Essential roles of Cdc42 and MAPK in cadmium-induced apoptosis in Litopenaeus vannamei

International Nuclear Information System (INIS)

Peng, Ting; Wang, Wei-Na; Gu, Mei-Mei; Xie, Chen-Ying; Xiao, Yu-Chao; Liu, Yuan; Wang, Lei

2015-01-01

Highlights: • Cd 2+ induces Cdc42 and MAPKs pathway related gene of Litopenaeus vannamei up-regulation. • Reduction of THC, increase of ROS production and apoptotic cell rate were observed when the shrimps exposure to Cd 2+ . • DsRNA-suppression of LvCdc42 and MAPKs during Cd 2+ stress reduces the ROS production and apoptosis. • We conclude that LvCdc42 and MAPKs play key roles in Cd 2+ stress responses of shrimps. - Abstract: Cadmium, one of the most toxic heavy metals in aquatic environments, has severe effects on marine invertebrates and fishes. The MAPK signaling pathway plays a vital role in stress responses of animals. The mitogen-activated protein kinase (MAPK) signaling pathway plays a vital role in animals’ stress responses, including mediation of apoptosis induced by the Rho GTPase Cdc42. However, there is limited knowledge about its function in shrimps, although disorders exacerbated by environmental stresses (including heavy metal pollution) have caused serious mortality in commercially cultured shrimps. Thus, we probed roles of Cdc42 in Litopenaeus vannamei shrimps (LvCdc42) during cadmium exposure by inhibiting its expression using dsRNA-mediated RNA interference. The treatment successfully reduced expression levels of MAPKs (including p38, JNK, and ERK). Cadmium exposure induced significant increases in expression levels of LvCdc42 and MAPKs, accompanied by reductions in total hemocyte counts (THC) and increases in apoptotic hemocyte ratios and ROS production. However, all of these responses were much weaker in LvCdc42-suppressed shrimps, in which mortality rates were higher than in controls. Our results suggest that the MAPK pathway plays a vital role in shrimps’ responses to Cd 2+ . They also indicate that LvCdc42 in shrimps participates in its regulation, and thus plays key roles in ROS production, regulation of apoptosis and associated stress responses

Gene targeting implicates Cdc42 GTPase in GPVI and non-GPVI mediated platelet filopodia formation, secretion and aggregation.

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Huzoor Akbar

Full Text Available Cdc42 and Rac1, members of the Rho family of small GTPases, play critical roles in actin cytoskeleton regulation. We have shown previously that Rac1 is involved in regulation of platelet secretion and aggregation. However, the role of Cdc42 in platelet activation remains controversial. This study was undertaken to better understand the role of Cdc42 in platelet activation.We utilized the Mx-cre;Cdc42(lox/lox inducible mice with transient Cdc42 deletion to investigate the involvement of Cdc42 in platelet function. The Cdc42-deficient mice exhibited a significantly reduced platelet count than the matching Cdc42(+/+ mice. Platelets isolated from Cdc42(-/-, as compared to Cdc42(+/+, mice exhibited (a diminished phosphorylation of PAK1/2, an effector molecule of Cdc42, (b inhibition of filopodia formation on immobilized CRP or fibrinogen, (c inhibition of CRP- or thrombin-induced secretion of ATP and release of P-selectin, (d inhibition of CRP, collagen or thrombin induced platelet aggregation, and (e minimal phosphorylation of Akt upon stimulation with CRP or thrombin. The bleeding times were significantly prolonged in Cdc42(-/- mice compared with Cdc42(+/+ mice.Our data demonstrate that Cdc42 is required for platelet filopodia formation, secretion and aggregation and therefore plays a critical role in platelet mediated hemostasis and thrombosis.

Plexin-B2 negatively regulates macrophage motility, Rac, and Cdc42 activation.

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Kelly E Roney

Full Text Available Plexins are cell surface receptors widely studied in the nervous system, where they mediate migration and morphogenesis though the Rho family of small GTPases. More recently, plexins have been implicated in immune processes including cell-cell interaction, immune activation, migration, and cytokine production. Plexin-B2 facilitates ligand induced cell guidance and migration in the nervous system, and induces cytoskeletal changes in overexpression assays through RhoGTPase. The function of Plexin-B2 in the immune system is unknown. This report shows that Plexin-B2 is highly expressed on cells of the innate immune system in the mouse, including macrophages, conventional dendritic cells, and plasmacytoid dendritic cells. However, Plexin-B2 does not appear to regulate the production of proinflammatory cytokines, phagocytosis of a variety of targets, or directional migration towards chemoattractants or extracellular matrix in mouse macrophages. Instead, Plxnb2(-/- macrophages have greater cellular motility than wild type in the unstimulated state that is accompanied by more active, GTP-bound Rac and Cdc42. Additionally, Plxnb2(-/- macrophages demonstrate faster in vitro wound closure activity. Studies have shown that a closely related family member, Plexin-B1, binds to active Rac and sequesters it from downstream signaling. The interaction of Plexin-B2 with Rac has only been previously confirmed in yeast and bacterial overexpression assays. The data presented here show that Plexin-B2 functions in mouse macrophages as a negative regulator of the GTPases Rac and Cdc42 and as a negative regulator of basal cell motility and wound healing.

Phosphatidylserine and GTPase activation control Cdc42 nanoclustering to counter dissipative diffusion.

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Sartorel, Elodie; Ünlü, Caner; Jose, Mini; Massoni-Laporte, Aurélie; Meca, Julien; Sibarita, Jean-Baptiste; McCusker, Derek

2018-04-18

The anisotropic organization of plasma membrane constituents is indicative of mechanisms that drive the membrane away from equilibrium. However, defining these mechanisms is challenging due to the short spatio-temporal scales at which diffusion operates. Here, we use high-density single protein tracking combined with photoactivation localization microscopy (sptPALM) to monitor Cdc42 in budding yeast, a system in which Cdc42 exhibits anisotropic organization. Cdc42 exhibited reduced mobility at the cell pole, where it was organized in nanoclusters. The Cdc42 nanoclusters were larger at the cell pole than those observed elsewhere in the cell. These features were exacerbated in cells expressing Cdc42-GTP, and were dependent on the scaffold Bem1, which contributed to the range of mobility and nanocluster size exhibited by Cdc42. The lipid environment, in particular phosphatidylserine levels, also played a role in regulating Cdc42 nanoclustering. These studies reveal how the mobility of a Rho GTPase is controlled to counter the depletive effects of diffusion, thus stabilizing Cdc42 on the plasma membrane and sustaining cell polarity. Movie S1 Movie S1 sptPALM imaging of live yeast expressing Pil1-mEOS expressed at the genomic locus. Pil1-mEOS was simultaneously photo-converted with a 405 nm laser and imaged with a 561 nm laser using HiLo illumination. Images were acquired at 20 ms intervals, of which 300 frames are shown at 7 frames per second.

Defective homing is associated with altered Cdc42 activity in cells from patients with Fanconi anemia group A

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Zhang, Xiaoling; Shang, Xun; Guo, Fukun; Murphy, Kim; Kirby, Michelle; Kelly, Patrick; Reeves, Lilith; Smith, Franklin O.; Williams, David A.

2008-01-01

Previous studies showed that Fanconi anemia (FA) murine stem cells have defective reconstitution after bone marrow (BM) transplantation. The mechanism underlying this defect is not known. Here, we report defective homing of FA patient BM progenitors transplanted into mouse models. Using cells from patients carrying mutations in FA complementation group A (FA-A), we show that when transplanted into nonobese diabetic/severe combined immunodeficiency (NOD/SCID) recipient mice, FA-A BM cells exhibited impaired homing activity. FA-A cells also showed defects in both cell-cell and cell-matrix adhesion. Complementation of FA-A deficiency by reexpression of FANCA readily restored adhesion of FA-A cells. A significant decrease in the activity of the Rho GTPase Cdc42 was found associated with these defective functions in patient-derived cells, and expression of a constitutively active Cdc42 mutant was able to rescue the adhesion defect of FA-A cells. These results provide the first evidence that FA proteins influence human BM progenitor homing and adhesion via the small GTPase Cdc42-regulated signaling pathway. PMID:18565850

The small GTPase Cdc42 modulates the number of exocytosis-competent dense-core vesicles in PC12 cells

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Sato, Mai [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902 (Japan); Kitaguchi, Tetsuya [Cell Signaling Group, Waseda Bioscience Research Institute in Singapore (WABOIS), Waseda University, 11 Biopolis Way, 05-01/02 Helios, Singapore 138667 (Singapore); Numano, Rika [The Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka, Tennpaku-cho, Toyohashi, Aichi 441-8580 (Japan); Ikematsu, Kazuya [Forensic Pathology and Science, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523 (Japan); Kakeyama, Masaki [Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Murata, Masayuki; Sato, Ken [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902 (Japan); Tsuboi, Takashi, E-mail: takatsuboi@bio.c.u-tokyo.ac.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902 (Japan)

2012-04-06

Highlights: Black-Right-Pointing-Pointer Regulation of exocytosis by Rho GTPase Cdc42. Black-Right-Pointing-Pointer Cdc42 increases the number of fusion events from newly recruited vesicles. Black-Right-Pointing-Pointer Cdc42 increases the number of exocytosis-competent dense-core vesicles. -- Abstract: Although the small GTPase Rho family Cdc42 has been shown to facilitate exocytosis through increasing the amount of hormones released, the precise mechanisms regulating the quantity of hormones released on exocytosis are not well understood. Here we show by live cell imaging analysis under TIRF microscope and immunocytochemical analysis under confocal microscope that Cdc42 modulated the number of fusion events and the number of dense-core vesicles produced in the cells. Overexpression of a wild-type or constitutively-active form of Cdc42 strongly facilitated high-KCl-induced exocytosis from the newly recruited plasma membrane vesicles in PC12 cells. By contrast, a dominant-negative form of Cdc42 inhibited exocytosis from both the newly recruited and previously docked plasma membrane vesicles. The number of intracellular dense-core vesicles was increased by the overexpression of both a wild-type and constitutively-active form of Cdc42. Consistently, activation of Cdc42 by overexpression of Tuba, a Golgi-associated guanine nucleotide exchange factor for Cdc42 increased the number of intracellular dense-core vesicles, whereas inhibition of Cdc42 by overexpression of the Cdc42/Rac interactive binding domain of neuronal Wiskott-Aldrich syndrome protein decreased the number of them. These findings suggest that Cdc42 facilitates exocytosis by modulating both the number of exocytosis-competent dense-core vesicles and the production of dense-core vesicles in PC12 cells.

The small GTPase Cdc42 modulates the number of exocytosis-competent dense-core vesicles in PC12 cells

International Nuclear Information System (INIS)

Sato, Mai; Kitaguchi, Tetsuya; Numano, Rika; Ikematsu, Kazuya; Kakeyama, Masaki; Murata, Masayuki; Sato, Ken; Tsuboi, Takashi

2012-01-01

Highlights: ► Regulation of exocytosis by Rho GTPase Cdc42. ► Cdc42 increases the number of fusion events from newly recruited vesicles. ► Cdc42 increases the number of exocytosis-competent dense-core vesicles. -- Abstract: Although the small GTPase Rho family Cdc42 has been shown to facilitate exocytosis through increasing the amount of hormones released, the precise mechanisms regulating the quantity of hormones released on exocytosis are not well understood. Here we show by live cell imaging analysis under TIRF microscope and immunocytochemical analysis under confocal microscope that Cdc42 modulated the number of fusion events and the number of dense-core vesicles produced in the cells. Overexpression of a wild-type or constitutively-active form of Cdc42 strongly facilitated high-KCl-induced exocytosis from the newly recruited plasma membrane vesicles in PC12 cells. By contrast, a dominant-negative form of Cdc42 inhibited exocytosis from both the newly recruited and previously docked plasma membrane vesicles. The number of intracellular dense-core vesicles was increased by the overexpression of both a wild-type and constitutively-active form of Cdc42. Consistently, activation of Cdc42 by overexpression of Tuba, a Golgi-associated guanine nucleotide exchange factor for Cdc42 increased the number of intracellular dense-core vesicles, whereas inhibition of Cdc42 by overexpression of the Cdc42/Rac interactive binding domain of neuronal Wiskott–Aldrich syndrome protein decreased the number of them. These findings suggest that Cdc42 facilitates exocytosis by modulating both the number of exocytosis-competent dense-core vesicles and the production of dense-core vesicles in PC12 cells.

Interaction of the Small GTPase Cdc42 with Arginine Kinase Restricts White Spot Syndrome Virus in Shrimp.

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Xu, Ji-Dong; Jiang, Hai-Shan; Wei, Tian-Di; Zhang, Ke-Yi; Wang, Xian-Wei; Zhao, Xiao-Fan; Wang, Jin-Xing

2017-03-01

Many types of small GTPases are widely expressed in eukaryotes and have different functions. As a crucial member of the Rho GTPase family, Cdc42 serves a number of functions, such as regulating cell growth, migration, and cell movement. Several RNA viruses employ Cdc42-hijacking tactics in their target cell entry processes. However, the function of Cdc42 in shrimp antiviral immunity is not clear. In this study, we identified a Cdc42 protein in the kuruma shrimp ( Marsupenaeus japonicus ) and named it Mj Cdc42. Mj Cdc42 was upregulated in shrimp challenged by white spot syndrome virus (WSSV). The knockdown of Mj Cdc42 and injection of Cdc42 inhibitors increased the proliferation of WSSV. Further experiments determined that Mj Cdc42 interacted with an arginine kinase ( Mj AK). By analyzing the binding activity and enzyme activity of Mj AK and its mutant, Δ Mj AK, we found that Mj AK could enhance the replication of WSSV in shrimp. Mj AK interacted with the envelope protein VP26 of WSSV. An inhibitor of AK activity, quercetin, could impair the function of Mj AK in WSSV replication. Further study demonstrated that the binding of Mj Cdc42 and Mj AK depends on Cys 271 of Mj AK and suppresses the WSSV replication-promoting effect of Mj AK. By interacting with the active site of Mj AK and suppressing its enzyme activity, Mj Cdc42 inhibits WSSV replication in shrimp. Our results demonstrate a new function of Cdc42 in the cellular defense against viral infection in addition to the regulation of actin and phagocytosis, which has been reported in previous studies. IMPORTANCE The interaction of Cdc42 with arginine kinase plays a crucial role in the host defense against WSSV infection. This study identifies a new mechanism of Cdc42 in innate immunity and enriches the knowledge of the antiviral innate immunity of invertebrates. Copyright © 2017 American Society for Microbiology.

SU-F-T-675: Down-Regulating the Expression of Cdc42 and Inhibition of Migration of A549 with Combined Treatment of Ionizing Radiation and Sevoflurane

International Nuclear Information System (INIS)

Feng, Y; Feng, J; Huang, Z

2016-01-01

Purpose: Cdc42 is involved in cell transformation, proliferation, invasion and metastasis of human cancer cells. Cdc42 overexpression has been reported in several types of cancers. This study investigated the combined treatment effects of ionizing radiation and sevoflurane on down-regulating Cdc42 expression and suppressing migration of human adenocarcinoma cell line A549. Methods: Samples of A549 cells with Cdc42 overexpression were created and Cdc42 expression was determined by Western blotting. Increase of migration speed by Cdc42-HA overexpression was confirmed with an initial in-vitro scratch assay. The cells grown in culture media were separated into 2 groups of 6 samples: one for the control and the other was treated with 4% sevoflurane for 5hrs prior to a single-fraction radiation of 4Gy using a 6MV beam. Cell migration speeds of the 2 groups were measured with an initial in-vitro scratch assay. The scratch was created with a pipette tip immediately after treatment and images at 4 post-treatment time points (0h, 3h, 6h, 12h) were acquired. The distance between the two separated sides at 0h was used as reference and subsequent changes of the distance over time was defined as the cell migration speed. Image processing and measurement were performed with an in-house software. The experiment was repeated three times independently to evaluate the repeatability and reliability. Statistical analysis was performed with SPSS 19.0. Results: Western blotting showed the treatment down-regulated Cdc42 overexpression. Quantitative analysis and two-tailed t-test showed that cell migration speed of the treated group was higher than the control group at all time points after treatment (p < 0.02). Conclusion: Combined treatment of 6MV photon and sevoflurane can cause the effects of down-regulating Cdc42 overexpression and decrease of migration speed of A549 cells which provides potential of clinical benefit for the cancer therapy. More investigation is needed to further

SU-F-T-675: Down-Regulating the Expression of Cdc42 and Inhibition of Migration of A549 with Combined Treatment of Ionizing Radiation and Sevoflurane

Energy Technology Data Exchange (ETDEWEB)

Feng, Y [East Carolina University, Greenville, NC (United States); Feng, J [Tianjin University, Tianjin (China); Huang, Z [East Carolina University, Greenville, NC (United States)

2016-06-15

Purpose: Cdc42 is involved in cell transformation, proliferation, invasion and metastasis of human cancer cells. Cdc42 overexpression has been reported in several types of cancers. This study investigated the combined treatment effects of ionizing radiation and sevoflurane on down-regulating Cdc42 expression and suppressing migration of human adenocarcinoma cell line A549. Methods: Samples of A549 cells with Cdc42 overexpression were created and Cdc42 expression was determined by Western blotting. Increase of migration speed by Cdc42-HA overexpression was confirmed with an initial in-vitro scratch assay. The cells grown in culture media were separated into 2 groups of 6 samples: one for the control and the other was treated with 4% sevoflurane for 5hrs prior to a single-fraction radiation of 4Gy using a 6MV beam. Cell migration speeds of the 2 groups were measured with an initial in-vitro scratch assay. The scratch was created with a pipette tip immediately after treatment and images at 4 post-treatment time points (0h, 3h, 6h, 12h) were acquired. The distance between the two separated sides at 0h was used as reference and subsequent changes of the distance over time was defined as the cell migration speed. Image processing and measurement were performed with an in-house software. The experiment was repeated three times independently to evaluate the repeatability and reliability. Statistical analysis was performed with SPSS 19.0. Results: Western blotting showed the treatment down-regulated Cdc42 overexpression. Quantitative analysis and two-tailed t-test showed that cell migration speed of the treated group was higher than the control group at all time points after treatment (p < 0.02). Conclusion: Combined treatment of 6MV photon and sevoflurane can cause the effects of down-regulating Cdc42 overexpression and decrease of migration speed of A549 cells which provides potential of clinical benefit for the cancer therapy. More investigation is needed to further

Rac1 and Cdc42 are regulators of HRasV12-transformation and angiogenic factors in human fibroblasts

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Appledorn, Daniel M; Dao, Kim-Hien T; O'Reilly, Sandra; Maher, Veronica M; McCormick, J Justin

2010-01-01

The activities of Rac1 and Cdc42 are essential for HRas-induced transformation of rodent fibroblasts. What is more, expression of constitutively activated mutants of Rac1 and/or Cdc42 is sufficient for their malignant transformation. The role for these two Rho GTPases in HRas-mediated transformation of human fibroblasts has not been studied. Here we evaluated the contribution of Rac1 and Cdc42 to maintaining HRas-induced transformation of human fibroblasts, and determined the ability of constitutively activated mutants of Rac1 or Cdc42 to induce malignant transformation of a human fibroblast cell strain. Under the control of a tetracycline regulatable promoter, dominant negative mutants of Rac1 and Cdc42 were expressed in a human HRas-transformed, tumor derived fibroblast cell line. These cells were used to determine the roles of Rac1 and/or Cdc42 proteins in maintaining HRas-induced transformed phenotypes. Similarly, constitutively active mutants were expressed in a non-transformed human fibroblast cell strain to evaluate their potential to induce malignant transformation. Affymetrix GeneChip arrays were used for transcriptome analyses, and observed expression differences were subsequently validated using protein assays. Expression of dominant negative Rac1 and/or Cdc42 significantly altered transformed phenotypes of HRas malignantly transformed human fibroblasts. In contrast, expression of constitutively active mutants of Rac1 or Cdc42 was not sufficient to induce malignant transformation. Microarray analysis revealed that the expression of 29 genes was dependent on Rac1 and Cdc42, many of which are known to play a role in cancer. The dependence of two such genes, uPA and VEGF was further validated in both normoxic and hypoxic conditions. The results presented here indicate that expression of both Rac1 and Cdc42 is necessary for maintaining several transformed phenotypes in oncogenic HRas transformed human cells, including their ability to form tumors in athymic

Rac1 and Cdc42 are regulators of HRasV12-transformation and angiogenic factors in human fibroblasts

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Dao Kim-Hien T

2010-01-01

Full Text Available Abstract Background The activities of Rac1 and Cdc42 are essential for HRas-induced transformation of rodent fibroblasts. What is more, expression of constitutively activated mutants of Rac1 and/or Cdc42 is sufficient for their malignant transformation. The role for these two Rho GTPases in HRas-mediated transformation of human fibroblasts has not been studied. Here we evaluated the contribution of Rac1 and Cdc42 to maintaining HRas-induced transformation of human fibroblasts, and determined the ability of constitutively activated mutants of Rac1 or Cdc42 to induce malignant transformation of a human fibroblast cell strain. Methods Under the control of a tetracycline regulatable promoter, dominant negative mutants of Rac1 and Cdc42 were expressed in a human HRas-transformed, tumor derived fibroblast cell line. These cells were used to determine the roles of Rac1 and/or Cdc42 proteins in maintaining HRas-induced transformed phenotypes. Similarly, constitutively active mutants were expressed in a non-transformed human fibroblast cell strain to evaluate their potential to induce malignant transformation. Affymetrix GeneChip arrays were used for transcriptome analyses, and observed expression differences were subsequently validated using protein assays. Results Expression of dominant negative Rac1 and/or Cdc42 significantly altered transformed phenotypes of HRas malignantly transformed human fibroblasts. In contrast, expression of constitutively active mutants of Rac1 or Cdc42 was not sufficient to induce malignant transformation. Microarray analysis revealed that the expression of 29 genes was dependent on Rac1 and Cdc42, many of which are known to play a role in cancer. The dependence of two such genes, uPA and VEGF was further validated in both normoxic and hypoxic conditions. Conclusion(s The results presented here indicate that expression of both Rac1 and Cdc42 is necessary for maintaining several transformed phenotypes in oncogenic HRas

The small G-proteins Rac1 and Cdc42 are essential for myoblast fusion in the mouse

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Vasyutina, Elena; Martarelli, Benedetta; Brakebusch, Cord

2009-01-01

Rac1 and Cdc42 are small G-proteins that regulate actin dynamics and affect plasma membrane protrusion and vesicle traffic. We used conditional mutagenesis in mice to demonstrate that Rac1 and Cdc42 are essential for myoblast fusion in vivo and in vitro. The deficit in fusion of Rac1 or Cdc42 mut...... genetic analysis demonstrates thus that the function of Rac in myoblast fusion is evolutionarily conserved from insects to mammals and that Cdc42, a molecule hitherto not implicated in myoblast fusion, is essential for the fusion of murine myoblasts....

A New Genetically Encoded Single-Chain Biosensor for Cdc42 Based on FRET, Useful for Live-Cell Imaging

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Cox, Dianne; Hodgson, Louis

2014-01-01

Cdc42 is critical in a myriad of cellular morphogenic processes, requiring precisely regulated activation dynamics to affect specific cellular events. To facilitate direct observations of Cdc42 activation in live cells, we developed and validated a new biosensor of Cdc42 activation. The biosensor is genetically encoded, of single-chain design and capable of correctly localizing to membrane compartments as well as interacting with its upstream regulators including the guanine nucleotide dissociation inhibitor. We characterized this new biosensor in motile mouse embryonic fibroblasts and observed robust activation dynamics at leading edge protrusions, similar to those previously observed for endogenous Cdc42 using the organic dye-based biosensor system. We then extended our validations and observations of Cdc42 activity to macrophages, and show that this new biosensor is able to detect differential activation patterns during phagocytosis and cytokine stimulation. Furthermore, we observe for the first time, a highly transient and localized activation of Cdc42 during podosome formation in macrophages, which was previously hypothesized but never directly visualized. PMID:24798463

Cdc42 promotes host defenses against fatal infection

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Lee, Keunwook; Boyd, Kelli L; Parekh, Diptiben V

2013-01-01

attempted to specifically delete it in these cells by crossing the Cdc42(fl/fl) mouse with a FSP-1 cre mouse, which is thought to mediate recombination exclusively in fibroblasts. Surprisingly, the FSP-1cre;Cdc42(fl/fl) mice died at 3 weeks of age due to overwhelming suppurative upper airway infections...... showed that in addition to fibroblasts, the FSP-1 cre deleted Cdc42 very efficiently in all leukocytes. Thus, by using this non-specific cre mouse we inadvertently demonstrated the importance of Cdc42 in host protection from lethal infections and suggest a critical role for this small GTPase in innate...

Cdc42 controls primary mesenchyme cell morphogenesis in the sea urchin embryo.

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Sepúlveda-Ramírez, Silvia P; Toledo-Jacobo, Leslie; Henson, John H; Shuster, Charles B

2018-05-15

In the sea urchin embryo, gastrulation is characterized by the ingression and directed cell migration of primary mesenchyme cells (PMCs), as well as the primary invagination and convergent extension of the endomesoderm. Like all cell shape changes, individual and collective cell motility is orchestrated by Rho family GTPases and their modulation of the actomyosin cytoskeleton. And while endomesoderm specification has been intensively studied in echinoids, much less is known about the proximate regulators driving cell motility. Toward these ends, we employed anti-sense morpholinos, mutant alleles and pharmacological inhibitors to assess the role of Cdc42 during sea urchin gastrulation. While inhibition of Cdc42 expression or activity had only mild effects on PMC ingression, PMC migration, alignment and skeletogenesis were disrupted in the absence of Cdc42, as well as elongation of the archenteron. PMC migration and patterning of the larval skeleton relies on the extension of filopodia, and Cdc42 was required for filopodia in vivo as well as in cultured PMCs. Lastly, filopodial extension required both Arp2/3 and formin actin-nucleating factors, supporting models of filopodial nucleation observed in other systems. Together, these results suggest that Cdc42 plays essential roles during PMC cell motility and organogenesis. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Cdc42-mediated tubulogenesis controls cell specification

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Kesavan, Gokul; Sand, Fredrik Wolfhagen; Greiner, Thomas Uwe

2009-01-01

Understanding how cells polarize and coordinate tubulogenesis during organ formation is a central question in biology. Tubulogenesis often coincides with cell-lineage specification during organ development. Hence, an elementary question is whether these two processes are independently controlled......, or whether proper cell specification depends on formation of tubes. To address these fundamental questions, we have studied the functional role of Cdc42 in pancreatic tubulogenesis. We present evidence that Cdc42 is essential for tube formation, specifically for initiating microlumen formation and later...... for maintaining apical cell polarity. Finally, we show that Cdc42 controls cell specification non-cell-autonomously by providing the correct microenvironment for proper control of cell-fate choices of multipotent progenitors. For a video summary of this article, see the PaperFlick file with the Supplemental Data...

Different roles of the small GTPases Rac1, Cdc42, and RhoG in CALEB/NGC-induced dendritic tree complexity.

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Schulz, Jana; Franke, Kristin; Frick, Manfred; Schumacher, Stefan

2016-10-01

Rho GTPases play prominent roles in the regulation of cytoskeletal reorganization. Many aspects have been elaborated concerning the individual functions of Rho GTPases in distinct signaling pathways leading to cytoskeletal rearrangements. However, major questions have yet to be answered regarding the integration and the signaling hierarchy of different Rho GTPases in regulating the cytoskeleton in fundamental physiological events like neuronal process differentiation. Here, we investigate the roles of the small GTPases Rac1, Cdc42, and RhoG in defining dendritic tree complexity stimulated by the transmembrane epidermal growth factor family member CALEB/NGC. Combining gain-of-function and loss-of-function analysis in primary hippocampal neurons, we find that Rac1 is essential for CALEB/NGC-mediated dendritic branching. Cdc42 reduces the complexity of dendritic trees. Interestingly, we identify the palmitoylated isoform of Cdc42 to adversely affect dendritic outgrowth and dendritic branching, whereas the prenylated Cdc42 isoform does not. In contrast to Rac1, CALEB/NGC and Cdc42 are not directly interconnected in regulating dendritic tree complexity. Unlike Rac1, the Rac1-related GTPase RhoG reduces the complexity of dendritic trees by acting upstream of CALEB/NGC. Mechanistically, CALEB/NGC activates Rac1, and RhoG reduces the amount of CALEB/NGC that is located at the right site for Rac1 activation at the cell membrane. Thus, Rac1, Cdc42, and RhoG perform very specific and non-redundant functions at different levels of hierarchy in regulating dendritic tree complexity induced by CALEB/NGC. Rho GTPases play a prominent role in dendritic branching. CALEB/NGC is a transmembrane member of the epidermal growth factor (EGF) family that mediates dendritic branching, dependent on Rac1. CALEB/NGC stimulates Rac1 activity. RhoG inhibits CALEB/NGC-mediated dendritic branching by decreasing the amount of CALEB/NGC at the plasma membrane. Palmitoylated, but not prenylated form

Cdc42 and RhoA reveal different spatio-temporal dynamics upon local stimulation with Semaphorin-3A

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Federico eIseppon

2015-08-01

Full Text Available Small RhoGTPases, such as Cdc42 and RhoA, are key players in integrating external cues and intracellular signaling pathways that regulate growth cone (GC motility. Indeed, Cdc42 is involved in actin polymerization and filopodia formation, whereas RhoA induces GC collapse and neurite retraction through actomyosin contraction. In this study we employed Förster Resonance Energy Transfer (FRET microscopy to study the spatio-temporal dynamics of Cdc42 and RhoA in GCs in response to local Semaphorin-3A stimulation obtained with lipid vesicles filled with Semaphorin-3A and positioned near the selected GC using optical tweezers. We found that Cdc42 and RhoA were activated at the leading edge of NG108-15 neuroblastoma cells during spontaneous cycles of protrusion and retraction, respectively. The release of Semaphorin-3A brought to a progressive activation of RhoA within 30 seconds from the stimulus in the central region of the GC that collapsed and retracted. In contrast, the same stimulation evoked waves of Cdc42 activation propagating away from the stimulated region. A more localized stimulation obtained with Sema3A coated beads placed on the GC, led to Cdc42 active waves that propagated in a retrograde manner with a mean period of 70 seconds, and followed by GC retraction. Therefore, Semaphorin-3A activates both Cdc42 and RhoA with a complex and different spatial-temporal dynamics.

Defective tubulin organization and proplatelet formation in murine megakaryocytes lacking Rac1 and Cdc42

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Pleines, Irina; Dütting, Sebastian; Cherpokova, Deya

2013-01-01

Blood platelets are anuclear cell fragments that are essential for blood clotting. Platelets are produced by bone marrow megakaryocytes (MKs), which extend protrusions, or so-called proplatelets, into bone marrow sinusoids. Proplatelet formation requires a profound reorganization of the MK actin...... normally in vivo but displayed highly abnormal morphology and uncontrolled fragmentation. Consistently, a lack of Rac1/Cdc42 virtually abrogated proplatelet formation in vitro. Strikingly, this phenotype was associated with severely defective tubulin organization, whereas actin assembly and structure were...

Loss of Cdc42 leads to defects in synaptic plasticity and remote memory recall.

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Kim, Il Hwan; Wang, Hong; Soderling, Scott H; Yasuda, Ryohei

2014-07-08

Cdc42 is a signaling protein important for reorganization of actin cytoskeleton and morphogenesis of cells. However, the functional role of Cdc42 in synaptic plasticity and in behaviors such as learning and memory are not well understood. Here we report that postnatal forebrain deletion of Cdc42 leads to deficits in synaptic plasticity and in remote memory recall using conditional knockout of Cdc42. We found that deletion of Cdc42 impaired LTP in the Schaffer collateral synapses and postsynaptic structural plasticity of dendritic spines in CA1 pyramidal neurons in the hippocampus. Additionally, loss of Cdc42 did not affect memory acquisition, but instead significantly impaired remote memory recall. Together these results indicate that the postnatal functions of Cdc42 may be crucial for the synaptic plasticity in hippocampal neurons, which contribute to the capacity for remote memory recall.

Inhibition of Cdc42 and Rac1 activities in pheochromocytoma, the adrenal medulla tumor.

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Croisé, Pauline; Brunaud, Laurent; Tóth, Petra; Gasman, Stéphane; Ory, Stéphane

2017-04-03

Altered Rho GTPase signaling has been linked to many types of cancer. As many small G proteins, Rho GTPases cycle between an active and inactive state thanks to specific regulators that catalyze exchange of GDP into GTP (Rho-GEF) or hydrolysis of GTP into GDP (Rho-GAP). Recent studies have shown that alteration takes place either at the level of Rho proteins themselves (expression levels, point mutations) or at the level of their regulators, mostly RhoGEFs and RhoGAPs. Most reports describe Rho GTPases gain of function that may participate to the tumorigenesis processes. In contrast, we have recently reported that decreased activities of Cdc42 and Rac1 as well as decreased expression of 2 Rho-GEFs, FARP1 and ARHGEF1, correlate with pheochromocytomas, a tumor developing in the medulla of the adrenal gland (Croisé et al., Endocrine Related Cancer, 2016). Here we highlight the major evidence and further study the correlation between Rho GTPases activities and expression levels of ARHGEF1 and FARP1. Finally we also discuss how the decrease of Cdc42 and Rac1 activities may help human pheochromocytomas to develop and comment the possible relationship between FARP1, ARHGEF1 and the 2 Rho GTPases Cdc42 and Rac1 in tumorigenesis.

Functional Dysregulation of CDC42 Causes Diverse Developmental Phenotypes.

Science.gov (United States)

Martinelli, Simone; Krumbach, Oliver H F; Pantaleoni, Francesca; Coppola, Simona; Amin, Ehsan; Pannone, Luca; Nouri, Kazem; Farina, Luciapia; Dvorsky, Radovan; Lepri, Francesca; Buchholzer, Marcel; Konopatzki, Raphael; Walsh, Laurence; Payne, Katelyn; Pierpont, Mary Ella; Vergano, Samantha Schrier; Langley, Katherine G; Larsen, Douglas; Farwell, Kelly D; Tang, Sha; Mroske, Cameron; Gallotta, Ivan; Di Schiavi, Elia; Della Monica, Matteo; Lugli, Licia; Rossi, Cesare; Seri, Marco; Cocchi, Guido; Henderson, Lindsay; Baskin, Berivan; Alders, Mariëlle; Mendoza-Londono, Roberto; Dupuis, Lucie; Nickerson, Deborah A; Chong, Jessica X; Meeks, Naomi; Brown, Kathleen; Causey, Tahnee; Cho, Megan T; Demuth, Stephanie; Digilio, Maria Cristina; Gelb, Bruce D; Bamshad, Michael J; Zenker, Martin; Ahmadian, Mohammad Reza; Hennekam, Raoul C; Tartaglia, Marco; Mirzaa, Ghayda M

2018-01-17

Exome sequencing has markedly enhanced the discovery of genes implicated in Mendelian disorders, particularly for individuals in whom a known clinical entity could not be assigned. This has led to the recognition that phenotypic heterogeneity resulting from allelic mutations occurs more commonly than previously appreciated. Here, we report that missense variants in CDC42, a gene encoding a small GTPase functioning as an intracellular signaling node, underlie a clinically heterogeneous group of phenotypes characterized by variable growth dysregulation, facial dysmorphism, and neurodevelopmental, immunological, and hematological anomalies, including a phenotype resembling Noonan syndrome, a developmental disorder caused by dysregulated RAS signaling. In silico, in vitro, and in vivo analyses demonstrate that mutations variably perturb CDC42 function by altering the switch between the active and inactive states of the GTPase and/or affecting CDC42 interaction with effectors, and differentially disturb cellular and developmental processes. These findings reveal the remarkably variable impact that dominantly acting CDC42 mutations have on cell function and development, creating challenges in syndrome definition, and exemplify the importance of functional profiling for syndrome recognition and delineation. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Podocyte-specific loss of cdc42 leads to congenital nephropathy

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Scott, Rizaldy P; Hawley, Steve P; Ruston, Julie

2012-01-01

in the absence of Cdc42, indicating a disruption of the slit diaphragm. Kidneys from Rac1- and RhoA-mutant mice, however, had normal glomerular morphology and intact foot processes. A nephrin clustering assay suggested that Cdc42 deficiency, but not Rac1 or RhoA deficiency, impairs the polymerization of actin...

Binding of Cdc42 to phospholipase D1 is important in neurite outgrowth of neural stem cells

International Nuclear Information System (INIS)

Yoon, Mee-Sup; Cho, Chan Ho; Lee, Ki Sung; Han, Joong-Soo

2006-01-01

We previously demonstrated that phospholipase D (PLD) expression and PLD activity are upregulated during neuronal differentiation. In the present study, employing neural stem cells from the brain cortex of E14 rat embryos, we investigated the role of Rho family GTPases in PLD activation and in neurite outgrowth of neural stem cells during differentiation. As neuronal differentiation progressed, the expression levels of Cdc42 and RhoA increased. Furthermore, Cdc42 and PLD1 were mainly localized in neurite, whereas RhoA was localized in cytosol. Co-immunoprecipitation revealed that Cdc42 was bound to PLD1 during differentiation, whereas RhoA was associated with PLD1 during both proliferation and differentiation. These results indicate that the association between Cdc42 and PLD1 is related to neuronal differentiation. To examine the effect of Cdc42 on PLD activation and neurite outgrowth, we transfected dominant negative Cdc42 (Cdc42N17) and constitutively active Cdc42 (Cdc42V12) into neural stem cells, respectively. Overexpression of Cdc42N17 decreased both PLD activity and neurite outgrowth, whereas co-transfection with Cdc42N17 and PLD1 restored them. On the other hand, Cdc42V12 increased both PLD activity and neurite outgrowth, suggesting that active state of Cdc42 is important in upregulation of PLD activity which is responsible for the increase of neurite outgrowth

FMNL2 and -3 regulate Golgi architecture and anterograde transport downstream of Cdc42

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Kage, Frieda; Steffen, Anika; Ellinger, Adolf

2017-01-01

The Rho-family small GTPase Cdc42 localizes at plasma membrane and Golgi complex and aside from protrusion and migration operates in vesicle trafficking, endo- and exocytosis as well as establishment and/or maintenance of cell polarity. The formin family members FMNL2 and -3 are actin assembly fa...

RIT1 controls actin dynamics via complex formation with RAC1/CDC42 and PAK1.

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Uta Meyer Zum Büschenfelde

2018-05-01

Full Text Available RIT1 belongs to the RAS family of small GTPases. Germline and somatic RIT1 mutations have been identified in Noonan syndrome (NS and cancer, respectively. By using heterologous expression systems and purified recombinant proteins, we identified the p21-activated kinase 1 (PAK1 as novel direct effector of RIT1. We found RIT1 also to directly interact with the RHO GTPases CDC42 and RAC1, both of which are crucial regulators of actin dynamics upstream of PAK1. These interactions are independent of the guanine nucleotide bound to RIT1. Disease-causing RIT1 mutations enhance protein-protein interaction between RIT1 and PAK1, CDC42 or RAC1 and uncouple complex formation from serum and growth factors. We show that the RIT1-PAK1 complex regulates cytoskeletal rearrangements as expression of wild-type RIT1 and its mutant forms resulted in dissolution of stress fibers and reduction of mature paxillin-containing focal adhesions in COS7 cells. This effect was prevented by co-expression of RIT1 with dominant-negative CDC42 or RAC1 and kinase-dead PAK1. By using a transwell migration assay, we show that RIT1 wildtype and the disease-associated variants enhance cell motility. Our work demonstrates a new function for RIT1 in controlling actin dynamics via acting in a signaling module containing PAK1 and RAC1/CDC42, and highlights defects in cell adhesion and migration as possible disease mechanism underlying NS.

RIT1 controls actin dynamics via complex formation with RAC1/CDC42 and PAK1.

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Meyer Zum Büschenfelde, Uta; Brandenstein, Laura Isabel; von Elsner, Leonie; Flato, Kristina; Holling, Tess; Zenker, Martin; Rosenberger, Georg; Kutsche, Kerstin

2018-05-01

RIT1 belongs to the RAS family of small GTPases. Germline and somatic RIT1 mutations have been identified in Noonan syndrome (NS) and cancer, respectively. By using heterologous expression systems and purified recombinant proteins, we identified the p21-activated kinase 1 (PAK1) as novel direct effector of RIT1. We found RIT1 also to directly interact with the RHO GTPases CDC42 and RAC1, both of which are crucial regulators of actin dynamics upstream of PAK1. These interactions are independent of the guanine nucleotide bound to RIT1. Disease-causing RIT1 mutations enhance protein-protein interaction between RIT1 and PAK1, CDC42 or RAC1 and uncouple complex formation from serum and growth factors. We show that the RIT1-PAK1 complex regulates cytoskeletal rearrangements as expression of wild-type RIT1 and its mutant forms resulted in dissolution of stress fibers and reduction of mature paxillin-containing focal adhesions in COS7 cells. This effect was prevented by co-expression of RIT1 with dominant-negative CDC42 or RAC1 and kinase-dead PAK1. By using a transwell migration assay, we show that RIT1 wildtype and the disease-associated variants enhance cell motility. Our work demonstrates a new function for RIT1 in controlling actin dynamics via acting in a signaling module containing PAK1 and RAC1/CDC42, and highlights defects in cell adhesion and migration as possible disease mechanism underlying NS.

Ang II-AT2R increases mesenchymal stem cell migration by signaling through the FAK and RhoA/Cdc42 pathways in vitro.

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Xu, Xiu-Ping; He, Hong-Li; Hu, Shu-Ling; Han, Ji-Bin; Huang, Li-Li; Xu, Jing-Yuan; Xie, Jian-Feng; Liu, Ai-Ran; Yang, Yi; Qiu, Hai-Bo

2017-07-12

not Losartan, indicating that FAK activation and F-actin reorganization were downstream of AT2R. These data indicate that Ang II-AT2R regulates human bone marrow MSC migration by signaling through the FAK and RhoA/Cdc42 pathways. This study provides insights into the mechanisms by which MSCs home to injury sites and will enable the rational design of targeted therapies to improve MSC engraftment.

Cdc42 is crucial for the establishment of epithelial polarity during early mammalian development

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Wu, Xunwei; Li, Shaohua; Chrostek-Grashoff, Anna

2007-01-01

To study the role of Cdc42 in the establishment of epithelial polarity during mammalian development, we generated murine Cdc42-null embryonic stem cells and analyzed peri-implantation development using embryoid bodies (EBs). Mutant EBs developed endoderm and underlying basement membrane, but exhi......To study the role of Cdc42 in the establishment of epithelial polarity during mammalian development, we generated murine Cdc42-null embryonic stem cells and analyzed peri-implantation development using embryoid bodies (EBs). Mutant EBs developed endoderm and underlying basement membrane...

Prominin-2 expression increases protrusions, decreases caveolae and inhibits Cdc42 dependent fluid phase endocytosis

Energy Technology Data Exchange (ETDEWEB)

Singh, Raman Deep, E-mail: Takhter.Ramandeep@mayo.edu; Schroeder, Andreas S.; Scheffer, Luana; Holicky, Eileen L.; Wheatley, Christine L.; Marks, David L., E-mail: Marks.david@mayo.edu; Pagano, Richard E.

2013-05-10

localize to lipid rafts and recruit cholesterol into protrusions and away from caveolae, leading to increased phosphorylation of caveolin-1, which inhibits Cdc42-dependent endocytosis. This study provides a new insight for the role for prominins in the regulation of PM lipid organization.

Regulated degradation of the APC coactivator Cdc20

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Robbins Jonathan A

2010-09-01

Full Text Available Abstract Background Cdc20 is a highly conserved activator of the anaphase-promoting complex (APC, promoting cell-cycle-regulated ubiquitination and proteolysis of a number of critical cell-cycle-regulatory targets including securin and mitotic cyclins. APC-Cdc20 activity is tightly regulated, and this regulation is likely important for accurate cell cycle control. One significant component of Cdc20 regulation is thought to be Cdc20 proteolysis. However, published literature suggests different mechanisms and requirements for Cdc20 proteolysis. The degree to which Cdc20 proteolysis is cell-cycle regulated, the dependence of Cdc20 proteolysis on Cdc20 destruction boxes (recognition sequences for APC-mediated ubiqutination, either by Cdc20 or by the related Cdh1 APC activator, and the need for APC itself for Cdc20 proteolysis all have been disputed to varying extents. In animals, Cdc20 proteolysis is thought to be mediated by Cdh1, contributing an intrinsic order of APC activation by Cdc20 and then by Cdh1. One report suggests a Cdh1 requirement for Cdc20 proteolysis in budding yeast; this idea has not been tested further. Results We characterized Cdc20 proteolysis using Cdc20 expressed from its endogenous locus; previous studies generally employed strongly overexpressed Cdc20, which can cause significant artifacts. We analyzed Cdc20 proteolysis with or without mutations in previously identified destruction box sequences, using varying methods of cell cycle synchronization, and in the presence or absence of Cdh1. Cdc20 instability is only partially dependent on destruction boxes. A much stronger dependence on Cdh1 for Cdc20 proteolysis was observed, but Cdh1-independent proteolysis was also clearly observed. Cdc20 proteolysis independent of both destruction boxes and Cdh1 was especially detectable around the G1/S transition; Cdh1-dependent proteolysis was most notable in late mitosis and G1. Conclusions Cdc20 proteolysis is under complex control

Frequent alterations of SLIT2–ROBO1–CDC42 signalling pathway ...

Indian Academy of Sciences (India)

breast cancer; alterations of SLIT2–ROBO1 signalling; active CDC42; ... proportion of four subtypes were tested for molecular alterations of SLIT2, ... reduced expression of phospho Serine-71 CDC42 predicted poor survival of BC patients.

Frequent alterations of SLIT2–ROBO1–CDC42 signalling pathway ...

Indian Academy of Sciences (India)

2016-09-07

Sep 7, 2016 ... Keywords. breast cancer; alterations of SLIT2–ROBO1 signalling; active CDC42; pSer71-CDC42 . Journal of ... have already been studied in head and neck squamous cell ...... lung, oral, cervical, breast, kidney (Dallol et al.

Cdc42 is crucial for the maturation of primordial cell junctions in keratinocytes independent of Rac1

DEFF Research Database (Denmark)

Du, Dan; Pedersen, Esben; Wang, Zhipeng

2008-01-01

Cell-cell contacts are crucial for the integrity of all tissues. Contrasting reports have been published about the role of Cdc42 in epithelial cell-cell contacts in vitro. In keratinocytes, it was suggested that Rac1 and not Cdc42 is crucial for the formation of mature epithelial junctions, based...... on dominant negative inhibition experiments. Deletion of the Cdc42 gene in keratinocytes in vivo slowly impaired the maintenance of cell-cell contacts by an increased degradation of beta-catenin. Whether Cdc42 is required for the formation of mature junctions was not tested. We show now that Cdc42-deficient...... immortalized and primary keratinocytes form only punctate primordial cell contacts in vitro, which cannot mature into belt-like junctions. This defect was independent of enhanced degradation of beta-catenin, but correlated to an impaired activation and localization of aPKCzeta in the Cdc42-null keratinocytes...

RhoA, Rac1 and Cdc42 differentially regulate aSMA and collagen I expression in mesenchymal stem cells.

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Ge, Jianfeng; Burnier, Laurent; Adamopoulou, Maria; Kwa, Mei Qi; Schaks, Matthias; Rottner, Klemens; Brakebusch, Cord

2018-04-26

Mesenchymal stem cells (MSC) are suggested to be important progenitors of myofibroblasts in fibrosis. To understand the role of Rho GTPase signaling in TGFβ-induced myofibroblast differentiation of MSC, we generated a novel MSC line and descendants of it lacking functional Rho GTPases and Rho GTPase signaling components. Unexpectedly, our data revealed that Rho GTPase signaling is required for TGFβ-induced expression of αSMA, but not of collagen I α1 (col1a1). While loss of RhoA and Cdc42 reduced αSMA expression, ablation of the Rac1 gene had the opposite effect. Although actin polymerization and MRTFa were crucial for TGFβ-induced αSMA expression, neither Arp2/3 dependent actin polymerization nor cofilin dependent severing and depolymerization of F-actin were required. Instead, F-actin levels were dependent on cell contraction and TGFβ-induced actin polymerisation correlated with increased cell contraction mediated by RhoA and Cdc42. Finally, we observed impaired collagen I secretion in MSC lacking RhoA or Cdc42. These data give novel molecular insights into the role of Rho GTPases in TGFβ signaling and have implications for our understanding of MSC function in fibrosis. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Mechanism of IRSp53 inhibition and combinatorial activation by Cdc42 and downstream effectors.

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Kast, David J; Yang, Changsong; Disanza, Andrea; Boczkowska, Malgorzata; Madasu, Yadaiah; Scita, Giorgio; Svitkina, Tatyana; Dominguez, Roberto

2014-04-01

The Rho family GTPase effector IRSp53 has essential roles in filopodia formation and neuronal development, but its regulatory mechanism is poorly understood. IRSp53 contains a membrane-binding BAR domain followed by an unconventional CRIB motif that overlaps with a proline-rich region (CRIB-PR) and an SH3 domain that recruits actin cytoskeleton effectors. Using a fluorescence reporter assay, we show that human IRSp53 adopts a closed inactive conformation that opens synergistically with the binding of human Cdc42 to the CRIB-PR and effector proteins, such as the tumor-promoting factor Eps8, to the SH3 domain. The crystal structure of Cdc42 bound to the CRIB-PR reveals a new mode of effector binding to Rho family GTPases. Structure-inspired mutations disrupt autoinhibition and Cdc42 binding in vitro and decouple Cdc42- and IRSp53-dependent filopodia formation in cells. The data support a combinatorial mechanism of IRSp53 activation.

Involvement of the Cdc42 pathway in CFTR post-translational turnover and in its plasma membrane stability in airway epithelial cells.

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Romain Ferru-Clément

Full Text Available Cystic fibrosis transmembrane conductance regulator (CFTR is a chloride channel that is expressed on the apical plasma membrane (PM of epithelial cells. The most common deleterious allele encodes a trafficking-defective mutant protein undergoing endoplasmic reticulum-associated degradation (ERAD and presenting lower PM stability. In this study, we investigated the involvement of the Cdc42 pathway in CFTR turnover and trafficking in a human bronchiolar epithelial cell line (CFBE41o- expressing wild-type CFTR. Cdc42 is a small GTPase of the Rho family that fulfils numerous cell functions, one of which is endocytosis and recycling process via actin cytoskeleton remodelling. When we treated cells with chemical inhibitors such as ML141 against Cdc42 and wiskostatin against the downstream effector N-WASP, we observed that CFTR channel activity was inhibited, in correlation with a decrease in CFTR amount at the cell surface and an increase in dynamin-dependent CFTR endocytosis. Anchoring of CFTR to the cortical cytoskeleton was then presumably impaired by actin disorganization. When we performed siRNA-mediated depletion of Cdc42, actin polymerization was not impacted, but we observed actin-independent consequences upon CFTR. Total and PM CFTR amounts were increased, resulting in greater activation of CFTR. Pulse-chase experiments showed that while CFTR degradation was slowed, CFTR maturation through the Golgi apparatus remained unaffected. In addition, we observed increased stability of CFTR in PM and reduction of its endocytosis. This study highlights the involvement of the Cdc42 pathway at several levels of CFTR biogenesis and trafficking: (i Cdc42 is implicated in the first steps of CFTR biosynthesis and processing; (ii it contributes to the stability of CFTR in PM via its anchoring to cortical actin; (iii it promotes CFTR endocytosis and presumably its sorting toward lysosomal degradation.

Coordination by Cdc42 of Actin, Contractility, and Adhesion for Melanoblast Movement in Mouse Skin

DEFF Research Database (Denmark)

Woodham, Emma F; Paul, Nikki R; Tyrrell, Benjamin

2017-01-01

traverse the dermis to reach the epidermis of the skin and hair follicles. We previously established that Rac1 signals via Scar/WAVE and Arp2/3 to effect pseudopod extension and migration of melanoblasts in skin. Here we show that RhoA is redundant in the melanocyte lineage but that Cdc42 coordinates...... multiple motility systems independent of Rac1. Similar to Rac1 knockouts, Cdc42 null mice displayed a severe loss of pigmentation, and melanoblasts showed cell-cycle progression, migration, and cytokinesis defects. However, unlike Rac1 knockouts, Cdc42 null melanoblasts were elongated and displayed large...... null cells lacked the ability to polarize their Golgi and coordinate motility systems for efficient movement. Loss of Cdc42 de-coupled three main systems: actin assembly via the formin FMNL2 and Arp2/3, active myosin-II localization, and integrin-based adhesion dynamics....

A TOCA/CDC-42/PAR/WAVE functional module required for retrograde endocytic recycling

Science.gov (United States)

Bai, Zhiyong; Grant, Barth D.

