋅m-2⋅year-1. The fertilization treatments increased activities of enzymes hydrolyzing carbon (C)-rich compounds but decreased phosphatase activities, especially in the organic soils. Activities of two enzymes that degrade N-rich compounds were not affected by the fertilization treatments. The fertilization treatments increased ratios of enzyme activities degrading C-rich compounds to those for N-rich compounds or phosphate, which could lead to changes in SOM chemistry over the long term and to losses of soil C. Accelerated SOM decomposition caused by increased nutrient availability could significantly offset predicted increased C fixation via stimulated net primary productivity in Arctic tundra ecosystems. PMID:24204773

  17. Homocysteine activates T cells by enhancing endoplasmic reticulum-mitochondria coupling and increasing mitochondrial respiration.

    PubMed

    Feng, Juan; Lü, Silin; Ding, Yanhong; Zheng, Ming; Wang, Xian

    2016-06-01

    Hyperhomocysteinemia (HHcy) accelerates atherosclerosis by increasing proliferation and stimulating cytokine secretion in T cells. However, whether homocysteine (Hcy)-mediated T cell activation is associated with metabolic reprogramming is unclear. Here, our in vivo and in vitro studies showed that Hcy-stimulated splenic T-cell activation in mice was accompanied by increased levels of mitochondrial reactive oxygen species (ROS) and calcium, mitochondrial mass and respiration. Inhibiting mitochondrial ROS production and calcium signals or blocking mitochondrial respiration largely blunted Hcy-induced T-cell interferon γ (IFN-γ) secretion and proliferation. Hcy also enhanced endoplasmic reticulum (ER) stress in T cells, and inhibition of ER stress with 4-phenylbutyric acid blocked Hcy-induced T-cell activation. Mechanistically, Hcy increased ER-mitochondria coupling, and uncoupling ER-mitochondria by the microtubule inhibitor nocodazole attenuated Hcy-stimulated mitochondrial reprogramming, IFN-γ secretion and proliferation in T cells, suggesting that juxtaposition of ER and mitochondria is required for Hcy-promoted mitochondrial function and T-cell activation. In conclusion, Hcy promotes T-cell activation by increasing ER-mitochondria coupling and regulating metabolic reprogramming.

  18. Ribulose diphosphate carboxylase synthesis in euglena: increased enzyme activity after transferring regreening cells to darkness.

    PubMed

    Lord, J M; Merrett, M J

    1975-05-01

    The transfer of dark-grown cultures of Euglena gracilis Klebs strain Z regreening in the light back into darkness resulted in a dramatic increase in ribulose diphosphate carboxylase activity. On a culture volume basis activity increased 4-fold over a 24-hour dark period, although on a protein basis activity declined because of rapid cell division. Mixed assays with light- and dark-growing cell extracts provided no evidence for the removal of an inhibitor of ribulose diphosphate carboxylase upon transferring regreening cells back to darkness. Although ribulose diphosphate carboxylase activity increased over a 24-hour dark period, there was no concomitant increase in the potential of the cells for photosynthetic carbon dioxide fixation.Higher light intensities than the optimum for ribulose diphosphate carboxylase synthesis during regreening resulted in a greater relative rate of synthesis on transfer to darkness so that the maximum activity of ribulose diphosphate carboxylase reached in the dark was constant, regardless of light intensity during regreening. A tentative hypothesis to explain these results is that the synthesis of the large and small subunits of ribulose diphosphate carboxylase occur at different stages of cell development, light being necessary for the synthesis of the large subunit and also for regulating the synthesis of the small subunit.

  19. K153R polymorphism in myostatin gene increases the rate of promyostatin activation by furin.

    PubMed

    Szláma, György; Trexler, Mária; Buday, László; Patthy, László

    2015-01-30

    Recent studies demonstrated an association between the K153R polymorphism in the myostatin gene with extreme longevity, lower muscle strength and obesity but the molecular basis of these associations has not been clarified. Here, we show that the K153R mutation significantly increases the rate of proteolysis of promyostatin by furin, but has no effect on the activity of the latent complex or the cleavage of the latent complex by bone morphogenetic protein 1 (BMP-1). The increased rate of activation of K153R mutant promyostatin may explain why this polymorphism is associated with obesity, lower muscle strength and extension of lifespan.

  20. Diagnosis and characterization of mania: Quantifying increased energy and activity in the human behavioral pattern monitor.

    PubMed

    Perry, William; McIlwain, Meghan; Kloezeman, Karen; Henry, Brook L; Minassian, Arpi

    2016-06-30

    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 subjects (HCS, n=39) in the human Behavioral Pattern Monitor (hBPM) which quantifies motor activity and goal-directed behavior in an environment containing novel stimuli. Archival hBPM data from 17 schizophrenia patients were used in sensitivity and specificity analyses. Manic BD patients exhibited higher motor activity than HCS and higher novel object interactions. hBPM activity measures were not correlated with observer-rated symptoms, and hBPM activity was more sensitive in accurately classifying hospitalized BD subjects than observer ratings. Although the findings can only be generalized to inpatient populations, they suggest that increased energy, particularly specific and goal-directed exploration, is a distinguishing feature of BD mania and is best quantified by objective measures of motor activity. A better understanding is needed of the biological underpinnings of this cardinal feature.

  1. Texting to Increase Physical Activity Among Teenagers (TXT Me!): Rationale, Design, and Methods Proposal

    PubMed Central

    Cantu, Dora; Bhatt, Riddhi; Baranowski, Tom; Rodgers, Wendy; Jago, Russell; Anderson, Barbara; Liu, Yan; Mendoza, Jason A; Tapia, Ramsey; Buday, Richard

    2014-01-01

    Background 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 maintained through adulthood. Because teens text a great deal, text messages promoting walking, a low cost physical activity, may be an effective method for promoting sustainable physical activity. Objective The objective of our study was to determine the effect of pedometers, self selected step goals, and texts grounded in the self-determination theory (SDT) on physical activity among the teens. Methods “TXT Me!” was a 12 week intervention that texted 14-17 year olds to increase their daily physical activity by increasing the number of steps they take each day. The intervention was grounded in the SDT. Formative research with the teens helped construct the intervention and develop the texts. A total of 84 texts were developed (12 to set a step goal, and 72 promoting autonomy, competence, and relatedness). The pilot evaluation used a four group, randomized design (n=160). After baseline data collection, the participants were randomized to one of four conditions (no treatment control, pedometer only, pedometer + weekly prompts, pedometer + weekly prompts + SDT grounded texts). Data were collected at baseline and immediately upon completion of the study. The primary outcome was physical activity, measured by 7 days of accelerometry. Basic psychological needs, physical activity motivation, process evaluation, and program satisfaction data were also collected. Results To our knowledge, this is one of the first studies to explore the use of stand alone, SDT grounded texts, supported by pedometers and prompts to set a self selected step goal, as a method for increasing physical activity among teens. Conclusions This pilot study will contribute valuable information

  2. Spirulina elicits the activation of innate immunity and increases resistance against Vibrio alginolyticus in shrimp.

    PubMed

    Chen, Yu-Yuan; Chen, Jiann-Chu; Tayag, Carina Miranda; Li, Hui-Fang; Putra, Dedi Fazriansyah; Kuo, Yi-Hsuan; Bai, Jia-Chin; Chang, Yu-Hsuan

    2016-08-01

    The effect of Spirulina dried powder (SDP) on the immune response of white shrimp Litopenaeus vannamei was studied in vitro and in vivo. Incubating shrimp haemocytes in 0.5 mg ml(-1) SDP caused the degranulation of haemocytes and a reduction in the percentage of large cells within 30 min. Shrimp haemocytes incubated in 1 mg ml(-1) SDP significantly increased their phenoloxidase (PO) activity, serine proteinase activity, and respiratory burst activity (RB, release of superoxide anion). A recombinant protein of lipopolysaccharide and β-1,3-glucan binding protein (LGBP) of the white shrimp was produced, named rLvLGBP, and examined for its binding with SDP. An ELISA binding assay showed that rLvLGBP binds to SDP with a dissociation constant of 0.0507 μM. In another experiment, shrimp fed diets containing SDP at 0 (control), 30, and 60 g kg(-1) after four weeks were examined for LGBP transcript level and lysozyme activity, as well as phagocytic activity, clearance efficiency, and resistance to Vibrio alginolyticus. These parameters were significantly higher in shrimp receiving diets containing SDP at 60 g kg(-1) or 30 g kg(-1) than in controls. In conclusion, shrimp haemocytes receiving SDP provoked the activation of innate immunity as evidenced by the recognition and binding of LGBP, degranulation of haemocytes, reduction in the percentage of large cells, increases in PO activity, serine proteinase activity, superoxide anion levels, and up-regulated LGBP transcript levels. Shrimp receiving diets containing SDP had increased lysozyme activity and resistance against V. alginolyticus infection. This study showed the mechanism underlying the immunostimulatory action of Spirulina and its immune response in shrimp.

  3. Let's Move for Pacific Islander Communities: an Evidence-Based Intervention to Increase Physical Activity.

    PubMed

    LaBreche, Mandy; Cheri, Ashley; Custodio, Harold; Fex, Cleo Carlos; Foo, Mary Anne; Lepule, Jonathan Tana; May, Vanessa Tui'one; Orne, Annette; Pang, Jane Ka'ala; Pang, Victor Kaiwi; Sablan-Santos, Lola; Schmidt-Vaivao, Dorothy; Surani, Zul; Talavou, Melevesi Fifita; Toilolo, Tupou; Palmer, Paula Healani; Tanjasiri, Sora Park

    2016-06-01

    Pacific Islander (PI) populations of Southern California experience high obesity and low physical activity levels. Given PI's rich cultural ties, efforts to increase physical activity using a community-tailored strategy may motivate members in a more sustainable manner. In this paper, we (1) detail the program adaptation methodology that was utilized to develop the Weaving an Islander Network for Cancer Awareness, Research and Training (WINCART) Center's PI Let's Move Program, a culturally tailored program aimed to increase physical activity levels among members of PI organizations in Southern California, and (2) share the program's pilot evaluation results on individual and organizational changes. The WINCART Center applied the National Cancer Institute's program adaptation guidelines to tailor the evidence-based Instant Recess program to fit the needs of PIs. The end product, the PI Let's Move Program, was piloted in 2012 with eight PI organizations, reaching 106 PI adults. At baseline, 52 % of participants reported that they were not physically active, with the average number of days engaged in medium-intensity physical activity at 2.09 days/week. After the 2-month program, participants increased the number of days that they engaged in medium-intensity physical activity from 2.09 to 2.90 days/week. Post-pilot results found that 82 % of participants reported intentions to engage in physical activity for at least the next 6 months. At baseline, only one organization was currently implementing a physical activity program, and none had implemented an evidence-based physical activity program tailored for PIs. After the 2-month timeframe, despite varying levels of capacity, all eight organizations were able to successfully implement the program. In conclusion, results from our program provide evidence that disparity populations, such as PIs, can be successfully reached through programs that are culturally tailored to both individuals and their community

  4. Spirulina elicits the activation of innate immunity and increases resistance against Vibrio alginolyticus in shrimp.

    PubMed

    Chen, Yu-Yuan; Chen, Jiann-Chu; Tayag, Carina Miranda; Li, Hui-Fang; Putra, Dedi Fazriansyah; Kuo, Yi-Hsuan; Bai, Jia-Chin; Chang, Yu-Hsuan