2015-01-01

Endosome-to-Golgi transport is required for the function of many key membrane proteins and lipids, including signaling receptors, small-molecule transporters, and adhesion proteins. The retromer complex is well-known for its role in cargo sorting and vesicle budding from early endosomes, in most cases leading to cargo fusion with the trans-Golgi network (TGN). Transport from recycling endosomes to the TGN has also been reported, but much less is understood about the molecules that mediate this transport step. Here we provide evidence that the F-BAR domain proteins TOCA-1 and TOCA-2 (Transducer of Cdc42 dependent actin assembly), the small GTPase CDC-42 (Cell division control protein 42), associated polarity proteins PAR-6 (Partitioning defective 6) and PKC-3/atypical protein kinase C, and the WAVE actin nucleation complex mediate the transport of MIG-14/Wls and TGN-38/TGN38 cargo proteins from the recycling endosome to the TGN in Caenorhabditis elegans. Our results indicate that CDC-42, the TOCA proteins, and the WAVE component WVE-1 are enriched on RME-1–positive recycling endosomes in the intestine, unlike retromer components that act on early endosomes. Furthermore, we find that retrograde cargo TGN-38 is trapped in early endosomes after depletion of SNX-3 (a retromer component) but is mainly trapped in recycling endosomes after depletion of CDC-42, indicating that the CDC-42–associated complex functions after retromer in a distinct organelle. Thus, we identify a group of interacting proteins that mediate retrograde recycling, and link these proteins to a poorly understood trafficking step, recycling endosome-to-Golgi transport. We also provide evidence for the physiological importance of this pathway in WNT signaling. PMID:25775511

The structure of FMNL2-Cdc42 yields insights into the mechanism of lamellipodia and filopodia formation

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Kühn, Sonja; Erdmann, Constanze; Kage, Frieda; Block, Jennifer; Schwenkmezger, Lisa; Steffen, Anika; Rottner, Klemens; Geyer, Matthias

2015-05-01

Formins are actin polymerization factors that elongate unbranched actin filaments at the barbed end. Rho family GTPases activate Diaphanous-related formins through the relief of an autoregulatory interaction. The crystal structures of the N-terminal domains of human FMNL1 and FMNL2 in complex with active Cdc42 show that Cdc42 mediates contacts with all five armadillo repeats of the formin with specific interactions formed by the Rho-GTPase insert helix. Mutation of three residues within Rac1 results in a gain-of-function mutation for FMNL2 binding and reconstitution of the Cdc42 phenotype in vivo. Dimerization of FMNL1 through a parallel coiled coil segment leads to formation of an umbrella-shaped structure that--together with Cdc42--spans more than 15 nm in diameter. The two interacting FMNL-Cdc42 heterodimers expose six membrane interaction motifs on a convex protein surface, the assembly of which may facilitate actin filament elongation at the leading edge of lamellipodia and filopodia.

Unraveling the molecular mechanism of interactions of the Rho GTPases Cdc42 and Rac1 with the scaffolding protein IQGAP2.

Science.gov (United States)

Ozdemir, E Sila; Jang, Hyunbum; Gursoy, Attila; Keskin, Ozlem; Li, Zhigang; Sacks, David B; Nussinov, Ruth

2018-03-09

IQ motif-containing GTPase-activating proteins (IQGAPs) are scaffolding proteins playing central roles in cell-cell adhesion, polarity, and motility. The Rho GTPases Cdc42 and Rac1, in their GTP-bound active forms, interact with all three human IQGAPs. The IQGAP-Cdc42 interaction promotes metastasis by enhancing actin polymerization. However, despite their high sequence identity, Cdc42 and Rac1 differ in their interactions with IQGAP. Two Cdc42 molecules can bind to the Ex-domain and the RasGAP site of the GTPase-activating protein (GAP)-related domain (GRD) of IQGAP and promote IQGAP dimerization. Only one Rac1 molecule might bind to the RasGAP site of GRD and may not facilitate the dimerization, and the exact mechanism of Cdc42 and Rac1 binding to IQGAP is unclear. Using all-atom molecular dynamics simulations, site-directed mutagenesis, and Western blotting, we unraveled the detailed mechanisms of Cdc42 and Rac1 interactions with IQGAP2. We observed that Cdc42 binding to the Ex-domain of GRD of IQGAP2 (GRD2) releases the Ex-domain at the C-terminal region of GRD2, facilitating IQGAP2 dimerization. Cdc42 binding to the Ex-domain promoted allosteric changes in the RasGAP site, providing a binding site for the second Cdc42 in the RasGAP site. Of note, the Cdc42 "insert loop" was important for the interaction of the first Cdc42 with the Ex-domain. By contrast, differences in Rac1 insert-loop sequence and structure precluded its interaction with the Ex-domain. Rac1 could bind only to the RasGAP site of apo-GRD2 and could not facilitate IQGAP2 dimerization. Our detailed mechanistic insights help decipher how Cdc42 can stimulate actin polymerization in metastasis.

Cdc42 expression in keratinocytes is required for the maintenance of the basement membrane in skin

DEFF Research Database (Denmark)

Wu, Xunwei; Quondamatteo, Fabio; Brakebusch, Cord

2006-01-01

, structure and number of hemidesomosomes were not significantly changed in the Cdc42 mutant skin compared with the control mice and no blister formation was observed in mutant skin. These data indicate that Cdc42 in keratinocytes is important for maintenance of the basement membrane of skin....... process, which requires directed secretion, deposition and organization of basement membrane components at the basal side of epithelial cells. In the current study, we analyzed the maintenance of skin basement membrane in mice with a keratinocyte-restricted deletion of the Cdc42 gene. In the absence...

Continuous cell injury promotes hepatic tumorigenesis in cdc42-deficient mouse liver

DEFF Research Database (Denmark)

van Hengel, Jolanda; D'Hooge, Petra; Hooghe, Bart

2008-01-01

be required for liver function. METHODS: Mice in which Cdc42 was ablated in hepatocytes and bile duct cells were generated by Cre-loxP technology. Livers were examined by histologic, immunohistochemical, ultrastructural, and serum analysis to define the effect of loss of Cdc42 on liver structure. RESULTS...... of 2 months, the canaliculi between hepatocytes were greatly enlarged, although the tight junctions flanking the canaliculi appeared normal. Regular liver plates were absent. E-cadherin expression pattern and gap junction localization were distorted. Analysis of serum samples indicated cholestasis...

Microgravity simulation activates Cdc42 via Rap1GDS1 to promote vascular branch morphogenesis during vasculogenesis

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Shouli Wang

2017-12-01

Full Text Available Gravity plays an important role in normal tissue maintenance. The ability of stem cells to repair tissue loss in space through regeneration and differentiation remains largely unknown. To investigate the impact of microgravity on blood vessel formation from pluripotent stem cells, we employed the embryoid body (EB model for vasculogenesis and simulated microgravity by clinorotation. We first differentiated mouse embryonic stem cells into cystic EBs containing two germ layers and then analyzed vessel formation under clinorotation. We observed that endothelial cell differentiation was slightly reduced under clinorotation, whereas vascular branch morphogenesis was markedly enhanced. EB-derived endothelial cells migrated faster, displayed multiple cellular processes, and had higher Cdc42 and Rac1 activity when subjected to clinorotation. Genetic analysis and rescue experiments demonstrated that Cdc42 but not Rac1 is required for microgravity-induced vascular branch morphogenesis. Furthermore, affinity pull-down assay and mass spectrometry identified Rap1GDS1 to be a Cdc42 guanine nucleotide exchange factor, which was upregulated by clinorotation. shRNA-mediated knockdown of Rap1GDS1 selectively suppressed Cdc42 activation and inhibited both baseline and microgravity-induced vasculogenesis. This was rescued by ectopic expression of constitutively active Cdc42. Taken together, these results support the notion that simulated microgravity activates Cdc42 via Rap1GDS1 to promote vascular branch morphogenesis.

Genetic deletion of cdc42 reveals a crucial role for astrocyte recruitment to the injury site in vitro and in vivo

DEFF Research Database (Denmark)

Robel, Stefanie; Bardehle, Sophia; Lepier, Alexandra

2011-01-01

signals, the small RhoGTPase Cdc42, selectively in mouse astrocytes in vitro and in vivo. We used an in vitro scratch assay as a minimal wounding model and found that astrocytes lacking Cdc42 (Cdc42Δ) were still able to form protrusions, although in a nonoriented way. Consequently, they failed to migrate...... in a directed manner toward the scratch. When animals were injured in vivo through a stab wound, Cdc42Δ astrocytes developed protrusions properly oriented toward the lesion, but the number of astrocytes recruited to the lesion site was significantly reduced. Surprisingly, however, lesions in Cdc42Δ animals...

Cdc42/N-WASP signaling links actin dynamics to pancreatic β cell delamination and differentiation

Science.gov (United States)

Kesavan, Gokul; Lieven, Oliver; Mamidi, Anant; Öhlin, Zarah Löf; Johansson, Jenny Kristina; Li, Wan-Chun; Lommel, Silvia; Greiner, Thomas Uwe; Semb, Henrik

2014-01-01

Delamination plays a pivotal role during normal development and cancer. Previous work has demonstrated that delamination and epithelial cell movement within the plane of an epithelium are associated with a change in cellular phenotype. However, how this positional change is linked to differentiation remains unknown. Using the developing mouse pancreas as a model system, we show that β cell delamination and differentiation are two independent events, which are controlled by Cdc42/N-WASP signaling. Specifically, we show that expression of constitutively active Cdc42 in β cells inhibits β cell delamination and differentiation. These processes are normally associated with junctional actin and cell-cell junction disassembly and the expression of fate-determining transcription factors, such as Isl1 and MafA. Mechanistically, we demonstrate that genetic ablation of N-WASP in β cells expressing constitutively active Cdc42 partially restores both delamination and β cell differentiation. These findings elucidate how junctional actin dynamics via Cdc42/N-WASP signaling cell-autonomously control not only epithelial delamination but also cell differentiation during mammalian organogenesis. PMID:24449844

Divergent functions of the Rho GTPases Rac1 and Cdc42 in podocyte injury

DEFF Research Database (Denmark)

Blattner, Simone M; Hodgin, Jeffrey B; Nishio, Masashi

2013-01-01

-specific deletion of Rac1 prevented foot process effacement. In a long-term model of chronic hypertensive glomerular damage, however, loss of Rac1 led to an exacerbation of albuminuria and glomerulosclerosis. In contrast, mice with podocyte-specific deletion of Cdc42 had severe proteinuria, podocyte foot process...... effacement, and glomerulosclerosis beginning as early as 10 days of age. In addition, slit diaphragm proteins nephrin and podocin were redistributed, and cofilin was dephosphorylated. Cdc42 is necessary for the maintenance of podocyte structure and function, but Rac1 is entirely dispensable in physiological...... steady state. However, Rac1 has either beneficial or deleterious effects depending on the context of podocyte impairment. Thus, our study highlights the divergent roles of Rac1 and Cdc42 function in podocyte maintenance and injury.Kidney International advance online publication, 15 May 2013; doi:10...

Multiple alterations of platelet functions dominated by increased secretion in mice lacking Cdc42 in platelets

DEFF Research Database (Denmark)

Pleines, Irina; Eckly, Anita; Elvers, Margitta

2010-01-01

formation and exocytosis in various cell types, but its exact function in platelets is not established. Here, we show that the megakaryocyte/platelet-specific loss of Cdc42 leads to mild thrombocytopenia and a small increase in platelet size in mice. Unexpectedly, Cdc42-deficient platelets were able to form...

Cdc42 and Tks5: a minimal and universal molecular signature for functional invadosomes.

Science.gov (United States)

Di Martino, Julie; Paysan, Lisa; Gest, Caroline; Lagrée, Valérie; Juin, Amélie; Saltel, Frédéric; Moreau, Violaine

2014-01-01

Invadosomes are actin-based structures involved in extracellular-matrix degradation. Invadosomes, either known as podosomes or invadopodia, are found in an increasing number of cell types. Moreover, their overall organization and molecular composition may vary from one cell type to the other. Some are constitutive such as podosomes in hematopoietic cells whereas others are inducible. However, they share the same feature, their ability to interact and to degrade the extracellular matrix. Based on the literature and our own experiments, the aim of this study was to establish a minimal molecular definition of active invadosomes. We first highlighted that Cdc42 is the key RhoGTPase involved in invadosome formation in all described models. Using different cellular models, such as NIH-3T3, HeLa, and endothelial cells, we demonstrated that overexpression of an active form of Cdc42 is sufficient to form invadosome actin cores. Therefore, active Cdc42 must be considered not only as an inducer of filopodia, but also as an inducer of invadosomes. Depending on the expression level of Tks5, these Cdc42-dependent actin cores were endowed or not with a proteolytic activity. In fact, Tks5 overexpression rescued this activity in Tks5 low expressing cells. We thus described the adaptor protein Tks5 as a major actor of the invadosome degradation function. Surprisingly, we found that Src kinases are not always required for invadosome formation and function. These data suggest that even if Src family members are the principal kinases involved in the majority of invadosomes, it cannot be considered as a common element for all invadosome structures. We thus define a minimal and universal molecular signature of invadosome that includes Cdc42 activity and Tks5 presence in order to drive the actin machinery and the proteolytic activity of these invasive structures.

Cdc42 is not essential for filopodium formation, directed migration, cell polarization, and mitosis in fibroblastoid cells

DEFF Research Database (Denmark)

Czuchra, Aleksandra; Wu, Xunwei; Meyer, Hannelore

2005-01-01

of Cdc42 did not affect filopodium or lamellipodium formation and had no significant influence on the speed of directed migration nor on mitosis. Cdc42-deficient cells displayed a more elongated cell shape and had a reduced area. Furthermore, directionality during migration and reorientation of the Golgi...

Novel Activities of Select NSAID R-Enantiomers against Rac1 and Cdc42 GTPases.

Directory of Open Access Journals (Sweden)

Tudor I Oprea

Full Text Available Rho family GTPases (including Rac, Rho and Cdc42 collectively control cell proliferation, adhesion and migration and are of interest as functional therapeutic targets in numerous epithelial cancers. Based on high throughput screening of the Prestwick Chemical Library® and cheminformatics we identified the R-enantiomers of two approved drugs (naproxen and ketorolac as inhibitors of Rac1 and Cdc42. The corresponding S-enantiomers are considered the active component in racemic drug formulations, acting as non-steroidal anti-inflammatory drugs (NSAIDs with selective activity against cyclooxygenases. Here, we show that the S-enantiomers of naproxen and ketorolac are inactive against the GTPases. Additionally, more than twenty other NSAIDs lacked inhibitory action against the GTPases, establishing the selectivity of the two identified NSAIDs. R-naproxen was first identified as a lead compound and tested in parallel with its S-enantiomer and the non-chiral 6-methoxy-naphthalene acetic acid (active metabolite of nabumetone, another NSAID as a structural series. Cheminformatics-based substructure analyses-using the rotationally constrained carboxylate in R-naproxen-led to identification of racemic [R/S] ketorolac as a suitable FDA-approved candidate. Cell based measurement of GTPase activity (in animal and human cell lines demonstrated that the R-enantiomers specifically inhibit epidermal growth factor stimulated Rac1 and Cdc42 activation. The GTPase inhibitory effects of the R-enantiomers in cells largely mimic those of established Rac1 (NSC23766 and Cdc42 (CID2950007/ML141 specific inhibitors. Docking predicts that rotational constraints position the carboxylate moieties of the R-enantiomers to preferentially coordinate the magnesium ion, thereby destabilizing nucleotide binding to Rac1 and Cdc42. The S-enantiomers can be docked but are less favorably positioned in proximity to the magnesium. R-naproxen and R-ketorolac have potential for rapid

Primary angle closure glaucoma (PACG) susceptibility gene PLEKHA7 encodes a novel Rac1/Cdc42 GAP that modulates cell migration and blood-aqueous barrier function.

Science.gov (United States)

Lee, Mei-Chin; Shei, William; Chan, Anita S; Chua, Boon-Tin; Goh, Shuang-Ru; Chong, Yaan-Fun; Hilmy, Maryam H; Nongpiur, Monisha E; Baskaran, Mani; Khor, Chiea-Chuen; Aung, Tin; Hunziker, Walter; Vithana, Eranga N

2017-10-15

PLEKHA7, a gene recently associated with primary angle closure glaucoma (PACG), encodes an apical junctional protein expressed in components of the blood aqueous barrier (BAB). We found that PLEKHA7 is down-regulated in lens epithelial cells and in iris tissue of PACG patients. PLEKHA7 expression also correlated with the C risk allele of the sentinel SNP rs11024102 with the risk allele carrier groups having significantly reduced PLEKHA7 levels compared to non-risk allele carriers. Silencing of PLEKHA7 in human immortalized non-pigmented ciliary epithelium (h-iNPCE) and primary trabecular meshwork cells, which are intimately linked to BAB and aqueous humor outflow respectively, affected actin cytoskeleton organization. PLEKHA7 specifically interacts with GTP-bound Rac1 and Cdc42, but not RhoA, and the activation status of the two small GTPases is linked to PLEKHA7 expression levels. PLEKHA7 stimulates Rac1 and Cdc42 GTP hydrolysis, without affecting nucleotide exchange, identifying PLEKHA7 as a novel Rac1/Cdc42 GAP. Consistent with the regulatory role of Rac1 and Cdc42 in maintaining the tight junction permeability, silencing of PLEKHA7 compromises the paracellular barrier between h-iNPCE cells. Thus, downregulation of PLEKHA7 in PACG may affect BAB integrity and aqueous humor outflow via its Rac1/Cdc42 GAP activity, thereby contributing to disease etiology. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Two closely related Rho GTPases, Cdc42 and RacA, of the en-dophytic fungus Epichloë festucae have contrasting roles for ROS production and symbiotic infection synchronized with the host plant.

Science.gov (United States)

Kayano, Yuka; Tanaka, Aiko; Takemoto, Daigo

2018-01-01

Epichloë festucae is an endophytic fungus which systemically colonizes temperate grasses to establish symbiotic associations. Maintaining symptomless infection is a key requirement for endophytes, a feature that distinguishes them from pathogenic fungi. While pathogenic fungi extend their hyphae by tip growth, hyphae of E. festucae systemically colonize the intercellular space of expanding host leaves via a unique mechanism of hyphal intercalary growth. This study reports that two homologous Rho GTPases, Cdc42 and RacA, have distinctive roles in the regulation of E. festucae growth in planta. Here we highlight the vital role of Cdc42 for intercalary hyphal growth, as well as involvement of RacA in regulation of hyphal network formation, and demonstrate the consequences of mutations in these genes on plant tissue infection. Functions of Cdc42 and RacA are mediated via interactions with BemA and NoxR respectively, which are expected components of the ROS producing NOX complex. Symbiotic defects found in the racA mutant were rescued by introduction of a Cdc42 with key amino acids substitutions crucial for RacA function, highlighting the significance of the specific interactions of these GTPases with BemA and NoxR for their functional differentiation in symbiotic infection.

Stage-specific functions of the small Rho GTPases Cdc42 and Rac1 for adult hippocampal neurogenesis

DEFF Research Database (Denmark)

Vadodaria, Krishna C; Brakebusch, Cord; Suter, Ueli

2013-01-01

The molecular mechanisms underlying the generation, maturation, and integration of new granule cells generated throughout life in the mammalian hippocampus remain poorly understood. Small Rho GTPases, such as Cdc42 and Rac1, have been implicated previously in neural stem/progenitor cell (NSPC......) proliferation and neuronal maturation during embryonic development. Here we used conditional genetic deletion and virus-based loss-of-function approaches to identify temporally distinct functions for Cdc42 and Rac1 in adult hippocampal neurogenesis. We found that Cdc42 is involved in mouse NSPC proliferation......, initial dendritic development, and dendritic spine maturation. In contrast, Rac1 is dispensable for early steps of neuronal development but is important for late steps of dendritic growth and spine maturation. These results establish cell-autonomous and stage-specific functions for the small Rho GTPases...

A hot-spot mutation in CDC42 (p.Tyr64Cys) and novel phenotypes in the third patient with Takenouchi-Kosaki syndrome.

Science.gov (United States)

Motokawa, Midori; Watanabe, Satoshi; Nakatomi, Akiko; Kondoh, Tatsuro; Matsumoto, Tadashi; Morifuji, Kanako; Sawada, Hirotake; Nishimura, Toyoki; Nunoi, Hiroyuki; Yoshiura, Koh-Ichiro; Moriuchi, Hiroyuki; Dateki, Sumito

2018-03-01

Takenouchi-Kosaki syndrome (TKS) is a congenital malformation syndrome characterized by severe developmental delay, macrothrombocytopenia, camptodactyly, sensorineural hearing loss, and dysmorphic facial features. Recently, a heterozygous de novo mutation (p.Tyr64Cys) in the CDC42 gene, which encodes a key small GTP-binding protein of the Rho-subfamily, was identified in two unrelated patients with TKS. We herein report a third patient with TKS who had the same heterozygous CDC42 mutation. The phenotype of the patient was very similar to those of the two previously reported patients with TKS; however, she also demonstrated novel clinical manifestations, such as congenital hypothyroidism and immunological disturbance. Thus, despite the heterozygous mutation of CDC42 (p.Tyr64Cys) likely being a hot-spot mutation for TKS, its phenotype may be variable. Further studies and the accumulation of patients with CDC42 mutations are needed to clarify the phenotype in patients with TKS and the pathophysiological roles of the CDC42 mutation.

The signaling pathway of Campylobacter jejuni-induced Cdc42 activation: Role of fibronectin, integrin beta1, tyrosine kinases and guanine exchange factor Vav2

LENUS (Irish Health Repository)

Krause-Gruszczynska, Malgorzata

2011-12-28

Abstract Background Host cell invasion by the foodborne pathogen Campylobacter jejuni is considered as one of the primary reasons of gut tissue damage, however, mechanisms and key factors involved in this process are widely unclear. It was reported that small Rho GTPases, including Cdc42, are activated and play a role during invasion, but the involved signaling cascades remained unknown. Here we utilised knockout cell lines derived from fibronectin-\\/-, integrin-beta1-\\/-, focal adhesion kinase (FAK)-\\/- and Src\\/Yes\\/Fyn-\\/- deficient mice, and wild-type control cells, to investigate C. jejuni-induced mechanisms leading to Cdc42 activation and bacterial uptake. Results Using high-resolution scanning electron microscopy, GTPase pulldowns, G-Lisa and gentamicin protection assays we found that each studied host factor is necessary for induction of Cdc42-GTP and efficient invasion. Interestingly, filopodia formation and associated membrane dynamics linked to invasion were only seen during infection of wild-type but not in knockout cells. Infection of cells stably expressing integrin-beta1 variants with well-known defects in fibronectin fibril formation or FAK signaling also exhibited severe deficiencies in Cdc42 activation and bacterial invasion. We further demonstrated that infection of wild-type cells induces increasing amounts of phosphorylated FAK and growth factor receptors (EGFR and PDGFR) during the course of infection, correlating with accumulating Cdc42-GTP levels and C. jejuni invasion over time. In studies using pharmacological inhibitors, silencing RNA (siRNA) and dominant-negative expression constructs, EGFR, PDGFR and PI3-kinase appeared to represent other crucial components upstream of Cdc42 and invasion. siRNA and the use of Vav1\\/2-\\/- knockout cells further showed that the guanine exchange factor Vav2 is required for Cdc42 activation and maximal bacterial invasion. Overexpression of certain mutant constructs indicated that Vav2 is a linker

Polo kinase Cdc5 is a central regulator of meiosis I

Science.gov (United States)

Attner, Michelle A.; Miller, Matthew P.; Ee, Ly-sha; Elkin, Sheryl K.; Amon, Angelika

2013-01-01

During meiosis, two consecutive rounds of chromosome segregation yield four haploid gametes from one diploid cell. The Polo kinase Cdc5 is required for meiotic progression, but how Cdc5 coordinates multiple cell-cycle events during meiosis I is not understood. Here we show that CDC5-dependent phosphorylation of Rec8, a subunit of the cohesin complex that links sister chromatids, is required for efficient cohesin removal from chromosome arms, which is a prerequisite for meiosis I chromosome segregation. CDC5 also establishes conditions for centromeric cohesin removal during meiosis II by promoting the degradation of Spo13, a protein that protects centromeric cohesin during meiosis I. Despite CDC5’s central role in meiosis I, the protein kinase is dispensable during meiosis II and does not even phosphorylate its meiosis I targets during the second meiotic division. We conclude that Cdc5 has evolved into a master regulator of the unique meiosis I chromosome segregation pattern. PMID:23918381

The signaling pathway of Campylobacter jejuni-induced Cdc42 activation: Role of fibronectin, integrin beta1, tyrosine kinases and guanine exchange factor Vav2

Directory of Open Access Journals (Sweden)

Krause-Gruszczynska Malgorzata

2011-12-01

Full Text Available Abstract Background Host cell invasion by the foodborne pathogen Campylobacter jejuni is considered as one of the primary reasons of gut tissue damage, however, mechanisms and key factors involved in this process are widely unclear. It was reported that small Rho GTPases, including Cdc42, are activated and play a role during invasion, but the involved signaling cascades remained unknown. Here we utilised knockout cell lines derived from fibronectin-/-, integrin-beta1-/-, focal adhesion kinase (FAK-/- and Src/Yes/Fyn-/- deficient mice, and wild-type control cells, to investigate C. jejuni-induced mechanisms leading to Cdc42 activation and bacterial uptake. Results Using high-resolution scanning electron microscopy, GTPase pulldowns, G-Lisa and gentamicin protection assays we found that each studied host factor is necessary for induction of Cdc42-GTP and efficient invasion. Interestingly, filopodia formation and associated membrane dynamics linked to invasion were only seen during infection of wild-type but not in knockout cells. Infection of cells stably expressing integrin-beta1 variants with well-known defects in fibronectin fibril formation or FAK signaling also exhibited severe deficiencies in Cdc42 activation and bacterial invasion. We further demonstrated that infection of wild-type cells induces increasing amounts of phosphorylated FAK and growth factor receptors (EGFR and PDGFR during the course of infection, correlating with accumulating Cdc42-GTP levels and C. jejuni invasion over time. In studies using pharmacological inhibitors, silencing RNA (siRNA and dominant-negative expression constructs, EGFR, PDGFR and PI3-kinase appeared to represent other crucial components upstream of Cdc42 and invasion. siRNA and the use of Vav1/2-/- knockout cells further showed that the guanine exchange factor Vav2 is required for Cdc42 activation and maximal bacterial invasion. Overexpression of certain mutant constructs indicated that Vav2 is a linker

Insights into Cdc13 Dependent Telomere Length Regulation

Energy Technology Data Exchange (ETDEWEB)

M Mason; E Skordalakes

2011-12-31

Cdc13 is a single stranded telomere binding protein that specifically localizes to the telomere ends of budding yeasts and is essential for cell viability. It caps the ends of chromosomes thus preventing chromosome end-to-end fusions and exonucleolytic degradation, events that could lead to genomic instability and senescence, the hallmark of aging. Cdc13 is also involved in telomere length regulation by recruiting or preventing access of telomerase to the telomeric overhang. Recruitment of telomerase to the telomeres for G-strand extension is required for continuous cell division, while preventing its access to the telomeres through capping the chromosome ends prevents mitotic events that could lead to cell immortality, the hall mark of carcinogenesis. Cdc13 and its putative homologues human CTC1 and POT1 are therefore key to many biological processes directly associated with life extension and cancer prevention and can be viewed as an ideal target for cancer and age related therapies.

Parkin Regulates Mitosis and Genomic Stability through Cdc20/Cdh1.

Science.gov (United States)

Lee, Seung Baek; Kim, Jung Jin; Nam, Hyun-Ja; Gao, Bowen; Yin, Ping; Qin, Bo; Yi, Sang-Yeop; Ham, Hyoungjun; Evans, Debra; Kim, Sun-Hyun; Zhang, Jun; Deng, Min; Liu, Tongzheng; Zhang, Haoxing; Billadeau, Daniel D; Wang, Liewei; Giaime, Emilie; Shen, Jie; Pang, Yuan-Ping; Jen, Jin; van Deursen, Jan M; Lou, Zhenkun

2015-10-01

Mutations in the E3 ubiquitin ligase Parkin have been linked to familial Parkinson's disease. Parkin has also been implicated in mitosis through mechanisms that are unclear. Here we show that Parkin interacts with anaphase promoting complex/cyclosome (APC/C) coactivators Cdc20 and Cdh1 to mediate the degradation of several key mitotic regulators independent of APC/C. We demonstrate that ordered progression through mitosis is orchestrated by two distinct E3 ligases through the shared use of Cdc20 and Cdh1. Furthermore, Parkin is phosphorylated and activated by polo-like kinase 1 (Plk1) during mitosis. Parkin deficiency results in overexpression of its substrates, mitotic defects, genomic instability, and tumorigenesis. These results suggest that the Parkin-Cdc20/Cdh1 complex is an important regulator of mitosis. Copyright © 2015 Elsevier Inc. All rights reserved.

Vasoactive intestinal peptide-induced neurite remodeling in human neuroblastoma SH-SY5Y cells implicates the Cdc42 GTPase and is independent of Ras-ERK pathway

International Nuclear Information System (INIS)

Alleaume, Celine; Eychene, Alain; Harnois, Thomas; Bourmeyster, Nicolas; Constantin, Bruno; Caigneaux, Evelyne; Muller, Jean-Marc; Philippe, Michel

2004-01-01

Vasoactive intestinal peptide (VIP) is known to regulate proliferation or differentiation in normal and tumoral cells. SH-SY5Y is a differentiated cell subclone derived from the SK-N-SH human neuroblastoma cell line and possess all the components for an autocrine action of VIP. In the present study, we investigated the morphological changes and intracellular signaling pathways occurring upon VIP treatment of SH-SY5Y cells. VIP induced an early remodeling of cell projections: a branched neurite network spread out and prominent varicosities developed along neurites. Although activated by VIP, the Ras/ERK pathway was not required for the remodeling process. In contrast, pull-down experiments revealed a strong Cdc42 activation by VIP while expression of a dominant-negative Cdc42 prevented the VIP-induced neurite changes, suggesting an important role for this small GTPase in the process. These data provide the first evidence for a regulation of the activity of Rho family GTPases by VIP and bring new insights in the signaling pathways implicated in neurite remodeling process induced by VIP in neuroblastoma cells

miRNA-497 Negatively Regulates the Growth and Motility of Chondrosarcoma Cells by Targeting Cdc25A.

Science.gov (United States)

Lu, Yandong; Li, Fangguo; Xu, Tao; Sun, Jie

2016-01-01

Chondrosarcoma (CHS) is the second most common malignant bone sarcoma with increased risk of invasion and metastasis. However, the regulatory mechanisms of CHS tumorigenesis remain unknown. Here we investigated the novel role of miR-497 in regulating chondrosarcoma cell growth and cell cycle arrest. RT-PCR analysis showed that the expression of miR-497 is aberrantly downregulated in human chondrosarcoma samples and cells. After transfection with miR-497 mimic or antagomir, the proliferation and apoptosis of JJ012 and OUMS-27 chondrosarcoma cells were determined by CCK-8 assay and flow cytometric analysis, respectively. Results showed that the proliferation capacity of JJ012 and OUMS-27 cells was significantly decreased by miR-497 overexpression but increased by miR-497 repression. Apoptosis in both cell types was remarkably enhanced by miR-497 mimic but inhibited by miR-497 antagomir. By bioinformatics and luciferase reporter analysis, Cdc25A was proven to be a direct target of miR-497 in chondrosarcoma cells. Further studies indicated that miR-497 modulates the growth of chondrosarcoma cells by targeting Cdc25A, in which the cell cycle inhibitor p21 is involved through a p53-independent pathway. In conclusion, we demonstrated that miR-497 represents a potential tumor suppressor in human chondrosarcoma that regulates the growth of chondrosarcoma cells by targeting Cdc25A. This may provide a novel therapeutic target for chondrosarcoma.

Cdc42 and Rac1 signaling are both required for and act synergistically in the correct formation of myelin sheaths in the CNS

DEFF Research Database (Denmark)

Thurnherr, Tina; Benninger, Yves; Wu, Xunwei

2006-01-01

. This was characterized by the extraordinary enlargement of the inner tongue of the oligodendrocyte process and concomitant formation of a myelin outfolding as a result of abnormal accumulation of cytoplasm in this region. Ablation of Rac1 also resulted in the abnormal accumulation of cytoplasm in the inner tongue...... of the oligodendrocyte process, and we provide genetic evidence that rac1 synergizes with cdc42 in a gene dosage-dependent way to regulate myelination....

Rsr1 Focuses Cdc42 Activity at Hyphal Tips and Promotes Maintenance of Hyphal Development in Candida albicans

Science.gov (United States)

Pulver, Rebecca; Heisel, Timothy; Gonia, Sara; Robins, Robert; Norton, Jennifer; Haynes, Paula

2013-01-01

The extremely elongated morphology of fungal hyphae is dependent on the cell's ability to assemble and maintain polarized growth machinery over multiple cell cycles. The different morphologies of the fungus Candida albicans make it an excellent model organism in which to study the spatiotemporal requirements for constitutive polarized growth and the generation of different cell shapes. In C. albicans, deletion of the landmark protein Rsr1 causes defects in morphogenesis that are not predicted from study of the orthologous protein in the related yeast Saccharomyces cerevisiae, thus suggesting that Rsr1 has expanded functions during polarized growth in C. albicans. Here, we show that Rsr1 activity localizes to hyphal tips by the differential localization of the Rsr1 GTPase-activating protein (GAP), Bud2, and guanine nucleotide exchange factor (GEF), Bud5. In addition, we find that Rsr1 is needed to maintain the focused localization of hyphal polarity structures and proteins, including Bem1, a marker of the active GTP-bound form of the Rho GTPase, Cdc42. Further, our results indicate that tip-localized Cdc42 clusters are associated with the cell's ability to express a hyphal transcriptional program and that the ability to generate a focused Cdc42 cluster in early hyphae (germ tubes) is needed to maintain hyphal morphogenesis over time. We propose that in C. albicans, Rsr1 “fine-tunes” the distribution of Cdc42 activity and that self-organizing (Rsr1-independent) mechanisms of polarized growth are not sufficient to generate narrow cell shapes or to provide feedback to the transcriptional program during hyphal morphogenesis. PMID:23223038

Activated Cdc42 kinase regulates Dock localization in male germ cells during Drosophila spermatogenesis.

Science.gov (United States)

Abdallah, Abbas M; Zhou, Xin; Kim, Christine; Shah, Kushani K; Hogden, Christopher; Schoenherr, Jessica A; Clemens, James C; Chang, Henry C

2013-06-15

Deregulation of the non-receptor tyrosine kinase ACK1 (Activated Cdc42-associated kinase) correlates with poor prognosis in cancers and has been implicated in promoting metastasis. To further understand its in vivo function, we have characterized the developmental defects of a null mutation in Drosophila Ack, which bears a high degree of sequence similarity to mammalian ACK1 but lacks a CRIB domain. We show that Ack, while not essential for viability, is critical for sperm formation. This function depends on Ack tyrosine kinase activity and is required cell autonomously in differentiating male germ cells at or after the spermatocyte stage. Ack associates predominantly with endocytic clathrin sites in spermatocytes, but disruption of Ack function has no apparent effect on clathrin localization and receptor-mediated internalization of Boss (Bride of sevenless) protein in eye discs. Instead, Ack is required for the subcellular distribution of Dock (dreadlocks), the Drosophila homolog of the SH2- and SH3-containing adaptor protein Nck. Moreover, Dock forms a complex with Ack, and the localization of Dock in male germ cells depends on its SH2 domain. Together, our results suggest that Ack-dependent tyrosine phosphorylation recruits Dock to promote sperm differentiation. Copyright © 2013 Elsevier Inc. All rights reserved.

DNA replication initiator Cdc6 also regulates ribosomal DNA transcription initiation.

Science.gov (United States)

Huang, Shijiao; Xu, Xiaowei; Wang, Guopeng; Lu, Guoliang; Xie, Wenbing; Tao, Wei; Zhang, Hongyin; Jiang, Qing; Zhang, Chuanmao

2016-04-01

RNA-polymerase-I-dependent ribosomal DNA (rDNA) transcription is fundamental to rRNA processing, ribosome assembly and protein synthesis. However, how this process is initiated during the cell cycle is not fully understood. By performing a proteomic analysis of transcription factors that bind RNA polymerase I during rDNA transcription initiation, we identified that the DNA replication initiator Cdc6 interacts with RNA polymerase I and its co-factors, and promotes rDNA transcription in G1 phase in an ATPase-activity-dependent manner. We further showed that Cdc6 is targeted to the nucleolus during late mitosis and G1 phase in a manner that is dependent on B23 (also known as nucleophosmin, NPM1), and preferentially binds to the rDNA promoter through its ATP-binding domain. Overexpression of Cdc6 increases rDNA transcription, whereas knockdown of Cdc6 results in a decreased association of both RNA polymerase I and the RNA polymerase I transcription factor RRN3 with rDNA, and a reduction of rDNA transcription. Furthermore, depletion of Cdc6 impairs the interaction between RRN3 and RNA polymerase I. Taken together, our data demonstrate that Cdc6 also serves as a regulator of rDNA transcription initiation, and indicate a mechanism by which initiation of rDNA transcription and DNA replication can be coordinated in cells. © 2016. Published by The Company of Biologists Ltd.

Cdc42-dependent structural development of auditory supporting cells is required for wound healing at adulthood

DEFF Research Database (Denmark)

Anttonen, Tommi; Kirjavainen, Anna; Belevich, Ilya

2012-01-01

of a basolateral membrane protein in the apical domain were observed. These defects and changes in aPKCλ/ι expression suggested that apical polarization is impaired. Following a lesion at adulthood, supporting cells with Cdc42 loss-induced maturational defects collapsed and failed to remodel F-actin belts...

Regulation of the vertebrate cell cycle by the cdc2 protein kinase

International Nuclear Information System (INIS)

Draetta, G.; Brizuela, L.; Moran, B.; Beach, D.

1988-01-01

A homolog of the cdc2/CDC28 protein kinase of yeast is found in all vertebrate species that have been investigated. Human cdc2 exists as a complex with a 13-kD protein that is homologous to the suc1 gene product of fission yeast. In both human and fission yeast cells, the protein kinase also exists in a complex with a 62-kD polypeptide that has not been identified genetically but acts as a substrate in vitro. The authors have studied the properties of the protein kinase in rat and human cells, as well as in Xenopus eggs. They find that in baby rat kidney (BRK) cells, which are quiescent in cell culture, the cdc2 protein is not synthesized. However, synthesis is rapidly induced in response to proliferative activation by infection with adenovirus. In human HeLa cells, the protein kinase is present continuously. It behaves as a cell-cycle oscillator that is inactive in G 1 but displays maximal enzymatic activity during mitotic metaphase. These observations indicate that in a wide variety of vertebrate cells, the cdc2 protein kinase is involved in regulating mitosis. The authors' approach taken toward study of the cdc2 protein kinase highlights the possibilities that now exist for combining the advantages of ascomycete genetics with the cell-free systems of Xenopus and the biochemical advantages of tissue culture cells to investigate fundamental problems of the cell cycle

Cdc42 and Rab8a are critical for intestinal stem cell division, survival, and differentiation in mice

DEFF Research Database (Denmark)

Sakamori, Ryotaro; Das, Soumyashree; Yu, Shiyan

2012-01-01

The constant self renewal and differentiation of adult intestinal stem cells maintains a functional intestinal mucosa for a lifetime. However, the molecular mechanisms that regulate intestinal stem cell division and epithelial homeostasis are largely undefined. We report here that the small GTPases...... reminiscent of human microvillus inclusion disease (MVID), a devastating congenital intestinal disorder that results in severe nutrient deprivation. Further analysis revealed that Cdc42-deficient stem cells had cell division defects, reduced capacity for clonal expansion and differentiation into Paneth cells...... suggest that defects of the stem cell niche can cause MVID. This hypothesis represents a conceptual departure from the conventional view of this disease, which has focused on the affected enterocytes, and suggests stem cell-based approaches could be beneficial to infants with this often lethal condition....

Suppression of chemotaxis by SSeCKS via scaffolding of phosphoinositol phosphates and the recruitment of the Cdc42 GEF, Frabin, to the leading edge.

Science.gov (United States)

Ko, Hyun-Kyung; Guo, Li-wu; Su, Bing; Gao, Lingqiu; Gelman, Irwin H

2014-01-01

Chemotaxis is controlled by interactions between receptors, Rho-family GTPases, phosphatidylinositol 3-kinases, and cytoskeleton remodeling proteins. We investigated how the metastasis suppressor, SSeCKS, attenuates chemotaxis. Chemotaxis activity inversely correlated with SSeCKS levels in mouse embryo fibroblasts (MEF), DU145 and MDA-MB-231 cancer cells. SSeCKS loss induced chemotactic velocity and linear directionality, correlating with replacement of leading edge lamellipodia with fascin-enriched filopodia-like extensions, the formation of thickened longitudinal F-actin stress fibers reaching to filopodial tips, relative enrichments at the leading edge of phosphatidylinositol (3,4,5)P3 (PIP3), Akt, PKC-ζ, Cdc42-GTP and active Src (SrcpoY416), and a loss of Rac1. Leading edge lamellipodia and chemotaxis inhibition in SSeCKS-null MEF could be restored by full-length SSeCKS or SSeCKS deleted of its Src-binding domain (ΔSrc), but not by SSeCKS deleted of its three MARCKS (myristylated alanine-rich C kinase substrate) polybasic domains (ΔPBD), which bind PIP2 and PIP3. The enrichment of activated Cdc42 in SSeCKS-null leading edge filopodia correlated with recruitment of the Cdc42-specific guanine nucleotide exchange factor, Frabin, likely recruited via multiple PIP2/3-binding domains. Frabin knockdown in SSeCKS-null MEF restores leading edge lamellipodia and chemotaxis inhibition. However, SSeCKS failed to co-immunoprecipitate with Rac1, Cdc42 or Frabin. Consistent with the notion that chemotaxis is controlled by SSeCKS-PIP (vs. -Src) scaffolding activity, constitutively-active phosphatidylinositol 3-kinase could override the ability of the Src inhibitor, SKI-606, to suppress chemotaxis and filopodial enrichment of Frabin in SSeCKS-null MEF. Our data suggest a role for SSeCKS in controlling Rac1 vs. Cdc42-induced cellular dynamics at the leading chemotactic edge through the scaffolding of phospholipids and signal mediators, and through the reorganization of the

Caveolin-1 and CDC42 mediated endocytosis of silica-coated iron oxide nanoparticles in HeLa cells

Directory of Open Access Journals (Sweden)

Nils Bohmer

2015-01-01

Full Text Available Nanomedicine is a rapidly growing field in nanotechnology, which has great potential in the development of new therapies for numerous diseases. For example iron oxide nanoparticles are in clinical use already in the thermotherapy of brain cancer. Although it has been shown, that tumor cells take up these particles in vitro, little is known about the internalization routes. Understanding of the underlying uptake mechanisms would be very useful for faster and precise development of nanoparticles for clinical applications. This study aims at the identification of key proteins, which are crucial for the active uptake of iron oxide nanoparticles by HeLa cells (human cervical cancer as a model cell line. Cells were transfected with specific siRNAs against Caveolin-1, Dynamin 2, Flotillin-1, Clathrin, PIP5Kα and CDC42. Knockdown of Caveolin-1 reduces endocytosis of superparamagnetic iron oxide nanoparticles (SPIONs and silica-coated iron oxide nanoparticles (SCIONs between 23 and 41%, depending on the surface characteristics of the nanoparticles and the experimental design. Knockdown of CDC42 showed a 46% decrease of the internalization of PEGylated SPIONs within 24 h incubation time. Knockdown of Dynamin 2, Flotillin-1, Clathrin and PIP5Kα caused no or only minor effects. Hence endocytosis in HeLa cells of iron oxide nanoparticles, used in this study, is mainly mediated by Caveolin-1 and CDC42. It is shown here for the first time, which proteins of the endocytotic pathway mediate the endocytosis of silica-coated iron oxide nanoparticles in HeLa cells in vitro. In future studies more experiments should be carried out with different cell lines and other well-defined nanoparticle species to elucidate possible general principles.

The RNA-binding protein Spo5 promotes meiosis II by regulating cyclin Cdc13 in fission yeast.

Science.gov (United States)

Arata, Mayumi; Sato, Masamitsu; Yamashita, Akira; Yamamoto, Masayuki

2014-03-01

Meiosis comprises two consecutive nuclear divisions, meiosis I and II. Despite this unique progression through the cell cycle, little is known about the mechanisms controlling the sequential divisions. In this study, we carried out a genetic screen to identify factors that regulate the initiation of meiosis II in the fission yeast Schizosaccharomyces pombe. We identified mutants deficient in meiosis II progression and repeatedly isolated mutants defective in spo5, which encodes an RNA-binding protein. Using fluorescence microscopy to visualize YFP-tagged protein, we found that spo5 mutant cells precociously lost Cdc13, the major B-type cyclin in fission yeast, before meiosis II. Importantly, the defect in meiosis II was rescued by increasing CDK activity. In wild-type cells, cdc13 transcripts increased during meiosis II, but this increase in cdc13 expression was weaker in spo5 mutants. Thus, Spo5 is a novel regulator of meiosis II that controls the level of cdc13 expression and promotes de novo synthesis of Cdc13. We previously reported that inhibition of Cdc13 degradation is necessary to initiate meiosis II; together with the previous information, the current findings indicate that the dual control of Cdc13 by de novo synthesis and suppression of proteolysis ensures the progression of meiosis II. © 2014 The Authors Genes to Cells © 2014 by the Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

Redundant and nonredundant roles for Cdc42 and Rac1 in lymphomas developed in NPM-ALK transgenic mice

DEFF Research Database (Denmark)

Choudhari, Ramesh; Minero, Valerio Giacomo; Menotti, Matteo

2016-01-01

Increasing evidence suggests that Rho family GTPases could have a critical role in the biology of T-cell lymphoma. In ALK-rearranged anaplastic large cell lymphoma (ALCL), a specific subtype of T-cell lymphoma, the Rho family GTPases Cdc42 and Rac1 are activated by the ALK oncogenic activity. In ...

Daphnetin inhibits invasion and migration of LM8 murine osteosarcoma cells by decreasing RhoA and Cdc42 expression

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Fukuda, Hiroki [Department of Clinical and Translational Physiology, Kyoto Pharmaceutical University, Kyoto (Japan); Nakamura, Seikou [Department of Pharmacognosy, Kyoto Pharmaceutical University, Kyoto (Japan); Chisaki, Yugo [Education and Research Center for Clinical Pharmacy, Kyoto Pharmaceutical University, Kyoto (Japan); Takada, Tetsuya [Department of Clinical and Translational Physiology, Kyoto Pharmaceutical University, Kyoto (Japan); Toda, Yuki [Department of Medicinal Chemistry, Kyoto Pharmaceutical University, Kyoto (Japan); Murata, Hiroaki [Department of Orthopedics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto (Japan); Department of Orthopedic Surgery, Matsushita Memorial Hospital, Osaka (Japan); Itoh, Kazuyuki [Department of Biology, Osaka Medical Center of Cancer and Cardiovascular Diseases, Osaka (Japan); Yano, Yoshitaka [Education and Research Center for Clinical Pharmacy, Kyoto Pharmaceutical University, Kyoto (Japan); Takata, Kazuyuki [Department of Clinical and Translational Physiology, Kyoto Pharmaceutical University, Kyoto (Japan); Ashihara, Eishi, E-mail: ash@mb.kyoto-phu.ac.jp [Department of Clinical and Translational Physiology, Kyoto Pharmaceutical University, Kyoto (Japan)

2016-02-26

Daphnetin, 7,8-dihydroxycoumarin, present in main constituents of Daphne odora var. marginatai, has multiple pharmacological activities including anti-proliferative effects in cancer cells. In this study, using a Transwell system, we showed that daphnetin inhibited invasion and migration of highly metastatic murine osteosarcoma LM8 cells in a dose-dependent manner. Following treatment by daphnetin, cells that penetrated the Transwell membrane were rounder than non-treated cells. Immunofluorescence analysis revealed that daphnetin decreased the numbers of intracellular stress fibers and filopodia. Moreover, daphnetin treatment dramatically decreased the expression levels of RhoA and Cdc42. In summary, the dihydroxycoumarin derivative daphnetin inhibits the invasion and migration of LM8 cells, and therefore represents a promising agent for use against metastatic cancer. - Highlights: • Daphnetin, a coumarin-derivative, inhibited invasion and migration of LM8 cells. • Stress fibers and filopodia were decreased by daphnetin treatment. • Daphnetin decreased RhoA and Cdc42 protein expression.

Daphnetin inhibits invasion and migration of LM8 murine osteosarcoma cells by decreasing RhoA and Cdc42 expression

International Nuclear Information System (INIS)

Fukuda, Hiroki; Nakamura, Seikou; Chisaki, Yugo; Takada, Tetsuya; Toda, Yuki; Murata, Hiroaki; Itoh, Kazuyuki; Yano, Yoshitaka; Takata, Kazuyuki; Ashihara, Eishi

2016-01-01

Daphnetin, 7,8-dihydroxycoumarin, present in main constituents of Daphne odora var. marginatai, has multiple pharmacological activities including anti-proliferative effects in cancer cells. In this study, using a Transwell system, we showed that daphnetin inhibited invasion and migration of highly metastatic murine osteosarcoma LM8 cells in a dose-dependent manner. Following treatment by daphnetin, cells that penetrated the Transwell membrane were rounder than non-treated cells. Immunofluorescence analysis revealed that daphnetin decreased the numbers of intracellular stress fibers and filopodia. Moreover, daphnetin treatment dramatically decreased the expression levels of RhoA and Cdc42. In summary, the dihydroxycoumarin derivative daphnetin inhibits the invasion and migration of LM8 cells, and therefore represents a promising agent for use against metastatic cancer. - Highlights: • Daphnetin, a coumarin-derivative, inhibited invasion and migration of LM8 cells. • Stress fibers and filopodia were decreased by daphnetin treatment. • Daphnetin decreased RhoA and Cdc42 protein expression.

Cdc7-Dbf4 regulates NDT80 transcription as well as reductional segregation during budding yeast meiosis.

Science.gov (United States)

Lo, Hsiao-Chi; Wan, Lihong; Rosebrock, Adam; Futcher, Bruce; Hollingsworth, Nancy M

2008-11-01

In budding yeast, as in other eukaryotes, the Cdc7 protein kinase is important for initiation of DNA synthesis in vegetative cells. In addition, Cdc7 has crucial meiotic functions: it facilitates premeiotic DNA replication, and it is essential for the initiation of recombination. This work uses a chemical genetic approach to demonstrate that Cdc7 kinase has additional roles in meiosis. First, Cdc7 allows expression of NDT80, a meiosis-specific transcriptional activator required for the induction of genes involved in exit from pachytene, meiotic progression, and spore formation. Second, Cdc7 is necessary for recruitment of monopolin to sister kinetochores, and it is necessary for the reductional segregation occurring at meiosis I. The use of the same kinase to regulate several distinct meiosis-specific processes may be important for the coordination of these processes during meiosis.

Cdc7-Dbf4 Regulates NDT80 Transcription as Well as Reductional Segregation during Budding Yeast Meiosis

Science.gov (United States)

Lo, Hsiao-Chi; Wan, Lihong; Rosebrock, Adam; Futcher, Bruce

2008-01-01

In budding yeast, as in other eukaryotes, the Cdc7 protein kinase is important for initiation of DNA synthesis in vegetative cells. In addition, Cdc7 has crucial meiotic functions: it facilitates premeiotic DNA replication, and it is essential for the initiation of recombination. This work uses a chemical genetic approach to demonstrate that Cdc7 kinase has additional roles in meiosis. First, Cdc7 allows expression of NDT80, a meiosis-specific transcriptional activator required for the induction of genes involved in exit from pachytene, meiotic progression, and spore formation. Second, Cdc7 is necessary for recruitment of monopolin to sister kinetochores, and it is necessary for the reductional segregation occurring at meiosis I. The use of the same kinase to regulate several distinct meiosis-specific processes may be important for the coordination of these processes during meiosis. PMID:18768747

Cdc42 and phosphoinositide 3-kinase drive Rac-mediated actin polymerization downstream of c-Met in distinct and common pathways

DEFF Research Database (Denmark)

Bosse, Tanja; Ehinger, Julia; Czuchra, Aleksandra

2007-01-01

-WASP. Instead, actin polymerization was driven by Arp2/3 complex activation through the WAVE complex downstream of Rac. Together, our data establish an intricate signaling network comprising as key molecules Cdc42 and PI3-kinase, which converge on Rac-mediated actin reorganization essential for Listeria...

Overexpression of CDC25B, CDC25C and phospho-CDC25C (Ser216) in vulvar squamous cell carcinomas are associated with malignant features and aggressive cancer phenotypes

OpenAIRE

Wang, Zhihui; Trope, Claes G; Fl?renes, Vivi Ann; Suo, Zhenhe; Nesland, Jahn M; Holm, Ruth

2010-01-01

Background CDC25 phosphatases are important regulators of the cell cycle. Their abnormal expression detected in a number of tumors implies that their dysregulation is involved in malignant transformation. However, the role of CDC25s in vulvar cancer is still unknown. To shed light on their roles in the pathogenesis and to clarify their prognostic values, expression of CDC25A, CDC25B and CDC25C in a large series of vulvar squamous cell carcinomas were examined. ...

The Hsk1(Cdc7) Replication Kinase Regulates Origin Efficiency

OpenAIRE

Patel, Prasanta K.; Kommajosyula, Naveen; Rosebrock, Adam; Bensimon, Aaron; Leatherwood, Janet; Bechhoefer, John; Rhind, Nicholas

2008-01-01

Origins of DNA replication are generally inefficient, with most firing in fewer than half of cell cycles. However, neither the mechanism nor the importance of the regulation of origin efficiency is clear. In fission yeast, origin firing is stochastic, leading us to hypothesize that origin inefficiency and stochasticity are the result of a diffusible, rate-limiting activator. We show that the Hsk1-Dfp1 replication kinase (the fission yeast Cdc7-Dbf4 homologue) plays such a role. Increasing or ...

Rho Kinase (ROCK) collaborates with Pak to Regulate Actin Polymerization and Contraction in Airway Smooth Muscle.

Science.gov (United States)

Zhang, Wenwu; Bhetwal, Bhupal P; Gunst, Susan J

2018-05-10

The mechanisms by which Rho kinase (ROCK) regulates airway smooth muscle contraction were determined in tracheal smooth muscle tissues. ROCK may mediate smooth muscle contraction by inhibiting myosin regulatory light chain (RLC) phosphatase. ROCK can also regulate F-actin dynamics during cell migration, and actin polymerization is critical for airway smooth muscle contraction. Our results show that ROCK does not regulate airway smooth muscle contraction by inhibiting myosin RLC phosphatase or by stimulating myosin RLC phosphorylation. We find that ROCK regulates airway smooth muscle contraction by activating the serine-threonine kinase Pak, which mediates the activation of Cdc42 and Neuronal-Wiskott-Aldrich Syndrome protein (N-WASp). N-WASP transmits signals from cdc42 to the Arp2/3 complex for the nucleation of actin filaments. These results demonstrate a novel molecular function for ROCK in the regulation of Pak and cdc42 activation that is critical for the processes of actin polymerization and contractility in airway smooth muscle. Rho kinase (ROCK), a RhoA GTPase effector, can regulate the contraction of airway and other smooth muscle tissues. In some tissues, ROCK can inhibit myosin regulatory light chain (RLC) phosphatase, which increases the phosphorylation of myosin RLC and promotes smooth muscle contraction. ROCK can also regulate cell motility and migration by affecting F-actin dynamics. Actin polymerization is stimulated by contractile agonists in airway smooth muscle tissues and is required for contractile tension development in addition to myosin RLC phosphorylation. We investigated the mechanisms by which ROCK regulates the contractility of tracheal smooth muscle tissues by expressing a kinase inactive mutant of ROCK, ROCK-K121G, in the tissues or by treating them with the ROCK inhibitor, H-1152P. Our results show no role for ROCK in the regulation of non-muscle or smooth muscle myosin RLC phosphorylation during contractile stimulation in this tissue

42 CFR 34.2 - Definitions.

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Definitions. 34.2 Section 34.2 Public Health PUBLIC... OF ALIENS § 34.2 Definitions. As used in this part, terms shall have the following meanings: (a) CDC... International Health Regulations (http://www.who.int/csr/ihr/en/), as adopted by the Fifty-Eighth World Health...

The FEAR protein Slk19 restricts Cdc14 phosphatase to the nucleus until the end of anaphase, regulating its participation in mitotic exit in Saccharomyces cerevisiae.

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Ann Marie E Faust

Full Text Available In Saccharomyces cerevisiae mitosis, the protein Slk19 plays an important role in the initial release of Cdc14 phosphatase from the nucleolus to the nucleus in early anaphase, an event that is critical for proper anaphase progression. A role for Slk19 in later mitotic stages of Cdc14 regulation, however, has not been demonstrated. While investigating the role of Slk19 post-translational modification on Cdc14 regulation, we found that a triple point mutant of SLK19, slk19(3R (three lysine-to-arginine mutations, strongly affects Cdc14 localization during late anaphase and mitotic exit. Using fluorescence live-cell microscopy, we found that, similar to slk19Δ cells, slk19(3R cells exhibit no defect in spindle stability and only a mild defect in spindle elongation dynamics. Unlike slk19Δcells, however, slk19(3R cells exhibit no defect in Cdc14 release from the nucleolus to the nucleus. Instead, slk19(3R cells are defective in the timing of Cdc14 movement from the nucleus to the cytoplasm at the end of anaphase. This mutant has a novel phenotype: slk19(3R causes premature Cdc14 movement to the cytoplasm prior to, rather than concomitant with, spindle disassembly. One consequence of this premature Cdc14 movement is the inappropriate activation of the mitotic exit network, made evident by the fact that slk19(3R partially rescues a mutant of the mitotic exit network kinase Cdc15. In conclusion, in addition to its role in regulating Cdc14 release from the nucleolus to the nucleus, we found that Slk19 is also important for regulating Cdc14 movement from the nucleus to the cytoplasm at the end of anaphase.

cdc-25.4, a Caenorhabditis elegans Ortholog of cdc25, Is Required for Male Mating Behavior

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Sangmi Oh

2016-12-01

Full Text Available Cell division cycle 25 (cdc25 is an evolutionarily conserved phosphatase that promotes cell cycle progression. Among the four cdc25 orthologs in Caenorhabditis elegans, we found that cdc-25.4 mutant males failed to produce outcrossed progeny. This was not caused by defects in sperm development, but by defects in male mating behavior. The cdc-25.4 mutant males showed various defects during male mating, including contact response, backing, turning, and vulva location. Aberrant turning behavior was the most prominent defect in the cdc-25.4 mutant males. We also found that cdc-25.4 is expressed in many neuronal cells throughout development. The turning defect in cdc-25.4 mutant males was recovered by cdc-25.4 transgenic expression in neuronal cells, suggesting that cdc-25.4 functions in neurons for male mating. However, the neuronal morphology of cdc-25.4 mutant males appeared to be normal, as examined with several neuronal markers. Also, RNAi depletion of wee-1.3, a C. elegans ortholog of Wee1/Myt1 kinase, failed to suppress the mating defects of cdc-25.4 mutant males. These findings suggest that, for successful male mating, cdc-25.4 does not target cell cycles that are required for neuronal differentiation and development. Rather, cdc-25.4 likely regulates noncanonical substrates in neuronal cells.

Cdc7 kinase - a new target for drug development.

Science.gov (United States)

Swords, Ronan; Mahalingam, Devalingam; O'Dwyer, Michael; Santocanale, Corrado; Kelly, Kevin; Carew, Jennifer; Giles, Francis

2010-01-01

The cell division cycle 7 (Cdc7) is a serine threonine kinase that is of critical importance in the regulation of normal cell cycle progression. Cdc7 kinase is highly conserved during evolution and much has been learned about its biological roles in humans through the study of lower eukaryotes, particularly yeasts. Two important regulator proteins, Dbf4 and Drf1, bind to and modulate the kinase activity of human Cdc7 which phosphorylates several sites on Mcm2 (minichromosome maintenance protein 2), one of the six subunits of the replicative DNA helicase needed for duplication of the genome. Through regulation of both DNA synthesis and DNA damage response, both key functions in the survival of tumour cells, Cdc7 becomes an attractive target for pharmacological inhibition. There are much data available on the pre-clinical anti-cancer effects of Cdc7 depletion and although there are no available Cdc7 inhibitors in clinical trials as yet, several lead compounds are being optimised for this purpose. In this review, we will address the current status of Cdc7 as an important target for new drug development.

The F-box protein Cdc4/Fbxw7 is a novel regulator of neural crest development in Xenopus laevis

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Hartley Rebecca S

2010-01-01

Full Text Available Abstract Background The neural crest is a unique population of cells that arise in the vertebrate ectoderm at the neural plate border after which they migrate extensively throughout the embryo, giving rise to a wide range of derivatives. A number of proteins involved in neural crest development have dynamic expression patterns, and it is becoming clear that ubiquitin-mediated protein degradation is partly responsible for this. Results Here we demonstrate a novel role for the F-box protein Cdc4/Fbxw7 in neural crest development. Two isoforms of Xenopus laevis Cdc4 were identified, and designated xCdc4α and xCdc4β. These are highly conserved with vertebrate Cdc4 orthologs, and the Xenopus proteins are functionally equivalent in terms of their ability to degrade Cyclin E, an established vertebrate Cdc4 target. Blocking xCdc4 function specifically inhibited neural crest development at an early stage, prior to expression of c-Myc, Snail2 and Snail. Conclusions We demonstrate that Cdc4, an ubiquitin E3 ligase subunit previously identified as targeting primarily cell cycle regulators for proteolysis, has additional roles in control of formation of the neural crest. Hence, we identify Cdc4 as a protein with separable but complementary functions in control of cell proliferation and differentiation.

MDA-9/Syntenin (SDCBP) modulates small GTPases RhoA and Cdc42 via transforming growth factor β1 to enhance epithelial-mesenchymal transition in breast cancer.

Science.gov (United States)

Menezes, Mitchell E; Shen, Xue-Ning; Das, Swadesh K; Emdad, Luni; Sarkar, Devanand; Fisher, Paul B

2016-12-06

Epithelial-mesenchymal transition (EMT) is one of the decisive steps regulating cancer invasion and metastasis. However, the molecular mechanisms underlying this transition require further clarification. MDA-9/syntenin (SDCBP) expression is elevated in breast cancer patient samples as well as cultured breast cancer cells. Silencing expression of MDA-9 in mesenchymal metastatic breast cancer cells triggered a change in cell morphology in both 2D- and 3D-cultures to a more epithelial-like phenotype, along with changes in EMT markers, cytoskeletal rearrangement and decreased invasion. Conversely, over expressing MDA-9 in epithelial non-metastatic breast cancer cells instigated a change in morphology to a more mesenchymal phenotype with corresponding changes in EMT markers, cytoskeletal rearrangement and an increase in invasion. We also found that MDA-9 upregulated active levels of known modulators of EMT, the small GTPases RhoA and Cdc42, via TGFβ1. Reintroducing TGFβ1 in MDA-9 silenced cells restored active RhoA and cdc42 levels, modulated cytoskeletal rearrangement and increased invasion. We further determined that MDA-9 interacts with TGFβ1 via its PDZ1 domain. Finally, in vivo studies demonstrated that silencing the expression of MDA-9 resulted in decreased lung metastasis and TGFβ1 re-expression partially restored lung metastases. Our findings provide evidence for the relevance of MDA-9 in mediating EMT in breast cancer and support the potential of MDA-9 as a therapeutic target against metastatic disease.

Role of TGF-beta1-independent changes in protein neosynthesis, p38alphaMAPK, and cdc42 in hydrogen peroxide-induced senescence-like morphogenesis

DEFF Research Database (Denmark)

Chrétien, Aline; Dierick, Jean-François; Delaive, Edouard

2008-01-01

for p38(MAPK) activation, in turn triggering phosphorylation of L-caldesmon and HSP27. Cdc42 was also shown to be mainly responsible for the increase in TGF-beta1 mRNA level observed at 24 h after treatment with H(2)O(2) and onward. This study further clarified the mechanisms of senescence......The role of TGF-beta1 in hydrogen peroxide-induced senescence-like morphogenesis has been described. The aim of this work was to investigate whether TGF-beta1-independent changes in protein synthesis are involved in this morphogenesis and to study possible mechanisms occurring earlier than TGF-beta......1 overexpression. Among the multiple TGF-beta1-independent changes in protein neosynthesis, followed or not by posttranslational modifications, identified by proteomic analysis herein, those of ezrin, L-caldesmon, and HSP27 were particularly studied. Rho-GTPase cdc42 was shown to be responsible...

Overexpression of CDC25B, CDC25C and phospho-CDC25C (Ser216 in vulvar squamous cell carcinomas are associated with malignant features and aggressive cancer phenotypes

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Flørenes Vivi

2010-05-01

Full Text Available Abstract Background CDC25 phosphatases are important regulators of the cell cycle. Their abnormal expression detected in a number of tumors implies that their dysregulation is involved in malignant transformation. However, the role of CDC25s in vulvar cancer is still unknown. To shed light on their roles in the pathogenesis and to clarify their prognostic values, expression of CDC25A, CDC25B and CDC25C in a large series of vulvar squamous cell carcinomas were examined. Methods Expression of CDC25A, CDC25B, CDC25C and phosphorylated (phospho-CDC25C (Ser216 were examined in 300 vulvar carcinomas using immunohistochemistry. Western blot analysis was utilized to demonstrate CDC25s expression in vulvar cancer cell lines. Kinase and phosphatase assays were performed to exclude cross reactivity among CDC25s isoform antibodies. Results High nuclear CDC25A and CDC25B expression were observed in 51% and 16% of the vulvar carcinomas, respectively, whereas high cytoplasmic CDC25C expression was seen in 63% of the cases. In cytoplasm, nucleus and cytoplasm/nucleus high phospho-CDC25C (Ser216 expression was identified in 50%, 70% and 77% of the carcinomas, respectively. High expression of CDC25s correlated significantly with malignant features, including poor differentiation and infiltration of vessel for CDC25B, high FIGO stage, presence of lymph node metastases, large tumor diameter, poor differentiation for CDC25C and high FIGO stage, large tumor diameter, deep invasion and poor differentiation for phospho-CDC25C (Ser216. In univariate analysis, high expression of phospho-CDC25C (Ser216 was correlated with poor disease-specific survival (p = 0.04. However, such an association was annulled in multivariate analysis. Conclusions Our results suggest that CDC25C and phospho-CDC25C (Ser216 play a crucial role and CDC25B a minor role in the pathogenesis and/or progression of vulvar carcinomas. CDC25B, CDC25C and phospho-CDC25C (Ser216 were associated with

Overexpression of CDC25B, CDC25C and phospho-CDC25C (Ser216) in vulvar squamous cell carcinomas are associated with malignant features and aggressive cancer phenotypes

International Nuclear Information System (INIS)

Wang, Zhihui; Trope, Claes G; Flørenes, Vivi Ann; Suo, Zhenhe; Nesland, Jahn M; Holm, Ruth

2010-01-01

CDC25 phosphatases are important regulators of the cell cycle. Their abnormal expression detected in a number of tumors implies that their dysregulation is involved in malignant transformation. However, the role of CDC25s in vulvar cancer is still unknown. To shed light on their roles in the pathogenesis and to clarify their prognostic values, expression of CDC25A, CDC25B and CDC25C in a large series of vulvar squamous cell carcinomas were examined. Expression of CDC25A, CDC25B, CDC25C and phosphorylated (phospho)-CDC25C (Ser216) were examined in 300 vulvar carcinomas using immunohistochemistry. Western blot analysis was utilized to demonstrate CDC25s expression in vulvar cancer cell lines. Kinase and phosphatase assays were performed to exclude cross reactivity among CDC25s isoform antibodies. High nuclear CDC25A and CDC25B expression were observed in 51% and 16% of the vulvar carcinomas, respectively, whereas high cytoplasmic CDC25C expression was seen in 63% of the cases. In cytoplasm, nucleus and cytoplasm/nucleus high phospho-CDC25C (Ser216) expression was identified in 50%, 70% and 77% of the carcinomas, respectively. High expression of CDC25s correlated significantly with malignant features, including poor differentiation and infiltration of vessel for CDC25B, high FIGO stage, presence of lymph node metastases, large tumor diameter, poor differentiation for CDC25C and high FIGO stage, large tumor diameter, deep invasion and poor differentiation for phospho-CDC25C (Ser216). In univariate analysis, high expression of phospho-CDC25C (Ser216) was correlated with poor disease-specific survival (p = 0.04). However, such an association was annulled in multivariate analysis. Our results suggest that CDC25C and phospho-CDC25C (Ser216) play a crucial role and CDC25B a minor role in the pathogenesis and/or progression of vulvar carcinomas. CDC25B, CDC25C and phospho-CDC25C (Ser216) were associated with malignant features and aggressive cancer phenotypes. However, the

Role of AtCDC48 & the AtCDC48 Regulatory Protein Family, PUX, in Plant Cell Morphogenesis

Energy Technology Data Exchange (ETDEWEB)

Bednarek, Sebastian, Y.

2009-11-08

The long-term objective of this work is to understand the molecular events and mechanisms involved in secretory membrane trafficking and organelle biogenesis, which are crucial for normal plant growth and development. Our studies have suggested a vital role for the cytosolic chaperone Cdc48p/p97 during cytokinesis and cell expansion which are highly dependent upon secretory membrane trafficking. Localization studies have shown that the plant Cdc48p/p97, AtCDC48, and the Arabidopsis ortholog of the ER- and Golgi-associated SNARE, syntaxin 5, (referred to as SYP31) are targeted to the division plane during cytokinesis. In addition, AtCDC48 and SYP31 were shown to interact in vitro and in vivo. To characterize further the function of AtCDC48 and SYP31 we have utilized affinity chromatography and MALDI-MS to identify several plant-specific proteins that interact with SYP31 and/or modulate the activity of AtCDC48 including two UBX (i.e. ubiquitin-like) domain containing proteins, PUX1 and PUX2 (Proteins containing UBX domain). These proteins define a plant protein family consisting of 15 uncharacterized members that we postulate interact with AtCDC48. Biochemical studies have demonstrated that PUX2 is a novel membrane adapter for AtCDC48 that mediates AtCDC48/SYP31 interaction and is likely to control AtCDC48-dependent membrane fusion. In contrast, PUX1 negatively regulates AtCDC48 by inhibiting its ATPase activity and by promoting the disassembly of the active hexamer. These findings provide the first evidence that the assembly and disassembly of the CDC48/p97complex is actually a dynamic process. This new unexpected level of regulation for CDC48/p97 was demonstrated to be critical in vivo as pux1 loss-of-function mutants grow faster than wild-type plants. These studies suggest a role for AtCDC48 in plant cell cycle progression including cytokinesis and/or cell expansion. The proposed studies are designed to: 1) characterize further the localization and function of AtCDC

Ubiquitination of Cdc20 by the APC occurs through an intramolecular mechanism

Science.gov (United States)

Foe, Ian T.; Foster, Scott A.; Cheung, Stephanie K.; DeLuca, Steven Z.; Morgan, David O.; Toczyski, David P.

2012-01-01

SUMMARY Background Cells control progression through late mitosis by regulating Cdc20 and Cdh1, the two mitotic activators of the Anaphase Promoting Complex (APC). The control of Cdc20 protein levels during the cell cycle is not well understood. Results Here, we demonstrate that Cdc20 is degraded in budding yeast by multiple APC-dependent mechanisms. We find that the majority of Cdc20 turnover does not involve a second activator molecule, but instead depends on in cis Cdc20 autoubiquitination while it is bound to its activator-binding site on the APC core. Unlike in trans ubiquitination of Cdc20 substrates, the APC ubiquitinates Cdc20 independent of APC activation by Cdc20’s C-box. Cdc20 turnover by this intramolecular mechanism is cell cycle-regulated, contributing to the decline in Cdc20 levels that occurs after anaphase. Interestingly, high substrate levels in vitro significantly reduce Cdc20 autoubiquitination. Conclusion We show here that Cdc20 fluctuates through the cell cycle via a distinct form of APC-mediated ubiquitination. This in cis autoubiquitination may preferentially occur in early anaphase, following depletion of Cdc20 substrates. This suggests that distinct mechanisms are able to target Cdc20 for ubiquitination at different points during the cell cycle. PMID:22079111

Molecular cloning of the gene for the human placental GTP-binding protein Gp (G25K): Identification of this GTP-binding protein as the human homolog of the yeast cell-division-cycle protein CDC42

International Nuclear Information System (INIS)

Shinjo, K.; Koland, J.G.; Hart, M.J.; Narasimhan, V.; Cerione, R.A.; Johnson, D.I.; Evans, T.

1990-01-01

The authors have isolated cDNA clones from a human placental library that code for a low molecular weight GTP-binding protein originally designated G p (also called G25K). This identification is based on comparisons with the available peptide sequences for the purified human G p protein and the use of two highly specific anti-peptide antibodies. The predicted amino acid sequence of the protein is very similar to those of various members of the ras superfamily of low molecular weight GTP-binding proteins, including the N-, Ki-, and Ha-ras proteins (30-35% identical), the rho proteins and the rac proteins. The highest degree of sequence identity (80%) is found with the Saccharomyces cerevisiae cell division-cycle protein CDC42. The human placental gene, which they designate CDC42Hs, complements the cdc42-1 mutation in S. cerevisiae, which suggests that this GTP-binding protein is the human homolog of the yeast protein

START-GAP3/DLC3 is a GAP for RhoA and Cdc42 and is localized in focal adhesions regulating cell morphology

International Nuclear Information System (INIS)

Kawai, Katsuhisa; Kiyota, Minoru; Seike, Junichi; Deki, Yuko; Yagisawa, Hitoshi

2007-01-01

In the human genome there are three genes encoding RhoGAPs that contain the START (steroidogenic acute regulatory protein (StAR)-related lipid transfer)-domain. START-GAP3/DLC3 is a tumor suppressor gene similar to two other human START-GAPs known as DLC1 or DLC2. Although expression of START-GAP3/DLC3 inhibits the proliferation of cancer cells, its molecular function is not well understood. In this study we carried out biochemical characterization of START-GAP3/DLC3, and explored the effects of its expression on cell morphology and intracellular localization. We found that START-GAP3/DLC3 serves as a stimulator of PLCδ1 and as a GAP for both RhoA and Cdc42 in vitro. Moreover, we found that the GAP activity is responsible for morphological changes. The intracellular localization of endogenous START-GAP3/DLC3 was explored by immunocytochemistry and was revealed in focal adhesions. These results indicate that START-GAP3/DLC3 has characteristics similar to other START-GAPs and the START-GAP family seems to share common characteristics

Functional adaptation to loading of a single bone is neuronally regulated and involves multiple bones.

Science.gov (United States)

Sample, Susannah J; Behan, Mary; Smith, Lesley; Oldenhoff, William E; Markel, Mark D; Kalscheur, Vicki L; Hao, Zhengling; Miletic, Vjekoslav; Muir, Peter

2008-09-01

Regulation of load-induced bone formation is considered a local phenomenon controlled by osteocytes, although it has also been hypothesized that functional adaptation may be neuronally regulated. The aim of this study was to examine bone formation in multiple bones, in response to loading of a single bone, and to determine whether adaptation may be neuronally regulated. Load-induced responses in the left and right ulnas and humeri were determined after loading of the right ulna in male Sprague-Dawley rats (69 +/- 16 days of age). After a single period of loading at -760-, -2000-, or -3750-microepsilon initial peak strain, rats were given calcein to label new bone formation. Bone formation and bone neuropeptide concentrations were determined at 10 days. In one group, temporary neuronal blocking was achieved by perineural anesthesia of the brachial plexus with bupivicaine during loading. We found right ulna loading induces adaptive responses in other bones in both thoracic limbs compared with Sham controls and that neuronal blocking during loading abrogated bone formation in the loaded ulna and other thoracic limb bones. Skeletal adaptation was more evident in distal long bones compared with proximal long bones. We also found that the single period of loading modulated bone neuropeptide concentrations persistently for 10 days. We conclude that functional adaptation to loading of a single bone in young rapidly growing rats is neuronally regulated and involves multiple bones. Persistent changes in bone neuropeptide concentrations after a single loading period suggest that plasticity exists in the innervation of bone.

The Hsk1(Cdc7) replication kinase regulates origin efficiency.

Science.gov (United States)

Patel, Prasanta K; Kommajosyula, Naveen; Rosebrock, Adam; Bensimon, Aaron; Leatherwood, Janet; Bechhoefer, John; Rhind, Nicholas

2008-12-01

Origins of DNA replication are generally inefficient, with most firing in fewer than half of cell cycles. However, neither the mechanism nor the importance of the regulation of origin efficiency is clear. In fission yeast, origin firing is stochastic, leading us to hypothesize that origin inefficiency and stochasticity are the result of a diffusible, rate-limiting activator. We show that the Hsk1-Dfp1 replication kinase (the fission yeast Cdc7-Dbf4 homologue) plays such a role. Increasing or decreasing Hsk1-Dfp1 levels correspondingly increases or decreases origin efficiency. Furthermore, tethering Hsk1-Dfp1 near an origin increases the efficiency of that origin, suggesting that the effective local concentration of Hsk1-Dfp1 regulates origin firing. Using photobleaching, we show that Hsk1-Dfp1 is freely diffusible in the nucleus. These results support a model in which the accessibility of replication origins to Hsk1-Dfp1 regulates origin efficiency and provides a potential mechanistic link between chromatin structure and replication timing. By manipulating Hsk1-Dfp1 levels, we show that increasing or decreasing origin firing rates leads to an increase in genomic instability, demonstrating the biological importance of appropriate origin efficiency.

The Hsk1(Cdc7) Replication Kinase Regulates Origin Efficiency

Science.gov (United States)

Patel, Prasanta K.; Kommajosyula, Naveen; Rosebrock, Adam; Bensimon, Aaron; Leatherwood, Janet; Bechhoefer, John

2008-01-01

Origins of DNA replication are generally inefficient, with most firing in fewer than half of cell cycles. However, neither the mechanism nor the importance of the regulation of origin efficiency is clear. In fission yeast, origin firing is stochastic, leading us to hypothesize that origin inefficiency and stochasticity are the result of a diffusible, rate-limiting activator. We show that the Hsk1-Dfp1 replication kinase (the fission yeast Cdc7-Dbf4 homologue) plays such a role. Increasing or decreasing Hsk1-Dfp1 levels correspondingly increases or decreases origin efficiency. Furthermore, tethering Hsk1-Dfp1 near an origin increases the efficiency of that origin, suggesting that the effective local concentration of Hsk1-Dfp1 regulates origin firing. Using photobleaching, we show that Hsk1-Dfp1 is freely diffusible in the nucleus. These results support a model in which the accessibility of replication origins to Hsk1-Dfp1 regulates origin efficiency and provides a potential mechanistic link between chromatin structure and replication timing. By manipulating Hsk1-Dfp1 levels, we show that increasing or decreasing origin firing rates leads to an increase in genomic instability, demonstrating the biological importance of appropriate origin efficiency. PMID:18799612

Morphological Analysis of CDC2 and Glycogen Synthase Kinase 3β Phosphorylation as Markers of G2 → M Transition in Glioma

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José Javier Otero

2011-01-01

Full Text Available G2 → M transition is a strategic target for glioma chemotherapy. Key players in G2 → M transition include CDC2 and glycogen synthase kinase 3β (GSK3β, which are highly regulated by posttranslational phosphorylation. This report is a morphological analysis of CDC2 and GSK3β phosphorylation using immunohistochemistry in gliomas with different biological properties. GBM showed a 2.8-fold and 5.6-fold increase in number of cells positive for pThr161CDC2 and a 4.2- and 6.9-fold increase in number of cells positive for pTyr15CDC2 relative to oligodendroglioma and ependymoma, respectively. Elevated labeling for inhibited phospho-CDC2 (pTyr15CDC correlates with elevated levels of phosphorylated glycogen synthase kinase 3β (GSK3β. 71% of the GBM cases showed intermediate to high intensity staining for pSer9SGK3β 53% of oligodendroglioma, and 73% of ependymoma showed low intensity staining. CDC2 gene amplification correlates with increased survival in glioblastoma multiforme (GBM and astrocytoma WHO grades II-III, but not in oligodendroglioma WHO grades II-III.

Cell cycle sibling rivalry: Cdc2 vs. Cdk2.

Science.gov (United States)

Kaldis, Philipp; Aleem, Eiman

2005-11-01

It has been long believed that the cyclin-dependent kinase 2 (Cdk2) binds to cyclin E or cyclin A and exclusively promotes the G1/S phase transition and that Cdc2/cyclin B complexes play a major role in mitosis. We now provide evidence that Cdc2 binds to cyclin E (in addition to cyclin A and B) and is able to promote the G1/S transition. This new concept indicates that both Cdk2 and/or Cdc2 can drive cells through G1/S phase in parallel. In this review we discuss the classic cell cycle model and how results from knockout mice provide new evidence that refute this model. We focus on the roles of Cdc2 and p27 in regulating the mammalian cell cycle and propose a new model for cell cycle regulation that accommodates these novel findings.

Regulation of bone remodeling by vitamin K2.

Science.gov (United States)

Myneni, V D; Mezey, E

2017-11-01

All living tissues require essential nutrients such as amino acids, fatty acids, carbohydrates, minerals, vitamins, and water. The skeleton requires nutrients for development, maintaining bone mass and density. If the skeletal nutritional requirements are not met, the consequences can be quite severe. In recent years, there has been growing interest in promotion of bone health and inhibition of vascular calcification by vitamin K2. This vitamin regulates bone remodeling, an important process necessary to maintain adult bone. Bone remodeling involves removal of old or damaged bone by osteoclasts and its replacement by new bone formed by osteoblasts. The remodeling process is tightly regulated, when the balance between bone resorption and bone formation shifts to a net bone loss results in the development of osteoporosis in both men and women. In this review, we focus on our current understanding of the effects of vitamin K2 on bone cells and its role in prevention and treatment of osteoporosis. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Stage-specific control of neural crest stem cell proliferation by the small rho GTPases Cdc42 and Rac1

DEFF Research Database (Denmark)

Fuchs, Sebastian; Herzog, Dominik; Sumara, Grzegorz

2009-01-01

-renewal and proliferation of later stage, but not early migratory NCSCs. This stage-specific requirement for small Rho GTPases is due to changes in NCSCs that, during development, acquire responsiveness to mitogenic EGF acting upstream of both Cdc42 and Rac1. Thus, our data reveal distinct mechanisms for growth control......The neural crest (NC) generates a variety of neural and non-neural tissues during vertebrate development. Both migratory NC cells and their target structures contain cells with stem cell features. Here we show that these populations of neural crest-derived stem cells (NCSCs) are differentially...

ORACLS- OPTIMAL REGULATOR ALGORITHMS FOR THE CONTROL OF LINEAR SYSTEMS (CDC VERSION)

Science.gov (United States)

Armstrong, E. S.

1994-01-01

This control theory design package, called Optimal Regulator Algorithms for the Control of Linear Systems (ORACLS), was developed to aid in the design of controllers and optimal filters for systems which can be modeled by linear, time-invariant differential and difference equations. Optimal linear quadratic regulator theory, currently referred to as the Linear-Quadratic-Gaussian (LQG) problem, has become the most widely accepted method of determining optimal control policy. Within this theory, the infinite duration time-invariant problems, which lead to constant gain feedback control laws and constant Kalman-Bucy filter gains for reconstruction of the system state, exhibit high tractability and potential ease of implementation. A variety of new and efficient methods in the field of numerical linear algebra have been combined into the ORACLS program, which provides for the solution to time-invariant continuous or discrete LQG problems. The ORACLS package is particularly attractive to the control system designer because it provides a rigorous tool for dealing with multi-input and multi-output dynamic systems in both continuous and discrete form. The ORACLS programming system is a collection of subroutines which can be used to formulate, manipulate, and solve various LQG design problems. The ORACLS program is constructed in a manner which permits the user to maintain considerable flexibility at each operational state. This flexibility is accomplished by providing primary operations, analysis of linear time-invariant systems, and control synthesis based on LQG methodology. The input-output routines handle the reading and writing of numerical matrices, printing heading information, and accumulating output information. The basic vector-matrix operations include addition, subtraction, multiplication, equation, norm construction, tracing, transposition, scaling, juxtaposition, and construction of null and identity matrices. The analysis routines provide for the following

[Hormones and osteoporosis update. Regulation of bone remodeling by neuropeptides and neurotransmitters].

Science.gov (United States)

Takeda, Shu

2009-07-01

From the discovery of the regulation of bone remodelling by leptin, much attention has been focused on neurogenic control of bone remodelling. Various hypothalamic neuropeptides, which are involved in appetite regulation, are now revealed to be important regulators of bone remodelling. More recently, neurotransmitters, such as serotonin or catecholamines, are proven to be bone remodelling regulators.

An extracellular-matrix-specific GEF-GAP interaction regulates Rho GTPase crosstalk for 3D collagen migration.

Science.gov (United States)

Kutys, Matthew L; Yamada, Kenneth M

2014-09-01

Rho-family GTPases govern distinct types of cell migration on different extracellular matrix proteins in tissue culture or three-dimensional (3D) matrices. We searched for mechanisms selectively regulating 3D cell migration in different matrix environments and discovered a form of Cdc42-RhoA crosstalk governing cell migration through a specific pair of GTPase activator and inhibitor molecules. We first identified βPix, a guanine nucleotide exchange factor (GEF), as a specific regulator of migration in 3D collagen using an affinity-precipitation-based GEF screen. Knockdown of βPix specifically blocks cell migration in fibrillar collagen microenvironments, leading to hyperactive cellular protrusion accompanied by increased collagen matrix contraction. Live FRET imaging and RNAi knockdown linked this βPix knockdown phenotype to loss of polarized Cdc42 but not Rac1 activity, accompanied by enhanced, de-localized RhoA activity. Mechanistically, collagen phospho-regulates βPix, leading to its association with srGAP1, a GTPase-activating protein (GAP), needed to suppress RhoA activity. Our results reveal a matrix-specific pathway controlling migration involving a GEF-GAP interaction of βPix with srGAP1 that is critical for maintaining suppressive crosstalk between Cdc42 and RhoA during 3D collagen migration.

Cdc6 is a rate-limiting factor for proliferative capacity during HL60 cell differentiation

International Nuclear Information System (INIS)

Barkley, Laura R.; Hong, Hye Kyung; Kingsbury, Sarah R.; James, Michelle; Stoeber, Kai; Williams, Gareth H.

2007-01-01

The DNA replication (or origin) licensing pathway represents a critical step in cell proliferation control downstream of growth signalling pathways. Repression of origin licensing through down-regulation of the MCM licensing factors (Mcm2-7) is emerging as a ubiquitous route for lowering proliferative capacity as metazoan cells exit the cell division cycle into quiescent, terminally differentiated and senescent 'out-of-cycle' states. Using the HL60 monocyte/macrophage differentiation model system and a cell-free DNA replication assay, we have undertaken direct biochemical investigations of the coupling of origin licensing to the differentiation process. Our data show that down-regulation of the MCM loading factor Cdc6 acts as a molecular switch that triggers loss of proliferative capacity during early engagement of the somatic differentiation programme. Consequently, addition of recombinant Cdc6 protein to in vitro replication reactions restores DNA replication competence in nuclei prepared from differentiating cells. Differentiating HL60 cells over-expressing either wild-type Cdc6 or a CDK phosphorylation-resistant Cdc6 mutant protein (Cdc6A4) exhibit an extended period of cell proliferation compared to mock-infected cells. Notably, differentiating HL60 cells over-expressing the Cdc6A4 mutant fail to down-regulate Cdc6 protein levels, suggesting that CDK phosphorylation of Cdc6 is linked to its down-regulation during differentiation and the concomitant decrease in cell proliferation. In this experimental model, Cdc6 therefore plays a key role in the sequential molecular events leading to repression of origin licensing and loss of proliferative capacity during execution of the differentiation programme

Leptin regulates bone formation via the sympathetic nervous system

Science.gov (United States)

Takeda, Shu; Elefteriou, Florent; Levasseur, Regis; Liu, Xiuyun; Zhao, Liping; Parker, Keith L.; Armstrong, Dawna; Ducy, Patricia; Karsenty, Gerard

2002-01-01

We previously showed that leptin inhibits bone formation by an undefined mechanism. Here, we show that hypothalamic leptin-dependent antiosteogenic and anorexigenic networks differ, and that the peripheral mediators of leptin antiosteogenic function appear to be neuronal. Neuropeptides mediating leptin anorexigenic function do not affect bone formation. Leptin deficiency results in low sympathetic tone, and genetic or pharmacological ablation of adrenergic signaling leads to a leptin-resistant high bone mass. beta-adrenergic receptors on osteoblasts regulate their proliferation, and a beta-adrenergic agonist decreases bone mass in leptin-deficient and wild-type mice while a beta-adrenergic antagonist increases bone mass in wild-type and ovariectomized mice. None of these manipulations affects body weight. This study demonstrates a leptin-dependent neuronal regulation of bone formation with potential therapeutic implications for osteoporosis.

Two Cdc2 Kinase Genes with Distinct Functions in Vegetative and Infectious Hyphae in Fusarium graminearum.

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Huiquan Liu

2015-06-01

Full Text Available Eukaryotic cell cycle involves a number of protein kinases important for the onset and progression through mitosis, most of which are well characterized in the budding and fission yeasts and conserved in other fungi. However, unlike the model yeast and filamentous fungi that have a single Cdc2 essential for cell cycle progression, the wheat scab fungus Fusarium graminearum contains two CDC2 orthologs. The cdc2A and cdc2B mutants had no obvious defects in growth rate and conidiation but deletion of both of them is lethal, indicating that these two CDC2 orthologs have redundant functions during vegetative growth and asexual reproduction. However, whereas the cdc2B mutant was normal, the cdc2A mutant was significantly reduced in virulence and rarely produced ascospores. Although deletion of CDC2A had no obvious effect on the formation of penetration branches or hyphopodia, the cdc2A mutant was limited in the differentiation and growth of infectious growth in wheat tissues. Therefore, CDC2A plays stage-specific roles in cell cycle regulation during infectious growth and sexual reproduction. Both CDC2A and CDC2B are constitutively expressed but only CDC2A was up-regulated during plant infection and ascosporogenesis. Localization of Cdc2A- GFP to the nucleus but not Cdc2B-GFP was observed in vegetative hyphae, ascospores, and infectious hyphae. Complementation assays with chimeric fusion constructs showed that both the N- and C-terminal regions of Cdc2A are important for its functions in pathogenesis and ascosporogenesis but only the N-terminal region is important for its subcellular localization. Among the Sordariomycetes, only three Fusarium species closely related to F. graminearum have two CDC2 genes. Furthermore, F. graminearum uniquely has two Aurora kinase genes and one additional putative cyclin gene, and its orthologs of CAK1 and other four essential mitotic kinases in the budding yeast are dispensable for viability. Overall, our data

Two Cdc2 Kinase Genes with Distinct Functions in Vegetative and Infectious Hyphae in Fusarium graminearum.

Science.gov (United States)

Liu, Huiquan; Zhang, Shijie; Ma, Jiwen; Dai, Yafeng; Li, Chaohui; Lyu, Xueliang; Wang, Chenfang; Xu, Jin-Rong

2015-06-01

Eukaryotic cell cycle involves a number of protein kinases important for the onset and progression through mitosis, most of which are well characterized in the budding and fission yeasts and conserved in other fungi. However, unlike the model yeast and filamentous fungi that have a single Cdc2 essential for cell cycle progression, the wheat scab fungus Fusarium graminearum contains two CDC2 orthologs. The cdc2A and cdc2B mutants had no obvious defects in growth rate and conidiation but deletion of both of them is lethal, indicating that these two CDC2 orthologs have redundant functions during vegetative growth and asexual reproduction. However, whereas the cdc2B mutant was normal, the cdc2A mutant was significantly reduced in virulence and rarely produced ascospores. Although deletion of CDC2A had no obvious effect on the formation of penetration branches or hyphopodia, the cdc2A mutant was limited in the differentiation and growth of infectious growth in wheat tissues. Therefore, CDC2A plays stage-specific roles in cell cycle regulation during infectious growth and sexual reproduction. Both CDC2A and CDC2B are constitutively expressed but only CDC2A was up-regulated during plant infection and ascosporogenesis. Localization of Cdc2A- GFP to the nucleus but not Cdc2B-GFP was observed in vegetative hyphae, ascospores, and infectious hyphae. Complementation assays with chimeric fusion constructs showed that both the N- and C-terminal regions of Cdc2A are important for its functions in pathogenesis and ascosporogenesis but only the N-terminal region is important for its subcellular localization. Among the Sordariomycetes, only three Fusarium species closely related to F. graminearum have two CDC2 genes. Furthermore, F. graminearum uniquely has two Aurora kinase genes and one additional putative cyclin gene, and its orthologs of CAK1 and other four essential mitotic kinases in the budding yeast are dispensable for viability. Overall, our data indicate that cell cycle

Androgen receptor (AR) promotes clear cell renal cell carcinoma (ccRCC) migration and invasion via altering the circHIAT1/miR-195-5p/29a-3p/29c-3p/CDC42 signals.

Science.gov (United States)

Wang, Kefeng; Sun, Yin; Tao, Wei; Fei, Xiang; Chang, Chawnshang

2017-05-28

Increasing evidence has demonstrated that the androgen receptor (AR) plays important roles to promote the metastasis of clear cell renal cell carcinoma (ccRCC). The detailed mechanisms, especially how AR functions via altering the circular RNAs (circRNAs) remain unclear. Here we identified a new circRNA (named as circHIAT1) whose expression was lower in ccRCCs than adjacent normal tissues. Targeting AR could suppress ccRCC cell progression via increasing circHIAT1 expression. ChIP assay and luciferase assay demonstrated that AR suppressed circHIAT1 expression via regulating its host gene, Hippocampus Abundant Transcript 1 (HIAT1) expression at the transcriptional level. The consequences of AR-suppressed circHIAT1 resulted in deregulating miR-195-5p/29a-3p/29c-3p expressions, which increased CDC42 expression to enhance ccRCC cell migration and invasion. Increasing this newly identified signal via circHIAT1 suppressed AR-enhanced ccRCC cell migration and invasion. Together, these results suggested that circHIAT1 functioned as a metastatic inhibitor to suppress AR-enhanced ccRCC cell migration and invasion. Targeting this newly identified AR-circHIAT1-mediated miR-195-5p/29a-3p/29c-3p/CDC42 signals may help us develop potential new therapies to better suppress ccRCC metastasis. Copyright © 2017 Elsevier B.V. All rights reserved.

Cdc25A localisation and shuttling: characterisation of sequences mediating nuclear export and import

International Nuclear Information System (INIS)

Kaellstroem, Helena; Lindqvist, Arne; Pospisil, Vitek; Lundgren, Andreas; Karlsson Rosenthal, Christina

2005-01-01

The Cdc25 phosphatases play crucial roles in cell cycle progression by removing inhibitory phosphates from tyrosine and threonine residues of cyclin-dependent kinases. Cdc25A is an important regulator of the G1/S transition but functions also in the mitotic phase of the human cell cycle. In this paper, we investigate the sub-cellular localisation of exogenously expressed Cdc25A. We show that YFP-Cdc25A is localised both in the nucleus and the cytoplasm of HeLa cells and untransformed fibroblasts. Cell fusion assays and fluorescence loss in photobleaching (FLIP) assays reveal that the localisation is dynamic and the protein shuttles between the nucleus and the cytoplasm. We demonstrate that nuclear export of Cdc25A is partly mediated by an N-terminal nuclear export sequence (NES), in a manner not sensitive to the Exportin 1-inhibitor leptomycin B. A nuclear localisation signal (NLS) is also characterised, mutation of which leads to cytoplasmic localisation of Cdc25A. Our results imply that the Cdc25A phosphatase may interact with substrates and regulators both in the nucleus and the cytoplasm

A radiographic investigation of third carpal bone injury in 42 racing thoroughbreds

International Nuclear Information System (INIS)

De Haan, C.E.; O'Brien, T.R.; Koblik, P.D.

1987-01-01

A retrospective study of carpal radiographs from 42 racing thoroughbreds with carpal lameness was performed. Radiographs from 50 carpal examinations were available for review. The radiographic findings pertaining to the third carpal bone were described. Fractures and/or sclerosis occurred almost exclusively within the radial fossa. The occurrence of sclerosis without fracture in 20 of the 50 carpal examinations was higher than anticipated, occurring in both the right and left third carpal bone with equal frequency. The right third carpal bone was more frequently fractured and more severely affected than the left. The sclerotic changes seen in the radial fossa of the third carpal bone may be stress-induced, possibly preceding more serious changes in the joint such as cartilage damage or gross fracture. Earlier recognition of sclerosis of the third carpal bone may help prevent more serious changes from occurring

The role of cDC1s in vivo: CD8 T cell priming through cross-presentation [version 1; referees: 3 approved

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Derek Theisen

2017-02-01

Full Text Available The cDC1 subset of classical dendritic cells is specialized for priming CD8 T cell responses through the process of cross-presentation. The molecular mechanisms of cross-presentation remain incompletely understood because of limited biochemical analysis of rare cDC1 cells, difficulty in their genetic manipulation, and reliance on in vitro systems based on monocyte- and bone-marrow-derived dendritic cells. This review will discuss cross-presentation from the perspective of studies with monocyte- or bone-marrow-derived dendritic cells while highlighting the need for future work examining cDC1 cells. We then discuss the role of cDC1s as a cellular platform to combine antigen processing for class I and class II MHC presentation to allow the integration of “help” from CD4 T cells during priming of CD8 T cell responses.

BIOCHEMICAL MARKERS OF BONE RESORPTION AND HORMONAL REGULATION OF BONE METABOLISM FOLLOWING LIVER TRANSPLANTATION

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V. P. Buzulina

2013-01-01

Full Text Available Aim. Comparative evaluation of two biochemical markers of bone resorption and hormonal regulation of bone metabolism in liver recipients. Methods and results. Bоne densitometry of L2–L4 and neck of femur, serum level of some hormones (PTH, vitamin D3, estradiol, testosterone regulating osteoclastogenesis as well as com- parative analyses of two bone resorption markers β-crosslaps and tartrate-resistant acid phosphatase type 5b (TRAP-5b were fulfilled in patients after orthotopic liver transplantation (OLT. In 1 month after OLT bone density reduction of L2–L4 and neck of femur; decrease of vitamin D3, estradiol in women, testosterone in men and increase levels of bone resorption markers were observed. In 1 and 2 years after OLT the rise of bone density, increased levels of PTH, estradiol, testosterone and decreased β-crosslaps levels were revealed, while vitamin D3 and TRAP-5b levels remained stable. Conclusion. TRAP-5b was found to be a more speciffic marker of bone resorption, independent from collagen metabolism in liver. Osteoporosis defined in long-term period after OLT was associated with higher TRAP-5b and revialed in women with low estradiol level. 

The human homolog of S. cerevisiae CDC27, CDC27 Hs, is encoded by a highly conserved intronless gene present in multiple copies in the human genome

Energy Technology Data Exchange (ETDEWEB)

Devor, E.J.; Dill-Devor, R.M. [Univ. of Iowa College of Medicine, Iowa City (United States)

1994-09-01

We have obtained a number of unique sequences via PCR amplification of human genomic DNA using degenerate primers under low stringency (42{degrees}C). One of these, an 853 bp product, has been identified as a partial genomic sequence of the human homolog of the S. cerevisiae CDC27 gene, CDC27Hs (GenBank No. U00001). This gene, reported by Turgendreich et al. is also designated EST00556 from Adams et al. We have undertaken a more detailed examination of our sequence, MCP34N, and have found that: 1. the genomic sequence is nearly identical to CDC27Hs over its entire 853 bp length; 2. an MCP34N-specific PCR assay of several non-human primate species reveals amplification products in chimpanzee and gorilla genomes having greater than 90% sequence identity with CDC27Hs; and 3. an MCP34N-specific PCR assay of the BIOS hybrid cell line panel gives a discordancy pattern suggesting multiple loci. Based upon these data, we present the following initial characterization: 1. the complete MCP34N sequence identity with CDC27Hs indicates that the latter is encoded by an intronless gene; 2. CDC27Hs is highly conserved among higher primates; and 3. CDC27Hs is present in multiple copies in the human genome. These characteristics, taken together with those initially reported for CDC27Hs, suggest that this is an old gene that carries out an important but, as yet, unknown function in the human brain.

Osteocyte-Intrinsic TGF-β Signaling Regulates Bone Quality through Perilacunar/Canalicular Remodeling

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Neha S. Dole

2017-11-01

Full Text Available Poor bone quality contributes to bone fragility in diabetes, aging, and osteogenesis imperfecta. However, the mechanisms controlling bone quality are not well understood, contributing to the current lack of strategies to diagnose or treat bone quality deficits. Transforming growth factor beta (TGF-β signaling is a crucial mechanism known to regulate the material quality of bone, but its cellular target in this regulation is unknown. Studies showing that osteocytes directly remodel their perilacunar/canalicular matrix led us to hypothesize that TGF-β controls bone quality through perilacunar/canalicular remodeling (PLR. Using inhibitors and mice with an osteocyte-intrinsic defect in TGF-β signaling (TβRIIocy−/−, we show that TGF-β regulates PLR in a cell-intrinsic manner to control bone quality. Altogether, this study emphasizes that osteocytes are key in executing the biological control of bone quality through PLR, thereby highlighting the fundamental role of osteocyte-mediated PLR in bone homeostasis and fragility.

Osteocyte-Intrinsic TGF-β Signaling Regulates Bone Quality through Perilacunar/Canalicular Remodeling.

Science.gov (United States)

Dole, Neha S; Mazur, Courtney M; Acevedo, Claire; Lopez, Justin P; Monteiro, David A; Fowler, Tristan W; Gludovatz, Bernd; Walsh, Flynn; Regan, Jenna N; Messina, Sara; Evans, Daniel S; Lang, Thomas F; Zhang, Bin; Ritchie, Robert O; Mohammad, Khalid S; Alliston, Tamara

2017-11-28

Poor bone quality contributes to bone fragility in diabetes, aging, and osteogenesis imperfecta. However, the mechanisms controlling bone quality are not well understood, contributing to the current lack of strategies to diagnose or treat bone quality deficits. Transforming growth factor beta (TGF-β) signaling is a crucial mechanism known to regulate the material quality of bone, but its cellular target in this regulation is unknown. Studies showing that osteocytes directly remodel their perilacunar/canalicular matrix led us to hypothesize that TGF-β controls bone quality through perilacunar/canalicular remodeling (PLR). Using inhibitors and mice with an osteocyte-intrinsic defect in TGF-β signaling (TβRII ocy-/- ), we show that TGF-β regulates PLR in a cell-intrinsic manner to control bone quality. Altogether, this study emphasizes that osteocytes are key in executing the biological control of bone quality through PLR, thereby highlighting the fundamental role of osteocyte-mediated PLR in bone homeostasis and fragility. Published by Elsevier Inc.

Distinct bone marrow blood vessels differentially regulate haematopoiesis.

Science.gov (United States)

Itkin, Tomer; Gur-Cohen, Shiri; Spencer, Joel A; Schajnovitz, Amir; Ramasamy, Saravana K; Kusumbe, Anjali P; Ledergor, Guy; Jung, Yookyung; Milo, Idan; Poulos, Michael G; Kalinkovich, Alexander; Ludin, Aya; Kollet, Orit; Shakhar, Guy; Butler, Jason M; Rafii, Shahin; Adams, Ralf H; Scadden, David T; Lin, Charles P; Lapidot, Tsvee

2016-04-21

Bone marrow endothelial cells (BMECs) form a network of blood vessels that regulate both leukocyte trafficking and haematopoietic stem and progenitor cell (HSPC) maintenance. However, it is not clear how BMECs balance these dual roles, and whether these events occur at the same vascular site. We found that mammalian bone marrow stem cell maintenance and leukocyte trafficking are regulated by distinct blood vessel types with different permeability properties. Less permeable arterial blood vessels maintain haematopoietic stem cells in a low reactive oxygen species (ROS) state, whereas the more permeable sinusoids promote HSPC activation and are the exclusive site for immature and mature leukocyte trafficking to and from the bone marrow. A functional consequence of high permeability of blood vessels is that exposure to blood plasma increases bone marrow HSPC ROS levels, augmenting their migration and differentiation, while compromising their long-term repopulation and survival. These findings may have relevance for clinical haematopoietic stem cell transplantation and mobilization protocols.

Building strong bones: molecular regulation of the osteoblast lineage.

Science.gov (United States)

Long, Fanxin

2011-12-22

The past 15 years have witnessed tremendous progress in the molecular understanding of osteoblasts, the main bone-forming cells in the vertebrate skeleton. In particular, all of the major developmental signals (including WNT and Notch signalling), along with an increasing number of transcription factors (such as RUNX2 and osterix), have been shown to regulate the differentiation and/or function of osteoblasts. As evidence indicates that osteoblasts may also regulate the behaviour of other cell types, a clear understanding of the molecular identity and regulation of osteoblasts is important beyond the field of bone biology.

Tetraspanin CD9 regulates osteoclastogenesis via regulation of p44/42 MAPK activity

International Nuclear Information System (INIS)

Yi, TacGhee; Kim, Hye-Jin; Cho, Je-Yoel; Woo, Kyung Mi; Ryoo, Hyun-Mo; Kim, Gwan-Shik; Baek, Jeong-Hwa

2006-01-01

Tetraspanin CD9 has been shown to regulate cell-cell fusion in sperm-egg fusion and myotube formation. However, the role of CD9 in osteoclast, another multinucleated cell type, is not still clear. Therefore, we investigated the role of CD9 in osteoclast differentiation. CD9 was expressed in osteoclast lineage cells and its expression level increased during the progression of RANKL-induced osteoclastogenesis. KMC8, a neutralizing antibody specific to CD9, significantly suppressed RANKL-induced multinucleated osteoclast formation and the mRNA expression of osteoclast differentiation marker genes. To define CD9-regulated osteoclastogenic signaling pathway, MAPK pathways were examined. KMC8 induced long-term phosphorylation of p44/42 MAPK, but not of p38 MAPK. Constitutive activation of p44/42 MAPK by overexpressing constitutive-active mutant of MEK1 almost completely blocked osteoclast differentiation. Taken together, these results suggest that CD9 expressed on osteoclast lineage cells might positively regulate osteoclastogenesis via the regulation of p44/42 MAPK activity

Cell cycle- and cell growth-regulated proteolysis of mammalian CDC6 is dependent on APC-CDH1

DEFF Research Database (Denmark)

Petersen, B O; Wagener, C; Marinoni, F

2000-01-01

is targeted for ubiquitin-mediated proteolysis by the anaphase promoting complex (APC)/cyclosome in G(1). A combination of point mutations in the destruction box and KEN-box motifs in CDC6 stabilizes the protein in G(1) and in quiescent cells. Furthermore, APC, in association with CDH1, ubiquitinates CDC6...... in vitro, and both APC and CDH1 are required and limiting for CDC6 proteolysis in vivo. Although a stable mutant of CDC6 is biologically active, overexpression of this mutant or wild-type CDC6 is not sufficient to induce multiple rounds of DNA replication in the same cell cycle. The APC-CDH1-dependent...