    2016-08-01

    The effect of Spirulina dried powder (SDP) on the immune response of white shrimp Litopenaeus vannamei was studied in vitro and in vivo. Incubating shrimp haemocytes in 0.5 mg ml(-1) SDP caused the degranulation of haemocytes and a reduction in the percentage of large cells within 30 min. Shrimp haemocytes incubated in 1 mg ml(-1) SDP significantly increased their phenoloxidase (PO) activity, serine proteinase activity, and respiratory burst activity (RB, release of superoxide anion). A recombinant protein of lipopolysaccharide and β-1,3-glucan binding protein (LGBP) of the white shrimp was produced, named rLvLGBP, and examined for its binding with SDP. An ELISA binding assay showed that rLvLGBP binds to SDP with a dissociation constant of 0.0507 μM. In another experiment, shrimp fed diets containing SDP at 0 (control), 30, and 60 g kg(-1) after four weeks were examined for LGBP transcript level and lysozyme activity, as well as phagocytic activity, clearance efficiency, and resistance to Vibrio alginolyticus. These parameters were significantly higher in shrimp receiving diets containing SDP at 60 g kg(-1) or 30 g kg(-1) than in controls. In conclusion, shrimp haemocytes receiving SDP provoked the activation of innate immunity as evidenced by the recognition and binding of LGBP, degranulation of haemocytes, reduction in the percentage of large cells, increases in PO activity, serine proteinase activity, superoxide anion levels, and up-regulated LGBP transcript levels. Shrimp receiving diets containing SDP had increased lysozyme activity and resistance against V. alginolyticus infection. This study showed the mechanism underlying the immunostimulatory action of Spirulina and its immune response in shrimp. PMID:27368541

  5. Increased CD28 serum levels are not associated with specific clinical activity in systemic lupus erythematosus.

    PubMed

    Brambila-Tapia, Aniel J L; Gámez-Nava, Jorge I; Salazar-Páramo, Mario; Munoz-Valle, José F; González-López, Laura; Llamas-Covarrubias, Mara A; Gutiérrez-Urena, Sergio R; Vázquez-Del Mercado, Mónica; Dávalos-Rodríguez, Ingrid P

    2011-10-01

    CD28 is one of the main activator receptors involved in systemic lupus erythematosus (SLE) pathogenesis, and its expression and serum levels are significantly higher in patients with SLE and other autoimmune diseases than in healthy controls (HC). However, it is unknown whether this increase is associated with specific organ damage. Therefore, our objective was to measure the CD28 levels in serum from SLE and HC groups to confirm the CD28 serum levels increase, as reported previously, and to determine whether this increase was associated with specific organ activity and the SLE Disease Activity Index (SLEDAI). Forty SLE patients and 40 matched HC were included, and the age, disease duration, SLEDAI and Mexican SLEDAI were recorded for the SLE group. CD28 serum levels were measured by ELISA. There was a statistically significant increase in the CD28 serum levels of SLE patients compared to controls (p = 0.039); however, we did not find any significant correlation with disease activity indices or organ involvement, although we found a significant but low correlation with C3. Our results and a review of the literature suggest that the increase in CD28 serum levels may be the result of CD28 gene overexpression, which could be related to the decrease in CD28+ T cells, T-cell hyporesponsiveness and immune impairment that occurs in SLE.

  6. Less precise motor control leads to increased agonist-antagonist muscle activation during stick balancing.

    PubMed

    Reeves, N Peter; Popovich, John M; Vijayanagar, Vilok; Pathak, Pramod K

    2016-06-01

    Human motor control has constraints in terms of its responsiveness, which limit its ability to successfully perform tasks. In a previous study, it was shown that the ability to balance an upright stick became progressively more challenging as the natural frequency (angular velocity without control) of the stick increased. Furthermore, forearm and trunk agonist and antagonist muscle activation increased as the natural frequency of the stick increased, providing evidence that the central nervous system produces agonist-antagonist muscle activation to match task dynamics. In the present study, visual feedback of the stick position was influenced by changing where subject focused on the stick during stick balancing. It was hypothesized that a lower focal height would degrade motor control (more uncertainty in tracking stick position), thus making balancing more challenging. The probability of successfully balancing the stick at four different focal heights was determined along with the average angular velocity of the stick. Electromyographic signals from forearm and trunk muscles were also recorded. As expected, the probability of successfully balancing the stick decreased and the average angular velocity of the stick increased as subjects focused lower on the stick. In addition, changes in the level of agonist and antagonist muscle activation in the forearm and trunk was linearly related to changes in the angular velocity of the stick during balancing. One possible explanation for this is that the central nervous system increases muscle activation to account for less precise motor control, possibly to improve the responsiveness of human motor control. PMID:27010497

  7. Less precise motor control leads to increased agonist-antagonist muscle activation during stick balancing.

    PubMed

    Reeves, N Peter; Popovich, John M; Vijayanagar, Vilok; Pathak, Pramod K

    2016-06-01

    Human motor control has constraints in terms of its responsiveness, which limit its ability to successfully perform tasks. In a previous study, it was shown that the ability to balance an upright stick became progressively more challenging as the natural frequency (angular velocity without control) of the stick increased. Furthermore, forearm and trunk agonist and antagonist muscle activation increased as the natural frequency of the stick increased, providing evidence that the central nervous system produces agonist-antagonist muscle activation to match task dynamics. In the present study, visual feedback of the stick position was influenced by changing where subject focused on the stick during stick balancing. It was hypothesized that a lower focal height would degrade motor control (more uncertainty in tracking stick position), thus making balancing more challenging. The probability of successfully balancing the stick at four different focal heights was determined along with the average angular velocity of the stick. Electromyographic signals from forearm and trunk muscles were also recorded. As expected, the probability of successfully balancing the stick decreased and the average angular velocity of the stick increased as subjects focused lower on the stick. In addition, changes in the level of agonist and antagonist muscle activation in the forearm and trunk was linearly related to changes in the angular velocity of the stick during balancing. One possible explanation for this is that the central nervous system increases muscle activation to account for less precise motor control, possibly to improve the responsiveness of human motor control.

  8. Warming and earlier spring increase Western U.S. forest wildfire activity

    USGS Publications Warehouse

    Westerling, A.L.; Hidalgo, H.G.; Cayan, D.R.; Swetnam, T.W.

    2006-01-01

    Western United States forest wildfire activity is widely thought to have increased in recent decades, yet neither the extent of recent changes nor the degree to which climate may be driving regional changes in wildfire has been systematically documented. Much of the public and scientific discussion of changes in western United States wildfire has focused instead on the effects of 19th- and 20th-century land-use history. We compiled a comprehensive database of large wildfires in western United States forests since 1970 and compared it with hydroclimatic and land-surface data. Here, we show that large wildfire activity increased suddenly and markedly in the mid-1980s, with higher large-wildfire frequency, longer wildfire durations, and longer wildfire seasons. The greatest increases occurred in mid-elevation, Northern Rockies forests, where land-use histories have relatively little effect on fire risks and are strongly associated with increased spring and summer temperatures and an earlier spring snowmelt.

  9. Deletion of the Neurotrophic Factor neudesin Prevents Diet-induced Obesity by Increased Sympathetic Activity

    PubMed Central

    Ohta, Hiroya; Konishi, Morichika; Kobayashi, Yusuke; Kashio, Atsuki; Mochiyama, Takayuki; Matsumura, Shigenobu; Inoue, Kazuo; Fushiki, Tohru; Nakao, Kazuwa; Kimura, Ikuo; Itoh, Nobuyuki

    2015-01-01

    Some neurotrophic factors, which are potent regulators of neuronal development and function, have recently been implicated in the control of energy balance by increasing energy expenditure. We previously identified neudesin as a novel neurotrophic factor with potential roles in the central nervous system. Although neudesin is also expressed in various peripheral tissues including adipose tissue, its physiological roles have not yet been elucidated. We found that neudesin knockout (KO) mice were resistant to high-fat diet-induced obesity and obesity-related metabolic dysfunctions. neudesin KO mice exhibited increased energy expenditure due to increased sympathetic activity, which resulted in increased heat production and fatty acid oxidation in brown adipose tissue and enhanced lipolysis in white adipose tissue. Thus, neudesin, which may be a negative regulator of sympathetic activity, could represent a novel regulator of the development of obesity and obesity-related metabolic dysfunctions. PMID:25955136

  10. Evidence that elevated CO2 levels can indirectly increase rhizosphere denitrifier activity

    NASA Technical Reports Server (NTRS)

    Smart, D. R.; Ritchie, K.; Stark, J. M.; Bugbee, B.

    1997-01-01

    We examined the influence of elevated CO2 concentration on denitrifier enzyme activity in wheat rhizoplanes by using controlled environments and solution culture techniques. Potential denitrification activity was from 3 to 24 times higher on roots that were grown under an elevated CO2 concentration of 1,000 micromoles of CO2 mol-1 than on roots grown under ambient levels of CO2. Nitrogen loss, as determined by a nitrogen mass balance, increased with elevated CO2 levels in the shoot environment and with a high NO3- concentration in the rooting zone. These results indicated that aerial CO2 concentration can play a role in rhizosphere denitrifier activity.

  11. [Increase of rising activity of commercial yeasts by application of stress conditions during their propagation].

    PubMed

    Galvagno, M A; Cerrutti, P

    2004-01-01

    Rising activity determined as CO2 production of two commercial strains of Saccharomyces cerevisiae could be increased mainly in sweet bread doughs by introducing a "starvation/pulse feeding" schedule of sugar cane molasses during a fed-batch propagation. Such increase was strain dependent. Except for the trehalose intracellular level, other traits related to the yeast industrial performance were unaffected. Applicability of method for baker's yeast industrial production is discussed.

  12. Utilizing avidity to improve antifreeze protein activity: a type III antifreeze protein trimer exhibits increased thermal hysteresis activity.

    PubMed

    Can, Özge; Holland, Nolan B

    2013-12-01

    Antifreeze proteins (AFPs) are ice growth inhibitors that allow the survival of several species living at temperatures colder than the freezing point of their bodily fluids. AFP activity is commonly defined in terms of thermal hysteresis, which is the difference observed for the solution freezing and melting temperatures. Increasing the thermal hysteresis activity of these proteins, particularly at low concentrations, is of great interest because of their wide range of potential applications. In this study, we have designed and expressed one-, two-, and three-domain antifreeze proteins to improve thermal hysteresis activity through increased binding avidity. The three-domain type III AFP yielded significantly greater activity than the one- and two-domain proteins, reaching a thermal hysteresis of >1.6 °C at a concentration of <1 mM. To elucidate the basis of this increase, the data were fit to a multidomain protein adsorption model based on the classical Langmuir isotherm. Fits of the data to the modified isotherms yield values for the equilibrium binding constants for the adsorption of AFP to ice and indicate that protein surface coverage is proportional to thermal hysteresis activity.

  13. Aging of whiskey increases 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity.

    PubMed

    Aoshima, Hitoshi; Tsunoue, Hideaki; Koda, Hirofumi; Kiso, Yoshinobu

    2004-08-11

    1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of Japanese whiskey after various aging periods in oak barrels was measured to evaluate the antioxidative effects of whiskey. The activity of the whiskey increased with the aging period with high correlation. The activity of various types of whiskey was measured and shown to be correlated to the potentiation of the GABAA receptor response measured in a previous paper. However, the fragrant compounds in the whiskey which potentiated the GABAA receptor response had low DPPH radical scavenging activity, while phenol derivatives had high radical scavenging activity. The whiskey was extracted by pentane. The aqueous part showed the scavenging activity, whereas the pentane part did not. Thus, both the DPPH radical scavenging activity and the potentiation of the GABAA receptor response increased during whiskey aging in oak barrels, but were due to different components. The whiskey protected the H2O2-induced death of E. coli more than ethanol at the same concentration as that of the whiskey. The changes that occurred in the whiskey during aging may be the reason aged whiskies are so highly valued.

  14. AM fungal exudates activate MAP kinases in plant cells in dependence from cytosolic Ca(2+) increase.

    PubMed

    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.

  15. Improvements in knee biomechanics during walking are associated with increased physical activity after total knee arthroplasty.

    PubMed

    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.

  16. Aging of whiskey increases 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity.

    PubMed

    Aoshima, Hitoshi; Tsunoue, Hideaki; Koda, Hirofumi; Kiso, Yoshinobu

    2004-08-11

    1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of Japanese whiskey after various aging periods in oak barrels was measured to evaluate the antioxidative effects of whiskey. The activity of the whiskey increased with the aging period with high correlation. The activity of various types of whiskey was measured and shown to be correlated to the potentiation of the GABAA receptor response measured in a previous paper. However, the fragrant compounds in the whiskey which potentiated the GABAA receptor response had low DPPH radical scavenging activity, while phenol derivatives had high radical scavenging activity. The whiskey was extracted by pentane. The aqueous part showed the scavenging activity, whereas the pentane part did not. Thus, both the DPPH radical scavenging activity and the potentiation of the GABAA receptor response increased during whiskey aging in oak barrels, but were due to different components. The whiskey protected the H2O2-induced death of E. coli more than ethanol at the same concentration as that of the whiskey. The changes that occurred in the whiskey during aging may be the reason aged whiskies are so highly valued. PMID:15291502

  17. Comparative Effectiveness of After-School Programs to Increase Physical Activity

    PubMed Central

    Gesell, Sabina B.; Sommer, Evan C.; Lambert, E. Warren; Vides de Andrade, Ana Regina; Davis, Lauren; Beech, Bettina M.; Mitchell, Stephanie J.; Neloms, Stevon; Ryan, Colleen K.

    2013-01-01

    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. PMID:23984052

  18. Increasing or decreasing interest in activities: the role of regulatory fit.

    PubMed

    Higgins, E Tory; Cesario, Joseph; Hagiwara, Nao; Spiegel, Scott; Pittman, Thane

    2010-04-01

    What makes people's interest in doing an activity increase or decrease? Regulatory fit theory (E. T. Higgins, 2000) provides a new perspective on this classic issue by emphasizing the relation between people's activity orientation, such as thinking of an activity as fun, and the manner of activity engagement that the surrounding situation supports. These situational factors include whether a reward for good performance, expected (Study 1) or unexpected (Study 2), is experienced as enjoyable or as serious and whether the free-choice period that measures interest in the activity is experienced as enjoyable or as serious (Study 3). Studies 1-3 found that participants were more likely to do a fun activity again when these situational factors supported a manner of doing the activity that fit the fun orientation-a reward or free-choice period framed as enjoyable. This effect was not because interest in doing an activity again is simply greater in an enjoyable than a serious surrounding situation because it did not occur, and even reversed, when the activity orientation was important rather than fun, where now a serious manner of engagement provides the fit (Study 4a and 4b).

  19. No Evidence for Activity Adjustment in Response to Increased Density in Daphnia magna.

    PubMed

    Sereni, Laura; Einum, Sigurd

    2015-01-01

    Increased population density may lead to a decrease in energy available for growth and reproduction via effects on the activity level of individuals. Whilst this may be of particular importance for organisms that compete for defendable resources and/or have a high frequency of social interactions, it is less obvious how individual activity should covary with population density when food resources are not defendable or direct interactions among individuals are negligible. Based on observations that there is a general negative relationship between population density and metabolism it has been suggested that organisms actively reduce activity under increased density to accommodate an expected decrease in food availability. However, in the absence of direct activity measurements the validity of this hypothesis is unclear. Here we test for such anticipatory adjustments of activity levels in the planktonic cladoceran Daphnia magna Straus, a filter feeder whose food resources are not defendable, meaning that density responses can be evaluated in the absence of direct interactions. We tested for changes in activity in response to two separate density cues, one being the direct physical and visual stimuli resulting from being in the vicinity of conspecifics ('direct density experiment'), and the other being the detection of olfactory cues in their environment ('olfactory cue experiment'). Ten genetically distinct clones were used to evaluate the potential for genetic variation in these responses. Our measures of activity were highly repeatable, and there was significant variation in activity among clones. Furthermore, this clonal variation was consistent in the 'direct density' and 'olfactory cue' experiments. The estimated evolvability of the trait (1.3-3.2%) was within the range typically observed in behavioural traits. However, there was no indication that the activity level of individuals respond to population density, either directly to actual density or to olfactory

  20. Alkalosis and Dialytic Clearance of Phosphate Increases Phosphatase Activity: A Hidden Consequence of Hemodialysis

    PubMed Central

    Villa-Bellosta, Ricardo; González-Parra, Emilio; Egido, Jesús

    2016-01-01

    Background 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. Methods and Findings 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. Conclusion 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

  1. Increase of lipoprotein-lipase activity in skeletal muscle during heavy exercise. Relation to epinephrine excretion.

    PubMed

    Lithell, H; Cedermark, M; Fröberg, J; Tesch, P; Karlsson, J

    1981-11-01

    As part of the training programme for Swedish elite soldiers, a 10 day march is carried out with a heavy pack under active-service conditions. Six soldiers volunteered to take part in an investigation on the energy consumption with special regard to the lipid metabolism at different levels of physical effort. The degree of physical work was evaluated by continuous heart-rate recording and analysis of the excretion of epinephrine and norepinephrine in the urine. Fasting values of triglycerides and free fatty acids in blood plasma were determined and muscle biopsies (taken in the morning and in the afternoon) were analysed for lipoprotein-lipase (LPL) activity. After an overnight fast the free fatty acids were increased only in the mornings following days of heavy physical work. The plasma triglyceride concentrations were lowest in a morning proceeded by 3 days of heavy work. The muscle LPL activity in the morning was highest after a day of heavy work and lowest after days of rest. During days of heavy work this activity increased and was higher in the afternoon than in the morning. Muscle LPL activity in the afternoon was closely related to urinary excretion of epinephrine. The data indicate that LPL activity is elevated in the working skeletal muscle increasing the access of fatty acids. The degree of elevation is related to the degree of effort as described by the urinary excretion of morning. Muscle LPL activity in the afternoon was closely related to urinary excretion of epinephrine. The data indicate that LPL activity is elevated in the working skeletal muscle increasing the access of fatty acids. The degree of elevation is related to the degree of effort as described by the urinary excretion of morning. Muscle LPL activity in the afternoon was closely related to urinary excretion of epinephrine. The data indicate that LPL activity is elevated in the working skeletal muscle increasing the access of fatty acids. The degree of elevation is related to the degree

  2. Ghrelin increases food intake, swimming activity and growth in juvenile brown trout (Salmo trutta).

    PubMed

    Tinoco, Ana B; Näslund, Joacim; Delgado, María J; de Pedro, Nuria; Johnsson, Jörgen I; Jönsson, Elisabeth

    2014-01-30

    Several key functions of ghrelin are well conserved through vertebrate phylogeny. However, some of ghrelin's effects are contradictory and among teleosts only a limited number of species have been used in functional studies on food intake and foraging-related behaviors. Here we investigated the long-term effects of ghrelin on food intake, growth, swimming activity and aggressive contest behavior in one year old wild brown trout (Salmo trutta) using intraperitoneal implants. Food intake and swimming activity were individually recorded starting from day 1, and aggressive behavior was tested at day 11, after ghrelin implantation. Body weight and growth rate were measured from the beginning to the end of the experiment. Triglycerides and lipase activity in muscle and liver; monoaminergic activity in the telencephalon and brainstem; and neuropeptide Y (NPY) mRNA levels in the hypothalamus were analyzed. Ghrelin treatment was found to increase food intake and growth without modifying lipid deposition or lipid metabolism in liver and muscle. Ghrelin treatment led to an increased foraging activity and a trend towards a higher swimming activity. Moreover, ghrelin-treated fish showed a tendency to initiate more conflicts, but this motivation was not reflected in a higher ability to win the conflicts. No changes were observed in monoaminergic activity and NPY mRNA levels in the brain. Ghrelin is therefore suggested to act as an orexigenic hormone regulating behavior in juvenile wild brown trout. These actions are accompanied with an increased growth without the alteration of liver and muscle lipid metabolism and they do not seem to be mediated by changes in brain monoaminergic activity or hypothalamic expression of NPY.

  3. Activity-dependent alternative splicing increases persistent sodium current and promotes seizure

    PubMed Central

    Lin, Wei-Hsiang; Günay, Cengiz; Marley, Richard; Prinz, Astrid A.; Baines, Richard A.

    2012-01-01

    Activity of voltage-gated Na channels (Nav) is modified by alternative splicing. However, whether altered splicing of human Nav’s contributes to epilepsy remains to be conclusively shown. We show here that altered splicing of the Drosophila Nav (paralytic, DmNav) contributes to seizure-like behaviour in identified seizure-mutants. We focus attention on a pair of mutually-exclusive alternate exons (termed K and L), which form part of the voltage sensor (S4) in domain III of the expressed channel. The presence of exon L results in a large, non-inactivating, persistent INap. Many forms of human epilepsy are associated with an increase in this current. In wildtype (WT) Drosophila larvae ~70-80% of DmNav transcripts contain exon L, the remainder contain exon K. Splicing of DmNav to include exon L is increased to ~100% in both the slamdance and easily-shocked seizure-mutants. This change to splicing is prevented by reducing synaptic activity levels through exposure to the antiepileptic phenytoin or the inhibitory transmitter GABA. Conversely, enhancing synaptic activity in WT, by feeding of picrotoxin, is sufficient to increase INap and promote seizure through increased inclusion of exon L to 100%. We also show that the underlying activity-dependent mechanism requires the presence of Pasilla, an RNA-binding protein. Finally, we use computational modelling to show that increasing INap is sufficient to potentiate membrane excitability consistent with a seizure phenotype. Thus, increased synaptic excitation favors inclusion of exon L which, in turn, further increases neuronal excitability. Thus, at least in Drosophila, this self-reinforcing cycle may promote the incidence of seizure. PMID:22623672

  4. Leptin differentially increases sympathetic nerve activity and its baroreflex regulation in female rats: role of oestrogen.

    PubMed

    Shi, Zhigang; Brooks, Virginia L

    2015-04-01

    Obesity and hypertension are commonly associated, and activation of the sympathetic nervous system is considered to be a major contributor, at least in part due to the central actions of leptin. However, while leptin increases sympathetic nerve activity (SNA) in males, whether leptin is equally effective in females is unknown. Here, we show that intracerebroventricular (i.c.v.) leptin increases lumbar (LSNA) and renal (RSNA) SNA and baroreflex control of LSNA and RSNA in α-chloralose anaesthetized female rats, but only during pro-oestrus. In contrast, i.c.v. leptin increased basal and baroreflex control of splanchnic SNA (SSNA) and heart rate (HR) in rats in both the pro-oestrus and dioestrus states. The effects of leptin on basal LSNA, RSNA, SSNA and HR were similar in males and pro-oestrus females; however, i.c.v. leptin increased mean arterial pressure (MAP) only in males. Leptin did not alter LSNA or HR in ovariectomized rats, but its effects were normalized with 4 days of oestrogen treatment. Bilateral nanoinjection of SHU9119 into the paraventricular nucleus of the hypothalamus (PVN), to block α-melanocyte-stimulating hormone (α-MSH) type 3 and 4 receptors, decreased LSNA in leptin-treated pro-oestrus but not dioestrus rats. Unlike leptin, i.c.v. insulin infusion increased basal and baroreflex control of LSNA and HR similarly in pro-oestrus and dioestrus rats; these responses did not differ from those in male rats. We conclude that, in female rats, leptin's stimulatory effects on SNA are differentially enhanced by oestrogen, at least in part via an increase in α-MSH activity in the PVN. These data further suggest that the actions of leptin and insulin to increase the activity of various sympathetic nerves occur via different neuronal pathways or cellular mechanisms. These results may explain the poor correlation in females of SNA with adiposity, or of MAP with leptin. PMID:25398524