Cdc7-Dbf4 Regulates NDT80 Transcription as Well as Reductional Segregation during Budding Yeast Meiosis

OpenAIRE

Lo, Hsiao-Chi; Wan, Lihong; Rosebrock, Adam; Futcher, Bruce; Hollingsworth, Nancy M.

2008-01-01

In budding yeast, as in other eukaryotes, the Cdc7 protein kinase is important for initiation of DNA synthesis in vegetative cells. In addition, Cdc7 has crucial meiotic functions: it facilitates premeiotic DNA replication, and it is essential for the initiation of recombination. This work uses a chemical genetic approach to demonstrate that Cdc7 kinase has additional roles in meiosis. First, Cdc7 allows expression of NDT80, a meiosis-specific transcriptional activator required for the induct...

Bone Allografts: What Is the Risk of Disease Transmission with Bone Allografts?

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... HIV virus in freeze-dried bone allografts. Pract Periodontics Aesthet Dent 1995;7:13–22. Mellonig JT, ... source: Division of Oral Health , National Center for Chronic Disease Prevention and Health Promotion Follow CDC Email ...

Wise regulates bone deposition through genetic interactions with Lrp5.

Science.gov (United States)

Ellies, Debra L; Economou, Androulla; Viviano, Beth; Rey, Jean-Philippe; Paine-Saunders, Stephenie; Krumlauf, Robb; Saunders, Scott

2014-01-01

In this study using genetic approaches in mouse we demonstrate that the secreted protein Wise plays essential roles in regulating early bone formation through its ability to modulate Wnt signaling via interactions with the Lrp5 co-receptor. In Wise-/- mutant mice we find an increase in the rate of osteoblast proliferation and a transient increase in bone mineral density. This change in proliferation is dependent upon Lrp5, as Wise;Lrp5 double mutants have normal bone mass. This suggests that Wise serves as a negative modulator of Wnt signaling in active osteoblasts. Wise and the closely related protein Sclerostin (Sost) are expressed in osteoblast cells during temporally distinct early and late phases in a manner consistent with the temporal onset of their respective increased bone density phenotypes. These data suggest that Wise and Sost may have common roles in regulating bone development through their ability to control the balance of Wnt signaling. We find that Wise is also required to potentiate proliferation in chondrocytes, serving as a potential positive modulator of Wnt activity. Our analyses demonstrate that Wise plays a key role in processes that control the number of osteoblasts and chondrocytes during bone homeostasis and provide important insight into mechanisms regulating the Wnt pathway during skeletal development.

Characterization of cyclin-dependent kinases and Cdc2/Cdc28 kinase subunits in Trichomonas vaginalis.

Science.gov (United States)

Amador, Erick; López-Pacheco, Karla; Morales, Nataly; Coria, Roberto; López-Villaseñor, Imelda

2017-04-01

Cyclin-dependent kinases (CDKs) have important roles in regulating key checkpoints between stages of the cell cycle. Their activity is tightly regulated through a variety of mechanisms, including through binding with cyclin proteins and the Cdc2/Cdc28 kinase subunit (CKS), and their phosphorylation at specific amino acids. Studies of the components involved in cell cycle control in parasitic protozoa are limited. Trichomonas vaginalis is the causative agent of trichomoniasis in humans and is therefore important in public health; however, some of the basic biological processes used by this organism have not been defined. Here, we characterized proteins potentially involved in cell cycle regulation in T. vaginalis. Three genes encoding protein kinases were identified in the T. vaginalis genome, and the corresponding recombinant proteins (TvCRK1, TvCRK2, TvCRK5) were studied. These proteins displayed similar sequence features to CDKs. Two genes encoding CKSs were also identified, and the corresponding recombinant proteins were found to interact with TvCRK1 and TvCRK2 by a yeast two-hybrid system. One putative cyclin B protein from T. vaginalis was found to bind to and activate the kinase activities of TvCRK1 and TvCRK5, but not TvCRK2. This work is the first characterization of proteins involved in cell cycle control in T. vaginalis.

42 CFR 50.210 - Review of regulation.

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Review of regulation. 50.210 Section 50.210 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS POLICIES OF GENERAL... regulation. The Secretary will request public comment on the operation of the provisions of this subpart not...

Cdc20 mediates D-box-dependent degradation of Sp100

International Nuclear Information System (INIS)

Wang, Ran; Li, Ke-min; Zhou, Cai-hong; Xue, Jing-lun; Ji, Chao-neng; Chen, Jin-zhong

2011-01-01

Highlights: ► Cdc20 is a co-activator of APC/C complex. ► Cdc20 recruits Sp100 and mediates its degradation. ► The D-box of Sp100 is required for Cdc20-mediated degradation. ► Sp100 expresses consistently at both the mRNA and protein levels in cell cycle. -- Abstract: Cdc20 is a co-activator of the anaphase-promoting complex/cyclosome (APC/C complex), which recruits substrates at particular phases of the cell cycle and mediates their degradation. Sp100 is a PML-NB scaffold protein, which localizes to nuclear particles during interphase and disperses from them during mitosis, participates in viral resistance, transcriptional regulation, and apoptosis. However, its metabolism during the cell cycle has not yet been fully characterized. We found a putative D-box in Sp100 using the Eukaryotic Linear Motif (ELM) predictor database. The putative D-box of Sp100 was verified by mutational analysis. Overexpression of Cdc20 resulted in decreased levels of both endogenous Sp100 protein and overexpressed Sp100 mRNA in HEK 293 cells. Only an overexpressed D-box deletion mutant of Sp100 accumulated in HEK293 cells that also overexpressed Cdc20. Cdc20 knockdown by cdc20 specific siRNA resulted in increased Sp100 protein levels in cells. Furthermore, we discovered that the Cdc20 mediated degradation of Sp100 is diminished by the proteasome inhibitor MG132, which suggests that the ubiquitination pathway is involved in this process. However, unlike the other Cdc20 substrates, which display oscillating protein levels, the level of Sp100 protein remains constant throughout the cell cycle. Additionally, both overexpression and knockdown of endogenous Sp100 had no effect on the cell cycle. Our results suggested that sp100 is a novel substrate of Cdc20 and it is degraded by the ubiquitination pathway. The intact D-box of Sp100 was necessary for this process. These findings expand our knowledge of both Sp100 and Cdc20 as well as their role in ubiquitination.

Expression of microRNA related to bone remodeling regulation in plasma in patients with acromegaly

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Tatiana A. Grebennikova

2017-11-01

Full Text Available Backgraund. MiсroRNA are small regulatory factors that regulate gene expression by post-transcriptional regulation of mRNA, playing an important role in numerous cellular processes including organogenesis, apoptosis, cell proliferation and differentiation. Acromegaly causes bone fragility, but the pathogenetic mechanism is generally unknown. Aim. To evaluate levels of microRNA related to bone remodeling regulation in plasma samples from patients with acromegaly Materials and methods. Fasting plasma samples were taken and stored in aliquot at ≤ -80°C from consecutive subjects with clinically evident and biochemically confirmed active acromegaly and healthy volunteers matched by age, sex and body mass index (BMI. miRNeasy Serum/Plasma Kit, TaqMan Advanced miRNA cDNA Synthesis Kit, TaqMan Advanced miRNA Assays were used to assay plasma miRNA expression. Insulin-like growth factor 1 (IGF1 was measured by immunochemiluminescence assay (Liaison. Results. We enrolled 40 subjects 22 patients suffered from acromegaly and 18 matched healthy controls matched by sex, age and BMI. The median age of patients with acromegaly was 42 years (Q25;Q75 – 37;43 with no difference among the groups, p=0.205; BMI – 28 (24;32 kg/m2, p=0.253. The median IGF1 in subjects with acromegaly – 622 (514;1000 ng/ml was significantly higher as compared to the control group (p<0.001. Patients with acromegaly had significantly higher expression of microRNA-100-5р (p=0.051, microRNA-550а-5р (p=0.048, microRNA-7b-5р (p=0.005 and microRNA-96-5р (p=0.042 among 27 bone-specific microRNA tested in plasma Conclusions. This study reveals that several microRNAs, known to regulate bone remodeling can be detected in plasma samples of patients with acromegaly and may be suggested as biomarkers for skeletal involvement in patients with acromegaly.

Bone--bone marrow interface (endosteum) potential relationship of microenvironments in the regulation of response to internal emitters

International Nuclear Information System (INIS)

Wilson, F.D.; Pool, R.R.; Stitzel, K.; Momeni, M.H.

1976-01-01

The interface between bone and bone marrow is examined in relation to radiation effects, with attention to new concepts of hematopoiesis. Such concepts propose a functional role of stroma in regulating the commitment of pluripotent stem cells as well as in the production of colony stimulating activity (CSA) including candidate granulopoietin(s). Morphologic examples are included, underlining the concept that stroma (including bone) and hematopoietic elements respond as a functional unit to injury to marrow elements. The methylcellulose bone marrow culture system is reviewed as it may relate to a method for quantitation of hematopoietic colonies (CFU-C), humoral regulators for granulopoiesis (CSA), and potentially as a method of quantitating mesenchymal progenitor populations (PFU-C). Based on these and other observations cited, a model depicting a tentative positioning of cells at risk relative to bone-seeking radionuclides is presented

Down-regulation of mTOR leads to up-regulation of osteoprotegerin in bone marrow cells

International Nuclear Information System (INIS)

Mogi, Makio; Kondo, Ayami

2009-01-01

Osteoprotegerin (OPG)/osteoclastogenesis inhibitory factor regulates bone mass by inhibiting osteoclastic bone resorption. mTOR, which is the mammalian target of rapamycin, is a kinase and central regulator of cell growth, proliferation, and survival. By using Rapamycin, we studied whether mTOR pathway is associated with OPG protein production in the mouse bone marrow-derived stromal cell line ST2. Rapamycin markedly increased the level of soluble OPG in ST2 cells. This antibiotic treatment resulted in the suppression of phosphorylation of mTOR. Rapamycin had no effects on the proliferation, differentiation, or apoptosis of the cells. Treatment with bone morphogenetic protein-4, which can induce OPG protein in ST2 cells, also resulted in a decrease in the density of the phospho-mTOR-band, suggesting that the suppression of the phospho-mTOR pathway is necessary for OPG production in ST2 cells. Thus, suitable suppression of mTOR phosphorylation is a necessary requirement for OPG production in bone marrow stromal cells.

Blastomyces dermatitidis septins CDC3, CDC10, and CDC12 impact the morphology of yeast and hyphae, but are not required for the phase transition.

Science.gov (United States)

Marty, Amber J; Gauthier, Gregory M

2013-01-01

Blastomyces dermatitidis, the etiologic agent of blastomycosis, belongs to a group of thermally dimorphic fungi that change between mold (22°C) and yeast (37°C) in response to temperature. The contribution of structural proteins such as septins to this phase transition in these fungi remains poorly understood. Septins are GTPases that serve as a scaffold for proteins involved with cytokinesis, cell polarity, and cell morphology. In this study, we use a GFP sentinel RNA interference system to investigate the impact of CDC3, CDC10, CDC12, and ASPE on the morphology and phase transition of B. dermatitidis. Targeting CDC3, CDC10, and CDC12 by RNA interference resulted in yeast with aberrant morphology at 37°C with defects in cytokinesis. Downshifting the temperature to 22°C promoted the conversion to the mold phase, but did not abrogate the morphologic defects. CDC3, CDC10, and CDC12 knockdown strains grew as mold with curved, thickened hyphae. Knocking down ASPE transcript did not alter morphology of yeast at 37°C or mold at 22°C. Following an increase in temperature from 22°C to 37°C, all septin knockdown strains were able to revert to yeast. In conclusion, CDC3, CDC10, and CDC12 septin- encoding genes are required for proper morphology of yeast and hyphae, but are dispensable for the phase transition.

The Gcn2 Regulator Yih1 Interacts with the Cyclin Dependent Kinase Cdc28 and Promotes Cell Cycle Progression through G2/M in Budding Yeast.

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Richard C Silva

Full Text Available The Saccharomyces cerevisiae protein Yih1, when overexpressed, inhibits the eIF2 alpha kinase Gcn2 by competing for Gcn1 binding. However, deletion of YIH1 has no detectable effect on Gcn2 activity, suggesting that Yih1 is not a general inhibitor of Gcn2, and has no phenotypic defect identified so far. Thus, its physiological role is largely unknown. Here, we show that Yih1 is involved in the cell cycle. Yeast lacking Yih1 displays morphological patterns and DNA content indicative of a delay in the G2/M phases of the cell cycle, and this phenotype is independent of Gcn1 and Gcn2. Accordingly, the levels of phosphorylated eIF2α, which show a cell cycle-dependent fluctuation, are not altered in cells devoid of Yih1. We present several lines of evidence indicating that Yih1 is in a complex with Cdc28. Yih1 pulls down endogenous Cdc28 in vivo and this interaction is enhanced when Cdc28 is active, suggesting that Yih1 modulates the function of Cdc28 in specific stages of the cell cycle. We also demonstrate, by Bimolecular Fluorescence Complementation, that endogenous Yih1 and Cdc28 interact with each other, confirming Yih1 as a bona fide Cdc28 binding partner. Amino acid substitutions within helix H2 of the RWD domain of Yih1 enhance Yih1-Cdc28 association. Overexpression of this mutant, but not of wild type Yih1, leads to a phenotype similar to that of YIH1 deletion, supporting the view that Yih1 is involved through Cdc28 in the regulation of the cell cycle. We further show that IMPACT, the mammalian homologue of Yih1, interacts with CDK1, the mammalian counterpart of Cdc28, indicating that the involvement with the cell cycle is conserved. Together, these data provide insights into the cellular function of Yih1/IMPACT, and provide the basis for future studies on the role of this protein in the cell cycle.

The G2/M DNA damage checkpoint inhibits mitosis through Tyr15 phosphorylation of p34cdc2 in Aspergillus nidulans.

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Ye, X S; Fincher, R R; Tang, A; Osmani, S A

1997-01-02

It is possible to cause G2 arrest in Aspergillus nidulans by inactivating either p34cdc2 or NIMA. We therefore investigated the negative control of these two mitosis-promoting kinases after DNA damage. DNA damage caused rapid Tyr15 phosphorylation of p34cdc2 and transient cell cycle arrest but had little effect on the activity of NIMA. Dividing cells deficient in Tyr15 phosphorylation of p34cdc2 were sensitive to both MMS and UV irradiation and entered lethal premature mitosis with damaged DNA. However, non-dividing quiescent conidiospores of the Tyr15 mutant strain were not sensitive to DNA damage. The UV and MMS sensitivity of cells unable to tyrosine phosphorylate p34cdc2 is therefore caused by defects in DNA damage checkpoint regulation over mitosis. Both the nimA5 and nimT23 temperature-sensitive mutations cause an arrest in G2 at 42 degrees C. Addition of MMS to nimT23 G2-arrested cells caused a marked delay in their entry into mitosis upon downshift to 32 degrees C and this delay was correlated with a long delay in the dephosphorylation and activation of p34cdc2. Addition of MMS to nimA5 G2-arrested cells caused inactivation of the H1 kinase activity of p34cdc2 due to an increase in its Tyr15 phosphorylation level and delayed entry into mitosis upon return to 32 degrees C. However, if Tyr15 phosphorylation of p34cdc2 was prevented then its H1 kinase activity was not inactivated upon MMS addition to nimA5 G2-arrested cells and they rapidly progressed into a lethal mitosis upon release to 32 degrees C. Thus, Tyr15 phosphorylation of p34cdc2 in G2 arrests initiation of mitosis after DNA damage in A. nidulans.

Cdc20 mediates D-box-dependent degradation of Sp100

Energy Technology Data Exchange (ETDEWEB)

Wang, Ran; Li, Ke-min; Zhou, Cai-hong; Xue, Jing-lun [State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai (China); Ji, Chao-neng, E-mail: Chnji@fudan.edu.cn [State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai (China); Chen, Jin-zhong, E-mail: kingbellchen@fudan.edu.cn [State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai (China)

2011-12-02

Highlights: Black-Right-Pointing-Pointer Cdc20 is a co-activator of APC/C complex. Black-Right-Pointing-Pointer Cdc20 recruits Sp100 and mediates its degradation. Black-Right-Pointing-Pointer The D-box of Sp100 is required for Cdc20-mediated degradation. Black-Right-Pointing-Pointer Sp100 expresses consistently at both the mRNA and protein levels in cell cycle. -- Abstract: Cdc20 is a co-activator of the anaphase-promoting complex/cyclosome (APC/C complex), which recruits substrates at particular phases of the cell cycle and mediates their degradation. Sp100 is a PML-NB scaffold protein, which localizes to nuclear particles during interphase and disperses from them during mitosis, participates in viral resistance, transcriptional regulation, and apoptosis. However, its metabolism during the cell cycle has not yet been fully characterized. We found a putative D-box in Sp100 using the Eukaryotic Linear Motif (ELM) predictor database. The putative D-box of Sp100 was verified by mutational analysis. Overexpression of Cdc20 resulted in decreased levels of both endogenous Sp100 protein and overexpressed Sp100 mRNA in HEK 293 cells. Only an overexpressed D-box deletion mutant of Sp100 accumulated in HEK293 cells that also overexpressed Cdc20. Cdc20 knockdown by cdc20 specific siRNA resulted in increased Sp100 protein levels in cells. Furthermore, we discovered that the Cdc20 mediated degradation of Sp100 is diminished by the proteasome inhibitor MG132, which suggests that the ubiquitination pathway is involved in this process. However, unlike the other Cdc20 substrates, which display oscillating protein levels, the level of Sp100 protein remains constant throughout the cell cycle. Additionally, both overexpression and knockdown of endogenous Sp100 had no effect on the cell cycle. Our results suggested that sp100 is a novel substrate of Cdc20 and it is degraded by the ubiquitination pathway. The intact D-box of Sp100 was necessary for this process. These findings expand

C/EBP{delta} targets cyclin D1 for proteasome-mediated degradation via induction of CDC27/APC3 expression.

Science.gov (United States)

Pawar, Snehalata A; Sarkar, Tapasree Roy; Balamurugan, Kuppusamy; Sharan, Shikha; Wang, Jun; Zhang, Youhong; Dowdy, Steven F; Huang, A-Mei; Sterneck, Esta

2010-05-18

The transcription factor CCAAT/enhancer binding protein delta (C/EBPdelta, CEBPD, NFIL-6beta) has tumor suppressor function; however, the molecular mechanism(s) by which C/EBPdelta exerts its effect are largely unknown. Here, we report that C/EBPdelta induces expression of the Cdc27 (APC3) subunit of the anaphase promoting complex/cyclosome (APC/C), which results in the polyubiquitination and degradation of the prooncogenic cell cycle regulator cyclin D1, and also down-regulates cyclin B1, Skp2, and Plk-1. In C/EBPdelta knockout mouse embryo fibroblasts (MEF) Cdc27 levels were reduced, whereas cyclin D1 levels were increased even in the presence of activated GSK-3beta. Silencing of C/EBPdelta, Cdc27, or the APC/C coactivator Cdh1 (FZR1) in MCF-10A breast epithelial cells increased cyclin D1 protein expression. Like C/EBPdelta, and in contrast to cyclin D1, Cdc27 was down-regulated in several breast cancer cell lines, suggesting that Cdc27 itself may be a tumor suppressor. Cyclin D1 is a known substrate of polyubiquitination complex SKP1/CUL1/F-box (SCF), and our studies show that Cdc27 directs cyclin D1 to alternative degradation by APC/C. These findings shed light on the role and regulation of APC/C, which is critical for most cellular processes.

Regulation of bone mass through pineal-derived melatonin-MT2 receptor pathway.

Science.gov (United States)

Sharan, Kunal; Lewis, Kirsty; Furukawa, Takahisa; Yadav, Vijay K

2017-09-01

Tryptophan, an essential amino acid through a series of enzymatic reactions gives rise to various metabolites, viz. serotonin and melatonin, that regulate distinct biological functions. We show here that tryptophan metabolism in the pineal gland favors bone mass accrual through production of melatonin, a pineal-derived neurohormone. Pineal gland-specific deletion of Tph1, the enzyme that catalyzes the first step in the melatonin biosynthesis lead to a decrease in melatonin levels and a low bone mass due to an isolated decrease in bone formation while bone resorption parameters remained unaffected. Skeletal analysis of the mice deficient in MT1 or MT2 melatonin receptors showed a low bone mass in MT2-/- mice while MT1-/- mice had a normal bone mass compared to the WT mice. This low bone mass in the MT2-/- mice was due to an isolated decrease in osteoblast numbers and bone formation. In vitro assays of the osteoblast cultures derived from the MT1-/- and MT2-/- mice showed a cell intrinsic defect in the proliferation, differentiation and mineralization abilities of MT2-/- osteoblasts compared to WT counterparts, and the mutant cells did not respond to melatonin addition. Finally, we demonstrate that daily oral administration of melatonin can increase bone accrual during growth and can cure ovariectomy-induced structural and functional degeneration of bone by specifically increasing bone formation. By identifying pineal-derived melatonin as a regulator of bone mass through MT2 receptors, this study expands the role played by tryptophan derivatives in the regulation of bone mass and underscores its therapeutic relevance in postmenopausal osteoporosis. © 2017 The Authors. Journal of Pineal Research Published by John Wiley & Sons Ltd.

PPM1K Regulates Hematopoiesis and Leukemogenesis through CDC20-Mediated Ubiquitination of MEIS1 and p21

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Xiaoye Liu

2018-05-01

Full Text Available Summary: In addition to acting as building blocks for biosynthesis, amino acids might serve as signaling regulators in various physiological and pathological processes. However, it remains unknown whether amino acid levels affect the activities of hematopoietic stem cells (HSCs. By using a genetically encoded fluorescent sensor of the intracellular levels of branched-chain amino acids (BCAAs, we could monitor the dynamics of BCAA metabolism in HSCs. A mitochondrial-targeted 2C-type Ser/Thr protein phosphatase (PPM1K promotes the catabolism of BCAAs to maintain MEIS1 and p21 levels by decreasing the ubiquitination-mediated degradation controlled by the E3 ubiquitin ligase CDC20. PPM1K deficiency led to a notable decrease in MEIS1/p21 signaling to reduce the glycolysis and quiescence of HSCs, followed by a severe impairment in repopulation activities. Moreover, the deletion of Ppm1k dramatically extended survival in a murine leukemia model. These findings will enhance the current understanding of nutrient signaling in metabolism and function of stem cells. : Liu et al. show that the dynamics of BCAA metabolism in hematopoietic stem cells (HSCs and leukemia-initiating cells (LICs can be monitored by a genetically encoded fluorescent sensor. PPM1K promotes BCAA catabolism and maintains the glycolysis and quiescence of HSCs/LICs through the downregulation of CDC20-mediated ubiquitination of MEIS1 and p21. Keywords: branched-chain amino acids, PPM1K, ubiquitination, CDC20, MEIS1/p21, hematopoietic stem cells, leukemia-initiating cells

42 CFR 55a.107 - What other regulations apply?

Science.gov (United States)

2010-10-01

... FOR BLACK LUNG CLINICS General Provisions § 55a.107 What other regulations apply? Other regulations which apply to the Black Lung Clinics Program include, but are not limited to, the following: 42 CFR...

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

DEFF Research Database (Denmark)

Hein, Jamin B; Nilsson, Jakob

2016-01-01

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

Erk1 positively regulates osteoclast differentiation and bone resorptive activity.

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Yongzheng He

Full Text Available The extracellular signal-regulated kinases (ERK1 and 2 are widely-expressed and they modulate proliferation, survival, differentiation, and protein synthesis in multiple cell lineages. Altered ERK1/2 signaling is found in several genetic diseases with skeletal phenotypes, including Noonan syndrome, Neurofibromatosis type 1, and Cardio-facio-cutaneous syndrome, suggesting that MEK-ERK signals regulate human skeletal development. Here, we examine the consequence of Erk1 and Erk2 disruption in multiple functions of osteoclasts, specialized macrophage/monocyte lineage-derived cells that resorb bone. We demonstrate that Erk1 positively regulates osteoclast development and bone resorptive activity, as genetic disruption of Erk1 reduced osteoclast progenitor cell numbers, compromised pit formation, and diminished M-CSF-mediated adhesion and migration. Moreover, WT mice reconstituted long-term with Erk1(-/- bone marrow mononuclear cells (BMMNCs demonstrated increased bone mineral density as compared to recipients transplanted with WT and Erk2(-/- BMMNCs, implicating marrow autonomous, Erk1-dependent osteoclast function. These data demonstrate Erk1 plays an important role in osteoclast functions while providing rationale for the development of Erk1-specific inhibitors for experimental investigation and/or therapeutic modulation of aberrant osteoclast function.

Fission Yeast Apc15 Stabilizes MCC-Cdc20-APC/C Complexes, Ensuring Efficient Cdc20 Ubiquitination and Checkpoint Arrest.

Science.gov (United States)

May, Karen M; Paldi, Flora; Hardwick, Kevin G

2017-04-24

During mitosis, cells must segregate the replicated copies of their genome to their daughter cells with extremely high fidelity. Segregation errors lead to an abnormal chromosome number (aneuploidy), which typically results in disease or cell death [1]. Chromosome segregation and anaphase onset are initiated through the action of the multi-subunit E3 ubiquitin ligase known as the anaphase-promoting complex or cyclosome (APC/C [2]). The APC/C is inhibited by the spindle checkpoint in the presence of kinetochore attachment defects [3, 4]. Here we demonstrate that two non-essential APC/C subunits (Apc14 and Apc15) regulate association of spindle checkpoint proteins, in the form of the mitotic checkpoint complex (MCC), with the APC/C. apc14Δ mutants display increased MCC association with the APC/C and are unable to silence the checkpoint efficiently. Conversely, apc15Δ mutants display reduced association between the MCC and APC/C, are defective in poly-ubiquitination of Cdc20, and are checkpoint defective. In vitro reconstitution studies have shown that human MCC-APC/C can contain two molecules of Cdc20 [5-7]. Using a yeast strain expressing two Cdc20 genes with different epitope tags, we show by co-immunoprecipitation that this is true in vivo. MCC binding to the second molecule of Cdc20 is mediated via the C-terminal KEN box in Mad3. Somewhat surprisingly, complexes containing both molecules of Cdc20 accumulate in apc15Δ cells, and the implications of this observation are discussed. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Conserved CDC20 cell cycle functions are carried out by two of the five isoforms in Arabidopsis thaliana.

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Zoltán Kevei

Full Text Available The CDC20 and Cdh1/CCS52 proteins are substrate determinants and activators of the Anaphase Promoting Complex/Cyclosome (APC/C E3 ubiquitin ligase and as such they control the mitotic cell cycle by targeting the degradation of various cell cycle regulators. In yeasts and animals the main CDC20 function is the destruction of securin and mitotic cyclins. Plants have multiple CDC20 gene copies whose functions have not been explored yet. In Arabidopsis thaliana there are five CDC20 isoforms and here we aimed at defining their contribution to cell cycle regulation, substrate selectivity and plant development.Studying the gene structure and phylogeny of plant CDC20s, the expression of the five AtCDC20 gene copies and their interactions with the APC/C subunit APC10, the CCS52 proteins, components of the mitotic checkpoint complex (MCC and mitotic cyclin substrates, conserved CDC20 functions could be assigned for AtCDC20.1 and AtCDC20.2. The other three intron-less genes were silent and specific for Arabidopsis. We show that AtCDC20.1 and AtCDC20.2 are components of the MCC and interact with mitotic cyclins with unexpected specificity. AtCDC20.1 and AtCDC20.2 are expressed in meristems, organ primordia and AtCDC20.1 also in pollen grains and developing seeds. Knocking down both genes simultaneously by RNAi resulted in severe delay in plant development and male sterility. In these lines, the meristem size was reduced while the cell size and ploidy levels were unaffected indicating that the lower cell number and likely slowdown of the cell cycle are the cause of reduced plant growth.The intron-containing CDC20 gene copies provide conserved and redundant functions for cell cycle progression in plants and are required for meristem maintenance, plant growth and male gametophyte formation. The Arabidopsis-specific intron-less genes are possibly "retrogenes" and have hitherto undefined functions or are pseudogenes.

Parkin Regulates Mitosis and Genomic Stability through Cdc20/Cdh1

NARCIS (Netherlands)

Lee, S.B.; Kim, J.J.; Nam, H.J.; Gao, B.; Yin, P.; Qin, B.; Yi, S.Y.; Ham, H.; Evans, D.; Kim, S.H.; Zhang, J.; Deng, M.; Liu, T.; Zhang, H.; Billadeau, D.D.; Wang, L.; Giaime, E.; Shen, J.; Pang, Y.P.; Jen, J.; Deursen, J.M.A. van; Lou, Z.

2015-01-01

Mutations in the E3 ubiquitin ligase Parkin have been linked to familial Parkinson's disease. Parkin has also been implicated in mitosis through mechanisms that are unclear. Here we show that Parkin interacts with anaphase promoting complex/cyclosome (APC/C) coactivators Cdc20 and Cdh1 to mediate

Archaeal orthologs of Cdc45 and GINS form a stable complex that stimulates the helicase activity of MCM.

Science.gov (United States)

Xu, Yuli; Gristwood, Tamzin; Hodgson, Ben; Trinidad, Jonathan C; Albers, Sonja-Verena; Bell, Stephen D

2016-11-22

The regulated recruitment of Cdc45 and GINS is key to activating the eukaryotic MCM(2-7) replicative helicase. We demonstrate that the homohexameric archaeal MCM helicase associates with orthologs of GINS and Cdc45 in vivo and in vitro. Association of these factors with MCM robustly stimulates the MCM helicase activity. In contrast to the situation in eukaryotes, archaeal Cdc45 and GINS form an extremely stable complex before binding MCM. Further, the archaeal GINS•Cdc45 complex contains two copies of Cdc45. Our analyses give insight into the function and evolution of the conserved core of the archaeal/eukaryotic replisome.

CDC Disease Detective Camp

Centers for Disease Control (CDC) Podcasts

2010-08-02

The CDC Disease Detective Camp gives rising high school juniors and seniors exposure to key aspects of the CDC, including basic epidemiology, infectious and chronic disease tracking, public health law, and outbreak investigations. The camp also helps students explore careers in public health.  Created: 8/2/2010 by Centers for Disease Control and Prevention (CDC).   Date Released: 8/2/2010.

DLK1 is a novel regulator of bone mass that mediates estrogen deficiency-induced bone loss in mice

DEFF Research Database (Denmark)

Abdallah, Basem M; Ditzel, Nicholas; Mahmood, Amer

2011-01-01

. In a number of in vitro culture systems, Dlk1 stimulated osteoclastogenesis indirectly through osteoblast-dependent increased production of proinflammatory bone-resorbing cytokines (eg, Il7, Tnfa, and Ccl3). We found that ovariectomy (ovx)-induced bone loss was associated with increased production of Dlk1...... in the bone marrow by activated T cells. Interestingly, Dlk1(-/-) mice were significantly protected from ovx-induced bone loss compared with wild-type mice. Thus we identified Dlk1 as a novel regulator of bone mass that functions to inhibit bone formation and to stimulate bone resorption. Increasing DLK1...... production by T cells under estrogen deficiency suggests its possible use as a therapeutic target for preventing postmenopausal bone loss....

Digital expression profiling identifies RUNX2, CDC5L, MDM2, RECQL4, and CDK4 as potential predictive biomarkers for neo-adjuvant chemotherapy response in paediatric osteosarcoma.

Directory of Open Access Journals (Sweden)

Jeffrey W Martin

Full Text Available Osteosarcoma is the most common malignancy of bone, and occurs most frequently in children and adolescents. Currently, the most reliable technique for determining a patients' prognosis is measurement of histopathologic tumor necrosis following pre-operative neo-adjuvant chemotherapy. Unfavourable prognosis is indicated by less than 90% estimated necrosis of the tumor. Neither genetic testing nor molecular biomarkers for diagnosis and prognosis have been described for osteosarcomas. We used the novel nanoString mRNA digital expression analysis system to analyse gene expression in 32 patients with sporadic paediatric osteosarcoma. This system used specific molecular barcodes to quantify expression of a set of 17 genes associated with osteosarcoma tumorigenesis. Five genes, from this panel, which encoded the bone differentiation regulator RUNX2, the cell cycle regulator CDC5L, the TP53 transcriptional inactivator MDM2, the DNA helicase RECQL4, and the cyclin-dependent kinase gene CDK4, were differentially expressed in tumors that responded poorly to neo-adjuvant chemotherapy. Analysis of the signalling relationships of these genes, as well as other expression markers of osteosarcoma, indicated that gene networks linked to RB1, TP53, PI3K, PTEN/Akt, myc and RECQL4 are associated with osteosarcoma. The discovery of these networks provides a basis for further experimental studies of role of the five genes (RUNX2, CDC5L, MDM2, RECQL4, and CDK4 in differential response to chemotherapy.

Regulation of bone blood flow in humans

DEFF Research Database (Denmark)

Heinonen, Ilkka; Boushel, Robert; Hellsten, Ylva

2018-01-01

of cyclooxygenase (COX) enzyme, thus prostaglandin (PG) synthesis on femoral bone marrow blood flow by positron emission tomography in healthy young men at rest and during one leg dynamic exercise. In an additional group of healthy men, the role of adenosine (ADO) in the regulation of BBF during exercise......The mechanisms that regulate bone blood flow (BBF) in humans are largely unknown. Animal studies suggest that nitric oxide (NO) could be involved and in the present study we investigated the effects of inhibition of nitric oxide synthase (NOS) alone and in combination with inhibition.......036), but did not affect BBF significantly during exercise (5.5±1.4 ml/100g/min, p=0.25). On the other hand, while combined NOS and COX inhibition did not cause any further reduction of blood flow at rest (0.6±0.2 ml/100g/min), the combined blockade reduced BBF during exercise by ~21%, to 5.0±1.8 ml/100g/min (p...

A novel functional polymorphism in the Cdc6 promoter is associated with the risk for hepatocellular carcinoma

International Nuclear Information System (INIS)

Xiong Xingdong; Fang Jianhong; Qiu Fuen; Zhao Jing; Cheng Jiasen; Yuan Yunfei; Li Shengping; Zhuang Shimei

2008-01-01

Cdc6 is essential for DNA replication and its deregulation is involved in carcinogenesis. To date, the biological significance of the polymorphism in Cdc6 promoter is still unknown. In this study, we aimed to evaluate the influence of the Cdc6 -515A>G polymorphism (rs4134994) on the individual's susceptibility to cancer and on the function of Cdc6. The Cdc6 -515A>G polymorphism was genotyped in 387 hepatocellular carcinoma (HCC) and 389 age- and sex-matched healthy subjects. The association between the genotypes and the risk for HCC was then estimated by unconditional logistic regression analysis with adjustment for age, sex and HBV status. Compared with the AA homozygotes, the homozygous GG genotype (adjusted OR = 0.36, 95% confidence interval (CI) = 0.18-0.72, P = 0.004) or the combined AG/GG genotypes (adjusted OR = 0.56, 95% CI = 0.36-0.86, P = 0.008) were statistically significantly associated with the reduced risk for HCC. Moreover, the analysis using luciferase reporter system showed that the G-allelic Cdc6 promoter displayed a decreased transcriptional activity compared with the A-allelic one. These results indicate that the individuals with G allele may have reduced Cdc6 expression and are therefore in reduced risk for HCC. Further investigation using electrophoretic mobility shift assay (EMSA) revealed that the G allele had a stronger binding strength to nuclear protein(s) which might function as negative regulator(s) for Cdc6 transcription. Our findings suggest that the -515A>G polymorphism may affect the Cdc6 promoter binding affinity with nuclear protein(s) and in turn the Cdc6 expression, which consequently modulates the individual's susceptibility to HCC

The Proprioceptive System Regulates Morphologic Restoration of Fractured Bones

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Ronen Blecher

2017-08-01

Full Text Available Successful fracture repair requires restoration of bone morphology and mechanical integrity. Recent evidence shows that fractured bones of neonatal mice undergo spontaneous realignment, dubbed “natural reduction.” Here, we show that natural reduction is regulated by the proprioceptive system and improves with age. Comparison among mice of different ages revealed, surprisingly, that 3-month-old mice exhibited more rapid and effective natural reduction than newborns. Fractured bones of null mutants for transcription factor Runx3, lacking functional proprioceptors, failed to realign properly. Blocking Runx3 expression in the peripheral nervous system, but not in limb mesenchyme, recapitulated the null phenotype, as did inactivation of muscles flanking the fracture site. Egr3 knockout mice, which lack muscle spindles but not Golgi tendon organs, displayed a less severe phenotype, suggesting that both receptor types, as well as muscle contraction, are required for this regulatory mechanism. These findings uncover a physiological role for proprioception in non-autonomous regulation of skeletal integrity.

Osteocyte regulation of bone and blood.

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Divieti Pajevic, Paola; Krause, Daniela S

2018-02-16

This past decade has witnessed a renewed interest in the function and biology of matrix-embedded osteocytes and these cells have emerged as master regulators of bone homeostasis. They secrete two very powerful proteins, sclerostin, a Wnt-inhibitor, that suppresses bone formation, and receptor-activator of NF-kB ligand (RANKL), a cytokine required for osteoclastogenesis. Neutralizing antibodies against these proteins are currently used for the treatment of osteoporosis. Recent studies however, ascribed yet another function to osteocytes: the control of hematopoiesis and the HSPC niche, directly and through secreted factors. In the absence of osteocytes there is an increase in HSC mobilization and abnormal lymphopoiesis whereas in the absence of G s α signaling in these cells there is an increase of myeloid cells. How exactly osteocytes control hematopoiesis or the HSPC niche is still not completely understood. In this review we summarize the actions of osteocytes in bone and then analyze the effects of these cells on hematopoiesis. Future directions and gaps in current knowledge are further discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

Genetic Regulation of Bone and Cells by Electromagnetic Stimulation Fields and Uses Thereof

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Goodwin, Thomas J. (Inventor); Shackelford, Linda C. (Inventor)

2018-01-01

The present invention provides methods to modify the genetic regulation of mammalian tissue, bone, cells or any combination thereof by preferential activation, up-regulation and/or down-regulation. The method comprises steps of tuning the predetermined profiles of one or more time-varying stimulation fields by manipulating the B-Field magnitude, rising slew rate, rise time, falling slew rate, fall time, frequency, wavelength, and duty cycle, and exposing mammalian cells or tissues to one or more tuned time-varying stimulation fields with predetermined profiles. Examples of mammalian cells or tissues are chondrocytes, osteoblasts, osteocytes, osteoclasts, nucleus pulposus, associated tissue, or any combination. The resulted modification on gene regulation of these cells, tissues or bones may promote the retention, repair of and reduction of compromised mammalian cartilage, bone, and associated tissue.

Cdc25A promotes cell survival by stimulating NF-κB activity through IκB-α phosphorylation and destabilization

International Nuclear Information System (INIS)

Hong, Hey-Young; Choi, Jiyeon; Cho, Young-Wook; Kim, Byung-Chul

2012-01-01

Highlights: ► We examine the antiapoptotic mechanisms of Cdc25A. ► Smad7 decreases the phosphorylation of IκB-alpha at Ser-32. ► Smad7 positively regulates NF-κB activity through IκB-alpha ubiquitination. -- Abstract: Cell division cycle 25A (Cdc25A), a dual specificity protein phosphatase, exhibits anti-apoptotic activity, but the underlying molecular mechanisms are poorly characterized. Here we report that Cdc25A inhibits cisplatin-induced apoptotic cell death by stimulating nuclear factor-kappa B (NF-κB) activity. In HEK-293 cells, Cdc25A decreased protein level of inhibitor subunit kappa B alpha (Iκ-Bα) in association with increased serine 32-phosphorylation, followed by stimulation of transcriptional activity of NF-κB. Inhibition of NF-κB activity by chemical inhibitor or overexpression of Iκ-Bα in Cdc25A-elevated cancer cells resistant to cisplatin improved their sensitivity to cisplatin-induced apoptosis. Our data show for the first time that Cdc25A has an important physiological role in NF-κB activity regulation and it may be an important survival mechanism of cancer cells.

Ganodermanontriol (GDNT) exerts its effect on growth and invasiveness of breast cancer cells through the down-regulation of CDC20 and uPA

International Nuclear Information System (INIS)

Jiang, Jiahua; Jedinak, Andrej; Sliva, Daniel

2011-01-01

Highlights: ► Ganodermanontriol (GDNT), a Ganoderma mushroom alcohol, inhibits growth of breast cancer cells. ► CDC20 is over-expressed in tumors but not in the tumor surrounding tissue in breast cancer patients. ► GDNT inhibits expression of CDC20 in breast cancer cells. ► GDNT inhibits cell adhesion, cell migration and cell invasion of breast cancer cells. ► GDNT inhibits secretion of uPA and down-regulates expression of uPAR in breast cancer cells. -- Abstract: Ganoderma lucidum is a medicinal mushroom that has been recognized by Traditional Chinese Medicine (TCM). Although some of the direct anticancer activities are attributed to the presence of triterpenes—ganoderic and lucidenic acids—the activity of other compounds remains elusive. Here we show that ganodermanontriol (GDNT), a Ganoderma alcohol, specifically suppressed proliferation (anchorage-dependent growth) and colony formation (anchorage-independent growth) of highly invasive human breast cancer cells MDA-MB-231. GDNT suppressed expression of the cell cycle regulatory protein CDC20, which is over-expressed in precancerous and breast cancer cells compared to normal mammary epithelial cells. Moreover, we found that CDC20 is over-expressed in tumors when compared to the tissue surrounding the tumor in specimens from breast cancer patients. GDNT also inhibited invasive behavior (cell adhesion, cell migration, and cell invasion) through the suppression of secretion of urokinase-plasminogen activator (uPA) and inhibited expression of uPA receptor. In conclusion, mushroom GDNT is a natural agent that has potential as a therapy for invasive breast cancers.

Ganodermanontriol (GDNT) exerts its effect on growth and invasiveness of breast cancer cells through the down-regulation of CDC20 and uPA

Energy Technology Data Exchange (ETDEWEB)

Jiang, Jiahua; Jedinak, Andrej [Cancer Research Laboratory, Methodist Research Institute, Indiana University Health, Indianapolis, IN (United States); Sliva, Daniel, E-mail: dsliva@iuhealth.org [Cancer Research Laboratory, Methodist Research Institute, Indiana University Health, Indianapolis, IN (United States); Department of Medicine, School of Medicine, Indiana University, Indianapolis, IN (United States); Indiana University Simon Cancer Center, School of Medicine, Indiana University, Indianapolis, IN (United States)

2011-11-18

Highlights: Black-Right-Pointing-Pointer Ganodermanontriol (GDNT), a Ganoderma mushroom alcohol, inhibits growth of breast cancer cells. Black-Right-Pointing-Pointer CDC20 is over-expressed in tumors but not in the tumor surrounding tissue in breast cancer patients. Black-Right-Pointing-Pointer GDNT inhibits expression of CDC20 in breast cancer cells. Black-Right-Pointing-Pointer GDNT inhibits cell adhesion, cell migration and cell invasion of breast cancer cells. Black-Right-Pointing-Pointer GDNT inhibits secretion of uPA and down-regulates expression of uPAR in breast cancer cells. -- Abstract: Ganoderma lucidum is a medicinal mushroom that has been recognized by Traditional Chinese Medicine (TCM). Although some of the direct anticancer activities are attributed to the presence of triterpenes-ganoderic and lucidenic acids-the activity of other compounds remains elusive. Here we show that ganodermanontriol (GDNT), a Ganoderma alcohol, specifically suppressed proliferation (anchorage-dependent growth) and colony formation (anchorage-independent growth) of highly invasive human breast cancer cells MDA-MB-231. GDNT suppressed expression of the cell cycle regulatory protein CDC20, which is over-expressed in precancerous and breast cancer cells compared to normal mammary epithelial cells. Moreover, we found that CDC20 is over-expressed in tumors when compared to the tissue surrounding the tumor in specimens from breast cancer patients. GDNT also inhibited invasive behavior (cell adhesion, cell migration, and cell invasion) through the suppression of secretion of urokinase-plasminogen activator (uPA) and inhibited expression of uPA receptor. In conclusion, mushroom GDNT is a natural agent that has potential as a therapy for invasive breast cancers.

Chlamydia - CDC Fact Sheet

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... Archive STDs Home Page Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ( ... sheet Pelvic Inflammatory Disease (PID) – CDC fact sheet Gonorrhea – CDC fact sheet STDs Home Page Bacterial Vaginosis ( ...

Development, regulation, metabolism and function of bone marrow adipose tissues.

Science.gov (United States)

Li, Ziru; Hardij, Julie; Bagchi, Devika P; Scheller, Erica L; MacDougald, Ormond A

2018-05-01

Most adipocytes exist in discrete depots throughout the body, notably in well-defined white and brown adipose tissues. However, adipocytes also reside within specialized niches, of which the most abundant is within bone marrow. Whereas bone marrow adipose tissue (BMAT) shares many properties in common with white adipose tissue, the distinct functions of BMAT are reflected by its development, regulation, protein secretion, and lipid composition. In addition to its potential role as a local energy reservoir, BMAT also secretes proteins, including adiponectin, RANK ligand, dipeptidyl peptidase-4, and stem cell factor, which contribute to local marrow niche functions and which may also influence global metabolism. The characteristics of BMAT are also distinct depending on whether marrow adipocytes are contained within yellow or red marrow, as these can be thought of as 'constitutive' and 'regulated', respectively. The rBMAT for instance can be expanded or depleted by myriad factors, including age, nutrition, endocrine status and pharmaceuticals. Herein we review the site specificity, age-related development, regulation and metabolic characteristics of BMAT under various metabolic conditions, including the functional interactions with bone and hematopoietic cells. Copyright © 2018 Elsevier Inc. All rights reserved.

Cadmium, follicle-stimulating hormone, and effects on bone in women age 42-60 years, NHANES III

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Gallagher, Carolyn M., E-mail: 2crgallagher@optonline.net [PhD Program in Population Health and Clinical Outcomes Research, Stony Brook University, Health Sciences Center L3-R071, Stony Brook, New York 11794-8338 (United States); Department of Preventive Medicine, Stony Brook University Medical Center, Stony Brook, New York (United States); Moonga, Baljit S. [Stony Brook University School of Dental Medicine, New York (United States); Kovach, John S. [Department of Preventive Medicine, Stony Brook University Medical Center, Stony Brook, New York (United States)

2010-01-15

Background: Increased body burden of environmental cadmium has been associated with greater risk of decreased bone mineral density (BMD) and osteoporosis in middle-aged and older women, and an inverse relationship has been reported between follicle-stimulating hormone (FSH) and BMD in middle-aged women; however, the relationships between cadmium and FSH are uncertain, and the associations of each with bone loss have not been analyzed in a single population. Objectives: The objective of this study was to evaluate the associations between creatinine-adjusted urinary cadmium (UCd) and FSH levels, and the associations between UCd and FSH with BMD and osteoporosis, in postmenopausal and perimenopausal women aged 42-60 years. Methods: Data were obtained from the Third National Health Examination and Nutrition Survey, 1988-1994 (NHANES III). Outcomes evaluated were serum FSH levels, femoral bone mineral density measured by dual energy X-ray absorptiometry, and osteoporosis indicated by femoral BMD cutoffs based on the international standard. Urinary cadmium levels were analyzed for association with these outcomes, and FSH levels analyzed for association with bone effects, using multiple regression. Subset analysis was conducted by a dichotomous measure of body mass index (BMI) to proxy higher and lower adipose-synthesized estrogen effects. Results: UCd was associated with increased serum FSH in perimenopausal women with high BMI (n=642; {beta}=0.45; p{<=}0.05; R{sup 2}=0.35) and low BMI (n=408; {beta}=0.61; p{<=}0.01; R{sup 2}=0.34). Among perimenopausal women with high BMI, BMD was inversely related to UCd ({beta}=-0.04; p{<=}0.05) and FSH ({beta}=-0.03; p{<=}0.05). In postmenopausal women with low BMI, an incremental increase in FSH was associated with 2.78 greater odds for osteoporosis (109 with and 706 without) (OR=2.78; 95% CI=1.43, 5.42; p{<=}0.01). Conclusion: Long-term cadmium exposure at environmental levels is associated with increased serum FSH, and both FSH

Cdc20 control of cell fate during prolonged mitotic arrest

DEFF Research Database (Denmark)

Nilsson, Jakob

2011-01-01

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

BONE METABOLISM AND ITS REGULATION IN PATIENTS WITH ANKYLOSING SPONDYLITIS

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O. V. Bugrova

2016-01-01

Full Text Available Osteoporosis in ankylosing spondylitis (AS may exacerbate pain and functional disorders and increases the risk of fractures. The mechanisms  of its development in AS have not been adequately studied.Objective: to study bone mineral density (BMD  and its regulation in patients with AS.Subjects and methods. 70 patients (mean age, 43.2±9.2 years with a documented diagnosis of AS (mean disease duration, 17.1±7.8 years and a control group of 30 healthy individuals were examined. All the patients underwent estimation of BMD and the serum concentrations of osteocalcin,  CrossLaps, and key regulators of osteoclastogenesis, such as osteoprotegerin (OPG  and a receptor activator of nuclear factor kappa-B ligand (RANKL by an enzyme immunoassay. Results and discussion. In patients with AS, bone metabolism was characterized  by a decrease in bone formation and by some increase in bone tissue degradation especially in high AS activity. These patients showed the elevated levels of the major blocker of osteoclastogenesis OPG and the OPG/RANKL ratio, which can cause the process of ossification characteristic  of AS.

CDC Disease Detective Camp

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The CDC Disease Detective Camp gives rising high school juniors and seniors exposure to key aspects of the CDC, including basic epidemiology, infectious and chronic disease tracking, public health law, and outbreak investigations. The camp also helps students explore careers in public health.

Bone mass regulation of leptin and postmenopausal osteoporosis with obesity.

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Legiran, Siswo; Brandi, Maria Luisa

2012-09-01

Leptin has been known to play a role in weight regulation through food intake and energy expenditure. Leptin also has an important role in bone metabolism. The role of leptin is determined by leptin receptors, either central or peripheral to the bones. We discuss the role of leptin on bone and molecular genetics of osteoporosis in postmenopausal obese women. The role of leptin in bone preserves bone mineral density (BMD) through increased OPG levels leading to bind RANKL, resulting in reducing osteoclast activity. The estrogen role on bone is also mediated by RANKL and OPG. In postmenopausal women who have estrogen deficiency, it increases the rate of RANKL, which increases osteoclastogenesis. Obese individuals who have a high level of leptin will be effected by bone protection. There are similarities in the mechanism between estrogen and leptin in influencing the process of bone remodeling. It may be considered that the role of estrogen can be replaced by leptin. Molecular genetic aspects that play a role in bone remodeling, such as leptin, leptin receptors, cytokines (e.g. RANK, RANKL, and OPG), require further study to be useful, especially regarding osteoporosis therapy based on genetic analysis.

Sequencing Analysis of Mutant Allele $cdc$28-$srm$ of Protein Kinase CDC28 and Molecular Dynamics Study of Glycine-Rich Loop in Wild-Type and Mutant Allele G16S of CDK2 as Model

CERN Document Server

Koltovaya, N A; Kholmurodov, Kh T; Kretov, D A

2005-01-01

The central role that cyclin-dependent kinases play in the timing of cell division and the high incidence of genetic alteration of CDKs or deregulation of CDK inhibitors in a number of cancers make CDC28 of the yeast \\textit{Saccharomyces cerevisiae }very attractive model for studies of mechanisms of CDK regulation. Earlier it was found that certain gene mutations including \\textit{cdc28-srm} affect cell cycle progression, maintenance of different genetic structures and increase cell sensitivity to ionizing radiation. A~\\textit{cdc28-srm} mutation is not temperature-sensitive mutation and differs from the known \\textit{cdc28-ts }mutations because it has the evident phenotypic manifestations at 30 $^{\\circ}$C. Sequencing analysis of \\textit{cdc28-srm} revealed a single nucleotide substitution G20S. This is a third glycine in a conserved sequence GxGxxG in the G-rich loop positioned opposite the activation T-loop. Despite its demonstrated importance, the role of the G-loop has remained unclear. The crystal stru...