  5. covR Mediated Antibiofilm Activity of 3-Furancarboxaldehyde Increases the Virulence of Group A Streptococcus

    PubMed Central

    Ashwinkumar Subramenium, Ganapathy; Viszwapriya, Dharmaprakash; Iyer, Prasanth Mani; Balamurugan, Krishnaswamy; Karutha Pandian, Shunmugiah

    2015-01-01

    Background Group A streptococcus (GAS, Streptococcus pyogenes), a multi-virulent, exclusive human pathogen responsible for various invasive and non-invasive diseases possesses biofilm forming phenomenon as one of its pathogenic armaments. Recently, antibiofilm agents have gained prime importance, since inhibiting the biofilm formation is expected to reduce development of antibiotic resistance and increase their susceptibility to the host immune cells. Principal Findings The current study demonstrates the antibiofilm activity of 3Furancarboxaldehyde (3FCA), a floral honey derived compound, against GAS biofilm, which was divulged using crystal violet assay, light microscopy, and confocal laser scanning microscopy. The report is extended to study its effect on various aspects of GAS (morphology, virulence, aggregation) at its minimal biofilm inhibitory concentration (132μg/ml). 3FCA was found to alter the growth pattern of GAS in solid and liquid medium and increased the rate of auto-aggregation. Electron microscopy unveiled the increase in extra polymeric substances around cell. Gene expression studies showed down-regulation of covR gene, which is speculated to be the prime target for the antibiofilm activity. Increased hyaluronic acid production and down regulation of srtB gene is attributed to the enhanced rate of auto-aggregation. The virulence genes (srv, mga, luxS and hasA) were also found to be over expressed, which was manifested with the increased susceptibility of the model organism Caenorhabditis elegans to 3FCA treated GAS. The toxicity of 3FCA was ruled out with no adverse effect on C. elegans. Significance Though 3FCA possess antibiofilm activity against GAS, it was also found to increase the virulence of GAS. This study demonstrates that, covR mediated antibiofilm activity may increase the virulence of GAS. This also emphasizes the importance to analyse the acclimatization response and virulence of the pathogen in the presence of antibiofilm compounds

  6. Cell Surface Epidermal Growth Factor Receptors Increase Src and c-Cbl Activity and Receptor Ubiquitylation*

    PubMed Central

    Parks, Eileen E.; Ceresa, Brian P.

    2014-01-01

    There is an established role for the endocytic pathway in regulation of epidermal growth factor receptor (EGFR) signaling to downstream effectors. However, because ligand-mediated EGFR endocytosis utilizes multiple “moving parts,” dissecting the spatial versus temporal contributions has been challenging. Blocking all endocytic trafficking can have unintended effects on other receptors as well as give rise to compensatory mechanisms, both of which impact interpretation of EGFR signaling. To overcome these limitations, we used epidermal growth factor (EGF) conjugated to polystyrene beads (EGF beads). EGF beads simultaneously activate the EGFR while blocking its endocytosis and allow analysis of EGFR signaling from the plasma membrane. Human telomerase immortalized corneal epithelial (hTCEpi) cells were used to model normal epithelial cell biology. In hTCEpi cells, both cell surface and intracellular EGFRs exhibited dose-dependent increases in effector activity after 15 min of ligand stimulation, but only the serine phosphorylation of signal transducer and activator of transcription 3 (STAT3) was statistically significant when accounting for receptor phosphorylation. However, over time with physiological levels of receptor phosphorylation, cell surface receptors produced either enhanced or sustained mitogen-activated protein kinase kinase (MEK), Casitas B-lineage lymphoma (c-Cbl), and the pro-oncogene Src activity. These increases in effector communication by cell surface receptors resulted in an increase in EGFR ubiquitylation with sustained ligand incubation. Together, these data indicate that spatial regulation of EGFR signaling may be an important regulatory mechanism in receptor down-regulation. PMID:25074934

  7. Greater electroencephalographic coherence between left and right temporal lobe structures during increased geomagnetic activity.

    PubMed

    Saroka, Kevin S; Caswell, Joseph M; Lapointe, Andrew; Persinger, Michael A

    2014-02-01

    Interhemispheric coherence for 19 channel EEG activity collected over a three year period from 184 men and women who relaxed in a quiet, darkened chamber showed significant increased coherence between caudal temporal regions for the 11 Hz frequency band during increased (>∼8 nT) global geomagnetic activity at the time of measurement. Detailed analyses from source-localization indicated that a likely origin was the parahippocampal regions whose net differences at 10, 11 and 12 Hz intervals were significantly correlated with geomagnetic activity. Analyses of residuals to obtain a "purer" measure of parahippocampal contributions indicated that interhemispheric temporal lobe coherence across unit increments between 1 and 40 Hz revealed the most statistically significant peaks at 7.5 Hz and 19.5 Hz. These weak but reliable correlations between global geomagnetic activity and the degree of inter-temporal lobe coherence for normal people relaxing in a dark, quiet area are consistent with the results of multiple studies indicating that intrusive experiences such as "presences" or "hallucinations" are more frequent when global geomagnetic activity increases above ∼15-20 nT.

  8. Cocaine increases dopaminergic neuron and motor activity via midbrain α1 adrenergic signaling.

    PubMed

    Goertz, Richard Brandon; Wanat, Matthew J; Gomez, Jorge A; Brown, Zeliene J; Phillips, Paul E M; Paladini, Carlos A

    2015-03-13

    Cocaine reinforcement is mediated by increased extracellular dopamine levels in the forebrain. This neurochemical effect was thought to require inhibition of dopamine reuptake, but cocaine is still reinforcing even in the absence of the dopamine transporter. Here, we demonstrate that the rapid elevation in dopamine levels and motor activity elicited by cocaine involves α1 receptor activation within the ventral midbrain. Activation of α1 receptors increases dopaminergic neuron burst firing by decreasing the calcium-activated potassium channel current (SK), as well as elevates dopaminergic neuron pacemaker firing through modulation of both SK and the hyperpolarization-activated cation currents (Ih). Furthermore, we found that cocaine increases both the pacemaker and burst-firing frequency of rat ventral-midbrain dopaminergic neurons through an α1 adrenergic receptor-dependent mechanism within the ventral tegmental area and substantia nigra pars compacta. These results demonstrate the mechanism underlying the critical role of α1 adrenergic receptors in the regulation of dopamine neurotransmission and behavior by cocaine.

  9. rTMS Induced Tinnitus Relief Is Related to an Increase in Auditory Cortical Alpha Activity

    PubMed Central

    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

  10. Increased activity of the complement system in the liver of patients with alcoholic hepatitis.

    PubMed

    Shen, Hong; French, Barbara A; Liu, Hui; Tillman, Brittany C; French, Samuel W

    2014-12-01

    Inflammation has been suggested as a mechanism underlying the development of alcoholic hepatitis (AH). The activation of the complement system plays an important role in inflammation. Although it has been shown that ethanol-induced activation of the complement system contributes to the pathophysiology of ethanol-induced liver injury in mice, whether ethanol consumption activates the complement system in the human liver has not been investigated. Using antibodies against C1q, C3, and C5, the immunoreactivity of the complement system in patients with AH was examined by immunohistochemistry and quantified by morphometric image analysis. The immunoreactivity intensity of C1q, C3, and C5 in patients with AH was significantly higher than that seen in normal controls. Further, the gene expression of C1q, C3, and C5 was examined using real-time PCR. There were increases in the levels of C1q and C5, but not C3 mRNA in AH. Moreover, the immunoreactivity of C5a receptor (C5aR) also increased in AH. To explore the functional implication of the activation of the complement system in AH, we examined the colocalization of C5aR in Mallory-Denk bodies (MDBs) forming balloon hepatocytes. C5aR was focally overexpressed in the MDB forming cells. Collectively, our study suggests that alcohol consumption increases the activity of the complement system in the liver cells, which contributes to the inflammation-associated pathogenesis of AH.

  11. Nandrolone reduces activation of Notch signaling in denervated muscle associated with increased Numb expression

    SciTech Connect

    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.

    2011-10-14

    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.

  12. Cyclic strain increases protease-activated receptor-1 expression in vascular smooth muscle cells

    NASA Technical Reports Server (NTRS)

    Nguyen, K. T.; Frye, S. R.; Eskin, S. G.; Patterson, C.; Runge, M. S.; McIntire, L. V.

    2001-01-01

    Cyclic strain regulates many vascular smooth muscle cell (VSMC) functions through changing gene expression. This study investigated the effects of cyclic strain on protease-activated receptor-1 (PAR-1) expression in VSMCs and the possible signaling pathways involved, on the basis of the hypothesis that cyclic strain would enhance PAR-1 expression, reflecting increased thrombin activity. Uniaxial cyclic strain (1 Hz, 20%) of cells cultured on elastic membranes induced a 2-fold increase in both PAR-1 mRNA and protein levels. Functional activity of PAR-1, as assessed by cell proliferation in response to thrombin, was also increased by cyclic strain. In addition, treatment of cells with antioxidants or an NADPH oxidase inhibitor blocked strain-induced PAR-1 expression. Preincubation of cells with protein kinase inhibitors (staurosporine or Ro 31-8220) enhanced strain-increased PAR-1 expression, whereas inhibitors of NO synthase, tyrosine kinase, and mitogen-activated protein kinases had no effect. Cyclic strain in the presence of basic fibroblast growth factor induced PAR-1 mRNA levels beyond the effect of cyclic strain alone, whereas no additive effect was observed between cyclic strain and platelet-derived growth factor-AB. Our findings that cyclic strain upregulates PAR-1 mRNA expression but that shear stress downregulates this gene in VSMCs provide an opportunity to elucidate signaling differences by which VSMCs respond to different mechanical forces.

  13. Diabetes Promotes DMH-Induced Colorectal Cancer by Increasing the Activity of Glycolytic Enzymes in Rats

    PubMed Central

    Jia, Yanglei; Xu, Gang; Zhou, Wenjing; Wang, Zhenzheng; Meng, Linlin; Zhou, Songnan; Xu, Xia; Yuan, Huiqing; Tian, Keli

    2014-01-01

    The objective of the present study was to investigate the association between diabetes mellitus and colorectal carcinogenesis as well as the possible mechanism involved in this interaction. Diabetes rat models were induced with a low dose of STZ followed by a low dose of DMH to induce colorectal cancer. The formation of ACF in the colon and the incidence, number and size of tumors were measured. The activity of glycolytic enzymes in colonic tissues was also measured. The results demonstrated that both the total number of ACF and the number of foci that contain a different number of crypts were increased in diabetic rats. At the end of the experimental treatment, the incidence, number and size of tumors were also increased in diabetic rats. Overall, these data indicated that diabetes increased the risk of colorectal cancer. The activity of HK and PK in colonic tissues was increased in diabetic rats, whereas the activity of PDH was decreased. In addition, the activities of these enzymes in intratumor were higher than that of in peritumor. These data indicated that the high rate of glycolysis may play a role in colorectal carcinogenesis in diabetic rats. PMID:25329503

  14. Increasing Play Skills of Children with Autism Using Activity Schedules and Correspondence Training.

    ERIC Educational Resources Information Center

    Morrison, Rebecca S.; Sainato, Diane M.; BenChaaban, Delia; Endo, Sayaka

    2002-01-01

    A study investigated the effectiveness of correspondence training and photographic activity schedules on the on-task and play correspondence behavior of four preschool children with autism in an inclusive setting. Results indicate that all participants' on-task and play correspondence behavior increased, while experimenter prompts gradually…

  15. NFAT-133 increases glucose uptake in L6 myotubes by activating AMPK pathway.

    PubMed

    Thakkar, Chandni S; Kate, Abhijeet S; Desai, Dattatraya C; Ghosh, Asit Ranjan; Kulkarni-Almeida, Asha A

    2015-12-15

    NFAT-133 is an aromatic compound with cinammyl alcohol moiety, isolated from streptomycetes strain PM0324667. We have earlier reported that NFAT-133 increases insulin stimulated glucose uptake in L6 myotubes using a PPARγ independent mechanism and reduces plasma or blood glucose levels in diabetic mice. Here we investigated the effects of NFAT-133 on cellular signaling pathways leading to glucose uptake in L6 myotubes. Our studies demonstrate that NFAT-133 increases glucose uptake in a dose- and time-dependent manner independent of the effects of insulin. Treatment with Akti-1/2, wortmannin and increasing concentrations of insulin had no effect on NFAT-133 mediated glucose uptake. NFAT-133 induced glucose uptake is completely mitigated by Compound C, an AMPK inhibitor. Further, the kinases upstream of AMPK activation namely; LKB-1 and CAMKKβ are not involved in NFAT-133 mediated AMPK activation nor does the compound NFAT-133 have any effect on AMPK enzyme activity. Further analysis confirmed that NFAT-133 indirectly activates AMPK by reducing the mitochondrial membrane potential and increasing the ratio of AMP:ATP.