Drug design with Cdc7 kinase: a potential novel cancer therapy target

Directory of Open Access Journals (Sweden)

Masaaki Sawa

2008-11-01

Full Text Available Masaaki Sawa1, Hisao Masai21Carna Biosciences, Inc., Kobe, Japan; 2Genome Dynamics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, JapanAbstract: Identification of novel molecular targets is critical in development of new and efficient cancer therapies. Kinases are one of the most common drug targets with a potential for cancer therapy. Cell cycle progression is regulated by a number of kinases, some of which are being developed to treat cancer. Cdc7 is a serine-threonine kinase originally discovered in budding yeast, which has been shown to be necessary to initiate the S phase. Inhibition of Cdc7 in cancer cells retards the progression of the S phase, accumulates DNA damage, and induces p53-independent cell death, but the same treatment in normal cells does not significantly affect viability. Low-molecular-weight compounds that inhibit Cdc7 kinase with an IC50 of less than 10 nM have been identified, and shown to be effective in the inhibition of tumor growth in animal models. Thus Cdc7 kinase can be recognized as a novel molecular target for cancer therapy.Keywords: Cdc7 kinase, cell cycle, replication fork, genome stability, DNA damages, ATP-binding pocket, kinase inhibitor

Systematic Investigation of Expression of G2/M Transition Genes Reveals CDC25 Alteration in Nonfunctioning Pituitary Adenomas.

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Butz, Henriett; Németh, Kinga; Czenke, Dóra; Likó, István; Czirják, Sándor; Zivkovic, Vladimir; Baghy, Kornélia; Korbonits, Márta; Kovalszky, Ilona; Igaz, Péter; Rácz, Károly; Patócs, Attila

2017-07-01

Dysregulation of G1/S checkpoint of cell cycle has been reported in pituitary adenomas. In addition, our previous finding showing that deregulation of Wee1 kinase by microRNAs together with other studies demonstrating alteration of G2/M transition in nonfunctioning pituitary adenomas (NFPAs) suggest that G2/M transition may also be important in pituitary tumorigenesis. To systematically study the expression of members of the G2/M transition in NFPAs and to investigate potential microRNA (miRNA) involvement. Totally, 80 NFPA and 14 normal pituitary (NP) tissues were examined. Expression of 46 genes encoding members of the G2/M transition was profiled on 34 NFPA and 10 NP samples on TaqMan Low Density Array. Expression of CDC25A and two miRNAs targeting CDC25A were validated by individual quantitative real time PCR using TaqMan assays. Protein expression of CDC25A, CDC25C, CDK1 and phospho-CDK1 (Tyr-15) was investigated on tissue microarray and immunohistochemistry. Several genes' expression alteration were observed in NFPA compared to normal tissues by transcription profiling. On protein level CDC25A and both the total and the phospho-CDK1 were overexpressed in adenoma tissues. CDC25A correlated with nuclear localized CDK1 (nCDK1) and with tumor size and nCDK1 with Ki-67 index. Comparing primary vs. recurrent adenomas we found that Ki-67 proliferation index was higher and phospho-CDK1 (inactive form) was downregulated in recurrent tumors compared to primary adenomas. Investigating the potential causes behind CDC25A overexpression we could not find copy number variation at the coding region nor expression alteration of CDC25A regulating transcription factors however CDC25A targeting miRNAs were downregulated in NFPA and negatively correlated with CDC25A expression. Our results suggest that among alterations of G2/M transition of the cell cycle, overexpression of the CDK1 and CDC25A may have a role in the pathogenesis of the NFPA and that CDC25A is potentially

The protection of acetylcholinesterase inhibitor on β-amyloid-induced injury of neurite outgrowth via regulating axon guidance related genes expression in neuronal cells

Science.gov (United States)

Shen, Jiao-Ning; Wang, Deng-Shun; Wang, Rui

2012-01-01

Cognitive deficits in AD correlate with progressive synaptic dysfunction and loss. The Rho family of small GTPases, including Rho, Rac, and Cdc42, has a central role in cellular motility and cytokinesis. Acetylcholinesterase inhibitor has been found to protect cells against a broad range of reagents-induced injuries. Present studies examined if the effect of HupA on neurite outgrowth in Aβ-treated neuronal cells executed via regulating Rho-GTPase mediated axon guidance relative gene expression. Affymetrix cDNA microarray assay followed by real-time RT-PCR and Western Blotting analysis were used to elucidate and analyze the signaling pathway involved in Aβ and HupA’s effects. The effects of Aβ and HupA on the neurite outgrowth were further confirmed via immunofluorescence staining. Aβ up-regulated the mRNA expressions of NFAT5, LIMK1, EPHA1, NTN4 and RAC2 markedly in SH-SY5Y cells. Co-incubation of Aβ and HupA reversed or decreased the changes of NFAT5, NTN4, RAC2, CDC42 and SEMA4F. HupA treated alone increased NFAT5, LIMK1, NTN4 significantly. Following qRT-PCR validation showed that the correlation of the gene expression ratio between microarray and qRT-PCR is significant. Western blot result showed that the change of CDC42 protein is consistent with the mRNA level while RAC2 is not. The morphological results confirmed that HupA improved, or partly reversed, the Aβ-induced damage of neurite outgrowth. The protective effect of HupA from Aβ induced morphological injury might be correlative to, at least partially, regulating the network of neurite outgrowth related genes. PMID:23119107

Regulation of glycogenesis in bone marrow of irradiated body

Energy Technology Data Exchange (ETDEWEB)

Barkalaya, A I

1976-02-01

In connection with a stimulating effect of insulin on postradiation restoration of medullary hemopoiesis the authors studied the influence of insulin on glycogenesis of bone marrow in comparison with glycogenesis of the liver under the conditions of irradiation. As a result the experiment made on white mice the authors established that the level of glycogen in both tissues on the first two days after irradiation (750 R) increased. Later, the decrease of glycogen concentration was observed and its exhaustion was more marked. Insulin protected bone marrow and the liver from exhaustion of glycogen reserves and ensured a higher level of glycogen in the liver. It is supposed that the regulation mechanisms by means of insulin of glycogenesis in the bone marrow and the liver are mainly of the same type. The influence of insulin on carbohydrate metabolism in the bone marrow is likely to be of significance for postradiation hemopoiesis.

The protection of acetylcholinesterase inhibitor on β-amyloid-induced the injury of neurite outgrowth via regulating axon guidance related genes expression in neuronal cells.

Science.gov (United States)

Shen, Jiao-Ning; Wang, Deng-Shun; Wang, Rui

2012-01-01

Cognitive deficits in AD correlate with progressive synaptic dysfunction and loss. The Rho family of small GTPases, including Rho, Rac, and Cdc42, has a central role in cellular motility and cytokinesis. Acetylcholinesterase inhibitor has been found to protect cells against a broad range of reagents-induced injuries. Present studies examined if the effect of HupA on neurite outgrowth in Aβ-treated neuronal cells executed via regulating Rho-GTPase mediated axon guidance relative gene expression. Affymetrix cDNA microarray assay followed by real-time RT-PCR and Western Blotting analysis were used to elucidate and analyze the signaling pathway involved in Aβ and HupA's effects. The effects of Aβ and HupA on the neurite outgrowth were further confirmed via immunofluorescence staining. Aβ up-regulated the mRNA expressions of NFAT5, LIMK1, EPHA1, NTN4 and RAC2 markedly in SH-SY5Y cells. Co-incubation of Aβ and HupA reversed or decreased the changes of NFAT5, NTN4, RAC2, CDC42 and SEMA4F. HupA treated alone increased NFAT5, LIMK1, NTN4 significantly. Following qRT-PCR validation showed that the correlation of the gene expression ratio between microarray and qRT-PCR is significant. Western blot result showed that the change of CDC42 protein is consistent with the mRNA level while RAC2 is not. The morphological results confirmed that HupA improved, or partly reversed, the Aβ-induced damage of neurite outgrowth. The protective effect of HupA from Aβ induced morphological injury might be correlative to, at least partially, regulating the network of neurite outgrowth related genes.

Cdc25A promotes cell survival by stimulating NF-{kappa}B activity through I{kappa}B-{alpha} phosphorylation and destabilization

Energy Technology Data Exchange (ETDEWEB)

Hong, Hey-Young; Choi, Jiyeon [Department of Biochemistry, College of Natural Sciences, Kangwon National University, 192-1 Hyoja-2-dong, Chuncheon 200-701 (Korea, Republic of); Cho, Young-Wook [Korea Basic Science Institute, Chuncheon Center, Gangwondaehak-gil 1, Chuncheon 200-701 (Korea, Republic of); Kim, Byung-Chul, E-mail: bckim@kangwon.ac.kr [Department of Biochemistry, College of Natural Sciences, Kangwon National University, 192-1 Hyoja-2-dong, Chuncheon 200-701 (Korea, Republic of)

2012-04-06

Highlights: Black-Right-Pointing-Pointer We examine the antiapoptotic mechanisms of Cdc25A. Black-Right-Pointing-Pointer Smad7 decreases the phosphorylation of I{kappa}B-alpha at Ser-32. Black-Right-Pointing-Pointer Smad7 positively regulates NF-{kappa}B activity through I{kappa}B-alpha ubiquitination. -- Abstract: Cell division cycle 25A (Cdc25A), a dual specificity protein phosphatase, exhibits anti-apoptotic activity, but the underlying molecular mechanisms are poorly characterized. Here we report that Cdc25A inhibits cisplatin-induced apoptotic cell death by stimulating nuclear factor-kappa B (NF-{kappa}B) activity. In HEK-293 cells, Cdc25A decreased protein level of inhibitor subunit kappa B alpha (I{kappa}-B{alpha}) in association with increased serine 32-phosphorylation, followed by stimulation of transcriptional activity of NF-{kappa}B. Inhibition of NF-{kappa}B activity by chemical inhibitor or overexpression of I{kappa}-B{alpha} in Cdc25A-elevated cancer cells resistant to cisplatin improved their sensitivity to cisplatin-induced apoptosis. Our data show for the first time that Cdc25A has an important physiological role in NF-{kappa}B activity regulation and it may be an important survival mechanism of cancer cells.

Rad GTPase is essential for the regulation of bone density and bone marrow adipose tissue in mice.

Science.gov (United States)

Withers, Catherine N; Brown, Drew M; Byiringiro, Innocent; Allen, Matthew R; Condon, Keith W; Satin, Jonathan; Andres, Douglas A

2017-10-01

The small GTP-binding protein Rad (RRAD, Ras associated with diabetes) is the founding member of the RGK (Rad, Rem, Rem2, and Gem/Kir) family that regulates cardiac voltage-gated Ca 2+ channel function. However, its cellular and physiological functions outside of the heart remain to be elucidated. Here we report that Rad GTPase function is required for normal bone homeostasis in mice, as Rad deletion results in significantly lower bone mass and higher bone marrow adipose tissue (BMAT) levels. Dynamic histomorphometry in vivo and primary calvarial osteoblast assays in vitro demonstrate that bone formation and osteoblast mineralization rates are depressed, while in vitro osteoclast differentiation is increased, in the absence of Rad. Microarray analysis revealed that canonical osteogenic gene expression (Runx2, osterix, etc.) is not altered in Rad -/- calvarial osteoblasts; instead robust up-regulation of matrix Gla protein (MGP, +11-fold), an inhibitor of extracellular matrix mineralization and a protein secreted during adipocyte differentiation, was observed. Strikingly, Rad deficiency also resulted in significantly higher marrow adipose tissue levels in vivo and promoted spontaneous in vitro adipogenesis of primary calvarial osteoblasts. Adipogenic differentiation of wildtype calvarial osteoblasts resulted in the loss of endogenous Rad protein, further supporting a role for Rad in the control of BMAT levels. These findings reveal a novel in vivo function for Rad and establish a role for Rad signaling in the complex physiological control of skeletal homeostasis and bone marrow adiposity. Copyright © 2017 Elsevier Inc. All rights reserved.

Non-synonymous FGD3 Variant as Positional Candidate for Disproportional Tall Stature Accounting for a Carcass Weight QTL (CW-3 and Skeletal Dysplasia in Japanese Black Cattle.

Directory of Open Access Journals (Sweden)

Akiko Takasuga

2015-08-01

Full Text Available Recessive skeletal dysplasia, characterized by joint- and/or hip bone-enlargement, was mapped within the critical region for a major quantitative trait locus (QTL influencing carcass weight; previously named CW-3 in Japanese Black cattle. The risk allele was on the same chromosome as the Q allele that increases carcass weight. Phenotypic characterization revealed that the risk allele causes disproportional tall stature and bone size that increases carcass weight in heterozygous individuals but causes disproportionately narrow chest width in homozygotes. A non-synonymous variant of FGD3 was identified as a positional candidate quantitative trait nucleotide (QTN and the corresponding mutant protein showed reduced activity as a guanine nucleotide exchange factor for Cdc42. FGD3 is expressed in the growth plate cartilage of femurs from bovine and mouse. Thus, loss of FDG3 activity may lead to subsequent loss of Cdc42 function. This would be consistent with the columnar disorganization of proliferating chondrocytes in chondrocyte-specific inactivated Cdc42 mutant mice. This is the first report showing association of FGD3 with skeletal dysplasia.

MiR-27a Promotes Hemin-Induced Erythroid Differentiation of K562 Cells by Targeting CDC25B

Directory of Open Access Journals (Sweden)

Dongsheng Wang

2018-03-01

Full Text Available Background/Aims: MicroRNAs (miRNAs play a crucial role in erythropoiesis. MiR-23a∼27a∼24-2 clusters have been proven to take part in erythropoiesis via some proteins. CDC25B (cell division control Cdc2 phosphostase B is also the target of mir-27a; whether it regulates erythropoiesis and its mechanism are unknown. Methods: To evaluate the potential role of miR-27a during erythroid differentiation, we performed miR-27a gain- and loss-of-function experiments on hemin-induced K562 cells. We detected miR-27a expression after hemin stimulation at different time points. At the same time, the γ-globin gene also was measured via real-time PCR. According to the results of the chips, we screened the target protein of miR-27a through a dual-luciferase reporter assay and identified it via Western blot analyses. To evaluate the function of CDC25B, benzidine staining and flow cytometry were employed to detect the cell differentiation and cell cycle. Results: We found that miR-27a promotes hemin-induced erythroid differentiation of human K562 cells by targeting cell division cycle 25 B (CDC25B. Overexpression of miR-27a promotes the differentiation of hemin-induced K562 cells, as demonstrated by γ-globin overexpression. The inhibition of miR-27a expression suppresses erythroid differentiation, thus leading to a reduction in the γ-globin gene. CDC25B was identified as a new target of miR-27a during erythroid differentiation. Overexpression of miR-27a led to decreased CDC25B expression after hemin treatment, and CDC25B was up-regulated when miR-27a expression was inhibited. Moreover, the inhibition of CDC25B affected erythroid differentiation, as assessed by γ-globin expression. Conclusion: This study is the first report of the interaction between miR-27a and CDC25B, and it improves the understanding of miRNA functions during erythroid differentiation.

Chronic Alcohol Abuse Leads to Low Bone Mass with No General Loss of Bone Structure or Bone Mechanical Strength

DEFF Research Database (Denmark)

Ulhøi, Maiken Parm; Meldgaard, Karoline; Steiniche, Torben

2017-01-01

Chronic alcohol abuse (CAA) has deleterious effects on skeletal health. This study examined the impact of CAA on bone with regard to bone density, structure, and strength. Bone specimens from 42 individuals with CAA and 42 individuals without alcohol abuse were obtained at autopsy. Dual-energy X......-ray absorptiometry (DEXA), compression testing, ashing, and bone histomorphometry were performed. Individuals with CAA had significantly lower bone mineral density (BMD) in the femoral neck and significantly lower bone volume demonstrated by thinner trabeculae, decreased extent of osteoid surfaces, and lower mean...... wall thickness of trabecular osteons compared to individuals without alcohol abuse. No significant difference was found for bone strength and structure. Conclusion: CAA leads to low bone mass due to a decrease in bone formation but with no destruction of bone architecture nor a decrease in bone...

CDC Climat - 2011 Sustainable Development Report

International Nuclear Information System (INIS)

2012-08-01

CDC Climat is the Caisse des Depots (CDC) subsidiary that is dedicated to combating climate change. Its activities aim to support the transition towards a low resource and low greenhouse gas emission (GHG) economy, through services that are cutting-edge, pro table, and in line with CDC's public policy goals. Through its corporate purpose, CDC Climat embodies the CDC's commitments in the sustainable development field. CDC Climat supports the implementation of public GHG emission reduction policies, primarily through emission trading schemes at the European and international level. Since it was founded in 2010, and throughout 2011, its strategic priorities have consisted in: - developing a long-term policy for investing in carbon credits generated by environmental initiatives, as part of the project mechanisms set up by the Kyoto Protocol, and used in the European Emission Trading Scheme; - supporting the development of its investments in carbon finance operators, like BlueNext, the European carbon exchange, for instance; - broadening the scope of its research into climate economics, which is supported by CDC and available to everyone, in order to serve the public and private players concerned. Its teams have supported French and European governments, international organisations and the United Nations, and various NGOs in their work and thinking on the future of tools for combating climate change. They have specifically contributed reports based on their research and operational feedback. When it was founded, CDC Climat was closely linked to public policies aimed at combating climate change via allowance and carbon trading mechanisms. The difficulties encountered by international negotiations, together with the effects of the economic and financial downturn in Europe, have resulted in a very pronounced fall in the price of carbon assets on these markets since the summer of 2011, with no prospect of recovery for several years. This environment is calling some of the

Interleukin-6: a bone marrow stromal cell paracrine signal that induces neuroendocrine differentiation and modulates autophagy in bone metastatic PCa cells.

Science.gov (United States)

Delk, Nikki A; Farach-Carson, Mary C

2012-04-01

Autophagy reallocates nutrients and clears normal cells of damaged proteins and organelles. In the context of metastatic disease, invading cancer cells hijack autophagic processes to survive and adapt in the host microenvironment. We sought to understand how autophagy is regulated in the metastatic niche for prostate cancer (PCa) cells where bone marrow stromal cell (BMSC) paracrine signaling induces PCa neuroendocrine differentiation (NED). In PCa, this transdifferentiation of metastatic PCa cells to neuronal-like cells correlates with advanced disease. Because autophagy provides a survival advantage for cancer cells and promotes cell differentiation, we hypothesized that autophagy mediates PCa NED in the bone. Thus, we determined the ability of paracrine factors in conditioned media (CM) from two separate BMSC subtypes, HS5 and HS27a, to induce autophagy in C4-2 and C4-2B bone metastatic PCa cells by characterizing the autophagy marker, LC3. Unlike HS27a CM, HS5 CM induced LC3 accumulation in PCa cells, suggesting autophagy was induced and indicating that HS5 and HS27a secrete a different milieu of paracrine factors that influence PCa autophagy. We identified interleukin-6 (IL-6), a cytokine more highly expressed in HS5 cells than in HS27a cells, as a paracrine factor that regulates PCa autophagy. Pharmacological inhibition of STAT3 activity did not attenuate LC3 accumulation, implying that IL-6 regulates NED and autophagy through different pathways. Finally, chloroquine inhibition of autophagic flux blocked PCa NED; hence autophagic flux maintains NED. Our studies imply that autophagy is cytoprotective for PCa cells in the bone, thus targeting autophagy is a potential therapeutic strategy.

Final Report: Bone Mass Inheritance: A Project to Identify the Genetic Regulation of Bone Mass; FINAL

International Nuclear Information System (INIS)

Recker, Robert R. M.D.

2002-01-01

This project was designed to find human chromosomal locations that contain genes regulating peak bone density. It is part of a whole genome search for those loci,each responsible for at least 15% of the variation in the peak adult bone density. We accomplished this with a sib pair design, combined with simultaneous examination of extended kindreds. This project gave partial support of the recruitment which has now been completed. The project will extend into 2003. During the remainder of the project, a whole genome scan will be performed from the entire cohort of 2226 persons who have DNA archived, followed by linkage analysis. This project will meet the scientific objective leading eventually to expanded options for treating the condition that leads to bone thinning osteoporosis, and potential fractures in aging populations

13 CFR 120.851 - CDC ethical requirements.

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false CDC ethical requirements. 120.851... Company Loan Program (504) Other Cdc Requirements § 120.851 CDC ethical requirements. CDCs and their Associates must act ethically and exhibit good character. They must meet all of the ethical requirements of...

42 CFR 403.201 - State regulation of insurance policies.

Science.gov (United States)

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false State regulation of insurance policies. 403.201 Section 403.201 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS SPECIAL PROGRAMS AND PROJECTS Medicare Supplemental Policies General Provisions...

MicroRNA-301a mediated regulation of Kv4.2 in diabetes: identification of key modulators.

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Siva K Panguluri

Full Text Available Diabetes is a metabolic disorder that ultimately results in major pathophysiological complications in the cardiovascular system. Diabetics are predisposed to higher incidences of sudden cardiac deaths (SCD. Several studies have associated diabetes as a major underlying risk for heart diseases and its complications. The diabetic heart undergoes remodeling to cope up with the underlying changes, however ultimately fails. In the present study we investigated the changes associated with a key ion channel and transcriptional factors in a diabetic heart model. In the mouse db/db model, we identified key transcriptional regulators and mediators that play important roles in the regulation of ion channel expression. Voltage-gated potassium channel (Kv4.2 is modulated in diabetes and is down regulated. We hypothesized that Kv4.2 expression is altered by potassium channel interacting protein-2 (KChIP2 which is regulated upstream by NFkB and miR-301a. We utilized qRT-PCR analysis and identified the genes that are affected in diabetes in a regional specific manner in the heart. At protein level we identified and validated differential expression of Kv4.2 and KChIP2 along with NFkB in both ventricles of diabetic hearts. In addition, we identified up-regulation of miR-301a in diabetic ventricles. We utilized loss and gain of function approaches to identify and validate the role of miR-301a in regulating Kv4.2. Based on in vivo and in vitro studies we conclude that miR-301a may be a central regulator for the expression of Kv4.2 in diabetes. This miR-301 mediated regulation of Kv4.2 is independent of NFkB and Irx5 and modulates Kv4.2 by direct binding on Kv4.2 3'untranslated region (3'-UTR. Therefore targeting miR-301a may offer new potential for developing therapeutic approaches.

42 CFR 423.2063 - Applicability of laws, regulations and CMS Rulings.

Science.gov (United States)

2010-10-01

... 42 Public Health 3 2010-10-01 2010-10-01 false Applicability of laws, regulations and CMS Rulings..., ALJ Hearings, MAC review, and Judicial Review § 423.2063 Applicability of laws, regulations and CMS... on ALJs and the MAC. (b) CMS Rulings are published under the authority of the CMS Administrator...

42 CFR 405.1063 - Applicability of laws, regulations and CMS Rulings.

Science.gov (United States)

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Applicability of laws, regulations and CMS Rulings... Medicare Coverage Policies § 405.1063 Applicability of laws, regulations and CMS Rulings. (a) All laws and... the MAC. (b) CMS Rulings are published under the authority of the Administrator, CMS. Consistent with...

Klotho expression in long bones regulates FGF23 production during renal failure.

Science.gov (United States)

Kaludjerovic, Jovana; Komaba, Hirotaka; Sato, Tadatoshi; Erben, Reinhold G; Baron, Roland; Olauson, Hannes; Larsson, Tobias E; Lanske, Beate

2017-05-01

Circulating levels of bone-derived fibroblast growth factor 23 (FGF23) increase early during acute and chronic kidney disease and are associated with adverse outcomes. Membrane-bound Klotho acts as a permissive coreceptor for FGF23, and its expression was recently found in osteoblasts/osteocytes. We hypothesized that Klotho in bone cells is part of an autocrine feedback loop that regulates FGF23 expression during renal failure. Thus, we induced renal failure in mice with targeted deletion of Klotho in long bones. Uremic wild-type ( KL fl/fl ) and knockout ( Prx1-Cre;KL fl/fl ) mice both responded with reduced body weight, kidney atrophy, hyperphosphatemia, and increased bone turnover. Importantly, long bones of Prx1-Cre;KL fl/fl mice but not their axial skeleton failed to increase FGF23 expression as observed in uremic KL fl/fl mice. Consequently, Prx1-Cre;KL fl/fl mice had significantly lower serum FGF23 and parathyroid hormone levels, and higher renal 1-α-hydroxylase expression, serum 1,25-dihydroxyvitamin D, and calcium levels than KL fl/fl mice. These results were confirmed in two independent models of renal failure, adenine diet induced and 5/6 nephrectomy. Moreover, FGF23-treated bone cells required Klotho to increase FGF23 mRNA and ERK phosphorylation. In summary, our novel findings show that Klotho in bone is crucial for inducing FGF23 production upon renal failure. We propose the presence of an autocrine feedback loop in which Klotho senses the need for FGF23.-Kaludjerovic, J., Komaba, H., Sato, T., Erben, R. G., Baron, R., Olauson, H., Larsson, T. E., Lanske, B. Klotho expression in long bones regulates FGF23 production during renal failure. © FASEB.

Dsc E3 ligase localization to the Golgi requires the ATPase Cdc48 and cofactor Ufd1 for activation of sterol regulatory element-binding protein in fission yeast.

Science.gov (United States)

Burr, Risa; Ribbens, Diedre; Raychaudhuri, Sumana; Stewart, Emerson V; Ho, Jason; Espenshade, Peter J

2017-09-29

Sterol regulatory element-binding proteins (SREBPs) in the fission yeast Schizosaccharomyces pombe regulate lipid homeostasis and the hypoxic response under conditions of low sterol or oxygen availability. SREBPs are cleaved in the Golgi through the combined action of the Dsc E3 ligase complex, the rhomboid protease Rbd2, and the essential ATPases associated with diverse cellular activities (AAA + ) ATPase Cdc48. The soluble SREBP N-terminal transcription factor domain is then released into the cytosol to enter the nucleus and regulate gene expression. Previously, we reported that Cdc48 binding to Rbd2 is required for Rbd2-mediated SREBP cleavage. Here, using affinity chromatography and mass spectrometry experiments, we identified Cdc48-binding proteins in S. pombe , generating a list of many previously unknown potential Cdc48-binding partners. We show that the established Cdc48 cofactor Ufd1 is required for SREBP cleavage but does not interact with the Cdc48-Rbd2 complex. Cdc48-Ufd1 is instead required at a step prior to Rbd2 function, during Golgi localization of the Dsc E3 ligase complex. Together, these findings demonstrate that two distinct Cdc48 complexes, Cdc48-Ufd1 and Cdc48-Rbd2, are required for SREBP activation and low-oxygen adaptation in S. pombe . © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

E-cadherin and beta-catenin are down-regulated in prostatic bone metastases.

Science.gov (United States)

Bryden, A A G; Hoyland, J A; Freemont, A J; Clarke, N W; Schembri Wismayer, D; George, N J R

2002-03-01

To determine the E-cadherin and beta-catenin expression phenotype in untreated primary prostate cancer and corresponding bone metastases. Paired bone metastasis and primary prostate specimens were obtained from 14 men with untreated metastatic prostate carcinoma. The tumours were histologically graded by an independent pathologist. Expression of mRNA for E-cadherin and beta-catenin was detected within the tumour cells using in-situ hybridization with a 35S-labelled cDNA probe. The expression of E-cadherin and beta-catenin were graded as uniform, heterogeneous or negative. The mRNA for E-cadherin was expressed in 13 of 14 primary carcinomas and 11 bone metastases; beta-catenin was expressed by 13 and nine, respectively. Of the primary tumours, nine expressed E-cadherin and beta-catenin uniformly; in contrast, all metastases had down-regulated E-cadherin and/or beta-catenin. The down-regulation of E-cadherin and beta-catenin are a feature of the metastatic phenotype, which may be a significant factor in the genesis of bone metastases. However, this does not appear to be reflected in the expression of these molecules in the primary tumours.

Ufd1-Npl4 Recruit Cdc48 for Disassembly of Ubiquitylated CMG Helicase at the End of Chromosome Replication

Directory of Open Access Journals (Sweden)

Marija Maric

2017-03-01

Full Text Available Disassembly of the Cdc45-MCM-GINS (CMG DNA helicase is the key regulated step during DNA replication termination in eukaryotes, involving ubiquitylation of the Mcm7 helicase subunit, leading to a disassembly process that requires the Cdc48 “segregase”. Here, we employ a screen to identify partners of budding yeast Cdc48 that are important for disassembly of ubiquitylated CMG helicase at the end of chromosome replication. We demonstrate that the ubiquitin-binding Ufd1-Npl4 complex recruits Cdc48 to ubiquitylated CMG. Ubiquitylation of CMG in yeast cell extracts is dependent upon lysine 29 of Mcm7, which is the only detectable site of ubiquitylation both in vitro and in vivo (though in vivo other sites can be modified when K29 is mutated. Mutation of K29 abrogates in vitro recruitment of Ufd1-Npl4-Cdc48 to the CMG helicase, supporting a model whereby Ufd1-Npl4 recruits Cdc48 to ubiquitylated CMG at the end of chromosome replication, thereby driving the disassembly reaction.

Sprouty regulates cell migration by inhibiting the activation of Rac1 GTPase

International Nuclear Information System (INIS)

Poppleton, Helen M.; Edwin, Francis; Jaggar, Laura; Ray, Ramesh; Johnson, Leonard R.; Patel, Tarun B.

2004-01-01

Sprouty (SPRY) protein negatively modulates fibroblast growth factor and epidermal growth factor actions. We showed that human SPRY2 inhibits cell growth and migration in response to serum and several growth factors. Using rat intestinal epithelial (IEC-6) cells, we investigated the involvement of the Rho family of GTPases, RhoA, Rac1, and cdc42 in SPRY2-mediated inhibition of cell migration and proliferation. The ability of TAT-tagged SPRY2 to inhibit proliferation and migration of IEC-6 cells transfected with constitutively active mutants of RhoA(G14V), Rac1(G12V), and cdc42 (F28L) was determined. Constitutively active RhoA(G14V), Rac1(G12V), or cdc42(F28L) did not protect cells from the anti-proliferative actions of TAT-SPRY2. The ability of TAT-hSPRY2 to inhibit migration was not altered by of RhoA(G14V) and cdc42(F28L). However, Rac1(G12V) obliterated the ability of SPRY2 to inhibit cell autonomous or serum-induced migration. Also, the activation of endogenous Rac1 was attenuated by TAT-SPRY2. Thus, SPRY2 mediates its anti-migratory actions by inhibiting Rac1 activation

Tetraspanin 7 regulates sealing zone formation and the bone-resorbing activity of osteoclasts

Energy Technology Data Exchange (ETDEWEB)

Kwon, Jun-Oh; Lee, Yong Deok; Kim, Haemin; Kim, Min Kyung; Song, Min-Kyoung; Lee, Zang Hee; Kim, Hong-Hee, E-mail: hhbkim@snu.ac.kr

2016-09-02

Tetraspanin family proteins regulate morphology, motility, fusion, and signaling in various cell types. We investigated the role of the tetraspanin 7 (Tspan7) isoform in the differentiation and function of osteoclasts. Tspan7 was up-regulated during osteoclastogenesis. When Tspan7 expression was reduced in primary precursor cells by siRNA-mediated gene knock-down, the generation of multinuclear osteoclasts was not affected. However, a striking cytoskeletal abnormality was observed: the formation of the podosome belt structure was inhibited and the microtubular network were disrupted by Tspan7 knock-down. Decreases in acetylated microtubules and levels of phosphorylated Src and Pyk2 in Tspan7 knock-down cells supported the involvement of Tspan7 in cytoskeletal rearrangement signaling in osteoclasts. This cytoskeletal defect interfered with sealing zone formation and subsequently the bone-resorbing activity of mature osteoclasts on dentin surfaces. Our results suggest that Tspan7 plays an important role in cytoskeletal organization required for the bone-resorbing function of osteoclasts by regulating signaling to Src, Pyk2, and microtubules. - Highlights: • Tspan7 expression is up-regulated during osteoclastogenesis. • Tspan7 regulates podosome belt organization in osteoclasts. • Tspan7 is crucial for sealing zone formation and bone-resorption by osteoclasts. • Src and Pyk2 phosphorylation and microtubule acetylation mediate Tspan7 function.

Bone and fat connection in aging bone.

Science.gov (United States)

Duque, Gustavo

2008-07-01

The fat and bone connection plays an important role in the pathophysiology of age-related bone loss. This review will focus on the age-induced mechanisms regulating the predominant differentiation of mesenchymal stem cells into adipocytes. Additionally, bone marrow fat will be considered as a diagnostic and therapeutic approach to osteoporosis. There are two types of bone and fat connection. The 'systemic connection', usually seen in obese patients, is hormonally regulated and associated with high bone mass and strength. The 'local connection' happens inside the bone marrow. Increasing amounts of bone marrow fat affect bone turnover through the inhibition of osteoblast function and survival and the promotion of osteoclast differentiation and activation. This interaction is regulated by paracrine secretion of fatty acids and adipokines. Additionally, bone marrow fat could be quantified using noninvasive methods and could be used as a therapeutic approach due to its capacity to transdifferentiate into bone without affecting other types of fat in the body. The bone and fat connection within the bone marrow constitutes a typical example of lipotoxicity. Additionally, bone marrow fat could be used as a new diagnostic and therapeutic approach for osteoporosis in older persons.

CDC 7600 Module

CERN Multimedia

1970-01-01

The CDC 7600 has been created by Seymour Cray. It was designed to be compatible with the 6600, which allows for a substantial increase in performance. Furthermore the rise of new technologies has enabled this performance by reducing the minor cycle clock period from 100 ns to 27.5 ns (4 time faster). A very large machine, the 7600 had over 120 miles of hand-wired interconnections. It was the most powerful computer of its time. However, this speed caused a ground-loop problem causing intermittent faults, and eventually requiring all modules to be fitted with sheathed rubber bands. The CDC 7600 was replaced in 1983 by CRAY-1A.

CDC25A Protein Stability Represents a Previously Unrecognized Target of HER2 Signaling in Human Breast Cancer: Implication for a Potential Clinical Relevance in Trastuzumab Treatment

Directory of Open Access Journals (Sweden)

Emanuela Brunetto

2013-06-01

Full Text Available The CDC25A-CDK2 pathway has been proposed as critical for the oncogenic action of human epidermal growth factor receptor 2 (HER2 in mammary epithelial cells. In particular, transgenic expression of CDC25A cooperates with HER2 in promoting mammary tumors, whereas CDC25A hemizygous loss attenuates the HER2-induced tumorigenesis penetrance. On the basis of this evidence of a synergism between HER2 and the cell cycle regulator CDC25A in a mouse model of mammary tumorigenesis, we investigated the role of CDC25A in human HER2-positive breast cancer and its possible implications in therapeutic response. HER2 status and CDC25A expression were assessed in 313 breast cancer patients and we found statistically significant correlation between HER2 and CDC25A (P = .007. Moreover, an HER2-positive breast cancer subgroup with high levels of CDC25A and very aggressive phenotype was identified (P = .005. Importantly, our in vitro studies on breast cancer cell lines showed that the HER2 inhibitor efficacy on cell growth and viability relied also on CDC25A expression and that such inhibition induces CDC25A down-regulation through phosphatidylinositol 3-kinase/protein kinase B pathway and DNA damage response activation. In line with this observation, we found a statistical significant association between CDC25A overexpression and trastuzumab-combined therapy response rate in two different HER2-positive cohorts of trastuzumab-treated patients in either metastatic or neoadjuvant setting (P = .018 for the metastatic cohort and P = .021 for the neoadjuvant cohort. Our findings highlight a link between HER2 and CDC25A that positively modulates HER2- targeted therapy response, suggesting that, in HER2-positive breast cancer patients, CDC25A overexpression affects trastuzumab sensitivity.

Recurrent Hyperparathyroidism Due to a Novel CDC73 Splice Mutation.

Science.gov (United States)

Hattangady, Namita Ganesh; Wilson, Tremika Le-Shan; Miller, Barbra Sue; Lerario, Antonio Marcondes; Giordano, Thomas James; Choksi, Palak; Else, Tobias

2017-08-01

The recognition of hereditary causes of primary hyperparathyroidism (pHPT) is important because clinical care and surveillance differ significantly between sporadic and hereditary pHPT. In addition, the increasing number of genetic tests poses a challenge to classify mutations as benign or pathogenic. Functional work-up of variants remains a mainstay to provide evidence for pathogenicity. We describe a 52-year-old male patient with recurrent pHPT since age 35 years. Despite several neck surgeries with complete parathyroidectomy, he experienced persistent pHPT, necessitating repeated surgery for a forearm autotransplant, which finally resulted in unmeasurable parathyroid hormone (PTH) levels. Genetic testing revealed a new CDC73 variant (c.238-8G>A [IVS2-8G>A]), initially classified as a variant of uncertain significance. Parathyroid tissue from the initial surgeries showed loss of heterozygosity. Using an RT-PCR approach, we show that the mutation leads to the use of a cryptic splice site in peripheral mononuclear cells. In addition, a minigene approach confirms the use of the cryptic splice site in a heterologous cell system. The novel c.238-8G>A CDC73 variant activates a cryptic splice site, and the functional data provided justify the classification as a likely pathogenic variant. Our results underscore the importance of functional work-up for variant classification in the absence of other available data, such as presence in disease-specific databases, other syndromic clinical findings, or family history. In addition, the presented case exemplifies the importance to consider a hereditary condition in young patients with pHPT, particularly those with multi-gland involvement. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

Regulation of Cellular and Molecular Functions by Protein ...

Indian Academy of Sciences (India)

... a high-energy linkage. The free energy of hydrolysis 1 of protein bound tyrosine phosphate ... protein kinases, cdc2 kinase (which regulates cell division cycle) and related cdc ... residues in response to extracellular signals such as hormones or growth factors. ... involved in regulating glycogen metabolism. The activity of.

Bone mineral density, muscle strength and physical activity. A population-based study of 332 subjects aged 15-42 years.

Science.gov (United States)

Düppe, H; Gärdsell, P; Johnell, O; Nilsson, B E; Ringsberg, K

1997-04-01

The aim of this population-based study was to find out whether differences in levels of physical activity have an influence on bone mass quantity and whether quadriceps muscle strength is a reliable determinant of bone mass. Included were 175 men and 157 women, aged 15-42 years. Bone mineral density (BMD) was measured at various sites by dual X-ray absorptiometry (DXA) and single photon absorptiometry (SPA). Muscle strength was assessed using an isokinetic muscle force meter. A questionnaire was used to estimate the level of physical activity. We found a positive correlation between physical activity and BMD for boys at the distal forearm and for girls at the trochanter (age group 15-16 years). Active men (age group 21-42 years) had up to 9% higher BMD levels at the hip than those who were less active. Quadriceps muscle torque was not an independent predictor of BMD. Our data suggest that a higher level of physical activity-within the limits of a "normal life style"-may have a positive effect on BMD in the proximal femur of young adults, which in turn may lessen the subsequent risk of fracture.

Identification of genes differentially regulated in rat alveolar bone wound healing by subtractive hybridization.

Science.gov (United States)

Ohira, T; Myokai, F; Shiomi, N; Yamashiro, K; Yamamoto, T; Murayama, Y; Arai, H; Nishimura, F; Takashiba, S

2004-07-01

Periodontal healing requires the participation of regulatory molecules, cells, and scaffold or matrix. Here, we hypothesized that a certain set of genes is expressed in alveolar bone wound healing. Reciprocal subtraction gave 400 clones from the injured alveolar bone of Wistar rats. Identification of 34 genes and analysis of their expression in injured tissue revealed several clusters of unique gene regulation patterns, including the up-regulation at 1 wk of cytochrome c oxidase regulating electron transfer and energy metabolism, presumably occurring at the site of inflammation; up-regulation at 2.5 wks of pro-alpha-2 type I collagen involving the formation of a connective tissue structure; and up-regulation at 1 and 2 wks and down-regulation at 2.5 and 4 wks of ubiquitin carboxyl-terminal hydrolase l3 involving cell cycle, DNA repair, and stress response. The differential expression of genes may be associated with the processes of inflammation, wound contraction, and formation of a connective tissue structure.

The human ubiquitin-conjugating enzyme Cdc34 controls cellular proliferation through regulation of p27Kip1 protein levels

International Nuclear Information System (INIS)

Butz, Nicole; Ruetz, Stephan; Natt, Francois; Hall, Jonathan; Weiler, Jan; Mestan, Juergen; Ducarre, Monique; Grossenbacher, Rita; Hauser, Patrick; Kempf, Dominique; Hofmann, Francesco

2005-01-01

Ubiquitin-mediated degradation of the cyclin-dependent kinase inhibitor p27 Kip1 was shown to be required for the activation of key cyclin-dependent kinases, thereby triggering the onset of DNA replication and cell cycle progression. Although the SCF Skp2 ubiquitin ligase has been reported to mediate p27 Kip1 degradation, the nature of the human ubiquitin-conjugating enzyme involved in this process has not yet been determined at the cellular level. Here, we show that antisense oligonucleotides targeting the human ubiquitin-conjugating enzyme Cdc34 downregulate its expression, inhibit the degradation of p27 Kip1 , and prevent cellular proliferation. Elevation of p27 Kip1 protein level is found to be the sole requirement for the inhibition of cellular proliferation induced upon downregulation of Cdc34. Indeed, reducing the expression of p27 Kip1 with a specific antisense oligonucleotide is sufficient to reverse the anti-proliferative phenotype elicited by the Cdc34 antisense. Furthermore, downregulation of Cdc34 is found to specifically increase the abundance of the SCF Skp2 ubiquitin ligase substrate p27 Kip1 , but has no concomitant effect on the level of IkBα and β-catenin, which are known substrates of a closely related SCF ligase

Structure and dimerization of the catalytic domain of the protein phosphatase Cdc14p, a key regulator of mitotic exit in Saccharomyces cerevisiae.

Science.gov (United States)

Kobayashi, Junya; Matsuura, Yoshiyuki

2017-10-01

In the budding yeast Saccharomyces cerevisiae, the protein phosphatase Cdc14p orchestrates various events essential for mitotic exit. We have determined the X-ray crystal structures at 1.85 Å resolution of the catalytic domain of Cdc14p in both the apo state, and as a complex with S160-phosphorylated Swi6p peptide. Each asymmetric unit contains two Cdc14p chains arranged in an intimately associated homodimer, consistent with its oligomeric state in solution. The dimerization interface is located on the backside of the substrate-binding cleft. Structure-based mutational analyses indicate that the dimerization of Cdc14p is required for normal growth of yeast cells. © 2017 The Protein Society.

CDC Health Disparities and Inequalities Report--U.S. 2013

Science.gov (United States)

... Women's Health Health Literacy Health Equity CDC Health Disparities & Inequalities Report (CHDIR) Recommend on Facebook Tweet Share ... 2011 Report More Information CDC Releases Second Health Disparities & Inequalities Report - United States, 2013 CDC and its ...

Crystal structure of the karyopherin Kap121p bound to the extreme C-terminus of the protein phosphatase Cdc14p

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Junya [Division of Biological Science, Graduate School of Science, Nagoya University (Japan); Hirano, Hidemi [Division of Biological Science, Graduate School of Science, Nagoya University (Japan); Structural Biology Research Center, Graduate School of Science, Nagoya University (Japan); Matsuura, Yoshiyuki, E-mail: matsuura.yoshiyuki@d.mbox.nagoya-u.ac.jp [Division of Biological Science, Graduate School of Science, Nagoya University (Japan); Structural Biology Research Center, Graduate School of Science, Nagoya University (Japan)

2015-07-31

In Saccharomyces cerevisiae, the protein phosphatase Cdc14p is an antagonist of mitotic cyclin-dependent kinases and is a key regulator of late mitotic events such as chromosome segregation, spindle disassembly and cytokinesis. The activity of Cdc14p is controlled by cell-cycle dependent changes in its association with its competitive inhibitor Net1p (also known as Cfi1p) in the nucleolus. For most of the cell cycle up to metaphase, Cdc14p is sequestered in the nucleolus in an inactive state. During anaphase, Cdc14p is released from Net1p, spreads into the nucleus and cytoplasm, and dephosphorylates key mitotic targets. Although regulated nucleocytoplasmic shuttling of Cdc14p has been suggested to be important for exit from mitosis, the mechanism underlying Cdc14p nuclear trafficking remains poorly understood. Here we show that the C-terminal region (residues 517–551) of Cdc14p can function as a nuclear localization signal (NLS) in vivo and also binds to Kap121p (also known as Pse1p), an essential nuclear import carrier in yeast, in a Gsp1p-GTP-dependent manner in vitro. Moreover we report a crystal structure, at 2.4 Å resolution, of Kap121p bound to the C-terminal region of Cdc14p. The structure and structure-based mutational analyses suggest that either the last five residues at the extreme C-terminus of Cdc14p (residues 547–551; Gly-Ser-Ile-Lys-Lys) or adjacent residues with similar sequence (residues 540–544; Gly-Gly-Ile-Arg-Lys) can bind to the NLS-binding site of Kap121p, with two residues (Ile in the middle and Lys at the end of the five residues) of Cdc14p making key contributions to the binding specificity. Based on comparison with other structures of Kap121p-ligand complexes, we propose “IK-NLS” as an appropriate term to refer to the Kap121p-specific NLS. - Highlights: • The C-terminus of Cdc14p binds to Kap121p in a Gsp1p-GTP-dependent manner. • The crystal structure of Kap121p-Cdc14p complex is determined. • The structure reveals how

Crystal structure of the karyopherin Kap121p bound to the extreme C-terminus of the protein phosphatase Cdc14p

International Nuclear Information System (INIS)

Kobayashi, Junya; Hirano, Hidemi; Matsuura, Yoshiyuki

2015-01-01

In Saccharomyces cerevisiae, the protein phosphatase Cdc14p is an antagonist of mitotic cyclin-dependent kinases and is a key regulator of late mitotic events such as chromosome segregation, spindle disassembly and cytokinesis. The activity of Cdc14p is controlled by cell-cycle dependent changes in its association with its competitive inhibitor Net1p (also known as Cfi1p) in the nucleolus. For most of the cell cycle up to metaphase, Cdc14p is sequestered in the nucleolus in an inactive state. During anaphase, Cdc14p is released from Net1p, spreads into the nucleus and cytoplasm, and dephosphorylates key mitotic targets. Although regulated nucleocytoplasmic shuttling of Cdc14p has been suggested to be important for exit from mitosis, the mechanism underlying Cdc14p nuclear trafficking remains poorly understood. Here we show that the C-terminal region (residues 517–551) of Cdc14p can function as a nuclear localization signal (NLS) in vivo and also binds to Kap121p (also known as Pse1p), an essential nuclear import carrier in yeast, in a Gsp1p-GTP-dependent manner in vitro. Moreover we report a crystal structure, at 2.4 Å resolution, of Kap121p bound to the C-terminal region of Cdc14p. The structure and structure-based mutational analyses suggest that either the last five residues at the extreme C-terminus of Cdc14p (residues 547–551; Gly-Ser-Ile-Lys-Lys) or adjacent residues with similar sequence (residues 540–544; Gly-Gly-Ile-Arg-Lys) can bind to the NLS-binding site of Kap121p, with two residues (Ile in the middle and Lys at the end of the five residues) of Cdc14p making key contributions to the binding specificity. Based on comparison with other structures of Kap121p-ligand complexes, we propose “IK-NLS” as an appropriate term to refer to the Kap121p-specific NLS. - Highlights: • The C-terminus of Cdc14p binds to Kap121p in a Gsp1p-GTP-dependent manner. • The crystal structure of Kap121p-Cdc14p complex is determined. • The structure reveals how

Energy Balance, Myostatin, and GILZ: Factors Regulating Adipocyte Differentiation in Belly and Bone

Directory of Open Access Journals (Sweden)

Xingming Shi

2007-01-01

Full Text Available Peroxisome proliferator-activated receptor gamma (PPAR-γ belongs to the nuclear hormone receptor subfamily of transcription factors. PPARs are expressed in key target tissues such as liver, fat, and muscle and thus they play a major role in the regulation of energy balance. Because of PPAR-γ's role in energy balance, signals originating from the gut (e.g., GIP, fat (e.g., leptin, muscle (e.g., myostatin, or bone (e.g., GILZ can in turn modulate PPAR expression and/or function. Of the two PPAR-γ isoforms, PPAR-γ2 is the key regulator of adipogenesis and also plays a role in bone development. Activation of this receptor favors adipocyte differentiation of mesenchymal stem cells, while inhibition of PPAR-γ2 expression shifts the commitment towards the osteoblastogenic pathway. Clinically, activation of this receptor by antidiabetic agents of the thiazolidinedione class results in lower bone mass and increased fracture rates. We propose that inhibition of PPAR-γ2 expression in mesenchymal stem cells by use of some of the hormones/factors mentioned above may be a useful therapeutic strategy to favor bone formation.

Piezoelectric ceramic (PZT) modulates axonal guidance growth of rat cortical neurons via RhoA, Rac1, and Cdc42 pathways.

Science.gov (United States)

Wen, Jianqiang; Liu, Meili

2014-03-01

Electrical stimulation is critical for axonal connection, which can stimulate axonal migration and deformation to promote axonal growth in the nervous system. Netrin-1, an axonal guidance cue, can also promote axonal guidance growth, but the molecular mechanism of axonal guidance growth under indirect electric stimulation is still unknown. We investigated the molecular mechanism of axonal guidance growth under piezoelectric ceramic lead zirconate titanate (PZT) stimulation in the primary cultured cortical neurons. PZT induced marked axonal elongation. Moreover, PZT activated the excitatory postsynaptic currents (EPSCs) by increasing the frequency and amplitude of EPSCs of the cortical neurons in patch clamp assay. PZT downregulated the expression of Netrin-1 and its receptor Deleted in Colorectal Cancer (DCC). Rho GTPase signaling is involved in interactions of Netrin-1 and DCC. PZT activated RhoA. Dramatic decrease of Cdc42 and Rac1 was also observed after PZT treatment. RhoA inhibitor Clostridium botulinum C3 exoenzyme (C3-Exo) prevented the PZT-induced downregulation of Netrin-1 and DCC. We suggest that PZT can promote axonal guidance growth by downregulation of Netrin-1 and DCC to mediate axonal repulsive responses via the Rho GTPase signaling pathway. Obviously, piezoelectric materials may provide a new approach for axonal recovery and be beneficial for clinical therapy in the future.

Enhanced CDC of B cell chronic lymphocytic leukemia cells mediated by rituximab combined with a novel anti-complement factor H antibody.

Directory of Open Access Journals (Sweden)

Mark T Winkler

Full Text Available Rituximab therapy for B cell chronic lymphocytic leukemia (B-CLL has met with mixed success. Among several factors to which resistance can be attributed is failure to activate complement dependent cytotoxicity (CDC due to protective complement regulatory proteins, including the soluble regulator complement factor H (CFH. We hypothesized that rituximab killing of non-responsive B-CLL cells could be augmented by a novel human monoclonal antibody against CFH. The B cells from 11 patients with B-CLL were tested ex vivo in CDC assays with combinations of CFH monoclonal antibody, rituximab, and a negative control antibody. CDC of rituximab non-responsive malignant B cells from CLL patients could in some cases be augmented by the CFH monoclonal antibody. Antibody-mediated cytotoxicity of cells was dependent upon functional complement. In one case where B-CLL cells were refractory to CDC by the combination of rituximab plus CFH monoclonal antibody, additionally neutralizing the membrane complement regulatory protein CD59 allowed CDC to occur. Inhibiting CDC regulatory proteins such as CFH holds promise for overcoming resistance to rituximab therapy in B-CLL.

Mechanically stimulated bone cells secrete paracrine factors that regulate osteoprogenitor recruitment, proliferation, and differentiation

International Nuclear Information System (INIS)

Brady, Robert T.; O'Brien, Fergal J.; Hoey, David A.

2015-01-01

Bone formation requires the recruitment, proliferation and osteogenic differentiation of mesenchymal progenitors. A potent stimulus driving this process is mechanical loading, yet the signalling mechanisms underpinning this are incompletely understood. The objective of this study was to investigate the role of the mechanically-stimulated osteocyte and osteoblast secretome in coordinating progenitor contributions to bone formation. Initially osteocytes (MLO-Y4) and osteoblasts (MC3T3) were mechanically stimulated for 24hrs and secreted factors within the conditioned media were collected and used to evaluate mesenchymal stem cell (MSC) and osteoblast recruitment, proliferation and osteogenesis. Paracrine factors secreted by mechanically stimulated osteocytes significantly enhanced MSC migration, proliferation and osteogenesis and furthermore significantly increased osteoblast migration and proliferation when compared to factors secreted by statically cultured osteocytes. Secondly, paracrine factors secreted by mechanically stimulated osteoblasts significantly enhanced MSC migration but surprisingly, in contrast to the osteocyte secretome, inhibited MSC proliferation when compared to factors secreted by statically cultured osteoblasts. A similar trend was observed in osteoblasts. This study provides new information on mechanically driven signalling mechanisms in bone and highlights a contrasting secretome between cells at different stages in the bone lineage, furthering our understanding of loading-induced bone formation and indirect biophysical regulation of osteoprogenitors. - Highlights: • Physically stimulated osteocytes secrete factors that regulate osteoprogenitors. • These factors enhance recruitment, proliferation and osteogenic differentiation. • Physically stimulated osteoblasts secrete factors that also regulate progenitors. • These factors enhance recruitment but inhibit proliferation of osteoprogenitors. • This study highlights a contrasting

Mechanically stimulated bone cells secrete paracrine factors that regulate osteoprogenitor recruitment, proliferation, and differentiation

Energy Technology Data Exchange (ETDEWEB)

Brady, Robert T. [Tissue Engineering Research Group, Dept. of Anatomy, Royal College of Surgeons in Ireland (Ireland); Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin (Ireland); Advanced Materials and BioEngineering Research Centre (AMBER), Trinity College Dublin & Royal College of Surgeons in Ireland (Ireland); Dept. of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick (Ireland); O' Brien, Fergal J. [Tissue Engineering Research Group, Dept. of Anatomy, Royal College of Surgeons in Ireland (Ireland); Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin (Ireland); Advanced Materials and BioEngineering Research Centre (AMBER), Trinity College Dublin & Royal College of Surgeons in Ireland (Ireland); Hoey, David A., E-mail: david.hoey@ul.ie [Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin (Ireland); Dept. of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick (Ireland); The Centre for Applied Biomedical Engineering Research, University of Limerick (Ireland); Materials & Surface Science Institute, University of Limerick (Ireland)

2015-03-27

Bone formation requires the recruitment, proliferation and osteogenic differentiation of mesenchymal progenitors. A potent stimulus driving this process is mechanical loading, yet the signalling mechanisms underpinning this are incompletely understood. The objective of this study was to investigate the role of the mechanically-stimulated osteocyte and osteoblast secretome in coordinating progenitor contributions to bone formation. Initially osteocytes (MLO-Y4) and osteoblasts (MC3T3) were mechanically stimulated for 24hrs and secreted factors within the conditioned media were collected and used to evaluate mesenchymal stem cell (MSC) and osteoblast recruitment, proliferation and osteogenesis. Paracrine factors secreted by mechanically stimulated osteocytes significantly enhanced MSC migration, proliferation and osteogenesis and furthermore significantly increased osteoblast migration and proliferation when compared to factors secreted by statically cultured osteocytes. Secondly, paracrine factors secreted by mechanically stimulated osteoblasts significantly enhanced MSC migration but surprisingly, in contrast to the osteocyte secretome, inhibited MSC proliferation when compared to factors secreted by statically cultured osteoblasts. A similar trend was observed in osteoblasts. This study provides new information on mechanically driven signalling mechanisms in bone and highlights a contrasting secretome between cells at different stages in the bone lineage, furthering our understanding of loading-induced bone formation and indirect biophysical regulation of osteoprogenitors. - Highlights: • Physically stimulated osteocytes secrete factors that regulate osteoprogenitors. • These factors enhance recruitment, proliferation and osteogenic differentiation. • Physically stimulated osteoblasts secrete factors that also regulate progenitors. • These factors enhance recruitment but inhibit proliferation of osteoprogenitors. • This study highlights a contrasting

Menadione induces G2/M arrest in gastric cancer cells by down-regulation of CDC25C and proteasome mediated degradation of CDK1 and cyclin B1

Science.gov (United States)

Lee, Min Ho; Cho, Yoonjung; Kim, Do Hyun; Woo, Hyun Jun; Yang, Ji Yeong; Kwon, Hye Jin; Yeon, Min Ji; Park, Min; Kim, Sa-Hyun; Moon, Cheol; Tharmalingam, Nagendran; Kim, Tae Ue; Kim, Jong-Bae

2016-01-01

Menadione (vitamin K3) has been reported to induce apoptotic cell death and growth inhibition in various types of cancer cells. However, involvement of menadione in cell cycle control has not been considered in gastric cancer cells yet. In the current study, we have investigated whether menadione is involved in the cell cycle regulation and suppression of growth in gastric cancer cells. In the cell cycle analysis, we found that menadione induced G2/M cell cycle arrest in AGS cells. To elucidate the underlying mechanism, we investigated the cell cycle regulatory molecules involved in the G2/M cell cycle transition. After 24 h of menadione treatment, the protein level of CDK1, CDC25C and cyclin B1 in AGS cells was decreased in a menadione dose-dependent manner. In the time course experiment, the protein level of CDC25C decreased in 6 h, and CDK1and cyclin B1 protein levels began to decrease after 18 h of menadione treatment. We found that mRNA level of CDC25C decreased by menadione treatment in 6 h. Menadione did not have an influence on mRNA level of CDK1 and cyclin B1 though the protein levels were decreased. However, the decreased protein levels of CDK1 and cyclin B1 were recovered by inhibition of proteasome. Collectively, these results suggest that menadione inhibits growth of gastric cancer cells by reducing expression of CDC25C and promoting proteasome mediated degradation of CDK1 and cyclin B1 thereby blocking transition of the cell cycle from G2 phase to M phase. PMID:28077999

Chk1 regulates the S phase checkpoint by coupling the physiological turnover and ionizing radiation-induced accelerated proteolysis of Cdc25A

DEFF Research Database (Denmark)

Sørensen, Claus Storgaard; Syljuåsen, Randi G; Falck, Jacob

2003-01-01

Chk1 kinase coordinates cell cycle progression and preserves genome integrity. Here, we show that chemical or genetic ablation of human Chk1 triggered supraphysiological accumulation of the S phase-promoting Cdc25A phosphatase, prevented ionizing radiation (IR)-induced degradation of Cdc25A...

Injectable calcium sulfate/mineralized collagen-based bone repair materials with regulable self-setting properties.

Science.gov (United States)

Chen, Zonggang; Liu, Huanye; Liu, Xi; Cui, Fu-Zhai

2011-12-15

An injectable and self-setting bone repair materials (nano-hydroxyapatite/collagen/calcium sulfate hemihydrate, nHAC/CSH) was developed in this study. The nano-hydroxyapatite/collagen (nHAC) composite, which is the mineralized fibril by self-assembly of nano-hydrocyapatite and collagen, has the same features as natural bone in both main hierarchical microstructure and composition. It is a bioactive osteoconductor due to its high level of biocompatibility and appropriate degradation rate. However, this material lacks handling characteristics because of its particle or solid-preformed block shape. Herein, calcium sulfate hemihydrate (CSH) was introduced into nHAC to prepare an injectable and self-setting in situ bone repair materials. The morphology of materials was observed using SEM. Most important and interesting of all, calcium sulfate dihydrate (CSD), which is not only the reactant of preparing CSH but also the final solidified product of CSH, was introduced into nHAC as setting accelerator to regulate self-setting properties of injectable nHAC/CSH composite, and thus the self-setting time of nHAC/CSH composite can be regulated from more than 100 min to about 30 min and even less than 20 min by adding various amount of setting accelerator. The compressive properties of bone graft substitute after final setting are similar to those of cancellous bone. CSD as an excellent setting accelerator has no significant effect on the mechanical property and degradability of bone repair materials. In vitro biocompatibility and in vivo histology studies demonstrated that the nHAC/CSH composite could provide more adequate stimulus for cell adhesion and proliferation, embodying favorable cell biocompatibility and a strong ability to accelerate bone formation. It can offer a satisfactory biological environment for growing new bone in the implants and for stimulating bone formation. Copyright © 2011 Wiley Periodicals, Inc.

CDC WONDER: Births

Data.gov (United States)

U.S. Department of Health & Human Services — The Births (Natality) online databases in CDC WONDER report birth rates, fertility rates and counts of live births occurring within the United States to U.S....

New role for Cdc14 phosphatase: localization to basal bodies in the oomycete phytophthora and its evolutionary coinheritance with eukaryotic flagella.

Directory of Open Access Journals (Sweden)

Audrey M V Ah-Fong

Full Text Available Cdc14 protein phosphatases are well known for regulating the eukaryotic cell cycle, particularly during mitosis. Here we reveal a distinctly new role for Cdc14 based on studies of the microbial eukaryote Phytophthora infestans, the Irish potato famine agent. While Cdc14 is transcribed constitutively in yeast and animal cells, the P. infestans ortholog is expressed exclusively in spore stages of the life cycle and not in vegetative hyphae where the bulk of mitosis takes place. PiCdc14 expression is first detected in nuclei at sporulation, and during zoospore formation the protein accumulates at the basal body, which is the site from which flagella develop. The association of PiCdc14 with basal bodies was supported by co-localization studies with the DIP13 basal body protein and flagellar β-tubulin, and by demonstrating the enrichment of PiCdc14 in purified flagella-basal body complexes. Overexpressing PiCdc14 did not cause defects in growth or mitosis in hyphae, but interfered with cytoplasmic partitioning during zoosporogenesis. This cytokinetic defect might relate to its ability to bind microtubules, which was shown using an in vitro cosedimentation assay. The use of gene silencing to reveal the precise function of PiCdc14 in flagella is not possible since we showed previously that silencing prevents the formation of the precursor stage, sporangia. Nevertheless, the association of Cdc14 with flagella and basal bodies is consistent with their phylogenetic distribution in eukaryotes, as species that lack the ability to produce flagella generally also lack Cdc14. An ancestral role of Cdc14 in the flagellar stage of eukaryotes is thereby proposed.

Decreased uv mutagenesis in cdc8, a DNA replication mutant of Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Prakash, L.; Hinkle, D.; Prakash, S.

1978-01-01

A DNA replication mutant of yeast, cdc8, was found to decrease uv-induced reversion of lys2-1, arg4-17, tryl and ural. This effect was observed with all three alleles of cdc8 tested. Survival curves obtained following uv irradiation in cdc8 rad double mutants show that cdc8 is epistatic to rad6, as well as to rad1; cdc8 rad51 double mutants seem to be more sensitive than the single mutants. Since uv-induced reversion in cdc8 rad1 and cdc8 rad51 double mutants is like that of the cdc8 single mutants, we conclude that CDC8 plays a direct role in error-prone repair. To test whether CDC8 codes for a DNA polymerase, we have purified both DNA polymerase I and DNA polymerase II from cdc8 and CDC+ cells. The purified DNA polymerases from cdc8 were no more heat labile than those from CDC+, suggesting that CDC8 is not a structural gene for either enzyme

Calcium Regulation and Bone Mineral Metabolism in Elderly Patients with Chronic Kidney Disease

Directory of Open Access Journals (Sweden)

Vickram Tejwani

2013-05-01

Full Text Available The elderly chronic kidney disease (CKD population is growing. Both aging and CKD can disrupt calcium (Ca2+ homeostasis and cause alterations of multiple Ca2+-regulatory mechanisms, including parathyroid hormone, vitamin D, fibroblast growth factor-23/Klotho, calcium-sensing receptor and Ca2+-phosphate product. These alterations can be deleterious to bone mineral metabolism and soft tissue health, leading to metabolic bone disease and vascular calcification and aging, termed CKD-mineral and bone disorder (MBD. CKD-MBD is associated with morbid clinical outcomes, including fracture, cardiovascular events and all-cause mortality. In this paper, we comprehensively review Ca2+ regulation and bone mineral metabolism, with a special emphasis on elderly CKD patients. We also present the current treatment-guidelines and management options for CKD-MBD.

Bone remodelling: its local regulation and the emergence of bone fragility.

Science.gov (United States)

Martin, T John; Seeman, Ego

2008-10-01

Bone modelling prevents the occurrence of damage by adapting bone structure - and hence bone strength - to its loading circumstances. Bone remodelling removes damage, when it inevitably occurs, in order to maintain bone strength. This cellular machinery is successful during growth, but fails during advancing age because of the development of a negative balance between the volumes of bone resorbed and formed during remodelling by the basic multicellular unit (BMU), high rates of remodelling during midlife in women and late in life in both sexes, and a decline in periosteal bone formation. together resulting in bone loss and structural decay each time a remodelling event occurs. The two steps in remodelling - resorption of a volume of bone by osteoclasts and formation of a comparable volume by osteoblasts - are sequential, but the regulatory events leading to these two fully differentiated functions are not. Reparative remodelling is initiated by damage producing osteocyte apoptosis, which signals the location of damage via the osteocyte canalicular system to endosteal lining cells which forms the canopy of a bone-remodelling compartment (BRC). Within the BRC, local recruitment of osteoblast precursors from the lining cells, the marrow and circulation, direct contact with osteoclast precursors, osteoclastogenesis and molecular cross-talk between precursors, mature cells, cells of the immune system, and products of the resorbed matrix, titrate the birth, work and lifespan of the cells of this multicellular remodelling machinery to either remove or form a net volume of bone appropriate to the mechanical requirements.

Targeting Hsp90-Cdc37: A Promising Therapeutic Strategy by Inhibiting Hsp90 Chaperone Function.

Science.gov (United States)

Wang, Lei; Li, Li; Gu, Kai; Xu, Xiao-Li; Sun, Yuan; You, Qi-Dong

2017-01-01

The Hsp90 chaperone protein regulates the folding, maturation and stability of a wide variety of oncoproteins. In recent years, many Hsp90 inhibitors have entered into the clinical trials while all of them target ATPase showing similar binding capacity and kinds of side-effects so that none have reached to the market. During the regulation progress, numerous protein- protein interactions (PPI) such as Hsp90 and client proteins or cochaperones are involved. With the Hsp90-cochaperones PPI networks being more and more clear, many cancerous proteins have been reported to be tightly correlated to Hsp90-cochaperones PPI. Among them, Hsp90-Cdc37 PPI has been widely reported to associate with numerous protein kinases, making it a novel target for the treatment of cancers. In this paper, we briefly review the strategies and modulators targeting Hsp90-Cdc37 complex including direct and indirect regulation mechanism. Through these discussions we expect to present inspirations for new insights into an alternative way to inhibit Hsp90 chaperone function. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Isolation of a cdc28 mutation that abrogates the dependence of S ...

Indian Academy of Sciences (India)

We have isolated a mutation in the budding yeast Saccharomyces cerevisisae CDC28 gene that allows cdc13 cells, carrying damaged DNA, to continue with the cell division cycle. While cdc13 mutant cells are arrested as large-budded cells at the nonpermissive temperature 37°C, the cdc13 cdc28 double mutant culture ...

Conjugated linoleic acid prevents age-induced bone loss in mice by regulating both osteoblastogenesis and adipogenesis.

Science.gov (United States)

Lin, Guanlin; Wang, Huan; Dai, Jun; Li, Xiao; Guan, Ming; Gao, Shutao; Ding, Qing; Wang, Huaixi; Fang, Huang

2017-08-26

Osteoporosis (OP) can increase the risk of bone fracture and other complications, which is a major clinical problem. Previous researches have revealed that conjugated linoleic acid (CLA) can promote the bone formation. But the mechanisms are not clear. Thus, we tested the hypothesis that CLA acts on bone formation might be via mTOR Complex1 (mTORC 1) pathway by in vitro and vivo assays. We studied the effect of CLA mix on MC3T3-E1 pre-osteoblasts differentiation into osteoblasts, and bone formation under osteoporotic conditions. At the same time, 3T3-L1 pre-adipocyte with the same CLA mix concentration gradient for 8 days with adipogenic differentiation medium. We found that Alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN) expressions of pre-osteoblasts were up-regulated. Moreover in presence of CLA, peroxisome proliferators-activated receptor γ(PPARγ) and CCAAT/enhancer-binding protein (C/EBPα) were down-regulated. Osteoporosis mice bone parameters in the distal femoral meraphysis were significantly increased compared with placebo mice. Furthermore, the phosphor-S6 (P-S6) was suppressed and phosphor-AKT (P-AKT) was up-regulated. Consistently, CLA can stimulate differentiation of osteoblasts and inhibited pre-adipocytes differentiated into adipocytes via AKT/mTORC1 signal pathway. Overall CLA thus be a suitable candidate for the treatment of patients with postmenopausal osteoporosis and obesity. Copyright © 2017 Elsevier Inc. All rights reserved.

42 CFR 57.216 - What additional Department regulations apply to schools?

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false What additional Department regulations apply to schools? 57.216 Section 57.216 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN... schools? (a) Participating schools are advised that in addition to complying with the terms and conditions...

Regulated eukaryotic DNA replication origin firing with purified proteins.

Science.gov (United States)

Yeeles, Joseph T P; Deegan, Tom D; Janska, Agnieszka; Early, Anne; Diffley, John F X

2015-03-26

Eukaryotic cells initiate DNA replication from multiple origins, which must be tightly regulated to promote precise genome duplication in every cell cycle. To accomplish this, initiation is partitioned into two temporally discrete steps: a double hexameric minichromosome maintenance (MCM) complex is first loaded at replication origins during G1 phase, and then converted to the active CMG (Cdc45-MCM-GINS) helicase during S phase. Here we describe the reconstitution of budding yeast DNA replication initiation with 16 purified replication factors, made from 42 polypeptides. Origin-dependent initiation recapitulates regulation seen in vivo. Cyclin-dependent kinase (CDK) inhibits MCM loading by phosphorylating the origin recognition complex (ORC) and promotes CMG formation by phosphorylating Sld2 and Sld3. Dbf4-dependent kinase (DDK) promotes replication by phosphorylating MCM, and can act either before or after CDK. These experiments define the minimum complement of proteins, protein kinase substrates and co-factors required for regulated eukaryotic DNA replication.

Regulation of Long Bone Growth in Vertebrates; It Is Time to Catch Up.

Science.gov (United States)

Roselló-Díez, Alberto; Joyner, Alexandra L

2015-12-01

The regulation of organ size is essential to human health and has fascinated biologists for centuries. Key to the growth process is the ability of most organs to integrate organ-extrinsic cues (eg, nutritional status, inflammatory processes) with organ-intrinsic information (eg, genetic programs, local signals) into a growth response that adapts to changing environmental conditions and ensures that the size of an organ is coordinated with the rest of the body. Paired organs such as the vertebrate limbs and the long bones within them are excellent models for studying this type of regulation because it is possible to manipulate one member of the pair and leave the other as an internal control. During development, growth plates at the end of each long bone produce a transient cartilage model that is progressively replaced by bone. Here, we review how proliferation and differentiation of cells within each growth plate are tightly controlled mainly by growth plate-intrinsic mechanisms that are additionally modulated by extrinsic signals. We also discuss the involvement of several signaling hubs in the integration and modulation of growth-related signals and how they could confer remarkable plasticity to the growth plate. Indeed, long bones have a significant ability for "catch-up growth" to attain normal size after a transient growth delay. We propose that the characterization of catch-up growth, in light of recent advances in physiology and cell biology, will provide long sought clues into the molecular mechanisms that underlie organ growth regulation. Importantly, catch-up growth early in life is commonly associated with metabolic disorders in adulthood, and this association is not completely understood. Further elucidation of the molecules and cellular interactions that influence organ size coordination should allow development of novel therapies for human growth disorders that are noninvasive and have minimal side effects.

Genetic regulation of bone metabolism in the chicken: similarities and differences to Mammalian systems.

Directory of Open Access Journals (Sweden)

Martin Johnsson

2015-05-01

Full Text Available Birds have a unique bone physiology, due to the demands placed on them through egg production. In particular their medullary bone serves as a source of calcium for eggshell production during lay and undergoes continuous and rapid remodelling. We take advantage of the fact that bone traits have diverged massively during chicken domestication to map the genetic basis of bone metabolism in the chicken. We performed a quantitative trait locus (QTL and expression QTL (eQTL mapping study in an advanced intercross based on Red Junglefowl (the wild progenitor of the modern domestic chicken and White Leghorn chickens. We measured femoral bone traits in 456 chickens by peripheral computerised tomography and femoral gene expression in a subset of 125 females from the cross with microarrays. This resulted in 25 loci for female bone traits, 26 loci for male bone traits and 6318 local eQTL loci. We then overlapped bone and gene expression loci, before checking for an association between gene expression and trait values to identify candidate quantitative trait genes for bone traits. A handful of our candidates have been previously associated with bone traits in mice, but our results also implicate unexpected and largely unknown genes in bone metabolism. In summary, by utilising the unique bone metabolism of an avian species, we have identified a number of candidate genes affecting bone allocation and metabolism. These findings can have ramifications not only for the understanding of bone metabolism genetics in general, but could also be used as a potential model for osteoporosis as well as revealing new aspects of vertebrate bone regulation or features that distinguish avian and mammalian bone.

42 CFR 59.1 - To what programs do these regulations apply?

Science.gov (United States)

2010-10-01

... FOR FAMILY PLANNING SERVICES Project Grants for Family Planning Services § 59.1 To what programs do... 42 Public Health 1 2010-10-01 2010-10-01 false To what programs do these regulations apply? 59.1... of voluntary family planning projects. These projects shall consist of the educational, comprehensive...

CDC Kerala 1: Organization of clinical child development services (1987-2013).

Science.gov (United States)

Nair, M K C; George, Babu; Nair, G S Harikumaran; Bhaskaran, Deepa; Leena, M L; Russell, Paul Swamidhas Sudhakar

2014-12-01

The main objective of establishing the Child Development Centre (CDC), Kerala for piloting comprehensive child adolescent development program in India, has been to understand the conceptualization, design and scaling up of a pro-active positive child development initiative, easily replicable all over India. The process of establishing the Child Development Centre (CDC) Kerala for research, clinical services, training and community extension services over the last 25 y, has been as follows; Step 1: Conceptualization--The life cycle approach to child development; Step 2: Research basis--CDC model early stimulation is effective; Step 3: Development and validation of seven simple developmental screening tools; Step 4: CDC Diagnostic services--Ultrasonology and genetic, and metabolic laboratory; Step 5: Developing seven intervention packages; Step 6: Training--Post graduate diploma in clinical child development; Step 7: CDC Clinic Services--seven major ones; Step 8: CDC Community Services--Child development referral units; Step 9: Community service delivery models--Childhood disability and for adolescent care counselling projects; Step 10: National capacity building--Four child development related courses. CDC Kerala follow-up and clinic services are offered till 18 y of age and premarital counselling till 24 y of age as shown in "CDC Kerala Clinic Services Flow Chart" and 74,291 children have availed CDC clinic services in the last 10 y. CDC Kerala is the first model for comprehensive child adolescent development services using a lifecycle approach in the Government sector and hence declared as the collaborative centre for Rashtriya Bal Swasthya Karyakram (RBSK), in Kerala.

Anti-osteoporotic activity of harpagide by regulation of bone formation in osteoblast cell culture and ovariectomy-induced bone loss mouse models.

Science.gov (United States)

Chung, Hwa-Jin; Kyung Kim, Won; Joo Park, Hyen; Cho, Lan; Kim, Me-Riong; Kim, Min Jeong; Shin, Joon-Shik; Ho Lee, Jin; Ha, In-Hyuk; Kook Lee, Sang

2016-02-17

Harpagide, an iridoid glucoside, is a constituent of the root of Harpagophytum procumbens var. sublobatum (Engl.) Stapf, Devil's claw which has been used in patients with osteoarthritis (OA). In the present study, we investigated the anti-osteoporotic potential of harpagide and its underlying mechanism of action in in vitro cell culture and in vivo bone loss animal models. Harpagide was obtained from the alkalic hydrolysis of harpagoside, a major constituent of H. procumbens var. sublobatum Analysis of biomarkers for bone formation in osteoblastic MC3T3-E1 cells and bone resorption in osteoclast cells derived from mouse bone marrow cells was performed to evaluate the mechanism of action. The protective activity of harpagide against bone loss was also evaluated in ovariectomized (OVX) mouse model. Harpagide improved bone properties by stimulating the process of differentiation and maturation of osteoblast cells and suppressing the process of RANKL-induced differentiation of osteoclast cells. In OVX-induced bone loss mouse model, oral administration of harpagide significantly improved recovery of bone mineral density, trabecular bone volume, and trabecular number in the femur. Harpagide also prevented increase of trabecular separation and structure model index induced by OVX. Harpagide effectively inhibited the serum levels of biochemical markers of bone loss, including alkaline phosphatase, osteocalcin, C-terminal telopeptide, and tartrate-resistant acid phosphatase. Taken together, the present study demonstrates that harpagide has a potential for prevention of bone loss in OVX mice by regulating the stimulation of osteoblast differentiation and the suppression of osteoclast formation. Therefore, these findings suggest that harpagide might serve as a bioactive compound derived from H. procumbens var. sublobatum for improvement of age-dependent bone destruction disease. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Vitamin B12–dependent taurine synthesis regulates growth and bone mass

Science.gov (United States)

Roman-Garcia, Pablo; Quiros-Gonzalez, Isabel; Mottram, Lynda; Lieben, Liesbet; Sharan, Kunal; Wangwiwatsin, Arporn; Tubio, Jose; Lewis, Kirsty; Wilkinson, Debbie; Santhanam, Balaji; Sarper, Nazan; Clare, Simon; Vassiliou, George S.; Velagapudi, Vidya R.; Dougan, Gordon; Yadav, Vijay K.

2014-01-01

Both maternal and offspring-derived factors contribute to lifelong growth and bone mass accrual, although the specific role of maternal deficiencies in the growth and bone mass of offspring is poorly understood. In the present study, we have shown that vitamin B12 (B12) deficiency in a murine genetic model results in severe postweaning growth retardation and osteoporosis, and the severity and time of onset of this phenotype in the offspring depends on the maternal genotype. Using integrated physiological and metabolomic analysis, we determined that B12 deficiency in the offspring decreases liver taurine production and associates with abrogation of a growth hormone/insulin-like growth factor 1 (GH/IGF1) axis. Taurine increased GH-dependent IGF1 synthesis in the liver, which subsequently enhanced osteoblast function, and in B12-deficient offspring, oral administration of taurine rescued their growth retardation and osteoporosis phenotypes. These results identify B12 as an essential vitamin that positively regulates postweaning growth and bone formation through taurine synthesis and suggests potential therapies to increase bone mass. PMID:24911144

42 CFR 50.402 - To what program do these regulations apply?

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false To what program do these regulations apply? 50.402 Section 50.402 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS POLICIES OF GENERAL APPLICABILITY Public Health Service Grant Appeals Procedure § 50.402 To what program do...

CDC Child Growth Charts

Data.gov (United States)

U.S. Department of Health & Human Services — CDC child growth charts consist of a series of percentile curves that illustrate the distribution of selected body measurements in U.S. children. Pediatric growth...

Fission yeast cdc24(+) encodes a novel replication factor required for chromosome integrity.

Science.gov (United States)

Gould, K L; Burns, C G; Feoktistova, A; Hu, C P; Pasion, S G; Forsburg, S L

1998-07-01

A mutation within the Schizosaccharomyces pombe cdc24(+) gene was identified previously in a screen for cell division cycle mutants and the cdc24(+) gene was determined to be essential for S phase in this yeast. We have isolated the cdc24(+) gene by complementation of a new temperature-sensitive allele of the gene, cdc24-G1. The DNA sequence predicts the presence of an open reading frame punctuated by six introns which encodes a pioneer protein of 58 kD. A cdc24 null mutant was generated by homologous recombination. Haploid cells lacking cdc24(+) are inviable, indicating that cdc24(+) is an essential gene. The transcript of cdc24(+) is present at constant levels throughout the cell cycle. Cells lacking cdc24(+) function show a checkpoint-dependent arrest with a 2N DNA content, indicating a block late in S phase. Arrest is accompanied by a rapid loss of viability and chromosome breakage. An S. pombe homolog of the replicative DNA helicase DNA2 of S. cerevisiae suppresses cdc24. These results suggest that Cdc24p plays a role in the progression of normal DNA replication and is required to maintain genomic integrity.

Chronic central administration of Ghrelin increases bone mass through a mechanism independent of appetite regulation.

Directory of Open Access Journals (Sweden)

Hyung Jin Choi

Full Text Available Leptin plays a critical role in the central regulation of bone mass. Ghrelin counteracts leptin. In this study, we investigated the effect of chronic intracerebroventricular administration of ghrelin on bone mass in Sprague-Dawley rats (1.5 μg/day for 21 days. Rats were divided into control, ghrelin ad libitum-fed (ghrelin ad lib-fed, and ghrelin pair-fed groups. Ghrelin intracerebroventricular infusion significantly increased body weight in ghrelin ad lib-fed rats but not in ghrelin pair-fed rats, as compared with control rats. Chronic intracerebroventricular ghrelin infusion significantly increased bone mass in the ghrelin pair-fed group compared with control as indicated by increased bone volume percentage, trabecular thickness, trabecular number and volumetric bone mineral density in tibia trabecular bone. There was no significant difference in trabecular bone mass between the control group and the ghrelin ad-lib fed group. Chronic intracerebroventricular ghrelin infusion significantly increased the mineral apposition rate in the ghrelin pair-fed group as compared with control. In conclusion, chronic central administration of ghrelin increases bone mass through a mechanism that is independent of body weight, suggesting that ghrelin may have a bone anabolic effect through the central nervous system.

Bone remodeling and regulating biomarkers in women at the time of breast cancer diagnosis.

Science.gov (United States)

Yao, Song; Zhang, Yali; Tang, Li; Roh, Janise M; Laurent, Cecile A; Hong, Chi-Chen; Hahn, Theresa; Lo, Joan C; Ambrosone, Christine B; Kushi, Lawrence H; Kwan, Marilyn L

2017-02-01

The majority of breast cancer patients receive endocrine therapy, including aromatase inhibitors known to cause increased bone resorption. Bone-related biomarkers at the time of breast cancer diagnosis may predict future risk of osteoporosis and fracture after endocrine therapy. In a large population of 2,401 female breast cancer patients who later underwent endocrine therapy, we measured two bone remodeling biomarkers, TRAP5b and BAP, and two bone regulating biomarkers, RANKL and OPG, in serum samples collected at the time of breast cancer diagnosis. We analyzed these biomarkers and their ratios with patients' demographic, lifestyle, clinical tumor characteristics, as well as bone health history. The presence of bone metastases, prior bisphosphonate (BP) treatment, and blood collection after chemotherapy had a significant impact on biomarker levels. After excluding these cases and controlling for blood collection time, several factors, including age, race/ethnicity, body mass index, physical activity, alcohol consumption, smoking, and hormonal replacement therapy, were significantly associated with bone biomarkers, while vitamin D or calcium supplements and tumor characteristics were not. When prior BP users were included in, recent history of osteoporosis and fracture was also associated. Our findings support further investigation of these biomarkers with bone health outcomes after endocrine therapy initiation in women with breast cancer.

CDC Best Practices for Comprehensive Tobacco Control Programs - 2007

Data.gov (United States)

U.S. Department of Health & Human Services — Centers for Disease Control and Prevention (CDC). Best Practices for Comprehensive Tobacco Control Programs. Funding. CDC's Best Practices for Comprehensive Tobacco...

CDC Best Practices for Comprehensive Tobacco Control Programs - 2014

Data.gov (United States)

U.S. Department of Health & Human Services — Centers for Disease Control and Prevention (CDC). Best Practices for Comprehensive Tobacco Control Programs. Funding. CDC's Best Practices for Comprehensive Tobacco...

Cdc45-induced loading of human RPA onto single-stranded DNA.

Science.gov (United States)

Szambowska, Anna; Tessmer, Ingrid; Prus, Piotr; Schlott, Bernhard; Pospiech, Helmut; Grosse, Frank

2017-04-07

Cell division cycle protein 45 (Cdc45) is an essential component of the eukaryotic replicative DNA helicase. We found that human Cdc45 forms a complex with the single-stranded DNA (ssDNA) binding protein RPA. Moreover, it actively loads RPA onto nascent ssDNA. Pull-down assays and surface plasmon resonance studies revealed that Cdc45-bound RPA complexed with ssDNA in the 8-10 nucleotide binding mode, but dissociated when RPA covered a 30-mer. Real-time analysis of RPA-ssDNA binding demonstrated that Cdc45 catalytically loaded RPA onto ssDNA. This placement reaction required physical contacts of Cdc45 with the RPA70A subdomain. Our results imply that Cdc45 controlled stabilization of the 8-nt RPA binding mode, the subsequent RPA transition into 30-mer mode and facilitated an ordered binding to ssDNA. We propose that a Cdc45-mediated loading guarantees a seamless deposition of RPA on newly emerging ssDNA at the nascent replication fork. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Cdc15 Phosphorylates the C-terminal Domain of RNA Polymerase II for Transcription during Mitosis.

Science.gov (United States)

Singh, Amit Kumar; Rastogi, Shivangi; Shukla, Harish; Asalam, Mohd; Rath, Srikanta Kumar; Akhtar, Md Sohail

2017-03-31

In eukaryotes, the basal transcription in interphase is orchestrated through the regulation by kinases (Kin28, Bur1, and Ctk1) and phosphatases (Ssu72, Rtr1, and Fcp1), which act through the post-translational modification of the C-terminal domain (CTD) of the largest subunit of RNA polymerase II. The CTD comprises the repeated Tyr-Ser-Pro-Thr-Ser-Pro-Ser motif with potential epigenetic modification sites. Despite the observation of transcription and periodic expression of genes during mitosis with entailing CTD phosphorylation and dephosphorylation, the associated CTD specific kinase(s) and its role in transcription remains unknown. Here we have identified Cdc15 as a potential kinase phosphorylating Ser-2 and Ser-5 of CTD for transcription during mitosis in the budding yeast. The phosphorylation of CTD by Cdc15 is independent of any prior Ser phosphorylation(s). The inactivation of Cdc15 causes reduction of global CTD phosphorylation during mitosis and affects the expression of genes whose transcript levels peak during mitosis. Cdc15 also influences the complete transcription of clb2 gene and phosphorylates Ser-5 at the promoter and Ser-2 toward the 3' end of the gene. The observation that Cdc15 could phosphorylate Ser-5, as well as Ser-2, during transcription in mitosis is in contrast to the phosphorylation marks put by the kinases in interphase (G 1 , S, and G 2 ), where Cdck7/Kin28 phosphorylates Ser-5 at promoter and Bur1/Ctk1 phosphorylates Ser-2 at the 3' end of the genes. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

The effect of DNA replication on mutation of the Saccharomyces cerevisiae CDC8 gene.

Science.gov (United States)

Zaborowska, D; Zuk, J

1990-04-01

Incubation in YPD medium under permissive conditions when DNA replication is going on, strongly stimulates the induction of cdc+ colonies of UV-irradiated cells of yeast strains HB23 (cdc8-1/cdc8-3), HB26 (cdc8-3/cdc8-3) and HB7 (cdc8-1/cdc8-1). Inhibition of DNA replication by hydroxyurea, araCMP, cycloheximide or caffeine or else by incubation in phosphate buffer pH 7.0, abolishes this stimulation. Thus the replication of DNA is strongly correlated with the high induction of cdc+ colonies by UV irradiation. It is postulated that these UV-induced cdc+ colonies arise as the result infidelity in DNA replication.

Optimal experimental design in an epidermal growth factor receptor signalling and down-regulation model.

Science.gov (United States)

Casey, F P; Baird, D; Feng, Q; Gutenkunst, R N; Waterfall, J J; Myers, C R; Brown, K S; Cerione, R A; Sethna, J P

2007-05-01

We apply the methods of optimal experimental design to a differential equation model for epidermal growth factor receptor signalling, trafficking and down-regulation. The model incorporates the role of a recently discovered protein complex made up of the E3 ubiquitin ligase, Cbl, the guanine exchange factor (GEF), Cool-1 (beta -Pix) and the Rho family G protein Cdc42. The complex has been suggested to be important in disrupting receptor down-regulation. We demonstrate that the model interactions can accurately reproduce the experimental observations, that they can be used to make predictions with accompanying uncertainties, and that we can apply ideas of optimal experimental design to suggest new experiments that reduce the uncertainty on unmeasurable components of the system.

The protection of acetylcholinesterase inhibitor on β-amyloid-induced injury of neurite outgrowth via regulating axon guidance related genes expression in neuronal cells

OpenAIRE

Shen, Jiao-Ning; Wang, Deng-Shun; Wang, Rui

2012-01-01

Cognitive deficits in AD correlate with progressive synaptic dysfunction and loss. The Rho family of small GTPases, including Rho, Rac, and Cdc42, has a central role in cellular motility and cytokinesis. Acetylcholinesterase inhibitor has been found to protect cells against a broad range of reagents-induced injuries. Present studies examined if the effect of HupA on neurite outgrowth in Aβ-treated neuronal cells executed via regulating Rho-GTPase mediated axon guidance relative gene expressio...

Discovery and characterization of novel imidazopyridine derivative CHEQ-2 as a potent CDC25 inhibitor and promising anticancer drug candidate.

Science.gov (United States)

Song, Yu'ning; Lin, Xiaoqian; Kang, Dongwei; Li, Xiao; Zhan, Peng; Liu, Xinyong; Zhang, Qingzhu

2014-07-23

Cell division cycle (CDC) 25 proteins are key phosphatases regulating cell cycle transition and proliferation via the interactions with CDK/Cyclin complexes. Overexpression of CDC25 proteins is frequently observed in cancer and is related to aggressiveness, high-grade tumors and poor prognosis. Thus, inhibiting CDC25 activity in cancer treatment appears a good therapeutic strategy. In this article, refinement of the initial hit XDW-1 by synthesis and screening of a focused compound library led to the identification of a novel set of imidazopyridine derivatives as potent CDC25 inhibitors. Among them, the most potent molecule was CHEQ-2, which could efficiently inhibit the activities of CDC25A/B enzymes as well as the proliferation of various different types of cancer cell lines in vitro assay. Moreover, CHEQ-2 triggered S-phase cell cycle arrest in MCF-7, HepG2 and HT-29 cell lines, accompanied by generation of ROS, mitochondrial dysfunction and apoptosis. Besides, oral administration of CHEQ-2 (10 mg/kg) significantly inhibited xenografted human liver tumor growth in nude mice, while demonstrated extremely low toxicity (LD50 > 2000 mg/kg). These findings make CHEQ-2 a good starting point for further investigation and structure modification. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

β3-Adrenergic Regulation of EPC Features Through Manipulation of the Bone Marrow MSC Niche.

Science.gov (United States)

Vafaei, Rana; Nassiri, Seyed Mahdi; Siavashi, Vahid

2017-12-01

Mesenchymal stem cells (MSCs) reside in a specific niche in the bone marrow, however, biological features of this niche are still not fully understood. Given the interactions of MSCs with endothelial cells in different tissues, bone marrow MSC niche may influence the biological features of endothelial progenitor cells (EPCs). To understand the role of the sympathetic nervous system in regulation of the MSC niche, we examined whether the manipulation of the MSC niche via β3-adrenergic signals will affect EPC features. A selective β3 agonist (BRL37344) or a β3 antagonist (SR59230A) was administered in mice for 2 weeks to determine the potential effects of these regimens on the population of CD133 + stem cells in the bone marrow. Then, bone marrow-derived MSCs and EPCs were harvested and expanded from the mice to examine the effect of changes in the MSC niche on EPC features. Improved MSC colony forming potency with increased bone marrow stromal cell-derived factor 1 (SDF-1) (also known as C-X-C motif chemokine 12 [CXCL12]) expression was shown as a result of intensification of the bone marrow adrenergic signals through BRL37344 injection. On the other hand, the blockage of these signals limited the expression level of SDF-1 and resulted in bone marrow enrichment of CD133 + cells. Manipulation of the MSC niche and decreased SDF-1 expression via SR59230A injection also prompted EPCs to form more colonies with augmented proliferation and differentiation capacity. Overall, our results indicate that the β3-adrenergic signals regulate the MSC niche, thereby resulting in modulation of EPC biological features. J. Cell. Biochem. 118: 4753-4761, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Legumain Regulates Differentiation Fate of Human Bone Marrow Stromal Cells and Is Altered in Postmenopausal Osteoporosis

Directory of Open Access Journals (Sweden)

Abbas Jafari

2017-02-01

Full Text Available Secreted factors are a key component of stem cell niche and their dysregulation compromises stem cell function. Legumain is a secreted cysteine protease involved in diverse biological processes. Here, we demonstrate that legumain regulates lineage commitment of human bone marrow stromal cells and that its expression level and cellular localization are altered in postmenopausal osteoporotic patients. As shown by genetic and pharmacological manipulation, legumain inhibited osteoblast (OB differentiation and in vivo bone formation through degradation of the bone matrix protein fibronectin. In addition, genetic ablation or pharmacological inhibition of legumain activity led to precocious OB differentiation and increased vertebral mineralization in zebrafish. Finally, we show that localized increased expression of legumain in bone marrow adipocytes was inversely correlated with adjacent trabecular bone mass in a cohort of patients with postmenopausal osteoporosis. Our data suggest that altered proteolytic activity of legumain in the bone microenvironment contributes to decreased bone mass in postmenopausal osteoporosis.

Expression of CD44 3'-untranslated region regulates endogenous microRNA functions in tumorigenesis and angiogenesis.

Science.gov (United States)

Jeyapalan, Zina; Deng, Zhaoqun; Shatseva, Tatiana; Fang, Ling; He, Chengyan; Yang, Burton B

2011-04-01

The non-coding 3'-untranslated region (UTR) plays an important role in the regulation of microRNA (miRNA) functions, since it can bind and inactivate multiple miRNAs. Here, we show the 3'-UTR of CD44 is able to antagonize cytoplasmic miRNAs, and result in the increased translation of CD44 and downstream target mRNA, CDC42. A series of cell function assays in the human breast cancer cell line, MT-1, have shown that the CD44 3'-UTR inhibits proliferation, colony formation and tumor growth. Furthermore, it modulated endothelial cell activities, favored angiogenesis, induced tumor cell apoptosis and increased sensitivity to Docetaxel. These results are due to the interaction of the CD44 3'-UTR with multiple miRNAs. Computational algorithms have predicted three miRNAs, miR-216a, miR-330 and miR-608, can bind to both the CD44 and CDC42 3'-UTRs. This was confirmed with luciferase assays, western blotting and immunohistochemical staining and correlated with a series of siRNA assays. Thus, the non-coding CD44 3'-UTR serves as a competitor for miRNA binding and subsequently inactivates miRNA functions, by freeing the target mRNAs from being repressed.

Hispanic Health: CDC Vitalsigns

Science.gov (United States)

... Injury Prevention & Control Gateway to Health Communication & Social Marketing Practice On Other Web Sites MedlinePlus – Hispanic American ... MB] en Español [PDF – 1.61 MB] CDC Digital Press Kit Read the MMWR Science Clips Language: ...

Improved workability of injectable calcium sulfate bone cement by regulation of self-setting properties

Energy Technology Data Exchange (ETDEWEB)

Chen, Zonggang, E-mail: chenzg@sdu.edu.cn [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, Huanye [Department of Orthodontics, School of Stomatology, China Medical University, Shenyang 110001 (China); Liu, Xi [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Lian, Xiaojie [College of Mechanics, Taiyuan University of Technology, Taiyuan 030024 (China); Guo, Zhongwu [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Jiang, Hong-Jiang [Wendeng Hospital of Traditional Chinese Orthopedics and Traumatology, Shandong 264400 (China); Cui, Fu-Zhai, E-mail: cuifz@mail.tsinghua.edu.cn [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

2013-04-01

Calcium sulfate hemihydrate (CSH) powder as an injectable bone cement was prepared by hydrothermal synthesis of calcium sulfate dihydrate (CSD). The prepared materials showed X-ray diffraction peaks corresponding to the CSH structure without any secondary phases, implying complete conversion from CSD phase to CSH phase. Thermogravimetric (TG) analyses showed the crystal water content of CSH was about 6.0% (wt.), which is near to the theoretic crystal water value of CSH. From scanning electron microscopy (SEM) micrographs, sheet crystal structure of CSD was observed to transform into rod-like crystal structure of CSH. Most interesting and important of all, CSD as setting accelerator was also introduced into CSH powder to regulate self-setting properties of injectable CSH paste, and thus the self-setting time of CSH paste can be regulated from near 30 min to less than 5 min by adding various amounts of setting accelerator. Because CSD is not only the reactant of preparing CSH but also the final solidified product of CSH, the setting accelerator has no significant effect on the other properties of materials, such as mechanical properties. In vitro biocompatibility and in vivo histology studies have demonstrated that the materials have good biocompatibility and good efficacy in bone regeneration. All these will further improve the workability of CSH in clinic applications. Highlights: ► Calcium sulfate hemihydrate (CSH) can be an injectable bone cement. ► CSH was produced by hydrothermal synthesis of calcium sulfate dihydrate (CSD). ► CSD was introduced into CSH powder to regulate self-setting properties of CSH. ► Setting accelerator has no significant effect on the other properties of materials. ► Injectable CSH has good biocompatibility and good efficacy in bone regeneration.

Improved workability of injectable calcium sulfate bone cement by regulation of self-setting properties

International Nuclear Information System (INIS)

Chen, Zonggang; Liu, Huanye; Liu, Xi; Lian, Xiaojie; Guo, Zhongwu; Jiang, Hong-Jiang; Cui, Fu-Zhai

2013-01-01

Calcium sulfate hemihydrate (CSH) powder as an injectable bone cement was prepared by hydrothermal synthesis of calcium sulfate dihydrate (CSD). The prepared materials showed X-ray diffraction peaks corresponding to the CSH structure without any secondary phases, implying complete conversion from CSD phase to CSH phase. Thermogravimetric (TG) analyses showed the crystal water content of CSH was about 6.0% (wt.), which is near to the theoretic crystal water value of CSH. From scanning electron microscopy (SEM) micrographs, sheet crystal structure of CSD was observed to transform into rod-like crystal structure of CSH. Most interesting and important of all, CSD as setting accelerator was also introduced into CSH powder to regulate self-setting properties of injectable CSH paste, and thus the self-setting time of CSH paste can be regulated from near 30 min to less than 5 min by adding various amounts of setting accelerator. Because CSD is not only the reactant of preparing CSH but also the final solidified product of CSH, the setting accelerator has no significant effect on the other properties of materials, such as mechanical properties. In vitro biocompatibility and in vivo histology studies have demonstrated that the materials have good biocompatibility and good efficacy in bone regeneration. All these will further improve the workability of CSH in clinic applications. Highlights: ► Calcium sulfate hemihydrate (CSH) can be an injectable bone cement. ► CSH was produced by hydrothermal synthesis of calcium sulfate dihydrate (CSD). ► CSD was introduced into CSH powder to regulate self-setting properties of CSH. ► Setting accelerator has no significant effect on the other properties of materials. ► Injectable CSH has good biocompatibility and good efficacy in bone regeneration

Human CDT1 associates with CDC7 and recruits CDC45 to chromatin during S phase

DEFF Research Database (Denmark)

Ballabeni, Andrea; Zamponi, Raffaela; Caprara, Greta

2009-01-01

The initiation of DNA replication is a tightly controlled process that involves the formation of distinct complexes at origins of DNA replication at specific periods of the cell cycle. Pre-Replicative Complexes are formed during telophase and early G1. They rearrange at the start of S phase to form...... pre-Initiation Complexes, which are a prerequisite for DNA replication. The CDT1 protein is required for the formation of the pre-Replicative Complexes. Here we show that human CDT1 associates with the CDC7 kinase and recruits CDC45 to chromatin. Moreover, we show that the amount of CDT1 bound...

CDC Vital Signs–Opioid Prescribing

Centers for Disease Control (CDC) Podcasts

2017-07-06

This podcast is based on the July 2017 CDC Vital Signs report. Higher opioid prescribing puts patients at risk for addiction and overdose. Learn what can be done about this serious problem.  Created: 7/6/2017 by Centers for Disease Control and Prevention (CDC).   Date Released: 7/6/2017.

Bone marrow adipocytes as negative regulators of the hematopoietic microenvironment

Science.gov (United States)

Naveiras, Olaia; Nardi, Valentina; Wenzel, Pamela L.; Fahey, Frederic; Daley, George Q.

2009-01-01

Osteoblasts and endothelium constitute functional niches that support hematopoietic stem cells (HSC) in mammalian bone marrow (BM) 1,2,3 . Adult BM also contains adipocytes, whose numbers correlate inversely with the hematopoietic activity of the marrow. Fatty infiltration of hematopoietic red marrow follows irradiation or chemotherapy and is a diagnostic feature in biopsies from patients with marrow aplasia 4. To explore whether adipocytes influence hematopoiesis or simply fill marrow space, we compared the hematopoietic activity of distinct regions of the mouse skeleton that differ in adiposity. By flow cytometry, colony forming activity, and competitive repopulation assay, HSCs and short-term progenitors are reduced in frequency in the adipocyte-rich vertebrae of the mouse tail relative to the adipocyte-free vertebrae of the thorax. In lipoatrophic A-ZIP/F1 “fatless” mice, which are genetically incapable of forming adipocytes8, and in mice treated with the PPARγ inhibitor Bisphenol-A-DiGlycidyl-Ether (BADGE), which inhibits adipogenesis9, post-irradiation marrow engraftment is accelerated relative to wild type or untreated mice. These data implicate adipocytes as predominantly negative regulators of the bone marrow microenvironment, and suggest that antagonizingmarrow adipogenesis may enhance hematopoietic recovery in clinical bone marrow transplantation. PMID:19516257

Functions and Epigenetic Regulation of Wwox in Bone Metastasis from Breast Carcinoma: Comparison with Primary Tumors

Directory of Open Access Journals (Sweden)

Paola Maroni

2017-01-01

Full Text Available Epigenetic mechanisms influence molecular patterns important for the bone-metastatic process, and here we highlight the role of WW-domain containing oxidoreductase (Wwox. The tumor-suppressor Wwox lacks in almost all cancer types; the variable expression in osteosarcomas is related to lung-metastasis formation, and exogenous Wwox destabilizes HIF-1α (subunit of Hypoxia inducible Factor-1, HIF-1 affecting aerobic glycolysis. Our recent studies show critical functions of Wwox present in 1833-osteotropic clone, in the corresponding xenograft model, and in human bone metastasis from breast carcinoma. In hypoxic-bone metastatic cells, Wwox enhances HIF-1α stabilization, phosphorylation, and nuclear translocation. Consistently, in bone-metastasis specimens Wwox localizes in cytosolic/perinuclear area, while TAZ (transcriptional co-activator with PDZ-binding motif and HIF-1α co-localize in nuclei, playing specific regulatory mechanisms: TAZ is a co-factor of HIF-1, and Wwox regulates HIF-1 activity by controlling HIF-1α. In vitro, DNA methylation affects Wwox-protein synthesis; hypoxia decreases Wwox-protein level; hepatocyte growth factor (HGF phosphorylates Wwox driving its nuclear shuttle, and counteracting a Twist program important for the epithelial phenotype and metastasis colonization. In agreement, in 1833-xenograft mice under DNA-methyltransferase blockade with decitabine, Wwox increases in nuclei/cytosol counteracting bone metastasis with prolongation of the survival. However, Wwox seems relevant for the autophagic process which sustains metastasis, enhancing more Beclin-1 than p62 protein levels, and p62 accumulates under decitabine consistent with adaptability of metastasis to therapy. In conclusion, Wwox methylation as a bone-metastasis therapeutic target would depend on autophagy conditions, and epigenetic mechanisms regulating Wwox may influence the phenotype of bone metastasis.

Mechanotransduction by bone cells in vitro: mechanobiology of bone tissue

NARCIS (Netherlands)

Mullender, M.; El Haj, A.J.; Yang, Y.; van Duin, M.A.; Burger, E.H.; Klein-Nulend, J.

2004-01-01

Mechanical force plays an important role in the regulation of bone remodelling in intact bone and bone repair. In vitro, bone cells demonstrate a high responsiveness to mechanical stimuli. Much debate exists regarding the critical components in the load profile and whether different components, such

Expression of CD44 3′-untranslated region regulates endogenous microRNA functions in tumorigenesis and angiogenesis

Science.gov (United States)

Jeyapalan, Zina; Deng, Zhaoqun; Shatseva, Tatiana; Fang, Ling; He, Chengyan; Yang, Burton B.

2011-01-01

The non-coding 3′-untranslated region (UTR) plays an important role in the regulation of microRNA (miRNA) functions, since it can bind and inactivate multiple miRNAs. Here, we show the 3′-UTR of CD44 is able to antagonize cytoplasmic miRNAs, and result in the increased translation of CD44 and downstream target mRNA, CDC42. A series of cell function assays in the human breast cancer cell line, MT-1, have shown that the CD44 3′-UTR inhibits proliferation, colony formation and tumor growth. Furthermore, it modulated endothelial cell activities, favored angiogenesis, induced tumor cell apoptosis and increased sensitivity to Docetaxel. These results are due to the interaction of the CD44 3′-UTR with multiple miRNAs. Computational algorithms have predicted three miRNAs, miR-216a, miR-330 and miR-608, can bind to both the CD44 and CDC42 3′-UTRs. This was confirmed with luciferase assays, western blotting and immunohistochemical staining and correlated with a series of siRNA assays. Thus, the non-coding CD44 3′-UTR serves as a competitor for miRNA binding and subsequently inactivates miRNA functions, by freeing the target mRNAs from being repressed. PMID:21149267

CDC73 intragenic deletion in familial primary hyperparathyroidism associated with parathyroid carcinoma.

Science.gov (United States)

Korpi-Hyövälti, Eeva; Cranston, Treena; Ryhänen, Eeva; Arola, Johanna; Aittomäki, Kristiina; Sane, Timo; Thakker, Rajesh V; Schalin-Jäntti, Camilla

2014-09-01

CDC73 mutations frequently underlie the hyperparathyroidism-jaw tumor syndrome, familial isolated hyperparathyroidism (FIHP), and parathyroid carcinoma. It has also been suggested that CDC73 deletion analysis should be performed in those patients without CDC73 mutations. To investigate for CDC73 deletion in a family with FIHP previously reported not to have CDC73 mutations. Eleven members (six affected with primary hyperparathyroidism and five unaffected) were ascertained from the family, and multiplex ligation-dependent probe amplification was performed to detect CDC73 deletion using leukocyte DNA. A previously unreported deletion of CDC73 involving exons 1-10 was detected in five affected members and two unaffected members who were 26 and 39 years of age. Two affected members had parathyroid carcinomas at the ages of 18 and 32 years, and they had Ki-67 proliferation indices of 5 and 14.5% and did not express parafibromin, encoded by CDC73. Primary hyperparathyroidism in the other affected members was due to adenomas and atypical adenomas, and none had jaw tumors. Two affected members had thoracic aortic aneurysms, which in one member occurred with parathyroid carcinoma and renal cysts. A previously unreported intragenic deletion of exons 1 to 10 of CDC73 was detected in a three-generation family with FIHP, due to adenomas, atypical adenomas, and parathyroid carcinomas. In addition, two affected males had thoracic aortic aneurysms, which may represent another associated clinical feature of this disorder.