  16. An increase of Optical Activity in the Quasar 3C454.3

    NASA Astrophysics Data System (ADS)

    Jorstad, Svetlana

    2016-06-01

    The quasar 3C454.3 shows an increase of the optical activity during the last three nights. According to our observations at the Perkins telescope of the Lowell Observatory (Flagstaff, AZ) the brightness of the source on June 10 (JD 2457549.8770) in R band was 15.817+-0.018 with a of polarization of 2.27+-0.39%.

  17. Decreasing Sports Activity with Increasing Age? Findings from a 20-Year Longitudinal and Cohort Sequence Analysis

    ERIC Educational Resources Information Center

    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…

  18. NFAT-133 increases glucose uptake in L6 myotubes by activating AMPK pathway.

    PubMed

    Thakkar, Chandni S; Kate, Abhijeet S; Desai, Dattatraya C; Ghosh, Asit Ranjan; Kulkarni-Almeida, Asha A

    2015-12-15

    NFAT-133 is an aromatic compound with cinammyl alcohol moiety, isolated from streptomycetes strain PM0324667. We have earlier reported that NFAT-133 increases insulin stimulated glucose uptake in L6 myotubes using a PPARγ independent mechanism and reduces plasma or blood glucose levels in diabetic mice. Here we investigated the effects of NFAT-133 on cellular signaling pathways leading to glucose uptake in L6 myotubes. Our studies demonstrate that NFAT-133 increases glucose uptake in a dose- and time-dependent manner independent of the effects of insulin. Treatment with Akti-1/2, wortmannin and increasing concentrations of insulin had no effect on NFAT-133 mediated glucose uptake. NFAT-133 induced glucose uptake is completely mitigated by Compound C, an AMPK inhibitor. Further, the kinases upstream of AMPK activation namely; LKB-1 and CAMKKβ are not involved in NFAT-133 mediated AMPK activation nor does the compound NFAT-133 have any effect on AMPK enzyme activity. Further analysis confirmed that NFAT-133 indirectly activates AMPK by reducing the mitochondrial membrane potential and increasing the ratio of AMP:ATP. PMID:26546724

  19. Planar fuel cell utilizing nail current collectors for increased active surface area

    DOEpatents

    George, Thomas J.; Meacham, G. B. Kirby

    2002-03-26

    A plurality of nail current collector members are useful in the gas flow passages of an electrochemical device to optimize the active surfaces of the device and to provide structural support. In addition, the thicknesses of cathode and anode layers within the electrochemical device are varied according to current flow through the device to reduce resistance and increase operating efficiency.

  20. Text Messaging as a Tool to Increase Physical Activity in College Students

    ERIC Educational Resources Information Center

    Muñoz, Laura R.; La France, Kevin; Dominguez, Daniel; Goei, Kathleen; Herbers, Sharon; Gunter, M. Danielle; Fike, David; Carleton, William; Etnyre, Annette; Richardson, Cynthia; Allwein, David; Rauschhuber, Maureen; Norgan, Gary; Moore, Renée; Marquise, Lisa; Jones, Mary Elaine

    2014-01-01

    The purpose of this study was to assess the effectiveness of text messaging with pedometer intervention for increasing physical activity of college students. Using a two-group prospective randomized intervention-based design, the researchers gave 201 college students pedometers and divided them into intervention and control groups. The…

  1. Peers Increase Adolescent Risk Taking by Enhancing Activity in the Brain's Reward Circuitry

    ERIC Educational Resources Information Center

    Chein, Jason; Albert, Dustin; O'Brien, Lia; Uckert, Kaitlyn; Steinberg, Laurence

    2011-01-01

    The presence of peers increases risk taking among adolescents but not adults. We posited that the presence of peers may promote adolescent risk taking by sensitizing brain regions associated with the anticipation of potential rewards. Using fMRI, we measured brain activity in adolescents, young adults, and adults as they made decisions in a…

  2. Pedometers and Brief E-Counseling: Increasing Physical Activity for Overweight Adults

    ERIC Educational Resources Information Center

    VanWormer, Jeffrey J.

    2004-01-01

    Physical inactivity has emerged as a public health epidemic and is associated with the rising obesity rate. A multiple-treatments reversal design was utilized to test whether pedometer-aided self-monitoring and brief e-counseling could help 3 overweight adults increase their physical activity. Dependent measures were taken for pedometer steps and…

  3. Integrated Health and Physical Education Program to Reduce Media Use and Increase Physical Activity in Youth

    ERIC Educational Resources Information Center

    Clocksin, Brian D.; Wattson, Doris L.; Williams, Daniel P.; Randsell, Lynda

    2009-01-01

    The purpose of this project was to compare an integrated health and physical education curriculum, focused on reducing media use and on increasing physical activity in middle school adolescents, to traditional and nonintegrated health and physical education curricula. Two middle schools' health and physical education classes were assigned to an…

  4. Pedometers: A Strategy to Promote Increased Physical Activity among College Students

    ERIC Educational Resources Information Center

    Hackmann, Debra J.; Mintah, Joseph K.

    2010-01-01

    Inactive lifestyle behaviors are predominant in society, especially among the adult population. This study examined the issue of inactivity among college students. A pedometer was used as an intervention strategy, to increase awareness of, and motivate college students to achieve the minimum recommended amount of daily physical activity. A…

  5. Glucose deprivation increases tau phosphorylation via P38 mitogen-activated protein kinase.

    PubMed

    Lauretti, Elisabetta; Praticò, Domenico

    2015-12-01

    Alterations of glucose metabolism have been observed in Alzheimer's disease (AD) brain. Previous studies showed that glucose deprivation increases amyloidogenesis via a BACE-1-dependent mechanism. However, no data are available on the effect that this condition may have on tau phosphorylation. In this study, we exposed neuronal cells to a glucose-free medium and investigated the effect on tau phosphorylation. Compared with controls, cells incubated in the absence of glucose had a significant increase in tau phosphorylation at epitopes Ser202/Thr205 and Ser404, which was associated with a selective activation of the P38 mitogen-activated protein kinase. Pharmacological inhibition of this kinase prevented the increase in tau phosphorylation, while fluorescence studies revealed its co-localization with phosphorylated tau. The activation of P38 was secondary to the action of the apoptosis signal-regulating kinase 1, as its down-regulation prevented it. Finally, glucose deprivation induced cell apoptosis, which was associated with a significant increase in both caspase 3 and caspase 12 active forms. Taken together, our studies reveal a new mechanism whereby glucose deprivation can modulate AD pathogenesis by influencing tau phosphorylation and suggest that this pathway may be a new therapeutic target for AD.

  6. Increased activation of the human cerebellum during pitch discrimination: a positron emission tomography (PET) study.

    PubMed

    Petacchi, Augusto; Kaernbach, Christian; Ratnam, Rama; Bower, James M

    2011-12-01

    Recent years have seen a growing debate concerning the function of the cerebellum. Here we used a pitch discrimination task and PET to test for cerebellar involvement in the active control of sensory data acquisition. Specifically, we predicted greater cerebellar activity during active pitch discrimination compared to passive listening, with the greatest activity when pitch discrimination was most difficult. Ten healthy subjects were trained to discriminate deviant tones presented with a slightly higher pitch than a standard tone, using a Go/No Go paradigm. To ensure that discrimination performance was matched across subjects, individual psychometric curves were assessed beforehand using a two-step psychoacoustic procedure. Subjects were scanned while resting in the absence of any sounds, while passively listening to standard tones, and while detecting deviant tones slightly higher in pitch among these standard tones at four different performance levels. Consistent with our predictions, 1) passive listening alone elicited cerebellar activity (lobule IX), 2) cerebellar activity increased during pitch discrimination as compared to passive listening (crus I and II, lobules VI, VIIB, and VIIIB), and 3) this increase was correlated with the difficulty of the discrimination task (lobules V, VI, and IX). These results complement recent findings showing pitch discrimination deficits in cerebellar patients (Parsons et al., 2009) and further support a role for the cerebellum in sensory data acquisition. The data are discussed in the light of anatomical and physiological evidence functionally connecting auditory system and cerebellum.

  7. Microbial Translocation Is Associated with Increased Monocyte Activation and Dementia in AIDS Patients

    PubMed Central

    Ancuta, Petronela; Kamat, Anupa; Kunstman, Kevin J.; Kim, Eun-Young; Autissier, Patrick; Wurcel, Alysse; Zaman, Tauheed; Stone, David; Mefford, Megan; Morgello, Susan; Singer, Elyse J.; Wolinsky, Steven M.; Gabuzda, Dana

    2008-01-01

    Elevated plasma lipopolysaccharide (LPS), an indicator of microbial translocation from the gut, is a likely cause of systemic immune activation in chronic HIV infection. LPS induces monocyte activation and trafficking into brain, which are key mechanisms in the pathogenesis of HIV-associated dementia (HAD). To determine whether high LPS levels are associated with increased monocyte activation and HAD, we obtained peripheral blood samples from AIDS patients and examined plasma LPS by Limulus amebocyte lysate (LAL) assay, peripheral blood monocytes by FACS, and soluble markers of monocyte activation by ELISA. Purified monocytes were isolated by FACS sorting, and HIV DNA and RNA levels were quantified by real time PCR. Circulating monocytes expressed high levels of the activation markers CD69 and HLA-DR, and harbored low levels of HIV compared to CD4+ T-cells. High plasma LPS levels were associated with increased plasma sCD14 and LPS-binding protein (LBP) levels, and low endotoxin core antibody levels. LPS levels were higher in HAD patients compared to control groups, and were associated with HAD independently of plasma viral load and CD4 counts. LPS levels were higher in AIDS patients using intravenous heroin and/or ethanol, or with Hepatitis C virus (HCV) co-infection, compared to control groups. These results suggest a role for elevated LPS levels in driving monocyte activation in AIDS, thereby contributing to the pathogenesis of HAD, and provide evidence that cofactors linked to substance abuse and HCV co-infection influence these processes. PMID:18575590

  8. Increased migration of murine keratinocytes under hypoxia is mediated by induction of urokinase plasminogen activator.