CDC PRAMStat Data for 2010

Data.gov (United States)

U.S. Department of Health & Human Services — Centers for Disease Control and Prevention (CDC). PRAMS, the Pregnancy Risk Assessment Monitoring System, is a surveillance system collecting state-specific,...

CDC PRAMStat Data for 2005

Data.gov (United States)

U.S. Department of Health & Human Services — Centers for Disease Control and Prevention (CDC). PRAMS, the Pregnancy Risk Assessment Monitoring System, is a surveillance system collecting state-specific,...

CDC PRAMStat Data for 2003

Data.gov (United States)

U.S. Department of Health & Human Services — Centers for Disease Control and Prevention (CDC). PRAMS, the Pregnancy Risk Assessment Monitoring System, is a surveillance system collecting state-specific,...

CDC PRAMStat Data for 2000

Data.gov (United States)

U.S. Department of Health & Human Services — Centers for Disease Control and Prevention (CDC). PRAMS, the Pregnancy Risk Assessment Monitoring System, is a surveillance system collecting state-specific,...

CDC PRAMStat Data for 2008

Data.gov (United States)

U.S. Department of Health & Human Services — Centers for Disease Control and Prevention (CDC). PRAMS, the Pregnancy Risk Assessment Monitoring System, is a surveillance system collecting state-specific,...

CDC PRAMStat Data for 2009

Data.gov (United States)

U.S. Department of Health & Human Services — Centers for Disease Control and Prevention (CDC). PRAMS, the Pregnancy Risk Assessment Monitoring System, is a surveillance system collecting state-specific,...

CDC PRAMStat Data for 2004

Data.gov (United States)

U.S. Department of Health & Human Services — Centers for Disease Control and Prevention (CDC). PRAMS, the Pregnancy Risk Assessment Monitoring System, is a surveillance system collecting state-specific,...

CDC PRAMStat Data for 2006

Data.gov (United States)

U.S. Department of Health & Human Services — Centers for Disease Control and Prevention (CDC). PRAMS, the Pregnancy Risk Assessment Monitoring System, is a surveillance system collecting state-specific,...

CDC PRAMStat Data for 2002

Data.gov (United States)

U.S. Department of Health & Human Services — Centers for Disease Control and Prevention (CDC). PRAMS, the Pregnancy Risk Assessment Monitoring System, is a surveillance system collecting state-specific,...

CDC PRAMStat Data for 2001

Data.gov (United States)

U.S. Department of Health & Human Services — Centers for Disease Control and Prevention (CDC). PRAMS, the Pregnancy Risk Assessment Monitoring System, is a surveillance system collecting state-specific,...

CDC PRAMStat Data for 2007

Data.gov (United States)

U.S. Department of Health & Human Services — Centers for Disease Control and Prevention (CDC). PRAMS, the Pregnancy Risk Assessment Monitoring System, is a surveillance system collecting state-specific,...

Molecular Mechanism of Substrate Processing by the Cdc48 ATPase Complex.

Science.gov (United States)

Bodnar, Nicholas O; Rapoport, Tom A

2017-05-04

The Cdc48 ATPase and its cofactors Ufd1/Npl4 (UN) extract polyubiquitinated proteins from membranes or macromolecular complexes, but how they perform these functions is unclear. Cdc48 consists of an N-terminal domain that binds UN and two stacked hexameric ATPase rings (D1 and D2) surrounding a central pore. Here, we use purified components to elucidate how the Cdc48 complex processes substrates. After interaction of the polyubiquitin chain with UN, ATP hydrolysis by the D2 ring moves the polypeptide completely through the double ring, generating a pulling force on the substrate and causing its unfolding. ATP hydrolysis by the D1 ring is important for subsequent substrate release from the Cdc48 complex. This release requires cooperation of Cdc48 with a deubiquitinase, which trims polyubiquitin to an oligoubiquitin chain that is then also translocated through the pore. Together, these results lead to a new paradigm for the function of Cdc48 and its mammalian ortholog p97/VCP. Copyright © 2017 Elsevier Inc. All rights reserved.

The clinical research of bone scan in patients with fibrous dysplasia of bone

International Nuclear Information System (INIS)

Yuan Zhibin; Yu Jianfang; Luo Quanyong; Lu Hankui; Zhu Jifang; Zhu Ruisen

2002-01-01

Objective: To study the characteristics of fibrous dysplasia of bone in bone imaging and evaluate the diagnostic value of radionuclide bone scan in fibrous dysplasia of bone. Methods: All 42 cases of fibrous dysplasia of bone patients had radionuclide bone scan performed and compared with other imaging modalities. A retrospective study method was used to analyze the imaging results. Results: Although fibrous dysplasia of bone showed uptake of 99m Tc-MDP in the images, its appearance characteristic was different from those metastatic bone tumors and other bone diseases. Combining with X rays and other imaging modalities can improve the diagnostic accuracy of this disease. Conclusion: Radionuclide bone scan has got certain value in the diagnosis of fibrous dysplasia of bone. Combining with other imaging modality can make up its disadvantage of low specificity

42 CFR 9.13 - Other federal laws, regulations, and statutes that apply to the sanctuary.

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Other federal laws, regulations, and statutes that apply to the sanctuary. 9.13 Section 9.13 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... SANCTUARY SYSTEM § 9.13 Other federal laws, regulations, and statutes that apply to the sanctuary. (a...

System integration of CDC attenuation in the new Opel Astra; Systemintegration der CDC-Daempfung beim neuen Opel Astra

Energy Technology Data Exchange (ETDEWEB)

Balandat, W.; Kutsche, T. [ZF Sachs AG, Schweinfurt (Germany)

2004-08-01

The optional carriage system IDS Plus of the new Opel Astra was developed in close cooperation between opel, ZF Sachs and other suppliers. This networking approach resulted in a high degree of system integration with the electronic attenuation control system CDC as key element. (orig.) [German] Das optionale Fahrwerksystem IDS Plus im neuen Opel Astra entstand in enger Kooperation zwischen Opel, ZF Sachs und weiteren Zulieferern. Die Arbeit im Netzwerk fuehrte zu einer hohen Systemintegration, in deren Kern die elektronische Daempferregelung CDC steht. (orig.)

CDC Vital Signs–HIV Testing

Centers for Disease Control (CDC) Podcasts

2017-11-28

This podcast is based on the December 2017 CDC Vital Signs report. In the U.S., about 15 percent of people who have HIV don't know they have it. Learn about the importance of testing, early diagnosis, and treatment.  Created: 11/28/2017 by Centers for Disease Control and Prevention (CDC).   Date Released: 11/28/2017.

CDC's 29th Annual Joseph W. Mountin Lecture

Centers for Disease Control (CDC) Podcasts

In this podcast, William H. Foege, MD, MPH delivers the 29th Annual Joseph W. Mountin Lecture. Dr. Foege was a key leader in the smallpox effort and worked as an epidemiologist in the successful eradication campaign in the 1970s. Dr. Foege became chief of the Smallpox Eradication Program at CDC, and was appointed director of CDC in 1977.

75 FR 6670 - Agency Forms Undergoing Paperwork Reduction Act Review

Science.gov (United States)

2010-02-10

... (CDC) publishes a list of information collection requests under review by the Office of Management and... application of Federal regulations. The regulations in 42 Part 70 were developed to facilitate Federal action... permit issued by State health authority. 42 CFR 70.4 Report by the master of a Master of a vessel or 1...

[Bone homeostasis and Mechano biology.

Science.gov (United States)

Nakashima, Tomoki

The weight-bearing exercises help to build bones and to maintain them strength. Bone is constantly renewed by the balanced action of osteoblastic bone formation and osteoclastic bone resorption both of which mainly occur at the bone surface. This restructuring process called "bone remodeling" is important not only for normal bone mass and strength, but also for mineral homeostasis. Bone remodeling is stringently regulated by communication between bone component cells such as osteoclasts, osteoblasts and osteocytes. An imbalance of this process is often linked to various bone diseases. During bone remodeling, resorption by osteoclasts precedes bone formation by osteoblasts. Based on the osteocyte location within the bone matrix and the cellular morphology, it is proposed that osteocytes potentially contribute to the regulation of bone remodeling in response to mechanical and endocrine stimuli.

CDC WONDER: Mortality - Infant Deaths

Data.gov (United States)

U.S. Department of Health & Human Services — The Mortality - Infant Deaths (from Linked Birth / Infant Death Records) online databases on CDC WONDER provide counts and rates for deaths of children under 1 year...

Fisetin induces G2/M phase cell cycle arrest by inactivating cdc25C-cdc2 via ATM-Chk1/2 activation in human endometrial cancer cells

Directory of Open Access Journals (Sweden)

Zhan-Ying Wang

2015-06-01

Full Text Available Endometrial cancer is one of the most prevalent gynaecological malignancies where, currently available therapeutic options remain limited. Recently phytochemicals are exploited for their efficiency in cancer therapy. The present study investigates the anti-proliferative effect of fisetin, a flavonoid on human endometrial cancer cells (KLE and Hec1 A. Fisetin (20-100 µM effectively reduced the viability of Hec1 A and KLE cells and potentially altered the cell population at G2/M stage. Expression levels of the cell cycle proteins (cyclin B1, p-Cdc2, p-Cdc25C, p-Chk1, Chk2, p-ATM, cyclin B1, H2AX, p21 and p27 were analyzed. Fisetin suppressed cyclin B1 expression and caused inactiva-tion of Cdc25C and Cdc2 by increasing their phosphorylation levels and further activated ATM, Chk1 and Chk2. Increased levels of p21 and p27 were observed as well. These results suggest that fisetin induced G2/M cell cycle arrest via inactivating Cdc25c and Cdc2 through activation of ATM, Chk1 and Chk2.

Epigenetic regulation of fetal bone development and placental transfer of nutrients: progress for osteoporosis.

Science.gov (United States)

Bocheva, Georgeta; Boyadjieva, Nadka

2011-12-01

Osteoporosis is a common age-related disorder and causes acute and long-term disability and economic cost. Many factors influence the accumulation of bone minerals, including heredity, diet, physical activity, gender, endocrine functions, and risk factors such as alcohol, drug abuse, some pharmacological drugs or cigarette smoking. The pathology of bone development during intrauterine life is a factor for osteoporosis. Moreover, the placental transfer of nutrients plays an important role in the building of bones of fetuses. The importance of maternal calcium intake and vitamin D status are highlighted in this review. Various environmental factors including nutrition state or maternal stress may affect the epigenetic state of a number of genes during fetal development of bones. Histone modifications as histone hypomethylation, histone hypermethylation, hypoacetylation, etc. are involved in chromatin remodeling, known to contribute to the epigenetic landscape of chromosomes, and play roles in both fetal bone development and osteoporosis. This review will give an overview of epigenetic modulation of bone development and placental transfer of nutrients. In addition, the data from animal and human studies support the role of epigenetic modulation of calcium and vitamin D in the pathogenesis of osteoporosis. We review the evidence suggesting that various genes are involved in regulation of osteoclast formation and differentiation by osteoblasts and stem cells. Epigenetic changes in growth factors as well as cytokines play a rol in fetal bone development. On balance, the data suggest that there is a link between epigenetic changes in placental transfer of nutrients, including calcium and vitamin D, abnormal intrauterine bone development and pathogenesis of osteoporosis.

Endogenous GAS6 and Mer receptor signaling regulate prostate cancer stem cells in bone marrow.

Science.gov (United States)

Jung, Younghun; Decker, Ann M; Wang, Jingcheng; Lee, Eunsohl; Kana, Lulia A; Yumoto, Kenji; Cackowski, Frank C; Rhee, James; Carmeliet, Peter; Buttitta, Laura; Morgan, Todd M; Taichman, Russell S

2016-05-03

GAS6 and its receptors (Tryo 3, Axl, Mer or "TAM") are known to play a role in regulating tumor progression in a number of settings. Previously we have demonstrated that GAS6 signaling regulates invasion, proliferation, chemotherapy-induced apoptosis of prostate cancer (PCa) cells. We have also demonstrated that GAS6 secreted from osteoblasts in the bone marrow environment plays a critical role in establishing prostate tumor cell dormancy. Here we investigated the role that endogenous GAS6 and Mer receptor signaling plays in establishing prostate cancer stem cells in the bone marrow microenvironment.We first observed that high levels of endogenous GAS6 are expressed by disseminated tumor cells (DTCs) in the bone marrow, whereas relatively low levels of endogenous GAS6 are expressed in PCa tumors grown in a s.c. Interestingly, elevated levels of endogenous GAS6 were identified in putative cancer stem cells (CSCs, CD133+/CD44+) compared to non-CSCs (CD133-/CD44-) isolated from PCa/osteoblast cocultures in vitro and in DTCs isolated from the bone marrow 24 hours after intracardiac injection. Moreover, we found that endogenous GAS6 expression is associated with Mer receptor expression in growth arrested (G1) PCa cells, which correlates with the increase of the CSC populations. Importantly, we found that overexpression of GAS6 activates phosphorylation of Mer receptor signaling and subsequent induction of the CSC phenotype in vitro and in vivo.Together these data suggest that endogenous GAS6 and Mer receptor signaling contribute to the establishment of PCa CSCs in the bone marrow microenvironment, which may have important implications for targeting metastatic disease.

Denosumab for bone diseases: translating bone biology into targeted therapy.

Science.gov (United States)

Tsourdi, Elena; Rachner, Tilman D; Rauner, Martina; Hamann, Christine; Hofbauer, Lorenz C

2011-12-01

Signalling of receptor activator of nuclear factor-κB (RANK) ligand (RANKL) through RANK is a critical pathway to regulate the differentiation and activity of osteoclasts and, hence, a master regulator of bone resorption. Increased RANKL activity has been demonstrated in diseases characterised by excessive bone loss such as osteoporosis, rheumatoid arthritis and osteolytic bone metastases. The development and approval of denosumab, a fully MAB against RANKL, has heralded a new era in the treatment of bone diseases by providing a potent, targeted and reversible inhibitor of bone resorption. This article summarises the molecular and cellular biology of the RANKL/RANK system and critically reviews preclinical and clinical studies that have established denosumab as a promising novel therapy for metabolic and malignant bone diseases. We will discuss the potential indications for denosumab along with a critical review of safety and analyse its potential within the concert of established therapies.

Cytokines and growth factors which regulate bone cell function

Science.gov (United States)

Seino, Yoshiki

Everybody knows that growth factors are most important in making bone. Hormones enhance bone formation from a long distance. Growth factors promote bone formation as an autocrine or paracrine factor in nearby bone. BMP-2 through BMP-8 are in the TGF-β family. BMP makes bone by enchondral ossification. In bone, IGF-II is most abundant, second, TGF-β, and third IGF-I. TGF-β enhances bone formation mainly by intramembranous ossification in vivo. TGF-β affects both cell proliferation and differentiation, however, TGF-β mainly enhances bone formation by intramembranous ossification. Interestingly, TGF-β is increased by estrogen(E 2), androgen, vitamin D, TGF-β and FGF. IGF-I and IGF-II also enhance bone formation. At present it remains unclear why IGF-I is more active in bone formation than IGF-II, although IGF-II is more abundant in bone compared to IGF-I. However, if only type I receptor signal transduction promotes bone formation, the strong activity of IGF-I in bone formation is understandable. GH, PTH and E 2 promotes IGF-I production. Recent data suggest that hormones containing vitamin D or E 2 enhance bone formation through growth factors. Therefore, growth factors are the key to clarifying the mechanism of bone formation.

Bone mineralization is regulated by signaling cross talk between molecular factors of local and systemic origin: the role of fibroblast growth factor 23.

Science.gov (United States)

Sapir-Koren, Rony; Livshits, Gregory

2014-01-01

Body phosphate homeostasis is regulated by a hormonal counter-balanced intestine-bone-kidney axis. The major systemic hormones involved in this axis are parathyroid hormone (PTH), 1,25-dihydroxyvitamin-D, and fibroblast growth factor-23 (FGF23). FGF23, produced almost exclusively by the osteocytes, is a phosphaturic hormone that plays a major role in regulation of the bone remodeling process. Remodeling composite components, bone mineralization and resorption cycles create a continuous influx-efflux loop of the inorganic phosphate (Pi) through the skeleton. This "bone Pi loop," which is formed, is controlled by local and systemic factors according to phosphate homeostasis demands. Although FGF23 systemic actions in the kidney, and for the production of PTH and 1,25-dihydroxyvitamin-D are well established, its direct involvement in bone metabolism is currently poorly understood. This review presents the latest available evidence suggesting two aspects of FGF23 bone local activity: (a) Regulation of FGF23 production by both local and systemic factors. The suggested local factors include extracellular levels of Pi and pyrophosphate (PPi), (the Pi/PPi ratio), and another osteocyte-derived protein, sclerostin. In addition, 1,25-dihydroxyvitamin-D, synthesized locally by bone cells, may contribute to regulation of FGF23 production. The systemic control is achieved via PTH and 1,25-dihydroxyvitamin-D endocrine functions. (b) FGF23 acts as a local agent, directly affecting bone mineralization. We support the assumption that under balanced physiological conditions, sclerostin, by para- autocrine signaling, upregulates FGF23 production by the osteocyte. FGF23, in turn, acts as a mineralization inhibitor, by stimulating the generation of the major mineralization antagonist-PPi. © 2014 International Union of Biochemistry and Molecular Biology.

CDC Vital Signs: Preventing Melanoma

Science.gov (United States)

... not use the device. Include warning statements in marketing materials about the risk of using the device. ... MB] en Español [PDF – 1.16 MB] CDC Digital Press Kit Read the MMWR Science Clips Language: ...

Cytoskeletal Regulation by AUTS2 in Neuronal Migration and Neuritogenesis

Directory of Open Access Journals (Sweden)

Kei Hori

2014-12-01

Full Text Available Mutations in the Autism susceptibility candidate 2 gene (AUTS2, whose protein is believed to act in neuronal cell nuclei, have been associated with multiple psychiatric illnesses, including autism spectrum disorders, intellectual disability, and schizophrenia. Here we show that cytoplasmic AUTS2 is involved in the regulation of the cytoskeleton and neural development. Immunohistochemistry and fractionation studies show that AUTS2 localizes not only in nuclei, but also in the cytoplasm, including in the growth cones in the developing brain. AUTS2 activates Rac1 to induce lamellipodia but downregulates Cdc42 to suppress filopodia. Our loss-of-function and rescue experiments show that a cytoplasmic AUTS2-Rac1 pathway is involved in cortical neuronal migration and neuritogenesis in the developing brain. These findings suggest that cytoplasmic AUTS2 acts as a regulator of Rho family GTPases to contribute to brain development and give insight into the pathology of human psychiatric disorders with AUTS2 mutations.

CDC Vital Signs: Hispanic Health

Science.gov (United States)

... Injury Prevention & Control Gateway to Health Communication & Social Marketing Practice On Other Web Sites MedlinePlus – Hispanic American ... MB] en Español [PDF – 1.61 MB] CDC Digital Press Kit Read the MMWR Science Clips Language: ...

CDC Lab Values

Centers for Disease Control (CDC) Podcasts

More than fifteen hundred scientists fill the lab benches at CDC, logging more than four million hours each year. CDC’s laboratories play a critical role in the agency’s ability to find, stop, and prevent disease outbreaks. This podcast provides a brief overview of what goes on inside CDC’s labs, and why this work makes a difference in American’s health.

Protein Tyrosine Phosphatase-PEST and β8 Integrin Regulate Spatiotemporal Patterns of RhoGDI1 Activation in Migrating Cells

Science.gov (United States)

Lee, Hye Shin; Cheerathodi, Mujeeburahiman; Chaki, Sankar P.; Reyes, Steve B.; Zheng, Yanhua; Lu, Zhimin; Paidassi, Helena; DerMardirossian, Celine; Lacy-Hulbert, Adam; Rivera, Gonzalo M.

2015-01-01

Directional cell motility is essential for normal development and physiology, although how motile cells spatiotemporally activate signaling events remains largely unknown. Here, we have characterized an adhesion and signaling unit comprised of protein tyrosine phosphatase (PTP)-PEST and the extracellular matrix (ECM) adhesion receptor β8 integrin that plays essential roles in directional cell motility. β8 integrin and PTP-PEST form protein complexes at the leading edge of migrating cells and balance patterns of Rac1 and Cdc42 signaling by controlling the subcellular localization and phosphorylation status of Rho GDP dissociation inhibitor 1 (RhoGDI1). Translocation of Src-phosphorylated RhoGDI1 to the cell's leading edge promotes local activation of Rac1 and Cdc42, whereas dephosphorylation of RhoGDI1 by integrin-bound PTP-PEST promotes RhoGDI1 release from the membrane and sequestration of inactive Rac1/Cdc42 in the cytoplasm. Collectively, these data reveal a finely tuned regulatory mechanism for controlling signaling events at the leading edge of directionally migrating cells. PMID:25666508

Calcium isotope signature: new proxy for net change in bone volume for chronic kidney disease and diabetic rats.

Science.gov (United States)

Tanaka, Yu-Ki; Yajima, Nobuyuki; Higuchi, Yusuke; Yamato, Hideyuki; Hirata, Takafumi

2017-12-01

Herein, we measure the Ca isotope ratios ( 44 Ca/ 42 Ca and 43 Ca/ 42 Ca) in serum and bone samples collected from rats with chronic kidney disease (CKD) or diabetes mellitus (DM). For the serum samples, the isotope ratios are lower for the CKD (δ 44 Ca/ 42 Ca serum = 0.16 ± 0.11‰; 2SD, n = 6) and the DM (δ 44 Ca/ 42 Ca serum = -0.11 ± 0.25‰; 2SD, n = 7) rats than that for the control rats (δ 44 Ca/ 42 Ca serum = 0.25 ± 0.04‰; 2SD, n = 7). Bone samples from two distinct positions of 20 rats in total, namely, the center and proximal parts of the tibial diaphysis, are subject to Ca isotope analysis. The resulting δ 44 Ca/ 42 Ca values for the bone of the proximal part are about 0.3‰ lower than that for the serum samples from the same rats. The larger isotope fractionations between the serum and bone are consistent with previously reported data for vertebrate animals (e.g., Skulan and DePaolo, 1999), which suggests the preferential incorporation of lighter Ca isotopes through bone formation. For the bones from the control and CKD rats, there were no differences in the δ 44 Ca/ 42 Ca values between the positions of the bone. In contrast, the δ 44 Ca/ 42 Ca values of the bone for the DM rats were different between the positions of the bone. Due to the lower bone turnover rate for the DM rats, the δ 44 Ca/ 42 Ca for the middle of the diaphysis can reflect the Ca isotopes in the bone formed prior to the progression of DM states. Thus, the resulting δ 44 Ca/ 42 Ca values show a clear correlation with bone mineral density (BMD). This can be due to the release of isotopically lighter Ca from the bone to the serum. In the present study, our data demonstrate that the δ 44 Ca/ 42 Ca value for serum can be used as a new biomarker for evaluating changes in bone turnover rate, followed by changes in bone volume.

Can the growth factors PTHrP, Ihh and VEGF, together regulate the development of a long bone?

Science.gov (United States)

Brouwers, J E M; van Donkelaar, C C; Sengers, B G; Huiskes, R

2006-01-01

Endochondral ossification is the process of differentiation of cartilaginous into osseous tissue. Parathyroid hormone related protein (PTHrP), Indian hedgehog (Ihh) and vascular endothelial growth factor (VEGF), which are synthesized in different zones of the growth plate, were found to have crucial roles in regulating endochondral ossification. The aim of this study was to evaluate whether the three growth factors PTHrP, Ihh and VEGF, together, could regulate longitudinal growth in a normal human, fetal femur. For this purpose, a one-dimensional finite element (FE) model, incorporating growth factor signaling, was developed of the human, distal, femoral growth plate. It included growth factor synthesis in the relevant zones, their transport and degradation and their effects. Simulations ran from initial hypertrophy in the center of the bone until secondary ossification starts at approximately 3.5 months postnatal. For clarity, we emphasize that no mechanical stresses were considered. The FE model showed a stable growth plate in which the bone growth rate was constant and the number of cells per zone oscillated around an equilibrium. Simulations incorporating increased and decreased PTHrP and Ihh synthesis rates resulted, respectively, in more and less cells per zone and in increased and decreased bone growth rates. The FE model correctly reflected the development of a growth plate and the rate of bone growth in the femur. Simulations incorporating increased and decreased PTHrP and Ihh synthesis rates reflected growth plate pathologies and growth plates in PTHrP-/- and Ihh-/- mice. The three growth factors, PTHrP, Ihh and VEGF, could potentially together regulate tissue differentiation.

Cdc14 phosphatase directs centrosome re-duplication at the meiosis I to meiosis II transition in budding yeast [version 2; referees: 3 approved, 1 approved with reservations

Directory of Open Access Journals (Sweden)

Colette Fox

2017-02-01

Full Text Available Background Gametes are generated through a specialized cell division called meiosis, in which ploidy is reduced by half because two consecutive rounds of chromosome segregation, meiosis I and meiosis II, occur without intervening DNA replication. This contrasts with the mitotic cell cycle where DNA replication and chromosome segregation alternate to maintain the same ploidy. At the end of mitosis, cyclin-dependent kinases (CDKs are inactivated. This low CDK state in late mitosis/G1 allows for critical preparatory events for DNA replication and centrosome/spindle pole body (SPB duplication. However, their execution is inhibited until S phase, where further preparatory events are also prevented. This “licensing” ensures that both the chromosomes and the centrosomes/SPBs replicate exactly once per cell cycle, thereby maintaining constant ploidy. Crucially, between meiosis I and meiosis II, centrosomes/SPBs must be re-licensed, but DNA re-replication must be avoided. In budding yeast, the Cdc14 protein phosphatase triggers CDK down regulation to promote exit from mitosis. Cdc14 also regulates the meiosis I to meiosis II transition, though its mode of action has remained unclear. Methods Fluorescence and electron microscopy was combined with proteomics to probe SPB duplication in cells with inactive or hyperactive Cdc14. Results We demonstrate that Cdc14 ensures two successive nuclear divisions by re-licensing SPBs at the meiosis I to meiosis II transition. We show that Cdc14 is asymmetrically enriched on a single SPB during anaphase I and provide evidence that this enrichment promotes SPB re-duplication. Cells with impaired Cdc14 activity fail to promote extension of the SPB half-bridge, the initial step in morphogenesis of a new SPB. Conversely, cells with hyper-active Cdc14 duplicate SPBs, but fail to induce their separation. Conclusion Our findings implicate reversal of key CDK-dependent phosphorylations in the differential licensing of

CDC Vital Signs-HIV Testing

Centers for Disease Control (CDC) Podcasts

This podcast is based on the December 2017 CDC Vital Signs report. In the U.S., about 15 percent of people who have HIV don't know they have it. Learn about the importance of testing, early diagnosis, and treatment.

CDC Vital Signs-Legionnaires' Disease

Centers for Disease Control (CDC) Podcasts

This podcast is based on the June 2017 CDC Vital Signs report. Legionnaires' disease is a serious, often deadly lung infection. People most commonly get it by breathing in water droplets containing Legionella germs. Learn how to prevent infections from Legionella.

Cell cycle-dependent mobility of Cdc45 determined in vivo by fluorescence correlation spectroscopy.

Directory of Open Access Journals (Sweden)

Ronan Broderick

Full Text Available Eukaryotic DNA replication is a dynamic process requiring the co-operation of specific replication proteins. We measured the mobility of eGFP-Cdc45 by Fluorescence Correlation Spectroscopy (FCS in vivo in asynchronous cells and in cells synchronized at the G1/S transition and during S phase. Our data show that eGFP-Cdc45 mobility is faster in G1/S transition compared to S phase suggesting that Cdc45 is part of larger protein complex formed in S phase. Furthermore, the size of complexes containing Cdc45 was estimated in asynchronous, G1/S and S phase-synchronized cells using gel filtration chromatography; these findings complemented the in vivo FCS data. Analysis of the mobility of eGFP-Cdc45 and the size of complexes containing Cdc45 and eGFP-Cdc45 after UVC-mediated DNA damage revealed no significant changes in diffusion rates and complex sizes using FCS and gel filtration chromatography analyses. This suggests that after UV-damage, Cdc45 is still present in a large multi-protein complex and that its mobility within living cells is consistently similar following UVC-mediated DNA damage.

CDC Vital Signs–Preventing Stroke Deaths

Centers for Disease Control (CDC) Podcasts

2017-09-06

This podcast is based on the September 2017 CDC Vital Signs report. Each year, more than 140,000 people die and many survivors face disability. Eighty percent of strokes are preventable. Learn the signs of stroke and how to prevent them.  Created: 9/6/2017 by Centers for Disease Control and Prevention (CDC).   Date Released: 9/6/2017.

Rhizoma Dioscoreae extract protects against alveolar bone loss in ovariectomized rats via microRNAs regulation.

Science.gov (United States)

Zhang, Zhiguo; Song, Changheng; Zhang, Fangzhen; Xiang, Lihua; Chen, Yanjing; Li, Yan; Pan, Jinghua; Liu, Hong; Xiao, Gary Guishan; Ju, Dahong

2015-02-16

The aim of this study was to evaluate the osteoprotective effect of aqueous Rhizoma Dioscoreae extract (RDE) on the alveolar bone of rats with ovariectomy-induced bone loss. Female Wistar rats underwent either ovariectomy or sham operation (SHAM). The ovariectomized (OVX) rats were treated with vehicle (OVX), estradiol valerate (EV), or RDE. After treatments, the bone mineral density (BMD) and the three-dimensional microarchitecture of the alveolar bone were analyzed to assess bone mass. Microarrays were used to evaluate microRNA expression profiles in alveolar bone from RDE-treated and OVX rats. The differential expression of microRNAs was validated using real-time quantitative RT-PCR (qRT-PCR), and the target genes of validated microRNAs were predicted and further analyzed using Ingenuity Pathway Analysis (IPA). The key findings were verified using qRT-PCR. Our results show that RDE inhibits alveolar bone loss in OVX rats. Compared to the OVX rats, the RDE-treated rats showed upregulated expression levels of 8 microRNAs and downregulated expression levels of 8 microRNAs in the alveolar bone in the microarray analysis. qRT-PCR helped validate 13 of 16 differentially expressed microRNAs, and 114 putative target genes of the validated microRNAs were retrieved. The IPA showed that these putative target genes had the potential to code for proteins that were involved in the transforming growth factor (TGF)-β/bone morphogenetic proteins (BMPs)/Smad signaling pathway (Tgfbr2/Bmpr2, Smad3/4/5, and Bcl-2) and interleukin (IL)-6/oncostatin M (OSM)/Jak1/STAT3 signaling pathway (Jak1, STAT3, and Il6r). These experiments revealed that RDE could inhibit ovariectomy-induced alveolar bone loss in rats. The mechanism of this anti-osteopenic effect in alveolar bone may involve the simultaneous inhibition of bone formation and bone resorption, which is associated with modulation of the TGF-β/BMPs/Smad and the IL-6/OSM/Jak1/STAT3 signaling pathways via microRNA regulation.

CDC STATE System Tobacco Legislation - Preemption

Data.gov (United States)

U.S. Department of Health & Human Services — 1995-2018. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. Legislation—Preemption. The STATE...

Inter-species investigation of the mechano-regulation of bone healing: comparison of secondary bone healing in sheep and rat.

Science.gov (United States)

Checa, Sara; Prendergast, Patrick J; Duda, Georg N

2011-04-29

Inter-species differences in regeneration exist in various levels. One aspect is the dynamics of bone regeneration and healing, e.g. small animals show a faster healing response when compared to large animals. Mechanical as well as biological factors are known to play a key role in the process. However, it remains so far unknown whether different animals follow at all comparable mechano-biological rules during tissue regeneration, and in particular during bone healing. In this study, we investigated whether differences observed in vivo in the dynamics of bone healing between rat and sheep are only due to differences in the animal size or whether these animals have a different mechano-biological response during the healing process. Histological sections from in vivo experiments were compared to in silico predictions of a mechano-biological computer model for the simulation of bone healing. Investigations showed that the healing processes in both animal models occur under significantly different levels of mechanical stimuli within the callus region, which could explain histological observations of early intramembranous ossification at the endosteal side. A species-specific adaptation of a mechano-biological model allowed a qualitative match of model predictions with histological observations. Specifically, when keeping cell activity processes at the same rate, the amount of tissue straining defining favorable mechanical conditions for the formation of bone had to be increased in the large animal model, with respect to the small animal, to achieve a qualitative agreement of model predictions with histological data. These findings illustrate that geometrical (size) differences alone cannot explain the distinctions seen in the histological appearance of secondary bone healing in sheep and rat. It can be stated that significant differences in the mechano-biological regulation of the healing process exist between these species. Future investigations should aim towards

Stalking SARS: CDC at Work

Centers for Disease Control (CDC) Podcasts

2014-05-22

In this podcast for kids, the Kidtastics talk about the SARS outbreak and how CDC worked to solve the mystery.  Created: 5/22/2014 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 5/22/2014.

Calcium-containing scaffolds induce bone regeneration by regulating mesenchymal stem cell differentiation and migration.

Science.gov (United States)

Aquino-Martínez, Rubén; Angelo, Alcira P; Pujol, Francesc Ventura

2017-11-16

Osteoinduction and subsequent bone formation rely on efficient mesenchymal stem cell (MSC) recruitment. It is also known that migration is induced by gradients of growth factors and cytokines. Degradation of Ca 2+ -containing biomaterials mimics the bone remodeling compartment producing a localized calcium-rich osteoinductive microenvironment. The aim of our study was to determine the effect of calcium sulfate (CaSO 4 ) on MSC migration. In addition, to evaluate the influence of CaSO 4 on MSC differentiation and the potential molecular mechanisms involved. A circular calvarial bone defect (5 mm diameter) was created in the parietal bone of 35 Balb-C mice. We prepared and implanted a cell-free agarose/gelatin scaffold alone or in combination with different CaSO 4 concentrations into the bone defects. After 7 weeks, we determined the new bone regenerated by micro-CT and histological analysis. In vitro, we evaluated the CaSO 4 effects on MSC migration by both wound healing and agarose spot assays. Osteoblastic gene expression after BMP-2 and CaSO 4 treatment was also evaluated by qPCR. CaSO 4 increased MSC migration and bone formation in a concentration-dependent manner. Micro-CT analysis showed that the addition of CaSO 4 significantly enhanced bone regeneration compared to the scaffold alone. The histological evaluation confirmed an increased number of endogenous cells recruited into the cell-free CaSO 4 -containing scaffolds. Furthermore, MSC migration in vitro and active AKT levels were attenuated when CaSO 4 and BMP-2 were in combination. Addition of LY294002 and Wortmannin abrogated the CaSO 4 effects on MSC migration. Specific CaSO 4 concentrations induce bone regeneration of calvarial defects in part by acting on the host's undifferentiated MSCs and promoting their migration. Progenitor cell recruitment is followed by a gradual increment in osteoblast gene expression. Moreover, CaSO 4 regulates BMP-2-induced MSC migration by differentially activating the PI3

Caffeine stabilizes Cdc25 independently of Rad3 in S chizosaccharomyces pombe contributing to checkpoint override

Science.gov (United States)

Alao, John P; Sjölander, Johanna J; Baar, Juliane; Özbaki-Yagan, Nejla; Kakoschky, Bianca; Sunnerhagen, Per

2014-01-01

Cdc25 is required for Cdc2 dephosphorylation and is thus essential for cell cycle progression. Checkpoint activation requires dual inhibition of Cdc25 and Cdc2 in a Rad3-dependent manner. Caffeine is believed to override activation of the replication and DNA damage checkpoints by inhibiting Rad3-related proteins in both S chizosaccharomyces pombe and mammalian cells. In this study, we have investigated the impact of caffeine on Cdc25 stability, cell cycle progression and checkpoint override. Caffeine induced Cdc25 accumulation in S . pombe independently of Rad3. Caffeine delayed cell cycle progression under normal conditions but advanced mitosis in cells treated with replication inhibitors and DNA-damaging agents. In the absence of Cdc25, caffeine inhibited cell cycle progression even in the presence of hydroxyurea or phleomycin. Caffeine induces Cdc25 accumulation in S . pombe by suppressing its degradation independently of Rad3. The induction of Cdc25 accumulation was not associated with accelerated progression through mitosis, but rather with delayed progression through cytokinesis. Caffeine-induced Cdc25 accumulation appears to underlie its ability to override cell cycle checkpoints. The impact of Cdc25 accumulation on cell cycle progression is attenuated by Srk1 and Mad2. Together our findings suggest that caffeine overrides checkpoint enforcement by inducing the inappropriate nuclear localization of Cdc25. PMID:24666325

Development of the Fetal Bone Marrow Niche and Regulation of HSC Quiescence and Homing Ability by Emerging Osteolineage Cells

Directory of Open Access Journals (Sweden)

Süleyman Coşkun

2014-10-01

Full Text Available Hematopoietic stem cells (HSCs reside within a specialized niche where interactions with vasculature, osteoblasts, and stromal components regulate their self-renewal and differentiation. Little is known about bone marrow niche formation or the role of its cellular components in HSC development; therefore, we established the timing of murine fetal long bone vascularization and ossification relative to the onset of HSC activity. Adult-repopulating HSCs emerged at embryonic day 16.5 (E16.5, coincident with marrow vascularization, and were contained within the c-Kit+Sca-1+Lin− (KSL population. We used Osterix-null (Osx−/− mice that form vascularized marrow but lack osteolineage cells to dissect the role(s of these cellular components in HSC development. Osx−/− fetal bone marrow cells formed multilineage colonies in vitro but were hyperproliferative and failed to home to and/or engraft transplant recipients. Thus, in developing bone marrow, the vasculature can sustain multilineage progenitors, but interactions with osteolineage cells are needed to regulate long-term HSC proliferation and potential.

Development of the fetal bone marrow niche and regulation of HSC quiescence and homing ability by emerging osteolineage cells.

Science.gov (United States)

Coşkun, Süleyman; Chao, Hsu; Vasavada, Hema; Heydari, Kartoosh; Gonzales, Naomi; Zhou, Xin; de Crombrugghe, Benoit; Hirschi, Karen K

2014-10-23

Hematopoietic stem cells (HSCs) reside within a specialized niche where interactions with vasculature, osteoblasts, and stromal components regulate their self-renewal and differentiation. Little is known about bone marrow niche formation or the role of its cellular components in HSC development; therefore, we established the timing of murine fetal long bone vascularization and ossification relative to the onset of HSC activity. Adult-repopulating HSCs emerged at embryonic day 16.5 (E16.5), coincident with marrow vascularization, and were contained within the c-Kit(+)Sca-1(+)Lin(-) (KSL) population. We used Osterix-null (Osx(-/-)) mice that form vascularized marrow but lack osteolineage cells to dissect the role(s) of these cellular components in HSC development. Osx(-/-) fetal bone marrow cells formed multilineage colonies in vitro but were hyperproliferative and failed to home to and/or engraft transplant recipients. Thus, in developing bone marrow, the vasculature can sustain multilineage progenitors, but interactions with osteolineage cells are needed to regulate long-term HSC proliferation and potential. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Regulation of bone morphogenetic proteins in early embryonic development

Science.gov (United States)

Yamamoto, Yukiyo; Oelgeschläger, Michael

2004-11-01

Bone morphogenetic proteins (BMPs), a large subgroup of the TGF-β family of secreted growth factors, control fundamental events in early embryonic development, organogenesis and adult tissue homeostasis. The plethora of dose-dependent cellular processes regulated by BMP signalling demand a tight regulation of BMP activity. Over the last decade, a number of proteins have been identified that bind BMPs in the extracellular space and regulate the interaction of BMPs with their cognate receptors, including the secreted BMP antagonist Chordin. In the early vertebrate embryo, the localized secretion of BMP antagonists from the dorsal blastopore lip establishes a functional BMP signalling gradient that is required for the determination of the dorsoventral or back to belly body axis. In particular, inhibition of BMP activity is essential for the formation of neural tissue in the development of vertebrate and invertebrate embryos. Here we review recent studies that have provided new insight into the regulation of BMP signalling in the extracellular space. In particular, we discuss the recently identified Twisted gastrulation protein that modulates, in concert with metalloproteinases of the Tolloid family, the interaction of Chordin with BMP and a family of proteins that share structural similarities with Chordin in the respective BMP binding domains. In addition, genetic and functional studies in zebrafish and frog provide compelling evidence that the secreted protein Sizzled functionally interacts with the Chd BMP pathway, despite being expressed ventrally in the early gastrula-stage embryo. These intriguing discoveries may have important implications, not only for our current concept of early embryonic patterning, but also for the regulation of BMP activity at later developmental stages and tissue homeostasis in the adult.

CDC STATE System Tobacco Legislation - Licensure

Data.gov (United States)

U.S. Department of Health & Human Services — 1995-2018. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. Legislation—Licensure. The STATE System...

CDC STATE System Tobacco Legislation - Tax

Data.gov (United States)

U.S. Department of Health & Human Services — 1995-2017. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. Legislation-Tax. The STATE System...

CDC STATE System Tobacco Legislation - Tax

Data.gov (United States)

U.S. Department of Health & Human Services — 1995-2018. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. Legislation-Tax. The STATE System...

β-cryptoxanthin regulates bone resorption related-cytokine production in human periodontal ligament cells.

Science.gov (United States)

Nishigaki, Masaru; Yamamoto, Toshiro; Ichioka, Hiroaki; Honjo, Ken-Ichi; Yamamoto, Kenta; Oseko, Fumishige; Kita, Masakazu; Mazda, Osam; Kanamura, Narisato

2013-07-01

β-cryptoxanthin (β-cry) is a type of carotenoid found in certain fruits and vegetables. Although it has been shown that β-cry inhibits alveolar bone resorption, the molecular mechanisms for this have not yet been clarified. In the present study, we investigated the effects of β-cry on bone resorption related-cytokine production in human periodontal ligament (hPDL) cells. hPDL cells were stimulated with β-cry (1×10(-7)mol/l), mechanical stress (1 or 6MPa), and P. gingivalis. The production of interleukin (IL)-1β, IL-6, IL-8, tumour necrosis factor (TNF)-α, osteoprotegerin (OPG), and receptor activator of nuclear factor kappa-B ligand (RANKL) were analyzed by RT-PCR and ELISA. The production of IL-1β, IL-6, IL-8, and TNF-α was not induced in hPDL cells after stimulation with β-cry, although these cytokines were produced after stimulation with P. gingivalis. On the other hand, IL-6 and IL-8 were produced after exposure to 6MPa of mechanical stress. The production of IL-6 and IL-8 was significantly decreased by the addition of β-cry. Furthermore, β-cry up-regulated the production of OPG, but not RANKL. β-cry inhibited the production of IL-6 and IL-8 induced by mechanical stress and periodontopathogenic bacteria in hPDL cells. Moreover, β-cry up-regulated OPG production. These results suggest that β-cry may prevent bone resorption in periodontitis. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dlk1/FA1 Is a Novel Endocrine Regulator of Bone and Fat Mass and Its Serum Level Is Modulated By Growth Hormone

DEFF Research Database (Denmark)

Abdallah, B.M.; Ding, M.; Jensen, C.H.

2007-01-01

Fat and bone metabolism are two linked processes regulated by several hormonal factors. FA1 (fetal antigen 1) is the soluble form of dlk1 (delta like 1), which is a member of the Notch-Delta family. We have previously identified FA1 as a negative regulator of bone marrow mesenchymal stem cell...... differentiation. Here, we studied the effects of circulating FA1 on fat and bone mass in vivo by generating mice expressing high serum levels of FA1 (FA1-mice) using the hydrodynamic-based gene transfer procedure (HGTP). We found that increased serum FA1 levels led to a significant reduction in total body weight......, fat mass and bone mass in a dose-dependent manner. Reduced bone mass in FA1-mice was associated with the inhibition of mineral apposition rate and bone formation rates by 58% and 72% respectively. Since FA1 is co-localized with growth hormone (GH) in the pituitary gland, we explored the possible...

Dlk1/FA1 is a novel endocrine regulator of bone and fat mass and its serum level is modulated by growth hormone

DEFF Research Database (Denmark)

Abdallah, Basem; Ding, Ming; Jensen, Charlotte H

2007-01-01

Fat and bone metabolism are two linked processes regulated by several hormonal factors. Fetal antigen 1 (FA1) is the soluble form of dlk1 (delta-like 1), which is a member of the Notch-Delta family. We previously identified FA1 as a negative regulator of bone marrow mesenchymal stem cell...... differentiation. Here, we studied the effects of circulating FA1 on fat and bone mass in vivo by generating mice expressing high serum levels of FA1 (FA1 mice) using the hydrodynamic-based gene transfer procedure. We found that increased serum FA1 levels led to a significant reduction in total body weight, fat...... mass, and bone mass in a dose-dependent manner. Reduced bone mass in FA1 mice was associated with the inhibition of mineral apposition rate and bone formation rates by 58 and 72%, respectively. Because FA1 is colocalized with GH in the pituitary gland, we explored the possible modulation of serum FA1...

Mouse genome-wide association and systems genetics identify Asxl2 as a regulator of bone mineral density and osteoclastogenesis.

Directory of Open Access Journals (Sweden)

Charles R Farber

2011-04-01

Full Text Available Significant advances have been made in the discovery of genes affecting bone mineral density (BMD; however, our understanding of its genetic basis remains incomplete. In the current study, genome-wide association (GWA and co-expression network analysis were used in the recently described Hybrid Mouse Diversity Panel (HMDP to identify and functionally characterize novel BMD genes. In the HMDP, a GWA of total body, spinal, and femoral BMD revealed four significant associations (-log10P>5.39 affecting at least one BMD trait on chromosomes (Chrs. 7, 11, 12, and 17. The associations implicated a total of 163 genes with each association harboring between 14 and 112 genes. This list was reduced to 26 functional candidates by identifying those genes that were regulated by local eQTL in bone or harbored potentially functional non-synonymous (NS SNPs. This analysis revealed that the most significant BMD SNP on Chr. 12 was a NS SNP in the additional sex combs like-2 (Asxl2 gene that was predicted to be functional. The involvement of Asxl2 in the regulation of bone mass was confirmed by the observation that Asxl2 knockout mice had reduced BMD. To begin to unravel the mechanism through which Asxl2 influenced BMD, a gene co-expression network was created using cortical bone gene expression microarray data from the HMDP strains. Asxl2 was identified as a member of a co-expression module enriched for genes involved in the differentiation of myeloid cells. In bone, osteoclasts are bone-resorbing cells of myeloid origin, suggesting that Asxl2 may play a role in osteoclast differentiation. In agreement, the knockdown of Asxl2 in bone marrow macrophages impaired their ability to form osteoclasts. This study identifies a new regulator of BMD and osteoclastogenesis and highlights the power of GWA and systems genetics in the mouse for dissecting complex genetic traits.

7 CFR 923.42 - Accounting.

Science.gov (United States)

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Accounting. 923.42 Section 923.42 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... COUNTIES IN WASHINGTON Order Regulating Handling Expenses and Assessments § 923.42 Accounting. (a) If, at...

7 CFR 922.42 - Accounting.

Science.gov (United States)

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Accounting. 922.42 Section 922.42 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... IN WASHINGTON Order Regulating Handling Expenses and Assessments § 922.42 Accounting. (a) If, at the...

Osteoclasts secrete non-bone derived signals that induce bone formation

DEFF Research Database (Denmark)

Karsdal, Morten A; Neutzsky-Wulff, Anita V; Dziegiel, Morten Hanefeld

2008-01-01

Bone turnover is a highly regulated process, where bone resorption in the normal healthy individual always is followed by bone formation in a manner referred to as coupling. Patients with osteopetrosis caused by defective acidification of the resorption lacuna have severely decreased resorption......) from human osteoclasts cultured on either bone or plastic, and tested their effects on bone nodule formation by osteoblasts. Both types of CM were shown to dose-dependently induce bone nodule formation, whereas non-conditioned osteoclast culture medium had no effects. These data show that osteoclasts...

CDC Vital Signs-Heroin Epidemic

Centers for Disease Control (CDC) Podcasts

This podcast is based on the July 2015 CDC Vital Signs report. Heroin use and heroin-related overdose deaths are increasing. Most people are using it with other drugs, especially prescription opioid painkillers. Learn what can be done to prevent and treat the problem.

Cyp26b1 within the growth plate regulates bone growth in juvenile mice

International Nuclear Information System (INIS)

Minegishi, Yoshiki; Sakai, Yasuo; Yahara, Yasuhito; Akiyama, Haruhiko; Yoshikawa, Hideki; Hosokawa, Ko; Tsumaki, Noriyuki

2014-01-01

Highlights: • Retinoic acid and Cyp26b1 were oppositely localized in growth plate cartilage. • Cyp26b1 deletion in chondrocytes decreased bone growth in juvenile mice. • Cyp26b1 deletion reduced chondrocyte proliferation and growth plate height. • Vitamin A-depletion partially reversed growth plate abnormalities caused by Cyp26b1 deficiency. • Cyp26b1 regulates bone growth by controlling chondrocyte proliferation. - Abstract: Retinoic acid (RA) is an active metabolite of vitamin A and plays important roles in embryonic development. CYP26 enzymes degrade RA and have specific expression patterns that produce a RA gradient, which regulates the patterning of various structures in the embryo. However, it has not been addressed whether a RA gradient also exists and functions in organs after birth. We found localized RA activities in the diaphyseal portion of the growth plate cartilage were associated with the specific expression of Cyp26b1 in the epiphyseal portion in juvenile mice. To disturb the distribution of RA, we generated mice lacking Cyp26b1 specifically in chondrocytes (Cyp26b1 Δchon cKO). These mice showed reduced skeletal growth in the juvenile stage. Additionally, their growth plate cartilage showed decreased proliferation rates of proliferative chondrocytes, which was associated with a reduced height in the zone of proliferative chondrocytes, and closed focally by four weeks of age, while wild-type mouse growth plates never closed. Feeding the Cyp26b1 cKO mice a vitamin A-deficient diet partially reversed these abnormalities of the growth plate cartilage. These results collectively suggest that Cyp26b1 in the growth plate regulates the proliferation rates of chondrocytes and is responsible for the normal function of the growth plate and growing bones in juvenile mice, probably by limiting the RA distribution in the growth plate proliferating zone

Functions of mammalian Cdc7 kinase in initiation/monitoring of DNA replication and development

Energy Technology Data Exchange (ETDEWEB)

Kim, Jung Min; Yamada, Masayuki; Masai, Hisao

2003-11-27

Cdc7 kinase plays an essential role in firing of replication origins by phosphorylating components of the replication complexes. Cdc7 kinase has also been implicated in S phase checkpoint signaling downstream of the ATR and Chk1 kinases. Inactivation of Cdc7 in yeast results in arrest of cell growth with 1C DNA content after completion of the ongoing DNA replication. In contrast, conditional inactivation of Cdc7 in undifferentiated mouse embryonic stem (ES) cells leads to growth arrest with rapid cessation of DNA synthesis, suggesting requirement of Cdc7 functions for continuation of ongoing DNA synthesis. Furthermore, loss of Cdc7 function induces recombinational repair (nuclear Rad51 foci) and G2/M checkpoint responses (inhibition of Cdc2 kinase). Eventually, p53 becomes highly activated and the cells undergo massive p53-dependent apoptosis. Thus, defective origin activation in mammalian cells can generate DNA replication checkpoint signals. Efficient removal of those cells in which replication has been perturbed, through cell death, may be beneficial to maintain the highest level of genetic integrity in totipotent stem cells. Partial, rather than total, loss of Cdc7 kinase expression results in retarded growth at both cellular and whole body levels, with especially profound impairment of germ cell development.

Functions of mammalian Cdc7 kinase in initiation/monitoring of DNA replication and development

International Nuclear Information System (INIS)

Kim, Jung Min; Yamada, Masayuki; Masai, Hisao

2003-01-01

Cdc7 kinase plays an essential role in firing of replication origins by phosphorylating components of the replication complexes. Cdc7 kinase has also been implicated in S phase checkpoint signaling downstream of the ATR and Chk1 kinases. Inactivation of Cdc7 in yeast results in arrest of cell growth with 1C DNA content after completion of the ongoing DNA replication. In contrast, conditional inactivation of Cdc7 in undifferentiated mouse embryonic stem (ES) cells leads to growth arrest with rapid cessation of DNA synthesis, suggesting requirement of Cdc7 functions for continuation of ongoing DNA synthesis. Furthermore, loss of Cdc7 function induces recombinational repair (nuclear Rad51 foci) and G2/M checkpoint responses (inhibition of Cdc2 kinase). Eventually, p53 becomes highly activated and the cells undergo massive p53-dependent apoptosis. Thus, defective origin activation in mammalian cells can generate DNA replication checkpoint signals. Efficient removal of those cells in which replication has been perturbed, through cell death, may be beneficial to maintain the highest level of genetic integrity in totipotent stem cells. Partial, rather than total, loss of Cdc7 kinase expression results in retarded growth at both cellular and whole body levels, with especially profound impairment of germ cell development

Central and peripheral mechanisms of the NPY system in the regulation of bone and adipose tissue.

Science.gov (United States)

Shi, Yan-Chuan; Baldock, Paul A

2012-02-01

Skeletal research is currently undergoing a period of marked expansion. The boundaries of "bone" research are being re-evaluated and with this, a growing recognition of a more complex and interconnected biology than previously considered. One aspect that has become the focus of particular attention is the relationship between bone and fat homeostasis. Evidence from a number of avenues indicates that bone and adipose regulation are both related and interdependent. This review examines the neuropeptide Y (NPY) system, known to exert powerful control over both bone and fat tissue. The actions of this system are characterized by signaling both within specific nuclei of the hypothalamus and also the target tissues, mediated predominantly through two G-protein coupled receptors (Y1 and Y2). In bone tissue, elevated NPY levels act consistently to repress osteoblast activity. Moreover, both central Y2 receptor and osteoblastic Y1 receptor signaling act similarly to repress bone formation. Conversely, loss of NPY expression or receptor signaling induces increased osteoblast activity and bone mass in both cortical and cancellous envelopes. In fat tissue, NPY action is more complex. Energy homeostasis is powerfully altered by elevations in hypothalamic NPY, resulting in increases in fat accretion and body-wide energy conservation, through the action of locally expressed Y1 receptors, while local Y2 receptors act to inhibit NPY-ergic tone. Loss of central NPY expression has a markedly reduced effect, consistent with a physiological drive to promote fat accretion. In fat tissue, NPY and Y1 receptors act to promote lipogenesis, consistent with their roles in the brain. Y2 receptors expressed in adipocytes also act in this manner, showing an opposing action to their role in the hypothalamus. While direct investigation of these processes has yet to be completed, these responses appear to be interrelated to some degree. The starvation-based signal of elevated central NPY inducing

7 CFR 927.42 - Accounting.

Science.gov (United States)

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Accounting. 927.42 Section 927.42 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Order Regulating Handling Expenses and Assessments § 927.42 Accounting. (a) If, at the end of a fiscal...

Perseguir al SRAG: CDC en acción (Stalking SARS: CDC at Work)

Centers for Disease Control (CDC) Podcasts

2013-04-29

En este podcast los niños de Kidtastics hablan sobre el brote del SRAS y cómo trabajaron los CDC para resolver el misterio.  Created: 4/29/2013 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 8/10/2016.

UPEML, Computer Independent Emulator of CDC Update Utility

International Nuclear Information System (INIS)

2002-01-01

1 - Description of program or function: UPEML is a machine-portable CDC UPDATE emulation program. It is capable of emulating a significant subset of the standard CDC UPDATE functions, including program library creation and subsequent modification. 2 - Method of solution: UPEML was originally written to facilitate the use of CDC-based scientific packages on alternate computers. In addition to supporting computers such as the VAX/VMS, IBM, and CRAY/COS, Version 3.0 now supports UNIX workstations and the CRAY/UNICOS operating system. Several program bugs have been corrected in Version 3.0. Version 3.0 has several new features including 1) improved error checking, 2) the ability to use *ADDFILE and READ from nested files, 3) creation of compile file on creation, 4) allows identifiers to begin with numbers, and 5) ability to control warning messages and program termination on error conditions. 3 - Restrictions on the complexity of the problem: None noted

CDC WONDER: Daily Fine Particulate Matter

Data.gov (United States)

U.S. Department of Health & Human Services — The Daily Fine Particulate Matter data available on CDC WONDER are geographically aggregated daily measures of fine particulate matter in the outdoor air, spanning...

CUDC-907 Promotes Bone Marrow Adipocytic Differentiation Through Inhibition of Histone Deacetylase and Regulation of Cell Cycle.

Science.gov (United States)

Ali, Dalia; Alshammari, Hassan; Vishnubalaji, Radhakrishnan; Chalisserry, Elna Paul; Hamam, Rimi; Alfayez, Musaad; Kassem, Moustapha; Aldahmash, Abdullah; Alajez, Nehad M

2017-03-01

The role of bone marrow adipocytes (BMAs) in overall energy metabolism and their effects on bone mass are currently areas of intensive investigation. BMAs differentiate from bone marrow stromal cells (BMSCs); however, the molecular mechanisms regulating BMA differentiation are not fully understood. In this study, we investigated the effect of CUDC-907, identified by screening an epigenetic small-molecule library, on adipocytic differentiation of human BMSCs (hBMSCs) and determined its molecular mechanism of action. Human bone marrow stromal cells exposed to CUDC-907 (500 nM) exhibited enhanced adipocytic differentiation (∼2.9-fold increase, P < 0.005) compared with that of control cells. Global gene expression and signaling pathway analyses of differentially expressed genes revealed a strong enrichment of genes involved in adipogenesis, cell cycle, and DNA replication. Chromatin immune precipitation combined with quantitative polymerase chain reaction showed significant increase in H3K9ac epigenetic marker in the promoter regions of AdipoQ, FABP4, PPARγ, KLF15, and CEBPA in CUDC-907-treated hBMSCs. Follow-up experiments corroborated that the inhibition of histone deacetylase (HDAC) activity enhanced adipocytic differentiation, while the inhibition of PI3K decreased adipocytic differentiation. In addition, CUDC-907 arrested hBMSCs in the G0-G1 phase of the cell cycle and reduced the number of S-phase cells. Our data reveal that HDAC, PI3K, and cell cycle genes are important regulators of BMA formation and demonstrate that adipocyte differentiation of hBMSCs is associated with complex changes in a number of epigenetic and genetic pathways, which can be targeted to regulate BMA formation.

7 CFR 916.42 - Accounting.

Science.gov (United States)

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Accounting. 916.42 Section 916.42 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Expenses and Assessments § 916.42 Accounting. (a) If, at the end of a fiscal period, the...

7 CFR 915.42 - Accounting.

Science.gov (United States)

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Accounting. 915.42 Section 915.42 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Expenses and Assessments § 915.42 Accounting. (a) If, at the end of a fiscal year, the...

CDC WONDER: AIDS Public Use Data

Data.gov (United States)

U.S. Department of Health & Human Services — The AIDS Public Information Data Set (APIDS) for years 1981-2002 on CDC WONDER online database contains counts of AIDS (Acquired Immune Deficiency Syndrome) cases...

Anaphase-promoting complex/cyclosome protein Cdc27 is a target for curcumin-induced cell cycle arrest and apoptosis

International Nuclear Information System (INIS)

Lee, Seung Joon; Langhans, Sigrid A

2012-01-01

Curcumin (diferuloylmethane), the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC), is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C) which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy. Cell cycle profiles were determined in control and curcumin-treated medulloblastoma and various other cancer cell lines. Pull-down assays were used to confirm curcumin binding. APC/C activity was determined using an in vitro APC activity assay. We identified Cdc27/APC3, a component of the APC/C, as a novel molecular target of curcumin and showed that curcumin binds to and crosslinks Cdc27 to affect APC/C function. We further provide evidence that curcumin preferably induces apoptosis in cells expressing phosphorylated Cdc27 usually found in highly proliferating cells. We report that curcumin directly targets the SAC to induce apoptosis preferably in cells with high levels of phosphorylated Cdc27. Our studies provide a possible molecular mechanism why curcumin induces apoptosis preferentially in cancer cells and suggest that phosphorylation of Cdc27 could be used as a biomarker to predict the therapeutic response of cancer cells to curcumin

Anaphase-promoting complex/cyclosome protein Cdc27 is a target for curcumin-induced cell cycle arrest and apoptosis

Directory of Open Access Journals (Sweden)

Lee Seung Joon

2012-01-01

Full Text Available Abstract Background Curcumin (diferuloylmethane, the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC, is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy. Methods Cell cycle profiles were determined in control and curcumin-treated medulloblastoma and various other cancer cell lines. Pull-down assays were used to confirm curcumin binding. APC/C activity was determined using an in vitro APC activity assay. Results We identified Cdc27/APC3, a component of the APC/C, as a novel molecular target of curcumin and showed that curcumin binds to and crosslinks Cdc27 to affect APC/C function. We further provide evidence that curcumin preferably induces apoptosis in cells expressing phosphorylated Cdc27 usually found in highly proliferating cells. Conclusions We report that curcumin directly targets the SAC to induce apoptosis preferably in cells with high levels of phosphorylated Cdc27. Our studies provide a possible molecular mechanism why curcumin induces apoptosis preferentially in cancer cells and suggest that phosphorylation of Cdc27 could be used as a biomarker to predict the therapeutic response of cancer cells to

Anaphase-promoting complex/cyclosome protein Cdc27 is a target for curcumin-induced cell cycle arrest and apoptosis

Science.gov (United States)

2012-01-01

Background Curcumin (diferuloylmethane), the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC), is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C) which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy. Methods Cell cycle profiles were determined in control and curcumin-treated medulloblastoma and various other cancer cell lines. Pull-down assays were used to confirm curcumin binding. APC/C activity was determined using an in vitro APC activity assay. Results We identified Cdc27/APC3, a component of the APC/C, as a novel molecular target of curcumin and showed that curcumin binds to and crosslinks Cdc27 to affect APC/C function. We further provide evidence that curcumin preferably induces apoptosis in cells expressing phosphorylated Cdc27 usually found in highly proliferating cells. Conclusions We report that curcumin directly targets the SAC to induce apoptosis preferably in cells with high levels of phosphorylated Cdc27. Our studies provide a possible molecular mechanism why curcumin induces apoptosis preferentially in cancer cells and suggest that phosphorylation of Cdc27 could be used as a biomarker to predict the therapeutic response of cancer cells to curcumin. PMID:22280307

CDC Vital Signs–Cancer and Obesity

Centers for Disease Control (CDC) Podcasts

2017-10-04

This podcast is based on the October 2017 CDC Vital Signs report. Obesity is a leading cancer risk factor. Unfortunately, two out of three U.S. adults weigh more than recommended. Find out what can be done to help people get to and keep a healthy weight.  Created: 10/4/2017 by Centers for Disease Control and Prevention (CDC).   Date Released: 10/4/2017.

Calcium isotope ratios in animal and human bone

Science.gov (United States)

Reynard, L. M.; Henderson, G. M.; Hedges, R. E. M.

2010-07-01

Calcium isotopes in tissues are thought to be influenced by an individual's diet, reflecting parameters such as trophic level and dairy consumption, but this has not been carefully assessed. We report the calcium isotope ratios (δ 44/42Ca) of modern and archaeological animal and human bone ( n = 216). Modern sheep raised at the same location show 0.14 ± 0.08‰ higher δ 44/42Ca in females than in males, which we attribute to lactation by the ewes. In the archaeological bone samples the calcium isotope ratios of the herbivorous fauna vary by location. At a single site, the archaeological fauna do not show a trophic level effect. Humans have lower δ 44/42Ca than the mean site fauna by 0.22 ± 0.22‰, and the humans have a greater δ 44/42Ca range than the animals. No effect of sex or age on the calcium isotope ratios was found, and intra-individual skeletal δ 44/42Ca variability is negligible. We rule out dairy consumption as the main cause of the lower human δ 44/42Ca, based on results from sites pre-dating animal domestication and dairy availability, and suggest instead that individual physiology and calcium intake may be important in determining bone calcium isotope ratios.

Communications and Web services: What do CDC users desire in partner relationship management and does CDC's PHIN Directory meet the need?

Science.gov (United States)

Cervone, Maria A; Savel, Thomas G

2006-01-01

The National Center on Birth Defects and Developmental Disabilities (NCBDDD) at the Centers for Disease Control and Prevention (CDC) sought to establish a database to proactively manage their partner relationships with external organizations. A user needs analysis was conducted, and CDC's Public Health Information Network Directory (PHINDIR) was evaluated as a possible solution. PHINDIR could sufficiently maintain contact information but did not address customer relationships; however, its flexible architecture allows add-on applications via web services. Thus, NCBDDD's needs could be met via PHINDIR.

Cdc7 is required throughout the yeast S phase to activate replication origins.

Science.gov (United States)

Donaldson, A D; Fangman, W L; Brewer, B J

1998-02-15

The long-standing conclusion that the Cdc7 kinase of Saccharomyces cerevisiae is required only to trigger S phase has been challenged by recent data that suggests it acts directly on individual replication origins. We tested the possibility that early- and late-activated origins have different requirements for Cdc7 activity. Cells carrying a cdc7(ts) allele were first arrested in G1 at the cdc7 block by incubation at 37 degrees C, and then were allowed to enter S phase by brief incubation at 23 degrees C. During the S phase, after return to 37 degrees C, early-firing replication origins were activated, but late origins failed to fire. Similarly, a plasmid with a late-activated origin was defective in replication. As a consequence of the origin activation defect, duplication of chromosomal sequences that are normally replicated from late origins was greatly delayed. Early-replicating regions of the genome duplicated at approximately their normal time. The requirements of early and late origins for Cdc7 appear to be temporally rather than quantitatively different, as reducing overall levels of Cdc7 by growth at semi-permissive temperature reduced activation at early and late origins approximately equally. Our results show that Cdc7 activates early and late origins separately, with late origins requiring the activity later in S phase to permit replication initiation.

CDC Vital Signs–Safe Sleep for Babies

Centers for Disease Control (CDC) Podcasts

2018-01-09

This podcast is based on the January 2018 CDC Vital Signs report. Every year, there are about 3,500 sleep-related deaths among U.S. babies. Learn how to create a safe sleep environment for babies.  Created: 1/9/2018 by Centers for Disease Control and Prevention (CDC).   Date Released: 1/9/2018.

Moderate variations in CDC25B protein levels modulate the response to DNA damaging agents

International Nuclear Information System (INIS)

Aressy, B.; Bugler, B.; Valette, A.; Ducommun, B.; Biard, D.

2008-01-01

CDC25B, one of the three members of the CDC25 dual-specificity phosphatase family, plays a critical role in the control of the cell cycle and in the checkpoint response to DNA damage. CDC25B is responsible for the initial dephosphorylation and activation of the cyclin-dependent kinases, thus initiating the train of events leading to entry into mitosis. The critical role played by CDC25B is illustrated by the fact that it is specifically required for checkpoint recovery and that unscheduled accumulation of CDC25B is responsible for illegitimate entry into mitosis. Here, we report that in p53 colon carcinoma cells, a moderate increase in the CDC25B level is sufficient to impair the DNA damage checkpoint, to increase spontaneous mutagenesis, and to sensitize cells to ionising radiation and genotoxic agents. Using a tumour cell spheroid assay as an alternative to animal studies, we demonstrate that the level of CDC25B expression modulates growth inhibition and apoptotic death. Since CDC25B overexpression has been observed in a significant number of human cancers, including colon carcinoma, and is often associated with high grade tumours and poor prognosis, our work suggests that the expression level of CDC25B might be a potential key parameter of the cellular response to cancer therapy. (authors)

BONE MARROW ABONRMALITIES IN HIV INFECTION

Directory of Open Access Journals (Sweden)

Sharad Antiram Dhurve

2013-06-01

Full Text Available ABSTRACT Introduction; Hematological abnormalities are a common complication of HIV infection.  Bone marrow abnormalities occur in all stages of HIV infection.  Present work was carried out to study the bone marrow abnormalities in patients with HIV/AIDS.  Methods: 160 patients of HIV +ve were included in the study. A complete blood count, relevant biochemical investigations, CD4   counts were done, besides a thorough history and clinical examination. HIV positive patients were classified as those having AIDS and those without AIDS according to NACO criteria.   Bone marrow examination was performed for indication of anemia, leucopenia, pancytopenia and thrombocytopenia. Results: As per CDC criteria 59.81% patients had AIDS in 107 patients. The most common hematological abnormality was anemia, seen in 93.12% patients.  Bone marrow was normocellular in 79.06% of non-AIDS and 79.68% of AIDS, hypocellular in 13.95%.Thrombocytopenia was seen in 4 cases of ART (4.93% and 3 cases (4.68% of AIDS group. Abnormal cells like plasma cell, histocyte and toxic granule found in bone marrow. Conclusions: Myelodysplasia was more common in AIDS than in non AIDS patients. Granulocytic series is most commonly associated with evidence of dysplasia. Anemia in HIV patients can be a good clinical indicator to predict and access the underlying immune status. Thus bone marrow study is imperative to methodically observe and follow clinical and laboratory aberration in such patients in order to improve our diagnostic and therapeutic skills pertinent to HIV/AIDS.

[Frontier in bone biology].

Science.gov (United States)

Takeda, Shu

2015-10-01

Bone is an active organ in which bone mass is maintained by the balance between osteoblastic bone formation and osteoclastic bone resorption, i.e., coupling of bone formation and bone resorption. Recent advances in molecular bone biology uncovered the molecular mechanism of the coupling. A fundamental role of osteocyte in the maintenance of bone mass and whole body metabolism has also been revealed recently. Moreover, neurons and neuropeptides have been shown to be intimately involved in bone homeostasis though inter-organ network, in addition to "traditional" regulators of bone metabolism such as soluble factors and cytokines

CDC Vital Signs–African American Health

Centers for Disease Control (CDC) Podcasts

2017-05-02

This podcast is based on the May 2017 CDC Vital Signs report. The life expectancy of African Americans has improved, but it’s still an average of four years less than whites. Learn what can be done so all Americans can have the opportunity to pursue a healthy lifestyle.  Created: 5/2/2017 by Centers for Disease Control and Prevention (CDC).   Date Released: 5/2/2017.

Calcium-containing scaffolds induce bone regeneration by regulating mesenchymal stem cell differentiation and migration

Directory of Open Access Journals (Sweden)

Rubén Aquino-Martínez

2017-11-01

Full Text Available Abstract Background Osteoinduction and subsequent bone formation rely on efficient mesenchymal stem cell (MSC recruitment. It is also known that migration is induced by gradients of growth factors and cytokines. Degradation of Ca2+-containing biomaterials mimics the bone remodeling compartment producing a localized calcium-rich osteoinductive microenvironment. The aim of our study was to determine the effect of calcium sulfate (CaSO4 on MSC migration. In addition, to evaluate the influence of CaSO4 on MSC differentiation and the potential molecular mechanisms involved. Methods A circular calvarial bone defect (5 mm diameter was created in the parietal bone of 35 Balb-C mice. We prepared and implanted a cell-free agarose/gelatin scaffold alone or in combination with different CaSO4 concentrations into the bone defects. After 7 weeks, we determined the new bone regenerated by micro-CT and histological analysis. In vitro, we evaluated the CaSO4 effects on MSC migration by both wound healing and agarose spot assays. Osteoblastic gene expression after BMP-2 and CaSO4 treatment was also evaluated by qPCR. Results CaSO4 increased MSC migration and bone formation in a concentration-dependent manner. Micro-CT analysis showed that the addition of CaSO4 significantly enhanced bone regeneration compared to the scaffold alone. The histological evaluation confirmed an increased number of endogenous cells recruited into the cell-free CaSO4-containing scaffolds. Furthermore, MSC migration in vitro and active AKT levels were attenuated when CaSO4 and BMP-2 were in combination. Addition of LY294002 and Wortmannin abrogated the CaSO4 effects on MSC migration. Conclusions Specific CaSO4 concentrations induce bone regeneration of calvarial defects in part by acting on the host’s undifferentiated MSCs and promoting their migration. Progenitor cell recruitment is followed by a gradual increment in osteoblast gene expression. Moreover, CaSO4 regulates BMP-2-induced

SHP1 Regulates Bone Mass by Directing Mesenchymal Stem Cell Differentiation

Directory of Open Access Journals (Sweden)

Menghui Jiang

2016-07-01

Full Text Available Osteoblasts and adipocytes are derived from a common precursor, mesenchymal stem cells (MSCs. Alterations in the normal fate of differentiating MSCs are involved in the development of obesity and osteoporosis. Here, we report that viable motheaten (mev mice, which are deficient in the SH2-domain-containing phosphatase-1 (SHP1, develop osteoporosis spontaneously. Consistently, MSCs from mev/mev mice exhibit significantly reduced osteogenic potential and greatly increased adipogenic potential. When MSCs were transplanted into nude mice, SHP1-deficient MSCs resulted in diminished bone formation compared with wild-type MSCs. SHP1 was found to bind to GSK3β and suppress its kinase activity by dephosphorylating pY216, thus resulting in β-catenin stabilization. Mice, in which SHP1 was deleted in MSCs using SHP1fl/flDermo1-cre, displayed significantly decreased bone mass and increased adipose tissue. Taken together, these results suggest a possible role for SHP1 in controlling tissue homeostasis through modulation of MSC differentiation via Wnt signaling regulation.

CDC Vital Signs-Preventing Melanoma

Centers for Disease Control (CDC) Podcasts

This podcast is based on the June 2015 CDC Vital Signs report. Skin cancer is the most common form of cancer in the U.S. In 2011, there were more than 65,000 cases of melanoma, the most deadly form of skin cancer. Learn how everyone can help prevent skin cancer.

Radiologic study of 42 cases of Wilson disease

International Nuclear Information System (INIS)

Xie, Y.; Zhang, X.; Xu, X.; Zhang, Z.; Feng, Y.

1985-01-01

This paper reports 42 cases of bone and joint radiographic changes in hepatolenticular degeneration. The cases were proven clinically by opthalmologic and laboratory study, and their radiographic and joint changes were divided into five groups: no abnormal findings, osteoporosis, osteomalacia (rickets), distinct changes, and miscellaneous. Distinct changes include marginal bone fragments, angulation of carpal bones, squaring of metacarpal heads, and calcification of the joint capsule or tendon insertion. The mechanism causing the bone changes in heptolenticular degeneration is also discussed. (orig.)

Radiologic study of 42 cases of Wilson disease

Energy Technology Data Exchange (ETDEWEB)

Xie, Y.; Zhang, X.; Xu, X.; Zhang, Z.; Feng, Y.

1985-02-01

This paper reports 42 cases of bone and joint radiographic changes in hepatolenticular degeneration. The cases were proven clinically by opthalmologic and laboratory study, and their radiographic and joint changes were divided into five groups: no abnormal findings, osteoporosis, osteomalacia (rickets), distinct changes, and miscellaneous. Distinct changes include marginal bone fragments, angulation of carpal bones, squaring of metacarpal heads, and calcification of the joint capsule or tendon insertion. The mechanism causing the bone changes in heptolenticular degeneration is also discussed.

Identification of CDC25 as a Common Therapeutic Target for Triple-Negative Breast Cancer

Directory of Open Access Journals (Sweden)

Jeff C. Liu

2018-04-01

Full Text Available Summary: CDK4/6 inhibitors are effective against cancer cells expressing the tumor suppressor RB1, but not RB1-deficient cells, posing the challenge of how to target RB1 loss. In triple-negative breast cancer (TNBC, RB1 and PTEN are frequently inactivated together with TP53. We performed kinome/phosphatase inhibitor screens on primary mouse Rb/p53-, Pten/p53-, and human RB1/PTEN/TP53-deficient TNBC cell lines and identified CDC25 phosphatase as a common target. Pharmacological or genetic inhibition of CDC25 suppressed growth of RB1-deficient TNBC cells that are resistant to combined CDK4/6 plus CDK2 inhibition. Minimal cooperation was observed in vitro between CDC25 antagonists and CDK1, CDK2, or CDK4/6 inhibitors, but strong synergy with WEE1 inhibition was apparent. In accordance with increased PI3K signaling following long-term CDC25 inhibition, CDC25 and PI3K inhibitors effectively synergized to suppress TNBC growth both in vitro and in xenotransplantation models. These results provide a rationale for the development of CDC25-based therapies for diverse RB1/PTEN/TP53-deficient and -proficient TNBCs. : Liu et al. report that inhibition of the protein phosphatase CDC25 kills diverse triple-negative breast cancer (TNBC cells. Moreover, CDC25 antagonists cooperate with other drugs, such as PI3K inhibitors, to efficiently suppress growth of human TNBC engrafted into mice. Keywords: triple negative breast cancer, basal-like breast cancer, therapy, RB1, PTEN, TP53, CDC25, WEE1, CHK1, checkpoint control

Triple bone labeling of canine mandibles

DEFF Research Database (Denmark)

Pinholt, E M; Kwon, P H

1990-01-01

Fluorescence microscopy was used for evaluation of new bone formation in 16 canine mandibles augmented with hydroxylapatite (HA) granules. Three fluorochromes were injected at different time intervals during therapeutic radiation treatment. Oxytetracycline, DCAF, and alizarin-complexone were given...... intravenously to mark the bone level at these times, respectively. Oxytetracycline, which defined the baseline of bone at implantation of HA, was detectable in 42% of animals that were irradiated and in no animal of the nonirradiated control group. The marker DCAF, designating levels of bone at the start...

CDC 6600 Cordwood Module

CERN Multimedia

1964-01-01

The CDC 6600 cordwood module containing 64 silicon transistors. The module was mounted between two plates that were cooled conductive by a refrigeration unit via the front panel. The construction of this module uses the cord method, so called because the resistors seem to be stacked like cord between the two circuit boards in order to obtain a high density. The 6600 model contained nearly 6,000 such modules.

CDC Lab Values

Centers for Disease Control (CDC) Podcasts

2015-02-02

More than fifteen hundred scientists fill the lab benches at CDC, logging more than four million hours each year. CDC’s laboratories play a critical role in the agency’s ability to find, stop, and prevent disease outbreaks. This podcast provides a brief overview of what goes on inside CDC’s labs, and why this work makes a difference in American’s health.  Created: 2/2/2015 by Office of the Associate Director for Communication (OADC).   Date Released: 2/2/2015.

Selective effect of hydroxyapatite nanoparticles on osteoporotic and healthy bone formation correlates with intracellular calcium homeostasis regulation.

Science.gov (United States)

Zhao, Rui; Xie, Pengfei; Zhang, Kun; Tang, Zhurong; Chen, Xuening; Zhu, Xiangdong; Fan, Yujiang; Yang, Xiao; Zhang, Xingdong

2017-09-01

Adequate bone substitutes osseointegration has been difficult to achieve in osteoporosis. Hydroxyapatite of the osteoporotic bone, secreted by pathologic osteoblasts, had a smaller crystal size and lower crystallinity than that of the normal. To date, little is known regarding the interaction of synthetic hydroxyapatite nanoparticles (HANPs) with osteoblasts born in bone rarefaction. The present study investigated the biological effects of HANPs on osteoblastic cells derived from osteoporotic rat bone (OVX-OB), in comparison with the healthy ones (SHM-OB). A selective effect of different concentrations of HANPs on the two cell lines was observed that the osteoporotic osteoblasts had a higher tolerance. Reductions in cell proliferation, ALP activity, collagen secretion and osteoblastic gene expressions were found in the SHM-OB when administered with HANPs concentration higher than 25µg/ml. In contrast, those of the OVX-OB suffered no depression but benefited from 25 to 250µg/ml HANPs in a dose-dependent manner. We demonstrated that the different effects of HANPs on osteoblasts were associated with the intracellular calcium influx into the endoplasmic reticulum. The in vivo bone defect model further confirmed that, with a critical HANPs concentration administration, the osteoporotic rats had more and mechanically matured new bone formation than the non-treated ones, whilst the sham rats healed no better than the natural healing control. Collectively, the observed epigenetic regulation of osteoblastic cell function by HANPs has significant implication on defining design parameters for a potential therapeutic use of nanomaterials. In this study, we investigated the biological effects of hydroxyapatite nanoparticles (HANPs) on osteoporotic rat bone and the derived osteoblast. Our findings revealed a previously unrecognized phenomenon that the osteoporotic individuals could benefit from higher concentrations of HANPs, as compared with the healthy individuals. The in

Driver or passenger effects of augmented c-Myc and Cdc20 in gliomagenesis.

Science.gov (United States)

Ji, Ping; Zhou, Xinhui; Liu, Qun; Fuller, Gregory N; Phillips, Lynette M; Zhang, Wei

2016-04-26

Cdc20 and c-Myc are commonly overexpressed in a broad spectrum of cancers, including glioblastoma (GBM). Despite this clear association, whether c-Myc and Cdc20 overexpression is a driver or passenger event in gliomagenesis remains unclear. Both c-Myc and Cdc20 induced the proliferation of primary glial progenitor cells. c-Myc also promoted the formation of soft agar anchorage-independent colonies. In the RCAS/Ntv-a glia-specific transgenic mouse model, c-Myc increased the GBM incidence from 19.1% to 47.4% by 12 weeks of age when combined with kRas and Akt3 in Ntv-a INK4a-ARF (also known as CDKN2A)-null mice. In contrast, Cdc20 decreased the GBM incidence from 19.1% to 9.1%. Moreover, cell differentiation was modulated by c-Myc in kRas/Akt3-induced GBM on the basis of Nestin/GFAP expression (glial progenitor cell differentiation), while Cdc20 had no effect on primary glial progenitor cell differentiation. We used glial progenitor cells from Ntv-a newborn mice to evaluate the role of c-Myc and Cdc20 in the proliferation and transformation of GBM in vitro and in vivo. We further determined whether c-Myc and Cdc20 have a driver or passenger role in GBM development using kRas/Akt3 signals in a RCAS/Ntv-a mouse model. These results suggest that the driver or passenger of oncogene signaling is dependent on cellular status. c-Myc is a driver when combined with kRas/Akt3 oncogenic signals in gliomagenesis, whereas Cdc20 overexpression is a passenger. Inhibition of cell differentiation of c-Myc may be a target for anti-glioma therapy.

Profiling MHC II immunopeptidome of blood-stage malaria reveals that cDC1 control the functionality of parasite-specific CD4 T cells.

Science.gov (United States)

Draheim, Marion; Wlodarczyk, Myriam F; Crozat, Karine; Saliou, Jean-Michel; Alayi, Tchilabalo Dilezitoko; Tomavo, Stanislas; Hassan, Ali; Salvioni, Anna; Demarta-Gatsi, Claudia; Sidney, John; Sette, Alessandro; Dalod, Marc; Berry, Antoine; Silvie, Olivier; Blanchard, Nicolas

2017-11-01

In malaria, CD4 Th1 and T follicular helper (T FH ) cells are important for controlling parasite growth, but Th1 cells also contribute to immunopathology. Moreover, various regulatory CD4 T-cell subsets are critical to hamper pathology. Yet the antigen-presenting cells controlling Th functionality, as well as the antigens recognized by CD4 T cells, are largely unknown. Here, we characterize the MHC II immunopeptidome presented by DC during blood-stage malaria in mice. We establish the immunodominance hierarchy of 14 MHC II ligands derived from conserved parasite proteins. Immunodominance is shaped differently whether blood stage is preceded or not by liver stage, but the same ETRAMP-specific dominant response develops in both contexts. In naïve mice and at the onset of cerebral malaria, CD8α + dendritic cells (cDC1) are superior to other DC subsets for MHC II presentation of the ETRAMP epitope. Using in vivo depletion of cDC1, we show that cDC1 promote parasite-specific Th1 cells and inhibit the development of IL-10 + CD4 T cells. This work profiles the P. berghei blood-stage MHC II immunopeptidome, highlights the potency of cDC1 to present malaria antigens on MHC II, and reveals a major role for cDC1 in regulating malaria-specific CD4 T-cell responses. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

CDC Vital Signs-Preventing Stroke Deaths

Centers for Disease Control (CDC) Podcasts

This podcast is based on the September 2017 CDC Vital Signs report. Each year, more than 140,000 people die and many survivors face disability. Eighty percent of strokes are preventable. Learn the signs of stroke and how to prevent them.

Essential and distinct roles for cdc42 and rac1 in the regulation of Schwann cell biology during peripheral nervous system development

DEFF Research Database (Denmark)

Benninger, Yves; Thurnherr, Tina; Pereira, Jorge A

2007-01-01

During peripheral nervous system (PNS) myelination, Schwann cells must interpret extracellular cues to sense their environment and regulate their intrinsic developmental program accordingly. The pathways and mechanisms involved in this process are only partially understood. We use tissue-specific......During peripheral nervous system (PNS) myelination, Schwann cells must interpret extracellular cues to sense their environment and regulate their intrinsic developmental program accordingly. The pathways and mechanisms involved in this process are only partially understood. We use tissue...

7 CFR 981.42 - Quality control.

Science.gov (United States)

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Quality control. 981.42 Section 981.42 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Quality Control § 981.42 Quality control. (a) Incoming. Except as provided in this...

CDC STATE System Tobacco Legislation - Preemption Summary

Data.gov (United States)

U.S. Department of Health & Human Services — 1995-2018. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. Legislation—Preemption. The STATE...

Correlation of bone quality in radiographic images with clinical bone quality classification

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun Woo; Huh, Kyung Hoe; Kim, Jeong Hwa; Yi, Won Jin; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul [Seoul National University, Seoul (Korea, Republic of); Park, Kwan Soo [Inje University, Seoul (Korea, Republic of)

2006-03-15

To investigate the validity of digital image processing on panoramic radiographs in estimating bone quality before endosseous dental implant installation by correlating bone quality in radiographic images with clinical bone quality classification. An experienced surgeon assessed and classified bone quality for implant sites with tactile sensation at the time of implant placement. Including fractal dimension eighteen morphologic features of trabecular pattern were examined in each anatomical sites on panoramic radiographs. Finally bone quality of 67 implant sites were evaluated in 42 patients. Pearson correlation analysis showed that three morphologic parameters had weak linear negative correlation with clinical bone quality classification showing correlation coefficients of -0.276, -0.280, and -0.289, respectively (p<0.05). And other three morphologic parameters had obvious linear negative correlation with clinical bone quality classification showing correlation coefficients of -0.346, -0.488, and -0.343 respectively (p<0.05). Fractal dimension also had a linear correlating with clinical bone quality classification with correlation coefficients -0.506 significantly (P<0.05). This study suggests that fractal and morphometric analysis using digital panoramic radiographs can be used to evaluate bone quality for implant recipient sites.

Suppressed bone remodeling in black bears conserves energy and bone mass during hibernation.

Science.gov (United States)

McGee-Lawrence, Meghan; Buckendahl, Patricia; Carpenter, Caren; Henriksen, Kim; Vaughan, Michael; Donahue, Seth

2015-07-01

Decreased physical activity in mammals increases bone turnover and uncouples bone formation from bone resorption, leading to hypercalcemia, hypercalcuria, bone loss and increased fracture risk. Black bears, however, are physically inactive for up to 6 months annually during hibernation without losing cortical or trabecular bone mass. Bears have been shown to preserve trabecular bone volume and architectural parameters and cortical bone strength, porosity and geometrical properties during hibernation. The mechanisms that prevent disuse osteoporosis in bears are unclear as previous studies using histological and serum markers of bone remodeling show conflicting results. However, previous studies used serum markers of bone remodeling that are known to accumulate with decreased renal function, which bears have during hibernation. Therefore, we measured serum bone remodeling markers (BSALP and TRACP) that do not accumulate with decreased renal function, in addition to the concentrations of serum calcium and hormones involved in regulating bone remodeling in hibernating and active bears. Bone resorption and formation markers were decreased during hibernation compared with when bears were physically active, and these findings were supported by histomorphometric analyses of bone biopsies. The serum concentration of cocaine and amphetamine regulated transcript (CART), a hormone known to reduce bone resorption, was 15-fold higher during hibernation. Serum calcium concentration was unchanged between hibernation and non-hibernation seasons. Suppressed and balanced bone resorption and formation in hibernating bears contributes to energy conservation, eucalcemia and the preservation of bone mass and strength, allowing bears to survive prolonged periods of extreme environmental conditions, nutritional deprivation and anuria. © 2015. Published by The Company of Biologists Ltd.

Cyp26b1 within the growth plate regulates bone growth in juvenile mice

Energy Technology Data Exchange (ETDEWEB)

Minegishi, Yoshiki [Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Department of Plastic and Reconstructive Surgery, University of Fukui Hospital, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui 910-1193 (Japan); Department of Plastic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Sakai, Yasuo [Department of Plastic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Department of Plastic Surgery, Bellland General Hospital, 500-3 Higashiyama Naka-ku, Sakai, Osaka 599-8247 (Japan); Yahara, Yasuhito [Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Akiyama, Haruhiko [Department of Orthopaedic Surgery, Gifu University Graduate School of Medicine, 1-1 Yanagito, Gifu 501-1194 (Japan); Yoshikawa, Hideki [Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Hosokawa, Ko [Department of Plastic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Tsumaki, Noriyuki, E-mail: ntsumaki@cira.kyoto-u.ac.jp [Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Japan Science and Technology Agency, CREST, Tokyo 102-0075 (Japan)

2014-11-07

Highlights: • Retinoic acid and Cyp26b1 were oppositely localized in growth plate cartilage. • Cyp26b1 deletion in chondrocytes decreased bone growth in juvenile mice. • Cyp26b1 deletion reduced chondrocyte proliferation and growth plate height. • Vitamin A-depletion partially reversed growth plate abnormalities caused by Cyp26b1 deficiency. • Cyp26b1 regulates bone growth by controlling chondrocyte proliferation. - Abstract: Retinoic acid (RA) is an active metabolite of vitamin A and plays important roles in embryonic development. CYP26 enzymes degrade RA and have specific expression patterns that produce a RA gradient, which regulates the patterning of various structures in the embryo. However, it has not been addressed whether a RA gradient also exists and functions in organs after birth. We found localized RA activities in the diaphyseal portion of the growth plate cartilage were associated with the specific expression of Cyp26b1 in the epiphyseal portion in juvenile mice. To disturb the distribution of RA, we generated mice lacking Cyp26b1 specifically in chondrocytes (Cyp26b1{sup Δchon} cKO). These mice showed reduced skeletal growth in the juvenile stage. Additionally, their growth plate cartilage showed decreased proliferation rates of proliferative chondrocytes, which was associated with a reduced height in the zone of proliferative chondrocytes, and closed focally by four weeks of age, while wild-type mouse growth plates never closed. Feeding the Cyp26b1 cKO mice a vitamin A-deficient diet partially reversed these abnormalities of the growth plate cartilage. These results collectively suggest that Cyp26b1 in the growth plate regulates the proliferation rates of chondrocytes and is responsible for the normal function of the growth plate and growing bones in juvenile mice, probably by limiting the RA distribution in the growth plate proliferating zone.

CDC STATE System E-Cigarette Legislation - Licensure

Data.gov (United States)

U.S. Department of Health & Human Services — 1995-2018. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. E-Cigarette Legislation—Licensure. The...

CDC STATE System E-Cigarette Legislation - Preemption

Data.gov (United States)

U.S. Department of Health & Human Services — 1995-2018. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. E-Cigarette Legislation—Preemption. The...

CDC STATE System Tobacco Legislation - Youth Access

Data.gov (United States)

U.S. Department of Health & Human Services — 1995-2018. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. Legislation—Youth Access. The STATE...

CDC Vital Signs: Drinking and Driving

Science.gov (United States)

... Adapted from The ABCs of BAC, National Highway Traffic Safety Administration, 2005, and How to Control Your Drinking, WR Miller and RF Munoz, University of New Mexico, 1982. Self-reported annual drinking and driving episodes SOURCE: CDC Behavioral Risk Factor Surveillance System, ...

cAMP-response-element-binding protein positively regulates breast cancer metastasis and subsequent bone destruction

Energy Technology Data Exchange (ETDEWEB)

Son, Jieun; Lee, Jong-Ho; Kim, Ha-Neui; Ha, Hyunil, E-mail: hyunil74@hotmail.com; Lee, Zang Hee, E-mail: zang1959@snu.ac.kr

2010-07-23

Research highlights: {yields} CREB is highly expressed in advanced breast cancer cells. {yields} Tumor-related factors such as TGF-{beta} further elevate CREB expression. {yields} CREB upregulation stimulates metastatic potential of breast cancer cells. {yields} CREB signaling is required for breast cancer-induced bone destruction. -- Abstract: cAMP-response-element-binding protein (CREB) signaling has been reported to be associated with cancer development and poor clinical outcome in various types of cancer. However, it remains to be elucidated whether CREB is involved in breast cancer development and osteotropism. Here, we found that metastatic MDA-MB-231 breast cancer cells exhibited higher CREB expression than did non-metastatic MCF-7 cells and that CREB expression was further increased by several soluble factors linked to cancer progression, such as IL-1, IGF-1, and TGF-{beta}. Using wild-type CREB and a dominant-negative form (K-CREB), we found that CREB signaling positively regulated the proliferation, migration, and invasion of MDA-MB-231 cells. In addition, K-CREB prevented MDA-MB-231 cell-induced osteolytic lesions in a mouse model of cancer metastasis. Furthermore, CREB signaling in cancer cells regulated the gene expression of PTHrP, MMPs, and OPG, which are closely involved in cancer metastasis and bone destruction. These results indicate that breast cancer cells acquire CREB overexpression during their development and that this CREB upregulation plays an important role in multiple steps of breast cancer bone metastasis.

Deviation of the typical AAA substrate-threading pore prevents fatal protein degradation in yeast Cdc48.

Science.gov (United States)

Esaki, Masatoshi; Islam, Md Tanvir; Tani, Naoki; Ogura, Teru

2017-07-14

Yeast Cdc48 is a well-conserved, essential chaperone of ATPases associated with diverse cellular activity (AAA) proteins, which recognizes substrate proteins and modulates their conformations to carry out many cellular processes. However, the fundamental mechanisms underlying the diverse pivotal roles of Cdc48 remain unknown. Almost all AAA proteins form a ring-shaped structure with a conserved aromatic amino acid residue that is essential for proper function. The threading mechanism hypothesis suggests that this residue guides the intrusion of substrate proteins into a narrow pore of the AAA ring, thereby becoming unfolded. By contrast, the aromatic residue in one of the two AAA rings of Cdc48 has been eliminated through evolution. Here, we show that artificial retrieval of this aromatic residue in Cdc48 is lethal, and essential features to support the threading mechanism are required to exhibit the lethal phenotype. In particular, genetic and biochemical analyses of the Cdc48 lethal mutant strongly suggested that when in complex with the 20S proteasome, essential proteins are abnormally forced to thread through the Cdc48 pore to become degraded, which was not detected in wild-type Cdc48. Thus, the widely applicable threading model is less effective for wild-type Cdc48; rather, Cdc48 might function predominantly through an as-yet-undetermined mechanism.

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

Science.gov (United States)

Lipavská, Helena; Masková, Petra; Vojvodová, Petra

2011-05-01

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

Group I Paks Promote Skeletal Myoblast Differentiation In Vivo and In Vitro

DEFF Research Database (Denmark)

Joseph, Giselle A; Lu, Min; Radu, Maria

2017-01-01

fusion in Drosophila We report that both Pak1 and Pak2 are activated during mammalian myoblast differentiation. One pathway of activation is initiated by N-cadherin ligation and involves the cadherin coreceptor Cdo with its downstream effector, Cdc42. Individual genetic deletion of Pak1 and Pak2 in mice....... Furthermore, primary myoblasts lacking Pak1 and Pak2 display delayed expression of myogenic differentiation markers and myotube formation. These results identify Pak1 and Pak2 as redundant regulators of myoblast differentiation in vitro and in vivo and as components of the promyogenic Ncad/Cdo/Cdc42 signaling...

A Cdc42/RhoA regulatory circuit downstream of glycoprotein Ib guides transendothelial platelet biogenesis

DEFF Research Database (Denmark)

Dütting, Sebastian; Gaits-Iacovoni, Frederique; Stegner, David

2017-01-01

Blood platelets are produced by large bone marrow (BM) precursor cells, megakaryocytes (MKs), which extend cytoplasmic protrusions (proplatelets) into BM sinusoids. The molecular cues that control MK polarization towards sinusoids and limit transendothelial crossing to proplatelets remain unknown...

Clinical eveluation of metastasis from carcinoma of the prostate by bone scintiscanning

International Nuclear Information System (INIS)

Okada, Kiyoki; Igarashi, Jotaro; Nogaki, Joji; Kinoshita, Masayuki; Kishimoto, Takashi

1981-01-01

Eighty radioisotopic bone scintiscans in conjunction with radiographic skeletal survey were carried out in 47 patients with prostatic carcinoma encountered over the past 6 years. Five patients were excluded because of false positive bone scan. None of the patients was found with false negative bone scan irrespective of the presence of osteolytic lesions. In 21 of the remaining 42 cases (40.0%), increased information on bone metastasis was obtained by the bone scan. A positive bone scan was interpreted at 156 sites, of which 67 (42.9%) were negative on bone survey. Bone scan was superior to bone survey for detecting metastatic sites of the sternum, cervical and thoracic spine, ribs, scapula and skull. Serial bone scans in some cases demonstrated an objective response of the metastasis following hormonal treatment. At the time of bone scan, 22 of 47 cases (46.8%) showed an abnormal renal image, which represented the degree of bone metastasis as well as that of renal function. Thus, bone scan represents a useful tool for detecting metastatic lesions from prostatic carcinoma and for assessing the response to treatment. (author)

CDC WONDER: Online Tuberculosis Information System (OTIS)

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U.S. Department of Health & Human Services — The Online Tuberculosis Information System (OTIS) on CDC WONDER contains information on verified tuberculosis (TB) cases reported to the Centers for Disease Control...

CDC STATE System E-Cigarette Legislation - Tax

Data.gov (United States)

U.S. Department of Health & Human Services — 1995-2018. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. E-Cigarette Legislation—Tax. The STATE...

CDC Wonder Vaccine Adverse Event Reporting System

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U.S. Department of Health & Human Services — The Vaccine Adverse Event Reporting System (VAERS) online database on CDC WONDER provides counts and percentages of adverse event case reports after vaccination,...

Up-regulation of bone marrow stromal protein 2 (BST2) in breast cancer with bone metastasis

International Nuclear Information System (INIS)

Cai, Dongqing; Cao, Jie; Li, Zhen; Zheng, Xin; Yao, Yao; Li, Wanglin; Yuan, Ziqiang

2009-01-01

Bone metastases are frequent complications of breast cancer. Recent literature implicates multiple chemokines in the formation of bone metastases in breast cancer. However, the molecular mechanism of metastatic bone disease in breast cancer remains unknown. We have recently made the novel observation of the BST2 protein expression in human breast cancer cell lines. The purpose of our present study is to investigate the expression and the role of BST2 in bone metastatic breast cancer. cDNA microarray analysis was used to compare the BST2 gene expression between a metastatic to bone human breast cancer cell line (MDA-231BO) and a primary human breast cancer cell line (MDA-231). The BST2 expression in one bone metastatic breast cancer and seven non-bone metastatic breast cancer cell lines were also determined using real-time RT-PCR and Western blot assays. We then employed tissue array to further study the BST2 expression in human breast cancer using array slides containing 20 independent breast cancer tumors that formed metastatic bone lesions, 30 non-metastasis-forming breast cancer tumors, and 8 normal breast tissues. In order to test the feasibility of utilizing BST2 as a serum marker for the presence of bone metastasis in breast cancer, we had measured the BST2 expression levels in human serums by using ELISA on 43 breast cancer patients with bone metastasis, 43 breast cancer patients without bone metastasis, and 14 normal healthy controls. The relationship between cell migration and proliferation and BST2 expression was also studied in a human breast recombinant model system using migration and FACS analysis. The microarray demonstrated over expression of the BST2 gene in the bone metastatic breast cancer cell line (MDA-231BO) compared to the primary human breast cancer cell line (MDA-231). The expression of the BST2 gene was significantly increased in the bone metastatic breast cancer cell lines and tumor tissues compared to non-bone metastatic breast cancer

Rac1-dependent recruitment of PAK2 to G 2 phase centrosomes and their roles in the regulation of mitotic entry

DEFF Research Database (Denmark)

May, Martin; Schelle, Ilona; Brakebusch, Cord Herbert

2014-01-01

-GTPases Rac/Cdc42. In this study, Rac1 (but not RhoA or Cdc42) is presented to associate with the centrosomes from early G 2 phase until prometaphase in a cell cycle-dependent fashion, as evidenced by western blot analysis of prepared centrosomes and by immunolabeling. PAK associates with the G 2/M......-phase centrosomes in a Rac1-dependent fashion. Furthermore, specific inhibition of Rac1 by C. difficile toxinB-catalyzed glucosylation or by knockout results in inhibited activation of PAK1/2, Aurora A, and the CyclinB/Cdk1 complex in late G 2 phase/prophase and delayed mitotic entry. Inhibition of PAK activation...

Stability of the Human Hsp90-p50Cdc37 Chaperone Complex against Nucleotides and Hsp90 Inhibitors, and the Influence of Phosphorylation by Casein Kinase 2

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Sanne H. Olesen

2015-01-01

Full Text Available The molecular chaperone Hsp90 is regulated by co-chaperones such as p50Cdc37, which recruits a wide selection of client protein kinases. Targeted disruption of the Hsp90-p50Cdc37 complex by protein–protein interaction (PPI inhibitors has emerged as an alternative strategy to treat diseases characterized by aberrant Hsp90 activity. Using isothermal microcalorimetry, ELISA and GST-pull down assays we evaluated reported Hsp90 inhibitors and nucleotides for their ability to inhibit formation of the human Hsp90β-p50Cdc37 complex, reconstituted in vitro from full-length proteins. Hsp90 inhibitors, including the proposed PPI inhibitors gedunin and H2-gamendazole, did not affect the interaction of Hsp90 with p50Cdc37 in vitro. Phosphorylation of Hsp90 and p50Cdc37 by casein kinase 2 (CK2 did not alter the thermodynamic signature of complex formation. However, the phosphorylated complex was vulnerable to disruption by ADP (IC50 = 32 µM, while ATP, AMPPNP and Hsp90 inhibitors remained largely ineffective. The differential inhibitory activity of ADP suggests that phosphorylation by CK2 primes the complex for dissociation in response to a drop in ATP/ADP levels. The approach applied herein provides robust assays for a comprehensive biochemical evaluation of potential effectors of the Hsp90-p50Cdc37 complex, such as phosphorylation by a kinase or the interaction with small molecule ligands.

Implementation experiences of NASTRAN on CDC CYBER 74 SCOPE 3.4 operating system

Science.gov (United States)

Go, J. C.; Hill, R. G.

1973-01-01

The implementation of the NASTRAN system on the CDC CYBER 74 SCOPE 3.4 Operating System is described. The flexibility of the NASTRAN system made it possible to accomplish the change with no major problems. Various sizes of benchmark and test problems, ranging from two hours to less than one minute CP time were run on the CDC CYBER SCOPE 3.3, Univac EXEC-8, and CDC CYBER SCOPE 3.4. The NASTRAN installation deck is provided.

Periosteal PTHrP regulates cortical bone modeling during linear growth in mice.

Science.gov (United States)

Wang, Meina; VanHouten, Joshua N; Nasiri, Ali R; Tommasini, Steven M; Broadus, Arthur E

2014-07-01

The modeling of long bone surfaces during linear growth is a key developmental process, but its regulation is poorly understood. We report here that parathyroid hormone-related peptide (PTHrP) expressed in the fibrous layer of the periosteum (PO) drives the osteoclastic (OC) resorption that models the metaphyseal-diaphyseal junction (MDJ) in the proximal tibia and fibula during linear growth. PTHrP was conditionally deleted (cKO) in the PO via Scleraxis gene targeting (Scx-Cre). In the lateral tibia, cKO of PTHrP led to a failure of modeling, such that the normal concave MDJ was replaced by a mound-like deformity. This was accompanied by a failure to induce receptor activator of NF-kB ligand (RANKL) and a 75% reduction in OC number (P ≤ 0.001) on the cortical surface. The MDJ also displayed a curious threefold increase in endocortical osteoblast mineral apposition rate (P ≤ 0.001) and a thickened cortex, suggesting some form of coupling of endocortical bone formation to events on the PO surface. Because it fuses distally, the fibula is modeled only proximally and does so at an extraordinary rate, with an anteromedial cortex in CD-1 mice that was so moth-eaten that a clear PO surface could not be identified. The cKO fibula displayed a remarkable phenotype, with a misshapen club-like metaphysis and an enlargement in the 3D size of the entire bone, manifest as a 40-45% increase in the PO circumference at the MDJ (P ≤ 0.001) as well as the mid-diaphysis (P ≤ 0.001). These tibial and fibular phenotypes were reproduced in a Scx-Cre-driven RANKL cKO mouse. We conclude that PTHrP in the fibrous PO mediates the modeling of the MDJ of long bones during linear growth, and that in a highly susceptible system such as the fibula this surface modeling defines the size and shape of the entire bone. © 2014 Anatomical Society.

CDC STATE System Tobacco Legislation - Smokefree Campus

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U.S. Department of Health & Human Services — 1995-2016. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. Legislation – Smokefree Campuses. The...

CDC STATE System Tobacco Legislation - Preemption Summary

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U.S. Department of Health & Human Services — 1995-2017. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. Legislation—Preemption. The STATE...

CDC STATE System E-Cigarette Legislation - Preemption

Data.gov (United States)

U.S. Department of Health & Human Services — 1995-2017. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. E-Cigarette Legislation—Preemption....

CDC STATE System E-Cigarette Legislation - Licensure

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U.S. Department of Health & Human Services — 1995-2017. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. E-Cigarette Legislation—Licensure....

SIRT3/SOD2 maintains osteoblast differentiation and bone formation by regulating mitochondrial stress