    PubMed

    Daniel, Richard J; Groves, Richard W

    2002-12-01

    One of the key consequences of cutaneous wounding is the development of tissue hypoxia. Recent data have suggested that this is a potent stimulus for increased keratinocyte migration and hence re-epithelialization, although the mechanisms responsible for this remain unclear. In this study we have investigated the relationship between hypoxia, plasminogen activation, and in vitro wound healing. Exposure of keratinocyte cultures to hypoxia resulted in upregulation of urokinase plasminogen activator mRNA and a subsequent increase in urokinase plasminogen activator-mediated plasminogen activation, as determined by indirect chromogenic peptide assay and plasminogen-linked zymography. Analysis of keratinocyte wound healing in vitro confirmed enhanced wound closure in hypoxic cultures compared with normoxic cultures after 16 h. Pretreatment of normoxic and hypoxic cultures with mitomycin C and cytochalasin B indicated that in this system wound closure was due to keratinocyte migration rather than proliferation. Addition of the broad-spectrum serine proteinase inhibitor, p-aminobenzamidine, or the specific urokinase plasminogen activator inhibitors, amiloride and WX-293, significantly reduced wound closure in hypoxic cultures and abrogated the hypoxic enhancement of wound closure. These data indicate a central role for urokinase plasminogen activators in hypoxic keratinocyte migration and suggest a potential mechanism for enhanced re-epithelialization of wounds under low oxygen tensions. PMID:12485432

  9. Effects of Gradual Increases in O2 Concentration on Nodule Activity in Soybean 1

    PubMed Central

    Hunt, Stephen; King, Bryan J.; Layzell, David B.

    1989-01-01

    The objectives of this study were to determine whether attached nodules of soybean (Glycine max L. Merr.) could adjust to gradual increases in rhizosphere pO2 without nitrogenase inhibition and to determine whether the nitrogenase activity of the nodules is limited by pO2 under ambient conditions. A computer-controlled gas blending apparatus was used to produce linear increases (ramps) in pO2 around attached nodulated roots of soybean plants in an open gas exchange system. Nitrogenase activity (H2 production in N2:O2 and Ar:O2) and respiration (CO2 evolution) were monitored continuously as pO2 was ramped from 20 to 30 kilopascals over periods of 0, 5, 10, 15, and 30 minutes. The 0, 5, and 10 minute ramps caused inhibitions of nitrogenase and respiration rates followed by recoveries of these rates to their initial values within 30 minutes. Distinct oscillations in nitrogenase activity and respiration were observed during the recovery period, and the possible basis for these oscillations is discussed. The 15 and 30 minute ramps did not inhibit nitrogenase activity, suggesting that such inhibition is not a factor in the regulation of nodule diffusion resistance. During the 30 minute ramp, a stimulation of nitrogenase activity was observed, indicating that an O2-based limitation to nitrogenase activity occurs in soybean nodules under ambient conditions. PMID:16667018

  10. Increasing girls’ physical activity during an organised youth sport basketball program: a randomised controlled trial protocol

    PubMed Central

    2014-01-01

    Background Participation in organised youth sports (OYS) has been recommended as an opportunity to increase young peoples’ moderate-to-vigorous physical activity (MVPA) levels. Participants, however, spend a considerable proportion of time during OYS inactive. The purpose of this study, therefore, was to investigate whether coaches who attended coach education sessions (where education on increasing MVPA and decreasing inactivity during training was delivered) can increase players’ MVPA during training sessions over a 5-day basketball program compared to coaches who did not receive coach education sessions. Methods/design A convenience sample of 80 female players and 8 coaches were recruited into the UWS School Holiday Basketball Program in Greater Western Sydney, Australia. A two-arm, parallel-group randomised controlled trial was employed to investigate whether coaches who attended 2 coach education sessions (compared with a no-treatment control) can increase their players’ MVPA during training sessions over a 5-day basketball program. Objectively measured physical activity, directly observed lesson context and leader behaviour, player motivation, players’ perceived autonomy support, and coaching information (regarding training session planning, estimations on player physical activity and lesson context during training, perceived ability to modify training sessions, perceived importance of physical activity during training, intention to increase physical activity/reduce inactivity, and likelihood of increasing physical activity/reducing inactivity) were assessed at baseline (day 1) and at follow-up (day 5). Linear mixed models will be used to analyse between arm differences in changes from baseline to follow-up on all outcomes. Discussion The current trial protocol describes, to our knowledge, the first trial conducted in an OYS context to investigate the efficacy of an intervention, relative to a control, in increasing MVPA. This study’s findings will

  11. Components of the increased circulating proteolytic activity in pediatric burn patients.

    PubMed

    Neely, A N; Warden, G D; Rieman, M; Friedberg, D L; Holder, I A

    1992-12-01

    Total proteolytic activity (PA) is increased in the circulation of pediatric burn patients. The extent of the increase correlates with the percent total body surface area (TBSA) burned and is associated with increased susceptibility to fatal infection. To determine the source or sources of this PA, three factors were evaluated: (1) levels of proteinase inhibitors--antithrombin, alpha 2-antiplasmin, and alpha 1-proteinase inhibitor; (2) levels of proteinase--neutrophil elastase; and (3) activation of circulating proteolytic cascade systems as indicated by changes in levels of system components--plasminogen and prekallikrein. All assays measured functional levels of the proteins. Normal levels were determined in 25 consecutive well children who were seeing their pediatrician for checkups (14 boys, 11 girls, ranging in age from 10 months to 17 years). Twenty-five consecutive burn victims admitted to the Shriners Burns Institute, Cincinnati Unit (19 boys, six girls, aged 10 months to 17 years), with a mean full-thickness burn of 43.2% TBSA (range, 6%-87%) were studied in the first week postburn. Antithrombin, alpha 2-antiplasmin, plasminogen, and prekallikrein levels decreased (p < 0.001) postburn, whereas elastase increased (p < 0.001). We conclude that, in pediatric burn patients, decreased proteinase inhibitors, increased proteinase, and activation of circulating proteinase cascades all contribute to elevated total circulating PA postburn.

  12. Superoxide dismutase and catalase conjugated to polyethylene glycol increases endothelial enzyme activity and oxidant resistance

    SciTech Connect

    Beckman, J.S.; Minor, R.L. Jr.; White, C.W.; Repine, J.E.; Rosen, G.M.; Freeman, B.A.

    1988-05-15

    Covalent conjugation of superoxide dismutase and catalase with polyethylene glycol (PEG) increases the circulatory half-lives of these enzymes from <10 min to 40 h, reduced immunogenicity, and decreases sensitivity to proteolysis. Because PEG has surface active properties and can induce cell fusion, the authors hypothesized that PEG conjugation could enhance cell binding and association of normally membrane-impermeable enzymes. Incubation of cultured porcine aortic endothelial cells with /sup 125/I-PEG-catalase or /sup 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.

  13. Lumbricus terrestris L. activity increases the availability of metals and their accumulation in maize and barley.

    PubMed

    Ruiz, E; Alonso-Azcárate, J; Rodríguez, L

    2011-03-01

    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. PMID:21190761

  14. TRPA1 activation by lidocaine in nerve terminals results in glutamate release increase

    SciTech Connect

    Piao, L.-H.; Fujita, Tsugumi; Jiang, C.-Y.; Liu Tao; Yue, H.-Y.; Nakatsuka, Terumasa; Kumamoto, Eiichi

    2009-02-20

    We examined the effects of local anesthetics lidocaine and procaine on glutamatergic spontaneous excitatory transmission in substantia gelatinosa (SG) neurons in adult rat spinal cord slices with whole-cell patch-clamp techniques. Bath-applied lidocaine (1-5 mM) dose-dependently and reversibly increased the frequency but not the amplitude of spontaneous excitatory postsynaptic current (sEPSC) in SG neurons. Lidocaine activity was unaffected by the Na{sup +}-channel blocker, tetrodotoxin, and the TRPV1 antagonist, capsazepine, but was inhibited by the TRP antagonist, ruthenium red. In the same neuron, the TRPA1 agonist, allyl isothiocyanate, and lidocaine both increased sEPSC frequency. In contrast, procaine did not produce presynaptic enhancement. These results indicate that lidocaine activates TRPA1 in nerve terminals presynaptic to SG neurons to increase the spontaneous release of L-glutamate.

  15. Increased Asynchronous Release and Aberrant Calcium Channel Activation in Amyloid Precursor Protein Deficient Neuromuscular Synapses

    PubMed Central

    Yang, Li; Wang, Baiping; Long, Cheng; Wu, Gangyi; Zheng, Hui

    2007-01-01

    Despite the critical roles of the amyloid precursor protein (APP) in Alzheimer's disease pathogenesis, its physiological function remains poorly established. Our previous studies implicated a structural and functional activity of the APP family of proteins in the developing neuromuscular junction (NMJ). Here we performed comprehensive analyses of neurotransmission in mature neuromuscular synapse of APP deficient mice. We found that APP deletion led to reduced paired-pulse facilitation and increased depression of synaptic transmission with repetitive stimulation. Readily releasable pool size and total releasable vesicles were not affected, but probability of release was significantly increased. Strikingly, the amount of asynchronous release, a measure sensitive to presynaptic calcium concentration, was dramatically increased, and pharmacological studies revealed that it was attributed to aberrant activation of N- and L-type Ca2+ channels. We propose that APP modulates synaptic transmission at the NMJ by ensuring proper Ca2+ channel function. PMID:17919826

  16. Increasing total and biologically active chromium in wheat grain and spinach by spraying with chromium salts

    SciTech Connect

    Vicini, F.A.; Ellis, B.G.

    1981-06-01

    Recently, chromium has been shown to be necessary for glucose metabolism in man. But most plant species greatly restrict the uptake of Cr. This study was conducted to determine if both total and biologically active Cr could be increased in wheat grain or spinach by spraying the plants with either Cr/sub 2/(SO/sub 4/)/sub 3/ or Cr-EDTA. Concentrations of Cr in wheat grain were about doubled in a greenhouse experiment by spraying with either Cr source. Biologically active Cr (estimated by extraction with ethanol or NH/sub 4/OH) was increased from about 40 to greater than 50% of total Cr when wheat was sprayed with Cr salts. Total Cr in spinach leaves was increased by as much as 10-fold by spraying, with the sulfate source being more effective than the EDTA.

  17. Alpha-Amylase Activity in Blood Increases after Pharmacological, But Not Psychological, Activation of the Adrenergic System

    PubMed Central

    Nater, Urs M.; La Marca, Roberto; Erni, Katja; Ehlert, Ulrike

    2015-01-01

    Background & Aim 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. Methods 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 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. Conclusions 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. PMID:26110636

  18. Dopamine D3 receptor deletion increases tissue plasminogen activator (tPA) activity in prefrontal cortex and hippocampus.

    PubMed

    Castorina, A; D'Amico, A G; Scuderi, S; Leggio, G M; Drago, F; D'Agata, V

    2013-10-10

    Considerable evidence indicates that dopamine (DA) influences tissue plasminogen activator (tPA)-mediated proteolytic processing of the precursor of brain-derived neurotrophic factor (proBDNF) into mature BDNF (mBDNF). However, specific roles in this process for the dopamine D3 receptor (D3R) and the underlying molecular mechanisms are yet to be fully characterized. In the present study, we hypothesized that D3R deletion could influence tPA activity in the prefrontal cortex and hippocampus. Using D3R knockout (D3(-/-)) mice, we show that receptor inactivation is associated with increased tPA expression/activity both in the prefrontal cortex and, to a greater extent, in the hippocampus. Augmented tPA expression in D3(-/-) mice correlated with increased BDNF mRNA levels, plasmin/plasminogen protein ratio and the conversion of proBDNF into mBDNF, as well as enhanced tPA and mBDNF immunoreactivity, as determined by quantitative real time polymerase chain reaction (qRT-PCR), immunoblot and immunohistochemistry. In addition, when compared to wild-type controls, D3(-/-) mice exhibited increased basal activation of the canonical cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)-driven Akt/cAMP-response element-binding protein (CREB) signaling cascade, as determined by the increased Akt phosphorylation both at Thr304 and Ser473 residues, of DA and cAMP-regulated protein of 32kDa (DARPP-32) at Thr34 and a phosphorylation state-dependent inhibition of glycogen synthetase kinase-3β (GSK-3β) at Ser9, a substrate of Akt whose constitutive function impairs normal CREB transcriptional activity through phosphorylation at its Ser129 residue. Accordingly, CREB phosphorylation at Ser133 was significantly increased in D3(-/-) mice, whereas the GSK-3β-dependent phosphorylation at Ser129 was diminished. Altogether, our finding reveals that mice lacking D3Rs show enhanced tPA proteolytic activity on BDNF which may involve, at least in part, a potentiated Akt/CREB signaling

  19. Increase of carboxylesterase activity in Fasciola hepatica recovered from triclabendazole treated sheep.

    PubMed

    Scarcella, S; Miranda-Miranda, E; Cossío-Bayúgar, R; Ceballos, L; Fernandez, V; Solana, H

    2012-10-01

    In the present work, we evaluate in vivo the activity of carboxylesterase of Fasciola hepatica exposed to triclabendazole. We observed a statistically significant increase in enzyme activity at 24 and 48 h post treatment (P<0.01 and P<0.001, respectively). The zymogram of cytosolic fractions identified a protein of 170 kDa containing the carboxylesterase activity. The densitograms of the zymograms confirmed the phenomenon of enzyme induction under the experimental conditions of the assay. These results provide not only the understanding of the importance of this metabolic pathway in flukes but carboxylesterase would also be an enzyme that could participate more actively in the development of anthelmintic resistance at TCBZ.

  20. Nanocaged enzymes with enhanced catalytic activity and increased stability against protease digestion.

    PubMed

    Zhao, Zhao; Fu, Jinglin; Dhakal, Soma; Johnson-Buck, Alexander; Liu, Minghui; Zhang, Ting; Woodbury, Neal W; Liu, Yan; Walter, Nils G; Yan, Hao

    2016-02-10

    Cells routinely compartmentalize enzymes for enhanced efficiency of their metabolic pathways. Here we report a general approach to construct DNA nanocaged enzymes for enhancing catalytic activity and stability. Nanocaged enzymes are realized by self-assembly into DNA nanocages with well-controlled stoichiometry and architecture that enabled a systematic study of the impact of both encapsulation and proximal polyanionic surfaces on a set of common metabolic enzymes. Activity assays at both bulk and single-molecule levels demonstrate increased substrate turnover numbers for DNA nanocage-encapsulated enzymes. Unexpectedly, we observe a significant inverse correlation between the size of a protein and its activity enhancement. This effect is consistent with a model wherein distal polyanionic surfaces of the nanocage enhance the stability of active enzyme conformations through the action of a strongly bound hydration layer. We further show that DNA nanocages protect encapsulated enzymes against proteases, demonstrating their practical utility in functional biomaterials and biotechnology.

  1. Nanocaged enzymes with enhanced catalytic activity and increased stability against protease digestion

    PubMed Central

    Zhao, Zhao; Fu, Jinglin; Dhakal, Soma; Johnson-Buck, Alexander; Liu, Minghui; Zhang, Ting; Woodbury, Neal W.; Liu, Yan; Walter, Nils G.; Yan, Hao

    2016-01-01

    Cells routinely compartmentalize enzymes for enhanced efficiency of their metabolic pathways. Here we report a general approach to construct DNA nanocaged enzymes for enhancing catalytic activity and stability. Nanocaged enzymes are realized by self-assembly into DNA nanocages with well-controlled stoichiometry and architecture that enabled a systematic study of the impact of both encapsulation and proximal polyanionic surfaces on a set of common metabolic enzymes. Activity assays at both bulk and single-molecule levels demonstrate increased substrate turnover numbers for DNA nanocage-encapsulated enzymes. Unexpectedly, we observe a significant inverse correlation between the size of a protein and its activity enhancement. This effect is consistent with a model wherein distal polyanionic surfaces of the nanocage enhance the stability of active enzyme conformations through the action of a strongly bound hydration layer. We further show that DNA nanocages protect encapsulated enzymes against proteases, demonstrating their practical utility in functional biomaterials and biotechnology. PMID:26861509

  2. Nanocaged enzymes with enhanced catalytic activity and increased stability against protease digestion

    NASA Astrophysics Data System (ADS)

    Zhao, Zhao; Fu, Jinglin; Dhakal, Soma; Johnson-Buck, Alexander; Liu, Minghui; Zhang, Ting; Woodbury, Neal W.; Liu, Yan; Walter, Nils G.; Yan, Hao

    2016-02-01

    Cells routinely compartmentalize enzymes for enhanced efficiency of their metabolic pathways. Here we report a general approach to construct DNA nanocaged enzymes for enhancing catalytic activity and stability. Nanocaged enzymes are realized by self-assembly into DNA nanocages with well-controlled stoichiometry and architecture that enabled a systematic study of the impact of both encapsulation and proximal polyanionic surfaces on a set of common metabolic enzymes. Activity assays at both bulk and single-molecule levels demonstrate increased substrate turnover numbers for DNA nanocage-encapsulated enzymes. Unexpectedly, we observe a significant inverse correlation between the size of a protein and its activity enhancement. This effect is consistent with a model wherein distal polyanionic surfaces of the nanocage enhance the stability of active enzyme conformations through the action of a strongly bound hydration layer. We further show that DNA nanocages protect encapsulated enzymes against proteases, demonstrating their practical utility in functional biomaterials and biotechnology.

  3. Increased Activity of Rhizosphere and Hyphosphere Enzymes under Elevated CO2 in a Loblolly Pine Stand

    NASA Astrophysics Data System (ADS)

    Meier, I.; Phillips, R.

    2012-12-01

    The stimulatory effect of elevated atmospheric CO2 under global climate change on forest productivity has been predicted to decrease over time as pools of available N in soil become depleted, but empirical support for such progressive N limitation has been lacking. Increased N acquisition from soil depleted in inorganic nitrogen requires stimulation of the microbial processing of organic N, possibly through increasing C supply to soil by plant roots or mycorrhizal hyphae. Increases in (mycorr)rhizosphere C fluxes could stimulate microbes to produce extra-cellular enzymes that release N from SOM, feeding back from soil microsites to ecosystem-scale processes. We investigated the influence of elevated CO2 on root exudation and soil enzyme activity at the Duke Forest FACE site, USA, where loblolly pine (Pinus taeda L.) stands have been exposed to elevated CO2 for 14 years and N fertilization for five years. In each plot, root boxes containing acetate windows were installed in 2008. Two years after installation, we collected soils adjacent to root tips (the rhizosphere), hyphal tips (the hyphosphere) and bulk soil. We measured in situ root exudation rates from intact pine roots. Study objectives were to analyze (i) the influence of atmospheric CO2 on root exudation and extra-cellular enzyme activities, (ii) the influence of soil N availability in regulating these activities, and (iii) the relationship between the activities of enzymes involved in N cycling in soils and gross N transformations at soil microsites. Elevated atmospheric CO2 significantly increased the activity of β-1-4-N-acetylglucosaminidase (NAG) in the rhizosphere by almost 2.5 times (39 to 95 nmol h-1 g-1), and 1.6fold in the hyphosphere relative to ambient plots. NAG is an enzyme involved in the degradation of chitin from the cell walls of soil organisms, releasing absorbable forms of nitrogen. The activity of peroxidase, which degrades aromatic C compounds of SOM, increased significantly in the

  4. Exogenous Methyl Jasmonate Treatment Increases Glucosinolate Biosynthesis and Quinone Reductase Activity in Kale Leaf Tissue

    PubMed Central

    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, P<0.001). Concentrations required to double the specific QR activity (CD values) of I3C was calculated at 230 µM, which is considerably weaker at induction than other isothiocyanates like sulforphane. To confirm relationships between GS hydrolysis products and QR activity, a range of concentrations of MeJA sprays were applied to kale 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

  5. Pulsed Light Stimulation Increases Boundary Preference and Periodicity of Episodic Motor Activity in Drosophila melanogaster

    PubMed Central

    Qiu, Shuang; Xiao, Chengfeng; Robertson, R. Meldrum

    2016-01-01

    There is considerable interest in the therapeutic benefits of long-term sensory stimulation for improving cognitive abilities and motor performance of stroke patients. The rationale is that such stimulation would activate mechanisms of neural plasticity to promote enhanced coordination and associated circuit functions. Experimental approaches to characterize such mechanisms are needed. Drosophila melanogaster is one of the most attractive model organisms to investigate neural mechanisms responsible for stimulation-induced behaviors with its powerful accessibility to genetic analysis. In this study, the effect of chronic sensory stimulation (pulsed light stimulation) on motor activity in w1118 flies was investigated. Flies were exposed to a chronic pulsed light stimulation protocol prior to testing their performance in a standard locomotion assay. Flies responded to pulsed light stimulation with increased boundary preference and travel distance in a circular arena. In addition, pulsed light stimulation increased the power of extracellular electrical activity, leading to the enhancement of periodic electrical activity which was associated with a centrally-generated motor pattern (struggling behavior). In contrast, such periodic events were largely missing in w1118 flies without pulsed light treatment. These data suggest that the sensory stimulation induced a response in motor activity associated with the modifications of electrical activity in the central nervous system (CNS). Finally, without pulsed light treatment, the wild-type genetic background was associated with the occurrence of the periodic activity in wild-type Canton S (CS) flies, and w+ modulated the consistency of periodicity. We conclude that pulsed light stimulation modifies behavioral and electrophysiological activities in w1118 flies. These data provide a foundation for future research on the genetic mechanisms of neural plasticity underlying such behavioral modification. PMID:27684063

  6. Increased lactate/pyruvate ratio augments blood flow in physiologically activated human brain

    NASA Astrophysics Data System (ADS)

    Mintun, Mark A.; Vlassenko, Andrei G.; Rundle, Melissa M.; Raichle, Marcus E.

    2004-01-01

    The factors regulating cerebral blood flow (CBF) changes in physiological activation remain the subject of great interest and debate. Recent experimental studies suggest that an increase in cytosolic NADH mediates increased blood flow in the working brain. Lactate injection should elevate NADH levels by increasing the lactate/pyruvate ratio, which is in near equilibrium with the NADH/NAD+ ratio. We studied CBF responses to bolus lactate injection at rest and in visual stimulation by using positron-emission tomography in seven healthy volunteers. Bolus lactate injection augmented the CBF response to visual stimulation by 38-53% in regions of the visual cortex but had no effect on the resting CBF or the whole-brain CBF. These lactate-induced CBF increases correlated with elevations in plasma lactate/pyruvate ratios and in plasma lactate levels but not with plasma pyruvate levels. Our observations support the hypothesis that an increase in the NADH/NAD+ ratio activates signaling pathways to selectively increase CBF in the physiologically stimulated brain regions.

  7. Protecting cotton photosynthesis during moderate chilling at high light intensity by increasing chloroplastic antioxidant enzyme activity.

    PubMed

    Payton, P; Webb, R; Kornyeyev, D; Allen, R; Holaday, A S

    2001-12-01

    This study examined the effect of increasing chloroplastic superoxide dismutase (SOD), ascorbate peroxidase (APX), or glutathione reductase (GR) activity via plant transformation of cotton on the initial recovery of photosynthesis following exposures to 10 degrees C and high photon flux density (PFD). Growing wild-type or non-expressing segregate plants (controls) and transformants at two PFDs (600 micromol m(-2) s(-1) and full sun) resulted in a range of total antioxidant enzyme activities. Total SOD activities above that for control leaves grown in full sun did not substantially improve the recoveries of CO(2)-saturated photosynthesis, especially for stress treatments lasting more than 1 h, while elevated APX or GR activity did improve recoveries after 1-3 h of the chilling treatment. No synergistic effects were noted when the activities of more than one antioxidant enzyme were elevated in transgenic hybrids. Although these results suggest that the protection of photosynthesis can be realized by reducing either superoxide or H(2)O(2) levels, thereby reducing the possibility of hydroxyl radical formation, the situation is complicated, since elevated APX or GR activity can improve recoveries even when additional SOD activity has no effect. In conclusion, to enhance the protection of photosynthesis using stroma-targeted antioxidant enzymes, enhancing metabolism associated with H(2)O(2) is more effective than enhancing the capacity for superoxide scavenging. Although small, the improvement in the protection of photosynthetic capacity may be sufficient to improve cotton yield in temperate regions with large diurnal temperature fluctuations.

  8. Increased levels of peroxisomal active oxygen-related enzymes in copper-tolerant pea plants

    SciTech Connect

    Palma, J.M.; Gomez, M.; Yanez, J.; Del Rio, L.A.

    1987-10-01

    The effect in vivo of high nutrient levels of copper (240 micromolar) on the activity of different metalloenzymes containing Cu, Mn, Fe, and Zn, distributed in chloroplasts, peroxisomes, and mitochondria, was studied in leaves of two varieties of Pisum sativum L. plants with different sensitivity to copper. The metalloenzymes studied were: cytochrome c oxidase, Mn-superoxide dismutase (Mn-SOD) and Cu,Zn-superoxide dismutase I (Cu,Zn-SOD I), for mitochondria; catalase and Mn-SOD, for peroxisomes; and isozyme Cu,Zn-SOD II for chloroplasts. The activity of mitochondrial SOD isozymes (Mn-SOD and Cu,Zn-SOD I) was very similar in Cu-tolerant and Cu-sensitive plants, whereas cytochrome c oxidase was lower in Cu-sensitive plants. Chloroplastid Cu,Zn-SOD activity was the same in the two plant varieties. In contrast, the peroxisomal Mn-SOD activity was considerably higher in Cu-tolerant than in Cu-sensitive plants, and the activity of catalase was also increased in peroxisomes of Cu-tolerant plants. The higher activities of these peroxisomal active oxygen-related enzymes in Cu-tolerant plants suggest the involvement of reactive oxygen intermediates (O/sub 2//sup -/, OH) in the mechanism of Cu lethality, and also imply a function for peroxisomal Mn-SOD in the molecular mechanisms of plant tolerance to Cu in Pisum sativum L.

  9. Using pedometers to increase physical activity in overweight and obese women: a pilot study

    PubMed Central

    Pal, Sebely; Cheng, Cheryl; Egger, Garry; Binns, Colin; Donovan, Robert

    2009-01-01

    Background Most public health guidelines recommend that adults participate in 30 minutes of moderate intensity physical activity on most days of the week. Establishing new ways to achieve these targets in sedentary populations need to be explored. This research evaluated whether the daily use of pedometers could increase physical activity and improve health outcomes in sedentary overweight and obese women. Methods Twenty six overweight and obese middle-aged women were randomized into two groups: The control group was not able to record their steps daily, whilst the pedometer group, were asked to record the number of steps on a daily basis for 12 weeks. Results Our data showed that the pedometer group significantly increased their steps/day, by 36%, at the end of the 12 weeks, whereas the control group's physical activity levels remained unchanged. There was no significant difference in weight or body fat composition in the pedometer group compared to the control group. However, there was a significant decrease in systolic blood pressure in the pedometer group (112.8 ± 2.44 mm Hg) compared to the control group (117.3 ± 2.03 mm Hg) (p = 0.003). Conclusion In conclusion, this pilot study shows that the combination of having step goals and immediate feedback from using a pedometer was effective in increasing physical activity levels in sedentary overweight and obese women. Trial registration ACTRN12609000176268 PMID:19703317

  10. Porcine malignant hyperthermia susceptibility: increased calcium-sequestering activity of skeletal muscle sarcoplasmic reticulum.

    PubMed Central

    O'Brien, P J

    1986-01-01

    This study tested the hypothesis that calcium-sequestration by isolated sarcoplasmic reticulum was abnormal in skeletal muscle of malignant hyperthermia-susceptible swine. A heavy sarcoplasmic reticulum fraction was isolated from malignant hyperthermia and control muscle using differential and density-gradient centrifugation. Prior to onset of malignant hyperthermia, calcium-sequestering activity (Vmax at 37 degrees C, mumol calcium/mg/min) was twofold increased in malignant hyperthermia sarcoplasmic reticulum compared to control sarcoplasmic reticulum (1.96 +/- 0.50 versus 4.00 +/- 0.87, P less than 0.01), although thermodynamic and kinetic properties of this activity were otherwise indistinguishable between groups. This increased activity of the malignant hyperthermia sarcoplasmic reticulum fraction was associated with twofold increased concentration of Ca-ATPase and calsequestrin protein. When a malignant hyperthermia-reaction developed, calcium-uptake was depressed to less than 5% of control values. These data indicate that malignant hyperthermia is not initiated due to a defect in the calcium-sequestration mechanism, however, loss of calcium-uptake activity occurring after the onset of malignant hyperthermia might result in the propagation and irreversibility of the malignant hyperthermia reaction. Images Fig. 1. PMID:3742368

  11. VASP Increases Hepatic Fatty Acid Oxidation by Activating AMPK in Mice

    PubMed Central

    Tateya, Sanshiro; Rizzo-De Leon, Norma; Handa, Priya; Cheng, Andrew M.; Morgan-Stevenson, Vicki; Ogimoto, Kayoko; Kanter, Jenny E.; Bornfeldt, Karin E.; Daum, Guenter; Clowes, Alexander W.; Chait, Alan; Kim, Francis

    2013-01-01

    Activation of AMP-activated protein kinase (AMPK) signaling reduces hepatic steatosis and hepatic insulin resistance; however, its regulatory mechanisms are not fully understood. In this study, we sought to determine whether vasodilator-stimulated phosphoprotein (VASP) signaling improves lipid metabolism in the liver and, if so, whether VASP’s effects are mediated by AMPK. We show that disruption of VASP results in significant hepatic steatosis as a result of significant impairment of fatty acid oxidation, VLDL-triglyceride (TG) secretion, and AMPK signaling. Overexpression of VASP in hepatocytes increased AMPK phosphorylation and fatty acid oxidation and reduced hepatocyte TG accumulation; however, these responses were suppressed in the presence of an AMPK inhibitor. Restoration of AMPK phosphorylation by administration of 5-aminoimidazole-4-carboxamide riboside in Vasp−/− mice reduced hepatic steatosis and normalized fatty acid oxidation and VLDL-TG secretion. Activation of VASP by the phosphodiesterase-5 inhibitor, sildenafil, in db/db mice reduced hepatic steatosis and increased phosphorylated (p-)AMPK and p-acetyl CoA carboxylase. In Vasp−/− mice, however, sildendafil treatment did not increase p-AMPK or reduce hepatic TG content. These studies identify a role of VASP to enhance hepatic fatty acid oxidation by activating AMPK and to promote VLDL-TG secretion from the liver. PMID:23349495

  12. Prenatal Iron Deficiency in Guinea Pigs Increases Locomotor Activity but Does Not Influence Learning and Memory

    PubMed Central

    Fiset, Catherine; Rioux, France M.; Surette, Marc E.; Fiset, Sylvain

    2015-01-01

    The objective of the current study was to determine whether prenatal iron deficiency induced during gestation in guinea pigs affected locomotor activity and learning and memory processes in the progeny. Dams were fed either iron-deficient anemic or iron-sufficient diets throughout gestation and lactation. After weaning, all pups were fed an iron-sufficient diet. On postnatal day 24 and 40, the pups’ locomotor activity was observed within an open-field test, and from postnatal day 25 to 40, their learning and memory processes were assessed within a Morris Water Maze. The behavioural and cognitive tests revealed that the iron deficient pup group had increased locomotor activity, but solely on postnatal day 40, and that there were no group differences in the Morris Water Maze. In the general discussion, we propose that prenatal iron deficiency induces an increase in nervousness due to anxiety in the progeny, which, in the current study, resulted in an increase of locomotor activity. PMID:26186713

  13. Chondroitinase enhances cortical map plasticity and increases functionally active sprouting axons after brain injury.

    PubMed

    Harris, Neil G; Nogueira, Marcia S M; Verley, Derek R; Sutton, Richard L

    2013-07-15

    The beneficial effect of interventions with chondroitinase ABC enzyme to reduce axon growth-inhibitory chondroitin sulphate side chains after central nervous system injuries has been mainly attributed to enhanced axonal sprouting. After traumatic brain injury (TBI), it is unknown whether newly sprouting axons that occur as a result of interventional strategies are able to functionally contribute to existing circuitry, and it is uncertain whether maladaptive sprouting occurs to increase the well-known risk for seizure activity after TBI. Here, we show that after a controlled cortical impact injury in rats, chondroitinase infusion into injured cortex at 30 min and 3 days reduced c-Fos⁺ cell staining resulting from the injury alone at 1 week postinjury, indicating that at baseline, abnormal spontaneous activity is likely to be reduced, not increased, with this type of intervention. c-Fos⁺ cell staining elicited by neural activity from stimulation of the affected forelimb 1 week after injury was significantly enhanced by chondroitinase, indicating a widespread effect on cortical map plasticity. Underlying this map plasticity was a larger contribution of neuronal, rather than glial cells and an absence of c-Fos⁺ cells surrounded by perineuronal nets that were normally present in stimulated naïve rats. After injury, chondroitin sulfate proteoglycan digestion produced the expected increase in growth-associated protein 43-positive axons and perikarya, of which a significantly greater number were double labeled for c-Fos after intervention with chondroitinase, compared to vehicle. These data indicate that chondroitinase produces significant gains in cortical map plasticity after TBI, and that either axonal sprouting and/or changes in perineuronal nets may underlie this effect. Chondroitinase dampens, rather than increases nonspecific c-Fos activity after brain injury, and induction of axonal sprouting is not maladaptive because greater numbers are functionally

  14. Noxious stimulation in children receiving general anaesthesia evokes an increase in delta frequency brain activity

    PubMed Central

    Hartley, Caroline; Poorun, Ravi; Goksan, Sezgi; Worley, Alan; Boyd, Stewart; Rogers, Richard; Ali, Tariq; Slater, Rebeccah

    2014-01-01

    More than 235,000 children/year in the UK receive general anaesthesia, but it is unknown whether nociceptive stimuli alter cortical brain activity in anaesthetised children. Time-locked electroencephalogram (EEG) responses to experimental tactile stimuli, experimental noxious stimuli, and clinically required cannulation were examined in 51 children (ages 1–12 years) under sevoflurane monoanaesthesia. Based on a pilot study (n = 12), we hypothesised that noxious stimulation in children receiving sevoflurane monoanaesthesia would evoke an increase in delta activity. This was tested in an independent sample of children (n = 39), where a subset (n = 11) had topical local anaesthetic applied prior to stimulation. A novel method of time-locking the stimuli to the EEG recording was developed using an event detection interface and high-speed camera. Clinical cannulation evoked a significant increase (34.2 ± 8.3%) in delta activity (P = 0.042), without concomitant changes in heart rate or reflex withdrawal, which was not observed when local anaesthetic was applied (P = 0.30). Experimental tactile (P = 0.012) and noxious (P = 0.0099) stimulation also evoked significant increases in delta activity, but the magnitude of the response was graded with stimulus intensity, with the greatest increase evoked by cannulation. We demonstrate that experimental and clinically essential noxious procedures, undertaken in anaesthetised children, alter the pattern of EEG activity, that this response can be inhibited by local anaesthetic, and that this measure is more sensitive than other physiological indicators of nociception. This technique provides the possibility that sensitivity to noxious stimuli during anaesthesia could be investigated in other clinical populations. PMID:25218826

  15. Acute and chronic caffeine administration increases physical activity in sedentary adults.

    PubMed

    Schrader, Patrick; Panek, Leah M; Temple, Jennifer L

    2013-06-01

    Caffeine is a commonly used stimulant thought to have ergogenic properties. Most studies on the ergogenic effects of caffeine have been conducted in athletes. The purpose of this study was to test the hypothesis th